Aug 15, 2013

Mammal Evolution King ID'd

Remains of the oldest ancestor of the most evolutionarily successful and long-lived mammal lineage have just been unearthed in China, according to a new study.

The mammal —  one of several creatures known as multituberculates – looked like a cross between a small rat and a chipmunk. It lived 160 million years ago during the Cretaceous era, according to the paper, published in the journal Science.

This particular new species was Rugosodon eurasiaticus, which is the oldest known multituberculate. Its remains were found preserved in lake sediments, suggesting that it lived on the shores.

“The later multituberculates of the Cretaceous and the Paleocene are extremely functionally diverse: Some could jump, some could burrow, others could climb trees and many more lived on the ground,” explained Zhe-Xi Luo, a co-author of the paper. “The tree-climbing multituberculates and the jumping multituberculates had the most interesting ankle bones, capable of ‘hyper-back-rotation’ of the hind feet.”

China was a hotbed for dinosaurs during the Cretaceous, so one can imagine these little rodent-type animals scurrying around gigantic dinosaur legs, grabbing spilled food. Apparently these early mammals could eat almost anything that would fit into their mouths.

Its teeth were appropriate for gnawing on both plants and animals alike, revealing that it was an omnivore. Luo and colleagues believe that R. eurasiaticus was nocturnal and primarily lived on the ground. This makes its super-flexible ankles all the more surprising. Usually those are more associated with tree dwellers.

Multituberculate arose in the Jurassic period and went extinct in the Oligocene epoch. They occupied a diverse range of habitats for more than 100 million years before they were out-competed by more modern rodents.

Read more at Discovery News

Dig This: Badger Unearths Medieval Treasure

Some archaeologists pore over old maps and manuscripts to make historical discoveries. Others rely on pick axes, trowels and other tools.

But archaeologists in Germany simply turned to badgers, the digging mammals that are the bane of gardeners everywhere. A badger living in the countryside near the town of Stolpe recently uncovered a remarkable site: the 12th-century burial ground of eight people, two of whom were apparently Slavic warlords.

Two sculptors who live in the area had been watching a badger digging a large sett (den). Upon closer examination, they noticed a pelvic bone inside the sett. "We pushed a camera into the badger's sett and took photos by remote control," Hendrikje Ring, one of the sculptors, told Der Spiegel. "We found pieces of jewelry, retrieved them and contacted the authorities."

One warlord was buried with a two-edged sword and a large bronze bowl at his feet, The Local, an English-language news site, reports. "At the time, such bowls were used to wash the hands before eating," archaeologist Felix Biermann of Georg-August University in Göttingen told The Local. "The bowls would be a sign that a man belonged to the upper classes."

The same warrior also wore an elegant bronze belt buckle in the shape of an omega, with the head of a stylized snake at each end. "He was a well-equipped warrior," said Biermann, who is leading the team excavating the site. "Scars and bone breaks show that he had been hit by lances and swords, and had also fallen from a horse."

Another grave held the skeleton of a woman with a coin in her mouth. According to ancient religious beliefs, people were often buried with coins to pay a ferryman to transport them across the river that separated the living world from the realm of the dead.

This badger-assisted archaeological find isn't the first time historical artifacts have been discovered in unusual ways. The Dead Sea Scrolls were found in 1947 by a Bedouin shepherd boy who was searching for a sheep that had strayed from his flock. He threw a rock into a cave and, instead of a bleating lamb, heard the sound of pottery breaking, leading to the scrolls' discovery.

Read more at Discovery News

Time Really Flies on These Kepler Planets

Astronomers have found 13 candidate planets flying so close to their parent stars that a year on these worlds lasts between just three and 10 hours.

If confirmed, the planets, which were found by NASA’s Kepler space telescope, would add another twist to the quirky and dynamic relationship between stars and their orbiting planets.

“This does really force us to think hard about how planets form, where they can live and how they evolve. It seems like almost anytime you think of something crazy to go looking for, it’s out there somewhere,” astronomer Brian Jackson, a postdoctoral fellow at the Carnegie Institution for Science, told Discovery News.

“Like almost every discovery in extrasolar astronomy, it is basically causing people to have to go back and rewrite the textbooks,” he said.

For starters, astronomers do not know how the candidate planets ended so close to their parent stars, nor where they came from. The shortest distance between one of the newly found candidate planets and its host stars is about 865,000 miles. That suspected planet orbits its star every 3.3 hours.

By comparison, Mercury, the innermost planet in our solar system, is located about 36 million miles from the sun and it takes 88 days to complete an orbit.

"It’s been suggested for some time that the really hot super-Earths that are in close (to their host stars) are just the cores of evaporated ‘'hot Jupiters,'" University of Maryland astronomer Drake Deming told Discovery News.

Hot Jupiters are a type of extrasolar planet -- not found in our solar system -- where gas giants, similar to Jupiter and Saturn, orbit sizzlingly close to their host stars. These planets are believed to have solid cores of rock and ice deep in their interiors.

The candidate planets found by Jackson and colleagues may be what remained after hot Jupiters wandered too close to their parent stars and had their atmospheres stripped away.

Computer models suggest that any gas giant cores eventually would vaporize or make death spirals into their parent stars, but the Kepler data shows the objects may last long enough to be detected.

More work remains to eliminate the possibility that the light dips detected by the Kepler telescope are due to planets passing by, relative to Kepler’s line of sight, and not eclipsing binary stars.

Read more at Discovery News

Modern Galaxies Formed Fast, Hubble Shows

A sweeping census of galaxies dating back to when the universe was just 2.5 billion years old shows an early and puzzling divide between two main types -- the relatively flat, pancake-shaped galaxies that continue to pop out new stars and their spherical cousins which are filled with old stars that have remained virtually unchanged through the eons.

