Presently, there are about 40 million Americans over the age of 65, with the fastest-growing segment of the population over 80 years old. Traditionally, aging has been viewed as a period of progressive decline in physical, cognitive and psychosocial functioning, and aging is viewed by many as the "number one public health problem" facing Americans today.
But this negative view of aging contrasts with results of a comprehensive study of 1,006 older adults in San Diego by researchers from the University of California, San Diego School of Medicine and Stanford University. Results of the Successful Aging Evaluation (SAGE) study -- comprising a 25-minute phone interview, followed by a comprehensive mail-in survey -- will be published in the December 7 online issue of the American Journal of Psychiatry.
"While there is a growing public health interest in understanding and promoting successful aging, until now little published research has combined measures of physical health with cognitive and psychological assessments, in a large and randomly selected sample," said principal investigator Dilip V. Jeste, MD, Estelle and Edgar Levi Chair in Aging, Distinguished Professor of Psychiatry and Neurosciences, and director of UC San Diego's Stein Institute for Research on Aging, and the current President of the American Psychiatric Association (which was not involved in this study).
The SAGE study included adults between the ages of 50 and 99 years, with a mean age of just over 77 years. In addition to measures which assessed rates of chronic disease and disability, the survey looked at more subjective criteria such as social engagement and participants' self-assessment of their overall health.
"Sometimes the most relevant outcomes are from the perspective of the subjects themselves," said Jeste.
The study concludes that resilience and depression have significant bearing on how individuals self-rate successful aging, with effects that are comparable to that of physical health. "Even though older age was closely associated with worse physical and cognitive functioning, it was also related to better mental functioning," said co-author Colin Depp, PhD, associate professor of psychiatry at UC San Diego School of Medicine.
After adjusting for age, a higher self-rating of successful aging was associated with higher education, better cognitive function, better perceived physical and mental health, less depression, and greater optimism and resilience.
Participants were asked to rate the extent to which they thought they had "successfully aged," using a 10-point scale and using their own concept of the term. The study found that people with low physical functioning but high resilience, had self-ratings of successful aging similar to those of physical healthy people with low resilience. Likewise, the self-ratings of individuals with low physical functioning but no or minimal depression had scores comparable to those of physically healthy people with moderate to severe depression.
"It was clear to us that, even in the midst of physical or cognitive decline, individuals in our study reported feeling that their well-being had improved with age," Jeste said. This counterintuitive increase in well-being with aging persisted even after accounting for variables like income, education and marriage.
Jeste suggests there's a take-away message for clinicians, which is that an optimistic approach to the care of seniors may help reduce societal ageism. "There is considerable discussion In public forums about the financial drain on the society due to rising costs of healthcare for older adults -- what some people disparagingly label the 'silver tsunami.' But, successfully aging older adults can be a great resource for younger generations," he said.
Read more at Science Daily
Dec 7, 2012
A Magical Nighttime Journey Through a Fluorescent Reef
A coral reef is a world of kaleidoscopic shape and color. To see one at night, illuminated by its own fluorescence, is even more marvelous still.
This luminous parade was filmed off the coast of Egypt by Lynn Miner and Steffen Beyer, the founders of FireDiveGear, who custom-build photographic equipment for marine biologists and other undersea explorers.
Miner and Beyer dive in the blackness of night, with the only illumination coming from their own lights. These shine at a wavelength betwen 450 and 470 nanometers, a blue hue that is the only wavelength to penetrate below the sea’s upper waters.
In a sense, FireDiveGear’s lamps mimic sunlight as it’s experienced by life at those depths, only much, much brighter. With the right filters, it’s then possible to see what happens when light shines on reef dwellers. Their pigments become excited and emit photons, the phenomenon known as fluorescence.
“If you hit them with intense blue light, they shine back in purple, yellow, green, red, all the different colors,” explains Miner. “You don’t see those colors if you’re diving with a white light.”
As Al Dove on Deep Sea News describes, the biological function of fluorescence isn’t certain. Depending on the creature, it could have some purpose tied to the visual sensitivity of marine organisms to fluorescent light.
Deep-sea fluorescence could also be a fluke, a coincidental side-effect of other photochemical processes. All that’s certain is that fluorescence, what biologist Mikhail Matz of the University of Texas at Austin calls “the secret color of the deep,” is gorgeous.
“It’s an alternate universe. It’s abolutely a whole other world,” said Miner. “These stunningly beautiful creatures, the colors of these tropical fish — it’s hard to imagine. It’s hard to describe how beautiful they are, the brightness, the diversity.”
Like many divers, Miner is dismayed by the state of coral reefs in the early 21st century. Disease outbreaks, rising temperatures and human development threaten corals around the world.
Read more at Wired Science
How Maggots Heal Wounds
Maggots are efficient consumers of dead tissue. They munch on rotting flesh, leaving healthy tissue practically unscathed. Physicians in Napoleon’s army used the larvae to clean wounds. In World War I, American surgeon William Baer noticed that soldiers with maggot-infested gashes didn’t have the expected infection or swelling seen in other patients. The rise of penicillin in the 1940s made clinical maggots less useful, but they bounced back in the 1990s when antibiotic-resistant bacteria created a new demand for alternative treatments. In 2004, the U.S. Food and Drug Administration approved maggot therapy as a prescription treatment.
Although anecdotal reports suggested that maggots curb inflammation, no one had scientifically tested the idea. So a team led by surgical resident Gwendolyn Cazander of Leiden University Medical Center in the Netherlands siphoned samples of maggot secretions from disinfected maggots in the lab and added them to donated blood samples from four healthy adults. The researchers then measured the levels of so-called complement proteins, which are involved in the body’s inflammatory response.
Every blood sample treated with maggot secretions showed lower levels of complement proteins than did control samples—99.9% less in the best case, the team reports in the current issue of Wound Repair and Regeneration. Looking closer, the researchers found the broken-down remnants of two complement proteins—C3 and C4—in the secretion-treated samples, suggesting that the secretions had ripped the proteins apart. When the team tested blood samples from postoperative patients, whose wounded bodies were already scrambling to heal, they found that maggot secretions reduced the levels of complement proteins by 19% to 55%.
For good measure, the team tested the maggot secretions again after a day, a week, and a month to determine their shelf life. They also boiled some. To their surprise, the secretions were more effective after boiling and lost no potency after sitting on the shelf for a month.
It’s not surprising that maggot secretions would suppress the immune system, Cazander says. Otherwise, the larvae would probably be attacked by the body. She says she hasn’t yet seen such a reaction, even in patients treated with maggots for more than a year.
Cazander’s team is now working to isolate the complement-inhibiting compounds. A clinical drug featuring maggot secretions may be several years away—but if you can’t wait, the maggots themselves are available now.
Read more at Wired Science
Solving the Mystery of River Formation
When rain hits a tilted surface, like the side of a mountain or a hill, it tends to flow toward existing depressions. The flow of water erodes the rock or soil, widening and deepening the depressions. Called incision, the process is competitive and even somewhat cannibalistic. As individual rills grow from incision, they capture smaller neighbors, forming tributaries. One would expect incision to spread indefinitely if unchecked, but a process called soil creep smoothes over the land, filling up the cracks with a slow, yet steady, drift of soil.
Scientists have known for more than 100 years that these processes shape rivers, but they hadn’t been able to quantify their relative importance, or figure out how they work together to create river basins that are finely branched in some landscapes but not others, says Taylor Perron, a geomorphologist at the Massachusetts Institute of Technology in Cambridge and lead author of the new study. “We saw the form, but didn’t understand the mechanism that leads to the development of this branching shape.”
Look outside after a heavy rain and you may find a miniature Grand Canyon in your backyard, complete with a complex network of tributaries. The precise conditions that cause rivers of all sizes to form branches have long been a mystery; now, a new study pinpoints two opposing physical forces that work together to produce the intricate patterns. The discovery could help scientists better understand rivers at all scales and even on other worlds; for example, the icebound methane rivers on Titan, one of Saturn’s moons.
