Apr 21, 2012

Warning Signs from Ancient Greek Tsunami

In the winter of 479 B.C., a tsunami was the savior of Potidaea, drowning hundreds of Persian invaders as they lay siege to the ancient Greek village. New geological evidence suggests that the region may still be vulnerable to tsunami events, according to Klaus Reicherter of Aachen University in Germany and his colleagues.

The Greek historian Herodotus described the strange retreat of the tide and massive waves at Potidaea, making his account the first description of a historical tsunami. Reicherter and colleagues have added to the story by sampling sediments on the Possidi peninsula in northern Greece where Potidaea (and its modern counterpart, Nea Potidea) is located. The sediment cores show signs of "high-energy" marine events like significant waves, and excavations in the suburbs of the nearby ancient city of Mende have uncovered a high-energy level dated to the 5th century B.C. The Mende layer contains much older marine seashells that were probably scoured from the ocean bed and deposited during a tsunami.

Earthquake forecast modeling in the North Aegean Basin near the peninsula suggests that future earthquakes in the area could produce significant tsunami waves, although the area is not included currently in the ten "tsunami" prone regions of Greece. However, Reicherter and colleagues say their new findings suggest the Thermaikos Gulf where the peninsula is located should be included in tsunami hazard calculations, especially since the area is densely populated and home to many holiday resorts.

Read more at Science Daily

Cleopatra and Antony's Children Rediscovered

Cleopatra's twin babies now have a face. An Italian Egyptologist has rediscovered a sculpture of Alexander Helios and Cleopatra Selene, the offspring of Mark Antony and Cleopatra VII, at the Egyptian museum in Cairo.

Discovered in 1918 near the temple of Dendera on the west bank of the Nile, the sandstone statue was acquired by the Egyptian Museum in Cairo but has remained largely overlooked.

The back of the the 33-foot sculpture, catalogued as JE 46278 at the Egyptian museum, features some engraved stars -- likely indicating that the stone was originally part of a ceiling. Overall, the rest of the statue appears to be quite unusual.

"It shows two naked children, one male and one female, of identical size standing within the coils of two snakes. Each figure has an arm over the other’s shoulder,‭ ‬while the other hand grasps a serpent," Giuseppina Capriotti, an Egyptologist at the Italy's National Research Council, told Discovery News.

The researcher identified the children as Alexander Helios and Cleopatra Selene, Antony and Cleopatra's twins, following a detailed stylistic and iconographic analysis published by the Polish Centre of Mediterranean Archaeology at the University of Warsaw.

Capriotti noticed that the boy has a sun-disc on his head,‭ ‬while the girl boasts a crescent and a lunar disc. The serpents, perhaps two cobras, would also be different forms of sun and moon, she said. Both discs are decorated with the udjat-eye, also called the eye of Horus, a common symbol in Egyptian art. ‭

"Unfortunately the faces are not well preserved, but we can see that the boy has curly hair and a braid on the right side of the head, typical of Egyptian children. The girl’s hair is arranged in a way‬ similar to the so-called ‭m‬elonenfrisur‭ (‬melon coiffure ) an elaborated hairstyle often associated with the Ptolemaic dynasty, and Cleopatra particularly," said Capriotti.

The researcher compared the group statue with another Ptolemaic sculpture, the statue of Pakhom, governor of Dendera, now on display at the Detroit Institute of Arts, USA.

"Stylistically, the statues have several features in common. For example, the figures have round faces,‭ ‬little chins and big eyes," Capriotti said.

Since the statue of Pakhom was dated to 50-30 B.C., she concluded that the twin sculpture was produced by an Egyptian artist at the end of the Ptolemaic period, after Roman triumvir Mark Antony recognized his twins in 37 B.C.

The babies weren't the firsts for Cleopatra. The Queen of Egypt had already given birth in 47 B.C., when she bore Julius Caesar a child, Caesarion. In 36 B.C. she presented Antony with another son, Ptolemy Philadelphus.

At the time of their birth in 40 B.C., the twins were simply named Cleopatra and Alexander. When they were officially recognized by their father three years later, as Antony returned to Antioch, in present Turkey, and Cleopatra joined him, they were named Alexander Helios (Sun), and Cleopatra Selene (Moon).

"Antony's recognition of the children was marked by an eclipsys. Probably for this reason, and to mythologize their twin birth, the children were added those celestial names. Although in Egypt the moon was a male deity, in the sculpture the genders were reversed according to the Greek tradition," Capriotti said.

Read more at Discovery News

Brain Implant Helps Paralyzed Hand Move

The dream of true cybernetics -- merging man with machine -- just got a bit closer. Scientists at Northwestern University built a device that can send signals from the brain directly to paralyzed muscles, causing them to move by thought. This technology could help patients who have suffered spinal cord injuries regain the use of their limbs.

The work was done in rhesus monkeys, who were given a local anesthetic to block nerve activity at the elbow, which caused temporary paralysis of the hand. Before they were given the anesthetic, though, the monkeys were trained to grasp a ball, lift it and release it into a tube. The signals from their brains to their hands and arms during these activities were recorded via an electrode implanted painlessly into their brains. After many repetitions, the researchers were able to see what kinds of signals were necessary to cause the the limbs to move. It turned out that the information was encoded in only about 100 neurons.

Knowing that, the scientists designed a device, called a multi-electrode array, that was able to pick up the tell-tale signals from the 100 or so neurons, decipher them and send them to the muscles -- bypassing the anesthetized nerves.

The signals that reached the muscles made them contract, enabling the monkeys to pick up the balls almost as well as they did before they were given the anesthetic.

The motions weren't perfect. Lee E. Miller, a professor in neuroscience at Northwestern and the lead investigator of the study said it might be because it takes some time for a monkey to learn how to use its arm again this way.

Read more at Discovery News

Ready to Blow? Mexico Volcano Rumbles

Mexico's Popocatepetl volcano has rumbled continuously and spewed gases and glowing rocks to almost one mile (one kilometer) beyond its crater, authorities said Friday.

Popocatepetl is located about 34 miles (55 kilometers) east of the capital, Mexico City. More than 30 million people live within sight of the volcano.

In an increase of activity the volcano registered "62 expulsions of medium intensity, with the emission of water vapor, gas, ashes and glowing rocks," between Thursday night and Friday, said a statement from the National Center of Disaster Prevention.

Authorities raised the alert level Monday to five on a seven-point scale, extending a security radius around the 5.452-meter (17,887-feet) volcano but stopping short of starting evacuations from nearby communities.

Concerns are growing that should a larger eruption occur huge quantities of ash could be dumped on one of the world's largest metropolitan areas, potentially causing chaos for Mexico City's busy air traffic.

Residents in the nearby town of Santiago Xalitzintla said the volcano was now constantly rumbling.

"There was a strong humming sound all night... it's roaring," said Alvaro Perez.

Another resident said her family was scared of what might happen next.

"My smallest son, who is four years old, was woken up by the roar during the night," said Sofia Lopez. "'Mum, are we leaving now?' he asked me. I told him that it was OK, but the truth is that we're very scared."

NOAA's Geostationary Operational Environmental Satellite, GOES-13, captures visible and infrared images of weather over the eastern U.S. every 15 minutes, and spotted an ash and gas cloud streaming from the volcano over several hours during the morning of April 18, 2012.

The short, four second black and white video covers several hours and shows the volcano's ash blowing to the east, and over the central state of Puebla.

