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Top Stories in Science
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October 2007 Issue |
| [D] Defence and security |  |
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Nobel Peace Prize By the award of the Nobel Peace Prize to Al Gore and the IPCC, the Nobel Prize Committee has signalled its view that global warming is now one of the world's defining security issues. The Committee said that it wanted to bring into sharper focus the increased danger of violent conflicts and wars, within and between states, posed by climate change. [D][A][E][P][R][W][X]
Global warming summit A UN summit of world leaders has agreed on the need for action on climate change, but has yet to tackle the difficult subject of what that action might be and whether it is possible to stop global warming without sacrificing economic growth. Emissions would need to begin to decline by around 2015 in order to reach the 2050 goal. The Stern report warned that delaying action would mean far greater economic cost downstream. [D][A][E][P][R][W][X]
Consensus on climate change A global poll by the BBC World Service has surveyed the views of more than 22 thousand people in 21 countries on climate change and what needs to be done. The results found that large majorities believe that human activity causes global warming. An average of 65 percent said that major steps to reduce combat global warming need to start very soon. The poll shows majority support (73 percent on average) in all but two countries for an agreement in which developing countries would limit their emissions in return for financial assistance and technology from developed countries. [D][A][E][P][R][W][X]
Emergency response Armed conflicts and natural disasters cause significant psychological and social suffering to affected populations. This may be acute in the short term, but can also in the long-term undermine mental health and psychosocial well-being of the affected population and threaten peace, human rights and development. Hard scientific evidence about what response and support works best in emergency settings is still thin. But the international humanitarian agencies have now agreed on a new set of guidelines that capture the general consensus on best practice. [D][B][E][H][K][X]
Biosecurity The Stockholm Institute for Peace has published a policy paper on countering bio-threats and managing biological materials, technology and knowledge. It is focused on EU biosecurity and its main messages are that the management of bio-risks needs to be better harmonised and that more emphasis in needed on preventing proliferation - not only by physical security of buildings but also by raising awareness of the importance of ensuring knowledge, technology and dangerous pathogens or toxins do not fall into the wrong hands. The report says that the EU is tending to focus on ‘back-end’ aspects of bioterrorism, such as methods for detection, preparedness and response, rather than on ‘front-end’ activities that can help prevent the release of infectious agents. The report comes at a time when the UK has recently suffered a leak of foot and mouth virus from one of its laboratories and when there is also concern in the US that over 400 labs are now allowed to handle the deadliest substances. This number has nearly doubled since 2004. [D][K][X]
H7N1 vaccine A new flu vaccine developed as part of the EU-funded FLUPLAN (Preparing for an influenza pandemic) project has shown promise in clinical trials. Early results show that the drug is safe and does not cause serious side effects in healthy people. The vaccine is designed to protect against the H7N1 strain of flu. Like H5N1 subtype, the H7 strains have the potential to cause a pandemic. [D][H]
Lethality of H5N1 From tissue tests on a woman who was pregnant when she died from H5N1 bird flu, researchers at Peking University in Beijing have found that H5N1 can infect babies in the womb, but may not do much damage to the foetus. This finding adds to evidence that H5N1 kills mainly by turning on immune reactions that are most intense in adults. This suggests that at an early stage of an H5N1 infection antiviral treatment is crucial, but later on anti-immune treatment may be useful. [D][H]
Disposing of plutonium A report by the UK Royal Society has drawn attention to the danger from the growing UK stockpile of separated plutonium that has been produced from the reprocessing of spent fuel from nuclear power stations. The report recommends burning it as mixed oxide fuel (MOX) to ensure there is no risk that plutonium might fall into the hands of terrorists. [D][P]
Flood defence Dams formed of metal tripods and self-filling water bladders could be air-dropped to rapidly repair levees breached by storm damage, according to US government researchers. The self-filling bladders, which were originally developed by the US Department of Defense as temporary jetties, could also be used to temporarily dam estuaries to protect cities from storm surges. [D][A][E][M] |
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| [A] Aeronautics and space | |
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Research on-board the ISS About 200 experiments have already been carried out on the International Space Station (ISS) or are still in progress, and at least 500 more are planned over the next five years. They range from Earth observations to proving the worth of technologies for industry, including many that study the effect of microgravity and space radiation on animal, plant and human biology. Recently, much of the focus of ISS experiments has been to refine technologies that will help in exploring beyond the Moon to Mars. For example, how to handle liquids and colloids in the microgravity of space is a wide-ranging issue. [A][G][H][M][P][T]
Effect of space on bacteria It is well known that space flight alters cellular and physiological responses in astronauts including their immune response. Now researchers have found that space flight also alters bacteria. They sent flasks of Salmonella typhimurium bacteria aboard the Space Shuttle Atlantis in September 2006. Identical cultures were grown at the Kennedy Space Center in Florida at the same time, and both batches were examined genetically and tested in mice. The researchers found that, compared to bacteria that remained on Earth, the space-travelling Salmonella had changed expression of 167 genes, and their virulence was almost three times higher. [A][H]
Birth of space exploration Celebrating the 50th anniversary of the launch of Sputnik, Physics World has a review of the early years of space exploration. [A][P][T]
Dawn mission The Dawn spacecraft has been launched on its mission to explore two giant asteroids, Vesta and Ceres, in the asteroid belt between Mars and Jupiter. The spacecraft's ion propulsion has now been successfully tested in space and it is on course to pass Mars in 2009 and reach orbit around Vesta in 2011. In 2012 it will set off from Vesta to reach Ceres, a dwarf planet, in 2015. Vesta is roughly 500 km in diameter and comprises a rocky core with a surface of solidified lava. Ceres in contrast is a dwarf gas planet. A major objective of the mission is to discover how these two very different types of bodies could have formed in the same region. The Dawn spacecraft is carrying a high-definition camera and two spectrometers. The information it gathers will help in understanding the first stage of the solar system's creation 4.6 billion years and what kinds of elements form terrestrial planets such as Earth, Mars, Mercury, Venus and Ceres. Had Vesta and Ceres not been so close to Jupiter they might both have grown into full planets. [A][P]
Kaguya mission A Japanese spacecraft has been launched on a mission to study the origin of the Moon. Called Kaguya, it is the most advanced spacecraft sent to the Moon since the Apollo missions in the 1970s. The spacecraft is equipped with a wide variety of instruments, including ground-penetrating radar that will investigate the Moon's structure down to a few kilometres below the surface. Spectrometers will reveal the distribution of minerals on the Moon's surface, a laser altimeter will map its topography and a high-resolution camera will image its surface in detail. A high-definition television camera will capture movies of the Earth rising above the Moon's horizon to send back to Earth. Kaguya is also carrying two small probes which it will launch into orbits around the Moon. The trajectories of all three craft will be precisely measured to build up a detailed map of the Moon's gravity field. [A][R]
Water on Mars New high-resolution pictures and infrared spectra recorded by NASA's Mars Reconnaissance Orbiter (MRO) tend to support the view that Mars had liquid water only for brief periods during an otherwise cold and dry history. The images have shown branched channels and fanlike deposits adjacent to several large craters. These may have been produced by the flow of water, perhaps when meteoroids slammed into an ice-rich crust. However, a 300-kilometre-long system of channels called Athabasca Valles, which in previous lower-resolution images showed some resemblance to a frozen sea, seems more likely from the MRO images to be a remnant of a once-swollen river of lava. [A][R] |
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| [U] Unmanned vehicles and robotics | |
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Mars Rovers NASA's Mars Rovers, Spirit and Opportunity, have survived the global Mars dust storms that have raged for two months. The two rovers are proving remarkably rugged. They are now 44 months into a missions originally planned to last only three months. Spirit has climbed onto its long-term destination called Home Plate, a plateau of layered bedrock bearing clues to an explosive mixture of lava and water. Opportunity is descending into the giant Victoria Crater. This contains an exposed layer of bright rocks that may preserve evidence of interaction between the Martian atmosphere and surface from periods in the past when the Martian atmosphere might have been different from today. [U][A]
