Expert unlocks mechanics of how snakes move in a straight line

UC biology professor Bruce Jayne holds a vine snake in his lab.

Snakes are known for their iconic S-shaped movements. But they have a less noticeable skill that gives them a unique superpower.

Snakes can crawl in a straight line.

University of Cincinnati biologist Bruce Jayne studied the mechanics of snake movement to understand exactly how they can propel themselves forward like a train through a tunnel.

"It's a very good way to move in confined spaces," Jayne said. "A lot of heavy-bodied snakes use this locomotion: vipers, boa constrictors, anacondas and pythons."

His study titled "Crawling without Wiggling" was published in December in the Journal of Experimental Biology.

Snakes typically swim, climb or crawl by bending their spine into serpentine coils or using the leading edges to push off objects. An extreme example of their diversity of movement gives the sidewinder rattlesnake its name.

Jayne, a professor of biological sciences in UC's McMicken College of Arts & Sciences, already has unlocked the mechanics of three kinds of snake locomotion called concertina, serpentine and sidewinding. But the straightforward movement of snakes, called "rectilinear locomotion," has gotten less attention, he said.

This coordination of muscle activity and skin movement was first examined in 1950 by biologist H.W. Lissmann. He hypothesized that the snake's muscles combined with its loose, flexible and squishy belly skin enabled it to scoot forward without bending its spine.

"It's been almost 70 years without that type of locomotion being well understood," Jayne said.

Jayne and his graduate student and co-author, Steven Newman, tested Lissmann's hypothesis using equipment unavailable to researchers in the 1950s. Jayne used high-definition digital cameras to film boa constrictors while recording the electrical impulses generated by particular muscles. This produced an electromyogram (similar to an EKG) that showed the coordination between the muscles, the snake's skin and its body.

For the study, Newman and Jayne used boa constrictors, big-bodied snakes known for traveling in a straight line over the forest floor. They recorded high-definition video of the snakes moving across a horizontal surface hashed with reference marks. The researchers also added reference dots on the sides of the snakes to track the subtle movement of their scaly skin.

When the snake inches forward, the skin on its belly flexes far more than the skin over its ribcage and back. The belly scales act like treads on a tire, providing traction with the ground as the muscles pull the snake's internal skeleture forward in an undulating pattern that becomes fluid and seamless when they move quickly.

The snake's muscles are sequentially activated from the head toward the tail in a remarkably fluid and seamless way. Two of the key muscles responsible for this extend from the ribs (costo) to the skin (cutaneous) giving them their name costocutaneous.

"The vertebral column moves forward at a constant rate," Newman said. "One set of muscles pulls the skin forward and then it gets anchored in place. And opposite antagonistic muscles pull on the vertebral column."

The advantage of this kind of motion is obvious for a predator that eats rodents and other animals that spend time underground.

"Snakes evolved from burrowing ancestors. You can fit in much narrower holes or tunnels by moving this way than if you had to bend your body and push against something," Newman said.

The study was supported in part by a grant from the National Science Foundation.

Jayne said Lissmann's 1950 description largely was correct.

"But he hypothesized that the muscle that shortens the skin was the mechanism that propels a snake forward. He got that wrong," Jayne said. "But given the time he conducted the study, I marvel at how he was able to do it. I have tremendous admiration for his insights."

Industry has tried to mimic the limbless, serpentine movements of snakes in robots that can inspect pipelines and other underwater equipment. Newman said robots that can harness a snake's rectilinear motion could have profound applications.

"This research could inform robotics. It would be a big advantage to be able to move in straight lines in small, confined spaces. They could use snake-like robots for search-and-rescue in debris and collapsed buildings," Newman said.

Rectilinear locomotion is low gear for snakes that otherwise can summon surprising speed. They only use it when they are relaxed. The researchers observed that snakes reverted to traditional concertina and serpentine motions when they were startled or prodded to move.

An avid cyclist, Jayne has studied the physiology and biomechanics of cycling in a lab in Rieveschl. He has ongoing studies of riders' cardiovascular fitness. He measures their oxygen consumption in one minute per kilogram of body weight to learn more about how cyclists can increase their muscles' ability to burn lactase.

But he has always been most fascinated by snakes. His work has been published in more than 70 journal articles, most of them examining some aspect of snake behavior or biology. Most recently, Jayne has studied snake locomotion, particularly the amazing ability of some to climb trees.

Jayne teaches vertebrate zoology and human physiology and biomechanics at UC.

Jayne's lifelong interest in snakes has given science keen insights into many previously undocumented behaviors. He studied crab-eating snakes in Malaysia and is testing the acuity of snake vision in his own makeshift optical lab at UC.

By testing the limits of its mobility, Jayne can learn more about the snake's complex motor controls. This can shed light on how humans can execute coordinated movements.

"What allows them to go in all these different directions and deal with all of that three-dimensional complexity is they have a diversity or plasticity of neural control of the muscles," Jayne said. "Even if the animal had the physical strength to do something, it wouldn't necessarily have the neural control."

Jayne wants to learn more about how this refined motor control contributes to a snake's amazing contortions.

"They move in so many fascinating ways. Is that because they have such an incredible diversity of motor patterns that the nervous system can generate?" he said.

"Even though all snakes have the same body plan, there are fully aquatic snakes, snakes that move on flat surfaces, snakes that move in a horizontal plane, snakes that climb. They go everywhere," he said. "And the reason they can go everywhere is they have so many different ways of controlling their muscles. That's pretty intriguing."

Read more at Science Daily

Solving Darwin's 'abominable mystery': How flowering plants conquered the world

Flowering plant.

Scientists have found an explanation for how flowering plants became dominant so rapidly in ecosystems across the world -- a problem that Charles Darwin called an 'abominable mystery'. In a study publishing on January 11 in the open access journal PLOS Biology, Kevin Simonin and Adam Roddy, from San Francisco State University and Yale University respectively, found that flowering plants have small cells relative to other major plant groups and that this small cell size is made possible by a greatly reduced genome size.

For more than 200 years, scientists have speculated about the incredible diversity and success of flowering plants, which form the basis of our food system and are responsible for fueling much of the animal diversity we see today.

Over the last thirty years researchers have shown that the flowering plants have unparalleled rates of photosynthesis. This has allowed them to grow faster and to outcompete ferns and conifers which had dominated ecosystems for hundreds of millions of years. The secret to the metabolic success of flowering plants is their specialized leaves that facilitate faster rates of water transport and carbon dioxide uptake. But how were the flowering plants able to build leaves capable of these high rates of transpiration and photosynthesis?

This new research provides a mechanism. By scouring the literature for data, the authors argue that these anatomical innovations are directly linked to the size of their genome.

Because each cell has to contain a copy of the plant's genome, smaller genomes allow cells to be smaller, and if cells are smaller then more cells (such as those specialized for photosynthetic metabolism and water and nutrient transport) can be packed into a given volume of space. Additionally, by shrinking the size of each cell, water and nutrient delivery can be made more efficient.

Comparing hundreds of species, the researchers found that genome downsizing began about 140 million years ago and coincided with the spread of the earliest flowering plants around the world. "The flowering plants are the most important group of plants on earth, and now we finally know why they have been so successful," they say.

Although this research answers a major question, it opens the door to many more. Why were the flowering plants able to shrink their genomes more than other plant groups? What innovations in genome structure and packing have the flowering plants exploited? How have the ferns and conifers managed to elude extinction despite their large genomes and cells?

From Science Daily

Supermassive black hole caught burping — twice

This is an image of galaxy SDSS J1354+1327 (lower center) and its companion galaxy SDSS J1354+1328 (upper right). The inset panel to the right is a four-color image that combines Hubble red, green and blue filtered exposures with Chandra X-ray observations colored purple. The Hubble image shows the northern bubble of hot ionized gas in the vicinity of a supermassive black hole. The black hole appears to have blasted out jets of bright light from gas it’s accreting from thecompanion galaxy. This happened twice in the past 100,000 years. While astronomers have predicted such objects can flicker on and off as a result of gas-feeding events, this is the first time one has convincingly been caught in the act. The galaxy pair is 800 million light-years from Earth.

Astronomers have caught a supermassive black hole in a distant galaxy snacking on gas and then "burping" -- not once, but twice.

The galaxy under study, called SDSS J1354+1327 (J1354 for short), is about 800 million light-years from Earth. The team used observations from NASA's Hubble Space Telescope, the Chandra X-ray Observatory, as well as the W.M. Keck Observatory in Mauna Kea, Hawaii, and the Apache Point Observatory (APO) near Sunspot, New Mexico.

Chandra detected a bright, point-like source of X-ray emission from J1354, a telltale sign of the presence of a supermassive black hole millions or billions of times more massive than our Sun. The X-rays are produced by gas heated to millions of degrees by the enormous gravitational and magnetic forces near the black hole. Some of this gas will fall into the black hole, while a portion will be expelled in a powerful outflow of high-energy particles.

