Dec 21, 2011

Strange Heads Evolved Before Unusual Bodies

Evolution can be a heads or tails question, with scientists debating which parts of animals diversified first. It turns out that heads win, according to new research, with species evolving in their heads before other bodily changes become evident.

The findings suggest that food availability has been a primary driver of animal evolution, starting with the head and then on down.

"Species evolved to exploit new food sources before shifting into new habitats or evolving new ways to get around," said Lauren Cole Sallan, lead author of the study published in the latest Proceedings of the Royal Society B.

"Strange heads show up first -- crushing jaws, animals with big teeth, with long jaws -- but they're all pretty much attached to the same body," added Sallan, who is a graduate student in the Department of Organismal Biology and Anatomy at the University of Chicago.

She and co-author Matt Friedman of the University of Oxford set out to test models that attempt to explain how adaptive radiations occur within the animal kingdom. For example, after a major disruption, such as an extinction event, surviving species diversify into a myriad of forms.

One popular theory, the "early burst model," holds that there's a flurry of divergence followed by a long period of relative stability. Another argues that habitat-driven changes in body type precede diversification of head types.

To help resolve which is right, Sallan and Friedman analyzed two different adaptive radiations in the fossil record. The first was the explosion of ray-finned fishes after what's known as the Hangenberg extinction, an event 360 million years ago that decimated ocean life on Earth.

The second group was the acanthomorphs, a group of fish that diversified wildly around the time of the end-Cretaceous extinction that killed off non-avian dinosaurs.

For both groups, the researchers quantified differences in features like body depth, fin position, and jaw shape between species. They separated head features from body features in their study, to find out which changes actually occurred first and seemed to dominate.

Both sets of analyses found that diversification in head features came before diversification in body types. Earlier research on mammals, lungfish, birds and other animals suggests that these too followed the head-first pattern of evolution.

"An animal's first job is to obtain enough energy to live, however a main tenet of natural selection is that there isn't enough of any one food in a habitat to support everyone past a certain population size," explained Sallan. "So there are two choices to get ahead: eat other foods in the same place, or move away and hope to find a habitat with the same food. In many cases, changing to a new food is probably simpler."

More evidence is needed to see if humans also fit into the head-first model of evolution.

Read more at Discovery News

Star-Churning 'Blob' Lurks at Universe's Edge

What lurks at the very edge of the observable Universe? As it's so distant, and as the light from any primordial galaxies took so long to get here, by observing any object that far away is to also look back in time.

Now astronomers using the Japanese Subaru and Keck II telescopes -- observatories situated atop Mauna Kea, Hawaii -- have managed to look deep into the cosmic past revealing one of the most distant objects ever discovered. In fact, only two other objects have been spotted at a greater distance.

As it's so far away, this particular "blob" existed when the Universe was only a fraction of its current age -- when it was only 750 million years old, or 5 percent its current age. (Our Universe is precisely 13.75 billion years old, by the way.)

The blob in question appears to be a very young galaxy -- called GN-108036 -- with a surprisingly high star birth rate. It's birthing around 100 baby stars per year, 30 times the star production rate of our Milky Way.

"We're really surprised to know that GN-108036 is quite luminous in ultraviolet and harbors a powerful star formation," said astronomer Yoshiaki Ono of the University of Tokyo, Japan. "We had never seen such a vigorously star-forming galaxy at a comparable distance until the discovery of GN-108036."

The team's work is set to be published in The Astrophysical Journal.

Previous surveys didn't detect the galaxy because of its high star formation rate; it wasn't thought that (before the discovery of GN-108036) the earliest galaxies in the history of the Universe were so active.

"Perhaps those surveys were just too small to find galaxies like GN-108036," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "It may be a special, rare object that we just happened to catch during an extreme burst of star formation."

This young galaxy is interesting as it emerged soon after the "dark ages" of our Universe. This cosmic epoch would have been especially depressing as our entire Universe was choked with thick clouds of hydrogen. No light could traverse space without getting absorbed -- it was the epitome of a cosmos-wide pea soup fog.

Only when the earliest galaxies began to form, with throbbing black holes in their cores, was this opaque cosmic soup "burned away" by the ionizing radiation generated by quasars.

