Memory activation before exposure reduces life-long fear of spiders

By disrupting the recreation of fear memories, exposure therapy can be made more effective for anxiety disorder patients, suggests a new report.

Many people suffer from anxiety and fears, and a common treatment for these problems is exposure therapy. In a new study published in Current Biology, researchers at Uppsala University have shown how the effect of exposure therapy can be improved by disrupting the recreation of fear-memories in people with arachnophobia.

Studies show that up to 30 per cent of all people suffer an anxiety disorder at some point in their lives. Anxiety leads to great suffering for those affected, but can be treated with exposure therapy, in which the patient is gradually exposed to the object or context that provokes the reactions. If exposure therapy is successful, a new 'safe' memory is formed, which overshadows the old fear memory. But not everyone is helped by this treatment, in part because the learning that takes place during the treatment is not permanent; the memory may return at some point later on after an initially successful exposure. Memory researchers have now demonstrated that the improvement can be made more lasting.

When a person is reminded of something, the memory becomes unstable and is re-saved. If you disrupt the re-saving of the memory, so-called reconsolidation, the creation of the memory can be disrupted and the memory that is saved can be changed. A fear memory could thus be weakened or erased, and this offers hope for improved treatment of anxiety disorders. But until now there has been doubt if this would be possible because older and stronger memories have proven to be difficult to disrupt.

In a study published in the journal Current Biology, researchers from Uppsala University and Karolinska Institutet in Sweden have now for the first time shown that it is possible to use this method to reduce fear in life-long phobias. The researchers exposed individuals with arachnophobia to spider pictures while measuring their brain activity in the amygdala, a part of the brain that is strongly linked to fear.

They found that an activation of the fear memory, consisting of a mini-exposure 10 minutes before a more extensive exposure, led to significantly reduced amygdala activity when the subjects looked at the spider pictures again the following day. Because the memory is made unstable before exposure and re-saved in its weakened form, the fear does not return as easily. The day after exposure, the group that received an initial activation of their spider fear showed reduced amygdala activity in comparison with a control group. Avoidance of spiders also decreased, which could be predicted from the degree of amygdala activation.

'It is striking that such a simple manipulation so clearly affects brain activity and behaviour. A simple modification of existing treatments could possibly improve effects. This would mean more people getting rid of their anxieties after treatment and fewer relapses,' says Johannes Björkstrand, PhD student at the Department of Psychology, Uppsala University.

From Science Daily

More to rainbows than meets the eye

There's more to rainbows than meets the eye.

In-depth review charts the scientific understanding of rainbows and highlights the many practical applications of this fascinating interaction between light, liquid and gas.

There's more to rainbows than meets the eye. Knowledge gained from studying these multicoloured arcs of scattered light can be incredibly useful in ways that may not immediately spring to mind. Rainbow effects can warn of chemical contamination in the atmosphere, help to develop more efficient combustion engines and possibly even provide insight into the mechanics of reinforced concrete.

Writing in European Journal of Physics, Alexander Haußmann of the Institute of Applied Physics at the Technical University of Dresden, Germany, has reviewed the latest developments in the field of rainbow research. His article takes a comprehensive look at natural rainbows and touches on the many practical applications of this fascinating interaction between light, liquid and gas.

Haußmann has been studying rainbows for more than 20 years. His interest began at school where he and his friends would log meteorological data for fun to keep tabs on changes in the weather. Today, weather watching has become more sophisticated with the introduction of techniques such as radar remote sensing, but observing rainbows remains important. As Haußmann points out, these patterns of scattered light can provide considerable clues to the size distribution and shape of raindrops falling during wet weather. If paired with radar data, this information could be used to quantify the amount of rainwater reaching the ground. "If our analysis methods are precise enough, we can turn rainbows into optical remote sensing tools to study the physics of rain," he comments.

Haußmann's review delves deep into the challenges of simulating rainbows as mathematical modeling is an important tool in furthering our understanding of this field. There are some key points that add to the puzzle. "Rain drops are not exactly spherical, but become deformed into slightly flattened 'hamburger bun' shapes due to air drag as they fall through the sky," he explained. "This has a drastic influence on the appearance of rainbows and makes scattering calculations numerically very demanding."

As well as focusing on the science, the article also provides tips for capturing rainbows on camera, which could help to win bragging rights on Instagram and other popular photo-sharing websites. "Rainbows are short-lived and special phenomena such as twinned bows are pretty rare, so it's important to always have your camera to hand," recommends Haußmann. "This can be a smartphone or, in my case, an SLR camera with a fisheye lens to capture the full width of a rainbow in a single frame."

From Science Daily

Unexpected trove of gas discovered around larger stars

Artist impression of a debris disk surrounding a star in the Scorpius-Centaurus Association. ALMA discovered that -- contrary to expectations -- the more massive stars in this region retain considerable stores of carbon monoxide gas. This finding could offer new insights into the timeline for giant planet formation around young stars.

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) surveyed dozens of young stars -- some Sun-like and others approximately double that size -- and discovered that the larger variety have surprisingly rich reservoirs of carbon monoxide gas in their debris disks. In contrast, the lower-mass, Sun-like stars have debris disks that are virtually gas-free.

This finding runs counter to astronomers' expectations, which hold that stronger radiation from larger stars should strip away gas from their debris disks faster than the comparatively mild radiation from smaller stars. It may also offer new insights into the timeline for giant planet formation around young stars.

Debris disks are found around stars that have shed their dusty, gas-filled protoplanetary disks and gone on to form planets, asteroids, comets, and other planetesimals. Around younger stars, however, many of these newly formed objects have yet to settle into stately orbits and routinely collide, producing enough rubble to spawn a "second-generation" disk of debris.

"Previous spectroscopic measurements of debris disks revealed that certain ones had an unexpected chemical signature suggesting they had an overabundance of carbon monoxide gas," said Jesse Lieman-Sifry, lead author on a paper published in Astrophysical Journal. At the time of the observations, Lieman-Sifry was an undergraduate astronomy major at Wesleyan University in Middletown, Connecticut. "This discovery was puzzling since astronomers believe that this gas should be long gone by the time we see evidence of a debris disk," he said.

In search of clues as to why certain stars harbor gas-rich disks, Lieman-Sifry and his team surveyed 24 star systems in the Scorpius-Centaurus Association. This loose stellar agglomeration, which lies a few hundred light-years from Earth, contains hundreds of low- and intermediate-mass stars. For reference, astronomers consider our Sun to be a low-mass star.

The astronomers narrowed their search to stars between five and ten million years old -- old enough to host full-fledged planetary systems and debris disks -- and used ALMA to examine the millimeter-wavelength "glow" from the carbon monoxide in the stars' debris disks.

The team carried out their survey over a total of six nights between December 2013 and December 2014, observing for a mere ten minutes each night. At the time it was conducted, this study constituted the most extensive millimeter-wavelength interferometric survey of stellar debris disks ever achieved.