By comparing X-ray images from Chandra and visible-light (optical) images from Hubble, the team determined that the black hole is located in the center of the galaxy, the expected address for such an object. The X-ray data also provide evidence that the supermassive black hole is embedded in a heavy veil of dust and gas.

The results indicate that in the past, the supermassive black hole in J1354 appears to have consumed, or accreted, large amounts of gas while blasting off an outflow of high-energy particles. The outflow eventually switched off then turned back on about 100,000 years later. This is strong evidence that accreting black holes can switch their power output off and on again over timescales that are short compared to the 13.8-billion-year age of the universe.

"We are seeing this object feast, burp, and nap, and then feast and burp once again, which theory had predicted," said Julie Comerford of the University of Colorado (CU) at Boulder's Department of Astrophysical and Space Science, who led the study. "Fortunately, we happened to observe this galaxy at a time when we could clearly see evidence for both events."

So why did the black hole have two separate meals? The answer lies in a companion galaxy that is linked to J1354 by streams of stars and gas produced by a collision between the two galaxies. The team concluded that clumps of material from the companion galaxy swirled toward the center of J1354 and then were eaten by the supermassive black hole.

The team used optical data from Hubble, Keck, and APO to show that electrons had been stripped from atoms in a cone of gas extending some 30,000 light-years south from the galaxy's center. This stripping was likely caused by a burst of radiation from the vicinity of the black hole, indicating that a feasting event had occurred. To the north they found evidence for a shock wave, similar to a sonic boom, located about 3,000 light-years from the black hole. This suggests that a burp occurred after a different clump of gas had been consumed roughly 100,000 years later.

"This galaxy really caught us off guard," said CU Boulder doctoral student Rebecca Nevin, a study co-author who used data from APO to look at the velocities and intensities of light from the gas and stars in J1354. "We were able to show that the gas from the northern part of the galaxy was consistent with an advancing edge of a shock wave, and the gas from the south was consistent with an older outflow from the black hole."

Our Milky Way galaxy's supermassive black hole has had at least one burp. In 2010, another research team discovered a Milky Way belch using observations from the orbiting Fermi Gamma-ray Observatory to look at the galaxy edge on. Astronomers saw gas outflows dubbed "Fermi bubbles" that shine in the gamma-ray, X-ray, and radio wave portion of the electromagnetic spectrum.

Read more at Science Daily

Scarring molecule in fat tissue links obesity with distressed fat

The fat of obese people becomes distressed, scarred and inflamed, which can make weight loss more difficult, research at the University of Exeter has found.

An analysis of the health of adipose (fat) tissue in overweight people found that their fat can cease to cope as it increases in size and becomes suffocated by its own expansion.

Dr Katarina Kos, Senior Lecturer at the University of Exeter's Medical School, examined samples of fat and tissue from patients, including those with weight problems who have undergone bariatric surgery.

Fat in obese people can suffocate and struggle for oxygen supply, due in part to the increase in the fat cells' size. As cells get bigger they become distressed and struggle for oxygen which triggers inflammation in the fat tissue. The inflammation spills over from fat tissue into the blood stream and is eventually measurable in the circulation by a blood test.

Stressed and unhealthy fat tissue is also less able to accommodate more unused dietary energy. With fat tissue not being able to do its most vital job, which is storing excess calories, the excess energy can be increasingly diverted from fat tissue to vital organs, including the liver, muscle and heart. This can lead to obesity-related health complications such as fatty liver disease and cardiovascular disease.

Dr Kos found that fat tissue which is fibrous is also stiffer and more rigid. Previous studies of people who have had weight loss surgery showed that increased levels of scarring can make it harder to lose weight.

"Scarring of fat tissue may make weight loss more difficult," Dr Kos said. "But this does not mean that scarring makes weight loss impossible. Adding some regular activity to a somewhat reduced energy intake for a longer period makes weight loss possible and helps the fat tissue not to become further overworked. We know that doing this improves our blood sugar and is key in the management of diabetes."

Dr Kos, who leads the adipose tissue biology group at the University of Exeter, said where obese people carry their fat can have an impact on their health.

Scarring of fat tissue can change a person's body shape. They can develop an 'apple' body shape with a large tummy and more fat within the deeper layers of the tummy and around the organs. However, they can retain thin arms and legs, as there is little fat just below the skin. Although such people can appear relatively slim, fat can be deposited in their abdomen and in their internal organs, including their liver, pancreas, muscle and the heart. Fat can also be stored around and in the arteries causing arteriosclerosis, a stiffening of arteries predisposing people to high blood pressure, heart disease and strokes. Scarring of fat tissue has also been linked to diabetes.

"One could have very little fat below the skin and still be at risk of diabetes due to a lot of fat within the abdomen and inner organs," Dr Kos said.

Dr Kos, a clinician and specialist in adipose tissue physiology and obesity-related disorders, studied the abdominal fat tissue of obese people which had become fibrous or 'scarred' in order to identify what regulates this scarring and to look at how to reverse it. Scarring makes fat tissue less able to expand and less able to store nutritional energy surplus to its needs.

The research published in the journal Metabolism, examined a molecule called Lysyl oxidase (LOX) which regulates scarring by making tissue stiffer. The study, Lysyl oxidase and adipose tissue dysfunction, found that this molecule is more prevalent in fat tissue of obese people and that it was increased by inflammation and oxygen deprivation.

Dr Kos and her team examined fat tissues from patients who had undergone bariatric surgery and who gave permission for samples of adipose tissue to be examined. She also compared the properties of adipose tissue with leaner subjects who had undergone elective surgical procedures. There was a higher accumulation of the LOX molecule which regulates scarring in obese patients. Those with a higher BMI also tended to have more of the LOX gene expressed in their adipose tissue. She found that low oxygen levels and inflammation were the main drivers of higher LOX levels. The team also found that LOX was not influenced by major weight loss after bariatric surgery.

Read more at Science Daily

Faint galactic glow: Intriguing organic molecule benzonitrile in interstellar space

The aromatic molecule benzonitrile was detected by the GBT in the Taurus Molecular Cloud 1 (TMC-1).

Astronomers using the Green Bank Telescope have made the first definitive interstellar detection of benzonitrile, an intriguing organic molecule that helps to chemically link simple carbon-based molecules and truly massive ones known as polycyclic aromatic hydrocarbons. This discovery is a vital clue in a 30-year-old mystery: identifying the source of a faint infrared glow that permeates the Milky Way and other galaxies.

Astronomers had a mystery on their hands. No matter where they looked, from inside the Milky Way to distant galaxies, they observed a puzzling glow of infrared light. This faint cosmic light, which presents itself as a series of spikes in the infrared spectrum, had no easily identifiable source. It seemed unrelated to any recognizable cosmic feature, like giant interstellar clouds, star-forming regions, or supernova remnants. It was ubiquitous and a bit baffling.

The likely culprit, scientists eventually deduced, was the intrinsic infrared emission from a class of organic molecules known as polycyclic aromatic hydrocarbons (PAHs), which, scientists would later discover, are amazingly plentiful; nearly 10 percent of all the carbon in the universe is tied up in PAHs.

Even though, as a group, PAHs seemed to be the answer to this mystery, none of the hundreds of PAH molecules known to exist had ever been conclusively detected in interstellar space.

New data from the National Science Foundation's Green Bank Telescope (GBT) show, for the first time, the convincing radio fingerprints of a close cousin and chemical precursor to PAHs, the molecule benzonitrile (C?H?CN). This detection may finally provide the "smoking gun" that PAHs are indeed spread throughout interstellar space and account for the mysterious infrared light astronomers had been observing.

The results of this study are presented today at the 231st meeting of the American Astronomical Society (AAS) in Washington, D.C., and published in the journal Science.

The science team, led by chemist Brett McGuire at the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, detected this molecule's telltale radio signature coming from a nearby star-forming nebula known as the Taurus Molecular Cloud 1 (TCM-1), which is about 430 light-years from Earth.

"These new radio observations have given us more insights than infrared observations can provide," said McGuire. "Though we haven't yet observed polycyclic aromatic hydrocarbons directly, we understand their chemistry quite well. We can now follow the chemical breadcrumbs from simple molecules like benzonitrile to these larger PAHs."

Though benzonitrile is one of the simplest so-called aromatic molecules, it is in fact the largest molecule ever seen by radio astronomy. It also is the first 6-atom aromatic ring (a hexagonal array of carbon atoms bristling with hydrogen atoms) molecule ever detected with a radio telescope.

