Solar corona is more structured, dynamic than previously thought

The SwRI-led team processed solar coronal images to reveal universal gusts, jets and streams (green) emanating from the Sun, offering a possible explanation for the gusty solar wind found around Earth. The upcoming Parker Solar Probe will fly through this riotous torrent as the first spacecraft ever designed to 'touch' the Sun.

A Southwest Research Institute-led team discovered never-before-detected, fine-grained structures in the Sun's outer atmosphere, or corona. The team imaged this critical region in detail using sophisticated software techniques and longer exposures from the COR-2 camera on board NASA's Solar and Terrestrial Relations Observatory-A (STEREO-A).

The Sun's outer corona is the source of the solar wind, the stream of charged particles that flow outward from the Sun in all directions. Measured near Earth, the magnetic fields embedded within the solar wind are intertwined and complex.

"Previous images showed the outer corona as a smooth structure, but in deep space, the solar wind is turbulent and gusty," said SwRI's Dr. Craig DeForest, a solar physicist and lead author of "The Highly Structured Outer Corona," an article published by Astrophysical Journal July 18, 2018. "Using new techniques to improve image fidelity, we realized that the corona is not smooth, but structured and dynamic. Every structure that we thought we understood turns out to be made of smaller ones, and to be more dynamic than we thought."

To understand the corona, DeForest and his colleagues started with extended exposures of STEREO-A's coronagraph images -- pictures of the Sun's atmosphere produced by a special telescope that blocks out light from the bright solar disk. The coronagraph is sensitive enough to image the corona in great detail, but in practice its measurements are polluted by noise both from the space environment and the instrument itself. The team's key innovation was identifying and separating out that noise, boosting the signal-to-noise ratio and revealing the outer corona in unprecedented detail.

"We couldn't tinker with the instrument itself, so we took a software approach, squeezing out the highest quality data possible by improving the data's signal-to-noise ratio," DeForest said. "We developed new filtering algorithms, designed and tested to delineate the true corona from the noisy measurements."

The algorithms filtered out light and adjusted brightness. But the most challenging obstacle is inherent: blur due to the motion of the solar wind. "This technique adjusted images not just in space, not just in time, but in a moving coordinate system," DeForest said. "That allowed us to correct motion blur not just by the speed of the wind, but by how rapidly features changed in the wind."

With the resulting unprecedented view of the corona, the team made several groundbreaking discoveries. For example, coronal streamers -- magnetic loops that can erupt into coronal mass ejections that send blobs of solar material into space -- are far more structured than previously thought.

"What we found is that there is no such thing as a single streamer," DeForest said. "The streamers themselves are composed of myriad fine strands that, together, average to produce a brighter feature."

Then there's the theoretical Alfvén surface -- a proposed surface, or sheet-like layer where the gradually accelerating solar wind reaches a critical speed. But that's not what DeForest's team observed.

"What we found is that there isn't a clean Alfvén surface," DeForest said. "There's a wide 'no-man's land' or `Alfvén zone' where the solar wind gradually disconnects from the Sun, rather than a single clear boundary."

And the close look at the coronal structure also raised new questions. Techniques used to estimate the speed of the solar wind revealed that the wind suddenly changes its character at a distance of around 10 solar radii, well within the conventional boundary of the corona itself.

"Some interesting physics is happening around there," DeForest said. "We don't know what it is yet, but we do know that it is going to be interesting."

These first observations will provide key insight for NASA's upcoming Parker Solar Probe, the first-ever mission to gather measurements from within the outer solar corona.

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Sahara dust may make you cough, but it's a storm killer

On July 16, 2003, the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite captured this image of a river of Saharan dust streaming out over the Mediterranean Sea and northeastward to Italy.

The bad news: Dust from the Sahara Desert in Africa -- totaling a staggering 2 to 9 trillion pounds worldwide -- has been almost a biblical plague on Texas and much of the Southern United States in recent weeks. The good news: the same dust appears to be a severe storm killer.

Research from a team of scientists led by Texas A&M University has studied Saharan dust and their work is published in the current issue of the Journal of Climate of AMS (American Meteorological Society).

Texas A&M's Bowen Pan, Tim Logan, and Renyi Zhang in the Department of Atmospheric Sciences analyzed recent NASA satellite images and computer models and said the Saharan dust is composed of sand and other mineral particles that are swept up in air currents and pushed over the Atlantic Ocean to the Gulf of Mexico and other nearby regions.

As the dust-laden air moves, it creates a temperature inversion which in turn tends to prevent cloud -- and eventually -- storm formation.

It means fewer storms and even hurricanes are less likely to strike when the dust is present.

"The Saharan dust will reflect and absorb sunlight, therefore reduce the sunlight at the Earth's surface," said Pan.

"If we have more frequent and severe dust storms, it's likely that we have a cooler sea surface temperature and land surface temperature. The storms have less energy supply from the colder surface therefore will be less severe."

The study goes on to show that dust and storm formation don't mix.

"Our results show significant impacts of dust on the radiative budget, hydrological cycle, and large-scale environments relevant to tropical cyclone activity over the Atlantic," said Zhang.

"Dust may decrease the sea surface temperature, leading to suppression of hurricanes. For the dust intrusion over the past few days, it was obvious that dust suppressed cloud formation in our area. Basically, we saw few cumulus clouds over the last few days. Dust particles reduce the radiation at the ground, but heats up in the atmosphere, both leading to more stable atmosphere. Such conditions are unfavorable for cloud formation."

Zhang said that the chances of a hurricane forming tended to be much less and "our results show that dust may reduce the occurrence of hurricanes over the Gulf of Mexico region."

Logan said that recent satellite images clearly show the Saharan dust moving into much of the Gulf of Mexico and southern Texas.

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Lying in a foreign language is easier

Most people don't find it more difficult to lie in a foreign language than in their native tongue. However, things are different when telling the truth: This is clearly more difficult for many people in a foreign language than in their native one. This unexpected conclusion is the result of a study conducted by two psychologists from the University of Würzburg: Kristina Suchotzki, a postdoctoral research fellow at the Department of Psychology I, and Matthias Gamer, Professor of Experimental Clinical Psychology. The two scientists now present their insights in the latest issue of Journal of Experimental Psychology.

Their findings could be important for a lot of processes in which the trustworthiness of certain people must be evaluated -- for example in asylum procedures. In such situations, reports by non-native speakers tend to be perceived as less believable even though they may be truthful. Their discovery also explains another phenomenon, namely that people communicating in a foreign language are generally perceived as less trustworthy even though this may not be justified.

Scarce research on lying in a foreign language

"In our globalized world, more and more communication takes place in a language that is not the native language of some or all communication partners," Kristina Suchotzki describes the background of the study. There are a number of situations in which there are incentives for persons to lie. Imagine, for instance, business negotiations in which one business partner wants to convince the other of the advantage of her product. Or take a police interview in which the murder suspect tries to convince the police of his alibi at the time of the crime.

So far, forensic research has mostly focused on the perceived trustworthiness of people speaking in their native or a non-native language. This research has revealed that observers seem to be more likely to judge statements of native speakers as truthful compared to statements of non-native speakers. "Only little research, however, has investigated whether people do indeed lie less well in a non-native language," the psychologist says.

Two contradicting theories

There are two research theories to predict differences between deception and truth telling in a native compared to a second language: Research from cognitive load theory suggests that lying is more difficult in a foreign language. "Compared to truth telling, lying is a cognitively more demanding task," Kristina Suchotzki explains. Adding a foreign language imposes an additional cognitive challenge which makes lying even more difficult.

Lying is easier in a foreign language: This should be true according to the emotional distance hypothesis. This assumption is based on the fact that lying is associated with more emotions than staying with the truth. Liars have higher stress levels and are more tense. Research from linguistics, psychology, and psychophysiology shows that compared to speaking in a native language, communicating in a second language is less emotionally arousing. "Based on the emotional distance hypothesis, you would hence expect lying in a foreign language to be less arousing emotionally," Suchotzki says. Accordingly, this reduced emotional arousal would facilitate lying.

Experiments and results

To settle this question, the Würzburg psychologists conduced a number of experiments in which up to 50 test persons had to complete specific tasks. They were asked to answer a number of questions -- sometimes truthfully and sometimes deceptively both in their native language and in a foreign language. Some questions were neutral such as "Berlin is/is not in Germany"; other questions were clearly emotional like "Have you ever taken illegal drugs?" or "Would you work as a nude model?." While the test participants answered the questions, the scientists measured their response time, skin conductance and heart rate.

