viernes, 22 de enero de 2010
A preliminary U.S. Geological Survey assessment has found that the sequence of aftershocks following the magnitude 7 earthquake that struck near Port-au-Prince, Haiti on Jan. 12 is likely to continue for months, possibly years.
Though the frequency of aftershocks will decrease over time, there is still potential for quakes large enough to cause more damage in the coming months, and a small possibility of an event larger than the main shock, according to a team of USGS scientists.
Their initial probability estimates for the next 30 days are that there is a 3 percent chance of a magnitude 7 or greater quake, a 25 percent chance of a magnitude 6 or greater quake and a 90 percent chance of a magnitude 5 or greater quake.
“Any aftershock above magnitude 5.0 will be widely felt and has the potential to cause additional damage, particularly to vulnerable, already damaged structures,” according to the USGS statement released Thursday evening.
The forecast is based on the aftershocks Haiti has already experienced and general statistics on aftershocks.
Haiti experienced a magnitude 5.9 aftershock on Wednesday. The USGS expects two or three more of at least magnitude 5 in the nest 30 days.
The scientists are also concerned because it’s unclear how much of the Enriquillo-Plantain Garden fault, which bounds the North American and Caribbean plates, ruptured in the earthquake. Analysis of ground deformation at the surface using satellite and aerial photos and preliminary radar data suggests that the segment of the fault directly east of the rupture and directly under Port-au-Prince did not slip. This means it could rupture in the future.
At least four times in the past, earthquakes as big or bigger than the recent quake have struck Haiti. Two major quakes struck the capital city in 1751 and 1770. For this reason, the USGS cautions that as Port-au-Prince is rebuilt, future seismic risk must be taken into account.
A curious, comet-like object recently found in pictures from a ground-based telescope might actually be fallout from a high-speed asteroid collision, planetary scientists report.
If these suspicions are confirmed, the object would represent the first time astronomers have witnessed the immediate aftermath of such a cosmic smashup.
Dubbed P/2010 A2 (LINEAR), the fuzzy, tailed mystery object is about 130,000 miles (210,000 kilometers) to 190,000 miles (305,000 kilometers) long, stretching across part of our solar system's main asteroid belt.
The belt contains thousands of asteroids that orbit between Mars and Jupiter, some 250 million miles (402 million kilometers) from Earth.
It's believed most comets come from the cold, distant reaches of the solar system and travel on long, elliptical orbits, which keep the icy bodies far from the sun most of the time.
As a comet nears the sun, heat turns the comet's volatile ices into gases, and solar radiation pushes on those gases to create a tail.
But the newfound object suddenly appeared within the warmer asteroid belt and may even have originated there, puzzling astronomers.
"We're still trying to really figure out what it is," said University of Arizona planetary scientist Jim Scotti, who is part of one of the teams observing the object from the Kitt Peak National Observatory outside Tucson.
Explosive Asteroid Impact?
The object's oddities have some astronomers, including Scotti, thinking that the bright "tail" is actually a debris field created just after a small asteroid had smashed into a larger one. (See pictures of comets and asteroids.)
A 650-foot-wide (200-meter-wide) space rock apparently still sitting near the object's head could be one of the collision victims.
Odds are that the smaller impactor would have been only a few meters across, since asteroids of this size are far more common in the main belt.
If a collision occured, it's most likely that the space rocks didn't meet head on, Scotti said. Still, the impact speed could have ranged from 0.6 to 6 miles (1 to 10 kilometers) a second—fast enough to create a debris field visible from Earth.
Astronomers have yet to witness an actual asteroid collision. But there's plenty of evidence to suggest that the smashups happen all the time.
For instance, all known asteroids display telltale scars in the forms of impact craters. And some groups of asteroids are thought to have been born from collisions that fragmented their original "parents."
"With such evidence of collisions in the asteroid belt, it's not surprising that eventually we will see one," Scotti said.
The trick is, "I'm not sure we know what an asteroid collision really would look like in detail," he admitted.
"We have some ideas, but I'm not sure anyone has really sat down and modeled the size and velocity of the debris, or where all that debris goes and how long it would remain potentially observable."
For now, scientists can only wait and watch to see if P/2010 A2 (LINEAR) slowly dissipates, like debris from an explosion, or continues to act like a comet—which would pose a new round of puzzling questions.
A rare handful of comet-like bodies are known to orbit in the main asteroid belt. But if P/2010 A2 (LINEAR) is actually a comet, how did it conserve its water ice so close to the sun for some 4.5 billion years—roughly the age of the solar system—only to begin releasing gases now due to some unseen event?
"That's a long time to bake an object," Scotti said.
"It's hard to imagine how an object would maintain a reservoir of volatiles that it could use to suddenly start producing a tail. But you know, stranger things have happened."
Building on their previous work delivering cancer drugs with nanoparticles, MIT and Harvard researchers have turned their attention to cardiovascular disease, designing new particles that can cling to damaged artery walls and slowly release medicine.
The particles, dubbed "nanoburrs," are coated with tiny protein fragments that allow them to stick to damaged arterial walls. Once stuck, they can release drugs such paclitaxel, which inhibits cell division and helps prevent growth of scar tissue that can clog arteries.
"This is a very exciting example of nanotechnology and cell targeting in action that I hope will have broad ramifications," says MIT Institute Professor Langer, senior author of a paper describing the nanoparticles in the Proceedings of the National Academy of Sciences.
Langer and Omid Farokhzad, associate professor at Harvard Medical School and another senior author of the paper, have previously developed nanoparticles that seek out and destroy tumors. Their nanoburrs, however, are among the first particles that can zero in on damaged vascular tissue.
Mark Davis, professor of chemical engineering at Caltech, says the work is a promising step towards new treatments for cardiovascular and other diseases. "If they could do this in patients -- target particles to injured areas -- that could open up all kinds of new opportunities," says Davis, who was not involved in this research.
Currently, one of the standard ways to treat clogged and damaged arteries is by implanting a vascular stent, which holds the artery open and releases drugs such as paclitaxel. The researchers hope that their new nanoburrs could be used alongside such stents -- or in lieu of them -- to treat damage located in areas not well suited to stents, such as near a fork in the artery.
