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Top Stories in Science
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March 2007 Issue |
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| [D] Defence and security |  |
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Chronic military stretch Britain's armed forces are "very stretched" by the operations and operational tempo in Afghanistan and Iraq, according to the chief of the defence staff. UK troops are currently deployed operationally in Afghanistan, Iraq, Northern Ireland, Bosnia, Kosovo and various UN missions. The demands on the UK armed forces are likely to remain high in the years ahead because of continuing global instability. [D][X]
Drug protection against nuclear radiation Emergency workers attending the scene of a "dirty" bomb or nuclear blast could be protected from acute radiation syndrome by a new drug according to Hollis-Eden Pharmaceuticals of San Diego. They report that 5-androstenediol (AED), an adrenal gland hormone that stimulates marrow-cell growth, cuts the death rate among monkeys exposed to 6 grays of radiation to 12 percent. This radiation dose would normally kill around a third of them. The hormone works mainly by boosting blood platelets. [D][H]
What is stopping a pandemic? Although researchers think they know what mutations in H5N1 bird flu could cause it to become pandemic, they do not know what these mutations actually do. One new possibility is that the mutations influence how easily the influenza can take over the infected cell's nucleus in order to multiply. This involves viral polymerase binding to a cell protein called importin alpha that transports the polymerase into the nucleus. Researchers have produced high-resolution x-ray images of how the polymerase and importin alpha interact with each other. These show that the mutations known to be involved in the transmission of bird flu to humans are located in or near the site of this interaction, suggesting a connection. It is possible that interfering with the polymerase function could provide new ways to treat or prevent flu. [D][G][H]
Interim human bird flu vaccines According to the WHO, the rate of progress in developing vaccines against a bird flu pandemic is very encouraging. Manufacturers in the US, Europe and Australia are seeking authority from regulators to start manufacturing vaccines. In the US, experts have recommended going ahead with an experimental vaccine made by Sanofi-Aventis in order to protect critical workers and those at particular risk. The vaccine is only partially effective and is seen only as an interim measure. The hope is that its effectiveness can be boosted by better adjuvants that enhance the immune response. [D][H]
Community response websites The growth in community-driven websites and user-generated content could be exploited in a form of "digital community watch" in order to improve local security and emergency response. A pilot scheme could start later this year based at the University of Maryland and driven by 40,000 students and staff. The idea eventually is to create a US nationwide community response network of 911.gov websites. [D][I][K]
Evidence based justice Researchers in Washington State have used statistical meta-analyses to estimate how successful and cost-effective different interventions and methods of punishment are in reducing crime. They calculated the cost of each intervention and the financial benefits from the reduced crime. The results show that some interventions with young offenders are particularly cost-effective. In contrast, they found no evidence that electronic tagging of adult offenders to offset jail time helps to prevent crime. They emphasise that their analysis applies to Washington State and would need to be adapted for other locations. [D][H][K] |
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| [A] Aeronautics and space | |
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Space debris and the ISS The explosion of a Russian rocket stage in space has added to the space debris created by the anti-satellite test conducted by China on 11 January. Radar tracking has identified over a thousand pieces of debris from the Russian rocket and over 800 from the Chinese test. Only particles larger than about 10 cm diameter can be tracked using radar, and both explosions must have generated millions of smaller fragments. This debris is a threat to other satellites including the International Space Station. A NASA report to the US Congress has estimated there is a 55 percent chance that some sort of space debris could penetrate the space station over a 10-year period and a 9 percent chance of a catastrophic impact. [A][R][X]
Shuttle replacement NASA has announced that the replacement for the space shuttle will be delayed from 2014 to 2015 because of budget constraints. The shuttle is due to retire in 2010 and all its remaining missions are required to complete the International Space Station. [A]
Solar storms The huge solar events that occurred in early December are puzzling not just because the Sun is at a minimum in the sunspot cycle but also because the resulting blast of high energy particles was not confined close to the Sun's equatorial plane as expected. To forecast the path of a radiation storm, researchers have in the past relied on a model called the "Parker spiral" according to which the Sun's magnetic field emerges radially from the Sun's surface and then, because of the Sun's spinning motion, spirals outward into the solar system. This model predicts that radiation storms that begin near the equator should remain near the equator. Instead, the storms went from the equator towards the Sun's South Pole. This suggests that the solar magnetic field may contain kinks and twists that provide a passage for storms to travel from equator to poles. [A][I]
STEREO mission The STEREO spacecraft have not yet reached their final orbits but have already captured the first video of a coronal mass ejection (CME) as it advances from the Sun to Earth's orbit. Scientists were surprised by the way the CME's shape evolved as it propagated outwards. [A][I][R]
THEMIS mission NASA has launched the THEMIS satellites, which will study how geomagnetic substorms arise and propagate. The network of five satellites positioned along the Earth-Sun axis will be able to track the storms, which start from a single point in space and progress past the Moon's orbit within minutes. Over the two year mission, scientists hope to observe about 30 storms. The results should considerably improve future forecasting of space weather and also reveal which of two current hypotheses about space substorms is correct. One hypothesis is that they happen when solar activity compresses the magnetic field lines around Earth, causing large electrical currents to flow in the tenuous gas of charged particles in the magnetosphere. The other hypothesis is that substorms happen when compressed magnetic field lines suddenly relax in events called magnetic reconnections. [A][I][P][R]
Satellite fuel gauge Aerospace engineers at the Indian Institute of Science in Bangalore have worked out how to make fuel sit still in a microgravity environment so its volume can be accurately calculated. They say that putting a titanium alloy cone inside the fuel tank would cause the fuel to collect at the cone's vertex, which leads to the thruster. Being able to measure accurately how much fuel a geosynchronous satellite has left means that the satellite can be kept in operation as long as possible with confidence that it still has enough fuel to be finally moved into a higher graveyard orbit. [A][I][P][R] |
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| [U] Unmanned vehicles and robotics | |
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Combat robot An Israeli defence firm has unveiled a portable robot said to be capable of entering most combat zones alone and engaging enemies with an onboard armoury that includes a machine-pistol and grenades. The weapons are aimed using an onboard video camera. [U][D][R]
Sentry robot Samsung has developed a sentry robot for the South Korean government for border control. It uses a low-lightcamera and pattern recognition software to distinguish humans from animals or other objects. It is intended for use in the demilitarised exclusion zone and is equipped with a built-in machine gun. Its colour camera can pinpoint a target from up to 500 metres range in illumination down to 0.008 lux, about the same as a starlit night. The robot has three such cameras: two provide stereo imaging for surveillance and tracking and the third zooms in for targeting. A digital video recorder captures data for up to 60 days at a time. By calling up the robot’s ID number, operators in Seoul can also see in real time what is happening in the field. [U][D][R]
Teamworking robots Search-and-rescue robots capable of collaborating to form a single larger robot and also able to work separately have been developed in Germany. They can work individually to cover a search area quickly, but join together for tasks such as moving large objects or spanning large gaps. [U][D][R]
Teamworking robots European researchers have studied how complex robots can self-assemble from swarms of small autonomous mobile units to undertake specific tasks. [U][D][R]