When rain hits a tilted surface, like the side of a mountain or a hill, it tends to flow toward existing depressions. The flow of water erodes the rock or soil, widening and deepening the depressions. Called incision, the process is competitive and even somewhat cannibalistic. As individual rills grow from incision, they capture smaller neighbors, forming tributaries. One would expect incision to spread indefinitely if unchecked, but a process called soil creep smoothes over the land, filling up the cracks with a slow, yet steady, drift of soil.
Scientists have known for more than 100 years that these processes shape rivers, but they hadn’t been able to quantify their relative importance, or figure out how they work together to create river basins that are finely branched in some landscapes but not others, says Taylor Perron, a geomorphologist at the Massachusetts Institute of Technology in Cambridge and lead author of the new study. “We saw the form, but didn’t understand the mechanism that leads to the development of this branching shape.”
Perron and colleagues guessed that a certain ratio between rates of incision and soil creep acts as a “tipping point” for the creation of river branches. Below that unknown value, they expected that no tributaries would form, and that above that value, rivers would begin to capture smaller rivers and form a network of tributaries. To test their hypothesis, they compared California’s Salinas Valley with the Allegheny Plateau in southwest Pennsylvania. While each 25 km2 region contains thousands of river basins, the rivers in California are four times as finely branched as those in Pennsylvania. Neither region is strongly influenced by the faults and folds of a tectonic boundary, Perron says, allowing the team to compare incision and soil creep without too much interference from other variables.
After mapping the river networks in each region, the team created a mathematical model that included equations for soil creep and incision in river channels surrounded by raised mountain ridges. They manipulated the model to see if it could produce the same branching patterns, and it soon identified a specific ratio between the forces of incision and soil creep that acted like a tipping point or switch. Beyond the tipping point—a dimensionless value between 250 and 300—incision overrides soil creep, Perron says. Watching the modeled rivers go beyond that tipping point in accelerated geologic time is like watching petals on a flower that’s opening, he says: “You watch these valleys bloom as they cannibalize their neighbors.” Below that critical value, a river will shrink back to the size of its neighbors and ultimately lose its tributaries.
The new mathematical principle, reported today in Nature, will allow scientists to better evaluate the underlying forces at work in a river system even if they can’t take on-the-ground measurements, Perron says. The intricate networks of tributaries in California’s Salinas Valley, for example, indicate that incision is winning out over soil creep, he says—a sign of the softer rock and higher levels of runoff in the region, compared with Pennsylvania’s older, harder rocks and higher infiltration of water into the soil. That kind of analysis could be applied to much more distant rivers, he says: even the rivers of methane on Titan, Saturn’s moon. It also raises interesting questions: In a landscape made of ice, he asks, “What’s the analog to soil creep?”
Read more at Wired Science
Dec 6, 2012
Cavemen Trump Modern Artists at Animal Drawing
A new analysis of 1,000 pieces of prehistoric and modern artwork finds that "cavemen," or people living during the upper Paleolithic period between 10,000 and 50,000 years ago, were more accurate in their depictions of four-legged animals walking than artists are today. While modern artists portray these animals walking incorrectly 57.9 percent of the time, prehistoric cave painters only made mistakes 46.2 percent of the time.
Modern artists are also worse at capturing the gait of horses and other quadrupeds than taxidermists, anatomy textbook writers and toy figurine designers, the researchers report today (Dec. 5) in the open-access journal PLOS ONE.
Four-legged gait
Four-legged animals walk by moving their legs in the same sequence. First, the left-hind foot hits the ground, then the left-front foot, followed by the right-hind foot and finally the right-front foot. Only the speed at which four-legged animals complete this sequence differs.
But this simple gait often escapes the notice of artists. In 2009, biological physicist Gabor Horvath, a researcher at Eotvos University in Hungary, found that 63.6 percent of the animals depicted in anatomy textbooks were drawn in impossible gaits. Half of toy horses, lions, tigers and other quadrupeds were also wrong. Even depictions in natural history museums failed much of the time: Just over 41 percent of those showed errors.
In the new study, Horvath and his colleagues wanted to look at the same question over the history of art. In the 1880s, photographer Eadweard Muybridge used motion pictures to show how horses and other quadrupeds really walked. This knowledge spread, so Horvath and his colleagues split their analysis into three time periods: prehistoric art, historical art made before Muybridge's work, and art made after 1887, when Muybridge's work would have been public.
Getting animals right
The researchers plucked 1,000 examples of art from online collections, fine art books and Hungarian museums, as well as on stamps and coins. Chance alone would dictate that artists mess up depictions of four-legged gait 73.3 percent of the time, the researchers calculated. But art produced after prehistory but before Muybridge showed more errors than chance would allow. In fact, 83.5 percent of depictions from this time period were wrong.
The erroneous drawings even included one sketch of a horse by Leonardo da Vinci, known for his anatomical sketches. In the sketch, the horse has its right-hind foot and left-front foot down with its other two feet lifted, an unstable position. In fact, four-legged animals keep three legs on the ground at any given time.
It's possible that the high level of pre-Muybridge errors may reflect artists mimicking their peers' un-anatomical work, the researchers wrote. But Paleolithic man seems to have been a keen observer of four-footed fauna. Cave art got its depictions right about 54 percent of the time, far better than chance.
Read more at Discovery News
Psychic Sued for Police Hoax About Massacre
The case began June 6, when a psychic using the name 'Angel' called police and described a horrific scene of mass murder: dozens of dismembered bodies near a ranch house about an hour outside of Houston, Texas. There were rotting limbs, headless corpses and, chillingly, children in a mass grave.
Deputies from the Liberty County Sheriff's office went to investigate but didn't see anything amiss. After a second call the following day, dozens of officials from the Texas Department of Public Safety, the FBI and the Texas Rangers were on the scene—not to mention cadaver dogs, news helicopters and gawkers.
It all turned out to be a false alarm. There were no dead bodies; the psychic was wrong (or lying).
Though the incident became a national embarrassment, the police refused to apologize, saying that procedures were followed and that the severity of the claims warranted an investigation. Whether a tip comes from an ordinary citizen, an anonymous informant or a self-proclaimed psychic, information about mass murders cannot be ignored.
The ranch owners, Joe Bankson and Gena Charlton, were not amused and filed a lawsuit earlier this year. However, according to Anna Merlan of The Dallas Observer
Angel, who'd called in the tip by phone, vanished into the ether, leaving the couple to sue the media outlets for defamation and the sheriff's office for unreasonable search and seizure. ... Now, court records show that the plaintiffs seem to have located and sued the woman they think is an Angel in disguise. Her name is Presley Gridley, she goes by "Rhonda," and she lives in Stanton, Texas, about 800 miles away from their farmhouse.
According to Merlan, a Liberty County blogger named Allen Youngblood did some detective work and discovered a call Gridley made to a nearby county Sheriff's Department in which she told police to investigate a rural Texas farmhouse in search of two missing children who were the subject of an Amber Alert.
Gridley told the call-taker that the children were actually "in bad shape" in a farmhouse in Hull, Texas, a small town near Hardin, being hidden in a cellar or a container of some kind, along with another little boy. But first, she explains her credentials. "You'll think I'm crazy, but have you ever heard of Sylvia Browne?" she says. "She's actually a psychic. And I'm a reverend and a psychic. ... The spirits talk to me. There were 32 of them that told me they were kids and they're actually there, and they think these kids are there. ... These 32 souls are kids, and they said that's where they were actually killed. They were sacrificed there. ... y'all would also find their bones there. They said their bones are like in the walls. Also if you'll look with some kind of light or whatever, there's stuff written all over the walls in blood."
The psychic -- whether going by Angel, Rhonda, or Gridley -- was wrong. There were no bodies, children's bones in the walls, or walls scrawled with the blood of child sacrifices. The two missing children were found unharmed and in good health by the side of a road, not hidden in a farmhouse cellar with a young boy. Their older sister was charged with the kidnapping.