On the ground, officials in Puebla have prepared temporary shelters for possible evacuations and locals were wearing face masks to protect their lungs from ashes in a populous area around the volcano.

Read more at Discovery News

Apr 20, 2012

Ancient 'Bone Box' Called Oldest Christian Artifact

Long-unrecognized lettering confirms that first-century artifacts found within an ancient Jerusalem tomb are the earliest representations of Christianity ever found, researchers say.

Two Hebrew scholars who examined photographs showing the inside of the tomb agree that markings on an ossuary — a box made to hold human remains -- are stylized letters that spell out the name of Jonah, the researchers said Thursday (April 19). Jonah was the Old Testament prophet whose story of being swallowed by a great fish was embraced by the early followers of Jesus.

The tomb, located 6.5 feet (2 meters) below an apartment building in the East Talpiot neighborhood of Jerusalem, was discovered in 1981 but resealed after Orthodox Jewish groups opposed its excavation. Two decades later, the group got license to enter the tomb, which has been dated to before A.D. 70.

Researchers led by James Tabor of the University of North Carolina at Charlotte did not enter the tomb themselves but instead used a remote camera to explore it. Their analysis of the images was reported Feb. 28 in the journal The Bible and Interpretation.

The Hebrew scholars' translation of the stylized letters on the ossuary have yet to be published.

Troubled tomb

On one of the ossuaries was an inscription depicting "divine Jehovah," and a second had a picture that appeared to be a fish with a stick figure in its mouth, said to represent Jonah. If they fully understand these drawings, the researchers said, then they have found the oldest Christian artifacts, the earliest Christian art and the first evidence of faith in Jesus' resurrection. Similar depictions of Jonah were used by later Christian groups and became an important expression of the faith in later centuries.

When the tomb and its contents were first disclosed, many biblical scholars offered alternate interpretations of the iconography and disputed the tomb's connections to Christianity. They said the image is more likely a funerary monument and not a fish at all.

Hebrew hint

After the initial announcement, the team continued to examine the images from their robot scout. Strange markings inside the fish head stood out to the researchers, and they called upon James Charlesworth, a Hebrew script scholar from the Princeton Theological Seminary.

The researchers said Charlesworth confirmed their interpretation of the marks: The lines that make up what they thought was a stick figure could also be viewed as four Hebrew letters. The script is similar to that from the Dead Sea Scrolls and seems to spell out "YONAH," the Hebrew name of Jonah.

Read more at Discovery News

Earliest Painting of Transvestite Uncovered

An 18th-century portrait sold in New York to a British gallery as a "woman in a feathered hat" turns out to actually portray a man dressed as a woman, becoming the earliest known painting of a transvestite.

The transvestite painting, now called the "Chevalier D'Eon," is currently hanging in the Philip Mould Ltd. gallery in London and will possibly become a permanent feature in the British National Portraits Gallery, said art dealer and art historian Philip Mould, director of Philip Mould Ltd.

"We spent 30 years honing our skills at looking at British portraits, and you begin to spot anomalies," Mould told LiveScience. "Portraiture, despite the diversity of odd-looking people in the world, particularly in the 19th century, before advances in cosmetic science and dentistry and medical advances had taken place, but portraiture is always extremely straight-laced."

The finished portrait was typically a compromise between the artist (who was painting what he or she saw) and the sitter (who wanted to look their best); that means anomalies of facial features can be subtle.

Something about the "muscularity of his face" and a "suggestion of stubble" caught Mould's eye as odd. So Mould and a team of his "lost faces bureau" went to work to figure out the sitter in this painting, and along the way ended up finding the actual artist of the work.

Once the painting had been cleaned and restored, "his masculine traits became far more manifest," Mould said, including the masculine-angled face shape and the facial hair stubble. The other thing they noticed was the signature of the artist, which had been listed as Gilbert Stuart, actually was "T. Stewart."

Putting the pieces together, including the fact that Charles D'Eon spent a fair amount of time on the stage fencing, the team nailed down the painter as Thomas Stewart, who also spent a lot of time in the theatre, Mould said.

Since the painting's unveiling this week, "we've had an interesting succession of individuals coming to pay homage," Mould said. "It's a combination of mirth and respect for a man who was bold enough, brave enough, but also extrovert enough to state his case."

In fact, D'Eon apparently lived the second half of his life as a transvestite during a time when cross-dressing was essentially unheard of.

Here's how D'Eon's transvestitism came to pass: He joined King Louis XV's secret service in 1755, had his first major military posting in London in 1763, before being appointed Plenipotentiary Minister to London. However, within months, he had a falling-out with the ambassador appointed to replace him in London, accusing the ambassador of trying to murder him. D'Eon also made public secret documents and ended up being sent to prison, which he escaped.

Once escaped, D'Eon concealed his identity, reportedly, by dressing as a woman. Gossip about his gender began in 1770, with rumors that people were even betting on whether he was a man or a woman.

"D'Eon refused all offers to confirm or deny the rumor," Simon Burrows, professor of modern history at the University of Leeds, said in a statement in 2010. "He also demanded the French government pay off his debts and they agreed, terrified he would betray state secrets, including plans to invade England."

Read more at Discovery News

Life Beyond Earth? Jupiter's Moons May Have Clues

Hoping to better understand conditions where life can form and grow, scientists want to explore three of Jupiter's large icy moons which may resemble some of the planets found orbiting stars beyond our solar system.

Europa, Callisto and Jupiter's largest moon, Ganymede, are all believed to have liquid oceans beneath their icy shells, as well as organic chemistry and possible sources of energy beyond the dim amount of sunlight that reaches their distant surfaces. These are all conditions that may be required for life in much more distant planetary bodies.

"We thought for quite some time these were dead icy bodies, but we have recently actually discovered a fabulous collection of very geologically active things there," planetary scientist Athena Coustenis, with the Paris Observatory in France, said at the Astrobiology Science Conference in Atlanta this week.

A newly proposed mission, The Jupiter Icy Moons Explorer, nicknamed JUICE, would send a spacecraft to study the three moons and their habitability.

Mission planners selected Ganymede as an archetype of an exoplanet water world like GJ 1214b, a super-Earth discovered last year circling a star about 40 light-years from Earth.

"We think it is the best example of a liquid environment trapped between icy layers," JUICE science study team member Olga Prieto Ballesteros, with the Center of Astrobiology in Madrid, Spain, said during a presentation at the conference.

Europa poses an intriguing model to those exploring the possibility of alien life because its buried ocean is believed to be in direct contact with the moon's silicate mantle, a source of salts and other elements. Europa is thought to be like exoplanets that are between water worlds and Earth-like bodies.

Callisto was selected because it is the only known example of a non-active, but ocean-bearing world, Prieto Ballesteros said.

"The icy planetary bodies have opened the possibility to find habitats in deeper environments. We can say that these icy bodies will expand the classical concept of habitability," which previously was limited to places with liquid water on the surface, Prieto Ballesteros said.

"The key question is are these worlds habitable?" she said.

Read more at Discovery News

Look Up! The Lyrid Meteor Hunt Begins

It's been observed annually for over 2,500 years, with some years more spectacular than others. Each year, the April sky brightens around 21/22nd of the month with light from the Lyrid meteor shower and, of all the showers, this one is perhaps one of the most unreliable.

This year, the shower peaks around 3 a.m. (GMT) on April 22 and as a bonus, the moon is well out of the way so the sky will be nice and dark, granting us ideal meteor spotting conditions.

