Dec 17, 2016

How Climate Change Affected 2015’s Extreme Weather

A searing summer heat wave in Europe, sunny day flooding in Miami, one of Alaska's worst wildfire seasons and heavy rainfall in China — these were just some of the extreme weather events of 2015 for which climate change provided a discernable push, according to the Bulletin of the American Meteorological Society's annual attribution report, released Thursday.

Over the last five years, the BAMS report has examined more than 100 events as part of a burgeoning sub-field of climate science that uses observations and climate models to show how human-caused warming has already affected the odds or severity of many of the weather extremes we experience now.

Of those, the fingerprints of climate change have been found on about two-thirds, particularly for heat events, where the warming influence has been almost universal. Others, though, such as precipitation extremes, have been more of a mixed bag.

This year's report featured more types of events scattered over a wider area of the world than before. For the first time, researchers also had to consider the possible influence of an exceptionally strong El Niño, and tried to take attribution a step further by examining how climate change actually affected people, for example by impacting human health.

"If we can better understand why these events are happening, we can better predict and prepare for them in the future," lead editor of the report, Stephanie Herring, said during a press conference at the annual meeting of the American Geophysical Union, where the report was presented.

Clear Heat Connection

Ten of the heat events examined, including the global record-hot year, had a clear climate change influence, researchers found. An increase in heat extremes is one of the clearest outcomes of global warming.

One study found that summer heat waves, like the one that sent temperatures in central Europe to record highs, are occurring more frequently, while another found that record-breaking heat in Northwest China (where July temperatures soared above 110°F) was made three times more likely.

Two studies went beyond mere temperatures to look at the collective impact of heat and humidity — when both are high, that increases heat stress, with implications for human health. The deadly heat stress associated with an August 2015 heat wave in Egypt was found to be 70 percent more likely, underscoring the heavy toll of climate change on humans. Another study in the report found that high heat indices in separate heat waves in India and Pakistan were made at least 800 percent more likely by climate change.

Climate science isn't quite at the point where all extreme heat events can be assumed to have the imprint of climate change, Adam Sobel, a Columbia University climate scientists who wasn't involved in the report, said, but it is getting close.

Manmade warming was also found to play a role in other types of events where heat was a factor: Alaska's 2015 fire season, the second worst on record in terms of area burned, was found to be about 30 to 60 percent more likely because of climate change. Similarly, the "snowpack drought" in Washington state that resulted from high temperatures making precipitation fall as rain instead of snow was found to be more likely to occur in the future because of warming.

"The five years of this report from BAMS has shown that we've made enormous progress in attributing meteorological events," Friederike Otto, an author on several of the studies in the report, said during the AGU press conference. Otto, a climate scientist at the University of Oxford, also works with Climate Central's World Weather Attribution program, which attempts to conduct rapid attribution assessments in the days and weeks after an event.

No Climate Change Signal

Other events for which a climate change role was discernable included some types of events never before featured in the report. The nearly 2 feet of water that flooded the Miami area on Sept. 27, 2015, despite no storm in sight — a phenomenon called sunny-day flooding — has become 500 percent more likely, purely from the sea level rise that has occurred since the mid-90s, researchers found.

For other events, though, no clear influence from climate change could be detected. The extreme cold that kept the eastern U.S. in a deep freeze in the winter of 2014-15 was actually less likely to occur with warming, two studies found, despite other research that has suggested that declining Arctic sea ice could be causing more excursions of Arctic air over North America.

No climate change signal emerged for the delayed rainy season onset in Nigeria or for a heavy rainfall event in Chennai, India, either. In the latter case, increased aerosols might be masking any global warming-related trend, the authors say.

About 35 percent of the studies in all five BAMS reports haven't found a climate change influence, but Herring notes that may not mean that such an influence isn't there.

"There's lots of reasons why a paper may not find a role for climate change," she said. Any climate change trend may not yet be discernable or today's methods may not yet be sophisticated enough to tease it out. Or a study may not have looked at the right factors, "so we don't actually have the complete story yet," she said.

An El Niño Twist

The report editors also note that the studies don't cover an unbiased sample of events, as they are picked by the authors, who often choose weather extremes from their own backyard.

"One thing [the 2015 report] doesn't do is cover all of the extremes that occurred in 2015," co-editor Martin Hoerling, a NOAA climate scientist, said during the press conference. (The events to be included in the report are also picked before the analyses are completed, so what they find isn't known in advance.)

An added twist for 2015 was the major El Niño event that also altered weather patterns around the world, leaving the possibility that both El Niño and climate change might have influenced the same event.

"We didn't know if we'd be able to differentiate the two," Herring said. But several of the studies were able to tease apart their relative contributions.

Read more at Discovery News

If an Asteroid Hits the Ocean, Does It Make a Tsunami? (Probably Not)

Fifteen years ago, Galen Gisler had a gut feeling that something wasn't right about the Hollywood portrayal of asteroid impacts in the world's oceans.

"Movies like 'Deep Impact' and 'Armageddon' suggested that an ocean impact would produce a devastating tsunami that would affect everything along the shorelines surrounding an ocean basin ... but I was skeptical," Gisler, a scientist at Los Alamos National Laboratory in New Mexico, told Seeker.

Generally speaking, getting hit by an asteroid is a bad day for life on Earth, even if it is a part of the natural cycle of living in the dynamic and evolving solar system. Marauding space rocks fly around interplanetary space with no regard for Earth's precious biosphere. If they have our planet in their sights, they're going to hit us. And depending on their mass and speed, they could hit us hard.

But depending on where an asteroid hits, the fallout will vary greatly. If an asteroid was predicted to hit land near a major city, we might be able to evacuate in time (and disaster response agencies have carried out drills that focus on this possibility), but the damage to society, infrastructure and economy would be terrible, obviously. But if an asteroid hits one of our oceans — water makes up for 70 percent of our planet's surface and is therefore a more likely scenario — the scope of the impact is poorly understood.

Gisler is determined to better understand the realities of a massive impact in the ocean and presented his team's findings at the American Geophysical Union's Fall Meeting in San Francisco last week, showcasing the dramatic 3-D modeling results of an ocean-impacting asteroid. Never before has an impact scenario like this been studied in such detail and the simulation revealed that Gisler's original instincts had merit: devastating post-impact tsunamis we see in the movies are as fictional as the science fiction plot lines they are a part of.

"An asteroid impact is a point source and it only affects the immediate region around the impact point and moreover, to create a tsunami, you need something that disturbs the entire water column," said Gisler.

He likens an asteroid ocean impact to throwing a rock into a pond. Sure, the energy of the rock hitting the water will produce waves, but the ripples are very dispersive. In other words, they lose their energy very quickly. These dispersive waves in an ocean will be very localized and won't have the energy that a tsunami does. "It's very different physics," he added.

Tsunamis occur when there's large scale shifts of mass in the seabed, such during a submarine earthquake or landslide. These shifts cause a huge movement in a massive column of water, from the seabed to the surface, that can create wavelengths of a hundred kilometers or more, said Gisler, which is many times longer than the depth of the ocean (of a few kilometers). Tsunamis aren't very dispersive and therefore don't lose energy as they travel through the ocean basin, hitting coastlines hundreds or maybe thousands of kilometers away, often with devastating results.

But that's not to say an asteroid impact in the middle of an ocean wouldn't be dramatic.

"They're spectacular to be sure; they would produce splashes that go up tens of kilometers," he added. According to the model, a jet of water would also protrude from the ocean's surface by a few kilometers, producing rim waves surrounding the transient water crater reaching 400 meters in height. "That's awfully high! But unless it's very close to a shore, it's not going to be very dangerous."

In addition, a significant fraction of the kinetic energy of the impacting asteroid will go into vaporizing huge quantities of water, according to the team's award-winning video explaining the research findings. Water vapor is a potent greenhouse gas, so the injection of vapor into the stratosphere could linger for months or years, altering global climates.

Intense shock waves and violent winds will also wreak havoc on the surface, so the further the impact is from any populated coastal regions, the better.

Read more at Discovery News

Dec 16, 2016

A super flash from a star and a supermassive black hole

In just the right conditions, the destruction of a star in a black hole's gravitational tide should produce an unusual flash of light.
When astronomers and astrophysicists observe flashes of light in the dark sky, they assume they have seen a supernova. Possibly a star has burnt up its supply of nuclear fuel and collapsed, throwing off its outer layers into space; or maybe a dense white dwarf siphoned off material from a companion star until it exploded from excess weight. But a flash of light observed on June 14, 2015 did not fit any of the usual models.

