Oct 9, 2010

Black Death Blamed on Bacteria

Anthropologists said on Friday they had confirmed long-running suspicions that a germ called Yersinia pestis caused the plague that wiped out an estimated third of Europe's population in the Middle Ages.

Teeth and bones sampled from 76 skeletons found in "plague pits" in France, Germany, Italy and the Netherlands and sequenced for DNA intrusion are conclusive evidence that Y. pestis was to blame, they said.
Y. pestis has been in the dock for more than a century as the source of so-called Black Death, which gripped Europe in successive outbreaks from the 14th to the 18th century.

But scientific data to convict the bacterium have until now been sketchy or debatable.

As a result, a clutch of rival theories have blossomed, including the contention that an Ebola-style virus or the anthrax germ were to blame.

The study, published in the open-access journal PLoS Pathogens, also sheds unexpected light on the geographical route taken by the germ, which is believed to have originated in central or southern Asia before arriving in Europe through trade.

"The history of this pandemic is much more complicated than we had previously thought," said Stephanie Haensch, a co-leader of the research, at Johannes Gutenberg University in Mainz, Germany.

In samples where Y. pestis genes were found, the researchers ran a test for 20 DNA markers to identify a particular bacterial strain.

They wanted to see if there was a match for either of two types of Y. pestis that are still knocking around the world today, in parts of Africa, America, the Middle East and in the former Soviet Union.

But neither of these modern types, known as Orientalis and Medievalis, showed up.

Read more at Discovery News

200 New Species of Frogs, Spiders, Mammals and More Discovered

“In just two months of searching through a remote, mountainous rainforest in Papua New Guinea, scientists discovered 200 new species of animals and plants, including spiders, frogs, insects and mammals.

The surveys were done in 2009 in the Nakanai Mountains on the island of New Britain, which the country has nominated for World Heritage status. The new species could offer a boost to that effort.

“While very encouraging, these discoveries do not mean that our global biodiversity is out of the woods,” Leeanne Alonso of Conservation International said in a press release Oct. 5. “On the contrary, they should serve as a cautionary message about how much we still don’t know about Earth’s still hidden secrets.”

Some of the newly discovered species are truly spectacular, such as the pink-eyed beauty above, one of 20 leaf katydids found in the surveys.

Within the relatively small sample of 42 individuals of the leaf katydids in the Muller Range mountains, scientists Piotr Naskrecki and David Rentz found at least 20 new species.
We’ve got some of the most beautiful, strange and interesting of the new species in this gallery, along with a few very rare ones that hadn’t been seen in the area before.”

Read more at Wired

Oct 8, 2010

Students are more responsible drinkers than adult workers, survey claims

According to researchers students are more likely to drink less and are less likely to find it acceptable to end up in hospital or have a run-in with the police due to excessive alcohol intake.
The poll questioned 1,700 young people and found that almost a third of students claimed that they stopped drinking before they reached their personal limit compared to one quarter of young workers of a similar age.

Just 3 per cent of students thought it was acceptable to end up in hospital after drinking too much, compared to 5 per cent of young adults who were in work.

However, three in 10 students still admitted to blacking out, or losing their memory after drinking too much.
The survey, commissioned by the alcohol charity Drinkaware, found that less than one in ten (9 per cent) of students say they drink 16 units of alcohol or more - equivalent to eight pints of beer or eight glasses of wine - on a night out, compared to one in eight (12 per cent) of young working adults.

And the same proportion of students thought it was acceptable to get into trouble with the police for anti-social behaviour due to drinking, while 7 per cent of young adult workers said the same.

The survey did find that more than half (54 per cent) of students admit they still drink at least double the daily limit guidelines.

The same proportions of both students and young adult workers (29 per cent) said their friends would ridicule them if they chose to drink soft drinks on a night out.

Chris Sorek, Chief Executive of Drinkaware, said: "Despite the reputation students have of drinking to excess, being at university shouldn't be seen as synonymous with being drunk. We need to challenge this stereotype and combat the acceptability of drunkenness among all young adults, whether they are a student or not.

Read more at The Telegraph

The End of the World as We Know It?

A new study suggests the universe and everything in it could end within the Earth's lifespan -- less than 3.7 billion years from now -- and we won't know it when it happens.

But one expert says the result isn't valid because the researchers chose an arbitrary end point.

The universe began in a Big Bang about 13.7 billion years ago and has been expanding at an ever accelerating rate ever since.

According to standard cosmology models the most likely outcome for the universe is that it will expand forever.

But a team of physicists led by Raphael Bousso from the University of California, Berkeley, claim their calculations show the universe will end.