While aromatic rings are commonplace in molecules seen here on Earth (they are found in everything from food to medicine), this is the first such ring molecule ever seen in space with radio astronomy. Its unique structure enabled the scientists to tease out its distinctive radio signature, which is the "gold standard" when confirming the presence of molecules in space.

As molecules tumble in the near vacuum of interstellar space, they give off a distinctive signature, a series of telltale spikes that appear in the radio spectrum. Larger and more complex molecules have a correspondingly more-complex signature, making them harder to detect. PAHs and other aromatic molecules are even more difficult to detect because they typically form with very symmetrical structures.

To produce a clear radio fingerprint, molecules must be somewhat asymmetrical. Molecules with more uniform structures, like many PAHs, can have very weak signatures or no signature at all..

Benzonitrile's lopsided chemical arrangement allowed McGuire and his team to identify nine distinct spikes in the radio spectrum that correspond to the molecule. They also could observe the additional effects of nitrogen atom nuclei on the radio signature.

"The evidence that the GBT allowed us to amass for this detection is incredible," said McGuire. "As we look for yet larger and more interesting molecules, we will need the sensitivity of the GBT, which has unique capabilities as a cosmic molecule detector."

Read more at Science Daily

Earliest Butterfly and Moth Fossils Prove They Are Exceptional Survivors

Assorted moths in the University of Texas Insect Collection

Butterflies and moths appear to be very delicate creatures, and yet they turn out to be much tougher — both in terms of their anatomy and survival skills — than previously imagined.

About 70 sturdy scales from their wings were just identified in a drilled core from northern Germany that dates to 200 million years ago. The ancestors of today's moths and butterflies therefore date to at least the latter part of the Late Triassic (251–199 million years ago).

The findings, published in the journal Science Advances, extend the origin of these insects by 5 million years, since the previous related fossil record-holders — from the United Kingdom — date to 195 million years ago. There is little doubt that dinosaurs and other iconic animals from the time saw the insects fluttering around them, just as many of us do today.

"There is definitely evidence for dinosaurs roaming around the area from outcrops further north in Sweden, which can be considered part of the same region," senior author Bas van de Schootbrugge of Utrecht University told Seeker.

Unlike dinosaurs, moths and butterflies do not have bones that can fossilize and preserve. Their many wing scales, however, are made of chitin, which is the primary component of hard natural materials like crustacean exoskeletons and cephalopod beaks.

"The preservation of these scales does require some exceptional conditions, such as a low oxygen environment and rapid burial," van de Schootbrugge said, adding that the scales that he and his colleagues studied "were deposited in a very shallow lagoon that was oxygen depleted, which contributed to their exceptional preservation."

Examples of the oldest wing and body scales of primitive moths from the Schadelah-1 core photographed with transmitted light

The rest of the insects' bodies would have decomposed and then transported via rivers out to sea, together with plant material. This process would have pulverized and disassociated any larger pieces from each other and "would essentially be similar to putting a butterfly in a blender, although I do not recommend doing this," van de Schootbrugge deadpanned.

The Late Triassic scales come from insects in the order Lepidoptera, which is the second largest order in the class Insecta and includes butterflies, moths, skippers, caterpillars, borers, webworms, cankerworms, and bagworms. Technically, the Triassic scales all came from ancestral moths, since butterflies as we know them today are part of the family Papilionidae, which only emerged during the last 50 million years.

"True butterflies are therefore a relatively young group," lead author Timo van Eldijk, also of the University of Utrecht, told Seeker. "However, these butterflies evolved from moth-like ancestors. So, all butterflies are moths, but only some moths are butterflies."

The clade closest to Lepidoptera is Trichoptera that includes caddisflies. Both orders originated from a common ancestor that must have lived in the Late Triassic, and possibly even earlier. This ancestor did not have a proboscis, which is the elongated tubular, flexible mouthpart present in some moths and butterflies. Van Eldjik explained that the oldest living families of Lepidoptera, such as the Mycropterigidae, still have mandibles.

Conveniently, the more derived families with a proboscis are also distinguished by having hollow scales. Such scales were found within the Late Triassic assemblage, along with other types. Some ancestral moths therefore chewed their food, while others sucked their suppers.

Modern moths and butterflies with a proboscis sink it deep into flowers to sip nectar. This would have been impossible 200 million years ago, though, since flowers had not even evolved yet. The first known flowers in the fossil record date to about 140 million years ago.

Scanning electron microscope image of the dense covering of scales on the wings and body of a Glossatan (proboscis-bearing) moth

The researchers think that the Triassic ancestral moths were sipping pollination droplets secreted by gymnosperms, which were prevalent and actually pre-date the origin of Levidoptera.

"We hypothesize that feeding on pollination droplets was one of the key drivers behind the evolution of the proboscis," van de Schootbrugge said.

He added that, given the diverse pollen and spore specimens found with the insect remains, there were extensive forests of large trees with an understory of ferns and related plants at the northern German site, which is near Braunschweig. In a clay pit, not far from where the core was drilled, they found the remains of many insects, such as beetles.

"So, it was an extensive coastal area covered in thick vegetation with many organisms, much like what you would expect from a coastal forest in, for example, the Mississippi delta," van de Schootbrugge said.

He and his team suspect that the Triassic ancestral moths probably varied in size, similar to today's moths and butterflies. They said that it is currently not possible to speculate on their coloring or if there were any differences between the sexes.

They do know, however, that these winged insects went through egg, caterpillar, pupa, and adult stages, just as moths and butterflies do today. This life cycle, called "complete metamorphosis," evolved much earlier than the Late Triassic and occurs in other insects, such as flies, beetles, and wasps.

The scientists observe that Lepidoptera survived many mass extinction events. The Late Triassic was itself a time of global mass extinction. This was followed by the K/T extinction event about 66 million years ago, during which non-avian dinosaurs and many species went extinct. At least some of the ancestors of moths and butterflies survived that event.

"So, they seem hardier than what you might think at first," van de Schootbrugge said. "Now, climate change might not affect insects that much, as they can adapt rapidly. They are the most successful group of organisms on land right now, and climate change might allow them to explore high-latitude regions, increasing their geographical spread."

Read more at Seeker

Humans Achieved Old Age Prior to Modern Medicine

Information on human longevity in the historical record represents two extremes. On the one hand, there are the extreme claims in religion and myths: Methuselah in the Hebrew Bible supposedly lived to be 969 years old, early Christians indicated that Saint Servatius was 375, and a tombstone in the United Kingdom claims that a man named William Edwards died at age 168.

On the other extreme, there is the long-standing belief that people who lived in ancient times — before the advent of modern medicine and other conveniences — hardly ever reached advanced ages. As English philosopher Thomas Hobbes (1588–1679) wrote, "the life of man" is "solitary, poor, nasty, brutish, and short."

The truth lies somewhere in between, at least for Anglo-Saxons who died during the period from 475 and 625 AD. A new study on their burials, published in the Journal of Anthropological Archaeology, found that some men and women then lived over the age of 75, with women overall tending to live longer than men.

"To be sure, the advent of modern medicine, and a range of social developments, has led to the greater proportion of humanity living to old age," co-author Marc Oxenham of the Australian National University's School of Archaeology and Anthropology told Seeker.

"However," he added, "it is clear that thousands of years ago, humans were also living well into their 80s and 90s; just not a particularly high proportion of their communities managed that."

He and co-author Christine Cave looked at Anglo-Saxon burials in the UK cemeteries Greater Chesterford in Essex, Mill Hill in Kent, and Worthy Park in Hampshire.

The majority of adult age-at-death estimation techniques rely on the observation that as people age, parts of the body degenerate in a more or less predictable way. This approach only works up to about the age of 50 years, however, after which degeneration of the teeth and skeleton becomes highly variable.

"What this means is that we cannot accurately estimate the age-at-death of any individual skeleton after they reach an age of around 50 years, thus rendering the elderly — or those aged 60, 70, 80, 90 — in an archaeological population essentially invisible. In order to render these older people visible, we developed a simple new methodological approach," Oxenham said.

He explained that the new method involves seriating, or ordering, a collection of skeletal remains from a cemetery from youngest to oldest. The ordering can be based on any meaningful indicator of age. In this case, they used tooth wear as a proxy for age in order to seriate the targeted Anglo-Saxon population.

Once this was achieved, they obtained data on another population with known demographic parameters to act as a model for the archaeological sample. By fitting the seriated sample to the model, they said that they were able to specifically identify the ages of the deceased individuals in the three UK cemeteries.

They determined that 7 women and 2 men buried in the cemeteries were older than 75 when they died. Ten women and 6 men died between the ages of 65–74. The majority of people, however, died between the ages of 30–44.

Cave initially did her honors research on Anglo-Saxon burials of children, but there are not very many to study, so she basically ran out of material after a while.

