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Top Stories in Science
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June 2004 Issue |
| [D] Defence and security |  |
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The UN Security Council has unanimously approved a revised US-UK resolution on Iraq's future. Despite this, it is unlikely that NATO will agree to become involved as a military alliance in helping in Iraq, although some nations may assist individually. The UK has sent 370 additional troops, bringing the UK total to 8400, and may increase this by a further 3000 if needed. In order to increase its presence in the “arc of instability” from Africa through the Middle East, South Asia and South East Asia, the US is strategically restructuring its military presence round the world, substantially reducing its forces in Germany and South Korea. [D] In March, Beijing announced an 11.6 percent defence budget increase and said its annual budget would total $25 billion. DOD analysts are reported to believe that the actual spend is even higher, and China is seeking to strengthen its space capabilities while leveraging technological gains in its civilian sector to upgrade weapons and supporting networks. China plans to send two astronauts into space in 2005 on what will be only its second manned space mission. [D][A] According to the UN's International Atomic Energy Agency (IAEA), smuggling of radiological materials and the risk that terrorists will use dirty bombs are rising dramatically. Since 1993, there have been 300 confirmed cases of illicit trafficking in radiological materials, 215 of them in the past five years, and the IAEA warns that the real level of smuggling may be substantially higher. In addition, huge numbers of radioactive sources are missing, including 1000 in Iraq. The IAEA is particularly concerned about the security of hundreds of thermo-generators made in Russia and the US to provide power in remote areas. Just one of these can contain as much strontium-90 as was released by the Chernobyl accident in 1986. [D][P] A report by the UK Parliamentary Office of Science and Technology (POST) concludes controversially that flying an aircraft into a nuclear installation, and particularly into tanks holding nuclear waste, could cause millions of deaths. No-fly zones around nuclear plants may need to be larger and enforced more rigorously, according to the report. [D][A][P] Rates of thyroid cancers among women in Belarus are reported to have increased 12-fold in the years since the April 1986 explosion at the Chernobyl nuclear power plant in Ukraine. The Nuclear Policy Research Institute has called on the Bush administration to reassess its commitment to the expansion of nuclear power. [D][P] A series of revelations and new findings during the last year appears to leave little doubt that Iran has been engaged in an extensive undercover programme aimed at making and working with material that can be used in nuclear weapons. The former Iranian president Akbar Hashemi-Rafsanjani said in 2002 that Iranian use of nuclear weapons against Israel was not a far-fetched scenario. [D][T] The US intends to cut its stockpile of nuclear weapons by nearly half over the next eight years. The move is in addition to the existing pledge made under the Strategic Offensive Reductions Treaty in November 2001. [D] The QinetiQ X-Net, capable of bringing suspect cars, light trucks and small military vehicles to a complete halt, is to be deployed in Iraq following successful use by the US Marine Corps in Haiti. [D][M] According to a WHO report on the economic cost of interpersonal violence, in England and Wales the total annual costs of crime is estimated at over £35 billion, of which more than 60 percent is lost to murder, sexual assault and other violence-related injuries. [D] The US Senate has approved the Bioshield Act, which allows the US government to spend $5.6 billion over 10 years to develop and purchase "huge amounts" of vaccines or drugs to treat smallpox, anthrax, botulinum toxin, Ebola, plague, and other pathogens, and to by-pass normal procedures in order to accelerate bioterrorism research and respond to any emergency. [D] Botulinum neurotoxins are the most toxic known substances (by weight) and researchers are working to develop vaccines or drugs to combat their possible bioterror use. Research at Brookhaven National Lab has deciphered the near atomic-level structure of the catalytic domain of one botulinum toxin, type E. Changing just one amino acid in this domain is sufficient to render the toxin harmless. This means that it might be possible to design drugs that disable that amino acid or to use the non-toxic version as the basis of a vaccine. [D] |
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| [A] Aeronautics and space | |
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The Silent Aircraft Initiative (SAI) is working on new styles of aircraft to greatly reduce noise levels. A blended-wing concept is a strong contender along with putting the engines on top of the aircraft rather than underneath. [A][P][E] The flipper of the humpbacked whale incorporates bumps called tubercles. Wind tunnel tests have shown that the tubercle flipper has nearly eight percent better lift properties than a comparable smooth flipper. It withstands stall at a 40 percent steeper wind angle and produces as much as 32 percent lower drag. This could have a major benefit for aircraft and underwater vehicle design. [A][E] DARPA is seeking to develop a scaleable design for an airship for rapid force deployment that could transport 500 tonnes over a distance of 6000 nautical miles without refuelling. In the first phase of the programme, called WALRUS, DARPA also wants to investigate vacuum/air buoyancy compensator tanks and electrostatic atmospheric ion propulsion. [A][D][P] Lufthansa has introduced in-flight Wi-Fi. Passengers can surf the web and send emails from their own Wi-Fi-enabled laptop or handheld computers. They share a satcom download capability of five Mbits/sec to the aircraft and an uploading capacity of one Mbit/sec. [A][I] A report by the British Medical Association (BMA) concludes that the medical care available to people who fall ill on planes varies considerably between airlines. It recommends that much more aviation health research is needed on key issues such as deep vein thrombosis (DVT). [A][H] A privately developed spacecraft has carried a solo pilot to 65km altitude as part of ongoing preparations for its first full space flight, scheduled for 21 June, to an altitude of more than 100km. The immediate aim is to win the $10 million Ansari X-Prize, but the eventual aim is to provide commercial suborbital flights to 100km so that wealthy passengers can experience weightlessness and see the curvature of the Earth and the blackness of space. NASA awards astronaut status to anyone who reaches an altitude of 80.5 km (50 miles). [A][P] A rocket called GoFast has made history by becoming the first amateur rocket to reach 100 kilometres altitude - the official edge of space. The seven-metre-tall rocket was launched from Nevada's Black Rock Desert. [A][P] Wayward satellites could be dragged back into working orbits using a space tug that will automatically dock with the satellite using a grappling device to connect to one of its primary motors. The tug will then use an ion-propulsion engine to slowly move the satellite to another position. The proposed tug is set to make its maiden flight in 2007. [A][U][P] The Cassini-Huygens spacecraft will enter orbit around Saturn on 1 July to begin a four-year study of the ringed planet, its complex magnetic environment and its mysterious moons. The moon Titan is of greatest interest because conditions on Titan resemble Earth's own atmosphere billions of years ago and may give insight about the origin of life on Earth. In January 2005, the Huygens probe will plunge into Titan's atmosphere, and the hope is that it will remain operational long enough to transmit data on Titan's surface environment to Cassini in orbit. [A][F][U] |
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| [U] Unmanned vehicles and robotics | |
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The NASA Rover Opportunity, perched on the edge of the crater "Endurance", has used its remote sensing instruments to study rocks exposed in the steep sides of the crater. These rocks appear to be basalt, and because basalt is unstable in the presence of water at surface conditions, this suggests that any watery periods in Mars' past may have been cold and short-lived. Opportunity is now beginning to descend into the crater, keeping to rocky surface rather than sand so that hopefully it will be able to get back out. [U][A][R] Engineers at Stanford and NASA-JPL have developed a 4-legged spider-like rock-climbing robot, designed for future planetary missions. The spider cannot yet climb sheer cliffs, but it can follow a human rock-climber up an irregular surface without any guidance from a controller. As it moves one of its limbs to a new foothold, it simultaneously shifts its weight by repositioning the other three limbs to maintain balance. Route-planning software rapidly analyses different limb configurations before settling on the most efficient one for the next step. [U][A] For robots to successfully handle assembly in space they need to cope with floating with zero gravity and friction. US researchers are using a 2-dimensional analogue to study how this can be achieved. [U] Electrically activated muscles could eventually enable robots to smile, arm-wrestle, and perhaps fly like insects. There are many varieties of electrically activated muscles, based on moving either electrons or ions. Electronic muscles include passive dielectrics, piezoelectric polymers, graft elastomers, liquid crystals, and electrostrictive paper. Ionic muscles include polymer gels, polymer metal composites, conductive polymers, carbon nanotubes and electro-rheological liquids. Currently all of these technologies are rather weak and inefficient, and some suffer from short working lifetimes. [U][M][T] Researchers at University College London have used fMRI to study how the human brain learns from patterns of experience to forecast outcomes. The results show a remarkable similarity with machine learning, suggesting that human and robot intelligence may be less different than supposed. [U][B] A key reason that biological brains are much better than computers at recognising patterns and images may be that biological brains employ oscillatory memory systems, where the individual components can oscillate or freely change between states, rather than being limited to a binary number system. Researchers at Arizona State have now developed a mathematical and computational model for oscillatory networks that can see a pattern, store it and then retrieve that pattern when needed. The researchers say the model could be implemented using electronic circuits as phase-locked loops and they contrast it with the binary Hopfield model that underpins many neural network computers. [U][B][C] |
