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Top Stories in Science
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December 2007 Issue |
| [D] Defence and security |  |
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Arms embargoes The UN Security Council has imposed 27 arms embargoes since 1990. But, according to a study by the Stockholm International Peace Research Institute, many of these have been completely ineffective and only a quarter have worked well. The study found that embargoes were more like to work if UN peacekeepers were in place. It recommends that the UN Security Council needs to get countries to pass laws making it a crime to violate UN arms embargoes. [D][R]
CFE Treaty Russia has formally suspended its participation in a key arms control agreement dating from the Cold War. The Conventional Forces in Europe (CFE) treaty sets limits on troops and weaponry across Europe. The suspension means Russia can move troops without notifying NATO. Russia is unhappy with NATO expansion and US plans for missile defences in central Europe and says the CFE treaty no longer serves its interests. [D][X]
Nuclear proliferation A report drawing together information from the US's 16 intelligence agencies has concluded with "high confidence" that Iran stopped its nuclear weapons programme in 2003 in response to international pressure and there is "moderate confidence" that the programme has not been restarted. The report says that Iran may still be intending to develop nuclear weapons but is unlikely to have enough highly enriched uranium to build a bomb until sometime between 2010 and 2015. The report is a product of the US's new strengthened approach to intelligence analysis. Russia has delivered its first shipment of nuclear fuel to a reactor it is helping to build at Bushehr in Iran. This should allow Iran to comply with UN demands to halt its own uranium enrichment. [D][P][R]
Post-war-zone stress Post-traumatic stress disorder (PTSD) is known to affect soldiers who have served in war zones, but it may be more common than previously thought. Follow-up health screens given to US troops six months after their return from deployment have found that many who had no symptoms when screened immediately after their return developed serious PTSD several months later. Reservists, who went home to civilian life rather than staying within the military, were the hardest hit. A quarter had PTSD at the second screening and 36 percent were identified as having some kind of mental health problem, such as stress, depression, aggression, or suicidal thoughts. A recent survey of UK soldiers returning from Iraq has found substantially less evidence of stress, but the reasons for the difference are unclear. [D][B][H]
Non-lethal weapons Taser guns are being adopted increasingly by police round the world because they enable a suspect to be disarmed without causing permanent injury. Analyses by British and Canadian police research centres and by the US Air Force found that Tasers are generally effective and do not pose a significant health risk to the recipients of a shock. However, their use is controversial as some people have died. Now, a study led by the UK Defence Science and Technology Laboratory (Dstl) has ruled out the possibility that being TASER-shocked could cause the recipient's heart to beat irregularly. It found that the shock's current density is at least a factor of 60 below the level at which any erratic heartbeats are seen. [D][H]
Carbon nanotube body armour Simulations at the University of Sidney of the impact behaviour of carbon nanotubes indicate that they can absorb huge amounts of kinetic energy and bullets should just rebound off a bullet-proof vest made from such material. The simulations also suggest that the nanotubes are resistant to damage by repeated ballistic impacts. [D][C][M][N]
Carbon nanotube body armour Physicists at Cambridge University have made fibres from carbon nanotubes in a simple one-step process that could be adapted for commercial production. The fibres, which are just a few microns across, consist of hundreds of thousands of nanotubes bound together and are claimed to be stronger than any known material. They could have wide applications including in body armour and flat panel displays. [D][M][N][V] |
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| [A] Aeronautics and space | |
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Aircraft noise A study of the effects of aircraft noise, commissioned by the UK government in 2001, has found that noise at Heathrow is causing "consistently greater" annoyance than was the case in 1980, when the effects were previously measured. An estimated 258,000 people living near Heathrow currently experience noise levels at or above the permitted level of 57 decibels (db) and a further two million local residents experience noise levels above 50 db. The study found that people begin to be significantly disturbed at noise levels above 43 db. [A][E][H][P]
Plasma plumes When coronal mass ejections from the Sun hit the Earth, they cause giant plumes of plasma to form at the edges of the atmosphere. These plumes divert and delay satellite communications and can seriously affect GPS and aircraft navigation. It is not known how the plumes are generated, but there are hints that the plasma originates in the ionosphere above the equator. Scientists now hope to create a network of GPS receivers across equatorial Africa to provide real-time maps of ionospheric distortion over the equator similar to the maps that are already provided by GPS for higher latitudes. [A][R]
Venus Express The first year of results from the seven experiments on ESA's Venus Express mission have revealed that the basic machinery of Venus's atmosphere is similar to Earth's, despite dramatic differences in temperature and chemical make-up. Hadley-like convection cells in the lower atmosphere move between the equator and up to around 60 degrees latitude in each hemisphere. Similar features on Earth are one of the main drivers of the Earth's weather. The experiments have also shown how water in Venus's atmosphere has constantly escaped into space. This supports the view that Venus is not only similar in size to Earth but also started out as Earth's twin, with oceans to match, before evolving into a hot dry greenhouse planet as carbon dioxide accumulated in its atmosphere and the water was lost. [A][E][R]
Water on Mars Scientists have puzzled for decades over a group of mound-like structures, called the Medusa Fossae Formation, located at Mars's equator. Various explanations have been offered, including that they could be piles of volcanic ash or glacier-like structures made mostly of water ice. Now, new radar soundings have probed the material for the first time down to 2.5 kilometres below its surface. The way the radio waves interact with the material suggests that it must be either a vast amount of water ice or an extremely porous rocky material. If it is ice it could provide a water source for future human explorers. [A][R]
Life in other galaxies The spectroscopic signature of organic molecules can be seen throughout the Milky Way. These molecules may have provided the raw materials for life to form on the early Earth and possibly in many other parts of the galaxy. By looking for the presence of organic molecules in other galaxies that are similar to the Milky Way but at an earlier stage of their evolution, astronomers hope to work out how long these molecules have been abundant in the universe and how long the conditions suitable for carbon-based life may have been present. In 2004, astronomers found the signature of polycyclic aromatic hydrocarbons (PAHs) in light emitted from a very early galaxy about 10 billion light years away. However, doubts on this were cast when a wider survey in 2006 failed to find any trace of organic molecules in six other distant galaxies. Now, astronomers using the Very Large Telescope in Chile have found evidence of organic molecules in a galaxy about 2 billion light years away. [A][R] |
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| [U] Unmanned vehicles and robotics | |
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Perching aircraft Robot helicopters and aeroplanes capable of perching on steep surfaces are being developed by researchers at Georgia Tech and by another team at MIT. They say such drone aircraft could land on moving vehicles and unsteady ships and could hide inside caves. [U][A]
Intelligent home robots As a step towards making flexible home robots, researchers at Stanford have developed software that enables a robot to learn how to pick up an object that it has never encountered before. Importantly, the software does not rely on having a 3-D model of the object. Instead it looks for features in the object that a good for grasping, such as a handle. [U][C][K][R] |
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| [P] Propulsion and energy | |
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Improved solid-oxide fuel cells Proton-exchange-membrane fuel cells, the main type being developed by automakers for electric vehicles, can only run on hydrogen. Solid-oxide fuel cells (SOFCs) are more flexible, and can run on natural gas, diesel, and other liquid fuels that are easier to handle. The problem, however, is that SOFCs need to operate at high temperatures, typically 800 to 1000 degrees C, which makes them difficult to package for use in vehicles and portable generators. Now researchers at Harvard have developed a process that produces high-quality solid-oxide electrolytes that are only 25 nm thick - about a thousand times thinner than conventional SOFC electrolytes. The thinner electrolyte allows the SOFCs to run at only 300 degrees C. [P][M][N]
The future of biofuels Expanding the use of biofuels is central to the long-term energy strategy of the US and Europe. But, according to three linked articles in Technology Review, corn-based biofuel is starting to look very unattractive. Diverting land to grow biofuel corn has contributed to food shortages. These have pushed up the price of corn so much that corn-based ethanol is becoming too expensive. There is also risk of famine from reducing land for food production. Moreover, when one takes into account all the carbon costs, it is not clear that producing ethanol from corn even reduces overall carbon emissions. Far more promising is to produce biofuel from cellulose. This can exploit crops such grasses that can be grown on land too poor for producing food. Grasses can also lock up a great deal of carbon in the soil making them even more attractive in reducing carbon emissions. The problem is that to scale up production of cellulosic ethanol to sufficiently large volumes involves major process innovation and massive investment. Ethanol is also not ideal as a fuel, and producing more complex hydrocarbons could be better. [P][A][E][G][T][W]
