Dec 7, 2013

Cockroaches Munched on Dinosaur Poop

Scientists now have an answer to a question you never knew you had: What happened to all the dinosaur dung? Cockroaches vacuumed it up, a new study suggests. One animal's waste is another animal's gourmet meal.

Researchers from the Slovak Academy of Sciences in Slovakia stumbled on the finding by accident while researching the diet of ancient cockroaches in the now-extinct Blattulidae family. Using sophisticated imaging methods, they found particles of wood inside the roach's gut that they think came from dinosaur feces.

"Dinosaurs undoubtedly produced huge quantities of excrements," the researchers wrote in the study, detailed Dec. 4 in the journal PLOS ONE. "Although appearing trivial, cockroaches, one of the dominant insect orders during the Mesozoic were never examined as representing top candidates for partial processors of dinosaur dung."

Dung beetles and quickly maturing flies were rare during most of the Mesozoic (about 250 million to 65 million years ago). But ancient cockroaches roamed the Earth around the same time as herbivorous dinosaurs.

Using a method called synchrotron X-ray microtomography, the researchers created a virtual 3D version of a fossilized cockroach preserved in a piece of amber in Lebanon dating from the Lower Cretaceous (about 120 million years ago). The unfortunate roach expired in the act of relieving itself, leaving a partially extruded piece of fossilized poop, known as a coprolite, that contained bits of wood.

The wood particles had smooth edges, suggesting the roach didn't chew them. And the insect's digestive system wasn't capable of decomposing the wood. The most likely explanation, the researchers concluded, was that the roach ate some poop from an herbivorous dinosaur.

Other fossilized species of cockroaches have been found with undigested carbon-based debris in their guts, but only the bowel of the Blattulidae specimen contained wood. Members of the Blattulidae family represented about 1 percent of all insects and more than 30 percent of cockroaches alive during the Mesozoic, and probably co-existed with a dominant vertebrate group such as sauropod dinosaurs, the researchers said.

Read more at Discovery News

This Fly Hijacks an Ant’s Brain — Then Pops Its Head Off

We humans were just so proud of ourselves when we invented the guillotine after millennia of experimenting with how best to take heads off shoulders. Maybe a bit too proud, what with that whole Reign of Terror thing. Unbeknownst to those over-enthusiastic revolutionaries, evolution already had produced its own perfect beheader — a tiny fly whose larvae burrow into ants, take control of their minds, and eventually sever their heads from the inside.

These are nature’s flying guillotines: the epically named ant-decapitating flies of the genus Pseudacteon.

Twenty years ago, Sanford Porter, then an entomologist with the University of Texas, was in South America studying fire ants and discovered their numbers were a fraction of those of their invading comrades to the north. Here in America, these two introduced species, the red and black fire ants, cause billions of dollars each year in agricultural damage, pest control costs, and sweet, sweet profits for hospitals treating their excruciating stings.

So Porter searched for a natural enemy that might be keeping southern populations in check. Following a tip from a colleague, he began seeking out fire ants fending off attacks from tiny flies. He gathered some of these besieged individuals and returned to the United States, where he soon began finding maggots in the ants’ bodies. “And around about two weeks [after that] I found that the heads would fall off,” he told WIRED, “and lo and behold I could see the pupa inside the ant’s head.”

The flies he’d observed weren’t hunting the ants. They were much too small for that. Apparently not to be bothered with the stresses of parenthood, they were infesting the creatures with their young. Here, take this for me, the flies seemed to say, I’ve got a lot going on in my life right now.

Here’s how it works. Attracted by the smell of the fire ant’s alarm pheromone, the female ant-decapitating fly hovers a few millimeters from her target. “When they get into just the right position, they dive in,” said Porter, who is now with the USDA Agricultural Research Service. The fly has a sort of lock-and-key ovipositor, the shape of which varies widely between species, “and once that’s fit onto the ant’s body, around the legs somewhere, then what happens is that there’s an internal ovipositor that looks like a hypodermic needle, and that hits probably in the membranes in between the legs,” firing a tiny torpedo-shaped egg into the ant.

In only a few days the egg grows considerably inside the ant before hatching. The resulting maggot works its way through the ant into its head, where it will live for several weeks on the host’s bodily fluids, while maybe from time to time sarcastically asking what the ant is thinking about.

The lock-and-key ovipositor of a Pseudacteon pradei female.
Now, we can safely assume this is relatively distressing for the ant. Indeed, ant colonies maintain something called social immunity to isolate and exile such individuals whose behavior is deemed suspicious — for the good of the community. Yet strangely “the ant runs around, behaves outwardly normally, but even at this point the fly maggot is taking control of the behavior of the ant,” said Porter. Its confederates are none the wiser.

You see, as it develops, the larva needs its host to remain in the relative safety of the colony, where food is plentiful. Porter isn’t yet sure exactly how the maggot accomplishes this mind control, though it’s surely some sort of chemical release. (Did you catch that, CIA? A mind-controlling chemical. Query the NSA for a full transcript of my phone call with Porter for more details.)

But things get even stranger when the larva mercifully decides it’s time to kill its host. Around 24 hours before the maggot is ready to pupate, it finally mind-controls the ant out of the colony. In order for it to develop properly, the pupa needs high humidity, “so what they’re looking for is a place down deep in the leaf litter or plant litter or somewhere that they can dig down in where it remains moist and doesn’t get too hot,” said Porter.

“When they take over the behavior of the ant, that’s what the ant begins to seek,” he added. “When ants normally die, they end up in hot dry places because that keeps fungi and other pathogens from hurting the other ants. But that’s not what happens when they’re under control of the parasite.”

Astoundingly, this strategy has developed totally independently in the Cordyceps fungi, which invade ants’ minds in a similar manner to steer them to unfathomably precise positions in the rainforest to die. Two such completely unrelated organisms developing the same adaptation independently is known as convergent evolution, and this particular convergence is all the more incredible considering that fungi aren’t even animals. This ant-control adaptation has developed not merely between a family or order of organisms, but between kingdoms.

A Pseudacteon curvatus female with hook-shaped ovipositor.
The larva next eats away the brains and muscles and glands, completely hollowing out the head. It then pushes in and out of the ant’s mouth to create an exit route, and begins to pupate. To seal this hole, the pupa builds up a hardened tip that is the exact size of the mouth opening of the ant, protecting it as it continues to develop. And a few weeks later, a new tiny ant-decapitating fly finally crawls out of the ant’s disembodied head like Athena sprouting from Zeus, only Zeus got to remain alive.

This remarkable lifestyle, Porter theorized, is what keeps South American fire ant populations in check on their home turf. Without these specific flies in the U.S. (our native species have their own parasitic flies that don’t attack non-native species), the invasive fire ants run amok. So why not just import the southern flies to control the southern ants?

You might think this is a really bad idea, like bringing in cats to fix a rat problem and then having to bring in dogs to control the cats and pretty soon you’ve got grizzly bears running around making a mess of things. But as a parasite, ant-decapitating flies are extremely host-specific. Native varieties here in the U.S. attack native fire ant species, but very rarely touch invasive species. And likewise South American ant-decapitating flies only parasitize South American fire ants, so, theoretically, importing them wouldn’t pose a threat to our native varieties.

Read more at Wired Science

Dec 6, 2013

'Ugly Duckling' Pteranodons Floated, But Poorly

It might have been the ugliest duckling ever, but scientists using Canada geese for a model have determined that pteranodons, ancient flying reptiles, probably floated on water but not so prettily as their modern avian counterparts.

Like modern birds, the pteranodon had hollow bones, which would have made them light and buoyant. There is also evidence that the flying reptiles foraged in watery environments. But it takes computational modeling to work out exactly how they might have managed to float on water without drowning.

“This isn't about swimming. This isn't about diving,” clarified David Hone of Queen Mary University of London, who coauthored a paper on the work with Donald Henderson of Canada's Royal Terrell Museum of Paleontology. It's just about how the pteranodons floated.

First the researchers tested their flotation model by reproducing the depth and position of a floating Canada goose. Then they tried to make it work for a pteranodon, shifting different variables around just to make certain they covered most possible poses for the flying reptiles in the water. What they found was that the creatures probably didn't sit well on the water surface. In fact they barely could keep their mouths above the water.