In a nutshell, the results are as follows:

• Usually, it takes longer to answer emotional questions than neutral ones.
• Answers in the foreign language also take longer than their native language counterparts.
• Generally, it takes longer to tell a lie than to tell the truth.
• However, the time differences between deceptive and truthful answers are less pronounced in a second language than in the native language.
• The slight difference does not, however, result from giving a faster deceptive response. Rather in a foreign language, telling the truth takes longer than in one's native tongue.
• Whether neutral or emotional question: The time differences between telling the truth and lying are generally smaller in a foreign language.

The scientists believe that these findings reflect the "antagonistic effects of emotional distance and cognitive load." "Based on the cognitive load hypothesis, one would have expected increased effort for truth telling and lying in a foreign language, with the increased effort being more pronounced for lying," Kristina Suchotzki says. The data suggest that the increased cognitive effort is responsible for the prolongation of the truth response in the foreign language.

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From cradle to grave: Factors that shaped evolution

Planet Earth.

Understanding the many factors that have played into shaping the biodiversity within Earth's ecosystems can be daunting. In a major step to that end, an international team of researchers built a computer simulation that takes into account many of the fundamental factors that drive evolutionary adaptation and extinction.

Their study, published on July 20th in Science, brings us closer to knowing the complex interactions between topography and climate change, and how these factors influence the evolutionary histories and biodiversity of species in natural ecosystems.

The model created by researchers at the University of Connecticut, the Federal University of Goiás in Brazil, and The Open University in the U.K., details biogeographical cradles, museums, and graves. Cradles are areas where new species form; museums, areas where species persist; and graves, areas where extinctions take place.

"We had hoped to be able to model in the simulation the most fundamental processes that shape the geography of life on Earth," says Robert Colwell, emeritus professor of ecology and evolutionary biology at the University of Connecticut, who led the research with Brazilian colleague Thiago F. Rangel, in collaboration with Neil Edwards and Philip Holden in the UK.

To find these answers, the researchers looked to the most climatically and biologically diverse continent on earth, South America, to develop and test their model. As the Andes mountain range began to develop 25 million years ago, it created a varied landscape that would give rise to a rich biodiversity, and the perfect setting to study the ecology and evolution of biodiversity.

"The Andes are the longest mountain range on Earth, and the only trans-tropical one. They sit right beside the Amazon, the planet's largest tropical rainforest and river basin. This is the reason South America has such exuberant biodiversity," says Rangel.

Collaborators at The Open University built a model of the ancient climate of South America. Combining conventional and statistical approaches to climate modeling, the researchers were able to model, for the first time, the changing climate in detail over hundreds of millennia, far longer than would otherwise have been possible. The model spans a time scale of 800,000 years, to the earliest ice-core records, and estimates temperature and precipitation at 500-year intervals during repeated cycles of glaciation and thawing in a period called the late Quaternary climate cycles.

Speciation, or the evolution of new species from ancestral species, is a process made complicated by various factors, such as the changing climate, geographical, and topographical features. These factors can all lead to the splitting or isolation of populations and the establishment of new species. Over time, new species arise, persist, expand to new areas, or go extinct, and the reasons as to why any of those events occur are not always clear.

Through computer simulation, the team was able to estimate the lifetime trajectory of species, starting with origination and ending at one of three points: when the species splits into daughter species, when the species ended in extinction, or the species persisted.

At each time step of the simulation, the geographical range -- the location -- of each species was recorded. The team found that the trajectories were driven by the glacial cycles, leading to episodes of origination and extinction caused by changes in species ranges in the complex topography of the continent, allowing the researchers to map cradles and graves of diversity.

Surprisingly, the model was able to reproduce maps of biodiversity that closely resemble maps of present-day species of birds, mammal, and plants, despite accounting for only the most fundamental of processes and having no specific target pattern of biodiversity, according to Colwell.

"The majority of living species in South America are more ancient than 800,000 years, but our results suggest that even the ancient species have been moved around in the same way as younger species, all contributing the same patterns of species richness," says Colwell.

The researchers think the most likely explanation is the strong influence of changing climate during the glacial cycles, as it interacts with the topography of the landscape. Changes in temperature and precipitation will have profound impact on species ranges, fragmenting, shuffling, and eliminating ranges, regardless of the species' age.

"Our results demonstrate how intimately the evolution of life depends on the changing physical environment," says Neil Edwards of The Open University modeling team.

This model comes at a crucial time, one of unprecedented climate change. While the simulation is based on a different time period, it shows the dynamic power of climate change and the ways it shapes life on Earth.

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Evidence of Salmonella Paratyphi C found for the first time in medieval northern Europe

This is the face reconstruction of the young woman.

Genome research conducted by the University of Warwick suggests that enteric fever, a potentially lethal disease more commonly found in hot countries, was present in medieval Europe.

Salmonella Paratyphi C causes enteric fever, a life-threatening infection, and has been detected in a 800 year old human skeleton discovered in Trondheim, Norway.

Now scientists are speculating that the evolution of enteric fever could be linked to the domestication of pigs across northern Europe.

The research was conducted by a team of international collaborators led by Professor Mark Achtman of the University's Warwick Medical School and their paper Pan-genome Analysis of Ancient and Modern Salmonella enterica Demonstrates Genomic Stability of the Invasive Para C Lineage for Millennia has been published in the journal Current Biology.

He and his team analysed bacterial DNA found in the teeth and bones of the skeleton of a young woman who is believed to have migrated to Trondheim from the northernmost areas of Scandinavia or Northwest Russia by her early teens only to die there around the age of 19-24 years.

They reconstructed a genome of Salmonella Paratyphi C which causes enteric fever in areas of poor sanitation and lack of clean drinking water. Their discovery indicates that the young Norwegian died of this disease and suggests that these bacteria have long caused enteric fever across northern Europe,

Prof Achtman said: "Paratyphi C is very rare today in Europe and North America except for occasional travellers from South and East Asia or Africa, where the disease is more common. This is the first time that any Salmonella have been found in old human remains in Europe, which is surprising because other Salmonella are more common today, including Salmonella causing typhoid fever, called Typhi, and Salmonella causing food poisoning. Earlier this year, Vågene and co-authors described related Paratyphi C from skeletons in Mexico, who died in 1545 CE, and speculated the Paratyphi C entered the Americas together with Europeans."

The new results included comparative analyses of the Paratyphi C genome found in the skeleton against modern Salmonella genome sequences from EnteroBase, an online database developed at the University of Warwick and used internationally. This revealed that Paratyphi C represents the evolutionary descendants of a common ancestor, or clade, within the Para C lineage. The Para C Lineage includes Choleraesuis, which causes septicaemia in pigs and boar and Typhisuis which causes epidemic swine salmonellosis (chronic paratyphoid) in domestic pigs. These different host specificities likely evolved in Europe over the last 4,000 years and coincide with the timing of pig domestication in Europe.

According to historical records, humans have long been afflicted by bacterial infections, yet genomic analyses of living bacterial pathogens routinely estimate a date for the most recent common ancestor of no more than a few centuries. In general, evolutionary trees contain a stem group, which may include lineages that are now rare or extinct, as well as the crown group of living organisms. Historical reconstructions based only on the crown group ignore the older sub-lineages in the stem group and thereby provide an incomplete picture of the older evolutionary history of the pathogen. In contrast, analyses of ancient DNA such as the Paratyphi C genome can shed light on additional millennia of bacterial pathogen evolution that occurred prior to the origin of the crown group.

Professor Achtman added: "Using EnteroBase we were able to define the Para C lineage from 50,000 modern Salmonella enterica genomes and find that over its 3,000 year history only a few genomic changes occurred within the Para C lineage.

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Paralyzed mice with spinal cord injury made to walk again

A cross section of a mouse spinal cord, stained two different ways, showing increased expression of KCC2 in inhibitory neurons. This increased expression correlated with improved motor function, including ankle movement and stepping.

Most people with spinal cord injury are paralyzed from the injury site down, even when the cord isn't completely severed. Why don't the spared portions of the spinal cord keep working? Researchers at Boston Children's Hospital now provide insight into why these nerve pathways remain quiet. They also show that a small-molecule compound, given systemically, can revive these circuits in paralyzed mice, restoring their ability to walk.

The study, led by Zhigang He, PhD, in Boston Children's F.M. Kirby Neurobiology Center, was published online July 19 by the journal Cell.

"For this fairly severe type of spinal cord injury, this is most significant functional recovery we know of," says He. "We saw 80 percent of mice treated with this compound recover their stepping ability."