Nearly every meteor shower, and there are about 20 good ones each year, is the result of the Earth moving through the orbit of a comet. In the case of the Lyrid shower, it's the orbit of comet C/1861 G1 Thatcher and, as it continues on the 415 year orbit around the sun, it sheds material.

At the core of the comet is a solid nucleus that is made up of ices and rocks and for most of its life it's lurking in the cold depths of the Solar System reaching the outermost point at 110 times the distance between the Earth and sun -- around three-times the distance that Pluto orbits the sun.

When it returns to the warmth of the inner solar system, the heat of the sun warms the cometary ices, turning them from a solid straight into gas -- a process known as sublimation. The escaping gas helps to dislodge some of the dust and rock in the nucleus leading to a trail of debris along its orbit.

When the Earth moves through the comet's orbit it sweeps up the debris and as the particles impact our atmosphere we see them as meteors or "shooting stars." It's this process that means the best time to observe meteor showers is during the early hours of your location almost regardless of the exact time of the peak. This is because you will be on the forward-facing side of the Earth as it enters the cloud, almost like the front of your car getting covered by flies as you drive through a swarm.

The peak activity is determined by the density of the cloud of debris and it's at this point that the most particles will hit the Earth. To see the best display of any particular shower you need your 'early morning' to coincide with hitting the densest part of the debris. However, unfortunately, it's very hard to determine the exact point where peak activity occurs. For this year's Lyrids, peak is expected between 3am and 9am (GMT) on the 22nd, so if this coincides with your morning, you should be in a good place for a reasonably good show.

Read more at Discovery News

Apr 19, 2012

Distinct 'God Spot' in the Brain Does Not Exist, Study Shows

Scientists have speculated that the human brain features a "God spot," one distinct area of the brain responsible for spirituality. Now, University of Missouri researchers have completed research that indicates spirituality is a complex phenomenon, and multiple areas of the brain are responsible for the many aspects of spiritual experiences. Based on a previously published study that indicated spiritual transcendence is associated with decreased right parietal lobe functioning, MU researchers replicated their findings. In addition, the researchers determined that other aspects of spiritual functioning are related to increased activity in the frontal lobe.

"We have found a neuropsychological basis for spirituality, but it's not isolated to one specific area of the brain," said Brick Johnstone, professor of health psychology in the School of Health Professions. "Spirituality is a much more dynamic concept that uses many parts of the brain. Certain parts of the brain play more predominant roles, but they all work together to facilitate individuals' spiritual experiences."

In the most recent study, Johnstone studied 20 people with traumatic brain injuries affecting the right parietal lobe, the area of the brain situated a few inches above the right ear. He surveyed participants on characteristics of spirituality, such as how close they felt to a higher power and if they felt their lives were part of a divine plan. He found that the participants with more significant injury to their right parietal lobe showed an increased feeling of closeness to a higher power.

"Neuropsychology researchers consistently have shown that impairment on the right side of the brain decreases one's focus on the self," Johnstone said. "Since our research shows that people with this impairment are more spiritual, this suggests spiritual experiences are associated with a decreased focus on the self. This is consistent with many religious texts that suggest people should concentrate on the well-being of others rather than on themselves."

Johnstone says the right side of the brain is associated with self-orientation, whereas the left side is associated with how individuals relate to others. Although Johnstone studied people with brain injury, previous studies of Buddhist meditators and Franciscan nuns with normal brain function have shown that people can learn to minimize the functioning of the right side of their brains to increase their spiritual connections during meditation and prayer.

Read more at Science Daily

Swedish Stonehenge? Stone Structure Spurs Debate

Ancient Scandinavians dragged 59 boulders to a seaside cliff near what is now the Swedish fishing village of Kåseberga. They carefully arranged the massive stones -- each weighing up to 4,000 pounds (1,800 kilograms) -- in the outline of a 220-foot-long (67-meter) ship overlooking the Baltic Sea.

Archaeologists generally agree this megalithic structure, known as Ales Stenar ("Ale's Stones"), was assembled about 1,000 years ago, near the end of the Iron Age, as a burial monument. But a team of researchers now argues it's really 2,500 years old, dating from the Scandinavian Bronze Age, and was built as an astronomical calendar with the same underlying geometry as England's Stonehenge.

"We can now say Stonehenge has a younger sister, but she's so much more beautiful," said Nils-Axel Mörner, a retired geologist from Stockholm University who co-authored the paper on the interpretation, published in March in the International Journal of Astronomy and Astrophysics.

Other researchers familiar with the site are skeptical. Among other arguments, they cite the results of carbon dating to reject Mörner's interpretation.

Inspired by Stonehenge?

Mörner says his team observed that the sun rises and sets at specific points around Ales Stenar at the summer and winter solstices, hinting that an ancient culture could have built it as an astronomical calendar to time things like annual religious ceremonies or planting and harvesting crops.

They also observed that certain aspects of the stone ship's geometry matched those of Stonehenge, a Bronze Age monument that some enthusiasts believe was used as a calendar. (Those claims are contentious, and there are many other theories of Stonehenge's original purpose.)

The similarities led Mörner to propose the mysterious stone structure of Sweden was a Stonehenge-inspired astronomical calendar constructed by a Bronze Age Scandinavian community that regularly traveled and traded throughout Europe and the Mediterranean.

"The first thing is to see that, yes, it's a calendar," Mörner told LiveScience. "But Ale's Stones also tells us a lot more than we knew before about trading and travel in the Bronze Age among Scandinavia, England and Greece."

Beowulf, not the Bronze Age

Other researchers are not convinced.

"The idea that the stone ship might have been an astronomical calendar has no supporters among academic archaeologists," said Swedish archaeologist Martin Rundkvist, managing editor of the archaeology journal Fornvännen.

Rather, Ales Stenar was probably an ornate grave marker, he said.

The Swedish countryside is home to many similar megalithic structures, which are generally known as stone ships. Most of them date back to Sweden's Late Iron Age (approximately A.D. 500-1000), and they serve as burial monuments, Rundkvist said.

Archaeologists using radiocarbon dating have calculated that Ales Stenar was built about 1,400 years ago, near the end of Scandinavia's Iron Age -- long after the construction date estimated by Mörner's team.

Read more at Discovery News

Polar Bears Older Than Thought

Polar bears have been chilling on the ice far longer than is generally thought, new research suggests, and they probably interbred with brown bears at one point after the two species separated.

The new German study contradicts data from a study published last July in the journal Current Biology that suggested polar bears separated from brown bears 150,000 years ago. The new study analyzed the bears' mitochondrial DNA, a special "additional genome" that lives in the cell's energy factories and is passed down only from the mother. The new study concludes that the bears became separate species closer to 600,000 years ago.

If the polar bears were only 150,000 years old, as suggested by the previous study, they would have had to evolve many specialized traits in a curiously brief time, the German researchers said.

"I've been long puzzled by the suggestion that the polar bears would have been such a miraculous and rapidly evolving species," Frank Hailer of the Senckenberg Nature Research Society in Frankfurt told LiveScience. "I had this lingering question: Is it really true?"

Nuclear problem solver

Hailer and his colleagues looked at the polar bear's nuclear DNA, which comes from both parents and is much larger than the mitochondrial genome.

They compared 9,000 base-pair sequences (the chemicals that make up the "rungs" of DNA's ladderlike molecule) from the nuclear DNA of 45 polar, brown and black bears. This comparison let the researchers build a family tree, with the idea that the greater the genetic differences between the species, the farther they were apart in evolutionary time. They were able to estimate when the polar bears and brown bears separated.

