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Top Stories in Science
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April 2006 Issue |
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| [D] Defence and security |  |
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Globalisation and the world's poor An article in the April issue of Scientific American analyses how economic globalisation affects the world's poor. Extreme poverty is declining overall, particularly in East, South and South-East Asia. However this may be due more to improvement in infrastructure and to the Green Revolution that to globalisation. In Africa, extreme poverty has increased, but again this is due more to bad governance from unstable or failed political regimes. The article advocates that globalisation can help reduce poverty provided that action is taken to control the flow of short-term international capital and prevent financial crises, and to reduce protectionism in rich countries and restrictive practices in international companies. Also, for trade to make a country better off, the government of that country may have to redistribute wealth and income to some extent, so that the winners from the policy of opening the economy share their gains with the losers. [D][E][H][T][X]
Bird flu vaccine Yet another trial of an H5N1 bird flu vaccine in humans has ended in disappointment, with only high doses giving a good immune response. Researchers are beginning to wonder if the some feature of the H5N1 surface proteins, possibly the strategic placement of a sugar group, keeps the human immune system from responding as it usually does to flu proteins. Some teams are now investigating what might make the H5N1 proteins more immunogenic. [D][H]
Spread of avian flu Restoring tens of thousands of lost and degraded wetlands could go a long way towards reducing the threat of avian flu pandemics, according to the preliminary findings of a UN study. The loss of wetlands around the globe is forcing many wild birds onto alternative sites like farm ponds and paddy fields, bringing them into direct contact with chickens, ducks, geese, and other domesticated fowl. [D][E][H]
Treating poxviruses Many viruses, such as influenza, are surrounded by a single lipid membrane. To infect a cell the virus sheds this membrane by fusion with the cell membrane, allowing the virus core to be released into the cell. Poxviruses, including smallpox, have a double membrane. Researchers at Imperial College have discovered how such viruses manage to infect cells, and have also shown that disrupting the outer membrane with polyanionic compounds exposes the virus, allowing antiviral antibodies to be more effective and also limiting the spread of the virus in the body. This provides a new approach against poxviruses and their possible use in bioterrorism. [D][H]
Depleted uranium Depleted uranium is used for anti-tank weapons, tank armour and ammunition rounds, and there has been some concern over possible health hazards, particularly from material left on firing ranges. Research at Northern Arizona University has now shown that, independent of its radioactive properties, uranium can damage DNA as a heavy metal. They found that when cells are exposed to uranium, it binds to their DNA and the cells acquire mutations. This behaviour is not unique to uranium: other heavy metals are also known to bind to DNA. [D][G][H]
Global terrorism and rules of war The UK Secretary of State for Defence, in discussing the challenge of global terrorism, has controversially called for sweeping changes to international rules of war. He raised three key issues: the treatment of non-state terrorists under laws that were designed for war between nation states; the definition of an "imminent threat" to make it easier to take pre-emptive action; and, the legal basis for intervening to stop a humanitarian crisis. He warned that the world is facing a threat from groups unconstrained by any sense of morality or convention, and that legal grounds for mounting pre-emptive strikes or intervening to stop genocide are no longer adequate. [D][X] |
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| [A] Aeronautics and space | |
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Morphing aircraft Batteries expand and contract as they are charged and recharged. Engineers at MIT believe this can be exploited to enable aircraft to morph their shape like birds, or for a boat hull to change shape to allow more efficient movement in choppy, calm or shallow waters. They have found battery materials that expand by as much as 19 percent and can withstand stresses up to 200 megapascals, sufficient to change the shape of, for example, a helicopter rotor exposed to aerodynamic forces. The material is light weight and operates at voltages of less than 5 volts, which is more convenient compared with the hundreds of volts required by piezoelectric actuators. [A][E][M][P]
Bee flight When orchid bees extend their hind-legs they pitch forward to achieve maximal speed, and their legs trailing behind them produce lift forces to either side that help prevent the bee from rolling. The findings might be applied to design miniature flying machines. [A][U]
DVT risk People with acute infections of the respiratory or urinary tract have a doubled risk of having a deep vein thrombosis, according to scientists at the London School of Hygiene and Tropical Medicine. The extra risk, which would add to the DVT risk of long haul air flights, is greatest in the first two weeks following infection and declines steeply thereafter. [A][H]