Robot co-operation By studying swarms of robots with evolvable genomes, Swiss researchers have clarified how communication evolves in social organisms. Using computer simulation, they first studied the changing behaviour of 100 "colonies" of ten virtual robots over 500 generations, during which their virtual genomes were subjected to mutation and recombination to mimic the genetic variation introduced by sexual reproduction. The robots learned to forage successfully in a virtual environment containing food and poison sources that could only be discriminated at close range. The researchers then successfully transferred this learning to a colony of real robots. The findings demonstrate that sophisticated forms of communication including cooperative communication and deceptive signalling can evolve in groups of robots with simple neural networks. The findings also suggest that transfer of knowledge from evolutionary biology can be useful for designing efficient groups of cooperative robots. [U][X]
Superbot A modular robot that transforms itself into different shapes in order to walk, crawl and clamber up inclines has been demonstrated in the US. The modules can move independently, flip over and rotate like wheels, and have 3D accelerometers that let them know their precise orientation. The six sides of each module can dock with any other module. Once connected, the modules can communicate, coordinate shape changes and transmit power. [U]
Contact convoy road travel If vehicles could travel on highways under automated control, they could travel much closer together. This would reduce traffic congestion and increase average speed of travel. It would also improve fuel consumption if vehicles could travel in the slipstream of the vehicle in front. The problem is how to cope with a system failure. Researchers at the University of Manchester have proposed a solution in the form of an intelligent bumper that would extend to touch the car in front, should the main communication system break down. They have shown by computer simulation and experimental demonstration that a group of at least 20 cars could continue to travel safely and smoothly in the event of a main system failure, by detecting the status of the car immediately in front through their extended bumpers. Information on the other cars in the group would not be necessary. [U][E]
Insect navigation Insects and other flying animals are somehow able to maintain appropriate flying heights and execute controlled takeoffs and landings despite lacking the advantage of sophisticated instrumentation available to human aviators. Tests using a microhelicopter suggests that insects use optical flow to keep at the right height. Essentially, the higher the insect, the slower the ground will appear to move below as it flies along, enabling it to gauge its height. [U][A][R] |
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| [P] Propulsion and energy | |
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Aviation biofuel A new biofuel technology developed at North Carolina State has the potential to turn virtually any fat source, including vegetable oils, animal fat and even oils from algae, into aviation fuel. [P][A]
Changing energy industry According to McKinsey, the world’s providers of energy and energy-intensive commodities face a decade of unprecedented change and uncertainty as six macroeconomic, social, and business trends reshape the competitive landscape. These trends include booming demand for energy and basic-materials resources, particularly in developing economies; the shift of supplies of oil, natural gas, and basic materials to ever more remote (and often geopolitically unstable) locations; heightened scrutiny of the environmental effects of the production and consumption of energy and materials; and increasingly large capital investments needed at a time of regulatory uncertainty. [P][T][X]
Reporting of greenhouse gas emissions A lack of mandatory standards regulating the way businesses report their greenhouse gas emissions has led to massive under-reporting by UK companies, according a study commissioned by the charity Christian Aid. The study estimates that the 100 largest companies listed on the London Stock Exchange under-report their emission by about 191 million tonnes of carbon dioxide each year. If these emissions were included the worldwide activities of these companies could account for as much as 12 to 15 percent of global emissions instead of the current estimate of 2.1 percent. [P][E]
Thermoacoustic natural gas liquefier Worldwide, 100 billion cubic metres of natural gas is wasted every year. According to researchers this gas could instead be economically liquefied using thermoacoustics. The thermoacoustic liquefier burns a small fraction of the natural gas to heat one end of a steel pipe network. Then, the resulting acoustic energy is used to refrigerate the opposite end of the network, which cools and liquefies the rest of the natural gas. The liquefier requires no moving parts, contributing to its economy of operation and is particularly suitable for capturing gas from smaller oil-fields where a conventional liquefier would be too expensive. [P][M]
Testing geosequestration The safety of carbon sequestration is being tested in new facilities that incorporate comprehensive monitoring for any leaks. In Europe, drilling has started on a facility west of Berlin in which some 60,000 tonnes of carbon dioxide will be injected into a saline aquifer at a depth of over 700 metres over the next two years. Probes will be lowered into the bore holes to study the properties of the rocks at different depths using acoustic imaging. In Australia, a test facility is being built in the Otway Basin. It includes intensive monitoring of levels of carbon dioxide in soil, water and air. Tracers added to the injected carbon dioxide will enable any escape to be distinguished from carbon dioxide produced by vegetation or other natural sources. Importantly, Otway Basin lies on the south coast of Australia. This means that air measurements can be made while prevailing winds bring clean air from the Southern Ocean, uncontaminated by any industrial or natural sources of carbon dioxide. [P][E][M][R][S]
Sequestering carbon dioxide in saline aquifers An MIT study suggests that a very promising way to sequester carbon dioxide would be to inject it deep underground into porous rock, such as sandstone or limestone, saturated with saltwater. Because of its buoyancy, the injected gas will form a plume and begin to rise through the permeable rock. Once the injection stops, the plume will continue to rise, but saltwater will close around the back of the gas plume. The saltwater and carbon dioxide will juggle for position while flowing through the tiny pores in the rock. Because the rock's surface attracts water, the water will cling to the inner surface of the pores. These wet layers will swell, causing the pores to narrow and constrict the flow of carbon dioxide until the once-continuous plume of gas breaks into small bubbles or blobs. According to the study, these will remain trapped in the pore space until they slowly dissolve and, on an even larger timescale, react with rock minerals. [P][E]
Wave power Ocean waves could provide much of the world's electricity, but present wave power machines are relatively expensive and unproven compared to wind energy. Several technologies are being trailed around the world. One, the Pelamis system, consists of long steel tubes in sections that look like rounded train carriages. The tubes self-orient into the waves and these then travel down the length of the tubes causing each section to move up and down and side to side. The snake-like movements push hydraulic fluid through generators to produce electricity. A prototype Pelamis system has already been deployed off the coast of Scotland and an off-shore Pelamis wave farm is now being constructed in Portugal. The plan is that this will consist of 30 Pelamis systems located 5 km out to sea. The hope is that wave energy could eventually supply 20 percent of Portugal's power. [P][E]
Power skin Astronauts' spacesuits may one day be covered in motion-sensitive proteins that could generate power from the astronauts' movement, according to research in Cambridge, Massachusetts. Such "power skins" could also be used to coat future human bases on Mars, where they could produce energy from the Martian wind. [P][A][V]
Organic thermoelectricity Berkeley researchers have successfully generated electricity directly from heat by trapping organic molecules between metal nanoparticles. For temperature differentials of up to 30 degrees C, the output was measured as around 12 microvolts per degree. Though small, this could be a significant proof of concept towards a cheap thermoelectric technology that could cost-effectively scavenge energy from grow grade heat that is currently wasted, such as the heat from a car engine. [P][E][M][N] |
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| [M] Materials, structures and surfaces | |
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Strong ductile materials Recent advances in nanotechnology have made it possible to manipulate a material's nanostructure to make it both strong and ductile. Researchers from MIT, Georgia Tech and Ohio State have now developed a computer model that simulates at the atomic level how the nanomaterials behave under stress. This has revealed that ductility and strength are greatly influenced by twin boundaries. When there are smaller grains in the metal structure, and hence more grain boundaries for a given volume, there is more interaction between the boundaries and dislocations. Having more grain boundaries makes the material stronger but also more brittle. Adding nano-scale twin boundaries, which effectively subdivide the grains, has a similar strengthening effect, but the twin boundaries do not promote the same level of brittleness as grain boundaries do. [M][C][N]
