Aug 9, 2013

Ozone Hole Might Slightly Warm Planet, Computer Model Suggests

A lot of people mix up the ozone hole and global warming, believing the hole is a major cause of the world's increasing average temperature. Scientists, on the other hand, have long attributed a small cooling effect to the ozone shortage in the hole.

Now a new computer-modeling study suggests that the ozone hole might actually have a slight warming influence, but because of its effect on winds, not temperatures. The new research suggests that shifting wind patterns caused by the ozone hole push clouds farther toward the South Pole, reducing the amount of radiation the clouds reflect and possibly causing a bit of warming rather than cooling.

"We were surprised this effect happened just by shifting the jet stream and the clouds," said lead author Kevin Grise, a climate scientist at Lamont-Doherty Earth Observatory of Columbia University in New York City.

Grise notes this small warming effect may be important for climatologists trying to predict the future of Southern Hemisphere climate.

The work is detailed in Geophysical Research Letters, a journal of the American Geophysical Union. Grise collaborated on the study with Lorenzo Polvani of Columbia University, George Tselioudis of NASA Goddard Institute for Space Studies, Yutian Wu of New York University, and Mark Zelinka of Lawrence Livermore National Laboratory.

Hole in the sky

Each ozone molecule consists of three oxygen atoms bound together. These ozone molecules gather in the lower portion of the stratosphere about 20 to 30 kilometers (12 to 19 miles) above the ground -- about twice as high as commercial airliners fly.

Thankfully for the living things below, this layer of ozone shields Earth from some of the hazardous ultraviolet radiation barraging the atmosphere. Unchecked, these ultraviolet rays can cause sunburns, eye damage and even skin cancer.

In the 1980s, scientists discovered thinning of the ozone layer above Antarctica during the Southern Hemisphere's spring months. The cause of this "hole" turned out to be chlorofluorocarbons, such as Freon, from cooling systems, aerosols cans and degreasing solvents, which break apart ozone molecules. Even though the1987 Montreal Protocol banned these chlorofluorocarbons worldwide, the ozone hole persists decades later.

Many people falsely equate the ozone hole to global warming. In a 2010 Yale University poll, 61 percent of those surveyed believed the ozone hole significantly contributed to global warming. Additionally, 43 percent agreed with the statement "if we stopped punching holes in the ozone layer with rockets, it would reduce global warming."

An actual consequence of the ozone hole is its odd effect on the Southern Hemisphere polar jet stream, the fast flowing air currents encircling the South Pole. Despite the ozone hole only appearing during the spring months, throughout each subsequent summer the high-speed jet stream swings south toward the pole.

"For some reason when you put an ozone hole in the Southern Hemisphere during springtime, you get this robust poleward shift in the jet stream during the following summer season," said Grise. "People have been looking at this for 10 years and there's still no real answer of why this happens."

Cloud reflection

The team of scientists led by Grise wondered if the ozone hole's impacts on the jet stream would have any indirect effects on the cloud cover. Using computer models, they worked out how the clouds would react to changing winds.

"Because the jet stream shifts, the storm systems move along with it toward the pole," said Grise. "If the storm systems move, the cloud system is going to move with it."

High- and mid-level clouds, the team discovered, traveled with the shifting jet stream toward the South Pole and the Antarctic continent. Low-level cloud coverage dropped in their models throughout the Southern Ocean. While modeling clouds is a difficult task due to the variety of factors that guide their formation and movement, Grise noted that observational evidence from the International Satellite Cloud Climatology Project, a decades-long NASA effort to map global cloud distributions, supports their theory of migrating cloud coverage.

When the cloud cover moves poleward, the amount of energy the clouds can reflect drops, which increases the amount of radiation reaching the ground. "If you shift the reflector poleward," Grise explained, "you've moved it somewhere there is less radiation coming in."

In 2007, the Intergovernmental Panel on Climate Change reported a direct cooling effect from the thinning ozone layer -- specifically, a reduction of about 0.05 watts per square meter's worth of energy reaching the ground. However, Grise and his colleagues estimated the indirect effect of the shifting cloud coverage to be an increase of approximately 0.2 watts per square meter. Their result not only suggests that warming rather than cooling would be taking place, but also that there's a larger influence overall. Since the jet stream only shifts during the summer months, the warming only takes place in those months.

"Theoretically this net radiation input into the system should give some sort of temperature increase, but it's unknown if that signal could be detected or what the magnitude of it would be," said Grise. For comparison, worldwide, an average of about 175 watts per square meter reaches the ground from sunlight, according to the George Washington University Solar Institute.

Dennis Hartmann, an atmospheric scientist at the University of Washington in Seattle unrelated with the project, points out that since predicting cloud behavior is so challenging, the model used in Grise's study could be underestimating clouds north of the jet stream being pulled toward the equator and in turn reflecting more light, potentially reducing or even negating the warming effect. Hartmann added that he also has some concerns about the modeling of the low-level cloud response.

Still, "this is certainly a very interesting topic and potentially important from a practical perspective of predicting Southern Hemisphere climate and even global warming rates," he commented.

Read more at Science Daily

Why an Ice Age Occurs Every 100,000 Years: Climate and Feedback Effects Explained

Science has struggled to explain fully why an ice age occurs every 100,000 years. As researchers now demonstrate based on a computer simulation, not only do variations in insolation play a key role, but also the mutual influence of glaciated continents and climate.

Ice ages and warm periods have alternated fairly regularly in Earth's history: Earth's climate cools roughly every 100,000 years, with vast areas of North America, Europe and Asia being buried under thick ice sheets. Eventually, the pendulum swings back: it gets warmer and the ice masses melt. While geologists and climate physicists found solid evidence of this 100,000-year cycle in glacial moraines, marine sediments and arctic ice, until now they were unable to find a plausible explanation for it.

Using computer simulations, a Japanese, Swiss and American team including Heinz Blatter, an emeritus professor of physical climatology at ETH Zurich, has now managed to demonstrate that the ice-age/warm-period interchange depends heavily on the alternating influence of continental ice sheets and climate.

"If an entire continent is covered in a layer of ice that is 2,000 to 3,000 metres thick, the topography is completely different," says Blatter, explaining this feedback effect. "This and the different albedo of glacial ice compared to ice-free earth lead to considerable changes in the surface temperature and the air circulation in the atmosphere." Moreover, large-scale glaciation also alters the sea level and therefore the ocean currents, which also affects the climate.

Weak effect with a strong impact

As the scientists from Tokyo University, ETH Zurich and Columbia University demonstrated in their paper published in the journal Nature, these feedback effects between Earth and the climate occur on top of other known mechanisms. It has long been clear that the climate is greatly influenced by insolation on long-term time scales. Because Earth's rotation and its orbit around the sun periodically change slightly, the insolation also varies. If you examine this variation in detail, different overlapping cycles of around 20,000, 40,000 and 100,000 years are recognisable.

Given the fact that the 100,000-year insolation cycle is comparatively weak, scientists could not easily explain the prominent 100,000-year-cycle of the ice ages with this information alone. With the aid of the feedback effects, however, this is now possible.

Simulating the ice and climate

The researchers obtained their results from a comprehensive computer model, where they combined an ice-sheet simulation with an existing climate model, which enabled them to calculate the glaciation of the northern hemisphere for the last 400,000 years. The model not only takes the astronomical parameter values, ground topography and the physical flow properties of glacial ice into account but also especially the climate and feedback effects. "It's the first time that the glaciation of the entire northern hemisphere has been simulated with a climate model that includes all the major aspects," says Blatter.

