Feb 15, 2014

Mystery of NASA's 'Jelly Doughnut' Mars Rock Solved

NASA's Opportunity rover spotted an odd Martian rock that looked like a doughnut on Jan. 8. Four days earlier, however, the rock wasn't there at all. So how did the rock appear? Alien rock throwers? A nearby meteorite impact?

The truth is much less surprising. Scientists working with the intrepid robot have just confirmed that the rock (called Pinnacle Island) was simply kicked up by one of Opportunity's wheels as it made its way across the planet's surface.

"Once we moved Opportunity a short distance, after inspecting Pinnacle Island, we could see directly uphill an overturned rock that has the same unusual appearance," Opportunity deputy principal investigator Ray Arvidson, of Washington University in St. Louis, said in a statement. "We drove over it. We can see the track. That's where Pinnacle Island came from."

The rock stirred up enough controversy that a concerned citizen even filed a lawsuit against the space agency, claiming that NASA failed to properly investigate a possible fungus growing on the Red Planet.

Although researchers figured out where the rock came from, there are other weird aspects of the Pinnacle Island tale. Using Opportunity's tools, mission scientists have discovered that the rock has very high levels of sulfur and manganese. Both of those elements are water-soluble, suggesting that they were concentrated in the rock due to the "action of water," NASA officials said.

"This may have happened just beneath the surface relatively recently, or it may have happened deeper below ground longer ago and then, by serendipity, erosion stripped away material above it and made it accessible to our wheels," Arvidson said.

The rock is located in a spot on "Murray Ridge" along the wall of Endeavour Crater, where Opportunity is spending the Martian winter. Now that the rover is done examining Pinnacle Island, the Opportunity team is planning to drive the rover uphill to check out exposed rock layers on a different part of the Martian surface.

"We are now past the minimum solar-energy point of this Martian winter," Opportunity project manager John Callas, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "We now can expect to have more energy available each week. What's more, recent winds removed some dust from the rover's solar array. So we have higher performance from the array than the previous two winters."

Read more at Discovery News

Brain's 'sweet spot' for love found in neurological patient

A region deep inside the brain controls how quickly people make decisions about love, according to new research at the University of Chicago.

The finding, made in an examination of a 48-year-old man who suffered a stroke, provides the first causal clinical evidence that an area of the brain called the anterior insula "plays an instrumental role in love," said UChicago neuroscientist Stephanie Cacioppo, lead author of the study.

In an earlier paper that analyzed research on the topic, Cacioppo and colleagues defined love as "an intentional state for intense [and long-term] longing for union with another" while lust, or sexual desire, is characterized by an intentional state for a short-term, pleasurable goal.

In this study, the patient made decisions normally about lust but showed slower reaction times when making decisions about love, in contrast to neurologically typical participants matched on age, gender and ethnicity. The findings are presented in a paper, "Selective Decision-Making Deficit in Love Following Damage to the Anterior Insula," published in the journal Current Trends in Neurology.

"This distinction has been interpreted to mean that desire is a relatively concrete representation of sensory experiences, while love is a more abstract representation of those experiences," said Cacioppo, a research associate and assistant professor in psychology. The new data suggest that the posterior insula, which affects sensation and motor control, is implicated in feelings of lust or desire, while the anterior insula has a role in the more abstract representations involved in love.

In the earlier paper, "The Common Neural Bases Between Sexual Desire and Love: A Multilevel Kernel Density fMRI Analysis," Cacioppo and colleagues examined a number of studies of brain scans that looked at differences between love and lust.

The studies showed consistently that the anterior insula was associated with love, and the posterior insula was associated with lust. However, as in all fMRI studies, the findings were correlational.

"We reasoned that if the anterior insula was the origin of the love response, we would find evidence for that in brain scans of someone whose anterior insula was damaged," she said.

In the study, researchers examined a 48-year-old heterosexual male in Argentina, who had suffered a stroke that damaged the function of his anterior insula. He was matched with a control group of seven Argentinian heterosexual men of the same age who had healthy anterior insula.

The patient and the control group were shown 40 photographs at random of attractive, young women dressed in appealing, short and long dresses and asked whether these women were objects of sexual desire or love. The patient with the damaged anterior insula showed a much slower response when asked if the women in the photos could be objects of love.

Read more at Science Daily

Feb 14, 2014

Cosmic roadmap to galactic magnetic field revealed

Scientists on NASA's Interstellar Boundary Explorer (IBEX) mission, including a team leader from the University of New Hampshire, report that recent, independent measurements have validated one of the mission's signature findings -- a mysterious "ribbon" of energy and particles at the edge of our solar system that appears to be a directional "roadmap in the sky" of the local interstellar magnetic field.

Unknown until now, the direction of the galactic magnetic field may be a missing key to understanding how the heliosphere -- the gigantic bubble that surrounds our solar system -- is shaped by the interstellar magnetic field and how it thereby helps shield us from dangerous incoming galactic cosmic rays. "Using measurements of ultra-high energy cosmic rays on a global scale, we now have a completely different means of verifying that the field directions we derived from IBEX are consistent," says Nathan Schwadron, lead scientist for the IBEX Science Operations Center at the UNH Institute for the Study of Earth, Oceans, and Space. Schwadron and IBEX colleagues published their findings online today in Science.

Establishing a consistent local interstellar magnetic field direction using IBEX low-energy neutral atoms and galactic cosmic rays at ten orders of magnitude higher energy levels has wide-ranging implications for the structure of our heliosphere and is an important measurement to be making in tandem with the Voyager 1 spacecraft, which is in the process of passing beyond our heliosphere.

"The cosmic ray data we used represent some of the highest energy radiation we can observe and are at the opposite end of the energy range compared to IBEX's measurements," says Schwadron. "That it's revealing a consistent picture of our neighborhood in the galaxy with what IBEX has revealed gives us vastly more confidence that what we're learning is correct."

How magnetic fields of galaxies order and direct galactic cosmic rays is a crucial component to understanding the environment of our galaxy, which in turn influences the environment of our entire solar system and our own environment here on Earth, including how that played into the evolution of life on our planet.

Notes David McComas, principal investigator of the IBEX mission at Southwest Research Institute and coauthor on the Science Express paper, "We are discovering how the interstellar magnetic field shapes, deforms, and transforms our entire heliosphere."

To date, the only other direct information gathered from the heart of this complex boundary region is from NASA's Voyager satellites. Voyager 1 entered the heliospheric boundary region in 2004, passing beyond what's known as the termination shock where the solar wind abruptly slows. Voyager 1 is believed to have crossed into interstellar space in 2012.

Interestingly, when scientists compared the IBEX and cosmic ray data with Voyager 1's measurements, the Voyager 1 data provide a different direction for the magnetic fields just outside our heliosphere.

That's a puzzle but it doesn't necessarily mean one set of data is wrong and one is right. Voyager 1 is taking measurements directly, gathering data at a specific time and place, while IBEX gathers information averaged over great distances -- so there is room for discrepancy. Indeed, the very discrepancy can be used as a clue: understand why there's a difference between the two measurements and gain new insight.

Read more at Science Daily

Mixed genes: Interactive world map of human genetic history reveals likely genetic impacts of historical events

When individuals from different groups interbreed, their offspring's DNA becomes a mixture of the DNA from each admixing group. Pieces of this DNA are then passed along through subsequent generations, carrying on all the way to the present day. Researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, Oxford University and University College London (UCL) have now produced a global map detailing the genetic histories of 95 different populations across the world, spanning the last four millennia.

The interactive world map that is accessible via the internet, details the histories of genetic mixing between each of the 95 populations across Europe, Africa, Asia and South America. It shows likely genetic impacts of historical events including European colonialism, the Mongol Empire, the Arab slave trade and European traders near the Silk Road mixing with people in China.

The study, published this week in Science, is the first to simultaneously identify, date and characterise genetic mixing between populations. To do this, the researchers developed sophisticated statistical methods to analyse the DNA of 1490 individuals in 95 populations around the world. "DNA really has the power to tell stories and uncover details of humanity's past," said Simon Myers of Oxford University's Department of Statistics and Wellcome Trust Centre for Human Genetics, co-senior author of the study. "Because our approach uses only genetic data, it provides information independent from other sources. Many of our genetic observations match historical events, and we also see evidence of previously unrecorded genetic mixing. For example, the DNA of the Tu people in modern China suggests that in around 1200CE, Europeans similar to modern Greeks mixed with an otherwise Chinese-like population. Plausibly, the source of this European-like DNA might be merchants travelling the nearby Silk Road."

