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Tuesday, February 28, 2017

Possible Change in Water ‘Fingerprint’ of Comet Lovejoy Detected by NASA

A trip past the sun may have selectively altered the production of one form of water in a comet - an effect not seen by astronomers before, a new NASA study suggests.

Astronomers from NASA's Goddard Space Flight Center in Greenbelt, Maryland, observed the Oort cloud comet C/2014 Q2, also called Lovejoy, when it passed near Earth in early 2015. Through NASA's partnership in the W. M. Keck Observatory on Mauna Kea, Hawaii, the team observed the comet at infrared wavelengths a few days after Lovejoy passed its perihelion - or closest point to the sun.

The team focused on Lovejoy's water, simultaneously measuring the release of H2O along with production of a heavier form of water, HDO. Water molecules consist of two hydrogen atoms and one oxygen atom. A hydrogen atom has one proton, but when it also includes a neutron, that heavier hydrogen isotope is called deuterium, or the "D" in HDO. From these measurements, the researchers calculated the D-to-H ratio - a chemical fingerprint that provides clues about exactly where comets (or asteroids) formed within the cloud of material that surrounded the young sun in the early days of the solar system. Researchers also use the D-to-H value to try to understand how much of Earth's water may have come from comets versus asteroids.

Scientists from NASA’s Goddard Center for Astrobiology observed the comet C/2014 Q2 – also called Lovejoy – and made simultaneous measurements of the output of H2O and HDO, a variant form of water. This image of Lovejoy was taken on Feb. 4, 2015 – the same day the team made their observations and just a few days after the comet passed its perihelion, or closest point to the sun.
Credits: Courtesy of Damian Peach

The scientists compared their findings from the Keck observations with another team's observations made before the comet reached perihelion, using both space- and ground-based telescopes, and found an unexpected difference: After perihelion, the output of HDO was two to three times higher, while the output of H2O remained essentially constant. This meant that the D-to-H ratio was two to three times higher than the values reported earlier.

"The change we saw with this comet is surprising, and highlights the need for repeated measurements of D-to-H in comets at different positions in their orbits to understand all the implications," said Lucas Paganini, a researcher with the Goddard Center for Astrobiology and lead author of the study, available online in the Astrophysical Journal Letters.

Changes in the water production are expected as comets approach the sun, but previous understanding suggested that the release of these different forms of water normally rise or fall more-or-less together, maintaining a consistent D-to-H value. The new findings suggest this may not be the case.

"If the D-to-H value changes with time, it would be misleading to assume that comets contributed only a small fraction of Earth's water compared to asteroids," Paganini said, "especially, if these are based on a single measurement of the D-to-H value in cometary water."

The production of HDO in comets has historically been difficult to measure, because HDO is a much less abundant form of water. Lovejoy, for example, released on the order of 1,500 times more H2O than HDO. Lovejoy's brightness made it possible to measure HDO when the comet passed near Earth, and the improved detectors that are being installed in some ground-based telescopes will permit similar measurements in fainter comets in the future.

The apparent change in Lovejoy's D-to-H may be caused by the higher levels of energetic processes - such as radiation near the sun - that might have altered the characteristics of water in surface layers of the comet. In this case, a different D-to-H value might indicate that the comet has "aged" into a different stage of its lifecycle. Alternatively, prior results might have ignored possible chemical alteration occurring in the comet's tenuous atmosphere.

"Comets can be quite active and sometimes quite dynamic, especially when they are in the inner solar system, closer to the sun," said Michael Mumma, director of the Goddard Center for Astrobiology and a co-author of the study. "The infrared technique provides a snapshot of the comet's output by measuring the production of H2O and HDO simultaneously. This is especially important because it eliminates many sources of systematic uncertainty."

Contacts and sources:
Elizabeth Zubritsky
NASA's Goddard Space Flight Center

Surprising Discovery of Mayan Precious Jewel: “Like Finding the Hope Diamond in Peoria”

To say that UC San Diego archaeologist Geoffrey Braswell was surprised to discover a precious jewel in Nim Li Punit in southern Belize is something of an understatement.

"It was like finding the Hope Diamond in Peoria instead of New York," said Braswell, who led the dig that uncovered a large piece of carved jade once belonging to an ancient Maya king. "We would expect something like it in one of the big cities of the Maya world. Instead, here it was, far from the center," he said.

The jewel -- a jade pendant worn on a king's chest during key religious ceremonies -- was first unearthed in 2015. It is now housed at the Central Bank of Belize, along with other national treasures. 

The jade once belonging to an ancient Maya king is inscribed with 30 hieroglyphs. It was used during important religious ceremonies.

Courtesy G. Braswell/UC San Diego

Braswell recently published a paper in the Cambridge University journal Ancient Mesoamerica detailing the jewel's significance. A second paper, in the Journal of Field Archaeology, describes the excavations.

The pendant is remarkable for being the second largest Maya jade found in Belize to date, said Braswell, a professor in the Department of Anthropology at UC San Diego. The pendant measures 7.4 inches wide, 4.1 inches high and just 0.3 inches thick. Sawing it into this thin, flat form with string, fat and jade dust would have been a technical feat. But what makes the pendant even more remarkable, Braswell said, is that it's the only one known to be inscribed with a historical text. Carved into the pendant's back are 30 hieroglyphs about its first owner.

"It literally speaks to us," Braswell said. "The story it tells is a short but important one." He believes it may even change what we know about the Maya.

Also important: The pendant was "not torn out of history by looters," said Braswell. "To find it on a legal expedition, in context, gives us information about the site and the jewel that we couldn't have otherwise had or maybe even imagined."

Where the jewel was found

Nim Li Punit is a small site in the Toledo District of Belize. It sits on a ridge in the Maya Mountains, near the contemporary village of Indian Creek. Eight different types of parrot fly overhead. It rains nine months of the year.

The pendant was pictured on a carved image of a king at the site where it was unearthed.
Courtesy G. Braswell/UC San Diego

On the southeastern edge of the ancient Maya zone (more than 250 miles south of Chichen Itza in Mexico, where similar but smaller breast pieces have been found), Nim Li Punit is estimated to have been inhabited between A.D. 150 and 850. The site's name means "big hat." It was dubbed that, after its rediscovery in 1976, for the elaborate headdress sported by one of its stone figures. Its ancient name might be Wakam or Kawam, but this is not certain.

Braswell, UC San Diego graduate students Maya Azarova and Mario Borrero, along with a crew of local people, were excavating a palace built around the year 400 when they found a collapsed, but intact, tomb. Inside the tomb, which dates to about A.D. 800, were 25 pottery vessels, a large stone that had been flaked into the shape of a deity and the precious jade pectoral. Except for a couple of teeth, there were no human remains.

What was it doing there?

The pendant is in the shape of a T. Its front is carved with a T also. This is the Mayan glyph "ik'," which stands for "wind and breath." It was buried, Braswell said, in a curious, T-shaped platform. And one of the pots discovered with it, a vessel with a beaked face, probably depicts a Maya god of wind.

Wind was seen as vital by the Maya. It brought annual monsoon rains that made the crops grow. And Maya kings -- as divine rulers responsible for the weather -- performed rituals according to their sacred calendar, burning and scattering incense to bring on the wind and life-giving rains. According to the inscription on its back, Braswell said, the pendant was first used in A.D. 672 in just such a ritual.

Two relief sculptures on large rock slabs at Nim Li Punit also corroborate that use. In both sculptures, a king is shown wearing the T-shaped pendant while scattering incense, in A.D. 721 and 731, some 50 and 60 years after the pendant was first worn.

A stela from Nim Li Punit Maya site in what is now Belize

By the year 800, the pendant was buried, not with its human owner, it seems, but just with other objects. Why? The pendant wasn't a bauble, Braswell said, "it had immense power and magic." Could it have been buried as a dedication to the wind god? That's Braswell's educated hunch.

Maya kingdoms were collapsing throughout Belize and Guatemala around A.D. 800, Braswell said. Population levels plummeted. Within a generation of the construction of the tomb, Nim Li Punit itself was abandoned.

"A recent theory is that climate change caused droughts that led to the widespread failure of agriculture and the collapse of Maya civilization," Braswell said. "The dedication of this tomb at that time of crisis to the wind god who brings the annual rains lends support to this theory, and should remind us all about the danger of climate change."

The jade pendant was buried around A.D. 800 with other objects, including pottery and a large stone that had been flaked into the shape of a deity.
Courtesy G. Braswell/UC San Diego

Still and again: What was it doing there?