Using the model, the researchers were also able to explain why ice ages always begin slowly and end relatively quickly. The ice-age ice masses accumulate over tens of thousands of years and recede within the space of a few thousand years. Now we know why: it is not only the surface temperature and precipitation that determine whether an ice sheet grows or shrinks. Due to the aforementioned feedback effects, its fate also depends on its size. "The larger the ice sheet, the colder the climate has to be to preserve it," says Blatter. In the case of smaller continental ice sheets that are still forming, periods with a warmer climate are less likely to melt them. It is a different story with a large ice sheet that stretches into lower geographic latitudes: a comparatively brief warm spell of a few thousand years can be enough to cause an ice sheet to melt and herald the end of an ice age.

The Milankovitch cycles

The explanation for the cyclical alternation of ice and warm periods stems from Serbian mathematician Milutin Milankovitch (1879-1958), who calculated the changes in Earth's orbit and the resulting insolation on Earth, thus becoming the first to describe that the cyclical changes in insolation are the result of an overlapping of a whole series of cycles: the tilt of Earth's axis fluctuates by around two degrees in a 41,000-year cycle. Moreover, Earth's axis gyrates in a cycle of 26,000 years, much like a spinning top. Finally, Earth's elliptical orbit around the sun changes in a cycle of around 100,000 years in two respects: on the one hand, it changes from a weaker elliptical (circular) form into a stronger one. On the other hand, the axis of this ellipsis turns in the plane of Earth's orbit. The spinning of Earth's axis and the elliptical rotation of the axes cause the day on which Earth is closest to the sun (perihelion) to migrate through the calendar year in a cycle of around 20,000 years: currently, it is at the beginning of January; in around 10,000 years, however, it will be at the beginning of July.

Read more at Science Daily

Giant Mayan Frieze Tells Ancient Guatemala Story

Archaeologists working in a buried Mayan pyramid in Guatemala have discovered an enormous inscribed frieze richly decorated with images of gods and rulers, the Guatemalan government announced.

Dating to the 6th century, the carving has been hailed by local authorities as “the most spectacular frieze seen to date” and one of the best-preserved pieces of Mayan art ever discovered.

It was found at the pre-Columbian archaeological site of Holmul, in the northern province of Peten, by Guatemalan archaeologist Francisco Estrada-Belli below a 65-foot-high pyramid which was built over it in the 8th century.

Measuring 26 feet by nearly 7 feet, the 1,400-year-old carvings decorated the outside of a mysterious multi-roomed rectangular building. Found when Estrada-Belli and his team excavated a tunnel left open by looters, the monumental artwork depicts human figures in a mythological setting, suggesting these may be deified rulers.

“This is a unique find. It is a beautiful work of art and it tells us so much about the function and meaning of the building, which was what we were looking for,” Estrada-Belli, a professor at Tulane University’s anthropology department, said.

Painted in red, with details in blue, yellow and green, the stucco frieze is elaborately descriptive. It shows three human figures wearing bird headdresses and jade jewels. They are seated cross-legged on top of the head of a mountain spirit called witz.

A cartouche on the headdress contains glyphs identifying each individual by name, but only the central figure’s name is now readable. It says: Och Chan Yopaat, meaning “The Storm God enters the sky.”

Below the main character, two feathered serpents emerge from the mountain spirit and form an arch with their bodies. Under each of them is a seated figure of an aged god holding a sign that reads “First tamale.”

In front of the serpents’ mouths are the two additional human figures, also seated on mountain spirit heads.

An inscription of 30 glyphs in a band that runs at the base of the structure reveals the building was commissioned by Ajwosaj Chan K’inich, the ruler of Naranjo, a powerful kingdom to the south of Holmul in the northeast of Guatemala.

According to Alex Tokovinine, a Harvard University Maya epigrapher, the text places the building in the decade of the 590s. It also reveals a power struggle between two rival kingdoms — Tikal and the Snake Lords — fighting for control of the region.

Homul, the city-state where the frieze was found, once belonged to Tikal’s kingdom, but its rulers switched sides. In this view, the frieze would be a tribute to Homul’s defection.

Indeed, in the inscription, Ajwosaj, who was a vassal of the Snake Lords, claims to have restored the local ruling line and patron deities.

“Ajwosaj was one of the greatest rulers of Naranjo. The new inscription provides the first glimpse of the remarkable extent of Ajwosaj’s political and religious authority,” Tokovinine said.

It isn’t the first finding made by Estrada-Belli and his team at the mysterious building. Last year, the archaeologist unearthed a burial in cavity dug into the stairway leading up to the building. It contained the skeleton of an adult male accompanied by 28 ceramic vessels and a wooden funerary mask.

Read more at Discovery News

Earth vs. Sun: Flipping Magnetic Face Off

There are two very big magnets in our lives: the Earth's and the sun's. They both have a tendency to flip -- or reverse polarity -- over time. The sun does it very frequently -- once every 11 years or so. Earth, on the other hand, flips polarity very irregularly often taking millions of years between switches.

Why the difference? It has to do with how rowdy and dynamic the two bodies are.

The sun's flipping is caused by it being a gigantic spinning ball of conductive super-hot plasma. Or, as Discovery News' resident astrophysicist Dr. Ian O'Neill explains it: "The solar cycle ebbs and flows over an approximate 11 year period. From 'solar minimum' to 'solar maximum,' our nearest star’s internal magnetic field gets wound up by the sun’s differential rotation. Differential rotation means that the sun rotates faster at the equator than it does at the poles, dragging the magnetic field -- like an elastic band -- that is embedded in the superheated plasma. As the sun approaches solar max (as it is now) the magnetic field is at its most stressed, causing magnetic arcs to be forced from the solar interior and into the lower corona."

The Earth's magnetic field, on the other hand, is created in the outer core of the planet. This is a fluid part of the core, made mostly of iron and nickel, and is about 2,000 kilometers thick.

Temperature-driven convection currents in that metal fluid, as well as the Earth's spin, causes the fluid to spin and create electric currents. That creates magnetic fields, which are made even more powerful by the charged metals passing through them, creating electric currents of their own, and so on and so forth.

This vicious electromagnetic cycle is called the geodynamo. When these flows reverse, which can only happen under rare and complex conditions, the Earth's magnetic field reverses.

Now there's always someone who wants to believe that a solar magnetic reversal will cause the end of the world. The matter has been settled regarding the imminent magnetic field switch by the sun: it will not wipe out Earth, civilization, or even afternoon tea. But what about the switch in the Earth's polarity?

These are thought to include transition periods when Earth's magnetic field is temporarily very weak, which could expose us to a lot of harmful charged particles from the sun that are currently are deflected.

"If the Earth's magnetic field is weakened during a reversal, more of these particles will get through to the upper atmosphere. This could be a problem, but most likely the atmosphere is thick enough to protect the Earth's surface," explained Cathy Jordan, an Earth science educator affiliated with Cornell University.

The fact that the Earth's magnetic field switches is only known because geologists have detected it in rocks, especially volcanic rocks that are high in magnetic mineral content. When these rocks flow out onto the Earth's surface they cool and solidify, but not before they "feel" the Earth's magnetic field and line up their magnetic minerals with that field -- like a zillion little compasses.

Read more at Discovery News

Aug 8, 2013

Investigational Malaria Vaccine Found Safe and Protective

An investigational malaria vaccine has been found to be safe, to generate an immune system response, and to offer protection against malaria infection in healthy adults, according to the results of an early-stage clinical trial published Aug. 8 in the journal Science.

The vaccine, known as PfSPZ Vaccine, was developed by scientists at Sanaria Inc., of Rockville, Md. The clinical evaluation was conducted by researchers at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and their collaborators at the Walter Reed Army Institute of Research and the Naval Medical Research Center, both in Silver Spring, Md.