Waking up dormant spinal circuits

Many animal studies looking to repair spinal cord damage have focused on getting nerve fibers, or axons, to regenerate, or to getting new axons to sprout from healthy ones. While impressive axon regeneration and sprouting have been achieved, by He's lab and others, their impacts on the animals' motor function after a severe injury are less clear. Some studies have tried using neuromodulators such as serotonergic drugs to simulate the spinal circuits, but have gotten only transient, uncontrolled limb movement.

He and colleagues took another approach, inspired by the success of epidural electrical stimulation-based strategies, the only treatment known to be effective in patients with spinal cord injury. This treatment applies a current to the lower portion of the spinal cord; combined with rehabilitation training, it has enabled some patients to regain movement.

"Epidural stimulation seems to affect the excitability of neurons," says He. "However, in these studies, when you turn off the stimulation, the effect is gone. We tried to come up with a pharmacologic approach to mimic the stimulation and better understand how it works."

He, first author Bo Chen and colleagues selected a handful of compounds that are already known to alter the excitability of neurons, and are able to cross the blood-brain barrier. They gave each compound to paralyzed mice in groups of 10 via intraperitoneal injection. All mice had severe spinal cord injury, but with some nerves intact. Each group (plus a control group given placebo) was treated for eight to ten weeks.

Inhibiting inhibition by re-activating KCC2

One compound, called CLP290, had the most potent effect, enabling paralyzed mice to regain stepping ability after four to five weeks of treatment. Electromyography recordings showed that the two relevant groups of hindlimb muscles were active. The animals' walking scores remained higher than the controls' up to two weeks after stopping treatment. Side effects were minimal.

CLP290 is known to activate a protein called KCC2, found in cell membranes, that transports chloride out of neurons. The new research shows that inhibitory neurons in the injured spinal cord are crucial to recovery of motor function. After spinal cord injury, these neurons produce dramatically less KCC2. As a result, He and colleagues found, they can't properly respond to signals from the brain. Unable to process inhibitory signals, they respond only to excitatory signals that tell them to keep firing. And since these neurons' signals are inhibitory, the result is too much inhibitory signaling in the overall spinal circuit. In effect, the brain's commands telling the limbs to move aren't relayed.

By restoring KCC2, with either CLP290 or genetic techniques, the inhibitory neurons can again receive inhibitory signals from the brain, so they fire less. This shifts the overall circuit back toward excitation, the researchers found, making it more responsive to input from the brain. This had the effect of reanimating spinal circuits disabled by the injury.

"Restoring inhibition will allow the whole system to be excited more easily," He explains.

"Too much excitation not good, and too much inhibition is not good either. You really need to get a balance. This hasn't been demonstrated in a rigorous way in spinal cord injury before."

Combination treatment?

He and colleagues are now investigating other compounds that act as KCC2 agonists. They believe such drugs, or perhaps gene therapy to restore KCC2, could be combined with epidural stimulation to maximize a patient's function after spinal cord injury.

"We are very excited by this direction," says He. "We want to test this kind of treatment in a more clinically relevant model of spinal cord injury and better understand how KCC2 agonists work."

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Glowing bacteria on deep-sea fish shed light on evolution, 'third type' of symbiosis

Female deep-sea anglerfish captured in the Gulf of Mexico. A humpback blackdevil, Melanocetus johnsonii (top), and a triplewart seadevil, Cryptopsaras couesii (bottom).

You may recognize the anglerfish from its dramatic appearance in the hit animated film Finding Nemo, as it was very nearly the demise of clownfish Marlin and blue-tang fish Dory. It lives most of its life in total darkness more than 1,000 meters below the ocean surface. Female anglerfish sport a glowing lure on top of their foreheads, basically a pole with a light bulb on its end, where bioluminescent bacteria live. The light-emitting lure attracts both prey and potential mates to the fish.

Despite its recent fame, little is known about anglerfish and their symbiotic relationship with these brilliant bacteria, because the fish are difficult to acquire and study.

For the first time, scientists have sequenced and analyzed the genomes of bacteria that live in anglerfish bulbs. The bacteria were taken from fish specimens collected in the Gulf of Mexico.

The researchers report their findings in a new study, published in the journal mBio. The analysis revealed that the bacteria have lost some of the genes that are needed to live freely in the water. That's because the fish and bacteria developed a tight, mutually beneficial relationship, where the bacteria generate light while the fish supplies nutrients to the microbe.

"What's particularly interesting about this specific example is that we see evidence that this evolution is still underway, even though the fish themselves evolved about 100 million years ago," said Tory Hendry, assistant professor of microbiology at Cornell University and the paper's lead author. "The bacteria are still losing genes, and it's unclear why."

Most of the known symbiotic relationships between organisms and bacteria are between either a host and free-living bacteria that don't evolve to maintain a symbiosis, or a host and intracellular bacteria that live inside the host's cells and undergo huge reductions in their genomes through evolution.

The bacteria inside the bulb in anglerfish represents a third type of symbiosis, where preliminary data suggest these bacteria may move from the anglerfish bulb to the water. "It's a new paradigm in our understanding of symbiosis in general; this is a third type of situation where the bacteria are not actually stuck with their host but they are undergoing evolution," Hendry said.

Genetic sequencing showed that the genomes of these anglerfish bioluminescent bacteria are 50 percent reduced compared with their free-swimming relatives. The bacteria have lost most of the genes associated with making amino acids and breaking down nutrients other than glucose, suggesting the fish may be supplying the bacteria with nutrients and amino acids.

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Expected sea-level rise following Antarctic ice shelves' collapse

Rift propagation along the Larsen C Ice Shelf. This rift, which led to the calving of an iceberg twice the size of Luxembourg last year, raised questions about the future stability of Larsen C Ice Shelf in a warming world.

An international team of scientists has shown how much sea level would rise if Larsen C and George VI, two Antarctic ice shelves at risk of collapse, were to break up. While Larsen C has received much attention due to the break-away of a trillion-tonne iceberg from it last summer, its collapse would contribute only a few millimetres to sea-level rise. The break-up of the smaller George VI Ice Shelf would have a much larger impact. The research is published today in the European Geosciences Union journal The Cryosphere.

Recent, rapid warming in the Antarctic Peninsula is a threat to ice shelves in the region, with Larsen C and George VI considered to have the highest risk of collapse. Because these large ice platforms hold back inland glaciers, the ice carried by these glaciers can flow faster into the sea when the ice shelves collapse, which contributes to sea-level rise. The new study shows that a collapse of Larsen C would result in inland ice discharging about 4 mm to sea level, while the response of glaciers to George VI collapse could contribute over five times more to global sea levels, around 22 mm.

"These numbers, while not enormous in themselves, are only one part of a larger sea-level budget including loss from other glaciers around the world and from the Greenland, East and West Antarctic ice sheets. Taken together with these other sources, the impacts could be significant to island nations and coastal populations," explains study-author Nicholas Barrand, a glaciologist at the University of Birmingham in the UK. He adds: "The Antarctic Peninsula may be seen as a bellwether for changes in the much larger East and West Antarctic ice sheets as climate warming extends south."

Warming in the Antarctic Peninsula led, in 2002, to the dramatic collapse of Larsen B, an ice shelf just north of Larsen C. Unprecedented in its size, almost the entire ice shelf broke up in just over two weeks after being stable for the last 10,000 years.

"Larsen C is the most northerly remaining large ice shelf, therefore subject to the warmest temperatures, and the likeliest candidate for future collapse. George VI is further west and south, in a slightly cooler climate, but is still vulnerable to a warming atmosphere and ocean," says lead-author Clemens Schannwell, who conducted the work while at the University of Birmingham and the British Antarctic Survey.

Last summer, an iceberg twice the size of Luxembourg broke away from Larsen C. But despite the recent attention on this ice shelf, the team found its future collapse would have a modest effect on global sea level. By using computer models to simulate the interactions between the Antarctic Peninsula ice sheet and the ice shelves, the team found that the glacier response to collapse of Larsen C would add up to 2.5 mm to sea level by 2100 and 4.2 mm by 2300.

"The vulnerability to change at George VI Ice Shelf and the possible sea level implications from these changes, are far greater," says Schannwell. Sandwiched between the Antarctic Peninsula and Alexander Island, George VI Ice Shelf is, at 24,000 square kilometres, around half the size of Larsen C. But it would contribute far more to sea-level rise because it is fed by larger glaciers and is very effective at holding back the ice that drains into it from these glaciers. According to the simulations presented in the new The Cryosphere study, adjustment of the glaciers flowing into it following a collapse could contribute up to 8 mm to global sea levels by 2100 and 22 mm by 2300.

"Prior to our work, we didn't know what would happen to the upstream ice in the Antarctic Peninsula if these shelves were to be lost. This could have important implications for the local environment and for global sea levels, information that is essential for climate-change mitigation planning and policy," says Schannwell, who is now at the University of Tübingen in Germany.

