May 26, 2012

Structure of Human Protein Critical for Silencing Genes Solved

In a study published in the journal Cell on May 24, Cold Spring Harbor Laboratory (CSHL) scientists describe the three-dimensional atomic structure of a human protein bound to a piece of RNA that "guides" the protein's ability to silence genes. The protein, Argonaute-2, is a key player in RNA interference (RNAi), a powerful cellular phenomenon that has important roles in diverse biological processes, including an organism's development.

"Detailed knowledge of the structure of human Argonaute-2 and the way it interacts with its RNA guides will greatly improve our understanding of its biological mechanism of action," says CSHL Professor and HHMI Investigator Leemor Joshua-Tor, Ph.D., the study's leader. "Such precise structural information of the human Argonaute bound to an important RNA guide could potentially aid both basic research to understand the function of genes and also advance the development of RNAi as a therapeutic strategy in clinical settings."

Upon the activation of a gene within a cell, the gene's DNA is copied into a messenger RNA (mRNA) "transcript." The instructions encoded within this transcript are then used as a blueprint by the cell's protein synthesis machinery to generate a working protein. The gene is "silenced" or prevented from giving rise to the protein, however, when an Argonaute-2 protein that is bound to a small piece of "guide" RNA -- either a short-interfering RNA or a microRNA -- intercepts the mRNA molecule. The guide RNA, whose nucleotide sequence matches that of the target mRNA, acts as a homing device that helps the Argonaute-2 protein zero in on the mRNA target.

A few years ago, Joshua-Tor collaborated with CSHL Professor and HHMI Investigator Gregory Hannon, Ph.D., who is also a co-author in this study, to show that Argonaute proteins, which are made up of different domains or parts, act like a pair of molecular scissors that slice up target mRNAs, thus preventing proteins from being made and enforcing the silencing of their genes. The discovery of the Argonautes' "slicer" activity stemmed in part from solving the crystal structure of an Argonaute protein from Pyrococcus furiosus, an archebacterium that thrives in extremely high temperatures.

"But we still know nothing about the biological functions or mechanisms of action of archebacterial Argonautes," says Joshua-Tor. "We therefore next focused on solving the structures of Argonautes from higher organisms such as mammals, in which Argonaute functions and target recognition are well documented."

Joshua-Tor's team and other research groups subsequently determined the atomic structures of individual parts of Argonaute proteins from higher organisms. While these studies revealed several important details -- for example, the interaction between two parts of the Argonaute protein, called the PAZ and Mid domains, with the two ends of guide RNAs -- Joshua-Tor's goal was to solve the structure of the entire human Argonaute protein in complex with a single human guide RNA.

Overcoming a complicated series of technical challenges, her team has achieved this goal by analyzing the structure of a full-length human Argonaute-2 protein bound to a small RNA called miR-20a, which is known to play a role in cancer development. Although Argonautes from higher organisms diverged from their archebacterial cousins more than three billion years ago, the team's analysis shows remarkable similarity between the two structures, especially in the regions that are important for target recognition and slicing activity.

"Our structure shows that the guide RNA, which is anchored at both ends by the PAZ and Mid domains, kinks and twists its way through the structure of the entire protein, making several points of contact within each domain and with the linker loops that join them," explains Joshua-Tor. "The guide RNA thus acts like a backbone that rigidly locks together the otherwise flexible Argonaute protein and gives it stability."

Read more at Science Daily

Bigfoot: Beyond Footprints and DNA

Last week researchers from Oxford University and the Lausanne Museum of Zoology announced that they are seeking genetic materials (such as hair, skin, and blood samples) claimed to be of unknown animals such as Bigfoot. The goal of the Oxford-Lausanne Collateral Hominid Project is to catalogue and identify new species, including those long believed to be mythical.

Despite the publicity that the new project is garnering, this is far from the first time that alleged Bigfoot samples have been subjected to scientific testing.

In 2008, for example, the TV show "Destination Truth" recovered what was claimed to be a hair of a Yeti (formerly known as the Abominable Snowman). An analysis reportedly came back indicating that the sample contained "an unknown DNA sequence," though the full report was not made public and the results were never published in a journal -- as would be expected with a legitimate scientific discovery.

Then there was the strange case of a finger long claimed to be from a Yeti, once held in a monastery in Nepal which was examined by researchers at the Edinburgh Zoo last year. DNA testing solved the decades-old mystery and debunked the Yeti finger; it was actually human, probably from a monk.

For over a year Bigfoot buffs have followed the saga of Dr. Melba Ketchum, a veterinarian who claims to have definitive evidence of Bigfoot DNA. Ketchum says that her research will be published in a peer-reviewed scientific journal any time now, and has released virtually no information about her allegedly world-shaking findings, reminding those who question her that "until it is published, I cannot discuss our data at all."

Last week in a May 18 Facebook post, Ketchum once again promised that definitive Bigfoot DNA results would be published soon, and "that all is well and things are happening as expected."

'Unknown' and 'Unidentified'

The most compelling evidence for Bigfoot would be DNA analyses, since they are scientific and theoretically definitive. However answers are not always possible; "unknown" or "unidentified" results do not mean "Bigfoot."

There are many reasons why a given hair or DNA sample might come back unknown, including that it was contaminated or too degraded by environmental conditions. Or it could simply mean that the animal it came from was not among the reference samples that the laboratory used for comparison. We have no reference sample of Bigfoot DNA to compare it to, so by definition there cannot be a "conclusive match."

In his book Big Footprints (Johnson Books, 1992), veteran researcher Grover Krantz discussed alleged Bigfoot hair, feces, skin scrapings, and blood: "The usual fate of these items is that they either receive no scientific study, or else the documentation of that study is either lost or unobtainable. In most cases where competent analyses have been made, the material turned out to be bogus or else no determination could be made."

Indeed, twenty years later, the situation remains the same. When a definite conclusion has been reached through scientific analysis, the samples have invariably turned out to have prosaic sources -- "Bigfoot hair" turns out to be elk, bear, or cow hair, for example, or "Bigfoot blood" is revealed to be a car's transmission fluid.

Krantz gave one typical example: "A large amount of what looks like hair has been recovered from several places in the Blue Mountains since 1987. Samples of this were examined by many supposed experts ranging from the FBI to barbers. Most of these called it human, the Redkin Company found significant differences from human hair, but the Japan Hair Medical Science Lab declared it a synthetic fiber.

A scientist at [Washington State] University first called it synthetic, then looked more closely and decided it was real hair of an unknown type... However final confirmation came when E.B. Winn, a pharmaceutical businessman from Switzerland had a sample tested in Europe. The fiber was positively identified as artificial and its exact composition was determined: it is a product known commercially as Dynel, which is often used as imitation hair."

Read more at Discovery News

May 25, 2012

Like Curry? New Biological Role Identified for Compound Used in Ancient Medicine

Oregon State University scientists just identified a new reason why some curry dishes, made with spices humans have used for thousands of years, might be good for you.

New research has discovered that curcumin, a compound found in the cooking spice turmeric, can cause a modest but measurable increase in levels of a protein that's known to be important in the "innate" immune system, helping to prevent infection in humans and other animals.

This cathelicidin antimicrobial peptide, or CAMP, is part of what helps our immune system fight off various bacteria, viruses or fungi even though they hadn't been encountered before. Prior to this, it was known that CAMP levels were increased by vitamin D.

Discovery of an alternative mechanism to influence or raise CAMP levels is of scientific interest and could open new research avenues in nutrition and pharmacology, scientists said.

Turmeric is a flavorful, orange-yellow spice and an important ingredient in many curries, commonly found in Indian, South Asian and Middle Eastern cuisine. It has also been used for 2,500 years as a medicinal compound in the Ayurvedic system of medicine in India -- not to mention being part of some religious and wedding ceremonies. In India, turmeric is treated with reverence.

