Jun 28, 2014

New superconductor world record set

A world record that has stood for more than a decade has been broken by a team led by University of Cambridge engineers, harnessing the equivalent of three tonnes of force inside a golf ball-sized sample of material that is normally as brittle as fine china.

The Cambridge researchers managed to 'trap' a magnetic field with a strength of 17.6 Tesla -- roughly 100 times stronger than the field generated by a typical fridge magnet -- in a high temperature gadolinium barium copper oxide (GdBaCuO) superconductor, beating the previous record by 0.4 Tesla. The results are published today in the journal Superconductor Science and Technology.

The research demonstrates the potential of high-temperature superconductors for applications in a range of fields, including flywheels for energy storage, 'magnetic separators', which can be used in mineral refinement and pollution control, and in high-speed levitating monorail trains.

Superconductors are materials that carry electrical current with little or no resistance when cooled below a certain temperature. While conventional superconductors need to be cooled close to absolute zero (zero degrees on the Kelvin scale (or -273 °C) before they superconduct, high temperature superconductors do so above the boiling point of liquid nitrogen (-196 °C) which makes them relatively easy to cool and cheaper to operate.

Superconductors are currently used in scientific and medical applications, such as MRI scanners, and in the future could be used to protect the national grid and increase energy efficiency, due to the amount of electrical current they can carry without losing energy.

The current carried by a superconductor also generates a magnetic field, and the more field strength that can be contained within the superconductor, the more current it can carry. State of the art, practical superconductors can carry currents that are typically 100 times greater than copper, which gives them considerable performance advantages over conventional conductors and permanent magnets.

The new record was achieved using 25 mm diameter samples of GdBCO high temperature superconductor fabricated in the form of a large, single grain using an established melt processing method and reinforced using a relatively simple technique. The previous record of 17.2 Tesla, set in 2003 by a team led by Professor Masato Murakami from the Shibaura Institute of Technology in Japan, used a highly specialised type of superconductor of a similar, but subtly different, composition and structure.

"The fact that this record has stood for so long shows just how demanding this field really is," said Professor David Cardwell of Cambridge's Department of Engineering, who led the research, in collaboration with Boeing and the National High Field Magnet Laboratory at the Florida State University. "There are real potential gains to be had with even small increases in field."

To contain such a large field, the team used materials known as cuprates: thin sheets of copper and oxygen separated by more complex types of atoms. The cuprates were the earliest high temperature superconductors to be discovered, and have the potential to be used widely in scientific and medical applications.

While they are high quality superconductors with outstanding potential for practical applications, the cuprates can be as brittle as dried pasta when fabricated in the form of sintered ceramics, so trying to contain a strong magnetic field within bulk forms of the cuprates tends to cause them to explode.

In order to hold in, or trap, the magnetic field, the researchers had to modify both the microstructure of GdBCO to increase its current carrying and thermal performance, and reinforce it with a stainless steel ring, which was used to 'shrink-wrap' the single grain samples. "This was an important step in achieving this result," said Dr John Durrell who led the experiment in Florida.

The lines of magnetic flux in a superconductor repel each other strongly, making containing such a large field difficult. But, by engineering the bulk microstructure, the field is retained in the sample by so-called 'flux pinning centres' distributed throughout the material. "The development of effective pinning sites in GdBCO has been key to this success," said Dr Yun-Hua Shi, who has been responsible for developing the melt process fabrication technique at Cambridge for the past 20 years.

The result was the biggest ever trapped field achieved in a bulk, standalone material at any temperature.

"This work could herald the arrival of superconductors in real-world applications," said Professor Cardwell. "In order to see bulk superconductors applied for everyday use, we need large grains of superconducting material with the required properties that can be manufactured by relatively standard processes."

A number of niche applications are currently being developed by the Cambridge team and its collaborators, and it is anticipated that widespread commercial applications for superconductors could be seen within the next five years.

Read more at Science Daily

Astronomers closer to proving gravitational waves with precise measurements of rapidly rotating neutron star

When Albert Einstein proposed the existence of gravitational waves as part of his theory of relativity, he set in train a pursuit for knowledge that continues nearly a century later.

These ripples in the space-time continuum exert a powerful appeal because it is believed they carry information that will allow us to look back into the very beginnings of the universe. But although the weight of evidence continues to build, undisputed confirmation of their existence still eludes scientists.

Researchers from University of Warwick and Monash University have provided another piece of the puzzle with their precise measurements of a rapidly rotating neutron star: one of the smallest, densest stars in the universe.

Neutron stars, along with colliding black holes and the Big Bang, may all be sources of gravitational waves.

In work published in The Astrophysical Journal, the Monash and Warwick scientists significantly improved the precision with which they could measure the orbit of Scorpius X-1, a double star system containing a neutron star that feeds off a nearby companion star. This interaction makes it the strongest source of X-rays in the sky apart from the sun.

Dr Duncan Galloway from the Monash Centre for Astrophysics said that the main difficulty in searching for gravitational waves emitted by Scorpius X-1 was the lack of precise knowledge about the neutron star's orbit.

"We have made a concerted effort to refine Scorpius X-1's orbit and other parameters, with the goal of significantly boosting the sensitivity of searches for gravitational waves," Dr Galloway said.

"Detecting gravitational waves will open a new window for observation and allow us to study objects in the universe in a way that can't be achieved using traditional astronomy techniques."

Monash PhD student Ms Shakya Premachandra spent three months at the University of Warwick learning specific techniques and methods to improve the team's measurements.

Under the guidance of Dr Danny Steeghs from Warwick's Astronomy and Astrophysics Group, Ms Premachandra worked on the research data and learnt a specific software program developed by Warwick astronomers.

Read more at Science Daily

Jun 27, 2014

Not much force: Researchers detect smallest force ever measured

What is believed to be the smallest force ever measured has been detected by researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. Using a combination of lasers and a unique optical trapping system that provides a cloud of ultracold atoms, the researchers measured a force of approximately 42 yoctonewtons. A yoctonewton is one septillionth of a newton and there are approximately 3 x 1023 yoctonewtons in one ounce of force.

"We applied an external force to the center-of-mass motion of an ultracold atom cloud in a high-finesse optical cavity and measured the resulting motion optically," says Dan Stamper-Kurn, a physicist who holds joint appointments with Berkeley Lab's Materials Sciences Division and the UC Berkeley Physics Department. "When the driving force was resonant with the cloud's oscillation frequency, we achieved a sensitivity that is consistent with theoretical predictions and only a factor of four above the Standard Quantum Limit, the most sensitive measurement that can be made."

Stamper-Kurn is the corresponding author of a paper in Science that describes these results. The paper is titled "Optically measuring force near the standard quantum limit." Co-authors are Sydney Schreppler, Nicolas Spethmann, Nathan Brahms, Thierry Botter and Maryrose Barrios.

If you want to confirm the existence of gravitational waves, space-time ripples predicted by Albert Einstein in his theory of general relativity, or want to determine to what extent the law of gravity on the macroscopic scale, as described by Sir Isaac Newton, continues to apply at the microscopic scale, you need to detect and measure forces and motions that are almost incomprehensively tiny. For example, at the Laser Interferometer Gravitational-Wave Observatory (LIGO), scientists are attempting to record motions as small as one thousandth the diameter of a proton.

At the heart of all ultrasensitive detectors of force are mechanical oscillators, systems for translating an applied force into measureable mechanical motion. As measurements of force and motion reach quantum levels in sensitivity, however, they bump up against a barrier imposed by the Heisenberg uncertainty principle, in which the measurement itself perturbs the motion of the oscillator, a phenomenon known as "quantum back-action." This barrier is called the Standard Quantum Limit (SQL). Over the past couple of decades, a wide array of strategies have been deployed to minimize quantum back-action and get ever closer to the SQL, but the best of these techniques fell short by six to eight orders of magnitude.