The inscription on the back of the pendant is perhaps the most intriguing thing about it, Braswell said. The text is still being analyzed by Braswell's coauthor on the Ancient Mesoamerica paper, Christian Prager of the University of Bonn. And Mayan script itself is not yet fully deciphered or agreed upon.

But Prager and Braswell's interpretation of the text so far is this: The jewel was made for the king Janaab' Ohl K'inich. In addition to noting the pendant's first use in A.D. 672 for an incense-scattering ceremony, the hieroglyphs describe the king's parentage. His mother, the text implies, was from Cahal Pech, a distant site in western Belize. The king's father died before aged 20 and may have come from somewhere in Guatemala.

It also describes the accession rites of the king in A.D. 647, Braswell said, and ends with a passage that possibly links the king to the powerful and immense Maya city of Caracol, located in modern-day Belize.

"It tells a political story far from Nim Li Punit," Braswell said. He notes that Cahal Pech, the mother's birthplace, for example, is 60 miles away. That's a five-hour bus ride today, and back then would have been many days' walk -- through rainforest and across mountains. How did the pendant come to this outpost?

While it's possible it had been stolen from an important place and whisked away to the provinces, Braswell doesn't think so. He believes the pendant is telling us about the arrival of royalty at Nim Li Punit, the founding of a new dynasty. The writing on the pendant is not particularly old by Maya standards, but it's the oldest found at Nim Li Punit so far, Braswell said. It's also only after the pendant's arrival that other hieroglyphs and images of royalty begin to show up on the site's stelae, or sculptured stone slabs.

It could be that king Janaab' Ohl K'inich himself moved to Nim Li Punit, Braswell said. Or it could be that a great Maya state was trying to ally with the provinces, expand its power or curry favor by presenting a local king with the jewel. Either way, Braswell believes, the writing on the pendant indicates ties that had been previously unknown.

"We didn't think we'd find royal, political connections to the north and the west of Nim Li Punit," said Braswell, who has been excavating in Belize since 2001 and at Nim Li Punit since 2010. "We thought if there were any at all that they'd be to the south and east."

Even if you ignore the writing and its apparent royal provenance, the jade stone itself is from the mountains of Guatemala, southwest of Belize. There are few earlier indications of trade in that direction either, Braswell said.

We may never know exactly why the pendant came to Nim Li Punit or why it was buried as it was, but Braswell's project to understand the site continues. He plans to return in the spring of 2017. This time, he also wants to see if he might discover a tie to the Caribbean Sea. After all, that's a mere 12 miles downriver, a four-hour trip by canoe.

Contacts and sources:
Inga Kiderra
University of California San Diego (UC San Diego)

The Oldest Fossil Giant Penguin Reveals Earlier Diversification

Together with colleagues from New Zealand, Senckenberg scientist Dr. Gerald Mayr described a recently discovered fossil of a giant penguin with a body length of around 150 centimeters.

The new find dates back to the Paleocene era and, with an age of approx. 61 million years, counts among the oldest penguin fossils in the world. The bones differ significantly from those of other discoveries of the same age and indicate that the diversity of Paleocene penguins was higher than previously assumed. In their study, published today in the Springer journal The Science of Nature, the team of scientists therefore postulates that the evolution of penguins started much earlier than previously thought, probably already during the age of dinosaurs.

The Waipara giant penguin compared to an Emperor Penguin (the largest extant penguin species) and a human.

Credit: Senckenberg Gesellschaft für Naturforschung (Senckenberg Nature Research Society)

The fossil sites along the Waipara River in New Zealand's Canterbury region are well known for their avian fossils, which were embedded in marine sand a mere 4 million years after the dinosaurs became extinct. "Among the finds from these sites, the skeletons of Waimanu, the oldest known penguin to date, are of particular importance," explains Dr. Gerald Mayr of the Senckenberg Research Institute in Frankfurt.

Together with colleagues from the Canterbury Museum in New Zealand, Mayr now described a newly discovered penguin fossil from the famous fossil site. "What sets this fossil apart are the obvious differences compared to the previously known penguin remains from this period of geological history," explains the ornithologist from Frankfurt, and he continues, "The leg bones we examined show that during its lifetime, the newly described penguin was significantly larger than its already described relatives. Moreover, it belongs to a species that is more closely related to penguins from later time periods."

According to the researchers, the newly described penguin lived about 61 million years ago and reached a body length of approx. 150 centimeters -- making it almost as big as Anthropornis nordenskjoeldi, the largest known fossil penguin, which lived in Antarctica around 45 to 33 million years ago, thus being much younger in geological terms. 

"This shows that penguins reached an enormous size quite early in their evolutionary history, around 60 million years ago," adds Mayr. In addition, the team of scientists from New Zealand and Germany assumes that the newly discovered penguin species also differed from their more primitive relatives in the genus Waimanu in their mode of locomotion: The large penguins presumably already moved with the upright, waddling gait characteristic for today's penguins.

"The discoveries show that penguin diversity in the early Paleocene was clearly higher than we previously assumed," says Mayr, and he adds, "In turn, this diversity indicates that the first representatives of penguins already arose during the age of dinosaurs, more than 65 million years ago."

Contacts and sources:
Melanie Lehnert

Mayr, G. et al. (2017). A new fossil from the mid-Paleocene of New Zealand reveals an unexpected diversity of world's oldest penguins, The Science of Nature.DOI 10.1007/s00114-017-1441-0   http://dx.doi.org/10.1007/s00114-017-1441-0 

Nanofiber Mesh Wrapping Promotes Nerve Regeneration

A NIMS-Osaka University joint research team developed a mesh which can be wrapped around injured peripheral nerves to facilitate their regeneration and restore their functions.

A research team consisting of Mitsuhiro Ebara, MANA associate principal investigator, Mechanobiology Group, NIMS, and Hiroyuki Tanaka, assistant professor, Orthopaedic Surgery, Osaka University Graduate School of Medicine, developed a mesh which can be wrapped around injured peripheral nerves to facilitate their regeneration and restore their functions. 

This mesh incorporates vitamin B12 -- a substance vital to the normal functioning of nervous systems -- which is very soft and degrades in the body. When the mesh was applied to injured sciatic nerves in rats, it promoted nerve regeneration and recovery of their motor and sensory functions. The team is currently considering clinical application of the mesh to treat peripheral nerve disorders such as carpal tunnel syndrome (CTS).

Conceptual diagram showing a nanofiber mesh incorporating vitamin B12 and its application to treat a peripheral nerve injury
Credit:  NIMS-Osaka University

Artificial nerve conduits have been developed in the past to treat peripheral nerve injuries, but they merely form a cross-link to the injury site and do not promote faster nerve regeneration. Moreover, their application is limited to relatively few patients suffering from a complete loss of nerve continuity. Vitamin B12 has been known to facilitate nerve regeneration, but oral administration of it has not proven to be very effective, and no devices capable of delivering vitamin B12 directly to affected sites had been available. Therefore, it had been hoped to develop such medical devices to actively promote nerve regeneration in the many patients who suffer from nerve injuries but have not lost nerve continuity.

The NIMS-Osaka University joint research team recently developed a special mesh that can be wrapped around an injured nerve which releases vitamin B12 (methylcobalamin) until the injury heals. By developing very fine mesh fibers (several hundred nanometers in diameter) and reducing the crystallinity of the fibers, the team successfully created a very soft mesh that can be wrapped around a nerve. This mesh is made of a biodegradable plastic which, when implanted in animals, is eventually eliminated from the body. In fact, experiments demonstrated that application of the mesh directly to injured sciatic nerves in rats resulted in regeneration of axons and recovery of motor and sensory functions within six weeks.

The team is currently negotiating with a pharmaceutical company and other organizations to jointly study clinical application of the mesh as a medical device to treat peripheral nerve disorders, such as CTS.

This study was supported by the JSPS KAKENHI program (Grant Number JP15K10405) and AMED’s Project for Japan Translational and Clinical Research Core Centers (also known as Translational Research Network Program).

This research was published online in the April 2017 issue of Acta Biomaterialia on February 5, 2017.

