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Top Stories in Science
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March 2006 Issue |
| [D] Defence and security |  |
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US Defense strategy The US Department of Defense has published its Quadrennial Defense Review (QDR). Whilst maintaining US ability to fight two conventional wars almost simultaneously, the review emphasises the capability to handle very prolonged, irregular warfare, like that in Iraq and Afghanistan, including the propaganda war. The QDR identifies four categories of threat: traditional challenges from other nation states; irregular challenges - notably terrorism and insurgency; catastrophic challenges from the use of weapons of mass destruction; disruptive challenges that could counter US capabilities, perhaps through new technologies. Catastrophic challenges are seen as the gravest threat. [D][T]
Asymmetric warfare The March issue of IEEE Spectrum contains an informative primer on asymmetric warfare, analysing modern and past conflicts in terms of Lanchester's equation and Lawrence of Arabia's Principles of Insurgency. In the Cold War, NATO technological superiority was sufficient to compensate for the Warsaw Pact's numerical superiority. This technological superiority was decisively demonstrated in the 1991 Iraq war. In Iraq now, however, the US military finds itself on the other side of the Lanchester equation. As in Vietnam, it has great numerical superiority over its enemy but has yet to find effective ways to deal with low-tech counters. By choosing the time, place, and type of action, the insurgents can achieve a huge asymmetric advantage and even, in some cases, local numerical superiority. [D][T]
Terrorist attack The US National Academies have published, in cooperation with the US Department of Homeland Security, fact sheets on four types of terrorist attacks. The sheets draw on many reviewed publications and expert views and are intended to provide a clear explanation of the fundamentals of science, engineering, and health related to such attacks. They cover biological attack, chemical attack, nuclear attack and radiological attack. [D][H][T]
Cyber defence The US has tested the security of its cyber systems in a week-long simulated attack run by Homeland Security. The war game drew in 115 agencies, ranging from the FBI and CIA to the Red Cross, and tested vital infrastructure including power grids and banking systems. [D][I][X]
Nuclear non-proliferation The March issue of IEEE Spectrum has a review of the non-proliferation risks from expanding nuclear energy. It takes Brazil as an example of the difficult issues surrounding the spread of enrichment and reprocessing technology. Article IV of the Nuclear Non-Proliferation Treaty (NPT) allows nations to reprocess nuclear fuel provided that their facilities are inspected by the UN International Atomic Energy Agency. Unfortunately, this is not enough to prevent nations acquiring nuclear weapons. Article IV is now a critical issue with some countries demanding tighter control of sensitive nuclear technologies whilst others are complaining about the lack of progress toward disarmament. [D][P][T]
Risk from bird flu The H5N1 virus has so far killed around 100 people, but fortunately it has not spread from person to person. According to researchers at Scripps Institute, Avian flu viruses prefer binding to receptors of intestinal epithelial cells, whereas human flu viruses are usually specific for a different receptor on epithelial cells of the lungs and upper respiratory tract. Researchers at the University of Wisconsin-Madison have found that cells with the right receptors for current Avian H5N1 do actually exist deep in human lungs but are rare in the upper respiratory system, where the virus would need to multiply in order to be transmitted by coughing and sneezing. The research pinpoints several key mutations that would enable H5N1 to spread between people and that need to be watched for as signals of an imminent epidemic. [D][H]
Diversification of H5N1 An analysis of H5N1 influenza samples in Southeast Asia shows that as the virus expands geographically, it is significantly increasing its genetic diversity. The two strains that have so far caused human disease belong to two different, distinct genetic subgroups. Either of these has the potential to cause a human pandemic. [D][G][H]
Treating bird flu Scientists at the Karolinska Institute have suggested that drugs used to treat an often fatal immune disease called haemophagocytic lymphohitiocytosis (HLH) might also be effective against bird flu. The lethality of bird flu is associated with a profound over-response of the immune system, with over-production of certain immune messengers, such as interleukin 6, leading to sepsis with multi-organ failure. HLH produces similar symptoms, and can be treated with a cocktail of drugs including a key chemotherapy called etoposide, which kills excess immune cells. [D][H]
World poverty Almost 200 countries agreed in 1990 to cut worldwide hunger in half by 2015, but according to two papers at the 2006 AAAS meeting, there has been no real progress. Problems include disaster vulnerability, lack of energy services, poor soil fertility, drought frequency, malaria exposure, and distance to coasts. Science and technology provide the only real hope of progress. Recommended priorities for improvement include helping farmers to efficiently produce high-value foods, sustaining biodiversity, promoting sustainable and integrated land, water and forest management through a holistic approach, and producing more and better food at lower cost through genetic improvements. [D][H] |
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| [A] Aeronautics and space | |
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Reducing friction drag A long, streamlined object, such as an airplane wing, feels mostly "friction drag" as its surfaces slide past slower moving air. At higher speeds, the flow over the wing becomes turbulent, with small disturbances growing into turbulence some distance behind the leading edge. This can make the friction drag ten times larger. Now, researchers at the Royal Institute of Technology in Stockholm have shown, computationally and experimentally, that attaching small discs to aircraft wing surfaces can produce ribbons of spiralling flow in the air downstream that smooth out the turbulence. If the findings can be translated to real aircraft, they could provide major fuel savings. [A][C][E][M][P]
Exploiting aerodynamic drag Whereas an airfoil uses aerodynamic lift to carry its weight, dragonflies instead exploit aerodynamic drag. The dragonfly's four wings and an unusual pitching stroke, enable it to hover and even shift into reverse. These principles might be exploited in air vehicles. [A]
Air travel and DVT Sitting still for long periods cannot alone explain why air passengers are at higher risk of developing deep vein thrombosis (DVT), according to Dutch researchers. In a study involving 71 volunteers, they found that chemicals indicating clotting were higher during eight hours on a flight than sitting in the cinema. The results suggest that lower air pressure and oxygen levels during flight may play a role, but the researchers could not rule out other potential factors, such as stress or air pollution. [A][H]
Commercial space flight The commercial space flight company Space Adventures is working with the Russian Federal Space Agency and the Ansari family to create a fleet of commercial suborbital spaceships. These are likely to be based on the Russian Cosmopolis 21 (C-21) vehicle, and will carry as many as five people. Space Adventures also plans to build a $265 million spaceport in the United Arab Emirates, with prospects for additional ports in Singapore and North America. [A]
Crew Exploration Vehicle NASA has begun wind tunnel simulations for the Crew Exploration Vehicle, simulating the air flow and temperature changes the vehicle might experience in atmospheric flight. [A]
International space station The heads of the five space agencies in charge of the International Space Station (ISS) - from Canada, Russia, US, Europe and Japan - have reaffirmed plans to complete assembly of the space station by 2010. [A]
Space tether A slim cable for a space elevator has been built stretching a mile into the sky. This is a step towards NASA's Centennial Challenge of creating a tether 62,000 miles high that can be climbed by robotic lifters, powered by laser beams from Earth, ferrying cargo, satellites and eventually people into space. The cable, about 5 cm wide and the thickness of six sheets of paper, was made of three carbon-fibre composite strings sandwiched between four sheets of fibreglass tape. It was pulled aloft by three balloons. The company hopes to also exploit the current technology for aerial observation and communications. [A][I][M][O][R][U]
Sun spot cycle A new computer model of solar dynamics developed by scientists at NCAR has successfully simulated the strength of the past eight solar cycles with more than 98 percent accuracy. The model predicts that the next cycle will be 30 to 50 percent stronger than the last one and will peak about the year 2012. The NCAR model draws on research indicating that the evolution of sunspots is caused by a current of plasma that circulates between the Sun's equator and its poles over a period of 17 to 22 years. The plasma acts as a conveyor belt, transporting the imprints of sunspots from the previous two solar cycles. As they return toward the equator, they become stretched and twisted by the internal rotation of the Sun. Eventually coiled-up magnetic field lines rise up, tear through the Sun's surface, and create new sunspots, beginning the cycle again. [A][C][I][R]
