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Friday, December 28, 2012

Blink if your brain needs a rest


The mental break can last anywhere from a split second to a few seconds before attention is fully restored, researchers from Japan's Osaka University found. During that time, scans that track the ebb and flow of blood within the brain revealed that regions associated with paying close attention momentarily go offline. And in the brief break in attention, brain regions collectively identified as the "Default Mode Network" power up.

Discovered less than a decade ago, the default mode network is the brain's "idle" setting. In times when our attention is not required by a cognitive task such as reading or speaking, this far-flung cluster of brain regions comes alive, and our thoughts wander freely. In idle mode, however, our thoughts seldom stray far from home: We contemplate our feelings; we wonder what a friend meant by a recent comment; we consider something we did last week, or imagine what we'll do tomorrow.

 Most of us take between 15 and 20 such moments of downtime per minute, and scientists have observed that most blinking takes place near or at the point of an "implicit stop": While reading or listening to another person, that generally comes at the end of a sentence; while watching a movie, for instance, we're most likely to blink when an actor turns to leave the scene or when the camera shifts to follow the dialogue. 

The study, published this week in the journal Proceedings of the National Academies of Science, studied 20 healthy young subjects in a brain scanner as they watched "best bits" snippets from the British comedy "Mr. Bean." An earlier study had shown the researchers which implicit breakpoints in the "Mr. Bean" video most commonly elicited a spontaneous blink, so researchers knew when to look for changes in the brain's activation patterns. 

Sure enough, when subjects blinked, the researchers detected a momentary stand-down within the brain's visual cortex and somatosensory cortex - both involved with processing visual stimuli - and in areas that govern attention. The circuitry of the Default Mode Network stepped up to fill the momentary lapse in attention, and then yielded again as order - and attention - was restored.

In a separate experiment, the researchers established that the momentary rest that blinking appears to represent is a deliberate act, and not just a response to an absence of stimuli. When researchers inserted roughly nine 165 milliseconds of blank screentime per minute into the "Mr. Bean" video, subjects' Default Mode Network did not activate in response. Although the video gave them a blink's worth of time to rest, subjects did not recognize a breakpoint in the action, and therefore remained attentive. 

Though the current study didn't examine the relationship between blinking and deception, others have: While telling a lie, liars have been found to blink less - possibly because the act of deception requires rapt and uninterrupted attention to pull it off. In the seconds after telling a lie, however, the liar will blink far more frequently than a truth-teller. Perhaps the resulting downtime is necessary for the liar to consider whether the deceived person was buying the fib - or whether it was worth telling in the first place. 

Read more at: http://medicalxpress.com/news/2012-12-brain-rest.html#jCp

Source: http://medicalxpress.com

Friday, December 21, 2012

MIT discovers a new state of matter, a new kind of magnetism



Researchers at MIT have discovered a new state of matter with a new kind of magnetism. This new state, called a quantum spin liquid (QSL), could lead to significant advances in data storage. QSLs also exhibit a quantum phenomenon called long-range entanglement, which could lead to new types of communications systems, and more.
Generally, when we talk about magnetism’s role in the realm of technology, there are just two types: Ferromagnetism and antiferromagnetism. Ferromagnetism has been known about for centuries, and is the underlying force behind your compass’s spinning needle or the permanent bar magnets you played with at school. In ferromagnets, the spin (i.e. charge) of every electron is aligned in the same direction, causing two distinct poles. In antiferromagnets, neighboring electrons point in the opposite direction, causing the object to have zero net magnetism (pictured below). In combination with ferromagnets, antiferromagnets are used to create spin valves: the magnetic sensors used in hard drive heads.
Antiferromagnetic orderingIn the case of quantum spin liquids, the material is a solid crystal — but the internal magnetic state is constantly in flux. The magnetic orientations of the electrons (their magnetic moment) fluctuate as they interact with other nearby electrons. “But there is a strong interaction between them, and due to quantum effects, they don’t lock in place,” says Young Lee, senior author of the research. It is these strong interactions that apparently allow for long-range quantum entanglement.
The existence of QSLs has been theorized since 1987, but until now no one has succeeded in actually finding one. In MIT’s case, the researchers spent 10 months growing a tiny sliver of herbertsmithite (pictured above) — a material that was suspected to be a QSL, but which had never been properly investigated. (Bonus points if you can guess who herbertsmithite is named after.) Using neutron scattering — firing a beam of neutrons at a material to analyze its structure — the researchers found that the herbertsmithite was indeed a QSL.
Moving forward, Lee says that the discovery of QSLs could lead to advances in data storage (new forms of magnetic storage) and communications (long-range entanglement). Lee also seems to think that QSLs could lead us towards higher-temperature superconductors — i.e. materials that superconduct under relatively normal conditions, rather than -200C.
Really, though, the most exciting thing about quantum spin liquids is that they’re completely new, and thus we ultimately have no idea how they might eventually affect our world. “We have to get a more comprehensive understanding of the big picture,” Lee says. “There is no theory that describes everything that we’re seeing.”
Research paper: doi:10.1038/nature11659 – “Fractionalized excitations in the spin-liquid state of a kagome-lattice antiferromagnet”

