Science Article

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Precision surgeons

Operating on the human body requires high skill but also great control, something robots can provide. The idea of robotic surgery prompted early fears of unsupervised robots let loose to operate, but the reality is that robots now assist surgeons to perform precision procedures. The most successful of these is arguably the da Vinci robotic surgical system, which is used for keyhole surgery, to operate on anything from gall bladder removals and brain surgery to heart bypasses.

Similarly, tiny, wireless and robotic camera-capsules have been used diagnostically, by allowing them to pass through a patient's digestive system. Others have been designed to move about by remote control in the abdominal cavity, beaming images back to the surgeon, or even taking biopsy samples. Robot hands have even been developed to scan for breast cancer.

Actuators and sensors

But despite all the successes, there are still many challenges in robotics. These include producing better actuators (which control how robots move), sensors (which allow them to detect their environment) and ultimately making bots much smarter. Current motors, and hydraulic or pneumatic actuators, are either too weak, or too bulky and noisy. 

Bipedal and humanoid robots have proved a particular problem. Robots on wheels, or those that move like insects, have found it much easier to balance and get around.

And while much early research in robotics focused on using sonar sensors because they were cheap and easy to use, the focus today is on the more challenging, yet richer, vision-based navigation systems.

Similarly, while there is much research on making robotic arms and hands, the difficulty lies in making electronic skin sensitive enough to detect fragile or slippery objects by touch alone. A robot that mimics human speech is also under development.

The ultimate test perhaps is robot soccer. This is driving development in just about every area of robotics from the ability to run and kick a ball to communicating and demonstrating teamwork. The grand aim is to have a team of humanoid robots that can beat the best human soccer team in the world by 2050.

LIKE PCs, robots may soon become a key part of our everyday lives, but they present unique communication challenges that PCs do not. So roboticists are turning to people who have already solved many of these problems - actors, animators and dancers. 

Old Robot

The Merriam Webster Dictionary, 1998, defines robotics as “technology dealing with the design, construction, and operation of robots”.

Robotics encompasses such diverse areas of technology as mechanical, electrical, and electronic systems; computer hardware; and computer software. 

Ever since the Czech writer Karel Èapek first coined the term "robot" in 1921, there has been an expectation that robots would some day deliver us from the drudgery of hard work. The word - from the Czech "robota", for hard labour and servitude - described intelligent machines used as slaves in his play R.U.R. (Rossum's Universal Robots).

Today, over one million household robots, and a further 1.1 million industrial robots, are operating worldwide. Robots are used to perform tasks that require great levels of precision or are simply repetitive and boring. Many also do jobs that are hazardous to people, such as exploring shipwrecks, helping out after disasters, studying other planets and defusing bombs or mines.

Domestic invasion

Despite the longevity of the robot concept, robotic butlers that roam our homes and relieve us from housework still seemed far from reality until very recently. Instead, the vast majority of robots worked in factories performing the industrial functions of brainless machines.

However, a combination of increased computing power and advances made in the field of artificial intelligence, or AI, have now made software smart enough to make robots considerably more useful.

Suddenly people were happy to pay for robots that had no specific functional value. Instead these bots, such as Sony's Aibo robotic dog and its robo-pups served as robo-pets and companions, rather than slaves.

 
Movers and shakers

Nao Robot

And while we often think of robots being humanoid, such as Honda's Asimo and Sony's Qrio, there is as much interest, if not more, in emulating other creatures like insects, lobsters, orang-utans, alligators, snakes and fish. A robot guard dragon has even been created.

Whether they have two legs, many legs, or no legs at all, considerable advances have been made in robot locomotion, including bipedal walking, rambling, crawling, rock-climbing, bouncing, slithering and swimming.

Robot wars

One area where even more advances in autonomy have been made is the development of unmanned aerial vehicles, or UAVs. These are essentially remotely-controlled spy planes that are capable of flying themselves if they lose contact with their pilot. These planes can also be used to monitor forest fires. Some robots have even learnt to fly of their own accord.

Mars Rover robot

The Pentagon has started arming some UAVs, making them capable of responding with firepower against aggressive attacks - so-called unmanned combat vehicles, or UCVs. Robots that act as battlefield spies have also been designed.

In addition, NASA has already sent robotic rovers to Mars, developed robotic dirt scoopers, "flying eyes" and probes for interplanetary exploration and even sent droids off to try to explore asteroids. Space probes such as Huygens (which landed on Titan) and Russia's Venera 9 (which landed on Venus) are sometimes considered robots too. A robotic rover has even been used to explore Egyptian pyramids.

A military reconnaissance robot being developed at a British lab can keep moving even if it gets damaged on the battlefield. When any of the snake-like robot's "muscle" segments are damaged, clever software "evolves" a different way for it to wriggle across any terrain. The serpentine spy is a research project funded by aerospace company BAE Systems to make a low-cost military robot that can be dropped out of helicopters to carry out reconnaissance missions. 

A self-healing robot has long been a dream of robotics engineers, not least because the machines are notoriously unreliable and absolutely terrible at dealing with unforeseen circumstances. The snakebot is made up of modular vertebral units that "snap" together to form a snake-like body (see picture). 

Shape-memory Alloy

Each unit contains three separate "muscles" running down its length. The muscles are made out of wires of a shape-memory alloy called nitinol, an alloy of nickel and titanium whose crystal structure shrinks when an electric current is applied to it. Usefully, it regains its original shape and length once the current is removed.