The newest findings were made by researchers in the Linus Pauling Institute at OSU and published in the Journal of Nutritional Biochemistry, in collaboration with scientists from the University of Copenhagen in Denmark. The work was supported by the National Institutes of Health.

"This research points to a new avenue for regulating CAMP gene expression," said Adrian Gombart, an associate professor of biochemistry and biophysics in the Linus Pauling Institute. "It's interesting and somewhat surprising that curcumin can do that, and could provide another tool to develop medical therapies."

The impact of curcumin in this role is not nearly as potent as that of vitamin D, Gombart said, but could nonetheless have physiologic value. Curcumin has also been studied for its anti-inflammatory and antioxidant properties.

"Curcumin, as part of turmeric, is generally consumed in the diet at fairly low levels," Gombart said. "However, it's possible that sustained consumption over time may be healthy and help protect against infection, especially in the stomach and intestinal tract."

In this study, Chunxiao Guo, a graduate student, and Gombart looked at the potential of both curcumin and omega-3 fatty acids to increase expression of the CAMP gene. They found no particular value with the omega-3 fatty acids for this purpose, but curcumin did have a clear effect. It caused levels of CAMP to almost triple.

There has been intense scientific interest in the vitamin D receptor in recent years because of potential therapeutic benefits in treating infection, cancer, psoriasis and other diseases, the researchers noted in their report. An alternative way to elicit a related biological response could be significant and merits additional research, they said.

Read more at Science Daily

Oldest Jewish Archaeological Evidence On the Iberian Peninsula

Archaeologists of the Friedrich Schiller University Jena (Germany) found some of the oldest archaeological evidence so far of Jewish culture on the Iberian Peninsula at an excavation site in the south of Portugal, close to the city of Silves (Algarve). On a marble plate, measuring 40 by 60 centimetres, the name "Yehiel" can be read, followed by further letters which have not yet been deciphered. The Jena Archaeologists believe that the new discovery might be a tomb slab. Antlers, which were found very close to the tomb slab in the rubble gave a clue to the age determination.

"The organic material of the antlers could be dated by radiocarbon analysis with certainty to about 390 AD," excavation leader Dr. Dennis Graen of the Jena University explains. "Therefore we have a so-called 'terminus ante quem' for the inscription, as it must have been created before it got mixed in with the rubble with the antlers."

The earliest archaeological evidence of Jewish inhabitants in the region of modern-day Portugal has so far also been a tomb slab with a Latin inscription and an image of a menorah -- a seven-armed chandelier -- from 482 AD. The earliest Hebrew inscriptions known until now date from the 6th or 7th Century AD.

For three years the team of the University Jena has been excavating a Roman villa in Portugal, discovered some years ago by Jorge Correia, archaeologist of the Silves council, during an archaeological survey near the village of São Bartolomeu de Messines (Silves). The project was aiming at finding out how and what the inhabitants of the hinterland of the Roman province of Lusitania lived off. While the Portuguese coast region has been explored very well, there is very little knowledge about those regions. The new discovery poses further conundrums. "We were actually hoping for a Latin inscription when we turned round the excavated tomb slab," Henning Wabersich, a member of the excavation reports. After all, no inscriptions have been found so far and nothing was known about the identity of the inhabitants of the enclosure.

Only after long research the Jena Archaeologists found out which language they were exactly dealing with, as the inscription was not cut with particular care. "While we were looking for experts who could help with deciphering the inscription between Jena and Jerusalem, the crucial clue came from Spain" Dennis Graen says. "Jordi Casanovas Miró from the Museu Nacional d'Art de Catalunya in Barcelona -- a well-known expert for Hebrew inscriptions on the Iberian Peninsula -- is sure that the Jewish name "Yehiel" can be read, -- a name that is already mentioned in the Bible." Not only is the early date exceptional in this case, but also the place of the discovery: Never before have Jewish discoveries been made in a Roman villa, the Jena Archaelogist explains.

In the Roman Empire at that time Jews usually wrote in Latin, as they feared oppressive measures. Hebrew, as on the re-discovered marble plate, only came back into use after the decline of the Roman supremacy, respectively in the following time of migration of peoples from the 6th or 7th century AD. "We were also most surprised that we found traces of Romans -- romanised Lusitanians in this case -- and Jews living together in a rural area of all things," Dennis Graen says. "We assumed that something like this would have been much more likely in a city."

Information about the Jewish population in the region in general was mostly passed down by scriptures. "During the ecclesiastical council in the Spanish town Elvira about 300 AD rules of conduct between Jews and Christians were issued. This indicates that at this time there must have been a relatively large number of Jews on the Iberian Peninsula already," Dennis Graen explains -- but archaeological evidence had been missing so far. "We knew that there was a Jewish community in the Middle Ages not far from our excavation site in the town of Silves. It existed until the expulsion of the Jews in the year 1497."

Read more at Science Daily

Thousands of Invisibility Cloaks Trap a Rainbow

Many people anticipating the creation of an invisibility cloak might be surprised to learn that a group of American researchers has created 25,000 individual cloaks.

But before you rush to buy one from your local shop, the cloaks are just 30 micrometres in diameter and are laid out together on a 25 millimetre gold sheet.

This array of invisibility cloaks is the first of its kind and has been created by researchers from Towson University and University of Maryland who present their study on May 25, in the Institute of Physics and German Physical Society's New Journal of Physics.

Although the well-reported intention to make everyday objects disappear with a Harry Potter-style cloak is beyond this array of cloaks, they could be used to slow down, or even stop, light, creating what is known as a "trapped rainbow."

The trapped rainbow could be utilised in tiny biosensors to identify biological materials based on the amount of light they absorb and then subsequently emit, which is known as fluorescence spectroscopy. Slowed-down light has a stronger interaction with molecules than light travelling at normal speeds, so it enables a more detailed analysis.

Lead author of the study, Dr Vera Smolyaninova, said: "The benefit of a biochip array is that you have a large number of small sensors, meaning you can perform many tests at once. For example, you could test for multiple genetic conditions in a person's DNA in just one go.

"In our array, light is stopped at the boundary of each of the cloaks, meaning we observe the trapped rainbow at the edge of each cloak. This means we could do 'spectroscopy on-a-chip' and examine fluorescence at thousands of points all in one go."

The 25 000 invisibility cloaks are uniformly laid out on a gold sheet, with each having a microlens that bends light around itself, effectively hiding an area in its middle. As the light squeezes through the gaps between each of the cloaks, the different components of light, or colours, are made to stop at ever narrower points, creating the rainbow.

To construct the array of invisibility cloaks, a commercially available microlens array, containing all of the individual microlenses, was coated with a gold film. This was then placed, gold-side down, onto a glass slide which had also been coated with gold, creating a double layer. A laser beam was directed into the array to test performance of the cloaks at different angles.

Read more at Science Daily

Rare Sumatran Rabbit Photographed

Using camera traps, wildlife researchers including doctoral candidate Jennifer McCarthy and environmental conservation professor Todd Fuller of the University of Massachusetts Amherst recently captured photographs of one of the rarest animals on earth, the Sumatran striped rabbit. They say it may now be found only in two remote national parks on the Indonesian island.

Their pictures and other observations are reported in the current issue of Oryx, The International Journal of Conservation. The rare rabbit was first photographed in Kerinci Seblat National Park in 1998 and has rarely been seen since.

"Whether the rabbit does occur undetected in other parks is not certain, but the importance of protecting these two known strongholds of the species is critical," say McCarthy and colleagues. "As the human population of Sumatra rises, both parks are increasingly threatened by encroachment of villages and development of roads and infrastructure. It is important to focus conservation efforts in these areas to prevent a loss of what could be the final two populations of Sumatran striped rabbits."

Sumatra's Bukit Barisan Mountains, where the rabbits were captured on film, form the rugged backbone of the sixth largest island in the world. Since 2008, McCarthy and Fuller have been conducting an ecological study of the clouded leopard, Asiatic golden cat, marbled cat and leopard cats in Indonesia's Bukit Barisan Seletan National Park.

