Jun 3, 2017

Neuroscientists rewire brain of one species to have connectivity of another

This image shows Giant Nudibranch, Dendronotus iris.
Scientists at Georgia State University have rewired the neural circuit of one species and given it the connections of another species to test a hypothesis about the evolution of neural circuits and behavior.

Neurons are connected to each other to form networks that underlie behaviors. Drs. Akira Sakurai and Paul Katz of Georgia State's Neuroscience Institute study the brains of sea slugs, more specifically nudibranchs, which have large neurons that form simple circuits and produce simple behaviors. In this study, they examined how the brains of these sea creatures produce swimming behaviors. They found that even though the brains of two species -- the giant nudibranch and the hooded nudibranch -- had the same neurons, and even though the behaviors were the same, the wiring was different.

The researchers blocked some of the connections in the giant nudibranch using curare, a paralyzing poison used on blow darts by indigenous South Americans. This prevented the brain of the giant nudibranch from producing the pattern of impulses that would normally cause the animal to swim. Then, they inserted electrodes into the neurons to create artificial connections between the brain cells that were based on connections from the hooded nudibranch. The brain was able to produce rhythmic, alternating activity that would underlie the swimming behavior, showing these two species produce their swimming behavior using very different brain mechanisms.

The findings are published in the journal Current Biology.

"Behaviors that are homologous and similar in form would naturally be assumed to be produced by similar neural mechanisms," said Katz, co-author of the study and a Regent's Professor in the Neuroscience Institute at Georgia State. "This and previous studies show that connectivity of the neural circuits of two different species of sea slugs differ substantially from each other despite the presence of homologous neurons and behaviors. Thus, the evolution of microcircuitry could play a role in the evolution of behavior."

The study's results are significant for several reasons. First, they show that over the course of evolution, behaviors might be conserved, but the underlying neural basis for the behaviors could shift.

In addition, other work by these researchers and Katz's lab has underscored the conclusion that neurons are conserved, but differ in function across species. This has implications for extrapolating results across species in general and means caution must be taken in assuming that neural mechanisms are conserved even though brain regions and behaviors are present.

Sakurai is first author of the study and a research scientist in the Neuroscience Institute at Georgia State.

Read more at Science Daily

Rover findings indicate stratified lake on ancient Mars

Sedimentary Signs of a Martian Lakebed (Shallow Part): This evenly layered rock imaged in 2014 by the Mastcam on NASA's Curiosity Mars rover shows a pattern typical of a lake-floor sedimentary deposit near where flowing water entered a lake. Shallow and deep parts of an ancient Martian lake left different clues in mudstone formed from lakebed deposits.
A long-lasting lake on ancient Mars provided stable environmental conditions that differed significantly from one part of the lake to another, according to a comprehensive look at findings from the first three-and-a-half years of NASA's Curiosity rover mission. While previous work had revealed the presence of a lake more than three billion years ago in Mars' Gale Crater, this study defines the lake's chemical conditions and uses Curiosity's powerful payload to determine that the lake was stratified.

Stratified bodies of water exhibit sharp chemical or physical differences between deep water and shallow water. In Gale's lake, the shallow water was richer in oxidants than deeper water was.

"We're learning that in parts of the lake and at certain times, the water carried more oxygen," said Roger Wiens, a planetary scientist at Los Alamos National Laboratory and co-author of the study, published today in the journal Science. "This matters because it affects what minerals are deposited in the sediments, and also because oxygen is important for life. But we have to remember that at the time of Gale Lake, life on our planet had not yet adapted to using oxygen -- photosynthesis had not yet been invented. Instead, the oxidation state of certain elements like manganese or iron may have been more important for life, if it ever existed on Mars. These oxidation states would be controlled by the dissolved oxygen content of the water."

"These were very different, co-existing environments in the same lake," said Joel Hurowitz of Stony Brook University, lead author of the report. "This type of oxidant stratification is a common feature of lakes on Earth, and now we've found it on Mars. The diversity of environments in this Martian lake would have provided multiple opportunities for different types of microbes to survive."

Whether Mars has ever hosted any life is still unknown, but seeking signs of life on any planet, whether Earth, Mars or more-distant icy worlds, begins with reconstruction of the environment to determine if it was capable of supporting life. NASA is using Curiosity to explore habitable environments on the ancient surface of Mars.

Read more at Science Daily

Jun 2, 2017

Your Abdomen's Layer of Fat Is Also an Important Immune Organ

A medical illustration from Atlas and Text-book of Human Anatomy,(by Dr. Johannes Sobotta, shows the branches of the coeliac artery and the origin of the portal vein, 1911. After division of the anterior lamina of the great omentum the stomach has been drawn upward, so that its posterior surface looks forward, and the pancreas has been divided along the superior mesenteric vessels.
Scientists believe that the omentum — a little known organ considered the “policeman of the abdomen” – may have answers about how to halt the growth of aggressive tumors.

The omentum lies like an apron over the peritoneal, or abdominal, cavity — a large sheet of fat that stretches across the intestines, liver, and stomach. The function of the organ itself is poorly understood, but researchers at the University of Alabama at Birmingham believe that it may play an important role in the immune response to certain tumors.

In a review published today in journal Trends in Immunology, scientists look at the role of so-called milky spots — clusters of white blood cells that speckle the omentum. They circulate the liquid in the abdominal cavity and much like lymph nodes, they filter and identify foreign antigens in the body, deciding whether or not to trigger an immune response.

While they are considered a first line of defense against foreign toxins and infections, as Tony Randall, a professor of medicine at the university and co-author of the review explained, these milky spots don’t always make the right call.

“They make a good immune response to bacteria,” Randall said. In this case, the milky spots cause the omentum to release inflammatory molecules to protect the body. “But with tumor cells, rather than triggering a robust immune response, it kind of turns off,” he added. “The process has kind of gone wrong.”

It is an immunological puzzle that Randall and co-author Selene Meza-Perez want to better understand. If they can explain why the omentum is tolerating the grown of tumor cells within these milky-spots, perhaps they can identify the mechanisms that would trigger an immune response, halting the growth of these tumors.

Their suspicion is that the omentum is somehow connected to the mucosal immune system that has evolved to recognize foreign antigens in the gut. Because we introduce a wide variety of food from different plants and animals into our body when we eat, the gut has evolved to tolerate certain foreign substances.

“The gut identifies these different microbial cells, etc., and it is tolerant,” Randall said. “It doesn’t make an inflammatory response, because most of the stuff in our gut is innocuous, not a pathogen.”

While this function is helpful in the gut — an inflammatory response to foreign bodies in the stomach would be quite painful, Randall explained — it is detrimental in the omentum. With the immune system disengaged, the milky spots become a breeding ground for aggressive tumors, such as such as ovarian and gastrointestinal cancer.

And because the omentum is 99 percent fat, the tumor draws considerable energy from the organ, allowing cells to quickly multiply.

Read more at Discovery News

Thawing Arctic Glaciers Released ‘Explosive’ Methane — and Could Do So Again

Massive craters on the floor of the Barents Sea were formed around 12,000 years ago, but are still seeping methane and other gases.
Millennia ago, as the great glaciers of the Ice Age receded, methane that had been frozen under the seafloor melted and burst forth, leaving massive craters that remain on the ocean bottom to this day.

Today, new research suggests humankind should be concerned that a similar release of methane, a potent greenhouse gas that can harm marine ecosystems, might happen again as global warming melts the ice in the Arctic, Greenland, and elsewhere.

“We provide a model for abrupt and explosive methane releases,” said Karin Andreassen, a professor at CAGE Centre for Arctic Gas Hydrate, Environment, and Climate and the lead author of a study on Arctic methane published in the journal Science.

Examining craters formed by methane eruptions 12,000 years ago, Andreassen and her colleagues determined that enormous amounts of methane in hydrate form — an ice-like mix of water and gas — must have dissolved as the 6,500-feet-thick ice sheets retreated from the Barents Sea north of what is now Scandinavia and western Russia.

They found more than 100 craters on the seafloor that ranged from around 1,000 to almost 3,300 feet wide — larger than any discovered before — as well as thousands of smaller pockmarks, according to their research.

“The principle is the same as in a pressure cooker,” she said. “If you do not control the release of the pressure, it will continue to build up until there is a disaster in your kitchen. These mounds were over-pressured for thousands of years, and then the lid came off.”