For one thing, the intensity of the light was double that of the brightest supernova recorded up to that point. So astrophysicists were already asking what process could have caused it. And there were other anomalies, as well: Rather than gradually cooling, which is what happens in the average supernova, the temperature of the material emitting radiation went down -- and then up again, remaining at the higher level for quite a while. And the site of the flash was a puzzle, as well: Supernovae tend to occur in young, "blue" galaxies, but this one took place in an old "red" galaxy, in which the stars were not really candidates for exploding.

Postdoctoral fellow Giorgos Leloudas and Prof. Avishay Gal-Yam of the Particle Physics and Astrophysics Department of the Weizmann Institute of Science investigated. Together with colleagues at the Institute, Drs. Paul Vreeswijk, Ofer Yaron and Steve Schulze, Joel Johannson, and Ira Bar, as well as researchers around the world, they closely observed, measured and recorded the event. This led them to the discovery that the spectrum of the light had changed several times, and the hypothesis they formed based on this finding was that they had observed an extremely rare event: the destruction of a star by the gravitational tides of a black hole at the center of its galaxy.

The flash had, in fact, come from the middle of that distant galaxy, and further analysis suggested that the observations fit what is known about stars being caught in a black hole's gravitational tide.

The reason such an event, producing such a bright flash, is so rare is that two conditions must be met for it to occur: The star must stray close enough to the black hole to cross its "event horizon" -- the point at which it cannot escape the pull of the giant mass -- but the light produced in its destruction must somehow escape the black hole's all-consuming gravity. And for these conditions to occur, the galaxy's central black hole, which is immense even by black-hole standards, must be rotating at a relativistic speed -- close to the speed of light.

Read more at Science Daily

Mysterious Metallic Sound in the Mariana Trench Finally Identified

An otherworldly noise that was recorded near the Mariana Trench could be a never-before-heard whale call.

Dubbed the "Western Pacific Biotwang," this newly discovered call might be from a minke whale — a type of baleen whale — according to the researchers who documented the vocalization.

Regardless of what species it is, this whale has range: The call includes sounds that span frequencies that reach as low as 38 hertz and as high as 8,000 hertz. Humans can hear sounds between 20 and 20,000 Hz.

"It's very distinct, with all these crazy parts," Sharon Nieukirk, senior faculty research assistant in marine bioacoustics at Oregon State University, said in a statement. "The low-frequency moaning part is typical of baleen whales, and it's that kind of twangy sound that makes it really unique. We don't find many new baleen whale calls."

The call was recorded with autonomous seafaring robots, known as "passive acoustic ocean gliders," which can dive up to 3,280 feet (1,000 meters) below the surface. Scientists can send these devices out on solo missions to eavesdrop on whale conversations. Nieukirk and her colleagues collected their acoustic data in the fall of 2014 and the spring of 2015, in an area in the Pacific Ocean east of Guam around the Mariana Trench, the deepest part of the ocean.

The twangy, five-part call, which lasts up to 3.5 seconds, was recorded regularly during both the fall and spring. The researchers hope that other scientists will identify the call in other data sets so that they can confirm the source. But in their description of the whale call in the Journal of the Acoustical Society of America, Nieukirk and her colleagues wrote that they suspect a minke whale is responsible for the new call.

Because of the call's complex structure, frequencies and metallic-sounding conclusion, the researchers think that it most closely resembles the regionally specific calls that are produced by a group of dwarf minke whales off the northeast coast of Australia. (Those calls sound a bit like "Star Wars" sound effects.) They added that there are several types of minke whales in the survey area, but not much is known about their behavior — especially their vocal behavior.

"We don't really know that much about minke whale distribution at low latitudes," Nieukirk said. "The species is the smallest of the baleen whales, doesn't spend much time at the surface, has an inconspicuous blow, and often lives in areas where high seas make sighting difficult. But they call frequently, making them good candidates for acoustic studies."

The call still needs to be translated. Most baleen whales use specific vocalizations for seasonal breeding and feeding, but this call — since it seems to occur all year — may have a complex function, the researchers said.

Read more at Discovery News

That's No Moon... Actually, It Is. That's Saturn's 'Death Star' Moon Mimas

Saturn's moon Mimas looks suspiciously similar to the Death Star, a colossal planet-destroying space weapon that terrorizes a galaxy far, far away…

But there's no need to worry; there is no Death Star anywhere in this solar system. Mimas is just a harmless, and apparently lifeless, space rock. However, the mere sight of this Death Star look-alike would send shivers down the spines of the trillions of fictional characters in "Star Wars."

So why do Mimas and the Death Star look like distant relatives? Did Mimas' eerie appearance inspire the creators of "Star Wars," or is this Saturnian moon up to something seriously spooky?

"The appearance of Mimas was not seen in detail until the Voyager spacecraft flew through the Saturn system in 1980, so the design of the Death Star was not influenced by Mimas," a spokesperson at NASA's Jet Propulsion Laboratory told The answer is neither. Believe it or not, the striking resemblance between these two objects is a complete coincidence.

"Star Wars" creator George Lucas started dreaming up his concept for the Death Star in the 1970s, before the release of "Star Wars: Episode IV - A New Hope," the first movie of the saga, in 1977. In the film, the Death Star is dubbed the "ultimate weapon" for its outrageously powerful laser that can wipe out entire planets in just one shot. Its mobility and moon-like disguise are ideal for sneaking through space undetected.

Though George Lucas couldn't possibly have known what Mimas looked like when he created the concept of the Death Star, he certainly intended for the spacecraft to look like some type of moon. As Obi-Wan Kenobi famously said while approaching the Death Star in Episode IV, "That's no moon. … It's a space station!"

The two objects' similar shapes can be largely attributed to a giant basin on Mimas called the Herschel crater. This crater formed when an impactor collided with Mimas near the little moon's equator about 4.1 billion years ago. It measures 86 miles (139 kilometers) across, which is nearly one-third the diameter of Mimas. The impact was so huge that some scientists are surprised it didn't destroy the moon entirely.

A large, round indentation is also present on the Death Star. However, this one wasn't created by a collision. This concave feature of the otherwise spherical Death Star is a part of the station's "superlaser" emitter, or the epic space weapon capable of destroying entire worlds.

DS-1, the original Death Star design, is a central point in the plot of "Rogue One: A Star Wars Story" (which hits theaters on Friday, Dec. 16). The spacecraft measures 75 miles (120 km) in diameter. Mimas is actually about three times larger than the Death Star. Another rendition of the Death Star, DS-2, featured in "Return of the Jedi," is a bit larger, at 100 miles (160 km) across, which is larger than the first version but still smaller than Mimas.

Read more at Discovery News

Oddball Ceres Hides Huge Reservoirs of Water Ice

Ceres and Vesta, the two largest bodies in the main asteroid belt, may be contemporaries and neighbors, but the similarities stop there. Ceres, which is about as wide as Texas, is filled with frozen water and hydrated minerals, making it more like an icy moon of Jupiter or Saturn than Vesta, its dry, rocky sibling, new research shows.

Scientists aren't sure why Ceres and Vesta followed such different evolutionary paths, but they expect more answers as analysis of data collected by NASA's Dawn spacecraft continues. Dawn spent 14 months visiting Vesta before firing up its ion engine and settling into orbit around Ceres in March 2015.

Research published in this week's issues of Science and Nature Astronomy confirms a 30-year-old theory that Ceres is an ice-rich world.

"In Ceres' crust today we think we see about 10 percent (by weight) water ice," Dawn scientist Thomas Prettyman, with the Planetary Science Institute in Tucson, Arizona, told Seeker.

But water in the crust is just the beginning of the story. Ceres is replete with minerals and clays that can only form in the presence of water. Extrapolating from measurements made by Dawn, Prettyman estimates that the dwarf planet as a whole is 30 percent water.

Vesta had a different history, one that did not involve much water.

"What happened to Vesta is that it completely melted," Prettyman said.

Once its radioactive elements decayed, Vesta, made mostly of silicates, cooled and formed a basaltic crust, a mantle and an iron-rich core.

"This would have had to happen close to the sun, where you couldn't condense volatiles like water because it was too hot," Prettyman added.

Perhaps because Ceres was bigger than Vesta, or positioned farther from the sun, but it was able to accrete water into its body, setting the stage for a cascade of chemical alterations. Some models show that the separation of water and rock caused Ceres to form a frozen shell over a briny liquid layer that may still exist today.