Malaria is transmitted to humans by the bite of an infected mosquito. After the bite occurs, infectious malaria parasites in the immature, sporozoite stage of their life cycle first travel to the liver, where they multiply, and then spread through the bloodstream, at which time symptoms develop.

The PfSPZ Vaccine is composed of live but weakened sporozoites of the species Plasmodium falciparum, the most deadly of the malaria-causing parasites.

"The global burden of malaria is extraordinary and unacceptable," said NIAID Director Anthony S. Fauci, M.D. "Scientists and health care providers have made significant gains in characterizing, treating and preventing malaria; however, a vaccine has remained an elusive goal. We are encouraged by this important step forward."

The Phase I trial, which took place at the NIH Clinical Center in Bethesda, received informed consent from and enrolled 57 healthy adult volunteers ages 18 to 45 years who never had malaria. Of these, 40 participants received the vaccine and 17 did not. To evaluate the vaccine's safety, vaccinees were split into groups receiving two to six intravenous doses of PfSPZ Vaccine at increasing dosages. After vaccination, participants were monitored closely for seven days. No severe adverse effects associated with the vaccine occurred, and no malaria infections related to vaccination were observed.

Based on blood measurements, researchers found that participants who received a higher total dosage of PfSPZ Vaccine generated more antibodies against malaria and more T cells -- a type of immune system cell -- specific to the vaccine.

To evaluate whether and how well the PfSPZ Vaccine prevented malaria infection, each participant -- the vaccinees as well as the control group that did not receive vaccine -- was exposed to bites by five mosquitoes carrying the P. falciparum strain from which the PfSPZ Vaccine was derived. This controlled human malaria infection procedure -- a standard process in malaria vaccine trials -- took place three weeks after participants received their final vaccination. Participants were monitored as outpatients for seven days and then admitted to the NIH Clinical Center, where they stayed until they were diagnosed with malaria, treated with anti-malarial drugs and cured of infection, or shown to be free of infection.

The researchers found that the higher dosages of PfSPZ Vaccine were associated with protection against malaria infection. Only three of the 15 participants who received higher dosages of the vaccine became infected, compared to 16 of 17 participants in the lower dosage group who became infected. Among the 12 participants who received no vaccine, 11 participants became infected after mosquito challenge.

"In this trial, we showed in principle that sporozoites can be developed into a malaria vaccine that confers high levels of protection and is made using the good manufacturing practices that are required for vaccine licensure ," said Robert A. Seder, M.D., chief of the Cellular Immunology Section of the NIAID Vaccine Research Center and principal investigator of the trial.

An important challenge in the continued development of PfSPZ Vaccine is that the vaccine currently is administered intravenously -- a rare delivery route for vaccines. Previous studies at lower doses have shown that the more common intradermal (into the skin) and subcutaneous (under the skin) routes did not yield as strong an immune response as the intravenous route.

Read more at Science Daily

'Digging Up' 4-Billion-Year-Old Fossil Protein Structures to Reveal How They Evolved

Modern proteins exhibit an impressive degree of structural diversity, which has been well characterized, but very little is known about how and when over the course of evolution 3D protein structures arose. In a study published by Cell Press August 8 in Structure, researchers resurrected 4-billion-year-old Precambrian proteins in the laboratory and gained novel insights into protein evolution by analyzing their X-ray crystal structures. This method has revealed a remarkable degree of structural similarity among proteins since life first evolved on this planet, and it represents a powerful and novel approach to explore the evolution of protein structures.

"So far, attempts to understand protein structure evolution have been based on the comparison between structures of modern proteins. This is equivalent to trying to understand the evolution of birds by comparing several living birds," says senior study author Jose Sanchez-Ruiz of the University of Granada. "But it is most useful to study fossils so that changes over evolutionary time are apparent. Our approach comes as close as possible to 'digging up' fossil protein structures."

In a recent study, Sanchez-Ruiz and his collaborators constructed a phylogenetic tree of protein sequences by analyzing the amino acid sequences of thioredoxins -- proteins found in organisms from the three domains of life, including bacteria, archaea and eukaryotes. Using this phylogenetic tree, they were able to resurrect Precambrian proteins in the laboratory and characterize their features.

In the new study, Sanchez-Ruiz teamed up with Jose Gavira of the Andalusian Institute of Earth Sciences (Spanish National Research Council -- University of Granada) to analyze the X-ray crystal structures of the previously resurrected Precambrian proteins. They found that present-day thioredoxin structures are remarkably similar to those that existed at a time close to the origin of life, even though their amino acid sequences are very different. This finding supports a punctuated-equilibrium model of evolution in which protein structures remain constant over long time periods, with new changes occurring intermittently over short periods.

"In addition to uncovering the basic principles of protein structure evolution, our approach will provide invaluable information regarding how the 3D structure of a protein is encoded by its amino acid sequence," Sanchez-Ruiz says. "It could also provide information about how to design proteins with novel structures -- an important goal in protein engineering and biotechnology."

From Science Daily

Sharks vs. Dinosaurs: Deadly Encounters

Squalicorax and Duck-Billed Dinos

Sharks and dinosaurs were both prevalent during the same periods, but did they ever encounter each other? Recent evidence suggests that they likely did. Here are the most probable shark encounters with dinosaurs.

Squalicorax, a 16.5-foot-long shark, feasted on a duck-billed dinosaur during the Cretaceous. Remains of the two, documented in the journal Palaios, consisted of a chewed-up hadrosaur foot with a shark tooth embedded in it. Paleontologists are not sure if the shark scavenged on an already-dead dinosaur, which might have keeled over on land before winding up in the water, or if the coastal predator shark killed the dinosaur outright.

Spinosaurus Shark Feast?

The mega carnivore dinosaur Spinosaurus, with its crocodile-like snout, is thought to have craved both surf and turf. A tooth from this Cretaceous predator was found embedded in a pterosaur. Some pterosaurs lingered around water sources, similar to today’s shore birds. If Spinosaurus nabbed a pterosaur and was built for fish eating, it probably could have taken on a shark.

Fish-Loving Baryonyx

Baryonyx, like Spinosaurus, had a crocodile-like head. It also had huge claws built for lifting marine life, including reachable sharks, out of the water. Its tummy provides telltale evidence of fish feasting, remembering that sharks are fish too. Emily Rayfield of the University of Bristol, who studied the dinosaur, said, “On excavation, partially digested fish scales and teeth and a dinosaur bone were found in the stomach region of the animal, demonstrating that at least some of the time this dinosaur ate fish.”

Dinos and Sawsharks

Sawsharks are technically rays, but they are very closely related to sharks and look like them. David Ward of The Natural History Museum in London told Discovery News, “Sharks could have predated dinosaur carcasses, and dinosaurs might have eaten sawsharks when they were in shallow fresh water rivers and estuaries.”

Read more at Discovery News

NASA to Test Life's Origin on Earth Theory

Imagine Earth 4 billion years ago. The world was covered in an acidic ocean, its bottom studded with mineral chimneys or hydrothermal vents. These were not ordinary chimneys. They had pores that allowed selective molecules to pass through, setting up a chemical gradient.

The vents were the origins of all life on earth, according to a 25-year-old theory proposed by Mike Russell, a research scientist at NASA’s Jet Propulsion Laboratory, that is gaining traction in the astrobiology community. NASA’s Astrobiology Institute has invested $8 billion in proving the theory.

The water inside the vent was hot, and it slowly reacted with iron and other minerals to produce a basic environment – like baking soda in water. The ocean outside the vent was acidic and cool. Perfect conditions for a pre-historic membrane gradient.

