Tracing where your DNA was formed over 1,000 years ago is now possible, thanks to a revolutionary technique developed by a team of international scientists led by experts from the University of Sheffield.
The ground-breaking Geographic Population Structure (GPS) tool, created by Dr Eran Elhaik from the University of Sheffield's Department of Animal and Plant Sciences and Dr Tatiana Tatarinova from the University of Southern California, works similarly to a satellite navigation system as it helps you to find your way home, but not the one you currently live in -- but rather your actual ancestor's home from 1,000 years ago.
Previously, scientists have only been able to locate where your DNA was formed to within 700kms, which in Europe could be two countries away; however this pioneering technique has been 98 per cent successful in locating worldwide populations to their right geographic regions, and down to their village and island of origin.
The breakthrough of knowing where the gene pools that created your DNA were last mixed has massive implications for life-saving personalised medicine, advancing forensic science and for the study of populations whose ancestral origins are under debate, such as African Americans, Roma gypsies and European Jews.
Genetic admixture occurs when individuals from two or more previously separated populations begin interbreeding. This results in the creation of new gene pools representing a mixture of the founder gene pool.
Such processes are extremely common in history during migrations and invasions, for example, when the Vikings invaded Britain and Europe in the 11th Century and settled with locals some of them formed a new Viking-Anglo-Saxon gene pool, but some married other Vikings and maintained their original gene pool, allowing GPS to trace their Scandinavian origins.
Dr Eran Elhaik said: "If we think of our world as being made up of different colours of soup -- representing different populations -- it is easy to visualise how genetic admixture occurs. If a population from the blue soup region mixes with a population from the red soup region their off-springs would appear as a purple soup.
"The more genetic admixture that takes place, the more different colours of soup are introduced which makes it increasingly difficult to locate your DNA's ancestry using traditional tools like Spatial Ancestry analysis (SPA) which has an accuracy level of less than two per cent."
He added: "What we have discovered here at the University of Sheffield is a way to find not where you were born -- as you have that information on your passport -- but where your DNA was formed up to 1,000 years ago by modelling these admixture processes.
"What is remarkable is that, we can do this so accurately that we can locate the village where your ancestors lived hundreds and hundreds of years ago -- until now this has never been possible."
To demonstrate how accurate GPS predictions are, Dr Elhaik and his colleagues analysed data from 10 villages in Sardinia and over 20 islands in Oceania. The research published today in the journal Nature Communications shows that Dr Elhaik and his team were able to place a quarter of the residents in Sardinia directly to their home village and most of the remaining residents within 50km of their village. The results for Oceania were no less impressive with almost 90 per cent success of tracing islanders exactly to their island.
"This is a significant improvement compared to the alternative SPA tool that placed Oceanians in India," said Elhaik.
"In his third book, children's author L. Frank Baum revealed that Oz resided around Australia. It always troubled me that if I ever met anyone claiming to be from the wonderful world of Oz, I would like to be able to verify their origins and now we can!
"This technique also means that we can no longer easily classify people's ethnic identities with one single label. It is impossible for any of us to tick one box on a form such as White British or African as we are much complex models with our own unique identities. The notion of races is simply not plausible."
Tracing our ancestry is now a major social trend and genealogy is the number one hobby in America. An estimated one million people in the USA have already had their DNA genotyped. People can explore their DNA by simply taking a swab from inside their mouth and sending it to a company such as 23andme or ancestry.com for costs ranging from $99-$200.
Dr Elhaik's co-author, Dr Tatiana Tatarinova, developed a website making GPS accessible to the public.
"To help people find their roots, I developed a website that allows anyone who has had their DNA genotyped to upload their results and use GPS to find their ancestral home," said Dr Tatarinova, who is also an Associate Professor of Research Paediatrics at the Keck School of Medicine of the University of Southern California.
"We were surprised by the simplicity and precision of this method. People in a given geographical area are more likely to have similar genetics. When they also have genetic traits typically found in other, distant regions, the geographical origin of those traits is generally the closest location where those traits can be found."
Read more at Scince Daily
May 3, 2014
Nearby galaxy is a 'fossil' from the early universe
New work from a team of scientists including Carnegie's Josh Simon analyzed the chemical elements in the faintest known galaxy, called Segue 1, and determined that it is effectively a fossil galaxy left over from the early universe.
Astronomers hoping to learn about the first stages of galaxy formation after the Big Bang use the chemical composition of stars to help them unravel the histories of the Milky Way and other nearby galaxies. Using these chemical analysis techniques, the team was able to categorize Segue 1's uniquely ancient composition. Their work is published by Astrophysical Journal.
Stars form from gas clouds and their composition mirrors the chemical composition of the galactic gas from which they were born. Only a few million years after stars begin burning, the most-massive stars explode in titanic blasts called supernovae. These explosions seed the nearby gas with heavy elements produced by the stars during their lifetimes. The very oldest stars consist almost entirely of the two lightest elements, hydrogen and helium, because they were born before ancient supernova explosions built up significant amounts of heavier elements.
In most galaxies, this process is cyclical, with each generation of stars contributing more heavy elements to the raw material from which the next set of stars will be born. But not in Segue 1 -- in contrast to all other galaxies, the new analysis shows that Segue 1's star formation ended at what would ordinarily be an early stage of a galaxy's development. Segue 1 likely failed to progress further because of its unusually tiny size.
"Our work suggests that Segue 1 is the least chemically evolved galaxy known," Simon said. "After the initial few supernova explosions, it appears that only a single generation of new stars were formed, and then for the last 13 billion years the galaxy has not been creating stars."
Because it has stayed in the same state for so long, Segue 1 offers unique information about the conditions in the universe shortly after the Big Bang. Other galaxies have undergone multiple supernova explosions since their formation. The first supernovae to blow up, from the most massive stars, produce elements like magnesium, silicon, and calcium. Later explosions of smaller stars primarily make iron. Segue 1's uniquely low iron abundance relative to other elements shows that its star formation must have stopped before any of the iron-forming supernovae occurred.
This truncated evolution means that the products of the first explosions in Segue 1 have been preserved. Intriguingly, very heavy elements like barium and strontium are nearly absent from Segue 1's stars.
"The heaviest elements in this galaxy are at the lowest levels ever found," said Anna Frebel of the Massachusetts Institute of Technology, the leader of the team. "This gives us clues about what those first supernovae looked like."
Studying individual stars in dwarf galaxies can be difficult and Segue 1, which orbits our own Milky Way, is particularly puny, containing only about a thousand stars. Just seven stars in the entire galaxy are in the red giant phase of their lives, making them bright enough for modern telescopes to detect the features astronomers use to measure the abundance of each chemical element. Three of the seven red giants have heavy element abundances more than 3,000 times lower than that of the Sun, highlighting the primitive nature of the galaxy.
Read more at Science Daily
Astronomers hoping to learn about the first stages of galaxy formation after the Big Bang use the chemical composition of stars to help them unravel the histories of the Milky Way and other nearby galaxies. Using these chemical analysis techniques, the team was able to categorize Segue 1's uniquely ancient composition. Their work is published by Astrophysical Journal.
Stars form from gas clouds and their composition mirrors the chemical composition of the galactic gas from which they were born. Only a few million years after stars begin burning, the most-massive stars explode in titanic blasts called supernovae. These explosions seed the nearby gas with heavy elements produced by the stars during their lifetimes. The very oldest stars consist almost entirely of the two lightest elements, hydrogen and helium, because they were born before ancient supernova explosions built up significant amounts of heavier elements.
In most galaxies, this process is cyclical, with each generation of stars contributing more heavy elements to the raw material from which the next set of stars will be born. But not in Segue 1 -- in contrast to all other galaxies, the new analysis shows that Segue 1's star formation ended at what would ordinarily be an early stage of a galaxy's development. Segue 1 likely failed to progress further because of its unusually tiny size.
"Our work suggests that Segue 1 is the least chemically evolved galaxy known," Simon said. "After the initial few supernova explosions, it appears that only a single generation of new stars were formed, and then for the last 13 billion years the galaxy has not been creating stars."
Because it has stayed in the same state for so long, Segue 1 offers unique information about the conditions in the universe shortly after the Big Bang. Other galaxies have undergone multiple supernova explosions since their formation. The first supernovae to blow up, from the most massive stars, produce elements like magnesium, silicon, and calcium. Later explosions of smaller stars primarily make iron. Segue 1's uniquely low iron abundance relative to other elements shows that its star formation must have stopped before any of the iron-forming supernovae occurred.
This truncated evolution means that the products of the first explosions in Segue 1 have been preserved. Intriguingly, very heavy elements like barium and strontium are nearly absent from Segue 1's stars.
"The heaviest elements in this galaxy are at the lowest levels ever found," said Anna Frebel of the Massachusetts Institute of Technology, the leader of the team. "This gives us clues about what those first supernovae looked like."
Studying individual stars in dwarf galaxies can be difficult and Segue 1, which orbits our own Milky Way, is particularly puny, containing only about a thousand stars. Just seven stars in the entire galaxy are in the red giant phase of their lives, making them bright enough for modern telescopes to detect the features astronomers use to measure the abundance of each chemical element. Three of the seven red giants have heavy element abundances more than 3,000 times lower than that of the Sun, highlighting the primitive nature of the galaxy.
Read more at Science Daily
May 2, 2014
Circus Train Crash Mystery: Where's the Animal Graveyard?
The first car to go off the rails held the elephants.
The tigers, lions, horses, crocodiles, pythons and a gorilla known as the "Man-Slayer" followed as the Walter L. Main circus train careened off the tracks down a 30-foot-high (10 meters) embankment, with gold-gilt, steel-barred wagons crashing one on top of the other in the legendary pileup at Tyrone, a small town in central Pennsylvania, on Memorial Day 1893.
Today, the story has become ingrained in town lore. Big snakes are eyed with suspicion as possible descendants of escaped crash survivors. Elephants from other traveling circuses have stopped in Tyrone to lay wreaths out of respect for the dead. Bones, horseshoes, lion-cage locks and railroad spikes have turned up every time a new home is built on the site. But the exact location of the mass grave of dead circus animals has been lost to history. Researchers recently made an attempt to find it.
An initial search didn't turn up the hoard of bones researchers were looking for, but the team hopes further investigations will shed light on the crash.
"It was a little bit disappointing, but now we know where it isn't," local historian Paula Zitzler said.
Zitzler, who teaches at Penn State Altoona and wrote a book on the train crash, recently worked with a group of graduate students from Indiana University of Pennsylvania to probe a stretch of land near the accident site.