Venus express ESA's Venus Express spacecraft, launched in November 2005, has now entered orbit round Venus, having travelled 400 million kilometres in 5 months. It will orbit the planet for the next 500 days. Scientists hope to learn how Venus, which is similar to Earth in size, mass and composition, evolved so differently over the last 4.6 billion years. The first images returned from the spacecraft show the planet's south pole from a distance of 206,452km. This reveals that Venus's atmosphere has a giant vortex at the south pole similar to that which was known to exist at the north pole. [A][R]
Satellite thermal control Lightweight MEMS devices can be used on the outside of microsatellites to control their temperature. Known as the Variable Emittance Coatings for Thermal Control, the devices employ microscopic shutters controlled by integrated circuits. The satellite can be cooled by closing shutters to reflect the sun's heat or warmed by opening them. [A][J][P]
Deep space microwave communications For the first time, NASA's Deep Space Network has used a pair of antennas to successfully send two simultaneous signals to a spacecraft in deep space that were combined at the spacecraft to yield greater signal power. This opens the way to use large antenna arrays for deep space communication. [A][I]
Deep space laser communications US researchers have nearly trebled the efficiency of a miniscule detector capable of capturing single photons of light. The detector uses a superconducting coiled nanowire combined with an anti-reflection coating and a "photon trap" that helps channel incoming photons to be absorbed by the wire. The purpose is to make it possible to communicate over interplanetary distances at high bandwidth using laser beams. [A][I][O][S]
Cosmic ray hazards The solar system's up-and-down motion across the galactic disc periodically exposes it to higher doses of dangerous cosmic rays, according to new calculations. This could explain a mysterious dip in the Earth's biodiversity that has occurred every 62 million years. [A][E]
Ageing in space Cosmic ray damage to the telomeres of their cells may cause space travellers to age more rapidly on long space missions. Iron nuclei particles, which are a chief component of cosmic rays, are particularly damaging, much more so than gamma rays. Experiments with rats have shown that iron nuclei radiation causes aging of brain tissue. [A][G][H]
Life on Mars A new study of a meteorite that originated from Mars has revealed a series of microscopic tunnels that are similar in size, shape and distribution to tracks left on Earth rocks by feeding bacteria. Several types of bacteria are capable of using the chemical energy of rocks as a food source, and one group of bacteria in particular is capable of getting all of its energy from chemicals. The igneous rocks from Mars are similar to many of those found on Earth, and virtually identical to those found in a handful of environments, including a volcanic field found in Canada. [A] |
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| [U] Unmanned vehicles and robotics | |
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Bipedal robots A two-legged robot developed by researchers from Germany and Scotland has demonstrated that a system with a simple neuronal controller can walk in a natural manner. The robot, 30 cm tall, is controlled by a simple program that mimics the way neurons control reflexes in humans and other animals. It has few sensors and can detect just two things – when a foot touches the ground, and when a leg swings forward. Yet, it can walk at a record-breaking 3.5 leg-lengths per second. [U][B]
Artificial muscle Two types of methanol-powered artificial muscles have been developed by researchers aiming to create battery-free robotic limbs and prosthetics. The first type of muscle is made from a nickel-titanium shape-memory wire coated in a platinum catalyst. When fumes of methanol, hydrogen and oxygen pass over the platinum coating, they react, releasing heat that warms the wire, making it contract. When the flow of fuel is stopped, the wire expands and returns to its original length. The wire muscle can generate 100 times the force of a natural muscle of the same size. The second type of artificial muscle is made from sheets of carbon nanotubes, coated in a catalyst. As the fuel reacts with oxygen above the surface of the nanotube sheet, it releases a charge that makes the sheet expand. The hope is that these muscles could enable fuel-powered artificial limbs. They might also lead to "smart skins" and morphing structures for air and marine vehicles, to autonomous robots having very long mission capabilities and to smart sensors that detect and self-actuate to change the environment. [U][M][N] |
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| [P] Propulsion and energy | |
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Fuel cell batteries Methanol fuel cells may be powering laptops by early 2007, initially providing up to nine hours of operation. The technology has been boosted by recent decisions to change the rules that previously banned passengers from carrying any methanol onto aircraft. [P][A][D][I][R][U]
Safe sequestration The concern over proposals to sequester carbon dioxide into depleted undersea oil or gas reservoirs is that in the future these reservoirs might leak, allowing the carbon dioxide to escape into the atmosphere. Scientists are suggesting however that in some seabed locations, where sediment, temperature and pressure are suitable, the escaping carbon dioxide should combine with seawater to form carbon dioxide hydrates - ice-like compounds in which the water molecules form cavities that act as cages, trapping the carbon dioxide molecules. This hydrate formation would create a secondary seal, blocking sediment pores and cracks, and slowing or preventing further leakage of the carbon dioxide. [P][E][M]