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Newly discovered armored dinosaur from Utah reveals intriguing family history

A Natural History Museum of Utah field crew excavate bones from the skeleton of Akainacephalus johnsoni in 2009.

Fossils of a new genus and species of an ankylosaurid dinosaur -- Akainacephalus johnsoni -- have been unearthed in the Kaiparowits Formation of Grand Staircase-Escalante National Monument (GSENM), in Kane County, southern Utah, U.S.A., and are revealing new details about the diversity and evolution of this group of armored dinosaurs. Expected to look like other North American Late Cretaceous ankylosaurid dinosaurs with smooth bony armor on the skull, the new research suggests just the opposite and indicates that the defining features of Akainacephalus, specifically the spiky bony armor covering the skull and snout, align more closely with Asian ankylosaurids, who also have more pronounced spikes covering their skulls.

Akainacephalus was announced today in the open-access scientific journal PeerJ and unveiled on exhibit in the Past Worlds Gallery of the Natural History Museum of Utah at the Rio Tinto Center in Salt Lake City, Utah. The genus name is derived from the Greek words akaina, which means 'thorn' or 'spike', and cephalus, meaning 'head.' The species epithet johnsoni honors Randy Johnson, a dedicated museum volunteer who skillfully prepared its skull. Other talented volunteers helped to prepare the rest of the specimen.

"I'm a retired chemist, but I've always been interested in most of the science disciplines. I never thought that I would have the opportunity to actually work on fossils that could be important for paleontologists," said Randy Johnson. "Now that I'm a museum volunteer, I'm getting the opportunity to work on a large variety of fossils and consult with top paleontologists -- it's like a dream second career. I couldn't believe it when they told me they are naming the ankylosaur after me, a once in a lifetime honor," said Johnson.

Ankylosaurids are a group of four-legged herbivorous armored dinosaurs with imposing bony tail clubs. Though ankylosaurids originated in Asia between 125 -- 100 million years ago, they do not appear in the western North American fossil record until ~77 million years ago. The new species Akainacephalus lived 76 million years ago during the Late Cretaceous Period and offers the most complete skeleton of an ankylosaurid dinosaur found in the southwestern US. It includes a complete skull, much of the vertebral column, including a complete tail club, several fore and hind limbs elements, and bony body armor that includes two neck rings and spiked armor plates.

The unique arrangement of bony armor in the shape of small cones and pyramids covering the snout and head is the key research finding indicating that Akainacephalus is closely related to the New Mexican ankylosaurid Nodocephalosaurus kirtlandensis. Surprisingly, Akainacephalus and Nodocephalosaurus are more closely related to Asian ankylosaurids such as Saichania and Tarchia than to other Late Cretaceous North American ankylosaurids, including Ankylosaurus and Euoplocephalus. Both of the latter taxa possess flat skull armor.

"A reasonable hypothesis would be that ankylosaurids from Utah are related to those found elsewhere in western North America, so we were really surprised to discover that Akainacephalus was so closely related to species from Asia," remarked Randall Irmis, co-author of the study.

Though ankylosaurids originated in Asia between 125 -- 100 million years ago, they do not appear in the North American fossil record until around 77 million years ago. Akainacephalus once roamed the southern part of Laramidia, a landmass on the western coast of a shallow sea that flooded the central region, splitting the continent of North America in two. This caused isolation along western and eastern portions of the North American continent during the Late Cretaceous Period, between 95-70 million years ago.

Lead author Jelle Wiersma suggests that the geographic distribution of Late Cretaceous ankylosaurids throughout the Western Interior was the result of several geologically brief intervals of lowered sea level that allowed Asian ankylosaurid dinosaurs to immigrate to North America several times during the Late Cretaceous, resulting in the presence of two separate groups of ankylosaurid dinosaurs. This lowering of sea levels exposed the Beringian land bridge, allowing dinosaurs and other animals to move between Asia and North America.

"It is always exciting to name a new fossil taxon, but it is equally exciting if that taxon also provides additional insights into the bigger picture of its life, such as its diet or aspects of its behavior, and the environment it lived in," said Wiersma. "Such is exactly the case with Akainacephalus johnsoni; not only is this the first described and named Late Cretaceous ankylosaurid dinosaur from Utah, but this unique animal also strengthens the evidence that distinct northern and southern provincialism existed during the late Campanian stage in Laramidia, because to date, we don't see this type of ankylosaurid dinosaurs in the fossil record of northern Laramidia," he said.

Wiersma explained that additionally, together with its close relative Nodocephalosaurus from New Mexico, Akainacephalus looks very different compared to other North American ankylosaurids such as Ankylosaurus, but instead, look much more like Asian ankylosaurids including Saichania and Tarchia. From these observations we can conclude that at least two immigration events took place during Late Cretaceous times when lowered sea levels exposed the Beringian land bridge, connecting Asia with western North America.

Ankylosaurid dinosaurs, among many other groups of animals, eventually crossed this land bridge, emigrating from Asia into western North America, resulting into two different types of Late Cretaceous ankylosaurid dinosaurs: ones that evolved flatter skull armor like Ankylosaurus and Euoplocephalus, and ones possessing very spiky skull armor such as Akainacephalus and Nodocephalosaurus.

"It is extremely fascinating and important for the science of paleontology that we can read so much information from the fossil record, allowing us to better understand extinct organisms and the ecosystems they were a part of," concluded Wiersma.

These new findings are part of a study funded in large part by the Bureau of Land Management, as well as the Geological Society of America, and a University of Utah Department of Geology & Geophysics Graduate Student Grant. The project was led by University of Utah M.Sc. student Jelle Wiersma, now a Ph.D. student in the Dept. of Geosciences at James Cook University, Queensland, Australia. Wiersma was advised by co-author Dr. Randall Irmis, chief curator and curator of paleontology at the Natural History Museum of Utah, and associate professor in the Dept. of Geology and Geophysics, University of Utah.

Anklysaurid Dinosaurs on the Lost Continent of Southern Laramidia

Akainacephalus johnsoni was discovered in Grand Staircase-Escalante National Monument (GSENM) which encompasses a large area of high desert terrain in south-central Utah. This vast and rugged region, part of the National Landscape Conservation System administered by the Bureau of Land Management (BLM), was the last major area in the lower 48 states to be formally mapped by cartographers.

During the Late Cretaceous, GSENM was in the southern portion of Laramidia, which stretched from the Arctic Circle to the Gulf of Mexico. Akainacephalus is part of a growing number of new dinosaur discoveries over the past 15 years demonstrating the incredible diversity of animals and plants living on Laramidia between 80-75 million years ago. One of the most exciting conclusions from this work is that nearly every species of dinosaur discovered in GSENM is new to science, and Akainacephalus is no exception. Other recently discovered species include large and small meat-eating dinosaurs (e.g., tyrannosaurs), horned dinosaurs, and duck-billed dinosaurs. "A major long-term goal of our work in southern Utah is to try and understand why the species in GSENM differ from relatives of the same geologic age found in other parts of Laramidia," said Wiersma. Hypotheses for the differences include changes in sea level, climate differences across latitude, and physical barriers to animal movement such as mountains and large rivers.

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X-ray data may be first evidence of a star devouring a planet

This artist's illustration depicts the destruction of a young planet, which scientists may have witnessed for the first time.

For nearly a century, astronomers have puzzled over the curious variability of young stars residing in the Taurus-Auriga constellation some 450 light years from Earth. One star in particular has drawn astronomers' attention. Every few decades, the star's light has faded briefly before brightening again.

In recent years, astronomers have observed the star dimming more frequently, and for longer periods, raising the question: What is repeatedly obscuring the star? The answer, astronomers believe, could shed light on some of the chaotic processes that take place early in a star's development.

Now physicists from MIT and elsewhere have observed the star, named RW Aur A, using NASA's Chandra X-Ray Observatory. They've found evidence for what may have caused its most recent dimming event: a collision of two infant planetary bodies, which produced in its aftermath a dense cloud of gas and dust. As this planetary debris fell into the star, it generated a thick veil, temporarily obscuring the star's light.

"Computer simulations have long predicted that planets can fall into a young star, but we have never before observed that," says Hans Moritz Guenther, a research scientist in MIT's Kavli Institute for Astrophysics and Space Research, who led the study. "If our interpretation of the data is correct, this would be the first time that we directly observe a young star devouring a planet or planets."

The star's previous dimming events may have been caused by similar smash-ups, of either two planetary bodies or large remnants of past collisions that met head-on and broke apart again.

