Jul 16, 2016

Scientists move one step closer to creating an invisibility cloak

The 'cloak' in action.
Scientists at Queen Mary University of London (QMUL) have made an object disappear by using a composite material with nano-size particles that can enhance specific properties on the object's surface.

Researchers from QMUL's School of Electronic Engineering and Computer Science, worked with UK industry to demonstrate for the first time a practical cloaking device that allows curved surfaces to appear flat to electromagnetic waves.

While the research might not lead to the invisibility cloak made famous in J.K Rowling's Harry Potter novels quite yet, this practical demonstration could result in a step-change in how antennas are tethered to their platform. It could allow for antennas in different shapes and sizes to be attached in awkward places and a wide variety of materials.

Co-author, Professor Yang Hao from QMUL's School of Electronic Engineering and Computer Science, said: "The design is based upon transformation optics, a concept behind the idea of the invisibility cloak.

"Previous research has shown this technique working at one frequency. However, we can demonstrate that it works at a greater range of frequencies making it more useful for other engineering applications, such as nano-antennas and the aerospace industry."

The researchers coated a curved surface with a nanocomposite medium, which has seven distinct layers (called graded index nanocomposite) where the electric property of each layer varies depending on the position. The effect is to 'cloak' the object: such a structure can hide an object that would ordinarily have caused the wave to be scattered.

The underlying design approach has much wider applications, ranging from microwave to optics for the control of any kind of electromagnetic surface waves.

First author Dr Luigi La Spada also from QMUL's School of Electronic Engineering and Computer Science, said: "The study and manipulation of surface waves is the key to develop technological and industrial solutions in the design of real-life platforms, for different application fields.

"We demonstrated a practical possibility to use nanocomposites to control surface wave propagation through advanced additive manufacturing. Perhaps most importantly, the approach used can be applied to other physical phenomena that are described by wave equations, such as acoustics. For this reason, we believe that this work has a great industrial impact."

From Science Daily

Measuring oceans of activity in one drop of water

Technion scientists have measured and recorded thermal motion in a water droplet.
According to scientists from the Technion-Israel Institute of Technology, measuring a water droplet with a resolution comparable with the scale of a single atom will reveal that the droplet interface behaves like a miniature stormy sea. The waves in this ocean are generally referred to as "thermal capillary waves" and they exist even if the droplet is seen, to the naked eye, as being at rest.

Using that knowledge, the scientists developed technology to analyze the thermal capillary dynamics in a drop of water. The advancement could one day lead to a new generation of medical sensors that are able to identify abnormal cells.

The findings by graduate student Shai Maayani and Professor Tal Carmon of the Technion Faculty of Mechanical Engineering are published in Optica.

The measurement of thermal capillary waves, performed by Mr. Maayani, was made possible by turning the water droplet into a device the researchers called an "opto-capillary resonator." The device was used to introduce light into a water droplet to record the thermal capillary motion inside it. Being able to accurately measure this activity means that it could also be possible to support a controlled energy exchange between light and capillary waves in the drop.

"The surface of a water drop is constantly moving, due to what is called 'Brownian motion,' or 'thermal motion,'" said Prof. Carmon. "Thermal motion on the outer surface of a water droplet impacts many processes, including breaking of a single drop into many smaller droplets."

The researchers experimented with what are called "capillary oscillations" in a water droplet. These motions are governed by water's surface tension, the force that gives a drop of water its shape. Water droplets are a fundamental structure of self-contained liquid bounded almost completely by surfaces.

In their experiment, photons (particles of light) were confined to circulate along the equatorial line of the droplet, at a depth of 180 billionth of meter. Being so close to the drop interface, which host the thermal capillary waves, enabled recording this thermal motion of water.

According to the researchers, once inside the water droplet, light circulates up to 1,000 times around the circumference of the droplet, which helps in measuring the capillary waves. The number of times that light circulates is called 'optical finesse' and can be used to monitor the movements down to the size of 1/1000th of the very small wavelength of light.

"Optocapillary cavities can support a controlled energy exchange between light and capillaries," explained the researchers.

When light waves and water waves co-resonate in certain ways -- when they pass through one another -- there can be an exchange of energy between the two types of waves. The data from that interaction could be used to develop a new type of sensor. For example, if a biological cell is placed into a water drop the cell's reaction to waves -- whether waves of light, water or sound -- can reveal information about the nature of the cell.

Read more at Science Daily

Jul 15, 2016

Comprehensive map of primate brain development

Gross anatomy and layered architecture of the neocortex during prenatal and postnatal development. Nissl-stained brain sections show early expansion of dividing progenitor cells (pink) followed by later generation of cortical neurons (yellow, orange), paralleling the increased folding or gyrification of the developing cortex.
Researchers at the Allen Institute for Brain Science have published an in-depth analysis of a comprehensive molecular atlas of brain development in the non-human primate. This analysis uncovers features of the genetic code underlying brain development in our close evolutionary relative, while revealing distinct features of human brain development by comparison. The study is based on the NIH Blueprint Non-Human Primate (NHP) Atlas, a publicly available resource created by the Allen Institute and colleagues at the University of California, Davis and the California National Primate Research Center. This resource enables researchers to understand the underpinnings of both healthy brain development and many neuropsychiatric diseases. Analysis of the atlas is featured this week in the journal Nature.

"This is the most complete spatiotemporal map we have for any mammal's development, and we have it in a model system that provides directly meaningful insight into human brain development, structure, and function," says Ed Lein, Ph.D., Investigator at the Allen Institute for Brain Science. "This exceptional dataset is useful for exploring precisely where and when genes are active in relation to the events of brain development and the onset of brain disorders."

"Collaborating with the NIH on this project allowed us to make use of the Allen Institute's unique capabilities to generate high-quality, large scale data resources that enable the scientific community around the world to make valuable discoveries," says Allan Jones, Ph.D., CEO of the Allen Institute.

"While we know many of the details of gene expression in the adult brain, mapping gene expression across development has been one of the missing links for understanding the genetics of disorders like autism and schizophrenia," says Thomas R. Insel, Ph.D., former Director of the National Institute of Mental Health. "This new atlas will be the foundation for the next generation of studies linking the genetics of neurodevelopmental disorders to the development of specific brain pathways."

The goal of the NHP atlas was to marry the techniques of modern transcriptomics with the rich history of anatomical developmental studies by measuring gene activity at a series of ten important stages in prenatal and postnatal brain development. At each stage a technique called laser microdissection was used to precisely isolate fine layers and nuclei of cortical and subcortical brain regions associated with human psychiatric disease, thereby creating a high resolution time series of the generation and maturation of these brain regions and their underlying cell types. The gene expression data are complemented by neuroimaging and histological and cellular resolution gene expression reference data.

"This time series reveals how genes code for the enormous complexity of the human brain," says Trygve Bakken, M.D., Ph.D., Scientist II at the Allen Institute for Brain Science. "Prenatal development is a time of exceptionally rapid change reflected in gene usage, yet many of the molecular characteristics of the mature brain are not achieved until surprisingly late in postnatal development when brain development can be affected by physical activity and social interaction."

Because the atlas targeted areas of the brain associated with human disease, the authors collaborated with colleagues at the Baylor College of Medicine to use this molecular map to pinpoint when and where candidate genes for diseases like autism and schizophrenia become active. Genes associated with autism are particularly active in the prenatal neocortex in newly generated neurons, consistent with other studies and the early onset of autistic pathology. In contrast, genes for schizophrenia become active much later in development, also in neurons in the neocortex, which correlates with the disease's later onset.

"This tremendous resource is freely available to the research community and will guide important research into the etiology of many developmental disorders for years to come', says Michelle Freund, Ph.D., program officer at the National Institute of Mental Health.

Read more at Science Daily

Warm Jupiters not as lonely as expected

After analyzing four years of Kepler space telescope observations, astronomers from the University of Toronto have given us our clearest understanding yet of a class of exoplanets called "Warm Jupiters," showing that many have unexpected planetary companions.

The team's analysis, published July 10th in the Astrophysical Journal, provides strong evidence of the existence of two distinct types of Warm Jupiters, each with their own formation and dynamical history.