"The Dawn mission is trying to look back in time to the very earliest stage of the solar system," deputy principal investigator Carol Raymond, with NASA's Jet Propulsion Laboratory in Pasadena, Calif., told reporters at the American Geophysical Union conference in San Francisco.

Of particular interest, she added, is if Ceres' water and rock interacted in such a way that the dwarf planet became chemically suited for life.

Read more at Discovery News

Dec 15, 2016

Exciting new creatures discovered on ocean floor

Chimney Jabberwocky.
Scientists at the University of Southampton have discovered six new animal species in undersea hot springs 2.8 kilometres deep in the southwest Indian Ocean.

The unique marine life was discovered around hydrothermal vents at a place called Longqi ('Dragon's Breath'), 2000 kilometres southeast of Madagascar and is described in the journal Scientific Reports.

A research team, led by Dr Jon Copley, explored an area the size of a football stadium on the ocean floor, pinpointing the locations of more than a dozen mineral spires known as 'vent chimneys'. These spires, many of which rise more than two storeys above the seabed, are rich in copper and gold that is now attracting interest for future seafloor mining. However, the spires are also festooned with deep-sea animals, nourished by hot fluids gushing out of the vent chimneys.

The team, which includes colleagues at the Natural History Museum in London and Newcastle University, carried out genetic comparisons with other species and populations elsewhere to show that several species at Longqi are not yet recorded from anywhere else in the world's oceans.

The expedition, which took place in November 2011, provides a record of what lives on the ocean floor in the area, which is licensed for mineral exploration by the International Seabed Authority of the United Nations, before any mining surveys are carried out.

The Longqi vents are the first known in the region and the expedition was the first to explore them using a deep-diving remotely operated vehicle (ROV).

The deep-sea animals that are so far only known from Longqi include: a species of hairy-chested 'Hoff' crab, closely related to 'Hoff' crabs at Antarctic vents; two species of snail and a species of limpet; a species of scaleworm; and another species of deep-sea worm. Apart from one species of snail, which has been given the scientific name Gigantopelta aegis, most have not yet been formally described.

"We can be certain that the new species we've found also live elsewhere in the southwest Indian Ocean, as they will have migrated here from other sites, but at the moment no-one really knows where, or how well-connected their populations are with those at Longqi," said Dr Copley. "Our results highlight the need to explore other hydrothermal vents in the southwest Indian Ocean and investigate the connectivity of their populations, before any impacts from mineral exploration activities and future deep-sea mining can be assessed."

Read more at Science Daily

Scientists studying dolphins find Bay of Bengal a realm of evolutionary change

An adult humpback dolphin displays its characteristic pink coloration.
Marine scientists have discovered that two species of dolphin in the waters off Bangladesh are genetically distinct from those in other regions of the Indian and western Pacific Oceans, a finding that supports a growing body of evidence that the Bay of Bengal harbors conditions that drive the evolution of new life forms, according to a new study by the American Museum of Natural History(AMNH), WCS (Wildlife Conservation Society), and the cE3c -- Centre for Ecology, Evolution and Environmental Changes (Universidade de Lisboa).

In the comparative study using DNA collected from both Indo-Pacific humpback dolphins (Sousa chinensis) and Indo-Pacific bottlenose dolphins (Tursiops aduncus) and data from previous genetic studies, the authors of a newly published paper in Conservation Genetics have found that both populations of both species are distinct from populations in other parts of the Indian Ocean and western Pacific. This discovery follows the recent description of a possible new species of "river shark" in the same waters.

The authors of the study titled "Oceanic drivers of population differentiation in Indo-Pacific bottlenose (Tursiops aduncus) and humpback (Sousa spp.) dolphins of the northern Bay of Bengal" are: Dr. Ana R. Amaral of cE3c, Universidade de Lisboa, Portugal and AMNH's Sackler Institute of Comparative Genomics; Brian D. Smith and Rubaiyat M. Mansur of WCS; and Dr. Howard C. Rosenbaum of WCS and affiliated with AMNH.

"Our findings indicate that there is a connection between the presence of these distinct populations of dolphins and the unique oceanic habitat that is found in the Bay of Bengal," said Amaral, the lead author of the study. "The combination of a biologically rich yet isolated seascape could be driving speciation, or the emergence of new species."

Located in the northern Indian Ocean, the Bay of Bengal receives vast amounts of freshwater and organic matter from the Meghna, Brahmaputra, and Ganges Rivers; the confluence also supports the world's largest mangrove forest. In deeper waters, a submarine canyon called the Swatch-of-No-Ground (SoNG) recycles nutrients through upwelling, all of which creates a biologically productive coastal region with a complex interchange of currents that creates conditions for species to become isolated from other parts of the Indian Ocean.

During the study, researchers collected skin samples from 32 coastal Indo-Pacific and humpback dolphins. Genetic sequences were then extracted from the samples for comparison with previously published sequences for both species. The researchers found both dolphins to be genetically discrete from nearby populations, a tantalizing result that the authors say merits further investigation.

"The discovery of genetically distinct dolphin populations helps us to expand the body of knowledge of how these dolphin species have changed over time," said Howard Rosenbaum, Director of WCS's Ocean Giants Program who added that "these results have significant implications for identifying unique marine mammal populations, which in turn have important conservation implications for safeguarding the long-term biodiversity in this region."

"This is great news for Bangladesh," said Rubaiyat Mansur, Principal Researcher for WCS's Bangladesh Program. "Despite the challenges of wildlife conservation in our country, we take great pride in protecting our wildlife as evidenced by the recent declaration of Bangladesh's first marine protected area in the Swatch-of-No-Ground submarine canyon and adjacent estuarine waters."

The Indo-Pacific bottlenose dolphin that ranges between the Indian and western Pacific Oceans is a smaller version of the better-known common bottlenose dolphin (Tursiops truncatus). The waters of the Bay of Bengal's SoNG canyon are home to one of the world's largest populations of Indo-Pacific bottlenose dolphins.

Humpback dolphins in particular have been a topic of much debate among taxonomists due to the variations in appearance and genetics of animals that inhabit coastal waters from western Africa to the western Pacific. The genus Sousa now contains four species, one of which -- the Australian humpback dolphin (Sousa sahulensis) -- was recently designated as a separate species after a number of comparative studies combining morphology and genetic markers.

While the humpback dolphins in the Bay of Bengal are currently considered as a population of Indo-Pacific humpback dolphins (Sousa chinensis), the population occurs right in between the known ranges of the Indo-Pacific species and the Indian Ocean humpback dolphin (Sousa plumbea). This study's comparison of mitochondrial DNA across populations reveals a closer connection between the Bay of Bengal's humpback dolphins and the more distantly located Australian humpback dolphin.

Read more at Science Daily

Einstein's Theory Just Put the Brakes on the Sun's Spin

Although the sun is our nearest star, it still hides many secrets. But it seems that one solar conundrum may have been solved and a theory originally proposed in 1905 by Albert Einstein could be at the root of it all.

Twenty years ago, solar astronomers realized that the uppermost layer of the sun rotates slower than the rest of the sun's interior. This is odd. It is well known the sun rotates faster at its equator than at its poles — a phenomenon known as "differential rotation" that drives the sun's 11-year solar cycle — but the fact that the sun has a sluggish upper layer has been hard to understand. It's as if there's some kind of force trying to hold it in place while the lower layers churn below it.

Now, researchers from University of Hawaii Institute for Astronomy (IfA), Brazil, and Stanford University may have stumbled on an answer and it could all be down to fundamental physics. It seems that the light our sun generates has a braking effect on the sun's surface layers.

"The sun won't stop spinning anytime soon, but we've discovered that the same solar radiation that heats the Earth is 'braking' the sun because of Einstein's Special Relativity, causing it to gradually slow down, starting from its surface," said Jeff Kuhn, of IfA Maui, in a statement.

Special relativity predicts that photons, which carry the electromagnetic force (i.e. light), also carry a tiny amount of momentum. If you have enough photons travelling away from an object, they will carry away a large amount of momentum. In the case of the sun's 4 billion year lifetime, the surface has lost a lot of momentum to photons, causing a slowdown of the uppermost 5 percent of the sun. This mechanism, called the Poynting-Robertson effect, has been observed in interplanetary dust, which feels the drag of the sun's radiation, causing it to fall from the asteroid belt into the inner solar system.

