Rabu, 28 Desember 2011

Another Soyuz Rocket Launch Fails



Russia's recent poor launch record has continued with yet another Soyuz rocket failure.
This time, a Soyuz-2 vehicle failed to put a communications satellite into orbit after lifting away from the country's Plesetsk spaceport.

Debris is said to have re-entered the Earth's atmosphere and crashed to the ground.
In August, a Soyuz failure on a mission to resupply the space station led to a six-week suspension of flights.
Friday's rocket was carrying a Meridian-5 satellite, designed to provide communication between ships, planes and coastal stations on the ground, according to RIA Novosti.

t was a Soyuz-2.1b, the most modern version of the rocket that has been in service in various forms since the 1960s.
The failure is said to have occurred seven minutes into the flight. Sources being quoted by the Russian media talk of an anomaly in the rocket's third stage.



"The satellite failed to go into its orbit. A state commission will investigate the causes of the accident," the spokesman of Russia's space forces, Alexei Zolotukhin, was quoted as saying by the Interfax news agency.
August's botched launch involved a Soyuz-U. An inquiry into that incident eventually traced the problem to a blocked fuel line, again in the third stage of the vehicle.

But the U and 2.1b Soyuz variants use different engines in this segment of the rocket, so no immediate parallels between the two incidents can be drawn.
Friday's failure now puts a major question mark against the next Soyuz launch, scheduled for 28 December from the Baikonur Cosmodrome. This flight is intended to put in orbit six satellites for the Globalstar satellite phone company.

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And it will raise concern again among the partners on the International Space Station (ISS) that there may be systemic problems in the Russian launch sector.
Following the retirement of the American space shuttle in July, the Soyuz rocket is the only means of getting astronauts and cosmonauts to the ISS. August's failure saw manned flights stand down even longer than the six weeks for unmanned Soyuz rockets, and the hiatus put a severe strain on the operation of the space station.


Russia has experienced a number of launch mishaps in the past 13 months.
On 18 August, the week before the loss of the space station mission, a Proton vehicle failed to put a communications satellite in its proper orbit.

Back on 1 February, a Rokot launch also underperformed with a similar outcome.
And on 5 December last year, a Proton carrying three navigation spacecraft fell into the Pacific Ocean. This particular failure is widely believed to have contributed to the decision of the Russian government to replace the then space agency chief, Anatoly Perminov.

Vladimir Popovkin took over as the head of Roscosmos in April.
The rocket failures come on top of the loss of Phobos-Grunt, Russia's most ambitious planetary mission in decades. It became stuck in Earth orbit after its launch in November and will probably fall back to Earth next month.
Environment Clean Generations

New Particle Discovered at LHC: the Chi-b(3P)


For the first time since the Large Hadron Collider (LHC) was opened in 2009, physicists from the UK think they've detected their first new subatomic particle.

Researchers from the University of Birmingham and Lancaster University analysed data from the ATLAS experiment, where particles of matter are shot at each other at close to the speed of light, in the hopes that interesting new particles will appear in the resulting subatomic carnage.



The data shows a clear indication of a particle called Chi-b(3P), which is pronounced kye-bee-three-pee. It's a forge of the bottom quark (also known as the beauty quark) and its antiquark.

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Quarks are the building blocks of protons and neutrons, which in turn are the building blocks of atoms. Quarks come in a number of flavours like up, down, strange, charm, bottom, and top. This newly found particle tells us more about the strong nuclear forces that bind the quark and the antiquark.
The lighter partners of the Chi-b(3P) were observed in previous collision experiments around 25 years ago. This is a more excited state of Chi particle.

"Our new measurements are a great way to test theoretical calculations of the forces that act on fundamental particles, and will move us a step closer to understanding how the universe is held together," said Miriam Watson, a research fellow working in the Birmingham group .


Chi-b(3P) is also a boson, which are subatomic particles that obey Bose-Einstein statistics. A far more famous boson, the Higgs, is also being hunted for by the LHC. This theoretical field of particles is thought to give subatomic particles their mass as they wade through it. Earlier this month, physicists from the Cern research lab in Geneva announced that they have made significant progress in the hunt for the Higgs boson, but the result does not provide definitive evidence for the long-sought particle.With significantly more data to be gathered next year, "we can look forward to resolving this puzzle in 2012," said Atlas experiment spokesperson Fabiola Gianotti.
Environment Clean Generations

Neutrino Observatory - The Second-Largest Human Structure Ever Built


Forty different universities and institutions from across Europe are partnering on a project to build a neutrino observatory under the Mediterranean sea that will be the second-largest structure ever built by humans, after the Great Wall of China.
The KM3NeT telescope will have a volume of "several" cubic kilometres -- hence the odd name, which purportedly stands for "kilometre-cubed neutrino telescope". It will comprise of a number of towers -- each taller than the 830-metre Burj Khalifa in Dubai -- which will be filled with spheres containing photomultiplier tubes, which will record neutrinos passing through.