Biofuel from cellulose Termites are brilliant at digesting wood and they do it with microbes. Termites have a series of stomachs and each is a miniature bioreactor that harbours a distinct community of microbes under precisely defined conditions. Each community performs a different step in the process that converts woody polymers into sugars. If this process could be copied industrially, the sugars could then be fermented to produce biofuels such as ethanol. To help in this quest, researchers at Caltech and the US Department of Energy Joint Genome Institute have now identified more than 500 relevant genes from the termite's microbe communities. They plan next to identify genes for cellulose-digesting enzymes used by other species such as the Australian Tammar wallaby and the Asian longhorned beetle. From this they aim to find the best enzymes that might be used in industrial processes for converting cellulose into biofuels. [P][G]
Biofuel from cellulose A Dutch company is commercialising a process for converting agricultural waste directly into "biocrude," a mixture of small hydrocarbon molecules that can be processed into fuels such as gasoline or diesel in existing oil refineries. The company says the process relies on a nontoxic catalyst and produces clean-burning fuels that can be used in existing engines. On a laboratory scale, the process has been shown to work with many types of biomass from materials such as wood shavings, sugarcane waste, and various grasses. However, for scaling up, a key issue is to make the processing sufficiently simple that plants can be positioned close to the sources of biomass to reduce the cost of transport. [P][E][M]
Fuel from waste Fuel transport is a huge logistical burden for military forces. Around 70 percent of military trucks and convoys that are on the road in Iraq and Afghanistan are transporting fuel. At the same time, the military has to truck out waste from bases to dispose of it. To reduce this transportation burden, both in cost and risk of terrorist attack, the US DOD is developing portable systems that can be used at bases to convert coal, natural gas, and biomass into diesel and jet fuel. [P][A][D][E]
Hydrogen from waste Various methods are being reported to produce hydrogen from plant material and organic waste. Researchers at Penn State have shown that microbial fuel cells can efficiently produce hydrogen from cellulose and other biodegradable organic material. This is first fermented to produce acetic acid, which is consumed by the microbes to produce hydrogen with the help of a bias of 0.2 volts applied to the cell to provide enough potential. Other researchers have recently shown that hydrogen can be generated from organic waste by using algae in fuel cells and that hydrogen can be produced from glycerol using steam. Glycerol is the waste product left in large quantities from producing biodiesel. [P][M]
Technology and energy use An MIT study has found that, in spite of increasing energy prices, technological change per se has not been responsible for much reduction in energy use in the US, and that it may even have made energy consumption worse. The researchers studied the periods 1958 to 1996 and 1980 to 1996 and projected forwards from 2000 to 2050. Based on their findings from the past 50 years, and adjusting for a more realistic expectation for technological changes, they projected that the rates of growth for energy use and emissions in the US may accelerate rather than reduce. However, they observed that where taxes make energy much more expensive, as in Europe, consumption does reduce. [P][E][W]
Carbon sequestration In the Miller oilfield in the North Sea, BP had been pumping seawater into a porous sandstone oil reservoir to enhance the flow of oil. Data from this field reveal that silicates have dissolved rapidly in the newly-injected seawater. This is encouraging evidence that carbon dioxide can be permanently sequestered into depleted oil reservoirs in the North Sea. It indicates that injected carbon dioxide reacts rapidly with the water and minerals in the pores and quickly spreads into its local environment rather than remaining as a giant gas bubble that might later seep back to the surface. [P]
Extracting heavy oil The world has abundant reserves of heavy oil. But, it is very viscous, like syrup, or even solid in its natural state underground, and this makes it very difficult and expensive to extract. Now, however, with the price of crude reaching $100 a barrel, extracting some heavy oils is becoming economically attractive. One approach, developed at the University of Bath, is to inject air into the oil deposit down a vertical well and ignite the oil. The heat generated in the reservoir reduces the viscosity, allowing the oil to drain into a second, horizontal well from where it rises to the surface. This approach, which is being applied to a large field of heavy oil in Canada, is said to recover 70 to 80 percent of the oil, compared to only 10 to 40 per cent using other technologies. [P]
Managing wind power The output from individual wind farms varies according to the strength of the wind. But by interconnecting many wind farms with a transmission grid the power swings caused by wind variability can be greatly reduced. A Stanford study has analysed the optimum way to do this based on data from 19 sites in the US Midwest. By reducing the variability in output it is possible to reduce the electricity transmission capacity required, which is an important cost factor for transmitting wind power over long distances. [P]
China's carbon emissions In September 2007, Chinese officials announced plans to increase the proportion of renewables in China's overall energy mix from 8 percent in 2006 to 15 percent in 2020. This year China will invest more than $10 billion in additional renewable power capacity, including wind, solar, hydropower, biomass, and biofuels. However, according to the IEA, this is not enough to stem the runaway increases in carbon dioxide emissions from China and other rapidly developing countries. It predicts that demand for coal will increase by around 73 percent between 2005 and 2030, with four-fifths of this coal being burnt in China and India. At the same time, global carbon dioxide levels will rise by around 57 percent, with two-thirds of the increase coming from the US, China, India, and Russia. [P][E] |
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| [M] Materials, structures and surfaces | |
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Enzyme catalysis Enzymes are huge protein molecules that play a crucial role in catalysing chemical reactions among other molecules or atoms by lowering the energy barrier that would otherwise keep the reaction from happening. Only a few dozen atoms in the enzyme actually participate in the chemical reaction. However, other parts of the molecule may play a mechanical role. Researchers in Lyon and Lausanne have modelled the stiffer parts of enzymes and believe that some of the energy used in carrying out the catalytic task is mechanical energy in the form of a waggling or “breathing” motion in these stiffer parts. [M][G][N]
Superinsulation Cooper pairs normally give rise to superconductivity. But research at Brown University shows they can also produce an extremely insulating state in which they remain fixed, unable to move as a supercurrent. This very unexpected discovery, which was found using extremely thin samples of the superconductor bismuth, could help in understand the limits of superconductivity. [M][F]
Auxetic composite Auxetics are materials that contain hinge-like structures that flex when stretched. As a result, they becomes thicker when stretched instead of thinner, and this can give high energy absorption and fracture resistance. A EU-funded project called CHISMACOMB (CHIral SMArt honeyCOMB) has developed an auxetic, honeycomb-structure material that can be used in sandwich composite structures and embedded with sensors and electromagnetic actuators. Researchers at Bristol University have shown that CHISMACOMB and other auxetic materials are promising for aircraft wing applications, enabling wings to bend, twist, shrink and expand to continuously optimise their aerodynamic properties during flight. This can be used to reduce drag, noise and carbon emissions. The researchers say that Wing in Ground Effect vehicles (WIG) would make ideal use of this technology. [M][A][E][S][U]
Micro-liver Liver toxicity is one of the main reasons that pharmaceutical companies pull drugs off the market. Unfortunately, this toxicity is often not detected during initial drug trials because they rely on liver cells from rats and these do not always respond to toxins the way human cells do. Now, MIT researchers have devised a way to create tiny colonies of living human liver cells that mimic the human liver and can be used to screen new drugs. They use microlithography to precisely arrange the human liver cells and other supporting cells on a plate, forming colonies 0.5 mm in diameter. These colonies act much like a real liver and survive for up to six weeks. [M][H][J][N][S]
Printing organs A study at the University of Missouri has shown that using ink jet printing to build synthetic tissue does not harm the properties of the constituent cells and that the process in fact mimics the naturally occurring biological assembly of living tissues. In the study, the team used bio-ink particles in the form of spheres containing 10,000 to 40,000 cells, and printed them on to sheets of organic, cell friendly “bio-paper.” Once printed, the spheres began to fuse in the bio-paper into one structure. The researchers found that as the tissue structure begins to form, the cells go through a natural sorting process so that they move to the right locations. For example, an artery has three specific types of cells – endothelial cells, smooth muscle cells and fibroblast cells. Each type of cell needs to be in a specific location in the artery. As thousands and thousands of cells are added to the bio-paper under controlled conditions, the cells migrate automatically to their specific locations to make the correct structure. [M][B][G][H]