To make the snakebot move in a particular direction, a current is applied to certain wires. When the current is removed, the wires spring back and the robot will jump forward.

The software for making a robot wriggle like a snake is fairly straightforward. But ensuring that the snake will keep moving even if a segment is damaged is trickier, and relies on different segments taking over from the damaged ones.

Genetic Algorithm

The program starts off with a population of 20 digital chromosomes, with each consisting of an initially random binary digit that corresponds to a muscle wire - where a 1 represents its activation and a 0 its deactivation. Each of these chromosomes forms the basis of a series of movements in the robot.

The two best chromosomes are then saved, the remainder are mixed up or randomly mutated and the process is repeated. After a number of generations, the amount of improvement finally tends to taper off.

Bentley and his colleague Siavash Haroun Mahdavi at University College London borrowed a trick from evolution to allow their robot to adaptive ability and so tend to give up the ghost when circumstances change.

So, they make a bot like snake, thr name of is SNAKEBOT.

Your DNA contains a set of instructions for "building" a human. These instructions are inscribed in the structure of the DNA molecule through a genetic code. DNA has no reason to feel special. For decades it seemed that only a handful of molecules could store genetic information and pass it on. But now synthetic biologists have discovered that six others can pull off the same trick, and there may be many more to find.

A host of alternative nucleic acids have been made in labs over the years, but no one has made them work like DNA.

This problem has now been cracked. "This unique ability of DNA and RNA to encode information can be implemented in other backbones," says Philipp Holliger of the MRC Laboratory of Molecular Biology in Cambridge, UK.

Evolving XNA

Holliger's team focused on six XNAs (xeno-nucleic acids). DNA and RNA are made of a sugar, a phosphate and a base. The XNAs had different sugars, and in some of them the sugars are replaced with completely different molecules.

A key hurdle for the team was to create enzymes that could copy a gene from a DNA molecule to an XNA molecule, and other enzymes that could copy it back into DNA.

They started with enzymes that do this in DNA only. Over the years the team made incremental tweaks until they produced enzymes that could work on XNAs.

Once they had created these enzymes, they were able to store information in each of the XNAs, copy it to DNA, and copy it back into a new XNA. In effect, the first XNA passed its information on to the new one – albeit in a roundabout way.

This is the first time artificial molecules have been made to pass genes on to their descendants. Because the XNAs can do this, they are capable of evolution.

Journal reference: Science DOI: 10.1126/science.1217622

Tiny carbon nuggets in meteorites from Mars were formed by cooling magma, not left by ancient alien microbes. That's both good news and bad news for astrobiologists.

The 1996 discovery of carbonate structures in meteorite ALH-84001 – which travelled to Earth from Mars more than 13,000 years ago – was hailed at the time as evidence that alien microbes once lived on the red planet. However, subsequent studies of both the carbonate structures and tiny nuggets of macromolecular carbon (MMC) in the meteorite cast doubt on the claims.

Paradoxically, the find actually boosts prospects for finding signs of ancient life in Martian rocks. The carbon in MMC was originally chemically reduced – meaning it carries extra electrons and is quick to react. Such readily available and reactive carbon could have joined with other elements to create complex chemical molecules, perhaps even life.

NASA and the European Space Agency (ESA) were planning a pair of joint missions to Mars that could have made important strides in the search for past or present life.

The ExoMars Trace Gas Orbiter, which was to launch in 2016, would have followed up on hints of methane discovered in the Martian atmosphere by previous missions. The gas is of particular interest as it is commonly produced by microbes on Earth.

ExoMars ( Mars Rover)

The ExoMars rover, which had been slated for launch in 2018, would have drilled beneath the Martian surface to get samples of pristine material, possibly including complex carbon-based molecules that could have provided clues to past Martian life.

The Mars budget was slashed as a result, with NASA's contribution to the flagship ExoMars mission the main casualty.

NASA still hopes to mount a less costly mission to Mars in 2018, but it might not land on the surface. The agency has not specified exactly where it would go, but orbiters tend to be less expensive than rovers.

The proposed budget also confirms that NASA plans to continue building the James Webb Space Telescope with a launch targeted for 2018, and continue payments to private space companies like SpaceX to help them develop space taxis that could take crew to the International Space Station.

NASA wants $830 million for space taxi development in 2013. It asked for a similar amount in 2012, but Congress cut it by more than half, to about $400 million.

Computation is any type of calculation or the use of computer technology in Information processing. Computation is a process following a well-defined model understood and expressed in an algorithm, protocol, network topology, etc. Computation is also a way for find solve problem from some quetion about mathematics. Many software about computation has created and easy to use. Computation also can to be created animated.

Turing's achievements matter today begins with the story of how he set out to solve one of his era's biggest mathematical conundrums - and in the process defined the basis of all computers

The first computer

Up until the second world war, the word "computer" meant a person, These human computers were an essential part of the industrial revolution and performed often repetitive calculations, such as those necessary for the creation of books of log tables. 

But in 1936, Turing, aged just 24, laid the foundations for a new type of computer - one we would still recognise today - and so played a seminal role in the information technology revolution.

Turing did not set out to invent the model for the modern computer, though. He wanted to resolve a conundrum in mathematical logic. In the mid-1930s, he decided to attack the fearsomely named Entscheidungsproblem - or "decision problem" - posed by mathematician David Hilbert in 1928. In other words: does a step-by-step procedure exist that can determine whether any given statement in mathematics is true or false?

