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Tuesday, October 4, 2011

Five Reasons You Should Care About the New Ozone Hole Over the Arctic



Some answers from an atmospheric scientist
Two Poles, Two Holes These top two maps show total ozone, and the bottom show ozone deficit. The Arctic is in the left column and the Antarctic on the right. Nature/Manney et al.
A prolonged chill in the atmosphere high above the Arctic last winter led to a mobile, morphing hole in the ozone layer, scientists report in a new paper. It’s just like the South Pole hole we all studied in school, but potentially more harmful to humans — more of us live at northern latitudes. Here are five things you need to know about it.

1: THIS IS A NEW PROBLEM

Most of the public probably knows about the infamous ozone hole over the South Pole, which became one of the great environmental recovery efforts of the 1980s. The Arctic loses some ozone every year, too, but not like this, said Gloria Manney, who works at NASA's Jet Propulsion Laboratory and the New Mexico Institute of Mining and Technology in Socorro.
“No previous year rivals 2011, when the evolution of Arctic ozone more closely followed that typical of the Antarctic,” Manney and colleagues write in the Oct. 2 online issue of Nature. For the first time, the Arctic loss was enough to be considered a hole.
Both holes are driven by chemical reactions involving chlorine. In cold air and sunlight, chlorine is converted into compounds that break down ozone (itself a harmful substance at the surface, but a protective one at stratospheric altitudes). Antarctica experiences an annual ozone hole as a result. The Arctic is cold, too, but usually not as cold as the Antarctic, and not for as long. But winter 2010-2011 was different. Scientists aren’t sure why.
“The processes that control temperatures in the stratosphere in the winter are so complex; it depends on various factors,” Manney said in an interview. “In December, we couldn’t have told you we were going to have this unusually long cold period.”

2: IT COULD HAPPEN AGAIN

Without ozone, more radiation would get through to interfere with our DNA, and that of other life forms on Earth.The planet’s climate is an extremely complex system, so it’s hard to say what will happen if global surface temperatures rise as expected. But it’s generally accepted that an increase in surface temperatures will translate to a chill in the upper atmosphere, Manney said. So as the Arctic loses more of its ice sheet in the summer, the air will get even colder up above, meaning more of the chlorine reactions will take place.
“If the stratosphere cools as a result of the changing climate, we might see severe ozone depletion more often in the future,” she said.

3: IT'S TOO LATE TO STOP

Humans have already emitted enough chemicals to seed the process. The Montreal Protocol, which took effect in 1989, prohibits production of chemicals involved in ozone destruction. But human activity belched out plenty of those chemicals before international governments ever started noticing, let alone signing treaties. There’s still enough in the atmosphere for this effect to persist for decades, Manney said.

4: PEOPLE NEED OZONE

The air over the Arctic is extremely mobile and turbulent, forming a vortex that covers the entire region. It’s a massive area, equivalent to maybe five Californias, and it churns and moves about the Arctic Circle. In April 2011, the vortex — and the hole — moved over northern Russia and Mongolia, Manney said. The climate-monitoring scientists didn’t notice it at the time, but ground-level ultraviolet radiation monitors started to spike.
The ozone layer’s main utility is in protecting Earth from the sun’s UV rays. Without ozone, more radiation would get through to interfere with our DNA, and that of other life forms on Earth. A mobile ozone hole in the northern latitudes thus poses a risk to lots of people.


5: WE NEED MORE DATA

International groups of scientists monitor the Arctic with a suite of Earth-observing satellites, balloons, ground stations and more. But some of their instruments, especially the satellites, are not designed to last for much longer. The instruments onboard NASA’s Aura spacecraft, whose trace gas and cloud measurements were key to this study, were designed to last about 5 years and they’re now about 7, Manney said.
And as we’ve seen before, it’s tough to get a polar-observing satellite approved.
“There aren’t immediate plans for other satellites that give us the same kind of comprehensive measurements. So it is a concern as to whether and how much capability we’ll have to monitor not just ozone, but the other chemicals that contribute to destroying ozone,” Manney said.

... AND NOW FOR SOME GOOD NEWS

Combating greenhouse gas emissions and reversing global warming will help — if surface temps don’t rise dramatically, the stratosphere may not cool dramatically, and the chemical reactions that cause ozone depletion may not occur over the Arctic. What's more, humans have already made some progress with the Montreal Protocol, Manney said.
“Having done that, we expect that we are now on a path to where eventually, in several decades, we will stop having enough chlorine to form ozone holes,” she said. “And things we might be able to do to mitigate climate change would also decrease our odds of seeing more severe future ozone loss.”
As a scientist, Manney wouldn’t speculate about other possible solutions — like geoengineering or cloud-seeding projects that would warm up the stratosphere and prevent more ozone depletion, which we'll just go ahead and throw out there. But she does believe with better data and better models, she and others will eventually be able to predict where and when it happens, leading to better warning systems for people on the ground.
“There is the possibility of saying, ‘We’ve had severe ozone loss this winter, and the ozone vortex is expected to be here [in Russia or elsewhere], so you guys should put your sunscreen on,'” she said.

