New research into national education systems gives the first ranking of countries which are the 'best' at providing higher education.
The Universitas 21 Ranking was announced May 11, 2012 at an event at Lund University in Sweden. Universitas 21, a leading global network of research universities, has developed the ranking as a benchmark for governments, education institutions and individuals. It aims to highlight the importance of creating a strong environment for higher education institutions to contribute to economic and cultural development, provide a high-quality experience for students and help institutions compete for overseas applicants.
Rankings.
Research authors at the Melbourne Institute of Applied Economic and Social Research,University of Melbourne, looked at the most recent data from 48 countries across 20 different measures. The range of measures is grouped under four headings: resources (investment by government and private sector), output (research and its impact, as well as the production of an educated workforce which meets labour market needs), connectivity (international networks and collaboration which protects a system against insularity) and environment (government policy and regulation, diversity and participation opportunities). Population size is accounted for in the calculations.
Overall, in the Universitas 21 Ranking of higher education systems, the top five were found to be the United States, Sweden, Canada, Finland and Denmark.
Government funding of higher education as a percentage of GDP is highest in Finland, Norway and Denmark, but when private expenditure is added in, funding is highest in the United States, Korea, Canada and Chile. Investment in Research and Development is highest in Denmark, Sweden and Switzerland. The United States dominates the total output of research journal articles, but Sweden is the biggest producer of articles per head of population. The nations whose research has the greatest impact are Switzerland, the Netherlands, the United States, United Kingdom and Denmark. While the United States and United Kingdom have the world's top institutions in rankings, the depth of world class higher education institutions per head of population is best in Switzerland, Sweden, Israel and Denmark.
The highest participation rates in higher education are in Korea, Finland, Greece, the United States, Canada and Slovenia. The countries with the largest proportion of workers with a higher level education are Russia, Canada, Israel, United States, Ukraine, Taiwan and Australia. Finland, Denmark, Singapore, Norway and Japan have the highest ratio of researchers in the economy.
International students form the highest proportions of total student numbers in Australia, Singapore, Austria, United Kingdom and Switzerland. International research collaboration is most prominent in Indonesia, Switzerland, Hong Kong SAR, Denmark, Belgium and Austria. China, India, Japan and the United States rank in the bottom 25 percent of countries for international research collaboration. In all but eight countries at least 50 percent of students were female, the lowest being in India and Korea. In only five countries were there at least 50 percent female staff; the lowest being in Japan and Iran.
Lead author, Professor Ross Williams at the University of Melbourne, said: "In a globalised world, a strong higher education system is essential if a nation is to be economically competitive.
"While there are a number of well-regarded global rankings of individual institutions, these don't shed any light on the broader picture of how well a nation's system educates its students, the environment it provides for encouraging and supporting excellence. Students choose countries to study in as much as individual institutions, and the Universitas 21 Ranking offers clear data to support decision-making."
Read more at Science Daily
May 12, 2012
How Nature Shapes the Birth of Stars
The team, based at the University of Bonn in Germany, publish their results in the Monthly Notices of the Royal Astronomical Society.
Stars are thought to form in interstellar space from dark clouds of gas and dust. Their properties are expected to depend on the conditions of their dusty birth environment, in the same way that the temperature and constitution of clouds on Earth determines whether we experience drizzly weather, rain with large or small droplets, or a hail shower. In contrast, until now stars have appeared to unexpectedly form in the same manner everywhere. "Sites of star formation are the bad weather regions in a galaxy and the forming stars are, in a very rough analogy, like the raindrops condensing out of this material," comments team member Prof. Dr. Pavel Kroupa.
The group of scientists now have evidence that the mass distribution of stars does indeed depend on the environment in which they form. "Surprisingly, this evidence does not come to us from young regions of ongoing star formation, but from a very old class of objects, so called globular star clusters," says Dr. Michael Marks, lead author of the new paper. "The number of observed stars less massive than our Sun in globular clusters is at odds with their structure."
Globular clusters are massive congregations of thousands stars surrounding our Galaxy, the Milky Way. Star formation in these clusters ceased billions of years ago. "Nevertheless, using our simulations we found that the connection between star formation and birth environment can be understood when invoking a process that occurs very early in the life of any cluster, called residual-gas expulsion," continues Marks.
Once a star completes its formation it starts to shine and eventually the radiation coming from the cluster of freshly-hatched stars quickly drives out the gas from which they formed. The region of star birth is then destroyed, leaving behind stars of different masses. "This process leads to expansion of the whole aggregate of stars with the accompanying stripping of some of the stars from the cluster by the gravitational attraction of the young Milky Way. The faster the gas is blown out the stronger is the expansion and the more stars are removed," Kroupa explains. He adds, "The imprint of this process is still visible in the present-day mass distribution." This means that careful observations of present-day stellar populations in globular clusters allow their initial star content to be reconstructed.
The astronomers find globular clusters must have formed with many more massive stars than are counted in individual star forming regions today. "Otherwise the star birth region a globular cluster formed from is not destroyed quickly enough and the subsequent expansion is too weak to remove enough stars from the cluster," says Marks. "If this had happened the distribution of masses of stars we see today would be quite different." The deduced differences in the number of massive stars having formed in globular clusters depending on the cloud conditions is indeed in agreement with theoretical expectation.
According to their results, differences in the initial star content appear only when conditions in the star birth regions are very extreme compared to those we see today. "We do not observe these extreme environments in the present day, but these may have well been frequent when globular clusters were born around 12 billion years ago," Marks states. Their work predicts that stars form in the same way, with the same range of masses, in different sites in the present day Milky Way.
Read more at Science Daily
May 11, 2012
Tour the Pyramids Online
Engineered by software design firm Dassault Systèmes, in collaboration with Harvard University and the Museum of Fine Arts in Boston, the free application is available on multiple devices, including 3-D-enabled computer monitors and TVs, and immersive environments.
Indeed, this is not just another too-clean looking and ultimately boring 3-D virtual tour of Egypt's famous archaeological site.
"Many 3-D models of ancient sites have more to do with fantasy and video games than with archaeology. The colors, surfaces and textures are not researched and appear quite flat or unrealistic," Peter Der Manuelian, Philip J. King professor of Egyptology at Harvard University and director of the MFA's Giza Archives, told Discovery News.
"Our reconstructions strive to reflect as much existing excavation data as possible, and that includes a meticulous study of ancient colors, inscriptions, textures of walls, buildings and objects," Manuelian said.
The project draws on the work of George Andrew Reisner (1867-1942), an American Egyptologist who directed the work of the Harvard University—Museum of Fine Arts Boston Expedition at the Giza Plateau more than a century ago.
One of the first archaeologists to apply photography to excavation, Reisner is the main reason that the MFA boasts one of the finest Egyptian collections outside Egypt.
Practically unused until the beginning of the 1970s, this immense resource has been completely digitized and is now accessible within the Giza 3D project.
Read more at Discovery News
What's the Deal with 'Super-Earth' Exoplanets?
But don't let the name fool you. Super-Earths have very little in common with our own planet. That's not to say the discovery isn't fascinating, but it's more science as usual than the discovery of our next home.
There are many parts to this story, like the part about 55 Cancri e. It isn't a new find. Astronomers discovered it in 2005 and have since determined that it's one of five planets in a solar system orbiting the star 55 Cancri about 41 lightyears away in the constellation Cancer. They also know that 55 Cancri e orbits extremely close to its parent star and its star-facing side is heated and emits a thermal glow -- that's the infrared emission Spitzer picked up.
This isn't the first planet Spitzer has observed directly either -- usually astronomers "see" planets by a telltale dip in the brightness of the parent star as they pass in front of it (i.e. the "transit method"), or the "wobble" of a star as an exoplanet orbits it (i.e. the "radial velocity method"). But the $770 million telescope, which was launched in 2003, is searching for exoplanets directly by detecting their glow in the infrared spectrum.