That may sound familiar from 9th grade Biology. Our bodies too also have vital membrane gradients that allow us to generate and use up energy in the form of ATP (adenosine triphosphate). ATP moves along a membrane inside the cell, becoming energized, and then is moved across another membrane into a chamber where the energy is used up by our body. Simply put, we wouldn’t exist without membranes.

The hydrothermal vents were the gradients of early life, according to the theory called “metabolism first” proposed by Russell. Life forms figured out how to tap energy from these vents, and all other processes, such as the replication of DNA, came after.

That’s a tough theory for scientists to prove. Our modern oceans are no mimics of the hostile conditions of early Earth. The only way to go about this would be to reconstruct one of these ancient vents in the lab.

So, Russell and his colleagues have built a system resembling a “pillared Emerald City in the Wizard of Oz,” NASA wrote in a release.

They have manufactured a gel that resembles the porus vents of yore, as Nature reported in 2009. A series of glass tubes, thin barrels and valves recreate as-best-as-possible the early conditions. The goal is to see if the system spontaneously generates organic molecules such as ethane, methane and even simple amino acids which are the building blocks of proteins that form the basis of life.

So far, the scientists have been able to produce acetate, a compound generated by a pathway present in many bacteria, according to a recent study. Acetate can be a base for many key biological molecules.

In fact, compare some of the most ancient enzymes in life forms — acetyl coenzyme A synthase, for instance, which helps us generate energy — to minerals at these vents, and you’d see striking structural similarities, according to a recent study in Biochimica et Biophysica Acta.

Read more at Discovery News

Aug 7, 2013

'Hairy' Fossil Shows Early Mammals Were Furry

An extremely well-preserved rodentlike fossil recently discovered in China provides some of the best evidence yet for how the earliest human ancestors lived.

Named Megaconus mammaliaformis, the animal closely resembled but predated true mammals, living about 165 million years ago in a humid world dominated by early dinosaurs. It is one of two recently described ancestral mammal fossils that provide a significant leap forward for research in early mammal evolution.

Until now, most knowledge of M. mammaliaformis has been based on isolated teeth remains that suggested that the animals were not highly evolved. But the newly discovered intact skeleton — complete with some of the earliest evidence of hair — shows that these animals were more complex than previously thought, the team reports in the Aug. 8 issue of the journal Nature.

"Research always assumed that these were primitive and not highly specialized, but this animal shows that they were already highly specialized and highly adapted to special feeding strategies," said Thomas Martin, a paleontologist at the University of Bonn in Germany and one of the authors of the paper.

By closely examining the orientation of the animal's relatively flat teeth in relation to its jaw, the team determined that M. mammaliaformis evolved to grind plants, making it one of the earliest plant eaters in a world dominated by carnivores.

Hair impressions were also found on the fossil. The hair — which appears darker on the animal's back and lighter on its belly — are among the only premammalian hair impressions ever discovered. The hair likely evolved to keep the animals warm, which could indicate that it would otherwise lose heat quickly through a fast metabolism typical of modern rodents, Martin said.

"This is very important because the presence of hair was always postulated, but the direct evidence was never well preserved in fossils," Martin told LiveScience. "This is direct evidence, not just interpolated evidence."

The team calculated the weight of the animal's body based on the length of its limbs, estimating that it weighed roughly half a pound (250 grams) — about the size of a rat. The orientation of its legs in relation to the rest of its body suggests that the animal couldn't hop or climb, but instead maintained a walking gait similar to that of a modern hedgehog or armadillo.

To escape predators, including early dinosaurs and other mammaliaforms (a group that closely resembles but predates true mammals), the animal evolved a spur on the back of its heel that the researchers believe contained poison, similar to modern platypus spurs.

The animal likely roamed humid, junglelike forests full of evergreens and void of colorful flowers that had not yet evolved, Martin said. Fossilized fish surrounding M. mammaliaformis suggest that it died in an ancient lake.

The fossil owes its exceptional preservation to the extremely fine-grained silt, which consists largely of volcanic ash, in which it was found. Surrounding regions in China have yielded a multitude of other important fossils in recent years, including fossils of a similar animal described in the same issue of Nature.

The second animal was able to climb trees and has been identified as a mammal, though the authors have classified it within the same broader group to which M. mammaliaformis belonged. This apparent contradiction — that a mammaliaform and a true mammal fall within the same group — has called into question when the first true mammals evolved, but both groups agree that they will only be able to settle this debate upon further analysis of the fossils.

Read more at Discovery News

Sharks Dominated Prehistoric European Seas

Waters off of France and the U.K. were once teeming with sharks, many of which would have looked like today's range of shark species.

Samples of Late Cretaceous rock from the region turned up remains of 96 different types of prehistoric sharks, 18 of which represent new species, a paper in the Journal of Systematic Paleontology reports.

The sharks lived from 100 to 72 million years ago, but many looked like modern sharks.

"If you were to see a Cretaceous shark, I am pretty sure that it would look no different from one in an aquarium," senior author David Ward of The Natural History Museum in London told Discovery News. "Shark body design stabilized about 140 million years ago and, other than a few families that have suffered from extinction, remains the same now."

Lead author Guillaume Guinot, a researcher at the Natural History Museum in Switzerland, added that many of the identified fossil species have somewhat similar living representatives, such as today's angel sharks, carpetsharks, bullhead sharks, catsharks, cowsharks, dogfish sharks, sandtiger sharks and houndsharks. These are not direct relatives of the extinct sharks, however.

The Late Cretaceous sharks appear to have inhabited all sorts of water habitats off the coasts of what are now France and the U.K. Some sharks lived on or near the sea floor, while others actively hunted throughout the prehistoric seas. The largest sharks from the area at the time belonged to the genus Cretoxyrhina.

"This genus is also found in the Late Cretaceous seas of USA (the Western Interior Seaway) and probably reached 16.5 to 20 feet long and likely looked pretty much like the modern great white shark, although the two are not closely related," Guinot said.

Another big prehistoric shark from the region was Scapanorhynchus, which resembled a modern goblin shark and had a huge snout with enormous teeth.

It was a shark-eat-shark world then, with bigger sharks eating the smaller ones.

Ward shared, however, that giant marine reptiles known as plesiosaurs and mosasaurs, which looked a bit like underwater dinosaurs, were potential predators of sharks.

"It is difficult to distinguish between active predation and casual scavenging," Ward added. "Not having bone, sharks do not show bite marks."

Sharing the habitats with the ancient sharks were sea urchins, starfishes, tube worms, lobsters, crabs, numerous other fish and many other animals. If the sharks got close to shore, they could have been chased by some of the enormous crocodiles that lived around 100 million years ago.

Read more at Discovery News

Mystery of Byzantine Garbage Pit

Archaeologists digging at a site north of Tel Aviv have uncovered ancient coins and jewelry in a mysterious garbage dump, the Israel Antiquities Authority said in a statement.

Located near the ancient city of Apollonia-Arsuf, the Byzantine refuse pit is one of many unearthed in the area. But unlike the other garbage dumps, the pit measures more than 100 feet in diameter.

As they dug into it, the archaeologists found a hoard of 400 Byzantine coins, 200 intact Samaritan lamps and gold jewelry amid animal bones, pottery and glass fragments.

Most objects date to the 5th-7th centuries A.D.

What was a 1,500-year-old treasure doing in a garbage pit remains a mystery, said archaeologists Oren Tal of Tel Aviv University and Moshe Ajami of the Israel Antiquities Authority.

“The large amount of usable artifacts in the pit raises questions. Noteworthy among the jewelry is an octagonal ring with parts of verses from the Samaritan Pentateuch engraved in Samaritan script,” Tal and Ajami said.