Using ground-penetrating radar, the students scanned 12,450 square meters (about 3 acres) of private property. The team said they found an intriguing anomaly with a lower metal content than the surrounding soil, but bad weather kept them from digging large test pits. They did pull a few cores of dirt out of the ground, but these samples were inconclusive.
The students — Michelle Cole, Daniel Sandrowicz, Katharine Craig, Kate Adam and Kirk Smith — presented the results of their investigation, which was part of a class project, last weekend at the annual meeting of the Society for American Archaeology in Austin, Texas.
Runaway trains and runaway tigers
If archaeologists eventually uncover the grave, it's not clear exactly what they'll find. While researching the accident, Zitzler said it was difficult to get a full inventory on the casualties.
The train was traveling west down a slope of the Allegheny Front, approaching a bend that was notorious for crashes, Zitzler said. While 17-car coal trains could manage the steep mountainside with just one locomotive, many of the 17 cars on the Walter L. Main circus train were twice as long as the average coal car. The engineers wired ahead to request more braking power but were denied. As they guided the train down the slope, it quickly picked up speed and couldn't be stopped. The locomotive at the front made it around the curve, but the cars behind it flew off the tracks near a farm owned by a man named Hiram Friday.
Remarkably, only five people were killed. The train essentially piled up to the level of the tracks, Zitzler said, and the last few cars, where most of the circus performers rode, didn't go off the rails.
The animals, mostly at the front of the train, bore the brunt of the suffering. Two "sacred cows" and at least 50 horses were killed. (The traveling circus was known for its horse acts, such as chariot races and juggling shows performed on the animals' backs.) The elephants survived, albeit with some injuries, and the sturdy beasts were even put to work in the accident cleanup. The Man-Slayer lived through the accident, too; Zitzler said there are photos of the unhappy gorilla tied to a tree after the accident.
Other animals survived the crash only to be killed after they bolted from their broken cages. In the most famous incident, Hiram Friday's daughter Hannah was milking a cow a few days after the wreck when a Bengal tiger attacked and killed the cow. Friday was injured while fighting in the Civil War and forbid guns in his home, said his great-granddaughter Susie O'Brien, who lives on the property today. A bear hunter had to be called in to find the tiger in the nearby woods and shoot it. The beast's skull hangs in a local hunting club today.
Still more escapees may have evaded capture altogether. In the months and years after the accident, the local papers were peppered with reports of exotic animal sightings. In the nearby town of Warriors Mark, people on their way to church one Sunday morning reportedly saw three kangaroos hopping across the street. Men who went out fishing would say they saw strange birds, likely parrots, that made the treetops look as if they were dabbed with colorful paint, Zitzler said. A year after the accident, on Ascension Thursday (celebrated by some as the day Jesus ascended into heaven), revelers at a barn-raising at the Friday farm reportedly left before dark out of fear the circus animals were still lurking on the property.
The show must go on
While the lore lingered for decades, the wreckage from the accident was cleared in just three days. Amid the swift cleanup, the dead animals were buried in trenches on the Friday farm along with other wreckage too mangled to be reused. But there is no documentation of the mass grave's exact location.
O'Brien, who has been giving presentations about the wreck since 1993, has amassed a collection of artifacts found on her property and the nearby plots owned by her relatives, including bone bits, horseshoes and even an antique donkey-shaped bottle opener, perhaps from the dining car. Her goal has always been to conduct a study — perhaps a dig —at the site.
"I'm just curious to see what survived," O'Brien told Live Science. "I thought there might be interesting artifacts."
Zitzler said she thinks it would be interesting to dig a few tests pits around the site of the anomaly the students found, or expand the search to a wider area. But in her eyes, the most interesting part of the crash is perhaps not the elusive grave, but the social disturbance it caused in its immediate aftermath.
The circus was stranded in Tyrone for a week while the train cars were being fixed at the nearby railroad shop in Altoona. (Despite the horrible accident, the show did go on.) The Industrial Revolution was a period of not only technological transformation, but also heavy immigration, and the circus performers — many of them likely Europeans — may have raised suspicions among the people of Tyrone.
"I like to think of the circus performers in sequins and tights walking down the unpaved main street of Tyrone — and the townspeople looking and closing their doors," Zitzler said.
Read more at Discovery News
The tigers, lions, horses, crocodiles, pythons and a gorilla known as the "Man-Slayer" followed as the Walter L. Main circus train careened off the tracks down a 30-foot-high (10 meters) embankment, with gold-gilt, steel-barred wagons crashing one on top of the other in the legendary pileup at Tyrone, a small town in central Pennsylvania, on Memorial Day 1893.
Today, the story has become ingrained in town lore. Big snakes are eyed with suspicion as possible descendants of escaped crash survivors. Elephants from other traveling circuses have stopped in Tyrone to lay wreaths out of respect for the dead. Bones, horseshoes, lion-cage locks and railroad spikes have turned up every time a new home is built on the site. But the exact location of the mass grave of dead circus animals has been lost to history. Researchers recently made an attempt to find it.
An initial search didn't turn up the hoard of bones researchers were looking for, but the team hopes further investigations will shed light on the crash.
"It was a little bit disappointing, but now we know where it isn't," local historian Paula Zitzler said.
Zitzler, who teaches at Penn State Altoona and wrote a book on the train crash, recently worked with a group of graduate students from Indiana University of Pennsylvania to probe a stretch of land near the accident site.
Using ground-penetrating radar, the students scanned 12,450 square meters (about 3 acres) of private property. The team said they found an intriguing anomaly with a lower metal content than the surrounding soil, but bad weather kept them from digging large test pits. They did pull a few cores of dirt out of the ground, but these samples were inconclusive.
The students — Michelle Cole, Daniel Sandrowicz, Katharine Craig, Kate Adam and Kirk Smith — presented the results of their investigation, which was part of a class project, last weekend at the annual meeting of the Society for American Archaeology in Austin, Texas.
Runaway trains and runaway tigers
If archaeologists eventually uncover the grave, it's not clear exactly what they'll find. While researching the accident, Zitzler said it was difficult to get a full inventory on the casualties.
The train was traveling west down a slope of the Allegheny Front, approaching a bend that was notorious for crashes, Zitzler said. While 17-car coal trains could manage the steep mountainside with just one locomotive, many of the 17 cars on the Walter L. Main circus train were twice as long as the average coal car. The engineers wired ahead to request more braking power but were denied. As they guided the train down the slope, it quickly picked up speed and couldn't be stopped. The locomotive at the front made it around the curve, but the cars behind it flew off the tracks near a farm owned by a man named Hiram Friday.
Remarkably, only five people were killed. The train essentially piled up to the level of the tracks, Zitzler said, and the last few cars, where most of the circus performers rode, didn't go off the rails.
The animals, mostly at the front of the train, bore the brunt of the suffering. Two "sacred cows" and at least 50 horses were killed. (The traveling circus was known for its horse acts, such as chariot races and juggling shows performed on the animals' backs.) The elephants survived, albeit with some injuries, and the sturdy beasts were even put to work in the accident cleanup. The Man-Slayer lived through the accident, too; Zitzler said there are photos of the unhappy gorilla tied to a tree after the accident.
Other animals survived the crash only to be killed after they bolted from their broken cages. In the most famous incident, Hiram Friday's daughter Hannah was milking a cow a few days after the wreck when a Bengal tiger attacked and killed the cow. Friday was injured while fighting in the Civil War and forbid guns in his home, said his great-granddaughter Susie O'Brien, who lives on the property today. A bear hunter had to be called in to find the tiger in the nearby woods and shoot it. The beast's skull hangs in a local hunting club today.
Still more escapees may have evaded capture altogether. In the months and years after the accident, the local papers were peppered with reports of exotic animal sightings. In the nearby town of Warriors Mark, people on their way to church one Sunday morning reportedly saw three kangaroos hopping across the street. Men who went out fishing would say they saw strange birds, likely parrots, that made the treetops look as if they were dabbed with colorful paint, Zitzler said. A year after the accident, on Ascension Thursday (celebrated by some as the day Jesus ascended into heaven), revelers at a barn-raising at the Friday farm reportedly left before dark out of fear the circus animals were still lurking on the property.
The show must go on
While the lore lingered for decades, the wreckage from the accident was cleared in just three days. Amid the swift cleanup, the dead animals were buried in trenches on the Friday farm along with other wreckage too mangled to be reused. But there is no documentation of the mass grave's exact location.
O'Brien, who has been giving presentations about the wreck since 1993, has amassed a collection of artifacts found on her property and the nearby plots owned by her relatives, including bone bits, horseshoes and even an antique donkey-shaped bottle opener, perhaps from the dining car. Her goal has always been to conduct a study — perhaps a dig —at the site.
"I'm just curious to see what survived," O'Brien told Live Science. "I thought there might be interesting artifacts."
Zitzler said she thinks it would be interesting to dig a few tests pits around the site of the anomaly the students found, or expand the search to a wider area. But in her eyes, the most interesting part of the crash is perhaps not the elusive grave, but the social disturbance it caused in its immediate aftermath.
The circus was stranded in Tyrone for a week while the train cars were being fixed at the nearby railroad shop in Altoona. (Despite the horrible accident, the show did go on.) The Industrial Revolution was a period of not only technological transformation, but also heavy immigration, and the circus performers — many of them likely Europeans — may have raised suspicions among the people of Tyrone.
"I like to think of the circus performers in sequins and tights walking down the unpaved main street of Tyrone — and the townspeople looking and closing their doors," Zitzler said.
Read more at Discovery News
How the Ancient Egyptians Really Built the Pyramids
The ancient Egyptians who built the pyramids may have been able to move massive stone blocks across the desert by wetting the sand in front of a contraption built to pull the heavy objects, according to a new study.
Physicists at the University of Amsterdam investigated the forces needed to pull weighty objects on a giant sled over desert sand, and discovered that dampening the sand in front of the primitive device reduces friction on the sled, making it easier to operate. The findings help answer one of the most enduring historical mysteries: how the Egyptians were able to accomplish the seemingly impossible task of constructing the famous pyramids.
To make their discovery, the researchers picked up on clues from the ancient Egyptians themselves. A wall painting discovered in the ancient tomb of Djehutihotep, which dates back to about 1900 B.C., depicts 172 men hauling an immense statue using ropes attached to a sledge. In the drawing, a person can be seen standing on the front of the sledge, pouring water over the sand, said study lead author Daniel Bonn, a physics professor at the University of Amsterdam.