The study area is in Bjørnøyrenna close to the Arctic archipelago Svalbard.
It’s not clear how much of that methane reached the atmosphere, where it traps 84 times more heat in the atmosphere than carbon dioxide over a 20-year period, according to the Environmental Defense Fund.

Today, methane seepage is common throughout the oceans. Researchers believe bacteria consumes most of that methane, however, converting it into other chemicals like carbon dioxide that causes coral bleaching and other problems but also prevents it from reaching the surface to contribute to global warming.

The craters are connected to deeper gas chimneys, showing gas flow from deeper hydrocarbon reservoirs. Hundreds of gas flares are seen in the water above.
The large craters discussed in the study suggest methane blowouts could occur on a scale much larger than people have seen, especially as global warming worsens, Andreassen said.

It’s not clear what’s going on under glaciers that are melting now because studying them firsthand is difficult, she added.

“When we see what took place in the Barents Sea, this is also what we can expect to happen under today’s ice sheets,” she said.

Read more at Discovery News

‘Glass Frog’ Species Visibly Displays Its Beating Red Heart

You don’t have to be a biologist to see how so-called “glass frogs,” a group of largely arboreal tree frogs found in parts of Central and South America, earned that unusually descriptive name — their transparent underbellies are windows into their tiny bodies, revealing many of the organs tucked under their skin.

And in a new species recently discovered in Ecuador, the frog’s see-through skin on its underside extends over its chest as well, fully exposing its wee little, dark-red heart.

Researchers found the new species, which they named Hyalinobatrachium yaku, in three locations in Ecuador’s Amazonian lowlands, in the northeastern part of the country, at elevations of between about 980 to 1,150 feet (300 to 350 meters). [40 Freaky Frog Photos]

All frogs in this genus have undersides that are completely transparent, but having a heart that is completely exposed is very unusual, the researchers said. Only two other species of glass frogs have hearts as visible as H. yaku’s, and DNA analysis revealed that they weren’t the newcomer’s closest relatives, the scientists wrote in a study describing their new discovery.

A juvenile H. yaku, native to the Amazonian lowlands of Ecuador.
Heart of glass

Distinguishing between Hyalinobatrachium species can be challenging, because the frogs tend to be physically very similar, according to the study authors. In the case of H. yaku, distinctive vocalizations and dark-green spots on its head told the researchers that this was a new species. Genetic analysis confirmed that H. yaku was most closely related to H. pellucidum, a glass frog found in Ecuador and Peru.

The new species measures around 0.8 inches (21 millimeters) in length, of which about 37 percent is its head. Adults are colored “apple green to yellowish green” spotted with yellow, and on their backs they have a few “well-defined dark green spots,” which are unique to this species, according to the study authors.

Two of the sites where the scientists caught the frogs were quite distant from each other — about 68 miles (110 kilometers) apart — suggesting that the frogs’ range could extend far beyond the locations where the specimens were found. Because the frogs are arboreal, and therefore harder to find, it’s also possible that they are abundant in the region, even if they were only recently detected for the first time, the researchers wrote.

Read more at Discovery News

Do Stars Vanish Into a Black Hole or Crash Against a Surface? A New Test Answers

While there are lots of theories about black holes, a staple of singularity lore is that all black holes have event horizons — a one-way membrane through which particles fall in, never to return. Einstein's theory of general relativity says that all black holes have an event horizon where nothing, not even light, can escape the gravitational pull of these extremely dense objects.

But some have cast doubt about the existence of these event horizons. Stephen Hawking, one of the architects of modern black hole theory, wrote a paper in 2014 arguing that event horizons are incompatible with quantum theory. He instead proposed a more benign “apparent horizon,” which only temporarily holds matter and energy.

Another proposed alternative to event horizons is the “hard surface theory,” which suggests that matter within a black hole is destroyed by smashing into a solid surface. Instead of a singularity with no surface area, the black hole is a giant mass with a hard surface, and material being pulled closer — such as a star — would not actually fall into a black hole, but hit this hard surface and be destroyed. If that were the case, the collision should create a large burst of light.

But if event horizons do exist, there wouldn’t be flash of light. Instead, matter would just completely vanish when pulled in.

There are two possible ways to test the event horizon theory versus the hard surface theory. One is direct imaging of a black hole, and astronomers hope to do just that with the Event Horizon Telescope, a powerful array of telescopes around the world that is currently making observations of two supermassive black holes.

But a group of astronomers at the University of Texas at Austin and Harvard University didn’t want to wait for the Event Horizon Telescope data, and used another method to assess this basic principle of black holes. They say that their results, which they describe in a paper published in the journal Monthly Notices of the Royal Astronomical Society, constitute another successful validation of Einstein's theory.

“Our whole point here is to turn this idea of an event horizon into an experimental science, and find out if event horizons really do exist or not,” said Pawan Kumar, a professor of astrophysics at the University of Texas at Austin, in a statement. “Our motive is not so much to establish that there is a hard surface, but to push the boundary of knowledge and find concrete evidence that, really, there is an event horizon around black holes.”

Kumar, graduate student Wenbin Lu, and Ramesh Narayan, a theorist from the Harvard-Smithsonian Center for Astrophysics, figured out what a telescope would see when a star hit the hard surface of a supermassive object at the center of a nearby galaxy: The star’s gas would envelope the object, shining for months, maybe even years.

When they knew what to look for, the researchers estimated the rate at which stars fall into supermassive black holes to figure out how often this flash of light should be visible.

“We estimated the rate of stars falling onto supermassive black holes,” Lu said. “Nearly every galaxy has one. We only considered the most massive ones, which weigh about 100 million solar masses or more. There are about a million of them within a few billion light-years of Earth.”

The team looked at archival data from the 1.8 meter Pan-STARRS telescope in Hawaii, which had recently completed a three-year project to survey half of the northern hemisphere sky while searching for “transients” — distant bursts of light that glow for a while and then fade. Their goal was to find transients with the expected light signature of a star falling toward a supermassive object and hitting a hard surface.

“Given the rate of stars falling onto black holes and the number density of black holes in the nearby universe, we calculated how many such transients Pan-STARRS should have detected over a period of operation of 3.5 years,” Lu said. “It turns out it should have detected more than 10 of them, if the hard-surface theory is true.”

But they found… nothing. No object displayed the expected light signature that would show evidence of the hard surface theory. The team says this non-finding helps demonstrate that event horizons are real, and that matter completely vanishes when pulled into a black hole.

Read more at Discovery News

Jun 1, 2017

Mysterious new phase of matter: Breaking glass in infinite dimensions

Earlier calculations failed to find a 'fixed point' in three dimensions, or a spot where all the lines overlap (left). By taking these calculations one step further, Yaida was able to find the fixed point (right), showing that a new phase transition might exist in glasses at low temperatures.
Zoom in on a crystal and you will find an ordered array of atoms, evenly spaced like the windows on the Empire State Building. But zoom in on a piece of glass, and the picture looks a bit messier -- more like a random pile of sand, or perhaps the windows on a Frank Gehry building.

The highly-ordered nature of crystals makes them fairly simple to understand mathematically, and physicists have developed theories that capture all sorts of crystal properties, from how they absorb heat to what happens when they break.

But the same can't be said of glassy, amorphous or otherwise "disordered" materials such as the glass in our windows and vases, frozen food, and certain plastics. There are no widely agreed-upon theories to explain their physical behavior.

For nearly 30 years, physicists have debated whether a mysterious phase transition, present in theoretical models of disordered materials, might also exist in real-life glasses. With the help of some mathematical wizardry borrowed from particle physics -- plus dozens of pages of algebraic calculations, all done by hand -- Duke University postdoctoral fellow Sho Yaida has laid this mystery to rest.

Yaida's insights open up the possibility that some types of glass may exist in a new state of matter at low temperatures, influencing how they respond to heat, sound and stress, and how and when they break.

"We found hints of the transition that we didn't dare say was evidence of the transition because part of the community said that it could not exist," said Patrick Charbonneau, associate professor of chemistry at Duke and Yaida's advisor. "What Sho shows is that it can exist."

Mind-boggling as it may seem, Charbonneau said, the mathematics behind glasses and other disordered systems is actually much easier to solve by assuming that these materials exist in a hypothetical infinite-dimensional universe. In infinite dimensions, their properties can be calculated relatively easily -- much like how the properties of crystals can be calculated for our three-dimensional universe.