"Insect" tape Insects walk on walls and ceilings using two types of attachment structures: smooth pads (e.g. grasshoppers) and hairy surfaces (e.g. beetles and other coleopterans). By analysing hairy attachment for over 300 different species of insects, researchers from the Max Planck Institute and from Case Western Reserve have developed an adhesive tape with the highest stickiness (60 kilopascals) so far achieved for any tape with reversible adhesion. The tape also remains sticky for several thousand adhesion cycles - the highest number ever achieved. If it gets dirty, washing with soapy water restores its initial stickiness. [M][N][W] |
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| [E] Environment, transport and marine | |
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Biodiversity and productivity A new international analysis has provided the most comprehensive evidence yet that natural habitats with a greater variety of plant species are more productive. Diverse communities are more likely to contain highly productive species, but even more important is the way various plants are ‘complementary’ in how they use biological resources. Certain plants dominate the productivity of their natural habitats, but supporting species complement them and enhance the productivity of plant communities even further. [E][G][X]
Photoprotection By having highly tuned defence mechanisms, many plant species can successfully inhabit extreme environments where there is little water, low fertility, strong sunlight and extremes of temperature. Researchers in the UK, France and the Netherlands have now unravelled one key defence mechanism by which certain plants protect their leaves from being damaged by excessive sunlight. They do this by converting the excess sunlight into heat, which is harmlessly dispersed without damaging the leaf's photosynthesis capability. The researchers found this photoprotection depends on a small number of key molecules in the leaf that change their shape when the amount of light absorbed is excessive. The researchers were also able to track the conversion of light energy to heat, a process that takes less than a nanosecond. Understanding photoprotection may enable food and biofuel crops to be developed to thrive in harsher environments. [E][G][P]
Drought resistant plants Genetically engineered crop plants that survive droughts and can grow with 70 percent less irrigation water have been developed by an international team. The researchers inserted a gene that interrupted the process of programmed leaf cell death that normally leads to the loss of the plant's leaves during drought. The resulting plants survived on just 30 percent of the normal amount of irrigation water and went more than two weeks without being watered, during which they maintained relatively high water content and continued their photosynthetic activity. All the normal plants grown as controls died, but the GM plants had only a minimal reduction in yield. The experiments were done on tobacco, chosen because it is big, fast growing and a good model for many other crop plants. The researchers are hopeful that similar results will be found in crop plants such as tomatoes, rice, wheat, canola and cotton. [E][D][G][P]
Saving the Amazon Scientists at Oxford University and the UK Meteorological Office, together with leading experts on Amazonian science, have examined options for preserving the Amazon forest and protecting its species as the global climate changes. They have concluded that the forest's deep root systems and the ability of the plants to acclimatise to the increased temperatures and lack of water mean that the forest is resilient to climatic drying and is unlikely to disappear provided that it is left intact. However, this resilience breaks down when the forest is opened up and fragmented by roads, logging and agriculture, and areas become vulnerable to fires. Once burnt, a forest becomes even more vulnerable to further risks of fires, and once the forest starts breaking up, rainfall in the region is likely to decline. [E][D][X]
Greenland icecap melting As the Greenland icecap melts, the loss in the weight of ice is causing the bedrock underneath to rebound upwards. Measurements from GPS receivers located on the bedrock below the ice show that the landmass is rising by up to 4 cm a year, notably on the south-east tip of Greenland. The researchers say that the rate of uplift has dramatically accelerated in recent years. They calculate that the uplift is due partly to the ice cap melting but mainly to glaciers flowing more rapidly out to sea. This is consistent with other evidence of polar meltdown. [E][D][R]
Carbon efficient homes The UK government is introducing legislation that will require carbon dioxide emissions in the UK to be cut by at least 60 percent from 1990 levels by 2050, and possibly by as much as 80 percent. A report by Oxford University's Environmental Change Institute projects how carbon emission from UK homes could be cut by up to 80 percent by 2050. The report's blueprint includes: legally binding emission targets obliging the housing sector to cut emissions by 3.8 percent each year from 2008; building new homes in urban areas to increase the density of dwellings, cut car use and encourage take-up of micro generation systems; "robust programme" of tax incentives; reducing VAT on energy efficient goods; developing a database of energy efficiency for every home, and targeting funding at those in greatest need of support. [E][M][P][W]
Water technology A portable dew-harvesting kit inspired by the way that spiders' webs collect early morning dew is being developed by Israeli architects. This design is aimed at areas that have a heavy dew fall, such as the edge of deserts. A prototype system that used a 10 metre square canopy of canvas attached to trees by ropes collected more than 20 litres of water in a day. [E] |
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| [R] Remote sensing and sensor systems | |
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Ocean monitoring array Seven years after its initiation, the international ocean observing array, known as Argo, has hit its initial target of operating 3,000 robotic floats in ice-free areas of the deep ocean around the world. The floats, spaced about 300 kilometres apart, systematically gather information about temperature and salinity to a depth of 2,000 metres. This information is improving climate forecasts and providing new insights into how the ocean and atmosphere interact. A particular benefit has been to improve the accuracy of calculations of ocean heat storage, which are key in determining the rate of global climate warming and sea level rise, now and for the future. [R][E][U]
Ocean observing system Warming seas, overfishing and pollution mean it is vital to improve the system for monitoring the world's oceans, according to the Partnership for Observation of the Global Oceans (Pogo), which includes many of the world's leading oceanographic research centres. An "adequate initial system" would include a stable network of satellites surveying vast extents of the surface of the oceans; fixed stations taking continuous measurements on the seafloor or as floats and buoys moored in the water column and at the surface; small robot submarine ocean monitors, some drifting with the currents, others motoring along programmed routes; marine animals ingeniously outfitted with electronic tags that equip them to capture and transmit data about the environments they visit; merchant marine and research vessels, opportunistically observing along their routes. [R][A][D][E][I]
Locating geothermal energy sources The helium isotope He-3 is made only in stars, but the Earth's mantle still retains considerable amounts of He-3 from the formation of the solar system. The Earth's crust, on the other hand, is rich in radioactive elements like uranium and thorium that decay by emitting He-4 nuclei. By measuring the ratio of He-3 to He-4 in ground water coming up to the surface, researchers at Lawrence Berkeley and the University of Arizona can tell whether it comes from the crust or from much deeper in the mantle. This provides a way to locate new sources of geothermal energy. [R][E][P]
World Digital Magnetic Anomaly Map The first global map of Earth's magnetic anomalies - caused by differences in the magnetisation of the rocks in the Earth's crust - has been assembled by an international team of researchers. To produce the map has taken many years of negotiation to obtain confidential data from governments and institutes. The map shows the variation in strength of the magnetic field after the Earth's dipole field has been removed. This varies from 35 microTesla at the Equator to 70 microTesla at the poles. After removal of the dipole field, the remaining variations of a few hundreds of nanoTesla are due to changes in the magnetic properties of the crustal rocks. As well as revealing ore deposits, magnetic anomalies can also show areas of ground water and sea weakness zones. [R][A][D][E][M]
Observing proto-galaxies Tiny galaxies, which may be the first building blocks of middle-size galaxies like the Milky Way, have been detected by an unprecedented long exposure taken with the 8.2-metre Antu telescope at the Very Large Telescope (VLT) observatory in Chile. The long exposure revealed 27 faint galaxies whose size and brightness suggest they are between 1 and 10 percent as massive as the Milky Way. Their distance means they are being observed at a time around 2 billion years after the big bang. Some even more distant galaxies have been observed previously, appearing as they were just 500 million years after the big bang. These may be the precursors of giant elliptical galaxies, the largest galaxies in the modern universe. [R][A][F]
Ultra-low field MRI scanner Conventional MRI scanners require large powerful magnets that can produce fields of several tesla. This makes MRI scanners expensive. In 2004, researchers at UC Berkeley showed that it is possible to produce MRI scans with magnetic fields a hundred times smaller by exploiting ultrasensitive SQUID detectors. The first demonstration used just one SQUID, but now researchers at Los Alamos have built a system with seven SQUIDs and have used it to scan the human brain. The scanner first hits a sample with a 30 millitesla magnetic field and then uses just 46 microtesla to capture images of the sample. The machine can also be used for magnetoencephalography (MEG), using the SQUID detectors to pick up the very weak magnetic fields produced by electrical activity in the brain. [R][B][H][S]