"We measured force with a sensitivity that is the closest ever to the SQL," says Sydney Schreppler, a member of the Stamper-Kurn research group and lead author of the Science paper. "We were able to achieve this sensitivity because our mechanical oscillator is composed of only 1,200 atoms."

In the experimental set-up used by Schreppler, Stamper-Kurn and their colleagues, the mechanical oscillator element is a gas of rubidium atoms optically trapped and chilled to nearly absolute zero. The optical trap consists of two standing-wave light fields with wavelengths of 860 and 840 nanometers that produce equal and opposite axial forces on the atoms. Center-of-mass motion is induced in the gas by modulating the amplitude of the 840 nanometer light field. The response is measured using a probe beam with a wavelength of 780 nanometers.

"When we apply an external force to our oscillator it is like hitting a pendulum with a bat then measuring the reaction," says Schreppler. "A key to our sensitivity and approaching the SQL is our ability to decouple the rubidium atoms from their environment and maintain their cold temperature. The laser light we use to trap our atoms isolates them from external environmental noise but does not heat them, so they can remain cold and still enough to allow us to approach the limits of sensitivity when we apply a force."

Schreppler says it should be possible to get even closer to the SQL for force sensitivity through a combination of colder atoms and improved optical detection efficiency. She also says there are back-action evading techniques that can be taken by performing non-standard measurements. For now, the experimental approach demonstrated in this study provides a means by which scientists trying to detect gravitational waves can compare the limits of their detection abilities to the predicted amplitude and frequency of gravitational waves. For those seeking to determine whether Newtonian gravity applies to the quantum world, they now have a way to test their theories. The enhanced force-sensitivity in this experiment could also point the way to improved atomic force microscopy.

Read more at Science Daily

Oldest Animal-Built Reef Found in Namibia

An ancient reef that once teemed with primitive sea life has been unearthed in Africa.

The reef, which dates to 548 million years ago, is the oldest animal-built reef ever found.

The coral-like creatures, dubbed Cloudina, may have built the superstructures to protect themselves from predators or to soak up the nutrients from ocean currents, said study co-author Rachel Wood, a geologist at the University of Edinburgh in Scotland.

During the Ediacaran Period, which lasted from about 635 million to 542 million years ago, all life lived in the sea, and most creatures were immobile and soft-bodied, with mysterious wavy, frondlike shapes.

But in the 1970s, scientists discovered evidence of Cloudina, the earliest fossil animals to have skeletons. The pencil-shaped sea creature could grow to about 5.9 inches (15 centimeters) long. A cross-section of the tubular shape shows that it would've been about 0.3 inches (8 millimeters) in diameter, Wood said.

"It's like a series of hollow ice-cream cones all stacked up," Wood told Live Science, referring to the appearance of the Cloudina skeleton. "It might have been related to corals and anemones and jellyfish."

Like modern-day corals, the youngest cone in the stack would have been alive, while the rest would be dead, Wood said.

But scientists knew little about how these enigmatic creatures lived.

Late last year, while excavating in Namibia in a region known for Ediacaran fossils, Wood and her colleagues found evidence for a vast network of reefs built by Cloudina about 548 million years ago. Like modern-day corals, the primeval creatures excreted calcium carbonate, which cemented them to each other and helped grow the reef.

The new finds are the oldest animal-built reefs ever discovered. Previously, the oldest animal-built reefs dated to around 530 million years ago, during the Cambrian Period, when the complexity and diversity of life on Earth exploded. (Slimy bacterial communities known as stromatolites have built vast, limestone reefs for almost 3 billion years, Wood said.)

The ancient Cloudina reefs the team discovered grew in patches atop a massive stromatolite-formed reef complex that spans nearly 4.3 miles (7 kilometers), Wood said.

"If you were snorkeling over it nearly 550 million years ago, you'd see areas of green surface, from stromatolites, and then you'd see these little patches of tubes all growing together, forming a little thicket, or mound, on the seafloor," Wood said.

Read more at Discovery News

Rare Incan 'Calculators' Found in Peru

Archaeologists working in Peru have discovered 25 well-preserved quipus, an ancient string-based device used to solve mathematical problems and to assist in record-keeping.

The find was made in the archaeological complex of Incahuasi, south of Lima, Alejandro Chu, reports Peru This Week. The items were found in ancient warehouses, or kallancas, and not in a funerary context as is the norm, making this a rather unique find. The placement of the quipus suggests they were used for administrative purposes. Incahuasi was one of the most important strategic cities built by the Incas in the valley of Lunahuana.

Quipu (also called "khipus" or "talking knots") typically consisted of colored, spun, and plied thread or strings from llama or alpaca hair. They aided in data collection and record-keeping, including the monitoring of tax obligations, census records, calendrical information, and military organization. The cords contained numeric and other values encoded on knots in a base-10 positional system. Some quipu had as many as 2,000 cords.

The Khipu Database Project describes quipus and how they worked:

Most of the existing khipu are from the Inka period, approx 1400 – 1532 CE. The Inka empire stretched from Ecuador through central Chile, with its heart in Cuzco, a city in the high Andes of southern Peru. Colonial documents indicate that khipu were used for record keeping and sending messages by runner throughout the empire. There are approximately 600 khipu surviving in museums and private collections around the world.

The word khipu comes from the Quechua word for "knot" and denotes both singular and plural. Khipu are textile artifacts composed of cords of cotton or occasionally camelid fiber. The cords are arranged such that there is one main cord, called a primary cord, from which many pendant cords hang. There may be additional cords attached to a pendant cord; these are termed subsidiaries. Some khipu have up to 10 or 12 levels of subsidiaries. Khipu are often displayed with the primary cord stretched horizontally, so that the pendants appear to form a curtain of parallel cords, or with the primary cord in a curve, so that the pendants radiate out from their points of attachment. When khipu were in use, they were transported and stored with the primary cord rolled into a spiral. In this configuration khipu have been compared to string mops.

Read more at Discovery News

World’s Most Beautiful Sponge Dismantles Its Victims Cell by Cell

The harp sponge would make for a pretty lousy household scrubber, except between blinds maybe. Seriously, how do you even clean between blinds? I’m 30 and I have no idea.
If you were a sea creature and you wanted to form a band, you’d have some tough decisions to make. Who should take vocals: dolphins or whales? And what about the drums? Presumably it’d be some sort of cephalopod, what with all those arms, but would it play on giant clams or brain corals? And good luck finding stringed instruments, unless you want to risk anaphylactic shock and strum some jellyfish.

But if you can manage it, plunge to around 10,000 feet deep and you’ll find your strings anchored right to the seafloor. This is the 3-foot-wide harp sponge, and there’s nothing quite like it on the planet. It’s hardly even a sponge as we would recognize it, having left behind the filter-feeding lifestyle and become a carnivore, passively nabbing tiny critters unlucky enough to float through its strings. Think SpongeBob SquarePants, only without the pants and with way more murder.

The remarkable image above is from 2012 when scientists, including marine biologist Henry Reiswig of British Columbia’s University of Victoria, collected two specimens and observed 10 more off the California coast using two remotely operated vehicles from the Monterey Bay Aquarium Research Institute. At such depths, though, collecting good specimens is exceedingly difficult because it can take hours to return to the surface.

“So all kinds of things can happen between the collection and getting a specimen back on deck where we can either look at it or preserve it,” said Reiswig. “So there’s a lot of mystery, a lot of intuition involved in this stuff.”

What scientists know so far about the harp sponge is essentially its morphology. But from that morphology, they can then hypothesize about its biology, determining that it’s an avid carnivore that relies on water currents to push tiny crustaceans into its picket-fence-like upright branches.

The ROV pilots had to shoo away a mysterious white box that had settled on their harp sponge specimen.
If you take a look at the photo at right, you’ll see these branches have tiny hair-like structures called filaments splitting off horizontally. Each of these is positively packed with tiny hooks known as spicules, perhaps 5,000 on each filament, which act essentially like velcro to snare miniscule prey.