Read more at Discovery News
Largest Egyptian Sarcophagus Identified
Made of red granite, the royal sarcophagus was built for Merneptah, an Egyptian pharaoh who lived more than 3,200 years ago. A warrior king, he defeated the Libyans and a group called the "Sea Peoples" in a great battle.
He also waged a campaign in the Levant attacking, among others, a group he called "Israel" (the first mention of the people). When he died, his mummy was enclosed in a series of four stone sarcophagi, one nestled within the other.
Archaeologists are re-assembling the outermost of these nested sarcophagi, its size dwarfing the researchers working on it. It is more than 13 feet (4 meters) long, 7 feet (2.3 m) wide and towers more than 8 feet (2.5 m) above the ground. It was originally quite colorful and has a lid that is still intact.
"This as far as I know is about the largest of any of the royal sarcophagi," said project director Edwin Brock, a research associate at the Royal Ontario Museum in Toronto, in an interview with LiveScience.
Brock explained the four sarcophagi would probably have been brought inside the tomb already nested together, with the king's mummy inside.
Holes in the entrance shaft to the tomb indicate a pulley system of sorts, with ropes and wooden beams, used to bring the sarcophagi in. When the workers got to the burial chamber they found they couldn't get the sarcophagi box through the door. Ultimately, they had to destroy the chamber's door jams and build new ones.
"I always like to wonder about the conversation that might have taken place between the tomb builders and the people from the quarry," said Brock in a presentation he gave recently at an Egyptology symposium in Toronto. "This study has shown a lot of interesting little human aspects about ancient Egypt [that] perhaps makes them look less godlike."
When he first examined fragments from Merneptah's tomb in the 1980s, they were "piled up in no particular order" in a side chamber. Even when put together, the fragments made up just one-third of the box, meaning researchers had to reconstruct the rest.
Brock's efforts got a boost with the launch of a full reconstruction project (affiliated with the Royal Ontario Museum) that started in March 2011. (Merneptah's tomb has been recently re-opened to the public.)
The four sarcophagi
Not only was the pharaoh's outer sarcophagus huge but the fact that he used four of them, made of stone, is unusual. "Merneptah's unique in having been provided with four stone sarcophagi to enclose his mummified coffined remains," said Brock in his presentation.
Within the outer sarcophagus was a second granite sarcophagus box with a cartouche-shaped oval lid that depicts Merneptah. Within that was a third sarcophagus that was taken out and reused in antiquity by another ruler named Psusennes I. Within this was a fourth sarcophagus, made of travertine (a form of limestone), that originally held the mummy of Merneptah.
Only a few fragments of this last box survive today; the mummy itself was reburied in antiquity after the tomb was robbed more than 3,000 years ago. It was after this robbery that the outer sarcophagus box, and the second box within it, were broken apart (the lids for both boxes being kept intact). They were destroyed not only for their parts but also to help get at the third box (that was reused by Psusennes).
Fire was used in breaking apart the outer sarcophagus box.
"Scorch marks, spalling [splinters] and circular cracking on various locations of the interior and exterior of the box attest to the use of fire to heat parts of the box, followed by rapid cooling with water to weaken the granite," writes Brock in his symposium abstract, adding that dolerite hammer stones also appear to have been used.
Why so big?
Why Merneptah built himself such a giant sarcophagus is unknown. Other pharaohs used multiple sarcophagi, although none, it appears, with an outer box as big as this.
Brock points out that Merneptah's father, Ramesses II, and grandfather, Seti I, both great builders, were apparently each buried in one travertine sarcophagus.
The decorations on Merneptah's different sarcophagi offer a clue as to why he built four of them. They contain illustrations "from two compositions that describe the sun god's journey at night, one is called the 'Book of Gates' and one is called the 'Amduat,'" Brock said. These books are divided into 12 sections, or "hours."
He notes that the same hours tend to be repeated on the box and lids of Merneptah's sarcophagi. One motif the king appears particularly fond of is the opening scenes of the "Book of Gates," including one depicting a realm that exists before the sun god enters the netherworld, according to Egyptologist Erik Hornung's book "The Ancient Egyptian Books of the Afterlife" (Cornell University Press, 1999, translation from German). "Upon his entry into the realm of the dead, the sun god is greeted not by individual deities but by the collective of the dead, who are designated the 'gods of the west’ and located in the western mountain range," Hornung writes.
Read more at Discovery News
New Dino Had Giant Nose
The duck-billed dinosaur, Latirhinus uitstlani ("lati" is Latin for "wide" and "rhinus" means nose in Greek), lived during the Late Cretaceous approximately 73 million years ago. Found in Coahuila state, it is described in the latest issue of Historical Biology: An International Journal of Paleobiology.
Its wide nasal cavity might have given it incredible smell-detecting ability.
"Also, it might have supported and provided enhanced space for a soft tissue structure, sort of like an inflatable bladder, for display, recognition and communication purposes in general," lead author Albert Prieto-Márquez told Discovery News.
Prieto-Márquez, a postdoctoral fellow at the Bayerische Staatssammlung für Paläontologie und Geologie in Munich, analyzed the fossils of the dinosaur with colleague Claudia Inés Serrano Brañas.
In addition to its big nose, the dinosaur possessed sturdy hind limbs ending in three toes, and relatively smaller and thinner forelimbs ending in 4 digits- meaning this animal was thumb-less.
"When walking and feeding, Latirhinus would normally walk on four legs, although when it needed to increase the pace and run, it could rise on its two hind legs," Prieto-Márquez said. "A long tail would extend posteriorly to counterbalance the anterior part of the body."
He added that these dinosaurs were herbivores with "a few thousand teeth closely packed together to form a grinding surface to chew the vegetation they fed upon."
Present-day northeastern Mexico, 73 million years ago, was the western half of two major continental landmasses that formed North America. The Cretaceous Western Interior Seaway is the body of water that split the two sections of land. The environment that Latirhinus inhabited was likely warmer and more humid than it is today, with lakes and bays nearby.
Prieto-Márquez said the new dinosaur is important for at least four major reasons.
"First, it expands our knowledge of the diversity of hadrosaurids (duck-billed dinosaurs) both anatomically -- it shows us how hadrosaurids were able to evolve really bizarre structures to become better adapted to their environment -- and regarding biodiversity, adding yet another new genus and species of these animals," he said.
Secondly, it helps to fill a gap in our knowledge of the fossil record of these animals in southern North America. He explained that dozens of duck-billed dinos have been unearthed in southern Canada and the Western Interior of the U.S. over the past 150 years, "in contrast to the comparatively sparser fossil record in the southern region of the continent."
Thirdly, this dinosaur, along with another one called Kritosaurus, provide a link between North American and South American dinosaurs of their kind.
Finally, the dinosaur strengthens prior speculation that this type of dinosaur and its relatives dominated the region back in the day.
Terry Gates, a research fellow at Ohio University, told Discovery News, "We have known for years that several kinds of duck-billed dinosaurs lived in Mexico during the Late Cretaceous, but diagnostic specimens have been hard to come by. Dr. Prieto-Márquez is one of the leaders in the field of duck-billed dinosaurs and has a keen eye for detecting differences among species."
Read more at Discovery News
Dec 5, 2012
Why We're Not Always Good Samaritans
Freelance photographer R. Umar Abbasi responded with a first-person account in today's Post, explaining that he simply followed his instincts and didn't have time to rescue the man:
"I just started running. I had my camera up — it wasn’t even set to the right settings — and I just kept shooting and flashing, hoping the train driver would see something and be able to stop.
"I had no idea what I was shooting. I’m not even sure it was registering with me what was happening. I was just looking at that train coming.
"It all went so quickly; from the time I heard the shouting until the time the train hit the man was about 22 seconds."
Neuroscience and psychology experts say we should probably lay off on the blame game. When it comes to good Samaritan acts, especially in a situation like this where time is limited to seconds, a variety of factors come into play.
In fact, cases where good Samaritans could save someone in a similar situation are quite rare, said Darcia Narvaez, Notre Dame Professor of Psychology and Director of the Collaborative for Ethical Education.