Contacts and sources:
National Institute for Materials Science (NIMS)

Citation: “Electrospun nanofiber sheets incorporating methylcobalamin promote nerve regeneration and functional recovery in a rat sciatic nerve crush injury model”; Koji Suzuki, Hiroyuki Tanaka, Mitsuhiro Ebara, Koichiro Uto, Hozo Matsuoka, Shunsuke Nishimoto, Kiyoshi Okada, Tsuyoshi Murase, and Hideki Yoshikawa; Acta Biomaterialia,http://dx.doi.org/10.1016/j.actbio.2017.02.004

Humans Cause More Wildfires Than Lightning, Longer Fire Season and Larger Fire Niche

A recent first-of-its-kind analysis of wildfire records over 20 years shows that human-started fires accounted for 84 percent of all wildfires, tripled the length of the fire season and dominated an area seven times greater than that affected by lightning-caused fires. Humans have "a remarkable influence" on modern U.S. wildfire regimes, they conclude.

Researchers co-led by Bethany Bradley at the University of Massachusetts Amherst and Jennifer Balch at the University of Colorado-Boulder report their findings in the current early online edition of Proceedings of the National Academy of Sciences.

They found that of the 1.5 million fires that required fire fighting between 1992-2012, human-caused fires accounted for almost half, 44 percent, of area burned. The researchers note that humans are expanding the "fire niche," a measure of ignition sources, fuel mass and dryness. Bradley explains, "Humans are expanding fires into more locations and environmental conditions than lightning is able to reach."

In an analysis of 20 years of wildfire records led by researchers at UMass Amherst and the University of Colorado-Boulder, they found human-started fires accounted for 84 percent of all wildfires, exhibiting 'a remarkable influence' on modern US wildfire regimes. Further, humans are expanding the fire niche into more locations and environments with historically low lightning-strike density.

Public domain. FEMA/Andrea Booher

"Humans create sufficient ignition pressure for wetter fuels to burn," the researchers say. "Human ignitions have expanded the fire niche into areas with historically low lightning strike density."

Bradley, Balch and colleagues suggest, "National and regional policy efforts to mitigate wildfire related hazards would benefit from focusing on reducing the human expansion of the fire niche." Further, they note that because the wildland-urban interface - houses intermingling with natural areas - is expected to double by 2030 from 9 percent of total U.S. land area now, "ignition pressure" and structure vulnerability will rise.

Bradley says, "It's generally pretty well known that people start a lot of fires; everything from campfires to burning yard waste to accidental fires in homes and other structures. But in the past, I used to think of 'wildfire' as a process that was primarily natural and driven by lightning. This analysis made me realize that human ignitions have an extraordinary impact on national fire regimes. From our analysis, we learned that human-started fires are amazingly common. We found that humans play a primary role in redistributing wildfires in space and over time."

Further, "It turns out that lightning-started fires happen primarily in the inter-mountain west and almost exclusively in the summer, whereas human-started fires happen pretty much everywhere and extend the fire season far into the spring and fall. Our paper is the first to document the remarkable influence of human ignitions on 'wildfire.' Since we humans are the source of most fires, we are also the solution to reducing the number of costly and damaging fires."

The research team, which included others from UMass Amherst, the Earth Lab and department of geography at the University of Colorado-Boulder and the University of Idaho, point out that "economic and ecological costs of wildfire in the United States have risen substantially in recent decades. While climate change has likely enabled a portion of the increase in wildfire activity, the direct role of people in increasing wildfire has been largely overlooked" until now.

Bradley says, "We saw significant increases in the numbers of large, human-started fires over time, especially in the spring. I think that's interesting, and scary, because it suggests that as spring seasons get warmer and earlier due to climate change, human ignitions are putting us at increasing risk of some of the largest, most damaging wildfires."

Balch says, "The hopeful news here is that we could, in theory, reduce human-started wildfires in the medium term. But at the same time, we also need to focus on living more sustainably with fire by shifting the human contribution to ignitions to more controlled, well-managed burns."

For this study, the researchers used the publicly available U.S. Forest Service's Fire Program Analysis-Fire-Occurrence Database, which includes federal, state and local wildfire records on public and private lands from 1992-2012. They did not include prescribed burns or agricultural fires. Earlier studies had focused only on the West, for example, or records from just one agency. Fire causes include arson, smoking, railroads, fireworks and children as well as campfires and burning debris.

To assess 20-year trends in human- vs. lightning-caused wildfires over time, they used only large fires that were independently verified by a multi-agency project providing consistent burn severity data and fire perimeter information to researchers and relevant agencies.

Contacts and sources:\
Daniel Fitzgibbons
University of Massachusetts Amherst

Newfound Primate Teeth Take a Bite Out of The Evolutionary Tree of Life

Fossil hunters have found part of an ancient primate jawbone related to lemurs -- the primitive primate group distantly connected to monkeys, apes and humans, a University of Southern California (USC) researcher said.

Biren Patel, an associate professor of clinical cell and neurobiology at the Keck School of Medicine of USC, has been digging for fossils in a paleontologically rich area of Kashmir in northern India for six years. Although paleontologists have scoured this region for a century, relics of small extinct primates were rarely found or studied.

Scientists named the new species Ramadapis sahnii and said that it existed 11 to 14 million years ago. It is a member of the ancient Sivaladapidae primate family, consumed leaves and was about the size of a house cat, said Patel, co-author of the new study in the Journal of Human Evolution.

The new species Ramadapis sahnii existed 11 to 14 million years ago and is a member of the ancient Sivaladapidae primate family. It consumed leaves and was about the size of a house cat.

Credit: Sheena Lad

"Among the primates, the most common ones in the Kashmir region are from a genus called Sivapithecus, which were ancestral forms of orangutans," Patel said. "The fossil we found is from a different group on the primate family tree -- one that is poorly known in Asia. We are filling an ecological and biogeographical gap that wasn't really well documented. Every little step adds to the understanding of our human family tree because we're also primates."

The last primate found in the area was 38 years ago. So, in addition to being a new species, this is the first primate fossil found in the area in decades.

"In the past, people were interested in searching for big things -- things they could show off to other people," Patel said. "A lot of the small fossils were not on their radar."

The inch-and-a-quarter partial mandible belongs to a primate weighing less than 11 pounds that had outlived its other adapidae cousins found in North America, Europe and Africa by millions of years.

"New primates are always a hot topic, and this one is the first of its kind from its area in Asia, which has significant consequences for understanding primate evolution in the Old World," said Michael Habib, an assistant professor of clinical cell and neurobiology at the Keck School of Medicine who was not involved in the study.

The question that remains is how the ecosystem in northern India supported this species when its relatives elsewhere were disappearing or had already gone extinct. Future fieldwork and recovering more fossil primates will help answer this question.

"People want to know about human origins, but to fully understand human origins, you need to understand all of primate origins, including the lemurs and these Sivaladapids," Patel said. "Lemurs and sivaladapids are sister groups to what we are -- the anthropoids -- and we are all primates."

Researchers from Hunter College of the City University of New York, New York Consortium in Evolutionary Primatology, Arizona State University, Stony Brook University and Panjab University also contributed to this study, which was supported by the Wenner-Gren Foundation, the American Association of Physical Anthropologists, the Institute of Human Origins and funding from some of the involved universities.

Contacts and sources:
Zen Vuong
University of Southern California (USC) 

Dogs, Toddlers Show Similarities in Social Intelligence

Most dog owners will tell you they consider their beloved pets to be members of their families. Now new research suggests that dogs may be even more like us than previously thought.

Evan MacLean, director of the Arizona Canine Cognition Center at the University of Arizona, found that dogs and 2-year-old children show similar patterns in social intelligence, much more so than human children and one of their closest relatives: chimpanzees. The findings, published in the journal Animal Behaviour (link to come), could help scientists better understand how humans evolved socially.

MacLean and his colleagues looked at how 2-year-olds, dogs and chimpanzees performed on comparable batteries of tests designed to measure various types of cognition. While chimps performed well on tests involving their physical environment and spatial reasoning, they did not do as well when it came to tests of cooperative communication skills, such as the ability to follow a pointing finger or human gaze.

Credit: Eduardo Merille/ Wikimedia Commons

Dogs and children similarly outperformed chimps on cooperative communication tasks, and researchers observed similar patterns of variation in performance between individual dogs and between individual children.

A growing body of research in the last decade has looked at what makes human psychology special, and scientists have said that the basic social communication skills that begin to develop around 9 months are what first seem to set humans apart from other species, said MacLean, assistant professor in the School of Anthropology in the UA College of Social and Behavioral Sciences.

"There's been a lot of research showing that you don't really find those same social skills in chimpanzees, but you do find them in dogs, so that suggested something superficially similar between dogs and kids," MacLean said. "The bigger, deeper question we wanted to explore is if that really is a superficial similarity or if there is a distinct kind of social intelligence that we see in both species.