"Egyptologists thought it was a purely ceremonial act," Bonn told Live Science. "The question was: Why did they do it?"
Bonn and his colleagues constructed miniature sleds and experimented with pulling heavy objects through trays of sand.
When the researchers dragged the sleds over dry sand, they noticed clumps would build up in front of the contraptions, requiring more force to pull them across.
Adding water to the sand, however, increased its stiffness, and the sleds were able to glide more easily across the surface. This is because droplets of water create bridges between the grains of sand, which helps them stick together, the scientists said. It is also the same reason why using wet sand to build a sandcastle is easier than using dry sand, Bonn said.
But, there is a delicate balance, the researchers found.
"If you use dry sand, it won't work as well, but if the sand is too wet, it won't work either," Bonn said. "There's an optimum stiffness."
The amount of water necessary depends on the type of sand, he added, but typically the optimal amount falls between 2 percent and 5 percent of the volume of sand.
Read more at Discovery News
Physicists at the University of Amsterdam investigated the forces needed to pull weighty objects on a giant sled over desert sand, and discovered that dampening the sand in front of the primitive device reduces friction on the sled, making it easier to operate. The findings help answer one of the most enduring historical mysteries: how the Egyptians were able to accomplish the seemingly impossible task of constructing the famous pyramids.
To make their discovery, the researchers picked up on clues from the ancient Egyptians themselves. A wall painting discovered in the ancient tomb of Djehutihotep, which dates back to about 1900 B.C., depicts 172 men hauling an immense statue using ropes attached to a sledge. In the drawing, a person can be seen standing on the front of the sledge, pouring water over the sand, said study lead author Daniel Bonn, a physics professor at the University of Amsterdam.
"Egyptologists thought it was a purely ceremonial act," Bonn told Live Science. "The question was: Why did they do it?"
Bonn and his colleagues constructed miniature sleds and experimented with pulling heavy objects through trays of sand.
When the researchers dragged the sleds over dry sand, they noticed clumps would build up in front of the contraptions, requiring more force to pull them across.
Adding water to the sand, however, increased its stiffness, and the sleds were able to glide more easily across the surface. This is because droplets of water create bridges between the grains of sand, which helps them stick together, the scientists said. It is also the same reason why using wet sand to build a sandcastle is easier than using dry sand, Bonn said.
But, there is a delicate balance, the researchers found.
"If you use dry sand, it won't work as well, but if the sand is too wet, it won't work either," Bonn said. "There's an optimum stiffness."
The amount of water necessary depends on the type of sand, he added, but typically the optimal amount falls between 2 percent and 5 percent of the volume of sand.
Read more at Discovery News
Finding ET May Be Harder Than Thought
Hopes of finding evidence of life on far off alien worlds by studying their atmospheric chemistry have been dashed by a new study that concludes it's almost impossible.
The research, reported in the Proceedings of the National Academy of Sciences, found atmospheric spectral readings from distant exoplanets will never be good enough to be useful in the search for life.
The findings support an underlying view among astronomers that it was always going to be difficult to take the spectrum of an Earth like exoplanet, according to the study's lead author Hanno Rein of the University of Toronto.
"I was a bit pessimistic when I calculated these numbers for the first time, they were not what I was expecting," said Rein. "We're not going to get any useful spectra at all."
Astronomers determine the chemical composition of a gas, by looking for specific signatures in light from a star shining through the atmosphere of a planet passing in front of it. The strongest indicators of life on another planet would be chemical signatures for molecules of methane and oxygen in that planet's atmosphere.
"We think these two molecules are likely to be produced by life on Earth and also on other planets," said Rein. "There are few geological mechanisms which produce molecules of methane and oxygen in large quantities. To be really sure, we want both molecules together at the same time, then we can be more certain that there's life on that planet."
Too far away
However, most of the exoplanets being found by astronomers are too far away to provide useful spectra.
"The spectral resolution is so low, that we can hardly say anything about them," said Rein. "It's a fundamental physical limit, even if we had perfect technology that measures every single photon we receive from an exoplanet, there's just not enough photons reaching us to say whether there's life on the planet or not."
The problem would be even worse if the exoplanet was orbited by a moon.
"From a long way away an exoplanet and moon system would appear so close together that they couldn't be separately resolved, and would look like a single atmosphere to us," said Rein. "If one had oxygen and the other had methane, it would suggest an oxygen-methane atmosphere, providing a false positive for signs of life when none exists."
Astronomers have successfully collected spectra from distant exoplanets, but these were hot Jupiters, gas giants very close to their host stars, nothing that looks similar to the Earth.
"Earth is much smaller than a gas giant, so the combination of finding an Earth-sized planet, in the habitable zone, and then taking its spectra, is just very hard," said Rein.
On the positive side, Rein believes looking for the right objects would allow good atmospheric spectra to be taken.
Read more at Discovery News
The research, reported in the Proceedings of the National Academy of Sciences, found atmospheric spectral readings from distant exoplanets will never be good enough to be useful in the search for life.
The findings support an underlying view among astronomers that it was always going to be difficult to take the spectrum of an Earth like exoplanet, according to the study's lead author Hanno Rein of the University of Toronto.
"I was a bit pessimistic when I calculated these numbers for the first time, they were not what I was expecting," said Rein. "We're not going to get any useful spectra at all."
Astronomers determine the chemical composition of a gas, by looking for specific signatures in light from a star shining through the atmosphere of a planet passing in front of it. The strongest indicators of life on another planet would be chemical signatures for molecules of methane and oxygen in that planet's atmosphere.
"We think these two molecules are likely to be produced by life on Earth and also on other planets," said Rein. "There are few geological mechanisms which produce molecules of methane and oxygen in large quantities. To be really sure, we want both molecules together at the same time, then we can be more certain that there's life on that planet."
Too far away
However, most of the exoplanets being found by astronomers are too far away to provide useful spectra.
"The spectral resolution is so low, that we can hardly say anything about them," said Rein. "It's a fundamental physical limit, even if we had perfect technology that measures every single photon we receive from an exoplanet, there's just not enough photons reaching us to say whether there's life on the planet or not."
The problem would be even worse if the exoplanet was orbited by a moon.
"From a long way away an exoplanet and moon system would appear so close together that they couldn't be separately resolved, and would look like a single atmosphere to us," said Rein. "If one had oxygen and the other had methane, it would suggest an oxygen-methane atmosphere, providing a false positive for signs of life when none exists."
Astronomers have successfully collected spectra from distant exoplanets, but these were hot Jupiters, gas giants very close to their host stars, nothing that looks similar to the Earth.
"Earth is much smaller than a gas giant, so the combination of finding an Earth-sized planet, in the habitable zone, and then taking its spectra, is just very hard," said Rein.
On the positive side, Rein believes looking for the right objects would allow good atmospheric spectra to be taken.
Read more at Discovery News
This Marsupial Has Marathon Sex Until It Goes Blind and Drops Dead
When antechinus makes eyes, run. Something terrible is about to happen around you. |
Males relentlessly bound from partner to partner, as massive hormone releases in their bodies cause their immune systems to crash and their fur to fall out. They bleed internally. Some males even go blind, yet still stumble around the leaf litter hoping for one last tryst. In a few short weeks, every single male lies dead, leaving the females to raise their offspring. And so it seems that in perpetually dangerous Australia, even the sex can kill you.
For these three weeks of sexual kamikaze, antechinus males are concerned with nothing–absolutely nothing–other than mating with as many females as they possibly can. Ecologist Andrew Baker of Australia’s Queensland University of Technology, who studies these critters’ astonishing habits, has even picked up a copulating pair, who ignored him entirely and went about their business in his hands. “It’s pretty frenzied,” said Baker. “There’s no courtship or anything like that. The males basically just grab the females and go for it.”
Driving males to such feats are astronomical levels of testosterone. Think of an MMA fight wrapped in an Insane Clown Posse concert wrapped in the Insane Clown Posse playing during an MMA fight. While the hormone mobilizes all the sugars in the antechinus’ body so it doesn’t need to feed for the three-week orgy, it also glitches the mechanism responsible for regulating the production of cortisol, a stress hormone that in small amounts results in bursts of energy and higher pain tolerances.
With runaway levels of cortisol, though, the males’ bodies literally begin to fall apart. Bone density plummets and blood-sugar levels go nuts. Their immune systems essentially degrade to worthlessness, as open sores form and never heal. Of course, females are also quite stressed during all of this, but they don’t produce anywhere near the same levels of testosterone, so their cortisol regulation remains normal.
The whole affair is one of nature’s most striking manifestations of the true meaning of life: At a very basic level, all critters, including you and me, are on this planet to pass along their genes, even if it means an early demise. Antechinus males, after all, were only born after the previous year’s mating season. Not a single one reaches 12 months old, while females live up to three years.
And while it may not seem like anything other than strange hedonism, the males, with their mass suicide, in a way help guarantee the success of the offspring they’ll never get to enlighten with what would have been a truly epic sex talk. (You see, son, when a man loves a woman very much, it’s not long before he goes blind and dies.)
“It’s all geared toward the young being born when spring starts,” said Baker, “so there will be a big flush of insects in spring. The female will give birth to the young and then she’ll have plenty of food available because the population has been halved, because all the males are dead.”
In the eight to 12 weeks leading up to the mating season, though, males are taking more than their fair share of food, scurrying around frantically and hoovering up insects. “They’re spending all of their time building up food and fat stores,” said Baker, “because they know they’re going to need it across that intensive mating block.”
Plus, the more weight you pack on, the more energy you can devote to producing sperm, which males store in enormous quantities before the mating season begins. Bigger males will also beat out smaller ones for the right to mate–Baker has found individuals that are twice the weight of others (MMA enthusiasts, obviously).
Well, sure, she’s carrying sperm from smaller, less fit males. But larger males produce more sperm, boosting the chance that theirs will win out in the fertilization game. And obviously, with that many partners the competition is fierce. Indeed, a single brood will consist of young from several different fathers.
She’ll actually give birth to up to three times as many young as she has teats. This, too, is where good genes from their fathers benefit the diminutive, barely developed young. “They haven’t got much going for them except for a really strong mouth and sucking mechanism and some little hands and arms to crawl their way up,” said Baker. “They’ll crawl up and attach to a teat and then once all the teats are occupied all the other extras that were born will die within an hour or two.”