Satellite rejuvenation NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) astronomy satellite is back in full operation after a remarkable rejuvenation that shows what can be achieved by ingenious and painstaking remote reprogramming. FUSE was launched in 1999, and NASA has twice extended what was originally planned to be just a three-year mission. FUSE suffered a near-death loss of control in December 2004 that initially appeared impossible to repair. [A][C][R][U]
Mars Reconnaissance Orbiter NASA's Mars Reconnaissance Orbiter (MRO) has successfully entered an elliptical orbit around MARS. Over the next six months, the probe will steadily reduce the size of its orbit using air resistance against its solar panels to slow itself down. Once it is in the optimum position, it will study the planet's climate, look at water-containing minerals, and probe beneath the Martian surface searching for ice. The orbiter also has cameras on board that will be able to take close-up images of the planet's surface. [A][R]
Life on Saturn's moons Scientists have estimated that major asteroid impacts on Earth, such as the impact believed to have killed the dinosaurs, could have ejected enough material for some to have reached far off moons. Some of these moons, such as Saturn's moon Titan, may be capable of supporting life, and could have been seeded with life from Earth carried on the ejected material. Saturn’s tiny moon Enceladus might also be able to support life. According to Cassini mission scientists, Enceladus is brimming with liquid water, but it is a mystery what source of heat can be keeping the water liquid. [A] |
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| [U] Unmanned vehicles and robotics | |
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Quadruped robot A four-legged robot is being developed as a robotic pack mule for the US military under a project funded by DARPA. The machine, which moves like a cross between a goat and a pantomime horse, can negotiate steep slopes, cross rocky ground and deal with a sharp kick. [U][D]
AUVs Autonomous underwater vehicles provide a new way to study ocean mammals, such as whales. They promise to be substantially more effective and cheaper than using surface ships or fixed sensors. [U][E]
Robotic surgery Surgeons may soon be able to operate on a beating heart. Motion compensation software that synchronises the movement of robotic surgical tools with that of the heart will make it possible to operate without stopping or even slowing the heart down. The software, developed at Imperial College London, has been designed for use with a type of surgical robot called da Vinci to perform procedures such as arterial bypass surgery. [U][H] |
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| [P] Propulsion and energy | |
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Ion engine A team from the European Space Agency (ESA) and the Australian National University (ANU) has developed a new 'ion engine' for use in space travel. The new device, known as the Dual-Stage 4-Grid (DS4G), is reported to be capable of producing an exhaust plume more than four times the speed of the best-performing ion engine devices currently available. [P][A]
Hydrogen storage Chemists at UCLA and the University of Michigan have developed a metal-organic framework (MOF) material that can hold 7.5 percent by weight of hydrogen. This is nearly three times more than has been reported previously and is sufficient to provide practical fuel storage for hydrogen powered vehicles. Unfortunately, this high storage requires cooling the MOF to liquid nitrogen temperature (77 degrees Kelvin). But, the researchers, who have tested 500 different MOFs, say this is an important step towards MOFs that work well at room temperature. [P][M]
Lithium hybrid-electric batteries Researchers at MIT have developed a new type of lithium battery that could become a cheaper alternative to the batteries that now power hybrid electric cars. Until now, lithium batteries have not had the rapid charging capability or safety level needed for use in cars. At present, hybrid cars run on nickel metal hydride batteries, which power an electric motor and can rapidly recharge while the car is decelerating or standing still. The new lithium battery uses lithium nickel manganese oxide, which is safer and cheaper than lithium cobalt oxide used in batteries for electronics. The battery material has also been modified so that the battery charges or discharges in about 10 minutes, nearly fast enough for use in cars. [P][E][M]
Giant electrocaloric effect Electrocaloric materials change temperature when an applied electric field is removed from them. However, the effect is too small to be useful: the best materials have achieved a temperature change of only 2.5 degrees C for an applied fields of 750 volts. Now, however, UK researchers have discovered a "giant electrocaloric effect" in perovskite PZT (an insulating oxide containing lead, zirconium and titanium). They calculated that the material cools down by as much as 12 degrees C with an electric field of just 25 V. The effect is strongest at 222 degrees C, but the researchers hope that by introducing dopants into the PZT they can reduce this to near room temperature. Giant electrocaloric thin films could be used in cooling electronic components, in biotechnology systems such as reactors and sensors, and in microelectromechanical (MEMS) and infrared imaging systems. The technology might also find use in automotive and aerospace applications, air conditioning and even domestic refrigeration. [P][A][C][E][J][M][S]
Nuclear power Following a year of evidence-gathering and research, the UK government's principle advisory body on sustainable development has concluded by a narrow majority that nuclear power is not the answer to tackling climate change or increasing the security of energy supplies. Even if the UK's existing nuclear capacity were doubled, it would only deliver an 8 percent reduction in carbon dioxide emissions by 2035. The report concludes that an "aggressive" expansion of energy efficiency and renewables is more effective and avoids the problems of uncertain costs, nuclear waste and risk of nuclear proliferation. [P][E]
Solar versus nuclear Researchers at Imperial College are arguing that the UK should invest in solar photovoltaics rather than a new generation of nuclear power. The UK currently generates 12 gigawatts of electricity from nuclear power stations, around one sixth of the country's total electricity output. This is the same amount of electricity that it is predicted Germany will generate through photovoltaics by 2012 if it continues to expand its solar energy programme at its present rate. In addition, early tests of the new generation of quantum well photovoltaic cells now under development, indicate that they could produce twice as much electricity per unit area as conventional photovoltaic technology. [P][E][J]
Thermonuclear power The International Thermonuclear Experimental Reactor (ITER) project is intended to be the single experimental link required between existing devices and a demonstration power plant, loosely referred to as "DEMO". ITER is due to power up in 2016 and DEMO could be operational by 2035. One of the reasons why achieving fusion power is so demanding is the vast range of time- and space-scales associated with the underlying physics. Only with ITER can these critical aspects of fusion be addressed simultaneously. [P][M][T]
Thermonuclear power The enormous practical problems in building a thermonuclear power plant could mean that a functioning power-producing fusion reactor may still be at least 50 years away, according to US experts, and might never be commercially viable compared with other renewable energy sources. The issues include the costs of building a reactor, and the difficulties of repairing and maintaining the reaction vessel. The massive blanket of lithium and rare metals that must surround the fusion-generating plasma in order to absorb its emitted neutrons will degrade and become radioactive over time, requiring regular dismantling and replacement. [P][M]
Billion degree temperature Sandia's Z-machine has unexpectedly produced extremely high temperatures of two billion degrees, hotter than the interior of stars. The radiated x-ray output was also unexpectedly high, as much as four times the expected kinetic energy input. A possible explanation is that the Z's magnetic energies create microturbulences that increase the kinetic energies of ions caught in the field's grip. The achievement of such extreme temperatures, if its cause were fully understood and harnessed, could in the distant future mean that smaller, less costly nuclear fusion plants would be possible. It may also explain how astrophysical entities like solar flares maintain their extreme temperatures. [P][A]
Faster photosynthesis Throughout nature, photosynthesis relies on the enzyme rubulose 1,5-bisphosphate carboxylase/oxygenase, also called RuBisCO. While RuBisCO is the most abundant enzyme in the world, and has had a billion years of evolution, it is about a thousand times slower than most other enzymes. For decades scientists have tried to mutate RuBisCO into something more efficient, but without success. Now, US researchers have used directed evolution to mutate the RuBisCO gene and achieve a five fold increase in RuBisCO expression. The work has been done in E coli bacteria, but it should be possible to transfer the results to plants, enabling them to use and convert carbon dioxide more quickly. [P][E][G] |
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| [M] Materials, structures and surfaces | |
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Carbon fibre composites If the cost of commercial-grade carbon fibre could be reduced from around $20 per kg to around $9 per kg, carbon fibre composites could be used to replace much of the ferrous metal in automobiles. Replacing half the ferrous metal with carbon fibre composites could reduce a vehicle's weight by 60 percent and its fuel consumption by 30 percent, according to some studies. Moreover, gains in fuel efficiency, made in part because smaller engines could be used with lighter vehicles, would reduce greenhouse gas and other emissions by a further 10 to 20 percent. [M][E][P]