The two types include those that have companions and thus, likely formed where we find them today; and those with no companions that likely migrated to their current positions.

According to lead-author Chelsea Huang, a Dunlap Fellow at the Dunlap Institute for Astronomy & Astrophysics, University of Toronto, "Our findings suggest that a big fraction of Warm Jupiters cannot have migrated to their current positions dynamically and that it would be a good idea to consider more seriously that they formed where we find them."

Warm Jupiters are large, gas-giant exoplanets -- planets found around stars other than the Sun. They are comparable in size to the gas-giants in our Solar System. But unlike the Sun's family of giant planets, Warm Jupiters orbit their parent stars at roughly the same distance that Mercury, Venus and the Earth circle the Sun. They take 10 to two hundred days to complete a single orbit.

Because of their proximity to their parent stars, they are warmer than our system's cold gas giants -- though not as hot as Hot Jupiters, which are typically closer to their parent stars than Mercury.

It has generally been thought that Warm Jupiters didn't form where we find them today; they are too close to their parent stars to have accumulated large, gas-giant-like atmospheres. So, it appeared likely that they formed in the outer reaches of their planetary systems and migrated inward to their current positions, and might in fact continue their inward journey to become Hot Jupiters. On such a migration, the gravity of any Warm Jupiter would have disturbed neighbouring or companion planets, ejecting them from the system.

But, instead of finding "lonely," companion-less Warm Jupiters, the team found that 11 of the 27 targets they studied have companions ranging in size from Earth-like to Neptune-like.

"And when we take into account that there is more analysis to come," says Huang, "the number of Warm Jupiters with smaller neighbours may be even higher. We may find that more than half have companions."

1. Launched in 2009, the Kepler space telescope has discovered over 2000 exoplanets orbiting distant stars located in a patch of sky in the constellation Cygnus (and the number is rising as exoplanet candidates are confirmed as actual exoplanets through follow-up observations). Kepler cannot see an exoplanet orbiting its parent star; they are too far away, too small, and their parent stars too bright for any telescope to resolve them. Instead, Kepler measures the brightness of a star with enough accuracy to detect the slight decrease in brightness caused by an exoplanet moving in front of it.

2. In addition to the insight into Warm Jupiters, the analysis also provided the most conclusive evidence yet that Hot Jupiters lack companions and likely migrated to their current orbits. One exception is the recently discovered HJ known as WASP-47b, which was found to have companions.

Read more at Science Daily

Dark energy measured with record-breaking map of 1.2 million galaxies

The Sloan Digital Sky Survey and its Baryon Oscillation Spectroscopic Survey has transformed a two-dimensional image of the sky (left panel) into a three-dimensional map spanning distances of billions of light years, shown here from two perspectives (middle and right panels). This map includes 120,000 galaxies over 10% of the survey area. The brighter regions correspond to the regions of the Universe with more galaxies and therefore more dark matter.
A team of hundreds of physicists and astronomers have announced results from the largest-ever, three-dimensional map of distant galaxies. The team constructed this map to make one of the most precise measurements yet of the dark energy currently driving the accelerated expansion of the Universe.

"We have spent five years collecting measurements of 1.2 million galaxies over one quarter of the sky to map out the structure of the Universe over a volume of 650 cubic billion light years," says Jeremy Tinker of New York University, a co-leader of the scientific team carrying out this effort. "This map has allowed us to make the best measurements yet of the effects of dark energy in the expansion of the Universe. We are making our results and map available to the world."

These new measurements were carried out by the Baryon Oscillation Spectroscopic Survey (BOSS) program of the Sloan Digital Sky Survey-III. Shaped by a continuous tug-of-war between dark matter and dark energy, the map revealed by BOSS allows scientists to measure the expansion rate of the Universe and thus determine the amount of matter and dark energy that make up the present-day Universe. A collection of papers describing these results was submitted this week to the Monthly Notices of the Royal Astronomical Society.

BOSS measures the expansion rate of the Universe by determining the size of the baryonic acoustic oscillations (BAO) in the three-dimensional distribution of galaxies. The original BAO size is determined by pressure waves that travelled through the young Universe up to when it was only 400,000 years old (the Universe is presently 13.8 billion years old), at which point they became frozen in the matter distribution of the Universe. The end result is that galaxies have a slight preference to be separated by a characteristic distance that astronomers call the acoustic scale. The size of the acoustic scale at 13.7996 billion years ago has been exquisitely determined from observations of the cosmic microwave background from the light emitted when the pressure waves became frozen. Measuring the distribution of galaxies since that time allows astronomers to measure how dark matter and dark energy have competed to govern the rate of expansion of the Universe.

"We've made the largest map for studying the 95% of the universe that is dark," noted David Schlegel, an astrophysicist at Lawrence Berkeley National Laboratory (Berkeley Lab) and principal investigator for BOSS. "In this map, we can see galaxies being gravitationally pulled towards other galaxies by dark matter. And on much larger scales, we see the effect of dark energy ripping the universe apart."

Shirley Ho, an astrophysicist at Berkeley Lab and Carnegie Mellon University (CMU), co-led two of the companion papers and adds, "We can now measure how much the galaxies and stars cluster together as a function of time to such an accuracy we can test General Relativity at cosmological scales."

Ariel Sanchez of the Max-Planck Institute of Extraterrestrial Physics led the effort to estimate the exact amount of dark matter and dark energy based on the BOSS data and explains: "Measuring the acoustic scale across cosmic history gives a direct ruler with which to measure the Universe's expansion rate. With BOSS, we have traced the BAO's subtle imprint on the distribution of galaxies spanning a range of time from 2 to 7 billion years ago."

To measure the size of these ancient giant waves to such sharp precision, BOSS had to make an unprecedented and ambitious galaxy map, many times larger than previous surveys. At the time the BOSS program was planned, dark energy had been previously determined to significantly influence the expansion of the Universe starting about 5 billion years ago. BOSS was thus designed to measure the BAO feature from before this point (7 billion years ago) out to near the present day (2 billion years ago).

Jose Vazquez of Brookhaven National Laboratory combined the BOSS results with other surveys and searched for any evidence of unexplained physical phenomena in the results. "Our latest results tie into a clean cosmological picture, giving strength to the standard cosmological model that has emerged over the last eighteen years."

Rita Tojeiro of the University of St. Andrews is the other co-leader of the BOSS galaxy clustering working group along with Tinker. "We see a dramatic connection between the sound wave imprints seen in the cosmic microwave background 400,000 years after the Big Bang to the clustering of galaxies 7-12 billion years later. The ability to observe a single well-modeled physical effect from recombination until today is a great boon for cosmology."

The map also reveals the distinctive signature of the coherent movement of galaxies toward regions of the Universe with more matter, due to the attractive force of gravity. Crucially, the observed amount of infall is explained well by the predictions of general relativity.

"The results from BOSS provide a solid foundation for even more precise future BAO measurements, such as those we expect from the Dark Energy Spectroscopic Instrument (DESI)," says Natalie Roe, Physics Division director at Berkeley Lab. "DESI will construct a more detailed 3-dimensional map in a volume of space ten times larger to precisely characterize dark energy -- and ultimately the future of our universe."

Read more at Science Daily

Egypt's Oldest Writings Found

Egyptian authorities have unveiled the country's oldest papyri, which date date back 4,500 years.

The 30 papyri -- six of which are now on display at the Egyptian museum in Cairo -- were found in 2013 inside caves in the ancient Red Sea port of Wadi al-Jarf by a mission led by French Egyptologist Pierre Tallet and Egyptian Egyptologist Sayed Mahfouz.

"They contain the oldest known examples of Egyptian writing," Antiquities minister Khaled el-Anany said.

The papyri provide information about the lives of workers in the port during the reign of fourth dynasty King Khufu, also known as Cheops, for whom the Great Pyramid of Giza was built as a tomb.

The hieroglyphs reveal that workers and employees at Wadi al-Jarf port participated in the construction of the pyramid.

While most papyri are accounting documents, one papyrus was written by a middle-ranking official called Merer who was in charge of a team of sailors.

