Divers searched a lake near the city of Chelyabinsk, where a hole several metres wide had opened in the ice, but had so far failed to find any large fragments, officials said. Search teams said they had found small objects up to about 1 cm wide that might be fragments, but no larger pieces.
The scarcity of evidence on the ground has fuelled scores of conspiracy theories over what caused the fireball and the huge shockwave that hit Chelyabinsk, which plays host to many defence industry plants.
Nationalist leader Vladimir Zhirinovsky told reporters in Moscow it could have been "war-mongers" in the United States. "It's not meteors falling. It's a new weapon being tested by the Americans," he said.
A priest from near the explosion site called it an act of God. Social media sites were flooded with speculation about what might have caused the explosion.
"Honestly, I would be more inclined to believe that this was some military thing," said Oksana Trufanova, a local human rights activist.
Asked about the speculation, an official at the local branch of Russia's Emergencies Ministry simply replied: "Rubbish".
Residents of Chelyabinsk, an industrial city 1,500 km (950 miles) east of Moscow, heard an explosion, saw a bright light and then felt a shockwave that blew out windows and damaged the wall and roof of a zinc plant.
The meteor travelled through the atmosphere at 19 miles per second, according to Russian space agency Roscosmos, leaving a long white trail visible as far as 125 miles away.
NASA estimate the object was around 55 feet across before entering Earth's atmosphere and weighed about 10,000 tons.
It exploded miles above Earth, releasing nearly 500 kilotons of energy - about 30 times the size of the nuclear bomb dropped on the Japanese city of Hiroshima in World War Two, NASA added.
"We would expect an event of this magnitude to occur once every 100 years on average," said Paul Chodas of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California.
"When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones."
The Chelyabinsk regional governor said the strike caused about 1 billion roubles ($33 million) worth of damage.
Life in the city had largely returned to normal by Saturday although 50 people were still in hospital. Officials said more than 1,200 people were injured, mostly by flying glass.
Repair work had to be done quickly because of the freezing temperatures, which sank close to -20 degrees Celsius (-4 Fahrenheit) at night.
Read more at The Telegraph
Feb 16, 2013
Meet the Youngest Video Game Programmer
Zora Ball, a first grader at the Harambee Institute of Science and Technology Charter School in Philadelphia, created the video game in a class focused on science, technology, engineering and mathematics led by Tariq Al-Nasir, who heads the STEMnasium Learning Academy.
Al-Nasir’s organization uses open-source software called Bootstrap and Alice 2.0 that was originally developed for university-level coursework. While sixth and seventh graders are usually advanced enough to begin learning it, Al-Nasir told me he made the software more accessible with a programming language called Racket.
Once he got them into a this new programming environment, Al-Nasir was essentially teaching math to Ball and her classmates in a fun way. The students designed interactive games involving three elements: a player, a goal and something to avoid, all moving along X and Y coordinates. Then they picked a setting for the game.
For Zora Ball, that meant making the player a ballerina who’s searching for a jewel in a nail salon while trying to avoid a vampire — something she doesn’t like, Al-Nasir said. ”She was obviously very comfortable understanding that the danger is moving on the X and the player will be moving on the Y coordinate,” he added.
The Philadelphia Tribune’s Damon C. Williams called Zora the youngest individual to create a full version of a mobile application video game. Recently Zora demonstrated her skills at Will.i.am’s TRANS4M benefit show in Los Angeles, where she showed the singer a new game she’d made. Will.i.am was the player, microphones were the goal and the danger was a bad note, Al-Nasir explained.
And to think that in first grade my big achievement was making a Guy Smiley puppet with a popsicle stick. Seriously, nice work Zora.
Next, Al-Nasir said his first grade students are going to be designing more elaborate games based on the Alice programming language and then entering them into a competition. Meanwhile his eighth and ninth grade students are developing an app using Java and C programming called “Let Freedom Ring” in tribute to Martin Luther King Jr.