Writing in the prepublication blog arXiv.org Bousso and colleagues say there's a "measure problem" in the cosmological theory of eternal inflation.

Eternal inflation is a quantum cosmological model where inflationary bubbles can appear out of nothing. Some expand and go on forever, others collapse and disappear again.

These bubbles, each being a universe, pop in and out of existence like bubbles in boiling water.

They argue, in an eternally inflating universe, every event that is possible will eventually occur -- not just once, but an infinite number of times. This makes predicting when each event will occur impossible, such as the probability that a universe like ours exists.

"If infinitely many observers throughout the universe win the lottery, on what grounds can one still claim that winning the lottery is unlikely?" they write.

Read more at Discovery News

Solar System’s Deepest Canyon Sinks Miles Into Mars

On the Martian surface, the mountains are high and the canyons are low. Really, really low.

Not only is the martian volcano Olympus Mons the highest peak in the solar system, Melas Chasma, the canyon pictured above, is the deepest in the solar system. In this image from the European Space Agency’s Mars Express orbiter, the valley on the left (darker area) sits a whopping 5.6 miles below the plateau on the right (lighter area).

Compared to the average shape of Mars, known as the “aeroid,” the canyon floor sinks down about 3.1 miles. Planetary scientists would love to use sea level measurements to describe Martian surface features, but there’s no ocean on the red planet anymore and any signs of an ocean are long since warped by millions of years of surface deformation.

The photo above covers about 7,700 square miles, or about the size of New Jersey, which makes it only a tiny postage stamp of Mars’ deepest, longest and most prominent scar — the 2,500-mile-long Valles Marineris rift valley (below).

Read more at Wired

Oct 7, 2010

Oldest Evidence for Dinosaurs in Tiny Footprints

The earliest known fossils associated with dinosaurs have been identified in 250-million-year-old rocks from Poland.

The fossils -- footprints made by dinosaur relatives known as dinosauromorphs -- suggest that dinosaurs evolved from small, four-legged animals that lived during the Early Triassic just a few million years after the "Great Dying," Earth's most severe extinction event to date.

"For some reason, the major dinosaur lineages survived this extinction -- we don't know exactly why, and it may have been little more than random fortune -- and they probably then had the freedom to flower in a post-apocalyptic world," lead author Stephen Brusatte told Discovery News.

"(Dinosauromorphs) are the very closest relatives to dinosaurs, animals that were right on the cusp of becoming dinosaurs, shared many features with dinosaurs, probably looked and behaved like dinosaurs, but are not bona fide dinosaurs by definition," Brusatte, a paleontologist at the American Museum of Natural History, explained.
The finding was published in the Proceedings of the Royal Society B

Brusatte and colleagues Grzegorz Niedzwiedzki and Richard Butler analyzed multiple fossilized animal tracks dating from the Early and Middle Triassic at the Holy Cross Mountains in southern Poland, an exciting new frontier for early dinosaur research.
The oldest tracks from this site are only about a half an inch in length, so the scientists conclude they belonged to an animal that was approximately the same size as a modern housecat, weighing at most around four pounds. Its hind legs were also longer than its forelimbs, since the footprints overstep the handprints.

Read more at Discovery News

'Mini-Pompeii' Found in Norway

Norwegian archaeologists have unearthed a Neolithic “mini Pompeii” at a campsite near the North Sea, they announced this week.

Discovered at Hamresanden, not far from Kristiansand’s airport at Kjevik in southern Norway, the settlement has remained undisturbed for 5,500 years, buried under three feet of sand.

“We expected to find an 'ordinary' Scandinavian Stone Age site, badly preserved and small. Instead, we discovered a unique site, buried under a thick sand layer,” lead archaeologist Lars Sundström, of the Museum of Cultural History at the University in Oslo, told Discovery News.

Digging about 80 meters (262 feet) from the shoreline, in the headland formed by the river Topdalselva and the North Sea, Sundström’s team first unearthed what appears to be the remains of a walled structure.

“So far, we have evidence of a 30-meter (98.5-foot) bank made from sand mixed with clay and silt. We believe that this bank has been shoveled up against a wooden wall in order to support it," Sundström said.

The structure, whose length continues beyond the limits of the excavation trenches, is made of large stones.
"They must have been carried from some distance, since the area is devoid of stone naturally," Sundström said.
Most likely a seasonal aggregation site conveniently located between a river and the sea, the settlement is filled with shards of beaker-shaped vessels, many of which could be restored to the original state.

Read more at Discovery News

Oct 6, 2010

Chief scientist who questioned evolution theory fired

“The Education Ministry’s chief scientist, Dr. Gavriel Avital, was dismissed on Monday following a scandal-filled trial period of less than a year.