Noble metal nitrides Using extreme temperatures and pressures, researchers have made two noble metal nitrides, one containing iridium and another containing platinum. Both have a diamond-like hardness, and some compositions might have very low, nearly superconductive, electrical resistance. The strength and durability of these materials could make them viable replacements for the titanium nitrides as surface coatings, and they may have useful electronic and optoelectronic properties. [M][J][O]
Shape memory nanomaterial German researchers have incorporated magnetic nanoparticles in thermoplastic polymers to create shape-memory materials. Applying a magnetic field to a temporarily deformed piece of the material causes it to change back to its original shape, a phenomenon that could be exploited in medical applications. The scientists believe that the presence of nanoparticles enables heating of the polymer, which induces the shape change. [M][H][N]
Synthetic collagen Collagen is the most important structural protein in the body, reinforcing connective tissue, bones and teeth, and forming long, fibrous cables to strengthen tendons. It forms sheets of tissue that support the skin and every internal organ. Scientists have been trying to make synthetic collagen for 30 years, but without success because they could not find a way to link the easily made short snippets of collagen into the long, fibrous molecules necessary to mimic the real thing. Now, however, US scientists have discovered a method for making human collagen in the lab. The key was to modify the ends of the snippets to they could fit together and stick, and hence self assemble into the long, thin fibres of native collagen. The material could have wide applications, not just in medicine but also in nanotechnology and sensors. [M][G][H][N]
Turbulence In the 1920s, a British scientist, Lewis Fry Richardson, predicted that in strong turbulence the mean-square separation of a fluid element pair should grow as the third power of time, and would be independent of initial separation. This result, known as the Richardson-Obukhov law, is commonly used in models of transport in turbulence. In the 1950s, the Australian George Batchelor in Cambridge added the amendment that for short timescales, pair dispersion is not independent of initial separation and should increase as time squared. Using high speed cameras, an international team of researchers has now been able to test the theories experimentally. The experiment showed that when the initial separation is large relative to the turnover time of the eddies, particle separation obeys Batchelor dispersion, independent of the turbulence's severity. However, if the initial separation is smaller, then the particles will only exhibit Batchelor dispersion initially before transitioning to behaviour consistent with the Richardson-Obukhov law. [M][A][C][E][G][J][N][P]
Vortex growth Understanding how large vortices grow could lead to a better understanding of how hurricanes and large ocean eddies form. It has generally been supposed that the growth occurs by smaller vortices merging. However, new results suggest that large vortices instead drain energy from smaller vortices, leaving the depleted vortices either to wither away or to renew their resources by draining still smaller vortices. Through computer modelling at Johns Hopkins and laboratory experiments at Los Alamos on thin salt-water layers, researchers were able to observe and measure the energy transfer, which occurs by stretching of small-scale vortices caught up within the large-scale vortices. [M][A][C][E][X] |
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| [E] Environment, transport and marine | |
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Accuracy of climate models Scientists have found evidence that, around 91 million years ago, temperatures in the tropical Atlantic Ocean may have reached 42 degrees C, about 14 degrees C higher than today. Carbon dioxide levels in the atmosphere were high at that time, but researchers say that even allowing for this and for high methane concentrations as well, current climate models cannot explain how such extreme ocean temperatures occurred. This may indicate that current climate models are underestimating future ocean warming. [E][C][P][X]
Glacier melting The most comprehensive survey yet undertaken of the massive ice sheets covering both Greenland and Antarctica shows that there was a net loss of ice from the combined polar ice sheets between 1992 and 2002 and a corresponding rise in sea level. The survey documents for the first time extensive thinning of the West Antarctic ice shelves and an increase in snowfall in the interior of Greenland, as well as thinning at the edges. All are signs of a warming climate predicted by computer models. Another new study has found that the glaciers in southern Greenland are moving faster. Kangerdlugssuaq Glacier went from standing still in 1996 to flowing at a rate of 14 km a year by 2005, making it one of the fastest moving glaciers in the world. All of Greenland's coastal glaciers are already experiencing or may soon experience such speedups. In Antarctica, satellite measurements of changes in the Earth's gravity show that the continent is losing 152 cubic km of ice each year. [E][A][R]
Rising sea levels Scientists have confirmed that climate warming is changing how much water remains locked in the Antarctic and Greenland ice sheets. Using radar altimeter data from ESA’s ERS-1 and ERS-2, they mapped the height of the ice sheets and found there was a net loss of ice from the combined sheets between 1992 and 2002 and a corresponding rise in sea level. [E][A][R]
Water supply Measurements of the volume of water that rivers return to the oceans show that, around the world, rivers have become fuller over the past century. Researchers at the UK Meteorological Office have found this cannot be explained by more rainfall or haze or changes in land use, but can be explained by the effect of higher concentrations of atmospheric carbon dioxide on transpiration from plants. A plant takes in carbon dioxide through small holes, called stomata, found in its leaves. With more carbon dioxide available, the stomata need to open for less time. So, less water is lost to the atmosphere and the plant draws less moisture from the soil, allowing more to flow into rivers. The researchers believe this adds around 2,000 cubic km to the annual runoff of 40,000 cu km. In some areas this may make the risk of flooding worse; in others it may help to maintain water supplies. [E][D][X]
Particulate pollution New data from a four-year study of 11.5 million Medicare enrolees show that short-term exposure to fine particle air pollution from such sources as motor vehicle exhaust and power plant emissions significantly increases the risk for cardiovascular and respiratory disease among people over 65 years of age. [E][H][N]
Bioremediation A special strain of the soil bacterium Pseudomonas putida is able to convert polystyrene foam into a biodegradable plastic, according to research at University College Dublin. Polystyrene foam is a difficult material to recycle, and the bacteria might be able to solve the problem disposing of polystyrene cups, plates and utensils. [E][G]
Collapsing fish stocks Fish stocks are now in decline throughout the world and it may be politically impossible to prevent a global collapse of fisheries in the way that various regional fisheries have already collapsed. The overall global catch peaked in the late 1980s, but the peak catch occurred earlier in those parts of the world where industrial fishing developed first - in the mid-1970s in the North Atlantic. In the southern Atlantic, where the industrialization of fishing started later, the fish catch peaked in the mid-1990s. [E][D][X]
Deep ocean mining Advances in marine geology and deep ocean technology now make it realistic to mine undersea deposits of polymetallic sulphides. These sulphur-rich sea floor ore bodies are produced worldwide in underwater volcanic regions by "black smokers." The black smokers are formed when seawater seeps into the porous sea bottom, is heated and re-emerges through vents carrying dissolved minerals. Over time these form ore deposits, some of which are rich in gold, silver, copper, lead and zinc. [E][M][R][U] |
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| [R] Remote sensing and sensor systems | |
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Night vision in cars Night vision systems can enable car drivers to see as much as three or four times farther ahead at night and help them quickly distinguish among objects. Some car manufacturers are now confident that they can package night vision as part of a suite of safety systems to appeal to buyers of expensive cars. Some are offering near infrared systems that use an infrared beam to illuminate the road ahead. Others are offering far infrared systems that can see much further and require no illumination, but are larger and more expensive. [R][E][S][T][V]
3D navigation system Siemens has developed a navigation system with a three-dimensional map display. These true-to-life images of entire streets and intersections make it easier for drivers to find their destinations even in unfamiliar urban areas. The system will be launched on the market in mid 2008. [R][V]
Bat echolocation New research shows bats have complex skills to deal with 'clutter'. Using an array of high-speed infrared cameras and strategically placed microphones, researchers at the University of Maryland were able to match slowed video and audio recordings of the bat's echolocation activity and corresponding movement as it pursued an insect tethered to a string. The insect could be out in the open, or nestled in among leaves. The bats spent more time strobing when the insect was positioned near a plant, a strong indication that they used sonar strobe groups to try to distinguish the insect from the background clutter. [R]
