Our species caused 322 animal extinctions over the past 500 years, with two-thirds of those occurring in the last two centuries, according to a paper published in a special issue of the journal Science this week.
Many animals are threatened with human-caused extinction now, with researchers expressing particular concern over amphibian and invertebrate (creatures without a backbone) losses. Numbers of the latter group have nearly halved as our population doubled in size over the past 35 years.
Ecologists, zoologists and other scientists believe that, without urgent steps to stem the losses, we are facing global scale tipping points from which we may never look back or recover.
"Indeed, if current rates (of human population growth) were to continue unchecked, population size would be, by 2100, about 27 billion persons -- clearly an unthinkable and unsustainable option," co-author Rodolfo Dirzo, professor of environmental sciences at Stanford University, told Discovery News.
Dirzo and his colleagues call for "decreasing the per capita human footprint," by developing and implementing carbon-neutral technologies, producing food and goods more efficiently, consuming less and wasting less.
They also say it is essential that we ensure lower human population growth projections are the "ones that prevail."
Haldre Rogers and Josh Tewksbury, authors of another paper in the same issue, believe that, "animals do matter to people, but on balance, they matter less than food, jobs, energy, money, and development."
They continued, "As long as we continue to view animals in ecosystems as irrelevant to these basic demands, animals will lose."
Keeping animals alive and ecosystems healthy translate to big bucks on a global scale. Tewksbury, director of the Luc Hoffmann Institute of the World Wide Fund for Nature, pointed out that Southeast Asia's Mekong River Basin, through its fisheries, supports 60 million people. Rogers, a researcher in Rice University's Department of Ecology & Evolutionary Biology, added that 73 percent of visitors to Namibia are nature-based tourists, with their money accounting for 14.2 percent of that nation's economic growth.
"Whale watching in Latin America alone generates over 275 million dollars a year," Tewksbury said. "Multiple studies have demonstrated how turtles are worth more alive than dead."
In the United States, he added, shark-watching results in $314 million per year, directly supporting 10,000 jobs.
He and the other researchers point out that human health, pollination, pest control, water quality, food availability and other critical factors are also dependent on ecosystem stability.
In the United States, he added, shark-watching results in $314 million per year, directly supporting 10,000 jobs.
He and the other researchers say that human health, pollination, pest control, water quality, food availability and other critical factors are also dependent upon ecosystem stability.
Yet another paper in the latest issue of Science outlines controversial measures, beyond basic conservation efforts, to improve the current situation. These include re-wilding, meaning placement of underrepresented species back into the wild; human removal of invasive species; and, perhaps most controversial of all, de-extinction: bringing already extinct species back to life.
"People are currently grappling with the implications of de-extinction, including how to select the best candidate species," co-author Philip Seddon, a zoologist at the University of Otago, told Discovery News.
Rogers said that restoration and re-introduction have shown progress.
"The return of the bald eagle and the California condor to the skies and the wild turkey to the lands of the U.S. are great success stories," she said.
She and Tewksbury are also working on the island of Guam, where the invasive brown tree snake has rid the island of birds, causing the forests there to be without seed dispersers for 30 years. This, in turn, has contributed to financial challenges for locals.
Read more at Discovery News
Jul 24, 2014
New T-Rex Tracks Add to Pack-Hunting Theory
Some 70 million years ago, three tyrannosaurs stalked together across a mud flat in Canada, possibly searching for prey.
The new insight comes from several parallel tyrannosaur tracks unearthed in Canada. The dinosaur tracks provide stronger evidence for a controversial theory: That the fearsome mega-predators hunted in packs.
The ferocious beasts may have "stuck together as a pack to increase their chances of bringing down prey and individually surviving," said study co-author Richard McCrea, a curator at the Peace Region Palaeontology Center in Canada.
Paleontologists have long debated whether Tyrannosaurus rex and its cousins, such as Albertosaurus, hunted alone or in groups.
While most researchers believe the predators were lone wolves, so to speak, multiple Albertosaurus specimens found in a single bone bed in Canada's Dry Island Buffalo Jump Provincial Park have led some to propose that tyrannosaurs were pack animals.
But finding groups of bones together isn't definitive evidence for pack hunting, because bones can move after death. Other circumstances can cause fossil skeletons to accumulate in one location. For instance, many carnivores wandered individually into classic predator traps, such as the La Brea tar pits in Los Angeles, but probably didn't hunt together in life, McCrea said.
In 2011, a local hunting outfitter and guide, Aaron Fredlund, unearthed two tyrannosaur track marks in the foothills of the Canadian Rockies in British Columbia and then told McCrea's team about the discovery.
The team eventually discovered a patch 197 feet (60 meters) long by 13 feet (4 m) wide filled with footprints from multiple dinosaurs, including tyrannosaurs, other small theropods, and duck-billed dinosaurs called hadrosaurs. These dinosaurs were apparently walking in the silty sediments from an overflowing river and formed the track marks about 70 million years ago. A thick layer of volcanic ash then preserved the marks, McCrea said.
In total, the team found seven tracks that were made by three tyrannosaurs. Though the researchers couldn't identify the specific species, it's likely given the period and location where they were found that Albertosaurus, Gorgosaurus or Daspletosaurus left the tracks, McCrea said.
Though the other dinosaur tracks there are all pointing in random directions, the tyrannosaur footprints are parallel with each other. The tyrannosaurs also left prints of about the same depth in the wet sediments, suggesting they crossed through the area at the same time. (As the mud dries, the depth of footprints becomes shallower.)
The new find may be one of the world's oldest examples of a missed connection. "The hadrosaur footprints are much more shallow, indicating that they came later," possibly just a few hours or days after the tyrannosaurs, McCrea told Live Science.
The new tracks suggest that the tyrannosaurs may have hunted in packs to take down large prey, just as wolves do today.
"An individual wolf would not be able to take out a moose, but a pack of them would," McCrea said.
Similarly, pack hunting could explain how tyrannosaurs could kill hadrosaurs, which are almost as large as the predators, without sustaining horrific injuries, he said.
That doesn't mean tyrannosaurs would have been friendly to one another. In fact, other fossils reveal that the dinosaurs liked to head-bite each other. But the tyrannosaurs may have stuck together to hunt because it increased their odds of survival, McCrea said.
Read more at Discovery News
The new insight comes from several parallel tyrannosaur tracks unearthed in Canada. The dinosaur tracks provide stronger evidence for a controversial theory: That the fearsome mega-predators hunted in packs.
The ferocious beasts may have "stuck together as a pack to increase their chances of bringing down prey and individually surviving," said study co-author Richard McCrea, a curator at the Peace Region Palaeontology Center in Canada.
Paleontologists have long debated whether Tyrannosaurus rex and its cousins, such as Albertosaurus, hunted alone or in groups.
While most researchers believe the predators were lone wolves, so to speak, multiple Albertosaurus specimens found in a single bone bed in Canada's Dry Island Buffalo Jump Provincial Park have led some to propose that tyrannosaurs were pack animals.
But finding groups of bones together isn't definitive evidence for pack hunting, because bones can move after death. Other circumstances can cause fossil skeletons to accumulate in one location. For instance, many carnivores wandered individually into classic predator traps, such as the La Brea tar pits in Los Angeles, but probably didn't hunt together in life, McCrea said.
In 2011, a local hunting outfitter and guide, Aaron Fredlund, unearthed two tyrannosaur track marks in the foothills of the Canadian Rockies in British Columbia and then told McCrea's team about the discovery.
The team eventually discovered a patch 197 feet (60 meters) long by 13 feet (4 m) wide filled with footprints from multiple dinosaurs, including tyrannosaurs, other small theropods, and duck-billed dinosaurs called hadrosaurs. These dinosaurs were apparently walking in the silty sediments from an overflowing river and formed the track marks about 70 million years ago. A thick layer of volcanic ash then preserved the marks, McCrea said.
In total, the team found seven tracks that were made by three tyrannosaurs. Though the researchers couldn't identify the specific species, it's likely given the period and location where they were found that Albertosaurus, Gorgosaurus or Daspletosaurus left the tracks, McCrea said.
Though the other dinosaur tracks there are all pointing in random directions, the tyrannosaur footprints are parallel with each other. The tyrannosaurs also left prints of about the same depth in the wet sediments, suggesting they crossed through the area at the same time. (As the mud dries, the depth of footprints becomes shallower.)
The new find may be one of the world's oldest examples of a missed connection. "The hadrosaur footprints are much more shallow, indicating that they came later," possibly just a few hours or days after the tyrannosaurs, McCrea told Live Science.
The new tracks suggest that the tyrannosaurs may have hunted in packs to take down large prey, just as wolves do today.
"An individual wolf would not be able to take out a moose, but a pack of them would," McCrea said.
Similarly, pack hunting could explain how tyrannosaurs could kill hadrosaurs, which are almost as large as the predators, without sustaining horrific injuries, he said.
That doesn't mean tyrannosaurs would have been friendly to one another. In fact, other fossils reveal that the dinosaurs liked to head-bite each other. But the tyrannosaurs may have stuck together to hunt because it increased their odds of survival, McCrea said.
Read more at Discovery News
100,000-Year-Old Case of Brain Damage Discovered
An ancient skeleton unearthed in Israel may contain the oldest evidence of brain damage in a modern human.
The child, who lived about 100,000 years ago, survived head trauma for several years, but suffered from permanent brain damage as a result, new 3D imaging reveals.
Given the brain damage, the child was likely unable to care for himself or herself, so people must have spent years looking after the little boy or girl, according to the researchers who analyzed the 3D images. People from the child's group left funerary objects in the youngster's burial pit as well, the study authors said.
Those signs of care for a disabled person suggest that the roots of human compassion go way back, said Hélène Coqueugniot, an anthropologist at the Centre National de la Recherche Scientifique (CNRS) at the University of Bordeaux in France, and lead author of the study.