Hussein Abdel-Bassir, head of Scientific Publication Department at the ministry, said the document provides an everyday account of the sailors's work as they hauled limestone blocks from the quarries of Tura on the east bank of the Nile to the Great Pyramid at Giza plateau through the Nile and its canals.

The papyri also list revenues transferred from various Egyptian provinces to feed pyramid builders and pay their wages. Revenues were written in red, while payments to workers in black.

"The documents indicate the highly efficient administrative system in Khufu's reign," Egypt's ministry of Antiquities said.

From Discovery News

Biodiversity Plunges Below Levels 'Safe' for Humans

Having a range of different plant and animal species helps guarantee the health of the Earth, but a study Thursday suggested that biodiversity may be declining beyond safe levels.

On 58 percent of the world's land surface, which is home to 71 percent of the global population, "the level of biodiversity loss is substantial enough to question the ability of ecosystems to support human societies," said the report in the US journal Science.

Researchers at University College London based their study on data from hundreds of international scientists, crunching 2.38 million records for more than 39,000 species at more than 18,000 sites in the world.

They sought to estimate how biodiversity has changed over time, particularly since humans arrived and built on land.

Areas most affected included grasslands, savannas and shrublands, followed by many of the world's forests and woodlands, said the report.

Using a reference known as the Biodiversity Intactness Index (BII), which captures changes in species abundance, researchers said a safe limit of change is generally considered about a 10 percent reduction in BII.

In other words, "species abundance within a given habitat is 90 percent of its original value in the absence of human land use," said the report.

The study showed that global biodiversity has fallen below that threshold, to 84.6 percent.

"This is the first time we've quantified the effect of habitat loss on biodiversity globally in such detail and we've found that across most of the world biodiversity loss is no longer within the safe limit suggested by ecologists," said lead researcher Tim Newbold of UCL.

"In many parts of the world, we are approaching a situation where human intervention might be needed to sustain ecosystem function."

Read more at Discovery News

Jul 14, 2016

Ducklings Are Surprisingly Smart, Abstract Thinkers

Newly hatched ducklings are capable of abstract thinking, according to research that finds these little young birds quickly get the concepts of sam and different.

This ability had only been known in animals whose intelligence is well documented, such as humans, other apes, crows and parrots. Ducklings even take the skill to a whole other level above the other animals that are not of our own species.

"To our knowledge this is the first demonstration of a non-human organism learning to discriminate between abstract relational concepts without any reinforcement training," Alex Kacelnik of Oxford University's Department of Zoology said in a press release.

"The other animals that have demonstrated this ability have all done so by being repeatedly rewarded for correct performance, while our ducklings did it spontaneously, thanks to their predisposition to imprint when very young," he added. "And because imprinting happens so quickly, the ducklings learned to discriminate relational concepts much faster than other species, and with a similar level of precision."

Ducklings with their mother in River Cherwell at Oxford, U.K.
He and his team explained that imprinting, which allows ducklings to identify and follow their mother, can occur in as little as 15 minutes after the baby birds hatch. The scientists say that it is a powerful form of learning that can allow ducklings to follow any moving object, so long as they see it within the species' typical "sensitive period" for imprinting.

Kacelnik and colleagues initially presented ducklings with a pair of objects either the same as, or different from, each other in shape or in color. The objects moved around the ducklings in a circle, operated by a mobile-type motor from above. At this stage, the ducklings imprinted on the pairs of moving objects that were presented to them.

Next, each duckling was allowed to follow one of two pairs of objects composed of shapes or colors to which the duckling had not previously been exposed. For example, if an individual duckling had originally been exposed to a pair of spherical objects, in the choice test it might have had to choose between following a pair of pyramids (same) or a pair made up of one cube and one cuboid (different).

The ducklings showed that they understood the concepts of "same" and "different," since they elected to follow objects that matched one of these two relationships, depending on what they had imprinted on earlier, even though the baby birds had never before seen these newer sets of particular items and colors.

Read more at Discovery News

Trove of Bronze Age Textiles Found at Britain's Pompeii

A treasure trove of finely woven textiles has been unearthed during the final part of a 10-month excavation at a site in the UK county of Cambridgeshire which has been described as Britain's Pompeii.

Known as Must Farm, the settlement was home to several families who lived in a number of circular wooden houses built on stilts above a river. It was abandoned in haste 3,000 years ago as a giant fire destroyed the houses. The dwelings fell into the river, where thick silt and clay preserved the contents.

Charred in the fire that destroyed the houses and buried in the anaerobic waterlogged environment, the black, fragile textile fragments are some of the most finely-made Bronze Age fabrics ever discovered in Europe.

The fragments were all found inside the round houses along with plant fibers, balls of thread, and tools for spinning and weaving.

"This illustrates different stages of textile production," Susanna Harris, an expert in fabrics and a lecturer in archaeology at the University of Glasgow, said.

Some woven textiles are of superfine quality, even by modern standards, with threads around the diameter of coarse human hair (100 microns).

Fired clay weights found in the houses suggest the textile was produced using two clay weights so that the warp threads were held under tension on a loom.

"We found different types of fabric at Must Farm: woven textiles, a basketry technique called twining (weft twining) and knotted net," Harris told Discovery News.

"The textiles could have been used for clothing, although now they are just fragments. Nets could have been used for fishing, trapping or to carry things. The twining is a coarser material and could have been used for matting or for a range of other things such as containers or household item," Harris added.

Most of the superfine fabrics were made of linen. People used flax, a domesticated crop known to have been farmed in Britain from the Neolithic period onwards.

But fabrics were also made using wild species available in the local environment, such as the non-stinging fen nettle and lime bast, processed from the inner bark of lime trees.

"The textiles would have been soft and supple," Harris said.

Carried out by the University of Cambridge, the excavation has now come to a close. In the past months, archaeologists found an extraordinary time capsule buried just over six feet below the ground surface, where the river bed actually was in 1000-800 BC.

Such was the level of preservation that the footprints of those living there are still visible in the waterlogged sediments.

The way the objects were found indicate people were forced to leave everything behind when the houses caught on fire.

They left their clothing, jewelry, tools, furniture, and abandoned the meals in the cooking pots.

It is not known whether it was an accident or fire was set deliberately by hostile forces.

However, tree-ring analysis of the oak structures has suggested that at the time of the fire, the houses were still new and had only been lived in for a few months.

Read more at Discovery News

Turtles Evolved Shells for Digging, Not Protection

Artistic rendering of the early turtle ancestor Eunotosaurus (foreground) burrowing with a herd of Bradysaurus nearby.
The age-old question, "Why do turtles have shells?" would seem to have an obvious answer, protection, yet new research finds that turtles first evolved shells to help with digging underground to escape hot, dry environments.

The findings, published in the journal Current Biology, add to the growing list of key anatomical features that evolved to solve one problem but were then applied to another function. The features, known as "exaptations," include everything from feathers to the gas bladder of early fish, which evolved to become lungs in terrestrial animals.

The new study focused on a 260-million-year-old fossil of the oldest "proto turtle," or early turtle ancestor, which in this case is called Eunotosaurus africanus. Its remains were found by then 8-year-old Kobus Snyman, who spotted it on his father's farm in the Karoo region of South Africa.

"The weather was extremely arid in the Karoo Basin of South Africa 260 million years ago," lead author Tyler Lyson said. "A common mechanism for dealing with arid environments, among both extant and extinct animals, is to burrow underground. Burrows provide a more moderate and stable environment."

Lyson, who is the curator of vertebrate paleontology at the Denver Museum of Nature & Science, and his colleagues studied the fossil found by Snyman, as well as other Eunotosaurus specimens unearthed by two of the study's co-authors, Roger Smith and Bruce Rubidge from the University of Witwatersrand.

They determined that the animal's broad ribs, which over time replaced soft tissue with bone, provided a stable base from which Eunotosaurus could operate its front leg digging.

"A stable base is needed to counteract the force of the digging mechanism, in this case the forelimbs," Lyson explained. "Digging animals thus have adaptations to dig burrows (large hands, large claws, strong forelimbs, etc.) and adaptations to deal with counteracting the digging mechanism force."

The modification of the ribs that eventually led to the shell resulted in other dramatic changes, since the ribs and nearby muscles are involved in both breathing and locomotion. In fact, some early animals could not breathe and run at the same time. To this day, animals that retain such an early breathing mechanism, such as lizards, must hold their breath as they run.