"The question is whether this model has any relevance to the real world." Charbonneau said. For researchers who carried out these calculations, "the gamble was that, as you change dimension, things change slowly enough that you can see how they morph as you go from an infinite number of dimensions to three," he said.

One feature of these infinite dimensional calculations is the existence of a phase transition -- called the "Gardner transition" after pioneering physicist Elizabeth Gardner -- which, if present in glasses, could significantly change their properties at low temperatures.

But did this phase transition, clearly present in infinite dimensions, also exist in three? Back in the 1980s, a team of physicists produced mathematical calculations showing that no, it could not. For three decades, the prevailing viewpoint remained that this transition, while theoretically interesting, was irrelevant to the real world.

That is, until recent experiments and simulations by Charbonneau and others started showing hints of it in three-dimensional glasses.

"The new drive to look at this is that, when attacking the problem of glass formation, they found a transition very much like the one that appeared in these studies," Charbonneau said. "And in this context it can have significant materials applications."

Yaida, who has a background in particle physics, took a second look at the old mathematical proofs. These calculations had failed to find a "fixed point" in three dimensions, a prerequisite for the existence of a phase transition. But if he took the calculation one more step, he thought, the answer might change.

One month and 30 pages of calculations later, he had it.

"Moments like these are the reason why I do science," Yaida said. "It is just a point, but it means a lot to people in this field. It shows that this exotic thing that people found in the seventies and eighties does have a physical relevance to this three-dimensional world."

After a year of checks and re-checks, plus another 60-odd pages of supporting calculations, the results were published May 26 in Physical Review Letters.

"The fact that this transition might actually exist in three dimensions means that we can start looking for it seriously," Charbonneau said. "It affects how sound propagates, how much heat can be absorbed, the transport of information through it. And if you start shearing the glass, how it will yield, how it will break."

Read more at Science Daily

X-ray pulses create 'molecular black hole'

The extremely intense X-ray flash knocks so many electrons out of the iodine atom (right) such that it pulls in the electrons of the methyl group (left) like an elecetromagnetic version of a black hole, before finally spitting them out.
Scientists have used an ultra-bright pulse of X-ray light to turn an atom in a molecule briefly into a sort of electromagnetic black hole. Unlike a black hole in space, the X-rayed atom does not draw in matter from its surroundings through the force of gravity, but electrons with its electrical charge -- causing the molecule to explode within the tiniest fraction of a second. The study provides important information for analysing biomolecules using X-ray lasers, as the scientists report in the journal Nature.

The researchers used the free-electron laser LCLS at the SLAC National Accelerator Laboratory in the US to bath iodomethane (CH3I) molecules in intense X-ray light. The pulses reached intensities of 100 quadrillion kilowatts per square centimetre. The high-energy X-rays knocked 54 of the 62 electrons out of the molecule, creating a molecule carrying a positive charge 54 times the elementary charge. "As far as we are aware, this is the highest level of ionisation that has ever been achieved using light," explains the co-author Robin Santra from the research team, who is a leading DESY scientist at the Center for Free-Electron Laser Science (CFEL).

This ionisation does not take place all at once, however. "The methyl group CH3 is in a sense blind to X-rays," says Santra, who is also a professor of physics at the University of Hamburg. "The X-ray pulse initially strips the iodine atom of five or six of its electrons. The resulting strong positive charge means that the iodine atom then sucks electrons away from the methyl group, like a sort of atomic black hole." In fact, the force exerted on the electrons is considerably larger than that occurring around a typical astrophysical black hole of ten solar masses. "The gravitational field due to a real black hole of this type would be unable to exert a similarly large force on an electron, no matter how close you brought the electron to the black hole," says Santra.

The process happens so quickly that the electrons that are sucked in are then catapulted away by the same X-ray pulse. The result is a chain reaction in the course of which up to 54 of iodomethane's 62 electrons are torn away -- all within less than a trillionth of a second. "This leads to an extremely high positive charge building up within the space of a ten-billionth of a metre. That rips the molecule apart," says co-author Daniel Rolles of DESY and Kansas State University.

Observing this ultra-fast dynamic process is highly significant to the analysis of complex molecules in so-called X-ray free-electron lasers (XFEL) such as the LCLS in California and the European XFEL, which is now going into service on the outskirts of Hamburg. These facilities produce extremely high-intensity X-rays, which can be used, among other things, to determine the spatial structure of complex molecules down to the level of individual atoms. This structural information can be used by biologists, for example, to determine the precise mechanism by which biomolecules work. Other scientists have already shown that the molecules reveal their atomic structure before exploding. However, to study the dynamics of biomolecules, during photosynthesis for example, it is important to understand how X-rays affect the electrons.

In this study, iodomethane serves as a model system. "Iodomethane is a comparatively simple molecule for understanding the processes taking place when organic compounds are damaged by radiation," says co-author Artem Rudenko from Kansas State University. "If more neighbours than a single methyl group are present, even more electrons can be sucked in."

Santra's group at CFEL has for the first time managed to describe these ultra-high-speed dynamics in theoretical terms, too. This was made possible by a new computer program, the first of its kind in the world. "This is not only the first time that this experiment has been successfully carried out; we even have a numerical description of the process," points out co-author Sang-Kil Son from Santra's group, who was in charge of the team that developed the computer program. "The data are highly relevant to studies using free-electron lasers, because they show in detail what happens when radiation damage is produced."

Apart from DESY, Kansas State University and SLAC, Tohoku University in Japan, the Max Planck Institute for Nuclear Physics in Germany, the University of Science and Technology Beijing in China, the University of Århus in Denmark, Germany's national metrology institute Physikalisch-Technische Bundesanstalt, the Max Planck Institute for Medical Research in Germany, the Argonne National Laboratory in the US, Sorbonne University in France, the Brookhaven National Laboratory in the US, the University of Chicago in the US, Northwestern University in the US and the University of Hamburg in Germany were also involved in the study.

Read more at Science Daily

Scientists identify 100 memory genes, open new avenues of brain study

Neurosurgeon Dr. Bradley Lega uses a robotic surgical assistant to place electrodes into the brains of epilepsy patients. The tool helps scientists map the brain waves of these patients to understand what patterns are critical for forming memories.
Scientists have identified more than 100 genes linked to memory, opening new avenues of research to better understand memory processing in the human brain.

A study at the Peter O'Donnell Jr. Brain Institute includes the results of a new strategy to identify genes that underlie specific brain processes. This strategy may eventually help scientists develop treatments for patients with memory impairments.

"Our results have provided a lot of new entry points into understanding human memory," said Dr. Genevieve Konopka, Assistant Professor of Neuroscience with the O'Donnell Brain Institute at UT Southwestern Medical Center. "Many of these genes were not previously linked to memory, but now any number of labs could study them and understand their basic function in the brain. Are they important for brain development; are they more important for aspects of behavior in adults?"

The study published in Cerebral Cortex stems from previous research by Dr. Konopka that linked specific genes to resting-state brain behavior. She wanted to use that same assessment to evaluate brain activity during active information processing.

To do so, she collaborated with Dr. Bradley Lega, a neurosurgeon with the O'Donnell Brain Institute conducting memory research on epilepsy patients while helping to locate the source of their seizures. Dr. Lega maps the brain waves of these patients to understand what patterns are critical for successful memory formation.

Combining their techniques, the doctors found that a different group of genes is used in memory processing than the genes involved when the brain is in a resting state. A number of them had not previously been linked to any brain process, Dr. Konopka said.

Dr. Lega is hopeful the findings can help scientists better understand and treat a range of conditions involving memory impairment, from epilepsy to Alzheimer's disease.

He also hopes the study's success in combining genetics and cognitive neuroscience will encourage more scientists to reach beyond their areas of expertise to elevate their research.

Read more at Science Daily

LIGO detects gravitational waves for third time

This artist's conception shows two merging black holes similar to those detected by LIGO. The black holes are spinning in a nonaligned fashion, which means they have different orientations relative to the overall orbital motion of the pair. LIGO found hints that at least one black hole in the system called GW170104 was nonaligned with its orbital motion before it merged with its partner.
The Laser Interferometer Gravitational-wave Observatory (LIGO) has made a third detection of gravitational waves, ripples in space and time, demonstrating that a new window in astronomy has been firmly opened. As was the case with the first two detections, the waves were generated when two black holes collided to form a larger black hole.