McCarthy says, "As part of my dissertation research on the four felids, or cats, we also happened to get pictures of this very rare rabbit. There had been a few camera-trap photos seen of it before, but very, very rarely. We wanted to take these observations a step further, so we worked with colleagues from the University of Delaware and the Wildlife Conservation Society's Indonesia Program to contact every researcher we knew throughout Sumatra who was doing camera-trap research, probably 20 or 30 people. This gave us good coverage of the island."

"We asked them about sightings of the Sumatran striped rabbit and report the results in our paper." Overall, the conservation biologist adds, "The biggest news is that we only received recent sighting information from these two parks. For the first time, we can pinpoint that these two areas may be the only ones remaining where this species occurs. We can't say they don't occur elsewhere, but we are saying it's important to preserve those areas in order to save the species."

Habitats critical to many forms of wildlife in the parks face constant pressure from nearby coffee and palm oil plantations and from those who want logging roads built, she adds. Roads would not only destroy habitat but would allow humans, including poachers, access into relatively wild and remote places. In Sumatra between 2000 and 2009, more than 7.6 million acres (3.1 million hectares) of forest were lost to such encroachment, McCarthy says.

Much of her work was done at fairly high altitudes, in dense rainforest and rugged terrain, along volcanic ridges up to 3,900 feet (1,200 meters) high, where human encroachment is low, McCarthy says. The area has a relatively high density of wildlife, including tigers, so the investigators never travel alone and always have a park ranger with them. After walking miles to visit their cameras and snares, they roll out their sleeping bags in local villages as guests of families with no electricity, running water or modern plumbing.

McCarthy says, "It's such a beautiful place. I hope we are able to increase conservation initiatives. At this point we really need to increase the involvement of local people in order to save these areas. There is some appreciation of the value of wildlife, especially for the tiger. But the root of the problem, the loss of habitat, hasn't really slowed down. We feel our presence and the fact that our research supports a park ranger has helped to make a difference."

Read more at Science Daily

May 24, 2012

Exotic Particles, Chilled and Trapped, Form Giant Matter Wave

Physicists have trapped and cooled exotic particles called excitons so effectively that they condensed and cohered to form a giant matter wave.

This feat will allow scientists to better study the physical properties of excitons, which exist only fleetingly yet offer promising applications as diverse as efficient harvesting of solar energy and ultrafast computing.

"The realization of the exciton condensate in a trap opens the opportunity to study this interesting state. Traps allow control of the condensate, providing a new way to study fundamental properties of light and matter," said Leonid Butov, professor of physics at the University of California, San Diego. A paper reporting his team's success was recently published in the scientific journal Nano Letters.

Excitons are composite particles made up of an electron and a "hole" left by a missing electron in a semiconductor. Created by light, these coupled pairs exist in nature. The formation and dynamics of excitons play a critical role in photosynthesis, for example.

Like other matter, excitons have a dual nature of both particle and wave, in a quantum mechanical view. The waves are usually unsynchronized, but when particles are cooled enough to condense, their waves synchronize and combine to form a giant matter wave, a state that others have observed for atoms.

Scientists can easily create excitons by shining light on a semiconductor, but in order for the excitons to condense they must be chilled before they recombine.

The key to the team's success was to separate the electrons far enough from their holes so that excitons could last long enough for the scientists to cool them into a condensate. They accomplished this by creating structures called "coupled quantum wells" that separate electrons from holes in different layers of alloys made of gallium, arsenic and aluminum.

Then they set an electrostatic trap made by a diamond-shaped electrode and chilled their special semiconducting material in an optical dilution refrigerator to as cold as 50 milli-Kelvin, just a fraction of a degree above absolute zero.

A laser focused on the surface of the material created excitons, which began to accumulate at the bottom of the trap as they cooled. Below 1 Kelvin, the entire cloud of excitons cohered to form a single matter wave, a signature of a state called a Bose-Einstein condensate.

Other scientists have seen whole atoms do this when confined in a trap and cooled, but this is the first time that scientists have seen subatomic particles form coherent matter waves in a trap.

Varying the size and depth of the trap will alter the coherent exciton state, providing this team, and others, the opportunity to study the properties of light and mater in a new way.

Read more at Science Daily

Beam Me Up: 'Tractor Beams' of Light Pull Small Objects Towards Them

'Tractor beams' of light that pull objects towards them are no longer science fiction. Haifeng Wang at the A*STAR Data Storage Institute and co-workers have now demonstrated how a tractor beam can in fact be realized on a small scale.

Tractor beams are a well-known concept in science fiction. These rays of light are often shown pulling objects towards an observer, seemingly violating the laws of physics, and of course, such beams have yet to be realised in the real world. Haifeng Wang at the A*STAR Data Storage Institute and co-workers have now demonstrated how a tractor beam can in fact be realized on a small scale. "Our work demonstrates a tractor beam based only on a single laser to pull or push an object of interest toward the light source," says Wang.

Based on pioneering work by Albert Einstein and Max Planck more than a hundred years ago, it is known that light carries momentum that pushes objects away. In addition, the intensity that varies across a laser beam can be used to push objects sideways, and for example can be used to move cells in biotechnology applications. Pulling an object towards an observer, however, has so far proven to be elusive. In 2011, researchers theoretically demonstrated a mechanism where light movement can be controlled using two opposing light beams -- though technically, this differs from the idea behind a tractor beam.

Wang and co-workers have now studied the properties of lasers with a particular type of distribution of light intensity across the beam, or so-called Bessel beams. Usually, if a laser beam hits a small particle in its path, the light is scattered backwards, which in turn pushes the particle forward. What Wang and co-workers have now shown theoretically for Bessel beams is that for particles that are sufficiently small, the light scatters off the particle in a forward direction, meaning that the particle itself is pulled backwards towards the observer. In other words, the behaviour of the particle is the direct opposite of the usual scenario. The size of the tractor beam force depends on parameters such as the electrical and magnetic properties of the particles.

Although the forces are not very large, such tractor beams do have real applications, says Wang. "These beams are not very likely to pull a human or a car, as this would require a huge laser intensity that may damage the object," says Wang. "However, they could manipulate biological cells because the force needed for these doesn't have to be large."

Read more at Science Daily

Were the Cavemen of the Danube Flutists?

Early modern humans could have spent their evenings sitting around the fire, playing bone flutes and singing songs 40,000 years ago, newly discovered ancient musical instruments indicate. The bone flutes push back the date researchers think human creativity evolved.

Researchers were studying a modern human settlement called Geißenklösterle, a part of the Swabian caves system in southern Germany, when they came across the bone flutes. One is made of mammoth ivory, while the other seems to be made of bones from a bird. They also found a collection of perforated teeth, ornaments and stone tools at the site.

"These results are consistent with a hypothesis we made several years ago that the Danube River was a key corridor for the movement of humans and technological innovations into central Europe between 40,000 and 45,000 years ago," study researcher Nick Conard, of Tübingen University, said in a statement.

"Geißenklösterle is one of several caves in the region that has produced important examples of personal ornaments, figurative art, mythical imagery and musical instruments. The new dates prove the great antiquity of the Aurignacian in Swabia." The Aurignacian refers to an ancient culture and the associated tools.

Old bones

The flutes are the earliest record of technological and artistic innovations that are characteristic of the Aurignacian period. This culture also created the oldest known example of art meant to represent a person, found in the same cave system in 2008 (that statue seems to be about 35,000 years old). The musical instruments indicate that these early humans were sharing songs and showing artistic creativity even earlier than previously thought.

The researchers radiocarbon-dated bones found in the same layer of the archaeological dig as the flutes. This carbon dating uses the level of radioactive carbon, which is naturally occurring in the world and decays predictably into nonradioactive carbon, to estimate the age of organic materials.