Physicists Say Speed-of-Light-Breaking Neutrinos Would've Lost Their Energy Along the Way



Another day, another wrinkle in the year's biggest physics story
The Loading Station at OPERA CERN
Last week’s bombshell physics news--those superluminal neutrinos that CERN’s OPERA experiment clocked moving faster than the speed of light--are already getting the rigorous vetting that OPERA’s researchers were hoping for. And some physicists are already rejecting the notion that CERN’s neutrinos broke the cosmic speed limit outright. A paper posted late last week, titled “New Constraints on Neutrino Velocities,” argues that any particle traveling faster than light would shed a great deal of their energy along the way.
And since that didn’t happen, those neutrinos couldn’t have traveled faster than light. Case closed.
So let’s go a little deeper here. The physicists behind this assessment, Andrew Cohen and Sheldon Glashow of Boston University (Glashow has a Nobel under his belt, so these are no middling minds), ignore the debate over whether or not it’s possible for a fundamental particle to outpace the speed of light, and instead look directly at the OPERA neutrinos themselves.

In looking at the neutrino beams that landed at Italy’s Gran Sasso laboratory, Cohen and Glashow found that it was about the same as the beam emitted from CERN in Switzerland. That is, the neutrinos were of roughly the same high-energy flavor at their origin and at their destination.
But that’s not possible if these neutrinos surpassed the speed of light, they say. A neutrino achieving superluminal speeds would emit other lower energy particles--most likely an electron-positron pair-- along the way, and in doing so lose a good deal of its own energy. So the neutrino beam arriving at Gran Sasso should have been “significantly depleted” of high-energy neutrinos.
But this was not the case. Which means, they say, that in all likelihood these neutrinos never achieved superluminal speeds. The anomaly is an error in the data or measurement of the speed, or some other brand of misunderstanding or miscalculation.
Which makes a certain amount of sense, writes Steve Nerlich over at Universe Today over the weekend. Neutrinos do move very fast, straight through the Earth (neutrinos don’t interact much with normal matter), relying on GPS time-stamping and other methods of man-made measurement that are very precise but certainly not infallible to determine time and distance traveled.
And it’s not like these neutrinos were clocked doubling the speed of light or something like that--the difference is 60 nanoseconds. That’s another way of saying that the neutrinos in question are thought to have traveled at 1.0025 times the speed of light. That’s certainly a small enough margin to be explained away by some kind of measurement error.
Still, the jury remains out on this one, and we certainly don’t want to dismiss a perfectly good game-changing science story just because it seems hard to reconcile with the status quo. After all, if OPERA’s result turns out to be confirmed it is going to completely reorient physics as we know them. More on this as it develops.
[SciAm]

ALMA, the World's Largest Radio Telescope, Grabs Its First Images

By Rebecca Boyle
ALMA's First Image This is ALMA's first image, showing the Antennae Galaxies in two different wavelength ranges. The image was captured during the observatory's early testing phase, using only 12 antennas working together — the array will eventually have 66. European Southern Observatory
The world’s largest astronomical facility has opened its eyes, turning nearly two dozen antennae toward the heavens to study the building blocks of the cosmos. The Atacama Large Millimeter/submillimeter Array consists of 20 radio antennae for now, but will contain 66 by 2013, giving it a higher resolution than the Hubble Space Telescope.
Appropriately enough, the first images captured the Antennae Galaxies, a pair of colliding galaxies replete with stars and stellar nurseries. ALMA’s 39- and 23-foot dish antennae can resolve areas of dense, cold gas that other telescopes could not detect.

ALMA sits in the high Chilean desert, about 16,000 feet above sea level and above much of the interfering atmosphere. These pictures were made with 12 telescopes situated relatively close together; science observations during the next few months will be even clearer.
Closer-situated antennae yield a wide field of view, so astronomers can search for items they want to study in more detail. Moving the antennae farther apart provides a narrower focus, like using a finer lens on a regular telescope. Instead of tunable knobs, ALMA has 192 separate antennae pads for the huge dishes to be moved around.
Astronomers submitted more than 900 research proposals for the telescope’s first 9 months of observations, which the European Southern Observatory whittled down to about 100. A few key subjects:
  • A nearby star system called AU Microscopii, just 33 light-years away, with an infant star harboring a ring of planetisimals;
  • The dusty disk surrounding HD142527, a young star 400 light-years away, which has enough material to make a dozen Jupiters;
  • and the great Sagittarius A, the supermassive black hole at the center of the Milky Way.
ALMA observes light at millimeter and sub-millimeter wavelengths, allowing observations of the farthest and oldest phenomena in the observable universe. It’s powerful enough to study the cold, dark remnants of exploded stars, including the first stars, which died a few hundred million years after the Big Bang — that’s an era known as the cosmic dawn.
While this is all going on, more of the 100-ton antennae will keep being added until the observatory is complete sometime in 2013.
Antenna Network Spies Antenna Galaxies: This image combines data from the Hubble Space Telescope and the ALMA network. Appropriately enough, it depicts the Antennae Galaxies, a pair of distorted colliding spiral galaxies about 70 million light-years away in the constellation Corvus (the Crow). ALMA, the world's most complex ground telescope, is an array of radio antennae.  European Southern Observatory
[ESO]