"It's speculation, but if you have one collision of two pieces, it's likely that afterward they may be on some rogue orbits, which increases the probability that they will hit something else again," Guenther says.

Guenther is the lead author of a paper detailing the group's results, which appears today in the Astronomical Journal. His co-authors from MIT include David Huenemoerder and David Principe, along with researchers from the Harvard-Smithsonian Center for Astrophysics and collaborators in Germany and Belgium.

A star cover-up

Scientists who study the early development of stars often look to the Taurus-Auriga Dark Clouds, a gathering of molecular clouds in the constellations of Taurus and Auriga, which host stellar nurseries containing thousands of infant stars. Young stars form from the gravitational collapse of gas and dust within these clouds. Very young stars, unlike our comparatively mature sun, are still surrounded by a rotating disk of debris, including gas, dust, and clumps of material ranging in size from small dust grains to pebbles, and possibly to fledgling planets.

"If you look at our solar system, we have planets and not a massive disk around the sun," Guenther says. "These disks last for maybe 5 million to 10 million years, and in Taurus, there are many stars that have already lost their disk, but a few still have them. If you want to know what happens in the end stages of this disk dispersal, Taurus is one of the places to look."

Guenther and his colleagues focus on stars that are young enough to still host disks. He was particularly interested in RW Aur A, which is at the older end of the age range for young stars, as it is estimated to be several million years old. RW Aur A is part of a binary system, meaning that it circles another young star, RW Aur B. Both these stars are about the same mass as the sun.

Since 1937, astronomers have recorded noticeable dips in the brightness of RW Aur A every few decades. Each dimming event appeared to last for about a month. In 2011, the star dimmed again, this time for about half a year. The star eventually brightened, only to fade again in mid-2014. In November 2016, the star returned to its full luminosity.

Astronomers have proposed that this dimming is caused by a passing stream of gas at the outer edge of the star's disk. Still others have theorized that the dimming is due to processes occurring closer to the star's center.

"We wanted to study the material that covers the star up, which is presumably related to the disk in some way," Guenther says. "It's a rare opportunity."

An iron-clad signature

In January 2017, RW Aur A dimmed again, and the team used NASA's Chandra X-Ray Observatory to record X-ray emission from the star.

"The X-rays come from the star, and the spectrum of the X-rays changes as the rays move through the gas in the disk," Guenther says. "We're looking for certain signatures in the X-rays that the gas leaves in the X-ray spectrum."

In total, Chandra recorded 50 kiloseconds, or almost 14 hours of X-ray data from the star. After analyzing these data, the researchers came away with several surprising revelations: the star's disk hosts a large amount of material; the star is much hotter than expected; and the disk contains much more iron than expected -- not as much iron as is found in the Earth, but more than, say, a typical moon in our solar system. (Our own moon, however, has far more iron than the scientists estimated in the star's disk.)

This last point was the most intriguing for the team. Typically, an X-ray spectrum of a star can show various elements, such as oxygen, iron, silicon, and magnesium, and the amount of each element present depends on the temperature within a star's disk.

"Here, we see a lot more iron, at least a factor of 10 times more than before, which is very unusual, because typically stars that are active and hot have less iron than others, whereas this one has more," Guenther says. "Where does all this iron come from?"

The researchers speculate that this excess iron may have come from one of two possible sources. The first is a phenomenon known as a dust pressure trap, in which small grains or particles such as iron can become trapped in "dead zones" of a disk. If the disk's structure changes suddenly, such as when the star's partner star passes close by, the resulting tidal forces can release the trapped particles, creating an excess of iron that can fall into the star.

The second theory is for Guenther the more compelling one. In this scenario, excess iron is created when two planetesimals, or infant planetary bodies, collide, releasing a thick cloud of particles. If one or both planets are made partly of iron, their smash-up could release a large amount of iron into the star's disk and temporarily obscure its light as the material falls into the star.

"There are many processes that happen in young stars, but these two scenarios could possibly make something that looks like what we observed," Guenther says.

He hopes to make more observations of the star in the future, to see whether the amount of iron surrounding the star has changed -- a measure that could help researchers determine the size of the iron's source. For instance, if the same amount of iron appears in, say, a year, that may signal that the iron comes from a relatively massive source, such as a large planetary collision, versus if there is very little iron left in the disk.

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Research on British teeth unlocks potential for new insights into ancient diets

This is a skeleton sampled for the study, dating to the post-medieval period in Britain. The analysis suggests the Victorians were partial to a bowl of porridge, while in modern diets potatoes, soybeans and peanuts are flavour of the day.

Goofy, yellow and crooked: British smiles have sometimes had a less-than-flattering international image, but a new study has put tartar from our infamously bad teeth to good use.

Researchers analysing the teeth of Britons from the Iron Age to the modern day have unlocked the potential for using proteins in tooth tartar to reveal what our ancestors ate.

Dental plaque accumulates on the surface of teeth during life and is mineralised by components of saliva to form tartar or "dental calculus," entombing proteins from the food we eat in the process.

Identifying evidence of many foods, particularly plant crops, in diets of the past is a challenge as they often leave no trace in the archaeological record. But proteins are robust molecules that can survive in tartar for thousands of years.

Archaeological tooth tartar has previously been shown to preserve milk proteins, but the international study, led by researchers at the University of York and the Max Planck Institute for the Science of Human History, has proved for the first time that it can also reveal more precise information about a wider range of food proteins, including those from plants.

The discovery could provide new insights into the diets and lifestyles of our ancestors, adding to the value of dental remains in our understanding of human evolution.

The team plans to use the results of this study to help refine their protein-detection methods, and to explore particular problem areas of ancient diet research.

Senior author, Dr Camilla Speller, from the Department of Archaeology at the University of York, said: "This approach may be particularly useful in the detection of understudied vegetative crops, especially in regions where macrobotantical remains are not preserved.

"It may offer a more precise way of identifying foodstuffs compared to other methods such as ancient DNA and isotope analysis as it can distinguish between different crops and indicate whether people were consuming dairy products, like milk or cheese."

Analysing 100 archaeological samples from across Britain, as well as 14 samples from living dental patients and recently deceased individuals, the research team found that potential dietary proteins could be found in about one third of the analysed samples.

Dr Speller added: "In the teeth we look at from individuals who lived around the Victorian era we identified proteins related to plant foods, including oats, peas and vegetables in the cabbage family. Occasionally, we find evidence of milk and oats in the same mouth -- I like to think it's from eating porridge!"

In the modern samples, the researchers found proteins that reflected a global British diet, such as those related to potatoes, soybeans and peanuts, as well as milk proteins.

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Atlantic circulation is not collapsing -- but as it shifts gears, warming will reaccelerate

These lines show different ways of gauging the strength of the Atlantic overturning circulation. Direct monitoring only began in 2004, so other oceanic measures are needed to extend the dataset back to 1950.

A huge circulation pattern in the Atlantic Ocean took a starring role in the 2004 movie "The Day After Tomorrow." In that fictional tale the global oceanic current suddenly stops and New York City freezes over.

While many aspects of the movie are unrealistic, oceanographers are concerned about the long-term stability of the Atlantic Ocean circulation, and previous studies show that it has slowed dramatically in the past decade. New research from the University of Washington and the Ocean University of China finds the slowdown is not caused by global warming but is part of regular, decades-long cycle that will affect temperatures in coming decades.

The paper was published July 19 in the journal Nature.

"Climate scientists have expected the Atlantic overturning circulation to decline long-term under global warming, but we only have direct measurements of its strength since April 2004. And the decline measured since then is 10 times larger than expected," said corresponding author Ka-Kit Tung, a UW professor of applied mathematics with an adjunct appointment in atmospheric sciences.

"Many have focused on the fact that it's declining very rapidly, and that if the trend continues it will go past a tipping point, bringing a catastrophe such as an ice age. It turns out that none of that is going to happen in the near future. The fast response may instead be part of a natural cycle and there are signs that the decline is already ending."

The results have implications for surface warming. The current's speed determines how much surface heat gets transferred to the deeper ocean, and a quicker circulation would send more heat to the deep Atlantic. If the current slows down, then it will store less heat, and Earth will be likely to see air temperatures rise more quickly than the rate since 2000.

"The global climate models can project what's going to happen long-term if carbon dioxide increases by a certain amount, but they currently lack the capability to predict surface warming in the next few decades, which requires a knowledge of how much the excess heat trapped by greenhouse gases is being absorbed by the oceans," Tung said.

The Atlantic Meridional Overturning Circulation, or AMOC, is a conveyor belt that brings surface water northward in the Atlantic; from there, the heavier salty water sinks and returns at depth from the Labrador and Nordic seas, near the North Pole, all the way south to the Southern Ocean. Most people are interested in what happens at the surface -- the Gulf Stream and associated Atlantic currents carry warmer water north, bringing mild temperatures to Western Europe.