"It is some of the most ancient evidence of compassion and altruism," Coqueugniot said.
The child's skeleton was first uncovered decades ago in a cave site known as Qafzeh in Galilee, Israel, which also contained 27 partial skeletons and bone fragments, as well as stone tools and hearths.
The child, whose sex couldn't be determined, was found with a visible fracture in the skull and a pair of deer antlers placed across the chest.
The researchers wanted to know more about the damage to the child's skull, so they created a cast of the interior of it and then used computed tomography (CT) scanning to create a 3D picture of the head.
The images revealed that the child suffered a blunt-force trauma at the front of the skull that created a compound fracture, with a piece of bone depressed in the skull. It wasn't clear whether child abuse or an accident caused the injury, the researchers concluded.
In addition, tooth growth indicated that the youngster was 12 or 13 years old when he or she died, but the child's brain volume was more akin to that of a 6- or 7-year-old — likely because the head trauma permanently halted brain growth, Coqueugniot told Live Science.
The brain injury would have led to difficulties in controlling movements and speaking, as well as caused personality changes and impaired the child's social functioning, the researchers wrote in their study, which was published July 23 in the journal PLOS ONE.
Yet despite the youngster's severe disability, he or she was apparently cared for, in life and in death. Despite lacking the ability to survive on his or her own, the Paleolithic child lived for several years after the head injury. And when the child died, someone wanted to honor his or her memory by placing the deer antlers in his or her burial — a funerary marker that wasn't found in any of the other burials at the site, Coqueugniot said.
"He was very, very special in this group, and he has a very, very special burial," Coqueugniot said.
The findings are not the oldest example of compassion and care for the disabled in a hominid; a 500,000-year-old fossil human from Sima de los Huesos in Spain shows signs of severe brain deformity starting at birth, but that child still lived to age 5, which mean someone cared for the child despite his or her disorder.
Read more at Discovery News
The child, who lived about 100,000 years ago, survived head trauma for several years, but suffered from permanent brain damage as a result, new 3D imaging reveals.
Given the brain damage, the child was likely unable to care for himself or herself, so people must have spent years looking after the little boy or girl, according to the researchers who analyzed the 3D images. People from the child's group left funerary objects in the youngster's burial pit as well, the study authors said.
Those signs of care for a disabled person suggest that the roots of human compassion go way back, said Hélène Coqueugniot, an anthropologist at the Centre National de la Recherche Scientifique (CNRS) at the University of Bordeaux in France, and lead author of the study.
"It is some of the most ancient evidence of compassion and altruism," Coqueugniot said.
The child's skeleton was first uncovered decades ago in a cave site known as Qafzeh in Galilee, Israel, which also contained 27 partial skeletons and bone fragments, as well as stone tools and hearths.
The child, whose sex couldn't be determined, was found with a visible fracture in the skull and a pair of deer antlers placed across the chest.
The researchers wanted to know more about the damage to the child's skull, so they created a cast of the interior of it and then used computed tomography (CT) scanning to create a 3D picture of the head.
The images revealed that the child suffered a blunt-force trauma at the front of the skull that created a compound fracture, with a piece of bone depressed in the skull. It wasn't clear whether child abuse or an accident caused the injury, the researchers concluded.
In addition, tooth growth indicated that the youngster was 12 or 13 years old when he or she died, but the child's brain volume was more akin to that of a 6- or 7-year-old — likely because the head trauma permanently halted brain growth, Coqueugniot told Live Science.
The brain injury would have led to difficulties in controlling movements and speaking, as well as caused personality changes and impaired the child's social functioning, the researchers wrote in their study, which was published July 23 in the journal PLOS ONE.
Yet despite the youngster's severe disability, he or she was apparently cared for, in life and in death. Despite lacking the ability to survive on his or her own, the Paleolithic child lived for several years after the head injury. And when the child died, someone wanted to honor his or her memory by placing the deer antlers in his or her burial — a funerary marker that wasn't found in any of the other burials at the site, Coqueugniot said.
"He was very, very special in this group, and he has a very, very special burial," Coqueugniot said.
The findings are not the oldest example of compassion and care for the disabled in a hominid; a 500,000-year-old fossil human from Sima de los Huesos in Spain shows signs of severe brain deformity starting at birth, but that child still lived to age 5, which mean someone cared for the child despite his or her disorder.
Read more at Discovery News
'Uncontacted' Amazon People Treated for Flu
Advocates for indigenous tribes and Brazilian officials are worried that a group of people in the Amazon who had been living in isolation from the outside world may have contracted the flu — a potentially deadly disease that these individuals had never been exposed to before.
Five young men and two young women became sick after they emerged from their remote home turf in Peru in late June and made contact with people living in a settled community. On three separate occasions, they voluntarily made contact with Ashaninka people in the village of Simpatia, just across the border in western Brazil's Acre state, said Fiona Watson, a researcher and field director with the advocacy group Survival International, who spoke with Brazilian officials who went to the region. During each visit, the newly contacted individuals were friendly with the Ashaninka people and stayed for several hours, Watson said.
But representatives from Brazil's Indian Affairs Department, or FUNAI, noticed that the group of seven showed signs of influenza during their visit on June 30, Watson said. Over the course of several days in July, these people received medical treatment for the flu and flu vaccines in case they later encounter other strains of the virus. They went back into the forest on July 11.
The news worries advocates because uncontacted groups are extremely vulnerable to diseases to which they have no immunity. Past epidemics of malaria and the flu, for example, have devastated other tribes. What's more, this particular group may be at risk of violence from illegal loggers and drug traffickers in the region. Through interpreters, these seven individuals, who speak a Panoan language, reported that they were fleeing violent attacks in their home territory in Peru; they apparently came into contact with non-Indians who had fired gunshots at them near the source of the Envira River.
"The nightmare scenario is that they return to their former villages carrying flu with them," Stephen Corry, director of Survival International, said in a statement. "It's a real test of Brazil's ability to protect these vulnerable groups. Unless a proper and sustained medical program is immediately put in place, the result could be a humanitarian catastrophe."
In light of recent events, FUNAI reopened a post in the region that had been closed since 2011 when it was overrun by drug traffickers and illegal loggers. Officials with the Brazilian agency also said they were working with Peruvian authorities to monitor and protect uncontacted people in the area.
Read more at Discovery News
Five young men and two young women became sick after they emerged from their remote home turf in Peru in late June and made contact with people living in a settled community. On three separate occasions, they voluntarily made contact with Ashaninka people in the village of Simpatia, just across the border in western Brazil's Acre state, said Fiona Watson, a researcher and field director with the advocacy group Survival International, who spoke with Brazilian officials who went to the region. During each visit, the newly contacted individuals were friendly with the Ashaninka people and stayed for several hours, Watson said.
But representatives from Brazil's Indian Affairs Department, or FUNAI, noticed that the group of seven showed signs of influenza during their visit on June 30, Watson said. Over the course of several days in July, these people received medical treatment for the flu and flu vaccines in case they later encounter other strains of the virus. They went back into the forest on July 11.
The news worries advocates because uncontacted groups are extremely vulnerable to diseases to which they have no immunity. Past epidemics of malaria and the flu, for example, have devastated other tribes. What's more, this particular group may be at risk of violence from illegal loggers and drug traffickers in the region. Through interpreters, these seven individuals, who speak a Panoan language, reported that they were fleeing violent attacks in their home territory in Peru; they apparently came into contact with non-Indians who had fired gunshots at them near the source of the Envira River.
"The nightmare scenario is that they return to their former villages carrying flu with them," Stephen Corry, director of Survival International, said in a statement. "It's a real test of Brazil's ability to protect these vulnerable groups. Unless a proper and sustained medical program is immediately put in place, the result could be a humanitarian catastrophe."
In light of recent events, FUNAI reopened a post in the region that had been closed since 2011 when it was overrun by drug traffickers and illegal loggers. Officials with the Brazilian agency also said they were working with Peruvian authorities to monitor and protect uncontacted people in the area.
Read more at Discovery News
Looking for ET's Industrial Pollution on Alien Worlds
If ET is anything like us, scientists may be able to ferret out advanced civilizations beyond Earth by scanning planets’ atmospheres for telltale industrial pollutants.
Researchers looked at two ozone-eating chlorofluorocarbons (CFCs) that would be easy to detect with the infrared light-splitting spectrometer being built for the James Webb Space Telescope, a follow-on to the Hubble observatory that is due to launch in 2018.
The targets would be white dwarf stars, which are much smaller than the sun. An Earth-sized orbiting planet passing by, relative to the telescope’s line of sight, would block a significant amount of the parent star’s light, allowing for relatively quick scans.
“We consider industrial pollution a biomarker for intelligent life,” Henry Lin, a Harvard University undergraduate and Intel Foundation Young Scientist Award recipient, told Discovery News.
"However, maybe this super-sophisticated alien civilization ... would consider industrial pollution a sign of unintelligent life. After all, it doesn’t seem very intelligent to pollute your own atmosphere with things that can make life difficult," he said.
Lin’s advisor and research collaborator Avi Loeb, also at Harvard, offers a caveat: Perhaps ET purposely engineered or terraformed its atmosphere to make a cold planet like Mars habitable.
“In principle, there might be a reason for why pollution is a good thing,” Loeb told Discovery News.
Lin, Loeb and atmospheric chemist Gonzalo Gonzalez Abad, with the Harvard-Smithsonian Center for Astrophysics, studied two types of easily detectable CFCs -- tetrafluoromethane (CF4) and trichlorofluoromethane (CCl3F), both of which are produced by industrial processes.
Based on computer models, they estimate that planets circling in the so-called "habitable zone" of parent white dwarf stars would have a two-minute transit, relative to Earth's line of sight, every 10 hours. The habitable zones are temperature regions where water can exist as a liquid on a planet's surface. Water is believed to be necessary for life.
