Trilingual World Observatory: italiano, english, română. GLOBAL NEWS & more... di Redazione
\\ Home Page : Storico : en - Science and Society (invert the order)
Di seguito gli interventi pubblicati in questa sezione, in ordine cronologico.

Socio-economic disparities in diet patterns and nutrient intake are well documented in research. People with lower incomes and less education typically have less healthful eating habits than people with higher incomes and more education. But little is known about the extent to which those disparities are driven by higher monetary costs of nutritious foods.

Now, a new study from University of Washington researchers concludes, for the first time, that socio-economic disparities in diet quality are directly affected by diet costs. The study, "Are socio-economic disparities in diet quality explained by diet costs?" is published in advance online in the Journal of Epidemiology & Community Health.

UW researchers have previously found that better quality diets are more costly than less nutritious diets, and that there is a rising disparity in the price of healthful foods. "The twist with this new study is that we've connected the dots that could explain why people in a lower socio- economic status have less nutritious diets," said Pablo Monsivais, UW acting assistant professor of epidemiology.

Monsivais, with Program Manager Anju Aggarwal and UW Professor Adam Drewnowski, studied data of more than 1,300 men and women from the Seattle Obesity Study, a population-based study of food access, diet quality and health among King County, Wash. residents.

The researchers first looked at how diet cost was associated with educational attainment and household income, two indicators of socio-economic position. They used statistical methods to control for total calorie intake and other factors. The average diet cost was higher for people with higher educational attainment and higher household income. People with lower educational attainment had diet costs that were an average of $1.09 per day lower than that of persons in the highest group ($8.19 to $9.28 per day).

People with the highest educational attainment or income also enjoyed the most nutritious diets. Those in the highest income group reported diets that were on average 9.3 points higher in nutrient density than diets reported by the lowest income group (96.6 versus 87.3 percent), after controlling for dietary and demographic factors. However, after taking the cost of food into account, the difference in dietary nutrient density between the highest and lowest groups shrank to 1.4 percentage points (93.0 versus 91.6 percent). "These results tell us that cost is a major factor in explaining the differences in eating habits between people of lower and higher socioeconomic level" said Monsivais.

Monsivais said the Seattle study should be replicated on a wider, more diverse (in terms of education, income) section of Americans--or in another country. "What is the average person's concept of nutritious food, too?" Monsivais said. "We don't know that, and it might explain some amount of the variation we found."

The Centers for Disease Control and Prevention's NHANES (National Health and Nutrition Examination Survey) could also be tapped to further explore the socio-economic question, he said.

Study results provide fodder for new and different nutrition policy and interventions, which for the last several decades have been mostly premised on the idea that poor diets were due to a lack of nutrition knowledge or insufficient motivation for healthy eating. "The most universal policy change or intervention would be to rethink how we encourage the production of foods," said the researcher. "In this country, we have a very expensive agricultural subsidy program that targets a limited range of foods that are not part of a nutritious diet. We do not support fresh produce or seafood, but instead support the production of inexpensive sugars, fat and refined grains. We need to align public health priorities with agricultural policies because it affects the largest number of people."

In addition, Monsivais said states could be more creative with public school food programs and other nutrition efforts that impact low-income people. California has experimented with an electronic benefits transfer program (food stamps) that rewards people who buy fresh produce, which makes having a healthier diet easier and more affordable.

Food retailers and grocers could also help consumers make healthier choices, said Monsivais. When you swipe a "member" card at a local store, it could be used in a helpful and healthful way, offering up coupons for items that are nutrient-rich. "If we could overlay a health lens on top of the member cards and make recommendations that are aligned with the way consumers eat and incentives, we could make it interesting for people."

