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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"The sooner, the better" for COC on South China Sea: Shanmugam

SINGAPORE: Foreign Affairs Minister K Shanmugam has reiterated the need for a Code of Conduct (COC) on the South China Sea, saying the sooner it is started the better.

He said this in a live interview with the BBC on Friday morning, covering issues such as the South China Sea claims, US-China relations and ASEAN.

He was asked whether it is possible to have some kind of resolution via ASEAN.

Mr Shanmugam replied that ASEAN has been trying to make it clear that territorial disputes can only be solved by the claimant states themselves.

But the regional grouping can put in place a structure that shows and tells people how they have to structure their conduct with each other. And this is why ASEAN has been pushing for the COC.

Mr Shanmugam said the COC should apply to all countries in the way they interact with each other in the region.

Asked how concerned Asia should be over what's perceived as an increasingly assertive China, Mr Shanmugam said this has to be looked at in context.

He said no leader of China, as well as leaders of many countries, can afford to be seen to be soft on sovereignty.

The real issue is whether they can put in place a modus vivendi to deal with territorial and sovereignty issues.

Mr Shanmugam pointed out that the actual disputes will take a very long time to settle and stressed that the issue is how countries behave so that the disputes do not escalate into clashes, which could be terrible for the region.

- CNA/ir

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X Games snowmobiler dies

By CNN Staff

updated 1:55 PM EST, Thu January 31, 2013

A photo of Caleb Moore's performance in the Snowmobile Freestyle Final during X Games Aspen 2013.

STORY HIGHLIGHTS

• NEW: Caleb Moore's brother also suffered an accident in the X Games


• Caleb Moore died a week after a snowmobile crash in the X Games


• The crash has raised new safety concerns about the games


• ESPN, which operates the X Games, says it will conduct a thorough review

(CNN) -- Snowmobiler Caleb Moore died Thursday, a week after a crash that has raised new safety concerns about the X Games. He was 25 years old.

"He will be truly missed and never forgotten," his family said in a statement.

"The family wishes to express their deep gratitude for all the prayers and support they have received from all the fans, friends and family around the world that Caleb has inspired. ... Arrangements for a celebration of life are being made and an announcement will be made in the coming days."

Moore, a freestyle snowmobiler, was attempting a backflip at the Winter X Games in Aspen, Colorado, when he couldn't rotate his machine enough to land properly. The skis dug into the lip of the slope, bringing the 450-pound snowmobile crashing down on him. The vehicle slammed into Moore's head and chest.

"We are deeply saddened by Caleb Moore's passing and our thoughts and prayers go out to his parents, Wade and Michelle, his brother, Colten, and the entire Moore family," ESPN, which organizes and televises the X Games, said in a statement. "He will be remembered for his natural passion for life and his deep love for his family and friends, and he will always be an inspiration to everyone he touched in the action sports community.

"As a result of this accident we will conduct a thorough review of this discipline and adopt any appropriate changes to future X Games."

The statement added that the X Games have long worked on safety issues and that nevertheless, "when the world's best compete at the highest level in any sport, risks remain. Caleb was a four-time X Games medalist attempting a move he has landed several times previously."

Colten Moore, 23, was also involved in an accident during Thursday's event. He was released from the hospital Saturday, according to his Facebook fan page.

Caleb Moore's Facebook page is carrying messages from fans. "R.I.P. Caleb," wrote Candi Clark-Hibbs, adding, "prayers to your family."

People we've lost in 2013: The lives they lived

CNN's Josh Levs, Brian Todd, Dugald McConnell, Christine Sever and Shawn Nottingham contributed to this report.

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Alaska Airlines plane lands safely after pilot passes out

Updated 3 a.m. EST

PORTLAND, Ore. An Alaska Airlines jetliner bound for Seattle made an emergency landing in Portland, Ore., Thursday night after the pilot lost consciousness, an airline spokesman said.

The co-pilot landed Flight 473 safely after declaring an emergency to get priority care for the pilot, spokesman Paul McElroy said. All of the airlines' pilots are trained to fly single-handedly.

The pilot lost consciousness "somewhere over Oregon," McElroy said, then later regained consciousness and left the cockpit. A doctor on board the flight tended to him in the cabin until the plane landed and was met by medical personnel on the runway.