"A good Samaritan act can fail at any point," Narvaez said. Some people simply fail to notice what's going on around them, she added.
In the days when the New York City subway was considered most dangerous, people often put blinders on when they went through the gates. Other people may notice, but the stress of the situation shuts down their higher order thinking, immobilizing them. Sometimes there may be a lack of motivation, a tendency to ignore the problem if they feel their life isn't about being compassionate to others -- those are the cases Narvaez worries about, theorizing that an increase in media violence can dull our willingness to act. And finally, those who notice and want to help may not know how to.
Two years ago, the stars seemed to align in the rescue of a man who fell onto the Washington, D.C., metro tracks after a seizure. A retired Marine who had experience navigating subway tracks happened to be standing by, and jumped from the opposite platform to help the man to safety.
"It makes a difference when you've had actual physical practice," Narvaez said. "He had the instinctive responses; in the military, you learn to act through the shock."
It makes sense, she said, that a photographer's natural reaction would be to flash his camera.
"I'd attribute it more to a lack of experience than of desire or will," she said.
Psychologists Bibb Latane and John Darley defined the "Bystander Effect" in their 1970 book, The Unresponsive Bystander: Why Doesn't He Help? based on a series of lab experiments. They found that when there are plenty of people witnessing the scene, people are less likely to offer help for two main reasons.
First, because we get our cues from others, if several people are not reacting, we may follow suit. Second, the responsibility gets watered down: If you're the only one present, the responsibility clearly lies with you. But if there's a crowd of 10, you may feel your responsibility is only 10 percent.
"We need to educate people that that's an inclination, and that you have to step out of that mindset," Narvaez said. "And if you're a victim, looking people in the eye can help. So if you're in a car accident, look someone in the eye and say, 'I need your help.'"
(An article in Slate outlines what to do if you find yourself stranded on subway tracks.)
In general, our brains reward altruistic behavior. Neuroscientist Jordan Grafman coauthored a study that showed that donating money activates a system in the brain concerned with reward and reinforcement more than receiving a gift.
"But many people are willing to give money and may not be willing to jump down in front of a train," he said. "Under conditions like danger, the pattern of activation in the brain is very different."
Professional photographers sympathize with Abbasi.
Read more at Discovery News
How Did the Oracle at Delphi Really Prophesize?
Even during the Oracle at Delphi's time, it was widely known that the Oracle's visions had a practical cause. Gas seeped out of the cracks in the cave where she sat, causing her to talk nonsense. This nonsense would then be interpreted by priests around her. Some of the predictions were surprisingly accurate, according to legend. Croesus, the richest man of his time, performed a kind of scientific test on oracles, when he had messengers go out to all of them and ask what he would be doing on a certain date. Delphi got the only correct answer -- cooking a tortoise in a pot. (Bold choice. I wouldn't think of the richest guy in the world doing his own cooking.)
Modern archaeologists weren't convinced -- not about the tortoise and not about the gas. They inspected the geology of the area for volcanic activity that might vent gas, and found nothing, not even in the distant past. Later, however, they took another look and found two fault lines converging just under the temple of Delphi. Perhaps the mystic "vapors" that the Oracle breathed in had seeped through these. In interdisciplinary team found that dissolving limestone along those lines gave off gas and spiked the local water.
The main components found in the water were ethane, methane and ethylene. Most think that it's ethylene that is the key component. Ethylene was one of the early painkillers used during medical procedures. It packed more of a punch than nitrous oxide. It smells a bit like flowers, and renders the sniffer euphoric, but extremely out-of-it. It's not especially bad for people (although various compounds of ethylene can be very harmful), and its main danger is that of suffocation. It displaces air and makes people too high to notice. The combination of extreme anesthesia, euphoria and lack of oxygen can make a person say all kinds of things.
Other scientists argue that ethylene wasn't the chemical that made the Oracle talk, though. Methane, which decidedly doesn't smell like flowers, can also cause hallucinations if inhaled in high enough doses. The methane theory isn't without its faults. Methane can kill people a lot faster than ethylene, particularly if it's being burned, or otherwise decomposing, to produce carbon dioxide. A by-product of the conversion is carbon monoxide, which attaches itself to red blood cells more readily than oxygen does. Too much can smother a person, but not before they often experiences confusion and hallucinations. Carbon monoxide is a regular by-product of burning fuels, though, and so there's no reason why the ancient Greeks, who surely had mastered fire, would consider the gas and its effects so special.
Read more at Discovery News
Oldest Dinosaur Found
The dinosaur, described in the latest Royal Society Biology Letters, was unearthed near present-day Lake Nyasa in Tanzania. It is named Nyasasaurus parringtoni, which combines the name Nyasa with the term for lizard. The name also honors Rex Parrington, a University of Cambridge paleontologist who first discovered the fossils.
Nyasasaurus walked the Earth about 10 million years before the current oldest dinosaur record holders -- such as swift-footed Eoraptor and Herrerasaurus -- suggesting that dinosaurs emerged in the Middle Triassic rather than in the latter years of that period. It also suggests that dinosaurs began as relatively small before some species grew to larger sizes.
"From the few preserved bones, we estimate Nyasasaurus to be about 10 feet long with a long neck," lead author Sterling Nesbitt, a University of Washington postdoctoral researcher in biology, told Discovery News. "These estimates are based on comparing the bones of Nyasasaurus to those of early dinosaurs and close relatives."
Co-author Paul Barrett; vice president of The Paleontological Society and head of the Natural History Museum's Division of Fossil Vertebrates, Anthropology and Micropaleontology; added that Nyasasaurus was also probably lightly built for a dinosaur (approximately 45-135 pounds), bipedal and with long hind legs. It lived in the southern portion of what was then the supercontinent Pangaea.
The scientists analyzed the dinosaur's fossilized bones, which are housed at the museum where Barrett works, as well as at the South African Museum in Cape Town. They have been in storage for at least 80 years. The late paleontologist Alan Charig named the specimen, but was unable to publish his report on the animal before he died. Charig is listed as a co-author of the current study.
The new paper gets to the heart of what a dinosaur is.
Barrett explains that dinosaurs are distinguished from other reptiles, in part, by rapid growth and certain bone characteristics.
"We can tell from the bone tissues that Nyasasaurus had a lot of bone cells and blood vessels," co-author Sarah Werning of UC Berkeley, explained. "In living animals, we only see this many bone cells and blood vessels in animals that grow quickly, like some mammals or birds."
She continued, "The bone tissue of Nyasasaurus is exactly what we would expect for an animal at this position on the dinosaur family tree. It's a very good example of a transitional fossil; the bone tissue shows that Nyasasaurus grew about as fast as other primitive dinosaurs, but not as fast as later ones."
An upper arm enlarged mass of bone, called an elongated deltopectoral crest, was also identified. It is another common feature of all early dinosaurs.
Some paleontologists have proposed that dinosaur diversity burst onto the scene in the Late Triassic. The new study refutes that idea, instead suggesting that dinosaurs were part of an earlier, large diversification of archosaurs, which were the dominant land animals during the Triassic period 250 million to 200 million years ago. They include dinosaurs, crocodiles and their kin.
Nyasasaurus, however, was found to be more closely related to birds than to crocodilians. Birds, in turn, "are the direct descendants of small, meat-eating dinosaurs," Barrett said.
The rocks that produced Nyasasaurus have also yielded giant fossil amphibians, fossils for reptiles, and fossils of cynodonts and dicynodonts, which were early mammal relatives.
Read more at Discovery News
Quasar Reveals Chemistry of Ancient Universe
The chemical composition of the cloud indicates that, in this region of space at least, the first generation of stars were still very young at this stage in the universe's development.
"We're looking back to when the first stars were turning on, but also when the first chemicals were made," Robert Simcoe, of Massachusetts Institute of Technology, told SPACE.com.
A Beacon Through the Fog
Earlier this year, astronomers discovered a bright radio source known as a quasar that lay over 13 billion light-years away. Because of the time it takes for light to travel, they were able to see quasar ULAS J1120+0641 as it was almost 13 billion years ago, when the universe was only 772 million years old.