Read more at Discovery News
Researchers looked at two ozone-eating chlorofluorocarbons (CFCs) that would be easy to detect with the infrared light-splitting spectrometer being built for the James Webb Space Telescope, a follow-on to the Hubble observatory that is due to launch in 2018.
The targets would be white dwarf stars, which are much smaller than the sun. An Earth-sized orbiting planet passing by, relative to the telescope’s line of sight, would block a significant amount of the parent star’s light, allowing for relatively quick scans.
“We consider industrial pollution a biomarker for intelligent life,” Henry Lin, a Harvard University undergraduate and Intel Foundation Young Scientist Award recipient, told Discovery News.
"However, maybe this super-sophisticated alien civilization ... would consider industrial pollution a sign of unintelligent life. After all, it doesn’t seem very intelligent to pollute your own atmosphere with things that can make life difficult," he said.
Lin’s advisor and research collaborator Avi Loeb, also at Harvard, offers a caveat: Perhaps ET purposely engineered or terraformed its atmosphere to make a cold planet like Mars habitable.
“In principle, there might be a reason for why pollution is a good thing,” Loeb told Discovery News.
Lin, Loeb and atmospheric chemist Gonzalo Gonzalez Abad, with the Harvard-Smithsonian Center for Astrophysics, studied two types of easily detectable CFCs -- tetrafluoromethane (CF4) and trichlorofluoromethane (CCl3F), both of which are produced by industrial processes.
Based on computer models, they estimate that planets circling in the so-called "habitable zone" of parent white dwarf stars would have a two-minute transit, relative to Earth's line of sight, every 10 hours. The habitable zones are temperature regions where water can exist as a liquid on a planet's surface. Water is believed to be necessary for life.
Read more at Discovery News
Jul 23, 2014
Record-Setting Bug Is Bigger Than Your Hand
The largest aquatic insect ever documented -- boasting scary-long mandibles and jumbo-jet wings -- has been discovered in China.
Local villagers in the country's Sichuan province came upon several specimens of the creature, which resembled a large dragonfly, and brought them to the Insect Museum of West China.
It turns out the villagers had made an incredible entomological find: a record-setting giant dobsonfly with a wingspan of more than 8 inches.
The find was bad news only for the poor South American helicopter damselfly, which was bounced from its previous place atop the largest-aquatic-insect hill when its wingspan of "only" 7.5 inches was bested.
The dobsonfly itself is not exactly a shocking creature to witness. There are more than 200 species of it worldwide, and they make a living in parts of Asia, South America and Africa. What is shocking it the size of the new find: dobsonflies of similar size had until now been unheard of.
The long, pincerlike mandibles are used for mating -- males use them to impress the ladies and hold them in place during the mating. Its wings, meanwhile, hardly ever see any use, as the bug spends most of its life under or on top of water, or laying low underneath rocks.
The giant dobsonfly can be a great barometer of water cleanliness. No slob, it has a preference for clean water that's relatively free of pollutants and a "goldilocks" pH level that's not too high or low. The big-winged bug will simply pack up and change addresses if a body of water doesn't meet its exacting standards.
From Discovery News
Local villagers in the country's Sichuan province came upon several specimens of the creature, which resembled a large dragonfly, and brought them to the Insect Museum of West China.
It turns out the villagers had made an incredible entomological find: a record-setting giant dobsonfly with a wingspan of more than 8 inches.
The find was bad news only for the poor South American helicopter damselfly, which was bounced from its previous place atop the largest-aquatic-insect hill when its wingspan of "only" 7.5 inches was bested.
The dobsonfly itself is not exactly a shocking creature to witness. There are more than 200 species of it worldwide, and they make a living in parts of Asia, South America and Africa. What is shocking it the size of the new find: dobsonflies of similar size had until now been unheard of.
The long, pincerlike mandibles are used for mating -- males use them to impress the ladies and hold them in place during the mating. Its wings, meanwhile, hardly ever see any use, as the bug spends most of its life under or on top of water, or laying low underneath rocks.
The giant dobsonfly can be a great barometer of water cleanliness. No slob, it has a preference for clean water that's relatively free of pollutants and a "goldilocks" pH level that's not too high or low. The big-winged bug will simply pack up and change addresses if a body of water doesn't meet its exacting standards.
From Discovery News
400-Year-Old Crucifix Found by Canadian Student
It is tiny in size — measuring only 1.1 inches in width — and its top is broken, but a 400- year-old copper crucifix found at Newfoundland's Avalon Peninsula earlier in July has big historical significance, according to historians. It symbolizes an early dream of religious freedom in North America.
The artifact is clearly a Catholic item, featuring a simple representation of Christ on the front and the Virgin Mary and Christ Child on the back. Yet it was found in a predominantly English settlement.
Back in England, its owner would could be fined, imprisoned or put to death for practicing Catholic faith, according to Barry Gaulton, Field Director of the Colony of Avalon and Associate Professor of Archaeology at Memorial University of Newfoundland.
"The Catholic iconography is unmistakable. As with all archaeological discoveries, the context in which the artifact was found tells us its story," Gaulton said in a release.
The story the crucifix tells is that of the dream of the Newfoundland's settler, Sir George Calvert. Calvert was an English lord who helped settle the colony around 1628. His vision was to create a community where all Christians could enjoy freedom of religion without fear of persecution. He was one of the early pioneers of religious freedom in North America.
Just the presence of the Catholic crucifix reveals that Calvert's vision had started to take shape. The small cross was found by Anna Sparrow, an undergraduate student at Memorial University in St. John’s.
As for who the crucifix belonged to, the archaeologists are not sure. They say it could have belonged to one of the craftsmen working on Calvert's house, or the colony's second governor, the Catholic gentleman Sir Arthur Aston, or even George Calvert himself.
Read more at Discovery News
The artifact is clearly a Catholic item, featuring a simple representation of Christ on the front and the Virgin Mary and Christ Child on the back. Yet it was found in a predominantly English settlement.
Back in England, its owner would could be fined, imprisoned or put to death for practicing Catholic faith, according to Barry Gaulton, Field Director of the Colony of Avalon and Associate Professor of Archaeology at Memorial University of Newfoundland.
"The Catholic iconography is unmistakable. As with all archaeological discoveries, the context in which the artifact was found tells us its story," Gaulton said in a release.
The story the crucifix tells is that of the dream of the Newfoundland's settler, Sir George Calvert. Calvert was an English lord who helped settle the colony around 1628. His vision was to create a community where all Christians could enjoy freedom of religion without fear of persecution. He was one of the early pioneers of religious freedom in North America.
Just the presence of the Catholic crucifix reveals that Calvert's vision had started to take shape. The small cross was found by Anna Sparrow, an undergraduate student at Memorial University in St. John’s.
As for who the crucifix belonged to, the archaeologists are not sure. They say it could have belonged to one of the craftsmen working on Calvert's house, or the colony's second governor, the Catholic gentleman Sir Arthur Aston, or even George Calvert himself.
Read more at Discovery News
Exorcism Death Priest Released from Prison
A Romanian priest sentenced to seven years in prison for his role in the exorcism death of a young nun in 2005 has recently been released. With assistance from four nuns, priest Daniel Corogeanu bound 23-year-old nun Irina Cornici to a cross, gagged her mouth with a towel, and left her for five days without food or water.
The ritual, Corogeanu explained, was an effort to drive devils out of the woman. Cornici died on June 15, 2005; an autopsy found she had died of suffocation and dehydration. Cornici had a history of schizophrenia that had been mistaken as a sign of demonic possession.
According to a news story in "The Croatian Times" Corogeanu stated,
"I consider myself not guilty because Irina Conrici's death was not down to the fact that we kept her locked up. We tied her up because she kept hitting and harming herself and we would have found her dead in her room eventually. I admit I tied her up and stuck a towel in her mouth and kept her like this for five days....Four nuns helped me tie her up and guarded Irina for days. They tried to give her food and water but she refused. All she accepted was holy water.... My biggest mistake was that I called the ambulance when I saw she was not moving.... Had I not called the ambulance, she would have been well now. It was the last stage of her exorcism and it is normal that a person possessed by demons faints when all the prayers end. She was supposed to recover after that."
Corogeanu stated that the exorcism he and the nuns performed was appropriate (in fact he called it "quite normal") and instead blamed Conrici's death on an overdose of adrenaline administered by paramedics who rescued her.
This is not the first time that exorcisms have cost innocent lives, often of young people. In 2003, an autistic 8-year-old boy in Milwaukee died during an exorcism by church members during a prayer service held to exorcise the evil spirits they blamed for his condition. In 2009 a young woman named Naila Mumtaz was killed by her husband, his parents, and a brother-in-law during an exorcism in England. A year later, also in England, 14-year-old Kristy Bamu was beaten and drowned by relatives during an exorcism.
Read more at Discovery News
The ritual, Corogeanu explained, was an effort to drive devils out of the woman. Cornici died on June 15, 2005; an autopsy found she had died of suffocation and dehydration. Cornici had a history of schizophrenia that had been mistaken as a sign of demonic possession.
According to a news story in "The Croatian Times" Corogeanu stated,
"I consider myself not guilty because Irina Conrici's death was not down to the fact that we kept her locked up. We tied her up because she kept hitting and harming herself and we would have found her dead in her room eventually. I admit I tied her up and stuck a towel in her mouth and kept her like this for five days....Four nuns helped me tie her up and guarded Irina for days. They tried to give her food and water but she refused. All she accepted was holy water.... My biggest mistake was that I called the ambulance when I saw she was not moving.... Had I not called the ambulance, she would have been well now. It was the last stage of her exorcism and it is normal that a person possessed by demons faints when all the prayers end. She was supposed to recover after that."