"We found that polar bears are much older than we previously knew from other studies; their appearance dated to about 600,000 years ago," Hailer said. "That would make sense around that time for something like a polar bear to evolve, because Arctic habitats were much larger than they are today, so there would have been much larger habitats that would have been suitable for a species like a polar bear."

Adapting to environment

The researchers say the mitochondrial DNA data could have come from a hybridization event between polar and brown bears 150,000 years ago during the last warm interglacial period. During that time, sea ice melted and polar bears took to the shores, where they came into contact with brown bears.

The researchers say this hybridization (similar to the hybrid "grolar" or "pizzly" bears seen in recent years in Canada) would have introduced the brown bear mitochondrial DNA into the polar bear population. If the DNA from the brown bears helped the polar bears survive the warm period, it's possible it could have easily spread throughout the population.

Read more at Discovery News

Ravens Remember and Greet You Accordingly

When you go outside, do the birds sound happy or angry when they see you? New research has found that at least one group of birds, ravens, remembers prior interactions with people and varies calls based on those earlier experiences.

So it's not too far fetched to think that if you bothered a bird some time ago, the bird might unleash the avian version of swearing the next time you approach.

The research, published in Current Biology, adds to the growing body of evidence that birds remember the appearance and voices of individuals, along with their prior encounters with them. Last year we told you how crows don't forget faces, for example.

We take such skills for granted in humans. In daily life, it's a given that we remember the faces and voices of multiple known individuals. Other studies show that different mammals can do the same thing.

If you want a lifelong buddy, you might consider getting a horse since they remember their human friends and act accordingly. We humans can be pretty nasty and complicated with each other at times, but give a horse a carrot and a head pat for a while and you'll receive near-guaranteed kindness in return.

Markus Boeckle and Thomas Bugnyar from the Department of Cognitive Biology of the University of Vienna demonstrate in their new study that ravens differentiate individuals based on familiarity. They also discovered that ravens memorize relationship bonds and affiliation.

The findings revealed that ravens change their call characteristics depending on whether they hear former "friends" or "foes." The study only covered up to three years, but bird memory may extend beyond that time.

So what does an angry bird sound like? When listening to a foe, a raven responds with a call that's lower than normal in tone and starts to include "rougher characteristics." The switch from the bird version of "Hey! How are you?" to "Buzz off" is similar to how we communicate such differences in our speech.

Strangers get an even rougher response from ravens. This is the equivalent of a person yelling, "Who are you?" if a stranger bangs on the door. There's an interesting scientific phenomenon behind having a louder, lower and rougher sounding response.

Read more at Discovery News

Apr 18, 2012

Nature's Billion-Year-Old Battery Key to Storing Energy

New research at Concordia University is bringing us one step closer to clean energy. It is possible to extend the length of time a battery-like enzyme can store energy from seconds to hours, a study published in the Journal of The American Chemical Society shows.

Concordia Associate Professor László Kálmán -- along with his colleagues in the Department of Physics, graduate students Sasmit Deshmukh and Kai Tang -- has been working with an enzyme found in bacteria that is crucial for capturing solar energy. Light induces a charge separation in the enzyme, causing one end to become negatively charged and the other positively charged, much like in a battery.

In nature, the energy created is used immediately, but Kálmán says that to store that electrical potential, he and his colleagues had to find a way to keep the enzyme in a charge-separated state for a longer period of time.

"We had to create a situation where the charges don't want to or are not allowed to go back, and that's what we did in this study," says Kálmán.

Kálmán and his colleagues showed that by adding different molecules, they were able to alter the shape of the enzyme and, thus, extend the lifespan of its electrical potential.

In its natural configuration, the enzyme is perfectly embedded in the cell's outer layer, known as the lipid membrane. The enzyme's structure allows it to quickly recombine the charges and recover from a charge-separated state.

However, when different lipid molecules make up the membrane, as in Kálmán's experiments, there is a mismatch between the shape of the membrane and the enzyme embedded within it. Both the enzyme and the membrane end up changing their shapes to find a good fit. The changes make it more difficult for the enzyme to recombine the charges, thereby allowing the electrical potential to last much longer.

"What we're doing is similar to placing a racecar in on snow-covered streets," says Kálmán. The surrounding conditions prevent the racecar from performing as it would on a racetrack, just like the different lipids prevent the enzyme from recombining the charges as efficiently as it does under normal circumstances.

Photosynthesis, which has existed for billions of years, is one of the earliest energy-converting systems. "All of our food, our energy sources (gasoline, coal) -- everything is a product of some ancient photosynthetic activity," says Kálmán.

But he adds that the main reason researchers are turning to these ancient natural systems is because they are carbon neutral and use resources that are in abundance: sun, carbon dioxide and water. Researchers are using nature's battery to inspire more sustainable, human-made energy converting systems.

Read more at Science Daily

Small Furry Hyrax Sings in Regional Dialects

Foundations of complex language have been found in colonies of unusual furry animals called hyraxes.

Hyraxes, which resemble rodents but are more closely related to elephants or manatees, often cluck, snort, squeak, tweet and wail songs from the perches of their rocky colonies.

By recording hundreds of the animals’ songs and applying clever mathematics, researchers discovered that differences in note arrangement, or syntax, in hyrax songs vary as the distance increases between colonies — a surprising occurrence of dialect.

“Dialect is usually seen only in animals with sophisticated vocalizations, like primates, bats and cetaceans. Such animals can copy and improvise on what they hear, which are very, very core building blocks of language,” said zoologist Arik Kershenbaum at the University of Haifa in Israel.

“It’s not obvious to human ears, but hyraxes also appear to have these building blocks,” said Kershenbaum, who co-authored the study of hyrax songs Apr. 18 in Proceedings of the Royal Society B.

Most hyraxes live in central Africa, southern Africa and parts of the Middle East. In Israel the rock hyrax is a pekingese-dog-size species, called Procavia capensis, which dominates the craggy landscape in colonies numbering from as small as 10 to as large as 50.

Like meerkats or prairie dogs, hyraxes keep lookouts while the colony forages. If the lookout spots a threat, he sings and the colony retreats into the rocks. Such songs may also be used as distress calls, in territory maintenance, male status claims and mating.

Songs are composed of bouts, which are made of 20 to 30 syllables. Hyraxes sing a bout, take a breath and then repeat.

“Songs can go on for 10 minutes or more and are quite enchanting and eerie,” Kershenbaum said. “In Israel we’re surrounded by hyraxes, and one morning while listening I thought, ‘There is no way these sounds are random. Evolution doesn’t favor random complexity like that.’”

To explore the rock hyrax’s syllabic singing, Kershenbaum and his colleagues toured nine sites across Israel and recorded more than 200 hyrax songs for a total of nearly 3,000 bouts. The team then codified bouts into strings of letters representing each of the five sounds and its order, like base pairs in the genetic code of DNA.

Mathematical algorithms, including one normally used to express the similarity of one string of DNA to another, revealed surprising changes in song syntax. The differences jumped as the distance from one colony to the next increased. Closer colonies sang songs in roughly similar orders, for example, while hyraxes in distant colonies sang songs with relatively jumbled notes.

“It’s not the kind of thing you can really detect by ear, if you’re not a hyrax, but these songs are phenomenally complex. The differences are quite subtle but consistent,” Kershenbaum said.

The researchers don’t yet understand what hyraxes use such hidden complexity for, if anything, but Kershenbaum plans to sample the rest of the animal kingdom for hidden syntactic dialects.