Whatever shut down star formation in those galaxies is unknown, but the new study, based on the single largest Hubble Space Telescope project, indicates it happened early and fast.

“For the first time we have access to very large samples of distant galaxies, observed with data that is very high quality,” astronomer Mauro Giavalisco, with the University of Massachusetts, told Discovery News.

“It’s pretty conclusive that the diversification of galaxies into this spheroidal-type and the disk-type is a process that started very early. It was already there in place at the time when the universe was a mere 2.5 billion years old. It's something that happened very quickly,” he said.

It was astronomer Edwin Hubble, for whom the space telescope is named, who first classified galaxies into two main types.

Scientists later fleshed out Hubble’s 1926 landmark work with additional details showing the two basic types of galaxies not only had different structures, but also different stellar populations.

Computer models have pretty much nailed down how big clouds of dust and gas can collapse under their own weight and pancake themselves into disks. These structures eventually feed a central region that ends up looking like a bulge. Our Milky Way galaxy is an example.

More puzzling is what happens in the other types of galaxies, the spheroids, or elliptical galaxies.

“These are essentially dead galaxies, but they're not small. They're massive galaxies with a lot of gravity,” Giavalisco said. “So why is it that a galaxy that potentially has all the gravity it needs to attract gas and keep making babies and keep forming stars, for some reason does not do that?"

“The quenching of the star-formation activity is a process that happens quickly in the history of the universe and we don’t know how,” he added.

One possibility is that these galaxies harbor monster-sized black holes that radiate out so much heat, gas in the galaxies can’t cool down to form stars.

Another idea it there are too many massive, hot stars squeezed together into too small of a space, generating so much heat that, like the black hole theory, gas cannot cool and form new stars.

“The galaxy dies, essentially self-strangulated," Giavalisco said. "But why does this only happen to spheroidal galaxies and not to disk galaxies? It’s not obvious. And why so quickly?”

The study, headed by BoMee Lee of the University of Massachusetts, pushes back the time frame for when modern galaxies emerged to about 2.5 billion years after the universe’s creation some 13.8 billion years ago.  Previous galaxy surveys studied objects that formed about 5 billion years after the Big Bang.

Read more at Discovery News

Aug 14, 2013

Dwarf Galaxy Caught Ramming Into a Large Spiral

Observations with NASA's Chandra X-ray Observatory have revealed a massive cloud of multimillion-degree gas in a galaxy about 60 million light years from Earth. The hot gas cloud is likely caused by a collision between a dwarf galaxy and a much larger galaxy called NGC 1232. If confirmed, this discovery would mark the first time such a collision has been detected only in X-rays, and could have implications for understanding how galaxies grow through similar collisions.

An image combining X-rays and optical light shows the scene of this collision. The impact between the dwarf galaxy and the spiral galaxy caused a shock wave − akin to a sonic boom on Earth -- that generated hot gas with a temperature of about 6 million degrees. Chandra X-ray data, in purple, show the hot gas has a comet-like appearance, caused by the motion of the dwarf galaxy. Optical data from the European Southern Observatory's Very Large Telescope reveal the spiral galaxy in blue and white. X-ray point sources have been removed from this image to emphasize the diffuse emission.

Near the head of the comet-shaped X-ray emission (mouse over the image for the location) is a region containing several very optically bright stars and enhanced X-ray emission. Star formation may have been triggered by the shock wave, producing bright, massive stars. In that case X-ray emission would be generated by massive star winds and by the remains of supernova explosions as massive stars evolve.

The mass of the entire gas cloud is uncertain because it cannot be determined from the two-dimensional image whether the hot gas is concentrated in a thin pancake or distributed over a large, spherical region. If the gas is a pancake, the mass is equivalent to forty thousand Suns. If it is spread out uniformly, the mass could be much larger, about three million times as massive as the Sun. This range agrees with values for dwarf galaxies in the Local Group containing the Milky Way.

The hot gas should continue to glow in X-rays for tens to hundreds of millions of years, depending on the geometry of the collision. The collision itself should last for about 50 million years. Therefore, searching for large regions of hot gas in galaxies might be a way to estimate the frequency of collisions with dwarf galaxies and to understand how important such events are to galaxy growth.

Read more at Science Daily

Oldest Gaming Tokens Found in Turkey

Small carved stones unearthed in a nearly 5,000-year-old burial could represent the earliest gaming tokens ever found, according to Turkish archaeologists who are excavating early Bronze Age graves.

Found in a burial at Başur Höyük, a 820- by 492-foot mound near Siirt in southeast Turkey, the elaborate pieces consist of 49 small stones sculpted in different shapes and painted in green, red, blue, black and white.

"Some depict pigs, dogs and pyramids, others feature round and bullet shapes. We also found dice as well as three circular tokens made of white shell and topped with a black round stone," Haluk Sağlamtimur of Ege University in İzmir, Turkey, told Discovery News.

According to the archaeologist, who presented his finding at the annual symposium of excavations, surveys and archaeometry in Muğla, similar pieces were previously found in Tell Brak and Jemdet Nasr, two settlement mounds in northeastern Syria and in Iraq respectively.

"But they were found as isolated, single objects, therefore they were believed to be counting stones," Sağlamtimur said.

"On the contrary, our gaming pieces were found all together in the same cluster. It's a unique finding, a rather complete set of a chess like game. We are puzzling over its strategy," he added.