In 1936, Turing published a paper that provided a definitive answer to Hilbert's question: no procedure exists for determining whether any given mathematical statement is true or false. Moreover, many of the important unresolved questions in mathematics are "undecidable" (Proceedings of the London Mathematical Society, Vol 42, p 230). This was good news for human mathematicians, because it meant that they would never be replaced by machines. But with his paper, Turing had achieved more than the resolution of Hilbert's question. To arrive at his result, he had also come up with the theoretical basis for modern computers.

First, he imagined a machine capable of reading symbols from a paper tape. You would feed the paper tape in, and the machine would examine the symbols, then make a decision about what to do next by following a set of internal rules. It could, for example, add two numbers that were written on the tape and print the result further along the tape. This would later come to be known as a Turing machine.

Turing realised that it would be possible to make a machine that could initially read a procedure from the tape, and use that to define its internal rules. By doing so, it was programmable, and could perform the same actions of any individual Turing machine, which had fixed internal rules. That flexible device, which we call a universal Turing machine, is a computer.

June 23 marks the 100th birthday of Alan Turing. If I had to name five people whose personal efforts led to the defeat of Nazi Germany, he helped decipher the messages created by the Nazi's Enigma coding machines.

My, my, my Delilah

Turing is often associated with breaking codes, but in 1943 he also spent time making them. At the secret UK government laboratory at Hanslope Park in Buckinghamshire, Turing led the development of a portable device for speaking securely with another person. It was named Delilah and could be used to scramble a telephone or radio conversation.

Delilah was revolutionary because the scrambling system was very hard to break, yet was portable. By contrast, the secure phone system that linked the British prime minister at 10 Downing Street to the US president in the White House was so large that it had to be installed in the basement of the Selfridges store on London's Oxford Street. Called SIGSALY, it weighed 50 tonnes and required thousands of watts of power. Other, smaller voice scramblers were insecure and easily decoded by the Nazis.

Delilah worked by combining the speech to be scrambled with what sounded like random noise, similar to an untuned radio. When put together, all an eavesdropper would hear was noise, but by careful synchronisation between two Delilah machines at either end, it was possible to filter out the random noise and hear the original speech.

Delilah generated a sequence of numbers that both the sender and receiver could reproduce from a secret key (a way of setting the machine known only to them). By sampling the waveform of the voice to be transmitted - just as modern computers sample music to produce numbers that are stored on a CD or in an MP3 music file - the voice became a stream of numbers. These could then be enciphered by adding each number to a corresponding number from the random sequence. At the other end, a subtraction of the same random number would reveal the original number, which could then be used to reproduce the voice waveform.

Cracking Nazi Codes

When studying at Princeton University in 1936, Turing wrote to his mother saying that he had discovered a way to use mathematics to encrypt messages. Three years later, he was back in the UK using his skills to break Nazi codes. His efforts at the British military intelligence base Bletchley Park significantly affected the course of the second world war.

At Bletchley, Turing was known universally as "The Prof". He quickly became arguably the most important code breaker there. Most famously, he helped decipher the messages created by the Nazi's Enigma coding machines. To do so, he and his colleagues had to use a combination of insight, intelligent guesses and clever engineering.

An Enigma machine employed rotating wheels that assigned each typed letter to a different coded letter of the alphabet. A second machine at the receiver's end would reverse the process, deciphering the message.

Enigma messages were impossible to crack by brute force, using either raw manpower or simple mechanical calculators, because of the huge number of "keys" used. A key is the crux of any code system: it is a secret "password" agreed on by two people communicating in code. In the case of Enigma, the key consisted of the way each machine was set up before a message was transmitted. Both sender and receiver would arrange their wheels in a pre-agreed fashion, as well as arranging a plugboard similar to that used in a telephone exchange. Depending on whether three or four wheels were used, that meant there were 26x26x26 (17,576) or 26x26x26x26 (456,976) possible keys. And the additional variations in the plugboard settings made messages even more secure.

Alan Turing is my favorite Scientist, (23 June 1912 – 7 June 1954). Maths genius Alan Turing honoured with an interactive Google doodle on 100th birthday in 23 June 2012.

A new short film about Alan Turing’s contribution to the birth of the modern computer and his work in Britain following the war is now available. Based on Turing’s work with the National Physics Laboratory (NPL), the film features Tom Vickers, who knew Turing and worked on the Pilot ACE at the Laboratory.

In space, a year can be a long time. Back at the beginning of 2004, the idea that the Red Planet had once been covered with rivers, lakes and seas was just a hypothesis. By 2005, two quad-bike-sized, roving-laboratories had collected abundant evidence on the ground that turned the idea into an established fact, including stratified sediments, and minerals that probably formed in the presence of water.

Anatomy of Mars Rovers

The story could so easily have been otherwise. After a year of stunning successes by NASA's twin Mars rovers Spirit and Opportunity, it is hard to remember just how much tension surrounded the landings. Following the loss of both the Japanese Mars orbiter Nozomi and the ESA's Beagle 2 probe just weeks earlier, and the Columbia space shuttle disaster in February 2003, much was riding on the missions' success. The roll call of past Mars missions is littered with other failures.

Landing sites were carefully selected to be those that might have flowed with water in warmer periods of the planet's history. NASA's Mars Odyssey orbiter, launched in 2001, had revealed features resembling old lakes, rivers and flood plains, as had its predecessor the Mars Global Surveyor. After a series of delays, rover-laden rockets were launched in June and July 2003.