Advanced computer-aided tomography A new CT scanner has been unveiled which can produce 3D body images of unprecedented clarity while reducing radiation dose by as much as 80 percent. It also generates images in a fraction of the time of other scanners: a full body scan takes less than a minute. [R][B][C][H][V]
Seeing molecular processes in living cells To study the biochemical processes in a cell, scientists normally have to cut through the cell's outer membrane to separate and analyze the cell's components. This kills the cell and provides only a snapshot of the cellular processes. Bioengineers at UC Berkeley have shown how to obtain a dynamic view of the molecular processes inside a living cell by using metallic nanoparticles inserted into the cell. This exploits the fact that it is easy to detect the optical absorption due to the plasmon resonance within a nanoparticle. Then, when a biomolecule attaches to a nanoparticle, energy exchange between the molecule's characteristic excitations and the plasmons shows up very sensitively as dips in the nanoparticle's plasmon optical absorption spectrum. This makes it possible not only to see what reactions are occurring but also where in the cell they are happening. [R][G][O][S] |
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| [S] Sensor devices | |
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Origami MEMS sensor Researchers in the US and Taiwan have developed a MEMS ultrasound probe that could provide panoramic views from inside the human body. Because of the short range, the probe can use high frequency ultrasound, which gives high resolution images. Such high frequency ultrasound cannot be used by external scanners because it can only penetrate short distances through tissue. The probe is shaped like a hexagonal tube about 1 mm across and 1 mm long, small enough that it can be threaded through blood vessels in the brain or swallowed as a pill. It is fabricated flat on a silicon wafer and is then folded to form the tube. [S][B][H][J][R]
Tomographic energy dispersive diffraction imaging (TEDDI) Conventional x-ray imaging systems, such as spiral CAT scanners, waste a lot of the available information. Now, scientists at the University of Manchester have developed a prototype X-ray system that harnesses all of the wavelengths in an x-ray beam to give a 3D colour x-ray image. The scientists say that the extra information can fingerprint the material present at each point in the 3D image, and the time taken for a sample scan is also reduced from hours to just a few minutes. This speed eliminates the problem of radiation damage for biomedical applications, allowing biopsy samples to be studied and normal tissue types to be distinguished from abnormal. Other potential applications are for identifying explosives, cocaine, heroin and other biomaterials in freight, and for strain-scanning whole fabricated components in the automotive or aerospace industries. Key to the new technology are energy sensitive detectors developed in collaboration with Rutherford Appleton and Daresbury Laboratories, and a 2D x-ray collimator developed with Cambridge University. [S][A][D][H][J][M][O][R][W]
Cheap tiny magnetic sensors Researchers at the NIST have developed arrays of tiny magnetic sensors that can each detect magnetic field changes as small as 70 femtoteslas. Each sensor consists of a single milliwatt infrared laser and a rice-grain-sized container holding a gas of about 100 billion rubidium atoms. These absorb the laser beam by an amount that increases with magnetic field. Other researchers have previously made similar magnetometers, but the NIST team used microfabrication techniques to miniaturize the vapour cell and to make the technology suitable for cheap mass production. The researchers say that arrays of the sensors could be battery-operated and could reduce the costs of non-invasive biomagnetic measurements such as foetal heart monitoring and magneto-encephalography (MEG), which measures the magnetic fields produced by electrical activity in the brain. The sensor arrays might also be used for detecting improvised explosive devices and mines. [S][B][D][H][J][O][R][V]
Free-surface microfluidic SERS US researchers believe that, using surface-enhanced Raman spectroscopy (SERS), they can improve the sensitivity of detecting explosives or drugs by as much as three orders of magnitude. Their method uses SERS to analyse molecules that are absorbed from the ambient air onto gold or silver nanoparticles in a microfluidic stream of water. The water flows in microchannels just a few microns deep that have a hydrophilic bottom to hold the water in place. They researchers think their technique can detect in a few seconds just a handful of molecules absorbed into the water surface. [S][D][J][N][O]
Cancer screening chip Malignant tumours continually shed cancer cells into the bloodstream. However, the concentration of these cells is extremely low - only about one per billion cells - and it has not been possible to detect them easily or accurately enough to be clinically useful. Now US researchers in Boston have designed a microfluidics device that can analyze whole blood in large enough volumes to detect these scarce tumour cells. The device consists of a business-card-size silicon chip dotted with 80,000 microscopic posts. Each post is coated with a molecule that binds to a specific protein found on most cells originating from solid tumours. When tested on blood samples from 68 patients with five types of cancer, the device detected cancer cells in all but one sample. Researchers also found that changes in the number of circulating cancer cells accurately reflected changes in the size of patients' tumours during treatment. [S][H][J]
Laser fingerprint scanner A portable device that uses optical coherence tomography (OCT) to image fingerprints has been developed by scientists in India. It sends light though the print and combines the reflected beam with a "reference beam" produced by bouncing light from a laser off a mirror. This produces an interference pattern at a photodetector, which can then be used to reconstruct a 3D image of the original fingerprint. The system has the advantage over conventional fingerprint detection methods that it provides 3D with high sensitivity and clarity and does not require any chemical processing. [S][D][O][R]
Atom flow gyro US researchers have for the first time demonstrated a superfluid flow of atoms in a Bose-Einstein condensate (BEC). The researchers applied laser light and magnetic fields to an ultracold gas of sodium atoms to create a donut-shaped BEC. This configuration stabilises circular superfluid flows, which are produced by the atoms absorbing the angular momentum of the laser photons. The experiment may provide ways to study the fundamental connection between BECs and superfluids. More practically, the technique may lead to ultraprecise navigation gyroscopes. [S][A][E][F][J][O][R][U] |
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| [O] Optoelectronics, optics and lasers | |
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Electromagnetic wormhole In the same way that negative refractive index metamaterials can be used to produce an invisibility cloak, so also they might be used to create an electromagnetic wormhole, according to mathematicians in the US, UK and Finland. They say that potential applications could include “optical cables” for measuring electromagnetic fields without disturbing them, or making a 3D video display. By placing a bar magnet close to one end of a wormhole, the magnetic field would emerge seemingly from nowhere at the other end and become a magnetic monopole. [O][M][S][V]
Negative refractive index modulator A negative refractive index material can be used to make a high speed optical modulator, according to researchers at Hewlett Packard and UC Berkeley. They achieved 50 percent modulation of a 1.7 micron infrared laser beam and found that the material could be switched in as little as 58 ps. This means the existing device can be switched at several tens of gigaHertz, and with optimisation, it may be possible to achieve 100 GHz. The modulation was produced optically using a 532-nm wavelength visible laser. [O][I][J]
Trapped rainbow optical storage Researchers at Surrey and Salford Universities have shown theoretically how it should be possible to slow down, stop and capture light using a negative refraction metamaterial. Unlike previous approaches, the technique does not involve using cryogenic temperatures and it works with a wide range of frequencies of light rather than just a single frequency. The theory shows that in a tapered layer of glass surrounded by two suitable layers of negative refractive index metamaterials, a packet of white light injected from the wide end will be completely stopped at some point. Each light frequency would be stopped at a different stage down the taper, creating a ‘trapped rainbow’. There are many potential applications in optical data processing and storage, optical fibre communication networks and integrated photonic signal processors, and also for quantum optical memories. [O][C][I][R]
Airy beams By using a computer-controlled spatial light modulator (SLM), scientists at the University of Florida have made the first observation of an unusual class of optical waves called Airy beams. Unlike most types of light waves, Airy beams have the ability to resist diffraction over long distances, and can also freely accelerate during propagation. The SLM modulated the phase of a Gaussian beam, which was then imaged on a CCD camera. The scientists used different phase masks to generate either one- or two-dimensional Airy beams. [O][C][I][R][V]
Attosecond technology Researchers at the University of Bath have made an important step towards generating pulses of light only an attosecond long. Such extremely short pulses could be used to study movement of electrons and other sub-atomic particles and to probe quantum systems. To make attosecond pulses requires creating a broad spectrum of light extending from visible to x-ray wavelengths through an inert gas. This normally requires a gigawatt of input power. But, by using a hollow photonic crystal fibre, the researchers trapped light and gas together and produced a broad spectrum with about a million times less power. The light is trapped inside the fibre core in modes called bound states within a continuum. The existence of these bound states between photons was predicted theoretically in the 1930s, but not observed experimentally until now. [O][F][N][S][X]