One side reads: “Adonai is his name,” the other side: “One God…”

Approximately a dozen discovered Samaritan rings have been recorded so far in scientific literature.

“This ring constitutes an important addition given the assemblage in which it was discovered,” the archaeologists said.

The site once served as the agricultural hinterland of Apollonia-Arsuf, which is located west of the excavation area and what is today the Apollonia National Park.

Excavations conducted there from the 1950s until the present indicate that the site was inhabited continuously for more than 1,500 years — from the Persian period in late 6th century B.C. until the end of the Crusader period in the 13th century.

Populated by both Christians and Samaritans during the Byzantine period, Arsuf featured industrial quarters with wine presses, olive presses, plastered pools and kilns for the productin of raw glass.

Read more at Discovery News

Kilonova Alert! Hubble Solves Gamma Ray Burst Mystery

Gamma ray bursts, or GRBs, are some of the most intense displays of energy in the Universe. The origin of the mysterious short-duration gamma-ray bursts have eluded astronomers for decades, but a recent observation of a “kilonova” by astronomers using the Hubble Space Telescope has finally nailed down the culprit.

GRBs were first discovered by accident by satellites used in the 1960s to enforce nuclear test ban treaties. When bright flashes of gamma rays were determined to be coming from space and not from Earth, we had a new scientific phenomenon to explore, instead of nuclear war (thankfully). GRBs were later separated into two broad categories: short and long bursts. We now know that long-duration GRBs signal the death of very massive stars in a “hypernova” but their few-second long short duration cousins have remained mysterious.

It has been suggested that short GRBs arise when two compact objects, such as a neutron star or black hole, collide, releasing an incredible amount of energy. This is because short GRBs have been located in galaxies with older populations of stars, likely to have neutron stars and black holes as the remnants of stellar evolution, but not likely to have massive stars.

Models of these collisions predicted a “kilonova,” an event more powerful than a nova formed when a white dwarf erupts, but less powerful than a supernova which occurs when a massive star blows itself apart. This kilonova at the collision of two neutron stars would be powered instead by radioactive material spewing forth from the collision. So many heavy elements are produced in the explosion that optical light may not get through as easily, but the explosion would be bright in the infrared.

Astronomers got a chance to test this model when GRB130603B detonated on June 3. It was detected by the Swift satellite, a workhorse of gamma-ray burst science that can quickly detect a burst and turn the satellite around to observe the afterglow. Since the burst itself lasted less than a second, this is a crucial tool for catching up with the phenomena and alerting astronomers back on Earth to start searching for the afterglow. The immediate observations following the burst showed no evidence of a supernova.

Follow-up imaging was done using the Hubble Space Telescope in optical and infrared in June 12-13, finding the kilonova that was predicted to be there. This is the first time that observational evidence of the neutron star merger has been seen, just as predicted. The kilonova also faded away when observed weeks later.

These neutron star mergers are thought to be a source of gravity waves, or ripples in the fabric of space-time that occur when two compact objects collide. Each event will have its own signature as the objects spin faster and faster around each other in a shrinking orbit that ultimately leads to the merger. Gravity waves are being searched for by projects such as Advanced LIGO, but their sensitivities require such a merger to happen within a few hundred million light years. This rare event occurred 4 billion light-years away.

Read more at Discovery News

The Sun Is About To (Magnetically) Flip!

Every 11 years or so, the sun does something quite profound — its magnetic field completely swaps polarity. This event occurs at the peak of the solar cycle, heralding the mid-point and the most active phase of Solar Cycle 24.

“It looks like we’re no more than 3 to 4 months away from a complete field reversal,” said solar physicist Todd Hoeksema of Stanford University in a NASA news release. “This change will have ripple effects throughout the solar system.”

Solar astronomers have been keeping a close eye on the magnetic conditions in the lowest regions of the sun’s atmosphere, measuring its magnetic field strength and direction. “The sun’s polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity. This is a regular part of the solar cycle,” said solar physicist Phil Scherrer, also of Stanford University.

Hoeksema and Scherrer work at Stanford’s Wilcox Solar Observatory, one of the few observatories on the planet that is capable of acquiring solar magnetograms. Wilcox has been monitoring the sun’s polarity since 1976, seeing in three “grand reversals” from three solar cycles. This will be its fourth and excitement is mounting, especially as we’re only a few months away from complete reversal.

The solar cycle ebbs and flows over an approximate 11 year period. From “solar minimum” to “solar maximum,” our nearest star’s internal magnetic field gets wound up by the sun’s differential rotation. Differential rotation means that the sun rotates faster at the equator than it does at the poles, dragging the magnetic field — like an elastic band — that is embedded in the superheated plasma. As the sun approaches solar max (as it is now) the magnetic field is at its most stressed, causing magnetic arcs to be forced from the solar interior and into the lower corona.

It is during this period that space weather is at its most ferocious, creating beautiful aurorae at the Earth’s poles caused by an intensified solar wind blasting energetic particles into the Earth’s magnetosphere. Also, this is a period of intensified flare and CME activity, potentially damaging satellites and interfering with communications on the ground.

A visible marker of the progression of the solar cycle is the appearance of sunspots — dark blemishes in the sun’s photosphere, marking the location of active regions and potential sites of magnetic eruptions.

So, as we experience solar maximum, the sun’s interior reaches a tipping point in its magnetic polarity, signified by a magnetic field weakening. When the field does switch polarity, it’s not just a local event. The sun’s magnetic field projects from the sun and sweeps throughout the sun’s environment — the heliosphere. As the field flips inside the sun, so does the interplanetary magnetic field, causing the magnetic field and associated electric “current sheet” to ripple and warp.

Read more at Discovery News

Aug 6, 2013

Crusader Hospital Unveiled in Jerusalem

A huge building which during the Crusader period was the largest hospital in the Middle East has been discovered in the heart of Jerusalem, the Israel Antiquities Authority (IAA) announced on Monday.

Located in the Christian Quarter of the Old City of Jerusalem, the 1,000-year-old hospital was identified following a decade-long reconstruction operation.

“Until a decade or so ago the building served as a bustling and crowded fruit and vegetable market. Since then it stood there desolate,” the IAA said in a statement.

According to Renee Forestany and Amit Re’em, the IAA excavation directors, the structure, only a small part of which was unearthed in the excavation, spread out over more than 150,000 square feet.

It featured massive pillars, ribbed vaults, rooms, smaller halls and ceilings as high as 20 feet.

The hospital was established between 1099 and 1291, with permission from the Muslim authorities, by a Christian military order called the Kinghts Hospitaller. Its members vowed to care for pilgrims who came to Jerusalem to die.

“We’ve learned about the hospital from contemporary historical documents, most of which are written in Latin,” Re’em and Forestany said.

The accounts mentioned a sophisticated structure that was “as large and as organized as a modern hospital,” the archaeologists said.

Indeed, the building had different wings and departments for patients suffering from different medical conditions. In times of emergency, it could take in up to 2,000 patients from all religions.

“There is information about Crusaders who ensured their Jewish patients received kosher food,” said the archaeologists.

However, the level of medical skills wasn’t as good as the hospital’s organization.

“They were completely ignorant in all aspects of medicine and sanitation,” Re’em and Forestany said.

Examples ranged from crosses carved into skulls to remove evil spirits and headaches to legs amputated just because of small infected wounds.

“The Muslim Arab population was instrumental in assisting the Crusaders in establishing the hospital and teaching them medicine. Arab culture has always held the medical profession in high regard and Arab physicians were famous far and wide,” the IAA archaeologists said.

It was the Muslim hero Salah a-Din, who conquered Jerusalem from the Crusaders, who helped preserve the structure, allowing 10 Crusader monks to run the hospital.