“A good analogy is a human,” Hone explained. “If I just lie in a swimming pool I barely have my mouth above the water.” And any waves would make it extremely hard to breathe.

But that does not mean pteranodons were bad at foraging in water, any more than it means humans can't swim, Hone said.

“It isn't necessarily a problem,” Hone said, citing modern birds that spend much of their lives over the ocean but are rather poor at floating on the surface. “Pterosaurs are the Cretaceous albatross.”

Other researchers who have modeled behaviors of pteranodon agree that the posture in the water is not a problem.

Read more at Discovery News

Sharks Do Get Cancer: Tumor Found in Great White

Scientists have known for more than 150 years that sharks get cancer. And yet the belief persists that the animals don't suffer from the disease.

That misconception is promoted in part by those who sell shark cartilage, who claim that the substance will help cure cancer, said David Shiffman, a shark researcher and doctoral student at the University of Miami. But no studies have shown that shark cartilage is an effective treatment, and the demand for the material has helped decimate shark populations, researchers say: Humans kill about 100 million sharks per year, according to a March 2013 study (although many factors contribute to the killing of sharks, including demand for shark-fin soup).

Recently, researchers in Australia noticed a large tumor protruding from the mouth of a great white shark, as well as another mass on the head of a bronze whaler shark. The great white's tumor measured 1 foot (30 centimeters) long and 1 foot wide, according to a study describing the tumors published online in November in the Journal of Fish Diseases.

"This was a very unusual sight as we have never before seen a white shark with tumors," said Rachel Robbins, a study co-author and shark biologist at the Fox Shark Research Foundation, near Adelaide, in southern Australia.

In total, scientists have now documented tumors in at least 23 species of sharks, including the two in the new study, Robbins said. "The main take-home message from the study is that it adds to the growing evidence of tumor formation in sharks, contrary to popular belief that sharks do not suffer from such anomalies," Robbins told LiveScience.

"Sharks get cancer," said Shiffman, who wasn't involved in the study. "Even if they didn't get cancer, eating shark products won't cure cancer any more than me eating Michael Jordan would make me better at basketball."

The belief that shark cartilage can treat cancer diverts patients from effective treatments, according to a 2004 review in the journal Cancer Research. The demand for cartilage also fuels widespread fishing for sharks. One in six known species of sharks, rays and skates are considered threatened with extinction by the International Union for Conservation of Nature, an environmental group, Shiffman said.

Read more at Discovery News

Top 10 Winter Holiday Myths


With Thanksgiving and Hanukkah behind us and Christmas and New Year's Day still ahead, the holiday season is in full swing.

Given the mix of stories and superstitions that constitute holiday preparations and celebrations, seasonal myths can carry over year to year along with the traditions themselves. Consider those myths debunked.

Holiday Travel

Anyone flying home for the holidays last week probably saw a familiar sight at the airport: frantic passengers, long lines at the security screening and a cramped seat on a plane. The day before Thanksgiving certainly does feel like the busiest air travel time of the year.

Except it's not. In fact, some years it's not even in the top 10. In 2006, it was the 36th busiest and 55th in 2007.

The busiest travel days of the year aren't anywhere near the winter holiday season, but rather take place in the summer, on Friday in June, July and August.

Savory Dreams

If you're still recovering from that food-induced coma you received on Thanksgiving, don't blame the tryptophan in your turkey. Despite the widespread belief that the amino acid triggers sleepiness, it's actually not the turkey's fault for causing drowsiness after a Thanksgiving meal.

Rather, it's the massive amount of carbohydrates and often alcohol that lead to that inevitable post-meal nap.

Traditional Thanksgiving?

Despite celebrating in what we believed the fashion of the Pilgrims at Plymouth, Thanksgiving today in no way resembles similar occasions that would have been held in the 17th century. Such events weren't organized or ritualized, according to a religious scholar at Davidson University.

When clergy did find occasion to call together parishioners to give thanks to God, Puritans didn't spend all day feasting, but rather sitting in church.

Our modern conception of Thanksgiving can be credited to a 19th-century magazine editor named Sarah Hale, who saw the holiday as a means of uniting Americans during a time of increasing factionalism.

In the Dark

Seasonal affective disorder (SAD) can lead to the winter blues, affecting some 5 percent of Americans. But the dark days of winter aren't as big a driver of depression in others, despite the lack of light being cited as a leading cause. Stress, sickness and other sources are more likely to blame.

Suicide Spike

Suicides don't spike during the holiday season, a grim myth with no statistical support. According to the Centers for Disease Control and Prevention, the suicide rate is at its lowest in December. It's actually at its highest in the spring and fall.

Read more at Discovery News

'Impossible' Alien World is Impossible. Yet There It Is

A giant extrasolar planet, or exoplanet, has been discovered orbiting a distant star. But this is no "ordinary" alien planet -- it shouldn't exist. To put it bluntly, it's an affront to current planet formation theories.

HD 106906b is a gas giant exoplanet with a mass 11 times that of Jupiter. So far, this may not seem too strange; hundreds of massive explanets have been spotted in our galaxy. But this one is peculiar in that it orbits its star 650 times the distance the Earth orbits the sun. It's this 650 AU (astronomical unit) distance that is causing some serious astronomical confusion.

"This system is especially fascinating because no model of either planet or star formation fully explains what we see," said Vanessa Bailey, fifth-year graduate student in the University of Arizona's Department of Astronomy and lead researcher of this study.

The exoplanet was discovered using the Magellan Telescopes' Adaptive Optics (MagAO) system, based in Chile. Adaptive optics are sophisticated laser systems used by ground based observatories to remove the atmospheric "wobble" when observing the night sky. This is the same effect as removing the "twinkle" from stars when viewed with the naked eye -- upper atmospheric turbulence causes the twinkle, the same effect that obscures the view for ground based observatories.

The leading planetary formation theory posits that planets grow from the agglomeration of smaller bodies, such as asteroids. Over millions of years, the planet gains mass as its gravitational field starts to pull in more and more dust, asteroids and other junk. However, this mechanism cannot be applied to HD 106906b -- at that orbital distance, this process acts slowly, making a planet of 11 Jupiter masses an impossibility.

A second theory could be invoked: Did HD 106906b rapidly form from the rapid gravitational collapse of a knot of material in the star's protoplanetary disk? Again, this mechanism is more likely to occur very close to the host star where plentiful material can be found; at 650 AU there would be little material to trigger the collapse.

So, according to Bailey, that leaves only one explanation. But there's a problem with that one, too.

"A binary star system can be formed when two adjacent clumps of gas collapse more or less independently to form stars, and these stars are close enough to each other to exert a mutual gravitation attraction and bind them together in an orbit," said Bailey in a UA news release. "It is possible that in the case of the HD 106906 system the star and planet collapsed independently from clumps of gas, but for some reason the planet's progenitor clump was starved for material and never grew large enough to ignite and become a star."

However, binary pairs exhibit a mass ratio typically no more than 10-to-1, a ratio HD 106906b clearly violates. "In our case, the mass ratio is more than 100-to-1," she added.

So how the heck did the 13 million years old HD 106906b form? For now we just don't know.

The nature of the HD 106906 star system may help to unravel the mystery of the errant exoplanet's nature. As it's a young system, large quantities of gas and dust are still present. These "leftovers" from planetary formation may help astronomers better understand the nature of the young world, an opportunity too good to miss. We are basically looking into an astronomical Petri dish where the actual planet-building mechanism is being laid out to see.

Read more at Discovery News

Dec 5, 2013

Ancient Dogs Found Buried in Pots in Egypt

Archaeologists have found some of the most curious canine burials ever unearthed in Egypt — two well preserved dogs buried in pots some 3,000 years ago.

Nicknamed Houdini and Chewie, the dog pots were discovered at Shunet ez Zebib, a large mud-brick structure located at Abydos — one of Egypt’s oldest standing royal monuments. The site was built around 2750 B.C and was dedicated to Khasekhemwy, a second dynasty king.

It is also known for the the thousands of ibis burials in jars that had been recovered in the dunes nearby, and for the interments of other animals, mostly raptors and canines.

