A catastrophic event -- such as a terrorist attack, a natural disaster, or market collapse -- often strikes twice. There is the damage caused by the event itself, as lives are lost or left in ruin. But there is also the second act, catalyzed by our response to the catastrophic event. This second act has the potential to cause just as much damage as the first.
In the year following the terrorist attacks of September 11, 2001, there were approximately 1,600 more traffic fatalities in the United States than expected. This figure suggests the possibility that fear may have been a strong motivator for many people, leading them to choose driving over flying. This change in behavior, motivated by fear, may have ultimately led to additional deaths through traffic fatalities.
But fear does not tell the whole story. As Wolfgang Gaissmaier and Gerd Gigerenzer of the Harding Center for Risk Literacy at the Max Planck Institute for Human Development in Berlin, Germany, observe, the changes in driving behavior observed after 9/11 varied widely across different regions of the United States and did not just occur in those states closest to the attacks where fear was presumably strongest.
Gaissmaier and Gigerenzer hypothesized that another factor might have played a central role: driving opportunity. While fear provides a motivational explanation, in order for people to substitute driving for flying there had to be an environmental structure that allowed fear to manifest in a behavior change.
The researchers explore this hypothesis in a new research article to be published in Psychological Science, a journal of the Association for Psychological Science.
They collected data on the number of miles driven and the number of traffic fatalities per month from each of the 50 states and the District of Columbia. They also gathered data on fear and driving opportunity. They used proximity to New York City to get an approximate measure of post-9/11 fear, as previous research had shown that proximity was linked with substantial stress reactions after the attacks. To measure driving opportunity, they assessed the length of nationally significant highways in each state in the National Highway System, divided by the number of state inhabitants and they also looked at the number of car registrations per inhabitant.
The results of the analyses show that people did in fact drive more following 9/11: Across all states, the average monthly increase in miles driven per inhabitant was 27.2 miles in the three months following the attacks. This increase was significantly greater than that observed in the same three-month period in the five years leading up to 2001.
Interestingly, people who were closer to New York City showed only a slight increase in driving. Increase in miles driven was strongly associated, however, with greater driving opportunity. Most importantly, increased driving was associated with an increase in traffic fatalities. These findings suggest that fear can lead people to engage in potentially dangerous behaviors, such as increased driving, but that understanding fear is not enough.
"To be able to foresee where the secondary effects of catastrophic events could have fatal consequences, we need to look at the environmental structures that allow fear to actually manifest in dangerous behaviors."
Read more at Science Daily
Aug 31, 2012
Why Dogs Really Do Feel Your Pain
The latest research, published in the journal Animal Cognition, found that pet dogs may truly be man (or woman's) best friend if a person is in distress. That distressed individual does not even have to be someone the dog knows.
"I think there is good reason to suspect dogs would be more sensitive to human emotion than other species," co-author Deborah Custance told Discovery News. "We have domesticated dogs over a long period of time. We have selectively bred them to act as our companions."
"Thus," she added," those dogs that responded sensitively to our emotional cues may have been the individuals that we would be more likely to keep as pets and breed from."
Custance and colleague Jennifer Mayer, both from the Department of Psychology at the University of London Goldsmiths College, exposed 18 pet dogs -- representing different ages and breeds -- to four separate 20-second human encounters. The human participants included the dogs' owners as well as strangers.
During one experimental condition, the people hummed in a weird way. For that one, the scientists were trying to see if unusual behavior itself could trigger canine concern. The people also talked and pretended to cry.
The majority of the dogs comforted the person, owner or not, when that individual was pretending to cry. The dogs acted submissive as they nuzzled and licked the person, the canine version of "there there." Custance and Mayer say this behavior is consistent with empathic concern and the offering of comfort.
As for what could be going on in the dog's head, yet another recent study, published in PLoS ONE, showed how the brains of dogs react as the canines view humans. In this case, the researchers trained dogs to respond to hand signals that meant the pups would receive a hot dog treat. Another signal meant no such treat was coming.
The caudate region of the dogs' brains, an area associated with rewards in humans, showed activation when the canines knew a tasty food treat was coming.
