Swarm-mongering: Brainless blobs flock together

Birds of a feather flock together and now so do brainless, inanimate blobs. Made of microscopic particles, the artificial swarms could shed light on the mysterious mechanisms behind the natural swarming seen in fish and birds. They might also lead to materials with novel properties like self-healing.

Animals such as birds, fish and even humans that move together in swarms have individual intelligence, but Jérémie Palacci of New York University and colleagues wondered whether inanimate objects could also swarm. "From a physicist's point of view, if many different systems behave in the same way there must be an underlying physical rule," he says.

To explore this idea, the team created microscopic plastic spheres, each one with a cubic patch of haematite, an iron oxide, on its surface. When submerged in hydrogen peroxide, the spheres spread out in a disordered fashion. The team then shone blue light on the particles, causing the haematite cubes to catalyse the breakdown of any nearby hydrogen peroxide into water and oxygen. As hydrogen peroxide concentration dropped temporarily in these regions due to the reaction, osmotic forces cause more hydrogen peroxide to flow into them, and that in turn buffets the spheres. The whole process then repeats.

Self-healing swarm

When two spheres come close enough to each other, the balance of chemical forces shifts so that the two spheres are attracted. If there are enough spheres in the same place they will cluster together to form shapes of symmetrically arranged particles, which the team call crystals (see video, above). These crystals continue to be buffeted by the movement caused by the breakdown of hydrogen peroxide – but now they move together as one object, replicating a life-like swarm. Switch off the light, however, and the reaction stops, causing the crystal to lose the forces that hold it together, and the particle distribution becomes disordered once again.

"This system shows that even though the particles have no social interaction or intelligence, you can exhibit collective behaviour with no biology involved," says Palacci. Since the haematite is magnetic, it is even possible to steer the crystals in one direction by applying a magnetic field. Such control might be useful if the artificial swarms are to be harnessed for applications.

As the particles automatically fill any gaps that form in the crystal, again thanks to the chemical dynamics of the system, they could be used to create a self-assembling, self-healing material. The work is published in the journal Science today.

Schooled by fish

Iain Couzin of Princeton University says these kinds of systems are very useful for studying biological collective behaviour because researchers have complete control over their interactions – unlike natural systems.

His team has its own swarming experiment published in the same issue of Science, based on schools of fish that prefer to stay in shade. Their paper shows that shining a light on some of the fish in the school causes them to speed up, to get away from the light. But as a result, non-illuminated fish also speed up, even though, if acting purely as individuals, they would have had no reason to do so. "We show just by using simple interactions that schools can have a sense of responsiveness to the environment that individuals do not have," he says.

Couzin sees no reason why such behaviour should be limited to natural systems. "In future it may be possible to create systems of particles that can make collective decisions – something we often think of as only possible in biological systems," he says.

Journal references: Living crystals: Science, DOI: 10.1126/science.1230020; Fish: Science, DOI: 10.1126/science.1225883

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Chua Chu Kang TC new managing agent's plans to improve services

SINGAPORE: Feedback from residents of estates managed by Chua Chu Kang Town Council will be tracked more efficiently, while officers can directly record defects into the estate maintenance system using their smartphones.

These are some of the changes planned by the town council's new managing agent, CPG Facilities Management (CPGFM).

It was appointed following an open tender and took over on 1 February from UGL Services Esmaco Operations, whose contract with the town council ended on 31 January.

CPGFM, whose contract is for four years, will manage the common property of more than 70,000 residential and commercial units in Chua Chu Kang Group Representation Constituency (GRC).

There are five divisions in the GRC - Bukit Gombak, Chua Chu Kang, Keat Hong, Nanyang and Yew Tee and Hong Kah North.

The managing agent plans to leverage technology to improve services.

Mr Zaqy Mohamad, chairman of Chua Chu Kang Town Council, said the transition and handover have been smooth and seamless.

CPGFM is a subsidiary of CPG Corporation, which was formed in April 1999 with the corporatisation of the former Public Works Department.

It is also the managing agent of Ang Mo Kio and Tampines town councils.

- CNA/ir

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Nokia begins work on graphene, world's strongest material

A model of a sheet of graphene.

(Credit:
Swedish Academy of Sciences)

Forget diamonds, graphene is now the world's hardest material. And, all sorts of developers most likely want to get their hands on it.

Nokia looks to be ahead of the game in this graphene race. The Finnish mobile phone maker announced today that it was one of the recipients of a $1.35 billion grant from the European Union to do research and development on the super-material over the next 10 years.