The newfound black hole, formed by the merger, has a mass about 49 times that of our sun. This fills in a gap between the masses of the two merged black holes detected previously by LIGO, with solar masses of 62 (first detection) and 21 (second detection).

"We have further confirmation of the existence of stellar-mass black holes that are larger than 20 solar masses -- these are objects we didn't know existed before LIGO detected them," says MIT's David Shoemaker, the newly elected spokesperson for the LIGO Scientific Collaboration (LSC), a body of more than 1,000 international scientists who perform LIGO research together with the European-based Virgo Collaboration. "It is remarkable that humans can put together a story, and test it, for such strange and extreme events that took place billions of years ago and billions of light-years distant from us. The entire LIGO and Virgo scientific collaborations worked to put all these pieces together."

The new detection occurred during LIGO's current observing run, which began November 30, 2016, and will continue through the summer. LIGO is an international collaboration with members around the globe. Its observations are carried out by twin detectors -- one in Hanford, Washington, and the other in Livingston, Louisiana -- operated by Caltech and MIT with funding from the National Science Foundation (NSF).

LIGO made the first-ever direct observation of gravitational waves in September 2015 during its first observing run since undergoing major upgrades in a program called Advanced LIGO. The second detection was made in December 2015. The third detection, called GW170104 and made on January 4, 2017, is described in a new paper accepted for publication in the journal Physical Review Letters.

In all three cases, each of the twin detectors of LIGO detected gravitational waves from the tremendously energetic mergers of black hole pairs. These are collisions that produce more power than is radiated as light by all the stars and galaxies in the universe at any given time. The recent detection appears to be the farthest yet, with the black holes located about 3 billion light-years away. (The black holes in the first and second detections are located 1.3 and 1.4 billion light-years away, respectively.)

The newest observation also provides clues about the directions in which the black holes are spinning. As pairs of black holes spiral around each other, they also spin on their own axes -- like a pair of ice skaters spinning individually while also circling around each other. Sometimes black holes spin in the same overall orbital direction as the pair is moving -- what astronomers refer to as aligned spins -- and sometimes they spin in the opposite direction of the orbital motion. What's more, black holes can also be tilted away from the orbital plane. Essentially, black holes can spin in any direction.

The new LIGO data cannot determine if the recently observed black holes were tilted but they imply that at least one of the black holes may have been non-aligned compared to the overall orbital motion. More observations with LIGO are needed to say anything definitive about the spins of binary black holes, but these early data offer clues about how these pairs may form.

"This is the first time that we have evidence that the black holes may not be aligned, giving us just a tiny hint that binary black holes may form in dense stellar clusters," says Bangalore Sathyaprakash of Penn State and Cardiff University, one of the editors of the new paper, which is authored by the entire LSC and Virgo Collaborations.

There are two primary models to explain how binary pairs of black holes can be formed. The first model proposes that the black holes are born together: they form when each star in a pair of stars explodes, and then, because the original stars were spinning in alignment, the black holes likely remain aligned.

In the other model, the black holes come together later in life within crowded stellar clusters. The black holes pair up after they sink to the center of a star cluster. In this scenario, the black holes can spin in any direction relative to their orbital motion. Because LIGO sees some evidence that the GW170104 black holes are non-aligned, the data slightly favor this dense stellar cluster theory.

"We're starting to gather real statistics on binary black hole systems," says Keita Kawabe of Caltech, also an editor of the paper, who is based at the LIGO Hanford Observatory. "That's interesting because some models of black hole binary formation are somewhat favored over the others even now and, in the future, we can further narrow this down."

The study also once again puts Albert Einstein's theories to the test. For example, the researchers looked for an effect called dispersion, which occurs when light waves in a physical medium such as glass travel at different speeds depending on their wavelength; this is how a prism creates a rainbow. Einstein's general theory of relativity forbids dispersion from happening in gravitational waves as they propagate from their source to Earth. LIGO did not find evidence for this effect.

"It looks like Einstein was right -- even for this new event, which is about two times farther away than our first detection," says Laura Cadonati of Georgia Tech and the Deputy Spokesperson of the LSC. "We can see no deviation from the predictions of general relativity, and this greater distance helps us to make that statement with more confidence."

"The LIGO instruments have reached impressive sensitivities," notes Jo van den Brand, the Virgo Collaboration spokesperson, a physicist at the Dutch National Institute for Subatomic Physics (Nikhef) and professor at VU University in Amsterdam. "We expect that by this summer Virgo, the European interferometer, will expand the network of detectors, helping us to better localize the signals."

The LIGO-Virgo team is continuing to search the latest LIGO data for signs of space-time ripples from the far reaches of the cosmos. They are also working on technical upgrades for LIGO's next run, scheduled to begin in late 2018, during which the detectors' sensitivity will be improved.

Read more at Science Daily

May 31, 2017

Outnumbered and on others' turf, misfits sometimes thrive

Two male sticklebacks of the same age -- one from a stream (top) and one from a lake (bottom) -- are each highly adapted to their own local environment. According to Bolnick, apart from a dramatic difference in size, the fish also differ in immune traits, body shape, armor to defend against predators, and "basically anything we can think to measure."
It's hard being a misfit: say, a Yankees fan in a room full of Red Sox fans or a vegetarian at a barbecue joint. Evolutionary biologists have long assumed that's pretty much how things work in nature too. Animals that wander into alien environments, surrounded by better-adapted locals, will struggle. But a team of researchers from The University of Texas at Austin was surprised to find that sometimes, misfits can thrive among their much more numerous native cousins.

"One hundred years of evolutionary theory is built around the idea that immigrants from one population dropped into another population of the same species don't do well," says Daniel Bolnick, a professor of integrative biology and the primary investigator on the study published today in the journal Nature. "Such immigrants are usually rare, and we have found that sometimes their rarity provides a competitive edge."

Bolnick and his team studied a small fish called a three-spined stickleback that lives in the lakes and streams of Vancouver, British Columbia. They studied two populations of the same species: one group that lives in a lake and another group in an adjacent stream.

Evolutionary theory suggests that taking the fish that are adapted to the lake environment and placing them into the stream would put them at a competitive disadvantage compared with the residents. In the dog-eat-dog world of natural selection, outsiders are often poorly adapted to a new environment and less likely to survive or pass on their genes. In the case of the sticklebacks, that's because the lake-adapted fish have different physical traits from their stream-adapted cousins -- such as their overall size, immune traits, body shape and defenses against predators -- that allow them to fare better back home but not necessarily in other environments.

Yet when the researchers did a series of experiments placing varying numbers of fish from one habitat into the other habitat with local fish, they found the transplants fared surprisingly well. Monitoring the fish in underwater cages over time, the researchers observed that survival had less to do with where a fish was from, and more to do with whether they were the common or rare type within their cage. In either habitat, when stream fish were in the minority, they survived better than when they were in the majority, for instance.

The scientists found that immigrants could fly under the radar in the face of some threats, which helped them beat the odds.

"You come in and you eat something nobody else around you eats, so you aren't competing for food," Bolnick says. "The local parasites don't know what to do with you because you have an unfamiliar immune system. So you're better off than the residents."

Bolnick notes that being less adapted to the environment also has some negative effects on immigrants, just as theory predicts, but their study shows that in some instances the benefits of rarity can outweigh the drawbacks of being in an unfamiliar environment.

"We found newcomers in the population pass on their genes more often than residents, and they contribute more to the next generation," Bolnick says.

The team found that this effect gives migrants an outsized impact on the genetics of their adopted population. This slows the pace of evolutionary divergence -- the rate at which each of the two populations might pick up new traits that make it differ more from the other.

Bolnick says this work could have implications for the protection and restoration of endangered species. For example, coral reefs are in decline around the world, but attempts to transplant corals from one location to another to restore reefs so far have met only limited success.

"My advice to someone doing any restoration work is that they can't just consider how well matched immigrants are to the local habitat," Bolnick points out. "They also need to consider how the immigrants' rarity affects their survival and reproduction."