Neutrinos are notoriously tricksy little particles, formed in certain types of radioactive decay. They get their name because they carry no electrical charge, but that property also means that they can pass through matter virtually unimpeded, making them difficult to spot. Whereas an electron passing through a 3-centimetre thick sheet of metal will lose significant amounts of energy, a neutrino of the same energy would need something like a light-year's worth of heavy metal to lose the same amount.

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Peter Fisher, a particle physicist at MIT, explained to Popsci: "Anytime you detect a particle, what you're always doing is having the particle interact with some kind of matter, whether it's water, steel, air or ice. The less the particle interacts, the more material you need for it to interact in."


KM3NeT uses the ocean instead. Hundreds of metres of seawater act as a shield, blocking interference from particles generated in our atmosphere, and allow the photomultipliers to capture the bright blue flash caused when a neutrino hits the nucleus of an atom and produces a charged particle known as a muon.
Giorgio Riccobene, a staff researcher at the Italian National Institute for Nuclear Physics, said: "This is the light we look for to reconstruct the trajectory of the muon," Riccobene said. "So, in this sense, it is an underwater telescope. The water allows us to see the reaction more clearly."

The structure is still in the planning phases, and funding is proving problematic given the current state of European finances and politics, but if all goes well then construction could begin as early as 2012.
Environment Clean Generations

Wash Your Clothes Using Sunlight


Material scientists have developed a new cotton fabric that cleans itself of stains and bacteria when exposed to sunlight. This would mean you could transform your garments from stinky to sparkly simply by simply hanging them out in the sunshine.

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Mingce Long and Deyong Wu from Donghua University developed the fabric using a coating made from a compound of titanium dioxide and nitrogen. This breaks down stains and kills microbes when exposed to some types of light.
Titanium dioxide has already found uses in self-cleaning windows, kitchen and bathroom tiles. The authors admit that there are already other self-cleaning fabrics but these tend to work most efficiently when exposed to intense ultraviolet rays. This coating works within the visible spectrum.



Fabric coated with the material could easily remove an orange dye stain when exposed to sunlight. Further nanoparticles made from silver and iodine helps to accelerate the discoloration process. The coating even remains after washing and drying the clothes. Although presumably that wouldn't be necessary if the Sun already did the leg-work.
The study appears in ACS Applied Materials & Interfaces
Environment Clean Generations

The Super-Strong Mice


A team of geneticists has tweaked the genes of mice and worms to create animals with muscles that are twice as strong as normal.
Researchers from the Salk Institute for Biological Studies and two Swiss institutions, Ecole Polytechnique Federale de Lausanne (EPFL) and the University of Lausanne teamed up for the study, which could lead to the development of treatments for muscle degeneration in people who can't exercise.

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The team created the super-strong high endurance creatures by suppressing a natural muscle growth inhibitor. Genome regulator NCoR1 is a molecular brake that decreases activity of certain genes. This brake can be "released" through mutation or using chemicals and this, in turn, reactivates gene circuits to provide more energy to muscle and enhance its activity. This lead to the creation of super mice with muscles that are twice as strong as those of regular mice, even when the muscle was inactive.



Ronald M Evans, a professor at Salk's Gene Expression Lab, says: "There are now ways to develop drugs for people who are unable to exercise due to obesity or other health complications, such as diabetes, immobility and frailty. We can now engineer specific gene networks in muscle to give the benefits of exercise to sedentary mice."

Researchers experimented with both mice and nematodes, genetically manipulating the offspring of these species to repress NCoR1, the muscle build-up inhibitor. Without the inhibitor, the muscle develops much more effectively.

The muscly mice were able to run faster and longer before showing signs of fatigue. They also exhibited better cold tolerance. Similar results were seen in nematode worms, which let the researchers conclude that their results could be relevant to a range of living creatures.

Under the microscope the muscles could be seen to be bigger, with denser fibres and with cells that had more mitochondria, the cellular organelles that deliver energy to the muscles.
So far the researchers haven't found any harmful side effects associated with eliminating the NCoR1 receptor from muscle and fat tissue, and are now investigating drug molecules that could be used to reduce the receptor's effectiveness. Johan Auwerx, the lead author from EPFL, said: "This could be used to combat muscle weakness in the elderly, which leads to falls and contributes to hospitalisations. In addition, we think that this could be used as a basis for developing a treatment for genetic muscular dystrophy."


He added that if these results are confirmed in humans, there's no question they will attract interest from athletes as well as medical experts.
Environment Clean Generations

Jupiter's Core Dissolving


Think climate change is bad? Things are rather worse in the outer solar system. Jupiter's rocky central core may well be dissolving into liquid.
The gas giant, which is twice as massive as all of the other planets orbiting the Sun put together, has a central core comprised of iron, rock and ice. It sits in the centre of the planet, submerged in a fluid of hydrogen and helium under intense pressures about 40 million times greater than atmospheric pressure on Earth, and temperatures around 16,000 degrees kelvin -- hotter than the surface of the Sun.