And this death will not be a pleasant one. As the catch struggles to free itself, over the course of 10 to 24 hours the cells on the sponge’s branch crawl up onto the critter. There’s no biting, and there are no toxins involved. The prey is simply immobilized and subsumed right into the sponge.

“So it eventually ends up as a little pocket, what we call a prey cyst,” said Reiswig. “And then once the prey dies in there, the cells around it migrate into any little opening—through the mouth, through the nose, through whatever openings there are between the skeleton, and starts to dismantle the cells of the copepod or small crustacean. Insidious!”

This sophistication is highly unusual for sponges, which are among the most primitive multicellular organisms, with no nervous systems or hearts or brains, or any other organs for that matter (and therefore would have made for the ultimate companion in the Wizard of Oz). They simply pump in water, filter out the nutritious bacteria and other particles, and absorb oxygen.

The harp sponge, though, has evolved a more complex carnivorous lifestyle to cope with the depths. Here not only is food incredibly scarce—unless a dead whale falls from the heavens, though that really wouldn’t do the sponge any good, especially if the whale landed on it—but currents are far calmer. That’s a big problem if you depend on them to bring you food, but by growing up to six rows of branches, the harp sponge greatly increases the surface area available to snag prey. It’s a brilliant adaptation to living in an aquatic wasteland.

The Sex Lives of Immobilized Beings

This strategy also solves the problem of sex when you can’t move. Most sponges, including the harp, are hermaphroditic, producing both sperm and eggs, so they’re simultaneously capable of fertilizing and being fertilized themselves. And the harp sponge has figured out a novel way to have sex: by pretending its sperm is prey.

The Monterey Bay Aquarium Research Institute’s remotely operated vehicle Doc Ricketts, one of two used by Reiswig and other scientists to observe the harp sponge. It’s unknown what music the man at lower right was listening to with those headphones. Probably Led Zeppelin, though. Zeppelin is good music for doing a science.
If you’re a carnivorous sponge, “you get to package your sperm into big packets that are about like prey, and then you can send them to somebody who can catch them,” said Reiswig. “There’s no use packaging your sperm if your partner down the road, maybe 100 meters or 1,000 meters away, can’t catch that package.”

Those spheres at the top of each branch in the pictures above are where the sperm is produced and released into the water column, while the smaller bumps about halfway down the animal are where the packages from another sponge have settled and fertilized eggs (it’s important that an individual sponge keeps these bits sufficiently separated, lest it fertilize itself—yeah, that’s a thing). Just like grabbing rare prey at these depths, you need to be damn sure that if there’s scant sperm floating about, you can snag it.

Observing fertilized specimens under a microscope, Reiswig found that once snagged on a hook, the package, also known as a spermatophore, begins to break down, likely due to enzymes released by the package itself. Instead of being digested, the sperm cells are then absorbed directly into the sponge and the waiting egg.

Read more at Wired Science

Jun 26, 2014

Scarred Girl Kicked out of KFC a Viral Media Hoax

It was an outrageous story that most of us saw — and many shared — on social media a few weeks ago: A woman named Kelly Mullins claimed that she visited a KFC restaurant with her granddaughter Victoria, who had been badly injured in a dog attack, and the pair were asked to leave because the girl’s scarred face disgusted other diners.

The story was first reported in the Laurel Leader-Call, which noted:
“The story began going viral on June 12 when ‘Victoria’s Victories’ (Facebook) page posted: ‘Does this face look scary to you? Last week at KFC in Jackson MS this precious face was asked to leave because her face scared the other diners. I personally will never step foot in another KFC again and will be personally writing the CEO.”
 After it went viral, employees and managers at both Jackson locations have faced death threats, have had drinks thrown at them through the drive-thru window and have faced constant verbal harassment.”

The story spread, boycotts were proposed, and sympathetic citizens made their outrage known. But soon doubts were raised about the claim.

The family changed their story, giving two different accounts of where the incident took place. Surveillance video from both franchise locations was obtained, and after hours of review neither Mullins nor her injured granddaughter could be seen anywhere.

Furthermore a review of the transactions at both locations failed to uncover an order matching what Mullins claimed they ate. In fact there’s no evidence that the little girl and her grandmother visited any KFC on the day in question, much less were asked to leave one because of a disfigurement.

Rick Maynard, a spokesman for KFC, issued a recent statement that read in part:
“Like the rest of America, the KFC family has been moved by the story of Victoria’s injuries and recovery. After the alleged incident was reported to us, two investigations took place, including one by an independent investigator. Neither revealed any evidence that the incident occurred and we consider the investigation closed.”

The oft-reliable mythbusting web site Snopes.com deems the story “probably false” and notes that the “Victoria’s Victories” Facebook page has been deleted.

What was the motivation for this hoax? One obvious answer is money, since the family set up an online fundraiser which surged past $130,000 after the grandmother’s claim went viral. But it is also possible that the original post was merely a little white lie intended to generate attention and sympathy.

That was apparently the case last year when Dayna Morales, a New Jersey waitress, made national news claiming she was left a hate-filled, anti-gay note instead of a tip. Morales posted a copy of a receipt on Facebook that read, “I’m sorry but I cannot tip because I do not agree with your lifestyle and how you live your life.”

The post went viral on social media, shared and Tweeted by well-meaning supporters for social justice. But questions soon arose about her claims after the family she accused of mistreating her showed their original receipt for the same transaction that included a tip. An investigation by her employer concluded that she made up the story, and she was eventually fired.

Sparking the Social Justice Witch Hunt

The pattern is not difficult to recognize: people taking their grievances to social media instead of through proper channels in order to harm others’ reputations using hordes of ill-informed social-justice bloggers. In decades past if you were upset with the actions of some person or company, there were clear guidelines for how to handle the situation. If it were a personal dispute it might involve speaking to a manager, contacting a homeowner’s association, a small claims civil lawsuit or even fisticuffs. If still unresolved, an aggrieved party might contact the local newspaper or television station and ask them to help seek justice.

If it’s a criminal issue, of course, the procedures are even clearer: Call the police and let them sort it out. If the police find probable cause to determine a crime was committed, someone will be arrested and it then becomes a matter for the courts.

But in these cases the complaint wasn’t a crime — leaving a homophobic note instead of a tip is rude and hurtful but not illegal, as is asking a scarred restaurant customer to leave — but instead a violation of social norms or morals. This is key to understanding why people take up these causes with such passion. These days mob justice doesn’t need to happen in the streets. It can happen online, and much more easily.

With the emergence of social media in recent years people with both real and imagined complaints have found a new forum to garner attention, sympathy and money from complete strangers. Why fill out a complaint form or wait for a return phone call when you can instantly tell your side of the story on Facebook or Twitter and get immediate reaction? The reaction could mean hundreds or thousands of people are outraged on your behalf, contacting the company’s home office and threatening a boycott unless this grave injustice is immediately remedied and an apology offered.

Of course this is terribly unfair to the accused company, which may know little or nothing about the incident until the angry calls and emails pour in, requiring days or  weeks to do an investigation of the claim to find out whether it’s completely true, completely false or somewhere in between (perhaps there was a misunderstanding or miscommunication).

As each day passes the publicity gets worse and worse, and even when the company is finally cleared of any wrongdoing, its name has been dragged through the mud. Unfortunately for KFC, their brand has become associated with the cruel mistreatment of an innocent girl, and it may take years for that to go away.

KFC Rumors and Urban Legends

This isn’t the first time  the fried chicken chain has been the target of false and malicious rumors. As Jan Harold Brunvand notes in his “Encyclopedia of Urban Legends,” the story of the Kentucky Fried Rat “is one of the best-known food contamination stories, being circulated since the early 1970s. It describes how a customer of a national fried-chicken franchise allegedly found a batter-fried rat in a bucket of chicken. Usually, the victim has eaten some of the rat before noticing the rodent’s tail and realizing the meat is not chicken.”

In some versions of the story the rat was added to the chicken by a malicious employee. In other versions, rat meat was added to the chicken as a cost-saving measure by a penny-pinching manager.