As a marsupial, antechinus gives birth to highly underdeveloped jelly beans. |
And the female must feed ravenously, for milk production in marsupials is extremely energy-intensive. In placentals, most of the energy in rearing young is spent in utero, as you mothers out there can attest (that’s not to say that significant energy isn’t eventually spent on the uniquely human duties of keeping kids from tumbling down stairs and eating crayons). “But marsupials are born small and immature,” said Baker, “and most of the energy is driven toward milk production. So when she’s producing milk for the growing young, it’s an incredible imposition on her energetics.”
Read more at Wired Science
May 1, 2014
First ever gravitationally lensed Type Ia supernovae discovered
Two teams of astronomers using the NASA/ESA Hubble Space Telescope have discovered three distant exploding stars that have been magnified by the immense gravity of foreground galaxy clusters, which act like "cosmic lenses." These supernovae are the first of their type ever to be observed magnified in this way and they offer astronomers a powerful tool to check the prescription of these massive lenses.
Massive clusters of galaxies act as "gravitational lenses" because their powerful gravity bends light passing through them [1]. This lensing phenomenon makes faraway objects behind the clusters appear bigger and brighter -- objects that might otherwise be too faint to see, even with the largest telescopes.
The new findings are the first steps towards the most precise prescription -- or map -- ever made for such a lens. How much a gravitationally lensed object is magnified depends on the amount of matter in a cluster -- including dark matter, which we cannot see directly [2]. Astronomers develop maps that estimate the location and amount of dark matter lurking in a cluster. These maps are the lens prescriptions of a galaxy cluster and predict how distant objects behind a cluster will be magnified when their light passes through it. But how do astronomers know this prescription is accurate?
Now, two independent teams of astronomers from the Supernova Cosmology Project and the Cluster Lensing And Supernova survey with Hubble (CLASH) have found a new method to check the prescription of a gravitational lens. They analysed three supernovae -- nicknamed Tiberius, Didius and Caracalla -- which were each lensed by a different massive galaxy cluster -- Abell 383, RXJ1532.9+3021 and MACS J1720.2+3536, respectively. Luckily, two and possibly all three of these supernovae appeared to be a special type of exploding star that can be used as a standard candle [3].
"Here, for the first time, we have found Type Ia supernovae that can be used like an eye chart for each lensing cluster," explained Saurabh Jha of Rutgers University, USA, a member of the CLASH team. "Because we can estimate the intrinsic brightness of the Type Ia supernovae, we can independently measure the magnification of the lens, which is not possible with other background sources."
The teams measured the brightnesses of the lensed supernovae and compared them to the explosion's intrinsic brightness to calculate how much brighter the exploding stars' were made due to gravitational lensing. One supernova in particular stood out, appearing to be about twice as bright as would have been expected if not for the cluster's magnification power.
The three supernovae were discovered in the CLASH survey, which used Hubble to probe the distribution of dark matter in 25 galaxy clusters. Two of the supernovae were found in 2012; the other in 2010 to 2011.
To perform their analyses, both teams used Hubble observations alongside observations from both space and ground-based telescopes to provide independent estimates of the distances to these exploding stars [4].
In some cases the observations allowed direct confirmation of a Type Ia pedigree. In other cases the supernova spectrum was weak or overwhelmed by the light of its parent galaxy. In those cases the brightening and fading behaviour of the supernovae in different colours was used to help establish the supernova type.
Each team compared its results with independent theoretical models of the clusters' dark matter content. They each came to the same conclusions: that the predictions fit the models.
"It is encouraging that the two independent studies reach quite similar conclusions," explained Supernova Cosmology Project team member Jakob Nordin of the E.O. Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley. "These pilot studies provide very good guidelines for making future observations of lensed supernovae even more accurate." Nordin is the lead author on the team's science paper describing the findings.
The Supernova Cosmology Project's galaxy cluster models were created by team members Johan Richard of the University of Lyon in France, and Jean-Paul Kneib of Ecole Polytechnique Federale de Lausanne in Switzerland. "It's really great to see that these supernovae are behaving in the way we expected," says Kneib. "The more confirmation we get that our complex cluster models are correct, the more we can rely on them, and use them to probe the early Universe."
Read more at Science Daily
Massive clusters of galaxies act as "gravitational lenses" because their powerful gravity bends light passing through them [1]. This lensing phenomenon makes faraway objects behind the clusters appear bigger and brighter -- objects that might otherwise be too faint to see, even with the largest telescopes.
The new findings are the first steps towards the most precise prescription -- or map -- ever made for such a lens. How much a gravitationally lensed object is magnified depends on the amount of matter in a cluster -- including dark matter, which we cannot see directly [2]. Astronomers develop maps that estimate the location and amount of dark matter lurking in a cluster. These maps are the lens prescriptions of a galaxy cluster and predict how distant objects behind a cluster will be magnified when their light passes through it. But how do astronomers know this prescription is accurate?
Now, two independent teams of astronomers from the Supernova Cosmology Project and the Cluster Lensing And Supernova survey with Hubble (CLASH) have found a new method to check the prescription of a gravitational lens. They analysed three supernovae -- nicknamed Tiberius, Didius and Caracalla -- which were each lensed by a different massive galaxy cluster -- Abell 383, RXJ1532.9+3021 and MACS J1720.2+3536, respectively. Luckily, two and possibly all three of these supernovae appeared to be a special type of exploding star that can be used as a standard candle [3].
"Here, for the first time, we have found Type Ia supernovae that can be used like an eye chart for each lensing cluster," explained Saurabh Jha of Rutgers University, USA, a member of the CLASH team. "Because we can estimate the intrinsic brightness of the Type Ia supernovae, we can independently measure the magnification of the lens, which is not possible with other background sources."
The teams measured the brightnesses of the lensed supernovae and compared them to the explosion's intrinsic brightness to calculate how much brighter the exploding stars' were made due to gravitational lensing. One supernova in particular stood out, appearing to be about twice as bright as would have been expected if not for the cluster's magnification power.
The three supernovae were discovered in the CLASH survey, which used Hubble to probe the distribution of dark matter in 25 galaxy clusters. Two of the supernovae were found in 2012; the other in 2010 to 2011.
To perform their analyses, both teams used Hubble observations alongside observations from both space and ground-based telescopes to provide independent estimates of the distances to these exploding stars [4].
In some cases the observations allowed direct confirmation of a Type Ia pedigree. In other cases the supernova spectrum was weak or overwhelmed by the light of its parent galaxy. In those cases the brightening and fading behaviour of the supernovae in different colours was used to help establish the supernova type.
Each team compared its results with independent theoretical models of the clusters' dark matter content. They each came to the same conclusions: that the predictions fit the models.
"It is encouraging that the two independent studies reach quite similar conclusions," explained Supernova Cosmology Project team member Jakob Nordin of the E.O. Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley. "These pilot studies provide very good guidelines for making future observations of lensed supernovae even more accurate." Nordin is the lead author on the team's science paper describing the findings.
The Supernova Cosmology Project's galaxy cluster models were created by team members Johan Richard of the University of Lyon in France, and Jean-Paul Kneib of Ecole Polytechnique Federale de Lausanne in Switzerland. "It's really great to see that these supernovae are behaving in the way we expected," says Kneib. "The more confirmation we get that our complex cluster models are correct, the more we can rely on them, and use them to probe the early Universe."
Read more at Science Daily
Early Image of Jesus Found in Egyptian Tomb
Spanish archaeologists have discovered what may be one of the earliest depictions of Jesus in an ancient Egyptian tomb.
Painted on the walls of a mysterious underground stone structure in the ancient Egyptian city of Oxyrhynchus, about 100 miles south of Cairo, the image shows a young man with curly hair and dressed in a short tunic.
“He raises his hand as if making a blessing,” said Egyptologist Josep Padró, who has spent over 20 years excavating sites in the area.
In this expedition, he led a team of archaeologists from the University of Barcelona, the Catalan Egyptology Society and the University of Montpellier.
“We could be dealing with a very early image of Jesus Christ,” Padró added.
Oxyrhynchus is known for the worship of the Egyptian god of the afterlife Osiris: indeed the underground structure was located in the middle of a processional route that joins the Nile with the Osireion, the temple dedicated to Osiris.
But the painting is from much later, dating from between the sixth and seventh century A.D.
To get to the underground chamber, Padró’s team removed over 45 tons of stones.
Finally, the archaeologists reached a rectangular crypt measuring about 26 feet long and 12 feet deep. They are unsure what the function of the structure was originally, but believe it might have possibly been another temple dedicated to Osiris.
Once inside, the archaeologists found five or six coats of paint on the walls, the last of which was from the Coptic period of the first Christians.
In addition to the image of the curly man, the walls feature symbols and images of plants and inscriptions written in the Coptic language, which are currently being translated.
Read more at Discovery News
Painted on the walls of a mysterious underground stone structure in the ancient Egyptian city of Oxyrhynchus, about 100 miles south of Cairo, the image shows a young man with curly hair and dressed in a short tunic.
“He raises his hand as if making a blessing,” said Egyptologist Josep Padró, who has spent over 20 years excavating sites in the area.
In this expedition, he led a team of archaeologists from the University of Barcelona, the Catalan Egyptology Society and the University of Montpellier.
“We could be dealing with a very early image of Jesus Christ,” Padró added.
Oxyrhynchus is known for the worship of the Egyptian god of the afterlife Osiris: indeed the underground structure was located in the middle of a processional route that joins the Nile with the Osireion, the temple dedicated to Osiris.
But the painting is from much later, dating from between the sixth and seventh century A.D.
To get to the underground chamber, Padró’s team removed over 45 tons of stones.
Finally, the archaeologists reached a rectangular crypt measuring about 26 feet long and 12 feet deep. They are unsure what the function of the structure was originally, but believe it might have possibly been another temple dedicated to Osiris.
Once inside, the archaeologists found five or six coats of paint on the walls, the last of which was from the Coptic period of the first Christians.
In addition to the image of the curly man, the walls feature symbols and images of plants and inscriptions written in the Coptic language, which are currently being translated.
Read more at Discovery News
Viral Video Claims to Prove 'Chemtrails' Conspiracy
For many years conspiracy theorists claimed the government conducts top secret chemical testing in the skies above us. As evidence they point to “chemtrails” — actually ordinary airplane contrails, or condensation trails — that, it’s claimed, have some sinister purpose.
In his conspiracy book “Above Top Secret,” Jim Marrs notes that “No one in a position of authority will admit that they exist, much less who is responsible, and what purpose they may serve. Unlike many mysteries, this one is visible to anyone who cares to look up on the days that large jets weave narrow and continuous vapor/chemical trails through the sky.”