In a separate paper published on May 22 in the journal Nature Ecology & Evolution, Bolnick and his colleagues made findings that also apply to species restoration. They found that stickleback adapt more closely to their environments than previously thought. So even fish from two streams that look similar might have different traits. That's because no two streams are exactly the same. There are subtle differences in water depth, flow rates, food sources and the presence of pathogens and predators.

Read mroe at Science Daily

Cassini Gets ‘Ringside Seat’ to Saturn's Changing Seasons

The hexagonal vortex at Saturn's north pole changed color significantly between June 2013 (left) and April 2017 (right), as seen in views from the Cassini spacecraft. For the left image, each frame occurs approximately 130 minutes after the previous one, and for the right, each frame follows after an average of 230 minutes. Researchers combined images taken with the spacecraft's red, green and blue filters for the natural-color views.
The Cassini spacecraft at Saturn watched over the ringed planet's solstice Wednesday (May 24), accomplishing the main goal of its second extended mission. A solstice occurs on Saturn roughly every 15 Earth years as its seasons change.

Cassini arrived at Saturn in 2004, and the spacecraft completed its primary mission to study the planet, its rings and its moons by 2008. Its first extended mission, which lasted until 2010, was to observe the system during the planet's equinox, when the sun strikes the rings edge-on and the days are of equal length on the north and south poles. The goal of its second extended mission — a seven-year plan called the Solstice Mission — was to observe all the way up to the north pole's summer solstice (when the days are longest at Saturn's north pole, and shortest at the planet's south pole) and investigate the system's seasonal changes.

"During Cassini's Solstice Mission, we have witnessed — up close for the first time — an entire season at Saturn," Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory (JPL) in California, said in a statement. "The Saturn system undergoes dramatic transitions from winter to summer, and thanks to Cassini, we had a ringside seat."

A giant storm passed by its own tail after circling Saturn in this true-color Cassini photo, taken Feb. 25, 2011, about 12 weeks after the storm started. Lightning deep in the planet's atmosphere produced significant radio noise during the storm. The storm formed and dispersed over the course of seven months; researchers said this type of Saturn storm happens only about every 30 Earth years.
During the Solstice Mission, researchers watched a huge storm encircle the planet and disperse over the course of seven months. They watched the hexagonal jet stream surrounding Saturn's north pole change from blue to yellow (except for the very center) over the course of the northern hemisphere's spring.

Cassini data suggests that the increased sunlight interacts with compounds in the upper atmosphere to form particles called photochemical aerosols, which accumulate into a yellowish haze. The very center may stay blue for one of two reasons, researchers said in an image caption: it hasn't been exposed to sunlight as long as the areas around it because it's at the very top of the planet, or the circulation in the whirling vortex pulls the compounds downward.

Cassini saw the seasonal changes come over the planet suddenly based on latitude, rather than gradually, the researchers said.

"Eventually, a whole hemisphere undergoes change, but it gets there by these jumps at specific latitude bands at different times in the season," Robert West, a member of Cassini's imaging team at JPL, said in the statement.

The solstice's intense sunlight heated Saturn's rings, letting Cassini's instruments better investigate ring particles' composition and the way they clump together. The planet's orientation compared to the sun and Earth, with its rings tipped maximally toward Earth, also meant that Cassini could easily send a radio signal through the densest part of the rings to investigate, according to the statement.

Storms on Saturn's moon Titan changed as Saturn moved through equinox and toward solstice. In this 2011 image, methane clouds can be seen concentrated near the moon's equator.
On Saturn's largest moon, Titan, methane storm clouds shifted up from the south toward the moon's equator from 2004 to 2010. Their corresponding shift northward as the solstice approached was surprisingly slow; according to the statement, cloud models had expected the activity to happen years earlier.

But some action was sudden: In 2013, haze and trace hydrocarbons formerly found only in the north suddenly built up in the Titan's south, indicating that its atmospheric circulation had changed direction due to the changing sun exposure, the statement said.

"Observations of how the locations of cloud activity change and how long such changes take give us important information about the workings of Titan's atmosphere and also its surface, as rainfall and wind patterns change with the seasons too," Elizabeth Turtle, a researcher on Cassini's imaging team at Johns Hopkins University's Applied Physics Laboratory in Maryland, said in the statement.

And on Saturn's moon Enceladus, which hosts a subsurface ocean and blasts geysers of material out through its plumes, the main seasonal change was its southern hemisphere's transition to winter darkness. This change let Cassini monitor the moon's temperature more easily, to investigate the intriguing moon.

Read more at Discovery News

‘Faceless Fish’ Among Bevy of Strange Species Hauled From the Ocean Depths

This Faceless Cusk was caught in the Jervis Bay Commonwealth Marine Reserve off New South Wales at depths of 4000 meters during the CSIRO RV Investigator voyage to the abyss.
Faceless fish and other weird and wonderful creatures, many of them new species, have been hauled up from the deep waters off Australia during a scientific voyage that has been studying parts of the ocean never explored before.

During a month-long journey off the country’s eastern seaboard, the research vessel Investigator has surveyed life lurking in a dark and cold abyss that plunges 2.5 miles (four kilometers) below the surface, using nets, sonar, and deep-sea cameras.

Tim O’Hara from Museums Victoria, who serves as chief scientist on board, told AFP on Wednesday that the search area was “the most unexplored environment on earth.”

Bright red spiky rock crabs, puffed-up coffinfish, blind sea spiders, and deep sea eels have been collected since the scientists began their voyage — from Launceston in Tasmania north towards the Coral Sea — on May 15.

They also came across an unusual faceless fish, which has only been recorded once before by the pioneering scientific crew of HMS Challenger off Papua New Guinea in 1873.

A species of rock crab (Neolithodes-cf-bronwynae) from the deep ocean displays a bright red and strikingly spiky shell.
“It hasn’t got any eyes or a visible nose and its mouth is underneath,” O’Hara said from the ship.

At such huge depths, it is so dark that creatures often have no eyes or produce their own light through bioluminescence, he added.

Carnivorous sponges that wield lethal spicules made of silicon — effectively glass — were another striking find. They get small crustaceans hooked on their Velcro-like spines, to be slowly digested in-situ. This technique differs from most deep-sea sponges, which feed on bacteria and other single-celled organisms filtered from passing currents.

“We’ve got 27 scientists on board who are leaders in their fields, and they tell me that around one-third of what we’ve found are new species,” said O’Hara, with several thousand specimens so far retrieved and two weeks of the trip still to go.

This puffed-up coffinfish collected by the RV Investigator belongs to a curious group of deep-sea anglerfishes that live on muddy or rocky seafloors worldwide. They can be difficult to identify, and it may some time before scientists determine whether this one is a new species.
Life at such depths is one of crushing pressures, no light, little food, and freezing temperatures, with animals that call it home evolving unique ways to survive.

As food is scarce, they are usually small and move slowly. Many are jelly-like and spend their lives floating about, while others have ferocious spines and fangs and lie in wait until food comes to them.

Working in such an environment was challenging, O’Hara admitted, with each fishing expedition taking up to seven hours to deploy and retrieve the equipment and its eight kilometers of cable from the sea floor, given it is so far down.

Read more at Discovery News

New Test Could Help Identify ‘Hidden’ HIV

Anwesha Sanyal holds up two vials with HIV-infected cells that she is preparing for Pitt Public Health's TZA test. The yellow indicates more stimulated HIV-infected cells.
Scientists working at the University of Pittsburg School of Public Health, led by Phalguni Gupta, have developed a test that they describe as “faster, less labor-intensive, and less expensive than the current ‘gold standard.’” It also seems to be much more effective. In experiments, their so-called TZA test was able to detect a 70-fold increase in the amount of “hidden” HIV found in asymptomatic patients with undetectable viral loads.

In a study published in the journal Nature Medicine, the researchers describe the test, which they hope could hold part of the answer to a long-standing question among doctors trying to find a cure for HIV: How can we determine when someone is truly cured?

“All this time infected people are taking the drugs and we don’t see any virus in the plasma, but actually the virus is hiding in the cells,” said Gupta, senior author on the study and vice chair of the department of infectious diseases and microbiology at the University of Pittsburg.

Current medicine has revolutionized the lives of those living with HIV. Thanks to antiretroviral treatment, known as ART, an infection that was once considered a death sentence has since become a manageable condition. But the treatment is still not able to completely eliminate HIV from the body.