Self-aware robots Though the Mars rovers have survived remarkably, the speed at which they have been able to explore Mars has been very slow. Hazard avoidance software restricts them to a 10 seconds of movement followed by 20 seconds of standing still so that the area ahead can be carefully scanned for potential dangers. According to simulated rover designed at the University of Vermont, future robots could explore alien terrain much faster if they were equipped with an innate sense of self and an insatiable curiosity. [U][A][R]
Tripedal robot A three-legged robot with an unconventional and graceful walk has been developed by US researchers. Like humans, it exploits gravity to save energy with each step, but it also flips its entire body upside-down with each stride. The robot is not designed to be a load carrier, but to deploy sensors to difficult-to-access areas. [U][R][S]
LittleDog DARPA has created a common robot platform called LittleDog on which research groups are competing to develop the best algorithms for controlling the robot puppy. The agency hopes this will help identify the best adaptive strategy for moving over irregular surfaces. [U]
Robots and gadgets for the elderly On present trends about 40 percent of Japan's population will be elderly by 2050. Companies have been developing high-tech gadgets and robots to assist the elderly, but these are not proving popular. The elderly find high tech products too complicated to understand and too difficult to use. They are costly to develop and manufacture, and often require supervision to use so that there is no economic benefit. Devices to monitor health are also not popular. Among the most high-profile failures was Hopis, a furry pink dog-like robot capable of monitoring blood sugar, blood pressure and body temperature. [U][H][I][K][S][V]
Robotic surgery As NASA sets its sites on manned missions back to the Moon and as far away as Mars, it is testing how well robotic technology could provide adequate medical care for astronauts during such extended spaceflights. On board a military C-9 aircraft flying in parabolic arcs over the Gulf of Mexico, four surgeons and four astronauts performed simulated surgery by hand and by using a robotic device developed by SRI International. The purpose was to determine if the robot's software can compensate for errors in movement that can occur during turbulence and under varying gravitational conditions. [U][A][H][V]
Emulating human vision A computer program that emulates the human brain turns out to fall for the same optical illusions humans do. This suggests the illusions are a by-product of the way babies learn to filter their complex surroundings. Researchers say this means future robots must be susceptible to the same tricks as humans are in order to see as well as us. [U][B] |
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| [P] Propulsion and energy | |
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Ion engine An ion engine prototype developed at NASA's Glenn Research Center has now accumulated more than 12,000 hours of operation and processed over 245 kilograms of xenon. This sets a new record for most propellant throughput ever demonstrated by an ion engine. [P][A]
Hydrogen-powered vehicles Toyota has announced that its new hydrogen powered fuel-cell car successfully completed a 350 mile road test on a single fuelling and finished with 30 percent of the hydrogen still in the tank. The car is 25 percent more fuel efficient than earlier versions, thanks to improvements in fuel cell technology. [P][E]
King Review on low carbon cars One year on from the Stern Review, the UK government has published an interim report on the scope for achieving emissions savings from low carbon cars. The report takes a comprehensive look at the technology options: cleaner fuels, more efficient vehicle technologies, and smart consumer choices. It uses a holistic framework that takes account of all of the carbon produced by manufacture, distribution and use of fuels and vehicles, including driving efficiency. In the shorter term, by adopting a small selection of the most cost-effective technologies for improving vehicle efficiency, a 30 percent savings could be achieved for the average vehicle relative to today’s equivalent model, for an additional production cost of around £1,000 to £1,500 per vehicle. This gives a much lower abatement cost than, for example, switching to biofuels. [P][E]
Magnetically enhance biofuels Researchers in Brazil have reported that they have boosted the production yield of ethanol from sugar cane by 17 percent and shaved two hours off of a 15-hour fermentation process simply by circulating the fermentation brew past six magnets with a combined field strength of 20 milliteslas. The results confirm similar findings in 2003. Magnetic fields are known to affect microbial and mammalian cells. [P][M]
Photosynthetic hydrogen Algae may be a good source of biofuels: besides being easy to grow and handle, some varieties are rich in oil similar to that produced by soybeans. Algae also produce hydrogen, and researchers at UC Berkeley say that genetically engineered algae might provide a viable source of photosynthetic hydrogen fuel. [P][G]
New nuclear power The New Jersey-based company NRG Energy has applied to build the first new nuclear power plant in the US in more than 30 years. The project will have to contend with public opposition to nuclear energy and also with a shortage of relevant expertise and manufacturing capacity due to the 30-year gap. [P][M][K][W]
Photocatalytic production of hydrogen Researchers at Max Planck have found that titanium disilicide acts as a photocatalyst that enables sunlight to split water into hydrogen and oxygen. The material also stores the gases produced and this allows them to be separated easily. The oxygen is released only at temperatures over 100 degrees C and in darkness, whilst the hydrogen is easily released at lower temperatures. [P][M]
Solar-thermal power Producing electricity by solar-thermal generation may already be cost competitive with conventional carbon-based power stations in areas with high levels of sunshine. Sunlight is used to convert water into steam that then drives a turbine. Proponents of solar thermal power also argue that storing energy thermally for use at night and on cloudy days is considerably more efficient than storing it electrically in batteries. Molten salts can store energy as latent heat when they melt and release it when they freeze. [P][M][O][T]
Nanowire generator Because even the tiniest battery is too big to be used in nanoscale devices, scientists are exploring nanosized systems that can salvage energy from the environment. Now, researchers at the University of Illinois have shown that a single piezoelectric nanowire can produce power by harvesting mechanical energy. The nanowire in the form of a single crystal of barium titanate was approximately 280 nm in diameter and 15 microns long. [P][N][S] |
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| [M] Materials, structures and surfaces | |
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Hydrogen storage materials Many materials have been investigated as potential candidates for high-capacity hydrogen storage. They include metal hydrides, metal-organic frameworks and functionalized carbon structures. The problem is that those materials that use chemisorption to store hydrogen in atomic form bind it too strongly and so the temperatures needed to release the hydrogen again are too high for practical applications. In contrast, with materials that hold hydrogen in molecular form, the binding is too weak and the required operating temperature is too low. Now computer simulations by scientists in China and the US suggest that electrically charged fullerenes might have the right binding energy for reversible hydrogen storage at room temperature and under near ambient conditions. [M][N][P]
Silicon grown at room temperature Crystalline and polycrystalline silicon films, used in solar cells, thin-film transistors and other electronic devices, are usually grown at high temperatures. Now, scientists at UCSB have shown that polycrystalline silicon films containing nanocrystals as small as 10?nm can be grown at room temperature from a plasma of silane heavily diluted with hydrogen. This could enable devices to be made on flexible substrates that cannot withstand high temperatures. [M][J][N][P]
TWIP-steel German researchers have developed a new type of steel that exploits so called twinning induced plasticity (TWIP) to give better crash protection for car passengers. In a crash, each part of the steel deforms to absorb energy but then strengthens. This provides better shape stability and also passes on the remaining deformation energy to the surrounding parts, which then also starts to deform. By dispersing energy over the whole surface, the collision is absorbed more efficiently. [M]
New aircraft material A new material called Central Reinforced Aluminium (CentrAl) makes aircraft wings immune to metal fatigue, according to researchers at Delft University, who developed the material in conjunction with industry. They say that using CentrAl reduces the weight of the wing by 20 percent compared to construction with carbon fibre reinforced plastic (CFRP) and the manufacturing and maintenance costs are also considerably lower. The CentrAl concept comprises a central layer of fibre metal laminate sandwiched between one or more thick layers of high-quality aluminium. This creates a robust construction material which is exceptionally strong as well as being insensitive to fatigue. [M][A][U]
Repairing fatigue-induced damage Researchers at Rensselaer Polytechnic Institute have developed a simple new technique for identifying and repairing small, potentially dangerous cracks in high-performance aircraft wings and in other structures made from polymer composites. By infusing a polymer with electrically conductive carbon nanotubes and then monitoring the structure’s electrical resistance, the researchers can pinpoint the location and length of a stress-induced crack. Once a crack is located, they send a short electrical charge to the area in order to heat up the carbon nanotubes and in turn melt an embedded healing agent. This flows into the crack, sealing it and providing a 70 percent recovery in strength. [M][A][N][W]