“The site provided a very secure structure, with conveniently soft, sandy fill that was easy for quick burials within a sacred space,” Salima Ikram, professor of Egyptology at The American University in Cairo, wrote in a recently published Festschrift in honor of Dieter Kessler, a renowned scholar in the field of animal cults and Egyptian religion.

A leading expert on animal mummies, Ikram analyzed the results of a 2009 excavation led by David O’Connor and Matthew Adams, respectively director and field director of the North Abydos Project at the Institute of Fine Arts, New York University. Digging in the Shunet ez-Zebib’s southeast corner, the archaeologists unearthed several jars containing animal burials.

“Of the many jars that were recovered, only 13 have thus far been properly investigated. Of these, four were empty, three contained ibises, and five were filled with dogs,” Ikram said.

While three pots contained skeletonized remains of dogs, the last two housed Houdini and Chewie, two animals with their fur largely intact.

“Although it is common to find birds in pots, it is rare to find other animals buried in this way,” Ikram told Discovery News.

In particular, no canine burials in pots have been recorded in the many dog cemeteries scattered throughout Egypt.

“These jars were probably made and used for some sort of storage, and then re-used as coffins for the dogs. They are quite charming as the dogs are curled up in the pots,” Ikra said.

Houdini was found in a large two-handled pot, and was buried without any wrappings.

“We could not figure out how such a large animal was fit into the pot, so we named him after the magician, Houdini,” Ikram said.

The animal’s fur was brown to auburn-coppery, with portions darker and stiffer, as if they had been anointed by some substance such as oil or even resin.

“It seems as if he were put into the pot, hind limbs first, then adjusted and the rest of the body pushed in so that he was curled around,” Ikram said.

Although it is likely that Houdini is a dog, certain identification of the species is impossible as the animal could not be removed from the jar without compromising its integrity.

“The color of his almost auburn fur is unusual in a dog, as is the length of the hairs, which tend to be shorter in Egyptian dogs than the 3.5 inches found in the case of Houdini,” Ikram said.

“The only other viable identification would be a fox, but the fur’s color is not in keeping with the foxes found in Egypt today,” she added.

Not as well preserved as Houdini, Chewie was found in a large jar filled with the broken pieces of another large pot, which was used as a packing material to keep the dog in situ.

“Once the broken bits of pottery were removed, the dog contained within the pot was completely visible,” Ikram said.

The lack of evidence of any textile in the jar suggests Chewie was buried without bandages.

“The bones from his right foreleg were pushing through the skin and yellow fur,” Ikram added.

According to the researcher, both animals were mature, probably around five years of age.

“They were probably votive offerings unless they held the position of sacred animals — perhaps the pot burials are indicative of their being Sacred rather than just Votive,”Ikram said.

How the two animals were pushed into pots from which they cannot be extracted now remains a mystery.

“Without further examination and chemical testing it is not possible to understand the process by which these two animals were preserved,” Ikram said.

Read more at Discovery News

Mummy Mystery: Multiple Tombs Hidden in Valley of Kings

Multiple tombs lay hidden in Egypt's Valley of the Kings, where royalty were buried more than 3,000 years ago, awaiting discovery, say researchers working on the most extensive exploration of the area in nearly a century.

The hidden treasure may include several small tombs, with the possibility of a big-time tomb holding a royal individual, the archaeologists say.

Egyptian archaeologists excavated the valley, where royalty were buried during the New Kingdom (1550–1070 B.C.), between 2007 and 2010 and worked with the Glen Dash Foundation for Archaeological Research to conduct ground- penetrating radar studies.

The team has already made a number of discoveries in the valley, including a flood control system that the ancient Egyptians created but, mysteriously, failed to maintain. The system was falling apart by the time of King Tutankhamun, which damaged many tombs but appears to have helped protect the famous boy-king's treasures from robbers by sealing his tomb.

The team collected a huge amount of data that will take a long time to analyze properly, wrote Afifi Ghonim, who was the field director of the project, in an email to LiveScience. "The corpus was so extensive it will take years, maybe decades, to fully study and report on," wrote Ghonim, an archaeologist with the Ministry of State for Antiquities in Egypt who is now chief inspector of Giza.

The project is part of "the most extensive exploration in the Valley of the Kings since Howard Carter's time," he said, referring to the Egyptologist whose team discovered King Tut's tomb in 1922.

The search for undiscovered tombs

"The consensus is that there are probably several smaller tombs like the recently found KV 63 and 64 yet to be found. But there is still the possibility of finding a royal tomb," wrote Ghonim in the email. "The queens of the late Eighteenth Dynasty are missing, as are some pharaohs of the New Kingdom, such as Ramesses VIII."

That sentiment was echoed by the famous, and at times controversial, Egyptologist Zahi Hawass at a lecture in Toronto this past summer. Hawass was the leader of the Valley of the Kings team.

"The tomb of Thutmose II, not found yet, the tomb of Ramesses VIII is not found yet, all the queens of dynasty 18 [1550-1292 B.C.] were buried in the valley and their tombs not found yet," said Hawass, former minister for antiquities, during the lecture. "This could be another era for archaeology," he added in an interview.

Ghonim said that it is hard to say how many tombs remain undiscovered but it is "more than just a couple."

Locating tombs in the Valley of the Kings is difficult to do even with ground-penetrating radar, a non-destructive technique in which scientists bounce high-frequency radio waves off the ground and measure the reflected signals to find buried structures.

Radar instruments and related computing power have vastly improved in the last couple of decades, scientists say. Even so, it "is difficult to avoid false positives in a place like the Valley of the Kings. There (are) many faults and natural features that can look like walls and tombs. Our work did help refine the technology for use here and it does have a place."

In one instance, radar work carried out by a previous team suggested that tombs dating from the Amarna period (the period within the New Kingdom in which Tutankhamun lived) could be found in a certain area of the main valley. The team excavated the spot but didn't find any tombs.

When the undiscovered tombs — those that do exist — are unearthed, they may not hold their original occupants. For instance, KV 64, a small tomb discovered in 2011by a University of Basel team, was found to hold a female singer named Nehmes Bastet who lived around 2,800 years ago. She apparently re-used a tomb that was created for an earlier, unknown, occupant.

Still, Ghonim said they could indeed find a tomb whose original occupants are buried within. "It is not impossible however for one or more to be intact," he said. And if they do find such pharaohs, they may also find their brains, as work by Hawass and Dr. Sahar Saleem of Cairo University suggests the Egyptians didn't remove the brains of their dead pharaohs in the mummification process.

An ancient flood control system

While the prospect of new tombs is tantalizing, they are but one of many things the researchers looked for in the valley. Last spring, the researchers gave a taste of what was to come at the Current Research in Egyptology conference at the University of Cambridge.

We "made a number of finds, which we believe will change our understanding of how the ancient Egyptians managed and utilized the site," Ghonim wrote in the email.

The researchers discovered, for instance, the ancient Egyptians created a flood control system in the valley that, for a time, prevented the tombs from being damaged by water and debris.

They detected a deep channel that would have run through the valley about 32 feet (10 meters) below the modern-day surface. As part of their anti-flood measures the Egyptians would have emptied this channel of debris and built side channels that diverted water into it, allowing water and debris to pass through the valley without causing damage.

Still, Ghonim said they could indeed find a tomb whose original occupants are buried within. "It is not impossible however for one or more to be intact," he said. And if they do find such pharaohs, they may also find their brains, as work by Hawass and Dr. Sahar Saleem of Cairo University suggests the Egyptians didn't remove the brains of their dead pharaohs in the mummification process.

An ancient flood control system

While the prospect of new tombs is tantalizing, they are but one of many things the researchers looked for in the valley. Last spring, the researchers gave a taste of what was to come at the Current Research in Egyptology conference at the University of Cambridge.

We "made a number of finds, which we believe will change our understanding of how the ancient Egyptians managed and utilized the site," Ghonim wrote in the email.

The researchers discovered, for instance, the ancient Egyptians created a flood control system in the valley that, for a time, prevented the tombs from being damaged by water and debris.

They detected a deep channel that would have run through the valley about 32 feet (10 meters) below the modern-day surface. As part of their anti-flood measures the Egyptians would have emptied this channel of debris and built side channels that diverted water into it, allowing water and debris to pass through the valley without causing damage.