"These results indicate that dogs pay very close attention to human signals," lead researcher Gregory Berns, director of the Emory Center for Neuropolicy, explained. "And these signals may have a direct line to the dog's reward system."
In that study, the reward was food, but Custance and Mayer think canines over the thousands of years of domestication have been rewarded so much for approaching distressed human companions that this may somehow be hardwired into today's dogs.
Read more at Discovery News
Two Mars Rovers Search for Clues to Life
The golf-cart sized Mars Exploration Rover Opportunity is expected to soon reach a patch of bedrock on the rim of Endeavour Crater, located on the opposite side of the planet from Curiosity's landing site. The rock is believe to contain clay minerals, which form in the presence of water.
Clays also are believed to exist in the lower layers of Mount Sharp, the three-mile high mound of sediment that rises from the floor of Gale Crater, where Curiosity touched down on Aug. 6.
The timing is ironic, and possibly fortuitous. Opportunity, along with its twin rover Spirit, were only designed for 90-day missions to determine if their landing sites showed signs of past water.
The answers from both were a resounding "yes," paving the way for the much better equipped and more robust Curiosity geochemistry robot, which just began a two-year quest to assess the planet's potential for microbial life.
"One way I like to think about it is that Opportunity is the field geologist doing the exploration type of stuff, and Curiosity is the geologist who then takes samples back to his lab to do more detailed analysis on them," planetary scientist Diana Blaney, with NASA's Jet Propulsion Laboratory in Pasadena, Calif., told Discovery News.
The different missions grew out of different, but complementary science goals.
"When Spirit and Opportunity were built, we had places (on Mars) that we knew had had water, but we really didn't have any evidence for any place where water had been around doing chemistry on the surface for a long time.
"In that era the big questions were 'What is the history of water at these particular locations on Mars?'" Blaney said.
With its 10 science instruments and a two-year design life, Curiosity, which is about the size of a small car, is intended to address two difficult follow-on questions: whether Mars had ingredients besides water, such as organics, necessary for life and whether it had the means to preserve it.
"The missions inform each other to a limited extent," said Cornell University's Steve Squyres, the lead scientist on the Opportunity mission and a participating investigator on Curiosity's.
Read more at Discovery News
Let It Snow, Let It Snow ... CO2
Of all the greenhouse gases, CO2 is the "control knob" of climate change. There's currently too much of it in our atmosphere, and the more of it that there is, the greater the effects of warming.
It sounds far-fetched, but researchers at Purdue University have put together a plan on how such a device would work.
“It’s kind of a novel idea and it’s going to take a lot of refrigeration units and a lot of cost,” said Ernest Agee, professor earth and planetary sciences at Purdue and author of the paper appearing in the Journal of Applied Meteorology and Climatology.
Water vapor turns to snow around 32 degrees Fahrenheit, but CO2 doesn’t switch from gas to solid until it gets down to a chilly -220 degrees Fahrenheit (133 Kelvin). The ambient air temperature in Antarctica can often reach -100 F, which gives the chilling process a head start.
But to transform the planet’s atmospheric CO2 into snow, it would take an estimated 446 individual refrigeration units that use a closed-loop liquid nitrogen process. The units would be powered by 16 1,200-megawatt wind turbines. That’s a lot of power.
Agee says the idea came to him during a discussion about Mars’ south polar ice cap, which was found to consist of CO2 by the Mars Global Surveyor and Odyssey missions.
He says Antarctica’s coastline would be the best place to put the chiller plants and the turbines since the coast gets blasts of high-powered winds that cascade down from the higher South Polar ice cap toward the ocean. The CO2 snow would be stored in insulated landfills. The winds can power the turbines, while excess heat from the chillers and electricity from the turbines can be harnessed to keep Antarctic research stations warm and dry.
Russell Donnelly, a University of Oregon physicist, is intrigued with Agee’s idea.“It’s quite exciting,” Donnelly said. “It’s certainly thinking big.”
Donnelly is pushing his own, slightly different idea of chilling carbon dioxide. He wants to install chillers at coal-burning power plants to remove C02 from smokestacks.
“You look at the hot gases of a stack, it would look impossible,” Donnelly said. “But you can cool them off with water sprays and down to room temperature without spending much money. Then if you start to refrigerate, you need to put just enough refrigeration to get the job done.”