Femtosecond laser therapy Physicists at Arizona State University have developed a laser technique that can destroy viruses and bacteria such as AIDS without damaging human cells. It may also help reduce the spread of hospital infections such as MRSA. It exploits a process called Impulsive Stimulated Raman Scattering (ISRS) in which femtosecond laser pulses produce lethal vibrations in the protein coat of microorganisms. The wavelengths and pulse widths are selected to avoid any damage to human cells, which have different structural compositions in their protein coats compared with bacteria and viruses. [O][H]
Opto-nanomechanical devices Researchers at MIT have proposed theoretically how one could make "smart" optical microchips featuring tiny machines with moving parts that respond to the radiation pressure of the light. A resonator based on this concept could automatically lock on to the frequency of the light, self-aligning its resonance to the control frequency and thereby allowing all-optical tuning and dimension control. Such chips might be used to remotely adjust the amount of bandwidth available in an optical network, or to automatically process signals flowing through fibre-optic networks, without using any electrical power. To take advantage of the radiation pressure, the machines are built from micron-scale ring-shaped cavities located on the chip surface. When the radiation pressure on the cavity walls is high enough, the cavity is forced to move. By coupling the resonating cavities with nano-scale cantilevers, optical devices analogous to MEMS devices can be created. [O][I][J][N]
Josephson terahertz source The ac Josephson effect can be used to generate terahertz radiation. The power output from a single Josephson junction is only picowatts. But, by stacking around a thousand Josephson junctions on top of one another and making them radiate coherently in phase with each other, researchers at Argonne National Laboratory and colleagues in Turkey and Japan have generated frequencies from 0.4 to 0.85 terahertz at a signal power of up to 0.5 microwatts. They used a high-temperature semiconductor called BSCCO that naturally contains stacks of Josephson junctions in its structure. It is comprised of superconducting sheets, a couple of atoms thick, separated by 1.5 nanometre insulating gaps. Applying the right voltage across the structure created a stationary electromagnetic wave that caused the junctions to all emit coherently. [O][D][M][R]
Testing Coulomb's law Coulomb’s inverse-square law states that the force between two electric charges is inversely proportional to the square of the distance between the charges. The law is a cornerstone of electromagnetic theory and if it were found not to hold, Maxwell’s equations and the Standard Model of particle physics would have to be modified. In 1983, the inverse square law was shown to be correct within 1 part in a 100,000 trillion (10^17). Now US researchers have proposed a new way, based on “charged-particle matter-wave interferometry” that could tests for deviations from the inverse-square law as small as one part in 10 billion trillion (10^22). [O][F]
Testing special relativity In Einstein's theory of special relativity, clocks that are moving with respect to an inertial system of observation are measured to be running slower. This effect, called time dilation, is described by the Lorentz transformation. Physicists in Germany and Canada have now verified this with ten times greater precision than ever before. They did this by improving on a technique called laser saturation spectroscopy to measure the time dilation of groups of lithium-7 ions injected at high speed into a magnetic storage ring. Time dilation would make it possible for passengers in a fast-moving space vehicle to travel further into the future while aging very little. Indeed, with a constant acceleration of just 1 g, a human space voyager could, because of time dilation, travel in one human lifetime as far as light has been able to travel since the big bang. [O][F] |
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| [I] IT, communications, networking and secure systems | |
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Nanotube radio Researchers at Lawrence Berkeley and UC Berkeley have created the first fully-functional radio made from a single carbon nanotube. The nanotube serves simultaneously as all essential components of a radio: the antenna, tuneable band-pass filter, amplifier, and demodulator. Using carrier waves in the 40-400 MHz range, the researchers demonstrated successful music and voice reception for both FM and AM signals. The nanotube radio essentially assembles itself and can be easily tuned to a desired frequency band after fabrication. Nanotube radio technology might lead to a new generation of wireless communication devices and monitors and could prove especially valuable for biological and medical applications. [I][G][H][M][N][S][V]
Shake-to-connect UK researchers have developed prototype software that allows a secure wireless link to be established between cellphones or other wireless devices just by holding them together and giving them a shake. Built in accelerometers are used to measure the movement of each device as it is shaken. Only if the devices are held tightly together will their accelerometer readings match perfectly, which tells the system it is safe to establish a connection. The researchers claim that this method is easier and more secure than selecting a device name from a list or entering a security code. [I][V]
Entropy-based cyber security To combat more powerful cyber-threats, such as Storm worms, researchers are developing a new generation of algorithms based on concepts related to entropy. Entropy-based security works because a worm's malicious activity changes, in subtle but unavoidable ways, the character of the flow of data on a network and hence the entropy of the network. Entropy-based programs can detect anomalous network behaviour in seconds, even on so-called backbone networks running at 10 billion bits per second. This means the software is fast enough to block threats that can span the globe in minutes. The normal traffic on the network is first monitored for long enough to determine which internal states of the system are associated with well-behaved Internet traffic. Then malicious activity introduced into the network can be detected because it has a designed, premeditated outcome that is different from any of the network's normal states. [I][K][T]
Suicide node network defence Computers on a distributed networks have no centralised control. Instead, organisation of the network is distributed between individual devices. This can make the network more efficient and robust, but there is a security risk that some devices may be compromised and made to transmit misleading data. Researchers at the University of Cambridge have proposed a way to defend against this. Their approach works by giving each and every devices on a network the ability to disconnect any nearby device deemed to be malevolent but at the cost of also disconnecting itself. [I][D] |
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| [K] Knowledge, information and technology management | |
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Telecommuting A meta-analysis of 46 studies of telecommuting involving 12,833 US employees has found that telecommuting gives many benefits, notably small but favourable effects on perceived autonomy, on work-family conflict, on job satisfaction and performance, and on turnover intent and stress. Also, the meta-analysis found that telecommuting has no damaging effects on the quality of workplace relationships or perceived career prospects, except that employees who worked away from their offices for three or more days a week reported some worsening of their relationships with co-workers. Telecommuting may be particularly beneficial for women. Study samples with greater proportions of women found they received higher performance ratings from their supervisors and that their career prospects were improved. [K][I][W]
Solving problems Computer-mediated group brainstorming, done across the web with no face-to face contact, is thought to provide a particularly cost effective way to generate ideas and solutions to problems. Compared to face-to-face brainstorming, it is touted as having the advantages of shorter meetings, increased participation by remote team members, and better documentation via electronic recording. However, experiments to test this by Sandia National Laboratory showed surprisingly that individuals working on their own to solve problems on their own were even more successful than groups in computer-mediated brainstorming. [K][V]
Smart phones Researchers at PARC have developed software that turns a mobile phone into a thoughtful personal assistant. Called Magitti, it uses a combination of cues, including time of day, location, past behaviours, recent text messages, to infer the user's current interests. It then shows a helpful list of suggestions, including concerts, movies, bookstores, and restaurants. The software will shortly begin public trials with young adults in Tokyo. This type of approach also opens the way for contextual personal advertising over mobile phones. [K][E][I][R][U][V][W]
Cognitive assistant A project funded by DARPA to produce a cognitive assistant that learns and organizes (CALO) is combining the expertise of researchers from 25 universities and corporations in many areas of artificial intelligence, including machine learning, natural-language processing, and Semantic Web technologies. CALO tries to assist users in three ways: by helping them manage information about key people and projects, by understanding and organizing information from meetings, and by learning and automating routine tasks. CALO can interact with other people, take on tasks such as scheduling meetings, coordinate among people's schedules, and make decisions such as deciding to reschedule a meeting if a key member becomes unable to attend. Importantly, CALO combines logical structure that is good at handling meaning with probabilistic approaches that are good at handling noise and uncertainty. [K][C][D][U][V][W]