"What we found is that there's this pattern, where dogs who are good at one of these social things tend to be good at lots of the related social things, and that's the same thing you find in kids, but you don't find it in chimpanzees," he said.

One explanation for the similarities between dogs and humans is that the two species may have evolved under similar pressures that favored "survival of the friendliest," with benefits and rewards for more cooperative social behavior.

"Our working hypothesis is that dogs and humans probably evolved some of these skills as a result of similar evolutionary processes, so probably some things that happened in human evolution were very similar to processes that happened in dog domestication," MacLean said. "So, potentially, by studying dogs and domestication we can learn something about human evolution."

The research could even have the potential to help researchers better understand human disabilities, such as autism, that may involve deficits in social skills, MacLean said.

Looking to dogs for help in understanding human evolution is a relatively new idea, since scientists most often turn to close human relatives such as chimpanzees, bonobos and gorillas for answers to evolutionary questions. Yet, it seems man's best friend may offer an important, if limited, piece of the puzzle.

"There are different kinds of intelligence, and the kind of intelligence that we think is very important to humans is social in nature, and that's the kind of intelligence that dogs have to an incredible extent," MacLean said. "But there are other aspects of cognition, like the way we reason about physical problems, where dogs are totally dissimilar to us. So we would never make the argument that dogs in general are a better model for the human mind -- it's really just this special set of social skills."

MacLean and his collaborators studied 552 dogs, including pet dogs, assistance-dogs-in-training and military explosive detection dogs, representing a variety of different breeds. The researchers assessed social cognition through game-based tests, in which they hid treats and toys and then communicated the hiding places through nonverbal cues such as pointing or looking in a certain direction. They compared the dogs' results to data on 105 2-year-old children who previously completed a similar cognitive test battery and 106 chimpanzees assessed at wildlife sanctuaries in Africa.

Contacts and sources:
Alexis Blue
University of Arizona

First Evidence of Rocky Planet Formation In Tatooine System

Evidence of planetary debris surrounding a double sun, ‘Tatooine-like’ system has been found for the first time by a UCL-led team of researchers.

Published today in Nature Astronomy and funded by the Science and Technology Facilities Council and the European Research Council, the study reports on the remains of shattered asteroids orbiting a double sun consisting of a white dwarf and a brown dwarf roughly 1000 light-years away in a system called SDSS 1557.

The discovery is remarkable because the debris appears to be rocky and suggests that terrestrial planets like Tatooine – Luke Skywalker’s home world in Star Wars – might exist in the system. To date, all exoplanets discovered in orbit around double stars are gas giants, similar to Jupiter, and are thought to form in the icy regions of their systems.

Credit: Mark Garlick, UCL, University of Warwick and University of Sheffield 

A disc of rocky debris from a disrupted planetesimal surrounds white dwarf plus brown dwarf binary star. The white dwarf is the burn-out core of a star that was probably similar to the Sun, the brown dwarf is only ~60 times heavier than Jupiter, and the two stars go around each other in only a bit over two hours.

In contrast to the carbon-rich icy material found in other double star systems, the planetary material identified in the SDSS 1557 system has a high metal content, including silicon and magnesium. These elements were identified as the debris flowed from its orbit onto the surface of the star, polluting it temporarily with at least 1017 g (or 1.1 trillion US tons) of matter, equating it to an asteroid at least 4 km in size.

Lead author, Dr Jay Farihi (UCL Physics & Astronomy), said: “Building rocky planets around two suns is a challenge because the gravity of both stars can push and pull tremendously, preventing bits of rock and dust from sticking together and growing into full-fledged planets. With the discovery of asteroid debris in the SDSS 1557 system, we see clear signatures of rocky planet assembly via large asteroids that formed, helping us understand how rocky exoplanets are made in double star systems."

In the Solar System, the asteroid belt contains the leftover building blocks for the terrestrial planets Mercury, Venus, Earth, and Mars, so planetary scientists study the asteroids to gain a better understanding of how rocky, and potentially habitable planets are formed. The same approach was used by the team to study the SDSS 1557 system as any planets within it cannot yet be detected directly but the debris is spread in a large belt around the double stars, which is a much larger target for analysis.

The discovery came as a complete surprise as the team assumed the dusty white dwarf was a single star but co-author Dr Steven Parsons (University of Valparaíso and University of Sheffield), an expert in double star (or binary) systems noticed the tell-tale signs. "We know of thousands of binaries similar to SDSS 1557 but this is the first time we've seen asteroid debris and pollution. The brown dwarf was effectively hidden by the dust until we looked with the right instrument", added Parsons, "but when we observed SDSS 1557 in detail we recognised the brown dwarf's subtle gravitational pull on the white dwarf."

The team studied the binary system and the chemical composition of the debris by measuring the absorption of different wavelengths of light or ‘spectra’, using the Gemini Observatory South telescope and the European Southern Observatory Very Large Telescope, both located in Chile.

Co-author Professor Boris Gänsicke (University of Warwick) analysed these data and found they all told a consistent and compelling story. "Any metals we see in the white dwarf will disappear within a few weeks, and sink down into the interior, unless the debris is continuously flowing onto the star. We'll be looking at SDSS 1557 next with Hubble, to conclusively show the dust is made of rock rather than ice."

Contacts and sources:
Rebecca Caygill
University College London (UCL)

Gang War Over Sex and Territory

Gang warfare is not unique to humans - banded mongooses do it too.

Now researchers from the University of Exeter have shed light on the causes of the fights - and found they are most common when females are receptive to breeding and when there is competition over food and territory.

The scientists, who studied a population of banded mongooses in Uganda, observed ferocious fighting between groups that often led to serious injury and even death.

During the conflicts, they saw individuals raiding dens and killing the pups of their neighbours, and males and females of rival groups mating with each other.

These are banded mongooses fighting.
Credit: Harry Marshall

"These fights are very chaotic, with 20 or 30 mongooses on each side arranged in battle lines," said lead author Dr Faye Thompson, of the Centre for Ecology and Conservation on the University of Exeter's Penryn Campus in Cornwall.

"They all rush forward and fighting breaks out, with some individuals chasing each other into bushes - but at the same time males and females from opposing groups will sometimes mate with each other.

"The fighting is costly to both individuals and groups. Individuals are more likely to die and litters are less likely to survive to emergence if their group is involved in an aggressive encounter with a rival."

Banded mongooses
Credit: Feargus Cooney

Intriguingly, they discovered that pregnant females were less likely to lose their litters after such conflicts.

Dr Thompson added: "We found that females were significantly less likely to abort their litter if their group was involved in a fight with another group during gestation.

"This is a puzzling result, but one possible explanation is that unborn litters may be seen as particularly valuable during periods of conflict with rival groups.

"Pregnant females could be finding some way to maintain their pregnancy, perhaps to offset mortality from fighting and make their group bigger and more competitive in the future."

Banded mongooses rarely leave the group into which they are born, so group members are usually genetically related to one another. Fights between groups may provide an opportunity to avoid inbreeding.

Credit: Harry Marshall

As a result, males or females sometimes lead their group into enemy territory in search of unrelated mating partners.

Professor Michael Cant of the University of Exeter, who leads the long-term study of banded mongooses in Uganda, said: "Intergroup conflict can be very intense in social animals but has really only been studied in depth in humans and chimpanzees before now."

"Our results suggest that fighting between groups is one of the major forces promoting solidarity and cooperation within groups in these highly social mammals."

The paper, published in the journal Animal Behaviour, is entitled: "Causes and consequences of intergroup conflict in cooperative banded mongooses."

Contacts and sources:
Alex Morrison
University of Exeter

The Most Power-Packed Galaxies Even Found Evade Understanding

When the universe was young, a supermassive black hole -- bloated to the bursting point with stupendous power -- heaved out a jet of particle-infused energy that raced through the vastness of space at nearly the speed of light.

Billions of years later, a trio of Clemson University scientists, led by College of Science astrophysicist Marco Ajello, has identified this black hole and four others similar to it that range in age from 1.4 billion to 1.9 billion years old. These objects emit copious gamma rays, light of the highest energy, that are billions of times more energetic than light that is visible to the human eye.

The previously known earliest gamma-ray blazars -- a type of galaxy whose intense emission is powered by extremely powerful relativistic jets launched by monstrous black holes -- were more than 2 billion years old. Currently, the universe is estimated to be approximately 14 billion years old.