Corogeanu stated that the exorcism he and the nuns performed was appropriate (in fact he called it "quite normal") and instead blamed Conrici's death on an overdose of adrenaline administered by paramedics who rescued her.
This is not the first time that exorcisms have cost innocent lives, often of young people. In 2003, an autistic 8-year-old boy in Milwaukee died during an exorcism by church members during a prayer service held to exorcise the evil spirits they blamed for his condition. In 2009 a young woman named Naila Mumtaz was killed by her husband, his parents, and a brother-in-law during an exorcism in England. A year later, also in England, 14-year-old Kristy Bamu was beaten and drowned by relatives during an exorcism.
Read more at Discovery News
Transiting Alien World with Longest Year Discovered
A newfound alien planet is one for the record books.
The alien planet Kepler-421b — which crosses the face of, or transits, its host star from Earth's perspective — takes 704 Earth days to complete one orbit, and thus has the longest year known for any transiting alien world, researchers said. (For comparison, Earth orbits the sun once every 365 days, and Mars completes a lap every 780 days.)
"Finding Kepler-421b was a stroke of luck," study lead author David Kipping, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, said in a statement. "The farther a planet is from its star, the less likely it is to transit the star from Earth's point of view. It has to line up just right."
To be clear, Kepler-421b does not have the longest year of any known alien planet. Many nontransiting worlds have much more far-flung orbits, including the gas giant GU Piscium b, which takes about 160,000 years to complete a lap around its host star.
Kepler-421b, which is about the size of Uranus, is located about 1,000 light-years from Earth, in the constellation Lyra. It was spotted by NASA's Kepler space telescope, which launched in March 2009 to hunt for transiting exoplanets by noting the tiny brightness dips caused when they cross in front of their stars.
Kepler has found nearly 1,000 alien worlds to date and has flagged more than 3,000 other "candidates" that still need to be confirmed by follow-up observations or study. Mission team members expect that at least 90 percent of these candidates will eventually turn out to be bona fide planets.
The spacecraft suffered a glitch in May 2013 that ended its original mission, but NASA recently signed off on a new mission, called K2, that will keep Kepler hunting for exoplanets, in addition to other cosmic bodies and phenomena.
Most of Kepler's finds thus far are worlds that orbit relatively close to their parent stars, since such planets transit relatively frequently. The instrument has generally required three transits to conclusively identify an exoplanet, but Kepler-421b was detected after it crossed its host star's face just twice, researchers said.
Kepler-421b circles its parent star, which is cooler and dimmer than Earth's sun, at an average distance of 100 million miles (160 million kilometers), researchers said. This places the exoplanet beyond its solar system's "snow line" — the boundary between rocky and gaseous planets. (Beyond the snow line, ice grains glom together to form gas giants, such as Jupiter and Saturn.)
Gaseous planets often don't remain beyond the snow line, however. Astronomers have discovered many "hot Jupiters" — giant worlds that have migrated inward significantly over time and now complete an orbit in just a few days (or, in some cases, a matter of hours).
Read more at Discovery News
The alien planet Kepler-421b — which crosses the face of, or transits, its host star from Earth's perspective — takes 704 Earth days to complete one orbit, and thus has the longest year known for any transiting alien world, researchers said. (For comparison, Earth orbits the sun once every 365 days, and Mars completes a lap every 780 days.)
"Finding Kepler-421b was a stroke of luck," study lead author David Kipping, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, said in a statement. "The farther a planet is from its star, the less likely it is to transit the star from Earth's point of view. It has to line up just right."
To be clear, Kepler-421b does not have the longest year of any known alien planet. Many nontransiting worlds have much more far-flung orbits, including the gas giant GU Piscium b, which takes about 160,000 years to complete a lap around its host star.
Kepler-421b, which is about the size of Uranus, is located about 1,000 light-years from Earth, in the constellation Lyra. It was spotted by NASA's Kepler space telescope, which launched in March 2009 to hunt for transiting exoplanets by noting the tiny brightness dips caused when they cross in front of their stars.
Kepler has found nearly 1,000 alien worlds to date and has flagged more than 3,000 other "candidates" that still need to be confirmed by follow-up observations or study. Mission team members expect that at least 90 percent of these candidates will eventually turn out to be bona fide planets.
The spacecraft suffered a glitch in May 2013 that ended its original mission, but NASA recently signed off on a new mission, called K2, that will keep Kepler hunting for exoplanets, in addition to other cosmic bodies and phenomena.
Most of Kepler's finds thus far are worlds that orbit relatively close to their parent stars, since such planets transit relatively frequently. The instrument has generally required three transits to conclusively identify an exoplanet, but Kepler-421b was detected after it crossed its host star's face just twice, researchers said.
Kepler-421b circles its parent star, which is cooler and dimmer than Earth's sun, at an average distance of 100 million miles (160 million kilometers), researchers said. This places the exoplanet beyond its solar system's "snow line" — the boundary between rocky and gaseous planets. (Beyond the snow line, ice grains glom together to form gas giants, such as Jupiter and Saturn.)
Gaseous planets often don't remain beyond the snow line, however. Astronomers have discovered many "hot Jupiters" — giant worlds that have migrated inward significantly over time and now complete an orbit in just a few days (or, in some cases, a matter of hours).
Read more at Discovery News
Jul 22, 2014
Global temperature reaches record high in June following record warmth in May
According to NOAA scientists, the globally averaged temperature over land and ocean surfaces for June 2014 was the highest for June since record keeping began in 1880. It also marked the 38th consecutive June and 352nd consecutive month with a global temperature above the 20th century average. The last below-average global temperature for June was in 1976 and the last below-average global temperature for any month was February 1985.
Most of the world experienced warmer-than-average monthly temperatures, with record warmth across part of southeastern Greenland, parts of northern South America, areas in eastern and central Africa, and sections of southern and southeastern Asia. Similar to May, scattered sections across every major ocean basin were also record warm. Notably, large parts of the western equatorial and northeastern Pacific Ocean and most of the Indian Ocean were record warm or much warmer than average for the month. A few areas in North America, Far East Russia, and small parts of central and northeastern Europe were cooler or much cooler than average.
A monthly summary (http://www.ncdc.noaa.gov/sotc/global/2014/6) from NOAA's National Climatic Data Center in Asheville, NC, is part of the suite of climate services NOAA provides to government, the business sector, academia and the public to support informed decision making.
Selected significant climate anomalies and events: June 2014.
Global temperature highlights: June
Polar ice highlights: June
Precipitation highlights: June
Most of the world experienced warmer-than-average monthly temperatures, with record warmth across part of southeastern Greenland, parts of northern South America, areas in eastern and central Africa, and sections of southern and southeastern Asia. Similar to May, scattered sections across every major ocean basin were also record warm. Notably, large parts of the western equatorial and northeastern Pacific Ocean and most of the Indian Ocean were record warm or much warmer than average for the month. A few areas in North America, Far East Russia, and small parts of central and northeastern Europe were cooler or much cooler than average.
A monthly summary (http://www.ncdc.noaa.gov/sotc/global/2014/6) from NOAA's National Climatic Data Center in Asheville, NC, is part of the suite of climate services NOAA provides to government, the business sector, academia and the public to support informed decision making.
Selected significant climate anomalies and events: June 2014.
Global temperature highlights: June
- The combined average temperature over global land and ocean surfaces for June 2014 was record high for the month at 61.20°F (16.22°C), or 1.30°F (0.72°C) above the 20th century average of 59.9°F (15.5°C). This surpasses the previous record, set in 2010, by (0.05°F) 0.03°C. Nine of the ten warmest Junes on record have all occurred during the 21st century, including each of the past five years. The margin of error associated with this temperature is +/- 0.16°F (0.09°C).
- The June global land temperature was the seventh highest for June on record at 1.71°F (0.95°C) above the 20th century average of 55.9°F (13.3°C). The margin of error is +/- 0.25°F (0.14°C). The seven highest June global land surface temperatures have occurred in the past decade.
- Thirty-one countries across every continent, with the exception of Antarctica, reported at least one station with a record warm June temperature. The period of record varies by station. Some national temperature highlights include:
- New Zealand observed its warmest June since national records began in 1909. The warmth was notable for both its intensity and coverage, with above-average temperatures from the top of the North Island to the bottom of the South Island.
- France observed its fifth warmest June in the country's 115-year period of record at 2.3°F (1.3°C) above the 1981-2010 average. A week-long heat wave contributed to the overall warmth for the month.
- Parts of Greenland were record warm during June. Kangerlussuaq in southwestern Greenland observed its record highest maximum June temperature of 23.2°C (73.8°F) on June 15, surpassing the previous record of 23.1°C (73.6°F) set in both 1988 and 2002. Records at this station date back to 1958.
- For the ocean, the June global sea surface temperature was 1.15°F (0.64°C) above the 20th century average of 61.5°F (16.4°C), the highest for June on record. This surpasses the previous all-time record for any month by 0.09°F (0.05°C), set in June 1998 and tied in October 2003, July 2009, and just last month in May 2014. The margin of error is +/- 0.07°F (0.04°C).
- Although neither El Niño nor La Niña conditions were present across the central and eastern equatorial Pacific Ocean during June 2014, NOAA's Climate Prediction Center estimates that there is about a 70 percent chance that El Niño conditions will develop during Northern Hemisphere summer 2014 and 80 percent chance it will develop during the fall and winter.
Polar ice highlights: June
- The average Arctic sea ice extent for June was 4.4 million square miles, 220,000 square miles (4.9 percent) below the 1981-2010 average and the sixth smallest June extent since records began in 1979, according to the National Snow and Ice Data Center. The seasonal sea ice extent decline during June was faster than average, with rapid ice loss near the end of month.