Nanorockets Could Deliver Drugs Within the Body


Nanorockets in Your Body Wikimedia Commons
The idea of nanorockets zipping around your body delivering drugs sounds a little Osmosis Jonesy, but German researchers have developed a less toxic fuel that might make that possible.
Replicating a tiny rocket inside the body brings some, well, health concerns. And those are valid; traditional rocket fuels like hydrazine are extremely toxic, highly flammable and dangerously unstable, all of which make it a pretty lousy candidate for a substance you'd like spurting out of a tiny rocket inside your body. Instead, the research team made rolled up metal nanotubes coated with platinum, so that platinum side would be on the inside, and put them in a weak hydrogen peroxide solution. The platinum catalyzed the peroxide, speeding its decomposition into water and oxygen, which forced gas bubbles out of the tube, generating thrust, even in bodily fluids such as blood, saliva or urine.
The rocket can travel up to 200 times its own length per second, and the researchers are able to control its speed by changing the temperature of the fluid. They can also steer the nanorocket using a magnetic field, to precisely direct the drugs to where they are needed.
While using peroxide is infinitely better than toxic rocket fuels, at 0.25 percent peroxide, it's still not completely safe. Researchers would like to dilute the solution further, or even better, create rockets that can be powered by glucose, or another substance already in the body.
Check out the rockets in action in the video below:


Nobel Prize for Medicine Awarded to Scientist Who Prolonged His Own Life With His Research



The prize, awarded jointly to three scientists, celebrates the discovery of the immune system's front-line responders--though one winner succumbed to cancer three days before
Dendritic Cell This confocal micrograph shows a migrating immature dendritic cell. The red dots are actin-rich podosomes, which help it move forward and conduct cellular surveillance. The discoverer of dendritic cells shares this year's Nobel Prize in Medicine. Wellcome Images
[UPDATE 6 p.m.] Immune cells that protect us from the dangers of this microbe planet are behind this year’s Nobel Prize in medicine. Two of the three winners discovered receptor proteins that can recognise microbial invaders, activating the innate immune response. The third discovered dendritic cells, which serve as surveillance cells and can switch on the body's adaptive immune response.
One half is awarded jointly to Bruce Beutler and Jules Hoffmann and one half goes to Ralph Steinman. But Steinman died on Friday after a battle with pancreatic cancer, according to Rockefeller University in New York, where he was a cell biologist and director of its Center for Immunology and Immune Diseases. He was diagnosed four years ago, and was able to extend his life using a dendritic-cell-based immunotherapy of his own design, the university said. He was 68.

The Nobel committee learned he died three hours after it officially bestowed him with the honor, the Nobel Assembly said Monday. Steinman's own university learned the sad news from his family, as officials were compiling information about his Nobel win. Nobel prizes are not awarded posthumously, but the Nobel Foundation's rules specify that if a person wins an award and dies before accepting it, the prize is still presented.
"The decision to award the Nobel Prize to Ralph Steinman was made in good faith, based on the assumption that the Nobel Laureate was alive," the assembly explained in a statement. "This was true – though not at the time of the decision – only a day or so previously." The foundation further explains that this situation is unprecedented in the history of the Nobel Prize.
The split award honors research into the immune system's dual nature. A group of first responder cells seek out and destroy invaders and block their ability to replicate, and a second group bats cleanup, producing antibodies that kill cells which have already been infected. Scientists now know a great deal about the genetic rules underlying these systems, but much of this knowledge stands on the shoulders of Beutler, Hoffmann and Steinman, the Nobel Assembly explains.
In 1996, Hoffmann, now 70, was working with some genetically modified fruit flies and infecting them with fungi or bacteria. He discovered that the activation of a gene called Toll is crucial for switching on the initial immune response that allowed his flies to fight off infection. Then in 1998, Beutler, now 54, was searching for a protein receptor involved in regulating septic shock, which results when the body is overwhelmed by infection. He found a mouse gene mutation that looked similar to Hoffmann’s Toll gene. This gene codes for a receptor — nicknamed a Toll-like receptor — that binds to a bacterial product involved in septic shock.
Together, the work showed that insects and vertebrates shared similar molecules that activated the innate immune response — and now scientists knew what the molecules looked like. Since then, scientists have identified a dozen more Toll-like receptors in mice and humans.
Decades before that work, Steinman was pioneering research on the secondary immune response, the adaptive response. In 1973, he discovered the dendritic cell — so named because it has little tails, like dendrites in neurons — and explained their function. They serve as the body’s surveillance cells, constantly moving around and sampling their environment. Steinman proved that dendritic cells activate T cells, a class of white blood cells important in adaptive immunity.
The immune researchers’ work has been crucial in understanding the treatment and prevention of diseases, from AIDS to cancer. The research is also relevant for understanding autoimmune and inflammatory diseases, in which the immune system attacks the body’s own cells.