They found the objects were between 42,000 and 43,000 years old, belonging to the Aurignacian culture dating from the upper Paleolithic period. So far, these dates are the earliest for the Aurignacian and predate equivalent sites from Italy, France, England and other regions.

Read more at Discovery News

Thousand-Year-Old Mummies Found in Peru

Belgian archaeologists have uncovered a spectacular 1,000-year-old tomb in Peru containing more than‭ ‬80‭ ‬skeletons and mummies, many of them infants.

Carved into the earth and covered with a roof of reeds supported by shaped tree trunks, the 60-foot-long, oval chamber was discovered at the site of Pachacamac,‭ ‬about 20 miles south of the capital, Lima.

One of the largest Prehispanic sites in South America, Pachacamac was an important religious, ceremonial, political and economic center, consecrated to the god Pacha Camac.

Pachacamac was ruled by the Ychsma lords from 900 A.D. to 1470 and was rich with temples, plazas and mud-brick pyramids with ramps.

The Inca Empire conquered the religious center less than a century before Spanish Conquistador Francisco Pizarro's brother, Hernando, plundered the site in 1533.

Within a few years of the conquest Pachacamac was completely abandoned.

Today, the impressive ruins make Pachacamac a candidate for inclusion on the list of UNESCO World Heritage sites.

The intact tomb was unearthed in front of the Temple of Pachacamac and had miraculously survived the pillaging of the colonial period‭.

A dozen newborn babies and infants were buried around the perimeter,‭ with ‬their heads oriented towards the tomb.‭ ‬The main chamber was divided into two sections,‭ ‬separated by a wall of mud bricks which served as a base for yet more burials.

Inside the chambers,‭ the team of ‬ archaeologists‭ ‬from the Université libre de Bruxelles‭ (‬ULB‭) ‬found the remains of more than‭ ‬70‭ ‬skeletons and mummies, all in the characteristic fetal position and many still wrapped.‭

The burials represented both sexes and all ages,‭ ‬and were often accompanied by offerings which included‭ ‬ceramic vessels,‭ ‬dogs,‭ ‬guinea pigs,‭ ‬copper and gold alloy artefacts,‭ and ‬masks‭ of‬ painted wood.‭

Babies and very young infants were particularly common.

"The ratio adult/children is unusually elevated at this burial," archaeologist Peter Eeckhout, who has been carrying out fieldwork at the site for the past‭ ‬20‭ ‬years, told Discovery News.

"We have, at this stage, two hypotheses: human sacrifice or stocking of babies dead from natural causes, kept until their disposal in the tomb because of its special character," Eeckhout said.

‭Several‬ individuals suffered mortal injuries,‭ ‬physical trauma or serious illness.

"One juvenile was killed by a blow on the skull. All over the cemetery we have lots of lethal disease traces, such as cancer and syphillis," Eeckhout said.

‭Indeed, ‬Eeckhout's previous work at the site‭ ‬has revealed many diseases in the skeletal population,‭ ‬leading to the suggestion that Pachacamac was a sort of Prehispanic Lourdes.‭ A‬s testified by Inca sources, the affected individuals had‭ ‬travelled to the site in search of a cure.

Read more at Discovery News

May 23, 2012

Seal Proves Bethlehem Existed Centuries Before Jesus

Israeli archaeologists have unearthed a 2,700-year-old clay seal with the name of Bethlehem, showing that the town existed centuries before it was revered as Jesus' birthplace.

Discovered during the sifting‭ ‬of‭ debris ‬removed‭ ‬from archaeological excavations near the walls of the Old City of Jerusalem, the coin-sized clay seal, or bulla, was imprinted with three lines in ancient Hebrew script: "in the seventh," "Bethlehem," and "to the king."

"It seems that in the seventh year of the reign of a king ‭(‬it is unclear if the king referred to is Hezekiah,‭ ‬Manasseh or Josiah‭)‬,‭ ‬a shipment was‭ ‬dispatched from Bethlehem to the king in Jerusalem," Eli Shukron, director of the excavation on behalf of the Israel Antiquities Authority, said in a statement on Wednesday.

Belonging to the group of‭ "fiscal‭" ‬bullae‭, ‬ the clay seal was likely placed on a tax shipment of silver or agricultural produce such as wine or wheat which was sent from Bethlehem to the King of Judah in Jerusalem in the 8th or 7th century BC.

"This is the first time the name Bethlehem appears outside the Bible,‭ ‬in an inscription from the First Temple period (1006-586 BC)‭ ‬which proves that Bethlehem was indeed a city in the Kingdom of Judah,‭ ‬and possibly also‭ ‬in earlier periods," Shukron said.

Located just south of Jerusalem, Bethlehem is first mentioned in the Bible in the verse‭ "‬in Ephrath,‭ ‬which is Bethlehem.‭" It was there that‬ Rachel, the matriarch of the Jewish people, died and was buried.

Read more at Discovery News

First Terrestrial Animals Shuffled Onto Land

The transition from swimming to walking involved some awkward first steps, according to a new study that recreated how one of the first animals, which left the sea for land, moved.

The study found that that the fishy four-limbed animal Ichthyostega used its front limbs like crutches, pushing its body up and forward onto land while its legs and tail trailed behind. It lived in water near the shoreline when not on land.

This was one small step for sea creatures but one big step for animal kind, because those early movements on land around 374-359 million years ago likely later evolved into walking, including human locomotion.

"Ichthyostega's muscular and mobile elbows would have also assisted in station holding (staying in one spot) while in the water and in lifting its head out of the water to breathe and process food," Stephanie Pierce of the Royal Veterinary College's Structure and Motion Laboratory told Discovery News.

"Ichthyostega probably used its paddle-like legs and tail to swim while in the water," she added. "The hind legs probably were not of much use on land, especially compared to the forelimbs."

Pierce and her colleagues Jennifer Clack and John Hutchinson reconstructed the first ever 3-D computer model of the tetrapod's skeleton. Ichthyostega, in addition to having big muscles, possessed huge fang-like teeth and probably ambushed its prey.

The model, which put together the fossils like a jigsaw puzzle in animation software, revealed that most books and museum displays showing Ichthyostega are incorrect. They usually represent this beast marching around like a large salamander with stocky legs.

Instead, the reconstruction determined that the shoulder and hip joint of this species prevented a conventional walking step, since its limbs were incapable of rotating along its long-axis. This motion is critical to locomotion for us and other modern land animals.

Earlier fish relatives of Ichthyostega and other tetrapods, called tetrapodomorphs, had the ability to rotate their fins. This allowed later animals to move well on land. The research was published in this week's issue of Nature.

A separate study, published in the Proceedings of the Royal Society B, looked at a 345-million-year-old eel called Tarrasius problematicus. Lauren Sallan of the University of Chicago discovered that this eel had a spine with multiple segments, similar to that of today's land-dwelling animals.

Read more at Discovery News

Is 'Planet X 2.0' Lurking Beyond Pluto's Orbit?

Before the doomsayers hijacked "Planet X" and used it as a phantom (a.k.a. "Nibiru") to scare people into believing the 2012 doomsday hype, the hunt for Planet X was an exciting astronomical quest to find a hypothetical world in the outermost reaches of the solar system in the early 20th century.

Although dwarf planet Pluto was discovered during the search for Planet X in 1930, apparently ending the quest, there is enduring evidence for the existence of a substantial planet gravitationally shaping the population of minor bodies in the Kuiper belt and beyond. The only problem is, we can't see it.

Earlier this month, at a meeting of the American Astronomical Society in Timberline Lodge, Ore., Rodney Gomes, an astronomer from the National Observatory of Brazil in Rio de Janeiro, announced the results of his simulation of a region beyond Pluto known as the "scattered disk," suggesting the presence of an as yet to be discovered massive world.