Elasticity of rubber The way rubber stretches has been a puzzle for many decades. Rubber is made of flexible long-chain molecules tied together in places by crosslinks. The arrangement looks like strands of spaghetti stuck to each other at random points. The classical theory of rubber elasticity, developed in the 1940s, adds together the entropies of the free sections between the fixed crosslinks, but assumes that as the rubber is stretched, each crosslink remains stationary. This model fits how rubber stretches linearly at small deformations but does not fit the strong non-linearity when the rubber is more highly stretched. Researchers at the University of Boulder have now explained this by developing a new theory that includes heat-driven movements of the positions of the crosslinks. They believe their theory should apply to a wide range of soft elastic materials. [M]
Carbon sponge gas storage Researchers in Missouri and Kansas have developed a method to convert corncob waste into carbon "sponge" with complex nanopores capable of storing natural gas at an unprecedented density of 180 times its own volume and at one seventh the pressure of conventional natural gas tanks. The new material can be formed into a variety of shapes with ideal characteristics for next-generation gas storage tanks on methane-powered automobiles. [M][N][P]
High temperature superconductivity Scientists at the Carnegie Institution and the Chinese University of Hong Kong have discovered that pressure and the substitution of different isotopes of oxygen have a similar effect on electronic properties of high-temperature superconductors. This finding adds considerable weight to the increasing evidence that high-temperature superconductivity, like conventional low temperature superconductivity, depends on phonons. [M][J][P]
New phase transition Researchers at Max Planck in Dresden have observed a new type of phase transition that defies current understanding. Until now, it was believed that phase transitions always involve fluctuations of one parameter. However, the Dresden experiments - involving a magnetic phase change - revealed completely unexpectedly that there was an additional change to electronic properties. This may arise from quantum entanglement between conduction electron spins and magnetic spins. Understanding such complex behaviour may be relevant to high temperature superconductivity. [M][F]
Bio-reinforcement Soil bacteria could be used to convert loose sand into sandstone to reinforce buildings against earthquakes, according to researchers at UC Davis. The new process, so far tested only at a laboratory scale, takes advantage of a natural soil bacterium, Bacillus pasteurii. The microbe causes calcium carbonate to be deposited around sand grains, cementing them together. [M][E][G]
Splash or plop French researchers have found that whether an object makes a splash when it hits water or a simple plop depends on how hydrophobic or hydrophilic its surface is. A hydrophobic surface create an air cavity where the water molecules retreat, which leads to the splash. The researchers say that the finding could prove useful in reducing splashing that occurs during high-speed water impacts, for example during air-to-water torpedo entries. [M][D]
Controlled electrowetting A tangled surface of Teflon-coated silicon nanowires can be used to electronically tune the shape of water droplets, according to researchers in Lille. Using this method with very hydrophobic surfaces could allow chemists to finely control chemical reactions by being able to move droplets around with great precision. [M][N]
Molten metal magnetism The Earth generates a magnetic field from the flow of molten metal in its core. The liquid metal moving through a magnetic field generates an electric current that in turn generates the magnetic field. The "self-generation" mechanism works by dramatically amplifying the small, random fields that always exist in magnetic materials. But, for this to happen, the flow must be complex, mixing up the longitudinal and latitudinal directions, and also rapid so that it tangles up magnetic field lines faster than they can untangle. This self-generation process was first demonstrated in the laboratory in 2000 by forcing liquid sodium into complex but non-turbulent flows using physical barriers to deflect it along precisely defined paths. Now French researchers have demonstrated self-sustaining magnetic fields more realistically using turbulent flows of liquid sodium in a large tank. This should help researchers better understand the factors that give rise to magnetic fields in planets and stars, as well as in the Earth. [M][A][E]
Finger-rafting For more than half a century, scientists and polar explorers have puzzled over the way thin floating ice sheets, when they collide, can join together with zipper like patterns of rectangular fingers that push over and under each other alternately. Researchers at Cambridge University and Yale have now developed a theory, which explains the phenomenon and suggests that it can occur for any material with the right properties. To demonstrate this, the researchers created similar patterns by gently forcing together thin layers of sealing wax floating on water. They speculate that finger rafting may have a role in shaping the boundaries of tectonic plates and could also exist on a planetary scale on Jupiter's ice-clad moon Europa. They also speculate that engineers may be able to create self-assembling nanostructures like gear teeth by pressing together two suitable materials. [M][A][E][N] |
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| [E] Environment, transport and marine | |
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Different forms of continental collision By using GPS, it is now possible to track movements of the Earth's surface as small as 1 mm per year. US and Chinese researchers have used GPS to record the precise movements of hundreds of points on the continent of Asia over a 10-year period. The data addresses the 40-year debate over how continents respond during collisions of tectonic plates. The "strong and brittle" theory suggests continents break into pieces during collisions; the "weak and viscous" theory suggests, on the contrary, that continents thicken and flow upon collision. The data suggests that in fact both are occurring: most of Asia is very strong and breaks like a ceramic plate, but there also are large areas like Tibet and the Tien Shan mountains that seem to deform more like Play-Doh. [E][M][R]
Different forms of continental collision About 55 million years ago, the Indian plate crashed into the Eurasian plate, forcing the land to slowly buckle and rise to form the Himalayas and the Tibetan Plateau - the world's largest and highest plateau, averaging 16,000 feet in elevation. From seismic waves, geologists at the University of Illinois have now located a huge chunk of the lithosphere that broke off from under the area of the Tibetan plateau around 15 million years ago. This confirms there was a different type of plate collision in which, instead of one plate being subducted under the other, the lithosphere was instead squashed thicker until it became so thick that it was unstable. As the chunk of lithosphere broke off and disappeared down into the lower mantle, the rebound upwards raised the Tibetan Plateau. [E][M][R]
Water in the mantle Analysis of 80,000 shear waves from more than 600,000 seismograms has revealed a large area in the Earth's lower mantle beneath eastern Asia where water is attenuating seismic waves from earthquakes. The volume of water trapped there is at least equal to the whole of the Arctic Ocean. This is the first evidence for water existing in the Earth's deep mantle. It is believed that the water helps to lubricate the movement of the tectonic plates. When plates are subducted, the water is released at the bottom of the mantle and large amounts can then collect in the mantle. [E][M][R]
How hurricanes evolve The strongest winds in a hurricane are the ones that rush round the wall of clouds surrounding the storm's calm eye. The eye can contract, intensifying the winds. Data gathered in 2005 by flying radar-equipped aircraft through several hurricanes has revealed how, as the eye contracts, a doughnut of dry air forms around the eyewall, encircling it like a moat. As this happens, a new, larger circular wall of clouds forms around the outside of the moat and a new larger eye forms that eventually replaces the inner eye and causes the wind speed to drop. This eyeball replacement was seen in both hurricanes Katrina and Rita before they intensified to category 5 status. The researchers say that the results will help in forecasting when and how future hurricanes may suddenly became stronger and much more destructive. [E][A][R]