- On the opposite pole, the Antarctic sea ice extent for June was 5.9 million square miles, 510,000 square miles (9.6 percent) above the 1981-2010 average. This marked the largest June Antarctic sea ice extent since records began in 1979, surpassing the previous record large June Antarctic sea ice extent that occurred in 2010 by about 100,000 square miles. Seven of the past 12 months have had a record large Antarctic sea ice extent.
- Combining the Arctic and Antarctic sea ice, June global sea ice was 10.3 million square miles, 2.9 percent above the 1981-2010 average. This was the third largest global June sea ice extent on record and the largest since 1982.
Precipitation highlights: June
- Extreme wetness was observed during June over regions including central North America and parts of eastern and northern Europe. Extreme dryness was scattered across different parts of the globe, including much of South Asia and Australia.
- In India, the southwest monsoon onset over Kerala occurred on June 6, five days later than the normal date of June 1. For the period June 1-30, rainfall across the country was just 60 percent of the 1951-2000 average for the country as a whole. Every region experienced rainfall deficits during this period, ranging from 43 percent of average in Central India to 72 percent of average on the South Peninsula. The monsoon season lasts from early June through late September.
- Australia received 68 percent of average rainfall during June. Western Australia received just 28 percent of their average rainfall for the month, the seventh lowest for June for the state.
Mammoth and mastodon behavior was less roam, more stay at home
Their scruffy beards weren't ironic, but there are reasons mammoths and mastodons could have been the hipsters of the Ice Age.
According to research from the University of Cincinnati, the famously fuzzy relatives of elephants liked living in Greater Cincinnati long before it was trendy -- at the end of the last ice age. A study led by Brooke Crowley, an assistant professor of geology and anthropology, shows the ancient proboscideans enjoyed the area so much they likely were year-round residents and not nomadic migrants as previously thought.
They even had their own preferred hangouts. Crowley's findings indicate each species kept to separate areas based on availability of favored foods here at the southern edge of the Last Glacial Maximum's major ice sheet.
"I suspect that this was a pretty nice place to live, relatively speaking," Crowley says. "Our data suggest that animals probably had what they needed to survive here year-round."
Could the past save the future?
Crowley's research with co-author and recent UC graduate Eric Baumann, "Stable Isotopes Reveal Ecological Differences Among Now-Extinct Proboscideans from the Cincinnati Region, USA," was recently published in Boreas, an international academic research journal.
Learning more about the different behaviors of these prehistoric creatures could benefit their modern-day cousins, African and Asian elephants. Both types are on the World Wildlife Fund's endangered species list. Studying how variable different types of elephants might have been in the past, Crowley says, might help ongoing efforts to protect these largest of land mammals from continued threats such as poaching and habitat destruction.
"There are regionally different stories going on," Crowley says. "There's not one overarching theme that we can say about a mammoth or a mastodon. And that's becoming more obvious in studies people are doing in different places. A mammoth in Florida did not behave the same as one in New York, Wyoming, California, Mexico or Ohio."
The wisdom in teeth
For their research, Crowley and Baumann looked to the wisdom in teeth -- specifically museum specimens of molars from four mastodons and eight mammoths from Southwestern Ohio and Northwestern Kentucky. Much can be revealed by carefully drilling a tooth's surface and analyzing the stable carbon, oxygen and strontium isotopic signatures in the powdered enamel.
Each element tells a different story. Carbon provides insight into an animal's diet, oxygen relates to overall climatic conditions of an animal's environment and strontium indicates how much an animal may have traveled at the time its tooth was forming.
"Strontium reflects the bedrock geology of a location," Crowley says. "So if a local animal grows its tooth and mineralizes it locally and dies locally, the strontium isotope ratio in its tooth will reflect the place where it lived and died. If an animal grows its tooth in one place and then moves elsewhere, the strontium in its tooth is going to reflect where it came from, not where it died."
Read more at Science Daily
According to research from the University of Cincinnati, the famously fuzzy relatives of elephants liked living in Greater Cincinnati long before it was trendy -- at the end of the last ice age. A study led by Brooke Crowley, an assistant professor of geology and anthropology, shows the ancient proboscideans enjoyed the area so much they likely were year-round residents and not nomadic migrants as previously thought.
They even had their own preferred hangouts. Crowley's findings indicate each species kept to separate areas based on availability of favored foods here at the southern edge of the Last Glacial Maximum's major ice sheet.
"I suspect that this was a pretty nice place to live, relatively speaking," Crowley says. "Our data suggest that animals probably had what they needed to survive here year-round."
Could the past save the future?
Crowley's research with co-author and recent UC graduate Eric Baumann, "Stable Isotopes Reveal Ecological Differences Among Now-Extinct Proboscideans from the Cincinnati Region, USA," was recently published in Boreas, an international academic research journal.
Learning more about the different behaviors of these prehistoric creatures could benefit their modern-day cousins, African and Asian elephants. Both types are on the World Wildlife Fund's endangered species list. Studying how variable different types of elephants might have been in the past, Crowley says, might help ongoing efforts to protect these largest of land mammals from continued threats such as poaching and habitat destruction.
"There are regionally different stories going on," Crowley says. "There's not one overarching theme that we can say about a mammoth or a mastodon. And that's becoming more obvious in studies people are doing in different places. A mammoth in Florida did not behave the same as one in New York, Wyoming, California, Mexico or Ohio."
The wisdom in teeth
For their research, Crowley and Baumann looked to the wisdom in teeth -- specifically museum specimens of molars from four mastodons and eight mammoths from Southwestern Ohio and Northwestern Kentucky. Much can be revealed by carefully drilling a tooth's surface and analyzing the stable carbon, oxygen and strontium isotopic signatures in the powdered enamel.
Each element tells a different story. Carbon provides insight into an animal's diet, oxygen relates to overall climatic conditions of an animal's environment and strontium indicates how much an animal may have traveled at the time its tooth was forming.
"Strontium reflects the bedrock geology of a location," Crowley says. "So if a local animal grows its tooth and mineralizes it locally and dies locally, the strontium isotope ratio in its tooth will reflect the place where it lived and died. If an animal grows its tooth in one place and then moves elsewhere, the strontium in its tooth is going to reflect where it came from, not where it died."
Read more at Science Daily
Secret Grizzly Bear Feeding Site Discovered
For a bear, it's the equivalent of an all-you-can-eat buffet.
A secret feeding site that draws dozens of grizzly bears has been identified along a Canadian river where salmon spawn.
Finding the feeding site for the grizzly bears and the "highways" they take to get to it could help policymakers ban trophy hunting in the region. The resulting protection could allow dwindling grizzly populations to rebound.
"Our hope is for grizzly bears to start returning to their historic range," said study co-author said Chris Filardi, director of Pacific programs at the American Museum of Natural History in New York.
The Heiltsuk people, a coastal First Nations people in British Columbia, have long known that grizzlies congregate along the Koeye (pronounced "kway") River.
"We have this traditional knowledge that has existed amongst our people for thousands of years now," said study lead author William Housty, the director of Coastwatch, a scientific initiative led by the Heiltsuk to manage resources and conservation in their territory.
To the Heiltsuk, the bear is a symbol of strength and authority, to be treated with respect.
"We look at it as though we're on their territory," Housty told Live Science, referring to the grizzly bears. "So we keep our distance, we give them their space."
But Canadian laws don't dictate that everyone leaves the bears alone: Grizzly hunting is still allowed in the region, Housty said.
To better protect the bear population, the Heiltsuk teamed up with scientists from the American Natural History Museum and the Nature Conservancy to create a bear census.
Grizzly bears are incredibly driven to investigate new and interesting smells, Filardi said.
"They're like big, thousand-pound noses wandering around," Filardi told Live Science.
So Housty and two other Heiltsuk researchers laced barbed-wire lures with a pungent scent such as skunk musk, and strategically placed them on trees and other spots that bears like to rub against.
The bears, lured by the scent, would sniff around, rub themselves on the snares, and leave stray hairs behind.
The team then genetically analyzed the hairs to identify individual bears. There were 50 to 60 bears congregating along a 5-mile-long (8 kilometers) stretch of river, Filardi said. (For comparison, Yellowstone National Park's grizzly population boasts just a few hundred, he noted.)
Many came all three years of the study, but a significant fraction came one year and not the next, or vice versa, suggesting the underlying grizzly population was fairly large, he added.
Over the course of the study, they team counted fewer new bears, which suggests the population was decreasing along the Koeye River, likely because fewer salmon were spawning there
By coordinating their findings with those of other First Nations tribes, the team found that some of those bears were coming from many miles away, along several bear "highways," with "on" and "off" ramps at certain key sites, Filardi said.
In some spots bears' footprints have worn holes the size of dinner plates in the mossy forest floor, Filardi said.
"The bears have just been stepping in each other's footprints for hundreds of years," Filardi said.
Those footprints make it easy to figure out how some bears reach the Koeye River watershed. But there may be many more as-yet-undiscovered bear migration routes to piece together, Housty said.
The Heiltsuk are now creating a map of these bear trails, though they are not sharing the map with outsiders, to avoid giving trophy hunters clues on where to hunt, Filardi said.
Read more at Discovery News
A secret feeding site that draws dozens of grizzly bears has been identified along a Canadian river where salmon spawn.
Finding the feeding site for the grizzly bears and the "highways" they take to get to it could help policymakers ban trophy hunting in the region. The resulting protection could allow dwindling grizzly populations to rebound.
"Our hope is for grizzly bears to start returning to their historic range," said study co-author said Chris Filardi, director of Pacific programs at the American Museum of Natural History in New York.
The Heiltsuk people, a coastal First Nations people in British Columbia, have long known that grizzlies congregate along the Koeye (pronounced "kway") River.
"We have this traditional knowledge that has existed amongst our people for thousands of years now," said study lead author William Housty, the director of Coastwatch, a scientific initiative led by the Heiltsuk to manage resources and conservation in their territory.
To the Heiltsuk, the bear is a symbol of strength and authority, to be treated with respect.