Read more at Discovery News

Earth On Extreme Tilt Away From Sun

The winter solstice is a vampire's delight. No other night is longer and no day shorter. But sorry blood-suckers, it also means the subsequent days get longer.

This year's winter solstice will occur at 12:30 a.m. Dec. 22. At that moment, the Sun will be directly overhead at 23.5 degrees south latitude, and the Earth's axial tilt will be as far from the Sun as possible.

When the celestial fireball finally makes its appearance in the northern hemisphere it keeps a low profile. On the winter solstice the sun follows the lowest path of the year in the sky of the northern hemisphere.

The Washington Post provided some details about the solstice sun over the United States' capital:

    The sun is above the horizon for approximately 9 hours, 26 minutes
    Sunrise occurs at 7:24 a.m. and sunset at 4:50 p.m.
    The sun angle at solar noon (12:07 p.m.) reaches its minimum height of 27.7º above the horizon (compared to 74.6º above the horizon on June 21)
    The sun rises at its southeasternmost point and sets at its southwesternmost point along the horizon (120º and 240º from due north, respectively)

For modern city-dwellers, the solstice is little more than a curiosity, but in ancient times it was of vital importance.

In the northern hemisphere, knowing when the dark days of winter would start to lengthen could give hope to people trying to make the harvest of the previous year stave off starvation for a few more months.

The day was so important, that some of humanity's earliest monumental structures were aligned with the rising or setting of the Sun on the winter solstice. Stonehenge in England, for example, is lined up with the winter solstice.

Festivals both ancient and modern marked the winter solstice.

The Romans celebrated Saturnalia around the time of the solstice with revelry and a social switcheroo in which masters served the slaves.

Read more at Discovery News

Planets May Have Survived Star's Death

Scientists have found a system of planets that appears to have survived being engulfed by their dying parent star.

The discovery raises questions about the ultimate fate of our solar system when the sun runs out of hydrogen gas in about 5 billion years and violently transform into an expanding red giant star.

Scientists believe all the planets from Earth inward will be destroyed when the sun expands, but new research suggests that if planets are large enough, they may outlast their parent star's death, even if they are engulfed.

Astronomers using NASA's Kepler telescope have found two planets orbiting very close to a star that is past the red-giant phase. The pair circle less than 1 percent of the distance that Earth orbits the sun.

From that position, the planets would have been deeply engulfed by the star when it expanded in its senior years. So how did they survive?

Lead researcher Stephane Charpinet, with the University of Toulouse in France, suggests the planets might not have started out where they are now and that they were most likely a lot bigger than Earth, with more material to weather the searing heat from their expanding star.

"The system was probably more like the many stellar systems that have been discovered so far, with giant planets orbiting relatively close to their parent star," Charpinet wrote in an email to Discovery News.

Another possibility is that the two planets found circling the evolved star aren't original members, points out astronomer Eliza Kempton, with the University of Southern California at Santa Cruz.

The planets could have formed anew from material that was left behind when the star blew off its outer layers after its red-giant phase, Kempton said.

"The expansion of the sun will surely kill off all life on Earth," she said. "However, the existence of planets orbiting an evolved star points to an interesting possibility that" all close-in planets are not entirely destroyed during stellar evolution."

Read more at Discovery News

Dec 20, 2011

Medieval Knights May Have Had PTSD

In movies, medieval knights are portrayed as courageous and loyal heroes who will fight to the death without fear or regret.

In reality, the lives of knights were filled with a litany of stresses much like those that modern soldiers deal with.

They were often sleep-deprived, exhausted and malnourished. They slept outside on hard ground, fully exposed to whatever weather befell them. And their lives were full of horror and carnage as they regularly killed other men and watched their friends die.

Faced with the trauma inherent in a life of combat, according to a new look at ancient texts, medieval knights sometimes struggled with despair, fear, powerlessness and delusions. Some may have even suffered from post-traumatic stress or related disorders, argues a Danish researcher, just as their modern-day counterparts do.

The research strives to add a dose of humanity to our understanding of knights, who are often considered cold and heartless killers.

"As a medievalist, it's a bit irritating to hear people say that the Middle Ages were just populated by brutal and mindless thugs who just wallowed in warfare," said Thomas Heebøll-Holm, a medieval historian at the University of Copenhagen. "I'm going for a nuanced picture of humans that lived in the past. They were people just like you and me, as far as we can tell."