The find confirms that board games likely originated and spread from the Fertile Crescent regions and Egypt more than 5,000 years ago (Senet from predynastic Egypt is considered the world's oldest game board). The tokens were accompanied by badly preserved wooden pieces or sticks. Sağlamtimur hopes they'll provide some hints on the rules and logic behind the game.

"According to distribution, shape and numbers of the stone pieces, it appears that the game is based on the number 4," he said.

Archaeological records indicate that board games were widely played in Mesopotamia. Several beautifully crafted boards were found by British archaeologist Leonard Wooley in the Royal cemetery of Ur, the ancient Sumerian city near the modern Iraqi city of Nasiriya which many consider the cradle of civilization.

Dating from the First Dynasty of Ur, around 2550-2400 B.C., the boards were associated with the "Game of Twenty Squares," a board game played around 3000 B.C. Beautiful tokens related to the game were found arranged in a row, with the colors alternating, in another Ur tomb. The set consisted of seven shell roundels inlaid with of five lapis lazuli dots and seven roundels of black shale inlaid with five dots of white shell.

Much more elaborate, the newly discovered gaming stones were recovered from one of nine graves found at Başur Höyük. The site was inhabited as early as from 7,000 B.C. and was on a trade route between Mesopotamia and East Anatolia.

Overall, the graves revealed a unique treasure made of painted and unpainted pottery, bronze spearhead, various ritual artifacts, seals with geometric motifs and about 300 well-preserved amorphous bronze artifacts.

The majority of pots featured bitumen residues. Sağlamtimur believes bitumen was most likely part of a burial ritual or was applied to prevent secondary use of the pots.

Tens of thousands of beads made of mountain crystal and other types of stones were also recovered from the burials.

"The gaming pieces, thousands of beads, hundreds of complete pots and metal artifacts indicate those graves were not ordinary burials but most probably belonged to individuals of a ruling class," Sağlamtimur said.

Radio carbon dating traced the grave goods back to 3100-2900 B.C., confirming the Early Bronze Age stylistic features of the items and the advanced technological level of the local population.

"The graves contained metal artifacts, ceramic finds and seals with different attributes and influences which indicate the local people were in close relationship with their surrounding cultural regions," Sağlamtimur said.

By the mid of the 4000 B.C., when the first great cities of history sprung up in Mesopotamia, the influence of the South Mesopotamia Uruk culture spread to the surrounding regions.

Significant differences emerged between the western communities of the Syrian-Turkish Euphrates Valley and the eastern settlements of the Al Jazira, the river plain of Mesopotamia which encompasses northwestern Iraq and northeastern Syria.

In the western communities the urbanization process was halted, while clans with warrior leaders announced their power through complex funerary rites and burials rich with metal and weapons.

Meanwhile, the urbanization process continued in the eastern settlements with the development of a new culture called Ninivite 5. Like the Uruk culture, Ninivite 5 did not pay great attention to the funerary rites and burials were not particularly rich with artifacts.

"The findings at Başur Höyük add to our knowledge as they reveal a coexistence of traditions and a continuity of relationships between the settlements in the northern mountains and the Mesopotamia sites," Marcella Frangipane, a professor of prehistoric archaeology at Rome's La Sapienza, told Discovery News.

Read more at Discovery News

Oldest Rock Art in North America Revealed

On the west side of Nevada's dried-up Winnemucca Lake, there are several limestone boulders with deep, ancient carvings; some resemble trees and leaves, whereas others are more abstract designs that look like ovals or diamonds in a chain.

The true age of this rock art had not been known, but a new analysis suggests these petroglyphs are the oldest North America, dating back to between 10,500 and 14,800 years ago.

Though Winnemucca Lake is now barren, at other times in the past it was so full of water the lake would have submerged the rocks where the petroglyphs were found and spilled its excess contents over Emerson Pass to the north.

To determine the age of the rock art, researchers had to figure out when the boulders were above the water line.

The overflowing lake left telltale crusts of carbonate on these rocks, according to study researcher Larry Benson of the University of Colorado Boulder. Radiocarbon tests revealed that the carbonate film underlying the petroglyphs dated back roughly 14,800 years ago, while a later layer of carbonate coating the rock art dated to about 11,000 years ago.

Those findings, along with an analysis of sediment core sampled nearby, suggest the petroglyph-decorated rocks were exposed first between 14,800 and 13,200 years ago and again between about 11,300 and 10,500 years ago.

"Prior to our study, archaeologists had suggested these petroglyphs were extremely old," Benson said in a statement. "Whether they turn out to be as old as 14,800 years ago or as recent as 10,500 years ago, they are still the oldest petroglyphs that have been dated in North America."

Researchers previously believed the oldest rock art in North America could be found at Long Lake, Ore., in carvings that were created at least 6,700 years ago, before being covered in ash from the Mount Mazama volcanic eruption.

The deeply carved lines and grooves in geometric motifs in the petroglyphs at Winnemucca Lake share similarities with their cousins in Oregon. As for what the petroglyphs represented to their Native American creators, researchers are still scratching their heads.

Read more at Discovery News

West Antarctica Warmed Quickly: 20,000 Years Ago

The modern meltdown of the Antarctic Ice Sheet mirrors the frozen continent's big thaw after the last ice age ended 20,000 years ago, a new study finds.

New ice core records from West Antarctica show the huge ice sheet started heating up about 20,000 to 22,000 years ago, 2,000 to 4,000 years earlier than previously thought. But in East Antarctica, which was higher in elevation, colder and drier than the West, the continent stayed in its deep-freeze cycle until 18,000 years ago. The results were published today (Aug. 14) in the journal Nature.