Read more at Discovery News
Feb 15, 2013
Why Good Hair Matters: First Animal Model of Recent Human Evolution Reveals That Mutation for Thick Hair Does Much More
The team, led by researchers from Harvard Medical School, Harvard University, the Broad Institute of MIT and Harvard, Massachusetts General Hospital, Fudan University and University College London, also modeled the spread of the gene mutation across Asia and North America, concluding that it most likely arose about 30,000 years ago in what is today central China. The findings are reported in the cover story of the Feb. 14 issue of Cell.
"This interdisciplinary approach yields unique insight into the generation of adaptive variation among modern humans," said Pardis Sabeti, associate professor in the Center for Systems Biology and Department of Organismic and Evolutionary Biology at Harvard University, and one of the paper's senior authors.
"This paper tells a story about human evolution in three parts," said Cliff Tabin, head of the HMS Department of Genetics and co-senior author. "The mouse model links multiple traits to a single mutation, the related association study finds these traits in humans, and computer models tell us where and when the mutation likely arose and spread."
Previous research in Sabeti's lab had identified the mutation as a strong candidate for positive selection. That is, evidence within the genetic code suggested the mutant gene conferred an evolutionary advantage, though what advantage was unclear.
The mutation was found in a gene for ectodysplasin receptor, or EDAR, part of a signaling pathway known to play a key role in the development of hair, sweat glands and other skin features. While human populations in Africa and Europe had one, ancestral, version of the gene, most East Asians had a derived variant, EDARV370A, which studies had linked to thicker scalp hair and an altered tooth shape in humans.
The ectodysplasin pathway is highly conserved across vertebrates -- the same genes do the same thing in humans and mice and zebrafish. For that reason, and because its effects on skin, hair and scales can be observed directly, it is widely studied.
This evolutionary conservation led Yana Kamberov, one of two first authors on the paper, to reason that EDARV370A would exert similar biological effects in an animal model as in humans. The HMS research fellow in genetics developed a mouse model with the exact mutation of EDARV370A -- a difference of one DNA letter from the original, or wild-type, population. That mouse manifested thicker hair, more densely branched mammary glands and an increased number of eccrine, or sweat, glands.
"This not only directly pointed us to the subset of organs and tissues that were sensitive to the mutation, but also gave us the key biological evidence that EDARV370A could have been acted on by natural selection," Kamberov said.
The findings prompted the team to look for similar traits in human populations. When co-first author Sijia Wang and the team including collaborators at Fudan examined the fingertips of Chinese volunteers at colleges and farming villages, they found that the sweat glands of Han Chinese, who carry the derived variant of the gene, were packed about 15 percent more densely than those of a control population with the ancestral variant.
At the same time, Wang and the team including collaborators at University College London were working to zero in on when and where the mutation arose. Computer models suggested that the derived variant of the gene emerged in central China between 13,175 and 39,575 years ago, with a median estimate of 30,925 years. Researchers concluded the derived variant is at least 15,000 years old, predating the migration from Asia by Native Americans, who also carry the mutation.
That time span suggests that different traits could have been under selection at different times. The mutation's many effects, known as pleiotropy, only complicate the question. If changes to the sweat glands conferred an advantage in new climates -- one of the theories the researchers plan to explore further -- changes to hair and to mammary glands could have conferred other advantages at other times.
Not all of these advantages need be direct effects on fitness. "When Pardis started this work, I would not have predicted that a gene that makes good hair would top of a list of mutations that confer evolutionary advantage among humans," said Bruce Morgan, HMS associate professor of dermatology at Massachusetts General Hospital and co-senior author on the paper. "However, in this case 'good hair' may have a biological meaning because it is genetically linked to a physiologically adaptive trait like increased sweating capacity. A cultural preference for a physically obvious trait like hair type could have arisen because individuals with it were more successful, and this would help increase selection on the new variant."
"That (pleiotropy) makes it harder for us to make a guess," Wang said. "If there were only one associated trait, we could say with confidence that's where the selective advantage comes from. But with many traits, we don't know which is the target of selection, and which are just hitchhiking." Wang intends to focus on that question in his new role, as a Max Planck independent research group leader in dermatogenomics at Chinese Academy of Sciences -- Max Planck Partner Institute for Computational Biology in Shanghai.