Source: PhysOrg


CAS technology could mean organ transplants of the future won't be the frantic race against time they are now. It has been possible to successfully cryopreserve semen, blood, embryos, oocytes, stem cells and other thin samples of small clumps of cells for a few decades now. However, cryopreservation of human internal organs, such as livers and hearts for storage and transplant, currently requires toxic doses of cryoprotectants – substances that protect biological tissue from freezing damage due to ice formation – in order to survive the cooling process. A solution could be at hand in the form of a technology used to preserve sushi that can instantly freeze water, meaning there is no time for cell damaging ice crystals to form. In fact, it’s already being used to preserve teeth.

The common misconception is that the freezing of organs will cause the cells to burst due to the formation of ice crystals within the cell, but this only occurs if the freezing rate exceeds the osmotic loss of water to the extracellular space. This makes it possible to freeze small biological samples in a process known as slow programmable freezing (SPF) or controlled-rate and slow freezing. This is currently for oocyte, skin, blood products, embryo, sperm, stem cells and general tissue preservation in hospitals, veterinary practices and research labs around the world.

However, freezing larger organs or even whole human beings can cause serious damage as a result of ice forming between cells, causing mechanical and chemical damage. To prevent this, larger doses of toxic cryprotectants are used to remove and replace water inside cells with chemicals that prevent freezing. While this can reduce the damage from freezing, the toxicity can still cause serious injuries that aren’t reversible with present technology – meaning we’re not likely to see James Bedford – the first person whose body was frozen and remains cryopreserved – up and about any time soon.

A newer technique known as vitrification, which involves an extremely rapid drop in temperature, claims to provide the benefits of crypreservation without damage due to ice crystal formation. But again, damaging levels of cryoprotectants are needed. This time to increase the viscosity and lower the freezing temperature inside the cell.

Freezing without cryoprotectants

Now a research group at Hiroshima University, borrowing supercooling technology used to preserve sushi and high-end food delicacies, has proven it is possible to freeze cells without the use of toxic cryprotectants. As reported on Singularity Hub, the “Cells Alive System” (CAS) produced by Japanese company ABI prevents freezing at supercool temperatures by vibrating the water using magnetic fields. This allows the water to be supercooled so that when the magnetic field is turned off, the water freezes instantaneously – too fast for damaging ice crystals to form.

The patented CAS technology is already being used at the world’s first commercial tooth bank, The Teeth Bank, to preserve teeth and potentially as an alternative source for harvesting stem cells. The Teeth Bank allows removed teeth, previously disposed of as worthless medical waste, to be stored and re-implanted when needed. Preserved teeth can even be sculpted into different teeth before re-implantation.

The CAS technology has even been proven to reserve the tooth ligaments – an important factor for re-implantation. A 2010 study published in the journal Cryobiology detailed how the ligaments of a fresh tooth slow frozen without the CAS technology were severely damaged, while the ligaments of another tooth frozen using the CAS technology survived showing only minor damage and grew as well as those from a fresh tooth.

The technology could obviously have potential for the preservation of internal organs that currently have only a brief window of viability after being removed from a donor. Thanks to burgeoning technology, it could also provide a way for people to store replacement organs grown from their own stem cells instead of waiting on a compatible donor.

Source: GizMag

By Admin (from 16/04/2011 @ 11:00:31, in en - Science and Society, read 1669 times)

Australian designer Jaron Dickson has come up with a concept for a hydrogen-powered, flying yacht. If that wasn’t cool enough, the yacht is based on the legendary Soviet super-vehicle the Ekranoplan. As a result, this cool little boat, which has been shortlisted for an Australian Design Award, is called the EkranoYacht – read on for a look!

For those of you not familiar with the Ekranoplan, it was a massive vehicle conceived in Scandinavia but realized by the Soviets during the Cold War. Essentially half plane, half boat, the Ekranoplan would ‘skim’ across the water (or land) on short wings using the ‘ground effect’. This allowed the vehicle to ‘fly’ just above the ground on of a cushion of high-pressure air created by the aerodynamic interaction between the wings and the surface. The Soviets design a massive 550-ton Ekranoplan that could transport vehicles and troops at an a stunning 450mph – all while remaining up to 66 feet over the water. Unsurprisingly, it earned the nickname “The Caspian Sea Monster”. Unfortunately, their production fell with the collapse of the Soviet Union.