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| [P] Propulsion and energy | |
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The US military market for electrically driven ships has encouraged progress in using high temperature superconductors in electric motors and electricity transmission. [P][D][E][M][T] A team at the Indian Institute of Science has developed a technique for making lead acid batteries substantially lighter, thereby increasing the energy density from 30 watt-hours/kg in normal lead acid batteries to more than more than 50 watt-hours/kg. This means that lead acid batteries could be used in electric vehicles and hybrid electric vehicles, rather than requiring much more expensive NiMH and lithium-ion batteries. At present, up to half the cost of these vehicles is in the batteries. [P][M] Portable power is now a critical limitation facing mobile phones and consumer electronics, from laptop computers to games consoles and music players such as Apple's iPod. Portable power is also a major issue for military electronics. Lower power electronics and displays will help, but what is needed is a radical improvement in battery life and power, and faster progress in portable fuel cell technology. [P][D][I][S][T][V] According to a recent report, the US market for large and advanced batteries was $6.4 billion in 2003 and is growing at 9 percent a year, driven by hybrid electric and electric vehicles, and by portable electronics. [P][M] Researchers have discovered that a semiconductor composed of ultrapure lead, antimony, silver and tellurium, known as LAST, is much more efficient in converting heat into electricity by the thermoelectric effect. This is because it has a very high electrical conductivity but a very low thermal conductivity, which is probably due to its nanoscale structures impeding the flow of heat. [P][M] Most fossil fuel power stations use pressurised steam heated to around 650 degrees C to drive the generators. Unfortunately, below 450 degrees C the steam pressure drops too low for efficient generation and this means that hot flue gases are wasted to the atmosphere. A US company has now developed a way to convert most of this heat into electricity. Instead of steam, it uses propane, which can be boiled and pressurised at much lower temperatures. This enables the flue gas to be cooled to around 55 degrees C, potentially increasing the efficiency of power stations from their current 35 percent to as much as 60 percent. The method can also be used to scavenge heat from other industrial flues, and the low flue gas temperature means that many pollutants that are currently emitted to the atmosphere, such as mercury oxide and cadmium oxide, will instead condense inside the stack and can be disposed of safely. [P][E] Around 65 percent of the electricity consumed by European industry is used to power systems driven by electric motors, according to a report from the European Copper Institute. The report estimates that adopting energy efficient systems could save European industry over 200 billion kWh each year, equal to 100 million tonnes reduction in carbon dioxide emissions and a saving of 10 billion euros a year in industry's operating costs. Technical solutions include changing to high efficiency motors, making more use of variable speed drives, using more sophisticated control systems, recovering heat for use elsewhere, and generally improving overall system design. [P][E][M][W][T] Electricity generating plants are the number one toxic air polluter in North America, accounting for almost half of all industrial air emissions in 2001, according to a new report by the Commission for Environmental Cooperation. [P][E] Danish engineers have produced the world's largest wind power rotor blade. By combining glass fibre reinforced epoxy with glass and carbon fibre in its most stressed areas, the blade is cheaper and lighter, and puts less stress on hub components and the overall tower structure. For off-shore wind farms, high reliability is very important. Blade sizes of 80-100 metres should be possible and commercially attractive within the next 10 years. [P][M] |
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| [M] Materials, structures and surfaces | |
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There is increasing evidence that magnetic spins play the key role in producing high temperature superconductivity (HTS). Two international teams have used the new MAPS spectrometer at the Rutherford Appleton Laboratory ISIS neutron source to observe the magnetic excitations in two HTS materials. One team has found that in yttrium barium copper oxide (YBCO) the copper spins were excited collectively rather than individually. Another team has found a similar pattern of magnetic excitations in lanthanum barium copper oxide (LBCO), and has provided experimental support for a controversial theory that high temperature superconductivity in LBCO and other materials may be due to a flow of "stripes". LBCO has alternating stripes with antiferromagnetic behaviour separated by stripes with holes, and the superconductivity might involve mobile hole stripes wiggling their way through the crystal lattice. [M][P] Composite materials are beginning to be used in civil and heavy engineering applications such as bridges and oil rigs. They are beneficial not only for strength and lightness but also for superior fire resistance and ability to stand ballistic shock and bomb blasts. [M][D][T] Boeing's 7E7 Dreamliner is using a very high proportion of composites, double the amount used by Airbus in the A380. [M][A] CSIRO has developed a way to age-harden aluminium to a point where the curing process can be completed by exposure to sunlight rather than in a furnace. They found that if the age-hardening process is interrupted, and the material is allowed to undergo secondary ageing at ambient temperature, the material becomes 20 percent tougher. The 'total-energy-to-rupture' point can also be extended by up to a factor of eight, enabling car crumple zones to absorb much more energy. [M][A][E][W] By focusing an intense electron beam onto the surface of metals, such as aluminium, titanium and stainless steel, a team at the Welding Institute (TWI) has found a way to fashion delicate metal projections up to 2 mm high and 0.2 mm wide. Tests show these act like ultra-strong Velcro to form much tougher joints between metals and lightweight composite materials in aircraft and cars. TWI expects the method will work on any material that melts, including glass and plastics. [M][H] Using a very small antenna, microwaves can heat sub-mm areas of soft tissue to 120 degrees C, according to research in Israel. One possible application would be "tissue welding" that binds together edges of cut tissue and wounds using "biological solder" such as albumin. [M][H][P] CSIRO has developed a polymer that is biocompatible and biodegradable, and can be used as a glue that can be injected to repair bone and other tissue, and to promote tissue growth. They hope that it will have wide in orthopaedics, orthodontics, drug delivery, wound care, tissue engineering and cartilage repair. [M][H] Many people with arthritis have severe problems with their finger joints. However, surgery has poor results because current artificial finger joints only last about 3 years. Scientists in Hong Kong have now invented a new joint that is made of a cobalt and chrome alloy and can be anchored permanently into the bone using the same technology used to anchor replacement teeth into the jaw. They believe these joints will last for 30 to 40 years, which is all that is needed for most patients. [M][H] A new mathematical model describes the percolation of a liquid or small particles through a porous material. One application is for understanding how to use sensor proteins and other nanoscale sensors to probe molecular-level reactions inside biological cells, including those linked to diseases such as strokes, cardiovascular disease and cancer. The model is also useful for many other percolation applications, including for improving porous materials to enhance the conductivity in batteries and flow paths in filters. [M][G][N][S] |
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| [E] Environment, transport and marine | |