Nuclear waste The continuing problem of how to dispose of radioactive waste is prompting an experiment in Japan to revisit an old idea of using high energy protons to transmute most of the long lived radioactive isotopes in the waste into ones that decay much more quickly. This would mean that the waste would only need to be stored for hundreds rather than tens of thousands of years. The transmutation process should also produce a net energy output. [P][E][M]
Convection French researchers have for the first time confirmed experimentally a 40 year old theory of convection. Using a water-filled convection cell, they managed to measure temperature differences as small as a few thousandths of a degree in the middle of a convecting fluid, far from the boundaries. From the temperature fluctuations they were also able to measure for the first time the size of the "blobs" of warm water that carried heat in their cell. The experiments showed a direct relationship between the amount of heat transported through convection and the Reynolds number. The researchers propose that this provides a simple way to measure heat flow in real-life situation, such as the atmosphere. Currently there is no good way to measure the flow of heat in such situations because it flows in all directions and is uncontrolled. [P][A][E][F][M] |
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| [M] Materials, structures and surfaces | |
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Green explosive US researchers say they have found how to use nitrotetrazole as a "green" primary explosive that could replace the lead-based explosives currently used in detonators. Nitrotetrazole itself has been studied for the past few decades as a next-generation explosive, but it only makes a good primary explosive when partnered with toxic perchlorate-based chemicals. The researchers overcame this by tweaking the distribution of charge on the nitrotetrazole molecule. This also changed the substance’s overall properties, such as its sensitivity to ignition through physical contact or heat, and could allow the substance to be tailored for specific applications. [M][D][P]
Calculating hardness Physicists in the Czech Republic have developed a way to predict the hardness of materials from first-principle calculations alone. Their new theory, which applies for both covalent and ionic bonding and agrees well with experimental data, says that the hardness of an ideal single crystal is proportional to the bond strengths and to the number of bonds in a unit cell volume of the crystal. Using their equation, the researchers have also found an unexpected result that contradicts conventional wisdom: atoms surrounded by relatively few other atoms are harder than those surrounded by lots of other atoms. [M][C]
Lattice solitons Solitons, or solitary waves, were first described by Scottish scientist John Scott Russell in 1834 after seeing such a wave on a canal. In the late 1980s, scientists theorised that solitons might exist in solids and molecules. German and US researchers, using X-ray and neutron scattering experiments, have now experimentally identified such localised vibrations in a crystal of uranium heated to 180 degrees C. Atoms in a crystal normally transmit their vibrations to their neighbours. But if an atoms vibrates very strongly, its frequency of vibration can change dramatically so that neighbouring atoms no longer resonate in lockstep. In uranium this nonlinearity may be even stronger because uranium atoms can exchange their vibrational energy with the energy of their outermost electrons. The researchers found that the localised vibrations, which have a wavelength as small as two atomic spacings, form randomly throughout the material. They also seem to play a role in the deformity of uranium since they act, in effect, as a new kind of lattice defect. [M][N]
Bioengineered organs The first long term success in implanting laboratory grown organs has been reported. Patients with defective bladders were treated with bioengineered bladders grown from their own cells. Each bladder was grown by placing muscle cells and cells from the lining of the patient's bladder onto a biodegradable bladder-shaped scaffold of collagen. After growing for about two months, the new bladder was implanted into the patient. Follow-up of the patients for an average of four years has shown that the technique is successful in the long term. [M][H]
Frictionless motion Researchers at USC and Brown University say they have achieved near-frictionless motion in water by using lasers to spin a molecule like a propeller. Free rotation can occur in gases, where molecules are far apart. This is the first known demonstration of friction being turned off in a room temperature liquid. The results might be useful in controlling chemical reactions. [M][O]
Super-superglue The waterproof glue that one species of water-loving bacteria uses to grip its surroundings is stronger than cyanoacrylate superglues and may be the strongest known natural adhesive. If a way is found to mass-produce the material, it could have uses in medicine, marine technology and a range of other applications. The challenge will be to produce large quantities of the glue without it sticking to everything that is used to produce it. [M][E][H]