The pilot, who was not identified, was taken to a hospital but there was no immediate word on his condition, McElroy said.

The Boeing 737-700, with 116 passengers and five crew members on board, left Los Angeles about 6:30 p.m. and was diverted to Portland, touching down there at about 9 p.m., reports CBS Portland affiliate KOIN-TV. It had been due to arrive in Seattle at 9:30 p.m.

McElroy says the pilot has been flying for Alaska for 28 years and was current on his six-month medical evaluation. The co-pilot is an 11-year Alaska Air veteran.

On Jan. 22, the co-pilot on an Alaska Airlines flight from Seattle to Las Vegas fainted briefly, and the pilot requested emergency landing priority to get prompt medical assistance for him.

"At this point, we do not believe there was a connection between the two incidents," McElvoy said.

Twenty passengers with a tight schedule for connecting flights were put on a Horizon Air shuttle flight to Seattle on Thursday night, the spokesman said.

A new pilot was dispatched to Portland to fly the remaining passengers to Seattle on board the same plane.

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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

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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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More people volunteering their services to help others: survey

SINGAPORE: More people are giving their time and making the effort to help others, with one in three serving as volunteers in 2012.

A survey by the National Volunteer & Philanthropy Centre (NVPC) found that about 32 per cent of its respondents were volunteers, which is the highest rate since it started the survey in 2000.

The same survey conducted in 2010 had 23 per cent.

The survey, conducted between July and September 2012, found that the increase was largely driven by the interest in informal volunteering.

This refers to activities like reading to the child of a needy neighbour, instead of being part of a formal organisation.

The survey also found that individual donations remained steady at about $1.1 billion in 2012, compared with $1.07 billion in 2010.

Those who earned below $1,000 a month donated a bigger share of their income - at 1.8 per cent.

That's higher than the 0.5 per cent for those earning between $5,000 and below $6,000.

More than 1,500 people took part in the survey, which did not include compulsory community work by students.

- CNA/de

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Suspect sought in Ariz. office shooting

By CNN Staff

updated 10:31 PM EST, Wed January 30, 2013

One victim was killed, and two others suffered non-life-threatening injuries after a shooting in Phoenix, police said.

STORY HIGHLIGHTS

• One of three shooting victims dies of injuries, Phoenix police say


• Other two victims have non-life-threatening injuries, police say


• Police identify suspect as Arthur Douglas Harmon, 70, last seen in a white Kia

Phoenix, Arizona (CNN) -- Phoenix police were searching Wednesday for a 70-year-old man suspected in the shooting of three people, one of whom died, in an office building.

Arthur Douglas Harmon had gone to the building to discuss "some type of litigation," Phoenix Police Public Information Officer Tommy Thompson told CNN affiliate KTVK.

After the meeting, at about 10:30 a.m. (12:30 p.m. ET), Harmon shot Steven Singer, 48; a 43-year-old man who was in critical condition, and a 32-year-old woman, Thompson said.

The law firm of Osborn Maledon identified one of its attorneys, Mark Hummels, as one of the victims. He was involved in a client mediation when he was shot, the Phoenix firm said.

"We believe the two men were his targets," Thompson said. The woman, whose injury was not life-threatening, "just happened to be in the way when the shooting occurred."

Harmon then fled in a 2013 Kia Optima, Arizona license plate AVS-2052, he said. Harmon shot at a witness who was following him, Thompson said. "Anybody who contacts him needs to be aware that he is armed and dangerous," he said.

Two other people who were not shot were also taken to a hospital, one for "some other type of injury not related to gunfire," and the other "may have been related to stress," Thompson said.

Former astronaut Mark Kelly referred to the shooting during a Senate Judiciary Committee hearing in Washington on gun violence. "There's 50 or so police cars on the scene," he said.

Kelly and his wife, former Rep. Gabrielle Giffords, D-Arizona, this month launched Americans for Responsible Solutions, which seeks to raise money to counter the influence of the gun lobby.

Two years ago, Giffords was shot in the head by a gunman in a parking lot in Tucson.

CNN's Deanna Hackney in Atlanta and Casey Wian in Phoenix contributed to this report.