Read more at Wired Science

Why Huge Dinosaurs Had Such Tiny Babies

A new study may explain many mysteries about dinosaurs, such as why enormous species had such small offspring, why non-flying dinos went extinct, and why today’s birds fly.

The paper, published in the journal Biology Letters, emphasizes how mammals and birds -- but not non-avian dinosaurs -- were able to persist beyond a major extinction 65.5 million years ago. The large body size and egg-laying ways of dinos may have helped to do them in, along with hungry mammals.

"The most successful (dinosaurs) were the very large ones that were able to escape the competition trap and replenish their numbers. After the mass extinction, they again tried to evolve large size, but to escape the competition trap they had to become multi-ton animals," lead author Daryl Codron told Discovery News.

"It seems that with all the mammals that were now in the way, birds simply could not become bigger," added Codron, a post-doctoral researcher at the University of Zurich’s Clinic for Zoo Animals, Exotic Pets and Wildlife.

Although large flightless birds exist today, such as ostriches and emus, they are a far cry from the gigantic sauropods and other big non-avian dinosaurs.

For the study, Codron and his team simulated both dinosaur and mammal communities comprising species from 27 size categories including the largest and smallest known species of each group. The researchers next used mathematical calculations to simulate what would happen to the adults and offspring of the animals, based on size and resource competition.

While larger mammals can have larger babies, the dinosaurs faced the physical limitations of laying eggs. This meant that even enormous dinosaurs, weighing up to 150 tons, had tiny offspring.

"One cannot have a very large egg with a very thin shell, otherwise it would simply break open," Codron explained. "The shell itself is limited in thickness. It cannot become so thick that gas can no longer diffuse through it, which would deprive the embryo of oxygen. For a very small egg-laying animal this is no problem, but it does mean that very large animals have to produce relatively small eggs."

Since very large adult dinosaurs tended to out-compete medium-sized adults, this and the egg limitations meant that most dino species were either small or large, with a gap in the medium size range, according to the researchers. In contrast, mammals fill all body size ecosystem niches available to them.

Once the catastrophic event 65.5 million years ago wiped out larger dinosaur species, dinos then had less surviving species from which to refill empty spots in the food chain. Mammals diversified and flourished, while non-avian dinosaurs disappeared.

The theory, however, could explain why living dinosaurs -- birds -- survived and evolved flight.

Codron said that "many people assume that dinosaurs were superior competitors, but there is now evidence that mammals were already diverse in those (dino-era) times, albeit small, and mammals may have preyed upon small dinosaur individuals and or eggs."

Read more at Discovery News

Rare Cosmic Effect Sheds Light on Galaxy Cluster Motion

Astronomers have confirmed a 40-year-old prediction that there should be tiny variations in the cosmic microwave background radiation (CMB) as a result of moving clusters of galaxies.

The results appeared in a paper published last month on the arXiv, and could shed additional light on how those clusters may have formed in the first place.

Back in 1972, an astrophysicist in Moscow, Russia, named Rashid Sunyaev found himself pondering the "afterglow" of the birth of our universe, a.k.a., the CMB, which offers a snapshot of those early days when the cosmos was a mere 380,000 years old.

Sunyaev and a colleague, Yakov Zel'dovich, didn't have the technology to make precise measurements of the CMB, but they figured that the light had to pass through lots of galaxy clusters as it traveled across the vast expanse of space -- and there should be tiny effects as a result of that interaction. The light should become just a wee bit cooler (redder) if that cluster is moving away from Earth, and very slightly hotter (bluer) if the cluster is moving toward Earth.

This should happen because there is a lot of very hot, ionized gas lurking between those galaxies, and quite a few so-called free electrons floating around as a result. (A gas becomes ionized when the temperature rises sufficiently to rip electrons away from atoms.)

Statistically, microwaves from the CMB would eventually collide with one of those electrons -- a rare event, to be sure, but those collisions should leave a detectable trace in the form of slight variations in temperature as a microwave moves through a galaxy cluster, traveling away from Earth.

We're talking a very slight variation, on the order of a few millionths of a degree, because a microwave doesn't hit an electron very often. This became known as the kSZ ("kinematic Sunyaev-Zel'dovich") effect. It was an interesting prediction, but physicists had no way of experimentally testing it for over 40 years.

Princeton astronomer David Spergal knew that two different kinds of data would be needed to detect the kSZ effect.

As a collaborator on the Atacama Cosmology Telescope (ACT), he figured it should be possible to strengthen the effect's signal, and decrease the noise, by averaging all of the ACTs temperature maps of the cosmic microwave background for thousands of galaxy clusters.

But one would also need accurate maps to pinpoint the exact locations of the clusters. That's where the Sloan Digital Sky Survey (SDSS) came in. The SDSS dataset includes the location of the 7500 brightest galaxies clusters.

The ACT operates in the microwave regime; the SDSS's Baryonic Oscillation Spectroscopic Survey (BOSS) operates in the visible light regime. It wouldn't have been possible to detect the kSZ effect by analyzing them separately. The power of the technique lies in combining the two.

Spergal assigned the painstaking and time-consuming task of combining these two datasets to Nick Hand, then a senior at Princeton, who was looking for a senior thesis project. (Hand is currently a graduate student at UC-Berkeley.)

First, Hand carefully marked where the the clusters were located. Then he used the ACT data to measure the CMB temperatures at those locations. When the analysis was completed, Hand confirmed that, indeed, the CMB temperatures were every so slightly higher in those spots, just as the kSZ effect predicted.

The kSZ effect should be particularly useful as a means of tracking how galaxy clusters move through the cosmos. And what about the gravitational forces that caused them to clump together in the first place? The most obvious culprits would be dark matter and dark energy, and because the kSZ effect is a direct means of probing how large-scale structures like galaxy clusters evolve in the universe, it could be used one day to evaluate competing theories.

Read more at Discovery News

Apr 17, 2012

Asteroid Craters On Earth Give Clues in Search for Life On Mars

Craters made by asteroid impacts may be the best place to look for signs of life on other planets, a study suggests. Tiny organisms have been discovered thriving deep underneath a site in the US where an asteroid crashed some 35 million years ago.

Scientists believe that the organisms are evidence that such craters provide refuge for microbes, sheltering them from the effects of the changing seasons and events such as global warming or ice ages.

Life forms

The study suggests that crater sites on Mars may also be hiding life, and that drilling beneath them could lead to evidence of similar life forms.

Researchers from the University of Edinburgh drilled almost 2 km below one of the largest asteroid impact craters on Earth, in Chesapeake Bay, US.

Samples from below ground showed that microbes are unevenly spread throughout the rock, suggesting that the environment is continuing to settle 35 million years after impact.

Microbe nutrients

Scientists say that heat from the impact of an asteroid collision would kill everything at the surface.

However, fractures to rocks deep below would enable water and nutrients to flow in and support life.

Some organisms grow by absorbing elements such as iron from rock.

The research was published in the journal Astrobiology.

Read more at Science Daily

Magnetic Fields Can Send Particles to Infinity

Researchers from the Complutense University of Madrid (UCM, Spain) have mathematically shown that particles charged in a magnetic field can escape into infinity without ever stopping. One of the conditions is that the field is generated by current loops situated on the same plane.

At the moment this is a theoretical mathematical study, but two researchers from UCM have recently proved that, in certain conditions, magnetic fields can send particles to infinity, according to the study published in the journal Quarterly of Applied Mathematics.