Quasars are faraway galaxies that are illuminated by huge black holes in their centers gobbling up copious amounts of matter.
Although distant galaxies are too faint to study in detail, quasars shine trillions of times brighter than the sun, making them much more luminous than normal galaxies at the same distance. But to Simcoe and his team, what was interesting was not the quasar itself but the cloud of hydrogen gas that lay between it and Earth.
"You can imagine the quasar is like a beacon, peering through some fog," Simcoe said. "What we're trying to do is study the properties of the fog."
The fog, or hydrogen gas, is racing away from the Milky Way at almost the same speed as the quasar, which means that the two are close.
With a team of astronomers, Simcoe used a specially-built spectrograph instrument on the Magellan Telescope in Chile to study the chemistry of the cloud. They found an absence of the heavy elements that exist in the universe today.
The early universe was composed of hydrogen and helium. It wasn't until the first stars ignited that heavier elements were created, and when these stars exploded in fiery deaths, space was seeded with the elements necessary to build planets. The lack of these elements in the early cloud of gas indicates that the stars around it have not yet had time to mix with their surroundings.
The astronomers also found that the gas had not yet been ionized, or stripped of electrons, like the hydrogen gas in space today.
"The only thing efficient enough to strip electrons away from protons is starlight, the light from hot stars," Simcoe said.
Stars heat up gas, making it transparent. The fact that the hydrogen remains opaque indicates that there are not many stars in that region of the universe.
But star formation in the early universe didn't start in a single area. The first generation of stars were scattered across space. So just because the region around the newly-discovered quasar isn't showing signs of stellar activity doesn't mean that no early stars existed at the time.
"In different spots in the universe, we expect star formation to turn on at different times," Simcoe said. "Basically what it means is that stars hadn't turned on yet in a global sense."
The research was published Wednesday (Dec. 5) in the online version of the journal Nature.
Depends on Your Perspective
Simcoe and his team can't tell whether the gas is part of a newly formed galaxy, or whether it makes up the diffuse material between collections of stars. The location of the hydrogen would give further insight into the early universe.
If the cloud is part of the protogalaxy that contains the quasar, it would consist of the ingredients for the first generation of stars. But the lack of heavy elements indicate that, though some stars may have already gone through their life cycle, the gas in the galaxy had not been thoroughly mixed.
However, in order for the gas to be part of the protogalaxy, the line of sight between Earth, the quasar, and the galaxy would have to be just right. According to Simcoe, the odds of that lineup are slim.
The gas is more likely part of the intergalactic material that floats between galaxies. Such gas would also provide broader clues about conditions in the universe. The lack of ionization would have wider implications than it would if found within a single galaxy, indicating that stars had not yet to begin to shine on a wider scale.
"The odds of seeing intergalactic gas is essentially 100 percent," Simcoe said, noting that such clouds would exist along all lines of sight.
Read more at Discovery News
Dec 4, 2012
New Jamaica Butterfly Species Emphasizes Need for Biodiversity Research
Belonging to the family of skipper butterflies, the new genus and species is the first butterfly discovered in Jamaica since 1995. Scientists hope the native butterfly will encourage conservation of the country's last wilderness where it was discovered: the Cockpit Country. The study appearing in today's Tropical Lepidoptera Research, a bi-annual print journal, underscores the need for further biodiversity research and establishing a baseline of organisms as more tropical areas suffer habitat destruction.
"My co-authors on this paper, Vaughn Turland and Delano Lewis, are really excited because they think this butterfly has the potential to be a new sort of flagship species for Jamaican habitat conservation, because it's a black and gold butterfly living in a green habitat, which together comprise the Jamaican national colors," said study co-author Andy Warren, senior collections manager at the McGuire Center for Lepidoptera and Biodiversity at the Florida Museum of Natural History on the UF campus. "Whether or not a tiny little butterfly is going to attract the type of conservation interest that the giant Homerus Swallowtail in Jamaica has remains to be seen."
With a wingspan of little more than 1 centimeter, Troyus turneri is about the size of a thumbnail with its wings spread, Warren said. The genus was named Troyus for the town of Troy, which is nearest to the region of the Cockpit Country where it was collected, and the species was named for Thomas Turner, an expert on Jamaica butterflies who contributed to its discovery.
Jamaica is considered one of the most thoroughly researched areas for butterflies in the Greater Antilles, which includes Cuba, Hispaniola, Jamaica and Puerto Rico. Until the discovery of T. turneri, researchers believed they knew all the butterflies in Jamaica, Warren said. The butterfly likely remained undiscovered for so long due to the inaccessible nature of the Cockpit Country, a 247-mile mostly undeveloped tangle of tropical vegetation. The species was described based on one male and one female specimen, collected in 2011 and 2012 within a quarter mile of each another.
"During 2011, after the discovery of the initial female specimen, we had actually written the description, but any time you have just a single specimen, the chance exists that it's just a real freak of something else," Warren said. "I was really keeping my fingers crossed that more specimens would be found this year. Well, we didn't get many more, but we got exactly one more and it was the male, so that was a huge relief."
The fact this new genus was discovered on an island thought to be well-known, 17 years after a new species had last been described, really shows the need for biodiversity studies, said Torben Larsen, a lepidopterist who specializes in skippers.
"There aren't so many butterflies in the country [Jamaica] and for a new one to turn up, I think it was an absolutely remarkable catch," said Larsen, who is affiliated with the African Butterfly Research Institute. "It really points to the need for continued and in-depth study of the fauna of butterflies, and in general, to get all of these things caught and put in a museum at least, because they do tend to be in rather special habitats."
Unlike other Jamaica skipper butterflies that have wings marked with spots of white or orange, T. turneri is dark brown and unmarked, except for a pale yellow band on its hind wing. Researchers used morphological analysis, including comparisons of the insect's genitalia, and DNA bar coding to determine it represented a new genus.
"We knew right away it was a new species because there's just nothing else that looks like it, but it took several months to determine that it actually should go in its own new genus," Warren said. "Of all the butterflies that are unique to Jamaica, this one is arguably the most unique -- every other butterfly on the island has other congeneric species either on another island or on the mainland, but this one doesn't have any close relatives anywhere."
There are about 20,000 known butterfly species worldwide. Jamaica has 135, with 35 species endemic to the country, including T. turneri.
Read more at Science Daily
Planet Rings Could Be Behind the Formation of Solar System Satellites
The results of this research are published in the Nov. 30, 2012 edition of Science.
There is a fundamental difference between giant planet systems, such as Jupiter and Saturn, and the terrestrial plants, such as Earth or Pluto. Whereas the giants are surrounded by rings and a myriad of small natural satellites, the terrestrial planets have few moons, or just one, and no rings. Until now, two models have been commonly used to explain the presence of regular satellites in our solar system. These indicate that the satellites of the terrestrial planets like Earth or Pluto were formed following a giant collision. They also indicate that the satellites of the giant planets were formed in a nebula surrounding the planet. They do not, however, account for the specific distribution and chemical composition of the satellites orbiting the giant planets. Another theory therefore seemed necessary.
In 2010 and 2011, a French research team developed a new model to describe how Saturn's moons came into being based on numerical simulations and Cassini probe data. The researchers discovered that Saturn's rings, which are very thin disks made up of small blocks of ice surrounding the planet, in turn gave birth to ice satellites. This is due to the fact that the rings spread over time and, when they reach a certain distance from the planet (known as the Roche limit or Roche radius), their ends agglomerate and form small bodies that break off and move away. This is how rings give birth to satellites orbiting the planet.