Searching virtual worlds Much of the entertainment value of virtual worlds such as Second Life lies in creating objects and trading them. So it is important to be able to find objects easily. Search engines are now being introduced in virtual worlds that can search for objects and for information about residents, such as their hobbies. This will make it easier to interact purposefully in a virtual world. Moreover, as virtual worlds become linked, it is even more important for users to be able to search multiple worlds to find what they want. However, the search still depends on tags labelling objects and places. What is really needed is the ability to recognised things automatically within a context of space and time. [K][V][X]
Networking technology and business An article in McKinsey quarterly reviews how business is being reshaped by networking technology. Advances in open standards mean that customers, suppliers, small specialist businesses and independent contractors can all be involved in co-creating and co-innovating sophisticated software and hardware products. Networking makes it possible to tap into top talent globally. Tools that promote tacit interactions, such as wikis, virtual team environments and videoconferencing may become as ubiquitous and essential to business as computers are now. Digital tagging allows much more to be automated and can join up islands of automation. Fixed assets can be utilised more efficiently by disaggregating monolithic systems into components that can be reused in many different value chains. The quality and quantity of information available to any business will continue to grow explosively and the challenge will be to use it well. The richness of information and search capabilities will make markets more and more transparent. [K][I][W][X]
Chinese research China overtook Japan and the UK to become the world's second most prolific producer of scientific research papers after the US in 2006, according to new figures from the Institute of Science and Technology Information of China (ISTIC). It says that Chinese scientists published 172,000 papers in major international journals and meetings in 2006. This is 8.4 percent of all papers published in the year. [K] |
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| [C] Computing, supercomputing, modelling and simulation | |
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Berry's phase quantum computing If a classical particle is subjected to a cyclic process, its final state is indistinguishable from its starting state. However, if a quantum state is subjected to a cyclic adiabatic process its phase is changed by an amount called Berry's phase. By cycling a quantum system around a closed loop, the changes in the Berry’s phase can be used to perform calculations. Importantly, Berry's phase depends only on the area enclosed by the cyclic path taken through the co-ordinate space and not on the precise path. So it is less affected by noise in individual co-ordinates. Hence a quantum computer exploiting Berry's phase is less vulnerable to noise causing decoherence. Quantum operations based on Berry’s phase have already been achieved in nuclear magnetic resonance and trapped-ion systems. Now, researchers in Switzerland, Canada and the US have also demonstrated it with solid-state superconducting qubits. [C][J][M][N]
DNA-based amplification If DNA-based computing is to have practical applications, it must include amplification. If, say, a circuit has to detect the presence of a tiny amount of DNA in its environment, the DNA would have to be "amplified" before the circuits could work. Polymerase chain reaction (PCR) can take a miniscule amount of DNA and amplify it exponentially, but the process relies on enzymes. Now researchers at Caltech have shown how to perform DNA amplification without needing enzymes. Their method exploits the fact that complimentary stretches of DNA will bind together. A "catalyst" strand of DNA is used to pull another strand free from several strands bound together. Once the target strand has been freed, another strand is used to detach the catalyst. The cycle then repeats. So a small amount of catalyst material releases a large amount of the output molecule. The reaction is also programmable, in the sense that one can choose the exact sequences of the various molecules to fit the design of a particular DNA-based digital circuit. [C][G][S]
Computational proteomics The IBM World Community Grid is the world's largest public humanitarian grid with more than 333,000 members and links to more than 780,000 computers. Eight projects have been run so far, including protein folding and FightAIDS@Home, which completed five years of HIV/AIDS research in just six months. Additional projects are in the pipeline including one to study the specific functions and interactions of proteins in the body and how defective proteins are related to cancer. This is using more than 86 million images of 9,400 unique proteins that could be linked to cancer, captured in the course of more than 14.5 million experiments. [C][G][H]
Simulating the brain Scientists in Switzerland working with IBM researchers have shown that their computer simulation of the neocortical column, arguably the most complex part of a mammal's brain, appears to behave like its biological counterpart. The researchers say these results suggest it should be possible within three years to model an entire mammal brain. The neocortical column of a rat's brain contains around 10,000 neurons and 30 million synaptic connections. A complete rat brain has about 200 million neurons and a human brain contains 50 to 100 billion neurons. A key question is whether by modelling specific brain functions it will be possible to understand behaviour. [C][B][U][V][X]
Simulating the brain Researchers at MIT are developing new imaging techniques and machine-learning algorithms to automatically construct wiring diagrams of the brain. So far they have used this to generate a partial wiring diagram of part of the rabbit retina. [C][B][K][R][V] |
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| [W] Whole life engineering, manufacture and testing | |
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MEMS design and manufacture MEMS manufacturing is extremely complex, involving sometimes hundreds of different steps. Each step may be controlled by a dozen or more parameters, including temperatures, pressures and chemical compositions. Because MEMS devices depend on mechanical as well as electrical properties, a small variation in any manufacturing parameter at any step could alter the performance. A European project has now developed software that can test, simulate, track and share new manufacturing processes. It will make it much easier to transfer MEMS devices into production and should greatly reduce the development times of complex MEMS devices. [W][J][N][S]
Nanosoldering Physicists at UC Berkeley have come up with a cheap, quick "nanosoldering" technique for connecting nano-sized objects without contaminating them with resists and solvent. The technique could be used to make clean electrical contacts between advanced structures such as graphene, nanowires and nanotubes. The researchers say it could open the way to building nanomachines piece-by-piece by fusing small components together, rather than using complicated chemical methods. [W][N]
Energy productivity According to a McKinsey study, the growth in worldwide energy demand can be cut in half or more over the next 15 years without reducing the benefits end users enjoy. The key is a concerted global effort to boost energy productivity. [W][E][P][X] |
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| [X] Systems, complexity and risk | |
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Profitability of fish stocks Australian and US researchers have modelled the relationship between fish stocks and profitability and have found that the more overexploited the fishery, the greater the profit gain from cutting catches and allowing stock rebuilding. Their results show that the highest profits are made when fish numbers are allowed to rise beyond levels traditionally considered optimal. This is because when fish are more plentiful, they are much cheaper to catch. The study modelled outputs for four different fish, plotting revenue and profit curves against fish biomass. The concept is already being taken up in Australia, the first country to change its harvest strategy to reflect the profit-maximizing stock calculation. But for it to work, fishermen must be guaranteed long term harvesting rights, so that they can reap the reward of waiting. [X][E]
Random-walk processes French physicists have developed a general theory that allows accurate evaluation of the mean First Passage Time (FTP) in complex media. Evaluating FTP is important in many contexts including biological modelling, neural firing dynamics, population genetics, spread of disease, and other random-walk stochastic processes. The scientists state that they have developed an analytical approach that provides a universal scaling dependence of the mean FTP on both the volume of the confining domain and the source-target distance. [X][B][C][G][I][M]
Predicting epidemic risk A new model to predict the spread of emerging diseases has been developed by researchers in the US, Italy, and France. It is based on actual travel and census data for more than three thousand urban areas in 220 countries, and predicts how likely an outbreak will be in each region and how widespread it might become. The model was tested using historical records of the global spread of the SARS virus in 2002-03. The results fitted very accurately with the actual pattern of the spread of SARS. It identified possible paths of the virus' spread along the routes of commercial air travel, highlighting particular epidemic pathways for the global spread of the disease. The researchers say this demonstrates the power of such modelling as a general tool in the analysis and forecasting of the global spreading of emerging diseases. [X][A][C][D][E][H] |
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| [V] Virtuality and human-machine interface | |
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Wearable camera A small digital camera developed by Microsoft Research UK can boost memory in people with mild Alzheimer's disease and loss of short-term memory. The camera is worn round the neck and takes wide-angle, low-resolution photographs every 30 seconds. It contains an accelerometer to stabilize the image and reduce blurriness, and it can be configured to take pictures in response to changes in movement, temperature, or lighting. The pictures can be collapsed into a movie that users can later review to jolt their memory. In some cases this can lead to long-term retention of memories over many months without the need to view the images repeatedly. [V][B][H][K][U]