Armed with an incredibly rich set of observations, the astronomers found the most gas-rich disks ever recorded in a single study. Among their sample of two dozen disks, the researchers spotted three that exhibited strong carbon monoxide emission. Much to their surprise, all three gas-rich disks surrounded stars about twice as massive as the Sun. None of the 16 smaller, Sun-like stars in the sample appeared to have disks with large stores of carbon monoxide.

This finding is counterintuitive because higher-mass stars flood their planetary systems with energetic ultraviolet radiation that should destroy the carbon monoxide gas lingering in their debris disks. This new research reveals, however, that the larger stars are somehow able to either preserve or replenish their carbon monoxide stockpiles.

"We're not sure whether these stars are holding onto reservoirs of gas much longer than expected, or whether there's a sort of 'last gasp' of second-generation gas produced by collisions of comets or evaporation from the icy mantles of dust grains," said Meredith Hughes, an astronomer at Wesleyan University and coauthor of the study.

The existence of this gas may have important implications for planet formation, says Hughes. Carbon monoxide is a major constituent of the atmospheres of giant planets. Its presence in debris disks could mean that other gases, including hydrogen, are present, but perhaps in much lower concentrations. If certain debris disks are able to hold onto appreciable amounts of gas, it might push back astronomers' expected deadline for giant planet formation around young stars, the astronomers speculate.

"Future high-resolution observations of these gas-rich systems may allow astronomers to infer the location of the gas within the disk, which may shed light on the origin of the gas," says co-author Antonio Hales, an astronomer with the Joint ALMA Observatory in Santiago, Chile, and the National Radio Astronomy Observatory in Charlottesville, Virginia. "For instance, if the gas was produced by planetesimal collisions, it should be more highly concentrated in regions of the disk where those impacts occurred. ALMA is the only instrument capable of making these kind of high-resolution images."

Read more at Science Daily

A mammoth undertaking: Can de-extinction be ecologically responsible?

UCSB graduate student Molly Hardesty-Moore and ecologist Douglas McCauley.

Can the woolly mammoth be brought back from the dead? Scientists say it's only a matter of time.

In fact this year, the International Union for Conservation of Nature issued its first official set of guidelines on resurrecting extinct species. What's more, university research labs and non-governmental agencies have projects in motion to bring back extinct species. But is all of this a good idea?

A new paper by UC Santa Barbara researchers explores de-extinction -- the process of resurrecting an extinct species -- as a potential win for conservation and suggests how to make it so.

In an analysis in the journal Functional Ecology, UCSB ecologist Douglas McCauley and colleagues recommend several ways in which the science of de-extinction would have to evolve in order to make it maximally benefit ecological communities and ecosystems.

"The idea of de-extinction raises a fundamental and philosophical question: Are we doing it to create a zoo or recreate nature?" said co-author Benjamin Halpern, director of UCSB's National Center for Ecological Analysis and Synthesis. "Both are reasonable answers, but restoring species to a natural state will be a much, much harder endeavor. We offer guidelines for how to make ecological de-extinction more successful and how to avoid creating 'eco-zombies.' "

Bringing back species useful for conservation requires big-picture thinking. For example, the grassland ecosystem in which the mammoth once lived looks totally different today. For a variety of reasons -- human population expansion among them -- some areas where these creatures once roamed cannot be restored to their former ecology.

"What some are proposing to do with de-extinction will be like manufacturing a part from the engine of a Model T and trying to shove it into a Tesla," said lead author McCauley, an assistant professor in UCSB's Department of Ecology, Evolution and Marine Biology. "You just can't take a part and put it into a brand new system and expect it to work without considering how its ecological context has changed.

"Good conservation is a holistic science that acknowledges the fact that many species interact in complex ways," McCauley added. "The rules in that complex web of life don't stay static but evolve dynamically."

The UCSB team developed three recommendations for restoring ecological function through de-extinction. The first suggests resurrecting recently extinct species rather than those that disappeared thousands of years ago. These creatures may fit more seamlessly into their ecosystems because there has been less time for change to occur. The researchers offer several examples of these "young" extinctions, including the Christmas Island pipistrelle bat, the Réunion giant tortoise and Australia's lesser stick-nest rat.

Secondly, the group advises choosing animals whose ecological jobs are truly irreplaceable. For example, the Christmas Island pipistrelle bat was once the only insect-eating bat in its habitat. Its de-extinction would plug a hole in an ecosystem that nature would otherwise have a hard time filling.

Ditto for the Réunion giant tortoise, which dispersed seeds throughout its Indian Ocean island habitat before being driven extinct by hungry mariners. Those plants still exist, although they are moving closer to extinction without the tortoises to perform their ecological function as seed distributors.

The third guideline, according to co-author Molly Hardesty-Moore, a graduate student in McCauley's lab, is to bring back species that can be restored to functionally meaningful abundance levels. "You need to have enough individuals to perform their function well enough to affect the ecosystem," she said. "One wolf hunting and killing has minimal impact, but hundreds of wolves performing that function will change the ecosystem."

Read more at Science Daily

300 Teeth: Duck-billed dinosaurs would have been dentist’s dream

Tethyshadros insularis, a hadrosaur. Duck-billed dinosaurs (hadrosaurs), who lived in the Cretaceous period between 90 million and 65 million years ago, sported this unique dental system, which had never been fully understood until it was examined at the microscopic level

Imagine how much dental care you'd need if you had 300 or more teeth packed together on each side of your mouth.

Duck-billed dinosaurs (hadrosaurs), who lived in the Cretaceous period between 90 million and 65 million years ago, sported this unique dental system, which had never been fully understood until it was examined at the microscopic level through recent research conducted by Aaron LeBlanc, a University of Toronto Mississauga PhD candidate; his supervisor, Professor Robert Reisz, the University of Toronto Mississauga vice-dean, graduate, and colleagues at the Royal Ontario Museum and the Museum of the Rockies.

Rather than shedding teeth and replacing them with new ones like other reptiles, hadrosaurs' mouths contain several parallel stacks of six or more teeth apiece, forming a "highly dynamic network" of teeth that was used to grind and shear tough plant material. Although hadrosaur teeth appear to be fused in place, LeBlanc and his colleagues show that the newest teeth were constantly pushed towards the chewing surface by a complex set of ligaments. When viewed under the microscope, the columns of teeth are not physically touching and are held together by the sand and mud that can get in between the teeth following the decay of the soft ligaments after the animals died.

"Hadrosaur teeth are actually similar to what we have because our teeth are not solidly attached to our jaws. Like us, hadrosaur teeth would have had some fine-scale mobility as they chewed thanks to this ligament system that suspended the teeth in place," says Reisz.

As they reached the grinding surface, hadrosaur teeth were essentially dead, filled with hard tissue -- unlike humans, whose teeth have an inner core filled with blood vessels and nerves.

"Since the teeth were already dead, they could be ground down to little nubbins," Reisz says.