Superstrength magnets Superstrong permanent magnets have many applications - from cell phones and data storage to hybrid vehicles. Magnet strength depends on the product of the magnet's maximum magnetisation and maximum coercivity, measured in megaGauss-Oersteds (MGOe). Today's strongest neodymium magnets achieve 54 MGOe. But theory predicts that one could achieve 100 MGOe with so-called energy-spring magnets. These are nanocomposites with grains of magnetically hard materials, which have high coercivity, embedded in a soft phase with low coercivity and high magnetization. The two phases interact by exchange coupling, and the grain size of the hard and soft phases must be homogenously controlled at the nanoscale for the coupling to be effective. Conventional nanocomposite compaction cannot achieve this because it requires extensive heat treatment that causes excessive grain growth. However, researchers at the University of Texas have now shown that warm compactions can produce good composite material at temperatures low enough to avoid grain growth. [M][N]
Muscle films Thin sheets of polymer coated with living muscle could be used to test new drugs, repair damaged body parts, or even create life-like bio-machines, according to Harvard researchers. They created the "muscular thin films" by attaching muscle cells to elastic polymer sheets. By laying down striped patterns of proteins on these polymers, they were able to make the muscle cells arrange themselves into muscle fibres, similar to those in animals. [M][H][N]
Nano-ice coating Thin diamond coatings are being used increasingly in medical implants, such as prosthetics, artificial heart valves and joint replacements, in order to increase their wear resistance. However, diamond can cause clotting by attracting coagulating proteins. Also, its hardness often results in more tissue abrasion than with other implant materials. The solution could be to coat the diamond with nano-ice, according to researchers at Harvard. Using computer simulations, they predict that layers of ice a few nanometres thick can remain frozen at body temperature when grown on top of diamond sheets with a surface layer of sodium. [M][H][N]
Water bridge Water has many surprising properties. Austrian researchers have now found that when exposed to a high-voltage DC electric field, water in two beakers climbs out of the beakers and crosses empty space to meet, forming a water bridge. The scientists found that water was being transported from one beaker to another, usually from the anode beaker to the cathode beaker. The liquid bridge, hanging unsupported between the beakers, had a diameter of 1-3 mm and could remain intact when the beakers were pulled apart at a distance of up to 25 mm. [M] |
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| [E] Environment, transport and marine | |
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Biofuels could increase global warming When nitrogenous fertilisers are used to grow crops, microbes convert part of the nitrogen to nitrous oxide, a potent greenhouse gas. A new study led by Nobel prize-winning chemist Paul Crutzen has found that the amount of nitrous oxide produced is about twice as much as previously thought. This implies that first-generation biofuel crops may actually be contributing to global warming rather than reducing it. For rapeseed biodiesel, which accounts for about 80 percent of the biofuel production in Europe, the relative warming due to nitrous oxide emissions is estimated at 1 to 1.7 times larger than the relative cooling effect due to saved fossil carbon dioxide emissions. For corn bioethanol, dominant in the US, the figure is 0.9 to 1.5. Only cane sugar bioethanol appears to produce any net benefit. [E][P][X]
Ocean fertilising pipes Promoting more algae growth by fertilising the ocean's surface has been advocated as a way to absorb more carbon dioxide to reduce global warming. Two UK scientists have suggested a way to achieve this fertilisation by using wave power to pump nutrient rich water up to the surface from deep below. They propose using giant vertical pipes around 10 metres in diameter and 100-to-200 metres deep. As the pipe moves down, cold water flows up and out onto the ocean surface. A simple valve blocks any downward flow when the pipe is moving upwards. With an average wave height of one metre, each pipe might bring about five tons of water per second up to the surface. The oceans could be seeded with millions of such pipes, which might be tethered or free floating. The snag is that as well as being rich in nutrients, water rising up the pipes will be rich in carbon - this could mean carbon dioxide is released into the atmosphere. [E][P]
Earth's past temperature A new method makes it possible to determine more reliably how sea temperatures have varied during past geological ages. Previous methods required knowledge of the chemistry of seawater in the distant past, which is poorly known. The new method relies only on measuring the distribution of the isotopes oxygen-18 and carbon-13 in a single shell or coral. It exploits the fact that the amount of bonding between oxygen-18 and carbon-13 depends on the temperature of seawater in which the organisms lived. Applying the new method to determine the sea temperatures in the Silurian period roughly 400 million years ago and the carboniferous period, 100 million years later, showed a strong correlation between temperature and previous estimates of past atmospheric concentrations of carbon dioxide. This provides further evidence of the role of atmospheric carbon dioxide in driving past global warming and cooling. [E]
What ended the Ice Age? Ice cores have shown that the endings of recent ice ages were accompanied by an increase in atmospheric carbon dioxide. Scientists have debated whether carbon dioxide triggered the warming or was released by an already warming sea and just accelerated the warming. Now a new study suggests the latter. The evidence comes from a sediment core from the western Pacific composed of fossilized surface-dwelling (planktonic) and bottom-dwelling (benthic) organisms. These organisms – foraminifera – incorporate different isotopes of oxygen from ocean water into their calcite shells, depending on the temperature. By measuring the change in these isotopes in shells of different ages, the researchers were able to reconstruct how the deep and surface ocean temperatures changed through time. They found that at the end of the most recent ice age, deep sea temperatures warmed about 1,300 years before the tropical surface ocean and well before the rise in atmospheric carbon dioxide. Warming appears to have started in the Antarctic at the time of the increased springtime solar radiation over Antarctica 19,000 years ago, which suggests this might have triggered the change. [E]
Stone age extinction What caused the extinction of mammoths and the decline of Stone Age people in North America about 13,000 years ago remains hotly debated. The possibilities include climate change, disease and overhunting by paleoindians. However, researchers have now found evidence that the cause may instead have been a comet impact. The evidence comes from a four-inch-thick “black mat” of carbon-rich material that marks the extinction. This mat occurs as far north as Canada, Greenland and Europe to as far south as the Channel Islands off the coast of California and eastward to the Carolinas. The mat includes nanodiamonds and fullerenes containing a concentration of helium 3 many times greater than found in the Earth’s atmosphere. Both features indicate extraterrestrial origin. The team believes the comet was two and a half to three miles in diameter and that it detonated 30 to 60 miles up with an explosive energy equivalent to 10 million megatons of TNT. [E]
Sustainable agriculture Indigenous breeds of livestock and chickens are being replaced by breeds that give higher yields of meat, milk and eggs, but which are less hardy. A good example is the black and white Holstein-Friesian dairy cow which has high milk yields and is now found in 128 countries and all of the world's regions. These cows cannot easily survive drought because they cannot walk long distances to find water. Agricultural researchers are calling for measures including the creation of regional gene banks that can save drought-resistance and disease-tolerant breeds that have evolved over thousands of years and are likely to be needed in the future to cope with climate change and outbreaks of indigenous diseases. Another recommendation calls for wider use of 'landscape genomics'. This approach involves using advanced genomic and geographical mapping techniques to predict which breeds are best suited to which environments and future circumstances around the world. [E][D][G]
Thundercloud bremsstrahlung It has been known for over a decade that 10 - 20 MeV gamma rays are produced during electrical storms. Now researchers at Japan’s RIKEN research institute have measured the energy distribution of a 40 second long gamma ray pulse during a very intense thunderstorm on 6 January 2007. This has confirmed that the pulse was made of bremsstrahlung and that its source was in the storm. The pulse arrived about a minute before the first lightning strike, which suggests it was produced while electrical energy was building up in the thundercloud. It is likely the process begins with a cosmic ray passing through the cloud and ionizing the air to produce electrons that are then accelerated towards the bottom of the cloud. These ionize atoms on the way and create a stream of high-energy electrons that produce the bremsstrahlung as they collide with and are deflected by atoms in the air. [E][A][P] |
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| [R] Remote sensing and sensor systems | |
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Sharpest ever images Researchers at Cambridge University and Caltech using the 200-inch telescope at the Palomar Observatory have produced the sharpest images of stars every achieved, either with space-based or ground-based telescopes. Images from ground-based telescopes are normally blurred by fluctuations in the atmosphere. But by using a combination of adaptive optics and so-called lucky imaging, the researchers obtained images that were twice as sharp as those of the space telescope. Lucky imaging is a widely used technique that exploits the fact that the atmospheric smearing fluctuates so that some images are less smeared than others. By taking a large number of images at a high frame rate and using computer software to select the best and combine them, the researchers produced their exceptionally sharp images. The technique can be applied to other large ground based telescopes. [R][A][C][O]