In turtles, as the ribs broadened over millions of years, they became less effective at helping to ventilate the lungs and more associated with locomotion, according to the researchers. The nearby hypoxial muscles, on the other hand, took on a purely respiratory role over time.

"Such a division of function allows turtles to breathe and walk simultaneously and helps them deal with the constraint of having a dual function for both the ribs and muscles," Lyson said.

The extreme changes turned out to be extremely fortuitous for turtles. When the Permian-Triassic mass extinction occurred 252 million years ago, burrowing likely helped to save them, Lyson believes.

When the Triassic-Jurassic extinction event happened much later, 66 million years ago, turtles had evolved to become largely aquatic, with their water environment helping to buffer them from the extinction that killed off dinosaurs (save for some birds) and many other animals. The ability to dig well helped the turtles live on both land and in water.

Hans-Dieter Sues, curator and department chairman of vertebrate paleontology at the Smithsonian Museum of Natural History, told Discovery News that shells helped to protect the vital organs of water-dwelling early turtles. He also believes that shells "may have initially helped with buoyancy control by making the animal heavier."

Read more at Discovery News

Dinosaurs Might Have Gone Up in Smoke

Artist's concept of a planetary collision.
A new theory on the extinction of dinosaurs and other animals at the end of the Cretaceous says that massive amounts of smoke and soot following the Chicxulub asteroid impact led to a devastating domino effect 66 million years ago.

The asteroid, which slammed into Earth at what is now Mexico's Yucatan Peninsula, not only immediately burnt some dinosaurs and other animals to a crisp, but also, according to the new study, hit the worst possible spot: an oil-rich area.

"The stratospheric soot was ejected from the oil-rich area by the asteroid impact and was spread globally," Kunio Kaiho of Tohoku University told Discovery News.

"The soot aerosols caused sufficiently colder climates at mid–high latitudes and drought with milder cooling at low latitudes on land, in addition to causing limited cessation of photosynthesis in global oceans within a few months to two years after the impact, followed by surface-water cooling in global oceans in a few years."

In short, it was curtains for dinosaurs and many other animals shortly after the asteroid hit.

The scientists found that sediments in both locations for the target time period shared the same composition of combusted organic molecules.

"Therefore, this is the soot from the asteroid crash," Kaiho said.

He and his team created a global climate model at the Meteorological Research Institute, and found that soot in the atmosphere after the asteroid impact would have produced colder climates at mid-high latitudes leading to the extinction of most species in these regions.

The soot, however, would have also caused droughts accompanied by mild cooling at lower latitudes that would have led to the extinction of dinosaurs, but would have allowed crocodiles and certain other animals to survive.

Global climate change caused by soot aerosol following the Chicxulub asteroid strike.
Water-dwelling species would have still had some resources. Small mammals and reptiles could have burrowed underground.

"The different habitats of the dinosaurs and small mammals and reptiles would have been key factors in determining their extinction or survival," he said.

Some dinosaurs, of course, did survive: birds.

As for the dinosaurs that were not immediately killed by the asteroid, the drastic climate change following the asteroid strike would have led to loss of soil moisture and vegetation in many areas.

Kaiho said that herbivorous dinosaurs would have consumed the ever-decreasing available plants, resulting in the eventual disappearance of such food, "similar to overgrazing leading to desertification today."

As the plant-eating dinosaurs died out, so too did the remaining carnivorous dinosaurs, suggests the new paper.

In terms of dinosaurs literally going up in smoke, Manabu Sakamoto of the University of Reading, who has conducted other research on the dinosaur extinction event, told Discovery News, "Some dinosaurs definitely would have been instantly killed in the impact."

Sakamoto added that still other dinosaurs might have perished in a tsunami caused by the blast, but "the majority of the remaining dinosaurs would have likely starved to death as vegetation died out owing to the layer of ash that blacked out the sky (nuclear winter)."

Read more at Discovery News

Jul 13, 2016

New Dinosaur Had Tiny T.rex Arms

Tiny forelimbs were apparently all the rage in the Late Cretaceous, as paleontologists have discovered a new dinosaur that had small Tyrannosaurus rex-like arms.

The new dino, named Gualicho shinyae, shared T. rex's meat-loving ways, according to the paper, published in the journal PLOS ONE. In future, research on it could solve mysteries about its tiny arms as well as those of T. rex and other dinosaurs sporting this look.

"By learning more about how reduced forelimbs evolved, we may be able to figure out why they evolved," co-author Peter Makovicky, who is The Field Museum's curator of dinosaurs, said in a press release.

The new dinosaur Gualicho showing the fossils that were found along with its other likely anatomy.
The research team consisted of an international group of researchers from The Field Museum, Universidad Maimónides in Argentina, the Dinosaur Institute at the Natural History Museum of Los Angeles County, and the Gobierno de la Provincia de Río Negro in Argentina.

Akiko Shinya, The Field Museum's chief fossil preparator, found the remains for the dinosaur during an expedition to the fossil-rich Huincul Formation of northern Patagonia. The species name shinyae honors Shinya, while the generic name Gualicho derives from Gualichu, a spirit revered by Patagonia's Tehuelche people.

Akiko Shinya, the Field Museum's chief fossil preparator for whom the new dinosaur is named, with Gualicho shinyae at the dig site.
The team joked about "the curse of Gualicho," since they had some bad luck. At one point, a truck even rolled over with scientists inside, but everyone was OK, save for some cuts and bruises.

The dino Gualicho lived about 100–66 million years ago and was an allosaurid, referring to a type of medium-to-large carnivorous two-legged dinosaurs. The researchers estimate that Gualicho weighed around 1,000 pounds, comparable to the heft of a modern polar bear.

Read more at Discovery News

Supernovas Blasted Prehistoric Earth With Radiation

A false-color image of an unrelated supernova remnant, G292.0+1.8, taken by the Chandra X-ray telescope.
Cancers in animals could have increased slightly after our planet was blanketed with radiation from two prehistoric supernovae, according to new research.

The star explosions took place between 1.7 million and 8.7 million years ago, irradiating the landscape with high-energy cosmic rays. Cosmic rays hit Earth every day, but the stellar explosions would have increased the radiation striking our planet.

When the cosmic rays hit molecules in our atmosphere, a cascade of secondary particles such as X-rays, protons and muons are produced. Some muon radiation is normal, but the supernovae would have temporarily tripled the dose for land animals and animals living in shallow waters, said co-author Adrian Melott, a University of Kansas physics researcher, in a statement.

"I was expecting there to be very little effect at all," he said. "The supernovae were pretty far way — more than 300 light years — that's really not very close."

Artist's impression of cosmic rays, which usually originate from outside the solar system, entering the heliopause (the sun's region of influence).
The radiation would have given animals the equivalent dose of one additional CT scan in radiation per year. CT scans take X-ray images from several angles to let doctors look inside tumors and other objects. The night sky also would have bathed in blue light from the explosions, making it difficult for animals to sleep.

Some researchers have speculated that there could be a link between increased cosmic rays and a cooler climate on Earth, although that link isn't proven for sure. (Simply put, the theory associates cosmic rays with aerosols, which could produce clouds, which in turn reduces the amount of solar radiation on the surface.) If a connection could be made, Melott said it is possible the supernovae were associated with a known, smaller mass extinction 2.59 million years ago when Earth went through repeated ice ages.

Read more at Discovery News

Juno Sends Back First Orbital Photo of Jupiter

Image relayed by NASA's Juno spacecraft on July 10. Three of Jupiter's moons, Io, the innermost moon, Europa, upper right, and Ganymede, lower right, are visible.
Having survived being slingshot around Jupiter, NASA's Juno spacecraft turned its camera back on this week and snapped a picture of its new home.

The space probe ended a five-year flight to the biggest planet in the solar system on July 4 with a do-or-die breaking maneuver so it could shed speed and fall into Jupiter's gravity well.

Juno will take a couple of months to re-position itself for 37 looping orbits around the planet's poles, coming at closest approach to about 2,600 miles (4,100 kilometers) above Jupiter's cloud tops.