Ok, science and history lesson over! Back to the EkranoYacht!

According to Dickson, who is a student at Monash University in Australia, the EkranoYacht is a “hydrogen powered wing-in-ground effect vehicle for permanent residence – set for 2025. The conventional ways of living have changed dramatically, people are less bound by the country or topographical location which they reside. Using hydrogen power and flying 4m above the water’s surface, the project focuses on more efficient sea travel and protecting the environment. To truly show your wealth and success is freedom, and the ultimate freedom is bringing you home where ever you go.”

Dickson added that, “Humans are always thinking of new ways travel and improve their dynamic lives. My design is a ‘blue-sky concept’, but this type of forward and different thinking could possibly turn into a reality one day. My project has the livability of a yacht and the convenience of an aeroplane.”

Source: Inhabitat

By Admin (from 17/04/2011 @ 11:00:39, in en - Science and Society, read 2228 times)

The world of computing is in transition. As chips become smaller and faster, they dissipate more heat, which is energy that is entirely wasted.

By some estimates the difference between the amount of energy required to carry out a computation and the amount that today's computers actually use, is some eight orders of magnitude. Clearly, there is room for improvement.

So the search is on to find more efficient forms of computation, and there is no shortage of options.

One of the outside runners in the race to take the world of logic by storm is reversible computing. By that, computer scientists mean computation that takes place in steps that are time reversible.

So if a logic gate changes an input X into a output Y, then there is an inverse operation which reverses this step. Crucially, these must be one-to one mappings, meaning that a given input produces a single unique output.

These requirements for reversibility place tight constraints on the types of physical systems that can do this kind of work, not to mention on their design and manufacture. Ordinary computer chips do not qualify--their logic gates are not reversible and they also suffer from another problem.

When conventional logic gates produce several outputs, some of these are not used and the energy required to generate them is simply lost. These are known as garbage states. "Minimization of the garbage outputs is one of the major goals in reversible logic design and synthesis," say Himanshu Thapliyal and Nagarajan Ranganathan at the University of South Florida.

Today, they propose a new way of detecting errors in computations and say that their method is ideally applicable to reversible computing and, what's more, naturally reduces the number of garbage states that a computation produces.

Before we look at their approach, let's quickly go over a conventional method of error detection. This simply involves doing the calculation twice and comparing the results. If they are the same, then the computation is considered error free.

This method has an obvious limitation if the original computation and its duplication both make the same error.

Thapliyal and Ranganathan have a different approach which gets around this problem. If a reversible computation produces a series of outputs, then the inverse computation on these outputs should reproduce the original states.

So their idea is to perform the inverse computation on the output states and if this reproduces the original states, then the computation is error free. And because this relies on reversible logic steps, it naturally minimises the amount of garbage states that are produced in between.

There are one or two caveats, of course. The first is that nobody has succeeded in building a properly reversible logic gate so this work is entirely theoretical.

But there are a number of computing schemes that have the potential to work like this. Thapliyal and Ranganathan point in particular to the emerging technology of quantum cellular automata and show how their approach might be applied.

The beauty of this approach is that it has the potential to be dissipation-free. So not only would it use far less energy than conventional computing, it needn't lose any energy at all. At least in theory.

At first glance, that seems to contradict one of the foundations of computer science: Rolf Landauer's principle that the erasure of a bit of information always dissipates a small amount of energy as heat. This is the basic reason that conventional chips get so hot.

But this principle need not apply to reversible computing because if no bits are erased, no energy is dissipated. In fact, there is no known limit to the efficiency of reversible computing. If a perfectly reversible physical process can be found to carry and process the bits, then computing could become dissipation free.