Donnelly and colleagues published a paper in the July 12 issue of the journal Physical Review E that spells out how he would build such a device.
He said the electricity would cost 25 percent more to produce, “but you would have an environmentally-friendly power plant.”
Read more at Discovery News
Aug 30, 2012
Surprisingly Bright Superbubble in Nearby Nebula
The massive stars produce intense radiation, expel matter at high speeds, and race through their evolution to explode as supernovas. The winds and supernova shock waves carve out huge cavities called superbubbles in the surrounding gas. X-rays from NASA's Chandra X-ray Observatory (blue) show hot regions created by these winds and shocks, while infrared data from NASA's Spitzer Space Telescope (red) outline where the dust and cooler gas are found. The optical light from the 2.2m Max-Planck-ESO telescope (yellow) in Chile shows where ultraviolet radiation from hot, young stars is causing gas in the nebula to glow.
A long-running problem in high-energy astrophysics has been that some superbubbles in the LMC, including N44, give off a lot more X-rays than expected from models of their structure. A Chandra study published in 2011 showed that there are two extra sources of the bright X-ray emission: supernova shock waves striking the walls of the cavities, and hot material evaporating from the cavity walls. The observations show no evidence for an enhancement of elements heavier than hydrogen and helium in the cavities, thus ruling out this possibility as an explanation for the bright X-ray emission. T
his is the first time that the data have been good enough to distinguish between different sources of the X-rays produced by superbubbles.
Read more at Science Daily
Extinct Human Genome Reveals Brown-Eyed Girl
Genetic analysis of the fossil revealed it apparently belonged to a little girl with dark skin, brown hair and brown eyes, researchers said. All in all, the scientists discovered about 100,000 recent changes in our genome that occurred after the split from the Denisovans. A number of these changes influence genes linked with brain function and nervous system development, leading to speculation that we may think differently from the Denisovans. Other changes are linked with the skin, eyes and teeth.
"This research will help [in] determining how it was that modern human populations came to expand dramatically in size as well as cultural complexity, while archaic humans eventually dwindled in numbers and became physically extinct," said researcher Svante Pääbo at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
Future research may turn up other groups of extinct humans in Asia "in addition to Neanderthals and Denisovans," Pääbo told LiveScience.
Although our species comprises the only humans left alive, our planet was once home to a variety of other human species. The Neanderthals were apparently our closest relatives, and the last of the other human lineages to vanish.
However, scientists recently revealed another group of extinct humans once lived at the same time as ours. DNA from fossils unearthed in Denisova Cave in southern Siberia in 2008 revealed a lineage unlike us and closely related to Neanderthals. The precise age of the Denisovan material remains uncertain — anywhere from 30,000 to 80,000 years of age.
"The Denisovan genome is particularly close to my heart, because it was the first time that a new group of extinct humans was discovered and defined just from DNA sequence evidence and not from the morphology of bones," Pääbo said.
Denisovan genes unzipped
Now, based on only a tiny sample of genetic material from a finger bone, scientists have sequenced the complete genome of the Denisovans (pronounced deh-NEESE-so-vans), as they are now called.
To make the most of what little genetic material they had, the researchers developed a technique that unzipped the double strands of DNA in the bone, doubling the amount of DNA they could analyze. This enabled them to sequence each position in the genome about 30 times over, generating an extremely thorough genome sequence.
"We have very few errors in the sequences, even less errors than we often have when you sequence a person today," Pääbo said. "With just a few technical reservations, there is actually today then no difference in what we can learn genetically about a person that lived 50,000 years ago and from a person today, provided that we have well-enough preserved bones."
Comparing the Denisovan genome with ours confirmed past research suggesting the extinct lineage once interbred with ours and lived in a vast range from Siberia to Southeast Asia. The Denisovans share more genes with people from Papua New Guinea than any other modern population studied.
In addition, more Denisovan genetic variants were found in Asia and South America than in European populations. However, this likely reflects interbreeding between modern humans and the Denisovans' close relatives, the Neanderthals, rather than direct interbreeding with the Denisovans, researchers said.