Hot Jupiters are gas giants that orbit their parent stars closer than Mercury orbits our Sun. These are big planets with big surfaces that reflect a lot of light and generate a lot of heat making them easier for telescopes to find. That Spitzer measured 55 Cancri e directly is impressive since as a super-Earth, it's much smaller than a hot-Jupiter and gives off a lot less light.
It's 55 Cancri e's classification as a super-Earth that's a little problematic. The term may be intuitive to astronomers, but to the rest of us it's incredibly misleading.
With the familiar name "Earth," it's easy to see why people read "super Earth" and get really excited. Our home planet Earth is pretty super. We have a temperate climate, fresh water, ample sunlight, a protective magnetic field, and a balanced atmosphere. Earth has everything that makes life possible. By extension, and by linguistic convention, a super-Earth should be better -- a bigger Earth with more fresh water, beach weather year round, a thicker or richer atmosphere, and anything else that could improve our own planet.
In actuality, super Earths are quite different from our Earth. Super Earths have masses roughly 10 times greater than Earth's, but 55 Cancri e shares its rocky nature with Earth -- that’s where the similarities end, however. But that isn't to say it’s not a really neat planet.
Read more at Discovery News
Mayan Ruins Describe Dates Beyond 2012 'Doomsday'
This shocking news has been revealed inside ancient ruins of the sprawling Maya city of Xultún in Guatemala's Petén region, supporting what archaeologists have known for a long time: the Mayans never predicted doomsday on Dec. 21, 2012.
During a National Geographic Society funded dig in the rainforest region, archaeologists uncovered a structure adorned with wonderfully preserved paintings and scrawled numbers -- apparently the workspace for the town's scribe some 1,200 years ago. The numbers have been identified as dates in the Maya calendars. As the ancient civilization developed extremely accurate ways to track celestial objects, many of these calendars relate to astronomical cycles.
According to lead archaeologist William Saturno of Boston University, the calendars mentioned are the 260-day ceremonial calendar, the 365-day solar calendar, the 584-day cycle of the planet Venus and the 780-day cycle of Mars.
The building, that was spotted by Saturno's student Max Chamberlain in 2010, was likely built before A.D. 890, a year when the last carved monument in Xultún was created, shortly before the downfall of the civilization. Interestingly, a date that corresponds to A.D. 813 (a time when the Maya had begun to collapse) was found scratched into a wall.
Despite what crazed doomsayers keep telling us, this is another piece of evidence that the Maya never pointed to 2012 as being an Apocalyptic year.
Although the 13th 'baktun' of the Mayan Long Count calendar (a period of time of around 394 years) is set to end this year, there is no indication that the numbers documented by the town's scribe point to bad things happening in 2012. If anything, the end of one cycle rolling into the next heralded a new age. Rather than calendars ending abruptly, Maya calendars were cyclical. Although modern civilization likes to get all hot and bothered about stories of doom, that's not what the Maya had in mind.
In this particular Xultún ruin, murals of kings and complex hieroglyphics adorn the walls of a small room in the building. Also, possibly a reference or wall chart for academics of the time, the Mayan calendars had been painstakingly etched out. Cycles of 17 baktuns had even been scribed to a pillar, along with a "ring number" -- a means of documenting past events.
"The ancient Maya predicted the world would continue, that 7,000 years from now, things would be exactly like this," said Saturno, whose research will appear in the journal Science this week. "We keep looking for endings. The Maya were looking for a guarantee that nothing would change. It's an entirely different mindset."
Even the National Institute of Anthropological History in Mexico blames "the West's messianic thinking" as the cause of distorting "the world view of ancient civilizations like the Mayans."
Also commenting on the cyclical design of the Maya calendars Anthony Aveni, professor of astronomy and anthropology at Colgate University and coauthor paper, said: "It's like the odometer of a car, with the Maya calendar rolling over from the 120,000s to 130,000. The car gets a step closer to the junkyard as the numbers turn over; the Maya just start over."
Archaeologist David Stuart of the University of Texas, who worked to decipher the Mayan glyphs, added: "The Mayan calendar is going to keep going for billions, trillions, octillions of years into the future. Numbers we can't even wrap our heads around."
Read more at Discovery News
The Volcanoes Are Alive with the Sound of Magma
Geophysicist Aurélien Dupont of the Pusan National University in South Korea studied the low-frequency sounds made by gases percolating through basaltic magma, a type of magma that flows easily because it has a low viscosity (or, roughly, thickness) and gas content. Volcanoes that spew basaltic lava tend to have gentle slopes, making impressive eruptive displays of rivers of lava running down their sides.
As the magma travels from the volcano's underground magma chamber, pockets of gas trapped inside it expand (and produce the low-frequency sound, or infrasound) until they reach the surface, where the gas can bubble away into the atmosphere.
Dupont and his colleagues used condenser microphones and microbarometers to track the underground sounds of Piton de la Fournaise volcano on Reunion Island in the Indian Ocean between 1992 and 2008. They found they could match the sounds produced by the gas to its flow out of vents in and around the volcano crater, and map the course of the eruption.
"If no volcanic gas escapes anymore from the vents, detections stop and the eruption is over. Infrasound can accurately characterize the beginning and the end of an eruption," Dupont said in a statement.
Read more at Discovery News
May 10, 2012
Mural Found On Walls a First for a Maya Dwelling; Painted Numbers Reflect Calendar Reaching Well Beyond 2012
Excavating for the first time in the sprawling complex of Xultún in Guatemala's Petén region, archaeologists have uncovered a structure that contains what appears to be a work space for the town's scribe, its walls adorned with unique paintings -- one depicting a lineup of men in black uniforms -- and hundreds of scrawled numbers. Many are calculations relating to the Maya calendar.
One wall of the structure, thought to be a house, is covered with tiny, millimeter-thick, red and black glyphs unlike any seen before at other Maya sites. Some appear to represent the various calendrical cycles charted by the Maya -- the 260-day ceremonial calendar, the 365-day solar calendar, the 584-day cycle of the planet Venus and the 780-day cycle of Mars, reports archaeologist William Saturno of Boston University, who led the exploration and excavation.
"For the first time we get to see what may be actual records kept by a scribe, whose job was to be official record keeper of a Maya community," Saturno said. "It's like an episode of TV's 'Big Bang Theory,' a geek math problem and they're painting it on the wall. They seem to be using it like a blackboard."
The discovery is reported in the June issue of National Geographic magazine and in the May 11 issue of the journal Science.
The project scientists say that despite popular belief, there is no sign that the Maya calendar -- or the world -- was to end in the year 2012, just one of its calendar cycles. "It's like the odometer of a car, with the Maya calendar rolling over from the 120,000s to 130,000," said Anthony Aveni, professor of astronomy and anthropology at Colgate University, a coauthor of the Science paper. "The car gets a step closer to the junkyard as the numbers turn over; the Maya just start over."
The mural represents the first Maya art to be found on the walls of a house. "There are tiny glyphs all over the wall, bars and dots representing columns of numbers. It's the kind of thing that only appears in one place -- the Dresden Codex, which the Maya wrote many centuries later. We've never seen anything like it," said David Stuart, Schele Professor of Mesoamerican Art and Writing at the University of Texas-Austin, who deciphered the glyphs.
The vegetation-covered structure was first spotted in 2010 by Saturno's student Max Chamberlain, who was following looters' trenches to explore the site of Xultún, hidden in the remote rain forest of the Petén. Then, supported by a series of grants from the National Geographic Society, Saturno and his team launched an organized exploration and excavation of the house, working urgently to beat the region's rainy seasons, which threatened to erase what time had so far preserved.
Xultún, a 12-square-mile site where tens of thousands once lived, was first discovered about 100 years ago by a Guatemalan worker and roughly mapped in the 1920s by Sylvanus Morley, who named the site "Xultún" -- "end stone." Scientists from Harvard University mapped more of the site in the 1970s. The house discovered by Saturno's team was numbered 54 of 56 structures counted and mapped at that time. Thousands at Xultún remain uncounted.