Thursday, December 20, 2012

Super-fine sound beam could one day be an invisible scalpel


ANN ARBOR—A carbon-nanotube-coated lens that converts light to sound can focus high-pressure sound waves to finer points than ever before. The University of Michigan engineering researchers who developed the new therapeutic ultrasound approach say it could lead to an invisible knife for noninvasive surgery.

Today's ultrasound technology enables far more than glimpses into the womb. Doctors routinely use focused sound waves to blast apart kidney stones and prostate tumors, for example. The tools work primarily by focusing sound waves tightly enough to generate heat, says Jay Guo, a professor of electrical engineering and computer science, mechanical engineering, and macromolecular science and engineering. Guo is a co-author of a paper on the new technique published in the current issue of Nature's journal Scientific Reports.

The beams that today's technology produces can be unwieldy, says Hyoung Won Baac, a research fellow at Harvard Medical School who worked on this project as a doctoral student in Guo's lab.

"A major drawback of current strongly focused ultrasound technology is a bulky focal spot, which is on the order of several millimeters," Baac said. "A few centimeters is typical. Therefore, it can be difficult to treat tissue objects in a high-precision manner, for targeting delicate vasculature, thin tissue layer and cellular texture. We can enhance the focal accuracy 100-fold."

The team was able to concentrate high-amplitude sound waves to a speck just 75 by 400 micrometers (a micrometer is one-thousandth of a millimeter). Their beam can blast and cut with pressure, rather than heat. Guo speculates that it might be able to operate painlessly because its beam is so finely focused it could avoid nerve fibers. The device hasn't been tested in animals or humans yet, though.

"We believe this could be used as an invisible knife for noninvasive surgery," Guo said. "Nothing pokes into your body, just the ultrasound beam. And it is so tightly focused, you can disrupt individual cells."

To achieve this superfine beam, Guo's team took an optoacoustic approach that converts light from a pulsed laser to high-amplitude sound waves through a specially designed lens. The general technique has been around since Thomas Edison's time. It has advanced over the centuries, but for medical applications today, the process doesn't normally generate a sound signal strong enough to be useful.

The U-M researchers' system is unique because it performs three functions: it converts the light to sound, focuses it to a tiny spot and amplifies the sound waves. To achieve the amplification, the researchers coated their lens with a layer of carbon nanotubes and a layer of a rubbery material called polydimethylsiloxane. The carbon nanotube layer absorbs the light and generates heat from it. Then the rubbery layer, which expands when exposed to heat, drastically boosts the signal by the rapid thermal expansion.

The resulting sound waves are 10,000 times higher frequency than humans can hear. They work in tissues by creating shockwaves and microbubbles that exert pressure toward the target, which Guo envisions could be tiny cancerous tumors, artery-clogging plaques or single cells to deliver drugs. The technique might also have applications in cosmetic surgery.