Read more at Science Daily
Frogs Find Safe Haven in West Africa
Nearly 800 West African amphibians were tested for the fungus and all of them were found to be free of the disease in a study published in PLOS ONE. Most of the species were frogs from a variety of habitats in seven nations, Bénin, Burkina Faso, Côte d’Ivoire, Ghana, Guinea, Liberia, Sierra Leone. Conditions in the rainforests of the regions are perfect for the fungus, but it seems that geography may have kept the fungus at bay.
The researchers suggested that a geographic barrier, the Dahomey Gap, may have protected West African frogs. The Dahomey Gap is strip of arid land that splits the Congo forest from the western African rainforest. The dry savannah of the Dahomey Gap may be blocking the fungus, which depends on moist conditions.
Unfortunately for frogs, the Dahomey Gap is no barrier to humans. Highways link the chytrid-infected regions to the east and south with the disease-free west. Some frogs that are regularly eaten can harbor the disease, and human commerce in these animals could spread the disease across the gap.
The disease doesn’t depend on live animals for transport. For example, the study’s authors called for researchers and tourists to avoid moving equipment across the Dahomey Gap. They also recommended mining tools be purchased anew, instead of transported from the east to the west in Africa. However, it seems unlikely that mining companies will spend millions of dollars to avoid infecting frogs.
Read more at Discovery News
Owl Makes 140-Mile Trip Stuck in SUV Grille
The owl was under veterinary care and expected to make a full recovery, the Sun Sentinel reported.
Sonji Coney-Williams was driving her Ford SUV along Florida’s Turnpike Thursday, Feb. 7, when she saw the bird in the dark in the middle of the road near Yeehaw Junction. “It didn’t move. It just stood there and I couldn’t stop,” she told the Sun Sentinel.
That night she checked into a hotel and the next morning as she was driving off a couple pointed to the grille on her SUV. “I lost it,” she said. “I told them I didn’t want to see it. I knew exactly what happened.”
But the bird was alive and Coney-Williams called the Florida Fish and Wildlife Conservation Commission. “FWC Officer Lex Corteguera removed the SUV’s grille and transported the feathered patient to the non-profit center. The center’s director, Sherry Schlueter, said the owl arrived dehydrated but responsive,” the Sun Sentinel reported.
Read more at Discovery News
Asteroid Buzzes Earth in Record-Breaking Flyby
The 150-foot-wide (45 meters) near-Earth asteroid 2012 DA14 cruised within 17,200 miles (27,000 kilometers) of Earth at 2:24 p.m. EST (1924 GMT) today, coming closer than many communications satellites circling our planet.
The flyby marked the closest approach by such a large asteroid that astronomers have ever known about in advance. But it wasn't even the most dramatic space-rock event of the day.
That distinction goes to a brilliant fireball that exploded early this morning in the skies over Russia's Chelyabinsk region, which is about 930 miles (1,500 km) east of Moscow. The blast damaged hundreds of buildings and wounded perhaps 1,000 people, according to media reports.
Scientists think the Russian fireball was caused by a object that was about 50 feet wide (15 m) and weighed about 7,000 tons before it hit Earth's atmosphere. For comparison, 2012 DA14 tips the scales at 140,000 tons or so. The two space rocks are completely unrelated, NASA researchers say, making the dual events a spooky cosmic coincidence.
Scientific treat
Astronomers had been looking forward to 2012 DA14's flyby for a while, since it gave them the rare chance to study a decent-size asteroid up close.
"We're going to use our radars to bounce radio waves off this asteroid, watch it spin, look at the reflections and understand its size, its shape and perhaps even a little bit about what it's made of," Jim Green, director of NASA's planetary science division, said in a video released by the space agency Thursday (Feb. 14).
Indeed, researchers around the world trained instruments on 2012 DA14, tracking the space rock as it cruised toward Earth, gave our planet a historically close shave and then slipped silently off into the depths of space once again.
There are lessons to be taken from today's asteroid flyby and fireball blast, researchers said.