"If a particle 'escapes' to infinity it means two things: that it will never stop, and "something else," Antonio Diaz-Cano, one of the authors, explained. Regarding the first, the particle can never stop, but it can be trapped, doing circles forever around a point, never leaving an enclosed space.

However, the "something else" goes beyond the established limits. "If we imagine a spherical surface with a large radius, the particle will cross the surface going away from it, however big the radius may be" the researcher declares.

Scientists have confirmed through equations that some particles can escape infinity. One condition is that the charges move below the activity of a magnetic field created by current loops on the same plane. Other requirements should also be met: the particle should be on some point on this plane, with its initial speed being parallel to it and far away enough from the loops.

"We are not saying that these are the only conditions to escape infinity, there could be others, but in this case, we have confirmed that the phenomenon occurs," Diaz-Cano states. "We would have liked to have been able to try something more general, but the equations are a lot more complex."

In any case, the researchers recognise that the ideal conditions for this study are "with a magnetic field and nothing else." Reality always has other variables to be considered, such as friction and there is a distant possibility of going towards infinity.

Nonetheless, the movement of particles in magnetic fields is a "very significant" problem in fields such as applied and plasma physics. For example, one of the challenges that the scientists that study nuclear energy face is the confinement of particles to magnetic fields.

Read more at Science Daily

Hubble Captures Incredible New Panorama of Tarantula Nebula

Millions of young stars shine brightly in this enormous stellar nursery at the heart of the Tarantula Nebula.

The Hubble space telescope captured this amazing panorama, which reveals intricate details about the expanse known as 30 Doradus. Located about 170,000 light-years away in the Large Magellanic Cloud — a small galaxy orbiting our Milky Way — 30 Doradus is one of the largest and most prolific star-forming regions in our galactic neck of the woods.

The region is so huge that, if it were as close to us as the Orion Nebula (the nearest stellar nursery to Earth, about 1,300 light-years away), it would be the size of 60 full moons in the sky and glow so brightly that it could cast shadows on the ground.

Though 30 Doradus isn’t quite that close, Hubble can still resolve the individual stars inside the region, allowing astronomers to study the lives of stars in detail.

Stars are born when a mass of gas and dust collapses under its own weight. The center of this mass gravitationally attracts more material, growing larger and heavier. The extra material increases the density and temperature in the central region. Eventually, the mass reaches a critical point and hydrogen will begin fusing into helium. The star ignites, releasing copious amounts of heat and energy.

Inside 30 Doradus, Hubble can spot stellar babies, only a few thousand years old and still wrapped in the remnants of the dusky cloud of gas that gave rise to them. It can also see massive stars a few tens of millions of years old, which burn through their fuel fast and die young.

The white region in the left side of the picture contains some of the most massive stars in the universe, weighing in at hundreds of times the sun’s mass. This stellar cluster is roughly 2 million to 3 million years old and contains about 500,000 stars in total. Intense ultraviolet light released by the young stars pushes against the surrounding gas and dust, carving out the beautiful structures and filigrees seen in this image. Some of this gas and dust will be mushed together, increasing its density and potentially sparking the birth of more new stars.

Read more at Wired Science

Humans Still Eating Humans

The recent arrest of three people in Brazil suspected of making empanadas out of human flesh (and then selling them) reminds us that though human cannibalism is rare in the modern world, it still persists.

Brazil, in particular, has been linked to cannibalism in recent years. The Lancet journal reported in 1994 “that eating human remains” was common among 250 people who lived in an Olinda slum. “Poverty and a lack of compliance with laws” were blamed, since the starving individuals were eating human body parts that they found in the Brazilian city’s garbage dump.

“Cannibalism is an ethologic behavior widespread among human primates and non-human primates,” Isabel Cáceres, a paleoecologist at the Universitat Rovira i Virgili, told Discovery News. Cáceres has studied the phenomenon -- going back up to 780,000 years ago in our ancestors.

“Probably, the practice of cannibalism in the genus Homo appears due to lack of resources and competition for territory in critical moments,” she added.

The recent case was apparently a cruel twist on that strategy. The suspects confessed to murdering at least two women, eating parts of their bodies, and using the rest to make meat pies sold in the town of Garanhuns near Sao Paulo.

One quote from one of the suspects also points to other factors. Fifty-one-year old Jorge Beltrao Negroponte told SBT Television, “I did certain things for purification, to protect people and deliver them to God.”

“Up until the late 18th century, the human body was a widely accepted therapeutic agent," said Richard Sugg, a member of the Centre for Seventeenth-Century Studies at Durham University. "The most popular treatments involved flesh, bone, or blood, along with a variety of moss sometimes found on human skills.”

In a paper for the Lancet, Sugg shared how a Franciscan monk in the 17th century made marmalade out of human blood, and even wrote a recipe for it. The instructions, in part, read: “stir it to a batter with a knife…pound it…through a sieve of finest silk.”

Sugg also mentioned how the word “mummy” in early-modern texts frequently refers to flesh from mummified human bodies, which were “applied topically or mixed into drinks,” since “this was a common remedy for bruising in the period.” The French King Francis (1494-1547) even carried mummified human flesh “in his purse,” according to Sugg, as a sort of good luck charm.

Opponents of this so-called “corpse medicine” began to emerge in the 16th century. By the late 18th century, hostility toward it became widespread and effective. The folklore about it, however, may persist in certain cultures, and not just due to health reasons.

“Thinking like past humans, without our present day tabu and social behavior that does not allow us to eat other humans and see this as a disgusting action, cannibalism could be observed as a clever strategy,” Yolanda Fernandez-Jalvo, a paleobiologist at the Museo National de Ciencia Naturales, told Discovery News. She studied cannibalism that occurred some 12,000 years ago at a site called Gough’s Cave in what is now Somerset, England.

“Think that if a member of your group dies (of natural causes), the body can give one day off from hunting, which was always dangerous at the time,” she added. And it could prove to be a “good solution” for disposing of the body “that may attract other dangerous carnivores that may attack the group.”

Read more at Discovery News

Apr 16, 2012

One of Earliest Farming Sites in Europe Discovered

University of Cincinnati research is revealing early farming in a former wetlands region that was largely cut off from Western researchers until recently. The UC collaboration with the Southern Albania Neolithic Archaeological Project (SANAP) will be presented April 20 at the annual meeting of the Society for American Archaeology (SAA).

Susan Allen, a professor in the UC Department of Anthropology who co-directs SANAP, says she and co-director Ilirjan Gjipali of the Albanian Institute of Archaeology created the project in order to address a gap not only in Albanian archaeology, but in the archaeology in Eastern Europe as a whole, by focusing attention on the initial transition to farming in the region.

"For Albania, there has been a significant gap in documenting the Early Neolithic (EN), the earliest phase of farming in the region," explains Allen. "While several EN sites were excavated in Albania in the '70s and '80s, plant and animal remains - the keys to exploring early farming - were not recovered from the sites, and sites were not dated with the use of radiocarbon techniques," Allen says.

"At that time (under communist leader Enver Hoxha), Albania was closed to outside collaborations and methodologies that were rapidly developing elsewhere in Europe, such as environmental archaeology and radiocarbon dating. The country began forming closer ties with the West following Hoxha's death in 1985 and the fall of communism in 1989, paving the way for international collaborations such as SANAP, which has pushed back the chronology of the Albanian Early Neolithic and helped to reveal how early farmers interacted with the landscape."