The mismatch between West and East is similar to today's Antarctica. Modern West Antarctica is one of the fastest-warming places on the planet. The middle of West Antarctica has warmed by 4.4 degrees Fahrenheit (2.4 degrees Celsius) since 1958, three times as fast as the overall rate of global warming. But relatively little warming — half a degree or less — has been measured in East Antarctica.

Looking at how Antarctica melted in response to past climate change can help researchers better predict the ice sheet's future behavior, said lead study author T.J. Fudge, a doctoral student at the University of Washington. "This most recent deglacial warming is the spot in time we can look at to really understand how our climate goes through big changes," Fudge told LiveScience.

The study is based on an ice core more than 2 miles (3,405 meters) long, covering 68,000 years, the longest U.S. ice core ever drilled. The five-year effort to retrieve the core ended in December 2011. Scientists are only halfway through the ice, having analyzed 30,000 years’ worth of annual layers, according to a statement from the University of Washington.

The authors — a consortium of 42 researchers signed off on the study — suggest that 20,000 years ago, warming in the Southern Ocean melted sea ice around Antarctica. The missing ice meant more storms traveled inland, boosting West Antarctica's warming.

"West Antarctica is influenced by the ocean much more than the ice up high in East Antarctica, so you are able to see this (warming) happening before you notice it in East Antarctica," Fudge said. "We're seeing something similar in the modern climate, where West Antarctica seems to be changing more quickly."

Read more at Discovery News

Aug 13, 2013

Testicle-Munching Fish: All That Dangerous?

A sharp-toothed, testicle-biting cousin to the piranha has been pulled up by a fisherman in Denmark, prompting fears by male skinny-dippers throughout Scandanavia and perhaps parts of the United States. The fish is the pacu, a vegetarian who, although it prefers fruits and nuts that drop into the Amazon River and its tributaries, has been known to confuse nuts for human flesh.

Experts at the Natural History Museum of Denmark reported the finding of the tropical fish by an angler in Oresund Strait between Denmark and Sweden. They originally thought it was a piranha, until experts at the museum made a positive ID.

"Discovering whether this fish is a lone wanderer or a new invasive species will be very exciting. And a bit scary. It's the first time this species has been caught in the wild in Scandinavia," Peter Ras Moller, associate professor at the museum and the University of Copenhagen, said in a statement.

In Papua New Guinea, where the pacu has also escaped, it is believed to have mistaken male reproductive organs for nuts. Two fishermen were reportedly were bitten and bled to death in 2011, according to Jeremy Wade, host of Animal Planet’s “River Monsters.”

The same Amazonian nut-cracking fish was found in a lake in Illinois last year.

Despite these incidents, one Amazon fishing guide says the pacu is not aggressive, but is good to eat.

“I like to pan fry it, or bake it,” said Anthony Giardenelli, owner of Otorongo Expeditions, a tour company that takes trips throughout in the Peruvian Amazon. “It’s very tasty,” he said by phone from his office in Iquitos.

Giardenelli has caught dozens of pacu fish each season as the floodwaters of the Amazon drive fish into the forest in search of food.

“They have evolved migrating in and out of flooded waters to eat fruit and nuts,” Giardenelli said. “They are attracted to anything splashing. Rubber tree seeds are one of their favorites. They are very hard-wired to follow a plopping noise in the water.”

Giardenelli says you he has heard the sound of pacu cracking nuts under water from a boat on the surface. “It sounds like two pool balls clacking together,” he added.

Experts believe the pacu could be spreading to these other waterways around the world by hobbyists who dump the fish overboard when they get too big for the home aquarium.

“It’s a plant eater,” said Stefan Tanner, an editor and translator at Amazonas Magazine. “If you release it in Denmark, it won’t survive the winter. If you release it in Florida, it may swim for a long time. Will it reproduce? That’s another question.”

Read more at Discovery News

Mini-Colosseum of 'Gladiator' Emperor Found

The Roman emperor Commodus might have cultivated the skills showcased in Ridley Scott’s blockbuster film “Gladiator” in a personal miniature Colosseum on his estate near Rome.

Archaeologists from Montclair State University, in New Jersey, believe that a large oval area with curved walls and floors made of marble is, in fact, the arena where the emperor killed wild beasts, earning the nickname “the Roman Hercules,” as recorded in historical writings.

Found in Genzano, a village southeast of Rome which overlooks Lake Nemi, a crater lake in the Alban Hills, the oval structure measures 200 feet by 130 feet and dates to the 2nd century.

It was found by the U.S. team as they excavated thermal baths at an estate known as the Villa of Antonines.

Based on literary references and the discovery in the 18th century of marble busts of imperial figures, the site is believed to have been the property of the Antonine Dynasty (138–193), which begun with the reign of Antoninus Pius and included emperors Marcus Aurelius, Lucius Verus and Commodus.

“We first noticed a small section of a curving structure next to the baths. Ground-penetrating radar mapped out the entire foundations revealing new specular curving structures,” Deborah Chatr Aryamontri, a co-director of the excavation, told the Italian daily Il Messaggero.

Forming an ellipse, the arena could sit more than 1,300 people. It featured an imperial box and was richly decorated with mosaic tesserae and luxurious, imported marbles.

“The very numerous pieces and fragments of marble of varied thickness and dimensions include white marbles as well as colored ones such as serpentine, porphyry, giallo antico, pavonazetto, cipollino and africano — basically the most common decorative types imported from North Africa and the Aegean region,” Chatr Aryamontri, and co-director Timothy Renner, wrote.

“The tesserae, or cubic tiles used for mosaics, include many from black and white compositions (leucitite and white limestone), while the remainder are small colored glass tesserae that represent a large part of the color spectrum and include transparent examples covered with gold leaf,” they added.