World-size radio telescope A radio telescope in Australia has been linked in real time to another in China and five in Europe, effectively creating a telescope almost as big as the Earth. [R][A][C][O]
New astronomical phenomenon Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say is unlike any radio signal detected before and may be a new type of astronomical phenomenon. This burst was strong but lasted only 5 milliseconds. Its frequency dispersion indicates it originated around 3 billion light years away. It may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole. The astronomers estimate on the basis of their results that hundreds of similar events should occur over the sky each day, but are not detected because it is so difficult to spot such short-duration bursts with current instruments. [R][A][F]
GigaPan imaging Researchers at Carnegie Mellon University, in collaboration with scientists at NASA Ames, have built a low-cost robotic device that enables any digital camera to produce gigapixel panoramas (GigaPans). The tripod-like robotic mount enables a digital camera to take hundreds of overlapping images of landscapes, buildings or rooms. Then, these images are digitally stitched together into a single image. The GigaPan camera system is part of a larger effort called the Global Connection Project whose purpose is to make people all over the world more aware of their neighbours. Children in various locations round the world will use the GigaPan camera to share images of their neighbourhoods, lives and cultures. [R][E][K][U][V][X]
Bird navigation For many years, scientists have known from behavioural experiments that migrating birds use an internal magnetic compass to navigate on their epic annual journeys. But exactly how the system works has been a mystery. Now research at the University of Oldenburg in Germany has found that specialised neurons in the eye, sensitive to magnetic direction, connect to a specific brain pathway to an area in the forebrain of birds that is responsible for vision. This suggests that the birds may be able to see the direction of the Earth's magnetic field as some form of visual pattern. [R][B][E][S]
Assured GPS accuracy The US DOD has retained the capability to degrade the accuracy of GPS if this is militarily necessary. However such degradation capability has been an increasing problem as civilians and civil systems have come to rely increasingly on high precision GPS. The DOD says it has now overcome this problem and can reduce the accuracy of signals received by civilians within a small area without needing to degrade the accuracy elsewhere. [R][A][D][E][I][U]
Imaging inflammation A technique that enables MRI scans to reveal areas of inflammation has been developed at Oxford University. It uses a marker that can be injected into the blood stream and attaches itself to particular molecules causing them to light up on MRI scans. The molecules, called VCAM-1, play a key role in inflammation in many diseases, including multiple sclerosis, arthritis, inflammatory bowel disease and atherosclerosis. The new technique has the potential to reveal disease activity much earlier and, crucially, before tissue destruction has occurred. [R][B][H]
Face recognition NEC has launched two new series of laptops with a unique security feature called "face pass" that uses a combination of eye zone extraction and facial recognition to identify the computer’s user. NEC says that the system performs accurate matching even when people wear glasses and hats, have different haircuts or facial hair, and show different facial expressions. To program the system, a user sets up a profile with three photographs of their face. Then when a user tries to log on, an integrated 2.0 megapixel camera scans their facial characteristics. NEC originally developed the technology for security applications, such as border control, prison management and corporate security. Recently, NEC announced the first automated border control system to use facial recognition technology that can identify people inside their cars. At checkpoints on the Hong Kong-Shenzhen border, the system reads a car’s license plate, and compares the driver’s face with the registered driver’s micro-chipped ID. [R][A][C][D][I][K][V]
Remote teraHertz sensing TeraHertz radiation (T-rays) would have advantages of mm-wave imaging for security applications because their shorter wavelengths would mean that T-ray imagers could be more compact and could give higher resolution images. The problems, however, are that there are currently no T-ray sources that are cheap and convenient enough for practical use, and T-rays are also absorbed quite strongly by the atmosphere, so that T-ray imaging only works at close range. Researchers in France report that they may have found a way to reduce the absorption problem by using a laser to generate a T-ray beam close to a distant target. They used a femtosecond laser whose output pulses were sufficiently intense that they were self-focussed by the atmosphere and ionised the air to produce hair-thin plasma filaments. The laser output was split into two parallel beams that created two parallel filaments. Discharges between the two filaments produce a beam of T-rays concentrated along the direction of the laser beams. The T-ray source can be generated at quite long ranges, possibly up to 1 km. [R][O][S]
Imaging entanglement Scientists have found that neutron beams produced at particle accelerators and nuclear reactors can be used to produce images of quantum entanglement. They observed the effects of entanglement in antiferromagnetic materials and now plan to apply the technique to high temperature superconductors and the design of quantum computers. [R][M][O] |
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| [S] Sensor devices | |
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Quick H5N1 detection A multinational team of researchers has developed a system that can detect the bird flu virus on a throat swab specimen in less than 30 minutes. Having a low-cost, easy-to-use test that could quickly identify the earliest cases of bird flu would greatly increase the ability to contain and combat a human H5N1 epidemic. The handheld system uses magnetic particles and permanent magnets to isolate, purify, and concentrate viruses contained in small droplets. The sample then undergoes testing by polymerase chain reaction (PCR) to identify the viral RNA. [S][D][H]
Lung cancer screening Part of the reason that lung cancer is so deadly is that it is usually not detected early enough before it has had a chance to spread. There has been no effective screening test for lung cancer. But now a US pharmaceutical company in Maryland believes it has found a simple blood test that can identify early lung cancer. The test works by detecting a protein called human aspartyl beta-hydroxylase (HAAH), which is linked to tumour growth. In preliminary tests the process correctly identified 99 percent of patients with lung cancer at various stages of development including people at the earliest stage. [S][G][H]
Measuring spin Using a new technique called low-temperature spin-polarized scanning tunnelling spectroscopy - essentially a scanning, tunnelling microscope that can probe the spin and energy-dependent electron density of a surface - researchers at UC Berkeley have succeeded in measuring the spin of isolated atoms. Being able to measure how individual spins couple to one another is important for both quantum computing and spintronics. [S][C][J][M]
Colossal phonoresistance The material manganite, which shows colossal magnetoresistance, has also been found to show colossal phonoresistance. A sharp burst of phonons can cause its resistance to fall by five orders of magnitude, according to physicists in the UK, US and Japan. The researchers fired a short terahertz (THz) laser pulse at a manganite sample while monitoring its electrical resistance. When the energy of the laser was tuned to a phonon frequency of about 17 THz, the resistance of sample dropped dramatically for about 5 ns before returning to its original value. The colossal phonoresistance effect might be used to make THz radiation detectors and other THz optoelectronic devices. [S][M]
Radio wave cooling Researchers at NIST have cooled a micron-sized cantilever using a process called capacitive cooling, in which the cantilever, pelted with radio waves, slows down by transferring energy to the surrounding radio frequency resonant circuit. The technique may allow macroscopic objects to be cooled to extremely low temperatures where they may show quantum mechanical behaviour. It might also be useful for cooling sensors. [S][J][M][N][O]
Filming molecular interactions Scientists at Cambridge University have succeeded for the first time scientists in filming a DNA-enzyme interaction in real time. They used a Scanning Atomic Force Microscope in Japan to film of a protective bacterial enzyme unravelling the DNA of a virus trying to infect the bacterium. This new capability give a clear view of the molecular interactions between proteins and DNA that previously could only be interpreted indirectly. This will help, for example, in finding how enzymes manage to latch on to the right point in a DNA molecule and in understanding processes such as DNA repair. [S][G][N] |
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| [O] Optoelectronics, optics and lasers | |
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X-ray microscopy US researchers have shown that lensless X-ray microscopes do not necessarily need large accelerator-based X-ray sources. Instead, a technique called high-harmonic generation can be used to make smaller “tabletop” X-ray microscopes based on a compact infrared laser. [O][G][J][N][O][R][S]
Focusing hard x-rays A team of researchers at Brookhaven National Laboratory have demonstrated a compound refractive lens that should with further development allow hard x-rays to be focused down to nanometre spot sizes suitable for probing chemical and biological materials and molecules with 1 nanometre resolution. [O][G][M][N]