Strangely enough, the ancient Egyptians "for some reason after building it, they let it fall into disrepair rather quickly. By (the) time Tutankhamun was buried, flooding events had become a problem again," Ghonim said.

"That was bad for most tombs, but good for Tutankhamun since, at least according to one theory, flooding events effectively sealed the tomb and made it inaccessible to later tomb robbers."

Today flood control is still a problem in the Valley of the Kings, and scientists are looking at ways to protect the tombs.

"There have been many studies recommending what to do, but the need to keep the valley open and the costs involved remain a problem. There's also the need to develop a consensus on such an important thing," Ghonim said.

More discoveries and challenges

Many more finds will be detailed in scientific publications in the future, including the excavation of huts used by the workers who built the tombs and the documentation of graffiti left throughout the valley's history.

Read more at Discovery News

Vast Undersea Freshwater Reserves Discovered

Australian researchers said Thursday they had established the existence of vast freshwater reserves trapped beneath the ocean floor which could sustain future generations as current sources dwindle.

Lead author Vincent Post, from Australia's Flinders University, said that an estimated 500,000 cubic kilometers (120,000 cubic miles) of low-salinity water had been found buried beneath the seabed on continental shelves off Australia, China, North America and South Africa.

"The volume of this water resource is a hundred times greater than the amount we've extracted from the Earth's sub-surface in the past century since 1900," said Post of the study, published in the latest edition of Nature.

"Freshwater on our planet is increasingly under stress and strain so the discovery of significant new stores off the coast is very exciting.

"It means that more options can be considered to help reduce the impact of droughts and continental water shortages."

UN Water, the United Nations' water agency, estimates that water use has been growing at more than twice the rate of population in the last century due to demands such as irrigated agriculture and meat production.

More than 40 percent of the world's population already live in conditions of water scarcity. By 2030, UN Water estimates that 47 percent of people will exist under high water stress.

Post said his team's findings were drawn from a review of seafloor water studies done for scientific or oil and gas exploration purposes.

"By combining all this information we've demonstrated that the freshwater below the seafloor is a common finding, and not some anomaly that only occurs under very special circumstances," he told AFP.

The deposits were formed over hundreds of thousands of years in the past, when the sea level was much lower and areas now under the ocean were exposed to rainfall which was absorbed into the underlying water table.

When the polar icecaps started melting about 20,000 years ago these coastlines disappeared under water, but their aquifers remain intact -- protected by layers of clay and sediment.

Post said the deposits were comparable with the bore basins currently relied upon by much of the world for drinking water and would cost much less than seawater to desalinate.

Read more at Discovery News

Rain of Rocks Help Build Earth's Mystery Moho

A dense crystalline "rain" falling into Earth's mantle could explain how a mysterious seismic boundary forms beneath the crust, according to a study published yesterday (Dec. 4) in the journal Nature.

The model, based on rock evidence from volcanic islands that smashed into Asia and Alaska, confirms long-standing ideas about how continents are born.

"There are a lot of things I think this study will resolve and a lot of questions that will remain," said lead author and MIT geologist Oliver Jagoutz.

The seismic boundary investigated by Jagoutz and co-author Mark Behn, of the Woods Hole Oceanographic Institution in Woods Hole, Mass., is called the Moho, after Croatian seismologist Andrija Mohorovicic. In 1909, Mohorovicic realized earthquake waves suddenly sped up at a sharply defined boundary that hovers about 25 miles (40 kilometers) beneath continents. The discovery revealed Earth was divided, with a lighter crust and denser mantle where the seismic waves traveled faster.

Because the Moho is so deep, no one has ever seen it directly, but scientists have spent entire careers explaining why it exists and how it forms.

Misplaced Moho

One enduring puzzle has been the missing Moho — the boundary's absence beneath volcanic island chains, such as Japan's Izu-Bonin islands, that rise above colliding tectonic plates. Because these "island arcs" are the building blocks of continents, the missing Moho is a mystery. For example, the East Coast of North America has a clear, crisp Moho, but it is also quilted from scores of volcanic chains slamming into the continent's edge several hundred million years ago. Another problem is the rocks in continents are about 10 percent richer in silica than oceanic crust, which is the source of magma that feeds volcanic island chains.

"If we want to produce continental crust in arcs, we are left with two problems," Jagoutz told LiveScience's OurAmazingPlanet. "The rocks we find on the surface of continents all resemble lavas that are erupted in subduction zones, but there needs to be a mechanism that brings the melt from 50 to 60 percent [richer in silica]," he said. "Another problem we have is the structural problem. Somehow we need to introduce this major structural discontinuity, the Moho, that we don't have in arcs but we have in continents."

To solve the Moho mystery, Jagoutz and Behn found a way to look at the lower crust via fragments of former volcanic island chains now shoved up to the surface in mountain belts in Pakistan and Alaska. These rocks were once 25 to 31 miles (40 to 50 km) deep. They created a geophysical model of the crust based on the rocks, and compared it to seismic data from today's island arcs.

Planetary windows

The Pakistan rocks resemble modern island arc settings. There's no sharp density contrast that would produce a Moho boundary. The layers reveal a thick, continuous section of rocks of similar density, such as gabbros, at the depth of the Moho. But in Alaska, these rocks are missing. Instead, at the depth where the Moho would sit, there's a sharp density increase in the rock layers, with rocks called harzburgites and dunites instead of gabbros.

Jagoutz thinks the missing dense rocks provide the clue to what happens at volcanic arcs.

Inside the Earth, in the lower crust, a "rain" of dense crystalline material (called cumulates) falls from the base of the crust. The rocks are denser than the underlying mantle and sink down into the Earth. This process, known as delamination or foundering, continually peels off pieces of the lower crust.

"It's like icebergs, but the stuff that's actually dropping off is actually underwater," Jagoutz said.

Removing these dense rock leaves lighter, silica-rich materials behind — like the rocks found in continents, Jagoutz said.

Sinking down

The researchers think the Moho starts to appear with big changes in volcanism, such as when melting stops or subduction shuts off. Because volcanic island chains appear above subduction zones, where a tectonic plate sinks into the mantle and releases fluids that trigger melting, new magma will rise upwards and replace the missing crust. But without new magma replenishing the crystalline rain, eventually a sharp boundary will appear between lighter material in the crust and the dense mantle below.

"When this happens, the mantle will remain relatively hot for a while and the material will continue to sink back down," Jagoutz said.

Read more at Discovery News

Extreme Cosmic Explosions Supercharged by Magnetism

Scientists have captured their best view yet of how extreme magnetic fields shape superfast jets from the most powerful explosions in the universe.

The new research tracked polarized light from cosmic explosions, known as gamma-ray bursts, and offered an unprecedented glimpse into how intense magnetic fields shape the evolution of the outbursts.

"Gamma-ray bursts are the most extreme particle accelerators in the universe," said Carole Mundell, a professor of extragalactic astronomy at Liverpool John Moores University, who led the new study. "They're objects of all kinds of extremes: extreme speeds, extreme gravity, extreme magnetic fields. So they're the ultimate laboratory for testing or laws of physics."

Gamma-ray bursts are believed to form at the end of a massive star's life, just as the body of the star collapses in on itself, creating a black hole. As this happens, the matter surrounding the black hole may release two jets of gamma-rays and highly energetic particles, in opposite directions away from the black hole. A single gamma-ray burst may radiate more energy in a few minutes than the star radiated in its entire lifetime.

Mysterious Origins of Cosmic Explosions

Scientists still don't understand how the particles surrounding a black hole can generate the intense bursts of light and particles seen in gamma-ray bursts.

One theory suggests that an organized magnetic field will accelerate particles on an invisible track around the black hole, causing them to radiate light (what's known as synchrotron radiation). As the black hole rapidly contracts, so do the particles and the magnetic field, causing the particles to accelerate even faster. The theory suggests that it is this rapid bump in acceleration, combined with energy stored in the particles themselves, that creates two massive jets of gamma-rays and particles.

If the energy in a gamma-ray burst was at least partly due to synchrotron radiation, then scientists could expect to see an imprint of that magnetic field in the light produced by this violent event.