Atlantic hurricanes and global warming Atmospheric scientists have uncovered fresh evidence to support the theory that global warming has contributed to the emergence of stronger hurricanes in the Atlantic Ocean. But the trend does not seem to apply in the world's other oceans. Sea-surface temperatures may be one reason why the Atlantic Ocean is unique. The average conditions in the Atlantic at any given time are just on the cusp of what it takes for a hurricane to form. The Atlantic is also unique in that the physical variables that converge to form hurricanes, including wind speeds, wind directions and temperatures, reinforce each other in a way that is not yet understood. [E][X]
Ocean dead zones Dead zones, where populations of marine life are suddenly wiped out, have been recorded off the coast of California and Oregon every year for the last five years, and also in the waters off Chile, Namibia and South Africa. The common factor between all of these areas is that currents off the coast rise from the deep ocean bringing nutrient-rich water that supports abundant marine life. Nearly half of the world's fisheries are in these areas. Researchers believe the dead zones happen when changes in the intensity of coastal winds, perhaps brought about by global warming, cause changes in the upwelling current. If the current is disrupted, the loss of nutrients means that species starve. Worse, if the current is greatly increased, the excess of nutrients can cause massive plankton blooming that then depletes the water of all its oxygen when the plankton dies, suffocating all the marine life. [E][X]
Future agriculture According to a study by researchers at the University of Iowa, industrial agriculture faces painful challenges: the end of cheap energy, depleted water resources, impaired ecosystem services, and unstable climates. Volatile weather conditions will make it difficult to sustain highly specialized cropping systems. Instead, agriculture may need to emphasise synergistic biodiversity. The researchers showed that when farms are converted from corn/soybean monocultures to more diverse operations, net farm income can more than double whilst generating significant environmental and social benefits. The study concludes that postmodern agriculture needs to be energy conserving, to feature both biological and genetic diversity, to exploit multi-product synergistic production, and to be largely self-regulating and self-renewing. It also needs to be knowledge intensive, operate on biological synergies, employ adaptive management, and feature ecological restoration rather than choosing between extraction and preservation. [E][G][P][R][W][X]
Underwater express A US DARPA programme is seeking to exploit supercavitation to give undersea craft new capabilities in speed and manoeuvrability. Supercavitation involves creating a bubble of air around the vessel. The bubble can provide a 60 to 70 percent reduction in drag, allowing much higher speed. The aim is to produce a new type of fast underwater craft for transporting high-value cargo and small units of personnel in coastal waters (littoral operations). [E][D][P]
Antarctic warming The northern tip of the Antarctic Peninsula, with its collapsing ice shelves, is one of the most rapidly warming parts of the Earth. However, according to researchers at Ohio State, data over the past 50 years suggests that, on average, the rest of Antarctica is not warming, despite predictions from climate models; nor is precipitation increasing as expected. The paucity of data makes it hard to determine precisely what is happening, but a possible explanation is that the Antarctic ozone hole is acting to cool Antarctica. With less ozone, there is less absorption of UV sunlight and the stratosphere is cooler. [E][R] |
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| [R] Remote sensing and sensor systems | |
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Antarctic lakes and river networks New satellite images and high-resolution laser profiles of the West Antarctic ice sheet have revealed that rivers of fast-flowing water are gushing beneath the ice sheet in an extensive arterial system of rapidly filling and emptying lakes. It was expected that the western ice sheet would contain subglacial water stores, but the scale of the network and the speed of the water flow is surprising. The lakes may play a crucial role in transporting ice from the remote interior of Antarctica towards the surrounding ocean. They coincide with the origin of tributaries of the Recovery Glacier. Upstream of the lakes, the ice sheet moves at just 2 to 3 metres per year; downstream the flow increases to nearly 50 metres per year. The lakes appear to provide a reservoir of water that lubricates the bed of the stream, facilitating ice flow and preventing the base of the sheet from freezing to the bedrock. [R][A][E]
Exoplanet spectrum NASA's Spitzer Space Telescope has provided the first spectra from two extrasolar planets. This achievement provides a new, direct way to analyze the atmosphere of alien worlds light-years from Earth. Both planets are hot gas giants and are so-called "transiting planets," meaning that the planet crosses in front of its star as seen from Earth. Spitzer recorded spectra both when the planets were behind their respective stars and when they passed in front of them, as seen from Earth. For each system, subtracting the spectrum of the star from that of the star and planet together yielded the spectrum of the planet. Surprisingly, neither spectrum shows signs of water vapour. The spectrum of one of the planets - called HD 209458b and about 153 light-years from Earth - shows evidence of the presence of silicate dust. [R][A]
Asteroid tracking During the past 10 years, astronomers have found an estimated 90 percent of the large asteroids that could threaten Earth with devastation on a global scale. In the coming decade, they expect to find most of the remaining global hazards, as well as many more smaller asteroids that pose regional threats. Among the smaller threats already found is the asteroid Apophis, which is calculated to have a 1 in 45,000 chance of hitting Earth on 13 April 2036, probably landing in the Pacific Ocean. With a mass of 20 million tonnes and a diameter of 250 metres, Apophis would not cause global devastation but could still cause a tsunami that would devastate the seaboards around the Pacific. A draft UN treaty to determine what would have to be done if a giant asteroid was on a collision course with Earth is to be drawn up this year. The aim is to set out global policies including who should be in charge of plans to deflect any object. [R][A][D]
Conformal radar US Air Force researchers have developed composite radar arrays that can serve as aircraft skin and as structural components. They believe the work will open up entirely new radar capabilities as well as materials advances. The hope is to use the technology in long-duration sensor aircraft. [R][A][D][I][M][U]
Airport screening US authorities are testing a controversial new X-ray machine to screen air passengers for weapons. The so-called backscatter x-ray machines can detect potentially threatening objects under a person's clothes by picking up x-rays scattered by materials. To avoid the "virtual nudity" problem, the equipment uses an algorithm that matches individuals to a general outline of the male or female form. Critics argue, however, that the resulting loss of detail reduces the effectiveness in detecting hidden objects. [R][A][D]
Airport explosive screening Scientists in Japan have developed a new technique for sensing explosives in luggage and landmines. It uses nuclear quadrupole resonance (NQR) to detect atoms of nitrogen in different positions in a molecule that can give a characteristic signature for different explosives including TNT. They successfully developed a machine that can pick up the very low resonant frequencies by using a SQUID (superconducting quantum interference device) cooled with liquid nitrogen. [R][A][D][S]
Atom recognition Atomic force microscopes (AFM) are routinely used to spot individual atoms on surfaces and to reveal how they are arranged. Now Japanese researchers have found a way to produce AFM images that reveal the chemical identity of individual atoms on a surface. The researchers were able to distinguish between atoms of lead, tin, and silicon. The technique works at room temperature and for insulators as well as for semiconductors and conducting materials. [R][J][M][N][S] |
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| [S] Sensor devices | |
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Higher resolution MRI The superconducting magnets in current MRI machines in hospitals and research laboratories use a superconducting alloy of niobium that can produce magnetic fields of up to 21 Tesla when operating at liquid helium temperature (4.2 degrees K). Researchers have now shown that by using a superconducting material known as Bi-2212 it should be feasible to build magnets capable of 30 Tesla operating under similar conditions. This would give a substantial increase in MRI resolution. [S][H][M][R]
Cryocooler A new cryogenic refrigerator has been demonstrated at NIST that operates at twice the usual frequency, achieving a long-sought combination of small size, rapid cooling, low temperatures and high efficiency. The cryocooler could be used to chill instruments for space and military applications, and is a significant step towards even smaller, higher-frequency versions for integrated circuits and microelectromechanical systems (MEMS). [S][J][M][R]