Denisovans began to diverge from modern humans in terms of DNA sequences about 800,000 years ago. Among the genetic differences between Denisovans and modern humans are likely changes that "are essential for what made modern human history possible, the very rapid development of human technology and culture that allowed our species to become so numerous, spread around the whole world, and actually dominate large parts of the biosphere," Pääbo said.
Eight of these genetic changes have to do with brain function and brain development, "the connectivity in the brain of synapses between nerve cells function, and some of them have to do with genes that, for example, can cause autism when these genes are mutated," Pääbo added.
What makes humans special?
It makes a lot of sense to speculate that what makes us special in the world relative to the Denisovans and Neanderthals "is about connectivity in the brain," Pääbo said. "Neanderthals had just as large brains as modern humans had — relative to body size, they even had a bit larger brains. Yet there is, of course, something special in my mind that happens with modern humans. It's sort of this extremely rapid technological cultural development that comes, large societal systems, and so on. So it makes sense that, well, what pops up is sort of connectivity in the brain."
The fact that differences are seen between modern humans and Denisovans in terms of autism-linked genes is especially interesting, because whole books have been written "suggesting that autism may affect sort of a trait in human cognition that is also crucial for modern humans, for how we put ourselves in the shoes of others, manipulate others, lie, develop politics and big societies and so on," Pääbo said.
The genetic diversity suggested by this Denisovan sample was apparently quite low. This was probably not due to inbreeding, the researchers say — rather, their vast range suggests their population was initially quite small but grew quickly, without time for genetic diversity to increase as well.
"If future research of the Neanderthal genome shows that their population size changed over time in similar ways, it may well be that a single population expanding out of Africa gave rise to both the Denisovans and the Neanderthals," Pääbo said.
Intriguingly, comparing the X chromosome, which is passed down by females, to the rest of the genome, which is passed down equally in males and females, revealed "there is substantially less Denisovan genetic material in New Guinea on the X chromosome than there is on the rest of the genome,"researcher David Reich at Harvard Medical School in Boston told LiveScience.
One possible explanation "is that the Denisovan gene flow into modern humans was mediated primarily by male Denisovans mixing with female modern humans," Reich said. "Another possible explanation is that actually there was natural selection to remove genetic material on the X chromosome that came from Denisovans once that entered the modern human population, perhaps because it caused problems for the people who carried it."
Read more at Discovery News
Stone Age Figurines Found Near Jerusalem
Found at Tel Moza, a couple miles north of Jerusalem, during a dig ahead of the widening of Highway 1, the 5.9-inch-long figurines are estimated to date between 9,000 and 9,500 years ago.
The first figurine, shaped in the image of a ram, is made of limestone and features intricately carved horns.
"The sculpting is extraordinary and precisely depicts details of the animal's image; the head and the horns protrude in front of the body and their proportions are extremely accurate," Anna Eirikh and Hamoudi Khalaily, directors of the excavation on behalf of the Israel Antiquities Authority (IAA), said in a statement.
"The legs of the figurine were incised in order to distinguish them from the rest of the body," they added.
The second figurine, fashioned on hard smoothed dolomite, is an abstract design. According to the archaeologists, it appears to depict a large animal with prominent horns that separate the elongated body from the head.
"The horns emerge from the middle of the head sideward and resemble those of a wild bovine or buffalo," the archaeologists said.
At that time humans began transitioning from nomadism, based on hunting and gathering, to sedentary life, based on farming and grazing.
One theory is that the statuettes were used as talismans.
"It is known that hunting was the major activity in this period. Presumably, the figurines served as good-luck statues for ensuring the success of the hunt," Khalaily said.
"They might have been the focus of a traditional ceremony the hunters performed before going out into the field to pursue their prey," he said.
Read more at Discovery News
WISE Discovers Galactic Hot DOGs
WISE scientists are calling their find "hot DOG," for hot, Dust-Obscured Galaxy, which is an apt description, considering the galaxies are twice as hot as similar objects and difficult to find since most of their radiation is blocked by shrouds of dust.
But WISE ferreted out about 1,000 hot DOGS, each of which can put out more than 1,000 times the energy of the Milky Way, thus earning themselves top billing on the list of most luminous objects in the universe.