It’s odd conspiracy theorists are so certain they exist but can’t even agree on what, exactly, they are or what they do. Some say it’s a sinister government mind-control experiment. Others say the trails are a form of weather control. Still others insist that experimental drugs are being tested on unsuspecting urban populations.
Hard evidence of the existence of these chemtrails has been elusive, but earlier this week a video surfaced that claims to provide proof. It shows a plane landing in a fog, with what are claimed to be jets of chemicals spewing from the wings.
According to the breathless description on one web site:
This is not the first time that someone has claimed to have found hard evidence of chemtrails. In “Above Top Secret,” Marrs offers this evidence:
However, David E. Thomas, a physicist writing in Skeptical Inquirer science magazine, took a closer look at the KSLA report. Thomas notes:
So the alarming levels of barium that conspiracy theorist Jim Marrs cited as evidence of chemtrails was in fact a mistake created by a TV reporter’s poor math skills.
What about the new video showing explosive proof of chemtrails? There are several problems with this theory — aside from the fact that no one has ever shown that chemtrails are real. First of all, it seems very unlikely that passenger airlines at commercial airports like the one seen in the video would be used in top-secret military experiments. Any passenger seated in a dozen or more window seats behind the airplane wings would have a clear view of any supposed “spraying” going on — which kind of defeats the purpose of having a super-secret conspiracy spraying plan no one can know about.
Secondly — despite claims to the contrary — the video does not show anything being sprayed from the wings; instead the “mysterious” trail is merely created by the air disruption as the plane’s wings flying through the fog.
Read more at Discovery News
In his conspiracy book “Above Top Secret,” Jim Marrs notes that “No one in a position of authority will admit that they exist, much less who is responsible, and what purpose they may serve. Unlike many mysteries, this one is visible to anyone who cares to look up on the days that large jets weave narrow and continuous vapor/chemical trails through the sky.”
It’s odd conspiracy theorists are so certain they exist but can’t even agree on what, exactly, they are or what they do. Some say it’s a sinister government mind-control experiment. Others say the trails are a form of weather control. Still others insist that experimental drugs are being tested on unsuspecting urban populations.
Hard evidence of the existence of these chemtrails has been elusive, but earlier this week a video surfaced that claims to provide proof. It shows a plane landing in a fog, with what are claimed to be jets of chemicals spewing from the wings.
According to the breathless description on one web site:
“A pilot of a commercial airliner made a mistake that irrefutably PROVES the existence of ‘CHEMTRAILS’—by forgetting to turn them off before he landed! We have video of the plane landing while still spraying CHEMTRAILS as it hits the runway. This is the first empirical evidence to back-up claims made (by) people, smeared as ‘conspiracy-theorists,’ who claimed airlines are being used by government to spray aerosols into the air without the knowledge or consent of the people being sprayed. With proof like this, the public now has legal standing to file lawsuits, utilize subpoenas and force discovery of evidence.”
This is not the first time that someone has claimed to have found hard evidence of chemtrails. In “Above Top Secret,” Marrs offers this evidence:
“One Louisiana TV station in late 2007 took upon itself the task of testing water captured under a crosshatch of aerial trails. According to investigative reporter Jeff Ferrell, ‘KSLA News 12 had the sample tested at a lab. The results: high level of barium, 6.8 parts per million, (ppm). That’s more than three times the toxic level set by the Environmental Protection Agency.’”
However, David E. Thomas, a physicist writing in Skeptical Inquirer science magazine, took a closer look at the KSLA report. Thomas notes:
“The actual video clearly shows 68.8 ug/L (micrograms per liter), or 68.8 ppb (parts per billion)…. 68.8 millionths of a gram per liter corresponds to 68.8 parts per billion, (and) the reporter was off by a factor of 100 because he read the ’68.8′ as ’6.8.’ Ferrell overestimated the amount of barium in the test report by a factor of 100…. The test result was not ‘three times the toxic level set by the EPA’; it was around thirty times less than the EPA’s toxic limit.”
So the alarming levels of barium that conspiracy theorist Jim Marrs cited as evidence of chemtrails was in fact a mistake created by a TV reporter’s poor math skills.
What about the new video showing explosive proof of chemtrails? There are several problems with this theory — aside from the fact that no one has ever shown that chemtrails are real. First of all, it seems very unlikely that passenger airlines at commercial airports like the one seen in the video would be used in top-secret military experiments. Any passenger seated in a dozen or more window seats behind the airplane wings would have a clear view of any supposed “spraying” going on — which kind of defeats the purpose of having a super-secret conspiracy spraying plan no one can know about.
Secondly — despite claims to the contrary — the video does not show anything being sprayed from the wings; instead the “mysterious” trail is merely created by the air disruption as the plane’s wings flying through the fog.
Read more at Discovery News
Magnetic Noose Knocks Magnetar Off-Kilter
Magnetars are the most magnetically-intense objects known in the Universe and now astrophysicists may have found one of these stellar husks being choked by a magnetic noose so much that its shape has been warped, causing it to wobble as it spins.
Spawned after a massive star goes supernova, magnetars are cousins of neutron stars (and, by extension, pulsars) — dense objects consisting primarily of degenerate neutron matter whose structure prevents itself from collapsing into a black hole. They are approximately 20 kilometers wide, yet more massive than our sun. This means that they have gargantuan densities — a thimbleful of magnetar material would have a mass of 100 million tons.
But density isn’t the only impressive thing about these objects. The magnetic field contained within the progenitor star is also squeezed into these tiny objects, taking our idea of magnetism to a whole new level.
Magnetic fields contained within these objects have been registered to a strength of 1011 Tesla, a billion times stronger than the strongest magnetic field that can be generated on Earth. However, it is thought there is an even stronger magnetic field wrapped as a torus — like a ring doughnut — around the magnetar’s equator that, until now, has been impossible to detect.
In new research published in the journal of Physical Review Letters, a magnetar called 4U 0142+61 has been studied by the Japanese Suzaku satellite, documenting the object’s rapid pulses of X-ray radiation. As the magnetar spins, strong beams of X-rays are generated at its poles. Like a lighthouse, these beams sweep past the Earth and are registered as pulses separated by 8.7 seconds.
Researchers led by Kazuo Makishima of the University of Tokyo noticed that the pulses from 4U 0142+61 were not consistent, however. Sometimes the pulses would appear early; at other times they’d appear late. Considering that pulses from “regular” pulsars are normally as precise as the most accurate atomic clocks on Earth, this particular magnetar is an oddity.
To explain this irregularity in X-ray pulses, the researchers think there is a very powerful toroidal magnetic field wrapped around the magnetar — measuring up to 1011 Tesla, a magnitude greater than the magnetar’s global magnetic field. The magnetar is therefore misshapen like a football oval, forcing the magnetar to wobble as it spins. The wobble has a period a fraction of the spin period, which would explain the strange X-ray pulse detection.
Read more at Discovery News
Spawned after a massive star goes supernova, magnetars are cousins of neutron stars (and, by extension, pulsars) — dense objects consisting primarily of degenerate neutron matter whose structure prevents itself from collapsing into a black hole. They are approximately 20 kilometers wide, yet more massive than our sun. This means that they have gargantuan densities — a thimbleful of magnetar material would have a mass of 100 million tons.
But density isn’t the only impressive thing about these objects. The magnetic field contained within the progenitor star is also squeezed into these tiny objects, taking our idea of magnetism to a whole new level.
Magnetic fields contained within these objects have been registered to a strength of 1011 Tesla, a billion times stronger than the strongest magnetic field that can be generated on Earth. However, it is thought there is an even stronger magnetic field wrapped as a torus — like a ring doughnut — around the magnetar’s equator that, until now, has been impossible to detect.
In new research published in the journal of Physical Review Letters, a magnetar called 4U 0142+61 has been studied by the Japanese Suzaku satellite, documenting the object’s rapid pulses of X-ray radiation. As the magnetar spins, strong beams of X-rays are generated at its poles. Like a lighthouse, these beams sweep past the Earth and are registered as pulses separated by 8.7 seconds.
Researchers led by Kazuo Makishima of the University of Tokyo noticed that the pulses from 4U 0142+61 were not consistent, however. Sometimes the pulses would appear early; at other times they’d appear late. Considering that pulses from “regular” pulsars are normally as precise as the most accurate atomic clocks on Earth, this particular magnetar is an oddity.
To explain this irregularity in X-ray pulses, the researchers think there is a very powerful toroidal magnetic field wrapped around the magnetar — measuring up to 1011 Tesla, a magnitude greater than the magnetar’s global magnetic field. The magnetar is therefore misshapen like a football oval, forcing the magnetar to wobble as it spins. The wobble has a period a fraction of the spin period, which would explain the strange X-ray pulse detection.
Read more at Discovery News
Apr 29, 2014
Albino Kingsnake Slithering Amok in Canary Islands
Animals in the Canary Islands are having a terrible time with a kind of snake that's common in the pet trade, the albino California kingsnake. Without a natural enemy to keep its population in check, the snake has been brutal on lizards, birds and mammals living on the islands.
Though the kingsnakes are of a species from California and bred in captivity, some of them found themselves in the Canary Islands as passengers in the pet trade and were able to escape their handlers. Once that jail break occurred, untold thousands of the pale slitherers -- which tend to be much larger than their in-the-wild counterparts -- have now bred and spread. The island of Gran Canaria in particular has enormous per-square-mile populations of the snake in certain areas.
Organized attempts to control the snakes with animals such as hawks and dogs have so far proven ineffective at culling the kingsnake's numbers. And, to make matters worse, snakes caught above ground are not at all representative of the number still on the loose, since the kingsnakes spend so much time unseen underground.
The once balanced ecosystem of the Canary Islands has been thrown into turmoil by the invasive reptile, which isn't too picky about what it will eat. Scientists on the scene worry that some native creatures, such as the gecko, may even be driven to extinction by the kingsnakes.
U.S. teams will visit the Canary Islands in May to help local officials and scientists deal with the snake invasion. The problem is so widespread there is even talk of Earth movers being used to essentially plow under the most snake-ridden areas.
From Discovery News
Though the kingsnakes are of a species from California and bred in captivity, some of them found themselves in the Canary Islands as passengers in the pet trade and were able to escape their handlers. Once that jail break occurred, untold thousands of the pale slitherers -- which tend to be much larger than their in-the-wild counterparts -- have now bred and spread. The island of Gran Canaria in particular has enormous per-square-mile populations of the snake in certain areas.