The team's excavations reveal that monumental construction at Xultún began in the first centuries B.C. The site thrived until the end of the Classic Maya period; the site's last carved monument dates to around 890 A.D. Xultún stood only about five miles from San Bartolo, where in 2001 Saturno found rare, extensive murals painted on the walls of a ritual structure by the ancient Maya.
"It's weird that the Xultún finds exist at all," Saturno said. "Such writings and artwork on walls don't preserve well in the Maya lowlands, especially in a house buried only a meter below the surface."
The Writing on the Walls
The house contains three intact walls, each telling its own story to researchers -- and posing its own mysteries:
The north wall
The north wall lies straight ahead as one enters the room. An off-center niche in the wall features a painting of a seated king, wearing blue feathers. A long rod made of bone mounted on the wall allowed a curtain to be pulled across the king's portrait, hiding it and revealing a well-preserved painting of a man whose image is wrapped around the wall; he is depicted in vibrant orange and holds a pen. Maya glyphs near his face call him "Younger Brother Obsidian," a curious title seldom seen in Maya text. Based on other Maya sites, Saturno theorizes he could be the son or younger brother of the king and possibly the artist-scribe who lived in the house. "The portrait of the king implies a relationship between whoever lived in this space and the royal family," Saturno said.
Four long numbers on the wall representing one-third of a million to 2.5 million days likely bring together all of the astronomical cycles -- such as those of Mars, Venus and the lunar eclipses -- the Maya thought important, dates that stretch some 7,000 years into the future. This is the first place Maya archaeologists have found that seems to tabulate all of these cycles in this way. Another number scratched into the plaster surface likely records the date -- 813 A.D., a time when the Maya world had begun to collapse.
Read more at Science Daily
Archaeologists Discover Lost Language
Researchers working at Ziyaret Tepe, the probable site of the ancient Assyrian city of Tušhan, believe that the language may have been spoken by deportees originally from the Zagros Mountains, on the border of modern-day Iran and Iraq.
In keeping with a policy widely practised across the Assyrian Empire, these people may have been forcibly moved from their homeland and resettled in what is now south-east Turkey, where they would have been set to work building the new frontier city and farming its hinterland.
The evidence for the language they spoke comes from a single clay tablet, which was preserved after it was baked in a fire that destroyed the palace in Tušhan at some point around the end of the 8th century BCE. Inscribed with cuneiform characters, the tablet is essentially a list of the names of women who were attached to the palace and the local Assyrian administration.
Writing in the new issue of the Journal of Near Eastern Studies, Dr John MacGinnis, from the McDonald Institute for Archaeological Research, University of Cambridge, explains how the nature of these names has piqued the interest of researchers.
"Altogether around 60 names are preserved," MacGinnis said. "One or two are actually Assyrian and a few more may belong to other known languages of the period, such as Luwian or Hurrian, but the great majority belong to a previously unidentified language."
"If the theory that the speakers of this language came from western Iran is correct, then there is the potential here to complete the picture of the world's first multi-ethnic empire. We know from existing texts that the Assyrians did conquer people from that region. Now we know that there is another language, perhaps from the same area, and maybe more evidence of its existence waiting to be discovered."
Ziyaret Tepe is on the River Tigris in south east Turkey, and has been the subject of extensive archaeological excavations since 1997. Recent work has revealed evidence that it was probably once the site of the Assyrian frontier city of Tušhan. In particular, it is thought that the remains of a monumental building excavated on the site are those of the governor's palace, built by the Assyrian King Ashurnasirpal II (883 -- 859 BCE).
The tablet was found in what may have been the palace's throne room by Dr Dirk Wicke of the University of Mainz, working as part of a team led by Professor Timothy Matney of the University Akron, Ohio. When a conflagration destroyed the palace, perhaps around the year 700 BCE, the tablet was baked and much of its contents on the obverse side preserved.
MacGinnis was handed the task of deciphering the tablet and has identified a total of 144 names, of which 59 can still be made out. His analysis systematically rules out not only common languages from within the Assyrian Empire, but also other languages of the time -- including Egyptian, Elamite, Urartian or West Semitic. Even at its most generous, his assessment suggests that only 15 of the legible names belong to a language previously known to historians.
The report also posits several theories about where this mysterious language may have come from. One notion is that it may be Shubrian -- the indigenous language spoken in the Tušhan area before the Assyrians arrived. As far as historians know, Shubrian was never written down. In addition, it is believed to have been a dialect of Hurrian, which is known and does not appear to bear any resemblance to most of the names on the tablet.
Another theory is that it was the language spoken by the Mushki -- a people who were migrating to Eastern Anatolia at around the time the tablet was made. This idea seems less plausible, however, as to appear on the list of the Assyrian administration, these people would either have infiltrated the Empire or been captured, and historians have evidence for neither.
More convincing is the theory that the language in question may have been spoken by a people from somewhere else in the Assyrian Empire who were forcibly moved by the administration.
This was standard practice for successive Assyrian Kings, particularly after the Empire began to expand during the 9th century. "It was an approach which helped them to consolidate power by breaking the control of the ruling elite in newly-conquered areas," MacGinnis said. "If people were deported to a new location, they were entirely dependent on the Assyrian administration for their well-being."
Although historians already know that the Zagros Mountains were in a region invaded and annexed by the Assyrians, it remains, to date, the one area under Assyrian occupation for which no known language exists. That makes it tempting to link the text on the tablet to the same region. An Assyrian King, Esarhaddon, even referred to an unidentified language, Mekhranian, which supposedly hailed from the Zagros, but in practice the area was probably a patchwork of chiefdoms and more than one dialect may have been in use.
Read more at Science Daily
Stone-Throwing Chimp Thinks Ahead
But some researchers were skeptical that Santino really was planning for a future emotional outburst. Perhaps he was just repeating previously learned responses to the zoo visitors, via a cognitively simpler process called associative learning. And it is normal behavior for dominant male chimps to throw things at visitors, such as sticks, branches, rocks, and even feces. Now Santino is back in the scientific literature, the subject of new claims that he has begun to conceal the stones so he can get a closer aim at his targets—further evidence that he is thinking ahead like humans do.
The debate over Santino is part of a larger controversy over whether some humanlike animal behaviors might have simpler explanations. For example, Sara Shettleworth, a psychologist at the University of Toronto in Canada, argued in a widely cited 2010 article entitled, “Clever animals and killjoy explanations in comparative psychology,” that the zookeepers and researchers who observed Santino’s stone-throwing over the course of a decade had not seen him gathering the stones, and thus could not know why he originally starting doing so. Santino, Shettleworth and some others argued, might have had some other reasons for caching the stones, and the stone throwing might have been an afterthought.
In the new study, published online today in PLoS ONE, primatologist Mathias Osvath of Lund University in Sweden—author of the earlier Santino paper—teams up with Lund University primatologist Elin Karvonen to report new observations of Santino’s behavior during 2010. Santino’s first attempts to throw stones during 2010 came during the May preseason. As a zoo guide led visitors toward Santino’s island compound, the chimpanzee began to engage in a typical dominance display: screeching, standing on two feet, and carrying a stone in his hand. The guide and the visitors retreated before Santino began hurling the stones, and then advanced again for a total of three approaches. When the people returned about 3 hours later, Santino advanced toward them, holding two stones, but he did not act aggressively, even picking up an apple from the water surrounding the island and nonchalantly munching on it. But when Santino got within close range, he suddenly threw one of the stones. (It didn’t hit anyone.)
The next day, Santino again threatened visitors with stones, but the group again backed away to avoid being hit. Santino was then observed pulling a heap of hay from inside his enclosure and placing it on the island close to where the visitors approached. He put several stones under the hay and waited until the group returned about an hour later. Then, without performing a dominance display, Santino pulled a stone from under the hay and threw it. Later, he pulled a stone that he had apparently hidden behind a log and tried to hit the visitors with that, as well.