New Telescope Tool's Magnetic Find

Mundell and her colleagues designed an instrument named RINGO2 to measure the polarization of optical light that is produced as a byproduct of a gamma-ray burst. RINGO2 observed gamma-ray bursts for two years on the Liverpool optical telescope.

On March 8, 2012, NASA's Swift satellite — which tracks gamma-ray bursts — alerted the Liverpool telescope to a cosmic explosion dubbed GRB 120308A. The subsequent study, which was detailed in the Dec. 5 edition of the journal Nature, found that optical light emitted early on by GRB 120308A was 28 percent polarized, and decreased to 10 percent polarization over time.

"If you take optical light and you scatter it from dust, as it comes through our Milky Way galaxy, you might observe a few percent polarization," Mundell said. "Really the only way to produce this high degree of polarization is to have large-scale ordered magnetic fields that are producing the synchrotron radiation with the electrons spiraling around the magnetic field."

Mundell said the reduction in the polarization of the light over time demonstrates that the light is polarized upon its creation near the black hole, and loses its polarization as it travels through space. For this reason, RINGO2 must observe the optical light almost immediately after the start of the gamma-ray burst, in order to observe the polarity.

Read more at Discovery News

Dec 4, 2013

Spooky Connection: Wormholes and the Quantum World

One of the biggest and most vexing problems in physics is how quantum dynamics and gravity relate to one another. But now, physicists may have uncovered an interesting crossover between general relativity and the quantum world, potentially providing a hint as to how general relativity can be reconciled with quantum dynamics, a pairing that, in the mathematical sense, is like trying to mix water and oil.

Wormholes are hypothetical “gateways” between two points in space and time. A consequence of the equations arising from Albert Einstein’s bedrock theory of General Relativity, wormholes have spawned countless science fiction dreams of time travel and zooming between two distant locations faster than the speed of light.

Although the physics of actually using a wormhole to traverse spacetime is highly debatable — at best, huge quantities of an as-yet unfathomable “exotic energy” would be needed to keep a “traversable wormhole” open — there are few physicists who would doubt their existence, regardless of whether or not we may ever actually observe their effects.

In the quantum world, an apparently disparate place when compared with general relativity (which governs gravitational interactions and, by extension, wormholes), “entanglement” between subatomic particles is possible. If one can “entangle” two particles, no matter how far apart they are separated, should any quantum changes occur to one entangled pair, that change will be experienced instantaneously by its entangled partner. Quantum changes can be communicated between entangled particles no matter how far they are separated — whether the distance be the width of a laboratory desk or if one entangled particle were magically transported to another galaxy — the quantum change is communicated instantaneously.

This strange quality of entangled particles could be used for, say, faster than light communications between two points or super-fast quantum computers where calculations are theoretically instantaneous.

Entanglement was abhorred by Einstein, who referred to the mechanism as “spooky action at a distance.” But in new calculations, researchers have found some potential common ground between wormholes and this spooky action between particles.

In a paper published last month in the journal Physical Review Letters, physicists from the University of Washington and Stony Brook University in New York point out that if one could entangle two black holes that were then pulled apart, a wormhole connecting the two black holes would be created and governed by an identical set of entanglement rules.

Black holes are known to exist at masses close to that of our sun to many billions of solar masses in the centers of galaxies. But microscopic black holes are also possible, in theory, so you wouldn’t need to worry too much about being sucked into a massive black hole to create an entangled pair of them — just pop out two black holes the size of atoms, entangle them and separate. The wormhole will form between the two. (At this point, if you’re scratching your head wondering how in the heck you’d accomplish such a feat, fear not, this is all theory. And in physics, it’s OK to imagine futuristic sci-fi technologies to make your theory jive.)

Sadly, the connecting wormhole could not be used for communication, at least not in the traditional sense. The only way to communicate with a buddy at the other end of the wormhole is “if you jump into your black hole, then the other person must jump into his black hole, and the interior world would be the same,” said physicist Andreas Karch, of the University of Washington.

But using two black holes and a wormhole as a superluminal telegraph system isn’t the point of this exercise.

The key thing to come out of these calculations is that the black holes, regardless of their size, will remain entangled, just like the entangled particles of the quantum world. In this case, any change to one black hole will be communicated instantaneously to the other black hole through the wormhole. Therefore, the wormhole, a construct born from general relativity, is acting in a very quantum manner.

Read more at Discovery News

Expandable Organs Allow Python to Digest Huge Meals

The first full study of a snake's genome has revealed the Burmese python to be one of the most evolutionarily advanced creatures on Earth, international researchers said Monday.

The findings shed new light on how these southeast Asian natives have survived and thrived, and may offer new inroads to treating human diseases, said the report in the Proceedings of the National Academy of Sciences.

"Snakes have basically undergone incredible changes at all levels of their biology, from the physiological to the molecular," principal investigator David Pollock said.

These changes took place in functionally important ways over the past five to 30 million years, allowing the slithering creatures to adapt like no other, said Pollock, associate professor of biochemistry and molecular genetics at the University of Colorado School of Medicine.

Of particular interest to scientists is just how the Burmese python -- which can grow to 20 feet (seven meters) or larger -- is able to eat creatures as large as the snake itself.

Not only can its head and jaw open wide enough to envelope a meal the size of a deer, the snake's organs supersize themselves and go into overdrive in order to speedily digest the animal before it rots.

In the space of a day or two, the snake's heart, small intestine, liver and kidneys increase in size, ranging from a third larger than before to double their pre-feast size.

Once the meal is digested, the organs return to normal.

An analysis of the Burmese python's genome suggests that a complex interplay between gene expression, protein adaptation and changes in the genome structure allows these snakes to do what others with the same genes cannot.

"You think of being a tube as being really simple, right?" said Pollock.

"But, in fact that makes life a lot harder, and they have got all sorts of adaptations in a sense that are very unique to make up for that."

Snakes went through a phase went they lived underground. During this phase of their evolution, their skulls elongated, their lung capacity went down in response to the lower amount of oxygen available, and their eyesight was diminished, he explained.

When they moved above ground, they developed the capacity to dramatically shift their metabolism, from low to high, in order to consume what might have been a rare meal.

"Their morphology has changed, their physiology, their metabolism, and their genes, their genomes have changed to match. So that is a pretty neat finding," said Pollock.

Understanding how the snake's body orchestrates such major changes in key organs could offer a new understanding of the mechanisms behind human conditions such as organ failure, ulcers, metabolic disorders and more, said co-author Stephen Secor.

"With its genome in hand, we can now explore the many untapped molecular mechanisms it uses to dramatically increase metabolic rate, to shut down acid production, to improve intestinal function, and to rapidly increase the size of its heart, intestine, pancreas, liver, and kidneys," said Secor, associate professor of biological sciences at the University of Alabama.

Read more at Discovery News

Bizarre Microbes Discovered in Desert Cave

Tucked beneath the desert in southern Arizona is Kartchner Caverns, a maze of remote, largely uninhabited underground passages and caverns that are cloaked in perpetual darkness. But this seemingly desolate cave system actually plays host to a surprisingly diverse array of microbes that survive underground despite the extreme dearth of light and nutrients, according to a new study.

A team of researchers led by scientists at the University of Arizona in Tucson discovered communities of microorganisms that live in the limestone caves of Kartchner Caverns State Park. These microbial ecosystems thrive by teasing out the limited nutrients in water runoff that drips into the cave through cracks in the cave's rocky exterior, the researchers said.

The unexpected discovery, published online Sept. 12 in the journal of the International Society for Microbial Ecology, could help scientists understand how bacteria, fungi and other microbes survive in extreme environments.

"We didn't expect to find such a thriving ecosystem feasting on the scraps dripping in from the world above," Julie Neilson, an associate research scientist in the University of Arizona's College of Agriculture and Life Sciences, said in a statement. "What is most interesting is that what we found mirrors the desert above: an extreme environment starved for nutrients, yet flourishing with organisms that have adapted in very unique ways to this type of habitat."

Living in darkness, the underground microbes are unable to carry out photosynthesis— the process that plants and other organisms use to convert sunlight into energy. Still, the types of microorganisms found in Kartchner Caverns shared similarities to the more familiar types found on the Earth's surface, the researchers said.