Neutron imaging Researchers at Rensselaer Polytechnic Institute have developed a tabletop accelerator that produces nuclear fusion at room temperature. This provides confirmation of an earlier experiment, while offering substantial improvements over the original design. The device, which uses two opposing crystals to generate a powerful electric field, could potentially lead to a portable, battery-operated neutron generator for a variety of applications, from non-destructive testing to detecting explosives and scanning luggage at airports. [R][D][S][W]
Telescope adaptive optics Europe's Very Large Telescope (VLT) in Chile, the world's largest optical telescope facility, can now use an "artificial star" as a reference for its adaptive optics used to correct for atmospheric turbulence. This will improve the VLT resolution by a factor of 10. The star is created with a laser, which is fired 90 km into the sky to make sodium atoms in the thermosphere glow. [R][O] |
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| [S] Sensor devices | |
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Microlens sensor Scientists at Georgia Tech have created technology capable of detecting trace amounts of biological or chemical agents in a matter of seconds, much faster than traditional methods, which can take hours or up to a day. The system uses hydrogel microlenses small enough that millions of them can fit on a one-inch-square plate. When antibodies on the microlenses come into contact with the antigen they are set to detect, they bind, causing the lenses to swell and become less dense. By projecting an image through the tiny lenses, scientists can view this swelling as a change in the microlens’ focal length. If the projected image is normally in focus, it goes out of focus when it comes into contact with the substance. The effect is reversible enabling the same lenses over and over again. [S][D][G][H][J][O]
Optical biosensor A new sensor technology, called arrayed imaging reflectometry, uses a silicon chip that is made so that laser light reflected off the chip is invisible unless target bacteria are present. A protein from the target bacteria is placed on the chip. Then if any target bacteria are present, they bind to the protein, altering the surface reflection. The developers believe that this is faster and cheaper than any competing biosensor technology. [S][G][H][J][O]
Mapping protein location Researchers at Purdue and Lawrence Berkeley have developed a new technique that automatically locates and maps the proteins involved in regulating cell behaviour within a cell's nucleus. They believe that this protein mapping can make it much easier to diagnose accurately whether abnormal cells at the pre-malignant stage will in fact develop into cancer and if so, what type it will be and how invasive. Using the technique on mammary tissue samples, the researchers showed that the distribution of proteins is markedly different between non-differentiated cells that were still multiplying, normal mammary cells and multiplying malignant cells. [S][G][H][R]
Fibre-optic cancer probe A novel device that could use light to harmlessly and almost instantly probe for early signs of cancer has been developed by researchers at Duke University. The technique called angle-resolved low coherence interferometry uses light to differentiate between normal and tumour cells from the size of the cell nucleus. This would allow physicians to search for cancer in epithelial cells that line body surfaces, including the skin, lungs and digestive and reproductive tracts, by simply inserting a fibre optic probe. Around 80 percent of cancers start in epithelial cells. [S][H][O]
3D nanostructure microscope A three-dimensional electron microscope for examining nanomaterial structure has been developed at Max Planck. It incorporates a high-resolution scanning electron microscope and an ion-beam microscope into a single instrument, and can simultaneously and automatically investigate the phase content, crystallographic texture, and crystal interfaces of materials at the nanoscale. [S][M][N] |
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| [O] Optoelectronics, optics and lasers | |
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Attosecond measurements Scientists at Imperial College London have made the fastest measurements ever of molecular dynamics. The new measurement procedure, derived from work at Max Planck, uses a single femtosecond laser pulse, which creates an electric field strong enough to wrest an electron from the molecule, causing the molecule to begin moving. The oscillating field of the laser pulse sometimes drives the free electron back towards the ion and if the electron is then recaptured a UV photon is emitted. The probability of this recapture decreases the further the molecule has travelled from its initial position. By measuring the intensity and spectrum of the UV light, it is possible to determine how the molecule changes over time with a resolution of a few hundred attoseconds. [O][N][S]
Optical atomic clock Scientists at NIST working with Russian colleagues have significantly improved the design of optical atomic clocks that hold thousands of atoms in a lattice made of intersecting laser beams. The lattice traps small numbers of ytterbium atoms in pancake-shaped "wells." A small external magnetic field combined with yellow laser light induces an otherwise "forbidden" oscillation between two energy levels in the atoms. This has an extremely precise resonance frequency with a strong signal that demonstrates the clock's potential for very high stability. More accurate time standards could improve communications and precise navigation systems, and enable new tests of physical theories. [O][I][R]
Entanglement laser Laser operation normally requires a population inversion in the light-amplifying medium. However, by interfering with the wave-patterns of atoms, light can be amplified without needing a population inversion. This effect has previously been demonstrated in the atoms of gases, and has now also been demonstrated in a solid by researchers from Imperial College London and the University of Neuchatel in Switzerland. The team created specially patterned crystals only a few nanometres in length that behaved like 'artificial atoms'. When light was shone into the crystals, it became entangled with the crystals at a molecular level rather than being absorbed, causing the material to become transparent. The material created by the entanglement is made up of molecules that are half matter and half light. This allows light to be amplified without population inversion. As light passes through this new material, it also slows right down and could potentially be completely stopped and stored. [O][C][F][I][M][N]
Source of entangled photons Scientists at Cambridge University and Toshiba have been able to generate pairs of entangled photons from a quantum dot with an efficiency of 70 percent. This performance approaches that required for quantum communications and computing. Their quantum dot source, 12 nm in diameter, is made from indium arsenide embedded within a gallium arsenide and aluminium arsenide cavity. When excited by a laser pulse, the quantum dot captures two electrons and two holes to form a "biexciton" state in the dot, which generates the two photons. The researchers found that entangled photons were only produced by dots that have a symmetric shape. [O][C][I][J][N]
Quantum telecloning Physicists in Japan and the UK have demonstrated "quantum telecloning" for the first time. Telecloning, which combines quantum cloning and teleportation into a single step, involves sending quantum information to more than one receiver. [O][C][I]
Quantum entanglement Entanglement" could occur at any temperature and not just in systems cooled to near zero, according to new calculations by European physicists. They have found that the photons in ordinary laser light can be quantum mechanically entangled with the vibrations of a macroscopic mirror, no matter how hot the mirror is. The result is unexpected because hot objects are usually thought of as classical rather than quantum mechanical. The result suggests that macroscopic entanglement is not as difficult to create as previously believed and this could be encouraging for making room-temperature quantum computers. [O][C][I] |
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| [I] IT, communications, networking and secure systems | |
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3G networks Mobile telephone companies are facing big difficulties in weaning customers off old phones that use older technologies. At the end of 2005 only 2 percent of mobile users were on 3G networks, according to statistics gathered by Informa Telecoms, despite the fact that in many nations 3G networks have been up and running for months if not years. [I][K]
Pervasive computing The English city of Bath is being equipped with a city-wide wireless computing network, turning the city into a laboratory for studying how people will use pervasive computing. Volunteers will be given state-of-the-art mobile phones and will work with the project over the next three years to see how these technologies affect their lives and test the appeal and usefulness of new applications. [I][C][K][V]
Instant messaging Fifteen operators, including Vodafone, Orange, T-Mobile and China Mobile have agreed to work together to push instant messaging (IM) over mobile networks. By getting people using IM on a mobile instead of a PC, the operators are hoping to repeat the success of text messaging and get better revenue from data services. [I][K]
Cognitive radio The March issue of Scientific American has a review article on cognitive radio. Smart radios and other new wireless devices will avoid transmission bottlenecks by switching instantly to nearby frequencies that they sense are clear. As cognitive radios send and receive signals, they will nimbly bound in and out of free bands. Wireless communications should become far more dependable and convenient and perhaps considerably cheaper than it is today. Indeed, if cognitive radio technology progresses as its developers hope, there might even be a glut of RF-spectrum options. [I][K][T]