Ever since the war in Vietnam, there has been a growing recognition that the terrors of battle, torture, terrorism and other horrific experiences can result in a type of severe psychological distress now known as PTSD. To be diagnosed with the disorder, people must suffer from uncontrollable and intense stress for at least a month after a horrifying event. Symptoms can include flashbacks, nightmares, depression and hyperactivity.

When soldiers go to war in modern times, Heebøll-Holm said, psychologists now recognize that the stresses they encounter can lower their psychological resistance until they finally succumb to anxiety disorders. Since medieval knights faced as many and possibly more hardships than modern soldiers do, he wondered if he might be able to find references to signs of trauma in warriors who fought during the Middle Ages.

In addition to other documents, Heebøll-Holm focused on three texts written by a 14th-century French knight named Geoffroi de Charny, who was also a diplomat and trusted adviser to King John II.

No one knows for sure why Charny wrote the documents, whose translated titles included "The Book of Chivalry" and "Questions Concerning the Joust, Tournaments and War." The most popular theory is that they were part of an effort to create an ideological program for the royal French chivalric order that would rival the British equivalent.

Though many of these texts have been thoroughly analyzed already, Heebøll-Holm was the first to look between the lines through the lens of modern military psychology. And while it's hard to ever completely understand a culture that was so very different (and far more religious) than our own, Heebøll-Holm found a number of examples that would suggest at least the potential for trauma in medieval knights.

Among his writings, for example, Charny wrote:

"In this profession one has to endure heat, hunger and hard work, to sleep little and often to keep watch. And to be exhausted and to sleep uncomfortably on the ground only to be abruptly awakened. And you will be powerless to change the situation. You will often be afraid when you see your enemies coming towards you with lowered lances to run you through and with drawn swords to cut you down. Bolts and arrows come at you and you do not know how best to protect yourself. You see people killing each other, fleeing, dying and being taken prisoner and you see the bodies of your dead friends lying before you. But your horse is not dead, and by its vigorous speed you can escape in dishonour. But if you stay, you will win eternal honour. Is he not a great martyr, who puts himself to such work?"

Read more at Discovery News

Mammals' Tusked Ancestor Roamed Tasmania

Scientists say rare fossils found in Tasmania's south-east prove that an ancient species of prehistoric animal did exist throughout Australia.

The dicynodont was an early ancestor of modern-day mammals and lived about 250 million years ago. Roughly the size of a cow, the plant-eating animal had two tusks and a horny beak.

Queensland Museum palaeontologist Andrew Rozefelds said they lived on every continent, including Antarctica. But until now, the only Australian specimen was found in Queensland almost 30 years ago. He said it is surprising more remains have not been found, given the animal's size.

"There must be more material out there to be found," he said. "Obviously we'd love to find more, because at the moment, [of] this entire group of animals called dicynodonts, there's only about four bones known from Australia. We've got better fossil records from Antarctica for these animals than we have for Australia."

He describes the dicynodont as a bizarre-looking creature.

"They're a strange-looking beast," he said. "They had tusks at the front of their skull, which makes you think maybe they were a carnivore but in fact they were a plant eater. They had slightly splayed legs, so their posture was quite different to say some of the modern mammals you see and they're very, very distantly related to modern mammals."

Bob and Penny Tyson discovered the bone fragments a few years ago when they were walking along the beach on the Tasman Peninsula. Mr Tyson had gone for a walk along the rocky foreshore when he found some rare amphibian skulls. He took a few photos of the fossils and then went back to the place where they were staying to get his wife.

She started looking closer to the waterline and found a fossilized tusk, right on the low tide mark, sitting in seaweed.

"It was sitting on top of the rock surface, so all the surrounding rock had been worn away," said Mrs Tyson. "It was just sitting there waiting to be knocked off."

University of Tasmania sedimentologist Dr Stuart Ball, who dated the fossils, said the remains are from the early Triassic period. They predate the dinosaurs by at least 30 million years. He said it is likely floods washed the animals' remains into billabongs, which is why only fragments have turned up.

Rozefelds said the latest find proves that not only did dicynodonts exist in Australia, but they may have survived here longer than anywhere else in the world. He said scientists from places like China have been contacting him about the Tasmanian find.