First to arrive was Spirit on 3 January 2004, at the Gusev Crater - the possible site of a prehistoric lakebed, just south of the Martian equator. Three weeks later, Spirit was followed by its twin, Opportunity, which landed on the other side of the planet at the Meridiani Planum - a site of possible ancient water action.

Both landings were virtually flawless. It has pretty much been that way ever since. Everything has worked better than expected, with just a few glitches, such as problems with a wheel mechanism, computer chips and onboard memory. Future rovers will be able to overcome some problems by self-diagnosis.

On the other side of the planet, Opportunity found good evidence of water much more rapidly. Haematite, a mineral which usually forms in the presence of water, was found to be the main component of tiny spherules termed "blueberries" that littered the plains. While Spirit was trundling its way to the Columbia Hills, Opportunity was set on a course for Endurance Crater - a feature where it later uncovered hints of possible past wet-dry climatic cycles.

Designed to last for 90 days, both rovers have now gone about four times that long and show no signs of stopping any time soon. In fact, with the Martian winter over and dust mysteriously getting cleaned off the solar panels, the rovers are actually gaining power and should continue to do so for a few more months.

Now that we know Mars had water, future missions are aimed at discovering how long it lasted and whether it persists today. More elaborate orbiters, giant rovers and - one day - human landings (plus perhaps even a permanent settlement) are planned to help answer these questions and continue the hunt for life on Mars.

A swallowable ultrasound device called uPill could end the need for painful daily injections

DAILY injections are a painful fact of life for many people with diabetes or cancer. Pills are an easier and more pleasant treatment method but substances like insulin do not penetrate tissue quickly enough to be effective when taken orally. Now a pill that uses ultrasound to speed up drug delivery could remove the need for needles.

Ultrasound has been used for years to accelerate the transfer of drugs through skin and can increase drug absorption by a factor of 10. The method works by heating up molecules inside skin tissue, making cell membranes more permeable. It is particularly good for delivering protein-based drugs such as some cancer medicines, insulin and various vaccinations.

This technique has now been applied to a pill. Designed by biomedical engineering company Zetroz, the uPill will use ultrasound to increase the absorption rate of drugs through tissue in the gastrointestinal tract, says Daniel Anderson at the Massachusetts Institute of Technology, who is part of the team developing the device.

The required drug would be applied as a coating to the uPill and, once swallowed, the device would send ultrasound waves through the patient's gut to aid absorption. It would then pass through the digestive system, as a camera pill does. The device was presented at the IdeaStream conference at MIT in May. Animal tests are now being carried out to see if the device can pass through the digestive system safely.

"The key thing here is the miniaturisation technology we are using to make an already small device a lot smaller," says George Lewis, co-founder of Zetroz and lead engineer for the uPill. The firm previously developed an ultrasound patch to deliver drugs through the skin. "We are developing the smallest ultrasound system in the world."

Anderson hopes the uPill could hit the market in the next couple of years. "It is far too early to claim victory but we are excited about the potential applications," he says. "It could create an entirely new class of drugs."

The pills won't come cheap - each one will cost $20 to $30. But while the device is, in theory, reusable, Anderson admits this probably won't be a hugely popular option.

Growing evidence suggests that not all cases of early-stage breast cancer would be deadly. Should surgeons be leaving well alone?

THE lump in her right breast was smaller than a pea. When she first noticed it, last August, 28-year-old photographer Ellen Doherty was busy working on an exhibition. She put off visiting the doctor for a month.

When Doherty finally went, the doctor said it was probably nothing to worry about. But they did a scan to be sure - and that led to several more tests. Finally they said she had a 2.8-millimetre tumour known as ductal carcinoma in situ, or DCIS.

Like many women given this diagnosis, Doherty had never heard of it before. She quickly devoured any information she could find, but came away confused.

The term "in situ" means that the cancerous cells are contained within the breast's milk ducts and have not invaded the surrounding tissue. This kind of lesion is not harmful unless it progresses past that stage and becomes invasive, but it is treated just as aggressively as invasive cancer. Yet this approach is increasingly being questioned as evidence emerges that for some women DCIS would not turn out to be dangerous.

In fact, DCIS could be regarded as a creation of modern medicine, as most cases are found through breast screening - 30 years ago it was rarely diagnosed. The fear is that screening may be leading us to cut out lumps that, left alone, would have never caused a problem. "Are we helping people by diagnosing it, or are we making things worse?" asks Beth Virnig, who monitors cancer surveillance and detection data at the University of Minnesota in Minneapolis. Breast cancer used to be discovered only if it formed a noticeable lump or caused other symptoms such as nipple discharge. Since the advent of breast screening programmes using X-rays known as mammograms in the 1980s, it is more commonly found that way. And that means growing numbers of DCIS cases are being detected. In the US, the incidence has grown more than eight-fold since the 1980s (see graph). DCIS now makes up about a quarter of breast cancer cases found through screening.

When a mammogram turns up an abnormality the next step is a biopsy to remove a small sample of the tissue in question. If the diagnosis is DCIS, the options are the same as for invasive cancer: excision of a lump containing the growth, if possible, or removal of the breast. To Doherty this seemed bizarre: "How can they cut one of your boobs off for something that's not going to kill you?"

Doherty had a lumpectomy in November, but while she was recovering, a doctor called to say the affected tissue was more widespread than they thought and they hadn't cut out enough. In January she had a mastectomy.