In the heart of an active galaxy, matter falling toward a supermassive black hole generates jets of particles traveling near the speed of light.
Credit: NASA's Goddard Space Flight Center
"The discovery of these supermassive black holes, which launch jets that emit more energy in one second than our sun will produce in its entire lifetime, was the culmination of a yearlong research project," said Ajello, who has spent much of his career studying the evolution of distant galaxies.
"Our next step is to increase our understanding of the mechanisms involved in the formation,

development and activities of these amazing objects, which are the most powerful accelerators in the universe. We can't even come close to replicating such massive outputs of energy in our laboratories. The complexities we're attempting to unravel seem almost as mysterious as the black holes themselves."

Ajello conducted his research in conjunction with Clemson post-doc Vaidehi Paliya and Ph.D candidate Lea Marcotulli. The trio worked closely with the Fermi-Large Area Telescope collaboration, which is an international team of scientists that includes Roopesh Ojha, an astronomer at NASA's Goddard Space Flight Center in Greenbelt, Maryland; and Dario Gasparrini of the Italian Space Agency. Their scientific paper titled "Gamma-Ray Blazars Within the First 2 Billion Years" was published Monday in a journal called Astrophysical Journal Letters. (Ackermann, M., et al. 2017, ApJL, 837, L5.)

The Clemson team's breakthroughs were made possible by recently juiced-up software on NASA's Fermi Gamma-ray Telescope. The refurbished software significantly boosted the orbiting telescope's sensitivity to a level that made these latest discoveries possible.

"People are calling it the cheapest refurbishment in history," Ajello said. "Normally, for the Hubble Space Telescope, NASA had to send someone up to space to physically make these kinds of improvements. But in this case, they were able to do it remotely from an Earth-bound location. And of equal importance, the improvements were retroactive, which meant that the previous six years of data were also entirely reprocessed. This helped provide us with the information we needed to complete the first step of our research and also to strive onward in the learning process."

Using Fermi data, Ajello and Paliya began with a catalog of 1.4 million quasars, which are galaxies that harbor at their centers active supermassive black holes. Over the course of a year, they narrowed their search to 1,100 objects. Of these, five were finally determined to be newly discovered gamma-ray blazars that were the farthest away - and youngest - ever identified.

"After using our filters and other devices, we were left with about 1,100 sources. And then we did the diagnostics for all of these and were able to narrow them down to 25 to 30 sources," Paliya said. "But we still had to confirm that what we had detected was scientifically authentic. So we performed a number of other simulations and were able to derive properties such as black hole mass and jet power. Ultimately, we confirmed that these five sources were guaranteed to be gamma-ray blazars, with the farthest one being about 1.4 billion years old from the beginning of time."

Marcotulli, who joined Ajello's group as a Ph.D student in 2016, has been studying the blazars' mechanisms by using images and data delivered from another orbiting NASA telescope, the Nuclear Spectroscopic Telescope Array (NuSTAR). At first, Marcotulli's role was to understand the emission mechanism of gamma-ray blazars closer to us. Now she is turning her attention toward the most distant objects in a quest to understand what makes them so powerful.

"We're trying to understand the full spectrum of the energy distribution of these objects by using physical models," Marcotulli said. "We are currently able to model what's happening far more accurately than previously devised, and eventually we'll be able to better understand what processes are occurring in the jets and which particles are radiating all the energy that we see. Are they electrons? Or protons? How are they interacting with surrounding photons? All these parameters are not fully understood right now. But every day we are deepening our understanding."

All galaxies have black holes at their centers - some actively feeding on the matter surrounding them, others lying relatively dormant. Our own galaxy has at its center a super-sized black hole that is currently dormant. Ajello said that only one of every 10 black holes in today's universe are active. But when the universe was much younger, it was closer to a 50-50 ratio.

The supermassive black holes at the center of the five newly discovered blazar galaxies are among the largest types of black holes ever observed, on the order of hundreds of thousands to billions of times the mass of our own sun. And their accompanying accretion disks - rotating swirls of matter that orbit the black holes - emit more than two trillion times the energy output of our sun.

One of the most surprising elements of Ajello's research is how quickly - by cosmic measures - these supersized black holes must have grown in only 1.4 billion years. In terms of our current knowledge of how black holes grow, 1.4 billion years is barely enough time for a black hole to reach the mass of the ones discovered by Ajello's team.

"How did these incomprehensibly enormous and energy-laden black holes form so quickly?" Ajello said. "Is it because one black hole ate a lot all the time for a very long time? Or maybe because it bumped into other black holes and merged into one? To be honest, we have no observations supporting either argument. There are mechanisms at work that we have yet to unravel. Puzzles that we have yet to solve. When we do eventually solve them, we will learn amazing things about how the universe was born, how it grew into what it has become, and what the distant future might hold as the universe continues to progress toward old age."

Contacts and sources:
Jim Melvin
Clemson University

Missing Link In Planet Formation: Astronomers Discover Spontaneous 'Dust Traps'

Planets are thought to form in the disks of dust and gas found around young stars. But astronomers have struggled to assemble a complete theory of their origin that explains how the initial dust develops into planetary systems. A French-UK-Australian team now think they have the answer, with their simulations showing the formation of 'dust traps' where pebble-sized fragments collect and stick together, to grow into the building blocks of planets. They publish their results in Monthly Notices of the Royal Astronomical Society.

Our Solar system, and other planetary systems, began life with disks of gas and dust grains around a young star. The processes that convert these tiny grains, each a few millionths of a metre (a micron) across, into aggregates a few centimetres in size, and the mechanism for making kilometre-sized 'planetesimals' into planetary cores, are both well understood.

An image of a protoplanetary disk, made using results from the new model, after the formation of a spontaneous dust trap, visible as a bright dust ring. Gas is depicted in blue and dust in red.

Credit: Jean-Francois Gonzalez

The intermediate stage, taking pebbles and joining them together into objects the size of asteroids, is less clear, but with more than 3,500 planets already found around other stars, the whole process must be ubiquitous.

Dr Jean-Francois Gonzalez, of the Centre de Recherche Astrophysique de Lyon, in France, led the new work. He comments: "Until now we have struggled to explain how pebbles can come together to form planets, and yet we've now discovered huge numbers of planets in orbit around other stars. That set us thinking about how to solve this mystery."

There are two main barriers that need to be overcome for pebbles to become planetesimals. Firstly the drag of gas on dust grains in a disk makes them drift rapidly towards the central star, where they are destroyed, leaving no material to form planets. The second challenge is that growing grains can be broken up in high-speed collisions, breaking them into a large number of smaller pieces and reversing the aggregation process.

This cartoon illustrates the stages of the formation mechanism for dust traps. The central star is depicted as yellow, surrounded by the protoplanetary disk, here shown in blue. The dust grains make up the band running through the disk.

In the first stage, the dust grains grown in size, and move inwards towards the central star. The now pebble-sized larger grains (in the second panel) then pile up and slow down, and in the third stage the gas is pushed outwards by the back-reaction, creating regions where dust accumulates, the so-called dust traps. The traps then allow the pebbles to aggregate to form planetesimals, and eventually planet-sized worlds.
Credit: © Volker Schurbert

The only locations in planet forming disks where these problems can be overcome are so-called 'dust traps'. In these high-pressure regions, the drift motion slows, allowing dust grains to accumulate. With their reduced velocity, the grains can also avoid fragmentation when they collide.

Until now, astronomers thought that dust traps could only exist in very specific environments, but the computer simulations run by the team indicate that they are very common. Their model pays particular attention to the way the dust in a disk drags on the gas component. In most astronomical simulations, gas causes the dust to move, but sometimes, in the dustiest settings, the dust acts more strongly on the gas.

This effect, known as aerodynamic drag back-reaction, is usually negligible, so up to now has been ignored in studies of growing and fragmenting grains. But its effects become important in dust rich environments, like those found where planets are forming.

The effect of the back-reaction is to slow the inward drift of the grains, which gives them time to grow in size. Once large enough, the grains are their own masters, and the gas can no longer govern their motion. The gas, under the influence of this back-reaction, will be pushed outwards and form a high-pressure region: the dust trap. These spontaneous traps then concentrate the grains coming from the outer disk regions, creating a very dense ring of solids, and giving a helping hand to the formation of planets.

Gonzalez concludes: "We were thrilled to discover that, with the right ingredients in place, dust traps can form spontaneously, in a wide range of environments. This is a simple and robust solution to a long standing problem in planet formation."

Observatories like ALMA in Chile already see bright and dark rings in forming planetary systems that are thought to be dust traps. Gonzalez and his team, and other research groups around the world, now plan to extend the trap model all the way to the formation of planetesimals.