DNA-based uranium detector Researchers at the University of Illinois have developed a simple, disposable sensor for detecting hazardous uranium ions, with a sensitivity that rivals the performance of much more sophisticated laboratory instruments. They say that the sensor provides a fast, on-site test for assessing contamination in the environment and the effectiveness of remediation strategies. The detector uses a single strand of DNA containing a binding site whose shape is specific to uranyl, the most soluble species of uranium ion and the one that poses the greatest hazard. To search for the unique sequence of DNA that could distinguish uranyl from other metal ions, the researchers used a combinatorial approach called in vitro selection. Simple and cost-effective, the selection process can sample a very large pool of DNA (up to 1,000 trillion molecules), amplify the desired sequence by the polymerase chain reaction, and introduce mutations to improve performance. [S][D][E][P]
Nanoscale thermomechanical probe A way to probe the thermomechanical response of a material at resolutions down to 50 nm has been developed by researchers at the University of Illinois and Georgia Tech. The new method is based on heated atomic force microscopy and will make it possible to explore temperature-related phenomena that occur on very small length scales, such as glass phase transitions and phase transitions at surfaces and interfaces in heterogeneous materials. [S][M][N]
Optical nanosensor According to researchers at UC Riverside, nanosized holes in ultrathin gold films on glass can be used as biochemical sensors. The new technique works by measuring the changes in the surface plasmon resonance peak in the absorption spectrum of light passing through the holes. It can be used to selectively sense cancer antigens down to the picogram level once the gold and glass surfaces have been modified with bioreceptors that bind the antigens. [S][H][N]
Breath test for lung cancer A breath test that can pick up lung cancer with "moderate accuracy" even in the early stages has been developed by researchers at the Cleveland Clinic in Ohio. The compact device was tested on a sample of 122 people, which included 49 people with lung cancer, 52 with other respiratory diseases and 21 healthy controls. It correctly identified 36 of the patients with lung cancer and correctly cleared 15 of the healthy subjects. It should be possible to make the test considerably more accurate since it is known that dogs can be trained to smell cancer on the breath of patients with 99 percent accuracy. Catching lung cancer early, when it is still treatable, could save many tens of thousands of lives per year. Lung cancer kills more people than any other cancer, in part because it is not usually detected until it has spread. [S][H]
Room temperature quantum Hall effect The quantum Hall effect is a quantum-mechanical version of the Hall effect in which the Hall conductance takes on quantized values. The effect is the basis for the international electrical resistance standard. It was first discovered in 1980 by the German physicist Klaus von Klitzing, who was awarded a Nobel Prize in 1985 for his discovery. Until recently it was believed that the quantum Hall effect was only observable at temperatures close to absolute zero. However, scientists in England, US and Netherlands have now succeeded in observing the effect at room temperature in graphene. [S][J][M] |
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| [O] Optoelectronics, optics and lasers | |
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Laser thermal tweezers Optical tweezers do not work for manipulating particles less than about 100 nm in diameter. This is because the "gradient trapping" force induced by the non-uniform optical field of the optical tweezers is overwhelmed by Brownian motion. However, researchers at Queensland University of Technology have calculated that it should instead be possible to trap and manipulate nanoparticles on surfaces by using thermophoresis - the anisotropic diffusion of atoms and particles from hot to cold regions in the presence of strong temperature gradients. In their model, they produced temperature gradients using two or more short interfering laser pulses operating in the visible range. They found that the thermophoresis is several orders of magnitude stronger at a surface than in a bulk medium and that the resulting trapping efficiency increases as the size of the particles decreases. As a result, it should be possible to use "thermal tweezers" to manipulate particles that are just nanometres wide. [O][G][J][N]
Nano-optics The electronic and optical properties of nanoparticle chains and arrays could be exploited in areas such as sub-wavelength waveguides, novel optical chips, lasing and sensing. However, to realize such applications, a complete theory of how light behaves in nanoparticles is still needed. A new theoretical description of how light travels through periodic nanorod arrays has been developed by researchers at Linköping University in Sweden. This shows that the size of the nanoparticles, their shapes, clustering and collective effects, are crucially important. The results also suggest that periodic nanorod arrays could be used as high-quality polarisers. [O][M][N][S]
Nano-optics Nanoholes and arrays of nanoholes in metal screens have many intriguing optical properties, including high transmission of light. Researchers in the UK and Spain have now shown that using a Penrose-like quasiperiodic structure of nanoholes - a complex pattern that is neither truly periodic nor random - they can focus monochromatic light into spots smaller than its wavelength. They suggest the device could find applications in high-density optical information storage, photolithography, and making a small "light pen" that can image inside cells and other microscale objects. [O][J][N][S]
Zero reflection optical coating A team of researchers from Rensselaer Polytechnic Institute has created an optical coating that reflects virtually no light. Using a technique called oblique angle deposition, they deposited layers of silica nanorods at an angle of precisely 45 degrees on top of a thin film of aluminium nitride. By altering the spacing between the nanorods, the scientists gave each layer a different refractive index, matching the top layer to nearly the refractive index of air and the bottom layer to nearly that of the substrate. In this way, by producing coatings in which there were no abrupt refractive index changes, the reflection was strongly reduced at all wavelengths and all incoming angles of light. The oblique angle evaporation technique is already widely used in industry, and the researchers say that the design can be applied to any type of substrate. The technology could have many applications including for brighter LEDs, more efficient solar cells, and a new class of "smart" light sources that adjust to specific environments. [O][J][M][N][P][S]
Super-thin laser mirror Engineers at UC Berkeley have created a new high-performance mirror that could dramatically improve the design and efficiency of the next generation of devices relying upon laser optics. These include high-definition DVD players, computer circuits and laser printers. The mirror uses a high-index-contrast sub-wavelength grating. It achieves 99.9 percent reflectivity, similar to distributed Bragg reflectors (DBRs), but it does so in a package that is at least 20 times thinner than a DBR, works over a considerably wider range of wavelengths, and is easier to manufacture. [O][C][J][N][P]
Deep-UV devices Beyond current blue lasers and LEDs based on gallium nitride, the next goal is to develop UV-emitting devices. This could enable a DVD to hold 250 gigabytes of data. A practical deep-UV LED could provide brilliantly white light and any other colour by using phosphors. For cheapness and UV efficiency, zinc oxide looks to be the best material. An article in March IEEE Spectrum reviews progress and challenges. The main hurdle is to make stable, reliable p-type ZnO material in order to make a pn junction. ZnO is naturally n-type, and the p-type can revert to n-type after a few months. [O][J][M][P][T][V]
x-ray laser For nearly half a century, scientists have been trying to figure out how to build a cost-effective and reasonably sized X-ray laser to provide super-high resolution imaging. Researchers at the University of Colorado believe they have a solution in sight. They have managed to increase by a factor of a hundred the brightness of a soft x-ray laser driven by a visible laser. They believe there is no fundamental problem preventing their technique being extended into the hard x-ray spectrum. It uses two counterpropagating visible laser beams. The first is a powerful laser beam that plucks an electrons from an atom of argon and then slams it back into the same atom to generate an x-ray photon. The second is a beam of weak pulses which is used to arrange that all of the electrons are slammed back at the right time to synchronise with and add coherently to the x-ray wavefront. [O][H][J][N][R][S]
Weapon laser A solid state electrically-powered laser has achieved 67 kW mean output power, close to the output required for a military laser weapon to shoot down missiles on the battlefield. [O][D][P]