"Instead, I moved to the other end of the age spectrum, the elderly, which is a much under-theorized area of archaeological study," she said. "The reasons for this include the difficulties of skeletal aging, but also relate to modern attitudes to the elderly, where they are often marginalized into their own areas, retired from mainstream society and even de-gendered, infantilized and patronized."

Such negative attitudes toward the elderly were even seen in the Anglo-Saxon burials, but mostly in the graves of women.

The researchers found women were more likely to be given prominent burials if they died young. These graves often included jewelry, like brooches, beads, and pins, along with other items associated with enhanced beauty. This suggests that attractiveness, often tied to youth, was valued in women.

Replica of the "Saxon Princess" bed burial at the Kirkleatham Museum in Redcar, UK

Oxenham explained that to avoid bias in determining what was considered a "normal" burial in the past, he and Cave looked for common grave attributes.

"For instance," he said, "it may be normal for children to be buried with toys, old females to be buried with one brooch and young males to be buried with a dagger in a hypothetical cemetery," he said. "Once we know what is 'normal,' we can then search for unusual burial practices, such as a child buried with a sword and an old male with the thimble."

In terms of normal burials, it appears to have been common for high status men to be buried with weapons, like a spear and a shield, or occasionally a sword. Such artifacts were present whether the men died relatively young, in their 30 or 40s, or at more advanced ages.

Women were more likely to be found in "non-normative" burials. Grave 103 at Great Chesterford, for example, contained the remains of a middle-aged woman who was buried face down close to the wall, with a dark stain occupying the space beside her and her belongings deposited in a corner.

The face down, or prone, position, is theorized to be associated with so-called "cunning women" who were labeled as witches. Such labeling was often done to diminish the financial and other powers of women in patriarchal societies.

Two other prone burials, graves 43 and 78 and Worthy Park, contain no grave goods. The former contained the remains of a 25 to 30-year-old woman who appears to have been bound and "carelessly placed in a too-short grave," according to the authors.

Grave 78 contained the remains of a possible 13 to 15-year-old rape victim, as evidenced by femoral injuries. She went to her grave with her feet and hands bound.

"The possibility that they were bound, and their placement face down, without grave goods, suggests either some form of post-mortem punishment by the community, or, conversely, extreme fear of these individuals by the community that necessitated this positioning and binding in order to prevent their resurrection and subsequent return to the community," Oxenham said.

"A third possibility,” he continued, “is that these were victims of community sanctioned murder or execution, or perhaps even sacrifice. Without additional evidence for a 'smoking gun' — evidence for trauma or the preserved garrottes seen in some bog bodies, for instance — it is very difficult, if not impossible, to support such an interpretation, although the possibility cannot obviously be ruled out."

As for why anyone would even bother to bury a maligned individual, the researchers explained that sanitation, moral, social and religious reasons compelled the ancients to do so. During superstitious times, failure to bury someone could have been linked with bad harvests, plagues, wars and other feared repercussions.

Graves 94 and 95 at Mill Hill held the remains of older women, both who were over 65 years at death.

"They may have been the last two individuals buried in the cemetery, and who also may have been the last two pagans in the community," Cave said.

Read more at Seeker

Genetic 'switches' behind human brain evolution

UCLA researchers mapped the genetic on/off switches driving neurogenesis in the brain and shaping the expansion of human cortex. The image shows schematics of slices of the mouse, macaque and human brain to scale. The interior of the slices is represented by a mouse brain. Strands of chromatin, where the on/off switches reside, are interlaced across the brains.

UCLA researchers have developed the first map of gene regulation in human neurogenesis, the process by which neural stem cells turn into brain cells and the cerebral cortex expands in size. The scientists identified factors that govern the growth of our brains and, in some cases, set the stage for several brain disorders that appear later in life.

The human brain differs from that of mice and monkeys because of its large cerebral cortex. The organ's most highly developed part, the cerebral cortex is responsible for thinking, perceiving and sophisticated communication. Scientists are just beginning to understand the molecular and cellular mechanisms that drive the growth of the human brain and the major role they play in human cognition.

Brain development is guided by the expression of genes in certain brain regions or cell types, as well as during specific time frames. Gene expression, the process by which the instructions in our DNA are converted into a functional product, such as a protein, is regulated at many levels by segments of DNA acting as on-off switches at key moments. But until now, there was no map that described the activity and location of these switches on a chromosome during neurogenesis.

Using a molecular biology technique called ATAC-seq, UCLA researchers mapped regions of the genome that are active during neurogenesis. They combined that data with gene expression data from those brain regions. The researchers also used previously published data about the folding patterns of chromosomes. Chromosomal folding patterns affect how genetic information is encoded. The combined data helped them identify regulatory elements for key genes in neurogenesis. One gene, called EOMES/Tbr2, when switched off, is associated with severe brain malformations.

The researchers confirmed the roles of the targeted genes by using CRISPR technology, a technique by which pieces of DNA in the cells can be removed, to edit out a subset of regulatory switches and then assess their effect on gene expression and neurogenesis.

Researchers found that some psychiatric disorders that develop later in life, such as schizophrenia, depression, ADHD and neuroticism, have their origins during the earliest stages of brain growth in the fetus. Even a person's future intellectual capabilities are set in motion during neurogenesis, researchers said.

Researchers also discovered a major mechanism that accounts for the human cerebral cortex being larger than it is in non-human primates. They identified a genome sequence that alters expression of a fibroblast growth factor receptor that regulates important biological processes including cell multiplication and division, and that assigns specific tasks to cells. The genome sequence is more active in humans than in mouse and non-human primates, which helps explain why human brains are larger.

The study's first author is Luis de la Torre-Ubieta of UCLA and the senior author is Dr. Daniel Geschwind of UCLA. The other authors are Jason Stein, Hyejung Won, Carli Opland and Daning Lu, all of UCLA; and Dan Liang of the University of North Carolina, Chapel Hill.

From Science Daily

Multiple sites rich in water ice found on Mars

Mars.

Erosion on Mars is exposing deposits of water ice, starting at depths as shallow as one to two meters below the surface and extending 100 meters or more.

The ice is a critical target for science and exploration: it affects modern geomorphology, is expected to preserve a record of climate history, influences the planet's habitability, and may be a potential resource for future exploration.

Whilst water ice is known to be present in some locations on Mars, many questions remain about its layering, thickness, purity, and extent.

Now, Colin Dundas and colleagues have pinpointed eight locations, using the Mars Reconnaissance Orbiter (MRO), where steep, pole-facing slopes created by erosion expose substantial quantities of sub-surface ice. The fractures and steep angles indicate that the ice is cohesive and strong, the authors say. What's more, bands and variations in color suggest that the ice contains distinct layers, which could be used to understand changes in Mars' climate over time (the ice sheets themselves likely formed as snow accumulated over time).

Since there are few craters on the surface at these sites, the authors propose that the ice was formed relatively recently. Images taken over the course of three Martian years reveal massive chunks of rock that fell from the ice as erosion occurred, leading the researchers to estimate that the ice is retreating a few millimeters each summer.

Because the ice is only visible where surface soil has been removed, Dundas et al. say it is likely that ice near the surface is even more extensive than detected in this study. The ice could be a useful source of water for future missions to Mars.

From Science Daily

Rising temperatures turning major sea turtle population female

A green sea turtle returns to the water following examination by researchers. A new study finds that green sea turtle colonies in the northern Great Barrier Reef are producing almost all female hatchlings.

Scientists have used a new research approach to show that warming temperatures are turning one of the world's largest sea turtle colonies almost entirely female, running the risk that the colony cannot sustain itself in coming decades, newly published research concludes.

Sand temperatures determine the sex of turtle hatchlings, with warmer temperatures resulting in more females. During the past two decades, temperatures on islands in Australia's northern Great Barrier Reef have increased to the point "that virtually no male turtles are now being produced from these nesting beaches," the researchers from the United States and Australia write this week in the journal Current Biology.

The study "raises new concerns over the immediate threats of climate change to sea turtle populations," say the researchers from NOAA Fisheries and the Queensland Department of Environment and Heritage Protection.

The study's results will be important for wildlife managers as they consider strategies to lower incubation temperatures at key rookeries around the world "to boost the ability of local turtle populations to adapt to the changing environment and avoid a population collapse or even extinction."

Although researchers have known for decades that warming temperatures alter the sex of sea turtle offspring, this is the first time they have directly documented the trend in a major wild population.

Researchers previously determined the sex of individual hatchlings through anatomical exams at nesting beaches, providing only a snapshot in time from only a few nests. The new study uses an innovative combination of endocrinology and genetics to assess the sex of hundreds of turtles across a large foraging ground, revealing the sex ratio of immature and mature turtles from different nesting beaches over many years.