The nanoburrs are targeted to a structure known as the basement membrane, which lines the arterial walls but is only exposed when those walls are damaged. To build their nanoparticles, the team screened a library of short peptide sequences to find one that binds most effectively to molecules on the surface of the basement membrane. They used the most successful, a seven-amino-acid sequence called C11, to coat the outer layer of their nanoparticles.
The inner core of the 60-nanometer-diameter particles carries the drug, which is bound to a polymer chain called PLA. A middle layer of soybean lecithin, a fatty material, lies between the core and the outer shell, which consists of a polymer called PEG that protects the particles as they travel through the bloodstream.
The drug can only be released when it detaches from the PLA polymer chain, which occurs gradually by a reaction called ester hydrolysis. The longer the polymer chain, the longer this process takes, so the researchers can control the timing of the drug's release by altering the chain length. So far, they have achieved drug release over 12 days, in tests in cultured cells.
Uday Kompella, professor of pharmaceutical sciences at the University of Colorado, says the nanoburr's structure could make it easier to manufacture, because the targeted peptides are attached to an outer shell and not directly to the drug-carrying core, which would require a more complicated chemical reaction. The design also reduces the risk of the nanoparticles bursting and releasing drugs prematurely, says Kompella, who was not involved in this research.
Another advantage of the nanoburrs is that they can be injected intravenously at a site distant from the damaged tissue. In tests in rats, the researchers showed that nanoburrs injected near the tail are able to reach their intended target -- walls of the injured carotid artery but not normal carotid artery. The burrs bound to the damaged walls at twice the rate of nontargeted nanoparticles.
Because the particles can deliver drugs over a longer period of time, and can be injected intravenously, patients would not have to endure repeated and surgically invasive injections directly into the area that requires treatment, says Juliana Chan, a graduate student in Langer's lab and lead author of the paper.
The team is now testing the nanoburrs in rats over a two-week period to determine the most effective dose for treating damaged vascular tissue. The particles may also prove useful in delivering drugs to tumors. "This technology could have broad applications across other important diseases, including cancer and inflammatory diseases where vascular permeability or vascular damage is commonly observed," says Farokhzad
For the first time, a text has been found in Old Persian language that shows the written language in use for practical recording and not only for royal display. The text is inscribed on a damaged clay tablet from the Persepolis Fortification Archive, now at the Oriental Institute at the University of Chicago. The tablet is an administrative record of the payout of at least 600 quarts of an as-yet unidentified commodity at five villages near Persepolis in about 500 B.C.
“Now we can see that Persians living in Persia at the high point of the Persian Empire wrote down ordinary day-to-day matters in Persian language and Persian script,” said Gil Stein, Director of the Oriental Institute. “Odd as it seems, that comes as a surprise — a very big surprise.”
Old Persian writing was the first of the cuneiform scripts to be deciphered, between about 1800 and 1845. When the script was cracked, scholars saw that the Old Persian language was an ancestor of modern Persian and a relative of Sanskrit. Knowing that, they could understand the inscriptions of Darius, Xerxes and their successors, the kings of the Persian Empire founded by Cyrus the Great in the mid-sixth century B.C. and destroyed by Alexander the Great and his successors after 330 B.C.
Until now, most scholars of Old Persian thought that Old Persian script and language were used only for the inscriptions of kings on cliff faces or palaces, or else to identify vessels of precious metals or other luxury goods that were connected with the kings and their palaces. To write records of administration or business, the Persians relied on languages and scripts — Aramaic, Babylonian, Elamite, and others — already in use at the advent of the Empire.
The Persepolis Fortifaction tablets were excavated at the imperial palace complex of Persepolis, in southwestern Iran, by the Oriental Institute in the 1930s and, through the permission of the Iranian government, were sent to the Oriental Institute in 1937 on a long-term loan for purposes of translation and analysis.
The Archive includes tens of thousands of clay tablets and fragments with texts in Elamite, an indigenous language already written in Iran for almost 2,000 years before the Persian Empire was founded. It also includes hundreds of clay tablets and fragments with texts in Aramaic, a Semitic language already used for practical recording over much of the Near East since the days of the Assyrian and Babylonian Empires (ninth to sixth centuries B.C.). It also includes thousands of tablets with no texts at all, but with impressions of seals.
But over the years of study, a few extraordinary items have also been discovered among the Persepolis tablets: a text in Phrygian (a language of western Anatolia, in modern Turkey), a text in Greek, and now a text in Persian, the language of the Empire’s rulers.
“Most of the scribes around Persepolis could speak and write more than one language, and this text might be just a quirky experiment done by one of them,” said Matthew W. Stolper, head of the Oriental Institute’s Persepolis Fortification Archive Project. “But it might also be the tip of an iceberg.” He explained that in 500 B.C., just as now, administrative records did not work as isolates, only as items in much larger files. Before 1933, there was only one known example of an Achaemenid administrative tablet written in Elamite, but since the discovery of the Persepolis Fortification Archive there are thousands. Like that first Achaemenid Elamite tablet, this Old Persian tablet “could also be the first forerunner of something much bigger.”
Because there are no other such documents in Old Persian, interpreting this one depends on comparisons with the Elamite and Aramaic documents with which it was found. “The Old Persian tablet departs so much from expectations that its authenticity would have been questioned if it had not been found in the Fortification Archive,” said Stolper, the John A. Wilson Professor in the Oriental Institute.
“This shows how important it is to keep the Persepolis Fortification texts together, to keep the Archive intact,” Stein said. “Unexpected discoveries are still being made, and the meaning and reliability of every piece depend on its connections with the whole information system of the entire Fortification Archive.”
Members of the Oriental Institute’s Persepolis Fortification Archive Project first announced the discovery of the Old Persian tablet in November, 2006, at a colloquium at the Collège de France and the University of Chicago’s Paris Center. They described the document in greater detail at a meeting of the American Oriental Society in March, 2007. An article by Stolper and Jan Tavernier, of the University of Leuven (Belgium), with images and discussion of the tablet
New technologies and academic collaborations are helping scholars at the University of Chicago analyze hundreds of ancient documents in Aramaic, one of the Middle East’s oldest continuously spoken and written languages.
Members of the West Semitic Research Project at the University of Southern California are helping the University’s Oriental Institute make very high-quality electronic images of nearly 700 Aramaic administrative documents. The Aramaic texts were incised in the surfaces of clay tablets with styluses or inked on the tablets with brushes or pens. Some tablets have both incised and inked texts.