For the moment, that's wild dream. But in the next few years, as quantum processes begin to play a larger part in computation of all kinds, we may well hear much more about reversible computing and its potential to slash the energy wasted in computing.



Split-cycle engines have been around for some time but until now have never matched the fuel efficiency of traditional internal combustion engines. That is about to change, with the latest split-cycle engines from the Scuderi Group offering greater fuel efficiency and up to 80 percent reduction in NOx emissions and 50 percent reduction in CO2.

Split-cycle engines feature paired cylinders, so a four-cylinder engine has two sets of paired cylinders working together, with a crossover passage linking the two cylinders in each pair to each other. The four strokes of the engine are split into two groups, with the left cylinder handling intake and compression and the second handling combustion and exhaust. The Scuderi™ Air-Hybrid design adds an air storage tank and controls that allow it to recapture and store the energy lost as the engine operates.

The new design solves some of theproblems that have hampered previous split-cycle designs. The low volume breathing problem is solved by outward-opening pneumatic valves and a reduction in the clearance between the piston and cylinder head to under 1 mm, which means virtually 100 percent of the compressed air is pushed out of the cylinder.

The thermal efficiency problem of previous designs has been solved by adopting After Top Dead Center (ATDC) firing, which avoids losses caused by recompressing the gas. Firing ATDC is achieved by high pressure air entering the cylinder and resulting in massive turbulence. Firing ATDC is a cleaner burn that also dramatically reduces NOx emissions and improves fuel efficiency.

The Southwest Research Institute (SwRI) has been testing a 1-liter, two-cylinder engine for almost a year. The preliminary results suggest a 30-36 percent increase in fuel efficiency for the naturally aspirated Scuderi™ Air-Hybrid and a 25 percent increase for the base model. The test engine generates 135 horsepower at 6,000 RPM, which is similar to results of bigger and more fuel-hungy cars.
Sal Scuderi, son of the inventor Carmelo Scuderi who died in 2002, said he expected efficiencies should improve still further as the designs are fine-tuned and new simulations are run with the engines in different vehicles.

The Scuderi engine can be built using conventional parts and minimal re-tooling is necessary, which makes it easier for manufacturers to adopt it. Scuderi says the technology should be licensed and on the road within three years.

Source: PhysOrg

By Admin (from 19/04/2011 @ 14:00:51, in en - Science and Society, read 1564 times)

There's a reason why Hollywood makes movies like Arachnophobia and Snakes on a Plane: Most people are afraid of spiders and snakes. A new paper published in Current Directions in Psychological Science, a journal of the Association for Psychological Science, reviews research with infants and toddlers and finds that we aren't born afraid of spiders and snakes, but we can learn these fears very quickly.

One theory about why we fear spiders and snakes is because so many are poisonous; natural selection may have favored people who stayed away from these dangerous critters. Indeed, several studies have found that it's easier for both humans and monkeys to learn to fear evolutionarily threatening things than non-threatening things. For example, research by Arne Ohman at the Karolinska Institute in Sweden, you can teach people to associate an electric shock with either photos of snakes and spiders or photos of flowers and mushrooms—but the effect lasts a lot longer with the snakes and spiders. Similarly, Susan Mineka's research (from Northwestern University) shows that monkeys that are raised in the lab aren't afraid of snakes, but they'll learn to fear snakes much more readily than flowers or rabbits.

The authors of the Current Directions in Psychological Science paper have studied how infants and toddlers react to scary objects. In one set of experiments, they showed infants as young as 7 months old two videos side by side—one of a snake and one of something non-threatening, such as an elephant. At the same time, the researchers played either a fearful voice or a happy voice. The babies spent more time looking at the snake videos when listening to the fearful voices, but showed no signs of fear themselves.