What affects dust inevitably affects the soup of super-heated gas in the sun's upper layers and, over its 5 billion year lifetime, the drag caused by photons being emitted from the sun has created a measurable and, until now, mysterious effect.

Using several years of data from NASA's Solar Dynamics Observatory (SDO), the researchers were able to measure waves traveling through the sun to precisely measure the size of the layer that is experiencing this slowdown. The technique, known as "helioseismology," is very similar to measuring the seismic waves travelling through the Earth to measure the strength of an earthquake. The material these seismic waves travel through changes the waves so seismologists can "see" underground.

Though the sun isn't a solid planet made from rock and metal, its dense plasma interior also allows waves to travel, creating oscillations on the surface that can be measured. Helioseismology therefore allows astronomers to "see" into our nearest star, revealing many details about its interior that may not be obvious on the surface. And in this case, by using helioseismology and studying the sun's magnetic field passing from space into the sun's interior, we can gauge how much of a drag Einstein's special relativity has had on the sun's surface.

"This is a gentle torque that is slowing it down, but over the Sun's 5 billion year lifetime it has had a very noticeable influence on its outer 35,000 kilometers [22,000 miles]," said Kuhn. These findings have accepted for publication in the journal Physical Review Letters and can be previewed on the arXiv pre-print service.

Read more at Discovery News

Breakthrough Surgery Restores Sight to People With Hemorrhaging in the Eye

It's been ten years or so, but Dr. Rajendra Apte remembers the patient vividly: a young man who'd gone blind after being struck by a car while jogging. The 20-year-old graduate school student had suffered multiple injuries, brain trauma and had undergone numerous surgeries to get to a point where he could finally walk again, if only with assistance.

Somewhere along the way, a medical professional had made the assumption that the young man's blindness was the result of his brain injury, and so he'd never been examined by an ophthalmologist — that is, until his family brought him to see Dr. Apte at Washington University.

"This patient, when I first saw him, he didn't speak anything. He was very quiet. The dad did most of the talking," Dr. Apte told Seeker. "Emotionally, he'd become a different person because of everything that had happened."

During the examination, Dr. Apte saw that in both eyes, the vitreous fluid, the gel that fills the space between the lens and the retina, had hemorrhaged and that blood had gotten into the space. He wondered if the man was blind, not because of damage to his brain's visual cortex, but because of a medical condition called Terson syndrome.

This syndrome sometimes afflicts people who have blood in their brain from a ruptured aneurysm. The blood and pressure that builds up in the brain can cause blood vessels around the eye's optic nerve to also burst, filling the eye with blood and preventing light from reaching photoreceptor cells in the retina. The same thing can happen to victims of severe trauma like car accidents.

Dr. Apte suggested doing a vitrectomy, a type of surgery that typically replaces the vitreous gel with saline solution. But in this case, the doctor would clean out the blood, which had coagulated in the six months since the accident, and replace it with saline solution. There was no guarantee it would work, he told family. And six months was a long time. They agreed.

A day after the surgery, the man could read Dr. Apte's eye chart — not just the top line, but down toward the bottom.

"It was pretty incredible," Dr. Apte said. "He just wouldn't stop talking. He was very animated and very excited. As soon as I saw him, the first thing he asked me was, 'When are we going to do surgery on the other eye?'"

He ended up seeing perfectly well in both eyes.

It was the first time Dr. Apte had thought that he should look more closely at the success rates of surgeries done on patients with Terson syndrome secondary to trauma. The idea stayed with him in the intervening years and when he had the opportunity to conduct an assessment, he did it.

This week, Dr. Apte, now a distinguished professor of ophthalmology and visual sciences at Washington University School of Medicine and his colleagues from Wayne State University in Detroit and the L.V. Prasad Eye Institute in India, report in the journal Ophthalmology on 20 different patients with Terson syndrome from three different medical institutions.

In some cases, both eyes had experienced hemorrhaging and in other cases, only one eye had. In total, the researchers looked at 28 eyes. They also divided the patients into two groups: those who'd had the vitrectomy within three months and those who'd had surgery after three months.

Some were legally blind prior to the surgery as a result of their injuries, but within a month of the procedure, had regained their vision. After a few months later, almost everyone had 20/20 vision. Dr. Apte stressed that the surgery won't return vision to patients who had vision loss from unrelated reasons before an accident.

Overall, the analysis was reassuring, Dr. Apte said. "Even if you have to wait for the surgery for several months, the outcomes were still good."

Read more at Discovery News

Dec 14, 2016

Breakup of supercontinent Pangea cooled mantle and thinned crust

Researchers at the University of Texas Institute for Geophysics used the location of seismic refraction data (circles) and mantle hotspots (white stars) to examine whether mid-plate volcanism substantially influenced the thickness of aged ocean crust. The modern mid-ocean ridge system is marked by a yellow line. Areas in violet outline large igneous provinces.
The oceanic crust produced by the Earth today is significantly thinner than crust made 170 million years ago during the time of the supercontinent Pangea, according to University of Texas at Austin researchers.

The thinning is related to the cooling of Earth's interior prompted by the splitting of the supercontinent Pangaea, which broke up into the continents that we have today, said Harm Van Avendonk, the lead author of the study and a senior research scientist at The University of Texas Institute for Geophysics. The findings, published in Nature Geosciences on Dec. 12, shed light on how plate tectonics has influenced the cooling of the Earth's mantle throughout geologic history.

"What we think is happening is that the supercontinent was like an insulating blanket," Van Avendonk said. "So when these continents started opening up and the deeper mantle was exposed, more or less, to the atmosphere and the ocean it started cooling much faster."

All authors are from the University of Texas Institute for Geophysics (UTIG), a research unit of the Jackson School of Geosciences.

The mantle is the very hot, but mostly solid, layer of rock between the Earth's crust and core. Magma from the mantle forms oceanic crust when it rises from the mantle to the surface at spreading centers and cools into the rock that forms the very bottom of the seafloor. Since about 2.5 billion years ago, the mantle has been cooling -- a phenomenon that doesn't influence the climate on the surface of the Earth and has nothing to do with the issue of short-term human-made climate change. This study suggests that since the breakup of Pangea, the cooling rate of the mantle has increased from 6-11 degrees Celsius per 100 million years to 15-20 degrees per 100 million years. Since cooler mantle temperatures generally produce less magma, it's a trend that's making modern day ocean crust thinner.

"It's important to note the Earth seems to be cooling a lot faster now than it has been over its lifetime," Van Avendonk said. "The current state of the Earth, where we have a lot of plate tectonic events, this allows the Earth to cool much more efficiently than it did in the past."

The research that led to the connection between the splitting of the supercontinent and crust thickness started when Van Avendock and Ph.D. student Jennifer Harding, a study co-author, noticed an unexpected trend when studying existing data from young and old seafloor. They analyzed 234 measurements of crustal thickness from around the world and found that, on a global scale, the oldest ocean crust examined -- 170 million year old rock created in the Jurassic -- is about one mile thicker than the crust that's being produced today.

"It's something that Jenny and I found, more or less, by accident," Van Avendonk said.

The link between crust thickness and age prompted two possible explanations -- both related to the fact that hotter mantle tends to make more magma: Mantle hot spots -- highly volcanic regions, such as the Hawaiian Islands and Iceland -- could have thickened the old crust by covering it in layers of lava at a later time. Or, the mantle was hotter in the Jurassic than it is now.

Van Avendonk mentioned this problem during a casual conversation with Joshua "Bud" Davis, a Ph.D. student in UTIG's plate tectonics research group and co-author, who said that the group could investigate both of the explanations using computer models of plate movement since the Jurassic and a global database of hotspots.

The analysis ruled out the hot spot theory -- thick layers of old crust formed just as easily at distances greater than 600 miles from hotspots, a distance that the researchers judged was outside the influence of the hotspots. In contrast, the analysis supported the hypothesis of mantle heating during the age of Pangea, and mantle cooling after the breakup of the supercontinent.

Read more at Science Daily

Juno Looks Into a Fierce Jupiter Storm During Dramatic Orbital Dive

Jupiter's thick atmosphere is filled with mesmerizing atmospheric phenomena. Storms bigger than our planet rage, waves of energy blast through the clouds and turbulence creates a scene that looks more familiar in the mixed watercolors on an artist's palette. Now, with the help of the Juno mission's JunoCam instrument, we've been given a birds-eye (or satellite-eye) view of one of the planet's stunning "pearls" — one of eight bright counterclockwise rotating storms that are currently rumbling in the Jovian southern hemisphere.