In this new study, two research lecturers, Aurélien Crida from the Université Nice Sophia Antipolis and the Observatoire de la Côte d'Azur and Sébastien Charnoz from the Université Paris Diderot and the CEA, set out to test the new model and discover whether it could be extended to other planets. Their calculations have brought several important facts to light. This model for satellite formation from planet rings explains why the largest satellites are located farther away from the planet than the smaller satellites. It also points to the accumulation of satellites close to the Roche limit, their "place of birth," on the outer edge of the rings. This distribution is in perfect agreement with Saturn's planetary system. The same model can also apply to the satellites of the giant planets, Uranus and Neptune, which are organized according to a similar layout. This suggests that these planets once had massive rings similar to Saturn's, which they then lost in giving birth to their satellites. Lastly, the model could also be applied to the formation of terrestrial planet satellites. And, according to the researchers' calculations, special cases exist where a single satellite may be formed from the ring around the planet. This is the case for Earth and the Moon, and for Pluto and Charon.
Read more at Science Daily
Even Planets With Thin Atmospheres Could Host Life
When searching for life in the universe, it makes sense to look for conditions roughly similar to our own planet. We have only one example of life, and it happens to exist on an Earth-sized planet with water and a thick atmosphere. Previous studies have shown that microbes were unable to grow when the atmospheric pressure was too low, but a new experiment seems to contradict this finding.
“Just because the planet doesn’t have a large atmosphere, we don’t have to dismiss it right away as non-habitable,” said Alexander Pavlov of NASA’s Goddard Spaceflight Center here at the American Geophysical Union conference on Dec. 3.
Pavlov and his team simulated a Mars-like environment in a large bell jar. It contained a sample of salty dirt meant to mimic Martian soil, was filled with a carbon dioxide atmosphere, and was cooled to low temperatures with liquid nitrogen. They introduced water and E. coli bacteria, a common microbe found all over Earth, into this environment and slowly lowered the pressure.
When the atmosphere reached around 23 millibars — a pressure about 40 times lower than found at the surface of the Earth — the water began to boil away. But enough of the liquid remained even as the pressure dropped that the E. coli were able to hang on and even thrive for a few days. Because the water was not replenished, it all boiled away after several days and the bacterial colony eventually collapsed.
Pavlov thinks that on Mars, warmer seasons such as spring and summer could melt subsurface ice and provide an oasis where hardy organisms could live. During these times, the temperature underground routinely reaches above the freezing point of water and a soil depth of just seven inches provides good protection against harsh ultraviolet radiation. Extremophile microbes, which live in environments far more dangerous than ordinary organisms can handle, could survive such conditions with ease.
Read more at Wired Science
Gladiator's Tomb to Be Reburied
A lack of fundings is forcing Italian archaeologists to bury again the large marble monument of Marcus Nonius Macrinus, a general and consul who achieved major victories in military campaigns for Antoninus Pius, the Roman emperor from 138 to 161 A.D., and Marcus Aurelius, emperor from 161 to 180 A.D.
Unearthed in 2008 on the banks of the Tiber near the via Flaminia, north of Rome, the tomb, complete with the dedicatory inscription, was hailed as "the most important ancient Roman monument to come to light for 20 or 30 years."
Rome's officials had planned to fully reconstruct the monumental tomb as the centerpiece of a new archaeological park, but the project failed due to a tight budget and a lack of private sponsors.
"It is a painful choice, but we cannot risk losing the monument. The marbles can't face another winter, we must bury the site in order to preserve it," Mariarosaria Barbera, Rome's archaeological superintendent, told the daily La Repubblica.
Born in Brescia in northern Italy in 138 A.D., Macrinus was one of Marcus Aurelius's favorite men. His life is believed to have inspired the fictional character Maximus Decimus Meridius in Ridley Scott's film.
In the movie, Meridus is also a general and a favorite of Marcus Aurelius, but this is where the similarities end.
Ironically, a lack of money has so far prevented his tomb from being restored in its full glory.
Read more at Discovery News
Dec 3, 2012
Grave Robbers Seek Bones for Voodoo Rituals
According to a Reuters news story,
"The incident is the most serious case of grave-robbing in the West African state, the world capital of voodoo where most of the country's 9 million residents practice a benign form of the official religion. Authorities in Dangbo, a village 6 miles from the capital Porto-Novo, began an investigation after a mason working at the cemetery said he spotted several masked men digging up the graves, from which organs and skulls were removed. 'The desecration of graves is about money in this region,' said Joseph Afaton, director of the cemetery. 'It is for sacrifices, or for bewitching.'"
Many Americans only think of witches and witchcraft around Halloween. But in many countries belief in witches is common, and black magic is considered part of everyday life. In Africa, witch doctors are consulted not only for healing diseases, but also for placing (or removing) magic curses or bringing luck -- much like many psychics and fortunetellers in America.
A 2010 Gallup poll found that belief in magic is widespread throughout sub-Saharan Africa; on average 55 percent of Africans believe in witchcraft.
Though graves are the most common source of bones, organs and limbs, in the past few years albino children and adults in Africa have been attacked and killed for their body parts. The belief and practice of using body parts for magical ritual or benefit is called muti.
Muti hunting was featured in the 2009 South African science-fiction film "District 9," in which the hero's body parts were sought after by a local warlord who believed that the limbs would give him magical powers. Muti murders are particularly brutal, with knives and machetes used to cut and hack off limbs, breasts, and other body parts from their living victims. Many of the albinos were beheaded, their heads carefully collected and preserved as gruesome good luck charms or for use in rituals.
Throughout most of history, medical knowledge of anatomy was poor and indirect, partly because of fear and taboos against cutting open corpses. The Renaissance brought an emphasis on practical, real-world knowledge, which necessarily meant examining and cutting up the dead.
In Europe, the rise of early medical centers created a strong demand for dead bodies; a few cadavers were made available by royal decree, usually the bodies of condemned criminals. In the 1700s, in fact, dissection was a punishment for serious crimes.
By 1720, theft from graveyards was common in London, England, and grave robbers (or "resurrection men," as they were known) were making a profit digging up bodies and selling them to anatomists and doctors. Among the most infamous of these criminals were Irish grave robbers and murderers Brendan Burke and William Hare, who committed sixteen murders and sold the bodies to a well-known London anatomist in 1828.
Read more at Discovery News
Hppy bthdy txt msng!
Interestingly, the technology that would start a cultural revolution in how people communicate did not originate from some high-tech lab in Silicon Valley.
The world's first SMS text (which stands for short message system) came from an office in Newbury, southern England.
Reading "Merry Christmas" -– and not "Merry Xmas" or ": -) Xmas" -- the message was sent on Dec. 3, 1992, by 22-year-old engineer Neil Papworth of the technology company Sema to a colleague at Vodafone UK who was enjoying a staff Christmas party.
Papworth was part of the team developing a Short Message Service Center for Vodafone UK. Deployed with the first GSM networks, SMS relied on concepts developed in 1984 by Friedhelm Hillebrand of Germany and Bernard Ghillebaert of France.
"I was chosen to go to Vodafone's Newbury offices to install, integrate and test the software and get it all working. Initially the idea was for them to use it essentially as a paging service," Papworth said.
Since mobile phones didn't yet have keyboards, he typed the holiday greeting out on a PC, while the recipient, Vodafone's director Richard Jarvis, received the message using a bulky Orbitel 901, also immortalized as the world's first GSM phone.
"I feel good that I was there and did what I did. I didn't know what would happen with text messaging after that though," Papworth told Discovery News.
Thumb-typed messages did not take the world by storm. During the first years of SMS, and long before Twitter, texting in 160 characters remained a tool for geeks and telephone engineers.
In 1995, GSM customers sent only 0.4 messages on average each per month; by the end of 2000 it was still only 35.
But when text messaging across all networks became possible and pay-as-you-go mobile phones became available, SMS texts rocketed, finding their natural market in young people.
Reports estimated that the total number of SMS sent globally tripled between 2007 and 2010, from about 1.8 trillion to a staggering 6.1 trillion.
Filled with truncated words and acronyms, SMS texts remained the most popular app in 2011, with 8 trillion text messages, or over 15 million each minute, sent.
The most prolific texters appear to be subscribers in the Philippines, who send an average of 600 messages each month.
As for Papworth, he now lives in Montreal with his wife and three kids and work as a software architect.
In past years, he has enjoyed quite a lot of media attention.