Over the course of the summer, Osvath and Karvonen observed repeated episodes of this behavior, and also recovered stones that Santino had hidden under hay or logs, racking up 114 days of observation. They recovered a total of 35 projectiles that Santino had apparently concealed: 15 under hay heaps, 18 behind logs, and two behind a rock structure on the island. The researchers conclude that Santino deliberately engaged in deceptive concealment of the stones, and that this was a new, innovative behavior on his part: Before 2010, Santino had never put stones under hay piles or behind logs.
This innovation, the team argues, is further evidence that Santino plans ahead for how he will react to the visitors’ approach to his compound, and that this is inconsistent with interpretations that he cached the stones for some other reason and then just happened to have them at hand when he got mad. By hiding the stones and then trying to deceive zoo visitors into thinking that his intentions were peaceful, Osvath and Karvonen argue, Santino was actually anticipating and planning for a future situation rather than simply responding repetitively to a past one.
And because the team was able to observe this new behavior from its very beginning, Osvath and Karvonen argue, the new study overcomes some of the objections to the earlier report. “No matter what mechanisms lie behind the behavior,” Osvath says, Santino is engaging in planning for the future, and “that is not trivial.”
But the “killjoys” are still not entirely convinced. Shettleworth calls the study “provocative,” but insists that further experiments with more animals are needed before Santino’s behavior can be interpreted as advance planning. “Did he bring the first hay pile into the arena with the intent of using it to hide projectiles? We cannot know,” Shettleworth says. She says that the authors should have tried additional tests such as putting a hay pile in the compound themselves and “seeing if the animal still persisted in carrying hay,” or “putting the hay piles in unfavorable locations for throwing.”
Read more at Wired Science
Earliest Evidence of Biblical Cult Discovered
Excavation within the remains of the roughly 3,000-year-old fortified city of Khirbet Qeiyafa, located about 19 miles (30 kilometers) southwest of Jerusalem, have revealed three large rooms used as shrines, along with artifacts, including tools, pottery and objects, such as alters associated with worship.
The three shrines were part of larger building complexes, and the artifacts included five standing stones, two basalt altars, two pottery libation vessels and two portable shrines, one made of pottery, the other of stone. The portable shrines are boxes shaped like temples.
The shrines themselves reflect an architectural style dating back as early as the time of King David (of the biblical David and Goliath story), providing the first physical evidence of a cult in the time of King David, according to an announcement by Yosef Garfinkel, an archaeologist at Hebrew University of Jerusalem.
The research is presented in the book, "Footsteps of King David in the Valley of Elah" (Yedioth Ahronoth, 2012).
Radiocarbon dating on burnt olive pits found in the ancient city of Khirbet Qeiyafa indicate it existed between 1020 B.C. and 980 B.C., before being violently destroyed.
According to Biblical tradition, the ancient Isrealites' belief in one God and their ban on human and animal figures set them apart from their neighbors. However, it hasn't been clear when these distinct practices arose.
The discoveries offer a clue to the timing, since they contain none of the human or animal figurines common at other sites. No bones from pigs showed up here or elsewhere in the city.
"This suggests that the population of Khirbet Qeiyafa observed two Biblical bans — on pork and on graven images — and thus practiced a different cult than that of the Canaanites or the Philistines," Garfinkel said in a press release issued by the university. The discoveries also offer support for the Biblical depiction of King David, he said.
Garfinkel suggests some of the features and styles of the structures appear analogous to those described in the Bible. For instance, one of the shrines, the clay one, is decorated with an elaborate façade that includes two guardian lions, two pillars, folded textile and three birds standing on the roof. The two pillars are suggestive, he said, of Yachin and Boaz described in the Bible as belonging to Solomon's Temple.
Read more at Discovery News
Vesta is a Baby Planet, Not an Asteroid
So concludes an international team of scientists treated to a virtual front row seat at Vesta for the past 10 months, courtesy of NASA's Dawn robotic probe.
They have a bit more ground to cover before Dawn leaves Vesta's cratered, lava-like surface in late August to rendezvous with the king of the asteroid belt, Ceres, another type of protoplanet believed to be flush with water ice.
Already however, the Dawn science team has confirmed long-held theories about Vesta's history, a timeline that dates back to within 300 million years of the beginning of the solar system's existence.
"Vesta is like a time probe we haven't had in the solar system before," Dawn lead scientist Christopher Russell, with the University of California, Los Angeles, told Discovery News.
"We have a body that formed very, very early so we know from Vesta what conditions were like back then. We would not have learned that from a body like the moon or Earth. We would not be able to go back that far in time," he said.
From meteorites -- some of which now have been directly sourced to Vesta -- scientists know that the solar system is about 4.6 billion years old. Analysis of craters on the moon date back a little more than 3 billion years. Evidence of earlier geologic lunar events were obliterated during a period of heavy bombardment, a fate Vesta apparently escaped.
Which is not to say the body, which spans about 330 miles in diameter, is without scars. Among the pits imaged by Dawn is a double-whammy crater -- a basin inside a basin -- that is believed to be the source of two groups of meteorites found on Earth.
"There is evidence in the meteoritic record to give us co-incident dates with the two impacts that we've dated on Vesta," Russell said.
Scientists also found rings around the impact basins, a phenomenon that may be related to Vesta's iron core.
"We haven't done simulations of this so we don't really know yet," Russell said. "I would guess that the iron core sort of holds Vesta in place and the (impacting body) rings around that."
Read more at Discovery News
May 9, 2012
Early Man Shared Florida With Mammoths
The discovery adds the far southeast corner of the United States to the list of places in North America where humans coexisted with massive creatures more than 10,000 years ago. The finding also adds to a growing body of evidence that modern humans spread rapidly after arriving in the Americas, though it’s still not clear when and where they first set foot on the continent.
“We found that humans came into Florida before the extinction of megafauna -- they were in Florida by 10,000 years ago,” said Bruce MacFadden, a paleontologist at the University of Florida, Gainesville. This is “clearly documenting that humans were widespread in North America.”
In 1913, construction of a drainage canal turned up fossils in Vero Beach, Fla., about 90 miles north of West Palm Beach. When geologists followed up, they unearthed the bones of all sorts of ancient animals that lived during the last Ice Age, including jaguars, capybaras, bison, peccaries, mastodons and other creatures, large and small. Alongside the animal bones in the same layer of soil lay human skeletons.
At first, the scientists assumed that the co-mingled bones came from animals and people that lived at the same time. Soon after, though, a famous archaeologist from the Smithsonian Institution who came to see the fossils raised doubts by proposing that people arrived long after the giants were gone and that the human bones came from more recent burials.
Despite subsequent archaeological finds in other parts of the United States showing that people coexisted with extinct megafauna during the last Ice Age, which ended about 10,000 years ago, controversy about the Vero Beach fossils has lingered. Complicating matters, the bones are too weathered to allow for radiocarbon dating, which would offer clear dates and ages.
To settle the debate, MacFadden and colleagues looked instead at levels of rare earth elements in 24 human bones and 48 animal bones from the site, now held in museum collections. Over time, fossils left underground absorb these elements at a predictable rate.
Both types of bones contained similar levels of rare earth elements, the researchers reported in the Journal of Vertebrate Paleontology. The technique couldn’t accurately date the bones, but it showed that they had all been in the ground for the same amount of time. That meant that they had lived at the same time, too. Many of the animals involved are known to have gone extinct when the last Ice Age ended.
The new findings echo what other studies have shown in Montana, New Mexico, Arizona, Ohio and elsewhere – that people lived alongside mastodons, mammoths and other massive mammals more than 10 millennia ago, said Kenneth Tankersley, an archaeological geologist at the University of Cincinnati.
Read more at Discovery News
Smallest Mammoth Discovered
These findings could help yield insights as to how giant animals can shrink to tiny sizes over evolutionary time, scientists added.