As such, we can't recreate those conditions experimentally on Earth. But that hasn't stopped planetary scientists Hugh Wilson and Burkhard Militzer of the University of California, Berkeley, giving it a go. They've performed quantum mechanical calculations to try and work out how one of the key ingredients of the core -- magnesium oxide -- responds in such an extreme situation.

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They found that under these intense pressures and temperatures, the magnesium oxide has very high solubility, meaning that it's likely to be dissolving into liquid. The exact rate of the erosion isn't known, but the pair had earlier predicted that the ice in the core is also dissolving. That means that Jupiter's core is likely to be smaller now than it was when the planet formed.


The research has been detailed in a paper submitted to Physical Review Letters, in which Wilson and Militzer say that the work has substantial implications for working out how to simulate these types of planets. "For large exoplanets exceeding Jupiter's mass, higher interior temperatures promote both solubility and redistribution, implying that the cores of sufficiently large super-Jupiters are likely to be completely redistributed," it reads.
We'll be able to find out more in 2016, when Nasa's Juno spacecraft arrives at the gas giant and begins to measure its gravitational field.
Environment Clean Generations

Minggu, 18 Desember 2011

In Third-Degree Burn Treatment, Hydrogel Helps Grow New, Scar-Free Skin


Johns Hopkins researchers have developed a jelly-like material and wound treatment method that, in early experiments on skin damaged by severe burns, appeared to regenerate healthy, scar-free tissue.

In the Dec. 12-16 online Early Edition of Proceedings of the National Academy of Sciences, the researchers reported their promising results from mouse tissue tests. The new treatment has not yet been tested on human patients. But the researchers say the procedure, which promotes the formation of new blood vessels and skin, including hair follicles, could lead to greatly improved healing for injured soldiers, home fire victims and other people with third-degree burns.
The treatment involved a simple wound dressing that included a specially designed hydrogel -- a water-based, three-dimensional framework of polymers. This material was developed by researchers at Johns Hopkins' Whiting School of Engineering, working with clinicians at the Johns Hopkins Bayview Medical Center Burn Center and the Department of Pathology at the university's School of Medicine.



Third-degree burns typically destroy the top layers of skin down to the muscle. They require complex medical care and leave behind ugly scarring. But in the journal article, the Johns Hopkins team reported that their hydrogel method yielded better results. "This treatment promoted the development of new blood vessels and the regeneration of complex layers of skin, including hair follicles and the glands that produce skin oil," said Sharon Gerecht, an assistant professor of chemical and biomolecular engineering who was principal investigator on the study.

Gerecht said the hydrogel could form the basis of an inexpensive burn wound treatment that works better than currently available clinical therapies, adding that it would be easy to manufacture on a large scale. Gerecht suggested that because the hydrogel contains no drugs or biological components to make it work, the Food and Drug Administration would most likely to classify it as a device. Further animal testing is planned before trials on human patients begin. But Gerecht said, "It could be approved for clinical use after just a few years of testing."

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John Harmon, a professor of surgery at the Johns Hopkins School of Medicine and director of surgical research at Bayview, described the mouse study results as "absolutely remarkable. We got complete skin regeneration, which never happens in typical burn wound treatment."

If the treatment succeeds in human patients, it could address a serious form of injury. Harmon, a coauthor of the PNAS journal article, pointed out that 100,000 third-degree burns are treated in U. S. burn centers like Bayview every year. A burn wound dressing using the new hydrogel could have enormous potential for use in applications beyond common burns, including treatment of diabetic patients with foot ulcers, Harmon said.
Guoming Sun, Gerecht's Maryland Stem Cell Research Postdoctoral Fellow and lead author on the paper, has been working with these hydrogels for the last three years, developing ways to improve the growth of blood vessels, a process called angiogenesis. "Our goal was to induce the growth of functional new blood vessels within the hydrogel to treat wounds and ischemic disease, which reduces blood flow to organs like the heart," Sun said. "These tests on burn injuries just proved its potential."

Gerecht says the hydrogel is constructed in such a way that it allows tissue regeneration and blood vessel formation to occur very quickly. "Inflammatory cells are able to easily penetrate and degrade the hydrogel, enabling blood vessels to fill in and support wound healing and the growth of new tissue," she said. For burns, the faster this process occurs, Gerecht added, the less there is a chance for scarring.


Originally, her team intended to load the gel with stem cells and infuse it with growth factors to trigger and direct the tissue development. Instead, they tested the gel alone. "We were surprised to see such complete regeneration in the absence of any added biological signals," Gerecht said.
Sun added, "Complete skin regeneration is desired for various wound injuries. With further fine-tuning of these kinds of biomaterial frameworks, we may restore normal skin structures for other injuries such as skin ulcers."
Gerecht and Harmon say they don't fully understand how the hydrogel dressing is working. After it is applied, the tissue progresses through the various stages of wound repair, Gerecht said. After 21 days, the gel has been harmlessly absorbed, and the tissue continues to return to the appearance of normal skin.