The powerful technique, christened 'Globetrotter', provides insight into past events such as the genetic legacy of the Mongol Empire. Historical records suggest that the Hazara people of Pakistan are partially descended from Mongol warriors, and this study found clear evidence of Mongol DNA entering the population during the period of the Mongol Empire. Six other populations, from as far west as Turkey, showed similar evidence of genetic mixing with Mongols around the same time.

"What amazes me most is simply how well our technique works," said Garrett Hellenthal of the UCL Genetics Institute, lead author of the study. "Although individual mutations carry only weak signals about where a person is from, by adding information across the whole genome we can reconstruct these mixing events. Sometimes individuals sampled from nearby regions can have surprisingly different sources of mixing. For example, we identify distinct events happening at different times among groups other than the Hazara sampled within Pakistan, with some inheriting DNA from sub-Saharan Africa, perhaps related to the Arab Slave Trade, another from East Asia, and yet another from ancient Europe. Nearly all our populations show mixing events, so they are very common throughout recent history and often involve people migrating over large distances."

The team used genome data for all 1490 individuals to identify 'chunks' of DNA that were shared between individuals from different populations. Populations sharing more ancestry share more chunks, and individual chunks give clues about the underlying ancestry along chromosomes.

Read more at Science Daily

This Toad Grows a Spiky Mustache and Stabs Rivals for the Ladies

The mustache is an accessory of great responsibility, for with it comes great power. Take, for instance, Tom Selleck in Three Men and a Baby, Alex Trebek in pre-2001 Jeopardy, and Freddie Mercury in all of eternity forever and always. Facial forces to be reckoned with, for sure, but to the best of my knowledge none of these men has ever maimed a rival with the mustache itself.

Amateurs, says the Emei mustache toad. This dapper little amphibian doesn’t just walk into the breeding season unarmed. For one chaotic month a year in China, males grow extremely sharp facial spikes, which they use to shank rivals for the choicest nesting sites.

Some 90 percent of all males end up injured. Victors win the right to mate. Losers shuffle away and seriously consider never growing a mustache again, because maybe it wasn’t a good idea in the first place and they were just curious how it would look, like that one time when I was in high school.

Their weapons are called, no joke, nuptial spines, and they’re made of keratin — the same stuff as your fingernails. The spines grow straight through the toad’s skin, and although they will at times pop off in combat, they’ll simply sprout once again, only to fall off at the end of the breeding season.

And if you think that mustache is handsome, wait until you hear about the toad’s other transformations. Its forearms will actually buff up considerably in the mating season, like a bro during a Jersey Shore summer. This, according to evolutionary biologist Cameron Hudson, likely aids both in combat and in amplexus: the amphibian sexy-time, in which strong forelimbs will help the male grasp the female.

In addition, “their skin also becomes much looser, folded, and wrinkled,” Hudson said in an email to WIRED. “We think that this transformation allows them to remain underwater for longer periods (since the breeding, combat and nest guarding is all aquatic) by increasing oxygen absorption through the skin’s larger surface area.”

This species is, after all, a terrestrial one that like most frogs and toads chooses to reproduce in water, which is ideal for their external fertilization. Males hole up in nest sites, the most sought-after being caves of overhanging rock where eggs can be safely deposited. Periodically surfacing to breathe, they will defend these dens zealously like tiny Smaugs, only without the fire-breathing on account of being underwater.

“Generally the battles occur when one male approaches the nest site of another male and tries to go in through the entrance,” said Hudson. “They usually start with the nest occupant trying to block the entrance and shove the intruder away with their head (also while vocalizing). As the fight escalates the intruder will try to grapple the owner and rotate him out of position.”

The combatants keep their heads low, aiming to flip one another. “Usually the fight ends when a male holds his opponent vertically,” added Hudson, “grappling him around the waist and stabbing him in the abdomen. The ‘grappler’ tries to bash his opponent against nearby rocks.”

These battles are vicious, as you can see in the video below. Strangely, though, losing doesn’t necessarily doom a toad’s chances of mating. “There are some potentially interesting questions about male strategy that came up during my research,” said Hudson, “in that fighting is energetically expensive, so sometimes it might be in your best interest to lose and find a new site (if they are available).”

Unusual for an amphibian, these males are considerably larger than the females. And technically that’s odd for any sort of creature, because the females of most animal species on this planet dwarf the males. Of course we and almost all other mammals are exceptions here, but our branch is only a tiny one on the tree of life. Elsewhere in the animal kingdom, females generally have more body mass because producing and maintaining eggs requires much more space and energy than does producing sperm.

What tends to reverse that size bias are selection pressures on the males to grow larger to fight for the right to mate, as Hudson believes the mustache toad has done. Though Hudson finds that being big doesn’t always guarantee victory in battle, large males do indeed have the highest reproductive success. This indicates that females prefer their fellas bulky, or that while larger males can suffer loses, they’re generally better able to control nest sites.

Here’s how it all goes down. When females show up to the river-bottom breeding grounds, the males call out, ideally from the comfort of a sweet nest. If a female is interested, she’ll approach and bump him on the chin with her head, as if to say, “I’m not one of those girls who hates mustaches.” He’ll then rub his chin back and forth across her head — which Hudson reckons is some sort of stimulation — as the pair moves around the nest for the female to scope the surroundings.

“Once they have decided to mate, the male grasps around [her] hips and turns sideways,” said Hudson. “As she begins to lay the eggs, he sticks them to the roof of the nest with his foot. The pair then rotates in a circle, which creates the distinct doughnut-shaped egg mass.”

But say you don’t find your nest before the females arrive. Interestingly, if a male and female have already done that tango and a new male shows up and evicts the successful male, he won’t destroy the already-fertilized eggs. This is quite strange from an evolutionary perspective: Helping protect offspring not of your own making is a waste of energy, not to mention that the young will compete with your own.

Hudson theorizes a few reasons why this may be. “The first is that females may prefer nests with eggs. It’s possible that they take this as a sign of a successful male, and good breeding partner. Another reason may be that if you have more eggs in the nest, yours are less likely to get eaten by a predator, or infected by water molds.”

Read more at Wired Science

1 in 4 Americans Don't Know Earth Orbits the Sun. Yes, Really.

Dear Science Communication Professionals: We have a problem.

Earlier this month, the Bill Nye vs. Ken Ham creationism “debate” received a disproportionate amount of press coverage. Considering there really is no debate to be had when it comes to the science of evolution, for bad or for worse, Nye faced a hostile audience at the Creationist Museum, Kentucky, in the hope to score some scientific points against Ham’s literal translation of the Bible and his absurd assertion that the world was created in 6 days and that the universe is 6,000 years old. In my opinion (an opinion shared by other science communicators), the Nye vs. Ham debate did little for science outreach, was all about who sounded more convincing and only gave creationists some free advertising.

And then, today, the National Science Foundation (NSF) delivered news of a pretty shocking poll result: around 1-in-4 Americans are unaware that the Earth orbits the sun. Let’s repeat that: One in four Americans — that represents one quarter of the population — when asked probably the most basic question in science (except, perhaps, “Is the Earth flat?” Hint: No.), got the answer incorrect. Suddenly I realized why the Nye vs. Ham debate was so popular.

But wait! I hear you cry, perhaps the NSF poll was flawed? Perhaps the poll sample was too small? Sadly not. The NSF poll, which is used to gauge U.S. scientific literacy every year, surveyed 2,200 people who were asked 10 questions about physical and biological sciences. On average, the score was 6.5 out of 10 — barely a passing grade. But for me personally, the fact that 26 percent of the respondents were unaware the Earth revolves around the sun shocked me to the core.

Perhaps I’m expecting too much of the U.S. education system? Perhaps this is just an anomaly; a statistical blip? But then, like the endless deluge of snow that is currently choking the East Coast, another outcome of the same poll appeared on the foggy horizon of scientific illiteracy: The majority of young Americans think astrology is a science.