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Climate change is already affecting the world's rivers, but climate models differ in their precise forecasts. The most recent results from Princeton suggest that many highly populated areas will become much drier, including north-east China, the grasslands of Africa, the Mediterranean and the southern and western coasts of Australia. Conversely some thinly populated areas will get much greater rainfall, particularly the thinly populated tropics and the far north of Canada and Russia. These predictions add further weight to proposals for future massive re-engineering of rivers. Canadian rivers could be diverted south to supply parts of the US. Diverting Siberian rivers south to irrigate the deserts around the Aral Sea has also been proposed as a way to prevent collapse of the Arctic salinity that drives the Gulf Stream. [E] Analysis of a three kilometre long ice core drilled from the Antarctic has revealed that over the past 740,000 years the Earth has had eight Ice Ages punctuated by brief warm spells. Over the past 400,000 years, these interglacial warm spells have lasted only around 10,000 years. However, the shape of the Earth's current orbit round the Sun is now similar to that 400,000 years ago, which produced an unusually long warm spell of 28,000 years. This may explain why the Earth has not yet entered a new Ice Age. Initial tests on gas trapped in the ice core show that current carbon dioxide levels are remarkable high, the highest they have been for at least 440,000 years. [E] An ice core 120 thousand years old, recovered from 3 km depth in a Greenland glacier, has been found to contain a remarkable number of bacteria, including more than 15 new species. The findings indicate that life might survive in ice on Mars. All the bacteria are micro-bacteria with diameters less than 0.3 microns. Having a very high surface to volume ratio may enable micro-bacteria to capture what scarce nutrients are available and to occupy tiny cracks containing rare liquid water. The findings suggest microbiologists may be overlooking a large proportion of bacterial biodiversity, because they often discard anything smaller than about 0.2 microns. [E][A][G] Geologists studying tiny cell-like structures in rock slices, and medical researchers studying human kidney stones, have in the past reported finding tiny lifeforms, which they called nanobacteria. Many people have dismissed the reports on the argument that it is inconceivable that anything so small can possibly self-replicate. Now researchers at the Mayo Clinic have provided the best evidence so far for the existence of nanobacteria. They may turn out to be a quite new lifeform, neither a bacterium nor a virus, and they may be responsible for a wide range of diseases, including the calcification of the arteries. [E][G][H] It might be possible to meet the world's expanding need for wood, without destroying so much wilderness forest, by developing "domesticated" transgenic trees with properties better tailored for specific human uses and for efficient growth. The risk of gene flow could be avoided if transgenic trees can be vegetatively propagated and do not flower, or flower at an unusual time so that they do not pollinate wild trees. [E][G][M][T] The European Environment Agency reports that European countries are failing to meet their environmental targets. The number of weather- and climate-related disasters in Europe during the 1990s was double the figure of the previous decade, and their average cost is conservatively estimated at around 10 billion euros per year and rising. Nitrate pollution is costing consumers heavily in cleaning up drinking water. Much of Europe's urban population is still exposed to air pollution above health protection levels, with low-level ozone and particulates the main concerns. The area of built-up land is growing much faster than the population, overall trends in waste generation are unsustainable, and current policy tools are inadequate. [E] A project near Lisbon is seeking to demonstrate how communities can eliminate damaging pollution and rely on renewable energy, with zero carbon emissions and almost zero waste. Similar developments, each providing for about 5,000 people, are planned in the US, China, South Africa and Australia, with homes, schools, factories, health and leisure facilities, local food sources and sustainable transport networks. There will be a second European scheme in the UK, in the Thames Gateway east of London. [E][P][X] Understanding how dolphins are able to swim so quickly and smoothly through water could help in designing energy-efficient boats, ships and submarines. Japanese physicists have discovered that the unusual skin of the dolphin, which flakes off and is completely replaced every two hours, plays a crucial role in helping reduce drag effects. [E][M] |
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| [R] Remote sensing and sensor systems | |
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ESA plans to launch a constellation of three satellites to provide the best ever survey of the Earth's geomagnetic field and its temporal evolution. High-precision and high-resolution measurements of the strength, direction and variation of the magnetic field, complemented by precise navigation, accelerometer and electric field measurements, will make it possible to separate out and model various sources of the geomagnetic field. The mission will improve understanding of the composition and processes of the Earth’s interior, and the influence of the Sun on the Earth's climatic system. [R][A][E] ESA's X-ray observatory, XMM-Newton, has now shown that cyclic X-ray "Sun-spot" behaviour is common to other stars as well as our Sun. [R][F][I] NASA's Turbulence Prediction and Warning System (TPAWS), which can automatically alert pilots to potentially dangerous turbulence, is about to make its first evaluation flights on a commercial airliner. TPAWS is a software signal processing upgrade to existing predictive radar Doppler wind shear systems that are already on aircraft. [R][A][K] As a first step towards a space traffic control system, s-band radar sensors on an unmanned aircraft successfully tracked and recorded several minutes of telemetry data from a rocket after its take-off. Such mobile tracking technology could allow rocket launches to take place from a wider variety of locations, freeing them from the need to launch within range of giant fixed arrays of ground-based dishes. Eventually rocket launches may be controlled from satellites. [R][A][U] Sandia has developed a system to prevent "friendly fire" by alerting a radar when it is illuminating a friendly platform. A radar sensor on the platform creates synthetic radar echoes. These are picked up by the radar and contain an additional signal that identifies the platform as friendly. The sensor can also assist battlefield situational awareness. [R][D][S] Migratory birds, as well as many other animals, are able to sense the magnetic field of the Earth. Research suggests that the sensing is done by light-absorbing molecules in the retina of a bird's eye, and that as a result the birds might be able to see the Earth's magnetic lines as patterns of colour or light intensity superimposed on their visual surroundings. [R][E][S] A sensing system has been installed at Cambridge and Illinois Universities that uses ultra-wideband radio and tags to track the indoor movements of people and objects with 10cm accuracy. When linked to wider systems, it could open the way for 'sentient computing networks' in which people interact continuously with the devices around them, creating new working environments. Such networks also have applications for security and telehealthcare. [R][D][H][I][K] Sixty million years of evolution has enabled bats to develop highly optimised biosonar systems in which they broadcast ultrasound at various frequencies and then detect the echoes to sense their surroundings. Understanding how this differs between bat species may enable much better designs for acoustic and electromagnetic antennas. [R][I][S] |
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| [S] Sensor devices | |
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By incorporating sensors and a rf transmitter into a total knee prosthesis, scientists at Scripps Institute can measure the forces in the knee joint directly and the load-carrying capabilities of the bone as the patient walks, climbs stairs and exercises. This will enable better knee replacement prostheses to be developed, and should also help in designing better sporting equipment and footwear. [S][B][H] A report by the Institute of Medicine for the US Army proposes a number of biological markers that could serve as indicators of hydration, muscle fatigue, bone health and stress, and could be adapted for military use. The aim is that soldiers should be wired up to sensors that raise the alarm when they near physical or mental exhaustion. [S][D][B][H] Computational molecular design has been used to create a protein to sense the nerve agent soman. It may be possible to engineer proteins to detect nerve agents such as sarin and other toxic substances, and to incorporate the proteins into detectors similar to smoke detectors that could be widely deployed as early-warning alarms and weapons monitors, or in the decontamination process after an attack. The protein sensors could warn of the presence of the agents and continuously monitor their level. [S][C][D][G] A device invented at Princeton can rapidly sort microscopic particles into extremely fine gradations of sizes. The device consists of an array of microscopic pillars etched into silicon. Air forces a liquid suspension of particles through the pillar array, which guides the particles into different paths. When the particles emerge from the array, they have been sorted into any number of "channels" according to size. A device less than 1 square inch could easily yield hundreds of channels, each just 1 percent different in size. The technology, partly funded by DARPA, may greatly accelerate the sequencing of genomes and could find uses in many other areas such as detecting bioterrorism agents. The researchers are now working to extend it down to very small particles, including clusters of just a few protein molecules. [S][D][G][J][M][N] Physicists in Germany have made an atomic force microscope capable of imaging features less than 100 picometres across. The new "higher-harmonic" force microscope uses a single carbon atom as a probe. It has a resolution that is at least three times better than that of traditional scanning tunnelling microscopes. [S][M][N] A new imaging method that combines coherent anti-Stokes Raman scattering (CARS) and tip enhancement can image individual molecules by feeling their vibrations. It can detect objects only dozens of atoms wide and might provide a future way to map the constituents of individual biomolecules. [S][G][N][O] A BioCD developed by Purdue University may pave the way for while-you-wait blood tests that screen patients for the onset of thousands of diseases. Antibodies are printed onto the CD tracks to bind to different disease marker proteins found in blood. [S][G][H][O] |