The hydrogel is mainly made of water with dissolved dextran -- a polysaccharide (sugar molecule chains). "It also could be that the physical structure of the hydrogel guides the repair," Gerecht said. Harmon speculates that the hydrogel may recruit circulating bone marrow stem cells in the bloodstream. Stem cells are special cells that can grow into practically any sort of tissue if provided with the right chemical cue. "It's possible the gel is somehow signaling the stem cells to become new skin and blood vessels," Harmon said.
Additional co-authors of the study included Charles Steenbergen, a professor in the Department of Pathology; Karen Fox-Talbot, a senior research specialist from the Johns Hopkins School of Medicine; and physician researchers Xianjie Zhang, Raul Sebastian and Maura Reinblatt from the Department of Surgery and Hendrix Burn and Wound Lab. From the Whiting School's Department of Chemical and Biomolecular Engineering, other co-authors were doctoral students Yu-I (Tom) Shen and Laura Dickinson, who is a Johns Hopkins Institute for NanoBioTechnology (INBT) National Science Foundation IGERT fellow. Gerecht is an affiliated faculty member of INBT.
The work was funded in part by the Maryland Stem Cell Research Fund Exploratory Grant and Postdoctoral Fellowship and the National Institutes of Health.
The Johns Hopkins Technology Transfer staff has filed a provisional patent application to protect the intellectual property involved in this project.

Closer for Higgs Boson, but Particle still Remains Elusive


Physicists from the Cern research lab in Geneva announced that they have made significant progress in the hunt for the Higgs boson, but the result does not provide definitive evidence for the long-sought particle.
The teams announced signals consistent with the appearance of the Higgs boson, and the results suggest a Higgs particle mass of about in the range of 115 to 130 gigaelectronvolts (GeV). However, the signals could also be explained if the Higgs field doesn't exist -- it could just be background fluctuation.

More data will be needed to establish the existence of the Higgs with confidence. The Atlas and CMS experiments will gather significantly more data in 2012 -- but until then, a definitive answer to the question "does the Higgs boson exist" is still out of reach.
"Given the outstanding performance of the LHC this year, we will not need to wait long for enough data and can look forward to resolving this puzzle in 2012," said Atlas experiment spokesperson Fabiola Gianotti.


Two teams of physicists working with Cern's Large Hadron Collider in Geneva are expected to announce that they have found the best evidence yet for the hypothetical elementary particle: the Higgs boson.
The teams -- Atlas and CMS -- have been working independently to hunt for signs of the elusive particle. But what is the Higgs boson, and why do you need to recreate events a fraction of a second after the Big Bang to find it?

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It's named after Edinburgh University physicist Peter Higgs, who proposed that atoms receive their mass from an invisible field that's spread throughout the cosmos. Like wading through treacle, atoms pick up mass as they whizz through the Higgs field.
The Higgs is an answer to the physics conundrum of why the building blocks of matter have a mass at all. This stops them from zipping about the universe at the speed of light, and allows them to bind together to form planets, humans, kangaroos and asteroids.

Its existence is essential for the Standard Model, which is the universally-accepted scientific theory to explain the dynamics of subatomic particles. The Higgs boson has always been the one missing ingredient to this model, but if it doesn't exist then the Standard Model shatters into pieces.


To find evidence for its existence, physicists built the LHC: a $10 billion (£6bn) particle accelerator that's housed in a 18-mile tunnel, deep beneath near the French-Swiss border. This monstrous physics laboratory can recreate conditions that existed a fraction of a second after the Big Bang.

The collider makes beams of protons move at close to the speed of light, before smashing them into each other. This spectacular head-on collision causes other types of particles to splinter off -- hopefully including the Higgs boson.
If it exists, the Higgs is so unstable that it would rapidly decay into more stable, and lighter subatomic particles. But that decay would leave behind a telltale fingerprint, showing up on the physicists' graphs as a very exciting bump.
CERN is to hold a seminar at 13:00 UTC on 13 December, "at which the ATLAS and CMS experiments will present the status of their searches for the Standard Model Higgs boson." The conference and a follow-up questions and answers session will be streamed over the web, here.

Massive Gas Cloud Tumbling into Nearby Black-Hole


The supermassive black hole at the heart of the Milky Way galaxy is about to have lunch. An enormous gaseous cloud, with almost three times the mass of planet Earth, is fast approaching the black hole's event horizon, and it will be ripped, shredded and gobbled down in 2013.
"It is not going to survive the experience," Stefan Gillessen, of the Max Planck Institute for Extraterrestrial Physics in Germany, confirms in no uncertain terms.
This unique event will give astronomers a front row seat to something that's never been observed up close, before: how a black hole gulps down gas, dust and stars as it grows ever bigger. All other black holes are too far away to see first hand, while our closest one is just 27,000 light years from Earth.