The “Kentucky Fried Rat” urban legend has more in common with this incident than might appear at first blush.

Read more at Discovery News

Chariots, Gold Found at Bronze-Age Burial Site

An ancient burial containing chariots, gold artifacts and possible human sacrifices has been discovered by archaeologists in the country of Georgia, in the south Caucasus.

The burial site, which would've been intended for a chief, dates back over 4,000 years to a time archaeologists call the Early Bronze Age, said Zurab Makharadze, head of the Centre of Archaeology at the Georgian National Museum.

Archaeologists discoveredthe timber burial chamber within a 39-foot-high (12 meters) mound called a kurgan. When the archaeologists reached the chamber they found an assortment of treasures, including two chariots, each with four wooden wheels.

The team discovered ornamented clay and wooden vessels, flint and obsidian arrowheads, leather and textile artifacts, a unique wooden armchair, carnelian and amber beads and 23 golden artifacts, including rare and artistic crafted jewelry, wrote Makharadze in the summary of a presentation he gave recently at the International Congress on the Archaeology of the Ancient Near East, held at the University of Basel in Switzerland.

"In the burial chamber were placed two four-wheeled chariots, both in good condition, design of which represents fine ornamental details of various styles," Makharadze wrote. Thechamber also contained wild fruits, he added.

While the human remains had been disturbed by a robbery, which probably occurred in ancient times, and were in a disordered position, the archaeologists found that seven people were buried in the chamber. "One of them was a chief and others should be the members of his family, sacrificed slaves or servants," Makharadze told Live Science in an email.

The burial dates back to a time before domesticated horses appeared in the area, Makharadze said. While no animals were found buried with the chariots, he said, oxen would have pulled them.

Other rich kurgan burials dating to the second half of the third millennium B.C. have also been found in the south Caucasus,said Makharadze in another paper he presented in February at the College de France in Paris. The appearance of these rich burials appears to be connected to interactions that occurred between nomadic people from the Eurasian steppes and farming communities within and near the south Caucasus, Makharadze said.

Read more at Discovery News

Neanderthals Ate Their Veggies, Oldest Poop Shows

Neanderthals in Spain weren't just meat eaters, suggests the first direct evidence of their omnivorous diet. An analysis of 50,000-year-old feces -- likely the oldest known human poop -- suggest they ate tubers, berries and nuts as well as meat.

Researchers from MIT and the University of La Laguna say we've probably overemphasized the role of meat in the Neanderthal diet based on traces of plant matter found in samples from a site in El Salt, Spain.

Previous research showed what sorts of prey Neanderthals consumed -- pigs vs. cows, for example -- and depicted Neanderthals as exclusively carnivorous. Later studies found plant remains in the teeth of Neanderthals, but that might also be misleading.

"Sometimes in prehistoric societies, they used their teeth as tools, biting plants, among other things," said Ainara Sistiaga, a graduate student at the University of La Laguna who led the study as a visiting student at MIT, in a statement. "We can't assume they were actually eating the plants based on finding microfossils in their teeth."

So the researchers decided to take a more direct approach.

"This study represents the first approach to Neanderthal diet through the analysis of fecal markers" found in soil, Sistiaga said.

The research shows Neanderthals ate meat as their primary food source, but the discovery of a compound from plant sources called 5β-stigmastanol shows that plants added variety to their diet that was previously unproven. Every sample studied showed signs of meat consumption, and some samples showed signs of plant matter.

Read more at Discovery News

Old Telescope Could Dissect Pluto's Icy Innards

Scientists are attempting to map Pluto's icy depths using old telescope data before a NASA spacecraft reaches the distant dwarf planet in 2015.

The researchers say they found hints of frozen chemicals hidden beneath Pluto's crust in data obtained by the James Clerk Maxwell Telescope (JCMT) on Hawaii in the late 1990s.

"This was a bit like using a telescope as a digger to mine into Pluto, but with less effort!" astrophysics researcher Jane Greaves of the University of St Andrews in Scotland said in a statement.

Pluto, which was only discovered in 1930, orbits between 2.7 billion and 4.5 billion miles (4.4 billion and 7.3 billion kilometers) from the sun. For comparison, Earth orbits 93 million, or 150 km, from our star. Powerful observatories, such as the Hubble Space Telescope, have taken detailed images and maps of Pluto in recent years, even discovering new moons around the dwarf planet. Nonetheless, Pluto has remained quite mysterious because it is so far away.

Earthlings will finally get a detailed look at part of the frigid body next year when NASA's New Horizons spacecraft flies by Pluto. The probe left Earth in 2006, the same year Pluto was dethroned from its position as our solar system's ninth planet. New Horizons will be just the fifth spacecraft to travel so far away from home, behind Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2.

In anticipation of this historic mission, Greaves and her undergraduate student Ailsa Whitelaw said they looked at old data from JCMT's SCUBA (Submillimeter Common-User Bolometer Array), two instruments which scanned the cosmos in the submillimeter range of the electromagnetic spectrum — wavelengths between far-infrared and microwave.

The researchers found evidence of invisible 0.85 mm waves emitted from beneath the surface of Pluto, which they believe could be linked to a possible dry layer of frozen nitrogen and methane hidden under a dark surface patch of water ice and frozen polymers.

Read more at Discovery News

Jun 25, 2014

Why Blood Tastes Good to Vampires ... Bats, That Is

The blood diet of vampire bats has reduced their ability to detect bitter and otherwise yucky tasting flavors, according to a new study that could help explain the unusual cravings of these flying mammals.

The study, published in the latest issue of the Proceedings of the Royal Society B, puts vampire bats on the growing list of animals with unusual senses of taste. That list includes marine mammals such as dolphins, which swallow their food whole and so don’t spend a lot of time savoring flavor.

Vampire bats aren't foodies either, unless that term includes raw blood cravers.

"Vampire bats are the only mammals that feed exclusively on blood," authors Wei Hong and Huabin Zhao of Wuhan University said. They explained "the extreme narrowness" of the bat's diet might have turned the bats into "poor tasters."

For the study, the researchers looked at taste receptor genes in all three species of vampire bats, as well as in 11 other types of bats. They also examined prior behavioral tests on vampire bats, which essentially determined whether or not the bats turned their nose up on certain flavors or liked them.

Vampire bats showed indifference to sweet flavors, so we now know they don't have a sweet tooth. These bats also had trouble detecting bitter, salty and sour tastes. That's significant, the researchers believe.

"Mammals typically have five primary taste modalities dedicated to the evaluation of diets, of which the bitter taste serves as an important natural defense against the ingestion of poisonous foods and is thus believed to be indispensable in animals," they wrote.

So much for that theory about being indispensable, since vampire bats have lost much of their ability to taste bitter flavors.

Hong and Zhao say that vampire bats find their food, not by taste, but by using a combination of smell, echolocation and heat detection. All of these allow them to "find their prey and locate the skin with rich capillaries."

It remains a mystery as to when and how vampire bats first got on their unusual all-blood diet. If the ancestors of the bats ate other things, then these animals might have once possessed a better ability to taste multiple flavors. That ability then could have been lost over time as the bats sipped more blood.

On the other hand, maybe vampire bats have almost always been this way. Researchers hope to solve the mystery as they’re trying to unravel the evolution of bitter taste detection in animals.

Read more at Discovery News

'Disco Clam' Has Built-in Glass Light Show

The “disco clam,” a cute little mollusk known for its light show, now has another remarkable claim to animal kingdom fame: It possesses mirrored, glass lips.

Credit for the finding goes to UC Berkeley researcher Lindsey Dougherty, who led the study published in the latest issue of the Journal of the Royal Society Interface.

“I’ve dived with humpback whales and great white sharks,” Dougherty said in a press release. “But when I saw the disco clam, I was enamored. I said then, ‘I’m going to do a Ph.D. on the disco clam.’”