Using electronics in-flight According to a review article in IEEE Spectrum, the question of whether cellphones and other portable electronic devices (PEDs) can safely be used on airline flights is made more complex by the increasing use of GPS-certified landing approaches, particularly when clouds or other weather problems make it impossible for pilots to see runways. The most common technologies used for landing are the VHF omnidirectional range system and the instrument landing system, both of which operate near 100 MHz, and GPS, which operates between 1200 and 1600 MHz. PEDs have the potential to interfere with each of them, but the most serious concern is for GPS receivers. There is a need for more data and also for harmonising RF emissions standards. [I][A][R][T]
Quantum encryption Canadian researchers have published the first experimental demonstration of a new quantum encryption technique that uses decoys to encrypt data. The technique varies the intensity of photons and introduces photonic "decoys." After the signals are sent, a second broadcast tells the receiving computer which photons carried the signal and which were decoys. If a hacker tries to "eavesdrop" on the data stream to figure out the encryption key, the mere act of eavesdropping changes the decoys, and shows the receiving computer that the data has been tampered with. [I][O]
Wi-Fi security Researchers at Indiana State have discovered a technique that allows an attacker to hijack almost any Wi-Fi computer connection to redirect users to incorrect sites. Someone using a wireless hot spot to access their bank account or a retail site cannot detect when they are redirected to a clone site that steals their passwords and account details. The researchers say that they have developed an active cookie technique that can protect against this and other pharming and man-in-the-middle attacks. [I] |
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| [K] Knowledge, information and technology management | |
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Online society A seven year study of an online community of 3,000 young people has found that the internet is becoming a new medium for social and civic engagement. The online group, aged from 10 to 16, represented 139 countries and many different social backgrounds and levels of computer proficiency. In a community almost entirely free of adult intervention, the members traded online messages about the ways technology could improve life for the world's young citizens. They then elected leaders to represent their community in a real world meeting with political and industry leaders from around the world. The leaders were elected not so much for their own ideas, but more for their ability to synthesise the ideas of others and to be highly socially adept. [K][I]
Web use A survey by Google has found that in the UK browsing the internet has overtaken watching TV as the nation's favourite leisure activity. The average web user now spends 164 minutes online each day, equal to more than 41 days per year, compared to 148 minutes or 37 days for TV viewers. The increasing availability of Wi-Fi and the advent of Wimax are likely to integrate the web further into many aspects of living and working. [K][I][V]
Knowledge maintenance Companies have a looming risk of serious knowledge loss as the baby boom generation reaches retirement. In aerospace and defence, for example, as much as 40 percent of the workforce in some companies will be eligible to retire within the next five years. At the same time, the number of engineering graduates in developed countries is in steep decline. Some companies are adapting their workplace to retain older workers longer. Flexible working and telecommuting, improving the ergonomics of factories, adapting workstations for older workers to make jobs less tiring, all enable older workers to stay longer. Maintaining a vigorous network of registered alumni enables firms to recruit retired people with specific expertise for particular projects. Better scientific understanding of the ageing brain can help in maintaining knowledge beyond 65. [K][A][H][I][T][U][V][W]
Learning and testing A US study confirms that testing can be used as a powerful means for improving learning and not just for assessing it. Students who self-test frequently while studying on their own may be able to learn more, in much less time, and retain it better in the long term. The researchers believe that the time is ripe for a thorough examination of the mnemonic benefits of testing and its potential for improving education and training. [K][B][V][W]
Women in science More women are pursuing higher education and doctoral degrees than ever before, but women are still rare in the mathematics-oriented professions. Researchers suggest that girls may move away from stereotypically masculine subjects, such as science and engineering, because the more competitive environment of these fields, particularly in research, is not a good fit with how girls approach school. Girls have a learning-oriented approach whereas boys naturally focus on outperforming others. [K][W] |
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| [C] Computing, supercomputing, modelling and simulation | |
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Counterfactual computation By combining quantum computation and quantum interrogation, scientists at the University of Illinois have confirmed a theoretical prediction that a quantum computer can gives results without actually running. Moreover, although the theoretical prediction was that such counterfactual computation would work only half the time at best, the new study suggests that it could become completely reliable. This scheme could have an advantage over straightforward quantum computing since a non-running computer will produce fewer errors. [C][O]
Quantum information Quantum information could be retrieved from a black hole, according to MIT research that suggests that only half a qubit is lost from the black hole regardless of how many bits are in the hole to begin with. The calculations suggest that information escapes almost perfectly through entanglement between the component of Hawking radiation that leaves the black hole and the other component that falls towards the point-like singularity of the black hole. When matter that has been sucked into the black hole interacts with the infalling Hawking radiation at the singularity, the interaction instantaneously produces a change in the Hawking radiation that has escaped the black hole. Fancifully, the result means that a black hole might be used as a vast quantum computer, except for the practical difficulty of programming it and reading out the results. [C][F]
Noise models By combining mathematical tools from three different disciplines – dynamical systems, control theory and fluid mechanics – an engineer at Princeton has developed a simple model that describes the noise from air flow over an opening. The model involves solving only four equations and the results are said to be in very close agreement with wind tunnel measurements and precise CFD treatments of the airflow. The huge simplification that is provided by the model makes it much easier to examine and optimise a wide range of designs in order to reduce noise. This research, which is funded by the US Air Force, may help in quietening jet engines, in enabling stealth aircraft to fly faster with weapons bay open, and in the development of ultra small, unmanned aircraft for surveillance or search-and-rescue missions. [C][A][E][P][U] |
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| [W] Whole life engineering, manufacture and testing | |
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Particle-spring design The design method known as particle-spring systems is a 3-dimensional design tool that models the gravitational load on a given shape's exterior. It was originally developed by computer scientists for creating graphics such as character animation and cloth simulation. Researchers at MIT say that particle-spring systems can be employed dynamically to find a structure's most efficient form and to allow the architect or engineer to interact with the form-finding program while it is still running. This could help in exploring the architectural design of old buildings and could support sustainable modern building practices by discovering more efficient, less-resource-consuming structures. [W][C][E]
Customised software As well as buying software, most companies develop, deploy, manage and update their own custom applications for specific business needs. This is expensive and time-consuming, and some companies are adopting the principles of packaged-software development, namely to standardise to meet the greatest number of needs, and to write once and sell many times. They are exploiting reusable software components and turning maintenance and management processes into standardised "products" for internal use. [W][C][I][K][T]
DNA design Researchers at Johns Hopkins have announced the development of a web-based, automated computer program that they say greatly simplifies the time-consuming and error-prone process of manually designing artificial pieces of DNA. [W][C][G][H][J][N]
Meetings and productivity Reports indicate that the average number of meetings at work more than doubled in the second half of the 20th century and that time spent in meetings keeps growing. A study covering nearly 1000 people has found that people who are low in accomplishment striving are positively impacted by meetings and have a greater sense of well-being. However, the study found that people high in accomplishment striving are predictably and negatively impacted by meetings, particularly if meetings are frequent, viewing them as interfering with the accomplishment of real work. [W][H][K]