On Sunday, Juno successfully completed its third close approach of Jupiter in its highly elongated orbit — a point known as "perijove." Before completing the maneuver at 12:04 p.m. ET, JunoCam was used to watch the finer details of Jupiter's atmosphere pop into view and at 24,600 miles (40,000 kilometers) from Jupiter's atmosphere, this scene was captured.

JunoCam isn't technically a science instrument on the spacecraft, it's actually an outreach project to engage the public in the mission by capturing high-resolution photos of Jupiter for enthusiasts to analyze and process while participating in decisions (via an online vote) of what the camera should focus on next. But just because it's not officially a science instrument, it doesn't mean the camera can't be used for science.

"The camera is on Juno to do outreach, that was why we put the camera on the [spacecraft] in the first place, but there's no reason we can't learn about Jupiter from looking at the pictures," JunoCam lead scientist Candice Hansen, with the Planetary Science Institute in Tucson, Arizona, said during a presentation at the American Geophysical Union Conference in San Francisco, where a batch of new images were unveiled.

The focus of this observation is the bright storm near the top of the image. Since 1986 a string of bright storms have persisted in this southern hemisphere region. There are currently eight bright storms, but over the past 30 years, that number has varied between six to nine storms. Observations like these will no doubt add another layer of understanding a to how these storms form and why they vary in number over such a short timescale.

From Discovery News

Bats Fish With Their Fingers, Glowworms Fish With Their Urine

Some animals have devised very unusual, yet effective, fishing techniques, using everything from fingers to their own urine in order to catch prey, report two new studies.

The findings, reported in the journal PLOS ONE, show how quickly animals can adapt to getting ahold of prey, and could offer humans with surprising benefits in the future.

Long-fingered bats (Myotis capaccinii) from Europe can instinctively grab fish with their long digits, the first study found. For years, the bats were thought to eat only insects, but they were not about to pass up an opportunity for easy eats when it became available.

"The only ponds we know the long-fingered bats regularly fish in are artificial pools that were built in 2002," lead author Ostaizka Aizpurua, a postdoctoral fellow at the University of Copenhagen's Natural History Museum of Denmark, told Seeker. She explained that the ponds are located at a golf course near Dénia, Spain.

"Interestingly," she added, "the first evidence of fish consumption was reported in 2003, suggesting that as soon as a high density of surface-feeder fish became available, bats were able to catch them."

Aizpurua and her colleagues observed the bats practice "trawling," where they drag their long digits in fish-filled water, going deeper if needed. When fish disappear under the water in an attempt to hide, this actually seems to stimulate the bat's hunting drive all the more.

The researchers also studied a population of strictly insect-eating long-fingered bats from a stream pool near Ròtova, Spain. While both bat groups were capable of similar modes of attack, the golf course bats had more exaggerated trawling moves, suggesting that they had previously honed their technique to improve their chances of catching fish, instead of just insects.

The good news for humans is that the fish are surface-feeders known as Gambusia holbrooki. Originally from America, they are an invasive species in Europe, so the bat fishing is a win-win: bats get a belly-full of nutritious food, while people gain a natural remover of the pesky fish.

The second paper describing an unusual animal mode of fishing focused on New Zealand Arachnocampa glowworms, which are actually a type of larvae that trap prey with sticky fishing lines of their own creation. The glowing tail light attracts prey, often mayflies, which get tangled up in the fishing lines.

Arachnocampa glowworm fishing lines in New Zealand.
Lead author Janek von Byern explained to Seeker that the glowworms do not actually eat their prey, but instead "suck it out," removing all of the internal nutrition.

The process begins with the glowworms releasing the fishing lines from their mouth. Analyzing the components of the lines from two caves on New Zealand's North Island, the scientists found that they contain water, proteins, fats and, to their surprise, the insect's own urine. While more tests are needed to confirm this, urine now makes sense as a component, because it can contain moisture-absorbing salts.

While rather unappetizing to contemplate, the glowworm eats the curtain of fishing lines—urine and all—once they have been used. The extra water drawn in by urea, the main product in urine, probably helps the glowworms avoid desiccation.

A clever aspect of the system is that a glowworm fishing line can only hold the weight of three mayflies before it breaks.

"This makes sense, because this limits the risk of too much prey being caught," von Byern said. "Otherwise, the whole nest may collapse, tearing off the cave wall and falling with the larva into the river below."

Yet another clever aspect is that the fishing lines are only "activated" when the humidity is over 80 percent. When dry, they are not sticky, and so do not trap prey.

As for how all of this could benefit people too, von Byern points out that a popular wood adhesive used to be made out of urea and formaldehyde. It was very simple, effective and cheap to make, but formaldehyde in the product was banned due to health concerns.

Read more at Discovery News

Human Ancestor 'Lucy’ Was Likely Part of a Female Harem

The ancient relative of humanity dubbed "Lucy" may have been one of a harem of gals who mated with a single male, according to research that suggests her species was polygynous.

Among the earliest known relatives of humanity whose skeletons were made for walking upright was Australopithecus afarensis, the species that included the famed 3.2-million-year-old Lucy. Members of the Australopithecus lineage, known as australopithecines, are among the leading candidates for direct ancestors of the human lineage, living about 2.9 million to 3.8 million years ago in East Africa.

To learn more about Lucy's species, researchers investigated the area of Laetoli in northern Tanzania, which previously yielded the earliest known footprints belonging to hominins— humans and related species dating back to the split from the chimpanzee lineage. Those footprints, which date to 3.66 million years ago, were excavated in 1978 at a place dubbed "site G." They are thought to belong to three members of A. afarensis walking in the same direction across wet volcanic ash.

Now, a team of researchers from institutions in Italy and Tanzania has discovered new 3.66-million-year-old tracks at Laetoli that they suggest also belonged to A. afarensis.

The footprints belonging to Australopithecus afarensis were found at Laetoli, in Tanzania.
"It is amazing that, almost four decades after the original discovery, we have new footprints from the very same sediments," said William Jungers, a paleoanthropologist at Stony Brook University in New York who did not take part in this research. "They could have been made on the same day millions of years ago."

These footprints — a kind of ichnofossil, or trace fossil — reveal that this extinct species may have had major differences in sizes between the sexes. This difference, in turn, suggests that the species might have been polygynous, where males have multiple female mates, the researchers said. Previous research suggested the fact that polygyny leads to a few males monopolizing all females leads to intense competition between males, which favors the evolution of larger males that can better deal with their rivals.

"For me, the most important implication is that the area might harbor more ichnofossils— knowledge that could be used to solve many problems regarding different aspects of hominins," said lead study author Fidelis Masao, a palaeolithic archaeologist at the University of Dar es Salaam in Tanzania.

The new sets of footprints belong to two individuals, and were discovered at a place now dubbed "site S," located about 490 feet (150 meters) south of the prints discovered in 1978. Surrounded by dozens of other animal footprints — such as those belonging to a rhino, a giraffe, some horses and guinea fowl — along with raindrop impressions, the new tracks were apparently made on the same surface at the same time, and went in the same direction and at a similar speed as the A. afarensis prints found in 1978. Back when this ancient hominin was alive, the landscape was a bit like it is today — a mix of bushland, woodland and grassland with a nearby forest along the river.

Masao said that,after they had discovered the new footprints, one of the local Maasai workers saidto him,"in not too good Swahili, 'Masao umepata choo.'" The worker meant to say, "Masao, you have become famous," but the Swahili word for "famous"is "cheo," not "choo,"Masao explained.

"The latter means 'toilet' or 'poop,'" Masao said.

Judging by the impressions each foot made in the earth and the distance between each track, the researchers could estimate the size and weight of the individuals who made each set of prints. One individual was likely male, about 5 feet 5 inches (1.65 m) tall and 98.5 lbs. (44.7 kilograms). The other was likely female, about 4 feet 10 inches (1.46 m) tall and 87 lbs. (39.5 kg), the researchers said.

The estimates from the new male exceed the estimated height and weight of the tallest previous specimen from Laetoli by more than 7.8 inches (20 cm) and 13.2 lbs. (6 kg). Indeed, the estimated size of the new male individual "makes him the largest Australopithecus afarensis specimen identified so far," said senior study author Giorgio Manzi, a paleoanthropologist at Sapienza University in Rome.