According to the archaeologists, several large blocks of worked peperino stone would have helped support an awning system (velarium) to shade spectators from the sun, just like at the Colosseum in Rome.

Most likely, it was in this opulent setting that Commodus practiced for his first semi-public appearances as a killer of animals and a gladiator.

Succeeding his father, Marcus Aurelius, Commodus ruled Rome from 180 A.D until 192 A.D., when he was strangled in his bath by a wrestler.

Immediately after he became emperor, he displayed his strength in gladiatorial combats at Rome’s Colosseum.

According to his contemporary Dio Cassius, Commodus killed men in his private gladiatorial bouts, and was known for “slicing off a nose, an ear or various other parts of the body.”

An accomplished left-handed fighter, determined to cast himself as “Hercules reborn,” Commodus was also a skilled hunter, showing his ability in the Colosseum by killing bears, tigers, hippopotamuses, elephants, but also domestic animals.

Read more at Discovery News

Brain Activity Shows Basis of Near-Death 'Light'

There may be a scientific explanation for the vivid near-death experiences, such as seeing a shining light, that some people report after surviving a heart attack, US scientists said Monday.

Apparently, the brain keeps on working for up to 30 seconds after blood flow stops, according to a study published in the Proceedings of the National Academy of Sciences.

University of Michigan scientists did their research on nine lab rats that were anesthetized and then subjected to induced cardiac arrest as part of the experiment.

In the first 30 seconds after their hearts were stopped, they all showed a surge of brain activity, observed in electroencephalograms (EEGs) that indicated highly aroused mental states.

"We were surprised by the high levels of activity," said senior author George Mashour, professor of anesthesiology and neurosurgery at the University of Michigan.

"In fact, at near-death, many known electrical signatures of consciousness exceeded levels found in the waking state, suggesting that the brain is capable of well-organized electrical activity during the early stage of clinical death."

Similar results in terms of brain activity were seen in rats that were asphyxiated, the researchers said.

"This study tells us that reduction of oxygen or both oxygen and glucose during cardiac arrest can stimulate brain activity that is characteristic of conscious processing," said lead author Jimo Borjigin.

"It also provides the first scientific framework for the near-death experiences reported by many cardiac arrest survivors."

About 20 percent of people who survive cardiac arrest report having had visions during a period known to doctors as clinical death.

Borjigin said she hopes her team's latest study "will form the foundation for future human studies investigating mental experiences occurring in the dying brain, including seeing light during cardiac arrest."

Mainstream science has long considered the brain to be inactive during this period, and some experts questioned how much a study on rats can truly reveal about the human brain.

"Do we know if animals experience 'consciousness'? Most philosophers and scientists are still at loggerheads over what the term refers to in humans, let alone in other species," said David McGonigle, a lecturer at Cardiff University.

"While recent research now suggests that animals may indeed have the kind of autobiographical memories that humans possess -- the kinds of memories that allow us to place ourselves in a certain time and place -- it seems unlikely that near death experiences would necessarily be similar across species."

Anders Sandberg, a research fellow at Oxford University described the research as "simple" and "well-done," but urged caution in interpreting the results.

Read more at Discovery News

A Gamma Ray Burst From the Primeval Universe

Gamma ray bursts (GRBs) are some of the most powerful explosions in the Universe and now a new GRB, detected by NASA’s Swift X-ray Telescope, has been spoted from a time in the Universe’s history when galaxies were just beginning to form.

Long duration GRBs occur when very massive stars run out of fuel for nuclear fusion in their cores. The collapse and subsequent violent explosion can rip a star completely to shreds in a hypernova. Twin beams of gamma rays burst forth from the event, and if Earth is in the path of one of those beams, we see the gamma ray burst. The Swift satellite catches these energetic events as soon as they happen all over the sky so that astronomers can quickly follow up with other telescopes.

This was the case with GRB 130606A, detected on June 6, 2013. A group of astronomers led by Robert Chornock of the Harvard Smithsonian Center for Astrophysics used the 6.5-meter Multiple Mirror Telescope in Arizona and the 8-meter Gemini North telescope in Hawaii to observe the afterglow of the explosion. With these two huge telescopes, the spectra of the GRB afterglow was observed.

The galaxy that hosted the burst turned out to be at a redshift of 5.91, converting to a distance of 12.7 billion light-years away. Only a few GRBs have been seen at this distance, in galaxies as they were in the first billion years of the Universe’s existence. This period of history is near the end of the epoch of reionization. Our telescopes are not yet powerful enough to measure the light from many galaxies at this time, but it is crucial in understanding how galaxies formed and evolved. (It is sometimes erroneously called the ‘dark ages,’ however, that is a term better used to describe the time before these galaxies even formed, when a few rare stars began to light up the dark, empty Universe.)

To date, quasars have been our only direct probe into this period of time, though low frequency radio telescopes are closing in on the signal of the hydrogen emissions between galaxies from this epoch. This GRB is the first of its kind to produce so much information from its spectrum, telling us much about the host galaxy. The astronomers used absorption lines to measure how many heavy elements (those heavier than helium, that is) were present in this galaxy. It turns out to have about 10 percent of the heavy elements as a star like our sun. That’s not quite ideal for forming rocky planets around stars just yet.

The GRB afterglow could also probe how much neutral hydrogen exists between galaxies at this time. Today, just about all of the hydrogen in between galaxies is ionized, but it only became this way during the first billion years of history when ultraviolet light from young stars in young galaxies ripped the electrons away from the hydrogen nuclei. The astronomers did find a bit of neutral hydrogen still around this GRB’s host galaxy, consistent with findings from quasars. This is promising, since multiple methods of probing the same astrophysical setting help reduce certain errors or biases. It’s always good to have a check!