LeBlanc says this tooth structure -- with its tough grinding surface -- was "well-adapted to break down tough plant material for digestion," through both shearing and grinding. This adaptation may have contributed to the hadrosaurs' longevity and proliferation.

Reisz says that hadrosaurs had "probably the most complex dental system ever made."

"It's very elegant -- not a single brick of teeth working as a solid unit," he says. "It's more like chain mail, providing flexibility as well as strength."

LeBlanc notes that the duck-billed dinosaur has been known for over 150 years and its dental system has long been recognized as unique, but no one had taken a look inside it at the microscopic level previously. He created thin sections of entire dental assemblies from the upper and lower jaws, that he then ground down, polished and examined under a powerful microscope. Working with their museum colleagues, he and Reisz were also able to explore how hadrosaur teeth form in embryos and hatchlings, providing a more complete picture of this unique model of dental evolution and development.

Read more at Science Daily

Etruscan Inscription Reveals Name of Goddess

The name of a powerful goddess of fertility has emerged from a 2,500-year-old inscribed slab, revealing what might be the longest Etruscan inscription on stone.

Written in the puzzling Etruscan language, the stone bears the name of Uni, the supreme goddess of the Etruscan pantheon -- basically the equivalent to the Greek goddess Hera and the Roman Juno.

Weighing about 500 pounds and nearly four feet tall by two feet wide, the sandstone slab, or stele, was discovered some months ago during the final stages of two decades of digging at Poggio Colla, some 22 miles miles north-east of Florence in the Mugello Valley.

It was found embedded in the foundations of a stone temple.

The 6th century B.C. slab is heavily abraded and chipped and contains text, written right to left, of more than 120 characters. It is divided into words by means of three vertically aligned dots.

"Cleaning at a restoration center in Florence has allowed better visibility of the inscribed signs, making it possible to identify a larger sequence of letters and words," Adriano Maggiani, a former professor at the University of Venice and one of the scholars working to decipher the inscription, told Discovery News.

"The presence in the inscription of the name Uni suggests the text has a religious character," he added.

Maggiani also identified the name Tinia, the Etruscan supreme deity, equivalent to ancient Greece's Zeus or Rome's Jupiter.

However, it appears the sanctuary was dedicated only to Uni, Tinia's female consort.

"It is my understanding that the structure of the line that includes both names has bearing on the matter," archaeologist Gregory Warden, professor emeritus at Southern Methodist University, Dallas, and co-director of the Mugello Valley Archaeological Project, told Discovery News.

He stressed that this is a preliminary reading and further research is necessary.

"Etruscan sanctuaries are often dedicated to more than one deity. And we have possible indications that the cult may have changed in nature. As always, you answer one question but raise many more," Warden added.

Indications that Uni was worshipped at the site comes from the location of the stone's discovery.

"The center of worship was an underground fissure that was ritually treated after the destruction of the temple," Warden said.

The ritual included placing a temple block in front of the fissure, along with a gold ring and a textile embroidered with gold.

"Underground cults of this type were often associated with female divinities," Warden said.

The abundance of weaving tools and a stunning deposit of gold jewelry discovered in previous excavations, already implied that the patron divinity was female. Four years ago, a unique scene of a goddess giving birth was found on a small fragment from a ceramic vessel.

It was the earliest scene of childbirth in western European art and again pointed to an Etruscan fertility goddess.

Recognizing beyond doubt the deity to which the sanctuary was dedicated would be a unique discovery as very few Etruscan sanctuaries can be conclusively identified.

Considered one of the most religious cultures of the ancient world, the Etruscans began to flourish around 900 B.C., and dominated much of Italy for five centuries.

Known for their art, agriculture, fine metalworking and commerce, they became absorbed into the Roman empire by 300-100 B.C.

Read more at Discovery News

Arctic gives clues on worst mass extinction of life

After an extreme global warming 252 million years ago, a severe mass extinction of life took place on Earth. A new study in the Arctic has been seeking clues as to what limited return of life to world´s oceans after this event.

Extreme global warming 252 million years ago caused a severe mass extinction of life on Earth. It took life up to 9 million years to recover. New study finds clues in the Arctic as to why this recovery took so long.

96 percent of marine species, and 70 percent of terrestrial life died off in the Permian-Triassic extinction event, as geologists know it. It is also known as The Great Dying Event for obvious reasons.

"The mass extinction was likely triggered by a explosive event of volcanic eruptions in what is now Siberia. These eruptions lasted for a million years and emitted enormous amounts of volatiles, such as carbon dioxide and methane, which made our planet unbearably hot." says Jochen Knies, researcher at Centre for Arctic Gas Hydrate, Environment and Climate at UiT The Arctic University of Tromsø.

Life took an extraordinary amount of time to recover from this extinction, from 5 to 9 million years. Why recovery was so delayed, has remained a mystery.

Clues are in the Arctic

Knies is the co-author of a study in Geology that took to the Arctic to look for clues as to what limited return of life to world´s oceans. The results of the study illustrate potential long-term impacts on marine ecosystems in response to global warming.

"What used to be the northwestern continental margin of the supercontinent Pangaea is now Canadian High Arctic. There we found evidence in geological records for a significant nutrient gap during this period. This means that global oceans were severely poor in nutrients such as nitrogen," says Knies.

This nutrient gap is most likely the result of extremely high ocean surface temperatures in the aftermath of the extinction.

Be cool -- stay alive

Our oceans are not a single body of water. They are comprised of layers and boundaries based on temperature (thermocline) and nutrients (nutricline) among others.

"The high temperatures caused deepening of the thermocline and nutricline in the ocean so that upwelling of nutrients from the bottom to the surface of ocean ceased. With that the marine algae productivity was stalled," according to Knies.

And without algae, which are the base of the food chain, the life in the ocean did not thrive.

Once oceans finally started cooling 6-7 million years after the extinction, nutrient rich waters returned.

"The boundaries that kept the nutrients from reaching the surface were weakened and the ocean waters were mixed. This caused the upwelling of nutrients, resuscitating the oceans, and leading to an explosion of life. The ecosystem voids created by the worst mass extinction in Earth history were finally filled." states Jochen Knies.

Read more at Science Daily

Humans Have Caused Climate Change For 180 Years

Humans have been changing Earth's climate for 180 years, earlier than scientists had previously believed, a new study reports.

The research, published in the journal Nature, involved 25 scientists from Australia, the United States, Europe and Asia, working together as part of the Past Global Changes 2000 Year (PAGES 2K) Consortium. Lead author Nerilie Abram, an associate professor at Australian National University, and colleagues examined detailed climate reconstructions spanning the past 500 years to determine when the current warming trend truly began, and analyzed thousands of years of climate models to confirm its cause.

After poring through climate histories preserved in the likes of corals, cave decorations, tree rings and ice cores, Abram and her team established that the first signals of climate change could be observed as early as the 1830s.