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| [O] Optoelectronics, optics and lasers | |
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An ultra-short pulse of light travelling in a material like water produces optical precursors that travel ahead of and further than the main pulse. They arise because a material such as water has a set of exceptional frequencies at which light can travel especially cleanly. The precursors appear at those favoured frequencies. The frequencies are not fixed, and they change as the precursor moves through the material. The effect may be useful for underwater communication and for extending the depth of imaging in the body. [O][M][R][S] When photons are entangled they share a single quantum state and therefore behave like a single particle with higher energy and corresponding shorter wavelength. Two teams have succeeded in entangling more than two photons for the first time. A Canadian team has entangled three photons and an Austrian team has created a four-photon entangled state. The wavelengths of the entangled states are three and four times shorter than the original wavelengths of the photons. Such entities might be used to stretch the resolution limit of optical lithography even further, and to increase optical storage density. Multiphoton entanglement might also lead to extremely precise measurement for detecting gravitational waves or the energy structure of atoms. [O][C][F][J][R][S] Quantum entanglement may be able to reduce by an order of magnitude the time needed to make measurements with ultraprecise atomic clocks. [O][F] Researchers demonstrated that when a single particle of light passes through a beam splitter, it travels in two directions simultaneously and remains intimately connected, just as two entangled photons are connected and communicate even when they are separated by large distances. The results may provide a way to perform quantum computing. [O][C] Physicists in China have now made a light bulb in which the conventional tungsten filament is replaced by carbon nanotubes. The nanotube filaments emit more light than tungsten filaments at the same applied voltage. The light is a combination of black body radiation and electroluminescence. The nanotube bulbs were able to operate continuously at 25 volts for more than 360 hours, and they continued working after being switched on and off more than 5000 times. [O][N] |
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| [I] IT, communications, networking and secure systems | |
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Short-range wireless technology will allow a single handset to access both mobile and fixed-line telephone services. BT and Japan's NTTDoCoMo have formed an alliance to search for technologies that could merge mobile and fixed-line operations, and BT and Vodafone are joining forces to launch a new joint mobile phone and fixed-line calls service. UK spending on mobile phones has grown 14 percent in the past year. [I] BT is planning to close down its Public Switched Telephone network (PSTN) in the UK and replace it with an internet protocol (IP) network. This will allow customers anywhere to plug into broadband using computers, mobiles or other devices. IP also enables more personalisation and integration of information, and it will facilitate new ways of working, such as web-based virtual meetings. It will alter the role of experts, allowing them to contribute efficiently and flexibly to web-based meetings and training. [I][K] Watching TV on a cell phone or iPod, or in cars or high-speed trains, could soon become a reality in Europe. Europe's specification for mobile digital video broadcast, DVB-H (for "handheld") is in field trials, and commercial services are scheduled to go live in 2005. [I][V] A researcher at the University of Rhode Island has developed a new type of radio antenna that, it is claimed, can achieve 80 to 100 percent of the transmission efficiency of a normal antenna whilst being only a third to a ninth the normal size. [I] In a step towards producing ultrasmall networked sensor chips, engineers at the University of Florida have installed a radio antenna less than one-tenth of an inch long on a chip, and have demonstrated that it can send and receive signals across a room. [I][J][S] The frequency and duration of sounds emitted by computer chips could help code breakers decipher encrypted messages, according to preliminary research carried out at the Weizmann Institute. [I] Wireless networks using the IEEE 802.11b protocol can be disrupted using a simple technology that constantly fools devices on the network into thinking the network is experiencing interference. This causes all the devices to stop transmitting. No way has yet been found to overcome the vulnerability. [I] May 2004 was one of the most sinister months to date for computer viruses, according to reports from several major anti-virus software vendors. Particularly significant is the increasing prevalence of viruses that are highly destructive, because they bring down networks, turn computers into zombies, or steal passwords and credit card details. [I] According to the UK police, most crimes now contain a digital element. Increasingly, mainstream investigations include the handling of digital evidence, such as the analysis of computer hard drives. However there is a big shortage of skills. According to a recent e-crimes report, of the 140,000 police officers in the UK, barely 1000 have so far been trained to handle digital evidence at the basic level. [I][D][K] The rapid growth of Internet spyware, and the legal ambiguity surrounding it, makes spyware potentially as big a threat as SPAM. [I][K][T] |
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| [K] Knowledge, information and technology management | |
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The wild predictions for e-commerce in the dot-com boom are now coming true, fuelled by the growth of broadband. In Britain in 2003, online spending averaged £470 per person and the over-55s age group spent most, at £527 per head. Retailing is being transformed. On-line auction is one growth area - eBay's net profit was $442m in 2003. Within a decade the majority of travel bookings will probably be made online. The movie and music business may also move heavily online. Paid-search and advertising are a fruitful business for the likes of Google and Yahoo, and for specialist search services, such as Factiva. However, cyber crime is also growing fast, and better online security technology is urgently needed. [K][D][I][T] According to government statistics, more than 2.1 million people in the UK now work fully from home and a further 8 million work partly from home. The number is expected to rise to more than half the UK working population. Broadband is the most important factor driving this growth. [K][E][I] Many patients say that the medical information and guidance they can find online is more complete and useful than they receive from their clinicians, according to an editorial in the British Medical Journal, which argues that a transformation is needed that gives more recognition to e-patients and to the scale of the medical techno-cultural revolution that is in progress. [K][H] QinetiQ scientists claim to have developed the world's first automatic breast cancer diagnostic system. The performance of the system is similar to that of a human pathologist and the systems speeds up diagnosis, makes it easier to compare prognostic features between patients. Content sensitive image compression also enables transmission of the very large quantity of images over realistic bandwidths in realistic times for expert opinion. [K][C][H][S] Sweden's Lund University has launched a new online facility that allows users to search for and retrieve articles from open-access journals that do not charge users to access articles. At present, 276 of the 1100 journals listed on the directory are searchable by article. Around 1200 open-access journals are currently available and these make up about 5 percent of all scholarly journals. For the other 95 percent of journals, about 15 percent of their articles are also open-access, because their authors have self-archived them. [K][T] The Royal Society has launched a new journal, Interface, to cover and promote cross-disciplinary research, such as the fusion of engineering and medical science. Methodologies from disciplines such as chemistry, computer science, or physics can provide insight into biological and medical sciences. Equally, advances in the life sciences are leading to innovations in the physical sciences. [K] |
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| [C] Computing, supercomputing, modelling and simulation | |
