Tuesday, May 31, 2016

Giant Martian Tsunamis Sculpted Coastal Terrain on Red Planet

New NASA-funded research indicates that giant tsunamis played a fundamental role in forming Martian coastal terrain, removing much of the controversy that for decades shrouded the hypothesis that oceans existed early in Mars’ history. 

Left: Color-coded digital elevation model of the study area showing the two proposed shoreline levels of an early Mars ocean that existed approximately 3.4 billion years ago. Right: Areas covered by the documented tsunami events extending from these shorelines.

Credits: Alexis Rodriguez

“Imagine a huge wall of red water the size of a high-rise building moving towards you at the speed of a jetliner,” said J. Alexis P. Rodriguez, former NASA Postdoctoral Program fellow at NASA’s Ames Research Center in California’s Silicon Valley, and senior research scientist at the Planetary Science Institute in Tucson, Arizona. “That could be a fair way to picture it in your mind.”

It is now widely accepted by the Mars research community that approximately 3.4 billion years ago, an extremely cold and dry desert existed at the surface of Mars, while enormous subsurface aquifers overlain by ice-rich permafrost retained most of the water on the Red Planet. Researchers think that, at that time in the planet’s history, several large aquifers catastrophically ruptured, carving large outflow channels and flooding Mars’ northern plains to form an ocean. However, an apparent lack of definite shoreline features made this uncertain. This new research shows that the shorelines exist below the present surface and were modified and buried by two mega-tsunami events.

“We were surprised to find that the older and younger tsunami deposits look so different,” said Rodriguez. “The older tsunami washed ashore and deposited enormous volumes of debris, and evidence for the water hurtling back into the ocean is represented in widespread ‘backwash.’”

Following the formation of the ocean, and in the absence of widespread river systems that could have refilled it, its coastline receded to a lower elevation. The research documents two mega-tsunami events – giant waves that may have formed as a result of impacts slamming into Mars’ ocean.

“We think that after the ocean shoreline receded to a lower elevation – which likely resulted during a period of extreme climatic cooling lasting several million years – the younger tsunami occurred with enormous waves freezing as it washed over the frozen Martian landscape. The waves froze rapidly, even before they had a chance to flow back into the ocean,” Rodriguez said.

A key implication of the study is that the tsunami deposits can be used to reconstruct the evolution of the Martian climate during the lifetime of the ocean, and the younger deposits likely contain ice remnants from the ancient ocean itself. From a bystander’s viewpoint, if Mars was also covered by red dust then, as it is today, the ocean might have looked red while the particles settled to the bottom.

View of a boulder-rich surface deposited by the older tsunami. These were then eroded by channels produced as the tsunami water returned to the ocean elevation level (white arrow shows flow return direction). Yellow bars are 10 meters.

Credits: Alexis Rodriguez

“The tsunami deposits likely contain rocks and sediments from the ocean floor that were picked up and transported landward by the enormous waves,” said Virginia Gulick, senior research scientist at the SETI Institute and NASA Ames, and a co-author on the paper. “Tsunami deposits are similar to flood deposits except that they are moving in the reverse – landward – direction.”

The researchers believe the ocean floor might have provided habitable environments, if the ocean persisted long enough. ”On Earth, tsunami deposits contain a significant mud or fine-grained component; on Mars, this finer-grained component could have preserved physical or chemical evidence of past microbial activity, if it existed,” said Gulick. “If there were habitable environments, then biosignatures also could have been preserved in the large boulders visible in the older flow deposits.”

The research was conducted using visible and thermal images, combined with digital topography from Mars Odyssey, the Mars Reconnaissance Orbiter (MRO), and the Mars Global Surveyor. The research team was supported by the NASA Postdoctoral Program, NASA’s Planetary Geology and Geophysics Program, NASA’s MRO HiRISE and the NASA Astrobiology Institute. 

Contacts and sources: 
Ames Research Center

Deep, Old Water Explains Why Antarctic Ocean Hasn't Warmed

The waters surrounding Antarctica may be one of the last places to experience human-driven climate change. New research from the University of Washington and the Massachusetts Institute of Technology finds that ocean currents explain why the seawater has stayed at roughly the same temperature while most of the rest of the planet has warmed.

The study resolves a scientific conundrum, and an inconsistent pattern of warming often seized on by climate deniers. Observations and climate models show that the unique currents around Antarctica continually pull deep, centuries-old water up to the surface - seawater that last touched Earth's atmosphere before the machine age, and has never experienced fossil fuel-related climate change. The paper is published May 30 in Nature Geoscience.

Observed warming over the past 50 years (in degrees Celsius per decade) shows rapid warming in the Arctic, while the Southern Ocean around Antarctica has warmed little, if at all.

Credit: K. Armour / UW

"With rising carbon dioxide you would expect more warming at both poles, but we only see it at one of the poles, so something else must be going on," said lead author Kyle Armour, a UW assistant professor of oceanography and of atmospheric sciences. "We show that it's for really simple reasons, and ocean currents are the hero here."

Gale-force westerly winds that constantly whip around Antarctica act to push surface water north, continually drawing up water from below. The Southern Ocean's water comes from such great depths, and from sources that are so distant, that it will take centuries before the water reaching the surface has experienced modern global warming.

Other places in the oceans, like the west coast of the Americas and the equator, draw seawater up from a few hundred meters depth, but that doesn't have the same effect.

"The Southern Ocean is unique because it's bringing water up from several thousand meters [as much as 2 miles]," Armour said. "It's really deep, old water that's coming up to the surface, all around the continent. You have a lot of water coming to the surface, and that water hasn't seen the atmosphere for hundreds of years."

The water surfacing off Antarctica last saw Earth's atmosphere centuries ago in the North Atlantic, then sank and followed circuitous paths through the world's oceans before resurfacing off Antarctica, hundreds or even a thousand years later.

Delayed warming of the Antarctic Ocean is commonly seen in global climate models. But the culprit had been wrongly identified as churning, frigid seas mixing extra heat downward. The study used data from Argo observational floats and other instruments to trace the path of the missing heat.

"The old idea was that heat taken up at the surface would just mix downward, and that's the reason for the slow warming," Armour said. "But the observations show that heat is actually being carried away from Antarctica, northward along the surface."

In the Atlantic, the northward flow of the ocean's surface continues all the way to the Arctic. The study used dyes in model simulations to show that seawater that has experienced the most climate change tends to clump up around the North Pole. This is another reason why the Arctic's ocean and sea ice are bearing the brunt of global warming, while Antarctica is largely oblivious.

"The oceans are acting to enhance warming in the Arctic while damping warming around Antarctica," Armour said. "You can't directly compare warming at the poles, because it's occurring on top of very different ocean circulations."

Knowing where the extra heat trapped by greenhouse gases goes, and identifying why the poles are warming at different rates, will help to better predict temperatures in the future.

"When we hear the term 'global warming,' we think of warming everywhere at the same rate," Armour said. "We are moving away from this idea of global warming and more toward the idea of regional patterns of warming, which are strongly shaped by ocean currents."

Contacts and sources:
Hannah Hickey
University of Washington 

Citation: Southern Ocean warming delayed by circumpolar upwelling and equatorward transport Kyle C. Armour, John Marshall, Jeffery R. Scott, Aaron Donohoe & Emily R. Newsom Nature Geoscience (2016) doi:10.1038/ngeo2731 http://dx.doi.org/10.1038/ngeo2731

Cosmic Cannibalism Turns Star into Brown Dwarf

Astronomers have detected a sub-stellar object that used to be a star, after being consumed by its white dwarf companion. The research, which appears in the journal Nature, was partly supported by a grant from the Royal Astronomical Society.

An international team of astronomers made the discovery by observing a very faint binary system, J1433, located 730 light-years away. The system consists of a low-mass object – about 60 times the mass of Jupiter – in an extremely tight 78-minute orbit around a white dwarf (the remnant of a star like our Sun).

An artist’s illustration of the white dwarf (right) stripping mass from the brown dwarf.
 Credit: Rene Breton, University of Manchester.