That industrial age is generally considered to have begun in Britain in the mid-to-late 1700s; the development of mass production transformed the country and ultimately the world, but the use of coal to power the steam engines and factories that made it possible released carbon dioxide, a greenhouse gas, levels of which have been increasing in the atmosphere ever since. During ice ages, CO2 levels were around 200 parts per million (ppm), and prior to the Industrial Revolution, they were around 280 ppm; in 2013, CO2 levels surpassed 400 ppm.

Interestingly, the study found that warming's footprints spread gradually across the globe. The Arctic began warming first, and continues to show the greatest extent of warming on the planet. Tropical oceans show signs of climate change at around the same time, followed in short order by Europe, Asia and North America, with sustained warming beginning about 50 years later in Australasia and South America. There are localized variations within such regional changes, however: Sea surface temperature in the eastern tropical Pacific may have undergone sustained warming "markedly later" than other tropical ocean regions.

The authors note that the point at which they say warming began was immediately preceded by some cooling in the tropical oceans and over Northern Hemisphere landmasses, largely caused by increased volcanic activity, such as the 1815 Tambora eruption. However, their reconstructions found that, even after accounting for a recovery from such conditions, the evidence was unambiguous: even the relatively small amount of greenhouse gases that had been released to that point were enough to stimulate warming.

"It was an extraordinary finding," said Abram. "It was one of those moments where science really surprised us. But the results were clear. The climate warming we are witnessing today started about 180 years ago."

From Discovery News

Rare Endangered Primate Spotted in Vietnam

A new group of critically endangered primates has been spotted in Vietnam, raising hopes the rare creatures may not be wiped out in the next decade as scientists had feared.

The Delacour's langur, black and white with a full face of whiskers, is indigenous to Vietnam, but their numbers have dwindled in recent years because of poaching and mining activity in the country's northern forests.

A team of scientists from Fauna and Flora International spotted a group of about 40 of the primates, mostly juveniles and infants, bringing their total population to less than 250.

"It's great news for this particular species because had we not found this new population, they were in grave danger of being wiped out within a decade," spokeswoman for FFI in Vietnam, Akofa Wallace, told AFP Tuesday.

"The fact that they are breeding is brilliant news," she added.

FFI did not say where scientists spotted the langurs, whose habitat is threatened by mining activity in the area, including charcoal production.

They are also targeted by poachers who hunt them for meat, with their bones used for traditional medicine and their pelts for decoration.

The primate was discovered in northern Vietnam in the 1930s by French scientist Jean Theodore Delacour, and are only found in Vietnam.

FFI country director Benjamin Rawson said urgent interventions were needed to protect the species, which numbered about 300 in the early 1990s.

"We continue to work alongside officials and local communities to ensure the Delacour's langur doesn't become this century's first primate extinction," Rawson said in a statement.

Read more at Discovery News

NASA Regains Contact With 'Dead' Solar Mission

NASA has finally re-established contact with a sun-watching probe that was thought to be lost in space after it abruptly went silent in 2014.

A signal from the long-lost spacecraft, called STEREO-B, was detected Sunday evening (Aug. 21) by NASA's Deep Space Network, a collection of space tracking stations that follows the agency's space missions across the solar system and beyond. NASA scientists had kept vigil for STEREO-B, making monthly searches for the probe until it phoned home Sunday at 6:57 p.m. EDT (2257 GMT).

Right now, it's unclear how healthy the spacecraft is after drifting in space for nearly two years. NASA lost contact with it on Oct. 1, 2014, after commanding a reset from Earth. The spacecraft's twin, STEREO-A, is still working normally.

"The STEREO Missions Operations team plans further recovery processes to assess observatory health, re-establish attitude control, and evaluate all subsystems and instruments," NASA officials wrote in a statement.

The STEREO spacecraft twins (their name is short for Solar and Terrestrial Relations Observatory) were launched in October 2006 and were originally supposed to last until 2008. With an extended mission, however, came challenges. For example, the orbits of both STEREO spacecraft went behind the sun in 2015, for three months each.

 STEREO-B was initially lost when NASA was testing a command loss timer, which is a reset triggered during solar conjunction. Conjunction was expected to happen between January and March 2015, when STEREO-B's orbit took it behind the sun, putting it out of contact with Earth.Both STEREO spacecraft have a command loss timer that resets the spacecraft every 72 hours when it is not communicating with Earth. In 2014, controllers deliberately stopped communicating with STEREO-A to test this process, and it worked perfectly after reorienting itself with respect to certain guide stars, and sending a signal to Earth.

With STEREO-B, however, the test did not play out as planned. The hard reset did occur, and STEREO-B sent a weak signal to Earth. But the spacecraft quickly faded into silence.

Only a few packets of data made it to Earth, but from that, the team concluded in December 2015 that the inertial measurement unit (which tells the spacecraft if it is rotating, and how fast) gave incorrect information into STEREO-B's guidance computer. At the time, NASA concluded that this set the spacecraft into a spin that left its solar panels out of sunlight most of the time, making it difficult to recharge the battery.

Read more at Discovery News

Immune breakthrough: Unscratching poison ivy's rash

Stylised image: Urushiol (in green), the 'active ingredient' in poison ivy, entrapped by CD1a molecule (in pink), which mediates the inflammatory response.

We all know that a brush with poison ivy leaves us with an itchy painful rash. Now, Monash University and Harvard researchers have discovered the molecular cause of this irritation. The finding brings us a step closer to designing agents to block this mechanism and sheds light on other serious skin conditions, such as psoriasis.

The international team of scientists have shown, for the first time, a connection between an immune molecule found in the skin and skin sensitisers -- the research was published overnight in Nature Immunology.

Professor Jamie Rossjohn, co-lead author with Dr Florian Winau, Harvard Medical School, confirmed the body's immune molecule, CD1a, plays a crucial role in mediating skin inflammation and irritation after contact with urushiol -- the 'active ingredient' found in plants endemic to Northern America and parts of Europe and Australia.

"A complex set of experiments, coupled with imaging techniques at the Australian Synchrotron revealed the molecular interplay between CD1a and urushiol. This highlights CDIa's role in sudden and uncomfortable skin reactions," Professor Rossjohn says.

Dr Tang Yongqing and Dr Jerome Le Nours say the research team needed a combination of scientific creativity and ingenuity to crack the CD1a-urushiol code.

"For over 35 years we have known CD1a is abundant in the skin," says Dr Le Nours. "Its role in inflammatory skin disorders has been difficult to investigate and until now has been really unclear. Our work, which included imaging the CD1a-urushiol connection, represents clear evidence that CD1a is instrumental in skin-related diseases."

"Our results were strengthened by in vivo and clinical studies at Harvard Medical School, in the United States," Dr Yongqing says.

The studies in Boston also showed that blocking the function of CD1a prevents the triggering of this skin-based allergic reaction, giving the researchers further evidence of just how important CD1a is.