"When we look at the black holes in the centres of other galaxies, we see them get bright and then fade, but we never know what is actually happening," said Eliot Quataert, a theoretical astrophysicist at University of California.
"This is an unprecedented opportunity to obtain unique observations and insight into the processes that go on as gas falls into a black hole, heats up and emits light. It's a neat window onto a black hole that's actually capturing gas as it spirals in."

Gillessen, Quataert and physicist Reinhard Genzel have been tracking the cloud since 2008, using the European Southern Observatory's Very Large Telescope in Chile. They have seen the gaseous entity speed up to a velocity of 8 million kilometres an hour, and are now starting to see its edges fray as it tumbles deeper into the black hole's gravitational whirlpool.

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This cloud is mostly helium and hydrogen, and it's particularly cold -- just 280 degrees celsius. It likely formed when plumes of gas from two nearby stars were shoved together by stellar winds, and it is now glowing under the ultraviolet radiation from surrounding hot stars.

The cloud will soon come within about 40 billion kilometres of the event horizon. That's the limit beyond which nothing, not even light, can escape from a black hole. By 2013 the team should see violent outbursts of X-rays and radio waves as the cloud gets hotter and is torn to shreds. The light emitted around the black hole could increase by a hundredfold to a thousandfold, Quataert has calculated.
The Chandra X-ray satellite has already scheduled its largest single chunk of observation time in 2012 near the Milky Way's central black hole.
Environment Clean Generations

Lovejoy Comet Lives after Solar Encounter


You would have been very optimistic if, before Comet Lovejoy's apparent suicidal near-miss of the sun's surface, you'd placed a bet on the icy interloper's survival. But if you did, you'd be laughing all the way to the bank.



This is why I don't gamble -- I was anything but optimistic of the chances the Kreutz Sungrazing comet -- officially designated as C/2011 W3 (Lovejoy) -- would live through the hellish temperatures it endured as it made the death-defying solar dive.

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But as NASA's Solar Dynamics Observatory (SDO) watched the comet emerge from the other side of the sun Thursday evening, Comet Lovejoy proved the doubters wrong and continued its orbit after passing only 87,000 miles above the sun's photosphere. In doing so, it had endured temperatures of over a million degrees Celsius.
Watch the video of the lucky comet zooming away from the limb of the sun:

The Methane Time Bomb


Arctic scientists discover new global warming threat as melting permafrost releases millions of tons of a gas 20 times more damaging than carbon dioxide 

 The first evidence that millions of tons of a greenhouse gas 20 times more potent than carbon dioxide is being released into the atmosphere from beneath the Arctic seabed has been discovered by scientists.

The Independent has been passed details of preliminary findings suggesting that massive deposits of sub-sea methane are bubbling to the surface as the Arctic region becomes warmer and its ice retreats.

Underground stores of methane are important because scientists believe their sudden release has in the past been responsible for rapid increases in global temperatures, dramatic changes to the climate, and even the mass extinction of species. Scientists aboard a research ship that has sailed the entire length of Russia's northern coast have discovered intense concentrations of methane – sometimes at up to 100 times background levels – over several areas covering thousands of square miles of the Siberian continental shelf.



In the past few days, the researchers have seen areas of sea foaming with gas bubbling up through "methane chimneys" rising from the sea floor. They believe that the sub-sea layer of permafrost, which has acted like a "lid" to prevent the gas from escaping, has melted away to allow methane to rise from underground deposits formed before the last ice age.
They have warned that this is likely to be linked with the rapid warming that the region has experienced in recent years.

Methane is about 20 times more powerful as a greenhouse gas than carbon dioxide and many scientists fear that its release could accelerate global warming in a giant positive feedback where more atmospheric methane causes higher temperatures, leading to further permafrost melting and the release of yet more methane.
The amount of methane stored beneath the Arctic is calculated to be greater than the total amount of carbon locked up in global coal reserves so there is intense interest in the stability of these deposits as the region warms at a faster rate than other places on earth.
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Orjan Gustafsson of Stockholm University in Sweden, one of the leaders of the expedition, described the scale of the methane emissions in an email exchange sent from the Russian research ship Jacob Smirnitskyi.
"We had a hectic finishing of the sampling programme yesterday and this past night," said Dr Gustafsson. "An extensive area of intense methane release was found. At earlier sites we had found elevated levels of dissolved methane. Yesterday, for the first time, we documented a field where the release was so intense that the methane did not have time to dissolve into the seawater but was rising as methane bubbles to the sea surface. These 'methane chimneys' were documented on echo sounder and with seismic [instruments]."

At some locations, methane concentrations reached 100 times background levels. These anomalies have been seen in the East Siberian Sea and the Laptev Sea, covering several tens of thousands of square kilometres, amounting to millions of tons of methane, said Dr Gustafsson. "This may be of the same magnitude as presently estimated from the global ocean," he said. "Nobody knows how many more such areas exist on the extensive East Siberian continental shelves.