Read more at Discovery News

Aug 12, 2013

Scientists Have Found New Evidence to Show How Early Humans Migrated Into Europe

Humans originated in Africa. But what route did they take as they began to disperse around the world 60,000 years ago? A new professor at the University of Huddersfield has played a key role in finding the answer to one of the most fundamental questions in the history of humankind.

Professor Richards, who moved to Huddersfield from the University of Leeds, is a pioneer in the field -- one of just two professors of archaeogenetics in the world. He uses DNA evidence to study human origins, comparing data from modern samples across the world and occasionally to that which can be obtained from ancient sources such as skeletal remains and fossilised teeth. It leads to a vivid picture of the migration patterns of humankind and the origins of civilisation.

The article in PLoS ONE provides new evidence to indicate that early humans migrated into Europe after the Last Glacial Maximum but before Neolithic times, giving us a clearer picture of how early humans were developing at this time.

Professor Richards spent ten years as a researcher at Oxford University before first coming to the University of Huddersfield for a lecturing post in 2000. He then moved to Leeds, where he was awarded his professorship, before returning to Huddersfield, where he is currently equipping archaeogenetics research facilities. He is joined by his colleagues Dr Maria Pala, Dr Paul Brotherton and Dr Martin Carr.

One laboratory is being set up for the main molecular biology work and a separate lab built for the analysis of ancient DNA. There must be no risk of the evidence being cross-contaminated. "It's like forensics but even more so. It has to be in another building, segregated from the rest of the work we do here," said Professor Richards.

Postgraduates will be recruited to study archaeogenetics at Huddersfield -- to join an expanding field of research that aims to establish the history of the dispersal of human populations around the world.

From Science Daily

California Seafloor Mapping Reveals Hidden Treasures

Science and technology have peeled back a veil of water just offshore of California, revealing the hidden seafloor in unprecedented detail. New imagery, specialized undersea maps, and a wealth of data from along the California coast are now available. Three new products in an ongoing series were released today by the U.S. Geological Survey -- a map set for the area offshore of Carpinteria, a catalog of data layers for geographic information systems, and a collection of videos and photos of the seafloor in state waters along the entire California coast,

"A program of this vast scope can't be accomplished by any one organization. By working with other government agencies, universities, and private industry the USGS could fully leverage all its resources," said USGS Pacific Region Director Mark Sogge. "Each organization brings to the table a unique and complementary set of resources, skills, and know-how."

The USGS is a key partner in the California Seafloor Mapping Program, a large, unique, and historically ambitious collaboration between state and federal agencies, academia, and the private sector to create a comprehensive base-map series for all of California's ocean waters. Scientists are collecting sonar data, video and photographic imagery, seismic surveys, and bottom-sediment data to create a series of maps of seafloor bathymetry, habitats, geology, and more, in order to inform coastal managers and planners, government entities, and researchers. With the new maps, decision makers and elected officials can better design and monitor marine reserves, evaluate ocean energy potential, understand ecosystem dynamics, recognize earthquake and tsunami hazards, regulate offshore development, and improve maritime safety.

"The Ocean Protection Council recognized early on that seafloor habitats and geology were a fundamental data gap in ocean management," said California's Secretary for Natural Resources and Ocean Protection Council Chair John Laird. "After an impressive effort by many partners to collect and interpret the data, the maps being produced now are providing pioneering science that's changing the way we manage our oceans."

Read more at Science Daily

Neandertals Made the First Specialized Bone Tools in Europe

Modern humans replaced Neandertals in Europe about 40,000 years ago, but the Neandertals' capabilities are still greatly debated. Some argue that before they were replaced, Neandertals had cultural capabilities similar to modern humans, while others argue that these similarities only appear once modern humans came into contact with Neandertals.

"For now the bone tools from these two sites are one of the better pieces of evidence we have for Neandertals developing on their own a technology previously associated only with modern humans," explains Dr. Shannon McPherron of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. He and Dr. Michel Lenoir of the University of Bordeaux have been excavating the site of Abri Peyrony where three of the bones were found.

"If Neandertals developed this type of bone tool on their own, it is possible that modern humans then acquired this technology from Neandertals. Modern humans seem to have entered Europe with pointed bone-tools only, and soon after started to make lissoir. This is the first possible evidence for transmission from Neandertals to our direct ancestors," says Dr. Soressi of Leiden University, Netherland. She and her team found the first of four bone-tools during her excavation at the classic Neandertal site of Pech-de-l'Azé I.

However, we cannot eliminate the possibility that these tools instead indicate that modern humans entered Europe and started impacting Neandertal behavior earlier than we can currently demonstrate. Resolving this problem will require sites in central Europe with better bone preservation.

How widespread this new Neandertal behavior was is a question that remains. The first three found were fragments less than a few centimeters long and might not have been recognized without experience working with later period bone tools. It is not something normally looked for in this time period. "However, when you put these small fragments together and compare them with finds from later sites, the pattern in them is clear," comments Dr. McPherron. "Then last summer we found a larger, more complete tool that is unmistakably a lissoir like those we find in later, modern human sites or even in leather workshops today."

Microwear analysis conducted by Dr. Yolaine Maigrot of the CNRS on of one of the bone tools shows traces compatible with use on soft material like hide. Modern leather workers still use similar tools today. "Lissoirs like these are a great tool for working leather, so much so that 50 thousand years after Neandertals made these, I was able to purchase a new one on the Internet from a site selling tools for traditional crafts," says Dr. Soressi. "It shows that this tool was so efficient that it had been maintained through time with almost no change. It might be one or perhaps even the only heritage from Neandertal times that our society is still using today."