Wakefield acceleration Researchers at SLAC have shown that the energy of a particle beam can be doubled by passing it through a plasma and exploiting wakefield acceleration. In the demonstration, a pulse of electrons first travelled 2 miles through the SLAC linear accelerator, gaining 42 billion electron volts (GeV) of energy. The pulse then passed through a plasma chamber 84 cm long filled with lithium gas. The electrons in the front of pulse created plasma and the plasma wake flowed back transferring the energy to the rest of the electrons, accelerating them to as high as 84 GeV. The approach could provide a cost effective way to produce particle beams with extremely high energy. However, several challenges remain before the technique can be used in practical particle accelerators. One is to reduce the energy spread of the electrons and accelerate a larger fraction of the beam to the highest energies; another is to show that positrons can also be accelerated in the same manner. [O][P] |
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| [I] IT, communications, networking and secure systems | |
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Human-implantable RFID tags RFID chips are being implanted in humans, particularly for medical reasons. By scanning a person’s chip, caregivers can retrieve an identification code that enables them to access the medical history of people who cannot otherwise communicate their identities, thereby speeding up their treatment, protecting against medical error, and possibly saving their lives. Implantable RFID chips could be used more widely, and could incorporate techniques to protect against invasion of privacy. But there remain serious ethical arguments against their widespread adoption. These issues are discussed in March IEEE Spectrum. An alternative approach in hospitals is for patients to carry their personal data in electronic tags embedded in wristbands. [I][J][H][T]
NFC payment Financial operators, including Visa, MasterCard, Barclaycard and HSBC, are developing and trailing near field communications (NFC) technologies for retail payment. NFC uses short-range wireless chips that can be embedded in credit, debit and other payment cards and in mobile phones to create a ‘contactless’ payment system. [I][T]
Commercialising quantum cryptography Quantum cryptography is now sufficiently mature as a technology that it is being offered as a product by several companies for totally secure fibre-optic links. A review in the March issues of PhysicsWeb and an article in March IEEE Spectrum describe the current technological progress and approaches to commercialisation. The absolute security of quantum cryptography comes from using single photons of light to carry the bits of the encryption/decryption keys. Current commercial systems use signal attenuation to prevent multiple photons being transmitted. The drawback is that this reduces the rate at which crypto keys can be sent. A newer approach is to insert decoy photons so that an eavesdropper will not know which photons are genuine and which are decoys. Checking for decoy photons disappearing can reveal that someone is listening in. [I][C][O][T] |
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| [K] Knowledge, information and technology management | |
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Shape search engine Molecular databases now contain many billions of molecules, and better search techniques are needed to handle this complexity. Researchers at Oxford University have developed a new method, dubbed Ultrafast Shape Recognition (USR), that can match 3-dimensional molecular shapes more than 1500 times faster than the best existing method. USR works by first identifying a molecule's centroid, then the atom closest to the centroid, the one farthest away, and the one that is farthest from this second atom. These atoms - essentially the centre and the extremes - are used as reference points for measuring distances to other atoms within the molecule. The researchers say the new technique might be useful for matching other 3D shapes, perhaps if the distance between the edges of a shape were used instead of the distance between atoms. [K][C][G][M][N][R]
Digital chronicling and knowledge preservation Today, people chronicle and share their experiences through blogging and mobile devices. Some use wearable sensors to capture health data. But memory will soon be sufficiently cheap that people will be able to record everything they see and hear throughout their lives, as well as data on their environment and health, and store all of this in a personal digital archive. In 20 years time, if current trends continue, $600 will buy 250 terabytes of storage, enough to chronicle every aspect of a person's life for 100 years. Digital chronicling also requires sensors to conveniently capture the data and computer search, analysis and metadata to make use of it. A project at Microsoft, called MyLifeBits, has begun a quest to develop such systems. As well as extending personal memory, such digital archiving could also enable organisations to ensure they do not lose important information when employees leave and so safeguard vital knowledge over decades. [K][B][C][H][I][S][T][V][W][X]
Maintenance of skills A new study at Stanford University has found that the experience of expert pilots actually counteracts the effects of aging on their flight performance. The study involved 118 non-commercial pilots from 40 to 69 years of age during flight simulation exercises. The authors believe the lack of a decline among the most experienced pilots is because of "crystallized intelligence". This is a specialized knowledge base that supports attention to key relationships between individual items of information, and helps in anticipating likely future events and in coordinating motor movement so as to respond faster and more accurately. This sort of knowledge, which is critical to musicians, athletes and strategists, is believed to defy aging better than individual memory recollection and normal processing ability. [K][B][W][X]
Planning skills Planning for the future is a complex skill that was previously believed to be unique to humans. Other animals were perceived to be incapable of dissociating themselves from the present and any current motivations. However, some birds also appear to have this ability. Researchers at Cambridge University have found that western scrub-jays will store food items they believe will be in short supply in the future. [K][B]
Metacognition in rats Researchers have found evidence that rats can possess knowledge of their own cognitive states. This ability, which can also be thought of as the capacity to assess or reflect on one's own mental processes, was previously only recognized in humans and other primates. The evidence comes from experiments that indicated in two ways that the rats could accurately assess in advance whether they had enough information to pass a test and opt out of the test - for a lesser reward - if they didn't. [K][B]
European Research Council The European Research Council has been officially launched. The ERC, which is the first pan-European funding agency to cover all fields of science, will award grants to individual researchers worth a total of Euro 7.5bn over the next seven years. [K] |
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| [C] Computing, supercomputing, modelling and simulation | |
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Training by simulation As simulation technology has improved, it has become increasingly important to military capability, to help model equipment and future operations, and for training. A few years ago the emphasis was on joint simulations to develop the understanding and techniques for joint operations between Services and different partners. Now, a lot of emphasis is on using complex simulation for training and operational planning in the individual Services. March Signal magazine has review articles describing progress in the US Navy, Army and Air Force. Among the technical challenges, accurately representing humans in simulations is still a big problem. [C][D][K][T][V]
Simulating materials ab-initio Intel and IBM recently announced their separate developments of high dielectric constant (high-k) metal gate technology for the next generation of silicon integrated circuits. IBM has now described the way it used supercomputer simulation to understand how the high-k hafnium dioxide gate insulator mixes with the underlying silicon to form hafnium silicates and how this affects the resulting dielectric constant and material behaviour. The approach, called ab initio molecular dynamics, models the interactions between the particles of the system from the basic laws of physics without employing any empirical data. The IBM team simulated various material compositions using 50 different models of hafnium silicates each containing up to 600 atoms and about 5,000 electrons. The complete simulation for all 50 models took about 250 days on IBM's Blue Gene supercomputer. [C][J][M][N]
Reducing power consumption Electricity consumption is becoming a serious and sometimes dominant cost of operating major computing and data storage facilities, as well as an issue for "green IT". Researchers are looking at many ways for reducing energy consumption, not only through lower power chip technologies but also by improving power-supply technology, data-centre architectures and thermal interfaces. [C][I][J][P][T]