"We look at it as though we're on their territory," Housty told Live Science, referring to the grizzly bears. "So we keep our distance, we give them their space."
But Canadian laws don't dictate that everyone leaves the bears alone: Grizzly hunting is still allowed in the region, Housty said.
To better protect the bear population, the Heiltsuk teamed up with scientists from the American Natural History Museum and the Nature Conservancy to create a bear census.
Grizzly bears are incredibly driven to investigate new and interesting smells, Filardi said.
"They're like big, thousand-pound noses wandering around," Filardi told Live Science.
So Housty and two other Heiltsuk researchers laced barbed-wire lures with a pungent scent such as skunk musk, and strategically placed them on trees and other spots that bears like to rub against.
The bears, lured by the scent, would sniff around, rub themselves on the snares, and leave stray hairs behind.
The team then genetically analyzed the hairs to identify individual bears. There were 50 to 60 bears congregating along a 5-mile-long (8 kilometers) stretch of river, Filardi said. (For comparison, Yellowstone National Park's grizzly population boasts just a few hundred, he noted.)
Many came all three years of the study, but a significant fraction came one year and not the next, or vice versa, suggesting the underlying grizzly population was fairly large, he added.
Over the course of the study, they team counted fewer new bears, which suggests the population was decreasing along the Koeye River, likely because fewer salmon were spawning there
By coordinating their findings with those of other First Nations tribes, the team found that some of those bears were coming from many miles away, along several bear "highways," with "on" and "off" ramps at certain key sites, Filardi said.
In some spots bears' footprints have worn holes the size of dinner plates in the mossy forest floor, Filardi said.
"The bears have just been stepping in each other's footprints for hundreds of years," Filardi said.
Those footprints make it easy to figure out how some bears reach the Koeye River watershed. But there may be many more as-yet-undiscovered bear migration routes to piece together, Housty said.
The Heiltsuk are now creating a map of these bear trails, though they are not sharing the map with outsiders, to avoid giving trophy hunters clues on where to hunt, Filardi said.
Read more at Discovery News
'Transformer' Pulsar is More Than Meets the Eye
Astronomers may have not yet found Cybertron but this “transforming” pulsar definitely has a shape-shifting double personality.
Using NASA’s Fermi Gamma-Ray Space Telescope, an international team of researchers has observed a peculiar type of binary star system named AY Sextantis that consists of a rapidly-spinning millisecond pulsar — that is, a bright radio-beaming neutron star, the compacted corpse of a dead star that’s since gone supernova — with a larger, low-mass star.
The dense neutron star periodically slurps up material from its swollen companion as the two whirl around each other every 4.8 hours, but when too much material from the low-mass star crowds the accretion disk surrounding the neutron star it gets hot enough to glow in x-ray wavelengths.
At this point turbulence in the disk at a mere 50 miles above the surface of the spinning neutron star gets the superheated material caught up in powerful magnetic fields. The radio beacons are snuffed out as jets blast from the star’s poles, crackling with gamma rays… AY Sextantis has transformed from a low-mass X-ray binary to a transient, compact, low-mass gamma-ray binary.
“It’s almost as if someone flipped a switch, morphing the system from a lower-energy state to a higher-energy one,” said Benjamin Stappers, astrophysicist at the University of Manchester, England, and lead on the research team. “The change appears to reflect an erratic interaction between the pulsar and its companion, one that allows us an opportunity to explore a rare transitional phase in the life of this binary.”
With such close proximity and rapid orbital period, the pulsar will soon completely dismantle its larger companion through its intermittent but energetic feeding periods.
Watch the video for an illustration of how this complex process is thought to occur:
Named PSR J1023+0038 (J1023 for short) the pulsar was first discovered in 2007 by Anne Archibald, a postdoctoral researcher at the Netherlands Institute for Radio Astronomy. It’s located about 4,400 light-years away in the southern constellation Sextans.
Read more at Discovery News
Using NASA’s Fermi Gamma-Ray Space Telescope, an international team of researchers has observed a peculiar type of binary star system named AY Sextantis that consists of a rapidly-spinning millisecond pulsar — that is, a bright radio-beaming neutron star, the compacted corpse of a dead star that’s since gone supernova — with a larger, low-mass star.
The dense neutron star periodically slurps up material from its swollen companion as the two whirl around each other every 4.8 hours, but when too much material from the low-mass star crowds the accretion disk surrounding the neutron star it gets hot enough to glow in x-ray wavelengths.
At this point turbulence in the disk at a mere 50 miles above the surface of the spinning neutron star gets the superheated material caught up in powerful magnetic fields. The radio beacons are snuffed out as jets blast from the star’s poles, crackling with gamma rays… AY Sextantis has transformed from a low-mass X-ray binary to a transient, compact, low-mass gamma-ray binary.
“It’s almost as if someone flipped a switch, morphing the system from a lower-energy state to a higher-energy one,” said Benjamin Stappers, astrophysicist at the University of Manchester, England, and lead on the research team. “The change appears to reflect an erratic interaction between the pulsar and its companion, one that allows us an opportunity to explore a rare transitional phase in the life of this binary.”
With such close proximity and rapid orbital period, the pulsar will soon completely dismantle its larger companion through its intermittent but energetic feeding periods.
Watch the video for an illustration of how this complex process is thought to occur:
Read more at Discovery News
Jul 21, 2014
Science and art bring back to life 300-million-year-old specimens of a primitive reptile-like vertebrate
Paleontologists from the Natural History Museum and academics from Lincoln, Cambridge and Solvakia have recreated the cranial structure of a 308-million-year-old lizard-like vertebrate that could be the earliest example of a reptile and explain the origin of all vertebrates that belong to reptiles, birds and mammals.
Dr Marcello Ruta, from the School of Life Sciences, University of Lincoln, UK, was one of the authors of the paper which is published in the Journal of Vertebrate Paleontology and produced a series of intricate hand-drawn recreations of the cranial structure of Gephyrostegus.
Paleontologists have provided a new cranial reconstruction of a long-extinct limbed vertebrate (tetrapod) from previously unrecognised specimens found in coal deposits from the Czech Republic.
The team of academics reviewed the cranial structural features of the Late Carboniferous Gephyrostegus bohemicus -- a small animal of generally lizard-like build that lived 308 million years ago.
This early tetrapod could be the earliest example of a reptile and explain the origin of amniotes, all vertebrates that belong to reptiles, birds and mammals.
Experts from, Comenius University in Bratislava (Slovakia), University Museum of Zoology in Cambridge, The Natural History Museum in London, and the University of Lincoln, UK, have been able to study additional specimens unavailable in previous works.
Their aim was to provide an analysis of early tetrapod relationships incorporating their new observations of Gephyrostegus. Their analysis used skeletal traits across a sample of early tetrapod groups to identify the likely affinities of Gephyrostegus.
Their results are detailed in the Journal of Vertebrate Paleontology.
Dr Marcello Ruta, from the School of Life Sciences, University of Lincoln, UK, was one of the authors and produced a series of intricate hand-drawn recreations of the cranial structure of Gephyrostegus.
Read more at Science Daily
Dr Marcello Ruta, from the School of Life Sciences, University of Lincoln, UK, was one of the authors of the paper which is published in the Journal of Vertebrate Paleontology and produced a series of intricate hand-drawn recreations of the cranial structure of Gephyrostegus.
Paleontologists have provided a new cranial reconstruction of a long-extinct limbed vertebrate (tetrapod) from previously unrecognised specimens found in coal deposits from the Czech Republic.
The team of academics reviewed the cranial structural features of the Late Carboniferous Gephyrostegus bohemicus -- a small animal of generally lizard-like build that lived 308 million years ago.
This early tetrapod could be the earliest example of a reptile and explain the origin of amniotes, all vertebrates that belong to reptiles, birds and mammals.
Experts from, Comenius University in Bratislava (Slovakia), University Museum of Zoology in Cambridge, The Natural History Museum in London, and the University of Lincoln, UK, have been able to study additional specimens unavailable in previous works.
Their aim was to provide an analysis of early tetrapod relationships incorporating their new observations of Gephyrostegus. Their analysis used skeletal traits across a sample of early tetrapod groups to identify the likely affinities of Gephyrostegus.
Their results are detailed in the Journal of Vertebrate Paleontology.
Dr Marcello Ruta, from the School of Life Sciences, University of Lincoln, UK, was one of the authors and produced a series of intricate hand-drawn recreations of the cranial structure of Gephyrostegus.
Read more at Science Daily
Mysterious dance of dwarf galaxies may force a cosmic rethink
The discovery that many small galaxies throughout the universe do not 'swarm' around larger ones like bees do but 'dance' in orderly disc-shaped orbits is a challenge to our understanding of how the universe formed and evolved.
The finding, by an international team of astronomers, including Professor Geraint Lewis from the University of Sydney's School of Physics, is announced today in Nature.
"Early in 2013 we announced our startling discovery that half of the dwarf galaxies surrounding the Andromeda Galaxy are orbiting it in an immense plane" said Professor Lewis. "This plane is more than a million light years in diameter, but is very thin, with a width of only 300,000 light years."
The universe contains billions of galaxies. Some, such as the Milky Way, are immense, containing hundreds of billions of stars. Most galaxies, however, are dwarfs, much smaller and with only a few billion stars.
For decades astronomers have used computer models to predict how these dwarf galaxies should orbit large galaxies. They had always found that they should be scattered randomly.
"Our Andromeda discovery did not agree with expectations, and we felt compelled to explore if it was true of other galaxies throughout the universe," said Professor Lewis.
Using the Sloan Digital Sky Survey, a remarkable resource of colour images and 3-D maps covering more than a third of the sky, the researchers dissected the properties of thousands of nearby galaxies.