The scattered disk is a sparsely populated region that overlaps with the Kuiper belt at around 30 AU (Neptune's orbit), and some scattered disk objects (or SDOs) have extreme orbits that extend to 100 AU.

One such small world is Sedna, a dwarf planet with a highly elongated orbit. "Sedna's orbit is truly peculiar," said Caltech planetary scientist Mike Brown, who led the team that discovered Sedna in 2003.

These extreme orbits, argues Gomes, could be due to the presence of an unknown massive planet. By his reckoning, a planet four times the size of Earth may be out there beyond the orbit of Pluto. In his simulation, he placed the gravitational field of a large planet and watched the effect it had on the SDO's orbits.

"Rodney Gomes is actively seeking further evidence, and I await his findings with interest!" Douglas Hamilton, an astronomer at the University of Maryland, told Life's Little Mysteries. "He has taken on a difficult task, but is taking the right approach. It is definitely a high-risk, high-reward, situation -- a discovery of a new planet would be spectacular!"

Although the presence of a massive planet may explain the extreme orbits, there is little else that suggests Planet X 2.0 really is out there. But the method of seeking out other worlds while looking for their gravitational influence on the orbits of other celestial bodies has been done before, with historic success.

In 1781, British astronomer Sir William Herschel noticed a perturbation in Uranus' orbit. By 1821, French astronomer Alexis Bouvard surmised that Uranus was being slightly "tugged" by the gravity of another, as yet to be discovered, massive planet in the outer solar system. In the 1840s, English and French astronomers John Couch Adams and Urbain Le Verrier independently went on to calculate where this mystery planet should be in the night sky by purely measuring these little deviations in Uranus' path.

Fifty-five years after Herschel noticed Uranus' perturbations, the distant planet was officially discovered by German astronomer Johann Galle in the location predicted by Couch Adams and Le Verrier. It was named Neptune.

Following the discovery of Neptune through studying perturbations in the orbit of Uranus, astronomers in the late 19th century still believed there must be another massive planet in the outer solar system causing additional perturbations to Uranus. By 1906, Percival Lowell -- founder of the Lowell Observatory in Flagstaff, Ariz. -- was inspired by these hints of another world and started a search for what he dubbed "Planet X."

It wasn't until 1930 that Clyde Tombaugh, an astronomer at Lowell Observatory, discovered Pluto. At the time, it was thought the search for Planet X had come to an end, but after follow-up observations in the decades after Pluto's discovery, the tiny world was found to have a minuscule gravitational field -- it wasn't the "Planet X" astronomers were looking for.

As it turned out, many of the perturbation measurements were eventually put down to observational error, but that didn't negate the potential for more large planets beyond our observational capabilities existing beyond the Kuiper belt -- the scenario that Gomes is currently investigating.

This new search for a hypothetical world is interesting, and reminiscent of Lowell's hunt for Planet X, but just because extreme SDO orbits hint at the presence of another body doesn't mean there has to be a Planet X 2.0.

"You can go back 100 years to claims of planets in the outer solar system and (their orbital anomalies) have all eventually gone away," said Hal Levison, a planetary scientist at the Southwest Research Institute in Boulder, Colo. "That should give you pause for thought. Just because there's not a good explanation for (the orbits of the scattered disc objects) besides another planet doesn't mean there won't be a good explanation in the future."

Read more at Discovery News

Chile's Vanishing Patagonian Lake

In less than 24 hours Lake Cachet II in Chile's southern Patagonia vanished, leaving behind just some large puddles and chunks of ice in the vast lake bed.

The lake's water comes from ice melting from the Colonia Glacier, located in the Northern Patagonian ice field, some 2,000 kilometers (1,250 miles) south of the capital, Santiago.

The glacier normally acts as a dam containing the water, but rising temperatures have weakened its wall. Twice this year, on January 27 and March 31, water from the lake bore a tunnel between the rocks and the glacier wall.

The result: Lake Cachet II's 200 million cubic liters of water gushed out into the Baker river, tripling its volume in a matter of hours, and emptying the five square kilometer (two square miles) lake bed.

Cachet II has drained 11 times since 2008 -- and with global temperatures climbing, experts believe this will increase in frequency.

"Climate models predict that as temperatures rise, this phenomenon, known as GLOFs (Glacial Lake Outburst Floods), will become more frequent," said glaciologist Gino Casassa from the Center for Scientific Studies (CES).

Casassa, a member of the 2007 Nobel Peace Prize-winning Intergovernmental Panel on Climate Change, told AFP there have been 53 similar cases of lakes draining in Chile between 1896 and January 2010, with increased frequency in the later years.

CES research assistant Daniela Carrion was camped out with a small research team taking measurements of the Colonia Glacier when the lake drained in March.

"When we woke up, we saw a change in the valley," Carrion told AFP. "The paths that we walked on had flooded, and the whole area was filled with large chunks of ice."

The lake dropped 31 meters (90 feet) when the water drained out, according to a report from the General Water Directorate, which monitors lake levels in Chile using satellite data.

When the lake starts draining an alarm system is triggered, giving residents in the sparsely-populated area up to eight hours to move animals and flee to higher ground.

The Tempanos Lake, also in far southern Chile, drained in a similar fashion in May 2007. Forest rangers working to save endangered huemuls -- mid-sized deer native to the region -- were surprised when they came across the empty lake. There were ice floes on the floor of the ten square kilometer lake bed, but no water.

Forestry officials had visited Tempanos in April and it was full, and when a team of scientists and naval officials flew over the area in July they found that the lake, which also is fed by waters from a nearby glacier, was starting to re-fill.

Read more at Discovery News

May 22, 2012

Flu Shot During Pregnancy Shows Unexpected Benefits in Large Study

Getting a flu shot during pregnancy provides unanticipated benefits to the baby, according to the authors of a large population-based study examining the issue. Specifically, the study showed that H1N1 vaccination during the pandemic was associated with a significantly reduced risk of stillbirth, preterm birth and extremely small babies at birth.

Researchers at the Ottawa Hospital Research Institute (OHRI), the CHEO Research Institute and the University of Ottawa (uOttawa) used data from Ontario's birth record database, BORN, to examine 55,570 single-child births that took place in Ontario during the H1N1 pandemic. The resulting paper was recently published by the American Journal of Public Health.

The study shows that, compared to pregnant women who were not immunized against H1N1, mothers who received the H1N1 vaccination were:

34% less likely to have a stillbirth, 28% less likely to deliver before 32 weeks, and 19% less likely to give birth to a child with a birth weight for gestational age in the bottom third percentile.

"These are all significant results, but especially interesting is the finding that the vaccinated mothers were one-third less likely to have a stillborn child," says lead author Deshayne Fell, an epidemiologist for BORN Ontario. "This is one of the only studies large enough to evaluate the association between maternal flu vaccination and stillbirth -- a very rare event."

"What surprised me and the research team was the strength of the protective benefits we found," says co-author Dr. Ann Sprague, the Scientific Manager of BORN Ontario at the Children's Hospital of Eastern Ontario (CHEO) Research Institute.

The study also found no increase in adverse outcomes for H1N1-vaccinated mothers and their babies during the weeks before and just after birth, also referred to as the perinatal period.

"The findings of this study are very helpful," says co-author Dr. Mark Walker, a Senior Scientist at OHRI, a High-Risk Obstetrician at The Ottawa Hospital, and a Professor and Tier One Research Chair in Perinatal Research at the University of Ottawa. "Pregnant women are generally very, very careful about what they put into their bodies. For health-care providers like me, such a large-scale study that shows no adverse perinatal outcomes resulting from the H1N1 flu vaccine will be extremely helpful when discussing maternal vaccination."

Of all the single-child births recorded from November 2009 to April 2010, 42% of the women received the H1N1 vaccination, which makes the findings robust. BORN -- the Better Outcomes Registry & Network -- collects data from all births in Ontario. In order to conduct the research for this study, questions about H1N1 vaccination were added to the database in advance of the H1N1 vaccine becoming available. BORN includes demographic data that allowed the research team to correct for smoking, education and income; however, as with any population-based study, it may not be possible to account for all influencing factors.