Discovered in Iran, these tablets form one of the largest groups of ancient Aramaic records ever found. They are part of the Persepolis Fortification Archive, an immense group of administrative documents written and compiled about 500 B.C. at Persepolis, one of the capitals of the Achaemenid Persian Empire. Archaeologists from the Oriental Institute discovered the archive in 1933, and the Iranian government has loaned it to the Oriental Institute since 1936 for preservation, study, analysis and publication.
The Persepolis texts have started to provide scholars with new knowledge about Imperial Aramaic, the dialect used for international communication and record-keeping in many parts of the Assyrian, Babylonian and Persian empires, including parts of the administration at the imperial court of Persepolis. These texts have even greater value because they are so closely connected with documents written in other ancient languages by the same administration at Persepolis.
“We don’t have many archives of this size. A lot of what’s in these texts is entirely fresh, but this also changes what we already knew,” said Annalisa Azzoni, an assistant professor at the Divinity School of Vanderbilt University. Azzoni is a specialist on ancient Aramaic and is now working with the Persepolis Fortification Archive Project at the Oriental Institute. “There are words I know were used in later dialects, for example, but I didn’t know they were used at this time or this place, Persia in 500 B.C. For an Aramaicist, this is quite an important discovery.”
Clearer images delivered more quickly
Scholars from the West Semitic Research Project at the University of Southern California helped the Persepolis Fortification Archive Project build and install an advanced electronic imaging laboratory at the Oriental Institute. Together, the two projects are making high-quality images of the Aramaic texts and the seal impressions associated with those texts. They are distributing the new images to the international research community through the Internet.
Inked and incised texts pose different problems that call for different imaging solutions. Making high-resolution scans under polarized and filtered light reveals the ink without interference from stains and glare, and sometimes shows faded characters that cannot be seen in ordinary daylight. Using another advanced imaging technique, called Polynomial Texture Mapping, researchers are able to see surface variations under variable lighting, revealing the marks of styluses and even the traces of pens in places where the ink itself has disappeared.
Distributing the results online will give worldwide communities of philologists and epigraphers images that are almost as good as the original objects―and in some cases actually clearer than the originals―to study everything from vocabulary and grammar to the handwriting habits of individual ancient scribes.
Researcher Marilyn Lundberg and her colleagues from the West Semitic Research Project built two Polynomial Texture Mapping devices from scratch at the Oriental Institute. They trained Persepolis Fortification Archive Project workers in using them, and also in using filtered light with a camera equipped with a high-resolution scanning device. Now a stream of raw images is uploaded every day to a dedicated server maintained by Humanities Research Computing at Chicago, then uploaded for post-processing at the University of Southern California. Fully processed imagery is available on InscriptiFact, the online application of the West Semitic Research Project, and in the Online Cultural Heritage Research Environment, the online application of the Persepolis Fortification Archive Project.
Seeing the whole picture
The Polynomial Texture Mapping apparatus looks a bit like a small astronomical observatory, with a cylindrical based topped by a hemispherical dome. The camera takes a set of 32 pictures of each side of the tablet, with each shot lit with a different combination of 32 lights set in the dome. After post-processing, the PTM software application knits these images to allow a viewer sitting at a computer to manipulate the apparent direction, angle and intensity of the light on the object, and to introduce various effects to help with visualization of the surface.
“This means that the scholar isn’t completely dependent on the photographer for what he sees anymore,” said Bruce Zuckerman, Director of the West Semitic Research Project and its online presence, InscriptiFact. “The scholar can pull up an image on the screen and relight an object exactly as he wants to see it. He can look at different parts of the image with different lighting, to cast light and shadow across even the faintest, shallowest marks of a stylus or pen on the surface, and across every detail of a seal impression.”
“This is a wonderful way to look at seal impressions,” said Elspeth Dusinberre, another Persepolis Fortification Project collaborator. Dusinberre, an associate professor of classics at the University of Colorado, is studying the imagery and the use of seals impressed on the Aramaic tablets. “Some of the impressions are faint, or incomplete, on curved surfaces or damaged surfaces. Sometimes Aramaic text is written across them. You need to be able to move the light around to highlight every detail, to see the whole picture.”
The Persepolis Fortification Archive also includes about 10,000 to 12,000 other tablets and fragments with cuneiform texts in Elamite―a few hundred of them with short secondary texts in Aramaic. There are also about 4,000 to 5,000 others with impressions of seals, but no texts, and there are a few unique documents in other languages and scripts, including Greek, Old Persian and Phrygian.
“That’s what makes this group of Aramaic texts so extraordinary,” Stolper said. “From one segment of the Persepolis Fortification Archive, the Elamite texts, we know a lot about conditions around Persepolis at about 500 B.C. When we can add a second stream of information, the Aramaic texts, we’ll be able to see things in a whole new light. They add a new dimension of the ancient reality.”
Impacts are far-reaching
The collaboration between the Oriental Institute at Chicago and the West Semitic Research Project at Southern California began with support from a substantial grant from the Andrew W. Mellon Foundation in 2007. To date, the teams have made high-quality images of almost all the monolingual Aramaic Fortification tablets. The next phase of the work, supported by a second Mellon grant that runs through 2010, will make images of the short Aramaic notes written on cuneiform tablets, seal impressions on uninscribed tablets and previously unrecorded Elamite cuneiform texts.
The tablets have been studied since they came to Chicago in 1936, and many of them have been sent back to Iran. Oriental Institute scholar Richard T. Hallock published about 2,100 of the Elamite texts in 1969, and Margaret Cool Root and Persepolis Fortification Archive Project collaborator Mark Garrison are completing a three-volume publication of the impressions made on those documents by about 1,500 distinct seals.
These publications have had far-reaching results. “They have transformed every aspect of modern study of the languages, history, society, institutions, art and religion of the Achaemenid Persian Empire,” Stolper said. “No serious treatment of the empire that Cyrus and Darius built and that Alexander destroyed can ignore the perspectives of the Fortification Archive.”
“If that is the effect of a sample of one component of the archive,” added Garrison, “imagine what will happen when we can have larger samples and other components, and not just the written record, but the imagery, the impressions made by thousands of different seals that administrators and travelers―the men and women who figure in the texts―employed.”