Ceramic coating Researchers at Pacific Northwest National Laboratory have developed a new ceramic-based coating for steel and superalloys that prevents corrosion, oxidation, carburisation and sulphidation in hostile environments. The coating is very durable and cannot be chipped or scratched off. [M][E][P][W] |
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| [E] Environment, transport and marine | |
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Accelerating rise in carbon dioxide According to NOAA, the average atmospheric concentration of carbon dioxide in 2005 reached 381 parts per million, an increase of 2.6 ppm since 2004. The annual increase, which has been recorded since the 1950s, has now exceeded 2 ppm for three of the past four years. Half a century ago, the annual increase was less than 1 ppm. [E][R]
Antarctic warming Winter air temperatures over Antarctica have risen by more than 2 degrees C in the last 30 years, a new study shows. The warming is seen across the whole of the continent and much of the Southern Ocean. It is much greater than is predicted by any of the 20 climate models that were used by the researchers to try to simulate the change. A likely reason for the discrepancy is that airflow over Antarctica is very complex and has to be simplified in the climate models. [E][C][R]
Melting glaciers Glacial earthquakes in Greenland have more than doubled in number since 2002, according to seismologists at Columbia University and Harvard. The quakes are caused when glaciers lurch and can be as strong as magnitude 5.1 on the moment-magnitude scale, which is similar to the Richter scale. The increase in their frequency provides another indicator of Arctic warming. [E][R]
Rising sea level Ice sheets across both the Arctic and Antarctic could melt more quickly than expected this century, according to two studies that blend computer modelling with paleoclimate records. The studies show that Arctic summers by 2100 may be as warm as they were nearly 130,000 years ago, when sea levels eventually rose up to 6 metres higher than today. [E][C]
Soil carbon uptake Recent assessments and model projections from the Intergovernmental Panel on Climate Change anticipate that global warming will be mitigated by large increases in soil carbon produced by faster plant grown due to higher carbon dioxide levels. However, this may be wrong. A 6-year study of how different perennial grasses grow under various conditions has concluded that plant growth will be limited by shortages of nitrogen and that nitrogen fixation will not be able to keep up with increasing carbon dioxide levels unless other essential nutrients, such as potassium, phosphorus and molybdenum, are added to the soil as fertilisers. [E][C]
Soil erosion As a result of soil erosion over the past 40 years, 30 percent of the world's arable land has become unproductive, according to a new study. The US is losing soil ten times faster than it is being replenished, and China and India are losing soil 30 to 40 times faster. It is estimated that the economic impact of soil erosion in the US is around $38 billion each year in productivity losses, and damage from soil erosion worldwide is estimated to be $400 billion per year. Erosion increases the amount of dust carried by wind, which carries about 20 human infectious disease organisms, including anthrax and tuberculosis. [E][H]
Soil health crisis According to a new study, three-quarters of African farmland is severely degraded to the point where it cannot even produce one tonne of grain per hectare, only 30 percent of productivity in Latin America and Asia. Farmers in sub-Saharan countries traditionally grew crops on cleared land for only a brief period before moving on to new areas, allowing the land to regain fertility. But population pressure now forces the farmers to grow crop after crop in the same area, and to clear and cultivate new land at the expense of wildlife and forests. [E][D]
Water resources Farming poses the biggest threat to fresh water supplies, according to a major UN report. Rising demand by irrigated agriculture now accounts for 70 per cent of freshwater withdrawals from aquifers, and only 30 percent of this water is returned to the environment. This compares with industry and households which return up to 90 percent of the water used. Agriculture is consuming ever more water as the world population increases and as people turn to a Western diet. [E][D][X]
Bioremediation of waterways Ultrasound and algae can be used together as tools to clean mercury from contaminated sediment, according to an Ohio State University study. The hope is that this could lead to a ship-borne device that cleans toxic metals from waterways without harming fish or other wildlife. The ultrasound releases the mercury very effectively from the sediment and the algae then absorb it within seconds. [E][H]
Hurricane season 2006 The signs are that the 2006 hurricane season is again likely to be severe according to predictions based on two key drivers: the speed of the trade winds in the Caribbean and tropical North Atlantic, which determine the vorticity (spinning up) of hurricanes; and, the sea surface temperature in the tropical North Atlantic, which provides the heat and moisture that are the storms' raw power. [E][D][X]