Organized attempts to control the snakes with animals such as hawks and dogs have so far proven ineffective at culling the kingsnake's numbers. And, to make matters worse, snakes caught above ground are not at all representative of the number still on the loose, since the kingsnakes spend so much time unseen underground.
The once balanced ecosystem of the Canary Islands has been thrown into turmoil by the invasive reptile, which isn't too picky about what it will eat. Scientists on the scene worry that some native creatures, such as the gecko, may even be driven to extinction by the kingsnakes.
U.S. teams will visit the Canary Islands in May to help local officials and scientists deal with the snake invasion. The problem is so widespread there is even talk of Earth movers being used to essentially plow under the most snake-ridden areas.
From Discovery News
Hippocrates' Legendary Tree 'Fingerprinted'
Some 2,400 years ago, Hippocrates, an ancient Greek scholar of medicine, sat down with his young pupils under the shade of a plane tree in Kos, Greece -- or so legend has it. Today, DNA researchers say they have identified the genetic fingerprint of that tree that served as one of medicine's earliest classrooms.
The original tree died hundreds of years ago, but in its place is a tree planted in 1776 that is thought to be a descendant of the original tree. Cuttings from this descendant have been presented as gifts to libraries, colleges and medical institutions around the world.
One of these cuttings was planted at the National Library of Medicine near Washington, D.C. and it's this specimen that was used by researchers at the Smithsonian's Laboratories of Analytical Biology to identify the famous tree's genetic fingerprint, or DNA barcode.
The effort was part of the Barcode of Life Project, which has banked the genetic blueprints of more than 200,000 species toward its goal of logging DNA barcodes from every species on Earth.
"I'm sure that Hippocrates would have been fascinated by the DNA Barcode Project and I think he would have been very excited about how DNA comparison and other modern methods are being used to better understand and ultimately treat human disease," Dr. David Lipman, director of the National Library of Medicine's National Center for Biotechnology Information, told BBC News.
Hippocrates was an ancient Greek physician and is considered the father of western medicine. He is credited with being the first to believe that diseases were caused naturally, not because of superstition and gods.
Read more at Discovery News
The original tree died hundreds of years ago, but in its place is a tree planted in 1776 that is thought to be a descendant of the original tree. Cuttings from this descendant have been presented as gifts to libraries, colleges and medical institutions around the world.
One of these cuttings was planted at the National Library of Medicine near Washington, D.C. and it's this specimen that was used by researchers at the Smithsonian's Laboratories of Analytical Biology to identify the famous tree's genetic fingerprint, or DNA barcode.
The effort was part of the Barcode of Life Project, which has banked the genetic blueprints of more than 200,000 species toward its goal of logging DNA barcodes from every species on Earth.
"I'm sure that Hippocrates would have been fascinated by the DNA Barcode Project and I think he would have been very excited about how DNA comparison and other modern methods are being used to better understand and ultimately treat human disease," Dr. David Lipman, director of the National Library of Medicine's National Center for Biotechnology Information, told BBC News.
Hippocrates was an ancient Greek physician and is considered the father of western medicine. He is credited with being the first to believe that diseases were caused naturally, not because of superstition and gods.
Read more at Discovery News
Ancient Caribou Hunting Site Found Beneath Lake Huron
An elaborate array of linear stone lanes and V-shaped structures has been discovered on an underwater ridge in Lake Huron, marking what is thought to be the most complex set of ancient hunting structures ever found beneath the Great Lakes, according to a new report.
Researchers based at the University of Michigan think the roughly 9,000-year-old-structure helped natives corral caribou herds migrating across what was then an exposed land-corridor — the so-called Alpena-Amberley Ridge — connecting northeast Michigan to southern Ontario. The area is now covered by 120 feet (347 meters) of water, but at the time, was exposed due to dry conditions of the last ice age.
Using underwater sonar and a remotely operated vehicle (ROV) equipped with a video camera, the researchers found two parallel lines of stones that create a 26-foot-wide (8 meters) and 98 foot-long (30 m) northwesterly-oriented lane that ends in a natural cul-de-sac. The team also found what appear to be V-shaped hunting blinds oriented to the southeast, and a rectangular area that may have been used as a meat cache, according to the researchers. The entire feature spans an area of about 92 feet by 330 feet (28 by 100 m), the team reports.
Scuba-trained members of the team investigated the site, and found 11 chipped stone flakes nearby the lanes, providing further evidence that the area was used as a hunting ground. The researchers think the flakes would have been used to repair and maintain stone tools.
Using a computer simulation, the team predicted where the caribou would have traveled during spring and autumn migrations, and identified two main choke points where the herds likely would have converged during both seasons. One of the two choke points fell directly within the newly discovered feature.
"The fact that all of the migrations tend to converge on these two locations ... would have provided predictability for ancient hunters, which is why we see so many structures located in these spots," study co-author John O'Shea, a researcher at the Museum of Anthropological Archaeology at the University of Michigan, told Live Science.
Autumn was the preferred season for caribou hunting, because the animals were at their fattest and their hides were of highest quality at that time of year. Even so, the distinct orientations of the lanes and V-shaped structures show that the hunters would have been able to intercept the animals in both the autumn — when the caribou traveled southeast for the winter — and the spring — when the herds traveled northwest back up to their breeding grounds. The setup and size of the structures also suggests the hunters used different strategies during the two seasons, with large groups of hunters likely working together in the spring, and smaller groups working independently in the autumn, the team reports.
"We were surprised by the apparent seasonal differences between the different kinds of structures," O'Shea said.
Read more at Discovery News
Researchers based at the University of Michigan think the roughly 9,000-year-old-structure helped natives corral caribou herds migrating across what was then an exposed land-corridor — the so-called Alpena-Amberley Ridge — connecting northeast Michigan to southern Ontario. The area is now covered by 120 feet (347 meters) of water, but at the time, was exposed due to dry conditions of the last ice age.
Using underwater sonar and a remotely operated vehicle (ROV) equipped with a video camera, the researchers found two parallel lines of stones that create a 26-foot-wide (8 meters) and 98 foot-long (30 m) northwesterly-oriented lane that ends in a natural cul-de-sac. The team also found what appear to be V-shaped hunting blinds oriented to the southeast, and a rectangular area that may have been used as a meat cache, according to the researchers. The entire feature spans an area of about 92 feet by 330 feet (28 by 100 m), the team reports.
Scuba-trained members of the team investigated the site, and found 11 chipped stone flakes nearby the lanes, providing further evidence that the area was used as a hunting ground. The researchers think the flakes would have been used to repair and maintain stone tools.
Using a computer simulation, the team predicted where the caribou would have traveled during spring and autumn migrations, and identified two main choke points where the herds likely would have converged during both seasons. One of the two choke points fell directly within the newly discovered feature.
"The fact that all of the migrations tend to converge on these two locations ... would have provided predictability for ancient hunters, which is why we see so many structures located in these spots," study co-author John O'Shea, a researcher at the Museum of Anthropological Archaeology at the University of Michigan, told Live Science.
Autumn was the preferred season for caribou hunting, because the animals were at their fattest and their hides were of highest quality at that time of year. Even so, the distinct orientations of the lanes and V-shaped structures show that the hunters would have been able to intercept the animals in both the autumn — when the caribou traveled southeast for the winter — and the spring — when the herds traveled northwest back up to their breeding grounds. The setup and size of the structures also suggests the hunters used different strategies during the two seasons, with large groups of hunters likely working together in the spring, and smaller groups working independently in the autumn, the team reports.
"We were surprised by the apparent seasonal differences between the different kinds of structures," O'Shea said.
Read more at Discovery News
Dark Matter Could Send Asteroids Crashing into Earth
Dark matter could sling lethal meteors at Earth, potentially causing mass extinctions like the cataclysm that ended the Age of Dinosaurs, Harvard scientists say.
Physicists think the mysterious, invisible substance called dark matter makes up five-sixths of all matter in the universe. It was first detected by the strength of its gravitational pull, which apparently helps keep the Milky Way and other galaxies from spinning apart, given the speeds at which they whirl.
Scientists have recently suggested that a thin, dense disk of dark matter about 35 light-years thick lies along the central plane of the Milky Way, cutting through the galaxy's disk of stars. The sun travels in an up-and-down, wavy motion through this plane while orbiting the center of the galaxy.
Researchers suggest this disk of clouds and clumps made of dark matter might disturb the orbits of comets in the outer solar system, hurling them inward. This could lead to catastrophic asteroid impacts on Earth, of the kind that likely ended the Age of Dinosaurs, said theoretical physicists Lisa Randall and Matthew Reece at Harvard University.
Past research has suggested meteor bombardment of Earth rises and falls in a cycle about 35 million years long. In the past, scientists have proposed a cosmic trigger for this cycle, such as a potential companion star for the sun with the dramatic name "Nemesis."
Instead of blaming a "death star" for these catastrophes, Randall and Reese point out that this cycle of doom closely matches the rate at which the sun passes through the central plane of the Milky Way. This hints that the galaxy's "dark disk" may be the actual culprit.
The researchers analyzed craters more than 12 miles (20 kilometers) wide created in the past 250 million years, and compared their pattern against the 35-million-year cycle. They found that it was three times more likely that the craters matched the dark matter cycle than that they occurred randomly.
This cycle might have killed off dinosaurs about 67 million years ago. "The cycle is slightly off for that mass extinction, but we have an incomplete data set regarding impact craters, so maybe with more information the cycle might fit what we know better," Randall told Space.com.
Although a three-to-one chance sounds impressive, the researchers cautioned that this statistical evidence is not overwhelming.
The scientists note that the European Space Agency's Gaia mission could reveal the existence or nonexistence of a dark matter disk. Launched in 2013, this mission will create a precise 3D map of stars throughout the Milky Way, potentially confirming or denying the existence of a dark disk that gravitationally influences stellar motions.
Read more at Discovery News
Physicists think the mysterious, invisible substance called dark matter makes up five-sixths of all matter in the universe. It was first detected by the strength of its gravitational pull, which apparently helps keep the Milky Way and other galaxies from spinning apart, given the speeds at which they whirl.
Scientists have recently suggested that a thin, dense disk of dark matter about 35 light-years thick lies along the central plane of the Milky Way, cutting through the galaxy's disk of stars. The sun travels in an up-and-down, wavy motion through this plane while orbiting the center of the galaxy.
Researchers suggest this disk of clouds and clumps made of dark matter might disturb the orbits of comets in the outer solar system, hurling them inward. This could lead to catastrophic asteroid impacts on Earth, of the kind that likely ended the Age of Dinosaurs, said theoretical physicists Lisa Randall and Matthew Reece at Harvard University.