Evolution of GPUs Graphics processor units (GPUs) have moved away from the traditional fixed-function 3D graphics pipeline toward a flexible general-purpose computational engine. They have become the first widely deployed commodity desktop parallel computer. The highly parallel workload demands extremely high arithmetic throughput and streaming memory bandwidth, but it tolerates considerable latency in an individual computation since final images are only displayed every 16 milliseconds. These workload characteristics have shaped the underlying GPU architecture. Whereas CPUs are optimized for low latency, GPUs are optimized for high throughput. [C][T][V] |
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| [W] Whole life engineering, manufacture and testing | |
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Moving to open source As use of open source software expands, it is becoming feasible for companies to use open source on PCs. This can mean using open tools to replace proprietary software on PCs and/or using web applications that offer similar capabilities but do not require maintenance of the software on local disks. A company could for example adopt the desktop application OpenOffice.org for office suite requirements while using Google's calendaring and e-mail functions. A review article in March IEEE Computer gives an overview of the options. [W][C][I][K]
Elusive software bugs Software testing is mainly suitable for dealing with faults that consistently manifest themselves under well-defined conditions. Diagnosing and isolating a software fault is much harder if the failure cannot be reproduced. Such faults are sometimes called Mandelbugs because they can cause the software to exhibit a chaotic and even nondeterministic behaviour with respect to the occurrence and non-occurrence of failures. Over time, bugs can cause errors to build up in the system increasing the chance of an eventual failure. This is called software ageing. Rebooting the system provides system rejuvenation by eliminating these ageing errors. Monitoring for signs of software ageing can help detect software faults that were missed during the development and testing phases. [W][C][I][R][X]
Silicon chip automated manufacturing In a single day, a state-of-the-art silicon IC fab can make nearly 100 trillion transistors. With over 40 such fabs in the world, this could add up to around half a million transistors a day for each and every person on Earth. Such facilities are by any standard the most complex, and, at an average cost of US $3 billion to build and equip, the most costly factories ever built by humankind. The ability to operate them successfully depends enormously on automated manufacturing technology (AMT) to test, adjust, and perfect the manufacturing processes. People venture out onto the fab floor only to attend to machines that the AMT system has sensed need repairs or routine maintenance. On each line, the AMT system takes thousands of different readings from hundreds of machines. These are used to automatically optimise the processing of each wafer, to continuously improve the process based on chip test results, and also to improve the AMT system itself. [W][C][J][T][U]
Printing 3-D objects Researchers at the Hebrew University of Jerusalem have developed a technique by which elaborate 3-dimensional objects can be created by heating 2-dimensional discs. The disc is soft and is coated with a monomer solution "blueprint" that selectively shrinks when heated. The resulting shape is determined by suitably varying the thickness of the deposited monomer layer. The technique may be useful for engineering prototypes. [W][M]
Home 3-D printer Researchers at Cornell have published designs and online support to enable amateurs to build low-cost 3-D printers. They say that whereas commercial 3-D printers cost $100,000 on average, their home 3-D printer called Fab@Home can be built for about $2,300 worth of off-the-shelf parts. [W][M]
Recycling electronics The problem of how to safely dispose of the mountains of circuit boards from discarded computers, cellphones and other electronics might be solved using a new technique developed by researchers in China. It involves crushing circuit boards and using a high-voltage electric field to separate metallic and non-metallic materials. Valuable metals such as copper can be reclaimed by distilling in a vacuum without releasing toxic fumes, while the non-metal components can be compacted into plates for use as building materials. The UN has launched a global initiative to tackle the growing problem of e-waste. [W][E]
Green construction Buildings account for about half of the UK's annual greenhouse gas emissions. The UK government aims to make all new homes carbon neutral by 2016. In response, some of the UK's leading property and construction firms have formed the UK Green Building Council, with the aim of transforming the £90bn sector into a "sustainable industry with the next 10 years". An important aim is not only to make future buildings carbon neutral but to greatly reduce the energy consumption of existing homes and offices because these will still account for three quarters of the buildings in the UK in 2050. [W][E][M][P] |
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| [X] Systems, complexity and risk | |
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Stability of populations Researchers in Israel have developed a rigorous mathematical model that explains why populations of predators and prey remain stable. The results affirm an old solution ecologists had intuited, namely that desynchronization between populations in different regions, coupled with migration between them, could create stability overall. The model also shows that the key feature is for the frequency of the oscillations in populations in different regions to depend on their amplitude, so that when populations are small, they tend to grow or shrink slowly, whereas when they are large, their size can change much more quickly. As well as being relevant for protecting threatened species living in fragmented habitats, the results could also be find use in medicine, aiding new antibacterial therapies that use bacteria-killing viruses. [X][E][H]
Treating disease ecologically In an ecosystem, a biological population must reproduce to survive. An environment that supports reproduction is called a population source, and an environment unsuitable for reproduction is a population sink. If sinks dominate over sources, the population is likely to become extinct. Ecologists at Yale have proposed that this principle might also apply within the human body and might be used to eliminate the population of a harmful virus, such as HIV. They have demonstrated the principle by using a non-human virus and variants of the bacteria cells it infects. In the case of HIV, the T-cells in the immune system are the source. HIV recognises T-cells by CD4 molecules on their surface and it then uses the functions of the T-cell nucleus to reproduce. The researchers propose that mature blood cells modified to have CD4 molecules on their surface to powerfully attract and bind HIV could provide a good sink. They lack a nucleus and therefore the HIV could not reproduce. They could also be introduced in sufficient quantities that would greatly outnumber the T-cells source habitats in the body. [X][E][G][H]
Leading change In today’s business environment, companies cannot settle for incremental improvement; they must periodically undergo performance transformations to get, and stay, on top. According to McKinsey, CEOs play a crucial role in managing such change, but the precise dimensions of their role are seldom articulated. The article argues that CEOs can have an impact in four ways: by making the transformation programme meaningful, often by a willingness and ability to make things personal, to engage others openly and to spotlight successes as they emerge; by inspiring others as a role model; by building a strong and committed top team; and by relentlessly pursuing impact though holding leaders accountable and getting directly involved personally when significant financial and symbolic value is at stake. [X][K] |
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| [V] Virtuality and human-machine interface | |
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Mobile clinical assistant The UK National Health Service is trialling an electronic clipboard that will cut the time doctors and nurses spend on paper work. The portable device lets clinicians access patient records at the bedside, write notes and order essential tests in real-time. The clipboard, which resembles a modified tablet computer, has been toughened to cope with hospital life and can be disinfected. It incorporates an RFID scanner and a barcode reader. An in-built camera allows pictures to be added to patient records. [V][C][H][I][K][R][W]
Inkless colour printing A US company, Zink Imaging, has developed a way to print colour pictures thermally without needing ink. It says it will use the technology to make hand-held printers that can be integrated into mobile phones and digital cameras, with the first products available at the end of 2007. During printing, a special paper passes through a thermal print head with a thin row of tiny heater elements. The applied heat causes dye molecules in the paper to change from crystals to amorphous glasses, releasing the colour. The paper contains layers with yellow, magenta and cyan dyes that together create a full colour print. Each heater element delivers a series of rapid heat pulses and the temperature and duration of each pulse determines how much colour is released in each of the three layers. [V][M][O]