"We were surprised to find that a large proportion of pairs of satellite galaxies have oppositely directed velocities if they are situated on opposite sides of their giant galaxy hosts," said lead author Neil Ibata of the Lycée International in Strasbourg, France.
"Everywhere we looked we saw this strangely coherent coordinated motion of dwarf galaxies. From this we can extrapolate that these circular planes of dancing dwarfs are universal, seen in about 50 percent of galaxies," said Professor Geraint Lewis.
"This is a big problem that contradicts our standard cosmological models. It challenges our understanding of how the universe works including the nature of dark matter."
The researchers believe the answer may be hidden in some currently unknown physical process that governs how gas flows in the universe, although, as yet, there is no obvious mechanism that can guide dwarf galaxies into narrow planes.
Read more at Science Daily
The finding, by an international team of astronomers, including Professor Geraint Lewis from the University of Sydney's School of Physics, is announced today in Nature.
"Early in 2013 we announced our startling discovery that half of the dwarf galaxies surrounding the Andromeda Galaxy are orbiting it in an immense plane" said Professor Lewis. "This plane is more than a million light years in diameter, but is very thin, with a width of only 300,000 light years."
The universe contains billions of galaxies. Some, such as the Milky Way, are immense, containing hundreds of billions of stars. Most galaxies, however, are dwarfs, much smaller and with only a few billion stars.
For decades astronomers have used computer models to predict how these dwarf galaxies should orbit large galaxies. They had always found that they should be scattered randomly.
"Our Andromeda discovery did not agree with expectations, and we felt compelled to explore if it was true of other galaxies throughout the universe," said Professor Lewis.
Using the Sloan Digital Sky Survey, a remarkable resource of colour images and 3-D maps covering more than a third of the sky, the researchers dissected the properties of thousands of nearby galaxies.
"We were surprised to find that a large proportion of pairs of satellite galaxies have oppositely directed velocities if they are situated on opposite sides of their giant galaxy hosts," said lead author Neil Ibata of the Lycée International in Strasbourg, France.
"Everywhere we looked we saw this strangely coherent coordinated motion of dwarf galaxies. From this we can extrapolate that these circular planes of dancing dwarfs are universal, seen in about 50 percent of galaxies," said Professor Geraint Lewis.
"This is a big problem that contradicts our standard cosmological models. It challenges our understanding of how the universe works including the nature of dark matter."
The researchers believe the answer may be hidden in some currently unknown physical process that governs how gas flows in the universe, although, as yet, there is no obvious mechanism that can guide dwarf galaxies into narrow planes.
Read more at Science Daily
Mystery of Stone Arch Formation May Be Solved
Arches of stone seem to defy explanation, but a new study may have solved the mystery of how these and other strange natural stone wonders form.
The bewildering shapes apparently owe their origin in large part to how rock can strengthen when squashed from above, scientists explained.
Mysterious rock formations such as arches, bridges, pillars and mushroom-shaped pedestal rocks occur all over the world. Geologists mostly think these form due to erosion from wind and water, as well as from the weathering effects of salt and frost.
However, lead author of the new study Jirí Bruthans, a geologist at Charles University in Prague, and his colleagues did not think erosion and weathering alone could explain how many of these natural sculptures arose. They also noted that prior research did not explain how the upper parts of arches remain stable.
Now, the researchers said they can help explain how these rock formations develop by accounting for the way rock can strengthen when compacted by weight from above.
"The results were shocking for me when I started to realize how simply nature carves all these shapes," Bruthans said.
The scientists conducted experiments with oven-dried cubes of sandstone that were weak enough that running water could erode them. As the sides of the cubes disintegrated from exposure to water, researchers saw that the weight of the sandstone above was held up by fewer and fewer sand grains. This increased the amount of force placed on those remaining grains from the sand above.
Experiments and numerical models revealed that once a critical weight from the higher parts of the sandstone was reached, the downward force locked the lower grains of sand together more tightly, increasing their resistance to erosion. In contrast, other parts of sandstone bearing less weight stayed vulnerable to erosion, and washed away.
The researchers also found that introducing weaknesses, such as notches or fractures, into the sandstone cubes could yield a diversity of shapes, including arches, pillars and pedestal rocks.
Read more at Discovery News
The bewildering shapes apparently owe their origin in large part to how rock can strengthen when squashed from above, scientists explained.
Mysterious rock formations such as arches, bridges, pillars and mushroom-shaped pedestal rocks occur all over the world. Geologists mostly think these form due to erosion from wind and water, as well as from the weathering effects of salt and frost.
However, lead author of the new study Jirí Bruthans, a geologist at Charles University in Prague, and his colleagues did not think erosion and weathering alone could explain how many of these natural sculptures arose. They also noted that prior research did not explain how the upper parts of arches remain stable.
Now, the researchers said they can help explain how these rock formations develop by accounting for the way rock can strengthen when compacted by weight from above.
"The results were shocking for me when I started to realize how simply nature carves all these shapes," Bruthans said.
The scientists conducted experiments with oven-dried cubes of sandstone that were weak enough that running water could erode them. As the sides of the cubes disintegrated from exposure to water, researchers saw that the weight of the sandstone above was held up by fewer and fewer sand grains. This increased the amount of force placed on those remaining grains from the sand above.
Experiments and numerical models revealed that once a critical weight from the higher parts of the sandstone was reached, the downward force locked the lower grains of sand together more tightly, increasing their resistance to erosion. In contrast, other parts of sandstone bearing less weight stayed vulnerable to erosion, and washed away.
The researchers also found that introducing weaknesses, such as notches or fractures, into the sandstone cubes could yield a diversity of shapes, including arches, pillars and pedestal rocks.
Read more at Discovery News
Oceans Make Exoplanets Stable for Alien Life
The role that Earth’s oceans have on our planet’s habitability is undeniable, but now scientists think that exoplanetary oceans are essential for alien life to evolve.
In a new study published by the journal Astrobiology, University of East Anglia (UEA), UK, researchers have come to the conclusion that, to make a planet habitable, a large liquid ocean is needed to stabilize its atmosphere.
“We know that many planets are completely uninhabitable because they are either too close or too far from their sun,” said David Stevens of UEA’s School of Maths. “A planet’s habitable zone is based on its distance from the sun and temperatures at which it is possible for the planet to have liquid water.
“But until now, most habitability models have neglected the impact of oceans on climate.”
The habitable zone surrounding any star is the distance at which it’s not too hot and not too cold to support liquid water on a planetary surface. Liquid water is vital for the evolution of life as we know it.
Earth orbits within our sun’s habitable zone, unsurprisingly, whereas Mars is located on the outside edge and Venus on the inside edge. The life-giving contrast between Earth, Mars and Venus couldn’t be more stark; Mars is a frozen, dry wasteland with dramatic surface temperature variations, and Venus is a choked, broiling world with searing surface temperatures. But Earth is stable, a factor that has allowed life to thrive for billions of years.
Although a planet’s distance from its star is important, whether or not it has an ocean appears to be a huge factor. In fact, the presence of an ocean is the ultimate planetary “climate control” for any planet, according to new computer models created by Stevens’ team.
“Oceans have an immense capacity to control climate,” he said in a UEA news release. “They are beneficial because they cause the surface temperature to respond very slowly to seasonal changes in solar heating. And they help ensure that temperature swings across a planet are kept to tolerable levels.”
Although Mars is located on the outside edge of the sun’s habitable zone, planetary scientists believe the red planet once possessed large bodies of water when the planet’s atmosphere was thicker. The presence of liquid water on the surface of ancient Mars is exciting — after all, on Earth, where there’s water there’s usually life. But the presence of possible Martian oceans may have stabilized the atmosphere, making it less prone to wild temperature fluctuations and more comfortable for life to gain a foothold. Modern Mars endures air temperature fluctuations of over 100 degrees Celsius (212 degrees Fahrenheit).
Read more at Discovery News
In a new study published by the journal Astrobiology, University of East Anglia (UEA), UK, researchers have come to the conclusion that, to make a planet habitable, a large liquid ocean is needed to stabilize its atmosphere.
“We know that many planets are completely uninhabitable because they are either too close or too far from their sun,” said David Stevens of UEA’s School of Maths. “A planet’s habitable zone is based on its distance from the sun and temperatures at which it is possible for the planet to have liquid water.
“But until now, most habitability models have neglected the impact of oceans on climate.”
The habitable zone surrounding any star is the distance at which it’s not too hot and not too cold to support liquid water on a planetary surface. Liquid water is vital for the evolution of life as we know it.
Earth orbits within our sun’s habitable zone, unsurprisingly, whereas Mars is located on the outside edge and Venus on the inside edge. The life-giving contrast between Earth, Mars and Venus couldn’t be more stark; Mars is a frozen, dry wasteland with dramatic surface temperature variations, and Venus is a choked, broiling world with searing surface temperatures. But Earth is stable, a factor that has allowed life to thrive for billions of years.
Although a planet’s distance from its star is important, whether or not it has an ocean appears to be a huge factor. In fact, the presence of an ocean is the ultimate planetary “climate control” for any planet, according to new computer models created by Stevens’ team.
“Oceans have an immense capacity to control climate,” he said in a UEA news release. “They are beneficial because they cause the surface temperature to respond very slowly to seasonal changes in solar heating. And they help ensure that temperature swings across a planet are kept to tolerable levels.”
Although Mars is located on the outside edge of the sun’s habitable zone, planetary scientists believe the red planet once possessed large bodies of water when the planet’s atmosphere was thicker. The presence of liquid water on the surface of ancient Mars is exciting — after all, on Earth, where there’s water there’s usually life. But the presence of possible Martian oceans may have stabilized the atmosphere, making it less prone to wild temperature fluctuations and more comfortable for life to gain a foothold. Modern Mars endures air temperature fluctuations of over 100 degrees Celsius (212 degrees Fahrenheit).