But the new paper argues that the most important step, from a climate perspective, is what happens next. In the North Atlantic, the saltier water from the tropics sinks almost a mile (1,500 meters). As it does, it carries heat down with it away from the surface.

Changes in the strength of the AMOC affect how much heat leaves our atmosphere. The new study uses a combination of data from Argo floats, ship-based temperature measurements, tidal records, satellite images of sea-surface height that can show bulges of warm water, and recent high-tech tracking of the AMOC itself to suggest that its strength fluctuates as part of a roughly 60- to 70-year, self-reinforcing cycle.

When the current is faster, more of the warm, salty tropical water travels to the North Atlantic. Over years this causes more glaciers to melt, and eventually the freshwater makes the surface water lighter and less likely to sink, slowing the current.

When the AMOC is in a slow phase, the North Atlantic becomes cooler, ice melt slows, and eventually the freshwater melt source dries up and the heavier saltier water can plunge down again, which speeds up the whole circulation.

The new study argues that this current is not collapsing, but is just transitioning from its fast phase to its slower phase -- and that this has implications for heating at the surface.

From 1975 to 1998, the AMOC was in a slow phase. As greenhouse gases were accumulating in the atmosphere, Earth experienced distinct warming at the surface. From about 2000 until now, the AMOC has been in its faster phase, and the increased heat plunging in the North Atlantic has been removing excess heat from the Earth's surface and storing it deep in the ocean.

"We have about one cycle of observations at depth, so we do not know if it's periodic, but based on the surface phenomena we think it's very likely that it's periodic," Tung said.

The new paper supports the authors' previous research showing that since 2000, during which observations show a slowdown in surface warming, heat has accumulated deep in the Atlantic Ocean. The new study shows this is the same period when Atlantic overturning circulation was in its fast phase.

Recent measurements of density in the Labrador Sea suggest the cycle is beginning to shift, Tung said. That means that in coming years the AMOC will no longer be sending more of the excess heat trapped by greenhouse gases deep into the North Atlantic.

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Omega 3 supplements have little or no heart or vascular health benefit

Omega 3 fats are readily available as over-the-counter supplements and they are widely bought and used.

New evidence published today shows there is little or no effect of omega 3 supplements on our risk of experiencing heart disease, stroke or death.

Omega 3 is a type of fat. Small amounts of omega 3 fats are essential for good health, and they can be found in the food that we eat. The main types of omega 3 fatty acids are; alphalinolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is normally found in fats from plant foods, such as nuts and seeds (walnuts and rapeseed are rich sources). EPA and DHA, collectively called long chain omega 3 fats, are naturally found in fatty fish, such as salmon and fish oils including cod liver oil.

Increased consumption of omega 3 fats is widely promoted globally because of a common belief that that it will protect against heart disease. There is more than one possible mechanism for how they might help prevent heart disease, including reducing blood pressure or reducing cholesterol. Omega 3 fats are readily available as over-the-counter supplements and they are widely bought and used.

A new Cochrane systematic review, published today in the Cochrane Library, combines the results of seventy-nine randomised trials involving 112,059 people. These studies assessed effects of consuming additional omega 3 fat, compared to usual or lower omega 3, on diseases of the heart and circulation. Twenty-five studies were assessed as highly trustworthy because they were well designed and conducted.

The studies recruited men and women, some healthy and others with existing illnesses from North America, Europe, Australia and Asia. Participants were randomly assigned to increase their omega 3 fats or to maintain their usual intake of fat for at least a year. Most studies investigated the impact of giving a long-chain omega 3 supplement in a capsule form and compared it to a dummy pill. Only a few assessed whole fish intake. Most ALA trials added omega 3 fats to foods such as margarine and gave these enriched foods, or naturally ALA-rich foods such as walnuts, to people in the intervention groups, and usual (non-enriched) foods to other participants.

The Cochrane researchers found that increasing long-chain omega 3 provides little if any benefit on most outcomes that they looked at. They found high certainty evidence that long-chain omega 3 fats had little or no meaningful effect on the risk of death from any cause. The risk of death from any cause was 8.8% in people who had increased their intake of omega 3 fats, compared with 9% in people in the control groups.

They also found that taking more long-chain omega 3 fats (including EPA and DHA), primarily through supplements probably makes little or no difference to risk of cardiovascular events, coronary heart deaths, coronary heart disease events, stroke or heart irregularities. Long-chain omega 3 fats probably did reduce some blood fats, triglycerides and HDL cholesterol. Reducing triglycerides is likely to be protective of heart diseases, but reducing HDL has the opposite effect. The researchers collected information on harms from the studies, but information on bleeding and blood clots was very limited.

The systematic review suggests that eating more ALA through food or supplements probably has little or no effect on cardiovascular deaths or deaths from any cause. However, eating more ALA probably reduces the risk of heart irregularities from 3.3 to 2.6%. The review team found that reductions in cardiovascular events with ALA were so small that about 1000 people would need to increase consumption of ALA for one of them to benefit. Similar results were found for cardiovascular death. They did not find enough data from the studies to be able to measure the risk of bleeding or blood clots from using ALA.

Increasing long-chain omega 3 or ALA probably does not affect body weight or fatness.

Cochrane lead author, Dr. Lee Hooper from the University of East Anglia, UK said: "We can be confident in the findings of this review which go against the popular belief that long-chain omega 3 supplements protect the heart. This large systematic review included information from many thousands of people over long periods. Despite all this information, we don't see protective effects.

"The review provides good evidence that taking long-chain omega 3 (fish oil, EPA or DHA) supplements does not benefit heart health or reduce our risk of stroke or death from any cause. The most trustworthy studies consistently showed little or no effect of long-chain omega 3 fats on cardiovascular health. On the other hand, while oily fish is a healthy food, it is unclear from the small number of trials whether eating more oily fish is protective of our hearts.

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Forty percent of people have a fictional first memory

How much of what we think of as our first memories are actual memories?

Researchers have conducted one of the largest surveys of people's first memories, finding that nearly 40 per cent of people had a first memory which is fictional.

Current research indicates that people's earliest memories date from around three to three-and-a-half years of age. However, the study from researchers at City, University of London, the University of Bradford and Nottingham Trent University found that 38.6 per cent of a survey of 6,641 people claimed to have memories from two or younger, with 893 people claiming memories from one or younger. This was particularly prevalent among middle-aged and older adults.

To investigate people's first memories the researchers asked participants to detail their first memory along with their age at the time. In particular, participants were told that the memory itself had to be one that they were certain they remembered. It should not be based on, for example a family photograph, family story, or any source other than direct experience.

From these descriptions the researchers then examined the content, language, nature and descriptive detail of respondents' earliest memory descriptions, and from these evaluated the likely reasons why people claim memories from an age that research indicates they cannot be formed.

As many of these memories dated before the age of two and younger, the authors suggest that these fictional memories are based on remembered fragments of early experience -- such as a pram, family relationships and feeling sad -- and some facts or knowledge about their own infancy or childhood which may have been derived from photographs or family conversations.

As a result, what a rememberer has in mind when recalling these early memories is a mental representation consisting of remembered fragments of early experience and some facts or knowledge about their own childhood, instead of actual memories.

Over time, such mental representations come to be recollectively experienced when they come to mind and so for the individual they quite simply are 'memories' with content strongly tied to a particular time. In particular, fictional very early memories were seen to be more common in middle-aged and older adults and about 4 in 10 of this group have fictional memories for infancy. The study is published in the journal Psychological Science.

Dr Shazia Akhtar, first author and Senior Research Associate at the University of Bradford said:

"We suggest that what a rememberer has in mind when recalling fictional improbably early memories is an episodic-memory-like mental representation consisting of remembered fragments of early experience and some facts or knowledge about their own infancy/childhood.

"Additionally, further details may be non-consciously inferred or added, e.g. that one was wearing nappy when standing in the cot. Such episodic-memory-like mental representations come, over time, to be recollectively experienced when they come to mind and so for the individual they quite simply are 'memories' which particularly point to infancy."

Professor Martin Conway, Director Centre for Memory and Law at City, University of London and co-author of the paper, said:

"In our study we asked people to recall the very first memory that they actually remembered, asking them to be sure that it wasn't related to a family story or photograph. When we looked through the responses from participants we found that a lot of these first 'memories' were frequently related to infancy, and a typical example would be a memory based around a pram.

"For this person, this type of memory could have resulted from someone saying something like 'mother had a large green pram'. The person then imagines what it would have looked like. Over time these fragments then becomes a memory and often the person will start to add things in such as a string of toys along the top.