Read more at Discovery News

Kents Cavern: inside the cave of stone-age secrets

The entrance to the cave was narrow and no more than 5ft high. Only one person at a time could enter, head stooped, a flickering light held in one hand, pickaxe in the other. They were a group of 12 explorers on that summer’s day in 1825, including local coastguards, a man determined to discover an ancient Roman temple, and a young Roman Catholic priest with an interest in fossils.

Father John MacEnery had recently arrived from Limerick as private chaplain to the Cary family at nearby Torre Abbey. He was the last to enter this strange world of darkness – of vast chambers, narrow fissures and magical stalactites that formed crystalline chandeliers and pillars, glinting in the lantern light.

Breaking off from the rest of the party who were vainly trying to break through the calcified floor, Father MacEnery investigated areas of the cave where the ground had already been disturbed. Beneath the stalagmites, in reddish brown earth, the priest saw something gleam. His candle reflected off the enamel of fossil teeth. He wrote later: “As I laid my hand on these relics of distant races… I shrank back involuntarily… I am not ashamed to own that, in the presence of these remains, I felt more awe than joy.”

The priest continued his search in silence, keeping “my good fortune a secret, fearing that amidst the press and avidity of the party to possess some fossil memorial of the day, my discoveries would be damaged.”

If he had known what he had stumbled upon, he might have held his finds even closer. For the teeth and other remains found in the cave are rewriting human prehistory.

It is now known that this cave, called Kents Cavern, outside Torquay in Devon, had been home to prehistoric hominids and animals extinct for half a million years.

In November, Professor Chris Stringer of the Natural History Museum announced that a human jaw found in the cave in 1927 is 7,000 years older than was thought and, at 42,000 years, this makes it the oldest Homo sapiens in northwest Europe.

This is yet more evidence that modern humans must have lived side-by-side with Neanderthals, an extinct cousin species, for tens of thousands of years.

But back in the 1820s, science knew nothing of humanity’s origins – or of what Britain was like millennia ago. Between 1825 and 1829, Father MacEnery made more astonishing discoveries. He unearthed the bones of extinct and exotic creatures, among them elephants, rhinos, sabre-tooth tigers, cave lions, bears and hyenas, from beneath the stalagmite cave floor.

For the early 19th century, this was momentous. It was just four years since the professor of the new science of geology at Oxford, William Buckland, had discovered similar fauna in a cave in Yorkshire. Science – and society as a whole – were barely coming to grips with the idea that animals which now exist only in tropical countries could once have tramped over the Dales. Now it seemed they had also lived on the English Riviera.

But Father MacEnery found something even more astonishing. As he dug, he discovered, on a bed of dirty red colour, “the singular phenomenon of flint instruments intermingled with fossil bones!” They were the unmistakeable tools of Stone Age humans. “This,” he wrote – his intellectual shock palpable – “electrified me”.

The 19th century was a frenzy of the new. Rapid developments in transport, industry and technology were paralleled by radical new philosophies and a revolution in the understanding of the age and nature of the Earth. The belief that our planet was just 6,000 years old, according to calculations based on Biblical texts, was fatally undermined by the geologists who were revealing the great antiquity of our world.

Buckland’s early writings reflect contemporary beliefs that fossil bones of strange extinct animals were, literally, antediluvian – they were the remains of creatures that had either failed to make it on to Noah’s Ark, or had vanished before the Flood.

Indeed, Buckland’s report on his Yorkshire finds is entitled Reliquiae Diluvianae – “Relics of the Flood” - and his ideas are a fascinating combination of cutting-edge science and Biblical belief.

As the fossil and geological evidence accumulated, Buckland concluded that, over time, there had been several floods. The last would have been a tremendous universal inundation – the one detailed in Genesis – thought to have taken place no more than 5,000 years ago. As humans were present only during this last catastrophe, Buckland stated unequivocally that humans and antediluvian creatures discovered in Britain and Europe had not co-existed. These animals had been wiped out before the arrival of man.

That was why Father MacEnery was so enthused by his discovery. This was clear evidence that contradicted Buckland, a man of great influence, who had also visited the Torquay cave. Father MacEnery, bursting with his momentous discovery and his realisation that it implied the co-existence of man and extinct beasts, “immediately communicated my impressions to Dr Buckland with all the earnestness of sincere conviction”.