Due to their close proximity, the white dwarf strips mass from its low-mass companion. This process has removed about 90 per cent of the mass of the companion, turning it from a star into a brown dwarf.

Most brown dwarfs are 'failed stars', objects that were born with too little mass to shine brightly by fusing hydrogen in their cores. By contrast, the brown dwarf in this system was born as a fully-fledged star, but has been stripped to its current mass by billions of years of stellar cannibalism.

The study used the X-Shooter instrument at the Very Large Telescope (VLT) in Cerro Paranal, Chile, in order to directly detect and characterise a system that has survived such a traumatic transition.

A temperature map of the irradiated brown dwarf, measured in Kelvin (for the equivalent in degrees Celsius subtract 273).
Credit: Juan Venancio Hernández Santisteban, University of Southampton

Lead author Juan Venancio Hernández Santisteban, a PhD student at the University of Southampton, said: "X-Shooter is a unique instrument that can observe astronomical objects simultaneously all the way from the ultraviolet to the infrared. This allowed us to dissect the light of this system and uncover the hidden signal from the faint brown dwarf.

"Our knowledge of binary evolution suggests that, if the companion star can survive the transition, brown dwarfs should be common in this type of system. However, despite several efforts, only a few candidate systems with tentative evidence for brown dwarf companions had previously been found. Our results now confirm that the successful transformation of a star to a brown dwarf is indeed possible."

The astronomers also used their data to map the surface temperature across the brown dwarf. This turns out to be non-uniform, since this cool sub-stellar object is strongly irradiated by its much hotter white dwarf companion. The map shows a clear temperature difference between the dayside (the side facing the white dwarf) and the nightside. On average, the difference amounts to 57 degrees Celsius, but the hottest and coldest parts of the brown dwarf's surface differ by a full 200 degrees Celsius.

Professor Christian Knigge, also from the University of Southampton, who initiated and supervised the project, said: "The construction of this surface temperature map is a significant achievement. In many giant planets – the so-called 'hot Jupiters' – irradiation by the host star completely overwhelms the planet's internal heat flux. By contrast, internal heat flux and external irradiation are comparable for the brown dwarf in our study. This represents an unexplored regime, making such systems valuable as laboratories for irradiated (sub-) stellar and planetary atmospheres."

Contacts and sources:
Glenn Harris
University of Southampton

Citation: "An irradiated brown-dwarf companion to an accreting white dwarf", Juan V. Hernández Santisteban, Christian Knigge, Stuart P. Littlefair, Rene P. Breton, Vikram S. Dhillon, Boris T. Gänsicke, Thomas R. Marsh, Magaretha L. Pretorius, John Southworth and Peter H. Hauschildt, Nature, doi:10.1038/nature17952.

Bugs Bunny’s Wisdom Confirmed by Science

Bugs Bunny hasn’t aged a day since his cartoon debut in 1940, and he rarely wears glasses. He can play all nine positions on a baseball field – at once. He also consistently outwits gangsters, hunters and water fowl.

Noseart B-52 3.jpg
Credit: Wikimedia

That could be due to all the carrots he consumes. Carrots contain high quantities of carotenoids – plant pigments that have been shown to provide health benefits, including reduced risk of diseases such as eye disease. The orange carrot is the richest source of vitamin A in the American diet.

Maybe the wily and youthful-looking rabbit has intuited for decades what can now be found in the scientific literature, as NC State researchers worked with colleagues from around the globe to sequence the carrot genome in order to learn more about the plant’s evolution and how it accumulates its high levels of carotenoids.

Massimo Iorizzo, a researcher with NC State’s Plants for Human Health Institute in Kannapolis and first author of a paper describing the carrot genome sequence, published in Nature Genetics, says the findings could support crop improvement efforts for sustained agricultural production and improved human health benefits.

The carrot genome sequence sheds light on beneficial carotenoid accumulation in light and dark orange carrots.

Photo courtesy of Massimo Iorizzo.

So what’s up with the carrot genome, doc?

The researchers examined 35 different types of carrot. First, by comparing white and light-orange carrots, which have lower levels of carotenoids, with carotenoid-rich bright orange carrots, the researchers found a specific gene that appears to control the accumulation of carotenoids in the vegetable.

In the paper, Iorizzo proposed a genetic mechanism that explains why carrot roots accumulate carotenoid pigments. “Orange carrots have co-opted light-induced genes to accumulate higher levels of carotenoids in their roots,” Iorizzo said. “Though grown in the dark, orange carrots act like they’re grown in the light.”

Evolutionarily, carrots split from grapes more than 100 million years ago, which is fortunate because Bugs enjoys carrot juice much more than wine. Carrots diverged from lettuce more than 70 million years ago.

The center of origin for carrot domestication was the Middle East and Central Asia; documentation shows that purple and yellow carrots were grown in Central Asia 1,100 years ago, with orange carrots first documented in the 16th century.

The paper also describes gene expansion contributing to flavor and carotenoid accumulation in modern carrots.

These colorful, high-carotenoid carrots have become popular, perhaps because of their health benefits: through breeding, carotene content has increased in the carrot by 50 percent in the United States since 1970. And that’s a good thing as vitamin A deficiency is a global problem, although less so in the United States.

Iorizzo says that the sequenced genome will significantly change the nature of research in carrot biology.

“It will serve as the basis in molecular breeding to assist in improving carrot traits such as enhanced levels of carotenoids, drought tolerance and disease resistance,” he said. “The primary focus of research of several laboratories around the world that conduct fundamental research on carrot genetics will shift more toward extensive genetic screens for genomewide association analysis and functional genomics.”

Hamid Ashrafti, an NC State assistant professor of horticultural science, is a co-author on the paper. Philipp Simon from the University of Wisconsin-Madison is the paper’s corresponding author.

Contacts and sources:
North Carolina State University

Fish Power? Electric Ray's Organ Provides Power To Generator

The electric ray may be the most electrosensitive of all animals. Their eyes are situated on the top of their heads, resulting in poor vision  that must be compensated for with the use of other senses, including the detection of electricity. Many species of rays and skates outside the family have electric organs located in the tail; however, the electric ray possesses two large electric organs on each side of its head, where current passes from the lower to the upper surface of the body. The organs are governed by four central nerves from each side of the electric lobe, or specialized brain lobe, which is of a different color from the rest of the brain.
Scientists from the RIKEN Quantitative Biology Center in Japan removed the electric organ from a torpedo and chemically stimulated the organ by injecting a solution of the neurotransmitter acetylcholine though a syringe. They were able to achieve more than a minute of continuous current, with a peak voltage of 91 mV and 0.25 mA of current. By increasing the number of syringes, they achieved a peak voltage of 1.5 V and a current of 0.64mA.

Spotted torpedo ray

The environmental impact of electric power generation is a pressing international concern. There are mandates to reduce the environment impact of power generation, leading to a push away from conventional thermal and nuclear power. Recently, biofuel cells such as glucose fuel cells and microbial fuel cells have been developed to meet these mandates. However, the performance of these fuel cells remains inferior to conventional systems.

Nature, researchers recently found, may be able to teach us a better way. Scientists from the RIKEN Quantitative Biology Center (QBiC) in Osaka began work to develop a new type of electricity generator, based on the knowledge that electric rays known as torpedoes can beat other systems by generating electric power with near 100% efficiency. The torpedo has electric organs with densely-aligned membrane proteins that convert the chemical energy of adenosine triphosphate (ATP) into ion transport energy, and a nervous system that controls the whole process.

QBiC's Yo Tanaka and his collaborators thought the principle used by the fish might be applied to make a breakthrough power generator. Their experiments, reported in Scientific Reports, artificially reproduced and controlled this phenomenon.

They began by looking at what happens in a live electric ray. Tanaka says, “When we used physical stimulation of a live torpedo, we detected less than 10 milliseconds of pulse current with a peak voltage 19 V and current of 8 A in the electrical response. Using this pulse, we found that we were able to store enough electricity to light up LED light or drive a toy car.”