The analysis revealed different sex ratios and trends in two nesting populations in the Great Barrier Reef. Green sea turtles from cooler southern nesting beaches were about 65 to 69 percent female, testing showed. Sea turtles from warmer northern beaches leaned even more heavily female, with 86.8 percent of adult turtles, 99.8 percent of sub-adult turtles, and 99.1 percent of juvenile turtles turning out to be female.

"This has given us an important new window into demographic changes in these populations over the last several decades, which have gone undetected until now," said Michael Jensen, a research biologist at NOAA Fisheries' Southwest Fisheries Science Center in La Jolla, Calif., and lead author of the new research. "The disconcerting thing is that we can now see how changes in the climate could affect the longevity of this and other sea turtle populations around the world."

Green sea turtles are protected under the Endangered Species Act and listed as endangered on the International Union for the Conservation of Nature's Red List. The Great Barrier Reef holds some of their largest populations in the world. An estimated 200,000 females nest on beaches in the northern Great Barrier Reef, most of them on two small coral cays. The same temperatures affecting the turtles are also leading to the bleaching of much of the northern Great Barrier Reef.

"Our findings add another dimension to the growing body of evidence that increasing temperatures are broadly affecting Great Barrier Reef ecosystems," the scientists write.

Sea turtles are among the most ancient species roaming the oceans, and have long adjusted to shifting climates. Increasing numbers of females may at first be a good thing for sea turtle populations, boosting the population's reproductive potential. The problem is that the modern climate appears to be changing faster than turtles can adjust to it.

Read more at Science Daily

Turkey-sized dinosaur from Australia preserved in an ancient log-jam

Diluvicursor pickeringi holotype: The holotype partial skeleton of Diluvicursor pickeringi after it was prepared from several blocks of sandstone by Lesley Kool of Monash University The fossil preserves most of the tail along with the right ankle and foot.

The partial skeleton of a new species of turkey-sized herbivorous dinosaur has been discovered in 113 million year old rocks in southeastern Australia. As reported in open access journal PeerJ, the fossilized tail and foot bones give new insight into the diversity of the small, bipedal herbivorous dinosaurs called ornithopods that roamed the great rift valley that once existed between Australia and Antarctica. The new dinosaur has been named Diluvicursor pickeringi, which means Pickering's Flood-Running dinosaur.

Lower Cretaceous rocks of the deep sedimentary basins that formed within the Australian-Antarctic rift are now exposed as wave-cut rock platforms and sea-cliffs along the south coast of Victoria. The skeleton of Diluvicursor pickeringi was discovered in 2005 by volunteer prospector George Caspar, eroding from such a rock platform at a locality called Eric the Red West, near Cape Otway.

"Diluvicursor shows for the first time that there were at least two distinct body-types among closely related ornithopods in this part of Australia," Dr Matt Herne, lead author of the new study said.

"One was lightly built with an extraordinarily long tail, while the other, Diluvicursor, was more solidly built, with a far shorter tail. Our preliminary reconstruction of the tail musculature of Diluvicursor suggests this dinosaur was a good runner, with powerful leg retracting muscles," Dr Herne said.

"Understanding the ecology of these dinosaurs -- what they ate, how they moved, where they roamed -- based on the interplay between anatomy and the environment presents exciting challenges for future research."

The species name honors the late David Pickering, who was Museums Victoria's Collection Manager, Vertebrate Palaeontology. David contributed significantly to Australian paleontology in the lab and field, and tirelessly assisted countless students of paleontology and researchers to achieve their goals. Sadly, David passed away just over a year ago on Christmas Eve 2016.

The site of Eric the Red West has additional importance as it helps build a picture the ancient rift valley ecosystem. Fossil vertebrate remains at this site were buried in deep scours at the base of a powerful river, along with flood-transported tree stumps, logs and branches.

"The carcass of the Diluvicursor pickeringi holotype appears to have become entangled in a log-jam at the bottom of this river," explained Dr Herne. "The sizes of some of the logs in the deposit and the abundance of wood suggest the river traversed a well-forested floodplain. The logs preserved at the site are likely to represent conifer forests of trees within families still seen in Australia today."

Read more at Science Daily

A repeating fast radio burst from an extreme environment

Arecibo Observatory, Puerto Rico

New detections of radio waves from a repeating fast radio burst have revealed an astonishingly potent magnetic field in the source's environment, indicating that it is situated near a massive black hole or within a nebula of unprecedented power.

The findings by an international team of astronomers, including Victoria Kaspi and Shriharsh Tendulkar of McGill University, appear in the January 11 edition of Nature and are highlighted on the cover of the journal.

A year ago, the astronomers pinpointed the location of the enigmatic fast radio burst (FRB) source named FRB 121102 and reported that it lies in a star-forming region of a dwarf galaxy more than 3 billion light years from Earth. The vast distance to the source implies that it releases an enormous amount of energy in each burst -- roughly as much energy in a single millisecond as the Sun releases in an entire day.

Now, using data from the Arecibo Observatory (Puerto Rico) and the Green Bank Telescope (West Virginia), the researchers have shown that the radio bursts from FRB121102 are highly polarized. The behavior of this polarized emission enables scientists to probe the source's environment in a new way.

Twisted polarization

When polarized radio waves pass through a region with a magnetic field, the polarization gets ``twisted'' by an effect known as Faraday rotation: the stronger the magnetic field, the greater the twisting. The amount of twisting observed in FRB 121102's radio bursts is among the largest ever measured in a radio source, leading the researchers to conclude that the bursts are passing through an extraordinarily strong magnetic field in a dense plasma.

"I could not believe my eyes when my colleagues emailed the results around," says Kaspi, who is a professor of physics at McGill and director of the McGill Space Institute. "This sort of enormous Faraday rotation is extremely rare. Once we digested it, we realized it was a huge clue about where this bizarre source resides."

One possible explanation for the hugely magnetized environment is that FRB 121102 is located close to a massive black hole in its host galaxy. Such highly magnetized plasmas have so far been seen only near the center of the Milky Way, which has its own massive black hole. But the authors also speculate that the twisting of the radio bursts could be explained if FRB 121102 is located in a powerful nebula (an interstellar cloud of gas and dust) or amid the remains of a dead star.

FRBs are a recently discovered class of transient astrophysical events, originating from deep in extragalactic space. Their physical nature remains a mystery. FRB 121102 is the only known repeating FRB, and this has also raised the question of whether it has a different origin compared to the apparently non-repeating FRBs. "FRB 121102 was already unique because of its repetition; now the huge Faraday rotation we have observed singles it out yet again. We're curious as to whether these two unique aspects are linked," says Daniele Michilli, PhD candidate at the University of Amsterdam and ASTRON (Netherlands Institute for Radio Astronomy).

New telescopes could provide answers

With a number of wide-field radio telescopes now coming online, more such sources are expected to be discovered in the coming year, and astronomers are poised to answer more fundamental questions about FRBs.

"The CHIME telescope in Penticton, British Columbia, should be an excellent instrument for detecting fast radio bursts and studying their polarization properties," says Shriharsh Tendulkar, postdoctoral researcher at the McGill Space Institute. "When it comes online in 2018, it should be capable of detecting between a few and a few dozen FRBs every day."

Read more at Science Daily

Black hole research could aid understanding of how small galaxies evolve

Size comparison of a dwarf galaxy (right inset, bottom) with a larger galaxy in the centre. Top inset: Dwarf galaxy overlain with some of the MaNGA data, revealing the winds from the supermassive black hole.

Scientists have solved a cosmic mystery by finding evidence that supermassive black holes prevent stars forming in some smaller galaxies.

These giant black holes are over a million times more massive than the sun and sit in the centre of galaxies sending out powerful winds that quench the star-making process. Astronomers previously thought they had no influence on the formation of stars in dwarf galaxies but a new study from the University of Portsmouth has proved their role in the process.

The results, presented today at a meeting of the American Astronomical Society, are particularly important because dwarf galaxies (those composed of up to 100 million to several billion stars) are far more numerous than bigger systems and what happens in these is likely to give a more typical picture of the evolution of galaxies.

"Dwarf galaxies outnumber larger galaxies like the Milky Way 50 to one," says lead researcher Dr Samantha Penny, of the University's Institute of Cosmology and Gravitation. "So if we want to tell the full story of galaxies, we need to understand how dwarf systems work."

In any galaxy stars are born when clouds of gas collapse under the force of their own gravity. But stars don't keep being born forever -- at some point star formation in a galaxy shuts off. The reason for this differs in different galaxies but sometimes a supermassive black hole is the culprit.

Supermassive black holes can regulate their host galaxy's ability to form new stars through a heating process. The black hole drives energy through powerful winds. When this wind hits the giant molecular clouds in which stars would form, it heats the gas, preventing its collapse into new stars.