What the what? Have I been transported back to the Dark Ages? Astrology, of course, is not a science, it is a spiritual belief system at best and at worst a pseudoscience driven by charlatans and the tabloid press. The positions of the stars and planets in the sky do not affect my mood and my horoscope has little bearing on the kind of person I am. 92 percent of the people of China, one of the birthplaces of astrology, know that astrology is bunk. Really America, get your act together.

Unfortunately, if we are to use the “Is astrology a science?” as a litmus test for scientific literacy, things are looking grim. In 2004, 66 percent of the American public said astrology was bunk. Every year since then, that majority has slipped — by 2012, only 55 percent of Americans considered astrology “not at all scientific.” Probably of most concern is the fact that only 42 percent of young respondents aged between 18-24 said astrology is “not at all scientific.”

But there is a small glimmer of hope. According to the same NSF poll, the vast majority of Americans seem to love science. Although they returned woeful test results, it seems America is hungry to learn about science and that science funding is essential for the well-being of the nation. But I’m now concerned about what America thinks science really is, especially in light of that astrology result. Also, just because the U.S. public wants to learn, can they find the institutions that will actually teach real science?

Read more at Discovery News

Feb 13, 2014

Color Explosion Led to Fabulous Dinos 150 M Years Ago

Dinosaurs went from drab to colorful fab just before 150 million years ago, according to a study published in the latest issue of the journal Nature.

The "Wizard of Oz"-type moment in evolution appears to coincide with the emergence of feathers.

Researchers determined this after studying pigment-containing organelles known as melanosomes. These specialized structures within cells in living organisms contain melanin, which is the most common light-absorbing pigment found in animals.

"Black, brown and grey colors are melanin-based," co-author Julia Clarke told Discovery News. "In birds, melanin-based colors include a slightly larger range of reddish brown, brown, black, grey, black and many forms of iridescence."

Clarke is an associate professor at the University of Texas at Austin's Jackson School of Geosciences. She and her colleagues compared the melanosomes of 181 diverse living animals, including birds, mammals and reptiles, as well as 13 fossil specimens and all previously published data on this subject.

Before it was determined that diversity in the shape and size of melanosomes is associated with the evolution of melanin-based color in non-avian dinosaurs, birds and mammals. This diversity in dinos happened suddenly, just as small, meat-eating maniraptoran dinosaurs were evolving feathers, the study found.

"This shift is not seen close to the origin of dinosaur 'fuzz' or 'protofeathers,' but is only associated with feathers," Clarke said. "The shift seems abrupt and occurs before the origin of anything we would call avian flight."

While she and her team are not sure why dinosaurs experienced such a color explosion, Clarke said the dramatic change could have facilitated mate selection. Just as pretty, colorful birds today catch our eye, colorful exteriors would have probably grabbed the attention of non-flying dinosaurs and literal 'early birds' seeking sexual partners.

Many of the genes involved in the melanin color system are also tied to basic functions such as food intake, reproductive behaviors, the "fight or flight" process and other things. So the researchers believe that the color explosion in certain dinosaurs might have been linked to larger changes in their anatomy and metabolism.

"What is most exciting is that tracking color could potentially offer insight into dinosaur physiology," Clarke said.

The research could, for example, help to reveal the precise bodily changes that took place just as non-avian dinosaurs were evolving into birds, and why those changes occurred in the first place.

Color for color's sake is also of interest, allowing us to better recreate and envision what long-extinct animals looked like. This has been a challenge for researchers studying rather drab-looking fossils.

"The presence of pigment must not be confused with color, as even with a specific pigment being recognized, there are/were many factors that contribute to an organism's entire color palette," paleontologist Phillip Manning of the University of Manchester told Discovery News.

Read more at Discovery News

Fossil Shows Pre-Dino Reptile Giving Birth

A birth that took place long before the first dinosaurs emerged can be seen now, thanks to a newly unearthed fossil.

The fossil, discovered in China and described in PLOS ONE, freezes in time the moment that an Ichthyosaur gave birth 248 million years ago.

To give you an idea of how long ago that was, the first dinosaurs emerged some 18 million years after this birthing event.

Ichthyosaurs evolved from terrestrial reptiles and moved to the water. This particular individual and her offspring belonged to the genus Chaohusaurus, the earliest known Mesozoic marine reptile.

“The study reports the oldest vertebrate fossil to capture the ‘moment’ of live-birth, with a baby emerging from the pelvis of its mother,” said author Ryosuke Motani, of the University of California at Davis, in a press release. “The 248-million-year old fossil of an ichthyosaur suggests that live-bearing evolved on land and not in the sea.”

He and his colleagues suspect live birth began on land because the infants were coming out head first, a posture associated with land-dwelling animal births.

In addition to showing the earliest live birth of an ancient marine reptile, the specimen is also thought to contain the oldest known fossil embryos of Mesozoic marine reptiles.

This mom and her babies are obviously long gone. At least one ichthyosaur species, however, survived until the Early Cretaceous, about 90 million years ago. While it’s long gone too, it shows how successful these animals — as a group — were during their lengthy time on our planet.

Taken from Discovery News

Medieval Skeletons Found at Florence's Uffizi

Dozens of skeletons might lie beneath the Uffizi Gallery in Florence, according to archaeologists who have dug up a medieval mass grave near the renowned museum.

Exposed during work to build an elevator in an area designed to house an expanded section of the Uffizi’s exhibit space, the skeletons belong to more than 60 individuals of various ages and genders who probably succumbed to a devastating epidemic.

“It appears they all died at the same time. Multiple graves contain up to 10 bodies, certainly buried in a hurry. Within the graves we also found some coins, all dating between the end of the 4th and the beginning of the 5th century A.D.,” Carlotta Cianferoni, director of Florence’s National Archaeological Museum, told Discovery News.

“The coins provide a rather accurate temporal reference, but of course we need to wait the results of the anthropological analysis and radiocarbon dating,” Cianferoni said.

According to the archaeologists, who have worked at the site for the past five months, the position and the way the bodies were laid in the graves indicate an emergency situation.

“The burials were made in a hurry and with the clear purpose of using less possible space. Bodies were laid side by side in opposite directions, feet against heads, while small, empty spaces were fitted with the bodies of children,” Cianferoni said.

The well-preserved skeletons were found near Piazza del Grano, a few feet away from the gallery and the Arno river, in an area which was probably subjected to floods in antiquity.

“We have unearthed just a small part of the necropolis. We cannot rule out the cemetery extended up to where the Uffizi Gallery now stands,” Cianferoni said.

Since the skeletons lack of signs of wounds or malnutrition, the archaeologists believe the cause of death was a “lethal epidemic,” such as the plague, cholera, dysentery or the flu.

Read more at Discovery News

Toxic Kitty Litter Parasite Found in Arctic Whales

A parasite found in cat feces, scooped out from litter boxes and flushed down the toilet, is showing up in Arctic beluga whales in a finding that is one of the most graphic examples of the world’s changing ecosystems, scientists said.

The finding, announced Thursday, comes with a warning for Inuit residents who eat whale meat. The cat parasite, known as Toxoplasma gondii, is infectious.

Toxoplasmosis, also known as "kitty liter disease" is the leading cause of infectious blindness in humans. It can be fatal to fetuses and people and animals with compromised immune systems.

How the parasite made its way into western Arctic Belugas is no mystery, say biologists Michael Grigg and Stephen Raverty, with the University of British Columbia.

Arctic ice, once a formidable barrier for distant pathogens, is melting, allowing an unprecedented passageway between the far north and warmer climates in the lower latitudes, the scientists said at the American Association for the Advancement of Science meeting in Chicago.

"What we're seeing with the big thaw is the liberation of pathogens gaining access to vulnerable new hosts and wreaking havoc," Grigg, who also works with the U.S. National Institutes of Health, said in a statement.

The parasitic highway is open in both directions. The researchers also reported that a parasite known as Sarcocystis, previously found only in the Arctic, is responsible for killing 406 grey seals in the north Atlantic in 2012.

The new strain of the parasite, now named Sarcocystis pinnipedi, also is responsible for the deaths of an endangered Steller sea lion, seals, Hawaiian monk seals, walruses, polar and grizzly bears in Alaska and as far south as British Columbia, Grigg said.