Steganographic interface Fujitsu is promoting a technology that can encode data into a picture that is invisible to the human eye but can be decoded by a camera phone. It exploits the fact that the human eye is poor at noticing differences in hue of the colour yellow. The technique makes it possible to incorporate simple information such as phone numbers or website addresses so that readers of printed material can easily access more information with their mobile phones, thus linking printed to digital media. [V][I][K]
Virtual living In the wake of virtual worlds like Second Life and such file-sharing stalwarts as YouTube and Flickr, Sony Computer Entertainment is using its PlayStation 3 and PlayStation Portable to usher in its own virtual online-connected community. The initiative, dubbed "Home," will allow gamers to create virtual avatars and congregate in 3-D homes and halls to socialize via text, audio or video chat; watch movie trailers or feature films; and play casual games. Gamers will be able to do all this via a free download. [V][C][K]
Virtual treatment of traumatic disorders Traumatized US soldiers are being treated for post-war psychological disorders by going out on patrol in a computer-generated "virtual Iraq." This uses a long-established therapeutic technique know as exposure therapy. It re-introduce veterans to the experiences that have inflicted mental scars until gradually they are no longer haunted by the memories. [V][B][C][D][H]
Virtual fabric "Virtual fabric" that feels just like the real thing is being developed by European researchers. Detailed models of the way fabrics behave are combined with new touch stimulating hardware to realistically simulate a texture's physical properties. The user can interact with these virtual fabrics by using a haptic glove with a powered mechanical control system attached to the back and an array of moving pins under each finger. The glove exerts a force on the wearer's fingers to provide the sensation of manipulating the fabric, while the "touching" pins convey a tactile sense of the material's texture. [V][C][M]
Neural-nanoelectronic interface US researchers have interfaced photovoltaic nanoparticle films to nerve cells and have demonstrated photoactivation of the cells. They believe it should be possible to tune the electrical characteristics of the nanoparticle films to get properties like colour sensitivity and differential stimulation in order to make an implantable artificial retina. The ability to stimulate nerves optically could also provide new ways to connect with artificial limbs and prostheses. [V][B][N]
Bionic eye A bionic eye implant that could help restore the sight of millions of blind people could be available to patients within two years. US researchers have been given the go-ahead to implant the prototype device in 50 to 75 patients. This follows the success of an earlier trial that has enabled six totally blind people to see again. A tiny electronic pad is placed onto the retina of one eye, so that the electrodes are in direct contact with the ganglion cells that transfer signals to the brain. Each of the devices' 16 electrodes can stimulate 20 to 30 cells. The user wears a pair of glasses that contains a miniature camera and that wirelessly transmits video to a cellphone-sized computer in the wearer's pocket. This computer processes the image information and wirelessly transmits it to a tiny electronic receiver implanted in the wearer's head. When received in the implanted chip, the digital information is transformed into electrical impulses sent into the ganglion cells. The prototype trials showed that the brain has a remarkable capability to translate quite rudimentary information into a meaningful level of vision. [V][B][H][J][R][U] |
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| [B] Brain research and human science | |
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Reading intention Using a new combination of functional magnetic resonance imaging and multivariate pattern recognition, researchers in Germany, Japan and the UK have shown it is possible to read from brain activity how a person is intending to act in the future. Their experiments confirmed that, as previously supposed, freely selected plans (as opposed to plans following external instruction) are stored in the middle regions of the prefrontal cortex, the brain region involved in orchestrating thoughts and actions in accordance with internal goals. The intentions are encoded in a whole spatial pattern of brain activity rather than in single neurons. Regions of the prefrontal cortex towards the front of the brain store the intention until it is executed, whereas regions further back take over once execution is started. [B][K][R][V]
Sleep deprivation and moral judgement According to a study at the Walter Reed Army Institute of Research, lack of sleep can affect a person's moral judgement. The findings could have implications for people that have to make decisions with life or death consequences, such as overworked medical professionals and sleep-deprived soldiers. The study participants were 26 healthy active-duty military personnel. They were presented with a variety of hypothetical dilemmas, first when well rested and later, after staying awake for 53 hours. Some questions had no moral content whilst other included complex moral quandaries. When sleep deprived, the participants required two second longer on average to answer questions if they had moral content. Previous brain-imaging studies have shown that sleep deprivation causes a dramatic decrease in the activity of the prefrontal cortex, the area of the brain that processes complex moral decisions. [B][D][H]
Brain mechanism of family life Researchers at UCSB have found evidence of a nonconscious mechanism in the human brain that identifies genetic siblings. In a study involving more than 600 test subjects, the researchers found that people felt more altruistic toward individuals that this mechanism recognized as siblings, and, at the same time, felt a greater aversion to engaging in incestuous sexual relations with them. The researchers say that their findings indicate these sensibilities are not primarily a result of socialization by parents or peers, but of motivational systems developed through evolution to respond to cues of genetic relatedness. The discovery of a mechanism designed to make family relationships non-erotic casts doubt on Freudian theory that family members are the first and most powerful objects of sexual desire. [B][X]
Brain plasticity Among the central mysteries of neurobiology is what properties of the young brain enable it to so adeptly wire itself to adapt to experience. This extraordinary plasticity occurs only during a narrow window of time. For example, children deprived of normal visual stimulation during an early critical period of the first few years of life suffer the permanent visual impairment of amblyopia, or lazy eye, which makes it difficult to read closely spaced letters. In experiments on mice, Italian researchers have found that normal visual exposure triggers a molecular cascade that, in young mice but not in older mice, alters a class of proteins called histones. This change then activates many genes and allows permanent alteration of neural pathways. To confirm that it is the change to the histones that is critical, the researchers gave the older mice a drug called trichostatin to activate and change their histones. This caused a significant increase in the plasticity of their visual cortices. The result suggests that it may be possible to use drugs such as trichostatin to make adult brains more plastic in order to treat brain lesions. [B][K][H]
Small-world brain networks Small-world networks have a distinctive structure, consisting of clusters of nodes with each node connected to its immediate neighbours and with a few nodes that connect to distant nodes. Many networks show this structure, including power grids and human society. Now experiments using EEGs suggest the brain also exploits small-world networks. Related brain networks appear from the EEGs to operate at different electrical frequencies, each of which acts as a unique channel for transmitting information, and at each frequency, the brain networks appear to have a small-world structure. The frequency-specific brain waves are fractal - they look like each other but operate on a unique scale. At the two highest network frequencies, which appear to relate to conscious thought and action, brain activity was observed to be synchronized over an area that is at least 22 cm long over the brain's folded surface. Especially at higher frequencies, the networks seem to operate on the edge of chaos so that synchronized activity relegated to a small brain area can rapidly expand into far-flung neural regions. [B][C][I][T][U]
Brain cell regeneration The presence of newly generated cells in a brain region responsible for processing smells has been revealed in middle-aged and elderly people. The finding adds to mounting evidence that brain cell regeneration continues throughout adulthood in humans. [B][H]
Nerve repair Human nerve stem cells transplanted into rats' damaged spinal cords have survived, grown and in some cases connected with the rats' own spinal cord cells in experiments at Johns Hopkins laboratory. This is evidence that, contrary to previous wisdom, nerve repair can occur in spinal cords. [B][H] Reversing prion diseases Experiments in mice suggest that diseases caused by prions, such as scrapie and CJD, | |||