Past research has suggested meteor bombardment of Earth rises and falls in a cycle about 35 million years long. In the past, scientists have proposed a cosmic trigger for this cycle, such as a potential companion star for the sun with the dramatic name "Nemesis."
Instead of blaming a "death star" for these catastrophes, Randall and Reese point out that this cycle of doom closely matches the rate at which the sun passes through the central plane of the Milky Way. This hints that the galaxy's "dark disk" may be the actual culprit.
The researchers analyzed craters more than 12 miles (20 kilometers) wide created in the past 250 million years, and compared their pattern against the 35-million-year cycle. They found that it was three times more likely that the craters matched the dark matter cycle than that they occurred randomly.
This cycle might have killed off dinosaurs about 67 million years ago. "The cycle is slightly off for that mass extinction, but we have an incomplete data set regarding impact craters, so maybe with more information the cycle might fit what we know better," Randall told Space.com.
Although a three-to-one chance sounds impressive, the researchers cautioned that this statistical evidence is not overwhelming.
The scientists note that the European Space Agency's Gaia mission could reveal the existence or nonexistence of a dark matter disk. Launched in 2013, this mission will create a precise 3D map of stars throughout the Milky Way, potentially confirming or denying the existence of a dark disk that gravitationally influences stellar motions.
Read more at Discovery News
Apr 28, 2014
Egyptologists identify tomb of royal children
Who had the privilege to spend eternal life next to the pharaoh? Close to the royal tombs in the Egyptian Valley of the Kings, excavations by Egyptologists from the University of Basel have identified the burial place of several children as well as other family members of two pharaohs.
Basel Egyptologists of the University of Basel Kings' Valley Project have been working on tomb KV 40 in the Valley of the Kings close to the city of Luxor for three years. From the outside, only a depression in the ground indicated the presence of a subterranean tomb. Up to now, nothing was known about the layout of tomb KV 40 nor for whom it was build and who was buried there.
The Egyptologists assumed that it was a non-royal tomb dating back to the 18th dynasty. They first cleared the six meter deep shaft which gives access to five subterranean chambers and then recovered the countless remains and fragments of funerary equipment.
Mummified royal children
The scientists discovered mummified remains of at least 50 people in the center chamber and in three side chambers. Based on inscriptions on storage jars, Egyptologists were able to identify and name over 30 people during this year's field season. Titles such as "Prince" and "Princess" distinguish the buried as members of the families of the two pharaohs Thutmosis IV and Amenhotep III who are also buried in the Valley of Kings. Both pharaohs belonged to the 18th dynasty (New Kingdom) and ruled in the 14th century BC.
The analysis of the hieratic inscriptions (related to hieroglyphics) revealed that tomb KV 40 contains the mummified remains of at least 8 hitherto unknown royal daughters, four princes and several foreign ladies. Most of them were adults, however, mummified children were also found: "We discovered a remarkable number of carefully mummified new-borns and infants that would have normally been buried much simpler," describes Egyptologist Prof. Susanne Bickel the findings. "We believe that the family members of the royal court were buried in this tomb for a period of several decades."
The identification of people buried in the proximity of the royal tombs gives the team of researchers important insight into who had the privilege to spend eternal life close to the pharaoh. "Roughly two thirds of the tombs in the Kings' Valley are non-royal. Because the tombs do not have inscriptions and have been heavily plundered we so far have only been able to speculate on who lies buried in them," explains Susanne Bickel in regard to the importance of the findings for the field of Egyptology.
Remains of later burials
Even though the tomb was looted several times in Antiquity as well as at the end of the 19th century, the researchers found countless fragments of funerary equipment, such as fragments of coffins and textiles. "The remains and the walls have been heavily affected by a fire that was most likely ignited by the torches of the tomb raiders," suspects Susanne Bickel. The fragments of various wooden and cartonnage coffins indicate that tomb KV 40 was used a second time as a burial ground: long after the abandonment of the valley as royal necropolis, members of priestly families of the 9th century BC were interred here.
Anthropological analyses as well as further examination on the burial goods will deliver important insight into the composition of the pharaonic court of the 18th dynasty as well as the conditions of life and the burial customs of its members.
Read more at Science Daily
Basel Egyptologists of the University of Basel Kings' Valley Project have been working on tomb KV 40 in the Valley of the Kings close to the city of Luxor for three years. From the outside, only a depression in the ground indicated the presence of a subterranean tomb. Up to now, nothing was known about the layout of tomb KV 40 nor for whom it was build and who was buried there.
The Egyptologists assumed that it was a non-royal tomb dating back to the 18th dynasty. They first cleared the six meter deep shaft which gives access to five subterranean chambers and then recovered the countless remains and fragments of funerary equipment.
Mummified royal children
The scientists discovered mummified remains of at least 50 people in the center chamber and in three side chambers. Based on inscriptions on storage jars, Egyptologists were able to identify and name over 30 people during this year's field season. Titles such as "Prince" and "Princess" distinguish the buried as members of the families of the two pharaohs Thutmosis IV and Amenhotep III who are also buried in the Valley of Kings. Both pharaohs belonged to the 18th dynasty (New Kingdom) and ruled in the 14th century BC.
The analysis of the hieratic inscriptions (related to hieroglyphics) revealed that tomb KV 40 contains the mummified remains of at least 8 hitherto unknown royal daughters, four princes and several foreign ladies. Most of them were adults, however, mummified children were also found: "We discovered a remarkable number of carefully mummified new-borns and infants that would have normally been buried much simpler," describes Egyptologist Prof. Susanne Bickel the findings. "We believe that the family members of the royal court were buried in this tomb for a period of several decades."
The identification of people buried in the proximity of the royal tombs gives the team of researchers important insight into who had the privilege to spend eternal life close to the pharaoh. "Roughly two thirds of the tombs in the Kings' Valley are non-royal. Because the tombs do not have inscriptions and have been heavily plundered we so far have only been able to speculate on who lies buried in them," explains Susanne Bickel in regard to the importance of the findings for the field of Egyptology.
Remains of later burials
Even though the tomb was looted several times in Antiquity as well as at the end of the 19th century, the researchers found countless fragments of funerary equipment, such as fragments of coffins and textiles. "The remains and the walls have been heavily affected by a fire that was most likely ignited by the torches of the tomb raiders," suspects Susanne Bickel. The fragments of various wooden and cartonnage coffins indicate that tomb KV 40 was used a second time as a burial ground: long after the abandonment of the valley as royal necropolis, members of priestly families of the 9th century BC were interred here.
Anthropological analyses as well as further examination on the burial goods will deliver important insight into the composition of the pharaonic court of the 18th dynasty as well as the conditions of life and the burial customs of its members.
Read more at Science Daily
Unique Crystals: Newfound Mineral Is Like No Other
A new purple-pink mineral that has a chemical composition and crystalline structure unlike any of the known 4,000 minerals has been discovered at a mining site in Western Australia, researchers report.
Now called putnisite, the mineral was discovered in a surface outcrop of Polar Bear Peninsula, Southern Lake Cowan, north of Norseman. While workers with a mining company were prospecting for nickel and gold, one of them noticed the bright-pink grains and sent the mineral to the Commonwealth Scientific and Industrial Research Organization (CSIRO), and then it was sent to Peter Elliott, a research associate with the South Australian Museum, for examination.
And, sure enough, the crystal was novel.
"A mineral is different from currently known minerals if it has either a different chemical composition or it has a different crystal structure, or sometimes both," Elliott told Live Science in an email. "Occasionally, a new mineral will have a chemistry that is very different to other minerals, or it will have a crystal structure that is very different to other minerals."
Elliott added, "Putnisite, a strontium calcium chromium sulfate carbonate, has both a unique chemical composition and a unique crystal structure." (The color of putnisite crystals ranges from pale to dark purple, with a pink streak, according to the researchers.)
Found on volcanic rock, the new mineral occurs as tiny crystals just 0.02 inches (0.5 millimeters) in diameter, and looks like spots of dark pink on dark-green-and-white rock; under a microscope, the mineral appears as cubelike crystals.
"When the rocks in the Lake Cowan area were deposited millions of years ago, they contained small concentrations of strontium calcium chromium and sulfur," Elliott said. "Over time, weathering released these elements and concentrated them, allowing putnisite to crystallize."
Though it is not uncommon to find a new mineral — 50 to 100 such specimens have been discovered in each of the past several years — they aren't usually discovered by miners, Elliott said.
Read more at Discovery News
Now called putnisite, the mineral was discovered in a surface outcrop of Polar Bear Peninsula, Southern Lake Cowan, north of Norseman. While workers with a mining company were prospecting for nickel and gold, one of them noticed the bright-pink grains and sent the mineral to the Commonwealth Scientific and Industrial Research Organization (CSIRO), and then it was sent to Peter Elliott, a research associate with the South Australian Museum, for examination.
And, sure enough, the crystal was novel.
"A mineral is different from currently known minerals if it has either a different chemical composition or it has a different crystal structure, or sometimes both," Elliott told Live Science in an email. "Occasionally, a new mineral will have a chemistry that is very different to other minerals, or it will have a crystal structure that is very different to other minerals."
Elliott added, "Putnisite, a strontium calcium chromium sulfate carbonate, has both a unique chemical composition and a unique crystal structure." (The color of putnisite crystals ranges from pale to dark purple, with a pink streak, according to the researchers.)
Found on volcanic rock, the new mineral occurs as tiny crystals just 0.02 inches (0.5 millimeters) in diameter, and looks like spots of dark pink on dark-green-and-white rock; under a microscope, the mineral appears as cubelike crystals.
"When the rocks in the Lake Cowan area were deposited millions of years ago, they contained small concentrations of strontium calcium chromium and sulfur," Elliott said. "Over time, weathering released these elements and concentrated them, allowing putnisite to crystallize."
Though it is not uncommon to find a new mineral — 50 to 100 such specimens have been discovered in each of the past several years — they aren't usually discovered by miners, Elliott said.
Read more at Discovery News
Bacteria Could Stop Dangerous Gas Leaks
Bacteria that live on methane and propane could be used to gobble up gas leaks before they contribute to global warming, according to a new study.
A bacterial strain (Methylocella silvestris) that grows on naturally occurring greenhouse gas leaks in the environment could also be used to target man-made leaks from fracking and oil spills, reports the study in today's Nature.
The bacterium is found in peat, tundra and forest soils in Northern Europe. It's also been found in the microbial environment around the Deepwater Horizon spill.