This zero-tolerance approach to DCIS is based on the assumption that, given the chance, it will progress to invasive cancer. Yet no one knows how often that assumption is correct.
Disappearing tumours

It may sound surprising but people can have small cancers that do them no harm; autopsies can reveal "incidental cancers" that were not the cause of death. Some tumours are so slow-growing that they never cause a problem, while others, including some cases of breast cancer, go away on their own, presumably eliminated by the immune system.

Scour the medical literature for a figure for how often DCIS progresses to invasive cancer if left untreated and you will find estimates as low as 14 per cent and as high as 75 per cent, a range so broad as to be almost meaningless. There has never been a large study of women given this diagnosis who don't have surgery, so the progression rate can only be inferred by indirect means.

Take, for instance, a study of laboratory tissue samples from women who had a breast lump biopsied many decades ago, and went untreated because tests at the time indicated it was benign. Re-examining those biopsies turned up some in which a mistake had been made and the woman actually had DCIS. Of 71 such cases where they could track down the women, about half had gone on to develop invasive breast cancer.

That figure is probably an overestimate, though, because the women in that study had DCIS that had grown big enough to be felt as a lump. "Mammographically detected DCIS has a much lower risk of invasive cancer than DCIS detected [as a lump]," says Karla Kerlikowske, an epidemiologist at the University of California, San Francisco (UCSF).

There is another kind of evidence that suggests our current approach might be wrong. If this condition usually progresses to invasive cancer, then catching and cutting out more cases of DCIS should lead to a drop in cases of invasive cancer. That is what has happened with colon cancer: the removal of small precancerous growths, or polyps, in the colon detected through screening by colonoscopy has coincided with falling rates of colon cancer (see graph).

Source 

In a vacuum-sealed flask on a lab bench in Germany sits an emerald-green crystal that will cause some jaws to drop. The crystal is the first stable compound containing a triple chemical bond between two boron atoms, a feat that had previously been limited to only two other non-metal elements – carbon and nitrogen.

BORON has been hiding secret skills but its cover is finally blown.

In a tightly sealed flask in a German lab sits an emerald-green crystal that is the first stable compound with a triple chemical bond between two boron atoms. Such bonds were previously reserved for an elite club of atoms, including carbon, which sits next to boron in the periodic table.

In another first, boron atoms have linked up with each other in chains. Carbon's tendency to do so is the basis for organic chemistry, making possible DNA, proteins, alcohols and plastics. Synthetic, or alien, life based on boron remains far-fetched - boron still can't link to other life-related compounds, for one thing. But the feats pave the way for boron-based polymers, and other structures previously undreamed of. "Certainly this will go into the textbooks," says Holger Braunschweig of the University of Würzburg in Germany.

Until now largely obscure, boron occupies a special spot in the periodic table. On one side are metals like beryllium, which give away their outermost electrons to form ionic bonds. On the other side are the non-metals carbon and nitrogen, which prefer sharing electrons in covalent bonds.

A single covalent bond is two electrons shared between two atoms. Carbon, with four outer electrons, and nitrogen with five, form triple covalent bonds consisting of six shared electrons, or three pairs. Boron has three outer electrons, so in principle should be capable of this too, but it has remained aloof. In 2002, Mingfei Zhou and colleagues at Fudan University in Shanghai, China, managed to make a boron triple bond - but only at 8 degrees above absolute zero.

Boron can hold up to eight outer electrons: a pair in each of four slots. In atomic boron, one of these slots is completely empty and the other three are half-full, with one electron apiece. To make triple-bonded boron that could survive at room temperature, Braunschweig and his colleagues filled all four slots. They filled up the empty slot by bonding each boron atom to a molecule that donated two electrons. Each boron atom then completed the filling of its slots by pairing up with another boron atom and pooling its original three electrons (see diagram). In the resulting compound, each boron atom has a full suite of eight outer electrons, making it stable (Science, DOI: 10.1126/science.1221138).

Braunschweig and his team have already begin investigating the reactivity of the novel compound. "It turns out that it shows a rich chemistry," he says.

Triple-bonding is not the only way the researchers got boron to mimic its superstar neighbour, carbon, though. They also coaxed boron atoms into forming a chain. Previous attempts to do this with boron failed and resulted in messy clusters. "It is extremely difficult to form chains of boron atoms," says Braunschweig. The secret was to attach the boron atoms to an iron scaffold, which allowed up to four to form a chain (Nature Chemistry, DOI: 10.1038/nchem.1379).

Next, Braunschweig and his team hope to free this boron chain from its scaffold and increase the chain length to form the boron equivalent of polyethylene, a common plastic. "The material, if it could be made, would have completely different physical behaviour from an ordinary carbon chain," Braunschweig says

There is something unnatural lurking in the waters of the port of Gijon, Spain, and researchers are tracking its every move. It is not some bizarre new form of marine life, but an autonomous robotic fish designed to sense marine pollution, taking to the open waves for the first time.

"With these fish we can find exactly what is causing the pollution and put a stop to it right away," explains Luke Speller, a scientist at the British technology firm BMT and the leader of SHOAL, a European project involving universities, businesses and the port of Gijon, which have joined forces to create the fish.

Currently the port relies on divers to monitor water quality, which is a lengthy process costing €100,000 per year. The divers take water samples from hundreds of points in the port, then send them off for analysis, with the results taking weeks to return. By contrast, the SHOAL robots would continuously monitor the water, letting the port respond immediately to the causes of pollution, such as a leaking boat or industrial spillage, and work to mitigate its effectsMovie Camera.