The gigantic building also served as an orphanage. Mothers who did not want their offspring would come there with covered heads and hand over their infants. Often, when twins were born, one of them was given to the orphanage. All orphans joined the order of the Hospitallers as adults.

Remains of horse and camel bones, as well as metal for shoeing the animals, indicate the structure also served as stables in the Middle Ages.

In the earthquake of 1457, the building collapsed. During the Ottoman Empire, what remained was used as a fruit and vegetable market that operated until 2000.

Read more at Discovery News

Bizarre 'Meteotsunami' Stirred Waves in UK

A tsunami that struck the UK in 2011 was caused by a storm roiling the ocean hundreds of miles away, a new study confirms.

The "meteotsunami" (or weather-induced tsunami) of June 27, 2011, caused swells on a normally calm estuary on a sunny day, left some people knee-deep in water and made other people's hair stand on end in southwest England. Scientists suspected that a storm was to blame for the bizarre waves, but the new study, published in the June issue of the journal Weather, confirms it.

"As far as Britain is concerned this is the first time that a meteotsunami has been recorded," said study co-author David Tappin, a marine geologist at the British Geological Survey.

Rare waves

Weather-induced waves happen when storms blast the ocean surface with a burst of pressure, creating a wave. But this wave only turns into a tsunami if the pressure wave forms a resonance with the weather pattern — meaning the wave is traveling at the same speed as the weather front itself.

The wave may be just a few inches high in the deep ocean. But once the wave hits a narrow inlet or V-shaped harbor, the waterway reflects and amplifies the wave's energy and the blip on the water's surface can rapidly grow to 20 feet (6 m) high, Tappin told LiveScience's OurAmazingPlanet.

Rare weather-induced monster waves have been reported in Majorca, Spain; the Great Lakes in the United States; and the Adriatic Sea. In 1979, a weather-induced tsunami struck Japan at Nagasaki Bay. The 13-foot-high (4 m) wave killed several people.

Unusual event

On June 27, 2011 — a sunny day — the normally placid estuary at the mouth of the Yealm River in southwest England reported waves up to 2.6 feet (0.8 m) high. On the tidal island of St. Michael's Mount in Cornwall, people crossing the causeway connecting the island to the mainland quickly found themselves knee-deep in water, and others reported their hair standing on end.

Tappin's team suspected that the Yealm Estuary wave was caused by a storm, because no sensors detected an underwater landslide or earthquake, which normally trigger tsunamis.

The team pored over Doppler radar, pressure measurements and tide data from coastal Portugal, Spain, France and England.

The researchers found that the night before, a storm was brewing in the Bay of Biscay (located between Spain and France), more than 300 miles (482 kilometers) away from the Yealm. Over the next several hours, the storm moved into the English Channel, and area gauges showed pressure fluctuations. During the same period, the tides were also modestly higher throughout Britain, Ireland, France and Spain.

The combination of data suggests that the storm caused the freak waves in the southwest of England, the team concluded.

Read more at Discovery News

Turning the Corner: Tuesday Marks Summer's Midpoint

The midpoint of the 2013 northern summer — that moment that comes exactly between the summer solstice on June 21 and the Sept. 22 autumnal equinox — occurs today, Tuesday Aug. 6, at 8:54 p.m. EDT (0054 GMT on Aug. 7).

Although the altitude of the sun has been decreasing and the amount of daylight has been diminishing since the summer solstice, any changes to this point have been relatively subtle. On the first day of summer in New York, for example, sunset occurred at 8:30 p.m. and the day (from sunrise to sunset) stretched for 15 hours and 5 minutes. On Tuesday, the sun will set at 8:06 p.m. in New York, with the loss of daylight since June 21 amounting to just 56 minutes.

And even though the first half of summer will soon be behind us, we have only just now passed the warmest part of the year for many locations in the Northern Hemisphere. This is despite the fact that the midday sun is now about 6 degrees lower than it was six weeks ago. (Your clenched fist held at arm's length measures about 10 degrees.)

But it is in the second half of summer that the effects of the southward shift of the sun’s direct rays start becoming much more noticeable. In fact, by Sept. 22, New Yorkers will see the sun setting before seven in the evening (6:56 p.m.), while the length of daylight will have been reduced by almost two full hours since Aug. 6.

Interestingly, for many northern locales, long-term records indicate the last two weeks of July are the warmest of the summer. But average daily temperatures fall rapidly thereafter, so that by the last day of August they are lower in many parts of the country than during any day since the summer season officially began in late June.

Meteorologists, in fact, consider the summer season to be over at the end of August; they regard "meteorological summer" to be defined by the three months with the hottest temperatures: June, July and August.

So for all those who have grown tired of hot and humid days and uncomfortably warm nights, take heart: In the days and weeks to come, you’ll more readily be able to sense the later sunrises and earlier sunsets and see the more southerly position of the afternoon sunsets on the horizon. And soon the weather will respond as well, cooling down toward the crisp nights of autumn.

Read more at Discovery News

Telescope Was Born From an Ancient Need for Fire

While working to correct an extreme case of myopia (otherwise known as short-sightedness), Dutch optician Hans Lippershey stumbled upon the fact that a particular arrangement of lenses seemed to magnify distant objects.

This was the birth of the modern telescope.

Lippershey’s first telescope, or ‘dutch perspective glass’ as it was first known, came with a whopping magnification of 3x! Galileo took the design and made a better one which gave 5x magnification -- this may not sound much compared to even the most modest amateur telescope today offering at least 50x, but it was historic.

Today’s amateur astronomers routinely operate at magnifications in excess of 200x or more. The story of the invention of the telescope has been sketchy, but before Lippershey or even Galileo hit the headlines, there were other discoveries long before that were key to its invention.

Anyone who has studied a telescope will know that its main component is a lens or mirror depending on the design. Refracting telescopes use lenses to refract or bend starlight to a focus; reflecting telescopes use mirrors to reflect and focus it.

Before the telescope could be invented, glass had to be readily available. Glass, such as obsidian, occurs naturally and is produced through volcanic processes. The first evidence for a manmade process producing glass goes back to around 3000 BC where tiny glass beads were produced in northern Syria and Egypt as a by-product of metal work.

Glass-making technology started to take off in parts of Asia and Egypt around 1500 BC and soon led to production of glass vessels and beads for jewellery. Glass production continued around the world at varying paces but while this was happening other crucial discoveries were being made.

As early as the 8th Century BC ancient Romans and Egyptians had been experimenting with glass spheres that were filled with water in an attempt to increase the power of sunlight to help start fires.

Just a hundred years later, lenses were being polished from crystals and quartz -- such as the well known Nimrud lens. This beautifully ground piece of rock was found in what is now Iraq is oval in shape and had a focal length of about 11 centimeters. It is thought it may have simply been a piece of jewellery but there is growing support that it may have been used to magnify the sunlight for fire lighting.

Records are a little hazy around the first use of glass lenses but there are various mentions in historic literature. For example, a play by Aristophane in 424 BC references a 'burning-glass' that is believed to be a lens used to start fires.

Read more at Discovery News

Aug 5, 2013

Shark Familes Not So Nuclear

A single litter of shark pups can have anywhere from one to five dads, according to a new study that sheds light on the complex sex and family lives of many sharks.

Multiple paternity appears to be very common among sharks and has been documented in at least six species so far: leopard sharks, small-spotted catsharks, bonnethead sharks, lemon sharks, nurse sharks and sandbar sharks.

The most widely accepted explanation for multiple paternity is what's known as "convenience polyandry."