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A distributed computing project called the Great Internet Mersenne Prime Search (GIMPS) has discovered the largest prime number yet found and the first with over seven million digits. [C][I] The first computer network in which communication is secured with quantum cryptography is operating in Cambridge, Massachusetts. The network currently has six servers and data flows through ordinary fibre optic cables over a 10 km distance between sites. [C][I][O] Leading US research universities and private-sector technology companies are deploying a nationwide networking infrastructure, called National LamdaRail (NLR), to support research in science, engineering, health care and education, and in new Internet technologies, protocols, applications and services. The NLR system initially will use four different wavelengths, each able to carry up to 10 gigabits/sec, and exploiting dense wave division multiplexing (DWDM), which has the potential to carry up to 40 such channels over one pair of optical fibres. [C][I][H][K][W] Georgia Tech have developed a virtual-reality based fire command training simulator to prepare fire officers to react in emergencies. It simulates the progress of a fire in a single-family home and responds to orders from a fire commander on the scene. The users can navigate around the fire scene and view from any angle, to direct fire-fighters and watch them execute commands. The system also lets them see how fire and smoke react to changes in the environment, such as opening windows. [C][D] |
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| [W] Whole life engineering, manufacture and testing | |
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Physicists in Ireland have developed a way to precisely self-assemble sub-micron scale devices into an integrated component using electric fields. At present assembly is done by pick-and-place machines. This works less well as devices are made smaller, because electrostatic, van der Waals and capillary forces start to override the gravitational forces needed to release the device from the tweezers. [W][J][O][S] Rapid manufacturing technology uses an additive manufacturing process to construct parts that are used as finished products or components, directly or with minimal post-processing. The technology is profoundly changing the way products are designed, manufactured and distributed. [W][M][T] For safety critical and real time applications, conventional microprocessors may be too slow to implement a fuzzy-logic solution. Implementing fuzzy-logic on a digital signal processor (DSP) can be the solution. [W][T] Low power consumption is not just achieved by using power-efficient processors. Optimising the software for lower power can make a vital difference. The architecture of newer FGPA's also supports low power consumption. [W][T] |
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| [X] Systems, complexity and risk | |
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A research project at MIT's Center for Transportation and Logistics is studying the impact of terrorism on supply chains, and identifying what companies can do to be resilient when disaster strikes. The risks are growing as global supply lines stretch, competition stiffens, customers become more demanding and political instability takes its toll around the world. However, according to the researchers, companies can become resilient by creating flexible supply chains and ensuring that security is part of their corporate culture. Companies that have accurate reporting, and that quickly circulate bad news as well as good news, are more resilient. [X][D][K][W] Analysis of networks of scientific collaboration can reveal if a laboratory is undertaking clandestine work, according to US researchers. The technique relies on the idea that in any network of objects, such as scientific collaborations or literature citations, the way a particular object fits into the network can reveal a lot of information about the object itself. [X][D][K] In human social networks, any individual is connected to any other by only six or seven human links. This occurs because human networks have many links that short-circuit long distances. According to US researchers who have modelled neuronal networks, short term memory, which resides in the prefrontal cortex, may exploit the same type of network, called a "small world network". They found that when 10 to 20 percent of the neurones participated in short cuts, the network formed self-sustaining loops of activity. These were stable until another strong activating pulse set off a different stable activity. This simple mechanism allowed a succession of short-term memories. [X][B][C] Re-introducing wolves back to Yellowstone National Park in 1995/96 has triggered a cascade of unanticipated changes in the park's ecosystem that provides a case study of how interconnected an ecosystem is. The wolves have culled the overlarge elk population. This has allowed regrowth of new trees previously destroyed by the elks and has benefited other flora and fauna, such as eagles, bears, beaver and trout. [X][E][T] Research into the many-sided interactions of proteins in yeast cells is revealing that such networks may have something in common with other kinds of network systems, from the World Wide Web to the electricity grid. "Hub" proteins, which are highly connected proteins that bind to many other proteins in the cell, can be divided into two general types. "Party" hubs interact with most of their partner proteins all at once. "Date" hubs bind to their partners at different times or locations. [X][C][I][K] Despite a great proliferation of treaties and organisations, environmental conditions worldwide are worsening, according to two publications by the United Nations University, which examine the complex dynamics of current multilateral agreements, the costs and benefits of different models, and approaches to reforming international environmental governance. [X][D][E] The National Science Foundation (NSF) is funding a programme of studies across all the social and behavioural sciences to encourage the coupling of theoretical political and social models and real-world tests of these models. Underlying this programme is the belief that past research in political and social science has taken too simplistic an approach, and that faulty results often result from using just one approach alone, such as formal models, case studies or applied statistical models. [X][K] |
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| [V] Virtuality and human-machine interface | |
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The use of 3-D displays that can switch electronically from 2-D to 3-D without the need for wearing goggles will help airport security by enabling staff using x-ray scanners to see the depth of objects. [V][A][D][S] Flat loud-speaker technology can substantially improve the quality of passenger announcements and other sound broadcast in trains and aircraft. [V][A][E] At the 2004 SID Conference, significant new technologies demonstrated included a liquid crystal on silicon (LCOS) HDTV, a polymer organic LED (PolyLED) TV, and a vibration touch screen technology developed by 3M and NXT, which recognises touch through vibrations to a substrate. [V] Virtual reality using haptic technology has been developed to teach physicians, physiotherapists and other practitioners how to diagnose back problems and manipulate the spine. The "Virtual Haptic Back" gives users the sensation of touching a human back. Users also see a three-dimensional image of a back on a computer screen. [V][H][K] The tongue is richly supplied with sensory and motor nerves. Researchers have developed a prototype tongue display unit with which "images" are transmitted via the tongue. These "images" can activate areas of the brain normally reserved for visual information. The aim is to enable blind people to "see" images or read Braille with their tongue, but the device can also be used by normally sighted people. [V] Smart homes for the ageing population will have intelligent systems to monitor activities and provide support. Researchers are exploring new interfaces designed for older people who do not, or cannot, learn to use a PC. [V][H][K][R] |
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| [B] Brain research and human science | |
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How the brain makes sense of the information contained in electrical impulses sent to it by millions of nerves from the body is still largely a mystery. Researchers at UCSD have found that individual neurones sort the information by each specialising on detecting specific features in the signal. One neurone may just respond to the first pulse in a signal, which is important for getting the timing of different signals right and in the correct order. Other neurones respond to a specific pulse repetition rate, and hence to the intensity of the stimulus. The researchers found that the differences in the way the individual neurones released and responded to the chemical transmitters could explain their differing responses to incoming information. [B][V] By genetically engineering fruit flies so that their neuronal connections become fluorescent during nerve signalling, researchers in Houston have observed what appears to be the initial stage of memory formation as the flies learned to associate an odour with a shock. They found this memory formation involved the recruitment of new synaptic connections into pre-existing ensembles of synapses. These connections appeared within 3 minutes after the experiment, suggesting that the synapses were already formed but remained "silent" until they were needed to represent the new memory. The new synaptic activity disappeared by 7 minutes after the experiment, but the learned association remained, suggesting that it had been transferred to some higher memory level. The technique should enable further parts of the memory process to be observed in flies and