These are not the first Neandertal bone tools, but up to now their bone tools looked like stone tools and were made with stone knapping percussive techniques. "Neandertals sometimes made scrapers, notched tools and even handaxes from bone. They also used bone as hammers to resharpen their stone tools," says Dr. McPherron. "But here we have an example of Neandertals taking advantage of the pliability and flexibility of bone to shape it in new ways to do things stone could not do."

The bone tools were found in deposits containing typical Neandertal stone tools and the bones of hunted animals including horses, reindeer, red deer and bison. At both Abri Peyrony and Pech-de-l'Azé I, there is no evidence of later occupations by modern humans that could have contaminated the underlying levels. Both sites have only evidence of Neandertals.

Read more at Science Daily

Mysterious Bat Killer Still Marching Across U.S.

The fungus that causes the deadly White Nose Syndrome in bats has been discovered on the wings of four bats in caves in Minnesota, adding another state to the growing list of where the disease has spread. The discovery suggests the fungus is continuing its rapid march north, south and west across North America after being first discovered in 2007 in New York.

The Minnesota discovery was made by biologists who have been collecting DNA samples from the wings of bats in an ongoing study to learn how the fungus spreads and the disease progresses. The researchers, speaking at a Friday press conference organized by the Minnesota Department of Natural Resources, said the detection of the fungus does not automatically mean the bats from the Forestville/Mystery Cave State Park and at Soudan Underground Mine State Park will become sick with the fatal disease, but that it's the most likely outcome.

"It's not a guarantee, but that's the kind of question we are trying to answer," said Winifred Frisk, who is leading the study from her lab at the University of California at Santa Cruz.

Her NSF-funded study is aimed at determining the timing of the disease, as well as the different bat species it affects. "Our questions are very much focusing on timelines," the detection, disease and mortality of the disease, she said.

"There is a lot we don't know about the fungus," said Jeremy Coleman, national White Nose Syndrome coordinator for the U.S. Fish and Wildlife Service.

It took some time to determine that the fungus was the main disease agent and just recently even the name of the fungus has been changed as a result of better genetic analyses. "We're still trying to figure out why this is a pathogenic fungus," he said.

Researchers still have no treatment for the disease. For now they are working with land managers to control its spread, using rules and warnings for disinfecting cavers' clothing and equipment. In some cases equipment used in a cave later found to harbor White Nose Syndrome fungus are completely banned from other caves, since normal washing is usually insufficient at killing fungal spores. the researchers explained.

The more advanced genetic testing has been a boon to the researchers because it has enabled to them to detect the fungus before bats get sick, as is the case in Minnesota. However, they are a long way from halting the disease.

One of the things that researchers have been hoping to see is a difference in how some bat populations resist the disease, Coleman said. Different populations of the same species can differ widely in this way because of their different locations, foods, living conditions and climate.

Read more at Discovery News

Aug 11, 2013

Fresh Analysis of Dinosaur Skulls Shows Three 'Species' Are Actually One

A new analysis of dinosaur fossils by University of Pennsylvania researchers has revealed that a number of specimens of the genus Psittacosaurus -- once believed to represent three different species -- are all members of a single species. The differences among the fossil remains that led other scientists to label them as separate species in fact arose from how the animals were buried and compressed, the study found.

"Because of the vagaries of fossilization, no two fossils are the same," said senior author Peter Dodson, professor of anatomy in Penn's School of Veterinary Medicine and professor of paleontology in the School of Arts and Sciences' Department of Earth and Environmental Science. "Animals are alive and they die, but what's crucial in paleontology is what happens to the animals after they die."

The research involved a cutting-edge technique, known as three-dimensional geometric morphometrics, which uses lasers to generate data about the shape of different specimens. This is the first time the approach has been used to study dinosaur fossils and could lead to a re-examination of the taxonomic classifications of additional dinosaur species as well as other long-extinct fossil organisms.

Brandon Hedrick, a doctoral student in the Department of Earth and Environmental Science, led the study in collaboration with Dodson. Their research will be reported in the journal PLOS ONE.

The investigation focused on dinosaurs in the genus Psittacosaurus, a word that comes from the Greek for "parrot lizard." The group was named for the animal's beaked face, not unlike that of a turtle. Originally discovered in 1923, 15 species have been classified as Psittacosaurus, though a recent analysis confirmed only nine of these as definite members of the genus. These animals were small plant-eaters that lived 120 to 125 million years ago. Paleontologists have discovered Psittacosaurus fossils in Mongolia, China and Russia and possibly in Thailand.

"Meat-eaters are sexy; plant-eaters are not," Dodson said. "This isn't a flashy dinosaur. But it has an interesting feature in that it's one of the most abundant dinosaurs known to science."

Indeed, many hundreds of Psittacosaurus specimens have been found. This abundance made the genus ideal for Hedrick and Dodson's comparative study, as it is easier to determine relationships within and between species when there are more individuals to compare.

"For example, if you have a single dachshund and a single beagle, they may appear to be different species until you found 40 dachshund-beagle mixes of various grades to examine," Hedrick said.

The scientists examined Psittacosaurus skulls discovered in the fossilized ashes of the Lujiatun beds of northeastern China's Yixian Formation. Paleontologists had previously identified the skulls as belonging to three different species, Psittacosaurus lujiatunensis, P. major or Hongshanosaurus houi.