Sources familiar with the affair said Avital was fired over past statements he had made, in which he questioned evolution and the global warming theory.

Avital, who was named chief scientist in December 2009, said Darwinism should be analyzed critically along with biblical creationism.

“If textbooks state explicitly that human beings’ origins are to be found with monkeys, I would want students to pursue and grapple with other opinions. There are many people who don’t believe the evolutionary account is correct,” he said.

“There are those for whom evolution is a religion and are unwilling to hear about anything else. Part of my responsibility, in light of my position with the Education Ministry, is to examine textbooks and curricula,”
Avital added, “If they keep writing in textbooks that the Earth is growing warmer because of carbon dioxide emissions, I’ll insist that isn’t the case.”"

Read more at Y Net News

The World’s First Artificial Heart

“This is the world’s first total artificial heart.

Surgeons Domingo Liotta and Denton Cooley placed it into Haskell Carp’s chest on April 4, 1969 in Houston. They removed it 64 hours later when a donor heart became available.

But the heart did what it was supposed to do, explained Judy Chelnick, an associate curator at the Smithsonian’s National Museum of American History. The patient did not live long, but not because the manmade heart malfunctioned. It worked just fine, laying the stage for many later variations.

The piece of medical history is now stored in a formaldehyde solution in a cabinet behind the scenes at the museum. The NMAH had kindly invited us over to look at their patent medicine collection, and we just happened to stumble upon Chelnick going about her business.

She pulled the heart from a cabinet and set it on a cart for us to look at. ”

Read more at The Atlantic

Oct 5, 2010

Neanderthals had deep sense of compassion, new study suggests

Researchers found that groups living in Europe between 500,000 and 40,000 years ago took care of sick or wounded individuals over a period of many years.
The interdependence of early communities, who would hunt and eat together, let to an emerging commitment to the welfare of others.

The University of York study, published in the journal Time and Mind, examined archaeological remains to see how emotions emerged from our ancestors.

The researchers' evidence showed how a child with a congenital brain abnormality was not abandoned but lived until five or six years old.

It also showed how a Neanderthal with a withered arm, deformed feet and blindness in one eye was taken care of for up to two decades.

A four-stage model, developed scientists from the university's Department of Archaeology, charts the beginnings of human empathy from six million years ago when the common ancestor of humans and chimpanzees began to "help" others.

They concluded that compassion in Homo erectus 1.8 million years ago began to be regulated as an emotion integrated with rational thought.

Care of sick individuals showed compassion towards others while special treatment of the dead suggested grief at the loss of a loved one and a desire to soothe individuals.

In modern humans, starting 120,000 years ago, compassion was extended to strangers, animals, objects and abstract concepts.

Read more at The Telegraph

Instant Expert: Rebuilding Human Minds

“Age-related memory loss—the kind where you remember friends from decades ago but can’t remember your grandchildren—is largely a mystery, but a class of com-pounds used to treat cancer has given neuroscientists clues to its molecular underpinnings. Scientists also suspect that the compounds responsible for this insight, called histone deacetylase inhibitors, could significantly slow memory loss—perhaps for years. (Two drugs used now to treat memory loss and Alzheimer’s disease work only for a short time.) A study on aging mice by scientists at the European Neuroscience Institute in Germany published this May in Science showed that histone deacetylase inhibitors helped mice perform more than 50 percent better on a memory test than controls did. Study co-author André Fischer says these drugs would be used together with others to treat Alzheimer’s patients.

The process of forming long-term memories—those that persist for more than a few dozen seconds—is poorly understood, but here’s what we know: Neuroscientists have evidence that the brain’s hippocampus is central to the process. To consolidate a memory, a cascade of electrical pulses fire across the gaps between neurons, called synapses. This triggers the release of neurotransmitters, which form new connections between neighboring neurons. But neurotransmitters can’t be synthesized without each cell tapping into its DNA.”

Read more at Pop Sci

Oct 4, 2010

Details of 18th-Century 'Ground Zero Ship' Revealed

NEW YORK - Since the remains of a wooden ship were unearthed at the World Trade Center construction site in mid-July, a horde of researchers has been putting the vessel under the microscope - sometimes literally - in a quest to piece together the true story of the resurrected ship, and save it from decay.

On Thursday, three of the experts most intimately involved with the 18th-century mystery ship - Michael Pappalardo, an archeologist, Norman Brouwer, a maritime historian, and Nichole Doub, a conservator - convened on a tiny stage here at the New York Academy of Sciences (NYAS) in front of a packed house, to discuss what science and history detectives have uncovered about the ship so far.

