Neutrinos Put Cosmic Ray Theory on Ice
|1:55:52 PM, Friday, April 20, 2012|
“(April 20, 2012 Phys.org) A telescope buried beneath the South Pole has failed to find any neutrinos accompanying exploding fireballs in space, undermining a leading theory of how cosmic rays are born.
IceCube, a detector made up of 5,160 optical sensors embedded up to 2.5km deep in the Antarctic ice, searched for evidence of neutrinos emitted from 300 fireballs, known as gamma ray bursts, observed between May 2008 and April 2010.
In Nature the team behind the experiments report that the search did not find a single neutrino, a result that challenges the idea that cosmic rays originate from gamma ray bursts (GRBs).
Cosmic rays are electrically charged particles, such as protons, that strike Earth from all directions, with energies up to one hundred million times higher than those created in manmade particle accelerators. Understanding their origins would provide crucial insights into the most energetic phenomena in the Universe.
Professor Subir Sarkar of Oxford University’s Department of Physics, who leads the UK involvement in IceCube, said: ‘Although this is a negative result it illustrates that cosmic neutrino detection has come of age – IceCube has achieved the necessary sensitivity to neutrino fluxes expected from likely sources of cosmic rays. It should not be long now before we find the real sources.’
The finding is likely to focus attention on the other prime candidate for creating cosmic rays: the massive black holes found at the centre of active galaxies.
‘The result of this neutrino search is significant because for the first time we have an instrument with sufficient sensitivity to open a new window on cosmic ray production and the interior processes of GRBs,’ said IceCube spokesperson and University of Maryland physics professor Greg Sullivan. ‘The unexpected absence of neutrinos from GRBs has forced a reevaluation of the theory for production of cosmic rays and neutrinos in a GRB fireball and possibly the theory that high energy cosmic rays are generated in fireballs.’
‘Although we have not discovered where cosmic rays come from, we have taken a major step towards ruling out one of the leading predictions,’ said IceCube principal investigator, and University of Wisconsin - Madison physics professor, Francis Halzen.”
Juice Leads Billion-Euro Space Race to Jupiter
|10:57:11 PM, Wednesday, April 18, 2012|
“A proposal to study Jupiter's icy moons is now the front runner to be chosen as a billion-euro space mission.
However, formal selection of the concept will have to wait until a key European space committee meets to discuss the various contenders in May.
The Juice mission would launch in 2022 and would help assess whether Jupiter's moons could support life.
It has been up against two other concepts in the European Space Agency's (Esa) Cosmic Vision competition.
The Juice (JUpiter ICy moon Explorer) proposal envisages an instrument-packed, near five-tonne satellite at launch that would be sent out to the Solar System's biggest planet, to make a careful investigation of three of its Galilean moons.
The spacecraft would use the gravity of the gas giant to initiate a series of close flybys around Callisto, Europa, and then finally to put itself in a settled orbit around Ganymede.
Emphasis would be put on "habitability" - in trying to understand whether there is any possibility that these moons could host microbial life.
The other mission concepts that have been up against Juice are Athena, which would be the biggest X-ray telescope ever built; and NGO, which would place a trio of high-precision satellites in space to detect gravitational waves.
Esa's Space Science Advisory Committee (SSAC) met earlier this month to consider the different ideas.
Its thoughts were then passed to the agency's executive, which has now tabled a formal proposal to member states, nominating Juice as the preferred mission to be implemented.
The 19 member-state delegations will have the final say during a gathering of the agency's Science Programme Committee (SPC) in Paris on 2 May. Selection requires a simple majority vote.
It is possible the SPC could decide to go against the executive, but there is wide expectation that it will accept the recommendation…”
3D Printers Could Create Customised Drugs on Demand
|10:39:44 PM, Wednesday, April 18, 2012|
“Scientists are pioneering the use of 3D printers to create drugs and other chemicals at the University of Glasgow.
Researchers have used a £1,250 system to create a range of organic compounds and inorganic clusters - some of which are used to create cancer treatments.
Longer term, the scientists say the process could be used to make customised medicines.
They predict the technique will be used by pharmaceutical firms within five years, and by the public within 20.
"We are showing that you can take chemical constituents, pass them through a printer and create what is effectively a chemical synthesiser in which the reaction occurs allowing you to get out something different at the end," researcher Mark Symes told the BBC.