Taken from Discovery News

Feb 12, 2014

Genome of American Clovis skeleton mapped: Ancestor of most present-day Native American populations

They lived in America about 13,000 years ago where they hunted mammoth, mastodons and giant bison with big spears. The Clovis people were not the first humans in America, but they represent the first humans with a wide expansion on the North American continent -- until the culture mysteriously disappeared only a few hundred years after its origin. Who the Clovis people were and which present day humans they are related to has been discussed intensely and the issue has a key role in the discussion about how the Americas were peopled. Today there exists only one human skeleton found in association with Clovis tools and at the same time it is among the oldest human skeletons in the Americas. It is a small boy between 1 and 1.5 years of age -- found in a 12,600 old burial site, called the Anzick Site, in Wilsall, Montana, USA. Now an international team headed by Danish researcher Eske Willerslev has mapped his genome thereby reviving the scientific debate about the colonization of the Americas.

Roughly estimated some 80 % of all present-day Native American populations on the two American continents are direct descendants of the Clovis boy's family. The remaining 20 % are more closely related with the Clovis family than any other people on Earth, says Lundbeck Professor Eske Willerslev from the Centre for GeoGenetics at the Natural History Museum of Denmark, University of Copenhagen. This surprising result has now been published in the scientific journal Nature. The discovery is so decisive that Nature has chosen to send the article to the press at a later time than usual as they fear the media embargo may be broken. A comprehensive international telephone press conference has been arranged and will be held in the Crow tribe's reservation in Montana -- close to where the boy was found. Behind the results are a group of international researchers led by Professor Eske Willerslev from Centre of Excellence in GeoGenetics, Natural History Museum at University of Copenhagen, Denmark.

The missing link

It is almost like finding the 'missing link' to the common ancestor of the Native Americans. The Clovis boy's family is the direct ancestor to roughly estimated 80 % of all present day Native Americans. Although the Clovis culture disappeared its people are living today. Put simply it is a sensation that we succeeded in finding an approximately 12,600 year old boy whose closest relatives can be regarded as the direct ancestor to so many people, Eske Willerslev says and adds: This also means that Clovis did not descend from Europeans, Asians or Melanesians, a theory that a number of scientists have advocated. They were Native Americans -- and the Native American ancestors were the first people in America. This is now a fact.

Shane Doyle, a historian from the Apsaalooke (Crow) tribe, who helped the team with consultations to the Montana tribes agrees: This discovery by Eske and his team proves something that tribal people have never doubted -- we've been here since time immemorial and all the ancient artifacts located within our homelands are remnants from our direct ancestors. But the discovery is only part of the importance of this study. The other part being Eske and his team's respectful commitment to interacting face to face with tribal communities and listening to Native American leaders, which has lead directly to the reburial of this little boy."

Also Sarah Anzick, a molecular biologist in the study and the steward of the remains that were found on private land is excited: After 46 years since the discovery on my family land, we are finally hearing this child's story through his genetic legacy. I find it remarkable that the descendants of the Clovis culture, which seemed to have vanished 12,600 years ago, are still alive and thriving today.

Interestingly, the teams find that Native American ancestors coming in from Siberia split into two groups. One group is ancestors to the Native Americans presently living in Canada and the other one -- which is represented by the Clovis boy -- is the ancestor to virtually all Native Americans in South America and Mexico. The US is still a white spot on the map when it comes to genome-wide data from Native Americans. The team members hope to be able to accessing such data in the future to understand the full picture.

The study validates the concept of continuity in the history of Native Americans, and suggests that modern Native Americans are direct descendants of the first people occupying this land, says Rasmus Nielsen, a co-author on the study and a Professor at UC Berkeley, who developed the method used for determining that many modern native Americans are direct descendants of the Clovis boy's family.

An Asian homeland for the First Americans

The first humans came from Siberia via the so-called Beringia Land Bridge, which during the latest ice age connected Siberia with North America and did not bring the Clovis culture with them. The Clovis culture arose after they arrived in America and the boy from Anzick was more a descendant of the first immigrants.

Michael Waters, the key archaeologist connected to the study and who has worked on many Clovis and older sites in North America elaborates: The genetic findings mesh well with the archaeological evidence to confirm the Asian homeland of the First Americans, more clearly define their genetic heritage, and is consistent with occupation of the Americas a few thousand years before Clovis. The findings do not support a western European origin of the First Americans as suggested by the Solutrean hypothesis. The genetic information provided by the Anzick boy is part of the larger story of modern human dispersal across Earth and is shedding new light on the last continent to be explored and settled by our species.

Read more at Science Daily

Jaw dropping: Scientists reveal how vertebrates came to have a face

A team of French and Swedish researchers have presented new fossil evidence for the origin of one of the most important and emotionally significant parts of our anatomy: the face. Using micron resolution X-ray imaging, they show how a series of fossils, with a 410 million year old armoured fish called Romundina at its centre, documents the step-by-step assembly of the face during the evolutionary transition from jawless to jawed vertebrates.

The research is published in Nature on 12 February 2014.

Vertebrates, or backboned animals, come in two basic models: jawless and jawed. Today, the only jawless vertebrates are lampreys and hagfishes, whereas jawed vertebrates number more than fifty thousand species, including ourselves. It is known that jawed vertebrates evolved from jawless ones, a dramatic anatomical transformation that effectively turned the face inside out.

In embryos of jawless vertebrates, blocks of tissue grow forward on either side of the brain, meeting in the midline at the front to create a big upper lip surrounding a single midline "nostril" that lies just in front of the eyes. In jawed vertebrates, this same tissue grows forward in the midline under the brain, pushing between the left and right nasal sacs which open separately to the outside. This is why our face has two nostrils rather than a single big hole in the middle. The front part of the brain is also much longer in jawed vertebrates, with the result that our nose is positioned at the front of the face rather than far back between our eyes.

Until now, very little has been known about the intermediate steps of this strange transformation. The scientists studied the skull of Romundina, an early armoured fish with jaws, or placoderm, from arctic Canada. The skull is part of a collection of the French National Natural History Museum in Paris.

Romundina has separate left and right nostrils, but they sit far back, behind an upper lip like that of a jawless vertebrate. "This skull is a mix of primitive and modern features, making it an invaluable intermediate fossil between jawless and jawed vertebrates," says Vincent Dupret of Uppsala University, one of two lead authors of the study.

By imaging the internal structure of the skull using high-energy X-rays at the European Synchrotron (ESRF) in Grenoble, France, the authors show that the skull housed a brain with a short front end, very similar to that of a jawless vertebrate.

"In effect, Romundina has the construction of a jawed vertebrate but the proportions of a jawless one," says Per Ahlberg, of Uppsala University and the other lead author of the study. "This shows us that the organization of the major tissue blocks was the first thing to change, and that the shape of the head caught up afterwards," he adds.

Read more at Science Daily

Drug References Found on Walls of Ancient Egyptian School

Archaeologists working in the western desert of Egypt have discovered a school dating back about 1,700 years that contains ancient Greek writings on its walls, including a text about ancient drug use that references Homer's "The Odyssey."

The school — which contains benches that students could sit on to read, or stand on and write on the walls — dates back to a time when the Roman Empire controlled Egypt, and Greek was widely spoken.

In use for less than 20 years, the school structure eventually became part of a large house that contained colorful art, including images of the Olympian gods, the researchers said.

The house and school are located in the ancient town of Trimithis (modern-day Amheida), which is in the Dakhla Oasis, about 200 miles (322 kilometers) west of the Nile River. The house, and some of the art, was first discovered in 1979. In 2001, a new exploration project at Amheida, now sponsored primarily by New York University, led to the discovery of the school, its Greek writings and more art scenes from the house.

A unique discovery

In the ancient world, schools were often part of other places — like private residences, city halls or temples — and, as such, are very difficult for archaeologists to identify, Raffaella Cribiore, a professor at New York University, wrote in the journal Zeitschrift für Papyrologie und Epigraphik (a journal that publishes ancient texts).

Although archaeologists know of another ancient school in Egypt — a university in Alexandria — the school at Amheida is unique because it was found with texts on its walls, Cribiore said. The texts are "further proof that teaching and learning took place there, and confirm that they belong to the only building so far discovered from antiquity that was certainly a school and showed educational activities," Cribiore wrote.