In experiments, the researchers demonstrated micro ultrasonic surgery, accurately detaching a single ovarian cancer cell and blasting a hole less than 150 micrometers in an artificial kidney stone in less than a minute.

"This is just the beginning," Guo said. "This work opens a way to probe cells or tissues in much smaller scale."

The researchers will present the work at the SPIE Photonics West meeting in San Francisco. The research was funded by the National Science Foundation and the National Institutes of Health.

Source: http://www.ns.umich.edu

Tuesday, December 18, 2012

Google Maps for iOS surpassed 10M downloads in less than 48 hours


It's official: Google Maps for iOS is a huge hit.

Jeff Huber, senior vice president of commerce and local at Google, revealed on his Google+ page on Monday that the new mapping app experienced more than 10 million downloads in less than 48 hours.

"We're excited for the positive reception of Google Maps for iPhone around the world," Huber continued. "Congratulations to the Maps Team on the recognition for the passion and hard work they poured into it, for this release and over the last 7+ years."

See also: Google Maps for iOS message: What Google really meant to say

Google Maps for the iPhone, iPod touch and iPad debuted late last Wednesday.

The launch of the app follows the firestorm this past fall surrounding Apple's beleaguered efforts to release its own mapping platform. Complaints ranged from inaccurate directions to completely erroneous locations altogether.

Apple CEO Tim Cook apologized for the problems, admitting that the Cupertino, Calif.-based company "fell short" with the new mapping platform included in iOS 6.

The iPhone maker followed up by highlighting alternative mapping apps in the App Store, and it was only a matter of time before Google trotted out its own.

For iOS users who still don't have the app but want to download it, Google Maps for iOS is available for free from iTunes now.

Source: http://www.zdnet.com

SimCity Developers' Reddit AMA Swiftly Turns Into WTF With The Online-Only DRM?


The developers of the latest SimCity learned a valuable lesson Friday during a Reddit AMA, one that will hopefully be passed on to other developers: people -- you know, the downstream consumers you're hoping will purchase your software? They hatehatehatehatehatehatehateHATE DRM.

EA, the publisher of SimCity, has seen fit to up the annoyance factor on legally purchased copies of the game by requiring an internet connection to play the latest title in the series, even in single player mode, and funneling the users through its horrendous Origin "service." Not only that, but players' games are saved online, so if you lose the connection, not only will you be prevented from playing your purchased game, but you'll be back at whatever point you were at when your service died.

The top voted question/comment digs right into the heart of the DRM issue:
What will happen to the game if I am playing and lose my internet connection - will the game still be playable and update the servers when my internet connection resumes or will it pause and wait for the connection?

As I have unreliable internet at times if I were to lose a connection and play for a while longer (assuming I would be able to continue to play) would my changes be saved locally in case my internet connection does not come back up before I need to stop playing (and then be uploaded when I next start the game).

I love what the game is looking like and look forward to the multi-player region games, but as you can tell I am concerned about what happens if my internet connection decides to drop for a few hours.
The first answer back, from Kip Katsarelis (Senior Producer) was far from comforting:
Sorry, I replied to it below. Not avoiding. Here was the reply...

"I actually just ran over to our online engineering team to get the latest info. We do handle "short" internet outages gracefully. Meaning, if your internet goes out while you're logged in and playing the game, we can can recover gracefully. You shouldn't notice a thing. "Short" is still being defined."
At least Katsarelis somewhat acknowledges that the term "short" is woefully undefined. And whether or not players "notice a thing" isn't really the sort of issue that should be getting sorted during an informal Q&A. While that answer was less than satisfactory, Kip's followup was downright laughable.
We will allow you to play for as long as we can preserve your game state. This will most likely be minutes.
The response to that bit of "online imagineering" was full of win, however.
My computer happens to have a hard drive that's suitable for preserving game state. Should I consider buying your game, or is it crippled to online-only?
It's not as though the "paying customers hate DRM" is a new development. It has been this way for years and paying customers have expressed their displeasure with being handed crippled software in exchange for perfectly functioning money, while those who have acquired the same software for free use the software much in the manner you would expect the paying customer to be able to: on his or her own terms, online connection or no. It's gotten bad enough that even EA's own employees are annoyed with DRM "solutions."