This study was funded by the Canadian Institutes of Health Research (CIHR). The Public Health Agency of Canada provided support to add the H1N1 questions to the BORN database. BORN is funded by Ontario's Ministry of Health and Long-Term Care, with its main offices based at the CHEO Research Institute.

Read more at Science Daily

Gold-Plated Fossil Solution

An international team of scientists in the University of Leicester's Department of Geology has found a solution to a research problem involving fossils right next door -- in the University's Chemistry Department.

Many objects, including fossils, can reveal a huge amount of scientific information when studied using the high power magnification of electron microscopes, but in order to study tiny fossils or microscopic details of larger fossils in this way, palaeontologists routinely coat the fossils with an ultra-thin layer of gold. This obviously changes the way the fossil looks, and so it is often necessary to remove the gold after analysis, but this is difficult and expensive and uses dangerous chemicals like cyanide.

University of Leicester chemists are developing industrial electro-plating and polishing techniques using liquid salts called 'ionic liquids' which are safe, cheap and environmentally friendly. Scientists from the two departments got together to see whether a similar process could be used on fossils. The work was supported by the Natural Environment Research Council (NERC).

They found that ionic liquids can remove gold quickly and easily without damaging even tiny, delicate fossils. The liquids are safe to handle, can be simply disposed of and can even dissolve the gold without affecting the glue that holds the fossil specimen in place for analysis.

Professor Mark Purnell, from the Department of Geology, said: "There are many cases where collecting the evidence required for research affects fossils or other objects in ways that might be considered as somewhat destructive -- gold coating for electron microscopy falls into this category. Understandably, this creates problems for places like museums which have to balance the value of research on their collections against the risk that specimens will be affected. This approach to gold removal offers a new way of tackling this problem that is safe for both researchers and the specimens."

Professor Andy Abbott, from the Department of Chemistry, added: "This is a very nice demonstration of the use of ionic liquids for metal recovery but it is just the tip of the iceberg as we are using this technology for the recycling of a wide range of alloys and waste materials. The University of Leicester is building a strong reputation for the development of sustainable materials."

Read more at Discovery News

Flesh-Eating Bacteria Explained

Aimee Copeland, a 24-year-old University of West Georgia graduate student, is breathing on her own today. It's a huge milestone in her continuing battle against a rare infection -- necrotizing fasciitis.

Copeland contracted the rare form of flesh-eating bacteria after a zip line accident over a river in Georgia on May 1.

The germs that cause flesh-eating disease are common in warm and brackish waters like ponds, lakes and streams and rivers like the one that Copeland fell into when her zip line broke. The bacteria are not a threat to most people.

Swimmers sometimes come into contact with aeromonas hydrophila -- the type of bacteria Copeland is fighting.

If swallowed, your immune system will attempt to fight off gastrointestinal infections. You may experience some diarrhea -- but in most cases, says Dr. William Schaffner, president of the National Foundation for Infectious Diseases, you're perfectly fine after towelling off.

If you have an open wound, like Copeland's, the bacteria can enter the body and quickly reproduce. While the bacteria don't actually eat flesh, they attack skin and tissue by giving off toxins.

"It requires the perfect storm of circumstances," Schaffner. "It's unlikely to happen. Which is also scientists' way of saying we don't really know."

When someone is infected, the bacteria spreads quickly by hiding from the body's immune system, making it difficult to diagnose. It's one of the fastest spreading infections known, according to The National Necrotizing Fasciitis Foundation.

Treatment starts with antibiotics, and usually involves removal of the infected areas as well. In Copeland's case, her hands were endangering her recovery, her father wrote on Facebook: "As always, my decision was simple. Do whatever it takes to give us the best chance to save Aimee's life." The bacteria live in areas devoid of oxygen, so exposing the wounds to oxygen through surgery helps prevent their spread. But because the infection moves so fast, and because the bacteria thrive deep within the tissue, undetected, surgeons often have to go back in a second or third time, Schaffner says.

In the most severe cases, organs can go into systemic shock, accompanied by respiratory and/or heart failure.

Jacqueline Roemmele, executive director of The National Necrotizing Fasciitis Foundation and NF survivor, says Copeland’s case is typical in terms of diagnosis and treatment.

“It’s pretty typical, and tragic,” Roemmele said. “It’s lightening fast, and drastic steps have to be taken quickly.”

Roemmele, who calls herself the “grandma of flesh-eating disease” because she contracted the bacteria 18 years ago, says the most important thing to watch out for is pain out of proportion to the injury.

“If you have a tiny cut on your leg, and 5-6 hours later your entire leg is killing you, and you have a fever, and your leg is turning red and swelling, don’t wait,” she says. “Get to a doctor.”

Copeland’s case is atypical, however, in that she contracted the bacteria through water, Roemmele says. Some have contracted the bacteria in shellfish, while shucking oysters, for example. And in a strikingly similar case to Copeland’s, a Long Island woman contracted the bacteria last year on spring break while playing in the water.

“She almost lost her leg; as she went into surgery, she was told her leg would be amputated,” Roemmele says. Instead, surgeons were able to remove only flesh, and she made it to her graduation ceremony two weeks after her skin grafts.

But most cases are caused by group A streptococcus bacteria that don’t respond to antibiotics, the culprit of the common Strep throat; a mixed bacterial infection can also occur after surgery.

Read more at Discovery News

Monster Telescope Combo Spies Feeding Black Hole

Astronomers are finally getting a look at the extreme processes inside and around black holes. By combining the light from three powerful infrared telescopes, an international team has observed the active gas and dust accretion around a supermassive black hole in the center of a galaxy tens of millions of light-years away.

Resolving these features isn't just confirmation of how mass accretes onto black holes in centers of galaxies, it's how the image was taken is a major step in our Earth-bound exploration of the cosmos.

The team, led by Gerd Weigelt, a director of the Max Planck Institute for Radio Astronomy in Bonn, Germany, resolved the inner ring of debris in the inner region of the active galaxy NGC 3783.

They used the AMBER interferometry instrument of the ESO's Very Large Telescope Interferometer in Chile to combine the infrared light from three telescopes. Sebastian Hoenig, a postdoctoral researcher at the UC Santa Barbara Department of Physics, called the method "a major milestone toward directly imaging the growth phase of supermassive black holes."

Interferometry is an imaging method that uses two or more -- in this case, three -- separate points on a telescope array to observe an object. The light from the individual telescopes in combined or "interfered" to create a complete picture.

Since each individual image contains high-resolution information, the combined image can give astronomers stunning detail. With separate vantage points, the clarity of the final image is similar to the clarity of a telescope if its diameter were the same as the distance between the two points. In other words, this technique gives astronomers a spectacular view without the impossibly large hardware.

This method was necessary to see such a small object -- the ring-shaped distribution of hot dust called a torus in the inner region of the active galaxy NGC 3783. The dust torus has an angular radius of only 0.7 milliarcseconds in the sky. That's 5 million times smaller than one degree. To resolve something this small, astronomers would need a telescope with a mirror at least 100 meters in diameter. As we don't have the technology to build such a large telescope, interferometry was the best bet.

This method was able to achieve an angular resolution equivalent to the resolution of a telescope with a diameter of 130 meters, 15 times higher than one of the VLTI telescopes alone. Each telescope has a mirror 8 meters (26 ft) in diameter.

Read more at Discovery News

May 21, 2012

Understanding Arctic Ocean's Carbon Cycle

Scientists from the Woods Hole Oceanographic Institution (WHOI) have conducted a new study to measure levels of carbon at various depths in the Arctic Ocean. The study, recently published in the journal Biogeosciences, provides data that will help researchers better understand the Arctic Ocean's carbon cycle -- the pathway through which carbon enters and is used by the marine ecosystem. It will also offer an important point of reference for determining how those levels of carbon change over time, and how the ecosystem responds to rising global temperatures.