"We're extrapolating from that to say that in the future you could buy common chemicals, slot them into something that 3D prints, just press a button to mix the ingredients and filter them through the architecture and at the bottom you would get out your prescription drug."
The 3D printing process involves the use of a robotically controlled syringe which builds an object out of a gel-based "ink", into which chemicals and catalysts are mixed.
"Chemists normally put chemicals in glassware to create a reaction," said Prof Lee Cronin, who came up with the idea…”
The Glass Brain by Katharine Dawson
|9:49:21 PM, Tuesday, April 17, 2012|
-- Artist Katharine Dawson used an MRI scan of her own brain to construct this laser-etched version encased in crystal.
Two Neutrons at the Same Time: Discovery of Dineutron Decay
|9:45:49 PM, Tuesday, April 17, 2012|
“(Phys.org, April 12, 2012) -- Nuclear physicists recently witnessed an atomic nucleus do something that nobody had ever seen one do before – two neutrons at the same time.
Emitting them, that is.
The experiment revealed a brand new form of nuclear decay, the process by which unstable atoms release energy and transform into more stable forms. But instead of emitting known patterns of radiation, the nucleus ejected two correlated neutrons simultaneously – a dineutron. Though physicists had long theorized about the existence of this form of decay, this was the first experiment to see the dineutron event in action.
“We have for the first time unambiguously observed dineutron decay and clearly identified it in beryllium-16,” said Artemis Spyrou, professor of nuclear physics.
The newly discovered dineutron decay mode joins the 15 other known forms of atomic decay, including double proton emission, double beta decay and double positron emission. The results hold promise to strengthen scientists’ understanding of the strong force that holds nuclei together and the processes taking place within neutron stars.
The researchers caught the act red-handed. Beryllium-16 is an unbound, unstable isotope with 4 protons and 12 neutrons that decays in less than a trillionth of a second. To produce the extremely short-lived nucleus, the physicists smashed a beam of boron-17 into a solid target, occasionally knocking out a proton and forming the desired beryllium-16…”
Engineered Stem Cells Seek out and Kill HIV in Living Mice
|9:42:28 PM, Tuesday, April 17, 2012|
“ScienceDaily (Apr. 12, 2012) — Expanding on previous research providing proof-of-principle that human stem cells can be genetically engineered into HIV-fighting cells, a team of UCLA researchers have now demonstrated that these cells can actually attack HIV-infected cells in a living organism.
The study, published April 12 in the journal PLoS Pathogens, demonstrates for the first time that engineering stem cells to form immune cells that target HIV is effective in suppressing the virus in living tissues in an animal model, said lead investigator Scott G. Kitchen, an assistant professor of medicine in the division of hematology and oncology at the David Geffen School of Medicine at UCLA and a member of the UCLA AIDS Institute.
"We believe that this study lays the groundwork for the potential use of this type of an approach in combating HIV infection in infected individuals, in hopes of eradicating the virus from the body," he said.
In the previous research, the scientists took CD8 cytotoxic T lymphocytes -- the "killer" T cells that help fight infection -- from an HIV-infected individual and identified the molecule known as the T cell receptor, which guides the T cell in recognizing and killing HIV-infected cells. However, these T cells, while able to destroy HIV-infected cells, do not exist in great enough quantities to clear the virus from the body. So the researchers cloned the receptor and used this to genetically engineer human blood stem cells. They then placed the engineered stem cells into human thymus tissue that had been implanted in mice, allowing them to study the reaction in a living organism.
The engineered stem cells developed into a large population of mature, multi-functional HIV-specific CD8 cells that could specifically target cells containing HIV proteins. The researchers also discovered that HIV-specific T cell receptors have to be matched to an individual in much the same way an organ is matched to a transplant patient…”
|9:37:37 PM, Tuesday, April 17, 2012|
-- Photo by Photoport.
Space Shuttle in Extreme Detail: Exclusive New Pictures
|9:31:15 PM, Tuesday, April 17, 2012|
“(Nat. Geo.) This week NASA's space shuttle Discovery will fly low over Washington, D.C., atop a jumbo jet and roll into its new permanent home with the Smithsonian Institution.
Discovery will touch down at Dulles International Airport on Tuesday, weather permitting, and the National Air and Space Museum's Steven F. Udvar-Hazy Center in Chantilly, Virginia, will host a big outdoor ceremony on Thursday to welcome their new space-worn acquisition.