For instance, The text referring to "The Odyssey" tells a legendary story of ancient drug use: Helen of Troy, for whom the Trojan War had been fought, gives her guests a drug (possibly opium) that "takes away grief and anger, and brings forgetfulness of every ill," the text reads. "Whoever should drink this down when it is mixed in the bowl would not let fall a tear down his cheek in the course of that day at least. Imitate." The word "imitate" appears to indicate the students should copy the passage in some way. Ancient records say that some people believed this passage had a magical quality to it that could calm young people.

In a different room of the school, the team discovered another text composed by a teacher telling students to bring their rhetorical skills up to the level of several deities, including the ancient Greek god Hermes. It also urged the students to work hard. "Be bold, my boys; the great god will grant you to have a beautiful crown of manifold virtue," part of the text reads. "Work hard for me, toils make men manly …"

School's out

The school wasn't in use for long, perhaps because the teacher moved or died, the researchers said. During this era, "a school was a teacher and ceased to exist when the latter moved or died," Cribiore wrote. After it closed, the school building was incorporated into a nearby house belonging to a town councillor named Serenos, who used part of it for storage.

In 1979, researchers found a painting of the Olympian gods in Serenos' house, and recent excavations have revealed more paintings including one of a banquet scene with a flute player. In one room, almost every surface "was decorated, either with colourful geometric motifs or lively figural scenes, such that the experience of entering the space for the first time in antiquity must have been overwhelming," wrote Susanna McFadden, a professor at Fordham University, in a book titled "Actes du XII Colloque de l'Association International pour la Peinture Murale Antique." (The book is to be published by the L'Associazione internazionale per la pittura murale antica in the future.)

Read more at Discovery News

Two New Portraits of Shakespeare Found

In the last years of his life, William Shakespeare was an elegant gentleman who spent time at his Stratford residence, sitting on an elaborately carved chair in the company of a book and an adoring dog.

About two decades earlier, he was a relatively young man exuding self-confidence and proud smiles.

These powerful images emerge from two previously unknown portraits of Shakespeare, according to Hildegard Hammerschmidt-Hummel, a professor of English at Mainz University, Germany.

"I subjected the images to fundamental tests of identity and authenticity, and these revealed that we are dealing with true-to-life portraits of Shakespeare, one from his youth, the second from his old age," Hammerschmidt-Hummel told Discovery News.

She announced the new finding this morning at a press conference at Mainz Cathedral.

According to the German academic, one portrait, possibly painted around 1594, when the poet was about 30 years old, depicts Shakespeare as a young London playwright and author of sonnets who has reached the first height of his unparalleled literary career.

"Showing amazing self-confidence, the man appears to cast his spell over the viewer with a touch of a triumphant smile," Hammerschmidt-Hummel said.

Hung in the bedchamber of Prince Franz (1740-1817), in the Gothic House of the Dessau-Wörlitz Garden Realm, the 2.4- by 2-foot portrait was seized in 1945 by the Soviet army.

"It has been lost ever since. Today there is only a high-quality, monochrome photograph from 1936, now in the Photo Marburg Picture Archive," Hammerschmidt-Hummel said.

Archival research shows Prince Franz brought the picture from his trip to England from 1763 to 1764. Records show it was given to him as a gift by Thomas Hart, a distant relative of Shakespeare.

While the Wörlitz portrait only depicts Shakespeare's facial features, the second portrait shows the whole person of Shakespeare for the first time.

"We can see he wasn't a very tall man," Hammerschmidt-Hummel said.

The painting is estimated to show Shakespeare at the age of 50, about two years before his death and it portrays the Bard as an affluent, older gentleman living in retirement. He sits on an elaborately carved chair, holding a a book in his left hand and resting his right hand on the head of a dog, which is sitting to his right.

Careful examination of the image has even determined the breed of the dog, which, according to the London veterinary Bruce Fogle, appears to be a Lurcher, (a cross between a Greyhound and a working dog). Little is known about the provenance and history of the portrait.

"I am calling it the Boaden Portrait because I found it in a rare, richly illustrated edition of James Boaden's work of 1824," Hammerschmidt-Hummel said.

Called "An Inquiry into the Authenticity of Various Pictures and Prints, which ...have been offered to the Public as Portraits of Shakespeare," the book displays the portrait as an engraving -- with no caption.

"Nevertheless, my research in close interdisciplinary collaboration with experts from other disciplines shows we are dealing here with an authentic portrait," Hammerschmidt-Hummel said.

"The portrait could only have come about by direct contact of the artist with his model, that is Shakespeare," said Jost Metz, a dermatologist who examined the portraits. Metz specializes in diagnosing signs of disease in Renaissance portraits.

Announced on the 450th anniversary of the poet's birth, the new finding adds to four portraits of the Bard which Hammerschmidt-Hummel authenticated in 2006 amid some controversy.

Before then, only two likenesses of Shakespeare, both posthumous, were accepted as authentic: a bust on his tomb in Stratford's Holy Trinity Church and an engraving shown in the Folio edition of his plays in 1623.

To authenticate the two new portraits, Hammerschmidt-Hummel used four images that had already been thoroughly tested by various experts and found to be genuine, as well as the two accepted likenesses: the Darmstadt Shakespeare death mask, the Davenant bust, the Chandos and the original Flower portraits. She authenticated the four portraits back in 2006.

The experts used forensic imaging technologies, 3D-measurements, laser-scan images and computer montages to compare the pictures.

The tests for authenticity on the new portraits brought to light a series of facial marks and idiosyncrasies that correspond to those found on all the other Shakespeare likenesses. In particular, the two newly found pictures show a growth on the upper left eyelid and swellings in the nasal corner of the left eye, which seem to represent different stages of a disease.

Read more at Discovery News

Feb 11, 2014

Giant mass extinction quicker than previously thought: End-Permian extinction happened in 60,000 years

The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96 percent of marine species and 70 percent of life on land -- including the largest insects known to have inhabited Earth. Multiple theories have aimed to explain the cause of what's now known as the end-Permian extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.

Now researchers at MIT have determined that the end-Permian extinction occurred over 60,000 years, give or take 48,000 years -- practically instantaneous, from a geologic perspective. The new timescale is based on more precise dating techniques, and indicates that the most severe extinction in history may have happened more than 10 times faster than scientists had previously thought.

"We've got the extinction nailed in absolute time and duration," says Sam Bowring, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. "How do you kill 96 percent of everything that lived in the oceans in tens of thousands of years? It could be that an exceptional extinction requires an exceptional explanation."

In addition to establishing the extinction's duration, Bowring, graduate student Seth Burgess, and a colleague from the Nanjing Institute of Geology and Paleontology also found that, 10,000 years before the die-off, the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere. This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life.

But what originally triggered the spike in carbon dioxide? The leading theory among geologists and paleontologists has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma. To determine whether eruptions from the Siberian Traps triggered a massive increase in oceanic carbon dioxide, Burgess and Bowring are using similar dating techniques to establish a timescale for the Permian period's volcanic eruptions that are estimated to have covered over five million cubic kilometers.

"It is clear that whatever triggered extinction must have acted very quickly," says Burgess, the lead author of a paper that reports the results in this week's Proceedings of the National Academy of Sciences, "fast enough to destabilize the biosphere before the majority of plant and animal life had time to adapt in an effort to survive."

Pinning dates on an extinction

In 2006, Bowring and his students made a trip to Meishan, China, a region whose rock formations bear evidence of the end-Permian extinction; geochronologists and paleontologists have flocked to the area to look for clues in its layers of sedimentary rock. In particular, scientists have focused on a section of rock that is thought to delineate the end of the Permian, and the beginning of the Triassic, based on evidence such as the number of fossils found in surrounding rock layers.

Bowring sampled rocks from this area, as well as from nearby alternating layers of volcanic ash beds and fossil-bearing rocks. After analyzing the rocks in the lab, his team reported in 2011 that the end-Permian likely lasted less than 200,000 years. However, this timeframe still wasn't precise enough to draw any conclusions about what caused the extinction.

Now, the team has revised its estimates using more accurate dating techniques based on a better understanding of uncertainties in timescale measurements.

With this knowledge, Bowring and his colleagues reanalyzed rock samples collected from five volcanic ash beds at the Permian-Triassic boundary. The researchers pulverized rocks and separated out tiny zircon crystals containing a mix of uranium and lead. They then isolated uranium from lead, and measured the ratios of both isotopes to determine the age of each rock sample.