Superlens material The resolution of a conventional lens is limited by diffraction to around one wavelength, making it impossible to use visible light to image very small objects. In contrast, a superlens, which is made using a material with negative refractive index, is capable in principle of perfect focusing. The problem, however, is to find a negative refractive index material that is sufficiently transparent at visible wavelengths. US and German researchers have now calculated that it should be possible to achieve this by using a new technique called electromagnetically-induced chirality (EIC). [O][S]
Plasmonic metamaterials A new fabrication technique, called soft interference lithography (SIL) and developed at Northwestern University, makes it possible to inexpensively produce large sheets of gold films with virtually infinite arrays of perforations and microscale "patches" of nanoscale holes. It could open the way for producing plasmonic metamaterials and devices in large quantities and for using such devices in practical optical systems. [O][J][M][N][S]
Much brighter quantum dots The fluorescence of quantum dots has been increased by a factor of over 550 by placing them on plastic sheets of photonic crystal tuned to the wavelength of a UV laser used to stimulate the quantum dots. Potential applications include high-brightness light-emitting diodes, optical switches and biosensing. [O][G][N][S]
Photonic matter It may be possible to create new forms of matter made entirely of light, according to theoretical research at Imperial College. Photons can be stored for relatively long times inside cavities in the form of microscopic doughnut of silicon. By implanting a few atoms of a different type in the silicon and by driving these atoms with laser light in the right way, one can induce a so-called photon blockade whereby the cavity-plus-atoms will accept only a single photon, repelling efforts to inject any further photons. This effect has been demonstrated experimentally for a single cavity. If one built an array of cavities, the single photons could hop from cavity to cavity repelling each other and acting rather like electrons in some exotic solids. The Imperial theorists have now shown how the repulsion between the photons can be increased by more than a factor of ten. This, they suggest, should make the repulsion strong enough to produce a photonic "Mott insulator" state in which the photons in different cavities would create a log-jam, each preventing neighbours from hopping. [O][C][F][M]
Polymer-based laser UCLA chemists have invented an inexpensive way to make luminescent polymer chains line up inside a silica host material. The aligned chains absorb and emit polarized light strongly, and can all contribute to emission in a polymer-based laser, producing polarized light without the need for any external optical elements. The chains also produce a graded index waveguide that confines the light in the host material. This and the alignment make it very much easier to achieve lazing. The technology may enable laptop LCD displays to be made brighter whilst also consuming less power. [O][N][V]
White light LED Researchers in India have developed a white light LED based on a new phosphor made from nanocrystals of cadmium sulphide mixed with manganese. They say that it produces a stable shade of white light that remains constant over time and appears superior in overall performance in comparison to previous generations of white LEDs. [O][J][M][N]
IC-compatible single photon source Researchers at Yale have created a single-photon source compatible with integrated circuits. The source is based on a superconducting tunnel junction qubit inside a 2 dimensional wire. This can transmit microwave photons carrying quantum information from one part of an integrated circuit to another. [O][C][I][J] |
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| [I] IT, communications, networking and secure systems | |
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Municipal Wi-Fi networks Ambitious plans for metropolitan Wi-Fi networks to provide free or low-cost wireless Internet access are being abandoned or scaled back by some US cities including San Francisco and Chicago. Cities and corporations are finding that because Wi-Fi does not penetrate buildings well, many more access points are needed than was expected. Other problems are poorer than expected growth in Wi-Fi subscribers and the risk that expensive municipal Wi-Fi infrastructure could be quickly overtaken by newer technologies including WiMAX. [I]
Wi-Fi reliability Wi-Fi tends to be an unreliable form of wireless communication, in part because the set of instructions that governs how it passes data through the air was never designed for the widespread use that Wi-Fi currently experiences. Network administrators try to fix Wi-Fi problems by looking at a number of things that could interfere with a signal: hardware malfunctions, software bugs, and outside devices such as microwave ovens and cordless phones. But these can all change quickly, making Wi-Fi failures difficult to anticipate and nearly impossible to accurately diagnose retrospectively. To address this problem, researchers at UCSD have developed a real-time system that comprehensively monitors and analyses Wi-Fi activity in a building to diagnose problems as they arise. [I][K]
100 Gbit/second Internet The Internet2 network parallels the regular Internet to provide ultra-fast communication for universities, corporations and researcher projects, notably the Large Hadron Collider. The network can now transmit data at 100 Gbits/second by using 10 different wavelength beams in one optical fibre. [I][K]
Virus-hard processor NEC has developed an anti-virus technology that removes viruses at CPU-level. It runs software in separate processes on each core of a multi-core CPU and is designed to spot a virus in any of the software processes and immediate isolate and shut down that core. This allows the device to continue operating whilst anti-virus updates are created and then downloaded from the Internet. The technology can be applied to cell phones, cars, and potentially to computers. [I][C][D][K][W]
How cybercrime is changing Internet crime has become increasingly professional and is now a multi-billion dollar industry, according to a report by computer security company Symantec. The underground economy is becoming more specialist. It has its own auction sites and marketplaces that sell valuable data such as credit card numbers and bank accounts, plus toolkits for novice cyber criminals. The production of new malicious programs is accelerating rapidly. There are signs that different sections of the underground economy are starting to collaborate to improve their chances of catching people out: high tech criminals with information culled from job sites, online games or social networking sites are teaming up with phishing gangs and spammers. [I][D][K]
Threat of information warfare Cyber attacks are mainly done by criminals or spammers. However, cyber warfare between countries has long been an issue of concern and as societies become increasingly cyber-dependent, the cyber warfare risk is becoming a serious concern. The finger is pointed particularly at China, whose stated military goals include improving the country's ability to wage information warfare. [I][D][I][K][W][X] |
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| [K] Knowledge, information and technology management | |
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Semantic web and bioinformatics The semantic web is an evolving extension of the World Wide Web in which web content can be expressed not only in natural language but also in a format that can be read and used by software agents. This enables them to find, share and integrate information more easily. So far, it has been little used. But it may soon be adopted by the big drug companies. The pharmaceutical industry is swimming in an ocean of data that need to be parsed and channelled into useful information. But just having data is not enough: competitive edge comes from systems and processes for analyzing data in the development of therapies. Companies are also trying to practice open innovation - using data from any available source, not just from within their own laboratories. This implies flexibly organising the oceans of data and being able to share this across the industry. The semantic web looks promising for this and its uptake could be the spur that makes it take off just as the world wide web did in 1995. [K][G][H][T][W][X]
Innovative management In an article in McKinsey Quarterly, two leading business gurus, Gary Hamel and Lowell Bryan, discuss how organisations and management are going to be transformed by digitisation, globalisation and the cyberspace revolution, by the emergence of thinking-intensive industries and the Web’s capacity to help aggregate and amplify human potential in new ways, and by the need to create organizations in which innovation is truly everyone’s responsibility. [K][T][W]
Formal knowledge networks Most large corporations have dozens if not hundreds of informal networks through which people share ideas and collaborate. These are a powerful source of horizontal collaboration across thick silo walls, but as ad hoc structures their performance depends on serendipity and they cannot be managed. By creating formal networks, companies can harness the advantages of informal ones and give management much more control over networking across the organization. An article in McKinsey Quarterly discusses the steps needed to formalize a network include giving it a “leader,” focusing interactions in it on specific topics, and building an infrastructure that stimulates the ongoing exchange of ideas. [K][W] |
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| [C] Computing, supercomputing, modelling and simulation | |