"The conventional thought has been that the permafrost 'lid' on the sub-sea sediments on the Siberian shelf should cap and hold the massive reservoirs of shallow methane deposits in place. The growing evidence for release of methane in this inaccessible region may suggest that the permafrost lid is starting to get perforated and thus leak methane... The permafrost now has small holes. We have found elevated levels of methane above the water surface and even more in the water just below. It is obvious that the source is the seabed."
The preliminary findings of the International Siberian Shelf Study 2008, being prepared for publication by the American Geophysical Union, are being overseen by Igor Semiletov of the Far-Eastern branch of the Russian Academy of Sciences. Since 1994, he has led about 10 expeditions in the Laptev Sea but during the 1990s he did not detect any elevated levels of methane. However, since 2003 he reported a rising number of methane "hotspots", which have now been confirmed using more sensitive instruments on board the Jacob Smirnitskyi.

Dr Semiletov has suggested several possible reasons why methane is now being released from the Arctic, including the rising volume of relatively warmer water being discharged from Siberia's rivers due to the melting of the permafrost on the land.
The Arctic region as a whole has seen a 4C rise in average temperatures over recent decades and a dramatic decline in the area of the Arctic Ocean covered by summer sea ice. Many scientists fear that the loss of sea ice could accelerate the warming trend because open ocean soaks up more heat from the sun than the reflective surface of an ice-covered sea.

Wall of Sound Against Riots


RIOT shields that project a wall of sound to disperse crowds will reduce violent clashes with police, according to a patent filed by defence firm Raytheon of Waltham, Massachusetts.



The device looks similar to existing riot shields, but it incorporates an acoustic horn that generates a pressure pulse. Police in the US already use acoustic devices for crowd control purposes that emit a loud, unpleasant noise.
The new shield described by Raytheon produces a low-frequency sound which resonates with the respiratory tract, making it hard to breathe. According to the patent, the intensity could be increased from causing discomfort to the point where targets become "temporarily incapacitated".

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Acoustic devices haven't seen wide adoption because their range is limited to a few tens of metres. The patent gets around this by introducing a "cohort mode" in which many shields are wirelessly networked so their output covers a wide area, like Roman legionaries locking their shields together. One shield acts as a master which controls the others, so that the acoustic beams combine effectively.
Raytheon declined to comment on the work.

"We do not have sufficient technical detail yet to determine if there are any hidden medical implications," says Steve Wright of Leeds Metropolitan University in the UK. "These are always a concern because of the risk to sensitive bodily functions such as hearing, or even inducing panic attacks in asthmatics."
The biggest danger, he warns, is that the technology would be used for political control. "If authorities in Egypt or Syria had this, would they use it for dispersal or to shove crowds into potentially lethal harm's way?"

Selasa, 06 Desember 2011

Kepler Team Confirms First Earth-like Planet in a Habitable Zone, And Finds 1,094 More Worlds


Nestled in the Goldilocks zone of a small, sun-like star is a room-temperature world a little more than twice the size of Earth. Scientists do not yet know if it is rocky or gaseous and whether it has water or clouds, but they do know that it’s the right size, and in the right place, for liquid water to exist. If it does exist, it may be one of the best places to look for life outside of our solar system.

The new planet, Kepler-22, is about 600 light-years away and the smallest planet confirmed to exist smack in the middle of the habitable zone of a sun-like star. It’s one of the most stunning announcements from the Kepler Space Telescope, which stares at a field of stars in the constellations Cygnus and Lyra and looks for blips in brightness to find other planets. While Kepler has (as of today) found more than 2,000 possible planets, finding an Earth-like world in a sun-like environment has proved elusive — until now.


“This is a major milestone on the road to finding Earth's twin,” said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington.
On top of this announcement today, the Kepler science team is sharing 1,094 more planet candidates, many of which are also potentially Earth-like and in habitable zones. Now there are 2,326 planet candidates in the sun-orbiting space telescope’s field of view, in a small sliver of the sky.

Kepler-22b’s discovery was first announced last February, when the Kepler team shared its initial treasure trove of planet candidates. Among 1,235 candidate worlds, there were 54 habitable zone candidates, Kepler-22b among them. Now it’s the first of these to be confirmed.
It takes 290 days to orbit around its star, Kepler-22, a G-class star a lot like the one we know best. “It’s almost a solar twin; it is very similar to our sun,” Natalie Batalha, Kepler deputy science team lead at San Jose State University, said in a press conference.

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The planet is about 15 percent nearer to its star than Earth is to the sun. But this is OK because the star is cooler (by about 220 degrees), a bit dimmer, and a little smaller than our star. So the planet is in a really analogous Earth-like orbit. The planet’s temperature is even pretty close to Earth’s, said William Borucki, the Kepler mission’s principal investigator at NASA’s Ames Research Center. “If greenhouse warming on this planet was similar (to atmospheric warming on Earth), its surface temperature would be something like 72° F,” he said.