The experimental setup

Credit: RIKENB

Then, in an attempt to generate more electricity, they removed the electric organ from a torpedo and chemically stimulated the organ by injecting a solution of the neurotransmitter acetylcholine though a syringe. They were able to achieve more than a minute of continuous current, with a peak voltage of 91 mV and 0.25 mA of current.

Tanaka continues, “By increasing the number of syringes, we achieved a peak voltage of 1.5 V and a current of 0.64mA. In addition, we found that it is possible to repeat power generation and keep the organ functional for up to one day.” By combining a fluid control device to control the stimulation as is done by the torpedo’s own nervous system, they were able to generate and store electricity with a peak voltage of 1.5 V and 0.25 mA of current.

Tanaka says he hopes the research will be a first step towards a future high-efficiency power generator that uses ATP directly and could lead to a modern, ultra-clean electric power generator.

Contacts and sources:

Citation: Yo Tanaka et al., An electric generator using living Torpedo electric organs controlled by fluid pressure-based alternative nervous systems, Scientific Reports (2016), doi: 10.1038/srep25899

Planet 9 Is an Alien World Stolen from Another Star by Our Sun

Caltech researchers found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles). In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the sun.

Through a computer-simulated study, astronomers at Lund University in Sweden show that it is highly likely that the so-called Planet 9 is an exoplanet. This would make it the first exoplanet to be discovered inside our own solar system. The theory is that our sun, in its youth some 4.5 billion years ago, stole Planet 9 from its original star.

Credit: Caltech

An extrasolar planet, or exoplanet, is by definition a planet located outside our solar system. Now it appears that this definition is no longer viable. According to astronomers in Lund, there is a lot to indicate that Planet 9 was captured by the young sun and has been a part of our solar system completely undetected ever since.

“It is almost ironic that while astronomers often find exoplanets hundreds of light years away in other solar systems, there’s probably one hiding in our own backyard”, says Alexander Mustill, astronomer at Lund University.

Credit: Lund University

Stars are born in clusters and often pass by one another. It is during these encounters that a star can “steal” one or more planets in orbit around another star. This is probably what happened when our own sun captured Planet 9.

In a computer-simulated model, Alexander together with astronomers in Lund and Bordeaux has shown that Planet 9 was probably captured by the sun when coming in close contact while orbiting another star.

“Planet 9 may very well have been ‘shoved’ by other planets, and when it ended up in an orbit that was too wide around its own star, our sun may have taken the opportunity to steal and capture Planet 9 from its original star. When the sun later departed from the stellar cluster in which it was born, Planet 9 was stuck in an orbit around the sun”, says Alexander Mustill.

“There is still no image of Planet 9, not even a point of light. We don’t know if it is made up of rock, ice, or gas. All we know is that its mass is probably around ten times the mass of earth.”

It requires a lot more research before it can be ascertained that Planet 9 is the first exoplanet in our solar system. If the theory is correct, Alexander Mustill believes that the study of space and the understanding of the sun and the Earth will take a giant leap forward.

“This is the only exoplanet that we, realistically, would be able to reach using a space probe”, he says.

Caltech's Konstantin Batygin, an assistant professor of planetary science, and Mike Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy, discuss new research that provides evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system.
Credit: Caltech AMT

The six most distant known objects in the solar system with orbits exclusively beyond Neptune (magenta) all mysteriously line up in a single direction. Also, when viewed in three dimensions, they tilt nearly identically away from the plane of the solar system. Batygin and Brown show that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration. 
Credit: Caltech/R. Hurt (IPAC); [Diagram created using WorldWide Telescope.

The researchers, Konstantin Batygin and Mike Brown, discovered the planet's existence through mathematical modeling and computer simulations but have not yet observed the object directly.

"This would be a real ninth planet," says Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy. "There have only been two true planets discovered since ancient times, and this would be a third. It's a pretty substantial chunk of our solar system that's still out there to be found, which is pretty exciting."

Brown notes that the putative ninth planet—at 5,000 times the mass of Pluto—is sufficiently large that there should be no debate about whether it is a true planet. Unlike the class of smaller objects now known as dwarf planets, Planet Nine gravitationally dominates its neighborhood of the solar system. In fact, it dominates a region larger than any of the other known planets—a fact that Brown says makes it "the most planet-y of the planets in the whole solar system."

Contacts and sources: 
Alexander Mustill.
Lund University

The article is published in Monthly Notices of the Royal Astronomical Society Letters, (MNRAS Letters). 

Citation: Mustill A, 2016. Is there an exoplanet in the Solar system? Published in the Monthly Notices of the Royal Astronomical Society Letters, (MNRAS Letters)
Link: http://mnrasl.oxfordjournals.org/content/460/1/L109

Male Cougar Travels 1500 Miles Looking for a Mate, Record Setting Trek From South Dakota to Connecticut

A male cougar in search of a mate traveled more than 1,500 miles from the Black Hills of South Dakota to Connecticut, leaving a trail of clues that enabled scientists to verify his odyssey.

The cougar’s journey, recounted in Journal of Mammalogy, shows a wealth of evidence that scientists can use to document animal movement, says co-author Roland Kays, a wildlife biologist with NC State University and the North Carolina Museum of Natural Sciences.

“This cougar did not have a tracking collar, so we relied on genetic connections from hair and fecal samples, along with photos from camera-traps operated by citizen scientists,” says Kays, who also featured the cougar’s story and photo in his new book, Candid Creatures.

A Wisconsin camera trap photographed the male cougar on his record-setting trek from South Dakota to Connecticut. Faint spots in the animal’s coat can still be seen, revealing the young age of this otherwise large male. 
Photo credit: Lue Vang

Researchers used forensic techniques to match the hair and droppings to DNA samples from the cougar, which died after being struck by a car in Connecticut. Combined with photos and findings from the necropsy, the evidence allowed researchers to make a positive ID of the animal, identify South Dakota as his point of origin, and trace his path, which included stops in Minnesota, Wisconsin and New York before his tragic death in Connecticut.

“This cougar didn’t know where he was going. He didn’t have a road map,” Kays says. “If he’d gone west, he would have found a girlfriend. Instead, he went east and just kept going and going.”

Although this is the longest dispersal ever recorded for a cougar, it is not the first animal to leave South Dakota and head into new territory, moving outside of the established range for the species. This shows that many western cougar populations are healthy and could end up reclaiming their old territory in the East, if a female ever joins the dispersing males to create a breeding population.

However, this example also casts doubt on the idea that any portion of the Northeast already has a cougar population.

“The wealth of verifiable evidence left by this single animal brings doubts about the hundreds of unverified sightings in the region,” Kays says. “This shows that big animals like this cannot move across the landscape without leaving scientific evidence proving their existence.”

Contacts and sources:
North Carolina State University

Photonic Fence Uses Lasers To Shoot Down Mosquitoes While Sparing Beneficial Insects

The photonic fence is a computerized pest control systemthat uses machine vision to identify insects and zaps the bad bugs with laser beams while allowing beneficial insects to live. It can even shoot down flying insects.

Disease-bearing insects have long been hazards to human and environmental health. Mosquitoes, dubbed the “the world’s deadliest animal,” can transmit malaria—a parasite that kills more than 600,000 people every year. Bed nets, insecticides, and antimalarial drugs have helped keep the disease in check in many parts of the world, but more tools are needed to limit contact between humans and mosquitoes.

A sequence showing a mosquito being zapped by the photonic fence 
Credit: Intellectual Ventures

To answer this challenge, Intellectual Ventures invented a tool that uses an unusual weapon to combat vector-borne diseases: light. Called a photonic fence, the invention works by combining low-cost sensor and laser technology with software to identify, track, and kill mosquitoes, thus eliminating
malaria’s primary transmission vector.

Credit: Intellectual Ventures

One Tool, Multiple Uses

Now their photonic fence technology has its lasers set on being a tool for not only global health organizations, but also for the agriculture industry. Global Good continues to develop light-based alternatives that offer an environmentally-responsible alternative to chemical pesticides as well as field-ready photonic fence prototypes to test new, efficient, and effective pest control products for health, commercial, and residential use around the world.