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Superconducting quantum bus Researchers at NIST and Yale have independently demonstration the first superconducting quantum bus that can transfer information between two qubits on a microchip. The bus allows selected qubits to communicate directly whilst bypassing qubits in between. It could enable many qubits to be joined together to make a full-scale quantum computer using standard chip manufacturing processes. Both teams created the bus from a squiggly superconducting wire between two superconducting qubits. In the Yale design, a virtual microwave photon transmitted along the bus coupled the two qubits, showing how qubits can be entangled to other remote qubits via a quantum bus. In the NIST design the bus resonates at a microwave frequency and can store quantum information as a standing wave as well as transmitting it between the two qubits. This resonant bus also offers a means of “refreshing” superconducting qubits to extend their coherence time. The NIST researchers believe that with design improvements, the technology might be used to repeatedly refresh the data and extend qubit lifetime more than 100-fold, sufficient to create a viable short-term quantum computer memory. [C][J]
Assessing quantum computer architectures In a future quantum computer, the loss of coherence caused by noise can hopefully be kept at an acceptable level with error-correction schemes. These use several noise-prone qubits to perform the role of one noise-free qubit. Making this work requires a good understanding of how noise affects the qubits and this depends on the specific design of the computer and type of qubit. The effects of noise can be measured using a technique called quantum process tomography, but this involves mapping all the possible states of the computer and requires an impractical number of measurements - four billion with eight qubits, for example. Fortunately, US researchers have now developed an approximate method that requires sufficiently few measurements that it could provide an efficient and practical way of comparing decoherence for different architectures. [C][O]
Acoustic quantum dots A quantum dot is a semiconductor nanostructure that confines the motion of electrons, holes or excitons (bound pairs of electrons and holes) in all three spatial directions. The confinement can be produced electrostatically, by interfaces, or by physical surfaces as in a semiconductor nanocrystal. Quantum dots can also be produced dynamically by the electric fields of surface acoustic waves, so that the acoustic dot travels along with the wave. Researchers at Cambridge have now observed electrons tunnelling into and out of such quantum dots. If, electrons in two very close acoustic wave channels could be entangled, this might produce a sort of flying qubit that could provide another approach for producing a quantum computer. [C][J][M][N][O] |
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| [W] Whole life engineering, manufacture and testing | |
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Designing secure networks A short article in physicsworld.com lists some good tips for designing and writing secure software, as used in the CERN grid computing network. [W][C]
Designing age-friendly cities WHO has published a guide on how to make cities more age-friendly. Altogether 35 cities in 22 countries from all continents participated in the study, which has produced a checklist of age-friendly features that planners should provide. Today there are 650 million people in the world aged 60; this number will increase to 1.2 billion by 2025 and to 2 billion by 2050. About half the world's population currently lives in cities; by 2030 this will increase to about 60 percent. These trends are occurring at a much faster rate in the developing world: currently, the number of older people in developing countries is about twice the number in developed countries. By 2050, some 80 percent of the older people will be living in less developed regions. [W][E][H][I][K][P][R][T][U][V][X]
Outsourcing and productivity In a globally competitive marketplace, companies are trying to introduce efficiencies wherever they can to improve their financial performance. One way they do that is by designing, or redesigning, jobs to make them more narrowly focused on specific tasks. However a US study has found that while this may improve productivity in the short term, it may lead to lower employee job satisfaction, higher levels of stress and poorer productivity in the long term. This may reduce the long term productivity benefits from outsourcing. [W][K] |
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| [X] Systems, complexity and risk | |
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Urban systems The European Commission has published as paper on urban mobility. It lists five key challenges that urban transport systems need to address, namely congestion, environmental issues, transport infrastructures, accessibility and safety. A core theme is that, to be effective, urban mobility policies need to be based on an approach which is as integrated as possible. It sets out options for tackling each of these challenges and the role that can be played by research and new technology such as intelligent transport systems, energy efficient vehicles, alternative fuels, night vision, collision avoidance and sleep warning sensors. [X][E][I][K][M][P][R][S][T][U][V]
Crowd dynamics Pressure waves travel through tightly-packed crowds on the verge of panic according to researchers who have studied CCTV footage of the stampede on Saudi Arabia's Jamarat Bridge during the Hajj of 2006. Low density crowds move in smooth flows like a fluid. But, the study showed that this broke down above a density of seven people per square metre. Sharp compression waves then moved through the crowd every 45 seconds, shifting people back and forth. At even higher densities, the crowd's movement became turbulent. Each person was jostled in random directions and one shove could affect people up to 12 metres away. Understanding this behaviour may help in spotting dangerous crowd situations in the future. [X][D][M]
Implementing Stern: post Kyoto agreement One year on from the Stern Review, the UK government has published a report that takes stock of progress and provides a forward look at what is needed in the new international agreement to replace the Kyoto agreement beyond 2012. The report cites 8 key requirements: a long-term goal of reducing global greenhouse gas emissions by at least 50 percent by 2050 on 1990 levels; deeper absolute emission reduction commitments by all developed countries; further fair and effective contributions by other countries; extending the carbon market, including innovative and enhanced flexible mechanisms; increasing cooperation on technology research, development, diffusion, deployment and transfer; enhancing efforts to address adaptation, including risk management instruments, finance and technologies for adaptation; addressing emissions from international aviation and maritime transportation; and reducing emissions from deforestation and enhancing sinks by sustainable forest management and land use practices. [X][A][C][D][E][K][P][R][T][W] |
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| [V] Virtuality and human-machine interface | |
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Power-efficient displays A new display technology called frustrated total internal reflection (FTIR) could, it is claimed, make handheld displays 60 percent more efficient, substantially extending the battery life of mobile devices. FTIR uses a membrane with microscopic structures on it that bend light toward a viewer. This membrane is separated from the screen by a thin air gap. When the membrane comes in contact with the screen, a pixel turns on, letting light through to the viewer. The membrane can be switched sufficiently quickly that time multiplexing can produce a colour display using light from 3 pulsed LEDs - one red, one green and one blue - to produce three RGB superimposed images. [V][I][O]
Larynx control system A motorised wheelchair that moves when the operator thinks of particular words has been demonstrated by a US company. The technology could help people with spinal injuries, or neurological problems like cerebral palsy or motor neurone disease, to operate computers, wheelchairs and other equipment despite serious problems with muscle control. The operator wears a sensor-laden neckband that picks up signals sent from the brain to the muscles of the larynx, even when no sound is actually produced. The signals are then matched to pre-recorded "words" stored during training exercises. [V][B][H]
Exoskeleton The weight of kit that has to be carried by troops is a big problem in difficult terrain, such as in Afghanistan. Researchers at MIT have developed a leg exoskeleton capable of carrying an 80-pound load without the use of motors. They say the prototype can support 80 percent of this weight while using less than one-thousandth of a percent of the power used by its motorized equivalents. Tests show the current exoskeleton interferes too much with the user's gait, increasing the energy expended in walking. But the MIT group believes that it should be possible to overcome this problem by carefully selecting and angling the springs. [V][D][U] |
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| [B] Brain research and human science | |
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Biological basis of intelligence Recent neuroscience studies suggest that intelligence is not determined by any single brain centre or any single neuroanatomical structure; rather it is related to how well information travels throughout the brain. Now from a review of 37 imaging studies related to intelligence, researchers at UC Irvine and the University of New Mexico believe they have identified that intelligence depends on the efficiency of a network integrating areas in the parietal and frontal lobes. [B][G][K]
How the brain is partitioned In the cerebral cortex, various specialised areas carry out different functions. The back of the cortex is predominantly specialized to process vision, whereas the front of the cortex handles motor functions and controls voluntary movement, as well as having a central role in higher cognitive functions. The area right above the ear handles sounds and speech, while the somatosensory area located in the middle top of the head interprets information about touch and pain. However little is known about what controls this patterning and how the area taken up by each function is controlled. It was known that a gene Emx2 instructs progenitor cells to develop into visual neurons. Now the team that uncovered the role of Emx2 has found that another genetic factor called COUP-TF1 prevents progenitor cells from taking on a motor area identity. In mice genetically engineered to have low levels of COUP-TF1 the frontal areas expand crushing the other areas to the back of the brain. [B][G]