A helpful Redditor compiled all the anti-DRM comments from the AMA into an easy-to-read, linked, multi-author screed on the unpopularity of online-connection-required DRM. Perhaps SimCity's devs can run this up the chain to EA in the small hope that a list of disgruntled potential customers might persuade the publisher to drop the online/Origin requirement before SimCity's release in March. It's highly doubtful this will work, as EA's president has stated that all EA games will include "online applications and digital services." If one was optimistic and a bit naive, it almost sounds like EA wants a connected community that expands the fanbase through social media. If one is firmly grounded in reality, however, it's just another way to say "all games will include some form of online-only component DRM."

So, very possibly, no lessons will be learned. People will go and pirate themselves a working version of SimCity, which will lead EA to believe that EVEN MORE DRM is required for the next iteration, which will piss off the next set of gamers, leading to more cracked, functional versions downloaded, and so on, until either a.) all piracy is eradicated (thru some sort of black magic[k] ceremony involving Chris Dodd, Cary Sherman, the remaining members of the BSA and the exhumed corpse of Sonny Bono) or b.) EA (and companies like it) stop dumping crippled software on customers in hopes of making absolutely no discernible dent in piracy levels.

Source: http://www.techdirt.com

Amazingly clear NASA radar imagery of large asteroid Toutatis at a distance of 6.9 million km

 
Asteroid Toutatis Slowly Tumbles by Earth

Scientists working with NASA's 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, Calif., have generated a series of radar data images of a three-mile-long (4.8-kilometer) asteroid that made its closest approach to Earth on Dec. 12, 2012. The radar data images of asteroid Toutatis have been assembled into a short movie, available online at: http://www.nasa.gov/multimedia/videogallery/index.html?media_id=157006881
 
The images that make up the movie clip were generated with data taken on Dec. 12 and 13, 2012. On Dec. 12, the day of its closest approach to Earth, Toutatis was about 18 lunar distances, 4.3 million miles (6.9 million kilometers) from Earth. On Dec. 13, the asteroid was about 4.4 million miles (7 million kilometers), or about 18.2 lunar distances.

The radar data images of asteroid Toutatis indicate that it is an elongated, irregularly shaped object with ridges and perhaps craters. Along with shape detail, scientists are also seeing some interesting bright glints that could be surface boulders. Toutatis has a very slow, tumbling rotational state. The asteroid rotates about its long axis every 5.4 days and precesses (changes the orientation of its rotational axis) like a wobbling, badly thrown football, every 7.4 days.

The orbit of Toutatis is well understood. The next time Toutatis will approach at least this close to Earth is in November of 2069, when the asteroid will safely fly by at about 7.7 lunar distances, or 1.8 million miles (3 million kilometers). An analysis indicates there is zero possibility of an Earth impact over the entire interval over which its motion can be accurately computed, which is about the next four centuries.
This radar data imagery will help scientists improve their understanding of the asteroid's spin state, which will also help them understand its interior.

The resolution in the image frames is 12 feet (3.75 meters) per pixel. NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.
 
 
DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

2012-397


Source: http://www.nasa.gov

Saturday, December 15, 2012

Millions of camera-trap images reveal Serengeti life



Scientists are using millions of images of Africa's elusive animals to find out how they co-exist in the Serengeti.
Hundreds of camera traps were set up across Serengeti National Park in one of the world's largest camera surveys.
The project, called Snapshot Serengeti, invites the public to collaborate with scientists to identify the animals via an interactive website.
The team says classifying the huge number of images will allow them to build a unique picture of wildlife.
Stretching 5,700 sq miles (14,763 sq km), the Serengeti is Tanzania's oldest national park, covering vast open grassland and wooded hills.
"The idea is that if we can say what's in [the pictures] and what the animals are doing then we can get the true picture of what... life on the Serengeti is like," said Dr Chris Lintott from the University of Oxford who specialises in citizen science.
The scientists are calling on members of the public to help them via the interactive website Snapshot Serengeti, launched this week.