In astronomical numbers, 1,000 is tiny, accounting for about 1-in-100,000 light sources, scientists said during a conference call with reporters on Wednesday.
About 70 percent of the hot DOGS are 10 billion light-years away, meaning they formed when the universe was quite young. (The most precise measurement for the age of the universe is 13.75 billion years.)
Scientists aren't sure if conditions were more suited for forming hot DOGS then, or if they are just a relatively quick phase in a galaxy's life and could exist in the modern universe as well.
The objects, however, are raising new questions about the relationship between black holes and their host galaxies. Hot DOGs seem to be far brighter than what their stars can account for, leading some astronomers to suspect that a super-active, supermassive black hole may have preceded the galaxy's formation.
Black holes are regions of space so dense with matter than not even photons of light can escape the grip of gravity. They can be detected as they consume nearby matter. The majority of galaxies are believed to contain a black hole, though some, like the one at the center of our Milky Way galaxy, are relatively quiet.
Read more at Discovery News
Aug 29, 2012
Building Blocks of Life Found Around Young Star
The astronomers found molecules of glycolaldehyde -- a simple form of sugar [1] -- in the gas surrounding a young binary star, with similar mass to the Sun, called IRAS 16293-2422. Glycolaldehyde has been seen in interstellar space before [2], but this is the first time it has been found so near to a Sun-like star, at distances comparable to the distance of Uranus from the Sun in the Solar System. This discovery shows that some of the chemical compounds needed for life existed in this system at the time of planet formation [3].
"In the disc of gas and dust surrounding this newly formed star, we found glycolaldehyde, which is a simple form of sugar, not much different to the sugar we put in coffee," explains Jes Jørgensen (Niels Bohr Institute, Denmark), the lead author of the paper. "This molecule is one of the ingredients in the formation of RNA, which -- like DNA, to which it is related -- is one of the building blocks of life."
The high sensitivity of ALMA -- even at the technically challenging shortest wavelengths at which it operates -- was critical for these observations, which were made with a partial array of antennas during the observatory's Science Verification phase [4].
"What it is really exciting about our findings is that the ALMA observations reveal that the sugar molecules are falling in towards one of the stars of the system," says team member Cecile Favre (Aarhus University, Denmark). "The sugar molecules are not only in the right place to find their way onto a planet, but they are also going in the right direction."
The gas and dust clouds that collapse to form new stars are extremely cold [5] and many gases solidify as ice on the particles of dust where they then bond together and form more complex molecules. But once a star has been formed in the middle of a rotating cloud of gas and dust, it heats the inner parts of the cloud to around room temperature, evaporating the chemically complex molecules, and forming gases that emit their characteristic radiation as radio waves that can be mapped using powerful radio telescopes such as ALMA.
IRAS 16293-2422 is located around 400 light-years away, comparatively close to Earth, which makes it an excellent target for astronomers studying the molecules and chemistry around young stars. By harnessing the power of a new generation of telescopes such as ALMA, astronomers now have the opportunity to study fine details within the gas and dust clouds that are forming planetary systems.
Read more at Science Daily
Warning On Deterioration of Famous Swedish Warship, Vasa
Ingela Bjurhager, Lars A. Berglund and colleagues explain that the Vasa sunk in the Stockholm harbor in 1628 on its maiden voyage after sailing less than a nautical mile. The ship was rediscovered in 1958, raised in 1961, treated with preservatives and finally put on display in the Vasa museum in 1990. The museum preserved the ship with polyethylene glycol (PEG) in a thick, wax-like preparation dissolved in water and sprayed onto the wood for 17 years. Concerns about deterioration arose, and the authors set out to determine the effects of PEG, iron from nails and rivets, and sulfur from decaying bacteria on the wood's strength.
The team analyzed the strength of wood taken from various locations in the ship's hull, which is largely made of oak. They report that at its worst, the wood had weakened as much as 80 percent. They suggest the loss of strength may be a result of letting the ship dry out after its recovery, allowing oxygen to react with the iron in the wood. Although they don't foresee an immediate danger to the ship, a clear understanding of the cause of the wood's degradation will be critical to preserving it for future generations. In parallel, an improved support structure is needed to minimize the stresses and deformations in the wooden hull.
Read more at Science Daily
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