To avoid as much radiation as possible, Juno will buzz Jupiter only once every 14 days. Even though its instruments are inside a titanium vault, Juno is expected to be nearly electronically fried after 20 months.

Juno's orbit was designed to maximize the odds of a successful science mission, the primary goal of which is to measure how much water Jupiter contains. That information will serve as a yardstick for calculating how far from the sun the biggest planet formed, setting the stage for everything else in the solar system, including Earth and its fortuitous position conductive to the evolution of life.

This week, NASA got its first picture from Juno since its camera was turned back on following the probe's July 4 plunge through Jupiter's radioactive welcome mat.

The image was taken 9:30 a.m. EDT on Sunday when Juno was 2.7 million miles (4.3 million kilometers) from Jupiter on the outbound leg of the first of two planned 53.5-day capture orbits, NASA said.

The image, released on Tuesday, shows Jupiter's famed Great Red Spot, a gigantic atmospheric storm that astronomers on Earth have been watching for four centuries.

Read more at Discovery News

Clouds Shifting Toward Poles With Climate Change

Over the last three decades, global cloud patterns have changed, and mid-latitude storm tracks--the paths that cyclones travel in the Northern and Southern hemispheres--have been drifting toward our planet's poles, according to a new study published in Nature.

The changes, documented by researchers from Lawrence Livermore National Laboratory, Scripps Institution of Oceanography, University of California, Riverside and Colorado State University match those predicted by climate model simulations, and they've probably had added to global warming that is causing climate change.

Joel Norris, a climate researcher at Scripps, called the study "the first credible demonstration that cloud changes we expect from climate models and theory are currently happening."

Those findings are good news for scientists who for years have struggled to model the role of clouds in climate change. But as Veerabhadran Ramanathan of Scripps, who was not involved in the study, told Science magazine, that's not such good news for the planet and its inhabitants. The movement of clouds toward the polls is "problematic for our future" and makes efforts to slow warming more urgent, he said.

Clouds play an important role in climate change models because they both reflect solar radiation back into space (the albedo effect) and restrict the escape of heat into space. But calculating how those processes balance one another has been difficult, in part because clouds themselves are influenced by climate change, even as they influence it.

Another problem, according to the Science article, is that researchers have been compelled to use data from satellites that were not set up to look at clouds. Geostationary satellites, for example, look directly down at the Earth's surface, rather than using the slanted view that would make it easier to detect clouds.

To overcome those problems, Norris and his colleagues performed corrections that accounted for those imperfections in cloud data, and then studied the results for clear-term patterns.

In addition to the drift in storm tracks, the scientists also confirmed that subtropical dry regions are expanding, and that the tops of the tallest clouds are getting taller. All of these changes can worsen global warming.

Read more at Discovery News

Jul 12, 2016

Deepest ever look into Orion

This spectacular image of the Orion Nebula star-formation region was obtained from multiple exposures using the HAWK-I infrared camera on ESO's Very Large Telescope in Chile. This is the deepest view ever of this region and reveals more very faint planetary-mass objects than expected.
An international team has made use of the power of the HAWK-I infrared instrument on ESO's Very Large Telescope (VLT) to produce the deepest and most comprehensive view of the Orion Nebula to date. Not only has this led to an image of spectacular beauty, but it has revealed a great abundance of faint brown dwarfs and isolated planetary-mass objects. The very presence of these low-mass bodies provides an exciting insight into the history of star formation within the nebula itself.

The famous Orion Nebula spans about 24 light-years within the constellation of Orion (constellation), and is visible from Earth with the naked eye, as a fuzzy patch in Orion's sword. Some nebulae, like Orion, are strongly illuminated by ultraviolet radiation from the many hot stars born within them, such that the gas is ionised and glows brightly.

The relative proximity of the Orion Nebula makes it an ideal testbed to better understand the process and history of star formation, and to determine how many stars of different masses form.

Amelia Bayo (Universidad de Valparaíso, Valparaíso, Chile; Max-Planck Institut für Astronomie, Königstuhl, Germany), a co-author of the new paper and member of the research team, explains why this is important: "Understanding how many low-mass objects are found in the Orion Nebula is very important to constrain current theories of star formation. We now realise that the way these very low-mass objects form depends on their environment."

This new image has caused excitement because it reveals a unexpected wealth of very-low-mass objects, which in turn suggests that the Orion Nebula may be forming proportionally far more low-mass objects than closer and less active star formation regions.

Astronomers count up how many objects of different masses form in regions like the Orion Nebula to try to understand the star-formation process. Before this research the greatest number of objects were found with masses of about one quarter that of our Sun. The discovery of a plethora of new objects with masses far lower than this in the Orion Nebula has now created a second maximum at a much lower mass in the distribution of star counts.

These observations also hint tantalisingly that the number of planet-sized objects might be far greater than previously thought. Whilst the technology to readily observe these objects does not exist yet, ESO's future European Extremely Large Telescope (E-ELT), scheduled to begin operations in 2024, is designed to pursue this as one of its goals.

Read more at Science Daily

Blue is an indicator of first star's supernova explosions: More than 13 billion years old

Artist's conception of evolution of metal-poor and "metal-rich" supernovae at different phases and simulated light curves from shock breakout (ultraviolet) through plateau (red, green and blue colors) to exponential decay. Both shock breakout and "plateau" phases are shorter, bluer, and fainter for metal-poor supernova in comparison with "metal-rich" supernova.
An international collaboration led by the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) have discovered that the color of supernovae during a specific phase could be an indicator for detecting the most distant and oldest supernovae in the Universe -- more than 13 billion years old.

For 100 million years after the big bang, the Universe was dark and filled with hydrogen and helium. Then, the first stars appeared, and heavier elements (referred to as "metals," meaning anything heavier than helium) were created by thermonuclear fusion reactions within stars.

These metals were spread around the galaxies by supernova explosions. Studying first generation supernovae provides a glimpse into what the Universe looked like when the first stars, galaxies, and supermassive black holes formed, but to date it has been difficult to distinguish a first generation supernova from an ordinary supernova.

A new study published in The Astrophysical Journal, led by Kavli IPMU Project Researcher Alexey Tolstov, identified characteristic changes between these supernovae types after experimenting with supernovae models based on extremely metal-poor stars with virtually no metals. These stars make good candidates because they preserve their chemical abundance at the time of their formation.

"The explosions of first generation of stars have a great impact on subsequent star and galaxy formation. But first, we need a better understanding of how these explosions look like to discover this phenomenon in the near future. The most difficult thing here is the construction of reliable models based on our current studies and observations. Finding the photometric characteristics of metal poor supernovae, I am very happy to make one more step to our understanding of the early Universe." said Tolstov.

Similar to all supernovae, the luminosity of metal-poor supernovae show a characteristic rise to a peak brightness followed by a decline. The phenomenon starts when a star explodes with a bright flash, caused by a shock wave emerging from the surface of the progenitor stars after the core collapse phase. Shock breakout is followed by a long ''plateau'' phase of almost constant luminosity lasting several months, before a slow exponential decay.

An international collaboration led by the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) have discovered that the color of supernovae during a specific phase could be an indicator for detecting the most distant and oldest supernovae in the Universe -- more than 13 billion years old. For 100 million years after the big bang, the Universe was dark and filled with hydrogen and helium. Then, the first stars appeared, and heavier elements (referred to as "metals," meaning anything heavier than helium) were created by thermonuclear fusion reactions within stars.

The team calculated light curves of metal-poor supernova, produced by blue supergiant stars, and "metal-rich" red supergiant stars. Both shock breakout and "plateau" phases are shorter, bluer, and fainter for metal-poor supernova in comparison with "metal-rich" supernova. The team concluded the color blue could be used as an indicator of a low-metallicity progenitor. The expanding universe makes it difficult to detect first star and supernova radiation, which shift into the near-infrared wavelength.

Read more at Science Daily

'Frankenstein' galaxy surprises astronomers

At left, in optical light, UGC 1382 appears to be a simple elliptical galaxy. But spiral arms emerged when astronomers incorporated ultraviolet and deep optical data (middle). Combining that with a view of low-density hydrogen gas (shown in green at right), scientists discovered that UGC 1382 is gigantic.
About 250 million light-years away, there's a neighborhood of our universe that astronomers had considered quiet and unremarkable. But now, scientists have uncovered an enormous, bizarre galaxy possibly formed from the parts of other galaxies.