"We discovered all the major players that make up a typical ecosystem," Neilson explained. "From producers to consumers, they're all there, just not visible to the naked eye."

Even without such biodiversity, simply living off the water dripping into Kartchner Caverns is an impressive feat, as there is a shortage of organic carbon — one of the building blocks of life on Earth — within the cave.

"Kartchner is unique because it is a cave in a desert ecosystem," Neilson said. "It's not like the caves in temperate areas such as in Kentucky or West Virginia, where the surface has forests, rivers and soil with thick organic layers, providing abundant organic carbon. Kartchner has about a thousand times less carbon coming in with the drip water."

These cave-dwelling microorganisms cultivate what little nutrients and energy are locked in the water molecules from decaying organic matter in the soil above ground, or from minerals dissolved in the rock fissures, the researchers said. The microbes have adapted means of using the chemical compounds present in the cave — in some cases, even eating rock to get energy from compounds such as manganese or pyrite, Neilson said.

"Instead of relying on organic carbon, which is a very scarce resource in the cave, they use the energy in nitrogen-containing compounds like ammonia and nitrite to convert carbon dioxide from the air into biomass," she said.

To reveal the cave's hidden microbial communities, the researchers swabbed stalactites and other formations hanging from the ceiling of Kartchner Caverns for DNA analysis. The genes found in these samples were used to reconstruct bacteria and archaea — single-celled microorganisms without a cell nucleus — that live in the limestone recesses.

Earlier studies indicated that stalactites act as islands for cave microbes, meaning there is little mixing between populations of microorganisms on different cave formations.

From their DNA analysis, the researchers not only encountered a diverse range of organisms that make up a complex food web within the cave, they also stumbled on some microbes that were likely previously unknown to science.

"Twenty percent of the bacteria whose presence we inferred based on the DNA sequences were not similar enough to anything in the database for us to be able to identify them," Neilson said. "On one stalactite, we found a rare organism in a microbial group called SBR1093 that comprised about 10 percent of the population on that stalactite, but it represented less than 0.5 percent of the microbes on any of the others."

The organism's DNA sequence has only been found three times in history: in a type of sedimentary rock in the salty waters of Shark Bay in Australia; in a site contaminated with hydrocarbons in France; and in a sewage treatment plant in Brisbane, Australia, Neilson said.

"This suggests there are many microbes out there in the world that we know almost nothing about," she added. "The fact that these organisms showed up in contaminated soil could mean they might have potential for application such as environmental remediation."

Read more at Discovery News

What Our Ancestors Looked Like

More Detailed Picture

DNA was just retrieved and sequenced from a 400,000-year-old representative of Homo heidelbergensis.

 DNA was just retrieved and sequenced from a 400,000-year-old representative of the genus Homo. The resulting near-complete mitochondrial genome sequence, detailed in this week's Nature, is now the oldest of its kind for any human species.

It revealed that Homo heidelbergensis, aka Heidelberg Man, lived during the Middle Pleistocene and shared a common ancestor with Denisovans, a group that migrated out of Africa early and later wound up in Siberia with a few other Homo species.

"In Africa a million years ago, they were all one group it seems, and then the ancestors of present-day humans and Neanderthals separated from the ancestors of the people that carried the Denisova mitochondrial DNA," co-author Svante Pääbo, director at the Max Planck Institute for Evolutionary Anthropology, told Discovery News.

The latest genetic analysis shows "that we can now study DNA from human ancestors that are hundreds of thousands of years old," he said. "This opens prospects to study the genes of the ancestors of Neanderthals and Denisovans. It is tremendously exciting."

Measuring Up

Homo heidelbergensis next to a Neanderthal and Cro-Magnon Human.
Yet another study focused on the height of Homo heidelbergensis and two other early human family tree members: Neanderthals and Cro-Magnon people, which were the earliest members of our species.

As the image shows, Heidelberg Man and the Neanderthals were pretty tough and muscular, but our species grew to be significantly taller.

Lost Cousin's Legacy

Neanderthal brains focused more on vision and movement, leaving less room for cognition related to social skills.
Neanderthals went extinct, or were absorbed into the modern human population, about 32,000 years ago. They had big brains, big muscles and, as seen here, big noses.

The influence of this human group lives on, according to Dan Dediu, a senior investigator in the Language and Genetics Department at the Max Planck Institute for Psycholinguistics, and his colleagues.

Dediu told Discovery News that humans today "might not only carry some Neanderthal genes in our own genomes as traces of our past encounters (with Neanderthals), but also our languages might as well preserve some faint signature of their languages as well, but until rigorous testing is attempted, this must remain pure -- even if exciting -- speculation."

'Hobbit' Human

A model of Homo floresiensis, also known as the "Hobbit Human."
Homo floresiensis, also known as "Hobbit Humans," lived on the island of Flores in Indonesia. They survived until relatively recent times, possibly until about 12,000 years ago. New research shows that possessed bigger brains than previously thought, even though their bodies were shorter than those of most adult humans.

"They were extremely short (about 3'6"), much shorter than any healthy living humans," Yousuke Kaifu of the National Museum of Nature and Science in Tokyo told Discovery News. "Their legs were short relative to their arms and feet, (features that) some researchers think were primitive."

Read more at Discovery News

Dec 3, 2013

Merriam-Webster's Word of the Year Is … Science!

While the Oxford University Press honored "selfies" as its 2013 Word of the Year, celebrating those quickly snapped self-portraits, Merriam-Webster is taking a more academic approach to its annual linguistic spotlight.

The dictionary has declared "science" its 2013 Word of the Year. The honor is based on increased interest as measured by the number of people looking up a word over time. If you haven't looked it up online, here's how Merriam-Webster defines science: "knowledge about or study of the natural world based on facts learned through experiments and observation."

Science, according to Merriam-Webster Editor-at-Large Peter Sokolowski, is the word behind the news in 2013.

"It is a word that is connected to broad cultural dichotomies: observation and intuition, evidence and tradition," Sokolowski said in a statement. "A wide variety of discussions centered on science this year, from climate change to educational policy. We saw heated debates about 'phony' science, or whether science held all the answers."

The result, he said, was a 176 percent increase in lookups of the word "science" in 2013 compared with 2012.

The second-most fascinating word of 2013 had a scientific bent as well, Merriam-Webster announced. That word was "cognitive," defined by the dictionary as "of, relating to, being, or involving conscious intellectual activity (as thinking, reasoning, or remembering)."

Cognitive may have gotten a boost from increasing awareness of traumatic brain injury in the National Football League, National Hockey League, and among military veterans, according to Merriam-Webster.

Read more at Discovery News

Skulls in China Reveal Mass Female Sacrifice

Archaeologists have uncovered more than 80 skulls of young women who may have been sacrificed 4,000 years ago in China.

The skulls were discovered in what is being called a mass grave at the Shimao Ruins at the site of a neolithic stone city in the northern province of Shaanxi.

"This collective burial might also have something to do with the founding ceremony of the city," Sun Zhouyong, deputy head of the Shaanxi Provincial Institute of Archaeology, told state broadcaster CCTV.

The women's bodies were not found according to China's official news agency Xinhua. Archaeologists in China suspect that a mass outbreak of violence or ethnic conflict may be the cause for the death of the women.

Zhouyong told CCTV that the first 40 skulls found last year at the Shimao Ruins showed "signs of being hit and burned." Archaeologists have since found more than 100 remains of murals and jadeware at the site which dates back to 2,000 BC.

This is not the first time evidence of human sacrifice in early China has been found. Kings and emperors were often buried with their servants and concubines who were sometimes killed first or buried alive.

Read more at Discovery News

'Secret' Labyrinth of Roman Tunnels Mapped

Deep under the streets and buildings of Rome is a maze of tunnels and quarries that dates back to the very beginning of this ancient city. Now, geologists are venturing beneath Rome to map these underground passageways, hoping to prevent modern structures from crumbling into the voids below.

In 2011, there were 44 incidents of streets or portions of structures collapsing into the quarries, a number that rose to 77 in 2012 and 83 to date in 2013. To predict and prevent such collapses, George Mason University geoscientists Giuseppina Kysar Mattietti and scientists from the Center for Speleoarchaeological Research (Sotterranei di Roma) are mapping high-risk areas of the quarry system.