other organisms. [B][G] Researchers have found that not all parts of the brain sleep to the same degree. Sleep is concentrated in those parts of the brain where the most consolidation of new information is required. The results show that during sleep the brain circuits are reshuffling themselves to aid learning, rather than simply recovering from use. [B][K] A study on the brain chemicals involved in sleep has found that cessation of activity in histamine cells causes loss of consciousness during sleep, while cessation of activity in cells containing the brain chemicals norepinephrine or serotonin causes loss of muscle tone in sleep. The findings also help explain why antihistamines, often taken to control allergies, cause drowsiness. [B] Researchers at Cambridge University have discovered that sheep prefer smiling or relaxed human faces, over angry or stressed ones. Among domestic animals, sheep are relatively low in intelligence, and the experiments therefore indicate that other domesticated animals may be much more sophisticated than previously believed in their ability to read and react to each other's emotions and those of humans. [B] A border Collie in Germany has demonstrated a remarkable ability to understand language. The dog, Rico, can understand over 200 words and can work out the meaning of new ones, apparently by a process of elimination. Rico was also able to remember the meaning of a new word on hearing it a second time a month after hearing it the first time. These skills are comparable to those of a 3 year old child, according to psychologists, and may suggest that language skills evolved earlier and are more advanced in non-primate mammals than previously thought. [B] A decade-long magnetic resonance imaging (MRI) study of normal brain development in people from ages 4 to 21 shows that "higher-order" brain centres, such as the prefrontal cortex, do not develop fully until young adulthood. [B] Experiments involving military personnel subjected to threatening behaviour during mock interrogations showed that memory is badly affected by intense stress. The finding casts serious doubt on the reliability of victim testimonies in cases involving psychological trauma. [B][K] A survey of 25,000 Britons in 26 jobs has indicated workers dealing directly with customers are more likely to suffer stress. Paramedics were found to have the greatest stress, ahead of teachers and social workers. Working irregular hours is also detrimental and leads to higher levels of depression and other problems, including insomnia and memory lapses. Recent research shows that regular small doses of caffeine throughout the day work better at maintaining alertness and performance than a few large doses. [B][H] Human beings are more aroused by rewards they actively earn than by rewards they acquire passively, according to experiments that used functional magnetic resonance imaging (fMRI) to measure brain activity in the striatum of subjects playing a target detection computer game. The striatum is a part of the brain previously associated with reward processing and pleasure. [B][K] According to a new psychological theory of religious need, the way that people are drawn to religion can be described in terms of 16 desires: power, independence, curiosity, acceptance, order, saving, honour, idealism, social contact, family, status, vengeance, romance, eating, physical exercise, and tranquillity. These explain why certain people are attracted to religion, why God images express psychologically opposite qualities, and the relationship between personality and religious experiences. Overall, religious people have a greater need for interdependence, honour and loyalty, whereas non-religious people showed a stronger need to be self-reliant and independent. [B][D][X] A preliminary study at Imperial College has found that applying transcranial magnetic stimulation (rTMS) to patients with incomplete spinal cord injuries led to improvements in their ability to move muscles and limbs, and ability to feel sensations. The researchers believe that the therapy may work by activating the surviving nerves to strengthen their connections. [B][H] Chemotaxis is the process by which living cells sense their local chemical environment and act accordingly. Research at Georgetown University has shown that nerve cell axons have extraordinarily sensitive chemotaxis and can grow along amazingly small concentration gradients of local proteins. [B][H][G] |
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| [H] Healthcare and medicine | |
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A new type of "self-healing" bandage that incorporates the patient's own cells, which have been multiplied by culturing, can greatly assist healing of difficult slow-healing wounds, including pressure sores, diabetic ulcers and severe burns. [H][D] Non-communicable diseases (NCDs), including cardiovascular disease, type 2 diabetes, cancers and obesity-related conditions, now account for 60 percent of deaths worldwide and almost half of the global burden of disease, according to the World Health Organisation. Member states have endorsed a WHO Global Strategy on Diet, Physical Activity and Health to limit the consumption of saturated fats and trans fatty acids, salt and sugars, and to increase consumption of fruit and vegetables and levels of physical activity. The strategy addresses the roles in this played by health services, of policies on food, agriculture, finance, regulation and schools, of surveillance systems, and of consumer education and communication including marketing, health claims and nutrition labelling. [H][D] The G8 nations have given their support to a US proposal for an international alliance to accelerate HIV vaccine research. [H][D] Around 800,000 infants are infected with HIV from their mothers each year, and in most cases this occurs via their mother's milk. Bacteria naturally present in the mouths of some people prevent such infection by binding to sugars present in the gp120 glycoprotein on the surface of the HIV virus. Laboratory trials have shown that this works against all forms of the HIV virus and that the best Lactobacillus strain reduces the level of HIV infection by over 99 percent. The hope is that by giving all babies a dose of the Lactobacillus it may be possible to prevent most infant HIV infections. The cheapness and simplicity of the method also makes it suitable anywhere in the world. [H][D] The family of bacteria that cause tuberculosis and leprosy have unique multilayered cell walls that make the microbes very tough and difficult to treat. TB currently kills 3 million people worldwide and the emergence of antibiotic resistant TB increases the threat. Research at the University of Wisconsin has detailed the workings of a key enzyme that the bacterium requires to maintain the integrity of its cell walls. This might be exploited to develop a new class of antibiotics against TB. [H][D][G] Currently about a quarter of schoolchildren in the US and a third of those in the UK suffer from asthma. Epidemiological studies have found that the rise in allergies and asthma worldwide in the past 20 years has tracked the increasing use of antibiotics. Now experiments have shown that mice whose gut flora had been manipulated, experienced a much higher immune response to fungal spores. This gives support to the theory that the flora of microbes in a person's gut plays an important role in training the immune system what stimuli to ignore. Changes to this flora caused by antibiotic treatment might leave the immune system over-sensitive. [H][E] Research at Brown University shows that low insulin levels directly improve longevity. This may explain some of the longevity benefit of a low-calorie diet, since this type of diet reduces insulin production. [H] Researchers at MIT, studying the ageing process in yeast, roundworms and mice, may have found a key to understanding why low calorie diets increase longevity. They have found that a single protein, Sirt1, senses short-term famine and turns off the receptors that normally keep fat stored in fat cells. The researchers believe that fat cells tell the body how fast to reproduce and age, and that low numbers of fat cells tell the body to hunker down for survival, making it age more slowly. The researchers hope that Sirt1 might enable people to gain the longevity benefits of low calorie diets without the side effects and without actually dieting. It might also be useful for preventing and treating fat-related diseases. The next step in the research is to determine if an increase in Sirt1 in the body leads to a higher rate of metabolism. [H][G] Differences in lifespan between species, and the effects of low calorie diets in increasing lifespan, have led scientists to think that a high metabolic rate is linked to shorter lifespan. However, UK scientists have now found in a 7-year study on mice that the most metabolically active 25 percent of the mice lived 36 percent longer than the least active. The higher metabolic rate appears to be associated with lower metabolic efficiency in which some metabolic processes in the cell just produce heat. A possibility is that the low metabolic efficiency may produce lower quantities of oxygen free radicals and therefore cause less damage to mitochondrial DNA and other cell components. [H][G] Mutations of mitochondrial DNA increase with age, but is has not been certain whether this is just a consequence of ageing or also a cause of ageing. Scientists at the Karolinska Institute have now found that mice with a deficient capability to repair damage to their mitochondrial DNA age considerably faster. This confirms that it may be possible to increase human lifespan by developing ways to protect mitochondrial DNA from damage. [H][G] UK researchers have discovered a new protein, called RIP140, which regulates the expression of a