Evolution of cognition When trying to understand someone's intentions, people including young children anticipate that others will act rationally by performing the most appropriate action allowed by the environment. Researchers at Harvard have now found that non-human primates also have this ability. The findings, from one of the broadest comparative studies of primate cognition, were consistent across three different species of primates. This suggests that this rational cognitive ability probably evolved as long as 40 millions years ago. [B][G]
Higher social skills Researchers have compared 105 2.5-year-old human children, 106 chimpanzees and 32 orangutans in a comprehensive battery of physical and social cognitive tests to identify what skills are distinctly human. The results show that the children are much better than the apes in understanding nonverbal communications, imitating another's solution to a problem and understanding the intentions of others. The findings support the cultural intelligence hypothesis that suggests that humans have distinctive social cognitive skills to interact in cultural groups. The researchers plan to systematically test a variety of primate species and eventually to compare this with the species' genomes as they become available in order to map out how cognitive ability has evolved. [B][G]
Chemistry of memory The mechanisms of memory in the brain are turning out to be much more complex than expected. A series of articles in Chemical and Engineering News summarises what is currently known about the complex chemical processes that underpin memory at the cellular level. Several companies are developing compounds that improve memory, but ethical issues abound. [B][G][H][N][T]
Insulin and Alzheimer’s Research in the last few years has raised the possibility that Alzheimer’s memory loss could be due to a novel third form of diabetes. Now scientists at Northwestern University have discovered why brain insulin signalling, which is crucial for memory formation, would stop working in Alzheimer’s disease. They have shown that a toxic protein called amyloid ß-derived diffusible ligand (ADDL) found in the brains of individuals with Alzheimer’s removes insulin receptors from nerve cells, rendering those neurons insulin resistant. The findings could help researchers determine which aspects of existing drugs now used to treat diabetes might protect neurons from ADDLs and improve insulin signalling in individuals with Alzheimer’s. [B][H]
Cause of depression The prevailing theory of depression is that affected people do not have enough of certain neurotransmitters called monoamines – serotonin, norepinephrine and dopamine – in the spaces between neurons. Most modern antidepressants work by blocking the absorption of these neurotransmitters back into the cell. It is not clear, however, what causes the levels of these neurotransmitters to be low. Now research at the University of Vienna has found evidence that in the case of people suffering from winter depression (SAD), the cause is that serotonin is being removed too fast. The researchers found that during winter a molecule called serotonin transporter (SERT), which "pumps" serotonin back into cells, was nearly twice as active in SAD-sufferers than in normal people. In contrast, in summer, when SAD symptoms disappeared, the SAD patients’ SERT activity slowed to normal levels. It is possible that SERT hyperactivity may be a factor in other forms of depression. [B][G][H] |
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| [H] Healthcare and medicine | |
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Treating obesity Scientists have discovered that a brain region called the melanocortin system controls whether excess energy is stored as fat or burned in the muscles. This system receives messages from the gut indicating whether it is hungry or full, and responds by causing the body to either take in or burn calories. Experiments in rats showed that when the melanocortin system is stimulated to increase activity, fat is metabolised, and when its activity is reduced, fat accumulation increases. This may provide a way to treat obesity. [H][B]
Hydrogen sulphide protection Researchers at the University of Alabama have shown that administering hydrogen sulphide directly into the heart significantly reduces tissue and cell damage caused by oxygen-starvation during a heart attack. In tests on mice, the hydrogen sulphide injection led to a 72 percent reduction in the amount of severe heart-tissue death caused by simulated heart attacks. The researchers have also shown that allicin in garlic may have cardiovascular benefit. Allicin breaks down into sulphur compounds that react with red blood cells to produce hydrogen sulphide. Recent reports from other researchers also indicate that inhaled hydrogen sulphide can induce a fully reversible “suspended animation” state in animals. [H]
Stress-protection and cancer Researchers at the Whitehead Institute have found that a protein heat-shock factor 1 (HSF1) that protects cells against heat shock, also helps cancer cells survive. HSF-1 and other heat-shock factors control heat shock proteins (HSPs) that guard against the abnormal activity of other proteins in the face of stressors such as heat and oxygen starvation. HSFs also influence an array of other genes involved in cell metabolism and other basic cell functions. It has long been known that HSP levels increase in many cancer cells. The researchers found that depletion of HSF-1 in diverse previously established human cancer cell lines strongly impaired their growth and survival, while having little effect on normal cells. Mice deficient in HSF-1 were found to be much less cancer-prone. These findings suggest that ancient protective mechanism that enable cells and organisms to cope with stresses such as heat-shock carry the penalty that they increase cancer. [H][G]
Anti-oxidants and cancer The possible anticancer benefits of anti-oxidants, such as vitamin C, have been a strong and controversial area of research for decades. The supposition has been that antioxidants grab volatile oxygen free radicals and thereby prevent them from causing DNA damage that can be involved in cancer. Now a team at John Hopkins has discovered in experiments on mice that antioxidants may be blocking cancer by a quite different mechanism. Rapidly growing tumours are often starved of oxygen, because they are growing rapidly and because they lack a good blood supply. The tumour cells can then be critically dependent for survival on a protein called HIF-1 (hypoxia-induced factor) that helps an oxygen-starved cell convert sugar to energy without using oxygen and also initiates the construction of new blood vessels. To do this, however, HIF-1 requires a supply of free radicals. The experiments revealed that antioxidants remove these free radicals and thereby stop HIF-1 functioning and thereby inhibit tumour growth. [H]
Sperm stem cells Stem cells that normally make sperm can be taught to make other tissues as well. This could provide men with a new source of stem cells that could be used to treat injuries, replace diseased tissue and perhaps regenerate organs. [H][G]
HIV vaccine blow Researchers have prematurely halted the much-anticipated trial of a new HIV vaccine, V520, after it failed to block or slow down infections. This is a major blow for the two-decade-long search for an AIDS vaccine. Conventional vaccines work by triggering the immune system into manufacturing antibodies against an infectious organism, but such vaccines have proved elusive for the rapidly mutating HIV. Therefore, researchers have focused on vaccines for training the immune system's T cells to recognise HIV. They were encouraged by studies that showed that monkeys receiving such vaccines against simian immunodeficiency virus, related to HIV, lived longer or had lower viral levels than usual. In the V520 vaccine, each of three HIV genes - gag, pol and nef - was inserted into a separate weakened adenovirus. Human cells infected by the viruses produced the gene products, giving T cells an advance exposure to them. Researchers must now find out why this approach has failed to provide protection. [H][G] |
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| [G] Genomics, biotechnology and bioinformatics | |
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Cytoplasmic hybrid embryos Currently embryonic stem cell research relies on human eggs left over from fertility treatment. These are in short supply, and the eggs are not always of a high quality. Using hybrid embryos made from animal cells by removing the animal DNA and replacing it with human DNA would avoid these restrictions. As with all other stem cell research, embryos would have to be destroyed at 14 days, and proponents have argued that the ethical issues of using such hybrid embryos, which cannot actually develop into humans, are less than with human embryos that could. However, public opinion is divided on this and is generally opposed to this research unless it is tightly regulated and unless it is sufficiently likely to lead to scientific or medical advancements. Following wide consultation, the UK's Human Fertilisation and Embryology Authority (HFEA) has now decided that cytoplasmic hybrid embryo research can be permitted with caution and careful scrutiny on a case by case basis. [G][H]
Caloric restriction and ageing For nearly 70 years scientists have known that caloric restriction prolongs life. In everything from yeast to primates, a significant decrease in calories can extend lifespan by as much as one-third. Now, researchers from Harvard, Cornell and NIH have discovered two genes in the mitochondrial DNA of mammalian cells that act as gatekeepers for cellular longevity. The genes, SIRT3 and SIRT4, are members of a larger class called sirtuins that includes SIRT1, already known to affect longevity. The researchers found that when cells experience certain kinds of stress, such as caloric restriction, SIRT3 and SIRT4 become more active. The mitochondria grow stronger, energy-output increases, the cell's aging process slows down and flagging mitochondria are prevented from developing leaky pores in their membranes that might release enzymes that lead to apoptosis. This same anti-ageing process mediated by SIRT3 also seems to be activated by exercise. The findings add to the evidence that mitochondrial deterioration is a major factor in ageing and suggest that SIRT3 and SIRT4 might be targets for anti-aging drugs. [G][H]