The microbe can grow on both methane and propane at a similar rate, said lead researcher Colin Murrell, an environmental sciences professor at the University of East Anglia in the U.K., in a statement.
"Molecule-for-molecule, the effect of methane on global warming is more than 20 times greater than carbon dioxide over a 100 year timeframe," Murrell said. "It is therefore very important that we understand how it can be removed biologically in the environment before it is released into the atmosphere."
From Discovery News
A bacterial strain (Methylocella silvestris) that grows on naturally occurring greenhouse gas leaks in the environment could also be used to target man-made leaks from fracking and oil spills, reports the study in today's Nature.
The bacterium is found in peat, tundra and forest soils in Northern Europe. It's also been found in the microbial environment around the Deepwater Horizon spill.
The microbe can grow on both methane and propane at a similar rate, said lead researcher Colin Murrell, an environmental sciences professor at the University of East Anglia in the U.K., in a statement.
"Molecule-for-molecule, the effect of methane on global warming is more than 20 times greater than carbon dioxide over a 100 year timeframe," Murrell said. "It is therefore very important that we understand how it can be removed biologically in the environment before it is released into the atmosphere."
From Discovery News
Space Clouds Glitter Where Stars Are Born
Like shiny gemstones embedded in a rocky matrix, star-forming clouds of dust and gas glimmer within the swirling structures of the galaxy in an infrared image from ESA’s Herschel Space Observatory.
The image was acquired as a part of Hi-GAL, a survey mapping the entire plane of the Milky Way in a wide range of infrared light that Herschel was specially designed to detect. The image above is just a small section of a larger version, which in itself is just 1/30th of the entire Hi-GAL survey. (Download a larger image here.)
Normally invisible to our eyes, vast filaments of gas and dust fill the plane of the galaxy where stars like our sun reside. As these cold clouds of interstellar material collapse, they get denser and denser until they eventually form stars, which then blaze with heat and light.
The energy from these newborn stars blasts out into nearby space, illuminating the shrouds of material they were born in as well as ionizing them with shockwaves of radiation.
These ionized “shock fronts” also release light in wavelengths corresponding to the elements within the clouds, and can also eventually lead to the formation of yet more stars — a continuous cycle of star birth on a galactic time scale.
From Discovery News
The image was acquired as a part of Hi-GAL, a survey mapping the entire plane of the Milky Way in a wide range of infrared light that Herschel was specially designed to detect. The image above is just a small section of a larger version, which in itself is just 1/30th of the entire Hi-GAL survey. (Download a larger image here.)
Normally invisible to our eyes, vast filaments of gas and dust fill the plane of the galaxy where stars like our sun reside. As these cold clouds of interstellar material collapse, they get denser and denser until they eventually form stars, which then blaze with heat and light.
The energy from these newborn stars blasts out into nearby space, illuminating the shrouds of material they were born in as well as ionizing them with shockwaves of radiation.
These ionized “shock fronts” also release light in wavelengths corresponding to the elements within the clouds, and can also eventually lead to the formation of yet more stars — a continuous cycle of star birth on a galactic time scale.
From Discovery News
Apr 27, 2014
Key regulator in pacemakers of our brain, heart discovered
Biologists have discovered how an outer shield over T-type channels change the electrochemical signaling of heart and brain cells. Understanding how these shields work will help researchers eventually develop a new class of drugs for treating epilepsy, cardiovascular disease and cancer.
The study from the University of Waterloo is published in the Journal of Biological Chemistry today and is featured as the "Paper of the Week" for its significance.
The researchers discovered T-type channels in the pond snail, Lymnaea stagnalis, can shift from using calcium ions to using sodium ions to generate the electrical signal because of an outer shield of amino acids called a turret situated above the channel's entrance.
Low voltage T-type channels generate tiny pulses of current at regular intervals by selectively passing positively charged cations across the cell's membrane through a gate-like channel. The channels are normally extremely selective, allowing just one sodium ion to pass for every 10,000 calcium ions.
The resulting rhythmic signals produced by this transfer of cations are what support the synchronous contraction of our heart muscles and neuronal firing in parts of the brain, like the thalamus, which helps regulate our sleep-wake cycle, or circadian rhythm.
In addition to their published findings, the researchers also found the shield-like turrets in pond snails restrict access of therapeutic drugs to the channel.
T-type channels in pond snails and other invertebrates are similar to those found in humans. Although pond snails reach only 7 cm in length, its simple neural network and physiology make it a popular model organism with neurobiologists.
Over-active T-type channels are linked to epilepsy, cardiac problems, neuropathic pain, as well as the spreading of several kinds of cancer. Drugs that could quench out-of-control T-type channel activity are unable to bind to the channels themselves.
Read more at Science Daily
The study from the University of Waterloo is published in the Journal of Biological Chemistry today and is featured as the "Paper of the Week" for its significance.
The researchers discovered T-type channels in the pond snail, Lymnaea stagnalis, can shift from using calcium ions to using sodium ions to generate the electrical signal because of an outer shield of amino acids called a turret situated above the channel's entrance.
Low voltage T-type channels generate tiny pulses of current at regular intervals by selectively passing positively charged cations across the cell's membrane through a gate-like channel. The channels are normally extremely selective, allowing just one sodium ion to pass for every 10,000 calcium ions.
The resulting rhythmic signals produced by this transfer of cations are what support the synchronous contraction of our heart muscles and neuronal firing in parts of the brain, like the thalamus, which helps regulate our sleep-wake cycle, or circadian rhythm.
In addition to their published findings, the researchers also found the shield-like turrets in pond snails restrict access of therapeutic drugs to the channel.
T-type channels in pond snails and other invertebrates are similar to those found in humans. Although pond snails reach only 7 cm in length, its simple neural network and physiology make it a popular model organism with neurobiologists.
Over-active T-type channels are linked to epilepsy, cardiac problems, neuropathic pain, as well as the spreading of several kinds of cancer. Drugs that could quench out-of-control T-type channel activity are unable to bind to the channels themselves.
Read more at Science Daily
Star is discovered to be a close neighbor of the Sun and the coldest of its kind
A "brown dwarf" star that appears to be the coldest of its kind -- as frosty as Earth's North Pole -- has been discovered by a Penn State University astronomer using NASA's Wide-field Infrared Survey Explorer (WISE) and Spitzer Space Telescopes. Images from the space telescopes also pinpointed the object's distance at 7.2 light-years away, making it the fourth closest system to our Sun.
"It is very exciting to discover a new neighbor of our solar system that is so close," said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State and a researcher in the Penn State Center for Exoplanets and Habitable Worlds. "In addition, its extreme temperature should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures."
Brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight. The newfound coldest brown dwarf, named WISE J085510.83-071442.5, has a chilly temperature between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius). Previous record holders for coldest brown dwarfs, also found by WISE and Spitzer, were about room temperature.
Although it is very close to our solar system, WISE J085510.83-071442.5 is not an appealing destination for human space travel in the distant future. "Any planets that might orbit it would be much too cold to support life as we know it" Luhman said.
"This object appeared to move really fast in the WISE data," said Luhman. "That told us it was something special." The closer a body, the more it appears to move in images taken months apart. Airplanes are a good example of this effect: a closer, low-flying plane will appear to fly overhead more rapidly than a high-flying one.
WISE was able to spot the rare object because it surveyed the entire sky twice in infrared light, observing some areas up to three times. Cool objects like brown dwarfs can be invisible when viewed by visible-light telescopes, but their thermal glow -- even if feeble -- stands out in infrared light.
After noticing the fast motion of WISE J085510.83-071442.5 in March, 2013, Luhman spent time analyzing additional images taken with Spitzer and the Gemini South telescope on Cerro Pachon in Chile. Spitzer's infrared observations helped to determine the frosty temperature of the brown dwarf.
WISE J085510.83-071442.5 is estimated to be 3 to 10 times the mass of Jupiter. With such a low mass, it could be a gas giant similar to Jupiter that was ejected from its star system. But scientists estimate it is probably a brown dwarf rather than a planet since brown dwarfs are known to be fairly common. If so, it is one of the least massive brown dwarfs known.
Combined detections from WISE and Spitzer, taken from different positions around the Sun, enabled the measurement of its distance through the parallax effect. This is the same principle that explains why your finger, when held out right in front of you, appears to jump from side to side when you alternate left-eye and right-eye views.
Read more at Science Daily
"It is very exciting to discover a new neighbor of our solar system that is so close," said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State and a researcher in the Penn State Center for Exoplanets and Habitable Worlds. "In addition, its extreme temperature should tell us a lot about the atmospheres of planets, which often have similarly cold temperatures."
Brown dwarfs start their lives like stars, as collapsing balls of gas, but they lack the mass to burn nuclear fuel and radiate starlight. The newfound coldest brown dwarf, named WISE J085510.83-071442.5, has a chilly temperature between minus 54 and 9 degrees Fahrenheit (minus 48 to minus 13 degrees Celsius). Previous record holders for coldest brown dwarfs, also found by WISE and Spitzer, were about room temperature.
Although it is very close to our solar system, WISE J085510.83-071442.5 is not an appealing destination for human space travel in the distant future. "Any planets that might orbit it would be much too cold to support life as we know it" Luhman said.
"This object appeared to move really fast in the WISE data," said Luhman. "That told us it was something special." The closer a body, the more it appears to move in images taken months apart. Airplanes are a good example of this effect: a closer, low-flying plane will appear to fly overhead more rapidly than a high-flying one.
WISE was able to spot the rare object because it surveyed the entire sky twice in infrared light, observing some areas up to three times. Cool objects like brown dwarfs can be invisible when viewed by visible-light telescopes, but their thermal glow -- even if feeble -- stands out in infrared light.
After noticing the fast motion of WISE J085510.83-071442.5 in March, 2013, Luhman spent time analyzing additional images taken with Spitzer and the Gemini South telescope on Cerro Pachon in Chile. Spitzer's infrared observations helped to determine the frosty temperature of the brown dwarf.
WISE J085510.83-071442.5 is estimated to be 3 to 10 times the mass of Jupiter. With such a low mass, it could be a gas giant similar to Jupiter that was ejected from its star system. But scientists estimate it is probably a brown dwarf rather than a planet since brown dwarfs are known to be fairly common. If so, it is one of the least massive brown dwarfs known.
Combined detections from WISE and Spitzer, taken from different positions around the Sun, enabled the measurement of its distance through the parallax effect. This is the same principle that explains why your finger, when held out right in front of you, appears to jump from side to side when you alternate left-eye and right-eye views.
Read more at Science Daily
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