Contacts and sources:
Dr Robert Massey
Royal Astronomical Society

Dr Jean-Francois Gonzalez
Centre de Recherche Astrophysique de Lyon
Observatoire de Lyon

The new work appears in "Self-induced dust traps: overcoming planet formation barriers", J.-F. Gonzalez, G. Laibe, and S. T. Maddison, Monthly Notices of the Royal Astronomical Society, in press. After the embargo expires the final paper will be available from OUP via http://doi.org/10.1093/mnras/stx016

Monday, February 27, 2017

Resurrecting Extinct Species: What Could Go Wrong?

Bringing back extinct species could lead to biodiversity loss rather than gain, according to work featuring University of Queensland researchers.

UQ scientist Professor Hugh Possingham said the research suggested further stretching already-strained conservation budgets to cover the costs of de-extinction could endanger extant species (species still in existence).

"If the risk of failure and the costs associated with establishing viable populations could also be calculated, estimates of potential net losses or missed opportunities would probably be considerably higher," Professor Possingham said.

"De-extinction could be useful for inspiring new science and could be beneficial for conservation if we ensure it doesn't reduce existing conservation resources.

This image shows a Lord Howe Island woodhen Gallirallus sylvestris.

Credit: Toby Hudson

"However, in general it is best if we focus on the many species that need our help now."

"Given the considerable potential for missed opportunity, and risks inherent in assuming a resurrected species would fulfil its role as an ecosystem engineer or flagship species, it is unlikely that de-extinction could be justified on grounds of biodiversity conservation."

The study was led by Dr Joseph Bennett, formerly of the ARC Centre for Environmental Decisions at UQ and now of Carleton University, Canada.

It analysed the number of species governments in New Zealand and New South Wales could afford to conserve.

"We based cost estimates on recently extinct species and similar extant species," Dr Bennett said.

The Lord Howe pigeon, eastern bettong, bush moa and Waitomo frog were among the extinct species included in calculations.

The researchers found reintroducing some recently extinct species to their old habitats might improve biodiversity locally, but government-funded conservation for 11 focal extinct species in New Zealand would sacrifice conservation for nearly three times as many (31) extant species.

External funding for conservation of the five focal extinct NSW species could instead be used to conserve more than eight times as many (42) extant species.

Although the technology for de-extinction is still some way off, the research found that careful thought would be required about what species to reintroduce, and where.

Professor Possingham is Chief Scientist with The Nature Conservancy, the world's largest conservation organisation, and a scientist with UQ's School of Biological Sciences, The Centre for Biodiversity and Conservation Science at UQ, the ARC Centre of Excellence for Environmental Decisions (CEED) and the Australian Government's National Environmental Science Program Threatened Species Recovery Hub.

Contacts and sources:
Hugh Possingham
University of Queensland 

The research is published in Nature Ecology and Evolution (DOI: 10.1038/s41559-016-0053). http://dx.doi.org/10.1038/s41559-016-0053

Getting Cyborg Cockroaches to Stay on Track: One Day They Will Explore Disaster Areas

New research from North Carolina State University offers insights into how far and how fast cyborg cockroaches - or biobots - move when exploring new spaces. The work moves researchers closer to their goal of using biobots to explore collapsed buildings and other spaces in order to identify survivors.

NC State researchers have developed cockroach biobots that can be remotely controlled and carry technology that may be used to map disaster areas and identify survivors in the wake of a calamity.

For this technology to become viable, the researchers needed to answer fundamental questions about how and where the biobots move in unfamiliar territory. Two forthcoming papers address those questions.

NC State researchers have found that by sending cockroach biobots random commands, the biobots spent more time moving, moved more quickly and were at least five times more likely to move away walls and into open space. The finding is a significant advance for developing biobots that can search collapsed buildings and other disaster areas for survivors.

Credit: Edgar Lobaton

The first paper answers questions about whether biobot technology can accurately determine how and whether biobots are moving.

The researchers followed biobot movements visually and compared their actual motion to the motion being reported by the biobot's inertial measurement units. The study found that the biobot technology was a reliable indicator of how the biobots were moving.

The second paper addresses bigger questions: How far will the biobots travel? How fast? Are biobots more efficient at exploring space when allowed to move without guidance? Or can remote-control commands expedite the process?

These questions are important because the answers could help researchers determine how many biobots they may need to introduce to an area in order to explore it effectively in a given amount of time.

For this study, researchers introduced biobots into a circular structure. Some biobots were allowed to move at will, while others were given random commands to move forward, left or right.

Credit: ARoS Lab

The researchers found that unguided biobots preferred to hug the wall of the circle. But by sending the biobots random commands, the biobots spent more time moving, moved more quickly and were at least five times more likely to move away from the wall and into open space.

"Our earlier studies had shown that we can use neural stimulation to control the direction of a roach and make it go from one point to another," says Alper Bozkurt, an associate professor of electrical and computer engineering at NC State and co-author of the two papers. "This [second] study shows that by randomly stimulating the roaches we can benefit from their natural walking and instincts to search an unknown area. Their electronic backpacks can initiate these pulses without us seeing where the roaches are and let them autonomously scan a region."

"This is practical information we can use to get biobots to explore a space more quickly," says Edgar Lobaton, an assistant professor of electrical and computer engineering at NC State and co-author on the two papers. "That's especially important when you consider that time is of the essence when you are trying to save lives after a disaster."

Lead author of the first paper, "A Study on Motion Mode Identification for Cyborg Roaches," is NC State Ph.D. student Jeremy Cole. The paper was co-authored by Ph.D. student Farrokh Mohammadzadeh, undergraduate Christopher Bollinger, former Ph.D. student Tahmid Latif, Bozkurt and Lobaton.

Lead author of the second paper, "Biobotic Motion and Behavior Analysis in Response to Directional Neurostimulation," is former NC State Ph.D. student Alireza Dirafzoon. The paper was co-authored by Latif, former Ph.D. student Fengyuan Gong, professor of electrical and computer engineering Mihail Sichitiu, Bozkurt and Lobaton.

Both papers will be presented at the 42nd IEEE International Conference on Acoustics, Speech and Signal Processing, being held March 5-9 in New Orleans.

Contacts and sources:
Matt Shipman
North Carolina State University

Earth Likely Began with a Solid Shell: Plate Tectonics Came Later in Earth's History Says New Research

Today's Earth is a dynamic planet with an outer layer composed of giant plates that grind together, sliding past or dipping beneath one another, giving rise to earthquakes and volcanoes. Others separate at undersea mountain ridges, where molten rock spreads out from the centers of major ocean basins.

But new research suggests that this was not always the case. Instead, shortly after Earth formed and began to cool, the planet's first outer layer was a single, solid but deformable shell. Later, this shell began to fold and crack more widely, giving rise to modern plate tectonics.

The outer layer of modern Earth is a collection of interlocking rigid plates, as seen in this illustration. These plates grind together, sliding past or dipping beneath one another, giving rise to earthquakes and volcanoes. But new research suggests that plate tectonics did not begin until much later in Earth's history.

Credit: USGS

The research, described in a paper published February 27, 2017 in the journal Nature, is the latest salvo in a long-standing debate in the geological research community: did plate tectonics start right away--a theory known as uniformitarianism--or did Earth first go through a long phase with a solid shell covering the entire planet? The new results suggest the solid shell model is closest to what really happened.

"Models for how the first continental crust formed generally fall into two groups: those that invoke modern-style plate tectonics and those that do not," said Michael Brown, a professor of geology at the University of Maryland and a co-author of the study. "Our research supports the latter--a 'stagnant lid' forming the planet's outer shell early in Earth's history."

To reach these conclusions, Brown and his colleagues from Curtin University and the Geological Survey of Western Australia studied rocks collected from the East Pilbara Terrane, a large area of ancient granitic crust located in the state of Western Australia. Rocks here are among the oldest known, ranging from 3.5 to about 2.5 billion years of age. (Earth is roughly 4.5 billion years old.) The researchers specifically selected granites with a chemical composition usually associated with volcanic arcs--a telltale sign of plate tectonic activity.

Brown and his colleagues also looked at basalt rocks from the associated Coucal formation. Basalt is the rock produced when volcanoes erupt, but it also forms the ocean floor, as molten basalt erupts at spreading ridges in the center of ocean basins. In modern-day plate tectonics, when ocean floor basalt reaches the continents, it dips--or subducts--beneath the Earth's surface, where it generates fluids that allow the overlying mantle to melt and eventually create large masses of granite beneath the surface.