Alas for the Irishman, Buckland would have none of it. He insisted that the flints had been introduced by later human inhabitants of the caves – by men digging to bury their dead, or digging through the stalagmite floor to make pits for ovens. Indeed, Buckland had found a flint blade there before MacEnery had, but does not appear to have told him.

Despite this, MacEnery had planned to publish his finds with the title Cavern Researches; he even printed a prospectus for it and had plates made by the famous natural history illustrator Georg Scharf.

His manuscript consists of disjointed narrative and essays, and copious notes – some made at the time, but many over the next decade – in which he tries, and fails, to reconcile the truth of what he had observed with Buckland’s views. At times he berates himself for falling into “the error of supposing human remains to be contemporaneous”, and then decides he is right and Buckland wrong, although “it is painful to dissent from so high an authority”.

Read more at The Telegraph

The Turin Shroud is fake. Get over it

First things first. The "authenticity" or otherwise of the Shroud of Turin does not have any implications for whether or not Christ was real, or whether He was divine. If it was a medieval forgery, it doesn't mean the stories aren't true; if it really was made in the first century AD, it doesn't mean they were. Until we find a reliable method of linking the shroud with Christ Himself – a nametag stitched in it by His mum, perhaps – the existence of a 2,000-year-old cloth does not imply that a particular person who died around the time it was made was the Son of God.

I mention this because today, we report that a group of scientists – working, unexpectedly, for the Italian sustainable energy agency ENEA – claim that the marks on the cloth could only have been made by ultraviolet radiation. They say that "When one talks about a flash of light being able to colour a piece of linen in the same way as the shroud, discussion inevitably touches on things like miracles and resurrection," and that they "hope our results can open up a philosophical and theological debate". They do, however, say "as scientists, we were concerned only with verifiable scientific processes."

The implication, of course, is that a divine light shone when Jesus's body was resurrected, and that this emitted a burst of high-frequency photons which burned an image on the cloth around him. This possibility has been discounted in the past by Raymond Rogers, a member of the Shroud of Turin Research Project (Sturp) which examined the fabric in the 1970s, who said: "If any form of radiation degraded the cellulose of the linen fibers to produce the image color, it would have had to penetrate the entire diameter of a fiber in order to color its back surface", but that the centres of the fibres are unmarked. There are many hypotheses about how the images could have been made, and they have each come in and out of favour. Without wanting to be too cocky, when the ENEA scientists say that radiation is the "only" way the image could have been made, I imagine that many of their fellow researchers will say it's the only way that they managed it.

However it was made, if – as many have claimed – the Shroud was made in the 13th century, then it isn't a relic of Christ, for obvious reasons. Radiocarbon dating has repeatedly placed the Shroud as medieval in origin – specifically, between 1260AD and 1390AD. There have been suggestions that the radiocarbon process got it wrong – but this is unlikely, according to Professor Christopher Ramsey of the Oxford Radiocarbon Accelerator Unit, one of three labs which carried out the research. "We're pretty confident in the radiocarbon dates," he told me. "There are various hypotheses as to why the dates might not be correct, but none of them stack up.

"One is that the samples were contaminated. But that doesn't work, because to make an 2,000-year-old object appear just 800 years old, about half the material would have to be contaminant, and that's if it was all modern. If it was older, it would have to be even more. Various tests done at the time of the original measurements also suggested that the material was fairly pure. It's also been hypothesised that the patch we tested was a modern repair, but most of us agree that's implausible, because the weave is very unusual and matches the rest of the shroud perfectly. Then there are more complicated notions, like contamination with carbon monoxide, but tests have shown that carbon monoxide doesn't react with the fabric under the circumstances that you might expect."

Regarding the ENEA findings, he is similarly sceptical. "Just because you can create similar results using an ultraviolet laser, that doesn't mean it's the only way it could have been made in the first place," he says. "There are several possibilities, and it could just be a chance effect due to a number of different phenomena. But in archaeological science, being able to reproduce something, doesn't imply that that's the technique used; it may simply show that you've got a new technique you want to try out." He adds that the confidence in the medieval result is such that, were it not suggested to be a relic, there would be no more discussion over its age.