"Basically, the female doesn't have much say about who she mates with," lead author Andrew Nosal of Scripps Institution of Oceanography's Marine Biology Research Division told Discovery News. "If a male encounters her and wants to mate, he will."

"At this point, the female has two options," Nosal continued. "She can attempt to fight and escape, but may incur greater injury in the process. Or she can acquiesce to minimize physical damage to her body...As a matter of convenience, to minimize the chance of injury, the female may just go along with it, even though there appears to be no biological need to mate with more than one male per reproductive cycle."

Nosal and colleagues Eric Lewallen and Ronald Burton focused their study on leopard sharks living off the coast of La Jolla, Calif. The study has been accepted for publication in the Journal of Experimental Marine Biology and Ecology.

To determine the number of shark dads per litter, the researchers took DNA samples from 449 leopard shark pups from 22 litters. The average litter size for this particular shark species is about 20 pups.

Over 36 percent of the litters were fathered by two males instead of just one. This would be like a human mother giving birth to quadruplets, with two of the kids having one dad and the other two having another dad.

For eight of the litters with two dads, half of those had an even paternal skew.

"In other words," Nosal explained, "the number of pups within a litter fathered by the first dad was the same as the number of pups fathered by the second dad."

In the other four litters with more than one father, however, the shared paternity wasn't so even, with one dad clearly dominating the group.

Domination comes into play during mating as well. In leopard sharks, Nosal said, "The male will bite the female and wrap his body around hers to copulate."

The gestation cycle for this shark is then 10-11 months, longer than the human cycle of nine months. Females must quickly recover and then mate within one to two months to remain "on schedule" to give birth at around the same time the following year. The females therefore mate with multiple males within a short period of time, sometimes leading to the multi-dad litters.

Once the pups emerge, they are on their own.

"There is no parental care in leopard sharks or any species of shark," Nosal explained. "Leopard sharks are born live with all the instincts they need to find food and avoid predators. There is evidence of size clustering (that is, young leopard sharks hanging out together), which may function in predator avoidance or increased foraging efficiency."

He continued that one young shark might find something to eat, leading to a "commotion" that attracts others to the food source.

Read more at Discovery News

Strange Ancient Ape Walked on All Fours

A bizarre ancient ape whose gait has stumped researchers for decades walked on all fours and swung from the trees, new research suggests.

Oreopithecus bambolii, an ape that lived on an isolated island 7 million to 9 million years ago in what is now Tuscany and Sardinia, Italy, didn't have the pelvis or spine necessary for regular upright walking, the researchers said. Rather, the beast traversed Earth on all fours.

Their conclusion, detailed online July 23 in the Journal of Human Evolution, overturns an earlier hypothesis that the mysterious ape independently evolved bipedal, or two-legged, walking.

Ape oddity

When O. bambolii was alive, Italy formed a string of islands that were covered with swampy forests and teeming with crocodilians. The ape went extinct after a land bridge connected their island to other land, allowing large saber-toothed cats and other predators to stalk the island.

But the strange creature was a bit of a mystery: Scientists couldn't decide whether it was an ape or a monkey. (Apes have longer arms for swinging through trees, and monkeys often have tails that let them grab branches). O. bambolii had apelike arms, odd teeth with ridges more like a monkey's and feet that each had one backward-pointing toe, similar to those found on birds.

"It's always been a kind of controversial beast. It's an ape that's not closely related to any living apes at all," said William Jungers, a physical anthropologist at Stony Brook University in New York who was not involved in the study.

In the 1990s, one group of researchers took a second look at O. bambolii's pelvis and spine, and concluded the animal had adapted to walk on two legs.

That was a bold claim.

Because no other mammals, aside from humans and their ancestors, routinely walked upright, anthropologists use bipedal adaptations to determine which fossil apes are in humans' direct evolutionary lineage, said study co-author Liza Shapiro, an anthropologist at the University of Texas at Austin.

If O. bambolii, which isn't considered a direct ancestor to humans, had independently evolved upright walking, that line of logic would have to be rethought.

"It would be really extraordinary to see an animal we don't think is closely related to us who got around this way," said William Sanders, a paleoanthropologist at the University of Michigan who was not involved in the study.

Second look

Shapiro and her colleague Gabrielle Russo, an anatomist at Northeast Ohio Medical University, decided to take a second look at O. bambolii.

The team carefully analyzed a fossilized Oreopithecus skeleton that was discovered by a French paleontologist in 1872.

Prior research suggested this specimen had a wider pelvis compared with apes' and a unique lower-back curvature called lordosis. Both of these features give humans better balance when walking upright.

But Shapiro's team looked at the skeleton from several perspectives and found no evidence of these changes: no lower-back curvature and no widening of the pelvis. It also lacked the distinctive widening of vertebrae at the base, which allows the human spine to stack like a pyramid and efficiently direct force into the pelvis.

The team concluded that O. bambolii wasn't a two-legged walker. Instead, it probably used its long, hanging arms and apelike spine to swing from the branches in a forest.

Earlier work had probably drawn different conclusions because the specimen's spine was crushed and distorted, Sanders said.

The new study should put the debate to rest, he said.

Read more at Discovery News

Mysterious Pentagram on Google Maps Explained

Conspiracy theorists, start your engines: On the wind-blown steppes of central Asia, in an isolated corner of Kazakhstan, there's a large pentagram etched into the Earth's surface. And now an archaeologist has revealed the source of the mysterious structure.

The five-pointed star surrounded by a circle, located on the southern shore of the Upper Tobol Reservoir, shows up vividly on Google Maps. There are almost no other signs of human habitation in the area; the closest settlement is the city of Lisakovsk, about 12 miles (20 kilometers) to the east.

The region surrounding Lisakovsk is riddled with ancient archaeological ruins. Bronze Age settlements, cemeteries and burial grounds — many of which have yet to be explored — dot the windswept landscape.

What is this bizarre symbol, measuring roughly 1,200 feet (366 meters) in diameter, doing on the side of a desolate lake in northern Kazakhstan? Naturally, many online comments have already linked the site with devil worship, nefarious religious sects or denizens of the underworld.

It certainly doesn't help that, upon zooming into the center of the pentagram, viewers will see two places highlighted by previous visitors to Google Maps: One spot is called Adam, the other, Lucifer — a name often linked to Satan.

The pentagram is an ancient symbol used by many (non-Satanic) cultures and religious groups. It has been adopted by the Mesopotamians, Pythagoreans (followers of Pythagoras, the ancient Greek mathematician), Christians, Freemasons and Wiccans.

The Kazakh pentagram certainly isn't the first odd discovery gleaned from Google Maps. Etched onto the desert floor of New Mexico are two large diamonds surrounded by a pair of overlapping circles. This is reportedly the site of a hidden bunker belonging to the Church of Scientology, according to the author of a book on the religious group.

Deep in the Gobi Desert, viewers of Google Maps can find a Yagi antenna array, a device that looks like a giant piece of cracked glass but is used for atmospheric research. And in a remote corner of Nevada, there's an enormous KFC advertisement, featuring the smiling face of Colonel Sanders.

Though it's difficult to discern from an aerial photograph exactly what the Kazakh pentagram is, Emma Usmanova, an archaeologist with years of experience working in the Lisakovsk area, has an answer.

Read more at Discovery News

Better Artificial Ear Grown

From artificial eyeballs to limbs, doctors have dreamed up dozens of ways to replace body parts when things go wrong.

Now they can add a new device to their repertoire: a lifelike, flexible ear made from cartilage cells seeded on a titanium scaffold.