Previous research suggested that the Coucal basalts could be the source rocks for the granites in the Pilbara Terrane, because of the similarities in their chemical composition. Brown and his collaborators set out to verify this, but also to test another long-held assumption: could the Coucal basalts have melted to form granite in some way other than subduction of the basalt beneath Earth's surface? If so, perhaps plate tectonics was not yet happening when the Pilbara granites formed.

To address this question, the researchers performed thermodynamic calculations to determine the phase equilibria of average Coucal basalt. Phase equilibria are precise descriptions of how a substance behaves under various temperature and pressure conditions, including the temperature at which melting begins, the amount of melt produced and its chemical composition.

For example, one of the simplest phase equilibria diagrams describes the behavior of water: at low temperatures and/or high pressures, water forms solid ice, while at high temperatures and/or low pressures, water forms gaseous steam. Phase equilibria gets a bit more involved with rocks, which have complex chemical compositions that can take on very different mineral combinations and physical characteristics based on temperature and pressure.

"If you take a rock off the shelf and melt it, you can get a phase diagram. But you're stuck with a fixed chemical composition," Brown said. "With thermodynamic modeling, you can change the composition, pressure and temperature independently. It's much more flexible and helps us to answer some questions we can't address with experiments on rocks."

Using the Coucal basalts and Pilbara granites as a starting point, Brown and his colleagues constructed a series of modeling experiments to reflect what might have transpired in an ancient Earth without plate tectonics. Their results suggest that, indeed, the Pilbara granites could have formed from the Coucal basalts.

More to the point, this transformation could have occurred in a pressure and temperature scenario consistent with a "stagnant lid," or a single shell covering the entire planet.

Plate tectonics substantially affects the temperature and pressure of rocks within Earth's interior. When a slab of rock subducts under the Earth's surface, the rock starts off relatively cool and takes time to gain heat. By the time it reaches a higher temperature, the rock has also reached a significant depth, which corresponds to high pressure--in the same way a diver experiences higher pressure at greater water depth.

In contrast, a "stagnant lid" regime would be very hot at relatively shallow depths and low pressures. Geologists refer to this as a "high thermal gradient."

"Our results suggest the Pilbara granites were produced by melting of the Coucal basalts or similar materials in a high thermal gradient environment," Brown said. "Additionally, the composition of the Coucal basalts indicates that they, too, came from an earlier generation of source rocks. We conclude that a multi-stage process produced Earth's first continents in a 'stagnant lid' scenario before plate tectonics began."

Contacts and sources:
Matthew Wright
University of Maryland
College of Computer, Mathematical, and Natural Sciences

Citation: The research paper, "Earth's first stable continents did not form by subduction," Tim Johnson, Michael Brown, Nicholas Gardiner, Christopher Kirkland and Hugh Smithies, was published February 27, 2017 in the journal Nature.

This work was supported by The Institute of Geoscience Research at Curtin University, Perth, Australia. The content of this article does not necessarily reflect the views of this organization.

A Rose Is a Rose Is a Transistor: Bionic Flowers Deliver Electric Power

 Flower power is taking on a whole new meaning. Life can be electric. Rechargeable rose bouquets are possible.  A bionic future gets nearer. 

In November 2015, the research group presented results showing that they had caused roses to absorb a conducting polymer solution. Conducting hydrogel formed in the rose's stem in the form of wires. With an electrode at each end and a gate in the middle, a fully functional transistor was created. The results were presented in Science Advances and have aroused considerable interest all over the world.

One member of the group, Assistant Professor Roger Gabrielsson, has now developed a material specially designed for this application. The material polymerizes inside the rose without any external trigger. The innate fluid that flows inside the rose contributes to create long, conducting threads, not only in the stem but also throughout the plant, out into the leaves and petals.

This is a supercapacitor Rose from Laboratory of Organic Electronic, Linköping University.

 Credit: Thor Balkhed

"We have been able to charge the rose repeatedly, for hundreds of times without any loss on the performance of the device. The levels of energy storage we have achieved are of the same order of magnitude as those in supercapacitors. The plant can, without any form of optimization of the system, potentially power our ion pump, for example, and various types of sensors," says Eleni Stavrinidou, Assistant Professor at the Laboratory of Organic Electronics.

The results are now to be published in the prestigious scientific journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

"This research is in a very early stage, and what the future will bring is an open question," says Eleni Stavrinidou.

Some examples are autonomous energy systems, the possibility of harvesting energy from plants to power sensors and various types of switches, and the possibility of creating fuel cells inside plants.

"A few years ago, we demonstrated that it is possible to create electronic plants, 'power plants', but we have now shown that the research has practical applications. We have not only shown that energy storage is possible, but also that we can deliver systems with excellent performance," says Professor Magnus Berggren, head of the Laboratory of Organic Electronics, Linköping University, Campus Norrköping.

The research into electronic plants has been funded by unrestricted research grants from the Knut and Alice Wallenberg Foundation. The foundation appointed Professor Magnus Berggren a Wallenberg Scholar in 2012.

Contacts and sources:
Eleni Stavrinidou
Magnus Berggren
Linköping University

Citation: In vivo polymerization and manufacturing of wires and supercapacitors in plants,
Eleni Stavrinidou, Roger Gabrielsson, K Peter R Nilsson, Sandeep Kumar Singh, Juan Felipe Franco-Gonzalez, Anton V Volkov, Magnus P Jonsson, Andrea Grimoldi, Mathias Elgland, Igor V Zozoulenko, Daniel T Simon and Magnus Berggren, Linköping University, PNAS 2017, DOI 10.1073/pnas.1616456114 http://dx.doi.org/10.1073/pnas.1616456114

Caution Subconscious at Work: How Your Brain Makes Articles Go Viral

The subconscious is at work when posts go viral on the internet, according to new research.

Activity in the self-related, mentalizing, and positive valuation regions of the brain combine unconsciously in our thoughts to determine what we want to read and share, such that brain scans from a small group of people can predict large-scale virality

It is a question that has mystified countless people: Why does one article spread like wildfire through social media and another -- seemingly similar -- doesn't? How does your brain decide what is valuable enough to read and share?

Christin Scholz and Elisa Baek, both students in the Ph.D. program at the Annenberg School for Communication at the University of Pennsylvania, are the lead authors behind two new research papers that document for the first time the specific brain activity that leads us to read or share articles -- in this case, health articles from the New York Times. And by looking at this specific pattern of brain activity in 80 people, they also were able to predict the virality of these articles among real New York Times readers around the world.
FMRI scan during working memory tasks
Credit: Wikimedia Commons

Fundamentally, explains Emily Falk, Ph.D., senior author on both papers and the director of Penn's Communication Neuroscience Lab, specific regions of the brain determine how valuable it would be to share information, and that value translates to its likelihood of going viral.

"People are interested in reading or sharing content that connects to their own experiences, or to their sense of who they are or who they want to be," she says. "They share things that might improve their relationships, make them look smart or

empathic or cast them in a positive light."

By using fMRI, the researchers were able to measure people's brain activity in real time as they viewed the headlines and abstracts of 80 New York Times health articles and rated how likely they were to read and share them. The articles were chosen for their similarity of subject matter -- nutrition, fitness, healthy living -- and number of words.

The researchers honed in on regions of the brain associated with self-related thinking, regions associated with mentalizing -- imagining what others might think -- and with overall value.

Although it might be intuitive to expect people would think about themselves in deciding what to read personally and think about others in deciding what to share, the researchers found something else: Whether they were choosing to read for themselves or deciding what to recommend to others, the neural data suggest that people think about both themselves and others.

In fact, the researchers report in an upcoming issue of Psychological Science, that thinking about what to share brought out the highest levels of activity in both of these neural systems.

"When you're thinking about what to read yourself and about what to share, both are inherently social, and when you're thinking socially, you're often thinking about yourself and your relationships to others," says Baek. "Your self-concept and understanding of the social world are intertwined."

A second study, to be published next week in the Proceedings of the National Academy of Sciences (PNAS), shows how these brain signals can be used to predict virality of the same news articles around the world.

When stories go viral through the 4 billion Facebook messages, 500 million tweets and 200 billion emails shared daily, they can have real impact on our health, politics and society. But not all articles are shared equally. Why do some articles get shared while others don't?

By looking at brain activity as 80 test subjects considered sharing the same New York Times health articles, researchers predicted an article's virality among the actual New York Times readership, which shared this group of articles a combined total of 117,611 times.

They found that activity in the self-related and mentalizing regions of the brain combine unconsciously in our minds to produce an overall signal about an article's value. That value signal then predicts whether or not we want to share.