"Future research could lead to the development of new treatments to combat minor skin irritations as well as chronic inflammatory skin diseases like psoriasis, eczema and rosacea," says Dr Yongqing.

"We now have a target to further investigate. Our basic discovery may make a big difference in the future treatment and prevention of inflammatory skin diseases," Dr Le Nours concludes.

Read more at Science Daily

Nanofiber scaffolds demonstrate new features in the behavior of stem and cancer cells

A discovery in the field of biomaterials may open new frontiers in stem and cancer cell manipulation and associated advanced therapy development. Novel scaffolds are shown enabling cells to behave in a different but controlled way in vitro due to the presence of aligned, self-assembled ceramic nanofibers of an ultra-high anisotropy ratio augmented into graphene shells.

"This unique hybrid nano-network allows for an exceptional combination of selective guidance stimuli for stem cell development, variations in immune reactions, and behavior of cancer cells," says Professor Michael Gasik from Aalto University.

These scaffolds, for example, were shown to be able to direct the preferential orientation of human mesenchymal stem cells, similarly to neurogenic lineage, to suppress of major inflammatory factors expression and to immobilize cancer cells.

The selective downregulation of specific inflammatory cytokines may be anticipated as a new tool for understanding the human immune system and ways of treating associated diseases. The effects observed are self-regulated by cells only, without the side effects usually arising from the use of external factors.

New scaffolds may help to control the fate of stem cells, such as development towards axons and neurites formation. This is important, for instance, in the development of Alzheimer's disease therapy. The discovery may also be very useful in developing new cancer tumour models, understanding how cancer develops, and developing new cancer therapies.

From Science Daily

Fossilized rivers suggest warm, wet ancient Mars

Extensive systems of fossilised riverbeds have been discovered on an ancient region of the Martian surface, supporting the idea that the now cold and dry Red Planet had a warm and wet climate about 4 billion years ago, according to UCL-led research.

The study, published in Geology and funded by the Science & Technology Facilities Council and the UK Space Agency, identified over 17,000km of former river channels on a northern plain called Arabia Terra, providing further evidence of water once flowing on Mars.

"Climate models of early Mars predict rain in Arabia Terra and until now there was little geological evidence on the surface to support this theory. This led some to believe that Mars was never warm and wet but was a largely frozen planet, covered in ice-sheets and glaciers. We've now found evidence of extensive river systems in the area which supports the idea that Mars was warm and wet, providing a more favourable environment for life than a cold, dry planet," explained lead author, Joel Davis (UCL Earth Sciences).

Since the 1970s, scientists have identified valleys and channels on Mars which they think were carved out and eroded by rain and surface runoff, just like on Earth. Similar structures had not been seen on Arabia Terra until the team analysed high resolution imagery from NASA's Mars Reconnaissance Orbiter (MRO) spacecraft.

The new study examined images covering an area roughly the size of Brazil at a much higher resolution than was previously possible -- 6 metres per pixel compared to 100 metres per pixel. While a few valleys were identified, the team revealed the existence of many systems of fossilised riverbeds which are visible as inverted channels spread across the Arabia Terra plain.

The inverted channels are similar to those found elsewhere on Mars and Earth. They are made of sand and gravel deposited by a river and when the river becomes dry, the channels are left upstanding as the surrounding material erodes. On Earth, inverted channels often occur in dry, desert environments like Oman, Egypt, or Utah, where erosion rates are low -- in most other environments, the channels are worn away before they can become inverted.

"The networks of inverted channels in Arabia Terra are about 30m high and up to 1-2km wide, so we think they are probably the remains of giant rivers that flowed billions of years ago. Arabia Terra was essentially one massive flood plain bordering the highlands and lowlands of Mars. We think the rivers were active 3.9-3.7 billion years ago, but gradually dried up before being rapidly buried and protected for billions of years, potentially preserving any ancient biological material that might have been present," added Joel Davis.

"These ancient Martian flood plains would be great places to explore to search for evidence of past life. In fact, one of these inverted channels called Aram Dorsum is a candidate landing site for the European Space Agency's ExoMars Rover mission, which will launch in 2020," said Dr Matthew Balme, Senior Lecturer at The Open University and co-author of the study.

The researchers now plan on studying the inverted channels in greater detail, using higher-resolution data from MRO's HiRISE camera.

From Science Daily

'Alien Megastructure' Star Is Still Really Weird

In September 2015, a team led by Yale University astronomer Tabetha Boyajian announced that a star about 1,500 light-years from Earth called KIC 8462852 had dimmed oddly and dramatically several times over the past few years.

These dimming events, which were detected by NASA's planet-hunting Kepler space telescope, were far too substantial to be caused by an orbiting planet, scientists said. (In one case, 22 percent of the star's light was blocked. For comparison, when huge Jupiter crosses the sun's face, the result is a dimming of just 1 percent or so.)

Boyajian and her colleagues suggested that a cloud of fragmented comets or planetary building blocks might be responsible, but other researchers noted that the signal was also consistent with a possible "alien megastructure" — perhaps a giant swarm of energy-collecting solar panels known as a Dyson sphere.

Astronomers around the world soon began studying Tabby's star with a variety of instruments, and reanalyzing old observations of the object, in an attempt to figure out what, exactly, is going on. But they have yet to solve the puzzle.

"I'd say we have no good explanation right now for what's going on with Tabby's star," Jason Wright, an astronomer at Pennsylvania State University, said earlier this month during a talk at the Search for Extraterrestrial Intelligence (SETI) Institute in Mountain View, California. "For now, it's still a mystery."

More Surprises

In fact, that mystery may have deepened over the past 12 months.

For example, in January, Bradley Schaefer, a professor of physics and astronomy at Louisiana State University, determined that, in addition to the weird short-term dimming events, the brightness of Tabby's star had dropped by about 20 percent overall between 1890 and 1989. That pattern is very difficult for known natural phenomena to explain, he said.

Schaefer came to this conclusion after poring over old photographic plates of the night sky that captured Tabby's star. Other researchers suggested that the trend Schaefer saw could have been caused by changes in the instruments used to take those photos over the century-long timespan. However, a new study bolsters Schaefer's interpretation.

In the new work, Benjamin Montet (of the California Institute of Technology and the Harvard-Smithsonian Center for Astrophysics) and Joshua Simon (of the Observatories of the Carnegie Institution of Washington) reanalyzed Kepler observations of Tabby's star from 2009 through 2013. They found that the object dimmed by 3 percent over that span, with a rapid 2-percent brightness dip over one 200-day period.

"Of a sample of 193 nearby comparison stars and 355 stars with similar stellar parameters, 0.6 percent change brightness at a rate as fast as 0.341 percent [per year], and none exhibit either the rapid decline by > 2 percent or the cumulative fading by 3 percent of KIC 8462852," Montet and Simon wrote in the new study, which they uploaded to the online preprint site ArXiv on Aug. 5. "No known or proposed stellar phenomena can fully explain all aspects of the observed light curve."