Study co-author Marco Cherin, a vertebrate paleontologist at the University of Perugia in Italy, noted that he and some of the other researchers walked barefoot at the site to avoid damaging the tracks. "We realized that the feet of many of us fit well with the footprints," Cherin told Live Science.

Similarly, the new female is an estimated 1.2 to 1.6 inches (3 to 4 cm) taller than previous female specimens from Laetoli, the researchers said. This new female is also more than 11.8 inches (30 cm) taller than Lucy.

When these new prints are considered together with the prints discovered in 1978, it suggests "several early bipedal hominids moving as a group through the landscape, after a volcanic eruption and a subsequent rainfall," Manzi told Live Science.

One tentative conclusion from these findings is that the group might have consisted of "one male, two or three females, and one or two juveniles," Manzi said. This idea, in turn, potentially suggests that this male — and, therefore, other males in the species — may have had more than one female mate, Cherin said. However, Cherin did caution that "the inferences on sexual dimorphism [differences between the sexes] and on social structure need to be evaluated carefully."

These findings suggest that sexual dimorphism may have been much more pronounced and certain in A. afarensisthan scientists had thought. Prior work found that high sexual dimorphism is linked with polygyny — for example, in gorillas. In contrast, humans and their closest living relatives, chimpanzees and bonobos, are only moderately sexually dimorphic.

Read more at Discovery News

Adam Gave Up His Penis Bone for Eve

Male gorillas, chimpanzees and macaques all have penis bones. Male mice have tiny ones. Even the earliest ancestral primates and carnivores had them, according to new research. What then happened to this useful bone in humans, which would likely eliminate the need for Viagra?

As the ancestors of humans became more monogamous, they lost their boned penises, suggests the new study, published in the journal Proceedings of the Royal Society B.

The paper is the first to confirm that the ancestor of all mammals did not have a penis bone—called the baculum—but that ancestral primates and carnivores had this bone, which facilitates erections and prolonged penetrations, otherwise known as intromission.

"We know that both chimpanzees and bonobos, our closest relatives, have small bacula, and it is likely that the most recent common ancestor we share with them had one too," co-author Matilda Brindle, a University College London anthropologist, told Seeker. "Exactly where over the course of hominin evolution the baculum disappeared is difficult to know."

She even thinks it is possible that early human males had this bone, but that "it may have just been too small to have been preserved." The chimp baculum today, she added, is only 0.2 inches long.

Brindle and co-author Christopher Opie examined the evolutionary history of the baculum. They looked at hundreds of animals that have, or lack, the bone to see if they could identify patterns. The researchers first determined that animals with a penis bone tend to have longer lasting intromission.

"We defined prolonged intromission as that which continued for longer than three minutes," Brindle said. "Short intromission was that which continued for less than three minutes. When all cultural aspects of sex are stripped away and a male's aim is solely to ejaculate, human intromission is classified as short."

Brown bear penis bones.
Nevertheless, animals that can experience prolonged mating, such as the brown bear and red fox, must do so in very limited breeding seasons. Humans, on the other hand, can theoretically mate all year long. So the sex lives of early humans probably meant short, yet repeated, bouts of sex for as much as the individuals could physically handle.

Prior research suggests that ancestral humans called australopithecines as well as early members of our genus Homo "were at least facultatively monogamous," Brindle said. This means that they were capable of, and likely often chose, monogamy, even if they were not restricted to this lifestyle.

Animals with a baculum tend to be more polygamous, which the authors defined as a mating system in which multiple males mate with multiple females.

"Humans tend to have monogamous or polygynous (one male, multiple females) mating systems," Brindle said. "When only one male has access to a female, post-copulatory sexual selection is relatively low or absent."

Humans are not the only primates without a penis bone. Tarsiers and several monkeys from Central and South America lack this bone too, according to the authors.

Tarsiers are romantic primates that spend a lot of time wooing. For example, they will "sing" in duets or in calling concerts involving multiple individuals. Like humans, they usually choose to be either monogamous or polygynous.

Alan Dixson of Victoria University of Wellington's School of Biological Sciences told Seeker that the new research confirms "that longer bacula typically occur in those primates and carnivores which mate for extended periods."

Many mysteries remain to be uncovered about animal mating. Little, for example, is known about bat mating durations.

Read more at Discovery News

Dec 13, 2016

How does water melt? Layer by layer!

We all know that water melts at 0°C. However, 150 years ago the famous physicist Michael Faraday discovered that at the surface of frozen ice, well below 0°C, a thin film of liquid-like water is present. This thin film makes ice slippery and is crucial for the motion of glaciers.

Since Faraday's discovery, the properties of this water-like layer have been the research topic of scientists all over the world, which has entailed considerable controversy: at what temperature does the surface become liquid-like? How does the thickness of the layer dependent on temperature? How does the thickness of the layer increases with temperature? Continuously? Stepwise? Experiments to date have generally shown a very thin layer, which continuously grows in thickness up to 45 nm right below the bulk melting point at 0°C. This also illustrates why it has been so challenging to study this layer of liquid-like water on ice: 45 nm is about 1/1000th part of a human hair and is not discernible by eye.

Scientists of the Max Planck Institute for Polymer Research (MPI-P), in a collaboration with researchers from the Netherlands, the USA and Japan, have succeeded to study the properties of this quasi-liquid layer on ice at the molecular level using advanced surface-specific spectroscopy and computer simulations. The results are published in the latest edition of the scientific journal Proceedings of the National Academy of Science (PNAS).

The team of scientists around Ellen Backus, group leader at MPI-P, investigated how the thin liquid layer is formed on ice, how it grows with increasing temperature, and if it is distinguishable from normal liquid water. These studies required well-defined ice crystal surfaces. Therefore much effort was put into creating ~10 cm large single crystals of ice, which could be cut in such a way that the surface structure was precisely known. To investigate whether the surface was solid or liquid, the team made use of the fact that water molecules in the liquid have a weaker interaction with each other compared to water molecules in ice. Using their interfacial spectroscopy, combined with the controlled heating of the ice crystal, the researchers were able to quantify the change in the interaction between water molecules directly at the interface between ice and air.

The experimental results, combined with the simulations, showed that the first molecular layer at the ice surface has already molten at temperatures as low as -38° C (235 K), the lowest temperature the researchers could experimentally investigate. Increasing the temperature to -16° C (257 K), the second layer becomes liquid. Contrary to popular belief, the surface melting of ice is not a continuous process, but occurs in a discontinuous, layer-by-layer fashion.

"A further important question for us was, whether one could distinguish between the properties of the quasi-liquid layer and those of normal water" says Mischa Bonn, co-author of the paper and director at the MPI-P. And indeed, the quasi-liquid layer at -4° C (269 K) shows a different spectroscopic response than supercooled water at the same temperature; in the quasi-liquid layer, the water molecules seem to interact more strongly than in liquid water.

Read more at Science Daily

New diamond harder than ring bling

The diamond in an anvil the scientists used to make nano-sized Lonsdaleite.
The Australian National University (ANU) has led an international project to make a diamond that's predicted to be harder than a jeweller's diamond and useful for cutting through ultra-solid materials on mining sites.

ANU Associate Professor Jodie Bradby said her team -- including ANU PhD student Thomas Shiell and experts from RMIT, the University of Sydney and the United States -- made nano-sized Lonsdaleite, which is a hexagonal diamond only found in nature at the site of meteorite impacts such as Canyon Diablo in the US.

"This new diamond is not going to be on any engagement rings. You'll more likely find it on a mining site -- but I still think that diamonds are a scientist's best friend. Any time you need a super-hard material to cut something, this new diamond has the potential to do it more easily and more quickly," said Dr Bradby from the ANU Research School of Physics and Engineering.

Her research team made the Lonsdaleite in a diamond anvil at 400 degrees Celsius, halving the temperature at which it can be formed in a laboratory.

"The hexagonal structure of this diamond's atoms makes it much harder than regular diamonds, which have a cubic structure. We've been able to make it at the nanoscale and this is exciting because often with these materials 'smaller is stronger'."

Lonsdaleite is named after the famous British pioneering female crystallographer Dame Kathleen Lonsdale, who was the first woman elected as a Fellow to the Royal Society.

The research is published in Scientific Reports.

Co-researcher Professor Dougal McCulloch from RMIT said the collaboration of world-leading experts in the field was essential to the project's success.

"The discovery of the nano-crystalline hexagonal diamond was only made possible by close collaborative ties between leading physicists from Australia and overseas, and the team utilised state-of-the-art instrumentation such as electron microscopes," he said.