The new technique, described July 30 in the Journal of the Royal Society Interface, is better than previous tissue-engineering efforts and could replace a laborious technique that requires plastic surgeons to fashion a crude ear shape out of a lump of cartilage. The procedure could be used in trauma injury patients who have lost an ear or in children with microtia, a congenital ear deformity, said bioengineer Tom Cervantes, who was at Massachusetts General Hospital at the time of the research.

Prosthetic Ears

In the race to create bionic humans, ears have been a surprisingly tricky challenge. Numerous artificial ears are in medical use, but most had problems. Ears made from cartilage cells would often shrivel once implanted onto an animal. Prosthetic ears typically weren't very flexible or realistic-looking. And the reigning practice of extracting cartilage from a person's ribs and fashioning it into an ear was laborious and difficult to match with a person's other ear. Recently, researchers reported they had used a 3-D printer to create a bioengineered ear.

"For something like the ear where it's very cosmetic in nature, having a proper shape is one of the most important requirements. We wouldn't want it to look like a shriveled nub," Cervantes, who is now at Stanford University School of Medicine in California, told LiveScience.

Cervantes and his colleagues wanted to create something that could be customized. The team started with a 3-D computer model and used that to create a titanium mesh of the basic ear shape. They then seeded the mesh with cartilage cells that formed their own matrix over the mesh.

To see how the ear would hold up when connected to a blood supply, the team implanted the ear on several rats' backs and studied them for several weeks. Unlike previous attempts, the ear didn't shrivel up nor become deformed.

Read more at Discovery News

Aug 4, 2013

New Coating Turns Ordinary Glass Into Super Glass

A new transparent, bioinspired coating makes ordinary glass tough, self-cleaning, and incredibly slippery, a team from the Wyss Institute for Biologically Inspired Engineering at Harvard University and Harvard School of Engineering and Applied Sciences (SEAS) reported online in the July 31 edition of Nature Communications.

The new coating could be used to create durable, scratch-resistant lenses for eyeglasses, self-cleaning windows, improved solar panels, and new medical diagnostic devices, said principal investigator Joanna Aizenberg, Ph.D., who is a Core Faculty Member at the Wyss Institute, Amy Smith Berylson Professor of Materials Science at SEAS, and a Professor of Chemistry and Chemical Biology.

The new coating builds on an award-winning technology that Aizenberg and her team pioneered called Slippery Liquid-Infused Porous Surfaces (SLIPS) -- the slipperiest synthetic surface known. The new coating is equally slippery, but much more durable and fully transparent. Together these advances solve longstanding challenges in creating commercially useful materials that repel almost everything.

SLIPS was inspired by the slick strategy of the carnivorous pitcher plant, which lures insects onto the ultraslippery surface of its leaves, where they slide to their doom. Unlike earlier water-repelling materials, SLIPS repels oil and sticky liquids like honey, and it resists ice formation and bacterial biofilms as well.

While SLIPS was an important advance, it was also "a proof of principle" -- the first step toward a commercially valuable technology, said lead author Nicolas Vogel, Ph.D., a postdoctoral fellow in applied physics at Harvard SEAS.

"SLIPS repels both oily and aqueous liquids but it's expensive to make and not transparent," Vogel said.

The original SLIPS materials also need to be fastened somehow to existing surfaces, which is often not easy.

"It would be easier to take the existing surface and treat it in a certain way to make it slippery," Vogel explained.

Vogel, Aizenberg, and their colleagues sought to develop a coating that accomplishes this and works as SLIPS does. SLIPS's thin layer of liquid lubricant allows liquids to flow easily over the surface, much as a thin layer of water in an ice rink helps an ice skater glide.

To create a SLIPS-like coating, the researchers corral a collection of tiny spherical particles of polystyrene, the main ingredient of Styrofoam, on a flat glass surface, like a collection of Ping-Pong balls. They pour liquid glass on them until the balls are more than half buried in glass. After the glass solidifies, they burn away the beads, leaving a network of craters that resembles a honeycomb. They then coat that honeycomb with the same liquid lubricant used in SLIPS to create a tough but slippery coating.

"The honeycomb structure is what confers the mechanical stability to the new coating," said Aizenberg.

By adjusting the width of the honeycomb cells to make them much smaller in diameter than the wavelength of visible light, the researchers kept the coating from reflecting light. This made a glass slide with the coating completely transparent.

These coated glass slides repelled a variety of liquids, just as SLIPS does, including water, octane, wine, olive oil, and ketchup. And, like SLIPS, the coating reduced the adhesion of ice to a glass slide by 99 percent. Keeping materials frost-free is important because adhered ice can take down power lines, decrease the energy efficiency of cooling systems, delay airplanes, and lead buildings to collapse.

Importantly, the honeycomb structure of the SLIPS coating on the glass slides confers unmatched mechanical robustness. It withstood damage and remained slippery after various treatments that can scratch and compromise ordinary glass surfaces and other popular liquid-repellent materials, including touching, peeling off a piece of tape, and wiping with a tissue.

"We set ourselves a challenging goal: to design a versatile coating that's as good as SLIPS but much easier to apply, transparent, and much tougher -- and that is what we managed," Aizenberg said.

The team is now honing its method to better coat curved pieces of glass as well as clear plastics such as Plexiglas, and to adapt the method for the rigors of manufacturing.

"Joanna's new SLIPS coating reveals the power of following Nature's lead in developing new technologies," said Don Ingber, M.D., Ph.D., the Wyss Institute's Founding Director. "We are excited about the range of applications that could use this innovative coating." Ingber is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children's Hospital, and Professor of Bioengineering at Harvard SEAS.

Read more at Science Daily

New Prehistoric Shark Looked Like the Devil

A new prehistoric shark, Diablodontus michaeledmundi aka “Devil-Tooth,” has been found in a chunk of Flagstaff, Ariz., limestone.

The shark must have been super tough, as its species survived the world’s biggest extinction event (the Permian-Triassic extinction).

Devil Tooth not only had wickedly shark teeth, it also sported head spikes that gave it a devilish appearance. The spikes either evolved for defense or for sexual selection. In other words, the spikes must have turned on members of the opposite sex, similar to how horns of some animals today catch the eyes of potential mates.

The shark, discovered in what is known as the Kaibab Formation of Arizona, represents a new extinct genus and species. It is described in the New Mexico Museum of Natural History and Science Bulletin.

This particular Devil Tooth individual lived about 260 million years ago. Lead author John-Paul Hodnett, a Northern Arizona University post-graduate, told me that Devil Tooth was a hybodont, or hump-toothed, shark. Hybodonts were an “extinct group of sharks that were close kin to modern sharks,” he said. “Hybodont sharks evolved during the late Paleozoic (approximately 300 million years ago) and miraculously survived the Permian-Triassic extinction event (approximately 252 million years ago) into the Mesozoic (the age of reptiles),” Hodnett continued.

In addition to its hook-shaped head spikes, Devil Tooth had spines on the front and back of its fins. It possessed an asymmetrical tail, a feature of many modern sharks. Its teeth were “advanced,” Hodnett said, as they had “well developed pointed cusps with slight cutting edges, a feature which was not seen until later hybodonts during the beginning of the Mesozoic.”

The shark retained a primitive root structure, however, more like that of early sharks. The size of its teeth suggests that Devil Tooth was close to 3.5 feet in length. Hodnett compared it to living leopard sharks, at least in terms of probable hunting style. Devil Tooth likely spent its days searching for small fish, soft-bodied marine animals and other sea life along coastal waters between the bottom and mid-water.

When Devil Tooth was alive, the Kaibab Formation “was a shallow marine sea that bordered to the west of a great desert during the middle Permian period (270-260 million years ago). At this time the ancestors of modern sharks were just starting to diversify, but remained small,” Hodnett explained.

Read more at Discovery News