Part of complete coverage on

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updated 7:49 AM EST, Mon January 28, 2013

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updated 3:00 PM EST, Mon January 28, 2013

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Mass shootings in 2012 reignited the debate over legislation to combat gun violence. Here's a look at laws already on the books in the United States dealing with firearms.

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N.Y. Times: China hacked our computers for past four months

BEIJING The New York Times says Chinese hackers repeatedly penetrated its computer networks over the past four months, stealing reporters' passwords and hunting for files on an investigation into the wealth amassed by the family of one of China's leaders.

In a report released late Wednesday, the Times said security experts hired to plug the breach tracked the attacks to China, in some cases computers identified with the Chinese military.

The newspaper reports that, "After surreptitiously tracking the intruders to study their movements and help erect better defenses to block them, The Times and computer security experts have expelled the attackers and kept them from breaking back in."

The attacks coincided with a Times investigation into how the family and relatives of Premier Wen Jiabao built a fortune worth more than $2 billion. The report says no Times customer data was compromised but that the passwords for all employees were stolen.

The newspaper adds, "The hackers tried to cloak the source of the attacks on The Times by first penetrating computers at United States universities and routing the attacks through them, said computer security experts at Mandiant, the company hired by The Times. This matches the subterfuge used in many other attacks that Mandiant has tracked to China."

Security experts say China carries out a widespread cyber-spying operation to steal secrets and intimidate critics.

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No Device Eliminates Concussion Risk, Experts Say

As the long-term consequences of concussions become clearer, a cottage industry has popped up to sell athletes and worried parents products designed to mitigate risks of concussions that even helmets cannot prevent.

Despite the bold claims of some companies, however, many experts say the Holy Grail in contact sports -- a device that prevents concussions -- simply does not exist. Indeed, experts say, there is no proof that any current device significantly reduces the risk of concussions beyond the protections already provided by helmets.

"Nightline" found several products for sale online that aim to reduce the risk of concussions or even alert parents and coaches when a kid has supposedly taken a concussion-level hit. The claims the manufacturers make are often breathtakingly reassuring.

Concern about the risk of concussion is mounting at every level of the gridiron from the NFL to colleges and even high schools. Concussions are the most common injury among high school football players.

Jennifer Branin, whose son Tyler Branin is one of the stars of the Woodbridge Warriors high school football team in Irvine, Calif., said "it was scary" the first time he had a concussion.

"He had lost his balance on the field," she said. "He got up and tried to continue, but couldn't keep his balance."

Junior Seau Had Brain Disease, Researchers Say Watch Video

She said the effects of the concussion lingered, causing Tyler to miss a week of school and football practice. Even months later, he complained of difficulty concentrating in class.

Parents such as Jennifer Branin, who is president of the team's booster club, and her husband, Andy Branin, a former college football player himself, were looking for a way to support their son's desire to play football while also keeping him safe.

"He wants to play and, as a mom, you may want to put bubble-wrap around them and protect them forever, but that's not going to happen," she said.

So Jennifer Branin decided to do something. She raised money to buy the team helmet inserts by Unequal Technologies for added protection.

Unequal Technologies, one of the highest profile players in this new market, described its product explicitly on the box as "Concussion Reduction Technology," or "CRT." It is a strip of composite material including bullet-proof Kevlar that is designed to stick inside the helmet as a liner to the existing helmet pads.

Unequal Technologies uses its material in products ranging from padded sleeves to shin guards. The company counts NFL players and X-Games athletes among its fans.

On board as paid spokesmen are Philadelphia Eagles quarterback Michael Vick and James Harrison, a linebacker for the Pittsburgh Steelers. Harrison is one of the hardest-hitting guys in the NFL and said he uses Unequal Technology's liners in his helmet.

"I don't know what it's made of but it works," Harrison says in one of Unequal's promotional videos. "I really don't feel like I'm taking a risk."

Vick wasn't wearing the CRT product when he suffered a season-ending concussion in November, but he has since promised that he will be wearing it when he returns to the field next season.

Rob Vito, founder and CEO of the Kennett Square, Pa.-based company, said he worked with scientists to create a military-grade composite material that can help protect athletes from all kinds of injuries from head to toe.

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