Schaefer's results, combined with those of Montet and Simon, make the comet hypothesis look less and less likely, Wright said in his SETI talk.

"Why would comets, over a century, make the star dimmer?" he said. "What's going on?"

Alien Megastructure?

The sustained dimming of Tabby's star is still consistent with at least some variants of the "alien megastructure" hypothesis, Wright said.

"Some people have sort of facetiously offered that perhaps this is a Dyson sphere under construction: You're seeing lots of material getting built," he said. "In just 100 years, they've blotted out 20 percent of the starlight. That seems kind of fast to me — but, you know, aliens, right?"

It's also possible that the alien megastructure — if it exists — is fully constructed, and some parts are just denser than others, Wright added.

"That would naturally make the star get brighter and dimmer, as dense parts of the swarm came around," he said. "So if I had to invoke megastructures to explain it, that seems consistent. You've got lots of panels of different shapes, different sizes, and the big ones make big dips and the little ones make little dips, and the whole swarm is sort of like a translucent screen that makes the whole thing dimmer."

But Wright and others have always stressed that the "E.T. did it" scenario is very unlikely, and that a more prosaic explanation will probably rise to the top eventually. And indeed, other recent observations throw some cold water on the alien-megastructure idea — and any other hypothesis that invokes some object or phenomenon near Tabby's star.

Any structure surrounding the star, be it alien-made or naturally occurring, would heat up and give off infrared radiation, Wright said. But he and his colleagues saw no signatures of such "waste heat" in data gathered by NASA'sWide-field Infrared Survey Explorer spacecraft. And another research team — which analyzed observations by the Submillimeter Array telescope and the Submillimeter Common-User Bolometer Array-2 instrument, both of which are in Hawaii — also came up empty.

Whatever is blocking the starlight from Tabby's star is "not surrounding the whole star — it must be along our line of sight," Wright said. "So you can do that if it's in a disk of some kind. And that hopefully will help constrain what the heck is going on."

Wright has a hunch that the answer lies far away from Tabby's star, out in the dark depths of space.

"I think I've all but abandoned circumstellar explanations, and I think now we're going to have to talk about [some] bizarre structure in the interstellar medium, and stuff like that," he said.

Read more at Discovery News

Stellar 'Time Bomb' Proves Cosmic Crime Doesn't Pay

This beautiful Hubble image shows the ghostly remains of a star, which detonated 160,000 light-years away, blasting hot gases through interstellar space. But this explosion wasn't caused by a massive star running out of hydrogen, it was a different type of supernova that started with a thieving white dwarf and ended with a boom.

The stellar remains, called DEM L71, were spied by Hubble's Wide Field Camera 3 in the Large Magellanic Cloud (a satellite galaxy that orbits the Milky Way) and was formed by a type of supernova seeded by a binary star system that consists of a white dwarf and another star.

White dwarfs are the leftover husks of stars that once resembled our sun. Rather than exploding when they reach the ends of their lives, they run out of hydrogen and puff up into spectacular red giants. Once expanded, violent stellar winds strip away their outer layers, creating a planetary nebula. In the center, a dense, tiny star remains that can persist for many billions of years long after its parent star becomes a distant memory. In around 4 billion years time, our own sun will experience this fate.

But things get interesting should a white dwarf be paired up with another star; it will steal the other star's gas, causing the white dwarf to form a new outer layer. As this stellar thievery unfolds, the white dwarf seals its own fate by inadvertently starting the timer on a bomb.

When the gas reaches a certain threshold around the white dwarf, swelling to around one and a half times the size of our sun, it becomes critically unstable and explodes as a special kind of supernova -- a Type 1a. (Aside: Type 1a supernovae are used as cosmic "standard candles" by astronomers to precisely measure cosmic distances as they explode with the same amount of gas, and therefore with the same luminosity, every time.) In the case of DEM L71, we're seeing the aftermath of what happens when the hot debris from the supernova ripped into the cool interstellar gases, creating this beautiful nebulous remnant.

In other words, if you're a greedy white dwarf, crime doesn't pay and, if you steal your neighbor's gas, you'll explode. Also, the binary partners of exploding stars have been found to survive, amazingly. Although the cosmos is often cruel and unforgiving, in this case, justice can be served.

From Discovery News

In the ocean, clever camouflage beats super sight

In a matchup of animal superpowers, a clever form of camouflage might beat super sight -- at least in the ocean.

There's nowhere to hide in the open ocean, far from the shore or the seafloor. But some fish have a clever disappearing trick. The silvery skin of fish like herring, sardines, mackerel and tuna act like mirrors, reflecting their watery surroundings to better blend in. The effect serves as a kind of underwater invisibility cloak that helps them hide in plain sight.

Researchers have long assumed that some animals could see through this silvery disguise, thanks to a superpower of their own: the ability to detect a property of light -- called polarization -- that humans can't see.

Octopuses and squid, shrimp and other crustaceans, and some fish such as trout and salmon all have the gift, called polarization vision.

"It's kind of like wearing polarized sunglasses," said Sonke Johnsen, biology professor at Duke University and the first author on a new study of how well animals see reflective camouflage in the ocean.

The polarization state of light changes when it bounces off a silvery fish's shiny scales. Scientists long presumed that this makes it easier for animals with polarization vision to make silvery fish out against the background, to eat them or avoid them.

But the newly released findings suggest otherwise.

In a study published Aug. 22 in the journal Current Biology, researchers went scuba diving in the waters around Australia's Great Barrier Reef and took hundreds of pictures of silvery fish, including tuna, amberjack, barracuda and queenfish.

The fish were photographed from six to 10 feet away using a custom-built underwater camera with tiny polarizing filters built into the sensor.

The researchers used the images to measure the polarization state and brightness of the light reflected from the fish and the background water. By combining this information with a mathematical model of visual perception, they were able to calculate the maximum distance from which silvery fish can be detected using polarization vision versus a "regular" light cue like brightness.

The fish did reflect a slightly contrasting polarization pattern with respect to the background water, which could theoretically betray their presence, the researchers found.

But surprisingly, the data showed that polarization vision doesn't help animals spot silvery fish from any farther away than they could without this special sensitivity.

"Sighting distance is important, because hunting and avoiding being eaten in the open ocean is about seeing other animals before they see you," Johnsen said. "Once you're seen, you're dead. It's over."

If animals with this superpower aren't better equipped to spot a hungry tuna approaching from afar, then why do so many marine animals have polarization vision, and how do they use it? On land, this "sixth sense" is known to help insects and other animals find food, mates and suitable sites to lay their eggs. But in the ocean, now its function is less clear, Johnsen said.

Read more at Science Daily

New flexible material can make any window 'smart'

This is a darkened electrochromic film on plastic prepared by chemical condensation.

Researchers in the Cockrell School of Engineering at The University of Texas at Austin have invented a new flexible smart window material that, when incorporated into windows, sunroofs, or even curved glass surfaces, will have the ability to control both heat and light from the sun. Their article about the new material will be published in the September issue of Nature Materials.