To compare and contrast the specimens, the researchers used two techniques. First they conducted a traditional study in which they examined every skull that had been classified as one of those three species -- a total of 74 specimens -- for a variety of characteristics that had been used in prior studies to distinguish the species. The Penn team also compared these fossils to skulls that had been classified as belonging to eight other Psittacosaurus species.

Next they completed a more high-tech analysis of 30 skulls from the three named species. Using a hand-held stylus that captures a point in space relative to a transmitter, they pinpointed 56 "landmarks," or particular anatomical locations, on each fossil and compared the relative position of those marks between specimens. They also used a hand-held, laser-emitting scanner to make a three-dimensional image of each specimen, similar to a CT scan, from which they also collected landmark data.

Based on the "old-fashioned" method of examining the physical skulls, the researchers concluded that the three purported species were in fact one. They propose that all three can be considered members of the species P. lujiatunensis.

Results from the geometric morphometric analysis, though not sufficient on its own to classify species, supported this conclusion and suggested that how an animal's body was crushed as it fossilized -- from the top, from the side or twisted -- could lead to inaccurate species determinations.

"Our study found all of these false 'species' that are not biological species but are apparent species caused by the process of fossilization," Dodson said.

Read more at Science Daily

Smart Enough to Know Better: Intelligence Is Not a Remedy for Racism

Smart people are just as racist as their less intelligent peers -- they're just better at concealing their prejudice, according to a University of Michigan study.

"High-ability whites are less likely to report prejudiced attitudes and more likely to say they support racial integration in principle," said Geoffrey Wodtke, a doctoral candidate in sociology. "But they are no more likely than lower-ability whites to support open housing laws and are less likely to support school busing and affirmative action programs."

Wodtke will present his findings at the 108th Annual Meeting of the American Sociological Association. The National Science Foundation and the National Institute of Child Health and Human Development, part of the National Institutes of Health, supported his research.

He analyzed data on the racial attitudes of more than 20,000 white respondents from the nationally representative General Social Survey. He examined how their cognitive ability, as measured by a widely used test of verbal intelligence, was linked with their attitudes about African-Americans, and about different policies designed to redress racial segregation and discrimination.

Respondents were about 47 years old at the time of the interview, on average, and had completed 12.9 years of education. They correctly answered an average of about six of the 10 cognitive ability test questions.

Among Wodtke's findings:

--High-ability whites were more likely than low-ability whites to reject residential segregation and to support school integration in principle, and they were more likely to acknowledge racial discrimination in the workplace. But there were only trivial differences across cognitive ability levels in support for policies designed to realize racial equality in practice.

--In some cases, more intelligent whites were actually less likely to support remedial policies for racial inequality. For example, about 27 percent of the least intelligent whites supported school busing programs, compared with 23 percent of the most intelligent whites.

"The principle-policy paradox is much more pronounced among high-ability whites than among low-ability whites," said Wodtke, who is also affiliated with the Population Studies Center at the U-M Institute for Social Research. "There's a disconnect between the attitudes intelligent whites support in principle and their attitudes toward policies designed to realize racial equality in practice.

"Intelligent whites give more enlightened responses than less intelligent whites to questions about their attitudes, but their responses to questions about actual policies aimed at redressing racial discrimination are far less enlightened. For example, although nearly all whites with advanced cognitive abilities say that 'whites have no right to segregate their neighborhoods,' nearly half of this group remains content to allow prejudicial real estate practices to continue unencumbered by open housing laws."

According to Wodtke, the broader implication of this study is that racism and prejudice don't simply come about as a result of low mental capacities or deficiencies in socialization. Rather, they result from the need of dominant groups to legitimize and protect their privileged social position within an intergroup conflict over resources.

"More intelligent members of the dominant group are just better at legitimizing and protecting their privileged position than less intelligent members," he said. "In modern America, where blacks are mobilized to challenge racial inequality, this means that intelligent whites say -- and may in fact truly believe -- all the right things about racial equality in principle, but they just don't actually do anything that would eliminate the privileges to which they have become accustomed.

Read more at Science Daily

A 12,000-Year-Old Loss Still Stings

Most of us stopped grieving over the loss of giants sloths and armadillo-like glyptodonts and other megafauna of the last ice age a few days after we picked the last bits of their flesh from our teeth some 12,000 years ago. But the Earth is still recovering from the loss, according to a new study of soils in Amazonia, where many of the giant beasts lived.

When those big South American plant eaters died off, they appear to have taken with them a key method for spreading certain nutrients over Amazonia. Their disappearance could even account for why phosphorus, an important soil nutrient, is so scarce in the Amazon basin today, according to new paper in the August 11 edition of the journal Nature Geoscience.

Researchers at Oxford and Princeton universities used a new mathematical model to study how the dung and corpses of those large beasts spread laterally through the landscape and discovered that they play a disproportionately large role in carrying nutrients around.

“For example, we estimate that the extinction of the Amazonian megafauna decreased the lateral flux of the limiting nutrient phosphorus by more than 98 percent, with similar, though less extreme, decreases in all continents outside of Africa,” wrote Christopher Doughty and his colleagues.

This resulted in strong decreases in phosphorus in eastern Amazonia, away from the fertile floodplains.

What’s more, that decline may be continuing today. The low phosphorus levels in Amazon basin soils could be at least partially a relic of a past ecosystem.

“We argue that the Pleistocene megafauna extinctions resulted in large and ongoing disruptions to terrestrial biogeochemical cycling at continental scales,” they wrote. “To the extent humans contributed to the megafaunal extinctions, this suggests that major human impacts on global biogeochemical cycles stretch back to well before the dawn of agriculture.”

Read more at Discovery News