But once the spaceship is settled into the museum, visitors won't be able to hop into the commander's seat and fiddle with switches—the institution intends to seal up Discovery indefinitely.
To provide an unprecedented look at Discovery and the other retired space shuttles, both inside and out, photographers with National Geographic recently captured more than two dozen ultrahigh-resolution, 360-degree pictures of each orbiter.
NASA and United Space Alliance, the agency's prime contractor for servicing the shuttles, made the interactive panoramas possible by granting news organizations unprecedented access to the hundred-ton spaceships after each final shuttle flight.
"When the shuttles were flying, workers had to maintain the integrity and cleanliness of the vehicles. We had to keep them safe for spaceflight" and so couldn't allow much outside access, said Lisa Fowler, a NASA spokesperson at Kennedy Space Center in Florida.
"Now that they're being readied for display, we've been able to grant more access into them."
The flight deck of Discovery, for instance, is shown above in a 2.74-gigapixel, zoomable image—equivalent in resolution to about 340 pictures taken with an 8-megapixel iPhone camera.
"It's awesome, although it doesn't look like the flight deck I flew on Discovery. That one still had old-fashioned style instrumentation," said Scott "Doc" Horowitz, a former NASA astronaut who was both a commander and pilot of Discovery.
"Pictures like this give you insight into just how complex it is to operate a vehicle that travels in space and pull off a manned space program," he said…”
Auroras Seen on Uranus For First Time
|6:31:31 PM, Sunday, April 15, 2012|
“(Nat. Geo. April 13, 2012) For the first time, astronomers have snapped photos of auroras lighting up Uranus's icy atmosphere.
Two fleeting, Earth-size auroral storms were imaged by the Hubble Space Telescope as they flared up on the dayside of the gas giant in November 2011.
"The last time we had any definite signals of auroral activity on Uranus was when NASA's Voyager 2 probe swung by in 1986," said study leader Laurent Lamy, an astronomer at the Observatoire de Paris in Meudon, France.
"But this is the first time we can actually see these emissions light up with an Earth-based telescope."
Uranus Auroras Seen in Stroke of Luck
Auroras are light displays often seen at the highest latitudes of Earth, Jupiter, and Saturn—all of which all have magnetospheres that act as shields against incoming solar storms.
Auroras tend to surround a planet's poles, where magnetic field lines converge and funnel incoming charged solar particles into the planet's atmosphere. There, the particles collide with air molecules, making the molecules glow.
Scientists tried unsuccessfully to detect auroras on Uranus in 1998 and 2005. In September 2011, Lamy and his team learned of an impending solar storm directed toward Uranus, which sits about 2.5 billion miles (4 billion kilometers) from Earth…”
Adele's 'Rolling In The Deep' Played on the Guzheng
|6:01:16 PM, Sunday, April 15, 2012|
-- I know this song is everywhere, but this is pretty cool. Guzheng.
Drug-Resistant Bacteria Found in 4-Million-Year-Old Cave
|5:39:20 PM, Sunday, April 15, 2012|
“(Nat. Geo.) Deep in the bowels of a pristine New Mexico cave, microbiologists have discovered nearly a hundred types of bacteria that can fight off modern antibiotic drugs.
The bacteria coat the walls of the Lechuguilla cave system on rock faces some 1,600 feet (487 meters) below Earth's surface. Until recently, the microscopic life-forms had encountered neither humans nor modern antibiotics.
That's because a thick dome of rock isolated the cave between four and seven million years ago. Any water that trickles through takes roughly ten thousand years to reach the cave's depths—which means the subterranean life has existed entirely in the absence of modern medicine.
While not infectious to humans, the cave bacteria can resist multiple classes of antibiotics, including new synthetic drugs. The discovery serves as an intriguing lead in the quest to understand how drug-resistant diseases emerge.
"Clinical microbiologists have been perplexed for the longest time. When you bring a new antibiotic into the hospital, resistance inevitably appears shortly thereafter, within months to years," said study leader Gerry Wright, a chemical biologist at McMaster University in Ontario.
"It's still a big question: Where is this coming from?" Wright said. "Almost no one thought to look at other bacteria, the ones that don't necessarily cause disease."