"Nokia is proud to be involved with this project, and we have deep roots in the field -- we first started working with graphene already in 2006," Nokia's CTO Henry Tirri said in a statement. "Since then, we have come to identify multiple areas where this material can be applied in modern computing environments. We've done some very promising work so far, but I believe the greatest innovations have yet to be discovered."

Besides being the hardest substance in the world -- 300 times stronger than steel -- graphene has all sorts of other noteworthy qualities. It is also the thinnest object ever obtained by man -- measuring just one atom thick -- and the lightest. It is made of a 2D crystal and looks a bit like scotch tape, only infinitely thinner. Graphene is also transparent, bendable, and a far better conductor than copper.

If Nokia is successful in its development of the material, it will be able to build cell phones that are extremely light, durable, and less susceptible to overheating.

"When we talk about graphene, we've reached a tipping point. We're now looking at the beginning of a graphene revolution," research leader at Nokia Research Center Jani Kivioja said in the statement. "Before this point in time, we figured out a way to manufacture cheap iron that led to the Industrial Revolution. Then there was silicon. Now, it's time for graphene."

Here is a video by Cambridge University about the properties of graphene:

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Sinkhole Swallows Buildings in China

Photograph from AFP/Getty Images

The sinkhole that formed in the southern Chinese city of Guangzhou (pictured) is, unfortunately, not a new occurrence for the country.

Many areas of the world are susceptible to these sudden formations, including the U.S. Florida is especially prone, but Guatemala, Mexico, and the area surrounding the Dead Sea in the Middle East are also known for their impressive sinkholes. (See pictures of a sinkhole in Beijing that swallowed a truck.)

Published January 31, 2013

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Arias' Lawyer Shows Ex-Boyfriend's Lewd Photos

Accused murderer Jodi Arias was kept away from the Mormon friends of her lover Travis Alexander and their torrid sex affair was kept secret by Alexander, even as he sent lewd photos of himself to her online, according to court testimony today.

The testimony in Arias' trial for killing Alexander in 2008 was intended to bolster the defense's argument that she killed him in self defense, that Alexander was a sexual deviant who treated Arias as his "dirty little secret."

Arias' attorneys introduced as evidence photos that Alexander took of his penis and sent to Arias, part of a string of graphic messages and sexual phone calls the two engaged in while Alexander, an elder in the Mormon church, was supposed to be chaste.

Today's witness was the latest in a string called by the defense, including Alexander's former girlfriend Lisa Daidone, who told the court that Alexander had professed to be a virgin.

Daniel Freeman continued his testimony today, describing how he was a friend of both Arias and Alexander but that Alexander kept Arias distanced from his Mormon pals.

"Travis had made more friends at (the Mormon) ward, and had (Ultimate Fighting Championship) fight nights at his house many times, and Jodi was in town, but she wasn't there," Freeman said.

"There was that group of friends, them and Jodi, two different groups, and so Lisa [Daidone] and friends from church were there, but Jodi wasn't there," Freeman said.

Jodi Arias Murder Trial: Former Boyfriend Takes Stand Watch Video

Jodi Arias Murder Trial: Defense's First Day of Witnesses Watch Video

Alexander's behavior, the defense hopes to prove, shows that he mistreated Arias.

Arias, 32, is on trial for murdering Alexander, whom she dated for a year and continued to have a sexual relationship for a year after that. Her attorneys claim that Alexander was abusive and controlling toward Arias, and that she was forced to kill him.

Freeman described how he took a trip with his sister, Alexander, and Arias, and how Alexander had asked him to come along so that he and Arias "would not get physical."

"I don't know that I can say he didn't want to be alone with her, but he liked that when I was there, and my sister was there. They weren't as physical," Freeman said.

Freeman admitted that he had no idea Alexander and Arias had been having a sexual relationship the entire time they were together. He said Alexander never mentioned that to his friends.

In fact, Freeman noted that Alexander was considered to be a church elder when he baptized Arias into the Church of Latter-Day Saints. Both a church elder and a convert were expected to abide by the church's strict law of chastity, which banned any sexual relations outside of marriage.

"One thing people give up in this baptism process was sex," prosecutor Juan Martinez said. "Did you know she was having oral sex with Mr. Alexander at the time of her baptism? Would that be an insincere baptism?"

"She would not be ready to be baptized in that case," Freeman said.

"You were asked about Miss Arias, whether she was worthy of baptism if she was performing oral sex, but what about the elder receiving oral sex?" defense attorney Kirk Nurmi said.

"They would not be worthy of performing that ordinance at that time until they had gone through repentance," Freeman said. "They would go to a discipline council and could face excommunication or a probation period or have their priesthood removed."

Freeman said that Alexander never confessed to having a sexual relationship with Arias.