"Today's events, both with 2012 DA14 and the Russian meteorite, are a reminder that our solar system is a crowded place," Chris Lewicki, president of asteroid-mining firm Planetary Resources, wrote in a blog post today.
Our planet has indeed been pummeled by asteroids many times over its history — perhaps most famously 65 million years ago, when a 6-mile-wide (10 km) behemoth wiped out the dinosaurs — and it will continue to be struck in the future.
The good news is that we probably don't have to worry about a potential civilization-ending strike anytime soon. NASA researchers have mapped out the orbits of 90 percent of the biggest and most dangerous near-Earth asteroids, and none of them seem to be on a collision course with Earth in the foreseeable future.
But there are a lot of smaller space rocks out there waiting to be discovered and mapped. Researchers have identified just 9,600 near-Earth asteroids to date, but they think a million or more are likely to be out there. (2012 DA14 itself was just discovered in February 2012.)
Spotting the most threatening of these space rocks may require lofting dedicated asteroid-hunting space telescopes, researchers say. The nonprofit B612 foundation plans to do just that; in 2017 or 2018, it aims to launch an instrument called the Sentinel Space Telescope, which would scan Earth's neighborhood from a Venus-like orbit, freeing it from having to contend with the glare of the sun.
Read more at Discovery News
Russian Meteor Explosion Not Caused by Asteroid Flyby
NASA asteroid expert Don Yeomans, head of the agency's Near-Earth Object Program Office, told SPACE.com that the object which exploded over a thinly inhabited stretch of eastern Europe today was most likely an exploding fireball known as a bolide.
More than 500 people were injured, mostly by glass cuts when windows shattered during the blast, according to the Russian Emergency Ministry.
"If the reports of ground damage can be verified, it might suggest an object whose original size was several meters in extent before entering the atmosphere, fragmenting and exploding due to the unequal pressure on the leading side vs the trailing side (it pancaked and exploded)," Yeomans told SPACE.com in an email. "It is far too early to provide estimates of the energy released or provide a reliable estimate of the original size."
Yeoman stressed that the bolide event was likely not associated at all with the incoming asteroid 2012 DA14, which will fly within 17,200 miles (27,000 kilometers) of Earth when it passes safely by our planet today.
"The asteroid will travel south to north," Yeomans said. "The bolide trail was not south to north and the separation in time between the fireball and 2012 DA14 close approach is significant."
Asteroid 2012 DA14 is 150 feet (45 meters) wide -- about half the size of a football field -- and will make its closest approach to Earth at 2:24 p.m. EST (1924 GMT) when it passes over Indonesia. It will be about 5,000 miles (8,046 kilometers) closer to Earth than the communications satellites circling the planet in geosynchronous orbits.
Read more at Discovery News
Feb 14, 2013
Unlocking the Mystery Behind Saturn's Moonlets
Saturn's F ring has long been of interest to scientists as its features rapid change on timescales from hours to years, and it is probably the only location in the solar system where large scale collisions happen on a daily basis.
When CASSINI began imaging the Saturn system back in 2006 the discovery of a proliferation of moonlets -- small natural satellites -- in Saturn's F ring was an unexpected find. Powerful tidal forces were thought to minimize the clumping of particles necessary to create these moonlets and scientists were at a loss to explain the high population in Saturn's rings.
As the processes at work in Saturn's rings are comparable to those of a protoplanetary disk, understanding them could be key to unlocking the secrets of our own solar system. Writing in the journal Scientific Reports, researchers from Loughborough's Department of Physics have revealed a new computer model which could help solve this mystery.
"Saturn's rings offer a nearby astrophysical laboratory to study and observe -- in real time -- many mechanisms and processes theorised to take place in astrophysical disks with the use of the CASSINI space craft," explains Loughborough physicist Phil Sutton. "And Saturn's F ring is probably the most active in the solar system. That's why we think it is so fascinating."
Work on Saturn's F ring, the outermost of the dense rings, has shown that the nearby 'shepherd' moon Prometheus directly influences the formation of moonlets in the ring itself. These moonlets can themselves create structures within the F ring. The interaction between Prometheus and the F ring transpires because of the difference in alignment of the elliptical F ring and the elliptical orbit of Prometheus. Over time changes in the rotational axis alters this alignment, resulting in very close approaches to the F ring by Prometheus. During the closest approaches over the course of one orbital period Prometheus moves towards and then back away from the F ring, creating structures known as streamer-channels.