It is the latest citizen science study organised by the Zooniverse project, led by the University of Oxford and Adler Planetarium. Previous Zooniverse collaborations with members of the public have included projects to classify ocean floor life and cancer samples.
The site allows users to identify animals by describing physical characteristics, in order to narrow the search down, explained Dr Lintott.
"Computers are really bad at identifying species," said Dr Lintott, director of Zooniverse.
He explained that tests carried out by the research team showed that non-scientific members of the public were just as effective at identifying species as the scientists.
Intimate moments
The team hopes that the prospect of viewing some unusual shots of animals' private lives will attract people to take part.
"One of my favourite photos [is] porcupines mating," said PhD researcher Ali Swanson from the University of Minnesota, US, who initiated the camera survey and regularly visits the camera traps.
"The cameras are catching photographs of things that I've never seen after being out there for a lot of the last three years."

Start Quote

Computers are really bad at identifying species”
Dr Chris LintottDirector of Zooniverse
For example, "male cheetahs like to spray the camera traps, so I get some very intimate shots," she told BBC Nature.
Many close-up shots are taken when animals approach the equipment to sniff and investigate: "we get a lot of noses, which is entertaining," said Ms Swanson.
Each time a camera senses motion it takes a sequence of three photographs, building up a flip-book-like database of images.
Using the action shots, researchers will investigate questions such as how carnivores interact with each other, and how predators and prey co-exist on the plains.
Traditionally, capturing animals' private lives on camera would have involved researchers in the field observing from a particular spot. But this method can create a picture of what's happening in a wider area.
The camera survey method allows Ms Swanson and her colleagues to observe how animals, especially carnivores, use their landscape: "They move over such huge areas and it's really hard to watch them," she said.
"The camera survey lets us study species on a scale we haven't been able to do before."



Friday, December 14, 2012

Scientists plan test to see if the entire universe is a simulation created by futuristic supercomputers


US scientists are attempting to find out whether all of humanity is currently living a Matrix-style computer simulation being run on supercomputers of the future.

According to researchers at the University of Washington, there are tests that could be done to begin to work out whether we are in fact real, or merely a simulation created by a futuristic android on its lunch break.

Currently, computer simulations are decades away from creating even a primitive working model of the universe. In fact, scientists are able to accurately model only a 100 trillionth of a metre, with work to create a model of a full human being still out of reach.

By looking for underlying patterns, physicists believe that it may be possible to work out if we are existing in a computer created universe, created many years in the future.  Looking at constraints imposed on simulations by limited resources could show signs that we are mere bit-part players in a Matrix-style film plot.
 
It will take many years to reach the computational power to give a real glimpse of whether we are living in a simulation, the scientists contend, but even by looking at the tiny portion of the universe that we can currently accurately model, it may be possible to detect 'signatures' of constraints on physical processes that could point to a simulation.

The researchers suggest that a signature could show up as a limitation in the energy of cosmic rays, for example.  By testing the behaviour of cosmic rays on underlying 'lattice' frameworks governing rules of physics that could exist in future models of the universe, the researchers could find patterns that could point to a simulation.

“This is the first testable signature of such an idea,” one of the researchers, Martin Savage, said.
Aside from the rather mind-boggling proposition that we may be part of a computer simulation, another researcher pointed out that this would bring up the possibility of inter-universe computer platforms, and the potential to communicate across these.

“Then the question is, ‘Can you communicate with those other universes if they are running on the same platform?’” UW graduate student, Zohreh Davoudi, asked.

How to Control an Army of Zombies


In the rain forests of Costa Rica lives Anelosimus octavius, a species of spider that sometimes displays a strange and ghoulish habit

When infected by thorny-headed worms (the orange spot), gammarids swim toward light. At the water's surface they become easy prey for birds, the next creature the worm needs to infect to complete its life cycle.