By 2010, the collaborating teams expect to have high-quality images of 5,000 to 6,000 Persepolis tablets and fragments, and to supplement these with conventional digital images of another 7,000 to 8,000 tablets and fragments. The images will be distributed online as they are processed, along with cataloging and editorial information.
“Thanks to electronic media, we don’t have to cut the parts of the archive up and distribute the pieces among academic specialties,” said Stolper. “We can combine the work of specialists in a way that lets us see the archive as it really was, in its original complexity, as one big thing with many distinct parts.”
Using texts and images, a University of Arkansas researcher has for the first time reconstructed the time when the use of porticos -- roof-covered structures supported by columns -- gave way to loggias, or recessed porticos.
In an article in the Journal of the Society of Architectural Historians, architecture professor Kim Sexton accounts for the time between the 7th and 12th centuries when there are no surviving porticos. In European history, loggias represented more than just interesting architectural features. They also served important cultural functions.
"It's important because we had porticos in Roman times, and then they come back in the Renaissance," she said. "It's unaccounted time -- what happened in between?"
Sexton argues that they returned to prominence because different ethnic groups used them "to display their judicial systems." As court proceedings were held outdoors, "they used different styles to frame that." At times there was German law and at other times, Roman law, and certain loggia announced each style.
"In this competitive kind of culture, they start to use the portico again," Sexton said. "From there it comes back into prominence in the Renaissance and late medieval Italy."
Loggias were "used to display activities that were kind of new, and maybe people felt unsure about their value. So that they wanted to display there was something good about the justice system." She compares it to television today, as a powerful medium that can influence behavior.
Loggias and porticos have long interested Sexton. "They seem at once so transparent in their function because they seem like simple shelters," she said. "But then, why did they come to be built with such magnificent architecture by some of the best architects of the Renaissance?"
Sexton discovered images in several medieval sources -- the center of a gem, illustrations of the book of Psalms, illuminations from law codes and encyclopedias. The article's most important image, which is in color on the journal's cover, shows the only known instance of a king in a loggia where a trial is actually in progress.
"If you see them empty, you're not getting what it's about," she said of loggias. "You have to see it when they're full of activity."
Sexton is associate professor of architecture, Fay Jones School of Architecture, University of Arkansas.
miércoles, 20 de enero de 2010
Before Toyota made cars, it made robots. It’s making them again, and wants to use them in a most unusual place.
When it was founded in 1926, Toyoda Automatic Loom Works (as it was then known) manufactured automatic fabric looms that could detect problems and shut down automatically. It marketed these revolutionary devices as having “autonomation” — automation with human intelligence.
Now Toyota, looking ahead at the second half of this century, sees a mounting health care crisis and aging population coming to Japan. It sees a future where manufacturing robotic workers is the hot new industry and “autonomation” takes on a whole new meaning.
And the first place we might see these robots is in hospitals.
Japan’s aging population and low birthrate point to a looming shortage of workers, and Japan’s elder care facilities and hospitals are already competing for nurses. This fact has not escaped Toyota, which runs Toyota Memorial Hospital in Toyota City, Japan. Taking a lead from Honda, Toyota in 2004 announced plans to build “Toyota Partner Robots” and begin selling them in 2010 after extensive field trials at Toyota Memorial.
Toyota doesn’t see these machines serving only as nurses. They’re also being designed to provide help around the house and do work at the factory. But it’s the idea of robotic nurses that drew support when Japan’s Machine Industry Memorial Foundation estimated Japan could save 2.1 trillion yen (about $21 billion) in health care costs each year using robots to monitor the nation’s elderly.
This is more than some futuristic fantasy. The government is drafting safety regulations for service robots, which would include nursing droids. A new agency, the Energy and Industrial Technology Development Organization, has launched a five-year project to improve safety standards for the machines. The South Korean Government has even drawn up a code of ethics for how robots should treat humans and, perhaps ironically, how humans should treat robots.
Toyota's 'partner robot' makes a little music.
“As aging of the population is a common problem for developed countries, Japan wants to become an advanced country in the area of addressing the aging society with the use of robots,” Motoki Korenaga, a ministry of trade and industry official, told Agence France-Presse.
It isn’t so far-fetched. Japan leads the world in building robots, and the bots show remarkable skill. Honda’s famous android, Asimo, has served tea, conducted the Detroit Symphony Orchestra and freaked-out James May of the BBC program Top Gear. Toyota’s robots have even played the violin and the trumpet.
Of course, there’s a huge difference between waving a conductor’s baton and providing aid and comfort to grandma. But Japan’s biggest automakers are determined to make this work. Honda has spent hundreds of millions of dollars developing its human-like robots, and Toyota has 200 people working on the project full-time. To put that in perspective, it might assign 500 engineers to developing a new car platform. Toyota also is working with at least 10 corporate suppliers and 11 universities.
Toyota’s experience building cars, particularly hybrids, will be invaluable. It makes all of its own motors, batteries and power electronics, and it has worked with electronics giant NEC to develop specialized computer vision processors. All are critical components for robots. And like Honda, Toyota’s robot and autonomous vehicle programs are sharing sensing, mapping and navigation technologies. And the automotive giant has the added advantage of running a hospital where it can test its robo-nurses. Toyota says the first of them could be in service next year, and their descendants could be working on the moon by 2020. Seriously.
Toyota and Honda aren’t going to stop building cars, but both see a big market for robots. Toyota is so bullish on bots, it sees them becoming a core business by 2020 (.pdf). Some may see these machines as a threat to our jobs, if not our safety — particularly if they’re serving as nurses. The last thing people want is T-100 checking their IV drip. But the Japanese seem to be thinking of bots like Astroboy — loyal creations willing to sacrifice themselves to save their humans friends.
Either way, Japan’s biggest automakers are doing what they can to make robots a reality.
The dreaded wood-eating shipworm is invading northern Europe's Baltic Sea. The animal threatens to munch through thousands of Viking vessels and other historic shipwrecks, scientists warn.
The sea's cool, brackish waters have for centuries protected the wrecks from the wormlike mollusks. But now global warming is making the Baltic Sea (map) more comfortable for the critters, a new study speculates.
Shipworms, which can obliterate a wreck in ten years, have already attacked about a hundred sunken vessels dating back to the 13th century in Baltic waters off Germany, Denmark, and Sweden, reported study co-author Christin Appelqvist.