From their measurements, the researchers determined a much more precise "age model" for the end-Permian extinction, which now appears to have lasted about 60,000 years -- with an uncertainty of 48,000 years -- and was immediately preceded by a sharp increase in carbon dioxide in the oceans.

'Spiraling toward the truth'

The new timeline adds weight to the theory that the extinction was triggered by massive volcanic eruptions from the Siberian Traps that released volatile chemicals, including carbon dioxide, into the atmosphere and oceans. With such a short extinction timeline, Bowring says it is possible that a single, catastrophic pulse of magmatic activity triggered an almost instantaneous collapse of all global ecosystems.

Read more at Science Daily

Crocodiles Can Climb Trees

Crocodiles can climb trees. And they do it well, too: Some of the toothy reptiles have been spotted as high as 32 feet up a tree.

That’s not somewhere a normally aquatic crocodile ends up by accident.

Once considered a characteristic of extinct crocodilians, this proclivity for scampering up trees is common in today’s crocodiles, a team of scientists reports in Herpetology Notes [pdf]. That’s surprising, because crocodiles don’t really have the anatomic adaptations needed to easily grip tree branches and scale tree trunks in the way that sloths or monkeys do. But various sightings suggested that the reptiles, and their alligator friends, were somehow managing to become tree-borne.

To determine just how frequently crocodiles climb into trees, the team looked in several places. The first was published scientific literature — all three references, one of which, dating back to 1972, described how baby crocodiles could “climb into bushes, up trees and even hang on reeds like chameleons.”

The second? Anecdotal reports from around the world describing crocodiles and alligators in trees. Turns out, the behavior has been seen quite a bit by people living in crocodile-rich areas. Among other places, arboreal crocodilians have been spotted in the mangrove swamps near Tulum, Mexico; in Mississippi (photo, above); in Colombia, where juveniles can be found 30 feet up; and along the Nile.

Next, the scientists set out to collect a few observations of their own. In Australia, they saw crocodiles in trees — and spotted one individual attempting to scale a chain-link fence. In the Everglades and Central America, many crocodiles were spotted basking on the concealed lower branches of mangrove trees. At some of these sites, the only way the reptiles could have reached their resting spot was by climbing up the tree trunk itself. And in Africa, Nile crocodiles and their relatives were seen just as frequently in trees as were some birds. In many instances, these reptiles were lying on tree limbs that were nowhere near the water. One was spotted on a log 13 feet above the water and 16 feet from the riverbank. “To reach this site the crocodile would have had to scale a [13-foot] completely vertical bank and then walk amongst the branches to reach the end of the tree,” the authors reported.

Read more at Wired Science

Signs of Salty Water Stain Slopes on Mars

RSL: it’s what all the coolest Mars researchers are talking about these days, but it’s not an acronym for a spacecraft or some new organic compound (or even some hip social media slang ROFLMAO). Rather it’s our best evidence yet that water exists on Mars in liquid form today, right now — even if it’s not yet 100 percent conclusive.

RSL, or recurring slope lineae, are dark streaks that have been observed appearing on the steep inner walls of craters or bedrock outcrops in the southern mid-latitudes on Mars. Images from the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter have repeatedly imaged these stains, which are thought — perhaps even hoped — to be the result of liquid water flowing downhill after the slopes have received enough sunlight to melt any ice tucked just below the surface.

Any water in RSL is expected to be very salty, which would allow it to stay liquid at considerably low temperatures, and even possibly contain some sort of iron-rich “antifreeze” component.

But despite several years of investigation, the water hasn’t been definitively found… yet.

“We still don’t have a smoking gun for existence of water in RSL, although we’re not sure how this process would take place without water,” said Lujendra Ojha, graduate student at the Georgia Institute of Technology in Atlanta and lead author of two new reports about RSL. He first discovered them in HiRISE images in 2011 while an undergraduate at the University of Arizona.

In recent observations of 13 RSL sites using another of MRO’s high-tech instruments — the Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM – Ojha and Georgia Tech assistant professor James Wray could not identify any clear indication of water, but there were signatures of iron-containing minerals left behind by the flows. And, like a process that results from a freeze-thaw cycle, there seemed to be more of this ferrous material when the seasonal temperatures were higher.

So what could cause RSL streaking besides water? The culprit could actually be a dry process: liquid-like flows of fine, grainy material that can create markings visible from orbit but don’t actually require water. If dry, lighter-toned surface material were to slide downhill, streaks of darker soil could be left behind — an ongoing process that’s been seen in other locations on Mars.

Still, water could very well be what’s darkening these Martian slopes but it hasn’t been directly detected yet with MRO’s impressive but nearly decade-old instruments — or perhaps it just isn’t looking at the right time.

According to a NASA news release, “the orbital observations have been made only in afternoons and could miss morning moisture.” Maybe on Mars it pays to be an early riser!

Read more at Discovery News

Deadliest Mushroom Is Spreading Worldwide

It’s big, meaty, looks innocuous, grows near-edible mushrooms and smells delicious, but the name reveals its toxicity: the death cap.

Native to Europe, the death cap is now an invasive species on every continent except Antarctica, Cat Adams, a Harvard graduate student, writes in Slate.

The spores spread “like glitter at a kids’ glitter party,” writes Adams, who is working on a literature review of the mushroom. In the United States, it’s adapted to grow on live oak trees and native pines, and has spread along the East and West Coasts and appears to be moving south into Mexico.

The good news? An ongoing clinical trial may have found an antidote: S. Todd Mitchell of Dominican Hospital in Santa Cruz and colleagues have treated more than 60 patients with a drug derived from milk thistle. The patients who have started the drug on time (within 96 hours of ingesting the mushroom) and who have still had kidney function intact have all survived.

“When administered intravenously, the compound sits on and blocks the receptors that bring amatoxin into the liver, thus corralling the amatoxins into the blood stream so the kidneys can expel them faster,” Adams wrote. “Only a few patients sought treatment later and did not survive.”

Although Mitchell needs more patients before publishing the research, he says there are virtually no downsides to the drug.

“When we present to FDA, it will be a slam dunk for approval,” he told Slate. “The drug has virtually no side effects, it’s very well tolerated, and if used correctly it’s awesomely effective.”

Taken from Discovery News

Feb 10, 2014

Female Spiders Judge Mates by Their Gift Wrap

For some spider suitors, the arachnid equivalent of a box of chocolates is an insect wrapped in silk. New research shows it's not just the gift but also the color of the wrapping that can seal the deal among one species.

Male spiders of the species Paratrechalea ornate reveal their health and suitability as a mate by the whiteness of their gift wrap, a new study suggests.

"Females evaluate the physical condition of a male based on his silk wrapping performance, and how the gifts he brings look," study researcher Mariana Trillo, of Uruguay's Instituto de Investigaciones Biológicas Clemente Estable, said in a statement. "Also, silk wrapping is a condition dependent trait and most probably allows a Paratrechalea ornata female to acquire information about her potential mate, including body condition and quality."

Trillo and colleagues conducted experiments with semi-aquatic Paratrechalea ornate spiders collected from the Santa Lucia River in Uruguay. During one test, the scientists painted the mouth parts of some of the male spiders white. (The spiders carry their nuptial gifts in their mouth parts.) The females paid more attention to the male spiders with painted mouths. They also mated with the painted males earlier and more often than the males without paint.

The scientists think their results suggest the white coloring of the silk is the main draw for female spiders. Because this species is most active during sunset and at night, white silk is easier to see over long distances. What's more, males in better physical shape produced whiter gifts because they used more silk in their wrapping, while the poor wrapping job of less healthy males resulted in a duller package. This means the color of the gifts could be a reflection of the male's body condition, which could help the females judge their suitors, the scientists say in the journal Naturwissenschaften.

Read more at Discovery News

Syria's Archaeological Sites Ravaged by Bombing, Looting

When Asma al-Assad, the British-born wife of Syrian President Bashar al-Assad, received an honorary Ph.D. in archeology in 2004 from the prestigious University of Rome "La Sapienza," she stressed that such knowledge should be used "to foster mutual respect for what human societies have achieved over the millennia across the globe."