A new study to be published in the Astrophysical Journal reveals the secret of UGC 1382, a galaxy that had originally been thought to be old, small and typical. Instead, scientists using data from NASA telescopes and other observatories have discovered that the galaxy is 10 times bigger than previously thought and, unlike most galaxies, its insides are younger than its outsides, almost as if it had been built using spare parts.

"This rare, 'Frankenstein' galaxy formed and is able to survive because it lies in a quiet little suburban neighborhood of the universe, where none of the hubbub of the more crowded parts can bother it," said study co-author Mark Seibert of the Observatories of the Carnegie Institution for Science, Pasadena, California. "It is so delicate that a slight nudge from a neighbor would cause it to disintegrate."

Seibert and Lea Hagen, a graduate student at Pennsylvania State University, University Park, came upon this galaxy by accident. They had been looking for stars forming in run-of-the-mill elliptical galaxies, which do not spin and are more three-dimensional and football-shaped than flat disks. Astronomers originally thought that UGC 1382 was one of those.

But while looking at images of galaxies in ultraviolet light through data from NASA's Galaxy Evolution Explorer (GALEX), a behemoth began to emerge from the darkness.

"We saw spiral arms extending far outside this galaxy, which no one had noticed before, and which elliptical galaxies should not have," said Hagen, who led the study. "That put us on an expedition to find out what this galaxy is and how it formed."

Researchers then looked at data of the galaxy from other telescopes: the Sloan Digital Sky Survey, the Two Micron All-Sky Survey (2MASS), NASA's Wide-field Infrared Survey Explorer (WISE), the National Radio Astronomy Observatory's Very Large Array and Carnegie's du Pont Telescope at Las Campanas Observatory. After GALEX revealed previously unseen structures to the astronomers, optical and infrared light observations from the other telescopes allowed the researchers to build a new model of this mysterious galaxy.

As it turns out, UGC 1382, at about 718,000 light-years across, is more than seven times wider than the Milky Way. It is also one of the three largest isolated disk galaxies ever discovered, according to the study. This galaxy is a rotating disk of low-density gas. Stars don't form here very quickly because the gas is so spread out.

But the biggest surprise was how the relative ages of the galaxy's components appear backwards. In most galaxies, the innermost portion forms first and contains the oldest stars. As the galaxy grows, its outer, newer regions have the youngest stars. Not so with UGC 1382. By combining observations from many different telescopes, astronomers were able to piece together the historical record of when stars formed in this galaxy -- and the result was bizarre.

"The center of UGC 1382 is actually younger than the spiral disk surrounding it," Seibert said. "It's old on the outside and young on the inside. This is like finding a tree whose inner growth rings are younger than the outer rings."

The unique galactic structure may have resulted from separate entities coming together, rather than a single entity that grew outward. In other words, two parts of the galaxy seem to have evolved independently before merging -- each with its own history.

At first, there was likely a group of small galaxies dominated by gas and dark matter, which is an invisible substance that makes up about 27 percent of all matter and energy in the universe (our own matter is only 5 percent). Later, a lenticular galaxy, a rotating disk without spiral arms, would have formed nearby. At least 3 billion years ago, the smaller galaxies may have fallen into orbit around the lenticular galaxy, eventually settling into the wide disk seen today.

Read more at Science Daily

Homo erectus walked as we do

The shapes of the fossil and modern footprints are nearly indistinguishable.
Fossil bones and stone tools can tell us a lot about human evolution, but certain dynamic behaviours of our fossil ancestors -- things like how they moved and how individuals interacted with one another -- are incredibly difficult to deduce from these traditional forms of paleoanthropological data. Researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, along with an international team of collaborators, have recently discovered multiple assemblages of Homo erectus footprints in northern Kenya that provide unique opportunities to understand locomotor patterns and group structure through a form of data that directly records these dynamic behaviours. Using novel analytical techniques, they have demonstrated that these H. erectus footprints preserve evidence of a modern human style of walking and a group structure that is consistent with human-like social behaviours.

Habitual bipedal locomotion is a defining feature of modern humans compared with other primates, and the evolution of this behaviour in our clade would have had profound effects on the biologies of our fossil ancestors and relatives. However, there has been much debate over when and how a human-like bipedal gait first emerged in the hominin clade, largely because of disagreements over how to indirectly infer biomechanics from skeletal morphologies. Likewise, certain aspects of group structure and social behaviour distinguish humans from other primates and almost certainly emerged through major evolutionary events, yet there has been no consensus on how to detect aspects of group behaviour in the fossil or archaeological records.

In 2009, a set of 1.5-million-year-old hominin footprints was discovered at a site near the town of Ileret, Kenya. Continued work in this region by scientists from the Max Planck Institute for Evolutionary Anthropology, and an international team of collaborators, has revealed a hominin trace fossil discovery of unprecedented scale for this time period -- five distinct sites that preserve a total of 97 tracks created by at least 20 different presumed Homo erectus individuals. Using an experimental approach, the researchers have found that the shapes of these footprints are indistinguishable from those of modern habitually barefoot people, most likely reflecting similar foot anatomies and similar foot mechanics. "Our analyses of these footprints provide some of the only direct evidence to support the common assumption that at least one of our fossil relatives at 1.5 million years ago walked in much the same way as we do today," says Kevin Hatala, of the Max Planck Institute for Evolutionary Anthropology and The George Washington University.

Based on experimentally derived estimates of body mass from the Ileret hominin tracks, the researchers have also inferred the sexes of the multiple individuals who walked across footprint surfaces and, for the two most expansive excavated surfaces, developed hypotheses regarding the structure of these H. erectus groups. At each of these sites there is evidence of several adult males, implying some level of tolerance and possibly cooperation between them. Cooperation between males underlies many of the social behaviours that distinguish modern humans from other primates. "It isn't shocking that we find evidence of mutual tolerance and perhaps cooperation between males in a hominin that lived 1.5 million years ago, especially Homo erectus, but this is our first chance to see what appears to be a direct glimpse of this behavioural dynamic in deep time," says Hatala.

From Science Daily

Jul 11, 2016

Is Lightning Hotter Than the Sun?

What's five times hotter than the sun and capable of sending a DeLorean back to the future?

Yep, the answer is a bolt of lightning, which can reach temperatures of roughly 30,000 kelvins (53,540 degrees Fahrenheit). The sun, on the other hand, is eclipsed in this case — its surface temperature is just 6,000 kelvins (10,340 degrees Fahrenheit). It's one amazing piece of science trivia, but what exactly does it all mean?

First, it's important to realize that the sun's surface is actually its coolest layer. Dive down to its core, and you'd encounter plasma temperatures of about 15 million kelvins (about 27 million degrees Fahrenheit). Things also heat up just above the sun's surface, as its atmosphere exceeds temperatures of 500,000 kelvins (about 900,000 degrees Fahrenheit).

"Power is the rate at which energy is used or transferred," explains University of Washington physics professor Robert H. Holzworth. "So power is energy per second, and the energy per second in lighting can be very high, but it only lasts a really, really, short time, like tens of microseconds. So the total energy isn't like the total energy from the sun, obviously, but the rate the energy dissipates can be very large. It's one of the most powerful natural phenomena on Earth."

But just where does all that energy come from?

"Ultimately that energy comes from the sun," Holzworth says. "The sun heats up the surface, which results in differential heating. One area is warmer than another, and warm air rises since it's less dense. When you have moisture in the air, that parcel of air can go up much higher than it would otherwise. That's the basis of very strong convection."

At this point, Holzworth explained, ice forms in the parcel of rising air.

"You can get very efficient charge transfer, so that you get positive and negative charges separated by the bouncing ice," Holzworth says. "It turns out that when you have ice collisions, there's some likelihood that, at certain places in the cloud, smaller ice formations such as snowflakes are going to get charged positive, leaving behind negative charge on the hail stones or the soft hail."