"Since 1990 there has been a big range expansion in the southern Baltic," said Appelqvist, a marine biologist at the University of Gothenburg in Sweden.
Until recently the wood-boring molluscs, which generally require relatively salty waters, were unable to survive in the low-salt Baltic.
Why shipworms are suddenly able to spread there remains a mystery, but studies suggest rising sea temperatures have something to do with it. In warmer water the animals, Appelqvist said, appear to be somehow "less stressed" by low salinity.
Global Worming Disaster?
The shipworm invasion could prove disastrous for marine archaeology in the region, home to long-submerged prehistoric timber settlements and remarkably preserved wrecks such as the salvaged 17th century Swedish warship the Vasa, a major museum attraction in Stockholm.
To defend the region's well-preserved wrecks from shipworms, researchers have suggested draping submerged vessels in polypropylene covers or covering e ships with seabed sediments and sandbags.
Such a project could reach positively oceanic proportions, given that the Baltic holds about a hundred thousand well-preserved shipwrecks—and counting.
"Really nice tall ships with the mast and everything intact are still being discovered," Appelqvist said. "Every time [researchers] go down there with remotely operated vehicles they find new wrecks."
Two predatory dinosaurs known as Guanlong wucaii struggle in a muddy pit in a painting of China's Xinjiang region during the late Jurassic period, about 160 million years ago. Guanlong, which means "crested dragon," was a small theropod, a group of bipedal raptors from the lineage that includes Tyrannosaurus rex.
The painting depicts one of China's mysterious dinosaur "death pits"—3.5- to 6.5-foot-deep (1- to 2-meter-deep) depressions filled with the largely complete skeletons of several small theropod species. Now a new study has pinpointed a possible origin of the traps: They may be the mud-filled footprints of the 20-ton sauropod dinosaur Mamenchisaurus.
lunes, 18 de enero de 2010
Deep inside the tomb of Scorpion I (no relation to the Rock), scientists discovered Egypt's oldest wines.
And now it appears the 5,000-year-old wines were spiked with natural medicines—centuries before the practice was thought to exist in Egypt, researchers say.
Archaeochemist Patrick McGovern and colleagues found chemical residues of herbs, tree resins, and other natural substances inside wine jars from the tomb, the previously discovered resting place of one of Egypt's first pharaohs (ancient Egypt time line).
While the additives may have been flavorful, they were picked for their medical benefits, said McGovern, of the University of Pennsylvania Museum of Archaeology and Anthropology.
The early Egyptians "were living in a world without modern synthetic medicines, and they were very aware of the benefits that natural additives can have—especially if dissolved into an alcoholic medium, like wine or beer," which breaks down plant alkaloids.
Papyrus records from as long ago as 1850 B.C. detail how such medicinal tipples were made to treat a range of ailments.
"Now this chemical evidence pushes that date back another 1,500 years," McGovern said.
Scorpion I's wines predate the advent of Egyptian vineyards and were imports from the Jordan River valley.
The wines suggest that imports from the southeastern Mediterranean contributed to the Egyptian pharmacopoeia, which laid the groundwork for Greek and Roman medical traditions.
The wine find is just one of several from ancient Egypt, China, and elsewhere that document ancient medicinal mixology.
"Over thousands of years, humans were searching their environment and trying to find natural medicinal materials," McGovern said. "They were tested empirically over generations, but then many were lost."
Now, collaborating with researchers at Penn Medicine's Abramson Cancer Center, McGovern's team is using biomolecular analysis to uncover the ancient wine-medicine recipes and hopefully put them to the test.
"We're trying to rediscover why ancient people thought these particular herbs were medically useful," he said, "and seeing if they are effective for the treatment of cancer or other modern diseases."
Findings to be published in tomorrow's issue of the journal PNA
Cleopatra and her kin knew a thing or two about crafting an alluring smoky eye.
Now French researchers suggest that the ancient Egyptians' heavily painted eyelids did more than attract admirers—they also protected against eye infections.
Artifacts and documents from ancient Egypt show that everyone, man or woman from servant to queen, wore black and green powders coated thickly around the eyes.
"People wore it on a daily basis," said study co-author Christian Amatore, from the Université Pierre et Marie Curie in Paris, France.
According to ancient Egyptian manuscripts, the eye makeup was believed to have a magical role, in which the gods Horus and Ra would protect wearers against several illnesses.
Bacterial eye infections such as conjunctivitus, for example, would have been a common problem along the Nile's tropical marshes.
But previous chemical analyses of powder residue, taken from ancient makeup containers, had isolated four lead-based compounds.
That would seem to suggest that the makeup was harmful, since lead can be highly toxic to humans.
Makeup's "Magic" Required Hard Work
Instead, the new study found that the low doses of lead salts in the makeup may have actually had beneficial properties: When the salts come into contact with skin, they boost the body's production of nitric oxide.
This chemical is known to stimulate the immune system and help fight off disease-causing bacteria.
Based on the amount of the lead compounds in the ancient makeup, a wearer's nitric oxide levels would have increased by 240 percent, the study found.
"Two of these chemicals do not occur naturally, and would have taken 30 days of hard work to make," Amatore said.
"In my opinion, [the ancient Egyptians] were aware that these compounds brought good health, and they were making them on purpose."
The research is detailed in the January 15, 2010, issue of the journalAnalytical Chemistry.
miércoles, 13 de enero de 2010
Wired Science News for Your Neurons Earth to Get Close Shave Wednesday From Newly Discovered Asteroid
An asteroid 30 to 50 feet across will pass by the Earth at just more than one-third the distance between the Earth and the moon on Wednesday. That’s the closest near-Earth object approach currently known between now and the flyby in 2024 of a similar-size object known as 2007 XB23.
The new asteroid, called 2010 AL30, was discovered by the NASA-funded Lincoln Near-Earth Asteroid Research program, and announced Monday by the Minor Planet Center at the Smithsonian Astrophysical Observatory.
The short amount of time between the spotting of the object and its near intersection with Earth is a good reminder that humans don’t know every object that could come hurtling out of space and collide with our planet.
“Visitors frequently ask me if I worry about the NEOs that I measure,” wrote Dr. P. Clay Sherrod of the Arkansas Sky Observatories, on a forum thread discussing the asteroid. “My response: ‘I don’t worry about those that we keep up with…. I am more concerned about the ones we never see coming.”