"What we're suggesting is that we have these biases to detect things like snakes and spiders really quickly, and to associate them with things that are yucky or bad, like a fearful voice," says Vanessa LoBue of Rutgers University, who cowrote the paper with David H. Rakison of Carnegie Mellon University and Judy S. DeLoache of the University of Virginia.

In another study, three-year-olds were shown a screen of nine photographs and told to pick out some target item. They identified snakes more quickly than flowers and more quickly than other animals that look similar to snakes, such as frogs and caterpillars. Children who were afraid of snakes were just as fast at picking them out than children who hadn't developed that fear.

"The original research by Ohman and Mineka with monkeys and adults suggested two important things that make snakes and spiders different," LoBue says. "One is that we detect them quickly. The other is that we learn to be afraid of them really quickly." Her research on infants and young children suggests that this is true early in life, too—but not innate, since small children aren't necessarily afraid of snakes and spiders.

Source: EurekAlert

By Admin (from 20/04/2011 @ 14:00:48, in en - Science and Society, read 2483 times)

Although modern prosthetic devices are more lifelike and easier for amputees to control than ever before, they still lack a sense of touch. Patients depend on visual feedback to operate their prostheses – they know that they’ve touched an object when they see their prosthetic hand hitting it. Without sensation, patients cannot accurately judge the force of their grip or perceive temperature and texture.

Todd Kuiken, a professor at Northwestern University and director of the Neural Engineering Center for Artificial Limbs at the Rehabilitation Institute of Chicago, has led the development of a new technique known as targeted reinnervation, which can help amputees control motorized prosthetic arms. He and his team now hope to extend the applications of targeted reinnervation to help patients regain sensory capabilities.

In targeted reinnervation, the motor nerves of a nearby target muscle (usually the chest) are deactivated. Then the residual motor nerves at the end of an amputated arm are transplanted from the stump to the chest. The nerves rewire themselves and grow into the chest muscle. Since amputation of a limb does not prevent the nerves left in the residual limb from signaling, the reinnervation procedure simply gives the signals a new destination.

After the procedure, when a person thinks about moving a muscle in the missing arm or hand, the chest muscle twitches. Electrodes pick up these signals and pass them on to a motorized prosthetic arm, allowing patients to control multiple motor functions like the simultaneous movement of both the elbow and hand to throw a ball.

The regrowth of sensory nerves after this procedure was discovered by accident. The first patient to undergo targeted reinnervation told Kuiken and his other doctors about an interesting sensation he experienced: when someone touched the area of his chest where his nerves had regrown, he felt as if someone was touching his missing hand. The sensory nerves from his arm stump had reinnervated the skin above his chest muscle. He was experiencing touch to the reinnervated skin as being applied to his missing limb. It turned out that sensory reinnervation such as this was common following the procedure.

Kuiken and his colleagues are currently exploring how to take advantage of sensory reinnervation to build prosthetic arms with sensors on the fingers that can transfer touch information from the prosthetic to the chest, allowing patients to “feel” what they are touching with their prostheses.

The next step is to figure out the mechanisms that guide reinnervation, with the hope of someday being able to direct the regrowth of nerves for more refined results. To better understand how sensory reinnervation affects brain reorganization, Kuiken and his colleague Paul Marasco examined the brains of rats after amputation and targeted reinnervation. In this experiment, published in The Journal of Neuroscience, Marasco and Kuiken looked at how the somatosensory cortex, the brain area that receives and processes input from sensory organs, changed in rats following forelimb amputation with and without the targeted reinnervation procedure.

One group of rats underwent forelimb amputation and then targeted reinnervation, while another group of rats underwent only the amputation. The rats that did not undergo targeted reinnervation effectively had the input between the cortex and the forepaw silenced. After thirteen weeks of recovery, the experimenters recorded brain activity in the primary somatosensory cortex of all the animals. Marasco and Kuiken were especially interested in the region known as the forelimb barrel subfield, which would normally process touch input from the amputated forepaw.