The mapping is important, Kysar Mattietti told LiveScience, because through the years, Roman citizens have taken the patching of the quarry systems into their own hands.

"The most common way is to take some big plastic bags and fill them with cement and stick them in the holes," she said.

Lucky geology

Volcanism created the land Rome was built upon. These volcanic rocks, or tuff, were a boon to Rome's earliest architects, who soon learned the tuff was strong and easy to carve into building blocks. Lighter, less compacted volcanic ash was used as a main ingredient in mortar.

The first Romans were savvy, Kysar Mattietti said. The geoscientists quarried outside the city, and found that even when the suburbs began to encroach over the quarries, the ancient Romans knew to keep the tunnels narrow enough so that the ground above was still supported.

But two things worked against the long-term stability of the tunnels.

The first was Mother Nature. As soon as the rock is exposed to air, it starts to weather, Kysar Mattietti said. The second problem was human. Later generations kept building, using the same quarries for rock and widening the tunnels beyond their original size to create new structures above them.

Secret passageways

The tunnels are something of an open secret in Rome. Over the years, once quarrying ended, people repurposed the underground labyrinth as catacombs, for mushroom farming and as an unofficial sewer system. During World War II, people used the tunnels as bomb shelters.

But younger Romans are less aware of the geological hazard under the city, Kysar Mattietti said. And few realize the quarries' extent.

"Since they weren't serving any use, people tend to forget what can be a problem," Kysar Mattietti said.

Now, Kysar Mattietti and other geoscientists are using laser 3-D scanning to search for hidden weaknesses in the tunnels. The researchers also enter the tunnels through manholes and map the labyrinth by hand once they're sure the area is safe.

"There might be cracks, so they will be showing as veins almost, or openings, so we map the openings and map any kind of detachment," she said. In some spots, the ceiling of the tunnel sloughs off like cracking plaster. In others, there are total collapses — sometimes not reaching quite to street level, but leaving very little ground between the surface and the void.

"It's interesting, because at times when you are down there, you can hear people on top," Kysar Mattietti said.

To fix critical points, city officials seal off the unstable point and pour mortar into the tunnel, filling the entire void instead of simply patching over the top.

"What the municipality wants to do is to basically have a map of the risk so at that point they can on their side decide what kind of intervention needs to be done," Kysar Mattietti said.

Read more at Discovery News

Ancient Humans Had Sex with Mystery Relatives

A new, improved sequencing of ancient human relative genomes reveals that Homo sapiens didn't only have sex with Neanderthals and a little-understood line of humans called Denisovans. A fourth, mystery lineage of humans was in the mix, too.

As reported by the news arm of the journal Nature, new genetic evidence suggests that several hominids -- human relatives closer than humans' current living cousin, the chimpanzee -- interbred more than 30,000 years ago. This group of kissing cousins included an unknown human ancestor not yet revealed by the ancient DNA record.

"It's implied it could be something like Homo erectus or similar," said Carles Lalueza-Fox, a paleogenomics researcher at Pompeu Fabra University in Spain, who was not involved in the research, but who was present at a talk on the findings given by lead author David Reich of Harvard Medical School at a meeting on ancient DNA sponsored by the Royal Society in London on Nov. 18. Homo erectus is an extinct species of human that originated in India and spread into Asia.

Ancient human lineages

Neanderthals are an extinct group of humans who lived between about 30,000 and 130,000 years ago. Despite their reputation as bone-headed dummies, Neanderthals were likely as advanced as modern humans in areas such as tool-making, though they were probably less socially adept.

Denisovans are a far more mysterious group. These early humans lived in Siberia and probably split off from the branch of the human family tree that would eventually give rise to Neanderthals about 300,000 years ago. Little is known about how Denisovans lived and what they looked like.

But genetic analyses of Neanderthals, Denisovans and modern humans suggest the three groups occasionally had sex and produced offspring. Denisovan genes show up in modern Pacific Islanders and in people from Southeast Asia and southern China. Neanderthal genes appear in 1 to 4 percent of modern Eurasian people, suggesting that Homo sapiens and Neanderthals interbred after modern humans trekked out of Africa.

For unknown reasons, Homo sapiens are the only human survivors, as all others in the Homo genus eventually went extinct.

New genomes, new discoveries

The new research has been submitted to a scientific journal for publication. Under the journal's rules, lead author Reich cannot speak to the news media about the study until the paper comes out.

A Nature News reporter who attended the Nov. 18 talk, however, reports that Reich and his colleagues have created much more complete sequences of the Denisovan and Neanderthal genomes than those used in previous research.

The sequences confirmed previous findings that Denisovans mated with the ancestors of Pacific Islanders and East Asians, but also revealed a surprise: Genetic traces of an unknown population of human ancestors were found in the Denisovan gene, suggesting even more interbreeding than previously expected. Mark Thomas, an evolutionary geneticist at University College London, described the ancient environment to Nature as a "'Lord of the Rings'-type world" with many human populations living side-by-side.

Lalueza-Fox said the question of the mystery fourth ancestor is a "paleontological debate," but that the genetic work done by Reich and his colleagues opens the door to a deeper understanding of the individual diversity of ancient human ancestors. New techniques will enable researchers to tease out original DNA from later contaminants, he said.

Read more at Discovery News

Merging Black Holes Trapped in Galactic Death Spiral

We now know that the vast majority of galaxies have supermassive black hole behemoths living in their cores. We also suspect that they grow when their host galaxies merge with other galaxies, eventually spawning the mother of all growth spurts: black hole mergers — when bigger black holes with masses millions or even billions of times the mass of the sun are created. Now, with the help of NASA’s Wide-field Infrared Survey Explorer (WISE), two supermassive black holes have been discovered, caught in the middle of a merging dance in the center of a galaxy 3.8 billion light-years away.

WISE’s primary mission came to an end in 2011 after its coolant ran dry, but a new batch of data has just been released and an oddity was discovered. Assumed to be a lively star-forming region, astronomers soon realized the infrared object known as WISE J233237.05-505643.5 had some weird properties. With the help of followup studies by the Australian Telescope Compact Array (ATCA) near Narrabri, Australia, and the Gemini South observatory in Chile, the real nature of the object was unraveled.

“At first we thought this galaxy’s unusual properties seen by WISE might mean it was forming new stars at a furious rate,” said WISE project manager Peter Eisenhardt, at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “But on closer inspection, it looks more like the death spiral of merging giant black holes.”

When active black holes “feed” on surrounding matter in galactic hubs, a superheated plasma forms around the black hole’s event horizon. Through complex physics in the intense relativistic environment that are not yet fully understood, jets blast from the poles of the spinning black hole, generating powerful emissions. In the case of WISE J233237.05-505643.5, it appears that two black holes are orbiting one another, separated by only a few light-years (which is very close considering the gigantic masses of these huge multi-million solar mass black holes), and one of the black hole’s jets are being “wiggled” by the gravitational interactions with its merging partner.

“We think the jet of one black hole is being wiggled by the other, like a dance with ribbons,” said Chao-Wei Tsai, of NASA’s Jet Propulsion Laboratory, lead author of this research set to appear in a paper to be published in the Dec. 10 issue of Astrophysical Journal. “If so, it is likely the two black holes are fairly close and gravitationally entwined.”

There’s only one way this extreme cosmic dance will end — both black holes will eventually spiral together, losing energy and momentum to gravitational waves rippling from their spacetime warping, collide and merge to form an even bigger black hole.

Black hole mergers are a rare event to observe and only a few candidates have been found. Some black hole merger candidates have been identified, but this example is the most distant discovered to date. Following the WISE discovery of the black hole pair, radio emission data from the ATCA spotted the strange zig-zag pattern one of the black holes’ jets seemed to be producing. Then, from infrared/optical data gathered by Gemini South, the anomalous jet wiggle was confirmed. Clumpiness in material surrounding one of the suspected black holes also indicates the local region is being perturbed by the gravitational presence of another black hole.