gene responsible for maintaining the body's temperature. In mice, reducing RIP140 causes the body to use up more energy and store less fat. On average, transgenic mice without RIP140 were 20 percent lighter than normal mice and accumulated 50 to 70 percent less fat for a similar food intake. If a drug can be found that blocks RIP140, it might provide a way to treat obesity. [H][G] The great problem in combating cancer is that it is so diverse and malignant cells continually mutate. However, Spanish researchers believe there may be a new way to prevent tumour enlargement and spread. They have evidence that all tumours grow in the same way, irrespective of the tissue or species in which they develop, and that growth is not exponential as commonly believed. Instead, tumours grow only at their surface, like the growth of crystals, and cells diffuse to settle in curved depressions where the competition for space is lowest and where they are best protected from the immune system. The researchers have now found that the mechanical pressure exerted by immune-system cells known as "neutrophils" around mouse tumours can prevent the diffusion of these cells and thus prevent tumour growth. [H][G] Chemotherapy is thought to work by triggering apoptosis in cancer cells. However, cancer cells that are immune to apoptosis can still be killed by some chemotherapy drugs. The reason, according to research at the University of Pennsylvania, is that the chemotherapeutic agents can also kill cancer cells by inhibiting their ability to break down glucose to produce the cellular fuel ATP, and hence starving them to death. Significantly, this "necrotic" cell death does trigger an immune response. This could open the way to a whole new and less toxic way to treat cancer. [H][G] Cancer cells become able to multiply indefinitely by inhibiting or lacking the cell-suicide (apoptosis) mechanism of normal cells. Researchers at Cancer Research UK and the University of London have exploited this to develop a genetically modified adenovirus that selectively kills cancer cells leaving normal tissue largely unaffected. The modified virus replicates only in cancer cells, destroying the cancer cell and producing large numbers of new viruses that infect surrounding cancer cells. The apoptosis mechanism prevents the virus replicating in normal cells. Clinical trials on humans are planned for 2005. [H][G] |
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| [G] Genomics, biotechnology and bioinformatics | |
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At Harvard, a new type of gene has been found in what was thought to be "junk" DNA. Instead of making proteins, as normal genes do, the new gene, called SRG1, regulates a nearby gene SER3. The researchers believe that SRG1 works by physically blocking the transcription of SER3. They found that transcription of SRG1 prevents the binding of a critical piece of SER3's transcriptional machinery. The intergenic space between protein-coding genes may well hold many more genes of this new type. If so, this will add a new layer of complexity to understanding how genes work. [G] The International Chimpanzee Chromosome 22 Consortium reports that 83 percent of chimpanzee chromosome 22 proteins are different from their human counterparts. This is a much bigger and more complicated difference than was believed from previously comparing the human and chimpanzee genomes at a more macro level. However, whether these detailed differences in the proteins are significant remains to be seen. [G] All life is based on only 20 amino acids, and a fundamental question is why this should be universal, and whether 20 is optimum. By exploiting the redundancy of the genetic code, a team at Scripps has modified a form of the E coli to use 22 amino acids. This proof-of-principle may enable proteins to be made within the context of living cells that have three, four, or more additional amino acids. [G][F] Attempts to use gene therapy to combat HIV have so far had little success. However, a company in Maryland is clinically trailing an approach that uses a modified form of HIV to deliver an "antisense" gene to the immune cells that HIV infects. This gene produces RNA complementary to the "sense" RNA of normal HIV. In theory, the RNAs should bind together, blocking the HIV virus from replicating in the cell. Lab tests have shown that the method, whilst not eliminating the HIV, slows its rate of replication by at least a factor of 100. [G][H] The world's first gene therapy trial to treat patients with pancreatic cancer is being launched in the UK. It uses a retrovirus modified to carry a gene for an enzyme that converts an inactive drug into a toxic form. Because retroviruses only replicate in dividing cells, cancer cells are primarily affected. This allows a hugely increased chemotherapy dose to be delivered safely. [G][H] In experiments on mice, gene therapy has been used successfully for the first time to cure a so-called dominant progressive brain disorder - caused by a single defective gene inherited from one parent. This involved blocking the mutant gene rather than just replacing it. The results offer hope that gene therapy may be able to treat Huntington's disease and similar neurodegenerative diseases, in which the brain makes mutant proteins that progressively build up in the brain. [G][B] The current test used for prostate cancer measures levels of prostate-specific antigen in the prostate. But this can over-diagnose the cancer and cannot distinguish between slow-growing and aggressive forms. Now UK scientists have found a gene, E2F3, that is key in determining how aggressive prostate cancer will be, and hence which patients need radical treatment. [G][H] Research in 2002 showed that fat cells could be converted into what appeared to be nerve cells. Now researchers at Duke University have confirmed that these new cells appear to act like nerve cells, providing the most compelling evidence so far that it may be possible to use the almost limitless supply of fat cells in the body to produce a large range of new tissue. The ability to produce large quantities of neurones could transform the treatment of the ageing brain. [G][B][H] Many technical obstacles must be overcome and questions resolved before stem cells can safely fulfil their promise. One challenge is to identify truly pluripotent stem cells. Another is to understand what prompts differentiation and to ensure that the right tissue is created in the right place in the patient. A third issue is to get the differentiated cells to integrate into existing tissue in the right way. Embryonic stem cells are also attacked by the recipient's immune system, and a huge number of different cell lines would be needed to be sure of finding a match. Using the patient's own stem cells solves the immunity problem, but such cells are very rare and hard to find. [G][H][T] Sperm inject not only the male DNA into an egg but also some RNA, according to US researchers. The function of the RNA is uncertain, but it may kick-start the egg to begin developing into an embryo. This may explain the low success rate of cloning, since cloning only involves the insertion of DNA into the egg. [G][H] |
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| [N] Nanotechnology and molecular technology | |
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Iron oxide nanoparticle can outline brain tumours to make them more visible under magnetic resonance imaging and can reveal other brain lesions that may not otherwise be detected. This can assist image-guided brain surgery and improve diagnosis of lesions caused by multiple sclerosis, stroke and other neurological disorders, as well as residual tumours. [N][B][H][S] Noble metal nanoparticles that are smaller than the wavelength of light show a pronounced resonance in their scattering spectrum for visible light. This "nanoparticle plasmon resonance" depends on factors such as the nanoparticle's material, size, shape and the dielectric properties of its immediate environment. Researchers at Northwestern University have used a localised surface plasmon resonance nanosensor to look at the behaviour of molecules that may be involved in the development of Alzheimer’s disease. [N][B][H][S] Optical tweezers use a focused laser beam to trap a microscopic object, usually one that is immersed in water. If the laser beam is polarised it can apply a torque to the particle and this can be measured by analysing the polarisation of the light coming out. By using this to control the polarisation of the laser beam, a constant controlled torque can be applied to the object, creating what has been called an "optical torque wrench." The technique could be useful for exploring cellular machinery such as molecular motors or the proteins that replicate DNA. [N][G][M][O][S] Until now, the only way to position carbon nanotubes has been to laboriously nudge them around individually with an atomic force microscope. Now a US company has shown that they can use a laser beam to pick up and manipulate many nanotubes in parallel, held in optical traps. They used a liquid crystal "beam splitter" to divide their laser beam to create 200 individually controllable optical traps. This allowed them to make triangles, squares, pentagons and hexagons from bundles of nanotubes on the surface of a microscope slide. [N][J][O] Liquid crystals can align nanotubes, and liquid crystal-nanotube dispersions could have applications in externally controlled molecular switches and electrical, magnetic, mechanical or optical sensors, according to researchers at the University of Manchester. [N][G][M][O][S] Because magnetisation increases with temperature for antiferromagnetic nanoparticles, Danish physicists believe that such nanoparticles might be engineered into a new class of material in which magnetisation can be switched quickly and without energy loss. This material would be valuable for use in high-frequency electronic devices. [N][J][M] Two groups of US researchers have discovered that semiconducting nanotubes can be made metallic, and vice versa, by applying a magnetic field. The hollow molecules change the energies of their electronic orbitals in response to the magnetic flux threaded through them. Since electronic orbitals not only determine the energy of the molecule but also its chemical, mechanical and other properties, it might be possible to control all three using a magnetic field. [N][J][M] |