"I've given radio interviews, been flown to London with my family for a movie premiere, featured in a Super Bowl ad, been an answer to a Jeopardy question and had many articles written on the achievement," Papworth said.
Read more at Discovery News
Voyager 1 Can 'Taste' the Interstellar Shore
The heliosphere is the sphere of influence of our sun -- it is basically a bubble in interstellar space inflated by the sun where all planets and all spacecraft are contained within.
After completing its primary mission of outer solar system exploration many years ago, Voyager 1 (and its twin probe Voyager 2) has been ploughing through the outermost reaches of the heliosphere, rapidly approaching the outermost limit of the solar system -- called the heliopause.
Although data collected by the aging Voyager 1 have been showing strong signs of flying beyond the heliopause, mission scientists at the AGU conference in San Francisco announced on Monday that hopes of an interstellar Voyager 1 are premature.
However, the mission is beginning to "taste" the interstellar shores.
It appears that the probe has flown into a new and unexpected region of the heliosphere where the rush of particles generated by the sun -- that, in turn, form the solar wind -- are carried by the weakening solar magnetic field, pushing against the interstellar medium. The outside (interstellar medium) pressure sweeps back the sun's magnetic field, channeling solar particles into a high-speed "magnetic highway." But high-energy particles from outside the heliopause are leaking into the highway and washing over the spacecraft's instruments.
"Although Voyager 1 still is inside the sun's environment, we now can taste what it's like on the outside because the particles are zipping in and out on this magnetic highway," Edward Stone, Voyager project scientist based at Caltech in Pasadena said in a NASA press release. "We believe this is the last leg of our journey to interstellar space. Our best guess is it's likely just a few months to a couple years away. The new region isn't what we expected, but we've come to expect the unexpected from Voyager."
Voyager 1 has been experiencing the outermost regions of the solar system for several years, hitting the solar system's "termination shock" in 2004. It then blasted into the "helioshieth", a region where the solar wind slowed rapidly and succumbed to turbulence. Most recently, Voyager 1 detected the solar wind particles slow to zero signifying that the probe must be approaching the outermost boundary before interstellar space. At the same time, a strengthening of the magnetic field was detected.
Most recently, a rapid drop in lower-energy particles (originating from the sun) coincided with a noticeable increase in high-energy particles (originating from interstellar space) leading many to speculate that Voyager 1 had officially left the solar system's heliopause. However, NASA scientists aren't yet ready to call Voyager 1 an "interstellar mission."
"If we were judging by the charged particle data alone, I would have thought we were outside the heliosphere," said Stamatios Krimigis, principal investigator of the low-energy charged particle instrument, based at the Johns Hopkins Applied Physics Laboratory, Laurel, Md. "But we need to look at what all the instruments are telling us and only time will tell whether our interpretations about this frontier are correct."
Read more at Discovery News
Curiosity Hints at Mars Organics, Perchlorate
The Curiosity rover found evidence of chlorine, sulfur and water in Mars dirt studied by its onboard laboratory, as well as organic compounds (chemicals containing carbon) inside its Sample Analysis at Mars instrument. However, the science team can't yet be sure whether these compounds truly come from Mars, or arise from contamination transported to the Red Planet onboard Curiosity.
"SAM has no definitive detection to report of organic compounds," Paul Mahaffy, SAM principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md., said during a press conference at the annual meeting of the American Geophysical Union in San Francisco.
"Even though [Mahaffy's] instrument detected organic compounds, first of all we have to determine whether they're indigenous to Mars," said John Grotzinger, Curiosity's project scientist.
The announcement came after recent rumors — which NASA attempted to dampen last week — that Curiosity had made a huge discovery on Mars.
The observation by Curiosity involved perchlorate, a reactive compound of oxygen and chlorine that had previously been found in the Martian arctic by NASA's Phoenix lander.
Curiosity's SAM instrument uses a tiny oven to cook Mars dirt samples, then study the gases they give off to determine their chemical makeup. Martian soil samples are placed in the device by a scoop on Curiosity's robotic arm.
When Curiosity cooked the perchlorate in its SAM oven, it created chlorinated methane compounds, one-carbon organic material.
"The chlorine is of Martian orgin, but it's possible the carbon may be of Earth origin, carried by Curiosity and detected by SAM's high sensitivity design," NASA officials wrote in a statement.
The new findings by Curiosity came during the rover's study of a patch of windblown Martian dust and sand called "Rocknest." It is a flat stretch of Mars terrain that is still miles away from Curiosity's first destination, rock outcrop called Glenelg at the base of the 3-mile (5 kilometers) Mount Sharp that rises from the center of the rover's landing site — the vast Gale Crater.
While scientists puzzle out the validity of Curiosity's SAM signals, the rover's other instruments have made curious discoveries, as well, mission scientists said.
Curiosity's arm-mounted tools have confirmed that the Martian soil at the Rocknest site is similar in chemical composition and appearance to the dirt seen by NASA's three other rovers: the small Pathfinder, and golf cart-size Spirt and Opportunity rovers.
Photos from the rover's Mars hand Lens Imager, or MAHLI, revealed that the sand drifts at Rocknest have a crusty surface that hides even darker, finer sand below.
Read more at Discovery News
Dec 2, 2012
Breakthrough in the Understanding of Embryonic Stem Cells
A significant breakthrough in the understanding of embryonic stem cells has been made by scientists from the Smurfit Institute of Genetics at Trinity College Dublin. The Trinity research group led by Dr Adrian Bracken and funded by Science Foundation Ireland, has just published their findings in the journal, Nature Structural & Molecular Biology.
The new research describes the process whereby genes that are 'on' in embryonic stem cells are switched 'off'. This process is essential in order to convert embryonic stem cells into different cell types such as neurons, blood or heart cells and therefore represents an important breakthrough in the area of regenerative medicine.
The research encompasses both embryonic stem cell research and epigenetics. Embryonic stem cell research is focused on a particular type of cell that is capable of generating the various tissues in the body; for example, muscle, heart or brain. It is particularly relevant due to its potential for regenerating diseased tissues and organs and for the treatment of a variety of conditions including Parkinson’s disease, diabetes and spinal cord injury
Epigenetics explains how cells in your body with exactly the same genes can be so different functionally. For example, a neuron and a muscle cell look and act very differently, yet contain exactly the same genes. The study of epigenetics has helped us understand that every type of cell has its own unique pattern of genes that are either switched 'on' or 'off'. Different types of cells arise therefore due to these differences.
This new research explores the role of a protein termed a ‘Polycomb group protein’ called PHF19 in mouse embryonic stem cells. Gerard Brien, the lead author on the paper, and PhD student in the laboratory of Dr. Adrian Bracken demonstrated that without PHF19, embryonic stem cells are incapable of generating specialised cells such as those of the heart, lung or brain. He next established that PHF19 plays a critical role in switching the embryonic stem cell genes from an 'on' to an 'off' state during conversion into specialised cells. PHF19 does this by reading an ‘epigenetic mark’ called H3K36me3, which is only found on genes that are 'on'. It then recruits additional ‘Polycomb’ and other proteins, which replace H3K36me3 with another mark, H3K27me3, that is found on genes that are 'off'.
Read more at Science Daily
The new research describes the process whereby genes that are 'on' in embryonic stem cells are switched 'off'. This process is essential in order to convert embryonic stem cells into different cell types such as neurons, blood or heart cells and therefore represents an important breakthrough in the area of regenerative medicine.
The research encompasses both embryonic stem cell research and epigenetics. Embryonic stem cell research is focused on a particular type of cell that is capable of generating the various tissues in the body; for example, muscle, heart or brain. It is particularly relevant due to its potential for regenerating diseased tissues and organs and for the treatment of a variety of conditions including Parkinson’s disease, diabetes and spinal cord injury
Epigenetics explains how cells in your body with exactly the same genes can be so different functionally. For example, a neuron and a muscle cell look and act very differently, yet contain exactly the same genes. The study of epigenetics has helped us understand that every type of cell has its own unique pattern of genes that are either switched 'on' or 'off'. Different types of cells arise therefore due to these differences.