Dwarfism often happens to species of large animals when they get trapped on islands, including dinosaurs. Scientists think dwarfism helps giants survive within the limits imposed by islands.
Ancient Mediterranean dwarf elephants are especially extreme examples of island dwarfism. Over the course of less than 800,000 years -- a short stint on an evolutionary scale -- these dwarfs are thought to have descended from larger European elephants, weighing 100 times as much, which lived on mainland Europe.
"There's a big question regarding these elephants -- how can something so big become dwarfs so small?" said researcher Victoria Herridge, a vertebrate paleontologist at the Natural History Museum in London.
To learn more, Herridge and her colleagues analyzed dwarf fossils first discovered in Crete (an island some say was the birthplace of the Greek god Zeus) more than a century ago. Paleontologists have long argued whether the remains belonged to curvy-tusked mammoths or straighter-tusked elephants.
Teeth discovered more recently in the same area in Crete now suggest the animal was in fact a mammoth, Mammuthus creticus. A newfound foreleg bone suggests it was the smallest mammoth known, standing only about 3 feet 8 inches (1.13 m) high at the shoulders and weighing only approximately 680 pounds (310 kilograms), making it about the size of a modern baby African or Asian elephant.
These dwarf mammoths were not woolly mammoths, scientists noted.
"When most people think of mammoths, they think of woolly mammoths," Herridge said. "We think this dwarf was more adapted to warmer environments, more in appearance like modern African or Asian elephants, with a sparse covering of hair, although they would have had curvy tusks like all mammoths."
Mammuthus creticusis the first evidence for extreme island dwarfism in mammoths. It would have been comparable in size to the smallest dwarf elephant known, the extinct species Palaeoloxodon falconeri from Sicily and Malta, which stood only about 3 feet 5 inches (1.04 m) high at the shoulder and weighed only approximately 525 lbs. (238 kg).
The fossils suggest this dwarf mammoth was descended from one of the first mammoth species to arrive in Europe from Africa, Mammuthus rumanus or Mammuthus meridionalis. As such, the researchers suggest dwarf mammoths may have evolved much earlier than previously thought — as far back as 3.5 million years ago.
"Now that we know what this dwarf species might have been descended from, we can ask bigger questions, such as how and why and how fast dwarfism happened here," Herridge said.
"This is an interesting period for Crete -- back then, it might have been made of small islands, smaller than today," Herridge said. "That's an interesting consideration for the extreme dwarfism we see here."
Given the scant fossils and the uncertainty about Crete's environment during this period, not much is known about how this dwarf might have lived. Still, its teeth do suggest it browsed on shrubs as opposed to grass like woolly mammoths.
Read more at Discovery News
Light From Small, Oozing Alien Planet Seen
NASA's infrared Spitzer Space Telescope spotted light from the alien planet 55 Cancri e, which orbits a star 41 light-years from Earth. A year on the extrasolar planet lasts just 18 hours.
The planet 55 Cancri e was first discovered in 2004 and is not a habitable world. Instead, it is known as a super-Earth because of its size: The world is about twice the width of Earth and is super-dense, with about eight times the mass of Earth.
But until now, scientists have never managed to detect the infrared light from the super-Earth world.
"Spitzer has amazed us yet again," said Spitzer program scientist Bill Danch of NASA headquarters in Washington in a statement today (May 8). "The spacecraft is pioneering the study of atmospheres of distant planets and paving the way for NASA's upcoming James Webb Space Telescope to apply a similar technique on potentially habitable planets."
Spitzer first detected infrared light from an alien planet in 2005. But that world was "hot Jupiter," a gas giant planet much larger than 55 Cancri e that orbited extremely close to its parent star. While other telescopes have performed similar feats since then, Spitzer's view of the 55 Cancri e is the first time the light from a rocky super-Earth type planet has been seen, researchers said.
Since the discovery of 55 Cancri e, astronomers have pinned down increasingly strange features about the planet. The researchers already knew it was part of an alien solar system containing five exoplanets centered on the star 55 Cancri in the constellation Cancer (The Crab).
But 55 Cancri e stood out because it is ultra-dense and orbits extremely close to its parent star; about 26 times closer than the distance between Mercury and our own sun.
The new Spitzer observations revealed that the star-facing side of 55 Cancri e is extremely hot, with temperatures reaching up to 3,140 degrees Fahrenheit (1,726 degrees Celsius). The planet is likely a dark world that lacks the substantial atmosphere needed to warm its nighttime side, researchers said.
And to top it all off, the planet is oozing.
Past observations of the planet by the Spitzer Space Telescope have suggested that one-fifth of 55 Cancri e is made up of lighter elements, including water. But the extreme temperatures and pressures on 55 Cancri e would create what scientists call a "supercritical fluid" state.
Supercritical fluids can be imagined as a gas in a liquid state, which can occur under extreme pressures and temperatures. On Earth, water can become a supercritical fluid inside some steam engines.
The previous studies of 55 Cancri e were performed by analyzing how the light from its parent star changed as the planet passed in front of it, a technique known as the "transit method." In the new study, astronomers used the Spitzer Space Telescope to determine the infrared light from 55 Cancri e itself.
Spitzer's new look at 55 Cancri e is consistent with supercritical-fluid waterworld theory. The planet is likely a rocky world covered with water in a supercritical fluid state and topped off with a steam blanket, researchers said.
"It could be very similar to Neptune, if you pulled Neptune in toward our sun and watched its atmosphere boil away," said the study's principal investigator Michaël Gillon of Université de Liège in Belgium. The lead author is Brice-Olivier Demory of the Massachusetts Institute of Technology in Cambridge.
The research is detailed in the Astrophysical Journal.
Read more at Discovery News
To Get Fossil Guts, Extreme Chemistry Needed
And yet paleontologists have discovered troves of exquisite fossils of entirely soft-bodied animals, such as the four-eyed arthropod Leanchoilia (above), that lived half a billion years ago. How can that be?
It turns out that the chemical makeup of the ocean half a billion years ago was very different than it is today. This period of extreme ocean chemistry stymied hungry bacteria and hindered decay -- granting humanity insight into a stage of our early ancestry that otherwise would have been lost to us forever.
Take Leanchoilia. It is just one of dozens of curious creatures, without skeletons or other hard parts, that represent the immediate aftermath of the Cambrian Explosion, the rapid flowering of complex life from our single-celled ancestors.
For more than a century since Leanchoilia and other soft-bodied creatures were first discovered in the famous Burgess Shale of British Columbia, scientists have wondered what made this peculiar preservation possible. The problem has been identifying conditions unique to that time period, explains Tim Lyons, a biogeochemist at the University of California, Riverside.
Now, a team led by paleontologist Robert Gaines of Pomona College in Claremont, Calif., has identified a striking global pattern of seawater chemistry that could finally explain how Leanchoilia and its contemporaries eluded decay. Their new interpretation, published in Proceedings of the National Academies of Science, entails three special conditions that came together to keep hungry bacteria at bay: a dearth of oxygen, not much sulfate and a surplus of calcium carbonate.
Based on this latest evidence, here is how Leanchoilia's remarkable preservation may have played out, step-by-step:
1. DEARTH OF OXYGEN
The first special condition working in Leanchoilia's favor was a dearth of oxygen in and near the seabed, where a storm or underwater avalanche quickly buried the creature's lifeless body in soft, gooey mud. So, oxygen-loving bacteria -- the fervent decomposers that dominate the entire ocean and seabed today -- weren’t much of a threat. (Gaines and his colleagues knew this from previous studies.)
2. NOT MUCH SULFATE
A second plus for Leanchoilia's preservation was an apparent scarcity of sulfate in the overlying seawater. This special chemistry suggests a second line of potential bacterial attackers were also starved of energy.