Previous research has shown that this process can prevent star formation in larger galaxies containing hundreds of billions of stars -- but it was believed a different process could be responsible for dwarf galaxies ceasing to produce stars. Scientists previously thought that the larger galaxies could have been interacting gravitationally with the dwarf systems and pulling the star-making gas away.

Data, however, showed the researchers that the dwarf galaxies under observation were still accumulating gas which should re-start star formation in a red, dead galaxy but wasn't. This led the team to the supermassive black hole discovery.

Dr Penny said: "Our results are important for astronomy because they potentially impact how we understand galaxy evolution. Supermassive black holes weren't thought to influence dwarf systems but we've shown that isn't the case. This may well have a big influence on future research as simulations of galaxy formation don't usually include the heating effect of supermassive black holes in low-mass galaxies, including the dwarf systems we have examined in this work."

Read more at Science Daily

Black hole breakthrough: New insight into mysterious jets

Image from a simulation produced using the Blue Waters supercomputer demonstrates that relativistic jets follow along with the precession of the tilted accretion disk around the black hole.

Through first-of-their-kind supercomputer simulations, researchers, including a Northwestern University professor, have gained new insight into one of the most mysterious phenomena in modern astronomy: the behavior of relativistic jets that shoot from black holes, extending outward across millions of light years.

Advanced simulations created with one of the world's most powerful supercomputers show the jets' streams gradually change direction in the sky, or precess, as a result of space-time being dragged into the rotation of the black hole. This behavior aligns with Albert Einstein's predictions about extreme gravity near rotating black holes, published in his famous theory of general relativity.

"Understanding how rotating black holes drag the space-time around them and how this process affects what we see through the telescopes remains a crucial, difficult-to-crack puzzle," said Alexander Tchekhovskoy, assistant professor of physics and astronomy at Northwestern's Weinberg College of Arts and Sciences. "Fortunately, the breakthroughs in code development and leaps in supercomputer architecture are bringing us ever closer to finding the answers."

The study, published in the Monthly Notices of the Royal Astronomical Society, is a collaboration between Tchekhovskoy, Matthew Liska and Casper Hesp. Liska and Hesp are the study's lead authors and graduate students at The University of Amsterdam, Netherlands.

Rapidly spinning black holes not only engulf matter but also emit energy in the form of relativistic jets. Similar to how water in a bathtub forms a whirlpool as it goes down a drain, the gas and magnetic fields that feed a supermassive black hole swirl to form a rotating disk -- a tangled spaghetti of magnetic field lines mixed into a broth of hot gas. As the black hole consumes this astrophysical soup, it gobbles up the broth but leaves the magnetic spaghetti dangling out of its mouth. This makes the black hole into a kind of launching pad from which energy, in the form of relativistic jets, shoots from the web of twisted magnetic spaghetti.

The jets emitted by black holes are easier to study than the black holes themselves because the jets are so large. This study enables astronomers to understand how quickly the jet direction is changing, which reveals information about the black hole spin as well as the orientation and size of the rotating disk and other difficult-to-measure properties of black hole accretion.

Whereas nearly all previous simulations considered aligned disks, in reality, most galaxies' central supermassive black holes are thought to harbor tilted disks -- meaning the disk rotates around a separate axis than the black hole itself. This study confirms that if tilted, disks change direction relative to the black hole, precessing around like a spinning top. For the first time, the simulations showed that such tilted disks lead to precessing jets that periodically change their direction in the sky.

An important reason precessing jets were not discovered earlier is that 3-D simulations of the region surrounding a rapidly spinning black hole require an enormous amount of computational power. To address this issue, the researchers constructed the first black hole simulation code accelerated by graphical processing units (GPUs). A National Science Foundation grant enabled them to carry out the simulations on Blue Waters, one of the largest supercomputers in the world, located at the University of Illinois.

The confluence of the fast code, which efficiently uses a cutting-edge GPU architecture, and the Blue Waters supercomputer allowed the team to carry out simulations with the highest resolution ever achieved -- up to a billion computational cells.

"The high resolution allowed us, for the first time, to ensure that small-scale turbulent disk motions are accurately captured in our models," Tchekhovskoy said. "To our surprise, these motions turned out to be so strong that they caused the disk to fatten up and the disk precession to stop. This suggests that precession can come about in bursts."

Because accretion onto black holes is a highly complex system akin to a hurricane, but located so far away we cannot discern many details, simulations offer a powerful way of making sense of telescope observations and understanding the behavior of black holes.

The simulation results are important for further studies involving rotating black holes, which are currently being conducted all over the world. Through these efforts, astronomers are attempting to understand recently discovered phenomena such as the first detections of gravitational waves from neutron star collisions and the accompanying electromagnetic fireworks as well as regular stars being engulfed by supermassive black holes.

The calculations also are being applied to interpreting the observations of the Event Horizon Telescope (EHT), which captured the first recordings of the supermassive black hole shadow in the center of the Milky Way.

Read more at Science Daily

Artificial muscles power up with new gel-based robotics

(a) Overview of wearing set-up of the assist wear. (b) Structure of the multilayered PVC gel actuator with two types of anode mesh electrodes. The red layer with small holes is comprised of slide electrodes to minimize the friction with the slide shafts. (c) Contraction and expansion movement of the stretching type actuator with the DC field turned on and off. (d) FlexiForce sensor-based motion detection (position estimator). (e) Power and controller.

Scientists are one step closer to artificial muscles. Orthotics have come a long way since their initial wood and strap designs, yet innovation lapsed when it came to compensating for muscle power -- until now.

A collaborative research team has designed a wearable robot to support a person's hip joint while walking. The team, led by Minoru Hashimoto, a professor of textile science and technology at Shinshu University in Japan, published the details of their prototype in Smart Materials and Structures, a journal published by the Institute of Physics.

"With a rapidly aging society, an increasing number of elderly people require care after suffering from stroke, and other-age related disabilities. Various technologies, devices, and robots are emerging to aid caretakers," wrote Hashimoto, noting that several technologies meant to assist a person with walking are often cumbersome to the user. "[In our] current study, [we] sought to develop a lightweight, soft, wearable assist wear for supporting activities of daily life for older people with weakened muscles and those with mobility issues."

The wearable system consists of plasticized polyvinyl chloride (PVC) gel, mesh electrodes, and applied voltage. The mesh electrodes sandwich the gel, and when voltage is applied, the gel flexes and contracts, like a muscle. It's a wearable actuator, the mechanism that causes movement.

"We thought that the electrical mechanical properties of the PVC gel could be used for robotic artificial muscles, so we started researching the PVC gel," said Hashimoto. "The ability to add voltage to PVC gel is especially attractive for high speed movement, and the gel moves with high speed with just a few hundred volts."

In a preliminary evaluation, a stroke patient with some paralysis on one side of his body walked with and without the wearable system.

"We found that the assist wear enabled natural movement, increasing step length and decreasing muscular activity during straight line walking," wrote Hashimoto. The researchers also found that adjusting the charge could change the level of assistance the actuator provides.

The robotic system earned first place in demonstrations with their multilayer PVC gel artificial muscle at the, "24th International Symposium on Smart Structures and Materials & Nondestructive Evaluation and Health Monitoring" for SPIE the international society for optics and photonics.

Read more at Science Daily

Astronomers detect 'whirlpool' movement in earliest galaxies; swirling gases soon after Big Bang

This is an artist's impression of spinning galaxies.

Astronomers have looked back to a time soon after the Big Bang, and have discovered swirling gas in some of the earliest galaxies to have formed in the Universe. These 'newborns' -- observed as they appeared nearly 13 billion years ago -- spun like a whirlpool, similar to our own Milky Way. This is the first time that it has been possible to detect movement in galaxies at such an early point in the Universe's history.

An international team led by Dr Renske Smit from the Kavli Institute of Cosmology at the University of Cambridge used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to open a new window onto the distant Universe, and have for the first time been able to identify normal star-forming galaxies at a very early stage in cosmic history with this telescope. The results are reported in the journal Nature, and will be presented at the 231st meeting of the American Astronomical Society.

Light from distant objects takes time to reach Earth, so observing objects that are billions of light years away enables us to look back in time and directly observe the formation of the earliest galaxies. The Universe at that time, however, was filled with an obscuring 'haze' of neutral hydrogen gas, which makes it difficult to see the formation of the very first galaxies with optical telescopes.

Smit and her colleagues used ALMA to observe two small newborn galaxies, as they existed just 800 million years after the Big Bang. By analysing the spectral 'fingerprint' of the far-infrared light collected by ALMA, they were able to establish the distance to the galaxies and, for the first time, see the internal motion of the gas that fuelled their growth.

"Until ALMA, we've never been able to see the formation of galaxies in such detail, and we've never been able to measure the movement of gas in galaxies so early in the Universe's history," said co-author Dr Stefano Carniani, from Cambridge's Cavendish Laboratory and Kavli Institute of Cosmology.