And that’s just what she’s doing. Check out her groovy video below, where you can get down to the disco clam:

For this latest study, Dougherty and her team conducted fieldwork at Lizard Island Research Station in Australia and the Raja Ampat Research and Conservation Center and Lembeh Resort in Indonesia. The researchers used a bunch of high-tech methods — transmission electron microscopy, spectrometry, high speed video, energy dispersive x-ray spectroscopy and computer modeling — to study the detailed internal structure of the margin of the clam’s lip. That’s where the light show happens.

The inside of the clam’s lip is packed with tiny spheres of silica, the primary component of glass. These spheres are only 340 nanometers in diameter, and they are ideal reflectors, particularly of the blue light that penetrates deeper into seawater than red light. The outside of the lip contains no silica nanospheres. As a result, when the clam lip is furled, no light is reflected.

This turns out to be the secret behind the light show. Previously it was thought that the flashing was due to bioluminescence, a chemical reaction. Other marine organisms, such as lantern sharks, use bioluminescence.

Read more at Discovery News

Trio of Monster Black Holes Rumble Spacetime

For the first time, three supermassive black holes have been discovered in a tight orbital dance inside the center of a galaxy 4 billion light-years away.

The discovery was made by radio telescopes located in Europe, Asia and South Africa, and astronomers believe that it’s extreme gravitational environments such as these that rumble spacetime, generating gravitational waves that are theorized to propagate throughout the cosmos.

“What remains extraordinary to me is that these black holes, which are at the very extreme of Einstein’s Theory of General Relativity, are orbiting one another at 300 times the speed of sound on Earth,” said Roger Deane, of the University of Cape Town, South Africa, in a press release. “Not only that, but using the combined signals from radio telescopes on four continents we are able to observe this exotic system one third of the way across the Universe.”

Two of the black holes are orbiting very close to one another, creating corkscrew-like jets of emissions from one of the black holes as they interact. The third black hole has a wider orbit and emits straight jets from its poles that aren’t impacted significantly by the other pair of black holes.

The observation was made possible by a global network of radio antennae that operate as one, vast array. The technique of linking radio telescopes on different continents and separated by up to 10,000 kilometers is known as Very Long Baseline Interferometry (VLBI) and, when linked, the observations can reveal detail in cosmological targets 50 times finer than the Hubble Space Telescope is capable of.

For this observation of the triple-black hole system, astronomers used data from the European VLBI Network (EVN) and correlated it at the Joint Institute for VLBI in Europe (JIVE) in Dwingeloo, the Netherlands.

Supermassive black holes are massive objects, ‘weighing-in’ at between 1 million to 10 billion times the mass of our sun. The majority of galaxies are known to contain these objects at their cores and are thought to have a key impact on galactic evolution and star formation. When galaxies merge, it is thought that the central black holes spiral in toward one another, eventually merging themselves.

It is therefore of paramount importance that astronomers study and understand supermassive black holes, so finding a triple system of supermassive black holes in tight orbits provide a privileged view into the life-cycle of these fascinating objects. And radio telescopes are the perfect tool for getting an up-close view.

“VLBI is widely recognized as one of the best ways to confirm close-pair black hole systems, but the main difficulty has always been pre-selecting the most promising candidates,” said JIVE scientist Zsolt Paragi. “Our research shows that close-pair black holes may be much more common than previously thought, although their detection require extremely sensitive and high-resolution observations.”

The researchers point out that next-generation radio telescopes, such as the Square Kilometer Array (SKA) that will be located in South Africa and Australia, will be perfect for further campaigns focused on compact black hole systems.

“We have always argued that next generation radio telescopes such as the SKA should operate in VLBI mode as well, jointly with existing radio telescope arrays,” added Paragi. “This will allow to broaden our understanding of how black holes grew and evolved together with their host galaxies.”

“It gives me great excitement as this is just scratching the surface of a long list of discoveries that will be made possible with the Square Kilometer Array (SKA),” said Deane.

Read more at Discovery News

The Higgs Boson Should Have Crushed the Universe

It’s funny when two seemingly distant theories conspire to destroy the universe.

This may seem a little far fetched, but if our understanding of the physics behind the recently-discovered Higgs boson (or, more specifically, the Higgs field — the ubiquitous field that endows all stuff with mass) is correct, our universe shouldn’t exist. That is, however, if another cosmological hypothesis is real, a hypothesis that is currently undergoing intense scrutiny in light of the BICEP2 results.

You may have heard about the controversy surrounding a certain telescope located near the South Pole. The BICEP2 telescope was built with one purpose in mind: to detect a specific type of polarized light being emitted by cosmic microwave background (CMB) radiation. In short, BICEP2 announced (perhaps prematurely) that they had detected this B-mode polarization, indicating the presence of gravitational waves. For these waves to be embedded in the CMB, one key hypothesis of the origin of the universe may be valid.

The hypothesis is called “cosmological inflation” and this model helps cosmologists explain many tricky questions about how our universe was formed.

But according to a group of British cosmologists, inflation really throws a wrench (a.k.a. “a spanner”) into the Cosmic engine — if the physics behind the recently discovered Higgs boson are solid, the rapid inflationary period immediately after the Big Bang nearly 14 billion years ago would have thrown our early universe into chaos.

In fact, things would have gotten so out of hand within the first second of our universe’s creation that we shouldn’t even be here — the universe would have collapsed — known, unsurprisingly, as the “Big Crunch” — into nothing even before matter could condense out of the Big Bang’s primordial mess of energy.

In research presented today (Tuesday) at the Royal Astronomical Society’s National Astronomy Meeting in Portsmouth, UK, Malcolm Fairbairn and Robert Hogan of King’s College London (KCL) discussed the implications of recent discoveries in particle physics and the origins of our universe. Their conclusions will likely cause some unrest.

Since the discovery of a Higgs-like boson by Large Hadron Collider (LHC) physicists in 2012, further studies and data analysis has proven that this particular boson really is the Higgs boson — a subatomic particle that mediates the Higgs field. The Higgs field is believed to fill the entire known universe and endows all matter with mass. Since its discovery, physicists have been getting up-close and personal with the Higgs and experimental analyses has not only proven its existence, scientists are also becoming very familiar with the boson’s (and, by extension, the field it exchanges) properties.

But the problem with the Higgs field is that, if given enough energy, it has the power to reverse cosmic expansion and create a Big Crunch.

The mathematics to arise from accepted Higgs field theory suggests the universe is currently sitting comfortably in a Higgs field energy “valley.” To get out of this valley and up the adjacent “hill” (as shown in the energy diagram, right), huge quantities of energy would need to be unleashed inside the field. But, if there were enough energy to push the universe over the hill and into the deeper energy valley next door, the universe would simply, and catastrophically, collapse.

This is where the BICEP2 results come in. If their observations are real and gravitational waves in the CMB prove cosmological inflation, the Higgs field has already been kicked by too much energy, pushing the Higgs field over the energy hill and deep into the neighboring valley’s precipice! For any wannabe universe, this is very bad news — the newborn universe would appear as a Big Bang, the Higgs field would become overloaded with an energetic inflationary period, and the whole lot would vanish in a blink of an eye.

“This is an unacceptable prediction of the theory because if this had happened we wouldn’t be around to discuss it,” said Hogan.

This is a fascinating insight as to how studies of the quantum world can have impacts on a cosmological scale and the outcome of this research could be another kick in the teeth for the BICEP2 findings. But there is another exciting implication if the BICEP2 observations are proven to be correct and provides much-needed evidence for inflation.

“If BICEP2 is shown to be correct, it tells us that there has to be interesting new particle physics beyond the standard model,” added Hogan.

Exotic, or “new,” physics is currently being hunted down by high-energy physicists at the LHC and other institutions around the world to help explain some of the biggest conundrums in science. For example, physicists are trying to understand how gravity ‘fits’ with the Standard Model (because, right now, it doesn’t), what dark matter is and why the universe is more matter than antimatter. Perhaps there are supersummetric particles that exist at higher energies than we can currently observe, meddling with our known quantum world in very subtle ways.