Evidence for low sulfate turned up when Gaines’ team analyzed the sulfur chemistry of Burgess Shale-type sediments from six locations around the world. That discovery is critical, because plenty of bacteria would have been perfectly happy to use sulfate instead of oxygen to fuel their dirty work, Lyons explains. As he noted in a commentary on the new study, sulfate is a common constituent of modern seawater, and in many marine settings, sulfate-loving bacteria wreak as much rot as the oxygen-dependent varieties do. In Leanchoilia's days, though, it seems both types were struggling.
Still, even a slim supply of sulfate diffusing into the sediment could have activated enough decay to consume all traces of its body long before its muddy shroud turned to rock, Lyons says. That suggests a third line of chemical defense must have hindered hungry microbes.
Read more at Discovery News
May 8, 2012
'Blindness’ May Rapidly Enhance Other Senses
Can blindness or other forms of visual deprivation really enhance our other senses such as hearing or touch? While this theory is widely regarded as being true, there are still many questions about the science behind it.
New findings from a Canadian research team investigating this link suggest that not only is there a real connection between vision and other senses, but that connection is important to better understand the underlying mechanisms that can quickly trigger sensory changes. This may demystify the true potential of human adaptation and, ultimately, help develop innovative and effective methods for rehabilitation following sensory loss or injury.
François Champoux, director of the University of Montreal's Laboratory of Auditory Neuroscience Research, will present his team's research and findings at the Acoustics 2012 meeting in Hong Kong, May 13-18, a joint meeting of the Acoustical Society of America (ASA), Acoustical Society of China, Western Pacific Acoustics Conference, and the Hong Kong Institute of Acoustics.
Studies have shown, in terms of hearing, that blind people are better at localizing sound. One study even suggested that blindness might improve the ability to differentiate between sound frequencies. "The supposed enhanced tactile abilities have been studied at a greater degree and can be seen as early as days or even minutes following blindness," says Champoux. "This rapid change in auditory ability hasn't yet been clearly demonstrated."
Two big questions about blindness and enhanced abilities remain unanswered: Can blindness improve more complex auditory abilities and, if so, can these changes be triggered after only a few minutes of visual deprivation, similar to those seen with tactile abilities?
"When we speak or play a musical instrument, the sounds have specific harmonic relations. In other words, if we play a certain note on a piano, that note has many related 'layers.' However, we don't hear all of these layers because our brain simply associates them all together and we only hear the lowest one," Champoux explains.
It's through this complex computation based on specific components of the sound that the brain can interpret and distinguish auditory signals coming from different people or instruments. The ability to identify harmonicity -- the harmonic relation between sounds -- is one of the most powerful factors involved in interpreting our auditory surroundings.
"Harmonicity can easily be evaluated using a simple task in which similar harmonic layers are set up and one of them is gradually modified until the individual notices two layers instead of one," says Champoux. "In our study, healthy individuals completed such a task while blindfolded. This task was administered twice, separated by a 90-minute interval during which the participants conversed with the experimenter in a quiet room. Half of the participants kept the blindfold on during the interval period, depriving them of all visual input, while the other half removed their blindfolds."
They found no significant differences between the two groups in their ability to differentiate harmonicity prior to visual deprivation. However, the results of the testing session following visual deprivation revealed that visually deprived individuals performed significantly better than the group that took their blindfolds off.
Read more at Science Daily
New findings from a Canadian research team investigating this link suggest that not only is there a real connection between vision and other senses, but that connection is important to better understand the underlying mechanisms that can quickly trigger sensory changes. This may demystify the true potential of human adaptation and, ultimately, help develop innovative and effective methods for rehabilitation following sensory loss or injury.
François Champoux, director of the University of Montreal's Laboratory of Auditory Neuroscience Research, will present his team's research and findings at the Acoustics 2012 meeting in Hong Kong, May 13-18, a joint meeting of the Acoustical Society of America (ASA), Acoustical Society of China, Western Pacific Acoustics Conference, and the Hong Kong Institute of Acoustics.
Studies have shown, in terms of hearing, that blind people are better at localizing sound. One study even suggested that blindness might improve the ability to differentiate between sound frequencies. "The supposed enhanced tactile abilities have been studied at a greater degree and can be seen as early as days or even minutes following blindness," says Champoux. "This rapid change in auditory ability hasn't yet been clearly demonstrated."
Two big questions about blindness and enhanced abilities remain unanswered: Can blindness improve more complex auditory abilities and, if so, can these changes be triggered after only a few minutes of visual deprivation, similar to those seen with tactile abilities?
"When we speak or play a musical instrument, the sounds have specific harmonic relations. In other words, if we play a certain note on a piano, that note has many related 'layers.' However, we don't hear all of these layers because our brain simply associates them all together and we only hear the lowest one," Champoux explains.
It's through this complex computation based on specific components of the sound that the brain can interpret and distinguish auditory signals coming from different people or instruments. The ability to identify harmonicity -- the harmonic relation between sounds -- is one of the most powerful factors involved in interpreting our auditory surroundings.
"Harmonicity can easily be evaluated using a simple task in which similar harmonic layers are set up and one of them is gradually modified until the individual notices two layers instead of one," says Champoux. "In our study, healthy individuals completed such a task while blindfolded. This task was administered twice, separated by a 90-minute interval during which the participants conversed with the experimenter in a quiet room. Half of the participants kept the blindfold on during the interval period, depriving them of all visual input, while the other half removed their blindfolds."
They found no significant differences between the two groups in their ability to differentiate harmonicity prior to visual deprivation. However, the results of the testing session following visual deprivation revealed that visually deprived individuals performed significantly better than the group that took their blindfolds off.
Read more at Science Daily
Human Body Part That Stumped Leonardo da Vinci Revealed
That's probably because Leonardo had a tough time finding female corpses to dissect, explains Peter Abrahams, a practicing physician at the University of Warwick Medical School in the United Kingdom.
Abrahams, a clinical anatomist, has lent his knowledge to an audio tour of the exhibit of Leonardo's anatomical drawings that opened May 4 in Buckingham Palace.
The Italian Renaissance artist learned anatomy as a way to improve his drawings of the human form, but he also brought a scientist's eye to the discipline.
"He wanted to understand how it worked," Abrahams told LiveScience. "He looked at humans like a mechanic would do. Most of that work is very, very relevant today."
Anatomists in Leonardo's time often dissected unclaimed bodies, such as of drunks and vagrants, and those bodies were more likely to be male, Abrahams said.
"It was definitely harder to get female bodies to dissect, and he didn't have many opportunities," Abrahams said.
Advances in anatomy
By Leonardo's time, few advances in human anatomy had been made since the second-century work by the Roman anatomist Galen, whose discoveries were largely based on animal dissections. Leonardo da Vinci had the advantage of access to human cadavers.
Abrahams says studying them would have been obnoxious work. "It must have been horrible, because they didn't have any form of embalming," he said. "Within two or three days that body decomposes."
Leonardo's sketches reveal a deep understanding of how the body worked, much of it still up-to-date. Modern anatomists have only begun in the last 60 years to look at the muscles and tendons of the finger in the detail that da Vinci did, Abrahams said. Leonardo was the first to draw the human spine with the correct curves. He also came tantalizingly close to understanding how blood moved through the body, a mystery that wouldn't be fully solved until 1628, more than a century after his death.
"In many ways, he was literally 100 years ahead of his time," Abrahams said.
The artist was also the first to draw a fetus in utero. Even so, many of his drawings of the female reproductive system get details wrong, Abrahams said. His drawings of the cervix and other female reproductive organs resembled those of animals more than humans, Abrahams said.
"Some of the drawings of the female pelvis he's tried to extrapolate from animals and not always got it right."
Read more at Discovery News
Rarest Gorilla Revealed in Camera Trap Video
Although the video, shot by Wildlife Conservation Society conservationists in Cameroon's Kagwene Gorilla Sanctuary, is only a few minutes long, it presents a vivid microcosm of these primates' lives -- their suffering at the hands of humans, their struggle, but also their pride.