As expected, the rats that underwent amputation without targeted reinnervation showed an almost complete silencing of brain activity in the forelimb barrel subfield. The receptive fields for the few active areas in this region were located on the residual shoulder.

In contrast, the rats that underwent targeted reinnervation showed extensive activity in the forelimb barrel subfield. The receptive fields for the active sites in these rats were small and densely clustered on the far end of the stump, and differed in proportion from the large and diffuse receptive fields observed on the residual limb of the amputation-only rats. It appeared that the sensory input from the reinnervated skin was processed within the cortical representation of the missing forepaw.

This helps explain why Kuiken’s earlier human patient reported feeling a touch on his chest as occurring on his missing hand. His somatosensory cortex, in particular the area devoted to the missing limb, had reorganized to accommodate the new sensory input. Sensations from the skin on his chest were being processed within the hand representation area of his somatosensory cortex.

Further somatosensory reorganization was evident in the rats. In most of the animals that underwent targeted reinnervation following amputation, there were regions of the forelimb barrel subfield (called dual receptive fields) that were responsive to both the stump and other regions of the body (the whiskers, lower lip, and hindlimb). The presence of dual receptive fields in these rats, but not in the amputation-only rats, suggests that the adjacent brain areas expanded into the denervated regions following the amputation. The sharing of space allowed those sensory nerves to keep transmitting signals, even after amputation.

Marasco and Kuiken’s results provide important insights into the sensory phenomena observed in human targeted reinnervation patients. The reorganization of somatosensory cortex in rats following the procedure supports the hypothesis that the reinnervated skin is able to act as a direct line of communication from a prosthetic device to the regions of the brain that process hand and limb sensations. This is likely the mechanism by which targeted reinnervation provides sensation that is perceived as coming from an amputated limb.

Ultimately, Marasco and Kuiken hope that this experiment will contribute to the building of better prosthetic limbs. Motorized prostheses that also provide sensory feedback have the potential to be more effective, capable of more functions, and easier to manipulate. Most importantly, they would not only function like a real human arm but also feel like one, allowing the prosthetic to be integrated more naturally into the patient’s self image.

Source: Technology Review

By Admin (from 22/04/2011 @ 08:00:12, in en - Science and Society, read 2460 times)

Just 13 days after receiving a pioneering larynx transplant, a Californian woman was able to speak her first words in a decade. Her own larynx was permanently damaged by an operation 11 years ago.

The first combined larynx and thyroid transplant was performed in 1998, but in the latest operation Brenda Charett Jensen of Modesto, California, received a section of trachea too. The feat, which took 18 hours, was performed last October at the Medical Center of the University of California, Davis, but announced only yesterday.

The transplant also works far better than the first because more of the donated organs' nerves have been plugged into the 52-year-old woman's own nervous system. This enables her to move muscles that control speaking by moving the vocal cords, and others that will eventually allow her to swallow again, once she relearns how to do it.

"It is a miracle," says Jensen. "I'm talking, talking, talking, which just amazes my family and friends." The sound of her voice is her own, rather than that of the donor.

Her own voice again

Jensen lost her speech 11 years ago through complications during surgery that blocked her airway. The blockage stopped her larynx working, so for years she has communicated with a handheld voice synthesiser. That operation also left her breathing dependent on a tracheotomy – a tube inserted into her windpipe. With the new trachea, the hope is that she should also be able to breathe normally and dispense with the tracheotomy.

One of the reasons that Jensen was chosen was that she was already on immunosuppressive drugs because of a previous kidney-pancreas transplant, reducing the risk of organ rejection.

Led by surgeon Gregory Farwell, the team transplanted the larynx, thyroid and trachea of a woman who died in an accident . The thyroid has to be transplanted too, because it supplies blood to the larynx.

Farwell and his colleagues plumbed numerous blood vessels from the donated organs into Jensen's own, and also reconnected five major nerves to maximise her control over the muscle tissue that came with the transplant.