Read more at Discovery News

Jun 24, 2014

Monarch Butterflies Use Magnetic Field to Navigate

Paris (AFP) - The North American monarch butterfly uses the Sun as well as Earth's magnetic field as navigational tools for its famous long-distance migration, scientists said Tuesday.

The insects with their characteristic orange-and-black wings flutter thousands of kilometres each year from the United States and southern Canada to the Michoacan mountains in central Mexico, where they overwinter.

The butterflies, whose Latin name is Danaus plexippus, have long been known to use a type of solar compass in the brain.

Yet, curiously, they are also able to migrate when skies are heavily overcast, which suggested co-reliance on a magnetic compass.

Now, biologists from Massachusetts say they have found evidence for this, making the butterfly the first long-distance migratory insect thought to use magnetic navigation.

They placed monarchs in a flight simulator, which they surrounded with different artificial magnetic fields to test the insects' directional sense.

Most headed equatorward in initial testing but turned north when the inclination angle of the magnetic field was reversed. The compass worked only in the presence of light at the upper edge of the visible light spectrum.

The butterflies' antennae appeared to contain light-sensitive magnetosensors to make this all work, the team found.

The research, published in the journal Nature Communications, sees the monarch join a lengthening list of birds, reptiles, amphibians, turtles and insects, including honeybees and termites, believed to use the magnetic field for navigation.

Read more at Discovery News

Wolves and Dogs Speak With Their Eyes

Wolves and dogs can communicate using their eyes alone, suggests a new study in the journal PLoS ONE.

The color of the face around the eye, the eye’s shape and the color and shape of both the iris and the pupil are all part of the elaborate eye-based communication system, according to the research, which could apply to humans as well.

Sayoko Ueda of the Tokyo Institute of Technology and Kyoto University led the study, which compared these characteristics of the face and eyes among 25 different types of canines.

The researchers identified three basic patterns:

A-type: Both pupil position in the eye outline and eye position in the face are clear.

B-type: Only the eye position is clear.

C-type: Both the pupil and eye position are unclear.

“A-type faces tended to be observed in species living in family groups all year-round, whereas B-type faces tended to be seen in solo/pair-living species,” Ueda and colleagues wrote.

Wolves and dogs exemplify the A-type. Humans fit into this category too! Such individuals invite you to look into their eyes. The researchers even suspect that the white of the eye (sclera) evolved, in part, to set off the darker hues of the iris and pupil.

Animals like foxes exemplify the B-type. For them, some information is likely conveyed by the eyes to others, but not much.

Then there is the elusive C-type, exemplified by animals like bush dogs. Their all-dark eyes blend in with their furry faces. The researchers point out that “various predators camouflage their eyes to increase their hunting success.” Consider that if you don’t know what an individual is looking at, you can’t predict his or her behavior.

Following the eyes can reveal interests and where an individual might go next. Both wolves and dogs are adept at following human gazes.

“The fact that the studied (canine) species with A-type faces tended to engage in group living suggests that they use the gaze signal in communication among group members, as the need for communication is larger for group-living species than for solo/pair-living species,” the researcher wrote.

Read more at Discovery News

19th Century 'Elixir of Long Life' Found

The elixir of long life is a bitter, alcohol-heavy concoction — if you trust a 150-year-old bottle unearthed at a hotel construction site in New York’s Lower East Side.

The site, once a German beer garden and music hall called the Atlantic Garden, contained hundreds of liquor bottles dating from as far back as the 1850s.

Among them was a greenish glass vial that was believed to help people cheat death.

Intrigued, the team behind the find at Chrysalis Archaeology tracked down the historic recipe in Germany. They found it in a 19th-century medical guide.

The ingredients included aloe, gentian, rhubarb, Spanish saffron, Zedoary (white turmeric), and one part water to three parts alcohol.

“Many of the ingredients are still used in herbal medicine or as natural remedies,” Alyssa Loorya, the president of Chrysalis, told Discovery News.

Aloe has an anti-inflammatory effect, gentian root and powdered rhubarb help digestion, the Zedoary (white turmeric) spice is said to purify the blood and help cell regeneration, while Spanish saffron is used to treat a number of health conditions, including depression.

With the tiny Elixir of Life bottle held less than an ounce, it’s likely that the bitter potion was taken one drop at a time.

Loorya’s team also unearthed another bottle that contained a popular 19th-century medicinal drink.

It was labeled Dr. Hostetter’s Stomach Bitters and it was indeed bitter.

The drink turned out to contain gentian root, orange peel, cinnamon, anise, coriander seed, cardamom seed, peruvian bark, gum kino, grain alcohol, water and sugar.

“We read Dr. Hostetter’s was so popular that it was served by the glass in bars throughout the U.S., including Alaska,” Loorya said.

Since both the Elixir of Life and Dr. Hostetter’s formulas required copious amounts of alcohol as a medium, “it may have been difficult for consumers to determine whether the active ingredients were actually effective,” Loorya added.

Read more at Discovery News

Why Do Jupiter's Moons Still Shine When Eclipsed?

Jupiter's largest moons don't go completely dark when the giant planet blocks their sunlight, astronomers have found.

The discovery could reveal more about Jupiter's mysterious upper atmosphere, which the researchers suspect is responsible for keeping the moons lit when they are not directly illuminated by the sun. This research could also help scientists better understand the atmospheres of alien planets, study team members said.

Jupiter, the largest planet in the solar system, has 67 known moons — more than any other planet. Jupiter's four largest moons — Io, Europa, Ganymede and Callisto — are known as the Galilean satellites, after their discoverer, famed astronomer Galileo Galilei.

The researchers made their discovery about the Galilean moons accidentally. Their original plan was to detect the diffuse light from the most distant parts of the universe. They wanted to find dark objects in space that could block this far-off light. The difference in brightness between those dark objects and the surrounding sky could then help them determine how bright the diffuse and distant light is.

The researchers assumed the Galilean satellites would be dark while immersed in Jupiter's shadow. As such, they "planned to use the Galilean satellites in eclipse as 'occulters' to block distant background emissions," said lead study author Kohji Tsumura, an astronomer at Tohoku University in Japan.

Instead, using the Subaru Telescope and Hubble Space Telescope, the researchers found an unexpected surprise: The Galilean satellites were still slightly bright even when eclipsed. This effect is especially pronounced for Ganymede and Callisto.

"This is a serendipitous discovery, which makes us surprised and excited," Tsumura told Space.com.

Making this discovery was very challenging because the Galilean satellites are extremely faint while eclipsed, and the incredibly bright face of Jupiter near them can blind attempts to see them. Furthermore, the eclipses only take place at specific times, and Jupiter and its moons are continuously in motion, which makes observations very complex, the researchers said.

All in all, when eclipsed, the luminosity of these moons was one-millionth to one-ten-millionth of their uneclipsed brightness — dim enough for the phenomenon to remain undetected until now, even though researchers have observed the Galilean moons in eclipse for centuries.

It remains uncertain what causes the slight brightening. However, Tsumura and his colleagues believe the upper part of Jupiter's atmosphere may be responsible.

Jupiter's clouds, which give the giant planet its striped appearance, grow from tiny particles called aerosols or hazes. Prior studies have hinted that these hazes form in the upper part of Jupiter's atmosphere. The researchers suggested that hazes in the upper atmosphere may scatter sunlight onto the Galilean satellites, illuminating them. This effect is similar to the one that causes Earth's moon to look red during a total lunar eclipse.

The new finding could help scientists analyze the hazes in Jupiter's atmosphere, which are otherwise difficult to study. By studying the spectrum of light from the eclipsed Jupiter moons, the researchers could learn about the compositions of the hazes, Tsumura said.

Read more at Discovery News

Jun 23, 2014

3-D map shows dusty structure of the Milky Way

A team of international astronomers has created a detailed three-dimensional map of the dusty structure of the Milky Way -- the star-studded bright disc of our own galaxy -- as seen from Earth's northern hemisphere. The map will be presented by Prof Janet Drew of the University of Hertfordshire at the National Astronomy Meeting (NAM) 2014 in Portsmouth on Monday 23 June.