Tracking moving objects It was thought that people cannot track more than four moving objects simultaneously. Now, experiments at Northwestern University suggest that people can track as many as eight moving objects provided that the objects are moving quite slowly. The finding could have wide implications, for example in video game design and air traffic monitoring. [V][A][B][C] |
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| [B] Brain research and human science | |
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Sleep and memory Scientists at the University of Arizona have shown that during sleep the brain reactivates memories of real-time experiences at a rate that is as much as six or seven times faster than the patterns were experienced when awake. They believe this faster speed enables the brain to reprocess temporary memories several times in order to find the best way to store them permanently. [B]
Building new brain circuits Understanding how new neurons integrate into the brain is important for using adult neural stem cells to replace brain cells lost by trauma or neurodegeneration. Researchers at Yale have studied how new neurons are integrated into the olfactory bulb. They found that the new neurons continue to mature for six to eight weeks after they are first generated and receive input from higher brain regions for up to 10 days before they can make any outputs to existing neighbouring cells. The other brain regions then continue to provide information to the new neurons as they integrate into existing networks. [B][H]
Neurite growth MIT researchers have identified that a family of proteins, called Ena/VASP proteins, are key to the formation of brain networks. The majority of neurons in the cerebral cortex have a single axon - a long, thin extension that relays information to other cells - and many shorter dendrites, which receive messages from other cells. The interconnection of these axons and dendrites is essential to create a functional neural circuit. It was already known that Ena/VASP proteins are involved in axon navigation. The new research shows they are also critical for the formation of neurites, which are the precursors of axons and dendrites. Understanding how neurites form could eventually make it possible to stimulate neurite growth to achieve brain repair. [B][H]
Brain rejuvenation Researchers at UC Irvine have shown that administering neural stem cells can rejuvenate the learning and memory abilities of mice that have been engineered to lose neurons in a way that simulates the aftermath of Alzheimer's disease, stroke and other brain injuries. However, the experiments showed surprisingly that the stem cells did not transform into new replacement neurons as was expected. Instead, they apparently rejuvenated the existing neurons by protecting them from committing suicide (apoptosis) and causing them to strengthen their interconnections and keep functioning. The researchers believe the stem cells are doing this by secreting a neurotrophin - a molecule that helps to stimulate and control neurogenesis. [B][G][H]
Protecting brain cells Two new animal studies have revealed that the transformation of amyloid beta into plaques in Alzheimer's disease can be prevented through an interaction between amyloid beta and another protein called cystatin C. The findings point to potential new treatments that mimic the effects of cystatin C. Recent studies have also shown cystatin C helps protect against a variety of insults that cause cell death in the brain. [B][G][H]
Treating MS Amiloride, a drug that has been used for decades to treat high blood pressure, may also be effective in treating multiple sclerosis (MS), according to research at Oxford University. In experiments on mice with a condition that mimics MS, amiloride was found to reduce degeneration of nerve tissue. It works by blocking the build up of high levels of calcium in nerve cells, which can lead to nerve damage. [B][H] |
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| [H] Healthcare and medicine | |
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Cataracts and protein clumping Milky-white cataracts, the world's leading cause of blindness, can occur when proteins in the lens of the eye aggregate into clumps. Researchers have found that although one pure lens protein forms clumps, a mixture of that same protein with another lens protein is less clumpy. By comparing experiments with extensive computer simulations, they conclude that the effect arises because the two proteins attract each other, but not too strongly. The findings could have benefits beyond cataract research because controlling similar attractions could help keep particles dispersed in material and food processing. [H][M][G]
Community-associated MRSA Methicillin-resistant Staphylococcus aureus (MRSA) normally infects people in hospital who have a weakened immune system. But a new form, known as community-associated MRSA (CA-MRSA), has recently emerged that can spread rapidly among healthy people. Researchers at NIAID have discovered that CA-MRSA is able to weaken the immune system in healthy people by producing a protein called phenol-soluble modulin (PSM) that kills immune cells by puncturing their membranes. [H][G]
Antibacterial clay There are anecdotal accounts dating back over millennia that clay has medicinal value, particularly in cleansing and protecting the skin. Now researchers studying a special type of French clay have found that it kills a diverse array of bacteria, including MRSA and other antibiotic-resistant strains and a particularly nasty pathogen that causes skin ulcers and leads to many amputations in Central and Western Africa. The hope is that identifying the chemical(s) and conditions in the clay that are producing this powerful antibacterial effect could be a big step in fighting bacterial infections that have no known cures. [H]
Preventing heart attack damage Following a heart attack, cardiac cells perversely die just as emergency treatments restore blood flow. Researchers at Ohio State have found that this happens because restoring blood flow causes mitochondria to trigger cell death. When the mitochondria are subjected to ischemia followed by reoxygenation, a boost of calcium occurs in the mitochondria and this triggers an enzyme to begin churning out toxic levels of the free radical nitric oxide. The high level of nitric oxide causes the mitochondria to send the death signal to the cell. The researchers do not know what causes the calcium boost, but they hope they may be able to prevent the cell death by inhibiting the enzyme and thereby stopping the production of nitric oxide. [H][G]
How the placenta survives attack The placenta acts like a parasite to hide itself from a mother's immune system and to thereby avoid attack, researchers at the University of Reading have found. They say it employs a cloaking mechanism very similar to that used by parasitic worms. The findings may help to provide better understanding of recurrent miscarriages and pre-eclampsia, and mimicking this method of avoiding immune rejection may also provide ways to tackle conditions like arthritis. [H][G]
Cancer-immune-system equilibrium A multinational team of researchers has shown that the immune system can stop the growth of a cancerous tumour without actually killing it. The results may help explain why some tumours seem to suddenly stop growing and go into a lasting period of dormancy, and they could mean that many "cancer-free" people actually have tumours that are held in a "stalemate equilibrium" at a small size. Using animal model, the researchers can now reproduce this condition in the laboratory and look directly at cancer cells being held in check by the immune system. The hope is that this can lead to therapies that can help the immune system to prevent tumours escaping from equilibrium or to re-establish equilibrium if this happens. [H]
Mouse cancer vaccine When cells become cancerous, the sugars on their surfaces undergo distinct changes that set them apart from healthy cells. For decades, scientists have tried to exploit these differences by training the immune system to attack cancerous cells before they can spread. Early attempts linked the sugars with foreign protein to alert the immune system. But the immune system attacked only the protein and linker molecules and not the sugars. Now, researchers at the University of Georgia have synthesized a vaccine that, in mice, has successfully triggered a strong immune response to cancer cells that kills the cells in vitro. The vaccine includes a tumour-associated sugar that triggers the immune system’s B cells plus part of a protein that triggers the immune system’s T cells and a linker molecule that stimulates the production of generalized immune components known as cytokines. [H][G]
Starving tumours Drugs that block the development of new blood vessels (angiogenesis) can prevent tumours getting enough nutrients to grow and survive. Currently such drugs work by blocking the action of vascular endothelial growth factor (VEGF), a molecule that promotes angiogenesis. However, VEGF is present in healthy tissue as well as in cancers and although VEGF inhibitors do successful stunt blood vessel growth in tumours, they also affect healthy tissues. Also, many tumours become resistant to VEGF inhibitors. European researchers have now found another approach. This exploits an antibody called TB-403 that blocks the action of Placental Growth Factor (PIGF). PIGF is another molecule responsible for promoting blood vessel growth in tumours, but unlike VEGF it is not found in healthy tissue. [H][G]
Inhibiting telomerase The enzyme telomerase is activated in as many as 90 percent of all human cancers. It enables the cancer cells to avoid telomere shortening and hence to become immortal. Telomerase has therefore been seen for many years as an ideal target for developing broadly effective anti-cancer drugs. Now, researchers working at the Wistar Institute have brought this goal closer by deciphering the three-dimensional structure of a domain of the telomerase molecule that is essential for its activity and might be exploited to produce a telomerase-inhibiting drug. [H][B][G]