"The first larynx transplant only reconnected three nerves," says Martin Birchall of University College London, who served as chief scientific adviser to the team, specialising in reconnection of the nerves. "Here, we've done five nerves with the intention of restoring much more laryngeal function than the original, and eventually getting rid of the tracheotomy."

Rapid progress

Birchall said that although the man who received the original larynx transplant at the Cleveland Research Clinic in Ohio in 1998 is doing well and has recovered some speech, he still has a tracheotomy. His vocal cords have never moved, whereas Jensen's were moving in just a fortnight. "We've already seen much quicker progress in speech," says Birchall.

The breakthrough is the latest to exploit rapid improvements in microsurgical techniques since the first face transplant in 2005. The increasingly ambitious use of more complex transplants including muscles, nerves and bones has also highlighted the greater functionality that this allows the recipient.

Birchall believes that recipients will benefit even more if their own stem cells are extracted and used to coat donated organs chemically stripped of all donor cells. Because all that's then left of the donated organ is a "scaffold" of the protein collagen, it can be covered with the recipient's own cells and transplanted into their body with no fear of rejection.

In 2008, Birchall was part of a team that demonstrated this can be done by performing the world's first trachea transplant.

Complex challenge

Birchall told New Scientist that such an approach would be possible with the larynx, but unlike the trachea – which is simply a tube – a recoated larynx would also have to include artificially constructed muscles and blood vessels because of its much more complex function.

"It's much more complex than the trachea, but we do have ways to address these things," says Birchall. "Regenerative medicine using stem cells is now moving at a furious pace, and the airways and plumbing systems are at the forefront," he says.

Hear and see her voice here.

Source: NewScientist

By Admin (from 23/04/2011 @ 08:00:50, in en - Science and Society, read 1918 times)

A new scientific discovery could have profound implications for nanoelectronic components. Researchers from the Nano-Science Center at the Niels Bohr Institute, University of Copenhagen, in collaboration with Japanese researchers, have shown how electrons on thin tubes of graphite exhibit a unique interaction between their motion and their attached magnetic field – the so-called spin. The discovery paves the way for unprecedented control over the spin of electrons and may have a big impact on applications for spin-based nanoelectronics. The results have been published in the prestigious journal Nature Physics.

Carbon is a wonderfully versatile element. It is a basic building block in living organisms, one of the most beautiful and hardest materials in the form of diamonds and is found in pencils as graphite. Carbon also has great potential as the foundation for computers of the future as components can be produced from flat, atom thin graphite layers, observed for the first time in the laboratory in 2004 – a discovery which elicited last year's Nobel Prize in Physics.

In addition to a charge all electrons have an attached magnetic field – a so-called spin. One can imagine that all electrons carry around a little bar magnet. The electron's spin has great potential as the basis for future computer chips, but this development has been hindered by the fact that the spin has proved difficult to control and measure.

In flat graphite layers the movement of the electrons do not affect the spin and the small bar magnets point in random directions. As a result, graphite was not an obvious candidate for spin based electronics at first.

New spin in curved carbon

"However, our results show that if the graphite layer is curved into a tube with a diameter of just a few nanometers, the spin of the individual electrons are suddenly strongly influenced by the motion of the electrons. When the electrons on the nanotube are further forced to move in simple circles around the tube the result is that all the spins turn in along the direction of the tube", explain the researchers Thomas Sand Jespersen and Kasper Grove-Rasmussen at the Nano-Science Center at the Niels Bohr Institute.

It has previously been assumed that this phenomenon could only happen in special cases of a single electron on a perfect carbon nanotube, floating freely in a vacuum – a situation that is very difficult to realize in reality. Now the researchers' results show that the alignment takes place in general cases with arbitrary numbers of electrons on carbon tubes with defects and impurities, which will always be present in realistic components.