The SHOAL fish are one and a half metres long, comparable to the size and shape of a tuna, but their neon-yellow plastic shell means they are unlikely to be mistaken for the real thing. A range of onboard chemical sensors detect lead, copper and other pollutants, along with measuring water salinity. They are driven by a dual-hinged tail capable of making tight turns that would be impossible with a propeller-driven robot.

They are also less noisy, reducing the impact on marine life. The robots are battery powered and capable of running for 8 hours between charges. At the moment the researchers have to recover them by boat, but their plan is that the fish will return to a charging station by themselves.

Working in a group, the fish can cover a 1 kilometre-square region of water, down to a depth of 30 metres. They communicate with each other and a nearby base-station using very low-frequency sound waves, which can penetrate the water more easily than radio waves. However, this means the fish have a low data transmission rate and can only send short, predefined messages. "It's a good solution, but it requires thinking carefully about what data to transmit and how to use that data," says Kristi Morgansen, a roboticist at the University of Washington, who was not involved in the research.

Navigation relies on a related system that communicates with four "pingers" at the corners of the port, which act much like GPS satellites for the fish. If one fish senses pollution in an area it can call the others to create a detailed map of high and low concentrations around it, helping port authorities to locate the exact source of the pollutant.

Versions of the fish have been working successfully in the lab for a few years now, but trialling them in a real-life port has proved more difficult. Rough weather has often prevented the researchers from venturing out on the waves, though Speller says the fish would be fine as they can simply dive below the water. But depth has also been a problem – the waterproofing on one component is unable to withstand the pressure at 30m underwater, so it requires a last-minute replacement.

Thankfully the fish are fitted with a variety of safety features if something goes wrong, such as airbags that inflate to make the fish surface, and a GPS and cellphone chip in the fin so that a distressed fish can send its location details to Speller's phone via text message.

Having demonstrated that the fish can sense pollution and communicate underwater, the SHOAL group now plans to commercialise the design and sell it to other ports in Europe and the rest of the world. The prototypes currently cost around £20,000 each, but mass production should bring that price down.

Source

SPACE exploration may have a new direction. In the 1960s, humans did the exploring but since the last moon landing in 1972, NASA's only explorers beyond low Earth orbit have been semi-autonomous robots. Now the agency is pondering a third approach, sending astronauts who would remain in orbit around alien worlds and explore via robotic rovers.

Mars Rover

On Earth, human-controlled robots are used for tasks ranging from delicate surgery to exploration of the deep sea. But in space, robotic "telepresence" could be even more promising.

Telerobotics would be orders of magnitude more productive for exploration than semi-autonomous robots like the Mars rovers Spirit and Opportunity, says NASA's George Schmidt, an organiser of the Exploration Telerobotics Symposium earlier this month at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Nothing beats having human cognition and dexterity in the field," he says.

But there is a hitch in trying to control from Earth a robot that's exploring another planet: the huge time lag as the signals travel back and forth. Real-time reactions are needed for it to work. For example, surgeons can perform operations well as long as the robot responds to their actions within about half a second. Greater latencies cause problems.

Latency on Earth is no more than a few hundred milliseconds, but latency between the Earth and moon is about 3 seconds, and that delay is enough to slow telerobotics dramatically, says Daniel Lester of the University of Texas at Austin, another organiser of the symposium. "You could use telepresence to tie a knot in 30 seconds on Earth, but it would take 10 minutes to tie it with 3-second latency."

Latency for signals to Mars is much longer - from 8 to 40 minutes depending on the planets' positions - so real-time control from Earth is impossible. The most plausible way to have robotic telepresence on Mars would be to station astronauts in orbit around the planet.

The first step towards this might be testing out robotic telepresence on Earth with simulated latencies. Rovers on the moon controlled from lunar orbit might come next. Rovers could also be controlled in real-time to explore the far side of the moon, not visited by the Apollo missions. To do this, NASA would have to station astronauts at lunar Lagrangian point L2 - a gravitationally neutral area of space which lies about 60,000 kilometres beyond the moon, in line with Earth.

Mars is a bigger challenge, of course, as is Venus, which is usually considered beyond the scope of human exploration because of its boiling, corrosive atmosphere. A Venus mission could be shorter as it is closer to us than Mars. However, any robots would require extensive modification to survive in Venus's hostile environment and, even then, they would not last the years that a Mars rover might. Nevertheless, having human telepresence would make exploration much more productive than if autonomous robots had to await commands from Earth.

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BELIEVE me, I will try my hardest, but I cannot stop what is going to happen to you in the next 5 minutes. It might be a memory that takes you away... a place that you knew, or an idea you once had. It could be hunger. It could be sex. It could already be happening now.

As you read these sentences, your mind will almost certainly wander at least once - just as mine is drifting as I decide how best to phrase these words so that they hold your attention. In fact, according to some estimates, we may spend nearly 50 per cent of our lives drifting away from the present moment into the world inside our heads.

Sigmund Freud considered such zoning out "infantile"; others feared it could lead to psychosis. Today, we know it is instead the sign of a healthy mind, allowing us to plan for the future by imagining different events, for instance. One particular virtue might even transform how we work, teach children, operate business and nurture ideas.

Drifting, it seems, is a sure sign that our creative juices are flowing. When it comes to arriving at brilliant ideas, the ability to concentrate is overrated. If a person's mind is wandering, they outperform their peers in a range of tasks where flashes of insight are important, from imaginative word games to exercises in original thinking and invention.