Delia Milliron, an associate professor in the McKetta Department of Chemical Engineering, and her team's advancement is a new low-temperature process for coating the new smart material on plastic, which makes it easier and cheaper to apply than conventional coatings made directly on the glass itself. The team demonstrated a flexible electrochromic device, which means a small electric charge (about 4 volts) can lighten or darken the material and control the transmission of heat-producing, near-infrared radiation. Such smart windows are aimed at saving on cooling and heating bills for homes and businesses.

The research team is an international collaboration, including scientists at the European Synchrotron Radiation Facility and CNRS in France, and Ikerbasque in Spain. Researchers at UT Austin's College of Natural Sciences provided key theoretical work.

Milliron and her team's low-temperature process generates a material with a unique nanostructure, which doubles the efficiency of the coloration process compared with a coating produced by a conventional high-temperature process. It can switch between clear and tinted more quickly, using less power.

The new electrochromic material, like its high-temperature processed counterpart, has an amorphous structure, meaning the atoms lack any long-range organization as would be found in a crystal. However, the new process yields a unique local arrangement of the atoms in a linear, chain-like structure. Whereas conventional amorphous materials produced at high temperature have a denser three-dimensionally bonded structure, the researchers' new linearly structured material, made of chemically condensed niobium oxide, allows ions to flow in and out more freely. As a result, it is twice as energy efficient as the conventionally processed smart window material.

At the heart of the team's study is their rare insight into the atomic-scale structure of the amorphous materials, whose disordered structures are difficult to characterize. Because there are few techniques for characterizing the atomic-scale structure sufficiently enough to understand properties, it has been difficult to engineer amorphous materials to enhance their performance.

"There's relatively little insight into amorphous materials and how their properties are impacted by local structure," Milliron said. "But, we were able to characterize with enough specificity what the local arrangement of the atoms is, so that it sheds light on the differences in properties in a rational way."

Graeme Henkelman, a co-author on the paper and chemistry professor in UT Austin's College of Natural Sciences, explains that determining the atomic structure for amorphous materials is far more difficult than for crystalline materials, which have an ordered structure. In this case, the researchers were able to use a combination of techniques and measurements to determine an atomic structure that is consistent in both experiment and theory.

"Such collaborative efforts that combine complementary techniques are, in my view, the key to the rational design of new materials," Henkelman said.

Milliron believes the knowledge gained here could inspire deliberate engineering of amorphous materials for other applications such as supercapacitors that store and release electrical energy rapidly and efficiently.

Read more at Science Daily

Europe's oldest known living inhabitant

Adonis, a Bosinan pine, more than 1,075 years old, living in the alpine forests of the Pindos mountains in northern Greece.

A Bosnian pine (Pinus heldreichii) growing in the highlands of northern Greece has been dendrocronologically dated to be more than 1075 years old. This makes it currently the oldest known living tree in Europe. The millenium old pine was discovered by scientists from Stockholm University (Sweden), the University of Mainz (Germany) and the University of Arizona (USA).

"It is quite remarkable that this large, complex and impressive organism has survived so long in such an inhospitable environment, in a land that has been civilized for over 3000 years" says Swedish dendrochronologist, Paul J. Krusic, leader of the expedition that found the tree. It is one of more than a dozen individuals of millennial age, living in a treeline forest high in the Pindos mountains.

"Many years ago I read a thesis about this very interesting forest in Greece. In our research, we try to build long chronologies to construct climate histories, so finding living trees of old age is one of our motivations. To age the tree, we needed to take a core of wood, from the outside to the center. The core is one meter and has 1075 annual rings" says Krusic.

The scientists hope the annual variations of the tree rings from trees like this and those fallen in centuries past, yet still preserved on the ground, will provide an informative history of climatic and environmental conditions, going back thousands of years. Considering where the tree was found, and its venerable age, the scientists have named this individual "Adonis" after the Greek god of beauty and desire.

"I am impressed, in the context of western civilization, all the human history that has surrounded this tree; all the empires, the Byzantine, the Ottoman, all the people living in this region. So many things could have led to its demise. Fortunately, this forest has been basically untouched for over a thousand years" says Krusic.

The millennium old trees were discovered during research expeditions conducted by the Navarino Environmental Observatory (NEO), a cooperation between Stockholm University, the Academy of Athens and TEMES S.A. The observatory studies climate change and its impact on environment and humans in the Mediterranean.

Timeline:

941 -- Adonis is a seedling. The Byzantine Empire is at its peak. From the North, the Vikings reach the Black Sea.

1041 -- Adonis is a 100 years old. In China, a book is published describing gunpowder. A man called Macbeth is crowned King of Scotland.

1191 -- Adonis is 250 years old. The universities of Oxford and Paris are founded. The third crusade battles Saladin in the Holy Land.

1441 -- Adonis is 500 years old. The Ottoman empire conquers Greece. Many Greek scholars flee to the west, influencing the Renaissance. In Sweden, the first parliament is held in Arboga. Johannes Gutenberg is about to test his first printing press.

1691 -- Adonis is 750 years old. Isaac Newton has formulated his Laws on Motion. Ice cream, tea and coffee are introduced in Europe.

1941 -- Adonis is a millennium old. World War II is ravaging the world. Greece is occupied by Nazi Germany, Italy and Bulgaria.

From Science Daily

Tool or weapon? Research throws light on stone artifacts' use as ancient projectiles

One of 55 round stone artifacts analyzed to determine their use as throwing weapons for hunting and defense.

A team of psychologists, kinesiologists and archaeologists at Indiana University and elsewhere are throwing new light on a longstanding archaeological mystery: the purpose of a large number of spherical stone artifacts found at a major archaeological site in South Africa.

IU Bloomington professor Geoffrey Bingham and colleagues in the United Kingdom and United States contend that the stones -- previously thought by some to be used as tools -- served instead as weapons for defense and hunting.

The research, which combines knowledge about how modern humans perceive an object's "throwing affordance" with mathematical analysis and evaluation of these stones as projectiles for throwing, appears in the journal Scientific Reports.

"Our study suggests that the throwing of stones played a key role in the evolution of hunting," said Bingham, a professor in the IU Bloomington College of Arts and Sciences' Department of Psychological and Brain Sciences and an author on the study. "We don't think that throwing is the sole, or even primary, function of these spheroids, but these results show that this function is an option that warrants reconsidering as a potential use for this long-lived, multipurpose tool."

The use of these stones, which date from between 1.8 million and 70,000 years ago, has puzzled archaeologists since they were unearthed at the Cave of Hearths in South Africa's Makapan Valley nearly 30 years ago.

The study's lead author, Andrew Wilson of Beckett Leeds University in England, and co-author, Qin Zhu of the University of Wyoming, were both Ph.D. students in Bingham's lab at IU. The other researchers are archaeologists Lawrence Barham and Ian Stanistreet, both of the University of Liverpool in England. Stanistreet is also affiliated with the Stone Age Institute at IU.