Freeman's testimony came on the third day of the defense's attempt to paint Alexander as a controlling, sex-obsessed liar who was cruel to Arias. Other witnesses have said that Alexander cheated on other women he dated with Arias, and lied to his friends and family about their relationship.

The defense also had Freeman point out that Alexander was strong and fit. They are expected to conclude that Alexander was physically threatening Arias when she killed him.

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Today on New Scientist: 30 January 2013

Timbuktu's precious scientific texts must be saved

Islamist militants in Mali have burned documents that attest to science in Africa before European colonisation - what remains must be protected

Think that massage feels good? Try adding drugs

Nerve bundles that respond to stroking have been identified and chemically activated in mice

How Obama will deliver his climate promise

The US is set to meet - and maybe exceed - Obama's pledge to cut US emissions by 17 per cent, which could give a boost to international climate talks

Minimum booze price will rein in alcohol abuse

Evidence suggests the UK government's proposal to set a minimum price for alcohol could save thousands of lives, and billions of pounds of public money

First real time-travel movies are loopers

Hollywood has played with time travel for decades, but now physicists have the first movies of what travelling to the past actually looks like

Surfer rides highest wave ever caught

Garret McNamara of Hawaii claims to have ridden the highest wave ever caught by a surfer, a 30-metre monster off the coast of Nazaré, Portugal

Infrared laptop trackpad ignores accidental touches

Longpad is a touchpad that extends the full width of your laptop and uses infrared sensors to ignore any unwanted touches

Close call coming: Averting the asteroid threat

With an errant space rock heading this way, just how good are our asteroid defences - and how do we avert the cataclysm?

The right to fight: women at war

The US military has accepted women into combat. What can science tell us about how women deal with being in the line of fire? And are they any different to men?

Earth and others lose status as Goldilocks worlds

Several planets are taking a hit thanks to a redefinition of the habitable zone - the area around a star in which liquid water can theoretically exist

The 10,000-year bender: Why humans love a tipple

Our taste for alcohol results from an evolutionary tussle between humans and yeast - one in which the microbes have often had the upper hand

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2 new commercial belts to bring jobs closer to homes

SINGAPORE: Jobs will be brought nearer to the homes to help ease the congestion in the city centre, with two new commercial belts.

The government, which outlined these developments in its Land Use Plan, will also make it easier for people to use public transport. And, it hopes to see 75 per cent of all journeys made by public transport by 2030, compared with the current 60 per cent.

The first new commercial belt is the North Coast Innovation Corridor, spanning Woodlands Regional Centre, Sembawang, the future Seletar Regional Centre and Punggol, to be ready in 10 to 15 years.

Seletar Regional Centre, for example, will be a major employment node for people living in the north and north east. There'll be more land for new business activities when the existing shipyard facilities in Sembawang are phased out.

By 2030, it'll be easier to get around using the Cross Island Line, Thomson Line and the new North-South Expressway.

Within the regional hubs, there are plans to start community bus services, which will operate during specific periods of the day.

The other commercial belt is the Southern Waterfront City - from Marina Bay along the waterfront from Keppel, through Telok Blangah to Pasir Panjang Terminal. It'll have more commercial and housing developments after 2027.

To serve the expected increase along the North-South corridor and optimise the use of roads, the government may introduce what it calls a "reversible flow" scheme along certain expressways.

This means the traffic can flow in one direction during the morning peak hours and move in the opposite direction during the evening peak period.

- CNA/ck

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Microsoft Surface sales well below shipments, says iSuppli

Surface RT tablet.

(Credit:
CNET)

Sales of Microsoft's first Surface tablet fell well short of the 1 million mark, while return rates were high, IHS iSuppli told CNET.

Shipments of the Surface RT device, which debuted last quarter, into the channel were about 1.25 million, but sales out of the channel "were significantly lower, maybe on the order of 55 to 60 percent of that figure," said Rhoda Alexander, an analyst at iSuppli, citing the market research firm's estimates.

That would put sales in the range of between roughly 680,000 and 750,000 based on those percentages.

That kind of "sales out" percentage is not unusual, however, according to Alexander, adding that she has seen similar percentages with newly introduced
Android devices.

And, needless to say, almost every manufacturer's sales-out figure pales against Apple's, the gold standard, where the percentage is typically in the mid to high 90 percent range or even 100 percent.

And Alexander said she sees little evidence of continued production of the Microsoft RT device -- which runs a limited version of
Windows 8 on top of an ARM processor -- in the first quarter because Microsoft is still trying to sell off inventory.