As the footage (see it below) begins, you can see one gorilla stopping briefly to rest under a tree, but then compelled to move forward by the troop. When another spots the camera trap, it briefly charges, Tarzan style, toward the screen, beating its chest.
Watching the footage, the connection to these magnificent animals, who are in turn so connected to us on the primate family tree, is undeniable. You can see how one gorilla has lost its hand, likely in a snare set by poachers, but the individual keeps moving and trying to survive. One can only wonder how hard that gorilla's life is now.
Fewer than 250 Cross River gorillas remain in the world. This video footage may be one of the last reminders of their existence. They are rarely observed by field researchers, so who knows when such footage will ever be captured again.
"This video gives us all a spectacular view into the hidden world of one of our closest relatives, which is in dire need of our help to survive," Steve Sanderson, WCS President and CEO, said in a press release.
Christopher Jameson, Director of WCS's Takamanda Mone's Landscape Project, adds, "The video represents the best images to date of Cross River gorillas, normally shy animals that flee at the slightest hint of human presence. The footage provides us with our first tantalizing glimpses of Cross River gorillas behaving normally in their environment. A person can study these animals for years and never even catch a glimpse of the gorillas, much less see anything like this."
Read more and see video at Discovery News
Fossil Fish Eye Surprise: Small Structures Reveal Pigment
Similar structures show up regularly on fossilized feathers, hair and eyes, and in recent years, some scientists have suspected they contained melanin, a dark pigment found in the hair, skin and eyes of humans and animals.
This study, the first thorough chemical analysis of these microscopic structures, opens the door to better understanding the appearance and behavior of long-dead animals, said study researcher Johan Lindgren of Lund University in Sweden.
The presence of melanin alone does not reveal the color an animal displayed since other factors, such as other microscopic features, can also determine color. However, melanin is evidence of dark areas, such as bands on feathers, and the shapes of the melanosomes may correspond to some basic hues, such as gray, black or brown, according to Lindgren.
The presence of dark patches can provide evidence of camouflage, social signaling or other clues to the animal's behavior, he told LiveScience.
The tiny structures Lindgren and colleagues studied came from the fossilized retina, at the back of the eye, belonging to a bony fish found in Denmark. This is a first step, he said.
"Now, hopefully, we will be able to do so in many other species, and be able to distinguish between different kinds of melanin and other pigments as well," he said.
Scientists have known about these tiny structures for a long time, but they believed them to be the remains of bacteria that had colonized an animal's body after its death.
In 2008, a group of researchers led by Jakob Vinther, now a postdoctoral student at the University of Texas at Austin, concluded that tiny, organic structures like these, found in fossilized features, were actually preserved cellular structures that contain melanin, called melanosomes.
The most recent study adds to evidence that these tiny structures were not left by bacteria, but came from the now-fossilized animals' bodies, Vinther told LiveScience in an email.
"It clearly shows convincing evidence that the melanosomes we have been working on for the last four years are composed of melanin as we have argued earlier on," he wrote.
Lindgren and colleagues used a variety of techniques to analyze the composition of the rounded, microscopic structures. They then compared the results with those of modern melanin, films created by bacteria and other compounds that common in sediments and have a molecular structure similar to melanin.
Read more at Discovery News
May 7, 2012
Of Yeast and Men: An Evolutionary Tale
A logistic challenge accomplished by the interplay of two factors: the spindle apparatus that acts as the molecular motor driving chromosome movements, and the kinetochore that constitutes the physical platform between the DNA and the mitotic spindle.
The attachment site formed by the kinetochore is an intricate protein network. While its components providing the direct contact point for the spindle are very well preserved from yeast to human, evolution of the DNA-binding proteins remained puzzling given that the underlying DNA template is highly variable.
Now, a novel study published in the June edition of Nature Cell Biology sheds light onto the cryptic molecular relationship between the yeast and human kinetochore. Principal investigator Stefan Westermann and his team tracked the missing evolutionary link and opened up new insights into the architecture and function of the key division organelle.
The correct shape pieces the puzzle together
"The clue was to take a close look at the protein sequence as well as specific sequence motifs that get an amino acid chain into its particular shape." says Stefan Westermann. "In this way, our bioinformatician Alexander Schleiffer was able to predict a number of novel DNA-binding kinetochore proteins and assigned them to the respective human homolog." Follow-up experiments strongly supported analogous function of the proteins. "Yeast is still an informative model organism and very easy to handle. Our current findings can now direct similar studies in more complex systems. There erroneous chromosome segregation is deleterious for the cell and a common cause of cancer" explains the scientist.
Read more at Science Daily
Examining Diets of Ancient Peoples
University of Nevada, Reno researchers G. Richard Scott and Simon R. Poulson discovered that very small particles of plaque removed from the teeth of ancient populations may provide good clues about their diets. Scott is chair and associate professor of anthropology in the College of Liberal Arts. Poulson is research professor of geological sciences in the Mackay School of Earth Sciences and Engineering.
Scott obtained samples of dental calculus from 58 skeletons buried in the Cathedral of Santa Maria in northern Spain dating from the 11th to 19th centuries to conduct research on the diet of this ancient population. After his first methodology met with mixed results, he decided to send five samples of dental calculus to Poulson at the University's Stable Isotope Lab, in the off chance they might contain enough carbon and nitrogen to allow them to estimate stable isotope ratios.
"It's chemistry and is pretty complex," Scott explained. "But basically, since only protein has nitrogen, the more nitrogen that is present, the more animal products were consumed as part of the diet. Carbon provides information on the types of plants consumed."
Scott said that once at the lab, the material was crushed, and then an instrument called a mass spectrometer was used to obtain stable carbon and nitrogen isotope ratios.
"It was a long shot," he said. "No one really thought there would be enough carbon and nitrogen in these tiny, 5- to 10- milligram samples to be measurable, but Dr. Poulson's work revealed there was. The lab results yielded stable carbon and nitrogen isotope ratios very similar to studies that used bone collagen, which is the typical material used for this type of analysis."
Scott explained that the common practice of using bone to conduct such research is cumbersome and expensive, requiring several acid baths to extract the collagen for analysis. The process also destroys bone, so in many instances, it isn't permitted by museum curators.
As for using hair, muscle and nails for such research, Scott said, "They are great, when you can find them. The problem is, they just don't hold up very well. They decompose too quickly. Dental calculus, for better or for worse, stays around a very long time."
Read more at Science Daily
Anthropologist Finds Explanation for Hominin Brain Evolution in Famous Fossils
The Taung fossil -- the first australopithecine ever discovered -- has two significant features that were analyzed by Falk and a group of anthropological researchers. Their findings, which suggest brain evolution was a result of a complex set of interrelated dynamics in childbirth among new bipeds, were published May 7 in the Proceedings of the National Academy of Sciences.
"These findings are significant because they provide a highly plausible explanation as to why the hominin brain might grow larger and more complex," Falk said.
The first feature is a "persistent metopic suture," or unfused seam, in the frontal bone, which allows a baby's skull to be pliable during childbirth as it squeezes through the birth canal. In great apes -- gorillas, orangutans and chimpanzees -- the metopic suture closes shortly after birth. In humans, it does not fuse until around 2 years of age to accommodate rapid brain growth.
The second feature is the fossil's endocast, or imprint of the outside surface of the brain transferred to the inside of the skull. The endocast allows researchers to examine the brain's form and structure.
After examining the Taung fossil, as well as huge numbers of skulls belonging to apes and humans, as well as corresponding 3-D CT (three-dimensional computed tomographic) scans, and taking into account the fossil record for the past 3 million years, Falk and her colleagues noted three important findings: The persistent metopic suture is an adaptation for giving birth to babies with larger brains; is related to the shift to a rapidly growing brain after birth; and may be related to expansion in the frontal lobes.