The psychologists researching the benefits of daydreaming would never claim to have found a formula for all creative achievement. But their results suggest that learning how to tread the line between focusing in and zoning out could help you to arrive at a breakthrough you might otherwise have missed.

One of the first psychologists to turn their attention to mind wandering was Jonathan Schooler of the University of California in Santa Barbara. One day he was listening to a talk on consciousness when the speaker mentioned the wandering mind. Schooler was so intrigued that he found it tricky to focus. "My mind kept wandering about mind wandering," he says. He found it peculiar that we should enter the state so frequently. "It's the mind escaping from the present," he says, "and we're doing it all the time."

His subsequent experiments helped to show just how often our minds stray off-piste. In one study, volunteers had to read extracts of Leo Tolstoy's War and Peace in his lab. Besides asking them to report whenever they noticed themselves drifting, he would also ask them what they were thinking about at random intervals, and at the end, he tested their comprehension of the text. These measures revealed that people's minds wandered from the words for more than 20 per cent of the time, often without them realising. When faced with other tasks, our capacity for distraction seems even greater; a recent study asking people to report their state of mind at random intervals during the day - via a smartphone app - showed that their attention was wandering from the task at hand a whopping 47 per cent of the time (Science, vol 330, p 932).

Flashes of inspiration

For a long time, this kind of mind wandering would have been considered a serious failing. Instead, the ability to filter out distractions and focus on a task - dubbed executive control - was considered to lie behind smart thinking. Since keeping your train of thought on track is necessary to remember information from moment to moment, short-term "working-memory" capacity is often used to gauge executive control. By this measure, a host of studies have shown that people who can focus well tend to ace analytical problems: they are whizzes at arithmetic and verbal reasoning tasks, and often have a higher IQ. If you wanted to be clever, it seemed that you would need to learn how to concentrate.

Yet there were hints that concentration wasn't all it was cracked up to be. While people with a high level of working memory are good at analytical problems, they tend to struggle on tasks that require flashes of inspiration. "Often the best way to solve a problem is to not focus," says Jennifer Wiley at the University of Illinois in Chicago, who recently reviewed the research (Psychology of Learning and Motivation, vol 56, p 185).

Consider the following brain-teaser, which represents one of the types of puzzle used in these studies. What single word can be added to "High, book and sour" to make another word or phrase? To solve it, you can't simply apply an analytical approach since that would involve crunching through every word in your vocabulary, says Wiley. Instead, the answer often comes out of the blue. Various studies show that people with high working-memory capacity, and therefore good executive control, can find it more difficult to solve these problems than people who are more easily distracted. (The answer, by the way, is "note".)

Update: NuSTAR was successfully launched over the Pacific Ocean at 9 am Pacific Standard Time on 13 June and is now in low Earth orbit

You don't have to be big to hunt black holes. NASA's telescope NuSTAR, which was due to take off from an island in the South Pacific on 13 June, is small enough to fit beneath the belly of an aircraft, even including its launch rocket. Once in orbit, it will unfold to the length of a school bus.

The Nuclear Spectroscopic Telescope Array will be the first telescope to bring high-energy X-rays into focus, letting astronomers map and study the extreme physics around black holes and the explosions of massive stars. Its images of these objects will be 10 times crisper and 100 times more sensitive than those of previous telescopes.

To make such sharp images, the telescope needs to focus X-rays with energies of up to 100 kiloelectronvolts – 10 times as energetic as those sought by previous X-ray telescopes – onto a small area. Visible light telescopes can manage this with a focusing lens relatively close to the eyepiece. But because the X-rays are so energetic, NuSTAR's camera needs to be 10 metres away from the focusing lens.

Ingenious model

NuSTAR is on a tight budget: the whole mission should cost only $170 million. As the team could not afford to launch a 10-metre-long telescope, NuSTAR got scrunched up.

"It's no ordinary-looking telescope," says NuSTAR's principal investigator, Fiona Harrison of the California Institute of Technology in Pasadena. Its "lens" is made up of 133 nested shells of fingernail-thin glass. At launch, the cameras will sit right next to the lenses. A week after it settles into orbit, NuSTAR will push the lenses away from the camera on a thin scaffold.

Harrison, who conceived of NuSTAR in the 1990s, thinks the cheap, ingenious scope could be a new model for budget-bedevilled NASA.

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IT SMELLS, it buzzes, it even dances like a honeybee. In a field in Germany, RoboBee is making its first attempts at speaking to the insects in their own language.

Bees are famous for communicating using the waggle dance - walking forward while rapidly vibrating their rear. In the 1940s, biologist Karl von Frisch realised that the length and angle of the dance correlated with the distance and direction of the food source the bee had just visited. Since then, most apiologists have held that dancers tell their fellows where to find food.

Now Tim Landgraf of the Free University of Berlin in Germany and colleagues have programmed their foam RoboBee, to mimic the dance. RoboBee is stuck to the end of a rod attached to a computer, which determines its "dance" moves. The rod is also connected to a belt which makes it vibrate. Like a real bee, it can spin, buzz its wings, carry scents and droplets of sugar water, and give off heat.

To program RoboBee, Landgraf took high-speed video of 108 real waggle dances, and put the footage through software that analysed the dances in detail (PLoS One, DOI: 10.1371/journal.pone.0021354). The outcome is "the most detailed description so far of the waggle dance", says Christoph Grüter of the University of Sussex in Brighton, UK, who was not involved in the study.