So there remain questions about how the Shroud of Turin was made, but there seems to be little reason to think that it's anywhere near old enough to have been Christ's. (Interestingly, John Calvin in 1543 already thought it was a fake: he pointed out that according to the Gospel of St John, two cloths were used to shroud Jesus, one on His body and one on His face; he also suggests that it is strange that none of those recording his death in the Gospels mentioned a miracle "so remarkable as the likeness of the body of our Lord remaining on its wrapping sheet".) It's a fascinating and mysterious object, but it says nothing about the questions of whether Christ was a historical figure, whether He was the Son of God, or whether He rose from the dead.

More importantly, I think, the rush to suggest that it does is a bit undignified. The intelligent faithful don't need trinkets like this to justify their belief, surely? We are constantly told that science cannot disprove God; that it is a non-scientific question, that the two fields of science and religion are non-overlapping. But then, when something which goes the other way occurs – something which might suggest that one or other given Bible story is true – suddenly all that goes out of the window. The Turin Shroud is (almost certainly) fake. It makes no difference to anything. Get over it.

From The Telegraph

Dec 19, 2011

Babies Remember Even as They Seem to Forget

Fifteen years ago, textbooks on human development stated that babies of six months of age or younger had no sense of "object permanence" -- the psychological term that describes an infant's belief that an object still exists even when it is out of sight. That meant that if mom or dad wasn't in the same room with junior, junior didn't have the sense that his parents were still in the world.

These days, psychologists know that isn't true: for young babies, out of sight doesn't automatically mean out of mind. But how much do babies remember about the world around them, and what details do their brains need to absorb in order to help them keep track of those things?

A new study led by a Johns Hopkins psychologist and child development expert has added a few pieces to this puzzle. Published in a recent issue of the journal Psychological Science, the study reveals that even though very young babies can't remember the details of an object that they were shown and which then was hidden, the infants' brains have a set of built in "pointers" that help them retain a notion that something they saw remains in existence even when they can't see it anymore.

"This study addresses one of the classic problems in the study of infant development: what information do infants need to remember about an object in order to remember that it still exists once it is out of their view?" said Melissa Kibbe, a post-doctoral researcher in the Department of Psychological and Brain Sciences at the Krieger School of Arts and Sciences at Johns Hopkins, who collaborated with colleague Alan Leslie at Rutgers University on the study. "The answer is, very little."

The team found that even though infants cannot remember the shapes of two hidden objects, they are surprised when those objects disappear completely. The conclusion? Infants do, indeed, remember an object's existence without remembering what that object is.

This is important, Kibbe explains, because it sheds light on the brain mechanisms that support memory in infancy and beyond.

"Our results seem to indicate that the brain has a set of 'pointers' that it uses to pick out the things in the world that we need to keep track of," explains Kibbe, who did the majority of the work on this study while pursuing her doctorate in Leslie's laboratory at Rutgers. "The pointer itself doesn't give us any information about what it is pointing to, but it does tell us something is there. Infants use this sense to keep track of objects without having to remember what those objects are."

In addition, the study may help researchers establish a more accurate timeline of the mental milestones of infancy and childhood.

In the study, six-month-olds watched as a triangle was placed behind a screen and then as a second object (a disk) was placed behind a second screen. Researchers then removed the first screen to reveal either the expected original triangle, the unexpected disk, or nothing at all, as if the triangle had vanished completely.

The team then observed the infants' reactions, measuring how long they looked at expected versus unexpected outcomes.

In the situation where the objects were swapped, the babies seemed to hardly notice a difference, Kibbe said, indicating that they didn't retain a memory of that object's shape. In their minds, a triangle and a disk were virtually interchangeable.

Read more at Science Daily

Sensational Bird Discovery in China

In June 2011, a team of Chinese and Swedish researchers rediscovered the breeding area for the poorly known Blackthroat Luscinia obscura, in the Qinling mountains, Shaanxi province, north central China.

Seven singing males were observed in Foping and seven more in Changqing National Nature Reserves -- which almost equals the total number of individuals observed of this species since its discovery in the late 19th century. Nearly all of the birds were on mountain slopes at 2400-2500 meters above sea level in large, dense expanses of bamboo in open coniferous and mixed coniferous-broadleaved forest.