This new research explores the role of a protein termed a ‘Polycomb group protein’ called PHF19 in mouse embryonic stem cells. Gerard Brien, the lead author on the paper, and PhD student in the laboratory of Dr. Adrian Bracken demonstrated that without PHF19, embryonic stem cells are incapable of generating specialised cells such as those of the heart, lung or brain. He next established that PHF19 plays a critical role in switching the embryonic stem cell genes from an 'on' to an 'off' state during conversion into specialised cells. PHF19 does this by reading an ‘epigenetic mark’ called H3K36me3, which is only found on genes that are 'on'. It then recruits additional ‘Polycomb’ and other proteins, which replace H3K36me3 with another mark, H3K27me3, that is found on genes that are 'off'.
Read more at Science Daily
Any Truth Behind Immortal Jellyfish Claim?
The 6,500-word narrative is a compelling read, but a critic at the Knight Science Journalism program at MIT urges skepticism.
"...the problem with this story is that much of what is reported is highly improbable, even unbelievable," writes Paul Raeburn. "And the writing is discursive to a fault."
The author, novelist Nathaniel Rich, traveled to Japan to meet a scientist who thinks that an organism known as Turritopsis dohrnii may unlock the secret to human immortality. The tiny jellyfish does a seemingly death-defying trick: After it grows from a polyp to an adult, it reverses the cycle and turns back into a polyp.
But Raeburn points out several red flags, among them: The author contends that the Turritopsis dohrnii is unique in its ability, but then quotes an expert who says that other species do the same thing. Then, another expert is quoted as saying that while the cells are immortal, the organism itself may not be. And it's unclear whether the scientist, Shin Kubota, is clouded by the idea of spiritual immortality.
The bottom line? Here's how Raeburn sums it up:
"It's clear that Rich was seduced by the romance of the story. Kubota is indeed a fascinating character and a prime candidate for a profile. What is missing here is a proper sense of journalistic detachment and skepticism. Kubota seems like a genial fellow, and Rich clearly likes and admires him. There's nothing wrong with that, except that Rich makes the fatal mistake of swallowing everything Kubota tells him. And when Rich briefly quotes critics, he seems to suggest that they dissent only because they do not understand Kubota's work."
So far, there is one correction appended to the online version. Stay tuned.
From Discovery News
New Clues Date Grand Canyon to Dino Days
So for 150 years, geologists have pondered the processes shaping the canyon, one of the world's great wonders and a living laboratory for understanding Earth history.
The gorge's rugged beauty, with its sheer cliff and steep slopes, looks young. And the general scientific consensus, updated at a 2010 conference, holds that the copper-colored Colorado River carved the Grand Canyon beginning 5 million to 6 million years ago. Many strong lines of evidence support this theory, including a pile of gravel and limestone pancaked with lava at a place called Muddy Creek. This geologic layer cake, at the western mouth of the canyon, locks down the Colorado River from exiting the canyon before 6 million years ago.
However, recent advances in dating techniques have upended the notion of a uniformly young Grand Canyon. The new approach determines when erosion uncovered rocks in the canyon. The big picture: there were two ancestral canyons, one in the west and one in the east. And the western canyon may be as old as 70 million years.
Grand Canyon's ancestors
The latest sally is a study reporting samples from the western Grand Canyon were close to the Earth's surface 70 million years ago. The evidence suggests the western Grand Canyon was cut to within 70 percent of its current depth of 3,200 feet (1,000 meters) long before the Colorado River existed. The results appear today (Nov. 29) in the journal Science.
"Our data suggests that there was in fact a large canyon present for most of the Grand Canyon by about 70 million years ago in its western segment, and that canyon was carved to nearly modern depths," said Rebecca Flowers, lead study author and a geology professor at the University of Colorado, Boulder. "In the eastern canyon, the canyon was higher, and lowered into its modern configuration sometime after 20 million years ago."
This much older western "paleocanyon" was incised by an ancient river flowing west to east. This Cretaceous river carved the western Grand Canyon to within a few hundred meters of its modern depth, and the eastern Grand Canyon to a higher level.
When combined with rock sample ages Flowers collected in the eastern Grand Canyon during this study and in 2008, the overview gives the Grand Canyon a complicated history. However, the research can fit into the constraints presented by the Muddy Creek barrier and other evidence supporting a young canyon, Flowers told OurAmazingPlanet.
"The presence of the [Muddy Creek] detritus represents the integration of the river system," Flowers said. That is, the Muddy Creek simply represents the Colorado River appropriating the paleocanyons and created a single drainage 6 million years ago.
Two canyons?
Geologist Richard Young, who has studied the Grand Canyon for nearly 50 years, said scientists have considered the idea of two Grand Canyon precursors — one west, one east — since the research community's first symposium in 1964.
"It really looks like they're onto something, but it's hard to make sense out of it," said Young, a professor at the State University of New York in Geneseo. "It's really good work and it's really interesting, so obviously there's something we're missing in the story. I'm sure we're going to be talking about it forever," he said.
Recent work by geologist Karl Karlstrom supports the idea for a paleocanyon in the east. "We showed very conclusively that there was a paleocanyon in the eastern Grand Canyon that was carved between 25 and 15 million years ago," said Karlstrom, a professor at the University of New Mexico in Albuquerque.
But Karlstrom is a strong advocate for a Grand Canyon quickly carved by the Colorado River starting 6 million years ago, not older rivers coming from the west. The western Grand Canyon region was cut across nearly at right angles by one or more paleocanyons with rivers that flowed north around 70 million years ago, but these paleorivers did not follow the modern course of Grand Canyon, Karlstrom said.
"The best answer is that Grand Canyon was carved by the west-flowing Colorado River in the last 5 to 6 million years and that earlier paleocanyons were likely re-used and deepened once the river found its present path," he said.
Southwest during the end of the dinosaurs
The American Southwest had a radically different appearance 70 million years ago. Most of the region's famed dinosaur fossils come from the Jurassic, and the canyon-cutting identified by Flowers and colleague Ken Farley of Caltech began in the Late Cretaceous.
Seen from the air, the flat Colorado plateau might be recognizable, but the rainbow-hued pillars and monuments of national parks such as Arches, Zion and Bryce had yet to take shape. Close to the west rose a volcanic arc similar to today's Andes — the precursor to California's Sierra Nevada Mountains. A wrinkled belt called the Sevier mountains was northwest of the plateau. To the east was the Western Interior Seaway. Rivers flowed out of mountains generally heading northeast into the ocean.
Read more at Discovery News
Cave Structure Tells Tale of 13,000 Winters
"Most other ways of estimating past climate, like tree-ring data, only tell us about summers, when plants are growing," Oxford University researcher Vasile Ersek said in a statement. But understanding ancient winters is also important for regions like western North America, where chilly conditions are critical for determining water resources.
For their study, Ersek and his colleagues examined a cave formation called a stalagmite that started forming 13,000 years ago in a cavern in what is now Oregon Caves National Monument. During the region's damp winters, water from the ground seeped through the cave's ceiling and trickled onto the floor, with the drips slowly forming the stalagmite over time.
The ratio of certain oxygen and carbon isotopes (atoms of the same element with a different number of neutrons) in these deposits provides information on ancient climate.
The researchers' measurements of these chemical components showed that the Pacific Northwest of recent prehistory saw rapid shifts between dry and warm, and wet and cold periods, similar to the currently observed Pacific Decadal Oscillation (PDO) — a pattern of climate variability that switches between negative and positive every couple of decades. In a positive, or warm, phase, the surface waters of the west Pacific become cool and part of the eastern ocean warms, while the opposite occurs during a negative, or cool, phase.
"Whilst we can't directly relate these changes to the Pacific Decadal Oscillation, the mechanisms involved do look similar," Ersek said in a statement from Oxford. "Getting a long-term perspective on these sorts of natural climate variations may help us to understand the potential for future loss of winter snow cover along the West Coast, as well as what's happening out in the Pacific to influence other cyclical climate events such as El Niño."
Read more at Discovery News
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