Lifespan and metabolism Decreasing the activity of the cancer-suppressing protein p53 can make fruit flies live as much as 58 percent longer. The p53 exerts its influence on lifespan through just 14 insulin-producing cells in the fly brain, according to research at Brown University. The researchers also found that caloric restriction, which normally prolongs the life of fruit flies, did not produce any lengthening of lifespan in flies genetically engineered to have suppressed p53. The 14 insulin-producing cells are the equivalent in humans of the insulin-producing beta cells in the pancreas. These findings support the notion that p53 reduction is one of the direct effects of caloric restriction and that lifespan regulation is linked to metabolic regulation. [G]
Cell necrosis Unlike apoptosis, which is a highly controlled process for cell death and recycling, cellular necrosis looks like a disordered process in which damage to one system in a cell leads to a cascade of secondary effects that eventually kill the cell. Now, however, a study led by investigators from the University of Pittsburgh has found that necrosis may be less chaotic than thought and may be controlled by a powerful protein, SRP-6. They discovered that nematode worms genetically engineered to be deficient in SRP-6 suffer a cascade of cell necrosis when exposed to a number of different stressors, including water, heat and lack of oxygen. SRP-6 staves off necrosis by protecting the cell's lysosome membrane. Without enough SRP-6 the membrane ruptures, releasing digestive enzymes into the cell. The findings indicate that necrosis can be interrupted and possibly repaired, even after the injury process is well underway. The researchers say this has exciting implications for heart disease, stroke and neurological illnesses. Also, if SRP-6 can be inhibited in cancer cells, this might force them to die. [G][H]
Cancer and ageing The startling discovery in 1993 by UCSF biologist Cynthia Kenyon that in nematode worms a change in just one gene, called daf-2, doubled the worms’ lifespan, has led to a lot of work on genes that control ageing. The gene daf-2 codes for a receptor for insulin and also for an insulin-like protein that promotes growth. It influences a gene called daf-16, which makes a so-called transcription factor - a protein that determines when and where hundreds of other genes are turned on. The UCSF team has now examined 734 genes known to be targets of daf-16 and identified 29 of these that either promote or suppress tumour cell growth. From this they have discovered that those genes that stimulate tumour growth also accelerate ageing itself, and conversely the genes that prevent tumour growth slow down the ageing process and extend lifespan. The researchers say that these findings greatly strengthen the view that the controls of lifespan and cancer have deep, common roots. [G][H]
Gene control So vital is the p53 tumour suppressor gene in controlling cancer that its dysfunction is linked to more than half of all human cancers. At the same time, the gene’s capacity for shutting down cell growth, even causing cells to commit suicide if necessary, is so absolute that it must be tightly regulated to maintain the optimal balance between protecting against cancer and permitting normal growth. Now, a study by scientists at Wistar Institute has revealed that one way p53 activation is controlled is through the number of methyl groups added at a particular site on the p53 protein. Adding just one methyl group (monomethylation) represses p53 action whilst adding a second methyl group (dimethylation) activates it. The researchers also confirmed that removing the second methyl group returned the protein to its repressed state. The researchers speculate that this cyclic on-off mechanism may not just be confined to p53 but may be widespread in the genome. [G][H]
Emerging model of the genome Current research is transforming the view of what the genome is. Single genes are proving to be fragmented, intertwined with other genes, and scattered across the whole genome, and the role of RNAs is turning out to be far more complex and important than previously thought. A single length of DNA can be transcribed in multiple ways and in both directions to produce many different RNAs from sections that may overlap gene boundaries. Indeed, the fundamental units of the genome may not be genes at all, but functional RNA transcripts. Only about 1.5 percent of the genome codes for proteins - the building materials. The remaining 98.5 percent is now thought to hold the instructions for how to assemble and operate the organism. Much of this non-coding DNA is translated into various RNAs: short nuclear RNAs (snRNAs) and short nucleolar RNAs (snoRNAs) that help control production of other RNAs; and microRNAs (miRNAs) and short interfering RNAs (siRNAs) that can modulate the activity of protein-coding genes. Recent research has linked mutations in the non-coding DNA to diseases including diabetes, autism, various cancers, and schizophrenia. [G][H][T]
MicroRNAs and cancer MicroRNAs (miRNAs) fine-tune protein production and play a powerful role in biological processes ranging from development to aging. Now scientists have proved that they can also prompt otherwise sedentary cancer cells to move and invade other tissues. [G][H]
Good news for RNAi therapy Strings of ribonucleic acid (messenger RNA) carry the instructions encoded in DNA to ribosomes, the cell's protein-building machines. By blocking the RNA, one can effectively disable specific genes. This approach called RNA interference (RNAi) is a powerful tool for research on gene function and also offers an entirely new way of tackling diseases including macular degeneration, Alzheimer's, motor neurone disease, Parkinson's disease, hepatitis and HIV. A problem arose in 2006, however, when experiments on mice found that using small hairpin RNA (shRNA) to disrupt communication to disease-causing genes killed the mice. This suggested that RNAi interfered with the normal function of cells. Now, researchers at MIT have found that a different approach to RNAi using small-interfering RNA (siRNA) does not have the same toxic effects. [G][H]
Protein folding The biological function of proteins depends on their folded shape. That shape is determined by the sequence of the amino acids, and understanding the folding mechanism and how the sequence determines the protein's unique three-dimensional architectures is a holy grail in molecular biology. Working on a smaller chain of amino acids known as a peptide, US researchers have now shown that the folding is determined largely by how parts of the peptide interact with water, and specifically how water wets the hydrophobic areas of the peptide. Small hydrophobic areas, up to the size of a water molecule, induce different behaviour in water than larger hydrophobic areas, and this difference is crucial for the folding. [G][C][N]
Human-specific genes Humans carry many more copies than other primates of a gene that produces a salivary enzyme that digests starch, researchers have found. They sampled saliva from 50 European-American undergraduates and found as many as 15 copies of the gene per person. By comparison, all 15 chimpanzees they sampled had exactly two copies each. People with more copies of the gene also had higher concentrations of the enzyme in their spit. The researchers argue that this gene may have played a crucial role in human evolution. Other primates eat mainly ripe fruits containing very little starch. Acquiring the ability to eat calorie-rich starches could have provided the energy for larger brains and also enabled humans to cope with a much wider diversity of habitats. [G][B][E]
Homo floresiensis It has been uncertain whether Homo floresiensis, the tiny human-like creature living and using tools in Indonesia just 18,000 years ago, really was a distinct species or just a malformed modern human. Now, analysis of Homo floresiensis's wrist bones suggest the former. It shows that the wrists are similar to those of a chimpanzee, or an early hominid such as Australopithecus, and that the creature had none of the specialisations for grasping that are seen in the wrist bones of modern humans. Other soon-to-be-published studies of the foot bones, upper arm and shoulder also suggest that the creature's anatomy differed from that of modern humans. [G]
Early man Newly discovered fossils, 1.77 million years old, found at a site called Dmanisi in Georgia show that the earliest known human ancestors to leave Africa for Asia possessed human-like spines and legs and feet that would have efficiently supported long-distance walking and running. However, they have strikingly small brains and primitive arms that appear more like those of australopithecines, an earlier line of hominids. The small brains and australopithecine-like arm traits in Dmanisi individuals also appear in Homo floresiensis. [G]
Palaeogenomics Analysis of hair from several ancient mammoths suggests that even tiny samples that are tens of thousands of years old can contain enough genetic material to allow reconstruction of the animal's mitochondrial DNA. It is likely the genetic material was preserved because keratin, the material of which hair is made, repels water, a major source of DNA degradation. Many other biological materials, including horns, hooves, feathers, and the sheaths on claws, are also made of keratin. The methods the researchers developed for efficiently generating and analyzing large amounts of ancient mitochondrial-genome sequences opens the way to generate such data for other extinct species, as well as to sequence the huge nuclear genome of an extinct species. There may be a huge treasure trove of well-preserved DNA in specimens held in museums round the world, not only of extinct species but also mummies of ancient bison, horses and humans. The researchers found that mammoth hair stored in a Russian museum for 200 years at room temperature still allowed for a complete analysis of its mitochondrial genome using only 0.2 grams of hair. [G] |
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