In the late 19th and early 20th centuries, about 10 Blackthroats were collected at two localities in the Gansu and Shaanxi provinces during the breeding season (May-August). Since then, there have been only a handful of mostly unconfirmed records from Sichuan and Yunnan provinces, China, from presumed breeding areas or on migration, including a few individuals found in bird markets. The most recent record is of a bird that was photographed on migration in the campus of the Sichuan University on 2 May 2011. In addition, one individual has been caught in Thailand in winter.

The Blackthroat resembles a European Robin Erithacus rubecula in size and general appearance, but with a jet black throat and breast in the male. The female is considered to have a pale brownish throat and breast, although no females definitely attributable to this species have been observed.

Read more at Science Daily

Plant-Eating Dinosaur Discovered in Antarctica

For the first time, the presence of large bodied herbivorous dinosaurs in Antarctica has been recorded. Until now, remains of sauropoda -- one of the most diverse and geographically widespread species of herbivorous dinosaurs -- had been recovered from all continental landmasses, except Antarctica. Dr. Ignacio Alejandro Cerda, from CONICET in Argentina, and his team's identification of the remains of the sauropod dinosaur suggests that advanced titanosaurs (plant-eating, sauropod dinosaurs) achieved a global distribution at least by the Late Cretaceous.

Their work has just been published online in Springer's journal Naturwissenschaften - The Science of Nature.

Sauropoda is the second most diverse group of dinosaurs, with more than 150 recognized species. It includes the largest terrestrial vertebrates that ever existed. Although many sauropod remains have been discovered in North and South America, Africa, Asia, Australia and Europe, there is no previous record of sauropoda in Antarctica. Other important dinosaur discoveries have been made in Antarctica in the last two decades -- principally in the James Ross Basin.Dr. Cerda and colleagues report the first finding of a sauropod dinosaur from this continent and provide a detailed description of an incomplete middle-tail vertebra, recovered from James Ross Island. The specific size and morphology of the specimen, including its distinctive ball and socket articulations, lead the authors to identify it as an advanced titanosaur.

These titanosaurs originated during the Early Cretaceous and were the predominant group of sauropod dinosaurs until the extinction of all non-bird dinosaurs at the end of the Cretaceous. Although they were one of the most widespread and successful species of sauropod dinosaurs, their origin and dispersion are not completely understood.

Read more at Science Daily

Geologists Find Source of Stonehenge’s Inner Stones

A team of geologists from Britain have pinpointed the exact quarry that Stonehenge’s innermost circle of rocks came from. It’s the first time that a precise source has been found for any of the stones at the prehistoric monument.

Robert Ixer of the University of Leicester and Richard Bevins of the National Museum of Wales painstakingly identified samples from various rock outcrops in Pembrokeshire, Wales.

For nine months the pair used petrography — the study of mineral content and textural relationships within rocks — to find the origins of Stonehenge’s rhyolite debitage stones. These spotted dolerites or bluestones form the inner circle and inner horseshoe of the site.

They found the culprit on a 65-metre-long outcropping called Craig Rhos-y-Felin, near Pont Saeson in north Pembrokeshire. It lies approximately 160 miles from the Stonehenge site.

The question remains though, as to how neolithic people transported huge chunks of rock from Wales to Wiltshire, some 5,000 years ago. Some historians reckon that these stone age builders quarried the stones in Pembrokeshire and brought them over to England, while others argue that giant glacial shifts moved the stones, hundreds of thousands of years earlier.

Ixer and Bevins hope that by finding the exact source for some of the monument’s stones, they will be able to discover new clues as to when and how they made their 160 mile journey.

Read more at Discovery News

Dec 18, 2011

Scientists May Be Able to Double Efficacy of Radiation Therapy

Scientists may have a way to double the efficacy and reduce the side effects of radiation therapy.

Georgia Health Sciences University scientists have devised a way to reduce lung cancer cells' ability to repair the lethal double-strand DNA breaks caused by radiation therapy.

"Radiation is a great therapy -- the problem is the side effects," said Dr. William S. Dynan, biochemist and Associate Director of Research and Chief, Nanomedicine and Gene Regulation at the GHSU Institute of Molecular Medicine and Genetics. "We think this is a way to get the same amount of cancer cell death with less radiation or use the same amount and maybe cure a patient that could not be cured before."