"Carbon is the currency of life. Where carbon is coming from, which organisms are using it, how they're giving off carbon themselves -- these things say a lot about how an ocean ecosystem works," says David Griffith, the lead author on the study."If warming temperatures perturb the Arctic Ocean, the way that carbon cycles through that system may change."

Griffith's team sampled suspended particles of organic matter, as well as organic carbon and carbon dioxide (CO2) dissolved into the surrounding water. This is the first time that researchers have focused broadly on measuring multiple types of carbon at the same time and place in the Arctic Ocean -- due to its remote location and the challenges of operating in sea ice, few comprehensive carbon surveys had been conducted there before this study.

Griffith and his colleagues conducted their fieldwork in 2008 aboard the Canadian Coast Guard icebreaker Louis S. St. Laurent. At two different spots in the Canada Basin, an area northwest of the Canadian coast, they gathered samples from 24 depths ranging from the surface to the ocean floor 3800 meters (roughly 12,500 feet) below.

Collecting samples at those intervals was necessary, Griffith says, because the Arctic Ocean is separated into distinct layers, each with its own unique carbon characteristics. At the surface is a freshwater layer from river runoff and sea-ice melt. Below that is a layer of cold water from the Pacific, and below that is a warm, salty Atlantic layer. The deepest layer is slowly replaced by mixing with overlying Atlantic water.

Measuring the different amounts of carbon in each layer (and determining its source) is an essential step in understanding the flow of carbon through the marine ecosystem, says Griffith: "It's kind of like understanding how freight and people move in a city. If you don't know what's coming in and out, it's really hard to understand how the city works."

To analyze the contents of his samples, Griffith turned to Ann McNichol, a WHOI senior researcher and staff chemist. At WHOI's National Ocean Sciences Accelerator Mass Spectrometer Facility (NOSAMS), she tallied the total number of carbon atoms in each specimen, including carbon-13, a stable isotope of the element. McNichol says that it can be used to determine where a particular pool of carbon originated, and how it may have been utilized by the marine ecosystem.

"Carbon-13 is primarily a source indicator," she says. "By measuring levels of carbon-13 at different depths, it's possible to determine if the carbon there was generated by the marine environment, ocean ice environment, or by terrestrial sources." The team also examined levels of carbon-14, a radioactive isotope that can help determine the age of each sample to further determine its source.

In addition to understanding the basic carbon cycle in the Arctic Ocean, Griffith's team hopes that the results of this baseline study will help evaluate how Arctic Ocean carbon levels and global climate interact. Griffith says there are several ways this could happen.

As the Arctic gradually warms, it may cause a more intense precipitation cycle over northern Canada, Alaska, and Siberia, generating more rainfall each year. This in turn would cause more runoff from melting permafrost and eroded soil -- both rich sources of organic carbon.

One possible outcome of that scenario could be an increase of carbon dioxide in the region. As bacteria in Arctic Ocean use the new influx of carbon as a food source, they may create CO2 as a byproduct. A second possibility, Griffith posits, is that warming temperatures and melting sea ice might boost the production of phytoplankton, tiny plant-like organisms that live near the ocean's surface and thrive on carbon dioxide in the water. As those phytoplankton die (or are eaten by other organisms and released as waste), they would sink to the sea floor, causing the carbon in their bodies to be sequestered in thick sediments -- effectively removing the increased carbon from the environment.

"Those are just a few aspects of what might happen. But for every one that we think about, there could be 10 others that drive the system in a different direction," says Griffith. "We don't yet have the kind of data to say anything definitive about how the Arctic would be affected by warming climate -- but what we do have is a very important baseline of data to help evaluate changes that will happen in the future. Without that, you're unfortunately just guessing at how things change over time."

Read more at Science Daily

Unique Gold Earring Found in Intriguing Collection of Ancient Jewelry in Israel

Hoard of gold and silver jewelry hidden for thousands of years could have Egyptian origin, say TAU researchers

Researchers from Tel Aviv University have recently discovered a collection of gold and silver jewelry, dated from around 1100 B.C., hidden in a vessel at the archaeological site of Tel Megiddo in the Jezreel Valley in northern Israel. One piece -- a gold earring decorated with molded ibexes, or wild goats -- is "without parallel," they believe.

According to Prof. Israel Finkelstein of TAU's Department of Archaeology and Near Eastern Cultures, the vessel was found in 2010, but remained uncleaned while awaiting a molecular analysis of its content. When they were finally able to wash out the dirt, pieces of jewelry, including a ring, earrings, and beads, flooded from the vessel. Prof. Finkelstein is the co-director of the excavation of Tel Megiddo along with Professor Emeritus David Ussishkin of Tel Aviv University and Associate Director Prof. Eric Cline of George Washington University in Washington, D.C.

The researchers believe that the collection, which was discovered in the remains of a private home in the northern part of Megiddo, belongs to a time period called "Iron I," and that at least some of the pieces could have originated in nearby Egypt. Some of the materials and designs featured in the jewelry, including beads made from carnelian stone, are consistent with Egyptian designs from the same period, notes Ph.D. candidate Eran Arie, who supervises the area where the hoard was found.

A treasure trove with mysterious origins

When the researchers removed the ceramic jug from the excavation site, they had no idea there was jewelry hidden within. The jewelry was well preserved and wrapped in textiles, but the circumstances surrounding it are mysterious. According to Prof. Finkelstein, it is likely that the jug was not the jewelry's normal storage place. "It's clear that people tried to hide the collection, and for some reason they were unable to come back to pick it up." The owners could have perished or been forced to flee, he says. Prof. Ussishkin believes that it was the jewelry collection of the Canaanite woman who lived in the house.

The assortment of jewelry is also out of the ordinary, notes Arie. Though the collection includes a number of lunette (moon-shaped) earrings of common Canaanite origin, researchers found an abundance of gold items in the collection and a number of beads made from carnelian, which was frequently used in the making of Egyptian jewellery in the same period. This points to a strong Egyptian connection, whether in influence or origin. Such a connection would not be surprising, according to Prof. Cline, who stated that interactions between Egypt and Megiddo are known to have taken place during both the Bronze Age and the Iron Age.

The most notable piece, the researchers agree, is a gold earring with a pattern of molded wild goats. "For unique items, we work to find parallels to help place the items in their correct cultural and chronological settings, but in this case we still haven't found anything," say the researchers.

Adding dimension to a multi-layer dig

It's another fascinating find from a unique archaeological site. Tel Megiddo was an important Canaanite city-state until the early 10th century B.C.E. and a pivotal center of the Northern Kingdom of Israel in the 9th and 8th centuries B.C.E. It is a multi-layered site with various time periods clearly differentiated, and in this time period there are 10 to 11 strata well-dated through radiocarbon analysis. "Such a sequence of radiocarbon dates doesn't exist anywhere else in the region," says Prof. Finkelstein.

The layer in which the jewelry was found has already been dated to the 11th century B.C., just after the end of Egyptian rule in the 12th century B.C., Arie says. Either the jewelry was left behind in the Egyptian withdrawal or the people who owned the jewelry were influenced by Egyptian culture.

Read more at Science Daily

Time-Lapse Video of Incredible Annular Solar Eclipse

Did you see the eclipse yesterday? In case of poor geographic location or general Sunday laziness, here’s a time-lapse video showing the celestial event in its full glory.

Created by amateur astrophotographer Cory Poole, a math and science teacher, the video gives a great overview of the entire eclipse from start to finish. Poole watched the event from Redding, California, which was directly in the path of the moon’s shadow, allowing him to capture the full extent of the “ring of fire.”

During this annular eclipse, the moon was slightly too far from the Earth to completely block out the sun, leaving a bright red ring that would make any Xbox player shiver.