Growing "Superbug" Problem
Lechuguilla is one of the deepest and most extensive cave systems in New Mexico's Carlsbad Caverns National Park. With at least 130 miles (209 kilometers) of mapped passages, Lechuguilla is also the planet's seventh longest known cave…”
In First Public Speech, North Korean Leader Talks of Military Superiority
|5:33:30 PM, Sunday, April 15, 2012|
“SEOUL, South Korea — In his first speech in public since assuming the leadership of North Korea, Kim Jong-un said Sunday that his “first, second and third” priorities were to strengthen the military, and he declared that superiority in military technology was “no longer monopolized by imperialists.”
Mr. Kim’s speech was followed by what South Korean officials said was the North’s biggest display of weapons in a military parade, including a missile the North appeared to be presenting for the first time. While it is not clear whether it was a new long-range missile or a mock-up, its display demonstrates the importance that the North Korean government places on weapons development despite an embarrassing failure of a rocket it launched last week.
South Korean officials would not comment on the North Korean missile, pending further examination.
Mr. Kim’s claim to superior military technology could sound poignant, coming two days after the North Korean rocket carrying a satellite disintegrated in midair. The failure of the rocket indicated that North Korea might still have a long way to go before mastering the technology for delivering warheads atop an intercontinental ballistic missile.
Mr. Kim’s speech on the 100th birthday of Kim Il-sung, his grandfather and the North’s founding president, was his public political debut. In an unexpected 20-minute speech, broadcast live inside North Korea, Mr. Kim demonstrated a new leadership style but reaffirmed his adherence to the “military first” policy of his father, Kim Jong-il, which has left North Korea locked in a prolonged confrontation with the United States and its allies…”
It Doesn’t Get Any More Hipster Than This
|5:22:22 PM, Sunday, April 15, 2012|
Could “Advanced” Dinosaurs Rule Other Planets?
|3:29:04 AM, Saturday, April 14, 2012|
“(American Chemical Society, http://portal.acs.org, April 11, 2012) New scientific research raises the possibility that advanced versions of T. rex and other dinosaurs — monstrous creatures with the intelligence and cunning of humans — may be the life forms that evolved on other planets in the universe. “We would be better off not meeting them,” concludes the study, which appears in the Journal of the American Chemical Society.
In the report, noted scientist Ronald Breslow, Ph.D., discusses the century-old mystery of why the building blocks of terrestrial amino acids (which make up proteins), sugars, and the genetic materials DNA and RNA exist mainly in one orientation or shape. There are two possible orientations, left and right, which mirror each other in the same way as hands. This is known as "chirality." In order for life to arise, proteins, for instance, must contain only one chiral form of amino acids, left or right. With the exception of a few bacteria, amino acids in all life on Earth have the left-handed orientation. Most sugars have a right-handed orientation. How did that so-called homochirality, the predominance of one chiral form, happen?
Breslow describes evidence supporting the idea that the unusual amino acids carried to a lifeless Earth by meteorites about 4 billion years ago set the pattern for normal amino acids with the L-geometry, the kind in terrestial proteins, and how those could lead to D-sugars of the kind in DNA.
“Of course,” Breslow says, “showing that it could have happened this way is not the same as showing that it did.” He adds: “An implication from this work is that elsewhere in the universe there could be life forms based on D-amino acids and L-sugars. Such life forms could well be advanced versions of dinosaurs, if mammals did not have the good fortune to have the dinosaurs wiped out by an asteroidal collision, as on Earth. We would be better off not meeting them.””
-- Praised be Raptor Jesus!
Majorana Particle Glimpsed in Lab
|1:27:04 AM, Saturday, April 14, 2012|
“Scientists think they may finally have seen evidence for a famously elusive quarry in particle physics.
The Majorana fermion was first predicted 75 years ago - a particle that could be its own anti-particle.
Now Dutch researchers, who have devised some exotic and minute circuitry to test for the Majorana's existence, believe their results show the fermion to be real.
The team has reported the details of its experiments in Science magazine.
"It opens up some very interesting ideas," said Leo Kouwenhoven from the Delft University of Technology.
Majoranas should behave quite differently from more familiar matter particles, such as electrons.
When these confront their opposites - positrons - they annihilate each other in a flash of gamma rays.
The idea that a particle existed that might be equal to its anti-particle was put forward by Italian Ettore Majorana, a brilliant theorist who mysteriously went missing after withdrawing all his money to go on a boat journey in 1938…”
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