The 32-foot- (9.7 meters) long timber structure is the back end and bottom quarter of what researchers believe was a two-masted trade vessel, a workhorse of its day. The area where it was found was part of the Hudson River in the late 18th century, and it's not clear if the ship sank, or if it was stuck in the river bottom on purpose to act as fill to make more "land" for Manhattan.

Brouwer is calling the boat a Hudson River sloop, and says it was probably between 60 and 70 feet (18 and 21 m) - about the size of an articulated, extra-long New York City bus.

The vessel may have traveled up and down the Hudson River and perhaps the Atlantic seaboard, ferrying goods like sugar, molasses, salt and rum between the warm Caribbean and the uniting colonies to the north.

"We found seeds, pits and nuts," said Pappalardo, of the firm AKRF, a consulting company working with the Lower Manhattan Development Corporation (LMDC), operators of the WTC site. "They might have been what the ship was used to transport, or they might have been eaten by the people on the boat. We're working our way through different scenarios."

Read more at Yahoo News

Gigantic Spider Webs Made of Silk Tougher Than Kevlar

“A spider discovered deep in the jungles of Madagascar spins the largest webs in the world, using silk that’s tougher than any known biological substance.

Named Caerostris darwini, or Darwin’s bark spider, the inch-wide arachnid’s webs can cover 30-square-foot areas, hanging in midair from 80-foot-long anchor lines.

The webs’ size generates enormous structural stresses, magnified by the struggles of trapped prey. Strands must “absorb massive kinetic energy before breaking,” and are “10 times better than Kevlar,” wrote University of Puerto Rico zoologist Igni Agnarsson in Public Library of Science One.

Agnarsson and Slovenian Academy of Sciences biologist Matjaž Kuntner discovered C. darwini in 2008. It’s similar in many ways to Caerostris species found in Africa, but those spiders live at the edges of forest clearings. In Madagascar, where animals have taken kaleidoscopic forms since the island split from mainland Africa 165 million years ago, C. darwini evolved to exploit the airspace above streams and rivers.”

Read more at Wired

Oct 3, 2010

Stonehenge Drew Prehistoric Tourists

Stonehenge’s circle of large standing stones was a top international tourist attraction already in prehistoric times, according to chemical analysis of the teeth of individuals found buried near the mysterious megaliths. Presented this week at a science symposium in London to mark the 175th anniversary of the British Geological Survey (BGS), the study involved a technique known as isotope analysis, which measures the ratio of strontium and oxygen isotopes in tooth enamel.

Strontium isotopes provide information on the geological setting of a person’s childhood, while the oxygen isotopes can pinpoint the climate in which the subject was raised.

The researchers tested the teeth from two males. One, known as the “Amesbury Archer,” was found in 2002, buried three miles from Stonehenge.

The other, dubbed “the Boy with the Amber necklace,” was found more recently on Boscombe Down, some three miles south-east of Stonehenge.
Read more at Discovery News

Oldest High-Altitude Settlements Discovered

The world's oldest known high-altitude human settlements, dating back up to 49,000 years, have been found sealed in volcanic ash in Papua New Guinea mountains, archaeologists said Friday.

Researchers have unearthed the remains of about six camps, including fragments of stone tools and food, in an area near the town of Kokoda, said an archaeologist on the team, Andrew Fairbairn.

"What we've got there are basically a series of campsites, that's what they look like anyway. The remains of fires, stone tools, that kind of thing, on ridgetops," the University of Queensland academic told AFP. "It's not like a village or anything like that, they are these campsite areas that have been repeatedly used."

Fairbairn said the settlements are at about 2,000 meters (6,600 feet) and believed to be the oldest evidence of our human ancestors, Homo sapiens, inhabiting a high-altitude environment.

"For Homo sapiens, this is the earliest for us, for modern humans," he said. "The nearest after this is round about 30,000 years ago in Tibet, and there's some in the Ethiopian highlands at around about the same type of age."

Fairbairn said he had been shocked to discover the age of the finds, using radio carbon dating, because this suggested humans had been living in the cold, wet and inhospitable highlands at the height of the last Ice Age.
"We didn't expect to find anything of that early age," he said.

The findings, published in the journal Science, suggest that the prehistoric highlanders of Papua New Guinea's Ivane Valley in the Owen Stanley Range Mountain made stone tools, hunted small animals and ate yams and nuts.

But why they chose to dwell in the harsh conditions of the highlands, where temperatures would have dipped below freezing, rather than remain in the warmer coastal areas, remains a mystery.

Read more at Discovery News