Productivity and management Research conducted in 2005 by McKinsey and LSE has looked at the relationship between management and performance in more than 700 midsize manufacturing companies in France, Germany, UK and US. The results show that a company's economic success depends strikingly on the quality of its managers. Companies that successfully apply a critical mass of proven management techniques—setting goals, tracking performance, energizing the shop floor, and nurturing talent—perform better, on average, than competitors that use such tools sporadically. Better-managed companies have fostered adaptability through more flexible working arrangements, greater autonomy over decision making, and better training; they create a flexible, empowering work environment that advances their employees' education, training, and skills; they tend to have a good work-life balance; and, they are also more likely to hire employees with undergraduate and advanced degrees. In general, in countries with more female managers, decision making is delegated further down in the ranks and employees have greater autonomy. [W][K][X] |
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| [X] Systems, complexity and risk | |
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Origin of species Charles Darwin's "Origin of the Species" did not actually explain how species originate but rather how the extraordinary variety of biological traits possessed by plants and animals arises from the single process of natural selection. Demonstrating that natural selection in fact creates new species has proved very elusive. Now a new study covering hundreds of different organisms, ranging from plants through insects, fish, frogs and birds, has shown that there is a positive link between the degree of adaptation to different environments by closely related groups and their reproductive isolation. The result supports the proposition that natural selection is a general force behind the formation of new species. [X][G]
Earth systems At the 2006 AAAS meeting a number of speakers discussed the health of the Earth's systems. The issues covered included: locating and monitoring Earth's "vital organs," those locations and processes that regulate the functioning of the entire planet; the system level research techniques needed to study Earth systems; sustainable use of the biosphere and the future of the larger Earth system; the processes of deterioration in the West Antarctic ice sheet; the new generation of Earth system models; the impact of humans on the Amazon and the risk that the region could suffer the same fate as the Sahara ecosystem did 6000 years ago; the risks of breakdown of North Atlantic currents; and, the threat of ocean acidification to marine ecosystems. [X][C][D][E][R]
Ocean ecosystem A leading group of epidemiologists, veterinarians and ecologists report that humans are affecting the oceans in ways that are changing the dynamics of disease. Previously harmless pathogens are becoming killers when combined with contaminants; "good" parasites that invisibly control the balance of species in an ecosystem are disappearing; and changes in sea surface temperature can trigger cholera outbreaks thousands of miles away. [X][E][H]
Tsunami risk The 2004 Sumatra-Andaman earthquake and the resulting disaster was so much larger than any previously known rupture of this type that scientists may need to reassess many subduction zones that were previously thought to be at low risk, according to a report. Possible examples are the Ryukyu Islands between Taiwan and Japan and, in the Caribbean, the subduction zone from Trinidad to Barbados and Puerto Rico. [X][C][D][E][R]
Stock market criticality Small stockmarket fluctuations are usually "Gaussian," or "normally" random, at least when measured over sufficiently long time scales. That means that price fluctuations are likely to be small, while larger fluctuations are less likely, their probabilities following a bell curve. However, researchers have found that in the 2-month periods surrounding major crashes such as the Black Monday event of October 19, 1987, fluctuations of all magnitudes were equally probable. Conceivably, the findings could one day lead to an early-warning system to predict crashes, and such a system might itself precipitate a crash, or create one artificially, by inducing panic. [X]
Motor systems By treating a bird's vocal organ and neurones as nonlinear systems, researchers have found that complex bird songs, involving notes of many frequencies and lengths, might be produced by surprisingly simple neurological structures and processes. The results suggest that many other motor patterns in animals might likewise be the result of neural architectures much simpler than one would imagine. The results could shed light on how birds learn to sing and perhaps on how humans learn to speak. A bird's vocal organ, or syrinx, is similar to the human larynx and consists of folds of tissue in the passage connecting the lungs to the vocal tract. [X][B][U][V]
Complex mechanical systems Two engineers at the University of Southern California (USC) have developed a new and potentially much more flexible method of mathematically describing mechanical systems. The method works by first decomposing a complex system into two or more simpler parts, which can be treated more easily, and then mathematically reintroducing the missing link or links between the parts. Melding the multiple parts back together into one system in many cases leads to a "singular mass matrix." This singularity means that the problem cannot be solved mathematically using the Lagrangian method. In 1964, Dirac discovered a method for handling singular Hamiltonian matrices in quantum mechanics. According to the engineers at USC, their new method provides a completely different way of handling singular matrices and appears to be first of a kind in classical mechanics. [X][A][C][M][W]
Many particle systems A new approach to path integral Monte Carlo (PIMC) simulations, called a worm algorithm, provides a way to work with quantum systems involving many interacting particles on a scale much larger than before. This is very applicable to superfluids and supersolids, and has revealed a possible “superglass” state. It could also provide a better understanding of defects in solids or the presences of interfaces between two crystalline samples, where it is necessary to have a model large enough to show the complex interactions between many particles, and still have particles left over for the interface. [X][C][F][M] |
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| [V] Virtuality and human-machine interface | |
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3D real image display A device that uses laser plasma to display 3D images in the air has been developed in Japan. It exploits air plasma emission near the focal point of a scanned laser beam to create an array of bright dots. [V][O]
Visualising information As mobile devices have come to dominate our computing landscape, physical limitations such as power, screen size, and network bandwidth have become key areas of research. New strategies to optimise the information displayed on small screens can make a wide range of mobile applications more intuitive and productive. [V][I][K][T]
Electric psychiatry The brain is both a chemical and an electrical organ. Psychiatry currently depends heavily on drugs but electronic implants and electromagnetic therapy are playing an increasing role, especially where drugs do not work. Vagus nerve stimulation is effective in quashing severe depression in about 16 percent of patients. Repetitive transcranial magnetic stimulation, which uses powerful magnets to generate current in well-defined portions of the brain, is also entering clinical use. Researchers are exploring three other technologies. One uses direct current to produce a change in the brain similar to that of magnetic stimulation. Another uses transcranial magnetic stimulators to spark seizures just as electroconvulsive therapy does but, it is hoped, without the associated amnesia. The third involves implanting electrodes in patients' brains to switch off malfunctioning brain circuits involved in depression and obsessive-compulsive disorders. [V][B][H][T]
Mental typewriter A computer controlled by the power of thought alone has been demonstrated at a major trade fair in Germany. The device could provide a way for paralysed patients to operate computers, or for amputees to operate electronically controlled artificial limbs. It also has non-medical applications, such as allowing faster action in computer games and entertainment. Users can learn to operate the device in just 20 minutes after going through 150 cursor moves in their minds. The device rapidly learns to recognise activity in the motor cortex thanks to machine-learning algorithms developed at the Fraunhofer Institute. [V][B][C][H][K]
Neural implants A number of groups around the world have gained ethical approval to develop implants that can monitor and control the behaviour of animals, from sharks to rats. A team funded by DARPA has developed a neural implant designed to enable a shark's brain signals to be manipulated remotely, controlling the animal's movements, and perhaps even decoding what it is feeling. This may enable sharks to be used for surveillance, exploiting their ability to glide quietly through the water, sense delicate electrical gradients and follow chemical trails. Sharks might be used to track vessels undetected. The technology can also help in understanding how sharks sense their environment and navigate. For communicating with a shark at sea, it will be equipped with a sonar shaped like a remora fish to minimise drag. [V][B][D][E][R]