Credit: Intellectual Ventures

The processor is configured to analyze one or more images to identify a biological property (e.g., genus, species, sex, mating status, gravidity, feeding status, age, or health status) of an organism (e.g., an insect, such as a mosquito, a bee, a locust, or a moth) in the field of view of the imager, using characteristic frequency, harmonic amplitude, shape, size, airspeed, ground speed, or location. 

The following figure from U.S. Patent 8,705,017 gives a synopsis of the triggering process to shoot down a mosquito. 

The disabling system is configured to disable the organism (e.g., by killing, damaging a wing or antenna, or impairing a biological function) responsive to the identified property (e.g., only disabling organisms of a determined genus, species, sex, or gravidity). The disabling system includes a laser (e.g., a UV-C laser or an infrared laser), and may be configured to accept location data from the processor for use in targeting the organism. 

The system is configured to identify probable biological status of a mosquito in the field of view of the imager using at least one datum selected from the group consisting of characteristic frequency, shape, airspeed, and ground speed, the processor being further configured to determine a probability that the mosquito is infected with malaria. 

Computer to Train Dogs Autonomously Based on Dog's Body Language

North Carolina State University researchers have developed and used a customized suite of technologies that allows a computer to train a dog autonomously, with the computer effectively responding to the dog based on the dog’s body language.

“Our approach can be used to train dogs efficiently and effectively,” says David Roberts, an assistant professor of computer science at NC State and co-author of a paper on the work. “We use sensors in custom dog harnesses to monitor a dog’s posture, and the computer reinforces the correct behavior quickly and with near-perfect consistency.”

“Because the technology integrates fundamental principles of animal learning into a computational system, we are confident it can be applied to a wide range of canine behaviors,” says Alper Bozkurt, an assistant professor of electrical and computer engineering and co-author of the paper. “For example, it could be used to more quickly train service dogs. Ultimately, we think the technology will be used in conjunction with human-directed training.”

Credit: NCSU

The dog harness fits comfortably onto the dog and is equipped with a variety of technologies that can monitor the dog’s posture and body language. Each harness also incorporates a computer the size of a deck of cards that transmits the sensor data wirelessly. The researchers published a paper about the harness’s potential applications in late 2014.

For the current study, the researchers wrote an algorithm that triggered a beeping sound and the release of dog treats from a nearby dispenser whenever the dog’s harness sensors detected that the dog went from standing to sitting.

The researchers had to ensure that the reinforcement was given shortly after the desired posture was exhibited, and also ensure that rewards were only given for the correct posture. This required a trade-off. If the algorithm ran long enough to ensure the correct posture with 100 percent certainty, the reinforcement was given too late to be effective for training purposes. But if the reinforcement was given immediately, there was a high rate of rewarding the wrong posture.

To address this, the researchers worked with 16 volunteers and their dogs to optimize the algorithm, finding the best possible combination of speed and accuracy. The researchers then compared the algorithm’s timing and accuracy to that of an expert human trainer.

The algorithm was highly accurate, rewarding the appropriate behavior 96 percent of the time. But the human trainer was better – with a 100 percent accuracy rate.

However, while the average response time was about the same for both algorithm and trainer, there was a lot of variation in the time of response from the trainer. The algorithm was incredibly consistent.

“That variation matters, because consistency is fundamentally important for all animal training,” Roberts says.

“This study was a proof of concept, and demonstrates that this approach works,” Bozkurt says. “Next steps include teaching dogs to perform specific behaviors on cue, and integrating computer-assisted training and human-directed training for use in various service dog applications.”

“In the long term, we’re interested in using this approach to animal-computer interaction to allow dogs to ‘use’ computers,” Roberts says. “For example, allowing an explosive detection dog to safely and clearly mark when it detects components of a bomb, or allowing diabetic alert dogs to use their physical posture and behaviors to call for help.”

Contacts and sources:
Alper Bozkurt
North Carolina State University

The paper, “Balancing Noise Sensitivity, Response Latency, and Posture Accuracy for a Computer-Assisted Canine Posture Training System,” is published in a special issue of the International Journal of Human-Computer Studies, which focuses on animal-computer interaction. Co-lead authors of the paper are John Majikes and Rita Brugarolas, who are Ph.D. students at NC State. Co-authors include Dr. Barbara Sherman, a clinical professor of animal behavior at NC State; Michael Winters, Sean Mealin and Katherine Walker, Ph.D. students at NC State; Sherrie Yuschak, a clinical technician in NC State’s College of Veterinary Medicine; and Pu Yang, a former Ph.D. student at NC State who now works for IBM. This work was supported by the National Science Foundation under grant number 1329738.

Sunday, May 29, 2016

Fossils of Bizarre Group of Extinct Snail-Eating Australian Marsupials Discovered

Fossil remains of a previously unknown family of carnivorous Australian marsupials that lived 15 million years ago have been discovered at the Riversleigh World Heritage Fossil Site in north-western Queensland by a University of New South Wales (UNSW) Australia-led team of researchers.

"Malleodectes mirabilis was a bizarre mammal, as strange in its own way as a koala or kangaroo," says study lead author UNSW Professor Mike Archer.

"Uniquely among mammals, it appears to have had an insatiable appetite for escargot--snails in the whole shell. Its most striking feature was a huge, extremely powerful, hammer-like premolar that would have been able to crack and then crush the strongest snail shells in the forest."

This is a reconstruction of the 15 million year old Malleodectes from Riversleigh chomping down on what appears to have been its favorite food -- snails. The massive, shell-cracking premolar tooth is clearly visible in the open mouth
Illustration by Peter Schouten

Research describing the new marsupials is published in the journal Scientific Reports.

Isolated teeth and partial dentitions of this unusual group, known as malleodectids, had been unearthed over the years at Riversleigh, where Professor Archer and his colleagues have excavated for almost four decades. But the profoundly different nature of the marsupials was not realized until a well-preserved portion of the skull of a juvenile was found in a 15 million year old Middle Miocene cave deposit at Riversleigh.

This juvenile specimen was only recently extracted from its limestone casing, using an acid bath at UNSW, which made it available for study with modern techniques including micro-computed tomography. The young animal still had its baby teeth, and was teething, with adult teeth that had been about to erupt when it was alive still embedded in its jaw.

"Details of the canine, premolar and molar teeth of this specimen have enabled its relationships to other Australian marsupials to be determined with reasonable confidence," says Professor Archer, of the PANGEA Research Centre in the UNSW School of Biological, Earth and Environmental Sciences.

"Although it is very different from the others, it appears to have been related to the dasyures - marsupial carnivores such as Tasmanian Devils and the extinct Tasmanian Tigers that are unique to Australia and New Guinea."

Nothing remains of the cave at Riversleigh, known as AL90 site, except its limestone floor, which contains the bones of thousands of animals that fell into, or lived in, the ancient cave.

"The juvenile malleodectid could have been clinging to the back of its mother while she was hunting for snails in the rocks around the cave's entrance, and may have fallen in and then been unable to climb back out," says team member UNSW Professor Suzanne Hand.

These are maxilla of the young malleodectid -- a snail-eating marsupial -- found in the fossil cave deposit at Riversleigh. Because this is a juvenile, the massive premolar is still unerupted below the tooth row.

Credit: Karen Black and Suzanne Hand/UNSW

"Many other animals that lived in this lush forest met a similar fate with their skeletons accumulating one on top of another for perhaps thousands of years, until the cave became filled with palaeontological treasures.

"Over millions of years the walls and ceiling of the cave were eroded away, leaving only the fossil-rich floor, which was discovered by our Riversleigh Project team members in 1990."

Subsequent quarrying of the cave floor has produced thousands of exquisite fossils including the articulated skeletons of the ram-sized, sloth-like Nimbadon - an extinct marsupial that fell in while moving overhead in the tree tops.

The Riversleigh World Heritage fossil deposits, which span the last 24 million years of Australian history, have produced many previously unknown kinds of animals such as Thingodonta, which may have been a woodpecker-like marsupial; Fangaroo, a tusked kangaroo; Drop crocs, which are strange leopard-like crocodiles that may have been arboreal; and Dromornis - the Demon Duck of Doom, which was one of the largest birds in the world.