HIV spreads throughout the body by infecting CD4+T cells, commonly referred to as T cells, which are a kind of white blood cells that plays an important role in protecting the body from infection. Currently, antiretroviral treatment can suppress HIV in active cells to levels that are virtually undetectable — to as little as one virus per million CD4+T cells.

But even when the viral load is undetectable, dormant HIV can remain in inactive CDT+4 cells. This so-called “latent HIV reservoir” is what the team at the University of Pittsburg hopes to identify and characterize. If the reservoir could be effectively reduced, patients would be able to go off of antiretroviral treatment while maintaining undetectable viral levels.

“We have to eradicate the virus in the latent condition — once we do, people can live without any drug,” Gupta said. “That’s the ultimate goal.

Last fall, a team in the United Kingdom announced the development of a “kick and kill” drug that they claimed would be able to draw HIV out of inactive cells and stimulate the immune system against infected cells. But before such a drug can be used, Gupta explained, scientists have a precise way to quantify the latent HIV reservoir, which would allow for the effectiveness of the drug to be measured.

While most of the DNA of HIV that has integrated into the inactive cells is defective and therefore unable to cause infection in the patient, creators of the TZA test note that there is the potential for this dormant HIV to be awakened, replicating, and causing a relapse of an otherwise healthy patient. For this reason, researchers say its crucial not only to identify this latent HIV reservoir, but also test its ability to replicate.

Gupta and his team have done this by identifying a specific gene that is activated only when replicating HIV is present. Once the replicating HIV is flagged, scientists say that technicians should be able to quantify it with greater ease.

Currently, this process is done by way of a test called a “quantitative viral outgrowth assay,” or Q-VOA, which authors describe as having a number of drawbacks. Aside from giving a minimal estimate of the latent HIV reservoir, the test requires a large volume of blood, and is labor-intensive, time-consuming, and expensive.

The TZA test, by contrast, requires much less blood, which offers a major advantage in pediatric applications. It is also expected to be cheaper, more accurate, and able to deliver results in just one week ­— half the time needed to grow out a viral sample with the Q-VOA test. While optimistic about the results, Gupta and his team are cautious to avoid sweeping conclusions about the significance of the test.

Read more at Discovery News

May 30, 2017

Groundwater 'pit stops' enabled survival, migration of our ancient ancestors

Oasis in Morocco
An international team led by a researcher at Cardiff University believe that the movement of our ancestors across East Africa was shaped by the locations of groundwater springs.

In a new study, the team argue that the springs acted as pit stops to allow early humans to survive as they moved across the African landscape.

The team believe that populations were able to mix with each other at these junctions, influencing genetic diversity and, ultimately, the evolution of the human population.

The results of the study have been published in the journal Nature Communications.

Humans are thought to have first evolved in Africa, and evidence currently suggests that early humans first migrated out of the continent probably between 2 million and 1.8 million years ago.

During this time, rainfall was affected by the African monsoon which strengthened and weakened on a 23,000 year cycle driven by the precession of the equinoxes. During intense periods of aridity, monsoon rains would have been light and drinking water in short supply.

By mapping persistent springs across the African landscape, the researchers have been able to model how our ancestors may have moved between water sources at different times and how this impacted their ability to traverse the landscape as the climate changed.

Lead author of the study Dr Mark Cuthbert, from Cardiff University's School of Earth and Ocean Sciences, said: "We found that the geology is really important in controlling how much rainfall gets stored in the ground during wet periods. Modelling the springs showed that many could still flow during long dry periods because this groundwater store acts like a buffer against climate change.

"As such, we begin to see that the geology, and not just the climate, control the availability of water -- the landscape was a catalyst for change in Africa."

Co-author of the study Professor Matthew Bennett, from Bournemouth University, said: "What we are seeing is the movement of people across vast areas of land. You can think of springs as the service stations or rest stops along the way, where people would be drawn to get their vital water sources.

"Through our mapping we have found the routes on the current landscape by which our ancestors may have walked, like motorways, taking people from one water source to the next. This is another vital clue in understanding how these people migrated across the African continent, from water source to source, and how this may have impacted on gene flow and mixing."

Read more at Science Daily

'Halos' discovered on Mars widen time frame for potential life

A mosaic of images from the navigation cameras on the NASA Curiosity rover shows "halos" of lighter-toned bedrock around fractures. These halos comprise high concentrations of silica and indicate that liquid groundwater flowed through the rocks in Gale crater longer than previously believed.
Lighter-toned bedrock that surrounds fractures and comprises high concentrations of silica -- called "halos" -- has been found in Gale crater on Mars, indicating that the planet had liquid water much longer than previously believed. The new finding is reported in a paper published in Geophysical Research Letters, a journal of the American Geophysical Union.

"The concentration of silica is very high at the centerlines of these halos," said Jens Frydenvang, a scientist at Los Alamos National Laboratory and the University of Copenhagen and lead author of the paper. "What we're seeing is that silica appears to have migrated between very old sedimentary bedrock and into younger overlying rocks. The goal of NASA's Curiosity rover mission has been to find out if Mars was ever habitable, and it has been very successful in showing that Gale crater once held a lake with water that we would even have been able to drink, but we still don't know how long this habitable environment endured. What this finding tells us is that, even when the lake eventually evaporated, substantial amounts of groundwater were present for much longer than we previously thought -- thus further expanding the window for when life might have existed on Mars."

Whether this groundwater could have sustained life remains to be seen. But this new study buttresses recent findings by another Los Alamos scientist who found boron on Mars for the first time, which also indicates the potential for long-term habitable groundwater in the planet's past.

The halos were analyzed by the rover's science payload, including the laser-shooting Chemistry and Camera (ChemCam) instrument, developed at Los Alamos National Laboratory in conjunction with the French space agency. Los Alamos' work on discovery-driven instruments like ChemCam stems from the Laboratory's experience building and operating more than 500 spacecraft instruments for national security.

Curiosity has traveled more than 16 km over more than 1,700 sols (martian days) as it has traveled from the bottom of Gale crater part way up Mount Sharp in the center of the crater. Scientists are using all the data collected by ChemCam to put together a more complete picture of the geological history of Mars.

The elevated silica in halos was found over approximately 20 to 30 meters in elevation near a rock-layer of ancient lake sediments that had a high silica content. "This tells us that the silica found in halos in younger rocks close by was likely remobilized from the old sedimentary rocks by water flowing through the fractures," said Frydenvang. Specifically, some of the rocks containing the halos were deposited by wind, likely as dunes. Such dunes would only exist after the lake had dried up. The presence of halos in rocks formed long after the lake dried out indicates that groundwater was still flowing within the rocks more recently than previously known.

From Science Daily

The first genome data from ancient Egyptian mummies

Verena Schuenemann at the Palaeogenetics Laboratory, University of Tuebingen.
An international team of scientists, led by researchers from the University of Tuebingen and the Max Planck Institute for the Science of Human History in Jena, successfully recovered and analyzed ancient DNA from Egyptian mummies dating from approximately 1400 BCE to 400 CE, including the first genome-wide nuclear data from three individuals, establishing ancient Egyptian mummies as a reliable source for genetic material to study the ancient past. The study, published today in Nature Communications, found that modern Egyptians share more ancestry with Sub-Saharan Africans than ancient Egyptians did, whereas ancient Egyptians were found to be most closely related to ancient people from the Near East.

Egypt is a promising location for the study of ancient populations. It has a rich and well-documented history, and its geographic location and many interactions with populations from surrounding areas, in Africa, Asia and Europe, make it a dynamic region. Recent advances in the study of ancient DNA present an intriguing opportunity to test existing understandings of Egyptian history using ancient genetic data.

However, genetic studies of ancient Egyptian mummies are rare due to methodological and contamination issues. Although some of the first extractions of ancient DNA were from mummified remains, scientists have raised doubts as to whether genetic data, especially nuclear genome data, from mummies would be reliable, even if it could be recovered. "The potential preservation of DNA has to be regarded with skepticism," confirms Johannes Krause, Director at the Max Planck Institute for the Science of Human History in Jena and senior author of the study. "The hot Egyptian climate, the high humidity levels in many tombs and some of the chemicals used in mummification techniques, contribute to DNA degradation and are thought to make the long-term survival of DNA in Egyptian mummies unlikely." The ability of the authors of this study to extract nuclear DNA from such mummies and to show its reliability using robust authentication methods is a breakthrough that opens the door to further direct study of mummified remains.