Neural signal coding Human hearing appears to be highly optimised in terms of signal coding, according to researchers at Carnegie Mellon, who have developed a new mathematical framework for understanding sound processing. They took a radically different approach to analysing how the brain processes sound signals. Abstracting from the neural code at the auditory nerve, they represented sound as a discrete set of time points, or a "spike code," in which acoustic components are represented only in terms of their temporal relationship with each other. They derived the optimal set of features for natural sounds and found this corresponded exactly to the patterns observed by neurophysiologists in the auditory nerves. The work could provide a predictive model to improve compressed digital audio files and for designing brain-like codes for cochlear implants. [V][B][C][H] |
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| [B] Brain research and human science | |
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Understanding language Humans can understand complex sentences, whilst apes only understand individual words. Researchers from the Max Planck have discovered that two areas in the human brain are responsible for different types of language processing. Simple language structures are processed in an area that is phylogenetically older, and which apes also possess. Complicated structures, by contrast, activate processes in a comparatively younger area which only exists in humans. [B]
Understanding actions By using transcranial magnetic stimulation, which disrupts brain function in healthy volunteers for less than a second, researchers have tested the role of the frontal cortex in tasks other than language, and have found that the left frontal cortex is essential for understanding other people's actions. [B]
Decision making Using fMRI, US researchers have found that distinct regions of the human brain are activated when people are faced with ambiguous choices versus choices involving only risk. Furthermore, whether or not a person is, by nature, impulsive appears to correlate with whether or not their brain prefers risky gambles to those that are ambiguous. The findings are relevant for modelling decision making under risk and ambiguity, and also for understanding why people make risky choices, and how such risk-taking can become pathological, as in addiction or compulsive gambling. [B][C][D][E][H][K][V][X]
Unconscious decisions New research suggests the conscious mind should be trusted only with simple decisions and that complex decisions are best left to the unconscious mind to work out. [B][K]
Dyscalculia Using fMRI, scientists at UCL have discovered the area of the brain linked to dyscalculia, a mathematics learning disability. The finding shows that the part of the brain used for counting is separate from that used to estimate "how much". The researchers hope that the work will lead to a better understanding, diagnosis and treatment for dyscalculia, like the discovery some years ago of the part of the brain responsible for dyslexia. [B][K]
Learning and memory Previous research has shown that rats replay specific brain firing sequences while sleeping. This is believed to be associated with long term memory. Now researchers at MIT have found that reverse replay also occurs when rats are awake and this probably allows immediately preceding events to be evaluated in precise temporal relation to a current anchoring event. The researchers found that the neurons in the rat's hippocampus fired during replay in precisely the reverse sequence to that during the preceding events. Understanding this replay is likely to be critical to understanding how animals learn from experience. [B]
Learning and memory Many neuroscientists believe that the cellular basis of learning and memory results from molecular-scale changes occurring at synapses, the communication junctions between neurons. In vitro and in vivo studies over the past decade have shown how different patterns of neuronal activity can alter synapses, and have revealed long-term or short-term synaptic plasticity. This has supported the notion that production of certain receptors is increased and that they are transported to the synapse during learning. Now research at Carnegie Mellon has provided the first evidence that the same mechanism observed in cultured cells do indeed operate in a normal, unaltered living brain. [B][K]
Learning and memory US and UK researchers have found, using EEG experiments, that memorising an event depends not just on the neural activity evoked by the event itself, but also on how the brain prepares beforehand. This suggests that it may be possible to improve memory by the right brain activity beforehand. [B][K]
Alzheimer's disease In experiments in mice, researchers in the US and Israel have found that a new compound known as AF267B relieves the cognitive symptoms of Alzheimer's disease, and also reduces the amount of beta-amyloid plaques and neurofibrillary tangles in the hippocampus and the cortex. Alzheimer patients have a major loss of the acetylcholine-producing neurons in their brain, and the researchers believe that AF267B works by mimicking the effects of the missing acetylcholine by binding to a receptor called M1. This causes an increase in the levels of an enzyme known as alpha secretase, which prevents the production of beta-amyloid. AF267B is able to cross the blood-brain barrier and it might therefore provide a therapy to halt the progression of Alzheimer's disease. [B][H]
Drug addiction Researchers have identified a key signalling molecule in the brain that appears to trigger the brain to "learn" a craving for cocaine. Their finding could offer an important target for drugs to treat addiction by short-circuiting that adaptive process. [B][D][H] |
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| [H] Healthcare and medicine | |
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Healthy lifestyle New research suggests that physical exercise and the right diet both encourage healthy brains to function at their optimum levels. Fitness prompts nerve cells to multiply, strengthens their connections, and protects them from harm. Benefits seem to extend to brains and nerves that are diseased or damaged. Eating a diet rich in omega-3 fatty acids may provide similar neurological effects as exercise. These findings could suggest new treatments for people with Alzheimer's disease, Parkinson's disease, and spinal cord injuries. [H][B][T]
Health and social networks In the largest study ever to quantify caregiver burden and the widower effect, researchers found that for people aged 65 and older, hospitalisation of a spouse can harm the wellbeing of his or her partner and significantly contribute to that partner's death. The risk remains elevated for up to two years, but the period of greatest risk is over the short run, within 30 days of a spouse's hospitalisation or death. This risk also varies with the ill spouse's diagnosis. The study covered more than a million people from 1993 to 2002. [H][X]
Spread of MRSA The superbug Methicillin-resistant Staphylococcus aureus (MRSA) uses amoebae to spread, according to researchers from the University of Bath. They have found that MRSA infects the amoeba (Acanthamoeba Polyphaga) and when this produces cysts in order to replicate, the MRSA bacteria goes with it and can spread around in air currents, by-passing most of the barriers a hospital would erect in order to prevent MRSA spreading. Evidence with other pathogens suggests that pathogens that emerge from amoeba are more resistant to antibiotics and more virulent. More information is needed about the ecology of amoebae, but since amoebae need water to live, it is possible that dry environments and the careful placing of sinks and other water sources could reduce the spread of MRSA. [H][G]
Treating necrotising fasciitis Group A Streptococcus is responsible for a wide range of diseases, from simple throat and skin infections to life-threatening conditions such as necrotising fasciitis and toxic shock syndrome. Researchers at UCSD have proved that the Strep bacteria can release an enzyme that degrades the DNA nets produced by neutrophils. These nets are composed of DNA and toxic compounds to entrap and kill invading bacteria and are a key component of the immune system. By degrading these nets, the Strep bacteria can escape and spread rapidly in body tissues. The researchers suggest that, instead of attempting to kill the bacteria directly with standard antibiotics, a better treatment may be to inhibit the DNA-degrading enzyme so that the pathogen is cleared by the normal immune defences. They have shown this treatment works well in mice. [H][G]
Obesity and disease Research on small patient groups has suggested that obesity raises the risk of thrombosis, heart disease, strokes and diabetes by increasing inflammation in the body. A study at Warwick University has now confirmed this in a large group of unselected people in three different ethnic groups. The study clearly showed that the levels of sE-selectin, a marker of inflammation produced by artery vessel walls, are strongly associated with measures of obesity, and in particular with the amount of fat around the waist. [H]
Prognostic assessment Researchers at the San Francisco VA Medical Center have created an index that is 81 percent accurate in predicting the likelihood of death within four years for people 50 and older. For patients and caregivers, predicting near-term likelihood of death is useful when making decisions about medical tests and clinical care. It is also useful in measuring the performance of hospitals and in evidence based practice. [H]
Attacking resistant tumours The cosmetic treatment Botox may have a new use as an adjuvant to cancer therapy. Botulinum toxin acts on the nervous system by blocking the release of neurotransmitters, particularly acetylcholine and norepinephrine. By impeding neurotransmitter release in the sympathetic nervous system, Botox injected into a tumour can prevent neuromuscular contractions of vessels in tumours, thereby exposing the tumour more strongly to chemotherapy drugs and oxygenation that enhances radiotherapy. [H]