The Riversleigh Project, which has been a major focus of the palaeontological team at UNSW, is about to carry out its 40th annual expedition to Riversleigh.

Once again, the team expects to discover yet more strange creatures that once populated Australia's ancient rainforests at a time when the northern regions of the continent looked more like Amazonian rainforests than the arid zone the area has become today.

Of particular interest for this year's expedition will be younger apparently Late Miocene rocks discovered by the team, assisted by funding from the Australian Research Council and the National Geographic Society, in a remote area now called "New Riversleigh". These will fill a key time period for the rich, long record of environmental change at Riversleigh.

Among the first tantalising discoveries from "New Riversleigh" has been yet another bizarre, hyper-carnivorous marsupial that looks like it might be a younger, far more powerful cousin of the earlier snail-eating malleodectids.

Like so many of the strange creatures continuously being discovered in Riversleigh's rocks, malleodectids went extinct long before humans arrived.

The most probable cause was a severe interval of climate change that began about 15 million years ago and ultimately transformed Australia's once widespread, animal-rich rainforests into the more open forests and grasslands of today.

"This climate change-driven transformation in Australia's wildlife over the last 15 million years is a timely reminder of the probable outcome of the next cycle of climate change, one we appear to have triggered ourselves," says Professor Archer.

The research team includes Professor Archer, Professor Suzanne Hand, Dr Karen Black, Dr Derrick Arena, Dr Laura Wilson and Dr Tzong Hung from UNSW; and Dr Robin Beck from Salford University, Manchester, and Shimona Kealy from the University of New England.

Contacts and sources:
  Deborah Smith 
Professor Mike Archer 
University of New South Wales

Archaeologists and Geographers Team to Predict Locations of Ancient Buddhist Sites

Geographic modeling reveals 121 possible locations of important Indian texts carved into rock surfaces in third-century B.C.

For archaeologists and historians interested in the ancient politics, religion and language of the Indian subcontinent, two UCLA professors and their student researchers have creatively pinpointed sites that are likely to yield valuable transcriptions of the proclamations of Ashoka, the Buddhist king of northern India’s Mauryan Dynasty who ruled from 304 B.C. to 232 B.C.
Studying the types of rock where known edicts are located helped UCLA researchers find likely sites of additional ones.
Ashoka edict Dhauli closeup photo credit J.W. Lehner
Credit:  J.W. Lehner

In a study published this week in Current Science, archaeologist Monica Smith and geographer Thomas Gillespie identified 121 possible locations of what are known as Ashoka’s “edicts.”

First they isolated shared features of 29 known locations of Ashokan edicts, which were found carved into natural rock formations in India, Pakistan and Afghanistan. They then harnessed species-distribution modeling tactics — which includes examining sophisticated geographic information systems datasets along with Google Earth images — to overlay those unique characteristics against a geological and population map of ancient India. They believe they have identified locations that hold the same characteristics as proven sites and are significantly accurate markers for future discovery.

Predictive modeling can be a powerful new tool for scholars and researchers, Smith said. The known edicts and other archaeological discoveries have previously come about through random discovery or comprehensive surveys of whole regions.

“With the realities of looking for artifacts on a continental scale, we need more effective tools, and a search mechanism like predictive modeling is a high-priority development,” said Smith, emphasizing that many nations are facing the challenge of balancing preservation with much-needed development.

The Ashoka monuments in particular are of huge importance, especially in India, Smith said. They constitute the earliest known writings in the region. The national symbol of the modern nation of India is a sculpture that dates to the time of King Ashoka.
Ashokan edict outside Dehli.

M.L. Smith

Ashoka’s edicts are also considered to be internationally significant as evidence of the power of an ancient political regime and as tangible expressions of religious practices related to Buddhism.

An excerpt of Ashoka’s edicts from Romila Thapar’s “Ashoka and the Decline of the Mauryas."

“I consider that I must promote the welfare of the whole world, and hard work and the dispatch of business are the means of doing so. Indeed there is no better work than promoting the welfare of the whole world...For this purpose has this inscription of Dhamma (dharma, righteousness) been engraved. May it endure long.”

Smith’s fieldwork has long taken place on the Indian subcontinent. For this study, and with the support of a transdisciplinary seed grant from the UCLA Office of the Vice Chancellor for Research, she partnered with Gillespie, whose expertise lies in determining the presence or absence of ecological and biological species in a given geography, with a special focus on the plants and trees native to Hawaii.

Gillespie, who has also visited India, said the project captured his imagination.

Gillespie and his team of UCLA doctoral candidates combed through data and images to check off a list of environmental consistencies in the known edict sites. Three factors in particular helped provide a reliable prediction of where more might be found — the specific kind of rock the text is carved in, the estimated population density of the area in A.D. 200-300 and the slope of the rock bearing the text.

“The models really give a high probability of occurrence in the sites we identified,” Gillespie said. “Looking at the data of the existing sites, their placement certainly appears to be non-random. The scribes tasked with carving these edicts really seemed to think about the geology of the chosen space, the towns that were nearby, even the low level of the rock face they carved upon.”

Gillespie and Smith hope that their predictive model will allow local students or teachers in India and Pakistan and Afghanistan to make the next discovery of Ashokan edicts.

Contacts and sources: 
Jessica Wolf

Likely Habitable Planet Found in Constellation Lyra

A distant planet known as Kepler-62f could be habitable, a team of astronomers reports.

The planet, which is about 1,200 light-years from Earth in the direction of the constellation Lyra, is approximately 40 percent larger than Earth. At that size, Kepler-62f is within the range of planets that are likely to be rocky and possibly could have oceans, said Aomawa Shields, the study’s lead author and a National Science Foundation astronomy and astrophysics postdoctoral fellow in UCLA’s department of physics and astronomy.

NASA’s Kepler mission discovered the planetary system that includes Kepler-62f in 2013, and it identified Kepler-62f as the outermost of five planets orbiting a star that is smaller and cooler than the sun. But the mission didn’t produce information about Kepler-62f’s composition or atmosphere or the shape of its orbit.

Kepler-62f, shown here in an artist’s rendering, is far enough from its star that its atmosphere would need a high concentration of carbon dioxide to maintain liquid water on the planet’s surface.

Artist's conception by NASA Ames/JPL-Caltech/T. Pyle

Shields collaborated on the study with astronomers Rory Barnes, Eric Agol, Benjamin Charnay, Cecilia Bitz and Victoria Meadows, all of the University of Washington, where Shields earned her doctorate. To determine whether the planet could sustain life, the team came up with possible scenarios about what its atmosphere might be like and what the shape of its orbit might be.

“We found there are multiple atmospheric compositions that allow it to be warm enough to have surface liquid water,” said Shields, a University of California President’s Postdoctoral Program Fellow. “This makes it a strong candidate for a habitable planet.”

  Credit: TED Talks/UCLA

On Earth, carbon dioxide makes up 0.04 percent of the atmosphere. Because Kepler-62f is much farther away from its star than Earth is from the sun, it would need to have dramatically more carbon dioxide to be warm enough to maintain liquid water on its surface, and to keep from freezing.

The team ran computer simulations based on Kepler-62f having:
An atmosphere that ranges in thickness from the same as Earth’s all the way up to 12 times thicker than our planet’s.
Various concentrations of carbon dioxide in its atmosphere, ranging from the same amount as is in the Earth’s atmosphere up to 2,500 times that level.
Several different possible configurations for its orbital path.

They found many scenarios that allow it to be habitable, assuming different amounts of carbon dioxide in its atmosphere.

Shields said that for the planet to be consistently habitable throughout its entire year, it would require an atmosphere that is three to five times thicker than Earth’s and composed entirely of carbon dioxide. (This would be analogous to replacing every molecule in Earth’s atmosphere with carbon dioxide, which means that the planet would have 2,500 times more carbon dioxide in its atmosphere.) Having such a high concentration of carbon dioxide would be possible for the planet because, given how far it is from its star, the gas could build up in the planet’s atmosphere as temperatures get colder to keep the planet warm.