Kepler-22 System: This diagram compares our own solar system to Kepler-22, a star system containing the first "habitable zone" planet discovered by NASA's Kepler telescope. The habitable zone is the sweet spot around a star where temperatures are right for water to exist in its liquid form. Kepler-22's star is a bit smaller than our sun, so its habitable zone is slightly closer in. The diagram shows an artist's rendering of the planet comfortably orbiting within the habitable zone, similar to where Earth circles the sun.  NASA/Ames/JPL-Caltech
 
It will be a mighty nice place to look for signs of life, he added. Jill Tarter, director of the Center for SETI Research at the SETI Institute, said astrobiologists are taking that to heart. “We will give a higher priority to worlds that our colleagues tell us are not too warm, not too cold, but just right,” she said.
With so many exoplanets, astronomers will need to start making some catalog decisions, ranking planets by their habitability potential. Along with the Earth Similarity Index we covered last month, the Kepler team has their own proposed planetary directory to make this easier. The Habitable Exoplanets Catalog ranks planets by their surface temperature, similarity to Earth, and capacity to sustain organisms at the bottom of the food chain.

Monday’s announcement came during the inaugural Kepler Science Conference in Mountain View, Calif. With the addition of 1,094 new candidate worlds, the number of planet candidates has increased by 89 percent and now totals 2,326. Of these, 207 are approximately Earth-size, 680 are super Earth-size, 1,181 are Neptune-size, 203 are Jupiter-size and 55 are larger than Jupiter. So since February, the number of Earth-size and super Earth-size candidates has increased by more than 200 and 140 percent, respectively.
That’s a lot of numbers, and here’s another good one: 10. That’s the number of these new candidates that are near-Earth-sized and in the habitable zones of their host stars. Kepler-22b is not among that list, so that makes at least 11 places elsewhere in the galaxy that might look very, very familiar.

There’s still a bit of work to do to quantify just what Kepler-22b looks like. Now that astronomers are convinced it’s a planet and they know where it is, confirming their findings with the Spitzer Space Telescope, they want to find out what it's made of. Ground-based telescopes like the Keck Observatory will start making some measurements next summer, when the field of sky that Kepler studies is visible from Earth.

And there is still much more to come, according to NASA scientists. Some software improvements have made it a little simpler to sift through Kepler light-curve data and hunt for planet candidates, so there will be at least one more big batch, according to Batalha. Among those, there may be many more Earth-like candidates to join the ranks.
“We are really zeroing in on the true Earth-sized habitable planets,” she said.
NASA
Environment Clean Generations

Two Behemoth Black Holes Could Swallow Billions of Suns

Astronomers have measured the two most enormous supermassive black holes found so far, vast realms of titanic gravity large enough to swallow 10 of our solar systems. The black holes are much bigger than predicted, suggesting extra-large galaxies and their black holes grow and evolve differently than smaller ones.
One of the monstrous black holes, in the center of the galaxy NGC 3842, weighs as much as 9.7 billion suns. It is about 331 million light-years away in the constellation Leo. The other one, NGC 4889, is of comparable or even greater mass, the researchers say — they’re not positive, but the numbers suggest it could be up to 21 billion solar masses. It's 336 million light-years away in the Coma galaxy cluster.

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Behemoth Black Hole This figure shows the immense size of the black hole discovered in the galaxy NGC 3842. The black hole is at its center and is surrounded by stars (shown as an artist's concept in the central figure). The black hole is seven times larger than Pluto's orbit. Our solar system (inset) would be dwarfed by it. Pete Marenfeld

The former heavyweight champ is a dwarf by comparison, tipping the scales at 6.3 billion solar masses. That black hole is at the center of the giant elliptical galaxy Messier 87.
Supermassive black holes of 10-billion-sun magnitude have been predicted based on the brightness of quasars, ultra-luminous distant objects that are largely thought to be spiraling discs surrounding the event horizons of black holes in the very early universe. But this is the first time such enormous black holes have ever been seen. They could be a missing link to the quasars, according to astronomer Michele Capellari, writing in a companion piece to the new black hole paper.




"These objects probably represent the missing dormant relics of the giant black holes that powered the brightest quasars in the early universe," she wrote.
To weigh the black holes, Nicholas McConnell and Chung-Pei Ma at the University of California-Berkeley used the Keck and Gemini observatories to measure the speed of stars moving around the black holes. The faster the stars were moving, the more gravity was needed to keep them in check, so the researchers used these velocities to calculate the black holes’ masses.
They found the black holes were much bigger than predictive math would suggest, which means astronomers still have a lot to learn about how the biggest black holes form and evolve.
“Our measurements suggest that different evolutionary processes influence the growth of the largest galaxies and their black holes,” the researchers write.
The paper will appear in the journal Nature.