Radiation therapy capitalizes on radiation's ability to kill cells by causing double-strand breaks in DNA. But the fact that varying levels of radiation are essentially everywhere -- food, air, the ground, etc. -- means all cells, including cancer cells, have internal mechanisms to prevent the lethal breakage.

GHSU scientists are targeting the natural defense mechanisms by packaging a piece of an antibody against one of them with folate, which has easy access to most cells, particularly cancer cells. Many cancers, including the lung cancer cells they studied, have large numbers of folate receptors so that cancer cells get a disproportionate share of the package.

Previous efforts to destroy cancer cells' ability to avoid radiation damage have focused on receptors on their surface, said Dr. Shuyi Li, molecular biologist, pediatrician and corresponding author on the study in the International Journal of Radiation Oncology.

To get a more direct hit, the scientists took advantage of folate receptors as a point of entry by chemically binding folate with the small piece of their antibody, ScFv 18-2. The package heads straight for the cell nucleus where a different chemical environment breaks the bond, freeing ScFv 18-2 to attack the regulatory region of DNA-dependent protein kinase, an enzyme essential to DNA repair.

"We are joining a targeting molecule with a cargo," said Dynan. "This strategy targets one of the key enzymes so it's harder to repair," Li said. This makes cancer cells more vulnerable to radiation.

Dynan and Li say the approach could be used to deliver any number of drugs directly inside cancer cells. Future studies include looking at other cell entry points as well as other targets to ensure they have the most effective package. Studies to date have been in human lung cancer cells in culture, so next steps also need to include animal studies.

Their approach mimics a natural process called endocytosis in which cells engulf proteins and other substances they want to let inside but can't fit through normal doorways.

Read more at Science Daily

Neanderthals built homes with mammoth bones

Archaeologists have discovered the remains of a 44,000 year old Neanderthal building that was constructed using the bones from mammoths.

The circular building, which was up to 26 feet across at its widest point, is believed to be earliest example of domestic dwelling built from bone.

Neanderthals, which died out around 30,000 years ago, were initially thought to have been relatively primitive nomads that lived in natural caves for shelter.

The new findings, however, suggest these ancient human ancestors had settled in areas to the degree that they built structures where they lived for extended periods of time.

Analysis by researchers from the Muséum National d'Histories Naturelle in Paris also found that many of the bones had been decorated with carvings and ochre pigments.

Laëtitia Demay, an archaeologist who led the research, said: "It appears that Neanderthals were the oldest known humans who used mammoth bones to build a dwelling structure.

"This mammoth bone structure could be described as the basement of a wooden cover or as a windscreen.

"Neanderthals purposely chose large bones of the largest available mammal, the woolly mammoth, to build a structure.

"The mammoth bones have been deliberately selected – long and flat bones, tusks and connected vertebrae – and were circularly arranged.

"The use of bones as building elements can be appreciated as anticipation of climatic variations. Under a cold climate in an open environment, the lack of wood led humans to use bones to build protections against the wind."

The bone structure was found near the town of Molodova in eastern Ukraine on a site that was first discovered in 1984. It was constructed of 116 large bones including mammoth skulls, jaws, 14 tusks and leg bones.

Inside at least 25 hearths filled with ash were also discovered, suggesting it had been used for some time.

The researchers believe that the Neanderthals both hunted and killed the mammoths for meat before using their bones but also collected some of the bones from animals that had died of natural causes.

The findings, which are to be published in the scientific journal Quaternary International add to the growing view that Neanderthals were in fact quite advanced humans who had their own culture and may have even used language to communicate.

The oldest known remains of a building ever discovered, however, are more than 500,000 years old, built by the ancient human ancestor Homo erectus on a hillside outside Tokyo using wooden posts sunk into the ground.

Simon Underdown, a senior lecturer in biological anthropology who researches Neanderthals at Oxford Brookes University, said: "It's another piece in the newly emerging Neanderthal jigsaw puzzle.

"Far from being the stupid cavemen of popular image it's becoming increasingly clear the Neanderthals were a highly sophisticated species of human.

Read more at The Telegraph