“But if it doesn’t have a mechanism to generate lots of carbon dioxide in its atmosphere to keep temperatures warm, and all it had was an Earth-like amount of carbon dioxide, certain orbital configurations could allow Kepler-62f’s surface temperatures to temporarily get above freezing during a portion of its year,” she said. “And this might help melt ice sheets formed at other times in the planet’s orbit.”

The research is published online in the journal Astrobiology, and will be in a future print edition.

The scientists made their calculations of the shape of the planet’s possible orbital path using an existing computer model called HNBody, and they used existing global climate models (the Community Climate System Model and the Laboratoire de Me´te´orologie Dynamique Generic model) to simulate its climate. It was the first time astronomers have combined results from these two different types of models to study an exoplanet, the term for a planet outside our solar system.

Shields said the same technique could be applied to understand whether exoplanets much closer to Earth could be habitable, so long as the planets are likely to be rocky, Shields said. (Gas planets have very different compositions.)

Aomawa Shields

Credit: Martin Cox

“This will help us understand how likely certain planets are to be habitable over a wide range of factors, for which we don’t yet have data from telescopes,” she said. “And it will allow us to generate a prioritized list of targets to follow up on more closely with the next generation of telescopes that can look for the atmospheric fingerprints of life on another world.”

Scientists do not know whether life could exist on an exoplanet, but Shields is optimistic about finding life in the universe.

More than 2,300 exoplanets have been confirmed, and a few thousand others are considered planet candidates, but only a couple dozen are known to be in the “habitable zone” — meaning that they orbit their star at a distance that could enable them to be warm enough to have liquid water on their surfaces, Shields said.

Shields earned a master’s degree in acting from UCLA and worked as an actor. In January 2015, she founded Rising Stargirls, a program that teaches middle school-aged girls of color about astronomy and astrobiology using theater, writing and visual art. Teachers can request a free copy of the Rising Stargirls discussion guide and activity book through the program’s website.

The Kepler space telescope is NASA’s first mission capable of detecting Earth-size planets around stars like our sun.

Contacts and sources: 
Stuart Wolper

Saturday, May 28, 2016

Ancient DNA Study Finds Phoenician from Carthage Had European Ancestry

A research team co-led by a scientist at New Zealand's University of Otago has sequenced the first complete mitochondrial genome of a 2500-year-old Phoenician dubbed the "Young Man of Byrsa" or "Ariche".

This is the first ancient DNA to be obtained from Phoenician remains and the team's analysis shows that the man belonged to a rare European haplogroup -- a genetic group with a common ancestor -- that likely links his maternal ancestry to locations somewhere on the North Mediterranean coast, most probably on the Iberian Peninsula.

A research team co-led by a scientist at New Zealand's University of Otago has sequenced the first complete mitochondrial genome of a 2500-year-old Phoenician dubbed the "Young Man of Byrsa" or "Ariche". This is the first ancient DNA to be obtained from Phoenician remains. Ariche was found to have belonged to a rare European haplogroup that likely links his maternal ancestry to locations somewhere on the North Mediterranean coast, most probably on the Iberian Peninsula.
Credit: Wikimedia/Elisabeth Daynes

The findings are newly published in the prestigious international journal PLOS ONE.

Study co-leader Professor Lisa Matisoo-Smith of the Department of Anatomy says the findings provide the earliest evidence of the European mitochondrial haplogroup U5b2c1 in North Africa and date its arrival to at least the late sixth century BC.

"U5b2c1 is considered to be one of the most ancient haplogroups in Europe and is associated with hunter-gatherer populations there. It is remarkably rare in modern populations today, found in Europe at levels of less than one per cent. Interestingly, our analysis showed that Ariche's mitochondrial genetic make-up most closely matches that of the sequence of a particular modern day individual from Portugal," Professor Matisoo-Smith says.

While the Phoenicians are thought to have originated from the area that is now Lebanon, their influence expanded across the Mediterranean and west to the Iberian Peninsula where they established settlements and trading posts. The city of Carthage in Tunisia, North Africa, was established as a Phoenician port by colonists from Lebanon and became the centre for later Phoenician (Punic) trade.

The researchers analysed the mitochondrial DNA of 47 modern Lebanese people and found none were of the U5b2c1 lineage.

Previous research has found that U5b2c1 was present in two ancient hunter-gatherers recovered from an archaeological site in north-western Spain, she says.

"While a wave of farming peoples from the Near East replaced these hunter-gatherers, some of their lineages may have persisted longer in the far south of the Iberian peninsula and on off-shore islands and were then transported to the melting pot of Carthage in North Africa via Phoenician and Punic trade networks."

Professor Matisoo-Smith says Phoenician culture and trade had a significant impact on Western civilisation. For example, they introduced the first alphabetic writing system.

"However, we still know little about the Phoenicians themselves, except for the likely biased accounts by their Roman and Greek rivals -- hopefully our findings and other continuing research will cast further light on the origins and impact of Phoenician peoples and their culture," she says.

Contacts and sources: 
Lisa Matisoo-Smith
University of Otago 

Friday, May 27, 2016

Women in Southern Germany Corded Ware Culture May Have Been Highly Mobile

Women in Corded Ware Culture may have been highly mobile and may have married outside their social group, according to a study published May 25, 2016 in the open-access journal PLOS ONE by Karl-Göran Sjögren from Göteborg University, Sweden, and colleagues.

The Corded Ware Culture is archaeologically defined by material traits, such as the burial of the dead under barrows alongside characteristic cord-ornamented pottery, and existed in much of Europe from ca. 2800-2200 cal. B.C. To better understand this culture, the authors of the present study examined human bones and teeth from seven sites in Southern Germany dating from different periods of Corded Ware culture, including two large cemeteries. They used carbon dating and additional dietary isotope analysis to assess the diet and mobility of the population during this period.

Location of sampled sites and other CW sites mentioned in the text.

Ctrfiy:  Map by K-G Sjögren, using public domain data.

The researchers found great dietary variation both between and within sites, indicating that the people of the Corded Ware culture subsisted in a variety of ways. Like humans in earlier cultures, they consumed both animal and plant matter. However, it is likely that at least some sites practiced more intense dairy and arable farming than in previous periods. Around 42% of individuals buried in one of the large cemetery sites were found to be non-local, with many females likely to have originated from elsewhere. This result may indicate that women across generations in this culture were very mobile.

Natural History Museum, Vienna ( Austria ). Corded ware axe from Lusice.
File:NHM - Lusice Prunkbeil 1.jpg
Credit; Wolfgang Sauber

The authors suggest that their evidence of varied diet and mobility supports the possibility of a stable system of female exogamy, where women married outside of their social group and moved to their husbands' settlements, in Corded Ware Culture.

Karl-Göran Sjögren notes: "Our results suggest that Corded Ware groups in southern Germany were highly mobile, especially the women. We interpret this as indicating a pattern of female exogamy, involving different groups with differing economic strategies, and suggesting a complex pattern of social exchange and economic diversity in Late Neolithic Europe."

Contacts and sources: 
Beth Jones

Citation: Sjögren K-G, Price TD, Kristiansen K (2016) Diet and Mobility in the Corded Ware of Central Europe. PLoS ONE 11(5): e0155083. doi:10.1371/journal.pone.0155083 freely available paper: http://dx.plos.org/10.1371/journal.pone.0155083

European Back To Africa Migration 45,000 Years Ago

A piece of international research led by the UPV/EHU-University of the Basque Country has retrieved the mitogenome of a fossil belonging to the first Homo sapiens population in Europe. 

The Palaeogenomics study conducted by the Human Evolutionary Biology group of the Faculty of Science and Technology, led by Concepción de la Rua, in collaboration with researchers in Sweden, the Netherlands and Romania, has made it possible to retrieve the complete sequence of the mitogenome of the Pestera Muierii woman(PM1)using two teeth. This mitochondrial genome corresponds to the now disappeared U6 basal lineage, and it is from this lineage that the U6 lineages, now existing mainly in the populations of the north of Africa, descend from.