Read more at Discovery News
Jul 20, 2014
Researchers identify brain network with mapping technique
Investigators at The Feinstein Institute for Medical Research have utilized a new image-based strategy to identify and measure placebo effects in randomized clinical trials for brain disorders. The findings are published in the August issue of The Journal of Clinical Investigation.
Parkinson's disease is the second most common neurodegenerative disease in the US. Those who suffer from Parkinson's disease most often experience tremors, slowness of movement (bradykinesia), rigidity, and impaired balance and coordination. Patients may have difficulty walking, talking or completing simple daily tasks. They may also experience depression and difficulty sleeping due to the disease. The current standard for diagnosis of Parkinson's disease relies on a skilled healthcare professional, usually an experienced neurologist, to determine through clinical examination that someone has it. There currently is no cure for Parkinson's disease, but medications can improve symptoms.
A team of researchers at the Feinstein Institute's Center for Neurosciences, led by David Eidelberg, MD, has developed a method to identify brain patterns that are abnormal or indicate disease using imaging techniques. To date, this approach has been used successfully to identify specific networks in the brain that indicate a patient has or is at risk for Parkinson's disease and other neurodegenerative disorders.
"One of the major challenges in developing new treatments for neurodegenerative disorders such as Parkinson's disease is that it is common for patients participating in clinical trials to experience a placebo or sham effect," noted Dr. Eidelberg. "When patients involved in a clinical trial commonly experience benefits from placebo, it's difficult for researchers to identify if the treatment being studied is effective. In a new study conducted by my colleagues and myself, we have used a new image-based strategy to identify and measure placebo effects in brain disorder clinical trials."
In the current study, the researchers used their network mapping technique to identify specific brain circuits underlying the response to sham surgery in Parkinson's disease patients participating in a gene therapy trial. The expression of this network measured under blinded conditions correlated with the sham subjects' clinical outcome; the network changes were reversed when the subjects learned of their sham treatment status. Finally, an individual subject's network expression value measured before the treatment predicted his/her subsequent blinded response to sham treatment. This suggests that this novel image-based measure of the sham-related network can help to reduce the number of subjects assigned to sham treatment in randomized clinical trials for brain disorders by excluding those subjects who are more likely to display placebo effects under blinded conditions.
From Science Daily
Parkinson's disease is the second most common neurodegenerative disease in the US. Those who suffer from Parkinson's disease most often experience tremors, slowness of movement (bradykinesia), rigidity, and impaired balance and coordination. Patients may have difficulty walking, talking or completing simple daily tasks. They may also experience depression and difficulty sleeping due to the disease. The current standard for diagnosis of Parkinson's disease relies on a skilled healthcare professional, usually an experienced neurologist, to determine through clinical examination that someone has it. There currently is no cure for Parkinson's disease, but medications can improve symptoms.
A team of researchers at the Feinstein Institute's Center for Neurosciences, led by David Eidelberg, MD, has developed a method to identify brain patterns that are abnormal or indicate disease using imaging techniques. To date, this approach has been used successfully to identify specific networks in the brain that indicate a patient has or is at risk for Parkinson's disease and other neurodegenerative disorders.
"One of the major challenges in developing new treatments for neurodegenerative disorders such as Parkinson's disease is that it is common for patients participating in clinical trials to experience a placebo or sham effect," noted Dr. Eidelberg. "When patients involved in a clinical trial commonly experience benefits from placebo, it's difficult for researchers to identify if the treatment being studied is effective. In a new study conducted by my colleagues and myself, we have used a new image-based strategy to identify and measure placebo effects in brain disorder clinical trials."
In the current study, the researchers used their network mapping technique to identify specific brain circuits underlying the response to sham surgery in Parkinson's disease patients participating in a gene therapy trial. The expression of this network measured under blinded conditions correlated with the sham subjects' clinical outcome; the network changes were reversed when the subjects learned of their sham treatment status. Finally, an individual subject's network expression value measured before the treatment predicted his/her subsequent blinded response to sham treatment. This suggests that this novel image-based measure of the sham-related network can help to reduce the number of subjects assigned to sham treatment in randomized clinical trials for brain disorders by excluding those subjects who are more likely to display placebo effects under blinded conditions.
From Science Daily
Universal three-body relation: Physicists succeed in revealing the scaling behavior of exotic giant molecules
When a two-body relation becomes a three-body relation, the behaviour of the system changes and typically becomes more complex. While the basic physics of two interacting particles is well understood, the mathematical description of a three- or many-body system becomes increasingly difficult, such that calculating the dynamics can blast the capacities of even modern supercomputers. However, under certain conditions, the quantum mechanical three-body problem may have a universal scaling solution. The predictions of such a model have now been confirmed experimentally by physicists of Heidelberg University. The scientists under Prof. Dr. Matthias Weidemüller investigated three-particle molecules, known as trimers, under exotic conditions. The scientific results were published in Physical Review Letters.
The scientific work done in Heidelberg is based on a theory which was posed by the Russian physicist Vitaly Efimov more than 40 years ago. It focuses on finding physical laws capable of predicting the behaviour and energy states of an arbitrary number of particles. According to Efimov's prediction, bound states of three atoms can be universally described under certain conditions. The scientist found that infinitely many quantum mechanical bound states for the "ménage à trois" exist, even if two of the atoms cannot bind together. These so-called Efimov trimers are formed due to the long-range quantum mechanical interaction and they are completely independent of the underlying type of the three interacting particles.
Prof. Weidemüller says that Efimov's prediction was considered "exotic" for a long time, since the conditions under which these molecular three-body bound states exist seemed unattainable in research. "Physicists with different scientific backgrounds have tried in vain to find signatures of the Efimov trimers," explains the Heidelberg scientist. It was only about ten years ago that scientists from Innsbruck were able to provide clear evidence for these trimers in systems consisting of three identical atoms. Shortly afterwards, physicists working with Prof. Dr. Selim Jochim in Heidelberg succeeded in measuring the exact binding energy of the Efimov trimers. In the course of scientific work performed at the Center for Quantum Dynamics and the Institute for Physics of Heidelberg University, further properties of the exotic Efimov trimers were investigated. To this end, the researchers cooled a gas of two different atomic species -- caesium and lithium -- to temperatures close to absolute zero. At the same time, they took care to precisely control the interaction between these lithium and caesium atom pairs.
In an ultra-high vacuum chamber the atoms were cooled solely by laser light and stored by light forces in a focused laser beam for several seconds. The coupling strength between the atoms can then be controlled by changing the magnetic field. For this Prof. Weidemüller's team made use of what are known as atomic scattering resonances. The evidence of the trimers is based on the decay into their three components at a well-defined coupling strength. The strength of this coupling scales independently of the respective trimer bound state according to a purely numeric scaling factor. "We proved that the universal scaling is also valid in systems with different atoms," says Rico Pires, who is working on his dissertation in Prof. Weidemüller's team.
These scientists also succeeded in confirming that the scaling factor changes for a trimer of different particles as opposed to a trimer state of identical atoms, as PhD student Juris Ulmanis explains. They thus showed that Efimov's theory is applicable to a large number of systems. Project leader Dr. Eva Kuhnle points to another success of the experimental work: "For the first time we were able to not only prove the existence of the trimer ground state, but also the first two excited states. These molecules consisting of three atoms then reach macroscopic sizes, comparable to that of a bacterium."
Read more at Science Daily
The scientific work done in Heidelberg is based on a theory which was posed by the Russian physicist Vitaly Efimov more than 40 years ago. It focuses on finding physical laws capable of predicting the behaviour and energy states of an arbitrary number of particles. According to Efimov's prediction, bound states of three atoms can be universally described under certain conditions. The scientist found that infinitely many quantum mechanical bound states for the "ménage à trois" exist, even if two of the atoms cannot bind together. These so-called Efimov trimers are formed due to the long-range quantum mechanical interaction and they are completely independent of the underlying type of the three interacting particles.
Prof. Weidemüller says that Efimov's prediction was considered "exotic" for a long time, since the conditions under which these molecular three-body bound states exist seemed unattainable in research. "Physicists with different scientific backgrounds have tried in vain to find signatures of the Efimov trimers," explains the Heidelberg scientist. It was only about ten years ago that scientists from Innsbruck were able to provide clear evidence for these trimers in systems consisting of three identical atoms. Shortly afterwards, physicists working with Prof. Dr. Selim Jochim in Heidelberg succeeded in measuring the exact binding energy of the Efimov trimers. In the course of scientific work performed at the Center for Quantum Dynamics and the Institute for Physics of Heidelberg University, further properties of the exotic Efimov trimers were investigated. To this end, the researchers cooled a gas of two different atomic species -- caesium and lithium -- to temperatures close to absolute zero. At the same time, they took care to precisely control the interaction between these lithium and caesium atom pairs.
In an ultra-high vacuum chamber the atoms were cooled solely by laser light and stored by light forces in a focused laser beam for several seconds. The coupling strength between the atoms can then be controlled by changing the magnetic field. For this Prof. Weidemüller's team made use of what are known as atomic scattering resonances. The evidence of the trimers is based on the decay into their three components at a well-defined coupling strength. The strength of this coupling scales independently of the respective trimer bound state according to a purely numeric scaling factor. "We proved that the universal scaling is also valid in systems with different atoms," says Rico Pires, who is working on his dissertation in Prof. Weidemüller's team.
These scientists also succeeded in confirming that the scaling factor changes for a trimer of different particles as opposed to a trimer state of identical atoms, as PhD student Juris Ulmanis explains. They thus showed that Efimov's theory is applicable to a large number of systems. Project leader Dr. Eva Kuhnle points to another success of the experimental work: "For the first time we were able to not only prove the existence of the trimer ground state, but also the first two excited states. These molecules consisting of three atoms then reach macroscopic sizes, comparable to that of a bacterium."
Read more at Science Daily
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