The team's conclusions are based upon a theoretical framework and computational tools developed in the Perception/Action Lab at IU, directed by Bingham, who investigates human coordinated action and perceptual capabilities. This includes judging an object's throwing affordance, which is the selection of the best object in terms of size, weight and shape for throwing at maximum distance, speed and damage.

Using these methods, the researchers used computational models to analyze 55 ball-shaped stone objects from the South African site, finding that 81 percent of the stones were the optimal size, weight and shape for hitting such a target at a 25-meter distance. The stones are about the size of tennis balls but much heavier.

The team also simulated the projectile motions the spheroids would undergo if thrown by an expert, as well as estimated the probability of these projectiles causing damage to a medium-sized prey such as an impala.

Research on biomechanics and perception, particularly vision, shows that the human shoulder joint and perceptual abilities are uniquely specialized for throwing objects aimed at a particular target at a distance of 20 to 30 meters, Bingham said. The stones, which predate thrown spears, likely served as projectile weapons for hunting and defense since they were found to perform best as hunting weapons when thrown overhand, he added.

"Humans are the only animals -- the only primates even -- with that talent," Bingham said. "We can throw something to hit something else -- like a quarterback throwing to the running back all the way down the field. That's how in large measure we survived the ice ages. The available food was largely on hoof, or it was 'mega-fauna,' such as a mammoth. You don't want to get close to them."

Previous research by archaeologists suggested that spherical stones were used as percussive tools for shaping or grinding other materials. Most of the objects analysed in this study had weights that produce optimal levels of damage from throwing, however, rather than simply being as heavy as possible.

"Imagine a human, searching for an object to throw so as to cause the most damage possible to potential prey or a competitor," Wilson said. "This is a perceptual task: the person needs to perceive throwing-relevant properties of objects and be able to discriminate between objects that vary in those properties."

Read more at Science Daily

Chimps Prefer Cooperation to Competition

Cooperation is often hailed as a key trait that separates humans from animals, but researchers said Monday that our closest relative, the chimpanzee, can learn to work as a team.

In fact, chimps prefer cooperation by a ratio of five to one over competition, and find ways to discourage peers from freeloading, said the study in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal.

"Given the ratio of conflict to cooperation is quite similar in humans and chimpanzees, our study shows striking similarities across species and gives another insight into human evolution," said lead author Malini Suchak, who was a graduate student at the Yerkes Research Center in Atlanta, Georgia, at the time of the study.

She is now an assistant professor of animal behavior, ecology and conservation at Canisius College in Buffalo, New York.

Previous studies that found chimps were unlikely to cooperate took place in strictly controlled lab settings.

So researchers at Yerkes National Primate Research Center tried instead to mimic the chimps' natural environment for this study, placing 11 of them in a grassy outdoor area near a rope-like apparatus they could tug to get treats and rewards.

But they had to work together to get the goods, either in groups of two or three.

Chimps were allowed to choose their own partners.

Though they started out primarily competing against each other, they soon figured out that it was more advantageous to help each other.

Across 94 hour-long test sessions, researchers tallied 3,656 successful cooperative acts.

On the flip side, there were more than 600 competitive interactions, when chimps stole -- or tried to steal -- rewards without working to get them, pushed others out of the way or started fights.

Chimps sometimes overcame these forms of competition by "directly protesting against others," said the study.

Or, they refused to work in the presence of a freeloader, a strategy known as "avoidance," and which humans use, too.

Other times, more dominant chimpanzees intervened to fend off the freeloaders, displaying what researchers called third-party punishment -- also a human strategy.

"We gave them the freedom to employ their own enforcement strategies," said Suchak.

"And it turns out, they are really quite good at preventing competition and favoring cooperation."

Read more at Discovery News

Birds Sing to Eggs When Temperature Climbs

Much like parents who talk to a pregnant woman's belly, some birds sing to their eggs before they hatch, and the reason may be to prepare them for a warming world, researchers said Thursday.

The study in the journal Science examined a peculiar habit of zebra finches, which sing to their eggs particularly when the weather is hot -- above 78 Fahrenheit (26 Celsius) -- and the end of their incubation period is near.

Eggs are unaffected by outside temperatures and are kept at steady temperature of 98.6 F when the parents are sitting on them.

What could they be saying? Could it have to do with the temperature outside?

"I would say it translates to: 'it's hot babies, get prepared!'," said lead author Mylene Mariette, in an email to AFP.

"That's what they are effectively telling their embryos."

To see what impact this chirping chatter might have on eggs, Mariette and Katherine Buchanan of Australia's Deakin University recorded the calls and played them for eggs in an incubator.

Some eggs were played regular contact calls from adult zebra finches, while others were exposed to particular calls made by expectant parents, chirping to their eggs before they hatch in warm weather.

Those who heard these so-called hot calls grew slower and emerged smaller when they hatched than the other birds.

This compact size would present a survival advantage, because having a small body makes it easier to cool down in hot climes.

As they tracked these hot-call birds over time, researchers found they had more offspring than the other birds that did not hear the preparatory calls during the hot weather.

Researchers believe that the calls somehow affect the babies' growth, since they are delivered in the last one-third of the incubation period when the hatchlings' temperature and regulation system is starting to develop.

Read more at Discovery News

People Tracked Celestial Events 5,000 Years Ago

Standing Stones of Stenness, a neolithic stone circle on Orkney Mainland.

Ancient "stone circles" in Scotland were constructed in line with the sun's and moon's movements some 5,000 years ago, new research reveals.

Researchers used 2D and 3D technology to test the alignment patterns in the circles of Callanish (on the Isle of Lewis) and Stenness (in Orkney). These stones date back to about 3000 B.C., about 500 years before Stonehenge's famous stone monument was constructed in England. The team also looked at much simpler monuments in Scotland dating to about 1000 B.C.

"Nobody before this has ever statistically determined that a single stone circle was constructed with astronomical phenomena in mind; it was all supposition," Gail Higginbottom, project leader and a visiting research fellow at the University of Adelaide and Australian National University, said in a statement.

"This research is finally proof that the ancient Britons connected the Earth to the sky with their earliest standing stones, and that this practice continued in the same way for 2,000 years," she added.

Researchers found that, for about half the sites, the northern horizon was higher and closer than the southern horizon. This would have made the summer solstice sun, marking the longest day of the year, appear to rise out of the highest peak in the North.

The other half of the sites had a southern horizon that was higher and closer than the northern horizon. In this case, the winter solstice sun (marking the year's shortest day) would have appeared at the highest point to the south, the researchers explained.

"These chosen surroundings would have influenced the way the sun and moon were seen, particularly in the timing of their rising and setting at special times, like when the moon appears at its most northerly position on the horizon, which only happens every 18.6 years," Higginbottom said.

The research was published in the Journal of Archaeological Science: Reports.

From Discovery News