The complete mitogenome of Pestera Muierii woman has been retrieved.

Credit: E. Trinkaus and A. Soficaru)

So the study has not only made it possible to confirm the Eurasian origin of the U6 lineage but also to support the hypothesis that some populations embarked on a back-migration to Africa from Eurasia at the start of the Upper Palaeolithic, about 40-45,000 years ago. The Pestera Muierii individual represents one branch of this return journey to Africa of which there is no direct evidence owing to the lack of Palaeolithic fossil remains in the north of Africa.

"Right now, the research group is analysing the nuclear genome the results of which could provide us with information about its relationship with the Neanderthals and about the existence of genomic variations associated with the immune system that accounts for the evolutionary success of Homo sapiens over other human species with whom it co-existed. What is more, we will be able to see what the phenotypic features of early Homo sapiens were like, and also see how population movements in the past influence the understanding of our evolutionary history," explained Prof Concepción de la Rúa.

Contacts and sources: 
Matxalen Sotillo
University of the Basque Country

Citation: M. Hervella, E.M. Svensson, A. Alberdi, T. Günther, N. Izagirre, A.R. Munters, S. Alonso, M. Ioana, 5, F. Ridiche, A. Soficaru, M. Jakobsson, M.G. Netea & C. de-la-Rua The mitogenome of a 35,000-year-old Homo sapiens from Europe supports a Palaeolithic back-migration to Africa.Scientific Reports DOI: 10.1038/srep25501

High Altitude Archaeology: Prehistoric Paintings Revealed

Archaeologists at the University of York have undertaken pioneering scans of the highest prehistoric paintings of animals in Europe.

Studying the rock paintings of Abri Faravel, a rock shelter in the Southern French Alps 2,133m above sea level, archaeologists used car batteries to power laser and white-light scanners in a logistically complex operation.

The paintings at the Abri Faravel. Two groups of roughly parallel lines, and two animals facing one another. (a) Normal light image; (b) Zoom of paintings – colours enhanced with DStretch with the YBR matrix

Photo and enhancement: C. Defrasne

Producing virtual models of the archaeological landscape, researchers have now published the scans in Internet Archaeology - an online, open-access journal.

Abri Faravel was discovered fortuitously in 2010. The rock shelter has seen phases of human activity from the Mesolithic to the medieval period, with its prehistoric rock paintings known to be the highest painted representations of animals (quadrupeds) in Europe.

View of the paintings from the interior of the rock shelter with the rock art colours enhanced with DStretch 
Photo: Loïc Damelet, CNRS/Centre Camille Jullian; enhancement: C. Defrasne

The study of Abri Faravel and its paintings is part of a wider collaborative project between the University of York and the Centre Camille Jullian, Aix-en-Provence, France. Undertaking research in the Parc National des E?crins, the long-running study investigates the development of human activity over the last 8,000 years at high altitude in the Southern Alps.

Research conducted so far includes the excavation of a series of stone animal enclosures and human dwellings considered some of the most complex high altitude Bronze Age structures. Artefacts found in Abri Faravel also include Mesolithic and Neolithic flint tools, Iron Age hand-thrown pottery, a Roman fibula and some medieval metalwork.

However, the paintings are the most unique feature of the site, revealing a story of human occupation and activity in one of the world's most challenging environments from the Mesolithic to Post-Medieval period.

The Faravel plateau viewed from the north – location of the Abri Faravel indicated with an arrow 

Photo: K. Walsh

Dr Kevin Walsh, Senior Lecturer in York's Department of Archaeology and project lead, said: "After years of research in this valley, the day we discovered these paintings was undeniably the highlight of the research programme.

"Whilst we thought that we might discover engravings, such as in the Vallée des Merveilles to the south-east, we never expected to find prehistoric paintings in this exposed area that affords so few natural shelters.

"As this site is so unusual, we made the decision to carry out a laser-scan of the rock shelter and the surrounding landscape, plus a white-light scan of the actual paintings. The scanning was logistically complex as our only source of electricity was car batteries, which, along with all of the scanning equipment, had to be carried up to the site.

"This is the only example of virtual models, including a scan of the art, done at high altitude in the Alps and probably the highest virtual model of an archaeological landscape in Europe."

Contacts and sources:
Saskia Angenent
University of York

Citation: Interpreting the Rock Paintings of Abri Faravel: laser and white-light scanning at 2133m in the Southern French Alps is published in Internet Archaeology. To read, visit:http://dx.doi.org/10.11141/ia.42.1

Giant Planet Found Orbiting Young Star, Finding Contradicts Theory of Planet Formation

In contradiction to the long-standing idea that larger planets take longer to form, U.S. astronomers today announced the discovery of a giant planet in close orbit around a star so young that it still retains a disk of circumstellar gas and dust.

"For decades, conventional wisdom held that large Jupiter-mass planets take a minimum of 10 million years to form," said Christopher Johns-Krull, the lead author of a new study about the planet, CI Tau b, that will be published in the Astrophysical Journal. "That's been called into question over the past decade, and many new ideas have been offered, but the bottom line is that we need to identify a number of newly formed planets around young stars if we hope to fully understand planet formation."

CI Tau b is at least eight times larger than Jupiter and orbits a 2 million-year-old star about 450 light years from Earth in the constellation Taurus. Johns-Krull and a dozen co-authors from Rice, Lowell Observatory, the University of Texas at Austin, NASA and Northern Arizona University made the peer-reviewed study available online this week.

This false-color image from a sub-millimeter interferometric telescope shows the circumstellar disk of gas and dust that surrounds star CI Tau.

Credit: Stephane Guilloteau/University of Bordeaux

Earth and the sun are more than 4 billion years old, and while the 3,300-plus catalog of exoplanets includes some older and some younger than Earth, the obstacles to finding planets around newly formed stars are varied and daunting, Johns-Krull said. There are relatively few candidate stars that are young enough, bright enough to view in sufficient detail with existing telescopes and still retain circumstellar disks of gas and dust from which planets form. Stars so young also are often active, with visual outbursts and dimmings, strong magnetic fields and enormous starspots that can make it appear that planets exist where they do not.

CI Tau b orbits the star CI Tau once every nine days. The planet was found with the radial velocity method, a planet-hunting technique that relies upon slight variations in the velocity of a star to determine the gravitational pull exerted by nearby planets that are too faint to observe directly with a telescope. The discovery resulted from a survey begun in 2004 of 140 candidate stars in the star-forming region Taurus-Auriga.

"This result is unique because it demonstrates that a giant planet can form so rapidly that the remnant gas and dust from which the young star formed, surrounding the system in a Frisbee-like disk, is still present," said Lisa Prato of Lowell Observatory, co-leader of the young planet survey and a co-author on the paper. "Giant planet formation in the inner part of this disk, where CI Tau b is located, will have a profound impact on the region where smaller terrestrial planets are also potentially forming."

Additional team members were Patrick Hartigan, Naved Mahmud, Wei Chen, Wilson Cauley and Joshua Jones, all of Rice; Christopher Crockett and Brian Skiff of Lowell Observatory; Daniel Jaffe, Jacob McLane and Gregory Mace of the University of Texas at Austin; and Charles Beichman of NASA's Jet Propulsion Laboratory. Cauley is currently a postdoctoral researcher at Wesleyan University, and Crockett now writes for Science News.

The team observed CI Tau dozens of times from the University of Texas at Austin's McDonald Observatory near Fort Davis, Texas; the Lowell Observatory in Flagstaff, Ariz.; the NASA Infrared Telescope Facility and the Keck II telescopes on Mauna Kea, Hawaii; and the Kitt Peak National Observatory's 2.1- and 4-meter telescopes in southern Arizona.

Initial optical radial velocity data from McDonald Observatory confirmed that a planet might be present, and the team added photometry measurements from Lowell and five years of infrared observations from Hawaii, Kitt Peak and McDonald to rule out the possibility that the optical signal resulted from starspots or another masking phenomenon.