Read more at Wired Science

Jurassic Squid Ink Same as Modern Squid Ink

Ink from 160-million-year-old giant squid is essentially identical to today's squid ink.

The discovery suggests that the ink and the ink-screen escape mechanism of squid have not evolved much (if at all) since the Jurassic Period. The finding, published in the latest Proceedings of the National Academy of Sciences, might just prove that if it isn't broken, nature isn't going to fix it.

Researchers came to the determination after studying ink sacs from two giant squid fossils found two years ago in England. The primary component of squid ink is melanin, a substance that gives skin, hair and certain other things color. It's why squid ink is so dark in color. (On a side note, some studies show that squid ink has some anti-tumor properties.)

Since melanin hasn't changed much over the years, this research indicates that melanin could be preserved intact in the fossils of a range of organisms. Recent research has revealed, for example, the color of certain dinosaurs and other long-gone animals.

"Though the other organic components of the squid we studied are long gone, we've discovered through a variety of research methods that the melanin has remained in a condition that could be studied in exquisite detail," co-author John Simon said in a press release. He's a chemistry professor and the executive vice president and provost at the University of Virginia.

One of the ink sacs studied is the only intact prehistoric ink sac ever discovered.

Simon and his colleagues used a combination of direct, high-resolution chemical techniques to determine that the melanin had been preserved. The researchers also compared the chemical composition of the ancient squid ink remains to that of modern squid ink from Sepia officinalis, a squid common to the Mediterranean, North and Baltic seas.

"It's close enough that I would argue that the pigmentation in this class of animals has not evolved in 160 million years," Simon said. "The whole machinery apparently has been locked in time and passed down through succeeding generations of squid. It's a very optimized system for this animal and has been optimized for a long time."

Usually animal tissue, made up mostly of protein, degrades quickly. All that's then left of prehistoric animals is their skeletal remains -- or so we used to think. The preservation of melanin proves that some organic matter can survive.

Read more at Discovery News

May 20, 2012

Drug Found for Parasite That Is Major Cause of Death Worldwide

Research by a collaborative group of scientists from UC San Diego School of Medicine, UC San Francisco and Wake Forest School of Medicine has led to identification of an existing drug that is effective against Entamoeba histolytica. This parasite causes amebic dysentery and liver abscesses and results in the death of more than 70,000 people worldwide each year.

Using a high-throughput screen for drugs developed by the research team, they discovered that auranofin -- a drug approved by the US Food and Drug Administration 25 years ago for rheumatoid arthritis -- is very effective in targeting an enzyme that protects amebae from oxygen attack (thus enhancing sensitivity of the amebae to reactive oxygen-mediated killing).

The results of the work, led by Sharon L. Reed, MD, professor in the UCSD Departments of Pathology and Medicine and James McKerrow, MD, PhD, professor of Pathology in the UCSF Sandler Center for Drug Discovery, will be published in the May 20, 2012 issue of Nature Medicine.

Entamoeba histolytica is a protozoan intestinal parasite that causes human amebiasis, the world's fourth leading cause of death from protozoan parasites. It is listed by the National Institutes of Health as a category B priority biodefense pathogen. Current treatment relies on metronidazole, which has adverse effects, and potential resistance to the drug is an increasing concern.

"Because auranofin has already been approved by the FDA for use in humans, we can save years of expensive development," said Reed. "In our studies in animal models, auranofin was ten times more potent against this parasite than metronidazole."

In a mouse model of amebic colitis and a hamster model of amebic liver abscess, the drug markedly decreased the number of parasites, damage from inflammation, and size of liver abscesses.

"This new use of an old drug represents a promising therapy for a major health threat, and highlights how research funded by the National Institutes of Health can benefit people around the world," said Reed. The drug has been granted "orphan-drug" status (which identifies a significant, newly developed or recognized treatment for a disease which affects fewer than 200,000 persons in the United States) and UC San Diego hopes to conduct clinical trials in the near future.

Read more at Science Daily

Newfound Exoplanet May Turn to Dust: Planet’s Dust Cloud May Explain Strange Patterns of Light from Its Star

Researchers at MIT, NASA and elsewhere have detected a possible planet, some 1,500 light years away, that appears to be evaporating under the blistering heat of its parent star. The scientists infer that a long tail of debris -- much like the tail of a comet -- is following the planet, and that this tail may tell the story of the planet's disintegration. According to the team's calculations, the tiny exoplanet, not much larger than Mercury, will completely disintegrate within 100 million years.

The team found that the dusty planet circles its parent star every 15 hours -- one of the shortest planet orbits ever observed. Such a short orbit must be very tight and implies that the planet must be heated by its orange-hot parent star to a temperature of about 3,600 degrees Fahrenheit. Researchers hypothesize that rocky material at the surface of the planet melts and evaporates at such high temperatures, forming a wind that carries both gas and dust into space. Dense clouds of the dust trail the planet as it speeds around its star.

"We think this dust is made up of submicron-sized particles," says co-author Saul Rappaport, a professor emeritus of physics at MIT. "It would be like looking through a Los Angeles smog."

The group's findings, published in the Astrophysical Journal, are based on data from the Kepler Observatory, a space-based telescope that surveys more than 160,000 stars in the Milky Way. The observatory records the brightness of each star at regular intervals; scientists then analyze the data for signs of new planets outside our own solar system.

A curiously stellar case

Astronomers using the Kepler satellite typically identify exoplanets by looking for regular dips in a star's brightness. For example, if a star dims every month, one possibility is that the dimming is due to a planet that travels around the star over the course of a month; each time the planet travels in front of the star, the planet blocks the same small amount of light.

However, Rappaport and his colleagues came across a curious light pattern from a star dubbed KIC 12557548. The group examined the star's light curves, a graph of its brightness over time, and found that its light dropped by different intensities every 15 hours -- suggesting that something was blocking the star regularly, but by varying degrees.

The team considered several explanations for the puzzling data, including the possibility that a planetary duo -- two planets orbiting each other -- also orbited the star. (Rappaport reasoned that the planetary pair would pass by the star at different orientations, blocking out different amounts of light during each eclipse.) In the end, the data failed to support this hypothesis: The dimming every 15 hours was judged far too short a period to allow sufficient room for two planetary bodies orbiting each other, in the same way that Earth and the moon together orbit the sun.

A dusty idea

Instead, the researchers landed on a novel hypothesis: that the varying intensities of light were caused by a somewhat amorphous, shape-shifting body.

"I'm not sure how we came to this epiphany," Rappaport says. "But it had to be something that was fundamentally changing. It was not a solid body, but rather, dust coming off the planet."

Rappaport and his colleagues investigated various ways in which dust could be created and blown off a planet. They reasoned that the planet must have a low gravitational field, much like that of Mercury, in order for gas and dust to escape from the planet's gravitational pull. The planet must also be extremely hot -- on the order of 3,600° F.

Rappaport says there are two possible explanations for how the planetary dust might form: It might erupt as ash from surface volcanoes, or it could form from metals that are vaporized by high temperatures and then condense into dust. As for how much dust is spewed from the planet, the team showed that the planet could lose enough dust to explain the Kepler data. From their calculations, the researchers concluded that at such a rate, the planet will completely disintegrate within 100 million years.

The researchers created a model of the planet orbiting its star, along with its long, trailing cloud of dust. The dust was densest immediately surrounding the planet, thinning out as it trailed away. The group simulated the star's brightness as the planet and its dust cloud passed by, and found that the light patterns matched the irregular light curves taken from the Kepler Observatory.

"We're actually now very happy about the asymmetry in the eclipse profile," Rappaport says. "At first we didn't understand this picture. But once we developed this theory, we realized this dust tail has to be here. If it's not, this picture is wrong."

Dan Fabrycky, a member of the Kepler Observatory science team, says the model may add to the many different ways in which a planet can disappear.

Read more at Science Daily