Our Own Black Hole, Through Adaptive Optics: Image of the center of our galaxy from laser-guide-star adaptive optics on the Keck Telescope. If a 10 billion solar mass black hole resided at the Milky Way's center, its immense event horizon would be visible, as illustrated by the central black disk. The actual black hole at the galactic center is 2,500 times smaller, however.  Andrea Ghez, Lynette Cook
 BBC
 Environment Clean Generations

Grabbing Moisture from Desert Air


The James Dyson Award winners for 2011 have been announced, and the grand prize winner is a piece of clever biomimicry that sits so perfectly in our wheelhouse that we couldn’t resist the urge to write about it. Edward Linacre of Swinburne University of Technology in Melbourne has tapped the Namib beetle--a desert dwelling species that survives in the most arid conditions on Earth--to create an irrigation system that can pull liquid moisture straight out of dry desert air.

Airdrop, as the system is known, borrows a trick from the Namib beetle, which can live in areas that receive just half an inch of rain per year by harvesting the moisture from the air that condenses on its back during the early morning hours. A hydrophilic skin helps to snare water molecules passing on the breeze, which then accumulate into droplets of consumable liquid water.


Airdrop mimics this idea, though on a larger scale. The self-powering device pumps water into a network of underground pipes, where it cools enough for water to condensate. From there the moisture is delivered to the roots of nearby plants. Linacre’s math shows that about 11.5 milliliters can be harvested from every cubic meter of air, and further development could raise that number even higher.

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Such a system could provide regular moisture to plants being grown in the world’s driest regions. And because it is low cost and self-powered, there’s not a lot of investment or maintenance involved in deploying Airdrop. The $14,000 award from Dyson (Linacre’s university also gets an additional $14,000) should help speed that along.

This year’s runners up included a quickly deployable divider for medical settings that lets healthcare professionals make the most of available space and an aide for the blind that uses a special cane and location-based social networking apps to help the visually impaired locate their friends. All of this year's entries can be seen here.

Turning Hydrogen Gas Into Metal


Today in relatively obscure but nonetheless meaningful scientific pursuits: two researchers at the Max-Planck Institute claim to have turned hydrogen into metal. That may seem unremarkable, but the fact is hydrogen--being an alkali metal--should exhibit the qualities of a metal under the right circumstances. Yet no one has ever coaxed the universe’s most abundant element into showing metallic qualities until now. Perhaps.
This all depends on how you qualify the term “metal.” There are some boilerplate qualifiers: Metals should conduct electricity and heat somewhat well, they should be malleable to some degree, and it makes sense that they should exist as solids under some circumstances.



But though many have tried, none have been able to make hydrogen behave like a metal under these criteria. Mikhail Erements and Ivan Troyan claim in a paper published in Nature Materials that they’ve done exactly that.
First, they placed some hydrogen in an alumina-epoxy gasket and placed that within a diamond anvil cell. This allowed them to test the opacity and electrical resistance of their sample via laser and electrodes, respectively.



Then, at room temperature, they dialed the pressure up to 220 gigapascals, at which point their sample became opaque and began to show conductive properties. In the next phase of their experiment, they also dialed down the temperature to roughly -400 degrees while upping the pressure to 260 GPa. Here, electrical resistance increased by 20 percent.

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This, they claim, is hydrogen exhibiting metallic properties.
Now, other researchers are going to have to replicate the se results before they can be described as truly meaningful. And then peer reviewers are going to have to hash out whether or not these qualities truly constitute “metallic” characteristics. What is most interesting is that they made hydrogen gas conductive at room temperature by applying pressure. Materials scientists have long been looking for superconductors that can move electricity over distances without losing so much of it as waste. Perhaps hydrogen was right there staring them in the face all along.

A 3-D Printer Makes Human Bones


We’re already printing organs to order, so why not Cmd+P some customized 3-D bone? Washington State University researchers have tweaked a 3-D rapid prototyper designed to create metal parts to print in a bone-like material that acts as a scaffold for new bone cells. In just a few years, the researchers say, doctors and dentists could be printing up custom bone tissue to order.

Reported in the journal Dental Materials, the bone-like material appears to cause no negative side effects and eventually dissolves. But before doing so, it serves as a scaffold for new bone cells. Placed in a medium of immature human bone cells, the printed structures encourage the growth of new bone that fuses with existing bone tissue.

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"If a doctor has a CT scan of a defect, we can convert it to a CAD file and make the scaffold according to the defect,” Susmita Bose, co-author and professor in WSU’s School of Mechanical and Materials Engineering, said in a press release.


In terms of potential for regenerative medicine, that’s fairly huge. It opens the door to the ability to create perfect--or nearly perfect--replacement implants for damaged or deformed bone tissue and grow new, corrective bone that is the real thing rather than a ceramic or metal analog. And the procedure is relatively fast. Networks of new bone cells reportedly grew within the 3-D printed structures within just a week of placing them in a culture with immature bone cells.