The researchers found that the gas in these newborn galaxies swirled and rotated in a whirlpool motion, similar to our own galaxy and other, more mature galaxies much later in the Universe's history. Despite their relatively small size -- about five times smaller than the Milky Way -- these galaxies were forming stars at a higher rate than other young galaxies, but the researchers were surprised to discover that the galaxies were not as chaotic as expected.

"In the early Universe, gravity caused gas to flow rapidly into the galaxies, stirring them up and forming lots of new stars -- violent supernova explosions from these stars also made the gas turbulent," said Smit, who is a Rubicon Fellow at Cambridge, sponsored by the Netherlands Organisation for Scientific Research. "We expected that young galaxies would be dynamically 'messy', due to the havoc caused by exploding young stars, but these mini-galaxies show the ability to retain order and appear well regulated. Despite their small size, they are already rapidly growing to become one of the 'adult' galaxies like we live in today."

Read more at Science Daily

Giant extinct burrowing bat discovered in New Zealand

The fossil dig site at St Bathans in New Zealand where the fossilised remains of an extinct giant burrowing bat, Vulcanops jennyworthyae, were found.

The fossilized remains of a giant burrowing bat that lived in New Zealand millions of years ago have been found by a UNSW Sydney-led international team of scientists.

Teeth and bones of the extinct bat -- which was about three times the size of an average bat today -- were recovered from 19 to 16-million-year-old sediments near the town of St Bathans in Central Otago on the South Island.

The study, by researchers from Australia, New Zealand, the UK and USA, is published in the journal Scientific Reports.

Burrowing bats are only found now in New Zealand, but they once also lived in Australia. Burrowing bats are peculiar because they not only fly; they also scurry about on all fours, over the forest floor, under leaf litter and along tree branches, while foraging for both animal and plant food.

With an estimated weight of about 40 grams, the newly found fossil bat was the biggest burrowing bat yet known. It also represents the first new bat genus to be added to New Zealand's fauna in more than 150 years

It has been named Vulcanops jennyworthyae, after team member Jenny Worthy who found the bat fossils, and after Vulcan, the mythological Roman god of fire and volcanoes, in reference to New Zealand's tectonic nature, but also to the historic Vulcan Hotel in the mining town St Bathans.

Other research team members include scientists from UNSW Sydney, University of Salford, Flinders University, Queensland University, Canterbury Museum, Museum of New Zealand Te Papa Tongarewa, the American Museum of Natural History, and Duke University.

"Burrowing bats are more closely related to bats living in South America than to others in the southwest Pacific," says study first author and UNSW Professor Sue Hand.

"They are related to vampire bats, ghost-faced bats, fishing and frog-eating bats, and nectar-feeding bats, and belong to a bat superfamily that once spanned the southern landmasses of Australia, New Zealand, South America and possibly Antarctica."

Around 50 million years ago, these landmasses were connected as the last vestiges of the southern supercontinent Gondwana. Global temperatures were up to 12 degrees Celsius higher than today and Antarctica was forested and frost-free. With subsequent fragmentation of Gondwana, cooling climates and the growth of ice-sheets in Antarctica, Australasia's burrowing bats became isolated from their South American relatives.

"New Zealand's burrowing bats are also renowned for their extremely broad diet. They eat insects and other invertebrates such as weta and spiders, which they catch on the wing or chase by foot. And they also regularly consume fruit, flowers and nectar," says Professor Hand, who is Director of the PANGEA Research Centre at UNSW.

"However, Vulcanops's specialized teeth and large size suggest it had a different diet, capable of eating even more plant food as well as small vertebrates -- a diet more like some of its South American cousins. We don't see this in Australasian bats today," she says.

Study co-author, Associate Professor Trevor Worthy of Flinders University says: "The fossils of this spectacular bat and several others in the St Bathans Fauna show that the prehistoric aviary that was New Zealand also included a surprising diversity of furry critters alongside the birds."

Study co-author Professor Paul Scofield of Canterbury Museum says: "These bats, along with land turtles and crocodiles, show that major groups of animals have been lost from New Zealand. They show that the iconic survivors of this lost fauna -- the tuataras, moas, kiwi, acanthisittid wrens, and leiopelmatid frogs -- evolved in a far more complex community that hitherto thought."

This diverse fauna lived in or around a 5600-square-km prehistoric Lake Manuherikia that once covered much of the Maniototo region of the South Island. When they lived, in the early Miocene, temperatures in New Zealand were warmer than today and semitropical to warm temperate forests and ferns edged the vast palaeolake.

Vulcanops provides new insight into the original diversity of bats in Australasia. Its lineage became extinct sometime after the early Miocene, as did a number of other lineages present in the St Bathans assemblage. These include crocodiles, terrestrial turtles, flamingo-like palaelodids, swiftlets, several pigeon, parrot and shorebird lineages and non-flying mammals. Most of these were probably warm-adapted species. After the middle Miocene, global climate change brought colder and drier conditions to New Zealand, with significant changes to vegetation and environments.

Read more at Science Daily

Mass extinctions remove species but not ecological variety

UChicago scientists examined how species (including these colorful marine bivalves) are lost in mass extinctions compared to environmental changes between the tropics and the poles.

Sixty-five million years ago, clouds of ash choked the skies over Earth. Dinosaurs, along with about half of all the species on Earth, staggered and died.

But in the seas, a colorful population of marine bivalves -- the group including oysters, clams and scallops -- soldiered on, tucked into the crevices of ocean floors and shorelines. Though they also lost half their species, curiously, at least one species in each ecological niche survived.

University of Chicago scientists documented this surprising trend in a study on extinctions published Jan. 5 in the Proceedings of the National Academy of Sciences. Though the mass extinction wiped out staggeringly high numbers of species, they barely touched the overall "functional" diversity -- how each species makes a living, be it filtering phytoplankton or eating small crustaceans, burrowing or clamping onto rocks. The same held true for the biggest mass extinction of all, 250 million years ago: more than 90 percent of all species on Earth died out, but no modes of life disappeared.

Strangely, the scientists said, nothing of the kind is seen in a different kind of biodiversity loss: the loss of species today as you move from the warm tropics to the chillier poles. The number of species drops 80 percent to 95 percent from the tropics to the cold, snowy north and south, and functional variety also declines by 50 percent to 60 percent. Thus losing diversity due to changed environment is entirely possible -- all the more reason why it's strange to see such a pattern of survival in mass extinctions.

"Multicellular life almost didn't make it out of the Paleozoic era, but every functional group did. Then we see that functional diversity drops way down from tropics to poles; it parallels species loss in a way that's totally different from the big extinctions. That's wild -- really fascinating and unexpected and strange," said co-author David Jablonski, the William R. Kenan Jr. Distinguished Service Professor of Geophysical Sciences.

This could have implications for how the mass extinction currently gathering steam could unfold and how badly it will affect Earth ecosystems, the authors said.

Jablonski and graduate student Stewart Edie, who is the first author on the paper, ran the numbers for two major mass extinctions in history: the relatively gradual end-Paleozoic extinction, perhaps driven by changing climates and ocean composition, and later, the sharper end-Cretaceous extinction, thought to be caused by a meteor impact and/or volcanic eruptions. Though they are very different stresses, the same pattern emerged.

"The rug gets pulled out from underneath all the species," said Edie. "The landscape of the world completely and suddenly changed, making it all the more surprising that all functional types survived. Even the functional groups with only one or two species somehow make it through."

The question is pressing because functional diversity is what makes ecosystems tick. Ecosystems are delicately balanced, and losing ecological roles throws a system out of whack: Think of a forest damaged when the deer population explodes because the wolves that prey on them are removed. That balance keeps soil fertile, oceans full of fish and grass growing for livestock.

Read more at Science Daily

How good bacteria control your genes

This is an image of the lining of the large intestine of a mouse. DNA is marked in red with the epigenetic marker known as crotonylation shown in green. Yellow shows areas where crotonylation and DNA are found together. Signals from gut bacteria can change the amount of crotonylation in the gut and so influence gene activity.

Scientists from the Babraham Institute near Cambridge in collaboration with colleagues from Brazil (here and here) and Italy have discovered a way that good bacteria in the gut can control genes in our cells. The work, published today (9th January) in Nature Communications, shows that chemical messages from bacteria can change the location of key chemical markers throughout the human genome. By communicating in this way, the bacteria may help to fight infections and to prevent cancer.

This work, led by Dr Patrick Varga-Weisz shows how chemicals produced by bacteria in the gut from the digestion of fruit and vegetables can affect genes in the cells of the gut lining. These molecules, called short chain fatty acids, can move from the bacteria and into our own cells. Inside our cells, they can trigger processes that change gene activity and that ultimately affect how our cells behave.