The findings show that Vashtëmi, located in southeastern Albania, was occupied around 6,500 cal BC, making it one of the earliest farming sites in Europe. The location of early sites such as Vashtëmi near wetland edges suggests that the earliest farmers in Europe preferentially selected such resource-rich settings to establish pioneer farming villages.

During this earliest phase of farming in Europe, farming was on a small scale and employed plant and animal domesticates from the Near East. At Vashtëmi, the researchers have found cereal-based agriculture including emmer, einkorn and barley; animals such as pigs, cattle and sheep or goats (the two are hard to tell apart for many bones of the skeleton); and deer, wild pig, rabbit, turtle, several species of fish and eels. What seems evident is that the earliest farmers in the region cast a wide net for food resources, rather than relying primarily on crops and domesticated animals, as is widely assumed.

Read more at Science Daily

Chimpanzee Ground Nests Offer New Insight Into Our Ancestors' Descent from the Trees

The first study into rarely documented ground-nest building by wild chimpanzees offers new clues about the ancient transition of early hominins from sleeping in trees to sleeping on the ground. While most apes build nests in trees, this study, published in the American Journal of Physical Anthropology, focused on a group of wild West African chimpanzees that often shows ground-nesting behaviour.

An international team of primatologists from the University of Cambridge and Kyoto University, led by Dr Kathelijne Koops, studied the chimpanzee (Pan troglodytes verus) population in the Nimba Mountains in Guinea, West Africa. All species of great ape build nests to sleep in each night. Construction of these shelters takes minutes as the apes bend, break and interweave branches into a circular frame, followed by tucking in smaller branches to form a sturdy but comfortable sleeping platform.

"We believe that, like modern apes, the common ancestor of chimpanzees and humans also slept in the trees 6 million years ago," said Dr Koops. "However, these nests are not preserved in the fossil or archaeological record, so it is impossible to study directly the ancient transition from sleeping in trees to building shelters on the ground. Recording this rare behaviour in the chimpanzee, our closest relative, may provide vital clues."

As the Nimba chimpanzees do not yet tolerate human presence at close range, the team used new molecular genetic techniques to analyse hairs collected from the nests. This allowed the team to establish the sex of chimpanzees displaying the behaviour and to identify individuals in the group.

The team showed that as chimpanzees sleep both on the ground and in the trees, the transition from trees to the ground did not require a special evolutionary adaptation. This suggests that early hominins may have slept on the ground before the emergence of Homo erectus ('upright man'), the first species which was fully adapted to living on the ground. "This is intriguing as it has long been believed that coming down from the trees was a crucial evolutionary shift," said Koops. "However, this chimpanzees' behaviour suggests a more deep-seated, gradual transition from tree-to-ground sleep."

Other theories for the tree-to-ground transition have included the use of fire and the scarcity of trees in open habitats. The team demonstrated that neither is a prerequisite for ground sleeping, as the chimpanzees live in a plentiful evergreen rainforest and do not create fire.

Read more at Science Daily

Aging Male Giraffes Go Black, Not Gray

Male giraffes become more illustrious with age, but rather than the silvery locks that distinguish the likes of Sean Connery and George Clooney, the hairy blotches on these long-necked mammals darken with age.

And new research suggests the appearance change takes about 1.8 years to complete, with male giraffes being completely covered in coal-black blotches by an average age of 9.4 years.

"What is fascinating about the color change is that it goes from light to dark," study researcher Fred Bercovitch, of the Primate Research Institute and Wildlife Research Center, Kyoto University, told LiveScience. "In gorillas who turn silverback, and in men, the color gets lighter, not darker with age."

Bercovitch and his colleague, local naturalist Phil Berry, analyzed 33 years of data from observations of the Thornicroft’s giraffe (Giraffa camelopardalis thornicroftii), a distinct subspecies endemic to the Luangwa Valley, Zambia. Data included an average of 10-plus years for each giraffe. Overall, they studied 10 males of known age and 26 whose ages were estimated based on the extent of blotch darkening when first observed.

The researchers paid close attention to the color of the spots, which are known to gradually change color from a sienna brown to a coal black, beginning with a darkening in the center of the blotch that slowly extends outward to the edges. (However, nobody had studied the giraffes long enough to pin down the timing of the change until now.)

Bercovitch thinks testosterone somehow drives this color change, though once the bulls reach maturity, and a full set of jet-black spots, the testosterone probably levels out.

With their data on coat-color changes, along with information on male deaths and disappearances, the researchers put together a life-history profile for the subspecies: Males that survive the first year of life become independent from mom by age 2, and leave their natal area at 4 to 8 years old. Coat color starts changing between ages 7 and 8, with about one to two years elapsing before the change is complete.

Males become mature bulls at about 10 years of age and have an average life expectancy of 14 to 16 years. Maximum longevity is about 21 to 22 years, they found.

Read more at Discovery News

Where's the Hottest Place on Earth?

The title of "world's hottest place" is often bestowed upon El Azizia, Libya, where the highest temperature ever measured on Earth was recorded, but a study of satellite temperature data shows that the crown belongs elsewhere, and that it can shift from year to year.

El Azizia took the record for highest temperature ever recorded on Sept. 13, 1922, when a thermometer on a weather station hit a whopping 136 degrees Fahrenheit (58 degrees Celsius), thanks to southerly winds blowing in hot air from over the Sahara Desert. The sweltering temperature displaced the previous record holder of 134 F, measured at the Furnace Creek weather station in Death Valley on July 10, 1913.

But neither of these places, hot though they may be, deserves the banner of "hottest place on Earth," according to new research by a University of Montana team using data from the U.S. Geological Survey's Landsat satellites.

"Most of the places that call themselves the hottest on Earth are not even serious contenders," said team member Steven Running in a NASA statement.

Running and his colleagues examined seven years of infrared data (which indicates temperature) from the Landsat satellites, and found that the winner in five of those years was actually the Lut Desert in Iran.

The reason Lut didn't previously make the list was because "the Earth’s hot deserts — such as the Sahara, the Gobi, the Sonoran and the Lut — are climatically harsh and so remote that access for routine measurements and maintenance of a weather station is impractical," said team member David Mildrexler. "The majority of Earth's hottest spots are simply not being directly measured by ground-based instruments."

Satellites, on the other hand, can get a reading on these hard-to-reach, harsh places because they can scan every piece of the Earth's surface. The satellites take what is called "land skin temperature," which tells the amount of heating of a certain parcel of ground from the sun, the atmosphere and other heat sources. The temperatures measured at weather stations, on the other hands, are taken a couple meters above the ground.

The single highest land skin temperature recorded in any year of the study was found in the Lut Desert in 2005 and measured a stunning 159.3 F (70.7 C). Lut had the highest surface temperature in 2004, 2006, 2007 and 2009 as well.

Read more at Discovery News

Apr 15, 2012

New Genes Linked to Brain Size, Intelligence

In the world’s largest brain study to date, a team of more than 200 scientists from 100 institutions worldwide collaborated to map the human genes that boost or sabotage the brain’s resistance to a variety of mental illnesses and Alzheimer’s disease. Published April 15 in the advance online edition of Nature Genetics, the study also uncovers new genes that may explain individual differences in brain size and intelligence.

“We searched for two things in this study,” said senior author Paul Thompson, professor of neurology at the David Geffen School of Medicine at UCLA and a member of the UCLA Laboratory of Neuro Imaging. “We hunted for genes that increase your risk for a single disease that your children can inherit. We also looked for factors that cause tissue atrophy and reduce brain size, which is a biological marker for hereditary disorders like schizophrenia, bipolar disorder, depression, Alzheimer’s disease and dementia.”