From time to time these spiders abandon their own webs and build radically different ones, a home not for the spider but for a parasitic wasp that has been living inside it. Then the spider dies — a zombie architect, its brain hijacked by its parasitic invader — and out of its body crawls the wasp’s larva, which has been growing inside it all this time.

The current issue of the prestigious Journal of Experimental Biology is entirely dedicated to such examples of zombies in nature. They are far from rare. Viruses, fungi, protozoans, wasps, tapeworms and a vast number of other parasites can control the brains of their hosts and get them to do their bidding. But only recently have scientists started to work out the sophisticated biochemistry that the parasites use

“The knowledge that parasites can manipulate their hosts is old. The new part is how they do it,” said Shelley Adamo of Dalhousie University in Nova Scotia, a co-editor of the new issue. “The last 5 to 10 years have really been exciting.” 

In the case of the Costa Rican spider, the new web is splendidly suited to its wasp invader. Unlike the spider’s normal web, mostly a tangle of threads, this one has a platform topped by a thick sheet that protects it from the rain. The wasp larva crawls to the edge of the platform and spins a cocoon that hangs down through an opening that the spider has kindly provided for the parasite. 

To manipulate the spiders, the wasp must have genes that produce proteins that alter spider behavior, and in some species, scientists are now pinpointing this type of gene. Such is the case with the baculovirus, a virus sprinkled liberally on leaves in forests and gardens. (The cabbage in a serving of coleslaw carries 100 million baculoviruses.) 

Human diners need not worry, because the virus is harmful only to caterpillars of insect species, like gypsy moths. When a caterpillar bites a baculovirus-laden leaf, the parasite invades its cells and begins to replicate, sending the command “climb high.” The hosts end up high in trees, which has earned this infection the name treetop disease. The bodies of the caterpillars then dissolve, releasing a rain of viruses on unsuspecting hosts below. 

David P. Hughes of Penn State University and his colleagues have found that a single gene, known as egt, is responsible for driving the caterpillars up trees. The gene encodes an enzyme. When the enzyme is released inside the caterpillar, it destroys a hormone that signals a caterpillar to stop feeding and molt. 

Dr. Hughes suspects that the virus goads the caterpillar into a feeding frenzy. Normally, gypsy moth caterpillars come out at night to feed and then return to crevices near the bottom of trees to hide from predators. The zombie caterpillars, on the other hand, cannot stop searching for food. 

“The infected individuals are out there, just eating and eating,” Dr. Hughes said. “They’re stuck in a loop.”
Other parasites manipulate their hosts by altering the neurotransmitters in their brains. This kind of psychopharmacology is how thorny-headed worms send their hosts to their doom. 

Their host is a shrimplike crustacean called a gammarid. Gammarids, which live in ponds, typically respond to disturbances by diving down into the mud. An infected gammarid, by contrast, races up to the surface of the pond. It then scoots across the water until it finds a stem, a rock or some other object it can cling to. 

The gammarid’s odd swimming behavior allows the parasite to take the next step in its life cycle. Unlike baculoviruses, which go from caterpillar to caterpillar, thorny-headed worms need to live in two species: a gammarid and then a bird. Hiding in the pond mud keeps a gammarid safe from predators. By forcing it to swim to the surface, the thorny-headed worm makes it an easy target. 

Simone Helluy of Wellesley College studies this suicidal reversal. Her research indicates that the parasites manipulate the gammarid’s brain through its immune system. 

The invader provokes a strong response from the gammarid’s immune cells, which unleash chemicals to kill the parasite. But the parasite fends off these attacks, and the host’s immune system instead produces an inflammation that infiltrates its own brain. There, it disrupts the brain’s chemistry — in particular, causing it to produce copious amounts of the neurotransmitter serotonin. 