Corresponding author from the University of Sydney, Professor David McKenzie, said he was doing the night shift in the United States laboratory as part of the research when he noticed a little shoulder on the side of a peak.

Read more at Science Daily

Aging process increases DNA mutations in important type of stem cell

Induced pluripotent stem cells produced for the study and viewed under a microscope.
As it is in much of life, the aging process isn't kind to an important type of stem cell that has great therapeutic promise.

Researchers at the Scripps Translational Science Institute (STSI) and The Scripps Research Institute (TSRI) who looked at the effect of aging on induced pluripotent stem cells (iPSCs) found that genetic mutations increased with the age of the donor who provided the source cells, according to study results published by the journal Nature Biotechnology.

The findings reinforce the importance of screening iPSCs for potentially harmful DNA mutations before using them for therapeutic purposes, said lead investigators Ali Torkamani, Ph.D., director of genome informatics at STSI, and Kristin Baldwin Ph.D., the study's co-lead investigators and associate professor of molecular and cellular neuroscience at the Dorris Neuroscience Center at TSRI.

"Any time a cell divides, there is a risk of a mutation occurring. Over time, those risks multiply," Torkamani said. "Our study highlights that increased risk of mutations in iPSCs made from older donors of source cells."

Researchers found that iPSCs made from donors in their late 80s had twice as many mutations among protein-encoding genes as stem cells made from donors in their early 20s.

That trend followed a predictable linear track paired with age with one exception. Unexpectedly, iPSCs made from blood cells donated by people over 90 years old actually contained fewer mutations than what researchers had expected. In fact, stem cells from those extremely elderly participants had mutation numbers more comparable to iPSCs made from donors one-half to two-thirds younger.

Researchers said the reason for this could be tied to the fact that blood stem cells remaining in elderly people have been protected from mutations over their lifetime by dividing less frequently.

"Using iPSCs for treatment has already been initiated in Japan in a woman with age-related macular degeneration," said paper co-author and STSI Director Eric Topol, M.D. "Accordingly, it's vital that we fully understand the effects of aging on these cells being cultivated to treat patients in the future."

STSI is a National Institutes of Health-sponsored site led by Scripps Health in collaboration with TSRI. This innovative research partnership is leading the effort to translate wireless and genetic medical technologies into high-quality, cost-effective treatments and diagnostics for patients.

Of the 336 different mutations that were identified in the iPSCs generated for the study, 24 were in genes that could impair cell function or trigger tumor growth if they malfunctioned.

How troublesome these mutations could be depends on how well the stem cells are screened to filter out the defects and how they are used therapeutically, Torkamani said. For example, cells made from iPSCs for a bone marrow transplant would be potentially dangerous if they contained a TET2 gene mutation linked to blood cancer, which surfaced during the study.

"We didn't find any overt evidence that these mutations automatically would be harmful or pathogenic," he said.

For the study, researchers tapped three sources for 16 participant blood samples: The Wellderly Study, an ongoing STSI research project that is searching for the genetic secrets behind lifelong health by looking at the genes of healthy elderly people ages 80 to 105; the STSI GeneHeart Study, which involves people with coronary artery disease; and TSRI's research blood donor program.

Read more at Science Daily

Dismissed Ruins Found to Be Ancient Greek City

An international team of researchers has discovered a mysterious ancient city on top of a hill in central Greece.

Scattered on and around the Strongilovoúni hill on the great Thessalian plains near a village called Vlochós, some 190 miles north of Athens, the ruins had been dismissed as part of a small, irrelevant settlement.

"The fact that nobody had ever explored the hill before is a mystery," Robin Rönnlund, a PhD student in Classical Archaeology and Ancient History at the University of Gothenburg and leader of the fieldwork, said.

Rönnlund and colleagues from the University of Bournemouth, completed the first field season during two weeks in September 2016. The work was done in collaboration with the Swedish Institute at Athens and the local archaeological service in Karditsa.

According to Rönnlund, the hill is hiding many secrets, although hardly anything is visible on the ground.

"We found a town square and a street grid that indicate we are dealing with quite a large city. The area inside the city wall measures over 40 hectares [0.15 square miles]," Rönnlund said.

Fragment of red-figure pottery from the late 6th century BC, probably by Attic painter Paseas.
Ancient pottery and coins unearthed by the archaeologists helped date the city to at least 2,500 years ago.

"Our oldest finds are from around 500 BC, but the city seems to have flourished mainly from the fourth to the third century BC before it was abandoned for some reason, maybe in connection with the Roman conquest of the area," Rönnlund said.

The researchers hope to avoid traditional excavation and plan to use ground-penetration radar instead. The technology will enable the team to leave the site in the same shape as it was in when they arrived.

Read more at Discovery News

The Neurons That Control Time Perception Have Been Found (in Mice)

Scientists may be one step closer to explaining why, neurologically speaking, time seems to fly during good times and crawl during bad, and they have the humble mouse to thank for it.

Neuroscientists from Portugal's Champalimaud Centre for the Unknown report in a new study in the journal Science that they have discovered neurons in the mouse brain that can be manipulated to tinker with the rodent's judgment of elapsed time.

The scientists came by their finding by training mice on tasks that depended on their sense of time. In a statement, the study's lead author Bassam Atallah remarked on the difficulty of a getting a mouse to indicate its assessment of time duration: "There was real doubt whether it could even be done."

But the team was able, over a period of months, to get a group of mice to estimate the length of time that elapsed – shorter or longer than 1.5 seconds – between two tones that were played. Correct answers won them a treat.

Then, the researchers zeroed in on something in the animal's brain they thought might bear fruit: dopamine-releasing neurons in a section called the substantia nigra pars compacta, an area previously known to be involved with the processing of time. In people with Parkinson's disease, a condition that includes hampered perception of time, the section is destroyed.

"Dopamine neurons are implicated in many of the psychological factors and disorders associated with changes in time estimation," the team explained in their study.

In early experiments, the scientists noticed a seeming link between the neurons' activity and the mice reacting to the tones that were played.

Later they found that they could stimulate the neurons with light to affect whether the mice underestimated or overestimated the duration between the tones.

"This result, together with the naturally occurring signals we observed in the previous experiments, demonstrate that the activity of these neurons was sufficient to alter the way the animals judged the passage of time," said study co-author Joe Paton.

The researchers think it's likely something similar may be going on in the human brain, when people perceive the passage of time, but they caution against excessive enthusiasm.

"When we study animals, the only thing we can measure is the animal's behavior. But we are never sure of what they perceive," said Paton. "We interpret this as 'a subjective experience of the animal', but it's no more than an interpretation. And that's the best we can do."

From Discovery News

Dec 12, 2016

ALMA finds compelling evidence for pair of infant planets around young star

ALMA image of the protoplanetary disk surrounding the young star HD 163296 as seen in dust. New observations suggested that two planets, each about the size of Saturn, are in orbit around the star. These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the star's protoplanetary disk.
Astronomers now know that our galaxy is teeming with planets, from rocky worlds roughly the size of Earth to gas giants bigger than Jupiter. Nearly every one of these exoplanets has been discovered in orbit around a mature star with a fully evolved planetary system.

New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) contain compelling evidence that two newborn planets, each about the size of Saturn, are in orbit around a young star known as HD 163296. These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the star's protoplanetary disk.

Previous observations of other young star systems have helped to reshape our understanding of planet formation. For example, ALMA's images of HL Tauri and TW Hydrae revealed striking gaps and prominent ring structures in the stars' dusty disks. These features may be the tantalizing first signs that planets are being born. Remarkably, these signs appeared around much younger stars than astronomers thought possible, suggesting that planet formation can begin soon after the formation of a protoplanetary disk.

"ALMA has shown us amazing images and never-before-seen views of the rings and gaps around young stars that could be the hallmarks of planet formation. However, since we were only looking at the dust in the disks with sufficient detail, we couldn't be sure what created these features," said Andrea Isella, an astronomer at Rice University in Houston, Texas, and lead author on a paper published in Physical Review Letters.

In studying HD 163296, the research team used ALMA to trace, for the first time, the distribution of both the dust and the carbon monoxide (CO) gas components of the disk at roughly the same level of detail.