Johns-Krull said the team has examined about half of the young stars in the Taurus-Auriga survey sample, and the data from several of these suggest that more planets may be found.

"Ours isn't the only group looking for planets around young stars, and my hope is that astronomers can find enough of them to shed light on some of the nagging questions about planet formation," Johns-Krull said. "For instance, the 'brown dwarf desert,' an unexplained paucity of objects that are larger than giant planets but smaller than stars. If close investigation of young stars reveals more brown dwarfs in short-period orbits than elsewhere, that could confirm the theory that they tend to merge with their central stars within a few million years of forming."

NASA, the National Science Foundation and the Arizona Space Grant consortium supported the research.

Contacts and sources:
David Ruth 
Rice University

The study and research data are available at: http://arxiv.org/abs/1605.07917

A Look Beyond The Black Hole Event Horizon

Black holes are still very mysterious celestial bodies which, according to the majority of physicists, do not, however, escape the laws of thermodynamics. As a result, these physical systems possess an entropy though no real agreement has been reached about the microscopic origin of this propriety and how it should be calculated

In principle, nothing that enters a black hole can leave the black hole. This has considerably complicated the study of these mysterious bodies on which generations of physicists have debated ever since 1916, the year their existence was hypothesized as a direct consequence of Einstein's Theory of Relativity. There is, however, some consensus in the scientific community on the fact that black holes possess an entropy, because their existence would otherwise violate the second law of thermodynamics. 

Predicted appearance of non-rotating black hole 
Credit: SISSA/Brandon Defrise Carter

In particular, Jacob Bekenstein and Stephen Hawking have suggested that the entropy - which we can basically consider a measure of the inner disorder of a physical system - of a black hole is proportional to its area and not to its volume, as would be more intuitive. This assumption also gives rise to the "holography" hypothesis of black holes, which (very roughly) suggests that what appears to be three-dimensional might in fact be an image projected onto a distant two-dimensional cosmic horizon just like a hologram which, despite being a two-dimensional image, appears to us as three-dimensional.

As we cannot see beyond the event horizon (the outer boundary of the back hole), the internal microstates that define its entropy are inaccessible: so how is it possible to calculate this measure? The theoretical approach adopted by Hawking and Bekenstein is semiclassical (a sort of hybrid between classical physics and quantum mechanics) and introduces the possibility (or necessity) of adopting a quantum gravity approach in these studies, in order to obtain a more fundamental comprehension of the physics of black holes.

Illustration: A supermassive black hole at the center of a galaxy.
Credit: NASA

Planck's length is the (tiny) dimension at which space-time stops being continuous as we see it, and takes on a discrete graininess made up of quanta, the "atoms" of space-time. The Universe at this dimension is described by quantum mechanics. Quantum gravity is the field of enquiry that investigates gravity in the framework of quantum mechanics: this force is a phenomenon that has been very well described within classical physics, but it is unclear how it behaves at the Planck scale.

Daniele Pranzetti and colleagues, in a new study published in Physical Review Letters, present an important result obtained by applying a second quantization formulation of Loop Quantum Gravity (LQG) formalism. LQG is a theoretical approach within the problem of quantum gravity, and Group Field Theory is the "language" through which the theory is applied in this work.

"The idea at the basis of our study is that homogenous classical geometries emerge from a condensate of quanta of space introduced in LQG in order to describe quantum geometries" explains Pranzetti. "This way, we obtained a description of black hole quantum states, suitable to describe also 'continuum' physics, that is, the physics of space-time as we know it".

Condensates, quantum fluids and the universe as a hologram

A "condensate" is a collection of 'atoms' - in this case space quanta - all of which share the same properties so that, even though there are huge numbers of them, we can nonetheless study their collective behavior simply, by referring to the microscopic properties of the individual particle. So now the analogy with classical thermodynamics seems clearer: just as fluids at our scale appear as continuous materials despite their consisting of a huge number of atoms, similarly, in quantum gravity, the fundamental constituent atoms of space form a sort of fluid, that is, continuous space-time. A continuous and homogenous geometry (like that of a spherically symmetric black hole) can, as Pranzetti and colleagues suggest, be described as a condensate, which facilitates the underlying mathematical calculations, keeping in account an a priori infinite number of degrees of freedom .

"We were therefore able to use a more complete and richer model compared with what done in the past in LQG, and obtain a far more realistic and robust result", continues Pranzetti. "This allowed us to resolve several ambiguities afflicting previous calculations due to the comparison of these simplified LQG models with the results of semiclassical analysis, as carried out by Hawking and Bekenstein". 

Another important aspect of Pranzetti and colleagues' study is that it proposes a concrete mechanism in support to the holographic hypothesis, whereby the three-dimensionality of black holes could be merely apparent: all their information could be contained on a two-dimensional surface, without having to investigate the structure of the inside (hence the link between entropy and surface area rather than volume).

Contacts and sources:
Federica Sgorbissa
International School Of Advanced Studies (SISSA)

Link to the original paper in Physical Review Letters: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.211301

Supermassive Black Holes in 'Red Geyser' Galaxies Cause Galactic Warming

An international team of scientists, including the University of Kentucky's Renbin Yan, have uncovered a new class of galaxies, called "red geysers," with supermassive black hole winds so hot and energetic that stars can't form.

Over the last few billion years, a mysterious kind of "galactic warming" has caused many galaxies to change from a lively place where new stars formed every now and then to a quiet place devoid of fresh young stars. But the mechanism that produces this dramatic transformation and keeps galaxies quiet has been one of the biggest unsolved mysteries in galaxy evolution.

Akira's (right) gravity pulls Tetsuo's (left) gas into its central supermassive black hole, fueling winds that have the power to heat Akira's gas. Because of the action of the black hole winds, Tetsuo's donated gas is rendered inert, preventing a new cycle of star formation in Akira.

Credit: Kavli IPMU

"These galaxies have the necessary ingredients for forming new stars but they are not doing it - why?" said Yan, an assistant professor of physics and astronomy at UK.

Researchers compare it to having deserts in densely clouded regions; rain and vegetation would be expected, not a barren landscape. Yan and astronomers from the Sloan Digital Sky Survey (SDSS) are solving the mystery in a study published today in Nature, announcing the discovery of the red geysers.

Red geysers are old galaxies hosting low-energy supermassive black holes which drive intense interstellar winds. These winds suppress star formation by heating up the ambient gas found in galaxies and preventing it from cooling and condensing into stars.

Yan, also the survey scientist for the survey called Mapping Nearby Galaxies at Apache Point Observatory (MaNGA), was working with the international team, including lead author Edmond Cheung of the University of Tokyo, to study hundreds of galaxies when they caught a supermassive black hole blasting away at the cold gas in its host galaxy.

"With MaNGA's technological upgrade to the Sloan Foundation Telescope, we can make detailed maps of galaxies ten to a hundred times faster than we could just ten years ago," Yan said.

Yan and his team at MaNGA are mapping the details of 10,000 nearby galaxies - the largest survey yet of its kind - with the goal to understand the galaxies' life cycles. Unlike previous SDSS surveys, they are not only mapping the centers of galaxies where supermassive black holes live, but the outer edges of the galaxies as well, which allowed them to discover the red geyser galaxy.

The winds powered by these supermassive black holes could come and go quickly. It is difficult to catch the moment they show up. "Since MaNGA studies so many galaxies, our snapshots can reveal even the quickest changes to galaxies," Yan said. "And that's how we found Akira."

"Akira," an example of a red geyser galaxy nicknamed by Cheung, has a companion galaxy that called "Tetsuo." Akira is pulling gas away from Tetsuo, which fuels Akira's supermassive black hole. The winds driven by the black hole are the reason that Akira is currently a red geyser galaxy.

Kevin Bundy, MaNGA principal investigator, came up with the name "red geyser" because these wind outbursts reminded him of the sporadic eruptions of a geyser and because failure to form new stars left the galaxy with only red stars.

As with global warming on Earth, galactic warming has long-term consequences for red geyser galaxies - their gas can no longer form new stars.

Contacts and sources:
Whitney Harder
University of Kentucky