Previous numerical modelling has used a massless F ring (where particles were non-interacting with each other) interacting with Prometheus and showed that the density of particles at streamer-channel edges increased over a series of orbital periods after the original encounter. However, the modelling did not account for the fast growth of moonlets necessary to explain the large population observed by CASSINI.
"In our paper we report the results of our numerical modelling that assumed an F ring with mass where all particles were gravitationally interacting," Mr Sutton explains. "What we see is an accelerated growth of the density seen at the same places on the streamer-channel edges than previously reported. This increase is around 5% each orbital period for the first five orbits, compared with a 0% increase for the same regions over the same time period using the non- interacting model.
"Where all the particles in the F ring interact with each other we see a more fluid-like motion. It is this fluid-like motion that creates turbulence and subsequent vortices within the F ring as a perpendicular force to the flow (Prometheus) disrupts it.
Read more at Science Daily
Bilingual Babies Know Their Grammar by 7 Months
Published February 14 in the journal Nature Communications and presented at the 2013 Annual Meeting of the American Association for the Advancement of Science (AAAS) in Boston, the study shows that infants in bilingual environments use pitch and duration cues to discriminate between languages -- such as English and Japanese -- with opposite word orders.
In English, a function word comes before a content word (the dog, his hat, with friends, for example) and the duration of the content word is longer, while in Japanese or Hindi, the order is reversed, and the pitch of the content word higher.
"By as early as seven months, babies are sensitive to these differences and use these as cues to tell the languages apart," says UBC psychologist Janet Werker, co-author of the study.
Previous research by Werker and Judit Gervain, a linguist at the Université Paris Descartes and co-author of the new study, showed that babies use frequency of words in speech to discern their significance.
"For example, in English the words 'the' and 'with' come up a lot more frequently than other words -- they're essentially learning by counting," says Gervain. "But babies growing up bilingual need more than that, so they develop new strategies that monolingual babies don't necessarily need to use."
Read more at Science Daily
Genders Not So Different?
That’s according to new research by psychologists who examined personality traits, such as being good at math, being aggressive, being a good listener or empathetic, playing video games or talking with friends -- that many of us believe split men and women.
"Just because men and women look very different and sometimes have different interests and behaviors, we shouldn't assume that what goes on in our heads is just as different, at least with the psychological characteristics we looked at," said Bobbi Carothers, a data analyst at the Center for Public Health Systems Science at Washington University in St. Louis. At the risk of being cliche, I'd say the take-home message is "Don't judge a book by its cover."
Carothers and Harry Reis, professor of psychology at the University of Rochester, analyzed data from 13 sex-difference studies over the past few decades. The studies included data from more than 13,000 research volunteers, most of them college students. They also examined studies of adolescents and mature adults.
The pair analyzed 122 different qualities such as preferences over how to spend their free time: golfing or scrap booking? Bath or boxing? They also looked at the so-called Big Five psychological traits: extraversion (sociability and enthusiasm); agreeableness, conscientiousness, emotional stability, and intellect. Other analyses examined how men and women chose sexual partners and mates.
Instead of scores falling along neat lines between males and females, like height or physical strength differences -- psychological indicators fell on a spectrum for both genders.
There are average differences, but they are not large enough to classify men and women as consistently separate gender categories. Reis said that their statistical analysis shows that it's hard to tell men and women apart, even when it comes to sexuality.
"Many people act as if men and women are different species," Reis said. "The message to me is that these qualities don't belong to one sex, these are human differences and any given individual can have more or less than any of them."
The study flies in the face of pop-psychology best-sellers such as "Men are From Mars, Women are From Venus" that argue the genders are hard-wired to behave differently in psychology and emotions. The results of Carothers and Reis’ analyses, "Men and Women Are From Earth," was published this month in the Journal of Personality and Social Psychology.
Read more at Discovery News
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