But that inventory carryover is also not unique to Microsoft. The Amazon
Kindle Fire, when it was first introduced, had excess inventory that carried over into the following quarter. As a result, Amazon temporarily cut production, Alexander said.

Surface RT has other challenges, too. The return rate on the device was "very high," Alexander said. "If you put the high return rate together with low sell-through [sales out] rate, that's indicative of a problem," she said, adding, again, that the Kindle Fire initially had very high return rates and low sell-through.

Why the high return rates? "It seems to be linked in a lot of cases to a steep learning curve of the [Windows 8] OS -- which is not necessarily intuitive," she said.

And another problem possibly looms big this year. There is a "distinct lack of interest" from device makers in pursuing RT devices at the moment, she said.

For Microsoft partners the question is, "where is the win for us?" -- according to Alexander.

During last week's earnings conference call, Chief Financial Officer Peter Klein repeated a number of times that Surface contributed to revenue. "Certainly this quarter [Surface] was a contributing factor to revenue growth in the Windows business," Klein said.

During the call, Microsoft cited Surface as a part of non-OEM revenue that grew 40 percent.

Microsoft has not talked about sales figures. And the company would not provide a number when contacted.

Microsoft is about to bring out a second line of tablets, the Surface Pro, that runs the full version of Windows 8 on top of a mainstream Intel processor. Alexander says she sees more momentum industrywide for these kinds of devices.

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New Theory on How Homing Pigeons Find Home

Jane J. Lee

Homing pigeons (Columba livia) have been prized for their navigational abilities for thousands of years. They've served as messengers during war, as a means of long-distance communication, and as prized athletes in international races.

But there are places around the world that seem to confuse these birds—areas where they repeatedly vanish in the wrong direction or scatter on random headings rather than fly straight home, said Jon Hagstrum, a geophysicist who authored a study that may help researchers understand how homing pigeons navigate.

Hagstrum's paper, published online Wednesday in the Journal of Experimental Biology, proposes an intriguing theory for homing pigeon disorientation—that the birds are following ultralow frequency sounds back towards their lofts and that disruptions in their ability to "hear" home is what screws them up.

Called infrasound, these sound waves propagate at frequencies well below the range audible to people, but pigeons can pick them up, said Hagstrum, who works at the U.S. Geological Survey in Menlo Park, California.

"They're using sound to image the terrain [surrounding] their loft," he said. "It's like us visually recognizing our house using our eyes."

Homeward Bound?

For years, scientists have struggled to explain carrier pigeons' directional challenges in certain areas, known as release-site biases.

This "map" issue, or a pigeon's ability to tell where it is in relation to where it wants to go, is different from the bird's compass system, which tells it which direction it's headed in. (Learn about how other animals navigate.)

"We know a lot about pigeon compass systems, but what has been controversial, even to this day, has been their map [system]," said Cordula Mora, an animal behavior researcher at Bowling Green State University in Ohio who was not involved in the study.

Until now, the two main theories say that pigeons rely either on their sense of smell to find their way home or that they follow the Earth's magnetic field lines, she said.

If something screwed up their sense of smell or their ability to follow those fields, the thinking has been, that could explain why pigeons got lost in certain areas.

But neither explanation made sense to Hagstrum, a geologist who grew interested in pigeons after attending an undergraduate lecture by Cornell biologist William Keeton. Keeton, who studied homing pigeons' navigation abilities, described some release-site biases in his pigeons and Hagstrum was hooked.

"I was just stunned and amazed and fascinated," said Hagstrum. "I understand we don't get dark matter or quantum mechanics, but bird [navigation]?"

So Hagstrum decided to look at Keeton's pigeon release data from three sites in upstate New York. At Castor Hill and Jersey Hill, the birds would repeatedly fly in the wrong direction or head off randomly when trying to return to their loft at Cornell University, even though they had no problems at other locations. At a third site near the town of Weedsport, young pigeons would head off in a different direction from older birds.

There were also certain days when the Cornell pigeons could find their way back home from these areas without any problems.

At the same time, homing pigeons from other lofts released at Castor Hill, Jersey Hill, and near Weedsport, would fly home just fine.

Sound Shadows

Hagstrum knew that homing pigeons could hear sounds as low as 0.05 hertz, low enough to pick up infrasounds that were down around 0.1 or 0.2 hertz. So he decided to map out what these low-frequency sound waves would have looked like on an average day, and on the days when the pigeons could home correctly from Jersey Hill.

He found that due to atmospheric conditions and local terrain, Jersey Hill normally sits in a sound shadow in relation to the Cornell loft. Little to none of the infrasounds from the area around the loft reached Jersey Hill except on one day when changing wind patterns and temperature inversions permitted.