Three years ago, Thompson’s lab partnered with geneticists Nick Martin and Margaret Wright at the Queensland Institute for Medical Research in Brisbane, Australia; and with geneticist Barbara Franke of Radboud University Nijmegen Medical Centre in the Netherlands. The four investigators recruited brain-imaging labs around the world to pool their brain scans and genomic data, and Project ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) was born.

“Our individual centers couldn’t review enough brain scans to obtain definitive results,” said Thompson, who is also a professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA. “By sharing our data with Project ENIGMA, we created a sample large enough to reveal clear patterns in genetic variation and show how these changes physically alter the brain.”

In the past, neuroscientists screened the genomes of people suffering from a specific brain disease and combed their DNA to uncover a common variant. In this study, Project ENIGMA researchers measured the size of the brain and its memory centers in thousands of MRI images from 21,151 healthy people while simultaneously screening their DNA.

“Earlier studies have uncovered risk genes for common diseases, yet it’s not always understood how these genes affect the brain,” explained Thompson. “This led our team to screen brain scans worldwide for genes that directly harm or protect the brain.”

In poring over the data, Project ENIGMA researchers explored whether any genetic variations correlated to brain size. In particular, the scientists looked for gene variants that deplete brain tissue beyond normal in a healthy person. The sheer scale of the project allowed the team to unearth new genetic variants in people who have bigger brains as well as differences in regions critical to learning and memory.

When the scientists zeroed in on the DNA of people whose images showed smaller brains, they found a consistent relationship between subtle shifts in the genetic code and diminished memory centers. Furthermore, the same genes affected the brain in the same ways in people across diverse populations from Australia, North America and Europe, suggesting new molecular targets for drug development.

“Millions of people carry variations in their DNA that help boost or lower their brains’ susceptibility to a vast range of diseases,” said Thompson. “Once we identify the gene, we can target it with a drug to reduce the risk of disease. People also can take preventive steps through exercise, diet and mental stimulation to erase the effects of a bad gene.”

In an intriguing twist, Project ENIGMA investigators also discovered genes that explain individual differences in intelligence. They found that a variant in a gene called HMGA2 affected brain size as well as a person’s intelligence.

DNA is comprised of four bases: A, C, T and G. People whose HMGA2 gene held a letter “C” instead of “T” on that location of the gene possessed larger brains and scored more highly on standardized IQ tests.

“This is a really exciting discovery: that a single letter change leads to a bigger brain,” said Thompson. “We found fairly unequivocal proof supporting a genetic link to brain function and intelligence. For the first time, we have watertight evidence of how these genes affect the brain. This supplies us with new leads on how to mediate their impact.”

Because disorders like Alzheimer’s, autism and schizophrenia disrupt the brain’s circuitry, Project ENIGMA will next search for genes that influence how the brain is wired. Thompson and his colleagues will use diffusion imaging, a new type of brain scan that maps the communication pathways between cells in the living brain.

Read more at Science Daily

Memory in Adults Impacted by Versions of Four Genes

Two research studies, co-led by UC Davis neurologist Charles DeCarli and conducted by an international team that included more than 80 scientists at 71 institutions in eight countries, has advanced understanding of the genetic components of Alzheimer's disease and of brain development. Both studies appear in the April 15 edition of the journal Nature Genetics.

The first study, based on a genetic analysis of more than 9,000 people, has found that certain versions of four genes may speed shrinkage of a brain region involved in making new memories. The brain area, known as the hippocampus, normally shrinks with age, but if the process speeds up, it could increase vulnerability to Alzheimer's disease, the research suggests.

The second paper identifies two genes associated with intracranial volume -- the space within the skull occupied by the brain when the brain is fully developed in a person's lifespan, usually around age 20.

DeCarli is a pioneer in the field of neuroimaging of the aging brain who has been at the forefront of developing and using quantifiable imaging techniques to define the relationship between structure and function in the healthy aging brain and to characterize the changes associated with vascular and Alzheimer's dementias. He is professor of neurology and director of the UC Davis Alzheimer's Disease Center and the UC Davis Imaging of Dementia and Aging Laboratory.

Genetic variants of hippocampus study

The gene variants identified in the first study do not cause Alzheimer's, but they may rob the hippocampus of a kind of "reserve" against the disease, which is known to cause cell destruction and dramatic shrinkage of this key brain site. The result is severe loss of memory and cognitive ability.

Scientists calculated that hippocampus shrinkage in people with these gene variants accelerates by about four years on average. The risk of Alzheimer's doubles every five years beginning at age 65, so a person of that age would face almost twice the Alzheimer's risk if he or she had these versions of the gene.

Looked at another way, if a person with one of these variants did get Alzheimer's, the disease would attack an already compromised hippocampus and so would lead to a more severe condition at a younger age than otherwise, the research suggests.

"This is definitely a case of 'bigger is better,'" said DeCarli. "We already know that Alzheimer's disease causes much of its damage by shrinking hippocampus volume. If someone loses a greater-than-average amount of volume due to the gene variants we've identified, the hippocampus is more vulnerable to Alzheimer's."

Why the aging hippocampus normally decreases in volume is unclear. The new research shows that the genes most strongly linked to shrinkage are involved in maturation of the hippocampus and in apoptosis, or programmed cell death -- a continual process by which older cells are removed from active duty.

The scientists suggest that if the gene variants they identified do affect either maturation or the rate at which cells die, this could underlie at least some of the increased rates of hippocampus shrinkage.

"Either by making more or healthier hippocampal neurons or preventing them from dying with advancing age, the healthy versions of these genes influence how people remember as they get older," said DeCarli. "The alternate versions of the genes may not fully provide these benefits."

The researchers hope that they can find ways to protect the hippocampus from premature shrinkage or slow its decline by studying the normal regulation of the proteins coded by these genes.

The genetic analysis draws on what is known as a genome-wide association study -- research aimed at finding the common genetic variants associated with specific diseases or other conditions. Different versions of a gene usually come down to changes in just one of the tens of thousands of DNA "letters" that make up genes. These one-letter differences are known as single-nucleotide polymorphisms, or SNPs.

The research involved more than 80 scientists at 71 institutions in 8 countries. Many researchers are needed for such a study in order to put together the large samples, or cohorts, of people whose genetic makeup is to be investigated, to measure the hippocampus from magnetic resonance pictures of the brain and for the labor-intensive statistical analysis of the findings.

The study used a very large assemblage of genetic and disease data called the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium, or CHARGE. The consortium brings together several population-based cohorts in the United States and Europe.

The cohort was made up of 9,232 dementia-free volunteers with an average age of 67. The study identified four different gene variants associated with hippocampus volume decline. One, known as rs7294919, showed a particularly strong link to a reduced hippocampus volume, suggesting that this gene is very important to hippocampus development or health.

The findings were then assessed in two other cohorts. One, including both normal and cognitively compromised people with an average age of 40, showed that three of the suspect SNPs were linked to reduced hippocampus volume. Analysis of results from the third group, comprised primarily of older people, showed a significant association between one of the SNPs and accelerated memory loss.

"With this study, we have new evidence that aging, the hippocampus and memory are influenced by specific genes," DeCarli said. "Understanding how these genes affect the development and aging of the hippocampus may give us new tools to delay memory loss with advanced age and possibly reduce the impact of such diseases as Alzheimer's disease."

Read more at Science Daily