The interaction between motion and spin was measured by sending a current through a nanotube, where the number of electrons can be individually controlled. The two Danish researchers explain that they have further demonstrated how you can control the strength of the effect or even turn it off entirely by choosing the right number of electrons. This opens up a whole range of new possibilities for the control of and application of the spin.

Unique Properties

In other materials, like gold for example, the motion of the electrons also have a strong influence on the direction of the spin, but as the motion is irregular, one cannot achieve control over the spin of the electrons. Carbon distinguishes itself once again from other materials by possessing entirely unique properties – properties that may be important for future nanoelectronics.


By Admin (from 24/04/2011 @ 08:00:22, in en - Science and Society, read 2186 times)

Having a computer that can read our emotions could lead to all sorts of new applications, including computer games where the player has to control their emotions while playing. Thomas Christy, a Computer Science PhD student at Bangor University is hoping to bring this reality a little nearer by developing a system that will enable computers to read and interpret our emotions and moods in real time.

Tom’s work focuses on ‘hands-on’ pattern recognition and machine learning. His supervisor Professor Lucy Kuncheva at the University’s School of Computer Science is a world expert in pattern recognition and classification, specifically in classifier ensembles. A classifier ensemble is a group of programmes that independently analyse data and decide to which label or group the data belongs. The final decision is reached by a ‘majority’ or consensus, and is often more accurate than individual classifier decisions.

The plan is to combine brain wave information collected from a single electrode that sits on the forehead as part of a ‘headset’, a skin conductance response (which will detect tiny changes in perspiration as first indicators of stress) and a pulse signal, reflecting the wearer’s heart rate. This information will form the data fed into a classifier ensemble set to determine which emotion a person is experiencing.

“I am particularly interested in developing a real-time ‘mood sensing’ device. It will combine already existing biometric detection devices into a lightweight portable system that will be able to perceive and indicate a person’s mood and level of stress and anxiety,” said Tom.

Tom is aiming to pioneer classification software techniques that will allow players’ emotions to be identified within the gaming environment. This will open up new and exciting markets for the gaming industry. New games can be created; where players must control their feelings in order to advance within their virtual environment.

“This area of emotional study is fast becoming an important part of research within Computer Science and is known as Affective Computing,” explained Prof. Lucy Kuncheva.

There are many other possible applications for this type of technology, for example marketing to determine customer preferences and brand effectiveness, monitoring anxiety levels of prospective soldiers during military training, providing instant neuro-feedback to combat addictive behaviours; the list is seemingly endless.

Tom is working in close collaboration with the Bangor University’s Schools of Electronic Engineering and Psychology and has had talks with Massachusetts Institute of Technology (MIT) in Boston, USA in pursuit of his research. He is looking for industrial collaborators and innovators who would be interested in this area.

Source: PhysOrg

Ci sono 3949 persone collegate

< ottobre 2021 >

en - Global Observatory (605)
en - Science and Society (594)
en - Video Alert (346)
it - Osservatorio Globale (503)
it - Scienze e Societa (555)
it - Video Alerta (132)
ro - Observator Global (399)
ro - Stiinta si Societate (467)
ro - TV Network (143)
z - Games Giochi Jocuri (68)

Catalogati per mese - Filed by month - Arhivate pe luni:

Gli interventi piů cliccati

Ultimi commenti - Last comments - Ultimele comentarii:
Now Colorado is one love, I'm already packing suitcases;)
14/01/2018 @ 16:07:36
By Napasechnik
Nice read, I just passed this onto a friend who was doing some research on that. And he just bought me lunch since I found it for him smile So let me rephrase that Thank you for lunch! Whenever you ha...
21/11/2016 @ 09:41:39
By Anonimo
I am not sure where you are getting your info, but great topic. I needs to spend some time learning much more or understanding more. Thanks for fantastic information I was looking for this info for my...
21/11/2016 @ 09:40:41
By Anonimo


27/10/2021 @ 09:12:28
script eseguito in 674 ms