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| [J] Microelectronics, MEMS and spintronics | |
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At Max Planck in Stuttgart, researchers have made rolled-up nanotubes of InAs/GaAs with tube walls containing alternating layers of crystalline and noncrystalline material. They also produced laterally modulated heterostructures by using a laser to remove arsenide from small regions and to oxidise them. Such heterostructures might form the basis of a new generation of electronic and opto-electronic devices. [J][N][O] Researchers at Lund University in Sweden have grown semiconductor nanowires in the form of trees, using metal-organic vapour phase epitaxy (MOVPE) and gold aerosol nanoparticles as catalysts to seed the growth of individual branches and sub-branches of the tree. They have grown trees composed of gallium phosphide, indium phosphide and gallium arsenide phosphide. The ability to grow such complex structures should open up new device potential. [J][N] Physicists in Germany and the US have made a single-electron transistor that operates mechanically using a nanometre-scale vibrating arm. Unlike previous nanoelectromechanical transistors, it does not rely on high magnetic fields produced by superconductors and does not need to be operated at cryogenic temperatures. [J][N] Harvard researchers have demonstrated another step towards highly functional and integrated nanosystems. They used a Langmuir-Blodgett technique to deposit nanowires over a large area with controlled alignment and spacing. They then patterned the nanowires into small regions and used photolithography to deposit arrays of metal electrodes. Typically, around 80 percent of the possible 3000 electrode connections were bridged by a nanowire, producing an array of nanowire transistor devices with a mobility of 300 cm2/Vs and unprecedented reproducibility. [J][N][S][V] |
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| [F] Fundamental science | |
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European physicists have coaxed a one-dimensional gas of atoms into a Tonks-Girardeau gas for the first time. This novel quantum state, which was first predicted about 40 years ago, blurs the distinction between boson and fermions. By increasing their mutual repulsion, the bosons are prevented from occupying the same position in space and forced to behave more like fermions. [F][O] More precise measurements at Fermilab of the mass of the top quark indicate that the likely mass of the Higgs boson is higher than previously thought. This may explain why the Higgs boson was not found at the previous expected mass of 96GeV/c2. The new estimated mass is around 117 GeV/c2, which is a range that accelerators have not yet searched. [F] To observe strings directly, physicists would need to magnify particles by 15 orders of magnitude more than the 13 orders of magnitude afforded by today's best techniques. However, it may be possible to test string theory by looking instead for the gravitational signature of strings left over from the creation of the Universe, exploiting the huge magnification provided by the expansion of the Universe. New calculations suggest that such "cosmic strings" might still survive as a gravitational footprint. Gravitational waves have yet to be directly detected, which is the mission of the current LIGO and LISA experiments. Confirming string theory as well as finding gravitational waves would be a double bonus. [F] Understanding why the expansion of the Universe is accelerating is one of the most important problems in physics. One theory is that gravity is becoming weaker due to gravitons leaking out of 4-dimensional space-time into higher brane dimensions. Leaky gravity should produce a detectable precession of the Moon's orbit and researchers are looking for this using laser beams reflected back by mirrors left on the Moon from Apollo 11. The existence of dark energy is the other theory. A key question is how much it has varied through the life of the Universe. To answer this, astronomers want to find thousands more type 1a supernovas, map many very distant galactic clusters, measure weak gravitational lensing, and observe anisotropy of the cosmic background radiation. Dark energy might also be revealed from the way the three types of neutrinos - tau, muon, and electron - convert into one another. Such "neutrino oscillations" can be described by a time-varying field that is like the time-varying dark energy described in some models. These predict a fourth type of neutrino, which is being sought in experiments at Fermilab. [F][T] The Chandra X-ray telescope has been used to study 26 clusters of galaxies between one and eight billion light years from Earth, spanning the time when the Universe slowed from its original expansion, before speeding up again. The results confirm that the transition from decelerating to accelerating expansion occurred around 6 billion years ago. The measurements agrees with previous data from supernova and microwave measurements. All three methods imply that, if ideas about dark energy are correct, about three-quarters of the energy in the Universe is dark energy, whose repulsive force is overriding the attractive force of gravity. [F][R] The "cosmic dark age" lasted from the fading of the big bang fireball to the time when the first stars ignited, several hundred million years later. During this period, hydrogen clouds formed into structures that eventually became the stars and galaxies. Researchers at Harvard have proposed that it may be possible study how these structures formed from the way they absorbed the residual background radiation from the fireball. Neutral hydrogen would have absorbed radio waves at 21 cm wavelength, but because of the subsequent expansion of the Universe, this will now be red-shifted to wavelengths of tens of metres, a region of the radio spectrum that astronomers have largely ignored. [F][R] A new analysis of data from the Wilkinson Microwave Anisotropy Probe shows no evidence that the Universe is a space-time "Hall of Mirrors". This means that the expansion of the Universe should give it a current diameter of at least 78 billion light years. [F][R] Understanding better how the Solar System formed is important for determining where other Earth-like plants are likely to exist in the galaxy. It has traditionally been assumed that the Solar System formed quietly from the slow collapse of an interstellar gas cloud. However, there is evidence that it might instead have formed in an intensely active region close to massive stars. Meteorites have patterns of isotopes that can only have been caused by the radioactive decay of iron-60, an isotope that has a half-life of only 1.5 million years and can only be formed in the heart of a massive star. [F] |
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| [T] Technology reviews | |
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The open-source model is a good way to produce software, as the example of Linux shows. There are now proposals that the open source model might work beneficially in other domains, including some areas of drug discovery. The Institute for OneWorld Health, the first non-profit pharmaceutical company in the US, has announced its intent to develop a volunteer network of corporate and industry pharmaceutical scientists that would promote development of medicines for neglected diseases. [T][C][G][H][K] The biotech industry has experienced some tough times since the technology boom ended, but according to a report by Ernst and Young, investors in the US have regained their confidence. America's 1,473 biotech firms attracted $14.4 billion of new investment in 2003, two-thirds more than in 2002. The industry's market capitalisation rose by more than 50 percent to almost $300 billion in 2003. [T][G][H] In a special report on trends in the electronics industry, EE Times has views from 50 CEOs, and 9 reports from analysts on the sustainability of the current recovery, MEMS sensors, systems-on-a-chip, flat-panel TV, DSP, wireless, memory, power-over-Ethernet and open wireless. For CEOs, the key driver is the consumer market. The killer-ap is enabling consumers to do everything they want easily, flexibly, anywhere, “smaller-faster-cheaper”, “mobility-plus-utility”. With manufacturing moving to the Far East, the high added-value is in systems engineering, managing complexity and constant innovation, with multidisciplinary collaboration reaching right along the value chain to create integrated solutions, expertise and ideas. Silicon complexity is a big challenge at 90nm geometry. All-layer-from-the-ground-up customised chips are becoming economically prohibitive. Solutions include open scalable architecture, multipurpose systems-on-a-chip, flexible cells bringing custom performance to standard cell design, full-chip simulation, and design-for-manufacturability and high yield. As well as Wi-Fi, UWB, RFID and smart cards, and the move to packet-switched IP networks, big emerging opportunities include the digital home and the human electronic cocoon of near-body, on-body and in-body electronics, the fast growth in optoelectronics, and the impact of high definition displays. [T][C][I][J][K][S][V][W] |
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