The lighter, positively charged ice particles continue to rise toward the top of the clouds. Meanwhile, the heavier, negatively charged ice particles plummet, thus separating the charge in a process known as gravity separation.

This process creates a strong electric field, which in turn ionizes the air around the cloud, separating air molecules into positive ions and electrons. Electrons move far more easily in ionized air. Once a channel of ionized air is established from cloud to ground (or between two points in a cloud), high-temperature current flows in the form of a lightning stroke that neutralizes the charge separation.

Richard E. Orville, director of Texas A&M University's atmospheric sciences department, equates the breakdown of an electrical buildup to an incident he witnessed in eighth grade involving a screwdriver and an electrical socket.

"There was a fellow sitting in front of me, and for some reason he had a screwdriver in his hand," Orville said. "He stuck it in the wall socket and received a very big discharge. Of course that's because you had an excess of electricity in a plug just waiting to be tapped, which we do every day when we plug in a device. So in this case, you've got a buildup of electrical charge in the base of a cloud, and breakdown occurs when the electric field gets high enough."

So while it wouldn't be accurate to say a bolt of lightning is hotter than the sun itself, these flashes of electrical energy do reach higher temperatures than the surface of the sun.

From Discovery News

New Dwarf Planet Discovered in Outer Solar System

Artist rendering of the orbit of newly found RR245 (orange line). Objects as bright or brighter than RR245 are labeled. The Minor Planet Center describes the object as the 18th largest in the Kuiper Belt.
Astronomers have found another Pluto-like dwarf planet located about 20 times farther away from the sun than Neptune.

The small planet, designed 2015 RR245, is estimated to be about 435 miles in diameter and flying in an elliptical, 700-year orbit around the sun.

At closest approach, RR245 will be about 3.1 billion miles from the sun, a milestone it is expected to next reach in 2096.

At its most distant point, the icy world is located about 7.5 billion miles away.

It was found by a joint team of astronomers using the Canada-France-Hawaii Telescope (CFHT) on Maunakea, Hawaii, in images taken in September 2015 and analyzed in February. The discovery was announced on Monday in the Minor Planet Electronic Circular.

The Minor Planet Center describes RR245 as the 18th largest object in the Kuiper Belt.

"The vast majority of the dwarf planets like RR245 were destroyed or thrown from the solar system in the chaos that ensued as the giant planets moved out to their present positions," the CFHT said. "RR245 is one of the few dwarf planets that has survived to the present day — along with Pluto and Eris, the largest known dwarf planets."

Observations of RR245 will continue. Once its precise orbit is known the dwarf planet will get an official name. As discoverers, the Outer Solar System Origins Survey team has naming rights.

Read more at Discovery News

Skeleton With Alien-Like Skull Found

Archaeologists in Mexico have unearthed the 1,600 year old skeleton of a woman with an elongated, "alien-like" skull and stone-encrusted teeth.

Found at a town called San Juan Evangelista, near the ancient ruins of Teotihuacan some 30 miles from Mexico City, the skeleton belongs to an upper class woman who died at around 35-40 years of age.

According to a statement by the National Anthropology and History Institute (INAH), the woman was buried with offerings. Archaeologists led by Veronica Ortega found 19 jars near the bones. They estimate the burial dates between 350-400 AD.

Dubbed "The Woman of Tlailotlacan," the skeleton features a skull that was deliberately deformed.

"It shows signs of erect tabular deformation which was achieved by a very extreme compression," anthropologist Jorge Velasco Archer said.

Tabular or flat-head deformations required compressing the child's frontal and occipital bones with boards or pads. The meaning of skull shaping wasn't just aesthetic but also religious and social.

The Maya themselves told Gonzalo Fernández de Oviedo, a Spanish chronicler, that head shaping was made to look "noble and handsome and better able to carry loads."

Velasco Archer noted that this type of cranial deformation is more likely found in the southern part of Mesoamerica rather than in the Mexican central region where Teotihuacan is located.

Encrusted with two round pyrite stones, the skull's front teeth confirmed the woman was a foreigner in Teotihuacan. The dental decoration technique is typical of Mayan regions in southern Mexico and Central America.

The woman also wore a prosthetic lower tooth made of a green stone known as serpentine.

"Tartar formation on the serpentine prosthetic teeth shows the woman used it for a long time," Velasco Archer said.

Analysis is ongoing to determine how the false tooth stood in place and whether some kind of cement was used.

Read more at Discovery News

Monkey-Made Nut Processing Site Found

A monkey-operated cashew nut processing site, dating to at least 700 years ago, has just been discovered in Brazil.

The findings, outlined in the journal Current Biology, document the earliest evidence for tool use by monkeys outside of Africa. Humans might have even first learned about cashew nuts from the industrious little primates.

"One of the ways that modern hunter gatherers gain information about the landscape is to observe the behavior of other animals -- alarm calls by monkeys can signal a predator threat that also affects humans, for example," lead author Michael Haslam, a senior research fellow in primate archaeology at the University of Oxford, told Discovery News.

"It's speculative," he added, "but noisy and prominent cashew processing by capuchin monkeys was unlikely to have been missed by ancient Brazilians."

The following three videos show the capuchins at work:

Haslam and his colleagues observed capuchin monkeys busily using stones as hand-held hammers and anvils to pound open cashew nuts, which are actually seeds within a hard fruit that grows on the brightly colored cashew apple. Pulp inside the apple is edible as well, but is hard to transport, explaining why the apples are not often found outside of Latin America.

To establish the antiquity of capuchin cashew processing at the site -- Serra da Capivara National Park in northeast Brazil -- the researchers conducted an excavation that recovered many capuchin stone tools. Small pieces of charcoal found with the large tool cache were radiocarbon dated to at least 700 years ago. This means that the tools predate the arrival of Europeans in the New World.

A capuchin cashew-processing stone covered with residue from the nuts.
The researchers estimate that around 100 generations of capuchins have processed cashews at the same site over the past seven centuries. The number could even be much higher. The monkeys are thought to have originated in Africa before traveling, perhaps unintentionally on floating vegetation, to the New World some 40 million years ago. The cashew trees, on the other hand, are native to Brazil. At Serra da Capivara, the trees date to about 8,500–7200 years ago.

Senior author Tiago Falótico, a postdoctoral research fellow at the University of São Paulo Institute of Psychology, said, "Cashews nuts are not a primary food source, but capuchins have a great preference for it when it is present. Some of the individuals even discarded apparently good cashew apples just to eat the nut."

He continued, "We know that cashew nuts are very energetic and balanced across carbohydrates, fat, and protein, characteristics that makes cashew nuts a good food choice."

Researchers Lydia Luncz and Tiago Falótico, who is standing under a cashew tree. Both are at the study site, Serra da Capivara National Park in northeast Brazil.
As for how the monkeys first learned how to process cashews, the researchers suggest that shelled edibles once helped save the capuchins from starvation.

Co-author Eduardo Ottoni, a professor in the Institute of Psychology at the University of São Paulo, explained that "robust" capuchins split off from slenderer built ones as they left the Amazon forest and reached the Atlantic forest.

"That involved crossing much drier areas where hard-shelled fruit was probably a key resource, hence their robust jaws," Ottoni said. "In such a context, stone-aided nut cracking was arguably very useful."

Capuchins do not just use tools to process cashews. Ottoni said that some select even heavier stones to bust open hard palm nuts in certain regions. The Serra da Capivara monkeys use different stones to dig plant roots and tubers.

They also use sticks as probes to dislodge prey -- mostly lizards -- from rock cracks. They use sticks to pull spiders out of their burrows and to collect honey. Each tool is carefully selected for size, weight and usefulness to the particular task.

Other monkeys, such as macaques, are also adept at using tools. Last year, for example, Amanda Tan from Nanyang Technological University and her team documented how macaques use one-handed hammering with the points of small tools to crack open oysters with precision at Piak Nam Yai and Thao Islands in Laem Son National Park, Thailand.

Read more at Discovery News

99-Million-Year-Old Fanged Spiders Stuck in Amber

About 99 million years ago, two bizarre spiders — each sporting hard, armored plates on their bodies and horns on their fangs — became mummified in sticky tree resin that turned into amber.