Thursday, December 13, 2012

Cassini spots a 400km river on Titan, Saturn's moon

Cassini Spots a Nile Like River Valley on Titan

Cassini has spotted a river valley, which scientists believe is filled with liquid, on Saturn’s moon Titan that stretches more than 400 km.

The international Cassini mission has spotted what appears to be a miniature extraterrestrial version of the Nile River: a river valley on Saturn’s moon Titan that stretches more than 400 km from its ‘headwaters’ to a large sea.

It is the first time images have revealed a river system this vast and in such high resolution anywhere beyond Earth.

Scientists deduce that the river is filled with liquid because it appears dark along its entire extent in the high-resolution radar image, indicating a smooth surface.

“Though there are some short, local meanders, the relative straightness of the river valley suggests it follows the trace of at least one fault, similar to other large rivers running into the southern margin of this same Titan sea,” says Jani Radebaugh, a Cassini radar team associate at Brigham Young University, USA.

“Such faults – fractures in Titan’s bedrock – may not imply plate tectonics, like on Earth, but still lead to the opening of basins and perhaps to the formation of the giant seas themselves.”

Titan is the only other world we know of that has stable liquid on its surface. While Earth’s hydrologic cycle relies on water, Titan’s equivalent cycle involves hydrocarbons such as ethane and methane.

Images from Cassini’s visible-light cameras in late 2010 revealed regions that darkened after recent rainfall.

Cassini’s visual and infrared mapping spectrometer confirmed liquid ethane at a lake in Titan’s southern hemisphere known as Ontario Lacus in 2008.

“This radar-imaged river by Cassini provides another fantastic snapshot of a world in motion, which was first hinted at from the images of channels and gullies seen by ESA’s Huygens probe as it descended to the moon’s surface in 2005,” says Nicolas Altobelli, ESA’s Cassini Project Scientist.

The Cassini–Huygens mission is a cooperative project of NASA, ESA and ASI, the Italian space agency. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and ASI, working with team members from the US and several European countries.

Source: http://scitechdaily.com/

 

Tuesday, December 4, 2012

The 61 countries that could easily be unplugged from the internet

 http://www.wired.co.uk


It's becoming the trademark move of failing regimes: silence your critics and cripple their communications by cutting off the internet. Libya did it. Egypt too. And last week, Syria pulled the plug on its own internet system.

According to new research from network monitoring company Renesys, it could just as easily happen in many other countries too, including Greenland, Yemen, and Ethiopia. Sixty-one of the world's countries have just one or two service providers connecting them to the rest of the internet.

"If you're a sufficiently small place it's almost inescapable that there will be so little internet that it's almost trivial to turn it off," says James Cowie, chief technology officer with Renesys.

On the other extreme, more than 30 countries -- including the UK, Canada and the US -- have over 40 network providers each at their electronic frontiers. They're almost impossible to unplug.

Renesys came up with its map (shown above) of the internet's most easily unplugged countries by studying the Border Gateway Protocol (BGP) tables stored in the memory of the big routers used by hundreds of internet service providers. These BGP tables tell the routers how to hop messages from one network to another, and once you start putting together four or five hundred of these tables, you get a pretty clear picture of how the internet is wired together.

So what makes for an easily un-switched country? "It's a high degree of centralisation and a low degree of diversity," Cowie says. "They tend to be places where naturally or organically though history or through regulation, the number of providers that get to exchange traffic with their foreign counterparts is very, very low."

So Greenland fits the mold. "Greenland probably wishes it had more diversity, but just the nature of Greenland and the expense of getting connectivity into Greenland means that they're limited to a small -- apparently very small -- set of providers," Cowie says.

Interestingly, though, Afghanistan does not.

According to Cowie, the Afghanistan once had a countrywide network. It wasn't great, but when it was destroyed in the war a new network formed like a kind of scar tissue over the country, connecting different regions to Iran, Pakistan, Uzbekistan, and Turkmenistan.

"Afghanistan, in the middle of them, buys internet connectivity from all of them," says Cowie. "So the government in Kabul is not any more capable of turning the internet off than they were of building an internet in the first place."