Read more at Discovery News

Dec 2, 2013

Understanding Hearing

Children learning to speak depend on functional hearing. So-called cochlear implants allow deaf people to hear again by stimulating the auditory nerve directly. Researchers at the Technische Universitaet Muenchen (TUM) are working to overcome current limits of the technology. They are investigating the implementation of signals in the auditory nerve and the subsequent neuronal processing in the brain. Using the computer models developed at the TUM manufacturers of cochlear implants improve their devices.

Intact hearing is a prerequisite for learning to speak. This is why children who are born deaf are fitted with so-called cochlear implants as early as possible. Cochlear implants consist of a speech processor and a transmitter coil worn behind the ear, together with the actual implant, an encapsulated microprocessor placed under the skin to directly stimulate the auditory nerve via an electrode with up to 22 contacts.

Adults who have lost their hearing can also benefit from cochlear implants. The devices have advanced to the most successful neuroprostheses. They allow patients to understand the spoken word quite well again. But the limits of the technology are reached when listening to music, for example, or when many people speak at once. Initial improvements are realized by using cochlear implants in both ears.

A further major development leap would ensue if spatial hearing could be restored. Since our ears are located a few centimeters apart, sound waves form a given source generally reach one ear before the other. The difference is only a few millionths of a second, but that is enough for the brain to localize the sound source. Modern microprocessors can react sufficiently fast, but a nerve impulse takes around one hundred times longer. To achieve a perfect interplay, new strategies need to be developed.

Modeling the auditory system

The perception of sound information begins in the inner ear. There, hair cells translate the mechanical vibrations into so-called action potentials, the language of nerve cells. Neural circuitry in the brain stem, mesencephalon and diencephalon transmits the signals to the auditory cortex, where around 100 million nerve cells are responsible for creating our perception of sound. Unfortunately, this "coding" is still poorly understood by science.

"Getting implants to operate more precisely will require strategies that are better geared to the information processing of the neuronal circuits in the brain. The prerequisite for this is a better understanding of the auditory system," explains Professor Werner Hemmert, director of the Department for Bio-Inspired Information Processing, at the TUM Institute of Medical Engineering (IMETUM).

Based on physiological measurements of neurons, his working group successfully built a computer model of acoustic coding in the inner ear and the neuronal information processing by the brain stem. This model will allow the researchers to further develop coding strategies and test them in experiments on people with normal hearing, as well as people carrying implants.

Read more at Science Daily

Baby Dino Fossil: So Intact It's Lifelike

It may be bony looking, but a newly unearthed fossil of a baby dinosaur is so complete that it appears to hop out of the rock in which it was entombed.

The dinosaur is now believed to be among the best preserved dinosaurs in the world and it is the first known baby Chasmosaurus belli fossil.

“It’s pretty exciting. It’s a super specimen and I’m very lucky to be the guy that found it,” Philip Currie, Canada Research Chair in Dinosaur Paleobiology at the University of Alberta, said in a press release. “There’s no question this is one of the very best ones I’ve ever found.”

The baby dinosaur lived 72 million years ago and was about three years old when it died. Currie thinks it probably drowned.

He found the remains on a steep hillside while dino hunting in Alberta’s badlands at a place called Dinosaur Provincial Park. At first he noticed a piece of skull protruding from the Earth. He thought it might be part of a turtle skeleton, just because of what was sticking out and because turtles were also common there, but a day’s worth of digging unveiled the young near-complete dinosaur.

The skeleton is fully intact minus the arms, which Currie thinks were eroded away by a sinkhole several thousand years ago.

Chasmosaurus was a horned, plant-eating dinosaur that was a relative of Triceratops. It once flourished in Alberta’s badlands.

The remains have rocketed to dino stardom at the University of Alberta’s Laboratory for Vertebrate Paleontology, a collection that includes more than 50,000 specimens ranging in age from 450 million to 10,000 years old.

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Weird Organ Makes Koalas Sound Like Frogs

Simple calculations suggest koalas should have high-pitched voices. That's because the pitch generated by an object is linked to its size, and usually animals' vocal chords tend to be large or small according to the mass of their bodies.

But koalas have relatively low voices, especially males, which produce bellowing sounds during the mating season that alternately sound like a donkey braying and a frog vomiting. The average pitch of this bellow is 20 times lower than an animal that weighs 8 kilograms (18 lbs.) and more typical of an animal the size of an elephant, according to a study published today (Dec. 2) in the journal Current Biology.

So what's the koalas' secret? The animals actually have an extra "organ" outside the larynx, which contains the vocal chords that mammals and other animals use. In the koala's case, the vocal chords consist of long fleshy folds of tissue in the soft pallet between the upper throat, or pharynx, and the nasal cavities. When the koalas breathe in, they can push air through these "velar vocal folds," as the authors call them, to make low-pitched sounds, according to the study. This is quite unusual, they wrote.

"We have discovered that koalas possess an extra pair of vocal folds that are located outside the larynx, where the oral and nasal cavities connect," Benjamin Charlton, a study co-author and researcher at the University of Sussex, said in a statement. "We also demonstrated that koalas use these additional vocal folds to produce their extremely low-pitched mating calls."

In their study, Charlton and colleagues examined the larynxes and throats of 10 male koalas and found these vocal folds in the animals. Female koalas have also been known to bellow and should also be studied, the researchers wrote.

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Ancient 'Ghostbuster' Creatures Pooped Together

Enormous herds of rhino-like animals turned parts of what is now Argentina into minefields of dung, new fossils reveal.

These massive herbivores were dicynodonts, mammal-like reptiles that looked something like a cross between a rhinoceros and the demon dogs from "Ghostbusters." Argentine researchers have now found that these dicynodonts pooped in communal latrines, designated areas for depositing dung.

Many modern-day animals, including elephants, llamas and rhinos, poop in communal latrines. Even raccoons do it, much to the irritation of homeowners whose backyards are chosen as the places to defecate. Fossilized hyena poop from several hundred thousand years ago was deposited in communal latrines, but the behavior has not been found further back in the fossil record.

"This is the only case of megaherbavore latrine and it's the oldest," found fossilized, said study researcher Lucas Fiorelli of the Centro Regional de Investigaciones Científicas y Transferencia Tecnológica in La Rioja, Argentina.

Herd of reptiles

Fiorelli and his colleagues began excavating in northwest Argentina two years ago and quickly uncovered fossilized poop — known as coprolites — by the bucket load. These coprolites date back to the middle Triassic, 240 million years ago. In this era, small dinosaurs were just beginning to appear, but the world belonged to strange mammal-like reptiles, including the famous sail-backed Dimetrodon.

In some areas, there were as many as 94 rounded fossil poops every 10 square feet (1 square meter). The coprolites varied in size from just about half an inch (1 centimeter) in diameter to more than a foot (35 cm) wide. Such variation in such a small area strongly suggested a herd of young and old animals living together, defecating communally.

In total, the researchers found eight separate latrine spots. Most of the coprolites were oval or spherical, with a few "sausagelike" outliers and a few shaped like cow patties. The only animal large enough to produce dung balls more than a foot in diameter in this region was Dinodontosaurus, a beaky, tusked bruiser that could weigh up to 6,600 pounds (3,000 kilograms). In comparison, a modern African female bush elephant weighs about 8,000 lbs. (3,600 kg).

Communal pooping

Modern animals use communal latrines for communication — a big pile of dung can say anything from "dominant male lives here" to "fertile female nearby!" Communal defecation also prevents animals from spreading parasites, because they don't poop where they eat, Fiorelli said. It's not possible to know why Dinodontosaurus engaged in communal pooping, but the behavior could have served a similar purpose.

"It's an important social behavior," Fiorelli said. "They were gregarious animals."

The discovery is not only the first evidence of Triassic communal latrines; it's also the first direct evidence of Dinodontosaurus's diet. Most researchers agreed that this weird creature was a vegetarian, but only based on the animal's beaklike jaw. The gray-brown coprolites contained no animal bones, only woody plant material, seeds and pollen, Fiorelli and his colleagues found. The analysis reveals that Dinodontosaurus was indeed herbivorous.

Fiorelli and his colleagues have plans for more excavations in the region. They also plan to take a closer look at the Dinodontosaurus poop, which provides direct evidence of the kind of plants that were in the area 240 million years ago.

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