What do real bees think of RoboBee's skills? In a field outside Berlin, Landgraf trained groups of honeybees to use a feeder, which he then closed. The bees stopped foraging and stayed in their hives. There they met RoboBee, which had been programmed with Landgraf's best guess at a waggle dance pointing to another feeder, which the bees had never visited.

The bees responded by leaving the hive, but returned to their old feeders. For now, it looks like RoboBee persuaded them to forage, but failed to communicate where to go. The team is confident RoboBee didn't just scare away the foragers, as honeybees respond to intruders by stinging, not fleeing.

Bees don't always pay attention to the waggle dance, says Grüter. He recently showed that bees become more responsive to other's waggle dances if their private food sources have dried up (Animal Behaviour, DOI: 10.1016/j.anbehav.2011.01.014). This suggests bee communication is even more sophisticated than von Frisch thought: the bees' responses depend on the circumstances.

Lars Chittka of Queen Mary, University of London says previous attempts to make waggle-dancing robots have not panned out, but he is keen to see how RoboBee's more sophisticated dancing fares. Its Achilles heel, though, may be a lack of legs: some studies suggest there is a tap-dance element to the dance.

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LIKE PCs, robots may soon become a key part of our everyday lives, but they present unique communication challenges that PCs do not. So roboticists are turning to people who have already solved many of these problems - actors, animators and dancers.

Nao Robot (France)

MASKED THEATRE The 50-centimetre-tall, white plastic Nao humanoid (see photo) looks adorable. But with such a plain, rigid face - just two big lights for eyes and a pinhole of a mouth - how does the bot do it? Julien Gorrias, a "behavioural architect" at Aldebaran Robotics in Paris, France, which makes the Nao, had solved the same problem in his former life as a masked actor by using expressive body movements. "The whole body was involved in making the mask live," he says. His insights have helped give Nao a tangible personality. "You have to feel like it is someone," he says. "Not a human, but someone."

HRP-4C Robot (Japan)

CARTOONS Humans can often guess what another human is about to do. Pixar's animated characters seem to anticipate their own actions: staring hungrily at a piece of cheese before grabbing it, say, creates the illusion of a thought process that makes a character believable. When the team created animations of the PR2 carrying out a task, onlookers were more certain of their interpretation of the robot's behaviour if its actions portrayed forethought. They also described the robot as more approachable.

INTELLIGENCE The lowest level of robot 'intelligence' is a simple automaton device. My definition of an automatoIn is a device where there is absolutely zero decisions made no matter the given environment. They are simple devices where the action it does is repetitive and automatic. A simple circuit with a motor or a combination of gears and a spring could easily be an automaton.

DANCE Humans naturally move in subtly different ways depending on their emotions and intentions, but unravelling how we do this in order to program it into a robot is tricky. The most important is describe how the timing, strength and angle of a dancer's movement will convey a different inner intention or emotion.

Our braininess is one of our species' defining features. With a volume of 1200 to 1500 cubic centimetres, our brains are three times the size of those of our nearest relative, the chimpanzee. This expansion may have involved a kind of snowball effect, in which initial mutations caused changes that were not only beneficial in themselves but also allowed subsequent mutations that enhanced the brain still further. "You have some changes and that opens opportunities for new changes that can help," says John Hawks at the University of Wisconsin-Madison.

In comparison to that of a chimp, the human brain has a hugely expanded cortex, the folded outermost layer that is home to our most sophisticated mental processes, such as planning, reasoning and language abilities. One approach to finding the genes involved in brain expansion has been to investigate the causes of primary microcephaly, a condition in which babies are born with a brain one-third of the normal size, with the cortex particularly undersized. People with microcephaly are usually cognitively impaired to varying degrees.

Genetic studies of families affected by primary microcephaly have so far turned up seven genes that can cause the condition when mutated. Intriguingly, all seven play a role in cell division, the process by which immature neurons multiply in the fetal brain, before migrating to their final location. In theory, if a single mutation popped up that caused immature neurons to undergo just one extra cycle of cell division, that could double the final size of the cortex.

Take the gene ASPM, short for "abnormal spindle-like microcephaly-associated". It encodes a protein found in immature neurons that is part of the spindle - a molecular scaffold that shares out the chromosomes during cell division. We know this gene was undergoing major changes just as our ancestors' brains were rapidly expanding. When the human ASPM sequence was compared with that of seven primates and six other mammals, it showed several hallmarks of rapid evolution since our ancestors split from chimpanzees (Human Molecular Genetics, vol 13, p 489).

Other insights come from comparing the human and chimp genomes to pin down which regions have been evolving the fastest. This process has highlighted a region called HAR1, short for human accelerated region-1, which is 118 DNA base pairs long (Nature, vol 443, p 167). We do not yet know what HAR1 does, but we do know that it is switched on in the fetal brain between 7 and 19 weeks of gestation, in the cells that go on to form the cortex. "It's all very tantalising," says Katherine Pollard, a biostatistician at The Gladstone Institutes in San Francisco, who led the work.

Equally promising is the discovery of two duplications of a gene called SRGAP2, which affect the brain's development in the womb in two ways: the migration of neurons from their site of production to their final location is accelerated, and the neurons extrude more spines, which allow neural connections to form (Cell, vol 149, p 192). According to Evan Eichler, a geneticist at the University of Washington in Seattle who was involved in the discovery, those changes "could have allowed for radical changes in brain function".