Dust and gas, making up the Interstellar Medium (ISM), fill space between stars in galaxies. The dust in the ISM is shaped by turbulent flows that form intricate fractal structures on scales ranging from thousands of light years down to hundreds of kilometres. Rather than measuring the dust itself to create the map, the team has used observations of more than 38 million stars to estimate how much starlight has been obscured by the ISM and thus how much dust lies in our line of sight to each star. This 'extinction' map derives from the newly released catalogue of the Isaac Newton Telescope Photometric H-alpha Survey of the Northern Galactic Plane (IPHAS), the first digital survey to cover the entire northern Milky Way.

"Because the Solar System is embedded in the disc of the Milky Way, our view of it is choked with dust, with the result we know less about its internal structure than we do about some external galaxies, such as M31 in Andromeda. " said Drew, the Principal Investigator for the IPHAS survey. "In this Northern survey, we are mainly looking at the parts of the Galactic disc that lie outside the Sun's orbit around the Galactic Centre. This 3-D map demonstrates with greater force than existing 2-D maps that dust in the outer disc does not trace the Perseus spiral arm and other expected structures in a simple way."

The map shows how extinction builds with distance away from the Sun (typically out to 12000 light years or more) in any part of the surveyed northern Milky Way. Detail on an angular scale 7 times finer than the angular size of the moon is caught. The fractal nature of the ISM is visible in the map, as are large-scale features, such as star-forming molecular clouds and bubbles of ionized gas around clusters of hot stars.

"We can see a number of specific features, including the Rosette Nebula and the star-forming belt in the Perseus Arm of the Milky Way," said Dr Stuart Sale, who led the team that created the map. "Our location within the Milky Way means that we can study the ISM in far greater detail than for any other galaxy. The knowledge that we gain from studying our own galaxy can subsequently be applied to others."

Read more at Science Daily

Earth-size 'diamond' in space: Remarkable white dwarf star possibly coldest, dimmest ever detected

A team of astronomers has identified possibly the coldest, faintest white dwarf star ever detected. This ancient stellar remnant is so cool that its carbon has crystallized, forming -- in effect -- an Earth-size diamond in space.

"It's a really remarkable object," said David Kaplan, a professor at the University of Wisconsin-Milwaukee. "These things should be out there, but because they are so dim they are very hard to find."

Kaplan and his colleagues found this stellar gem using the National Radio Astronomy Observatory's (NRAO) Green Bank Telescope (GBT) and Very Long Baseline Array (VLBA), as well as other observatories.

White dwarfs are the extremely dense end-states of stars like our Sun that have collapsed to form an object approximately the size of Earth. Composed mostly of carbon and oxygen, white dwarfs slowly cool and fade over billions of years. The object in this new study is likely the same age as the Milky Way, approximately 11 billion years old.

Pulsars are rapidly spinning neutron stars, the superdense remains of massive stars that have exploded as supernovas. As neutron stars spin, lighthouse-like beams of radio waves, streaming from the poles of its powerful magnetic field, sweep through space. When one of these beams sweeps across Earth, radio telescopes can capture the pulse of radio waves.

The pulsar companion to this white dwarf, dubbed PSR J2222-0137, was the first object in this system to be detected. It was found using the GBT by Jason Boyles, then a graduate student at West Virginia University in Morgantown.

These first observations revealed that the pulsar was spinning more than 30 times each second and was gravitationally bound to a companion star, which was initially identified as either another neutron star or, more likely, an uncommonly cool white dwarf. The two were calculated to orbit each other once every 2.45 days.

The pulsar was then observed over a two-year period with the VLBA by Adam Deller, an astronomer at the Netherlands Institute for Radio Astronomy (ASTRON). These observations pinpointed its location and distance from Earth -- approximately 900 light-years away in the direction of the constellation Aquarius. This information was critical in refining the model used to time the arrival of the pulses at Earth with the GBT.

By applying Einstein's theory of relativity, the researchers studied how the gravity of the companion warped space, causing delays in the radio signal as the pulsar passed behind it. These delayed travel times helped the researchers determine the orientation of their orbit and the individual masses of the two stars. The pulsar has a mass 1.2 times that of the Sun and the companion a mass 1.05 times that of the Sun.

These data strongly indicated that the pulsar companion could not have been a second neutron star; the orbits were too orderly for a second supernova to have taken place.

Knowing its location with such high precision and how bright a white dwarf should appear at that distance, the astronomers believed they should have been able to observe it in optical and infrared light.

Remarkably, neither the Southern Astrophysical Research (SOAR) telescope in Chile nor the 10-meter Keck telescope in Hawaii was able to detect it.

"Our final image should show us a companion 100 times fainter than any other white dwarf orbiting a neutron star and about 10 times fainter than any known white dwarf, but we don't see a thing," said Bart Dunlap, a graduate student at the University of North Carolina at Chapel Hill and one of the team members. "If there's a white dwarf there, and there almost certainly is, it must be extremely cold."

Read more at Science Daily

Motherless Male Zebra Finches Prefer Same-Sex Mates

Male zebra finches prefer to form lifelong pair bonds with other males if they're raised by their dad alone, new research shows.

This mate choice is likely the result of males "imprinting" on their fathers, researchers say.

Zebra finches are socially monogamous, meaning that each bird pairs up with a single mating partner for the rest of its life. These tiny birds are also known to form lifelong same-sex pair bonds, though scientists aren't sure what factors influence the sex of the birds' partner choice.

In the new study, published in the June issue of the journal Animal Behavior, researchers tested the mate choice of male and female zebra finches raised in the absence of adult females. Of the birds that formed pair bonds, 75 percent of the males and none of the females paired with members of the same sex. In comparison, all of the pair-bonded males and females that were reared by a mother and a father preferred opposite-sex mates.

"And it wasn't as if the males raised by their dad alone were outcompeted by the males raised by both parents," said study lead author Sunayana Banerjee, a psychologist at Cornell University in New York. "They were actively looking for other males to bond with."

Among animals, sexual imprinting is a common phenomenon, in which younglings learn the features of another individual and use this learning to inform their mate choice during adulthood, Banerjee told Live Science. By imprinting on a mother or father during early development, offspring acquire their preferences for future mates.

Previous research has shown that zebra finches' mate choices are also steered by sexual imprinting. For instance, one study found that females prefer partners with blue feather ornaments if their fathers had such a feature. And in another experiment, males with mothers that had a certain beak color preferred female partners with beaks that were more extreme in color than their mothers' beaks.

To see if parental imprinting also guides same-sex partner choices, Banerjee and her co-author Elizabeth Adkins-Regan, a behavioral neuroscientist at Cornell University, studied the development of two groups of zebra finches. In the control group, chicks grew up having both a mother and father. For the second group, the researchers removed the mothers from the nest shortly after the eggs hatched. (Top 10 Swingers of the Animal Kingdom)

Once the chicks became independent, the researchers moved them to unisex aviaries, which were within ear and eye distance of each other. They then weighed the birds, and found that the mother-deprived chicks didn't suffer from any nutritional deficiencies.

Banerjee and Adkins-Regan then conducted pair-bond tests by moving groups of the birds into aviaries with biased sex ratios. In experiments where they wanted to test the partner preferences of males, they used aviaries that had twice as many males as females; the opposite was true for experiments looking at the preferences of females. The skewed sex ratios ensured that the birds had to compete — through songs and aggression — for their partners.

Overall, mother-deprived males overwhelmingly chose to pair with other mother-deprived males. Control males preferred opposite-sex partners, as did the females from both groups.

"Apart from the courtship and pairing behaviors, [the mother-deprived males] didn't seem to have any behavioral differences that were obvious," Banerjee said.