"The persistent metopic suture, an advanced trait, probably occurred in conjunction with refining the ability to walk on two legs," Falk said. "The ability to walk upright caused an obstretric dilemma. Childbirth became more difficult because the shape of the birth canal became constricted while the size of the brain increased. The persistent metopic suture contributes to an evolutionary solution to this dilemma."
The later fusion of the metopic suture is most likely an adaptation of hominins who walked upright to be able to more easily give birth to babies with relatively large brains. The unfused seam is also related to the shift to rapidly growing brains after birth, an advanced human-like feature as compared to apes.
"The later fusion was also associated with evolutionary expansion of the frontal lobes, which is evident from the endocasts of australopithecines such as Taung," Falk said.
The Taung fossil, which is estimated to be around 2½ million years old, was discovered in 1924 in Taung, South Africa. It became the "type specimen," or main model, of the genus Australopithecus africanus when it was announced in 1925.
Read more at Science Daily
Dinosaur Farts May Have Warmed Ancient Earth
Sauropods are large plant-eating dinosaurs typified by such titans as Apatosaurus (once known as Brontosaurus) and Brachiosaurus. When they lived, during the Mesozoic era — from about 250 million years ago until the dinosaurs died out 65 million years ago — the climate was warm and wet. Nothing on Earth today compares with these giants.
The researchers found that the greenhouse gas methane produced by all sauropods across the globe would have been about 520 million tons per year, a number on par with the total amount of methane currently produced by both natural and man-made sources.
Questionable numbers
The researchers, led by David Wilkinson of Liverpool John Moores University in the United Kingdom, did their best to get an accurate estimate of how much gas these big dinosaurs would have created, but their answers are still just estimates based on multiple assumptions, they warn.
The greenhouse gas methane is a natural byproduct of the digestive process of plant eaters, especially in herbivores called ruminants (like cows and camels). The researchers suspect that like ruminants, sauropods would have harbored methane-producing bacteria in their intestines to help digest these fibrous foods.
There is currently no way to tell what kind of bacteria lived in the digestive systems of dinosaurs, what gasses they produced, or what those digestive systems would have looked like, but Wilkinson thinks they would have produced methane like today's animals.
"To process that amount of vegetation they have to be relying on microbes in their digestive system," Wilkinson told LiveScience. "But without a time machine you can't be sure."
Crunching gassy numbers
They used a mathematical model to determine how much gas these plant-eating giants would have eaten. They extended data on methane production by modern mammals, based on size, up into the reaches of the sauropods.
In their calculations the researchers used middle-of-the-road numbers: 10 sauropods, each weighing 20,000 pounds (9,071 kilograms), could have roamed 1 square kilometer of lush Mesozoic habitats. "We've taken a middle-ground value," Wilkinson said. "We tried to be reasonably conservative."
They found that these 10 sauropods would have contributed 7.6 tons (6.9 tonnes) of methane every year. Expanding this number to cover the amount of land estimated to be hospitable habitat for these animals (about half the land on Earth at the time), the researchers end up with more than 550 million tons (500 million tonnes) of methane produced every year.
"I was expecting a number like that produced by cows, so the size of the number really surprised me," Wilkinson said. "It's way, way, way ahead of the estimated methane production by modern livestock." (Cows produce 55 to 110 million tons (50 to 100 million tonnes) of methane each year, he estimated.)
Read more at Discovery News
May 6, 2012
Landmark cuckoo project reveals birds’ migration mystery
Five male birds were caught in Norfolk last May and fitted with satellite-tagged “backpacks” before being released. The scientists then monitored their progress over 12 months as they flew to Africa in the autumn, and returned in the spring.
The first two birds, named by the researchers as Lyster and Chris, arrived back in Britain last week, and after his lengthy journey, Lyster was seen just 10 miles from where he was tagged.
Dr Phil Atkinson, the head of international research at the BTO, spotted the cuckoo at the Norfolk Broads on Tuesday.
He said: “We saw him flying past, you can see the wire antenna poking out, so it was definitely him. It’s fantastic – we know where he’s been, we know the routes he’s taken, and now he’s back in the Broads.”
To lure the wild birds for the project, the BTO team glued a stuffed female cuckoo to a perch, and played a recording of a female’s “bubbling” call to spark the males’ interest.
The trackers – each of which cost more than £2,000 – were attached to the five captured birds like little backpacks, with soft straps that fit around their wings.
The project was carried out to discover why every year fewer of the birds return to Britain. Between 1995 and 2010 the population of cuckoos spending summer here fell by almost half, and the number is continuing to decline.
The RSPB estimates that there are now between 9,600 and 20,000 breeding pairs present in Britain each year.
According to a recent survey by the RSPB, of the 10 UK birds that have declined the most since 1995, eight are summer migrants, including the cuckoo, turtle dove, yellow wagtail and nightingale.
Previously, the lack of information about the cuckoos’ long migration has hampered the understanding of how to help conserve the birds.
Earlier this year it was reported that cuckoos arrived in the UK much earlier than normal. Their call was recorded by ornithologists as early as February, a month ahead of their usual arrival.
Most cuckoos are “brood parasites”, laying their eggs in the nests of other species of birds. The adults generally arrive in Britain in late March or April, and depart in July or August, with young birds leaving around a month later.
The cuckoo migration map has now shown the widely varied routes the birds take across Spain or Italy, over the Mediterranean, and across the Sahara desert to their wintering grounds in the rainforests of sub-Saharan Africa.
Dr Atkinson said: “They are African birds really. All the birds got down to Congo and survived, and it’s only on spring migration that we started to lose birds. We lost our first bird, Clement, in Cameroon on the return journey, so we think the crunch time is just before they cross the Sahara.”
He said that understanding the most challenging parts of a cuckoo’s journey and where they were most likely to die provided the project with “an incredible amount of new and important information”.
He added: “These birds move into west Africa, they fatten up as much as they can – enough to fuel their Saharan crossing. If they are not able to do that, I think that is going to be a real pinch point in terms of mortality.
"That is where we need to focus our research effort and conservation action.”
Like all migrating animals, cuckoos respond to the changing seasons. They depend on lush vegetation to provide the fruit and food for insects that they feed on.
This reliance on seasonal patterns means that a changing climate could make an already challenging journey impossible for them.
The BTO team plans to continue the project by fitting a group of female cuckoos with the same tracking devices.
Read more at The Telegraph
Did a Copying Mistake Make Humans So Smart?
When tested out in mice, researchers found this "error" caused the rodents' brain cells to move into place faster and enabled more connections between brain cells.
When any cell divides, it first copies its entire genome. During this process, it can make errors. The cell usually fixes errors in the DNA. But when they aren't fixed, they become permanent changes called mutations, which are sometimes hurtful and sometimes helpful, though usually innocuous.
One type of error is duplication, when the DNA-copying machinery accidentally copies a section of the genome twice. The second copy can be changed in future copies — gaining mutations or losing parts.
The researchers scanned the human genome for these duplications, and found that many of them seem to play a role in the developing brain.
"There are approximately 30 genes that were selectively duplicated in humans," study researcher Franck Polleux, of The Scripps Research Institute in La Jolla, Calif., said in a statement. "These are some of our most recent genomic innovations."
An extra copy of a gene gives evolution something to work with: Like modeling clay, this gene isn't essential like the original copy, so changes can be made to it without damaging the resulting organism.
The researchers studied one specific gene, called SRGAP2, which they think has been duplicated at least twice during the course of human evolution, first about 3.5 million years ago and then again about 2.5 million years ago.
The second, more recent, duplication seems to be incomplete, with only part of the gene being duplicated. The researchers think this partially duplicated gene is able to interfere with the actions of the original, ancestral copy of SRGAP2. When the researchers added the partially duplicated gene copy to the mouse genome (mice don’t normally have it) it seemed to speed the migration of brain cells during development, which makes brain organization more efficient.
These cells that expressed the incomplete duplication of SRGAP2 also had more "spines" — knoblike extensions on the cell surface that connect with other brain cells, which make them look more like human brain cells.
Read more at Discovery News
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