They remained there until recently, when scientists discovered the chunk of amber and analyzed the spiders locked inside.

These ancient, extinct spiders are part of a spider family called Tetrablemmidae, a group whose males often have horns on their heads and fangs, said study lead author Paul Selden, a professor of invertebrate paleontology at the University of Kansas.

But the newly identified species has rather "complex" horns that have two prongs at their tips, which is peculiar, even for a Tetrablemmid spider, Selden said.

"The new fossil is an adult male and takes these horns to an extreme," Selden told Live Science in an email. "Nevertheless, the new species can be firmly placed within the modern family and is similar to species living in Southeast Asia and China today."

Both of the amber fossils came from a mine in northern Burma (also known as Myanmar). Selden met with a dealer who was selling the polished specimens in China, and the scientist and his colleagues purchased those that were of scientific interest, he said.

Tetrablemmid spiders usually have six or fewer eyes, but the researchers couldn't find any on the Cretaceous-age specimens, likely because those body parts didn't preserve well, he said. However, the mummies look somewhat similar to the modern Tetrablemmid spiders in the genus Sinamma, which live in southwest China. Sinamma species have eyes on the upper part of the head, so the newfound species likely did too, the researchers said.

"What caught my eye about this spider was the enormous projection on its head, most likely bearing eyes, and the bizarre horns on its fangs," Selden said.

Selden and his colleagues named the new species Electroblemma bifida. The genus name refers to the Greek "elektron," or amber, and "blemma" or appearance, a common suffix used for tetrablemmid spiders. The species name refers to the two-pronged tip at the end of the horns on this spider's fangs, the researchers said.

In general, Tetrablemmid spiders have armor-like hard plates covering their bodies that protect them from predators, such as spider-hunting wasps, Selden said. These spiders are usually tiny, only about a quarter inch (0.6 centimeters) long. The mummified specimens are slightly smaller, with one measuring 0.06 inches (1.58 millimeters) long.

Read more at Discovery News

Jul 10, 2016

Dawn maps Ceres craters where ice can accumulate

At the poles of Ceres, scientists have found craters that are permanently in shadow (indicated by blue markings). Such craters are called "cold traps" if they remain below about minus 240 degrees Fahrenheit (minus 151 degrees Celsius). These shadowed craters may have been collecting ice for billions of years because they are so cold. This image was created using data from NASA's Dawn spacecraft.
Scientists with NASA's Dawn mission have identified permanently shadowed regions on the dwarf planet Ceres. Most of these areas likely have been cold enough to trap water ice for a billion years, suggesting that ice deposits could exist there now.

"The conditions on Ceres are right for accumulating deposits of water ice," said Norbert Schorghofer, a Dawn guest investigator at the University of Hawaii at Manoa. "Ceres has just enough mass to hold on to water molecules, and the permanently shadowed regions we identified are extremely cold -- colder than most that exist on the moon or Mercury."

Permanently shadowed regions do not receive direct sunlight. They are typically located on the crater floor or along a section of the crater wall facing toward the pole. The regions still receive indirect sunlight, but if the temperature stays below about minus 240 degrees Fahrenheit (minus 151 degrees Celsius), the permanently shadowed area is a cold trap -- a good place for water ice to accumulate and remain stable. Cold traps were predicted for Ceres but had not been identified until now.

In this study, Schorghofer and colleagues studied Ceres' northern hemisphere, which was better illuminated than the south. Images from Dawn's cameras were combined to yield the dwarf planet's shape, showing craters, plains and other features in three dimensions. Using this input, a sophisticated computer model developed at NASA's Goddard Space Flight Center, Greenbelt, Maryland, was used to determine which areas receive direct sunlight, how much solar radiation reaches the surface, and how the conditions change over the course of a year on Ceres.

The researchers found dozens of sizeable permanently shadowed regions across the northern hemisphere. The largest one is inside a 10-mile-wide (16-kilometer) crater located less than 40 miles (65 kilometers) from the north pole.

Taken together, Ceres' permanently shadowed regions occupy about 695 square miles (1,800 square kilometers). This is a small fraction of the landscape -- much less than 1 percent of the surface area of the northern hemisphere.

The team expects the permanently shadowed regions on Ceres to be colder than those on Mercury or the moon. That's because Ceres is quite far from the sun, and the shadowed parts of its craters receive little indirect radiation.

"On Ceres, these regions act as cold traps down to relatively low latitudes," said Erwan Mazarico, a Dawn guest investigator at Goddard. "On the moon and Mercury, only the permanently shadowed regions very close to the poles get cold enough for ice to be stable on the surface."

The situation on Ceres is more similar to that on Mercury than the moon. On Mercury, permanently shadowed regions account for roughly the same fraction of the northern hemisphere. The trapping efficiency -- the ability to accumulate water ice -- is also comparable.

By the team's calculations, about 1 out of every 1,000 water molecules generated on the surface of Ceres will end up in a cold trap during a year on Ceres (1,682 days). That's enough to build up thin but detectable ice deposits over 100,000 years or so.

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How plants sense electric fields

The functional potassium channel TPC1 consists of two identical subunits (left in the picture). Potassium ions (blue spheres) are guided through the canal pore when calcium ions that bind to the channel protein (green spheres) and changes in the electric field (flashes) actuate the voltage sensors (red cylinders). When the channel opens, an electrical signal (red current trace) is triggered and cells of the sample plant Arabidopsis thaliana depicted here exchange information.
An international group of researchers has pinpointed the sensor plants use to sense electric fields. A beneficial side effect: Their work could contribute to the understanding of how the Ebola virus enters human cells.

The cells of plants, animals and humans all use electrical signals to communicate with each other. Nerve cells use them to activated muscles. But leaves, too, send electrical signals to other parts of the plant, for example, when they were injured and are threatened by hungry insects.

"We have been asking ourselves for many years what molecular components plants use to exchange information among each other and how they sense the changes in electric voltage," says Professor Rainer Hedrich, Head of the Chair for Molecular Plant Physiology and Biophysics at the University of Würzburg.

Results published in Plant Biology

This question has been intriguing Hedrich since the mid 1980s when he was still a postdoc in the laboratory of Erwin Neher at the Max Planck Institute in Göttingen. "Back then, we used the patch clamp technique to make the first-time discovery of an ion channel in plants which is activated by calcium ions and an electric field." In 2005, other scientists then found the gene underlying this ion channel (name: TCP1). And now it has been Hedrich's team again that has identified that part of the channel which functions as a sensor for electric voltage and activates the channel.

Their detailed findings are published in the journal Plant Biology. Having received attention from the scientific world, the article has been recommended by the " Faculty of 1000" in the meantime. The renowned platform, which evaluates scientific publications, is operated by worldwide leaders in biology and medicine.

Teamwork discovered channel function

The discovery of the voltage sensor was made by international teamwork. Initially, Hedrich got support from Professor Thomas Müller of his own department. The structural biologist created a three-dimensional model of the TPC1 channel protein. This allowed areas in the protein to be localised that are eligible as voltage sensors. "Our model clearly showed that the TCP1 channel is made up of two interconnected, nearly identical protein units each capable of forming a potential voltage sensor," Müller explains.

An analysis of the evolution of the TCP1 gene shed even more light on the matter. The Würzburg scientists Jörg Schulz, Professor of Computation Biology, and Dirk Becker, a team leader at Julius von Sachs Plant Research Institute, found out that the gene first occurs with the evolution of cells that have a nucleus. Since then, all living beings, humans included, seem to have had it. "During the analysis, we noticed that the second unit of the TPC1 protein has hardly changed in millions of years. It is almost identical from simple protozoa to plants and humans," Becker further.

Mutations provided the decisive cue

So they had to look for the voltage sensor in the second protein unit. The work group of Würzburg electrophysiologist Irene Marten then delivered the decisive experimental cue: Plants that carry a mutation in a special subunit of the channel have lost their ability to respond to the electric field.

"Together with the former Würzburg biophysicists Gerald Schönknecht, presently researching at Oklahoma State University in the USA, and Ingo Dreyer, currently at University Talca in Chile, we then developed a mathematical model. This model can explain how the electric switch in the TPC1 channel protein works at the molecular level," Hedrich explains.

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