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The origins of pottery linked with intensified fishing in the post-glacial period

This is incipient Jōmon pottery from Hanamiyama site, Yokohama-shi, Kanagawa Prefecture, Japan.

A study into some of the earliest known pottery remains has suggested that the rise of ceramic production was closely linked with intensified fishing at the end of the last Ice Age.

Scientists examined 800 pottery vessels in one of the largest studies ever undertaken, focussing mainly on Japan- a country recognised as being one of the earliest centres for ceramic innovation.

A three-year study led by researchers at BioArCh, the University of York, concluded that the ceramic vessels were used by our hunter-gatherer ancestors to store and process fish, initially salmon, but then a wider range including shellfish, freshwater and marine fish and mammals as fishing intensified.

Climate

Scientists say this association with fish remained stable even after the onset of climate warming, including in more southerly areas, where expanding forests provided new opportunities for hunting game and gathering plants.

The research team were able to determine the use of a range of ceramic vessels through chemical analysis of organic food compounds that remained trapped in the pots despite ca. 10,000 years of burial.

The samples analysed are some of the earliest found and date from the end of the Late Pleistocene -- a time when our ancestors were living in glacial conditions -- to the post-glacial period when the climate warmed close to its current temperature and when pottery began to be produced in much greater quantity.

Lipids

The study has shed new light on how prehistoric hunter-gatherers processed and consumed foods over this period -- until now virtually nothing was known of how or for what early pots were used.

As part of the study, researchers recovered diagnostic lipids from the charred surface deposits of the pottery with most of the compounds deriving from the processing of freshwater or marine organisms.

Lead author, Dr Alex Lucquin, from BioArCh, Department of Archaeology, University of York, said: "Thanks to the exceptional preservation of traces of animal fat, we now know that pottery changed from a rare and special object to an every-day tool for preparing fish.

"I think that our study not only reveals the subsistence of the ancient Jōmon people of Japan but also its resilience to a dramatic change in climate.

Collaboration

Professor Oliver Craig, from the Department of Archaeology and Director of the BioArCh research centre at York, who led the study, said: "Our results demonstrate that pottery had a strong association with the processing of fish, irrespective of the ecological setting.

"Contrary to expectations, this association remained stable even after the onset of warming, including in more southerly areas, where expanding forests provided new opportunities for hunting and gathering.

"The results indicate that a broad array of fish was processed in the pottery after the end of the last Ice Age, corresponding to a period when hunter-gatherers began to settle in one place for longer periods and develop more intensive fishing strategies"

"We suggest this marks a significant change in the role of pottery of hunter-gatherers, corresponding massively with increased volume of production, greater variation in forms and sizes and the onset of shellfish exploitation."

Dr Simon Kaner, from the University of East Anglia, who was involved in the study, added: "The research highlights the benefits of this kind of international collaboration for unlocking some of the big questions about the human past, and the potential of engaging with established research networks as created by the Sainsbury Institute over the years."

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Social isolation: Animals that break away from the pack can influence evolution

This photo shows a cane toad. Cane toads (Rhinella marina) at the leading edge of their range expansion in Australia are more cut off from other individuals. Males from these peripheral populations display stronger social attraction than do toads from longstanding populations. Their enhanced social behavior might give them an advantage in conditions of relative social isolation by increasing the chances that they will transfer useful information, be protected against predators, and mate.

For some animals -- such as beetles, ants, toads, and primates -- short-term social isolation can be just as vital as social interaction to development and long-term evolution. In a review published July 17 in the journal Trends in Ecology & Evolution, two evolutionary biologists describe approaches for testing how an animal's isolation might impact natural selection and evolution. This framework can help design more effective breeding, reintroduction, and conservation strategies.

Research on evolution typically focuses on the importance of social interactions, including parent-offspring bonding, competition for resources, and courtship and mating rituals. But Nathan Bailey at the University of St Andrews in Scotland and his colleague Allen Moore at the University of Georgia realized that isolation must then be an extreme condition worthy of equal attention.

"The environment an animal experiences can influence which genes it expresses, when, and how much, so conditions of social isolation might cause expression of different traits," says Bailey. "This in turn could affect responses to natural selection in terms of survival and reproduction, which has evolutionary consequences. For some species, it might even mean that temporary social isolation is favorable."

The invasive cane toad Rhinella marina of Australia, for instance, will venture off on its own to expand into new territory, but the isolation this causes drives an uncharacteristically strong attraction to members of the opposite sex upon the toad's return to a social environment. This boosts the likelihood of both communication and successful mating, which are necessary for survival as the toads expand into new regions. This means that social isolation itself provides the conditions for natural selection to favor adaptations to cope with it.

Likewise, when poisoned, the European ant Temnothorax unifasciatus secludes itself from its kin until death. This eliminates contact with its nestmates, protecting them from the infection, ensuring its relatives' survival, and overall lessening some of the costs associated with social living, such as spreading disease.

"Traits expressed during social interactions might exist because they've been shaped by selection, but at the same time, social interactions themselves represent a type of environment that can select and shape how individuals behave," says Bailey.

This duality of social interaction as both trait and environment merits further study, and Bailey and Moore propose gaining a more complete understanding of social isolation's effects using a measurement termed the "index of social isolation." The index would allow researchers to compare an animal's ideal amount of isolation with how much it is actually experiencing.

To do this, researchers must first measure the optimal balance of interaction and isolation by testing individuals with different levels of each to find the best possible outcome in terms of survival and reproduction. Comparing this ideal to real observations will help determine whether animals are more or less isolated than they should be and ultimately allow for more effective designs for conservation strategies, reintroduction models, and breeding programs.

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Astronomers find a famous exoplanet's doppelganger

The infrared spectra of 2MASS 0249 c (top) and beta Pictoris b (bottom) are similar, as expected for two objects of comparable mass that formed in the same stellar nursery. Unlike 2MASS 0249 c, beta Pictoris b orbits much closer to its massive host star and is embedded in a bright circumstellar disk.

When it comes to extrasolar planets, appearances can be deceiving. Astronomers have imaged a new planet, and it appears nearly identical to one of the best studied gas-giant planets. But this doppelganger differs in one very important way: its origin.

"We have found a gas-giant planet that is a virtual twin of a previously known planet, but it looks like the two objects formed in different ways," said Trent Dupuy, astronomer at the Gemini Observatory and leader of the study.

Emerging from stellar nurseries of gas and dust, stars are born like kittens in a litter, in bunches and inevitably wandering away from their birthplace. These litters comprise stars that vary greatly, ranging from tiny runts incapable of generating their own energy (called brown dwarfs) to massive stars that end their lives with supernova explosions. In the midst of this turmoil, planets form around these new stars. And once the stellar nursery exhausts its gas, the stars (with their planets) leave their birthplace and freely wander the Galaxy. Because of this exodus, astronomers believe there should be planets born at the same time from the same stellar nursery, but are orbiting stars that have moved far away from each other over the eons, like long-lost siblings.

"To date, exoplanets found by direct imaging have basically been individuals, each distinct from the other in their appearance and age. Finding two exoplanets with almost identical appearances and yet having formed so differently opens a new window for understanding these objects," said Michael Liu, astronomer at the University of Hawaii Institute for Astronomy, and a collaborator on this work.

Dupuy, Liu and their collaborators have identified the first case of such a planetary doppelganger. One object has long been known: the 13-Jupiter-mass planet beta Pictoris b, one of the first planets discovered by direct imaging, back in 2009. The new object, dubbed 2MASS 0249 c, has the same mass, brightness, and spectrum as beta Pictoris b.

After discovering this object with the Canada-France-Hawaii Telescope (CFHT), Dupuy and collaborators then determined that 2MASS 0249 c and beta Pictoris b were born in the same stellar nursery. On the surface, this makes the two objects not just look-alikes but genuine siblings.

However, the planets have vastly different living situations, namely the types of stars they orbit. The host for beta Pictoris b is a star 10 times brighter than the Sun, while 2MASS 0249 c orbits a pair of brown dwarfs that are 2000 times fainter than the Sun. Furthermore, beta Pictoris b is relatively close to its host, about 9 astronomical units (AU, the distance from the Earth to the Sun), while 2MASS 0249 c is 2000 AU from its binary host.