In 2000, Adkins-Regan studied the partner preferences of zebra finches that were raised without fathers, and found that both males and females had a greater preference for same-sex partners. Specifically, 38 percent of males and 25 percent of females that were raised without their fathers paired with same-sex partners, compared with 13 percent of males and 0 percent of females that were raised by both parents.

Without their dads, the male offspring didn't learn normal songs and were likely less attractive to females, so they paired with other males. The female offspring, on the other hand, may have imprinted on their mothers during development, Adkins-Regan reasoned.

Banerjee suspects the way males and females choose mates may explain why the same-sex partner preferences appear stronger for mother-deprived males than for father-deprived females. "It could be that females are less dependent on visual cues than males are," Banerjee said, meaning that even after imprinting on their mothers, females would still seek out mates that have the best songs.

Read more at Discovery News

LHC Uncovers New Higgs Boson Decay Mechanism

Since the elusive Higgs boson was discovered in 2012, scientists have been poring over Large Hadron Collider (LHC) collision data for more evidence of interactions involving the particle. Now physicists of one LHC experiment have announced tantalizing evidence that the Higgs doesn’t only decay into other bosons; it also has the ability to decay into fermions — further proof that we are looking at a Standard Model Higgs boson and not something more exotic.

Theorized for decades, the hunt for the Higgs boson became the key reason why the LHC, the most powerful and expensive particle collider on the planet, was built. This historic physics quest came to a satisfactory conclusion when researchers overseeing experiments in two massive LHC detectors — the CMS (Compact Muon Solenoid) and ATLAS (A Toroidal LHC Apparatus) — revealed the discovery of a “new” boson that had a striking similarity to the theorized Higgs. Further experimental tests proved that this new boson was indeed the Higgs, a particle that mediates the Higgs field, a ubiquitous field that endows all matter with mass.

But until now, physicists have only seen one type of Higgs decay.

As particles (primarily protons) are accelerated close to the speed of light inside the LHC’s superconducting electromagnets and collided at unprecedented energies, physicists have glimpsed the extreme conditions that existed around the time of the Big Bang. By creating these mini-Big Bangs, energy can condense to form “free” particles that otherwise would not exist in nature. To track down any Higgs particles produced in these collisions, physicists need to investigate the particles produced from specific decays as outlined by Higgs theory.

The Higgs particle is highly unstable and decays very quickly. Until now, physicists have only detected one decay path — as the Higgs boson decays into other bosons. Bosons are the ‘force carriers’ of nature — e.g. the photon is a boson as it mediates the electromagnetic force; the W and Z bosons mediate the weak force (which is responsible for radioactive decay and nuclear fusion of atomic nuclei).

Now, for the first time, physicists have detected a regime where the Higgs also decays into fermions.

“We now know that the Higgs particle can decay into both bosons and fermions, which means we can exclude certain theories predicting that the Higgs particle does not couple to fermions,” said Vincenzo Chiochia, from the University of Zurich’s Physics Institute. Chiochia is a member of the international team who analyzed the new data and one of the hundreds of scientists involved with The CMS Collaboration. This new research has been published in the journal Nature Physics.

Fermions are the subatomic building blocks of all matter — including quarks, leptons (such as electrons) and combinations of quarks (hadrons like protons and neutrons) — and, according to these new results, the Higgs boson can decay into the bottom quarks (a heavy type of quark) and tau particles (a kind of heavy electron).

“In July 2012, we knew we had discovered some sort of boson, and it looked a lot like it was a Higgs boson,” said Paul Padley of Rice University and member of the CMS Collaboration. “To firmly establish it’s the Standard Model Higgs boson, there are a number of checks we have to do. This paper represents one of these fundamental checks.”

This new line of evidence focuses on the detection of a particle ‘excess’ signal around the 125 gigaelectron volt (GeV) Higgs boson — the same “vanilla” Standard Model Higgs that was announced in 2012.

It does fall short of being a discovery, however. This new Higgs decay process has an experimental significance of 3.8 sigma, but the researchers expect that significance to rise to 4.4 sigma after further analysis. A ‘discovery’ will only be announced when this statistical significance rises to 5 sigma, a level that can only be attained after analysis of more post-collision decay particles in the LHC’s detectors.

Read more at Discovery News

Jun 22, 2014

Mysterious 'magic island' appears on Saturn's moon Titan

Now you don't see it. Now, you do. And now you don't see it again. Astronomers have discovered a bright, mysterious geologic object -- where one never existed -- on Cassini mission radar images of Ligeia Mare, the second-largest sea on Saturn's moon Titan. Scientifically speaking, this spot is considered a "transient feature," but the astronomers have playfully dubbed it "Magic Island."

Reporting in the journal Nature Geoscience June 22, the scientists say this may be the first observation of dynamic, geological processes in Titan's northern hemisphere. "This discovery tells us that the liquids in Titan's northern hemisphere are not simply stagnant and unchanging, but rather that changes do occur," said Jason Hofgartner, a Cornell University graduate student in the field of planetary sciences, and the paper's lead author. "We don't know precisely what caused this 'magic island' to appear, but we'd like to study it further."

Titan, the largest of Saturn's 62 known moons, is a world of lakes and seas. The moon -- smaller than our own planet -- bears close resemblance to watery Earth, with wind and rain driving the creation of strikingly familiar landscapes. Under its thick, hazy nitrogen-methane atmosphere, astronomers have found mountains, dunes and lakes. But in lieu of water, liquid methane and ethane flow through riverlike channels into seas the size of Earth's Great Lakes.

To discover this geologic feature, the astronomers relied on an old technique -- flipping. The Cassini spacecraft sent data on July 10, 2013, to the Jet Propulsion Laboratory at the California Institute of Technology for image processing. Within a few days, Hofgartner and his colleagues flipped between older Titan images and the newly processed pictures for any hint of change. This is a long-standing method used to discover asteroids, comets and other worlds. "With flipping, the human eye is pretty good at detecting change," said Hofgartner.

Prior to the July 2013 observation, that region of Ligeia Mare had been completely devoid of features, including waves. Titan's seasons change on a longer time scale than Earth's. The moon's northern hemisphere is transitioning from spring to summer. The astronomers think the strange feature may result from changing seasons.

In light of the changes, Hofgartner and the other authors speculate on four reasons for this phenomenon:

• Northern hemisphere winds may be kicking up and forming waves on Ligeia Mare. The radar imaging system might see the waves as a kind of "ghost" island.

• Gases may push out from the sea floor of Ligeia Mare, rising to the surface as bubbles.

• Sunken solids formed by a wintry freeze could become buoyant with the onset of warmer temperatures during the late Titan spring.

• Ligeia Mare has suspended solids, which are neither sunken nor floating, but act like silt in a terrestrial delta.

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Limb regeneration: Do salamanders hold the key?

The secret of how salamanders successfully regrow body parts is being unravelled by UCL researchers in a bid to apply it to humans.

For the first time, researchers have found that the 'ERK pathway' must be constantly active for salamander cells to be reprogrammed, and hence able to contribute to the regeneration of different body parts.

The team identified a key difference between the activity of this pathway in salamanders and mammals, which helps us to understand why humans can't regrow limbs and sheds light on how regeneration of human cells can be improved.

The study published in Stem Cell Reports today, demonstrates that the ERK pathway is not fully active in mammalian cells, but when forced to be constantly active, gives the cells more potential for reprogramming and regeneration. This could help researchers better understand diseases and design new therapies.

Lead researcher on the study, Dr Max Yun (UCL Institute of Structural and Molecular Biology) said: "While humans have limited regenerative abilities, other organisms, such as the salamander, are able to regenerate an impressive repertoire of complex structures including parts of their hearts, eyes, spinal cord, tails, and they are the only adult vertebrates able to regenerate full limbs.

We're thrilled to have found a critical molecular pathway, the ERK pathway, that determines whether an adult cell is able to be reprogrammed and help the regeneration processes. Manipulating this mechanism could contribute to therapies directed at enhancing regenerative potential of human cells."

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