This new research shows that the short chain fatty acids increase the number of chemical markers on our genes. These markers, called crotonylations, were only discovered recently and are a new addition to the chemical annotations in the genome that are collectively called epigenetic markers. The team showed that short chain fatty acids increase the number of crotonylations by shutting down a protein called HDAC2. Scientists think that changes in crotonylation can alter gene activity by turning genes on or off.

The team studied mice that had lost most of the bacteria in their gut and showed that their cells contained more of the HDAC2 protein than normal. Other research has shown that an increase in HDAC2 can be linked to an increased risk of colorectal cancer (here and here). This could mean that regulating crotonylation in the genome of gut cells is important for preventing cancer. It also highlights the important role of good bacteria and a healthy diet in this process.

This research was made possible by support from the bilateral BBSRC-Brazil fund established as part of an agreement between Research Councils UK (RCUK) and the State of Säo Paulo Research Foundation (FAPESP) to welcome, encourage and support collaborative research between the UK and Brazil.

First author, Rachel Fellows, said: "Short chain fatty acids are a key energy source for cells in the gut but we've also shown they affect crotonylation of the genome. Crotonylation is found in many cells but it's particularly common in the gut. Our study reveals why this is the case by identifying a new role for HDAC2. This, in turn, has been implicated in cancer and offers an interesting new drug target to be studied further."

Read more at Science Daily

Alzheimer’s drug turns back clock in powerhouse of cell

The experimental drug J147 is something of a modern elixir of life.

The experimental drug J147 is something of a modern elixir of life; it's been shown to treat Alzheimer's disease and reverse aging in mice and is almost ready for clinical trials in humans. Now, Salk scientists have solved the puzzle of what, exactly, J147 does. In a paper published January 7, 2018, in the journal Aging Cell, they report that the drug binds to a protein found in mitochondria, the energy-generating powerhouses of cells. In turn, they showed, it makes aging cells, mice and flies appear more youthful.

"This really glues together everything we know about J147 in terms of the link between aging and Alzheimer's," says Dave Schubert, head of Salk's Cellular Neurobiology Laboratory and the senior author on the new paper. "Finding the target of J147 was also absolutely critical in terms of moving forward with clinical trials."

Schubert's group developed J147 in 2011, after screening for compounds from plants with an ability to reverse the cellular and molecular signs of aging in the brain. J147 is a modified version of a molecule found in the curry spice curcumin. In the years since, the researchers have shown that the compound reverses memory deficits, potentiates the production of new brain cells, and slows or reverses Alzheimer's progression in mice. However, they didn't know how J147 worked at the molecular level.

In the new work, led by Schubert and Salk Research Associate Josh Goldberg, the team used several approaches to home in on what J147 is doing. They identified the molecular target of J147 as a mitochondrial protein called ATP synthase that helps generate ATP-the cell's energy currency-within mitochondria. They showed that by manipulating its activity, they could protect neuronal cells from multiple toxicities associated with the aging brain. Moreover, ATP synthase has already been shown to control aging in C. elegans worms and flies.

"We know that age is the single greatest contributing factor to Alzheimer's, so it is not surprising that we found a drug target that's also been implicated in aging," says Goldberg, the paper's first author.

Further experiments revealed that modulating activity of ATP synthase with J147 changes the levels of a number of other molecules-including levels of ATP itself-and leads to healthier, more stable mitochondria throughout aging and in disease.

"I was very surprised when we started doing experiments with how big of an effect we saw," says Schubert. "We can give this to old mice and it really elicits profound changes to make these mice look younger at a cellular and molecular level."

The results, the researchers say, are not only encouraging for moving the drug forward as an Alzheimer's treatment, but also suggest that J147 may be useful in other age-associated diseases as well.

"People have always thought that you need separate drugs for Alzheimer's, Parkinson's and stroke" says Schubert. "But it may be that by targeting aging we can treat or slow down many pathological conditions that are old-age-associated."

The team is already performing additional studies on the molecules that are altered by J147's effect on the mitochondrial ATP synthase-which could themselves be new drug targets. J147 has completed the FDA-required toxicology testing in animals, and funds are being sought to initiate phase 1 clinical trials in humans.

Other researchers on the study were A. Currais, M. Prior, W. Fischer, C. Chiruta, D. Daugherty, R. Dargusch and P. Maher of the Salk Institute; E. Ratliff and K. Finley of San Diego State University; P.B. Esparza-Molto and J.M. Cuezva of the Universidad Autonoma de Madrid; and M. Petrascheck of The Scripps Research Institute.

Read more at Science Daily

Engineers grow functioning human muscle from skin cells

A stained cross section of the new muscle fibers. The red cells are muscle cells, the green areas are receptors for neuronal input, and the blue patches are cell nuclei.

Biomedical engineers have grown the first functioning human skeletal muscle from induced pluripotent stem cells.

The advance builds on work published in 2015 when researchers at Duke University grew the first functioning human muscle tissue from cells obtained from muscle biopsies. The ability to start from cellular scratch using non-muscle tissue will allow scientists to grow far more muscle cells, provide an easier path to genome editing and cellular therapies, and develop individually tailored models of rare muscle diseases for drug discovery and basic biology studies.

The results appear online Tuesday, January 9, in Nature Communications.

"Starting with pluripotent stem cells that are not muscle cells, but can become all existing cells in our body, allows us to grow an unlimited number of myogenic progenitor cells," said Nenad Bursac, professor of biomedical engineering at Duke University. "These progenitor cells resemble adult muscle stem cells called 'satellite cells' that can theoretically grow an entire muscle starting from a single cell."

In their previous work, Bursac and his team started with small samples of human cells obtained from muscle biopsies, called "myoblasts," that had already progressed beyond the stem cell stage but hadn't yet become mature muscle fibers. They grew these myoblasts by many folds and then put them into a supportive 3-D scaffolding filled with a nourishing gel that allowed them to form aligned and functioning human muscle fibers.

In the new study, the researchers instead started with human induced pluripotent stem cells. These are cells taken from adult non-muscle tissues, such as skin or blood, and reprogrammed to revert to a primordial state. The pluripotent stem cells are then grown while being flooded with a molecule called Pax7 -- which signals the cells to start becoming muscle.

As the cells proliferated they became very similar to -- but not quite as robust as -- adult muscle stem cells. While previous studies had accomplished this feat, nobody has been able to then grow these intermediate cells into functioning skeletal muscle.

The Duke researchers succeeded where previous attempts had failed.

"It's taken years of trial and error, making educated guesses and taking baby steps to finally produce functioning human muscle from pluripotent stem cells," said Lingjun Rao, a postdoctoral researcher in Bursac's laboratory and first author of the study. "What made the difference are our unique cell culture conditions and 3-D matrix, which allowed cells to grow and develop much faster and longer than the 2-D culture approaches that are more typically used."

Once the cells were well on their way to becoming muscle, Bursac and Rao stopped providing the Pax7 signaling molecule and started giving the cells the support and nourishment they needed to fully mature.

In the study, the researchers show that after two to four weeks of 3-D culture, the resulting muscle cells form muscle fibers that contract and react to external stimuli such as electrical pulses and biochemical signals mimicking neuronal inputs just like native muscle tissue. They also implanted the newly grown muscle fibers into adult mice and showed that they survive and function for at least three weeks while progressively integrating into the native tissue through vascularization.

The resulting muscle, however, is not as strong as native muscle tissue, and also falls short of the muscle grown in the previous study that started from muscle biopsies. Despite this caveat, the researchers say this muscle still holds potential that the stronger, older relative does not.

The pluripotent stem cell-derived muscle fibers develop reservoirs of "satellite-like cells" that are necessary for normal adult muscles to repair damage, while the muscle from the previous study had much fewer of these cells. The stem cell method is also capable of growing many more cells from a smaller starting batch than the biopsy method.

Both of the advantages point toward a possibility of using this new method for regenerative therapies and for creating models of rare diseases for future studies and individualized health care.

"The prospect of studying rare diseases is especially exciting for us," said Bursac. "When a child's muscles are already withering away from something like Duchenne muscular dystrophy, it would not be ethical to take muscle samples from them and do further damage. But with this technique, we can just take a small sample of non-muscle tissue, like skin or blood, revert the obtained cells to a pluripotent state, and eventually grow an endless amount of functioning muscle fibers to test."

The technique also holds promise for being combined with genetic therapies. Researchers could, in theory, fix genetic malfunctions in the induced pluripotent stem cells derived from a patient and then grow small patches of completely healthy muscle. While this could not heal or replace an entire body's worth of diseased muscle, it could be used in tandem with more widely targeted genetic therapies or to heal more localized problems.

Read more at Science Daily