These drastically different arrangements suggest that the planets' upbringings were not at all alike. The traditional picture of gas-giant formation, where planets start as small rocky cores around their host star and grow by accumulating gas from the star's disk, likely created beta Pictoris b. In contrast, the host of 2MASS 0249 c did not have enough of a disk to make a gas giant, so the planet likely formed by directly accumulating gas from the original stellar nursery. "2MASS 0249 c and beta Pictoris b show us that nature has more than one way to make very similar looking exoplanets," says Kaitlin Kratter, astronomer at the University of Arizona and a collaborator on this work. "beta Pictoris b probably formed like we think most gas giants do, starting from tiny dust grains. In contrast, 2MASS 0249 c looks like an underweight brown dwarf that formed from the collapse of a gas cloud. They're both considered exoplanets, but 2MASS 0249 c illustrates that such a simple classification can obscure a complicated reality."

The team first identified 2MASS 0249 c using images from CFHT, and their repeated observations revealed this object is orbiting at a large distance from its host. The system belongs to the beta Pictoris moving group, a widely dispersed set of stars named for its famous planet-hosting star. The team's observations at W.M. Keck Observatory determined that the host is actually a closely separated pair of brown dwarfs. So, altogether, the 2MASS 0249 system comprises two brown dwarfs and one gas-giant planet. Follow-up spectroscopy of 2MASS 0249 c with the NASA Infrared Telescope Facility and the Astrophysical Research Consortium 3.5-meter Telescope at Apache Point Observatory demonstrated that it shares a remarkable resemblance to beta Pictoris b.

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A dozen new moons of Jupiter discovered, including one 'oddball'

Various groupings of Jovian moons with the newly discovered ones shown in bold. The 'oddball,' called Valetudo after the Roman god Jupiter's great-granddaughter, has a prograde orbit that crosses the retrograde orbits.

Twelve new moons orbiting Jupiter have been found -- 11 "normal" outer moons, and one that they're calling an "oddball." This brings Jupiter's total number of known moons to a whopping 79 -- the most of any planet in our Solar System.

A team led by Carnegie's Scott S. Sheppard first spotted the moons in the spring of 2017 while they were looking for very distant Solar System objects as part of the hunt for a possible massive planet far beyond Pluto.

In 2014, this same team found the object with the most-distant known orbit in our Solar System and was the first to realize that an unknown massive planet at the fringes of our Solar System, far beyond Pluto, could explain the similarity of the orbits of several small extremely distant objects. This putative planet is now sometimes popularly called Planet X or Planet Nine. University of Hawaii's Dave Tholen and Northern Arizona University's Chad Trujillo are also part of the planet search team.

"Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our Solar System," said Sheppard.

Gareth Williams at the International Astronomical Union's Minor Planet Center used the team's observations to calculate orbits for the newly found moons.

"It takes several observations to confirm an object actually orbits around Jupiter," Williams said. "So, the whole process took a year."

Nine of the new moons are part of a distant outer swarm of moons that orbit it in the retrograde, or opposite direction of Jupiter's spin rotation. These distant retrograde moons are grouped into at least three distinct orbital groupings and are thought to be the remnants of three once-larger parent bodies that broke apart during collisions with asteroids, comets, or other moons. The newly discovered retrograde moons take about two years to orbit Jupiter.

Two of the new discoveries are part of a closer, inner group of moons that orbit in the prograde, or same direction as the planet's rotation. These inner prograde moons all have similar orbital distances and angles of inclinations around Jupiter and so are thought to also be fragments of a larger moon that was broken apart. These two newly discovered moons take a little less than a year to travel around Jupiter.

"Our other discovery is a real oddball and has an orbit like no other known Jovian moon," Sheppard explained. "It's also likely Jupiter's smallest known moon, being less than one kilometer in diameter."

This new "oddball" moon is more distant and more inclined than the prograde group of moons and takes about one and a half years to orbit Jupiter. So, unlike the closer-in prograde group of moons, this new oddball prograde moon has an orbit that crosses the outer retrograde moons.

As a result, head-on collisions are much more likely to occur between the "oddball" prograde and the retrograde moons, which are moving in opposite directions.

"This is an unstable situation," said Sheppard. "Head-on collisions would quickly break apart and grind the objects down to dust."

It's possible the various orbital moon groupings we see today were formed in the distant past through this exact mechanism.

The team think this small "oddball" prograde moon could be the last-remaining remnant of a once-larger prograde-orbiting moon that formed some of the retrograde moon groupings during past head-on collisions. The name Valetudo has been proposed for it, after the Roman god Jupiter's great-granddaughter, the goddess of health and hygiene.

Elucidating the complex influences that shaped a moon's orbital history can teach scientists about our Solar System's early years.

For example, the discovery that the smallest moons in Jupiter's various orbital groups are still abundant suggests the collisions that created them occurred after the era of planet formation, when the Sun was still surrounded by a rotating disk of gas and dust from which the planets were born.

Because of their sizes -- one to three kilometers -- these moons are more influenced by surrounding gas and dust. If these raw materials had still been present when Jupiter's first generation of moons collided to form its current clustered groupings of moons, the drag exerted by any remaining gas and dust on the smaller moons would have been sufficient to cause them to spiral inwards toward Jupiter. Their existence shows that they were likely formed after this gas and dust dissipated.

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Archaeologists discover bread that predates agriculture by 4,000 years

One of the stone structures of the Shubayqa 1 site. The fireplace, where the bread was found, is in the middle.

At an archaeological site in northeastern Jordan, researchers have discovered the charred remains of a flatbread baked by hunter-gatherers 14,400 years ago. It is the oldest direct evidence of bread found to date, predating the advent of agriculture by at least 4,000 years. The findings suggest that bread production based on wild cereals may have encouraged hunter-gatherers to cultivate cereals, and thus contributed to the agricultural revolution in the Neolithic period.

A team of researchers from the University of Copenhagen, University College London and University of Cambridge have analysed charred food remains from a 14,400-year-old Natufian hunter-gatherer site -- a site known as Shubayqa 1 located in the Black Desert in northeastern Jordan. The results, which are published today in the journal Proceedings of the National Academy of Sciences, provide the earliest empirical evidence for the production of bread:

"The presence of hundreds of charred food remains in the fireplaces from Shubayqa 1 is an exceptional find, and it has given us the chance to characterize 14,000-year-old food practices. The 24 remains analysed in this study show that wild ancestors of domesticated cereals such as barley, einkorn, and oat had been ground, sieved and kneaded prior to cooking. The remains are very similar to unleavened flatbreads identified at several Neolithic and Roman sites in Europe and Turkey. So we now know that bread-like products were produced long before the development of farming. The next step is to evaluate if the production and consumption of bread influenced the emergence of plant cultivation and domestication at all," said University of Copenhagen archaeobotanist Amaia Arranz Otaegui, who is the first author of the study.

University of Copenhagen archaeologist Tobias Richter, who led the excavations at Shubayqa 1 in Jordan, explained:

"Natufian hunter-gatherers are of particular interest to us because they lived through a transitional period when people became more sedentary and their diet began to change. Flint sickle blades as well as ground stone tools found at Natufian sites in the Levant have long led archaeologists to suspect that people had begun to exploit plants in a different and perhaps more effective way. But the flat bread found at Shubayqa 1 is the earliest evidence of bread making recovered so far, and it shows that baking was invented before we had plant cultivation. So this evidence confirms some of our ideas. Indeed, it may be that the early and extremely time-consuming production of bread based on wild cereals may have been one of the key driving forces behind the later agricultural revolution where wild cereals were cultivated to provide more convenient sources of food."

Charred remains under the microscope

The charred food remains were analysed with electronic microscopy at a University College London lab by PhD candidate Lara Gonzalez Carratero (UCL Institute of Archaeology), who is an expert on prehistoric bread:

"The identification of 'bread' or other cereal-based products in archaeology is not straightforward. There has been a tendency to simplify classification without really testing it against an identification criteria. We have established a new set of criteria to identify flat bread, dough and porridge like products in the archaeological record. Using Scanning Electron Microscopy we identified the microstructures and particles of each charred food remain," said Gonzalez Carratero.

"Bread involves labour intensive processing which includes dehusking, grinding of cereals and kneading and baking. That it was produced before farming methods suggests it was seen as special, and the desire to make more of this special food probably contributed to the decision to begin to cultivate cereals. All of this relies on new methodological developments that allow us to identify the remains of bread from very small charred fragments using high magnification," said Professor Dorian Fuller (UCL Institute of Archaeology).

Research into prehistoric food practices continues

A grant recently awarded to the University of Copenhagen team will ensure that research into food making during the transition to the Neolithic will continue:

"The Danish Council for Independent Research has recently approved further funding for our work, which will allow us to investigate how people consumed different plants and animals in greater detail. Building on our research into early bread, this will in the future give us a better idea why certain ingredients were favoured over others and were eventually selected for cultivation," said Tobias Richter.

Read more at Science Daily