For this study, an international team of researchers from the University of Tuebingen, the Max Planck Institute for the Science of Human History in Jena, the University of Cambridge, the Polish Academy of Sciences, and the Berlin Society of Anthropology, Ethnology and Prehistory, looked at genetic differentiation and population continuity over a 1,300 year timespan, and compared these results to modern populations. The team sampled 151 mummified individuals from the archaeological site of Abusir el-Meleq, along the Nile River in Middle Egypt, from two anthropological collections hosted and curated at the University of Tuebingen and the Felix von Luschan Skull Collection at the Museum of Prehistory of the Staatliche Museen zu Berlin, Stiftung Preussicher Kulturbesitz.

In total, the authors recovered mitochondrial genomes from 90 individuals, and genome-wide datasets from three individuals. They were able to use the data gathered to test previous hypotheses drawn from archaeological and historical data, and from studies of modern DNA. "In particular, we were interested in looking at changes and continuities in the genetic makeup of the ancient inhabitants of Abusir el-Meleq," said Alexander Peltzer, one of the lead authors of the study from the University of Tuebingen. The team wanted to determine if the investigated ancient populations were affected at the genetic level by foreign conquest and domination during the time period under study, and compared these populations to modern Egyptian comparative populations. "We wanted to test if the conquest of Alexander the Great and other foreign powers has left a genetic imprint on the ancient Egyptian population," explains Verena Schuenemann, group leader at the University of Tuebingen and one of the lead authors of this study.

Close genetic relationship between ancient Egyptians and ancient populations in the Near East

The study found that ancient Egyptians were most closely related to ancient populations in the Levant, and were also closely related to Neolithic populations from the Anatolian Peninsula and Europe. "The genetics of the Abusir el-Meleq community did not undergo any major shifts during the 1,300 year timespan we studied, suggesting that the population remained genetically relatively unaffected by foreign conquest and rule," says Wolfgang Haak, group leader at the Max Planck Institute for the Science of Human History in Jena. The data shows that modern Egyptians share approximately 8% more ancestry on the nuclear level with Sub-Saharan African populations than with ancient Egyptians. "This suggests that an increase in Sub-Saharan African gene flow into Egypt occurred within the last 1,500 years," explains Stephan Schiffels, group leader at the Max Planck Institute for the Science of Human History in Jena. Possible causal factors may have been improved mobility down the Nile River, increased long-distance trade between Sub-Saharan Africa and Egypt, and the trans-Saharan slave trade that began approximately 1,300 years ago.

Read more at Science Daily

Massive Marine Predator Terrorized Cephalopods During the Dinosaur Age

Pliosaur Luskhan itilensis.
A newly identified, 130-million-year-old marine reptile was enormous, measuring the length of nearly three grand pianos lined up, but it wasn't a top marine predator, a new study finds.

Researchers excavated the remains of this pliosaur — a type of short-necked plesiosaur with four flippers that lived during the dinosaur age — along the banks of the Volga River, near the Russian city of Ulyanovsk, in the fall of 2002. Now, scientists have classified the ancient marine reptile as a new species.

Unlike other pliosaurs, such as Pliosaurus funkei and Liopleurodon, which had larger teeth and likely dined on sizable four-legged prey, the newfound pliosaur probably wasn't a top predator, as it had "fairly small" teeth and likely hunted small prey such as cephalopods, including squid, and small fish, said study lead researcher Valentin Fischer, a lecturer in the geology department at the University of Liege in Belgium.

The scientists named the 26-foot-long (8 meters) newfound beast Luskhan itilensis. The name reflects the region's cultural history, as the area used to be part of the Mongol Empire. In Mongolian and Turkic mythology, "luuses" were spirits and masters of the water. "Khan" is the Mongolian word for "chief."

The species name refers to "Itil," the Volga River's ancient Turkic name. (Turkic refers to groups of people who used and still do live in the region.) Thus, the reptile's name essentially translates to "master spirit from the Volga," the researchers said.

L. itilensis' skull was long — 5 feet (1.5 m) — and its snout resembled those of the modern-day river dolphin and gharial, a long-snouted crocodile.

"We show that pliosaurids have actually evolved a long-snouted, 'piscivorous' [fish-eating] ecological niche multiple times in their history," Fischer told Live Science in an email. "Each time they have done this, they have actually evolved convergently with another, distantly related group of plesiosaurs called the polycotylids."

Read more at Discovery News

Inside Utah's Vast Telescopic Hotspot for Cosmic Rays

Scintillation detectors
An unconventional telescope spreads across Utah's dry Bonneville lake bed. Made up of hundreds of giant rusty detectors, the instrument studies cosmic rays, the high-energy particles that come from distant universal sources and Earth's atmosphere.

The Telescope Array (TA) project is made up of instruments that collect the particles produced when cosmic rays collide with charged particles in the air. The desert air makes the site ideal for this kind of work, because it's free from the humidity that might interfere with the paths of the particles tracing cosmic rays. Nearby, a giant telescope searches the horizon for flashes of ultraviolet light, invisible to human eyes, that indicate those initial collisions as well as from the secondary particles.

By studying the particles that cascade to Earth, scientists can learn about the energy of the original cosmic rays. Traveling through space, the cosmic rays are rapidly accelerated to energy levels millions of times higher than particles inside the Large Hadron Collider, the most powerful particle accelerator ever built.

It's known that some cosmic rays are accelerated by exploding stars called supernovas, and -low-energy cosmic rays are ejected from "ordinary" stars, similar to our sun, by solar flares that explode off the star's surface. But the source of high-energy cosmic rays remains a mystery. Large, energetic structures with strong shocks, such as the active centers of galaxies, are one potential source. Learning more about the rays may help scientists uncover additional sources of cosmic rays, and shine light on the process (or processes) that accelerates them through space.

The Telescope Array project is already off to a good start. In 2014, the project noticed that cosmic rays seemed to be in a greater cluster in the sky just south of the Big Dipper.

"What we're looking for are those incredibly rare events," Julie Callahan, project coordinator at the University of Utah who works on public outreach for the TA project, told Space.com.

In February, Callahan and I made the 2.5-hour drive from Salt Lake City to Delta, Utah, where scientists are hunting for answers to the mysteries about cosmic rays. We then ventured even farther away from civilization, making the 45-minute trek to the Telescope Array project's Middle Drum observatory, home to the giant telescopes and surrounded by the "scintillation detectors" (SDs) that operate around-the-clock.

The trip to nowhere

Callahan picked me up just south of Salt Lake City for the long drive to the project. The city, nestled in a valley surrounded by mountains, doesn't seem like a good site for night-sky observation. During the winter, Salt Lake City has what the locals refer to as "the inversion," where the surrounding mountains allow a cap of warm air to trap pollutants in the valley, creating a long-lasting gray cover over the city and nearby suburbs. The journey to the array will take us far from this atmospheric effect, though we'll be able to pick it out from 3 hours away.

As Callahan fills me in on the project, the suburbs melt away to a flat, scrub-filled desert with an occasional rocky mountain poking up unexpectedly. Eventually, we reach the small town of Delta, home to the Lon and Mary Watson Cosmic Ray Center, which serves as a base of operations for the Telescope Array (TA). The small concrete-block building sits just off the road, its side yard filled with strange rusty objects. A small sign on the building reveals the TA's purpose — hunting cosmic rays.

The Lon and Mary Watson Cosmic Ray Center in Delta, Utah, is the base of operations for the Telescope Array (TA) project, which studies powerful particles from space called cosmic rays. Read the full story about touring the Cosmic Ray Center and seeing the TA experiment here.
Led by the University of Utah, the Telescope Array project is composed of 28 international collaboration partners, including 19 institutes and universities from Japan. The Asian influence is obvious as I tour the site, especially in the storage room where boxes of parts and partially assembled scintillation detectors are stashed. While some of the boxes are marked in English, far more are labeled in Japanese, with no English translation, and many of the signs are also written in Japanese.

When I walk into the center, I'm greeted by a small visitor's area. Callahan, who arrived at her present position with an art background nearly two decades ago, helped to design the lobby's three-wall mural, which features an illustration of the desert and sky that surround the scintillation detectors. Posters describe the work being done by scientists working on the TA project, and a comic book uses manga (a Japanese illustration style) to provide even more detail about the science going on here. The fourth wall is a homage to the nearby Topaz internment camp that imprisoned Japanese-American citizens during World War II.