Even though the pool of test subjects -- 18-to-24-year olds, many of them university students, living around Philadelphia -- represented different demographics than the overall New York Times readership, brain activity in key brain regions that track value accurately scaled with the global popularity of the articles.

"If we can use a small number of brains to predict what large numbers of people who read the New York Times are doing, it means that similar things are happening across people," Scholz says. "The fact that the articles strike the same chord in different brains suggests that similar motivations and similar norms may be driving these behaviors. Similar things have value in our broader society."

Scholz acknowledges that exactly how we're thinking about ourselves and others varies from person to person. For example, one person may think that an article will make her friends laugh, while another may think that sharing it will help his friend solve a particular problem. But neural activity in regions associated with the self and with social considerations serves as a type of common denominator for various types of social and self-related thinking.

"In practice, if you craft a message in a way that makes the reader understand how it's going to make them look positive, or how it could enhance a relationship," Scholz says, "then we predict it would increase the likelihood of sharing that message."

Contacts and sources:
Julie Sloane
University of Pennsylvania

"The Value of Sharing Information: A Neural Account of Information Transmission," will be published in an upcoming issue of Psychological Science. In addition to Baek and Scholz, other co-authors include Matthew Brook O'Donnell, Ph.D., and Emily Falk, Ph.D.

"A Neural Model of Valuation and Information Virality" will be published next week in the Proceedings of the National Academy of Sciences (PNAS). In addition to Scholz and Baek, its co-authors include Matthew Brook O'Donnell, Ph.D., Hyun Suk Kim, Ph.D., Joseph N. Cappella, Ph.D., and Emily B. Falk, Ph.D.

Both studies were supported by The Defense Advanced Research Projects Agency (D14AP00048; PI Falk) and NIH (1DP2DA03515601; PI Falk).

Brain Sync: Headband Measures How Our Minds Align When We Communicate

Great ideas so often get lost in translation -- from the math teacher who can't get through to his students, to a stand-up comedian who bombs during an open mic night.

But how can we measure whether our audiences understand what we're trying to convey? And better yet, how can we improve that exchange?

Drexel University biomedical engineers, in collaboration with Princeton University psychologists, are using a wearable brain-imaging device to see just how brains sync up when humans interact. It is one of many applications for this functional near-infrared spectroscopy (or fNIRS) system, which uses light to measure neural activity during real-life situations and can be worn like a headband.  

This is a cartoon image of brain 'coupling' during communication

Drexel University

Published in Scientific Reports on February 27th, 2017, a new study shows that the fNIRS device can successfully measure brain synchronization during conversation. The technology can now be used to study everything from doctor-patient communication, to how people consume cable news.

"Being able to look at how multiple brains interact is an emerging context in social neuroscience," said Hasan Ayaz, PhD, an associate research professor in Drexel's School of Biomedical Engineering, Science and Health Systems, who led the research team. "We live in a social world where everybody is interacting. And we now have a tool that can give us richer information about the brain during everyday tasks -- such as natural communication -- that we could not receive in artificial lab settings or from single brain studies."

The current study is based on previous research from Uri Hasson, PhD, associate professor at Princeton University, who has used functional Magnetic Resonance Imaging (fMRI) to study the brain mechanisms underlying the production and comprehension of language. Hasson has found that a listener's brain activity actually mirrors the speaker's brain when he or she is telling story about a real-life experience. And higher coupling is associated with better understanding.

However, traditional brain imaging methods have certain limitations. In particular, fMRI requires subjects to lie down motionlessly in a noisy scanning environment. With this kind of set-up, it is not possible to simultaneously scan the brains of multiple individuals who are speaking face-to-face.

This is why the Drexel researchers sought to investigate whether the portable fNIRS system could be a more effective approach to probe the brain-to-brain coupling question in natural settings.

For their study, a native English speaker and two native Turkish speakers told an unrehearsed, real-life story in their native language. Their stories were recorded and their brains were scanned using fNIRS. Fifteen English speakers then listened to the recording, in addition to a story that was recorded at a live storytelling event.

The researchers targeted the prefrontal and parietal areas of the brain, which include cognitive and higher order areas that are involved in a person's capacity to discern beliefs, desires and goals of others. They hypothesized that a listener's brain activity would correlate with the speaker's only when listening to a story they understood (the English version). A second objective of the study was to compare the fNIRS results with data from a similar study that had used fMRI, in order to compare the two methods.

They found that when the fNIRS measured the oxygenation and deoxygenation of blood cells in the test subject's brains, the listeners' brain activity matched only with the English speakers. These results also correlated with the previous fMRI study.

This new research supports fNIRS as a viable future tool to study brain-to-brain coupling during social interaction. The system can be used to offer important information about how to better communicate in many different environments, including classrooms, business meetings, political rallies and doctors' offices.

"This would not be feasible with fMRI. There are too many challenges," said Banu Onaral, PhD, the H. H. Sun Professor in the School of Biomedical Engineering, Science and Health Systems. "Now that we know fNIRS is a feasible tool, we are moving into an exciting era when we can know so much more about how the brain works as people engage in everyday tasks."

This study was conducted at the Cognitive Neuroengineering and Quantitative Experimental Research (CONQUER) Collaborative, a multi-disciplinary brain observatory at Drexel University.

Contacts and sources:
Lauren Ingeno
Drexel University

Citation: Measuring speaker–listener neural coupling with functional near infrared spectroscopy
Scientific Reports 7, Article number: 43293 (2017) http://dx.doi.org/10.1038/srep43293

Materials That Emit Rainbows

Mechanochromic luminescent (MCL) materials change their color in response to a change in their environment, like pressure and temperature. To date, most MCL materials only change between two colors, limiting their applications.

The international research team comprising of chemists at Osaka University and physicists at Durham University has developed tricolor-changing MLC materials. Not only that, the developed materials exhibited efficient thermally activated delayed fluorescence (TADF) and allowed high performance organic light-emitting diodes (OLEDs) devices. The findings can be read about in Chemical Science.

Fig.1. Illustrative summary of the developed organic luminescent material

"Most MCL materials generate two colors by switching between a stable state and one metastable state. To realize multi-color MCL, more metastable states are necessary," explain Professors Youhei Takeda and Satoshi Minakata at the Department of Applied Chemistry, Graduate School of Engineering of Osaka University. To create these states, the chemist team led by Takeda and Minakata designed a new molecule by applying a conformationally-switchable phenothiazine (PTZ) as the donor.

Fig.2. Image of the change in luminescence colors of MCL materials

"By making the use of a promising and unique acceptor, dibenzophenazine (DBPHZ), which we previously developed, we made a PTZ-DBPHZ-PTZ triad," said Takeda. "In this structure, the PTZ moiety could take two distinct conformers, which therefore in principle creates in total four metastable states as a whole molecule."

In response to heating, fuming, and grinding, the molecule switched its color between yellow, red and orange. The team found that the three colors derive from different conformers in which each PTZ takes either an equatorial or axial conformation relative to the DBPHZ core.

Fig.3. Comparison of a) the previously reported and b) the developed molecular materials

"For red, both of PTZ units take an equatorial-equatorial conformer, for orange, PTZ had an equatorial-axial conformer, and for yellow, PTZ had an axial-axial conformer."

Most OLEDs devices with high energy conversion efficiencies depend on expensive precious metals. TADF light emitting devices, on the other hand, can achieve equal or better efficiency at much lower cost, which is why they have gained popularity for the design of displays in daily electronics like smart phones.

In collaboration with the physicists team at Durham University, the United Kingdom, led by Dr Data and Professor Monkman, they successfully made highly efficient OLED devices by applying the newly developed MCL-TADF molecule as an emissive material. Incorporating the PTZ-DBPHZ-PTZ triad into a light emitting device resulted in an efficiency three times higher than the theoretical maximum of conventional fluorescent materials.

Takeda says that, "Our molecule could become a basis for efficient light-emitting devices and pressure- and temperature-responsive sensors in the future."

Contacts and sources:

Citation: Thermally activated delayed fluorescent phenothiazine–dibenzo[a,j]phenazine–phenothiazine triads exhibiting tricolor-changing mechanochromic luminescence  Journal: Chemical Science
Authors:Masato Okazaki, Youhei Takeda, Przemyslaw Data, Piotr Pander, Heather Higginbotham, Andrew P. Monkman, and Satoshi Minakata
DOI: 10.1039/C6SC04863C
Funded by: Ministry of Education, Culture, Sports, Science and Technology, Japan, Japan Society for the Promotion of Science, Japan Prize Foundation