That happened to match a day when the Cornell pigeons had no problem returning home.

"I could see how the topography was affecting the sound and how the weather was affecting the sound [transmission]," Hagstrum said. "It started to explain all these mysteries."

The terrain between the loft and Jersey Hill, combined with normal atmospheric conditions, bounced infrasounds up and over these areas.

Some infrasound would still reach Castor Hill, but due to nearby hills and valleys, the sound waves approached from the west and southwest, even though the Cornell loft is situated south-southwest of Castor Hill.

Records show that younger, inexperienced pigeons released at Castor Hill would sometimes fly west while older birds headed southwest, presumably following infrasounds from their loft.

Hagstrum's model found that infrasound normally arrived at the Weedsport site from the south. But one day of abnormal weather conditions, combined with a local river valley, resulted in infrasound that arrived at Weedsport from the Cornell loft from the southeast.

Multiple Maps

"What [Hagstrum] has found for those areas are a possible explanation for the [pigeon] behavior at these sites," said Bowling Green State's Mora. But she cautions against extrapolating these results to all homing pigeons.

Some of Mora's work supports the theory that homing pigeons use magnetic field lines to find their way home.

What homing pigeons are using as their map probably depends on where they're raised, she said. "In some places it may be infrasound, and in other places [a sense of smell] may be the way to go."

Hagstrum's next steps are to figure out how large an area the pigeons are listening to. He's also talking to the Navy and Air Force, who are interested in his work. "Right now we use GPS to navigate," he said. But if those satellites were compromised, "we'd be out of luck." Pigeons navigate from point to point without any problems, he said.

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Former Police Captain Cleared of Ex-Wife's Murder

A former Ohio police captain has been cleared in the murder of his ex-wife and released from prison, where he had been for 15 years -- but prosecutors say they plan to appeal the ruling.

"I'm just a jumble of emotions and I just can't wait to hug all of my family," Douglas Prade told reporters outside the prison when he was released Tuesday afternoon, according to ABC News' Cleveland affiliate WEWS-TV.

He thanked "all of the people that supported me and communicated with me and told me to keep my spirits up."

Prade's ex-wife, Dr. Margo Prade, 41, was found shot to death in her minivan outside of her medical practice in November 1997.

Douglas Prade was an Akron, Ohio, police captain at the time.

At trial, he was convicted on murder and wiretapping charges and sentenced to life in prison.

Prade, now 66, maintained his innocence and, eventually, the Ohio Innocence Project took up his cause and petitioned for his release or a new trial based on new DNA testing.

One of the key factors in Prade's conviction was a bite mark found on Margo Prade's body. The prosecution brought in an expert that testified the bite mark came from Douglas Prade.

Phil Masturzo/Akron Beacon Journal/AP Photo

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The Ohio Innocence Project commissioned a new DNA test that was not available at the time of the trial. The test found that the DNA around the bite was not Douglas Prade's.

Summit County Court of Common Pleas Judge Judy Hunter ruled that Prade should be set free because the new DNA results were "clear and convincing" in Prade's favor, according to the Associated Press.

Prosecutor Sherri Walsh is strongly disputing the new DNA evidence.

"This is a gross misapplication of the law, and we will be appealing Prade's exoneration. The defendant had to present new evidence so convincing that no juror would have found him guilty, and he failed to do so," Walsh said in a statement. "The DNA evidence presented by the Ohio Innocence Project on behalf of Prade is contaminated and unreliable. It does not prove innocence."

Walsh said that all evidence points to Prade as the person who killed Margo Prade.

"He was a serial stalker," Walsh said. "He tapped her phones and recorded more than 400 of her personal calls. He had verbally abused and threatened her. And we know Margo was afraid of him."

Other evidence includes Prade's handwritten tally of the bills he owed subtracted from the life insurance money he'd get if his wife died, Walsh said. Two witnesses placed him at the murder scene.

"We have not seen any credible evidence that suggests innocence, and we are taking all available actions to keep a dangerous killer off the streets," Walsh said.

Margo Prade's family is also upset by the decision.

"I feel like my life is in danger and my family's life is in danger now," Margo Prade's nephew Tony Fowler told the AP. "[Dr. Prade and her mother] are probably turning over in their graves but God will have the final say."

Alison McCarty, the former prosecutor on the case, told WEWS she respected the court's decision, but emphasized that the case is not yet closed.

"[Margo Prade] was such a superstar and it was just such a tremendous loss, and her death still needs justice," McCarty said.

The state has 30 days to file a motion in the court of appeals requesting permission to appeal the decision for a new trial.

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