It's through the next door, however, that the work gets done. The middle of the building is a single giant room, divided in half by a partition lined with desks and decorated with posters. A pair of scintillation detectors sits on the left side of the room, under construction. On the right side are desks covered with electronics that make up the guts of those detectors.

Despite it being a weekday, there are only two men inside the building, doing basic custodial work. One is American, and the other speaks only Japanese. Everyone else is out in the desert at the Middle Drum facility.

After more than a decade, the project is receiving its first major upgrade of over 100 closely positioned scintillation detectors to hunt for cosmic rays at lower energies. Known as the Telescope Array Low Energy (TALE), the project requires placing the detectors closer together. A third of the new detectors will sit a quarter-mile (400 meters) apart from each other, and another third will be spaced a third of a mile (600 m) apart from each other. With three-quarters of a mile (1,200 m) separation, the last batch will have the same distance between them as TA's detectors. Another planned expansion, dubbed Telescope Array Times Four, will double the number of TALE detectors and quadruple the ground covered. According to Callahan, the success of the 2014 finding paved the way for the expansion by proving the project's scientific merits.

We pass through strips of clear plastic hang from the top of alarge opening that connects the rooms. The wide space allows a Skid-L,At the back of the building, a raised garage door opens up to the outside. In a mud-filled corral behind the building sit rows of new detectors, awaiting transport to Middle Drum.

Over the past few months, the team has been assembling the new scintillation detectors in preparation for the upgrade. From the corral, they will be trucked to the Middle Drum site, a remote, uninhabited location 45 minutes from Delta. The final deployment will require a helicopter to deliver the detectors to their resting places, and moving the detectors to Middle Drum by truck will reduce the flight time (and subsequent cost), while keeping the helicopter noise from bothering Delta's population.

A local contractor uses a skid lift to load the detectors onto the trailer.
Helicopters are a necessity for the upgrade. The project sits on public lands where vehicles must remain on roads; even bicycles are forbidden to go off-road. The team has occasionally rented horses to visit multiple scintillation detectors, but most of the time, they park on the nearest road and hike in to make checkups or repairs.

As I squish through the corral's thick mud, I'm greeted not by shiny new detectors but by rusted hunks of metal. The rust is a deliberate effort to avoid distracting the Air Force pilots that often fly over the desert, Callahan said. The boxes look like rusted hospital bed frames; Callahan said her husband compares them to pingpong tables.

The heart of the scintillation detector lies within the box on top of the frame. Two panels cover the box, and require several people — and a special grip — to open them. Inside sit two layers of a plexiglass-like acrylic material doped with a molecule that creates ultraviolet light when hit by a charged particle from a shower of particles created by a cosmic-ray collision in the atmosphere. Rows of fiber-optic cables inside of grooves gather the light and amplify the signal, which is sent back to the electronic portion of the detector. Antennae broadcast the data back to the Cosmic Ray Center for the scientists to observe. On top of the frame, solar panels power the whole system. Small wires above them keep the local birds, which include various raptors such as golden eagles, from sitting on the detector and pooping on the panels.

The scintillation detectors don’t sit in the corral for long after I arrive. I watch as a batch of them are loaded two-high and three-wide onto a trailer and carried out to the Middle Drum site. It took two days to transport all of the TALE detectors.

At Middle Drum, a local contractor and his team used a crane to lift the detectors from the truck and line them along the roadside. The following week, helicopters will arrive to carry them to their final homes in the desert.

'We could melt glass'

While the scintillation detectors will operate in the desert every hour of every day, the optical instruments at Middle Drum function only on clear nights with no moon. Two large buildings house the telescopes. The first building is home to the Telescope Array fluorescence telescope, which targets the horizon. The telescope's mirrors resemble those of a giant optical telescope designed to study distant stars, but this instrument is designed to look for ultraviolet light created by atoms in the Earth's atmosphere when they interact with cosmic rays.

Callahan poses near one of the cloverleaf mirrors used in the fluorescent telescopes that look for flashes of light created when cosmic rays interact with atoms in Earth's atmosphere.
In the second, taller building, the TALE telescopes target higher skies than their TA counterparts. Although the cosmic rays TALE will study still fall in the high-energy realm, they are less energetic than those identified by TA. The decreased energy means the showers end higher in the atmosphere, so TALE's telescopes peer above the horizon, looking for those faint ultraviolet flashes that occur when the cosmic rays collide with particles in the atmosphere.

The pair of buildings at Middle Drum tower over the desert, with exterior automatic doors stretching about 20 feet high, with only a few feet to the roof. TALE’s telescopes point higher into the atmosphere than TA’s, requiring greater height for the doorways through which they peer.

The two massive buildings are sealed tight. We pass through an office area where someone sits to monitor the fluorescence telescopes. Unlike the scintillation detectors, which aren't affected by light, the fluorescence telescopes are sealed off from sunlight during the daylight hours, because sunlight can permanently damage the mirrors. A sign on the door reminds us of the danger direct sunlight has for the instruments, and includes the image of a person having their face melted in the movie "Indiana Jones and the Raiders of the Lost Ark." This light sensitivity is so extreme, a sign on the road to the site requests that headlights be turned off and that flashlights be used with a red filter.

Each telescope consists of four round optical mirrors combined in a cloverleaf pattern. When the garage doors open on clear nights, the 3-inch mirrors collect light and focus it on a collection of 256 photomultiplier tubes. The channeled light should reveal any flashes on the horizon from cosmic rays. Like a powerful magnifying glass, it results in a very focused beam of light.

"We could melt glass with this thing," said Robert Cady, an assistant research professor at the University of Utah, who is working on the experiment.

Whenever the telescopes are operating, two people must be on site in case there's a problem. (With the telescope sitting in the middle of nowhere, safety concerns mean that no one is permitted to be at the site alone.) Most of the time, the work for those two employees is boring, Cady said, but their presence is necessary to protect the instruments.

"When something goes wrong, it goes really badly wrong," he said.

Among other things, the folks at the site must check the enormous garage doors to make certain they shut completely at the end of a run. If a mechanical issue keeps them from closing, each mirror must be covered. The tool of choice is king-size fitted sheets, which, Cady said, work perfectly.

Once or twice a year, the mirrors are washed to remove any accumulated dust, but the work must be done carefully to avoid scraping off the aluminum cover, Cady said.

Each cloverleaf sits on a metal frame, with its computer controls in a locker behind it. Everything in the giant warehouse is raised off the floor, thanks to lessons learned from a previous project, which suffered a rodent problem.

"Rats love to chew cables," Cady said. "We keep everything rat-proof, off the ground."

Hard to replace

Even though they're out in the middle of a desert, a few of the scintillation detectors have had to be replaced. A wet winter several years ago resulted in flooding, and several of the detectors were immersed. Cady and a colleague went out in a kayak to check on the instruments, and some had only their antenna sticking above the water. Those were trashed, and now sit in the corral. Another one was damaged in an auto accident when a motorist unaffiliated with the project crashed into it.

Simple exterior repairs can be made to the scintillation detectors in the field, but major repairs require them being taken back to Delta. There, the team can repair or replace major components in controlled conditions, without having to haul everything out to the middle of the desert.

While the detectors are inexpensive to replicate, the mirrors are another story. According to Cady, the equipment and space used to fabricate them no longer exists. So, while the mirrors themselves cost only a few thousand dollars, he estimated it would take more than $100,000 to get set up to build more. Fortunately, the project has 30 to 40 more mirrors in storage in Salt Lake City.

According to Cady, the biggest emergency event came at the beginning of the project, when three members of the team flipped their pickup truck in the desert. The helicopter that was placing the detectors carried the three into town, where an ambulance transported them to the hospital. All three survived.

Other problems include occasional wind damage to the detectors. Far more likely is that one of the team members will wind up stuck in the desert due to car trouble.

"We have the local mechanic on speed dial," Cady said.

Callahan often interacts with the people in the county, making sure they have an idea of what the giant array is doing. She sets up a booth at the state fair every year and welcomes the opportunity to share details with anyone who is interested in the Cosmic Ray Center.

Read more at Discovery News