New type of immune cell A new surprising type of immune cell has been discovered in mice. It has been named interferon-producing killer dendritic cell (IKDC) and it combines the ability of natural killer (NK) cells to kill foreign pathogens with the ability of dendritic cells to alert the rest of the immune system to the pathogen. IKDCs begin their lives behaving like an NK cell. After the cell encounters a pathogen, the cell switches roles from killer to dendritic-like messenger. According to the researchers, the swap occurs only once, and the cell then dies and is replenished. [H][G]
Gold therapy Gold compounds have been used for the treatment of rheumatoid arthritis and other autoimmune diseases for more than 75 years, but how gold works has been a mystery. Now, researchers at Harvard Medical School have found that special forms of gold, platinum and other classes of medicinal metals work by disabling a key immune system protein. This protein normally holds pieces of invading bacteria and virus on the surface of specialised antigen-presenting cells. These pieces alert and train lymphocytes to attack the pathogen. In diseases such a juvenile diabetes, lupus and rheumatoid arthritis, the antigen-presenting process goes wrong and causes the immune system to target the body instead. With this new understanding of how these metals function, it may now be possible to develop a new generation of gold-based drugs for treating rheumatoid arthritis and other autoimmune diseases that are more effective and have fewer side effects. [H][G] |
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| [G] Genomics, biotechnology and bioinformatics | |
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Longevity genes A handful of genes that control the body's defences during hard times can also dramatically improve health and prolong life in diverse organisms. Understanding how they work may reveal the keys to extending human life span while banishing diseases of old age. [G][H][T]
Rejuvenating cells A problem in growing replacement blood vessels and other replacement tissue for older patients is that cells biopsied from older patients grow only for a short time in the laboratory before they stop dividing as their telomeres become too short. The telomeres can be rejuvenated using telomerase delivered to the cells by gene therapy, but there has been concern that the cells might then lead to cancer, since cancer cells exploit telomerase to keep dividing. Researchers at Yale have now found, however, that blood vessel cells into which telomerase has been inserted actually have chromosomal makeups that are more normal than control cells. This suggests encouragingly that adding telomerase in fact protects chromosomal integrity. [G][H]
Reprogramming cancer cells One of the hallmarks of aggressive cancer cells is their unspecified, plastic nature, which is similar to that of embryonic stem cells. The idea was pioneered 30 years ago that the complex signals within an embryonic field might reprogram an adult metastatic cancer cell introduced into such an environment and cause it to contribute in a positive way to an embryonic structure. Scientists in the US have now demonstrated this experimentally in the case of malignant melanoma cells by using the embryonic environment of a chick embryo. The reprogrammed malignant melanoma cells became normal melanocytes, or pigment cells. This result may hold promise in treating malignant melanoma. [G][H]
Growth of human prostate Australian scientists have grown a human prostate from embryonic stem cells. The tissue behaves as a normal human prostate and can be used to test the different hormones and environmental factors that may play a role in the onset of prostate disease. [G][H][M]
Protein-protein interactions A detailed analysis of over 25,000 human protein-protein interactions could help biologists uncover more disease-related gene mutations. A surprising finding is that disease-related proteins, believed to have an important cellular function when working properly, did not necessarily have a high number of interactions with other proteins. [G][H]
Genome signature tagging Scientists at Brookhaven National Laboratory have developed a new, high-throughput technique for identifying the many species of microorganisms living in an unknown “microbial community.” The method has many applications, from assessing the microbes present in environmental samples and identifying species useful for cleaning up contamination to identifying pathogens and distinguishing harmless bacteria from potential bioterror weapons. [G][D][E][H]
Human evolution Human genes involved in metabolism, skin pigmentation, brain function and reproduction have evolved in response to recent environmental changes, according to a new study of natural selection in the human genome. Researchers at the University of Chicago developed a statistical test to find genomic regions that evolution has favoured over the last 15,000 years, from the end of the last ice age, through the beginning of agriculture, and increased population densities. The results show that many recent changes are adaptations in response to new diets and agriculture. [G][E][X]
Human evolution Although their genes are virtually identical, humans and chimpanzees differ substantially. The reason, according to a 30-year-old theory, is because evolution depends much more on changes in gene regulation than in genes themselves. Research has now provided powerful support for this theory. Comparing humans and chimpanzees, the researchers found that genes for transcription factors, which influence the activity of many genetic targets, were four times as likely to have changed their own expression patterns as were the genes they regulate. [G][E][X] |
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| [N] Nanotechnology and molecular technology | |
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Nanoengines The bacterial flagella motor provides a good biomimetic model for creating nanoengines. It is only 50 nm in size, and it has the same power-to-weight ratio as an internal combustion engine, spins at up to 100,000 rpm and achieves near-perfect efficiency. UK and Japanese researchers have unravelled much of how the motor works by changing the proteins normally found in the motor of E Coli to make it run on sodium instead of hydrogen ions. This allowed them to reduce its speed of rotation by lowering the level of sodium ions present. They also made the actions of the motor more easily detectable by attaching tiny beads to stubs of flagella. Ultimately 26 distinct steps could be observed in each of its revolutions. [N][G][H]
Lipid nanocapsules Lipids are the building blocks of cell membranes and they have potential for making artificial vessels for delivering drugs. The problem has been that artificial lipid capsules have been too delicate. Researchers have now found that they can be made stable by adding charged nanoparticles to the solution in which they are growing. The nanoparticles adhere to the capsules and prevent further growth, freezing them at the desired size. As well as transporting enzymes, DNA, proteins and drug molecules throughout living organisms, the capsules could also serve as surrogate factories where enzyme-catalyzed reactions are performed. By attaching biomolecules to the capsule's surface, novel colloidal-size sensors could be produced. [N][G][H][S]
Molecular computing Logic circuits that use enzymes and interconnected chemical reactions to perform calculations have been built at the Hebrew University of Jerusalem. Researchers believe that eventually enzyme-powered computers might be exploited inside living cells for biosensing and control. [N][B][G][H][S]
Nanostructured coatings MIT researchers have devised a new electroplating method that produces a coating of crystals of nickel and tungsten small enough that the resulting alloy is as hard as chromium. The technique could replace metal coatings such as chromium, which is dangerous for factory workers to produce. [N][M]
Nanopipe arrays Intricate networks of nanotubes can be formed spontaneously by depositing a thin film of copper on top of a layered crystal of vanadium selenide. US and German scientists have found that the nano-pipes actually form when the top layer of the crystal buckles upwards to relieve the molecular strain caused by the deposition of the metal. With better understanding, this might enable manufacture of nano-circuits that channel electrons through tiny tunnels. [N][J]
Superconducting nanotubes Physicists in Japan have shown that "entirely end-bonded" multi-walled carbon nanotubes can superconduct at temperatures as high as 12 K. This is 30 times higher than for single-walled carbon nanotubes. The superconducting nanotubes could be used to study fundamental 1-dimensional quantum effects and might also find practical applications in molecular quantum computing . [N][C][J][M]
Atomic wire The smallest wire width in mass produced electronic devices is about 50 nm, or about 500 atoms across. The ultimate limit of thinness would be wires only one atom wide. Dutch and US researchers have made such single atom wires by evaporating a puff of gold atoms onto an ultra clean silicon substrate cut to form staircase corrugations. The gold atoms self-assembled into wires up to 150 atoms long. Using a scanning tunnelling microscope the researchers observed the quantum mechanical excitations in the wire. [N][F][J][S] Nanotube skins Researchers at Rensselaer Polytechnic have developed a new process to make flexible, conducting 'nano skins' for a variety of applications, from electronic paper to sensors for detecting chemical and biological agents. Nanotube arrays tend to lose their shape when transferred because they are held together by weak forces. The new process grows an array of nanotubes on a separate platform and then fills the array with a soft polymer. When the polymer hardens, it is essentially peeled back from the platform, leaving a flexible skin with organised arrays of na | ||