These observations revealed three distinct gaps in HD 163296's dust-filled protoplanetary disk. The first gap is located approximately 60 astronomical units from the central star, which is about twice the distance from our Sun to Neptune. (An astronomical unit -- AU -- is the average distance from Earth to the Sun.) The other two gaps are 100 AU and 160 AU from the central star, well beyond the extent of our solar system's Kuiper Belt, the region of icy bodies beyond the orbit of Neptune.

Using ALMA's ability to detect the faint millimeter-wavelength "glow" emitted by gas molecules, Isella and his team discovered that there was also an appreciable dip in the amount of CO in the outer two dust gaps.

By seeing the same features in both the gas and the dust components of the disk, the astronomers believe they have found compelling evidence that there are two planets coalescing remarkably far from the central star. The width and depth of the two CO gaps suggest that each potential planet is roughly the same mass as Saturn, the astronomers said.

In the gap nearest to the star, the team found little to no difference in the concentration of CO gas compared to the surrounding dusty disk. This means that the innermost gap could have been produced by something other than an emerging planet.

"Dust and gas behave very differently around young stars," said Isella. "We know, for example, that there are certain chemical and physical process that can produce ringed structures in the dust like the ones we have seen previously. We certainly believe these structures could be the work of a nascent planet plowing through the dust, but we simply can't rule out other possible explanations. Our new observations provide intriguing evidence that planets are indeed forming around this one young star."

HD 163296 is roughly 5 million years old and about twice the mass of the Sun. It is located approximately 400 light-years from Earth in the direction of the constellation Sagittarius.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

Read more at Science Daily

Jersey was a must-see tourist destination for Neanderthals for over 100,000 years

Archaeologists at La Cotte de St Brelade.
New research led by the University of Southampton shows Neanderthals kept coming back to a coastal cave site in Jersey from at least 180,000 years ago until around 40,000 years ago.

As part of a re-examination of La Cotte de St Brelade and its surrounding landscape, archaeologists from Southampton, together with experts from three other universities and the British Museum, have taken a fresh look at artefacts and mammoth bones originally excavated from within the site's granite cliffs in the 1970s. Their findings are published in the journal Antiquity.

The researchers matched types of stone raw material used to make tools to detailed mapping of the geology of the sea bed, and studied in detail how they were made, carried and modified. This helped reconstruct a picture of what resources were available to Neanderthals over tens of thousands of years -- and where they were travelling from.

Lead author Dr Andy Shaw of the Centre for the Archaeology of Human Origins (CAHO) at the University of Southampton said: "La Cotte seems to have been a special place for Neanderthals. They kept making deliberate journeys to reach the site over many, many generations. We can use the stone tools they left behind to map how they were moving through landscapes, which are now beneath the English Channel. 180,000 years ago, as ice caps expanded and temperatures plummeted, they would have been exploiting a huge offshore area, inaccessible to us today."

Previous research focussed on particular levels in the site where mammoth bones are concentrated, but this new study took a longer-term perspective, looking at how Neanderthals used it and explored the surrounding landscape for over 100,000 years.

The team, including academics from the British Museum, University College London (UCL) and the University of Wales found that Neanderthals kept coming back to this particular place, despite globally significant changes in climate and landscape. During glacial phases (Ice Ages), they travelled to the site over cold, open landscapes, now submerged under the sea. They kept visiting as the climate warmed up and Jersey became a striking highpoint in a wide coastal plain connected to France.

Dr Beccy Scott of the British Museum added: "We're really interested in how this site became 'persistent' in the minds of early Neanderthals. You can almost see hints of early mapping in the way they are travelling to it again and again, or certainly an understanding of their geography. But specifically what drew them to Jersey so often is harder to tease out. It might have been that the whole Island was highly visible from a long way off -- like a waymarker -- or people might have remembered that shelter could be found there, and passed that knowledge on."

Paper author Dr Matt Pope, of the Institute of Archaeology at UCL, agrees: "La Cotte de St Brelade is probably the most important Neanderthal site in northern Europe and could be one of the last known places that Neanderthals survived in the region. It was certainly as important to them as it is to us, as we try and understand how they thrived and survived for 200,000 years.

"With new technology we have been able to reconstruct the environment of the La Cotte Neanderthals in a way earlier researchers couldn't. Our project has really put the Neanderthal back into the landscape, but emphasised how significant the changes in climate and landscape have been since then."

Project leader Professor Clive Gamble, of CAHO at the University of Southampton, comments: "Jersey is an island that endures, summed up by the granite cliffs of St Brelade's Bay. The elements which led to Neanderthals coming back for so many thousands of years shows how this persistence is deep rooted in Jersey's past. Our project has shown that more unites the past with the present than separates. We are not the only humans to have coped successfully with major environmental changes. Let's hope we are not the last."

Read more at Science Daily

New Spider Species Is Named After 'Harry Potter' Sorting Hat

A new spider species in India has been given a name that's sure to be a winner with Harry Potter fans.

The spider, Eriovixia gryffindori, just 7 millimeters (0.28 inches) long, was named as such because its shape reminded its discoverers of the magical "sorting hat" in the Harry Potter books. (When placed upon a new Hogwarts student's head, the hat comes to life and determines which house the student should belong to at the school for young wizards. It was originally owned by the wizard Godric Gryffindor.)

Mumbai researchers discovered the spider in the Kan forest of the Western Ghats, a mountainous region in southwest India. According to the scientists, the hat shape helps the spider blend in with dried leaves during daylight hours in order to protect itself from predators.

In a paper published in the Indian Journal of Arachnology, Mumbai researchers who discovered the new arachnid wrote that its name was "an ode from the authors, for magic lost, and found, in an effort to draw attention to the fascinating, but oft overlooked world of invertebrates, and their secret lives."

"As a youngster, I was very fond of reading Harry Potter books. So, when I encountered this tiny spider, I thought of the magical hat," lead author of the study, Javed Ahmed, told the Times of India.

Ahmed was also involved in the discovery in 2015 of a rare jumping spider called Portia albimana, an arachnid known for its hunting prowess, even tracking other spiders that are every bit as capable as hunters.

From Discovery News

A Rapidly Spinning Black Hole Was Seen Killing a Distant Star

Supermassive black holes are known to occupy the cores of the vast majority of galaxies, eating any material — dust, gas, stars, planets, aliens — their host galaxies can provide. But they rarely eat quietly. As graphically demonstrated in a galaxy some 4 billion light-years away, an unfortunate star strayed too close to the rapidly-spinning supermassive black hole in its galaxy's center, becoming a stellar smoothie of sorts.

Spotted by the All Sky Automated Survey for SuperNovae (ASAS-SN) project, the event in 2015 was recorded as the brightest supernova ever seen, but now a group of researchers don't think it was a supernova at all and point to one of the most destructive events known in the universe.

The event, dubbed ASASSN-15lh, was so bright that it was 20 times brighter than the total light output of our galaxy and its identification as a black hole-blended star has thrown the identification of other luminous supernovae into doubt.

"We observed the source for 10 months following the event and have concluded that the explanation is unlikely to lie with an extraordinarily bright supernova," said Giorgos Leloudas at the Weizmann Institute of Science, Israel, and the Dark Cosmology Center, Denmark in a statement. "Our results indicate that the event was probably caused by a rapidly spinning supermassive black hole as it destroyed a low-mass star."

Known as a "tidal disruption event," ASASSN-15lh was triggered by a star getting trapped in the black hole's gravitational well. Extreme tidal forces then caused incredible shear across the star, completely distorting it. This process, known as "spaghettification", pulled the stellar material into a long ribbon wrapping around the black hole, dragging the gases into its event horizon — the point at which nothing, not even light, can escape. During this time, extreme relativistic forces converted huge quantities of matter into pure energy, generating the record-breaking explosion that echoed over 4 billion light years to reach telescopes on Earth.

Because it happened 4 billion light-years away means that the event happened 4 billion years ago, when the universe was around 10 billion years old.

But observing this kind of energetic event so far away required intense follow-up observations to confirm that it was, indeed, not just a really bright supernova. After detection by ASAS-SN, the researchers used observations by the Very Large Telescope (VLT) at ESO's Paranal Observatory in Chile, the New Technology Telescope (NTT) at ESO's La Silla Observatory (also in Chile) and the Hubble Space Telescope to understand what was behind the explosion. Over the 10 months, ASASSN-15lh went through distinct phases consistent with a star being ripped to shreds. Also, as the explosion happened in a red, massive galaxy where superluminous supernovae are unlikely — ultraluminous supernovae typically occur in blue, star-forming dwarf galaxies.

Read more at Discovery News