To see how close the asteroid will get, check out this animation of the asteroid’s Earth approach (.avi) by Gerhard Dangl, an Austrian astronomer.
It should be noted that an asteroid this small probably would not cause major damage were it to impact Earth’s atmosphere, and would probably burn up before it reached the planet’s surface.
The new object will remain about three times farther away from Earth than Apophis, which has been the subject of much recent discussion, will in 2029.
Nearly 500 miles of data-transmitting cable will make NEPTUNE Canada's new Pacific Ocean observatory the largest of its kind. Underwater cameras will also capture seafloor wildlife.This week, scientists in Canadas British Columbia began collecting data from hundreds of scientific instruments on the seafloor of the Pacific Ocean using the largest and most advanced cabled ocean observatory in the world.
While data collection is its primary goal, underwater cameras add to the allure of this project, so scientists can see the animals living on and near the ocean floor.
Nearly 500 miles of looped cable carries both electricity and fiber optic lines for data transmission in both directions for the project known as NEPTUNE Canada. NEPTUNE is an acronym for North-East Pacific Time-series Underwater Networked Experiments.
The observatory, with 6 sites for data collection, stretches from Vancouver Island, over the Pacifics continental shelf, and into deep ocean.
The projects data collection is available to the public- scientists and students can log onto the internet to see the information.
NEPTUNE Canada, and its sister program VENUS, is coordinated by the University of Victoria with funding from the Canadian and British Columbia governments. Its intended to enhance scientists abilities to gather ocean data allowing 24/7 collection, rather than data from infrequent voyages and dives.
One oceanographer using NEPTUNE Canada is 3,000 miles away on the countrys east coast in St. Johns, Newfoundland.
SOUNDBITE: Paul Snelgrove, Memorial University of Newfoundland Ship costs are quite extensive, and were also very lucky if were able to get out there for even a week or two per year. So for the rest of the year, we have to try and guess whats going on. This is problematic because we think that unpredictable events like storms and underwater landslides can be very important. /With VENUS and NEPTUNE, our team can be there any time, to see whats happening on the sea floor and making decisions on how to sample, even though our group is scattered between Victoria and St. Johns.
Part of NEPTUNE Canadas aims include applications in the areas of climate change, earthquake and tsunami research, ocean productivity, non-renewable marine resources, and marine animal studies.
NEPTUNE Canada has been in the making for a decade, and its expected to provide information about the ocean floor for the next 25 years.
In the black depths of the frigid Arctic Ocean, scientists on a 2005 expedition found a splash of color: The brilliant, blood-red Crossota norvegica jellyfish (pictured).
The creature was spotted by a remotely operated vehicle 8,530 feet (2,600 meters) underwater during a two-month National Oceanic and Atmospheric Administration (NOAA) expedition to the Canada Basin, the deepest and least explored part of the Arctic waters.
Though C. norvegica is not a new species, several new deep-sea animals were discovered during the expedition--some of which were announced in recent research papers in 2009.
Biologist and team member Kevin Raskoff, of Monterey Peninsula College in California, was surprised at the diversity of jellyfish living in the extreme polar seas.
"We knew there were going to be interesting jellies up there," Raskoff said by email, "but the reality surpassed all of our imaginations!"
A Haitian woman emerges from the rubble on January 12 in the capital Port-au-Prince (Haiti map), which was completely devastated by a magnitude 7 earthquake.
The Haiti earthquake toppled buildings, including the president's National Palace, a hospital, and schools, trapping untold numbers in the debris and killing perhaps thousands of others.
After the Haiti earthquake, witnesses described "general mayhem" in the impoverished Caribbean city, which has no electricity, phone service, or passable roads, the New York Times reported.
"We can hear people calling for help from every corner. The aftershocks are ongoing and making people very nervous," observer Kristie van de Wetering told the Times.
As the dust settles following the Haiti earthquake, experts expect "catastrophic" damage and loss of life, the newspaper said. A third of Haiti's nine million people may need emergency aid, according to the International Red Cross.
Nearly a century after Capt. Robert Falcon Scott explored the southern continent, experts are working to save the British explorer's wooden hut (pictured on Ross Island, Antarctica, in August 2006) and three others in the area from slipping under the snow forever.
The sanctuary measures 50 feet (15 meters) long and 25 feet (7.6 meters) wide and was built to house up to 33 men.
Scott and his crew stayed at the hut before their ill-fated Terra Nova expedition to the South Pole in January 1912. Scott and four others died after being beaten to the pole by Norwegian explorer Roald Amundsen.
"Had we lived," Scott wrote in March 1912 in a message found with his body, "I should have had a tale to tell of the hardihood, endurance and courage of my companions which would have stirred the heart of every Englishman.”
A stash of frozen butter (pictured in December 2009) was recently discovered by experts excavating Scott's expedition base, including his hut.
The butter, which had lain hidden in the stable yard for a hundred years, was made by the Canterbury Central Co-operative Dairy Company in New Zealand.
Scott's ship, the Terra Nova, would've sailed from England with dry goods, said Rachel Morgan, a spokesperson for the Antarctic Heritage Trust, a nonprofit devoted to preserving the huts of Scott and other Antarctic explorers.
But "perishables like butter couldn't be taken through the tropics, so they had to source such things in New Zealand," Morgan said.
The dining table in the Terra Nova hut (pictured in 2009) still contains bottles and containers that Scott's crew used during meals.
Despite the cramped quarters, the hut was still divided into officers' quarters and "men's" quarters. Each group took their meals separately, Antarctic Heritage Trust's Morgan said.
viernes, 8 de enero de 2010
The first vertebrates to walk the Earth emerged from the sea almost 20 million years earlier than previously thought, say scientists who have discovered footprints from an 8-foot-long (2.4-meter-long) prehistoric creature.
Dozens of the 395-million-year-old fossil footprints were recently discovered on a former marine tidal flat or lagoon in southeastern Poland (prehistoric time line).
The prints were made by tetrapods—animals with backbones and four limbs—and could rewrite the history of when, where, and why fish evolved limbs and first walked onto land, the study says.
Because they are thought to have evolved from such creatures, reptiles, birds, and mammals—including humans—are today classified as tetrapods.
"These are the oldest tetrapod tracks and also the oldest evidence of true tetrapods," study co-author Grzegorz Niedƃwiedzki, a paleontologist at Warsaw University, commented via e-mail.