Awarded for her role in the development of historical and archaeological studies and the preservation of the Syrian heritage, the degree was handed to al-Assad amid the ruins of the fabled ancient city of Ebla. The ceremony changed for the first time the University’s 700-year-old tradition which required the honorary degree to be given inside the city of Rome.

Ten years later, Asma is banned from traveling to all EU member states except the U.K, while bombing and looting have ravaged most of her country's precious archaeological sites.

According to UNESCO, the U.N. cultural, education and science arm, illegal excavation in the past three years has spread everywhere, from Ebla, the site where Asma received her honorary Ph.D., to the ancient Sumerian city of Mari.

Apamea, a city founded in 300 B.C. by one of Alexander the Great"s generals, which boasted one of the longest and widest colonnades in the ancient world, "is completely destroyed by thousands and thousands of illegal diggings," Francesco Bandarin, assistant director-general for culture at the agency, warned at a news conference last week.

"A site has a value not only for the monuments that are destroyed but also for the values of the objects in the ground," Bandarin said. "When this is lost, the scientific value of the site is clearly, clearly compromised," he added.

To curb the destruction, the European Union gave UNESCO 2.5 million euros ($3.4 million) last week for a program aimed at fighting looting as well as raising awareness on Syria's endangered cultural heritage.

"I would like to thank Hollywood for bringing this issue to global attention," Bandarin said.

He referred to the premiere of "The Monuments Men," a film which, starring George Clooney, Matt Damon, Bill Murray and Cate Blanchett, deals with attempts to save paintings and other cultural artifacts from destruction and looting during World War II.

"Sometimes Hollywood is more powerful than all the U.N. system put together," Bandarin said.

Syria's cultural heritage is unique. As Asma al-Assad remarked in her acceptance speech of the doctorate, it's a land where "those essential human attributes -- culture, society and civilization -- first flourished."

Along with Mesopotamia, the country echoes the main advances made by humankind such as the birth of the first villages and what is believed to be the world's first alphabet. Ironically, it is also here that archaeologists found the first evidence for the use of chemical weapons.

Over four millennia, Syria's valleys and deserts have witnessed everything from Biblical civilizations, Roman conquerors and Christian Crusaders. The result is an abundance of unique monuments which include Roman cities, castles and forts, medieval Islamic markets, palaces, mosques and cathedrals.

"The country has tens of thousands of archaeological sites, not all of which have been recorded or even discovered yet. Before the crisis, new sites were being discovered all the time," Emma Cunliffe, Global Heritage Preservation Fellow Postgraduate Researcher at Durham University, and author of "Damage to the Soul: Syria's Cultural Heritage in Conflict," told Discovery News.

Such was the fascination with a country so rich in archaeological legacies, that in 2010 more than 8.5 million tourists visited it. To woo the Western tourism market, Syria re-branded itself as a sun-soaked, crime-free country boasting breathtaking beaches and some of the world's most precious historical sites.

That's a far cry from the "country of evil" described by Italian journalist Domenico Quirico, kidnapped in Syria for five months last year.

Since the civil war began in March 2011 more than 100,000 people have been killed and near 8 million people have been driven from their homes, with 2 million of them fleeing the country.

"Now cultural heritage is not at the top of anyone's list, and given the dramatic humanitarian crisis, nor should it be. However, it does still matter," Cunliffe said.

Syria has six sites inscribed to the World Heritage List: Aleppo with its stunningly preserved medieval settlement, Bosra, boasting the best-preserved Roman theater in the world, Damascus, with the spectacular 8th-century Great Mosque of the Umayyads and The site of Palmyra, one of the biggest attractions among tourists for its towering Roman colonnades built in a palm-fringed oasis.

Also among its treatures are the Qal'at Salah El-Din, also known as the fortress of Saladin, the castle of Crac des Chevaliers, the world's largest and best-preserved Crusader castle, and the ancient villages of northern Syria complete the list.

The fate of these jewels is yet unknown. According to Cunliffe, sites guards are often outnumbered and outgunned by determined teams of looters, while sites in areas of conflict are at risk from shelling and gunfire.

Read more at Discovery News

Gladiator Heads? Mystery of Trove of British Skulls Solved

A trove of skulls and other body parts unearthed in the heart of London may have once belonged to Roman gladiators, war captives or criminals, a new study suggests.

The remains, described in the January issue of the Journal of Archaeological Science, belonged to about 40 men, mostly ages 25 to 35, and were marred by violence: cheek fractures, blunt-force trauma to the head, decapitation and injuries from sharp weapons, said study co-author Rebecca Redfern, a curator and bioarchaeologist at the Museum of London.

Great Britain's ancient cities are littered with archaeological treasures, many of which are often dug up accidentally prior to construction. For instance, in 2013, the burial site of King Richard III was found under a parking lot in Leicester, England, and in April 2013, a medieval knight's tomb was uncovered under a Scottish parking lot.

The new site was excavated in 1988 prior to construction, and the skulls and remains of 40 people, along with scrap leather, were found at a marshy site in a pit.

During the Roman period, the area, near the London Wall, was filled with small timber workshops where shoemakers toiled. The site was also close to an amphitheater, and because of its proximity to a stream, it had religious and ritual purposes as well, Redfern said.

Due to a lack of funding, the skulls were never thoroughly analyzed but were instead taken to the Museum of London, where they languished for decades.

But after Redfern was tasked with clearing out the backlog of items in the museum's collection, she did a more thorough analysis.

Originally, Redfern and colleague Heather Bonney, an earth scientist at the Natural History Museum in London, assumed the skulls had washed up from a nearby cemetery after river flooding. But most cemeteries hold bodies of people who died at different ages, whereas these remains belonged to young men who bore marks of extreme violence.

By measuring the isotopes of carbon (atoms of carbon with different numbers of neutrons), in nearby pottery shards, the team concluded that the men died between A.D. 120 and 160. Because radioactive carbon decays at a reliable rate, the proportion of radioactive carbon relative to other forms of carbon can reveal how old an object is.

Further analysis led them to conclude that the remains were put into a shallow pit that was deliberately dug outside a shoemaker's shop.

The ages and evidence of trauma suggest the Roman-era remains once belonged to gladiators, executed criminals or war captives.

In Roman-era England, it was common for headhunters to collect "trophies" from war captives: For instance, Hadrian's Wall was spiked with the heads of enemy soldiers.

"If you were considered to be a barbarian, [the Roman warriors] didn't actually regard you as human," Redfern told Live Science. "You were subhuman."

So the Romans ironically saw the displaying of barbarian, decapitated heads "as an expression of military power and the force of civilization," Redfern said.

Political criminals and gladiators were also decapitated, likely in the nearby amphitheater.

Read more at Discovery News

Most Ancient Star Lurks On Our Cosmic Doorstep

Records for furthest, biggest and brightest are always being broken in astronomy, but one of the more intriguing records has just been smashed. Australian astronomers have found a Methuselah star that likely formed 13.6 billion years ago. As the Universe is 13.75 billion years old, this object is a rare cosmic jewel that truly stood the test of time.

But the best thing about this star is that it lurks inside our galaxy, a mere 6,000 light-years away, providing us with a close-up view into a time capsule from the dawn of our cosmos.

The star was discovered by astronomers at the Mount Stromlo Observatory in Australia who analyzed spectral data of millions of stars collected by SkyMapper at the Siding Spring Observatory, New South Wales. SkyMapper is an automated telescope that surveys Southern Hemisphere skies for planets, stars and asteroids. A few ‘low metallicity’ candidates were then studied using high-resolution spectral observations by the Magellan Telescopes in Chile. When they focused on the ancient star, called SMSS J031300.36-670839.3, Stefan Keller (of the Australian National University in Canberra) and his team noticed something strange.

“The telltale sign that the star is so ancient is the complete absence of any detectable level of iron in the spectrum of light emerging from the star,” Keller told AFP.

The theory is that the star’s extremely low metallicity is because it’s a “second generation” star, one that formed only a couple of hundred million years after the Big Bang. Second generation stars formed from the material cast off from the “first generation” of stars after they went supernova. Recent research suggests that not all of the first stars — formed from a primordial soup of gases, primarily hydrogen, helium and trace amounts of lithium — exploded energetically, however, adding a twist to our understanding about how the earliest stars formed. This means that heavier elements (heavier than helium) formed inside the fusion cores of some of these first stars were not ejected throughout interstellar space.