Replacing a defective immune system Researchers at Stanford University have found a way to transplant new blood-forming stem cells into the bone marrow of mice, effectively replacing their immune systems. Although the work was done on mice that are a poor mimic for the human immune system, it represents an important step towards the goal of being able to replace the immune system in people with an autoimmune disease such as multiple sclerosis. The researchers first injected the mice with molecules that latched on to specific proteins on the surface of their existing blood-forming stem cells, effectively destroying the cells. This eliminated the blood-forming stem cells without otherwise harming the mice. Then, when the researchers transplanted new blood-forming stem cells into the mice, these cells took up residence in the bone marrow and established a new blood and immune system. [H][B][G]
Manipulating the immune system An important new signalling molecule that prevents immune responses from running amok and damaging the body has been discovered by researchers at St. Jude Children's Research Hospital. The complex, which has been called interleukin-35 (IL-35), is one of a large group of signalling molecules called cytokines that cells use to communicate with each other. The researchers discovered that IL-35 is released by regulatory T cells, which are responsible for controlling the immune response. It acts like a brake on the activity of the aggressive immune cells called effector T lymphocytes. The discovery of IL-35 could make it possible to manipulate the immune system to enhance or restrict its activity. Blocking IL-35 could improve the effectiveness of anti-cancer vaccines and produce sterilizing immunity in chronic infections, such as hepatitis C and tuberculosis. Conversely boosting IL-35 could help combat autoimmune and inflammatory diseases such as Type 1 diabetes, inflammatory bowel disease (IBD) and asthma. [H][G] |
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| [G] Genomics, biotechnology and bioinformatics | |
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Cell membrane transport Understanding how materials such as nutrients and drugs are transported in and out of cells through the cell membrane could help in treating many diseases - for example, by preventing cancer cells from ejecting drugs before they can work. The critical problem has been to see the central part of this process. Researchers at Purdue have now succeeded in capturing a key step in this. They used x-ray crystallography to obtain a picture of a special protein, called an ABC transporter protein, as it holds a nutrient in a small cavity within the membrane and moves it through. ABC proteins are present in all living thing, and 49 different ABC proteins have been identified in humans. More than a dozen disease states are associated with malfunctions of these proteins. The researchers identified a special mutant of the ABC protein that locks halfway through the transport process. The mutant trapped the protein complex in a stable form that could be crystallised, making it possible to use x-ray crystallography to visualise the structure. [G][H][O][S]
Mighty-mice Mice genetically engineered to over express a single gene PEPCK-C, which codes for a metabolic enzyme, have turned out to be extraordinarily different from normal mice. They are seven times more active and have remarkable endurance. They eat 60 percent more, but remain fitter, trimmer and live and breed longer. Some female mice have had offspring at 2.5 years of age, an amazing feat considering most mice do not reproduce after they are one year old. Their metabolism is remarkably different and relies heavily on fatty acids as a source of energy during exercise whereas normal mice rapidly switch from fatty acid metabolism to using muscle glycogen (carbohydrates) as a fuel. The PEPCK-C mice also have more mitochondria and high concentrations of triglycerides in their skeletal muscles. Understanding these differences may reveal a lot about metabolism, fitness and longevity. [G][H]
Gene silencing in cancer cells Nucleosomes are the basic repeat elements of chromatin, the complex of DNA and protein that makes up the cell's chromosomes. The nucleosomes are interconnected by sections of linker DNA, like beads on a string. They provide the lowest level of compaction which is required to fit double-stranded DNA into the cell nucleus. They are also important in regulating transcription by preventing RNA polymerase from unnecessarily accessing the promoter regions of genes which are not needed by the cell, and they appear to be major carriers of epigenetically inherited information. Now, a new study led by researchers at USC has found how distinct changes in the density of nucleosomes within cancer cells causes genes to be silenced. The findings will enable researchers to explore new therapies to switch the genes back on and may lead to novel cancer treatments. [G][H]
Common cancer related gene A new study has confirmed previous indications that a gene B-MYB has an important role in the spread and development of cancer. The study found that two variants of this gene, which are carried by up to half of the world's population, are only half as common in people who have cancer than in a controls who had no evidence of cancer. [G][H]
Anti-cancer gene Researchers at the University of Kentucky discovered that a gene called Par-4 kills cancer cells, but not normal cells. They have now demonstrated that mice possessing Par-4 are resistant to all forms of cancer, even highly aggressive kinds, and also live significantly longer than control mice. Par-4 is selective for killing cancer cells and does not harm normal cells. Potentially, through bone marrow transplantation, the Par-4 molecule could be used to fight cancer cells in patients without the toxic and damaging side effects of chemotherapy and radiation therapy. [G][H]
Evolution of master genes In the conventional model of evolution, point mutations occur by chance in the genetic code and are passed on to future generations if they are beneficial. However, with this model alone, it is hard to explain how certain master genes such as p53 can have evolved to control large regulatory networks, selectively turning many other genes on and off. It has long been suspected that repetitive DNA sequences produced by endogenous retroviruses (ERVs), which constitute an estimated 8 percent of the human genome, serve as codes for gene regulatory networks. Researchers at UCSC have now provided concrete evidence to support this hypothesis. They found that more than one-third of all known p53-binding sites in the human genome are associated with ERVs. This suggests there is a second mechanism of evolution in which retroviruses insert DNA sequences and rearrange the genome, causing changes in gene regulation and expression. If a change in gene regulation is beneficial, it is passed on to future generations. [G][H]
New method of DNA analysis In 2000, scientists published the genome sequence for D. melanogaster - the fruit fly widely used in genomic research. A second fruit-fly species was sequenced several years later. But there are 1,500 species of fruit flies. So to fully understand the fruit-fly genome and how it has evolved, a consortium of more than a hundred labs around the world has now sequenced an additional 10 fruit-fly species and compared all 12 sequences for both nuclear and mitochondrial DNA. This comparison has revealed that each type of functional element changes in characteristic ways over time and that the patterns of change serve as evolutionary signatures that reveal new functional elements. By designing computer algorithms to mine the sequence data to find the evolutionary signatures, the researchers discovered thousands of previously unidentified functional elements, including 150 protein-coding genes and more than a hundred microRNA genes. The researchers say they should be able to apply the methodology of evolutionary signatures to any group of closely related species. They are now using this to analyze 32 mammalian genomes in order to help understand the human genome. [G][C]
Stem cell breakthrough Until now only embryonic stem cells (ESCs) were thought to be fully pluripotent with an unlimited capacity to become any of the 220 types of cell in the human body. Now two groups of researchers, in Japan and in the US, have succeeded in reprogramming skin cells to have all the pluripotent properties of ESCs. Known as induced pluripotent stem cells (IPSCs), the new cells are very similar to ESCs. This could mean that research is no longer dependent on using ESCs from human embryos. The breakthrough also means that it should be possible to treat patients with pluripotent stem cells derived from their own skin cells, reducing any risk of rejection. However, more research is needed to see if subtle differences between IPSCs and ESCs will affect their use for regenerating damaged tissues or for developing future treatments for diseases such as Parkinson's and Alzheimer's. [G][H]
Producing human embryonic stem cells Using a process called somatic cell nuclear transfer (SCNT), a team from Oregon Health & Science University have generated the first confirmed embryonic stem cells from an adult primate. This suggests that the same technique could produce human embryonic stem cells. The researchers implanted the contents of individual skin cells from adult male rhesus macaques into each of 304 macaque egg cells stripped of their genetic material. In two cases, according to the study, the hijacked eggs grew into early-stage embryos that yielded embryonic stem cell lines, indicating that the hosts successfully reprogrammed the skin cell DNA into an embryonic state. [G][H]
Search for shadow life If, as many scientists now believe, life can readily emerge under the right environmental conditions, it is possible that life arose on Earth more than once. Researchers are now seeking evidence of a second genesis by searching for exotic microbes that are biochemically different from all known organisms. If such "shadow life" is confined to the microbial realm, it is entirely possible that scientists have overlooked it. It might exist in extreme environments. It might have opposite chirality to normal life. It might use different amino acids or a different number of them. It might use different basic elements - arsenic, for example, in place of phosphorus. It might even exist as nanoscale lifeforms inside normal life, including humans. However, evolutionary convergence may mean that even if shadow life existed on the early Earth, it would have merged with normal life. In that case, markers of shadow biology may still exist in the geological record. [G][E][F][N][T] |
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