The tracks were made by several individuals of a four-limbed species that had digits, or toes, on each foot, according to the research.
"We are dealing with creatures that were walking," said Marek Narkiewicz, a geologist at the Polish Geological Institut and co-author of the study, to be published tomorrow in the journal Nature.
The footprints vary in size, some as wide as 10 inches (26 centimeters). The track sizes and shapes indicate flat-bodied, lizard-like creatures up to 8.2 feet (2.5 meters) long with stout legs, the researchers said.
Oldest Tetrapod Tracks
Discovered in an abandoned mountain quarry, the tracks suggest that tetrapods were traipsing the planet 18 million years earlier than previously indicated by the fossil record.
The tracks are also ten million years older than the oldest known fossils of lobe-finned fishes called elpistostegids, which are widely considered to be transitional forms between fish and tetrapods. (See a surviving lobe-finned fish, the coelacanth.)
The age of the newfound tracks suggest that "these transitional fish continued to exist alongside the tetrapods for quite some period of time," said Per Ahlberg, a paleontologist at Uppsala University in Sweden, who led the new research.
It's not so strange for one type of animal to live alongside its evolutionary successors, Ahlberg noted. Several feathered dinosaurs, for example, "continued to exist alongside the birds for millions of years."
The finding also suggests the fins-to-limbs evolution occurred in an intertidal or lagoon environment rather than a seasonally flooded forest, as indicated by earlier finds.
The tidal "scenario has considerable explanatory power," the researchers write in Nature.
Due to the regular coming and going of the tides, marine ancestors of tetrapods, for example, would have had easy access twice a day to marine animals stranded at low tide.
This reliable smorgasbord would have helped tetrapod ancestors find their legs, so to speak.
"If you're picking off dead and moribund animals in the strand land—those things left behind by the receding tide—well then you don't need to be terribly good at moving around," Ahlberg noted.
"You just need to be able to haul your way out, eat what you want to eat, and then haul your way back into the water again."
More Tetrapod Footprints Fossils Needed
The new tetrapod finding "could lead to significant shifts in our knowledge of the timing and ecological setting of early tetrapod evolution," said paleontologist Ted Daeschler via email. Daeschler studies fish-to-tetrapod evolution at the Academy of Natural Sciences in Philadelphia, Pennsylvania, but was not involved in the Nature study.
Daeschler notes, however, that tracks and trackways are notoriously difficult to interpret "with full confidence," and he's awaiting more evidence before abandoning existing explanations for the transition.
"No doubt that I will keep an open mind and keen eye on future developments," he said.
Vampires as an endangered species? Daybreakers takes the premise and sinks its fangs into the notion that sucking too much blood is just as unsustainable as overfishing. Neither a teen-friendly Twilight clone nor a True Blood-style Southern Gothic romp, Daybreakers is scarier than most contemporary takes.
The setup: Vampires have sucked the planet nearly dry and driven humans to the brink of extinction. The resultant blood shortage threatens vampire survival and sends scientists and money-hungry corporations on a race to find a substitute.
The R-rated Daybreakers, opening Friday, depicts a future world dominated by vampires. No longer shadowy outcasts, vampire cops try to control vampire riots when the blood supply falters. Vampire scientists work in vampire-run labs. Homeless vampires live beneath city streets and devolve into something far worse than hungry hobos when they can’t find food.
jueves, 7 de enero de 2010
The universe is one big dance party for black holes. New observations from the W.M. Keck Observatory in Hawaii and the Hubble Space Telescope found 33 merged galaxies in which pairs of supermassive black holes are “waltzing” around the galactic centers.
sciencenews“Our result shows that such waltzing black holes are much more common than we previously knew,” said Julie Comerford of the University of California, Berkeley. Comerford presented her results on January 4 at the winter meeting of the American Astronomical Society.
Finding pairs of black holes moving in a certain way can help estimate how often galaxy mergers occur in the universe. Observations have shown that nearly every galaxy has a supermassive black hole — a black hole with a mass of one million to one billion times that of the sun — at its center and that galaxies often collide and merge to create larger galaxies. Astronomers have expected to find many mid-merge galaxies by focusing on the two supermassive black holes, which should be orbiting each other in the middle. But so far, the dance floor has pretty much been empty.
“We expect the universe to be littered with these waltzing black holes,” Comerford said. “But until recently, only a few had ever been found.” Those missing black hole pairs posed problems for theories of how galaxies merge and grow.
Now, using two new observational techniques, Comerford and her colleagues have found 33 galaxies with dual supermassive black holes. The first technique found 32 black hole pairs in the DEEP2 Galaxy Redshift Survey conducted on the Keck II Telescope on Hawaii’s Mauna Kea, by determining whether each black hole is moving toward or away from Earth.Black holes are visible only when they can accrete gas and other material from the surrounding environment. Energy from the black hole heats the gas, lighting the gas up in visible wavelengths. When the black hole is moving away from Earth, the light from the accreted gas appears to be at a longer wavelength, or redshifted. When the black hole dances toward Earth, its light is blueshifted — meaning it has a shorter wavelength. The team identified waltzing pairs by looking for instances when one black hole was blueshifted and the other redshifted.
“It’s kind of the disco ball that tells you where the party is, where the black holes are dancing,” Comerford said.
The waltz is quick — both black holes are moving at velocities of about 200 kilometers per second. But the black holes are keeping “a chaste distance,” Comerford said. They are separated on average by about 3,000 to 8,000 light-years, or one-eighth to one-third the distance from the sun to the center of the Milky Way.
For the population of galaxies Comerford and her colleagues observed, which were mostly gas-poor galaxies 4 billion to 7 billion light years from Earth, galaxy mergers occur three times every billion years, Comerford said.
The final black hole duo was found serendipitously in a Hubble image of a galaxy called COSMOS J100043.15+020637.2. The galaxy sports a tidal tail of stars, gas and dust, a sure sign of a recent galaxy merger.
“It’s like a black eye, a sign that this galaxy has recently gone through a collision with another galaxy,” Comerford said.
The galaxy also has two bright nuclei, each of which could be a supermassive black hole surrounded by glowing dust and gas. Follow-up observations with the Keck II Telescope showed the telltale velocity shifts of dancing black holes.