In the case of SMSS J031300.36-670839.3, it appears that it formed primarily from the hydrogen and helium from the post-supernova material — leaving it extremely anemic. What’s more, the researchers think that this particular object formed from the remnants of only one first generation star.

Usually when astronomers analyze the spectra of stars, the chemical fingerprint of iron can be spotted. The more iron in the star, the younger it is. Each subsequent generation of star fuses more and more iron in their cores. As each generation of star reaches the end of its life and explodes as a supernova, the iron (and other heavy elements) from its interior is blasted throughout space. This iron intermingles with other interstellar gases that clump together, collapse and ignite to create the next generation of stars.

The iron fingerprint can therefore be used to “age” any stellar object, much like the rings in a log can be used to age a tree.

“We can use the iron abundance of a star as a qualitative ‘clock’ telling us when the star was formed,” said Keller.

SMSS J031300.36-670839.3, however, has no detectable sign of iron. Even within the margins for error, and astronomers assume an upper limit on the quantity of iron it contains, the star is still dated 13.6 billion years old. Previous “oldest star” record breakers have been dated to 13.2 billion years old.

“In the case of the star we have announced, the amount of iron present is less than one millionth that of the sun and a factor of at least 60 times less than any other known star. This indicates that our star is the most ancient yet found,” he added. This research as been published in the journal Nature.

Interestingly, the star is also rich in carbon. This factor provides us with a unique insight into stellar formation in the earliest epochs of our universe.

Read more at Discovery News

Feb 9, 2014

Surprising new clue to the roots of hunger, neurons that drive appetite

While the function of eating is to nourish the body, this is not what actually compels us to seek out food. Instead, it is hunger, with its stomach-growling sensations and gnawing pangs that propels us to the refrigerator – or the deli or the vending machine. Although hunger is essential for survival, abnormal hunger can lead to obesity and eating disorders, widespread problems now reaching near-epidemic proportions around the world.

Over the past 20 years, Beth Israel Deaconess Medical Center (BIDMC) neuroendocrinologist Bradford Lowell, MD, PhD, has been untangling the complicated jumble of neurocircuits in the brain that underlie hunger, working to create a wiring diagram to explain the origins of this intense motivational state. Key among his findings has been the discovery that Agouti-peptide (AgRP) expressing neurons – a group of nerve cells in the brain’s hypothalamus – are activated by caloric deficiency, and when either naturally or artificially stimulated in animal models, will cause mice to eat voraciously after conducting a relentless search for food.

Now, in a new study published on-line this week in the journal Nature, Lowell’s lab has made the surprising discovery that the hunger-inducing neurons that activate these AgRP neurons are located in the paraventricular nucleus -- a brain region long thought to cause satiety, or feelings of fullness. This unexpected finding not only provides a critical addition to the overall wiring diagram, but adds an important extension to our understanding of what drives appetite.

“Our goal is to understand how the brain controls hunger,” explains Lowell, an investigator in BIDMC’s Division of Endocrinology, Diabetes and Metabolism and Professor of Medicine at Harvard Medical School. “Abnormal hunger can lead to obesity and eating disorders, but in order to understand what might be wrong – and how to treat it – you first need to know how it works. Otherwise, it’s like trying to fix a car without knowing how the engine operates.”

Hunger is notoriously complicated and questions abound: Why do the fed and fasted states of your body increase or decrease hunger? And how do the brain’s reward pathways come into play – why, as we seek out food, especially after an otherwise complete meal, do we prefer ice cream to lettuce?

“Psychologists have explained how cues from the environment and from the body interact, demonstrating that food and stimuli linked with food [such as a McDonald’s sign] are rewarding and therefore promote hunger,” explains Lowell. “It’s clear that fasting increases the gain on how rewarding we find food to be, while a full stomach decreases this reward. But while this model has been extremely important in understanding the general features of the ‘hunger system,’ it’s told us nothing about what’s inside the ‘black box’ – the brain’s neural circuits that actually control hunger.”

To deal with this particularly complex brain region – a dense and daunting tangle of circuits resembling a wildly colorful Jackson Pollack painting – the Lowell team is taking a step-by-step approach to find out how the messages indicating whether the body is in a state of feeding or fasting enter this system. Their search has been aided by a number of extremely powerful technologies, including rabies circuit mapping and channelrhodopsin-assisted circuit mapping, which enable their highly specific, neuron-by-neuron analysis of the region.

“By making use of these new technologies, we are able to follow the synapses, follow the axons, and see how it all works,” says Lowell. “While this sounds like a relatively straightforward concept, it’s actually been a huge challenge for the neuroscience field.”

In this new paper, first authors Michael Krashes, PhD, and Bhavik Shah, PhD, postdoctoral fellows in the Lowell lab, employed rabies circuit mapping, a technology in which a modified version of the rabies virus is engineered to “infect” just one type of neuron – in this case, the AgRP neurons that drive hunger. The virus moves upstream one synapse and identifies all neurons that are providing input to AgRP starter neurons. Then, using a host of different neuron-specific cre-recombinase expressing mice (a group of genetically engineered animals originally developed in the Lowell lab) the investigators were able to map inputs to just these nerve cells, and then manipulate these upstream neurons so that they could be targeted for activation by an external stimulus.

“We wanted to know, of all the millions of neurons in a mouse brain, which provided input to the AgRP neurons,” explains Lowell. “And the shocking result was that there were only two sites in the brain that were involved – the dorsal medial hypothalamus and the paraventricular nucleus, with the input from the paraventricular neurons shown to be extremely strong.”

With this new information, the investigators now had a model to pursue. “We hypothesized that neurons in the paraventricular nucleus were communicating with and turning on the AgRP neurons. We developed mice that expressed cre-recombinase in many subsets of the paraventricular neurons and then, mapping the neurons one-by-one, we determined which was talking to which,” says Lowell. Their results revealed that subsets of neurons expressing thyrotropin-releasing hormone (TRH) and pituitary adenylate cylcase-activating polypeptide (PACAP) were in on the neuronal chatter.

Finally, through a chemogenetic technique known as DREADDs – Designer Receptor Exclusively Activated by Designer Drug – the authors used chemicals to specifically and selectively stimulate or inhibit these upstream neurons in the animal models. The fed mice, which had already consumed their daily meal and otherwise had no interest in food, proceeded to search out and voraciously eat after DREADD stimulation. Conversely, the fasting mice – which should have been hungry after a period of no food – ate very little when these upstream neurons were turned off.

Read more at Science Daily

Social or stinky? New study reveals how animal defenses evolve

When people see a skunk, the reaction usually is "Eww," but when they see a group of meerkats peering around, they often think "Aww."

Why some animals use noxious scents while others live in social groups to defend themselves against predators is the question that biologists Tim Caro of the University of California, Davis and Theodore Stankowich of California State University, Long Beach and sought to answer through a comprehensive analysis of predator-prey interactions among carnivorous mammals and birds of prey.

Their findings appear in the online edition of the journal Evolution.

"The idea is that we're trying to explain why certain antipredator traits evolved in some species but not others," said Stankowich, who noted that this study not only explains why skunks are stinky and why banded mongooses live in groups but also breaks new ground in the methodology of estimating predation risks.

Caro, Stankowich and Paul Haverkamp, a geographer who recently completed his Ph.D. at UC Davis, collected data on 181 species of carnivores, a group in which many species are small and under threat from other animals. They ran a comparison of every possible predator-prey combination, correcting for a variety of natural history factors, to create a potential risk value that estimates the strength of natural selection due to predation from birds and other mammals.

They found that noxious spraying was favored by animals that were nocturnal and mostly at risk from other animals, while sociality was favored by animals that were active during the day and potentially vulnerable to birds of prey.

"Spraying is a good close-range defense in case you get surprised by a predator, so at night when you can't detect things far away, you might be more likely to stumble upon a predator," Stankowich said.

Conversely, small carnivores like mongooses and meerkats usually are active during the day which puts them at risk from birds of prey. Living in a large social group means "more eyes on the sky" in daytime, when threats can be detected further away.

The social animals also use other defenses such as calling out a warning to other members of their group or even mobbing together to bite and scratch an intruder to drive it away.

Read more at Science Daily