But the black holes might not be two waltzers. Instead, the data could point to one black hole that is fleeing the galaxy. When two black holes merge together, they produce gravitational waves that carry momentum away from the resulting larger black hole. Gravitational waves pointed mostly in one direction can “kick” the black hole in the opposite direction. Black holes could wander through their host galaxies, or, if the kick is large enough, leave the galaxy behind.
Observations of the same galaxy by Francesca Civano of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and colleagues suggest that the two bright sources are flying apart at a velocity of about 1,300 kilometers per second. Civano also presented her results at the American Astronomical Society meeting on January 4.
“For a merger, that is a bit high,” Civano said. “But this number is completely normal for a gravitational wave kick.”
“Whether this thing is a dual pair of waltzing black holes or an ejected black hole, this is definitely a merger,” Comerford said. “It’s just whether you’re seeing it before the black holes merge [with each other] or after.”
A seam of coal formed 250 million years ago during worst extinction event on record appears to be responsible for the anomalously high lung cancer death rates among women in the rural Chinese county of Xuan Wei in Yunnan Province.
It’s long been known that the lung cancer mortality rates in the region were the worst in the world among female nonsmokers and some anomaly in the coal had been suspected. Lung cancer mortality in the region is up to 20 times the Chinese average. But it’s only in recent years that scientists have focused in on silica in the form of very fine quartz as the mineral that makes burning the stuff so deadly.
Now, in a paper published in December in Environmental Science and Technology, Chinese, British, and American researchers have proposed a link between the silica in the coal and the massive event that nearly wiped out life at the Permian-Triassic boundary.
“What we’re saying is that the geologic and climatic events that nearly extinguished life 250 million years ago is still having an impact because its imprint is in the coals that the people are using,” said Bob Finkelman, a geologist at the University of Texas, Dallas. “They are inhaling this material with nanoquartz that was precipitated 250 million years ago and in a sense it’s extinguishing life in the community
While relatively few people were looking, an unusual eclipse darkened New Year's Day.
On January 1 a giant space object blotted out our view of Epsilon Aurigae, a yellow supergiant star about 2,000 light-years from Earth. Based on studies of Epsilon Aurigae's previous eclipses, astronomers expect the star won't fully regain its bright shine until early 2011.Normally the star is so bright it can be seen with the naked eye even by city dwellers. For all but the most rural star-gazers, though, the mystery object that eclipses the star causes it to vanish for about 18 months every 27.1 years.
Ever since the star's periodic eclipses were first recorded in 1821, astronomers have been puzzling over how Epsilon Aurigae pulls off its lengthy disappearing act.
Now, "using data from the Spitzer Space Telescope, we've reached a solution to a nearly two-century-old mystery," study leader Don Hoard, of the California Institute of Technology, said today at an American Astronomical Association press briefing in Washington, D.C.
According to the new model, Epsilon Aurigae is a dying star being orbited by another star, and that stellar dance partner is cloaked in a wide disk of dark dust.
Based on the new Spitzer data, Hoard's team thinks the eclipse lasts so long because the dark disk is about 744,000,000 miles (1,197,351,936 kilometers) across—eight times as wide as the distance from Earth to the sun.
Binary star systems have long been known to cause stellar eclipses as seen from Earth. Epsilon Aurigae is unusual, though, because it has the longest lasting known eclipse.
The 18-month eclipse started last August, but it took the disk until now to fully obscure Epsilon Aurigae.
"If the eclipse was simply being caused by another [darker] star passing in front of the visible star, it shouldn't last that long," Hoard said.
Astronomers had suggested in the 1950s that whatever is passing in front of Epsilon Aurigae is masked by a disk of material.
The new Spitzer data, combined with readings of other light waves from ground and space-based observatories, suggest that the star inside the disk is a B-type, a blue star three times as hot as our sun.
At first, the team wasn't sure how to explain the readings.
Assuming Epsilon Aurigae is as massive as other similar stars, a lone B star, Hoard said, shouldn't be massive enough to generate enough gravity for the binary pair to orbit they way they do.
"So then we started thinking, Well, we need more mass but no more light" in the system for the disk model to work, he said.
The team started by wondering whether something else might join the B star at the center of the disk.
A black hole would add the mass the scientists thought was needed, but it would also add more light than has been observed in the system. That's because a black hole would gobble up matter from the disk, then spit it out in the form of detectable radiation. (Related: "Black Hole's "Jet Power" Revealed.")
Perhaps, though, the object in the disk wasn't the problem at all, the astronomers thought, but rather Epsilon Aurigae itself.
"So we back up for a minute and say, OK, what if [Epsilon Aurigae] is not a massive supergiant star? What if it's a low-mass … dying star?" Hoard said.
Such a star "can be big, but it doesn't have to have a lot of mass," Hoard said.
"And if we start with that assumption, everything just falls nicely into place."
In other words, the model of a large but low-mass star orbited by a B star shrouded in dust matches the centuries of data collected so far on Epsilon Aurigae—potentially explaining once and for all how the long, strange eclipse is possible.
"Details Need to Be Worked Out"
Other experts, however, are not quite ready to close the case file.
"Don says that we've solved it. I disagree," said Arne Henden, director of the nonprofit American Association of Variable Star Observers.
Even with the new model, he argued, the Epsilon Aurigae system is full of mysteries, such as the structure and composition of the supposed dark disk.
"What is the nature of this dusty disk? These are things you normally see around young stellar objects," said Henden, who is also a senior research scientist for the Universities Space Research Association at the U.S. Naval Observatory in Flagstaff, Arizona.
But the blue star in the new model would be much older, and its dusty disk seems to be filled with unusually large particles.
"There are still a lot of details that need to be worked out," study leader Hoard agreed.
Backyard Astronomers to the Rescue?
Both astronomers hope that during the current Epsilon Aurigae eclipse, modern technology combined with extensive public participation will help answer the lingering riddles.
Henden's star-observer organization is helping to organize a project called Citizen Sky, in which backyard astronomers are being trained to monitor Epsilon Aurigae's eclipse from start to finish.
Since the project's launch last September, more than 120 people in 19 countries have already submitted data.
"Technology has evolved tremendously since the last eclipse [in 1984], and amateur astronomers are able to get exquisite detail on a nightly basis," Henden said.
Aside from engaging the public in astronomy, he added, the Citizen Sky project "shows that classical astronomy"—using earthbound, optical telescopes—"is still alive and well."