Hurricanes and global warming Researchers at the Georgia Institute of Technology have released a new study that strengthens the link between the increase in hurricane intensity and the increase in tropical sea surface temperature. The study examined an alternative hypothesis that the increase might be due to other factors, notably wind shear. The study found that although wind shear does affect the intensity of individual storms or storm seasons, there is no trend in wind sheet that can account for the global 35-year increase in the number of the most intense hurricanes. [E][D][X] |
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| [R] Remote sensing and sensor systems | |
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International Polar Year The International Polar Year (IPY), beginning in March 2007, will involve 50,000 participants in the most intensive study of the polar regions since the International Geophysics Years (IGY) in 1957. The IGY provided the foundation for much of today's polar science knowledge. Proposals for the IPY include new research into ice cores to further knowledge of the Earth's climate one million years ago; mapping and modelling of permafrost thawing; tracking reindeer herds as the climate alters; looking at oil and gas development; and satellite observations. The IPY will also focus on indigenous communities. [R][A][E]
GPS profiling of the atmosphere A new constellation of six satellites in low earth orbit will use GPS signals to improve weather forecasts, monitor climate change, and enhance space weather research and forecasting. By measuring the refraction of GPS signals as they pass through the atmosphere and ionosphere, the satellite system can monitor the temperature and water vapour profiles in the atmosphere and the electron density in the ionosphere. The system should considerably enhance global data, particularly by providing measurements over the oceans where weather balloons cannot be used. [R][A][E]
Cosmic x-ray background X-ray observatories such as ESA's XMM-Newton and NASA's Chandra have been able to identify and directly count a large number of individual astronomical sources that already account for more than 80 percent of the measured cosmic diffuse X-ray background. However, the high energy component of the background is hard to determine because the radiation cannot be focused with lenses or mirrors. Now, using ESA's Integral gamma-ray observatory, researchers have succeeded in measuring the high-energy background. They did this by using the Earth as a shutter: they pointed Integral towards the Earth and measuring how much the background dropped while Earth passes in front of Integral's field of view. [R][A]
Acoustic helioseismology It takes about 27 days for the Sun to rotate on its axis. So, in the past, any sunspot, solar flares or other active region on the far side of the Sun - which might interfere with orbiting satellites, telecommunications and power transmission, or be a threat to astronauts - has remained hidden for up to 13 days, giving no warning until it rotated into view. A new method now makes it possible to see the entire far side of the sun. It uses data from the Michelson Doppler Imager (MDI) on board the SOHO research satellite. MDI creates images of the sun's interior by measuring the velocity of sound waves produced by hot, bubbling gases that well up to the surface. This data can now also be used to compute a picture of its back surface. [R][A][I][P]
Ocean surface velocities For more than a decade space-based radar instruments have been routinely observing ocean surface phenomena including wind, waves, oil slicks, even the eyes of hurricanes. Now by exploiting the Doppler shift in electromagnetic waves reflected from the water surface, satellite radar has also begun to enable direct measurements of the speed of the moving ocean surface itself. Initial tests have been carried out on tidal currents off Brest and Cherbourg. More evaluations are needed to consolidate and validate the method, but assuming it proves reliable it can make a significant contribution to operational oceanography. [R][E]
TeraHertz remote sensing Engineers at the Argonne National Laboratory have developed a suite of sensors that can quickly and effectively detect chemical, biological, nuclear and explosive materials. This includes the first-ever remote detection of chemicals and identification of unique explosives spectra using THz frequencies. Operating at frequencies between 0.1 and 10 terahertz, the detector are four to five orders of magnitude more sensitive and have an imaging resolution 100 to 300 times higher than is possible at microwave frequencies, according to Argonne. The technique is also an improvement over laser or optical sensing, which can be perturbed by atmospheric conditions, and over using X-rays, which can cause damage by ionization. [R][D][P][S]
Distributed Brillouin Sensing A new fibre-optic sensor system, developed at the University of Ottawa, can detect problems in structures such as natural-gas pipes and concrete columns more precisely and potentially earlier than before, it is claimed. The system uses the Brillouin effect to detect vibrations produced in the structure by deformation, cracks, and bending. [R][M][S][W]
Smart sensor networks The new IEEE 1451.4 standard offers a standard interface and protocol by which a sensor can describe itself over a network. It also eradicates one of the most common sources of sensor system errors - incorrectly transcribed calibration information from analogue sensor data sheets. The heart of IEEE 1451.4 is the use of a digital ROM embedded in the analogue sensor that stores the sensor's transducer electronic data sheet (TEDS) and identification information. When connected to an IEEE 1451.4-enabled data acquisition system, the ROM chip transmits the TEDS to the system, in a way similar to a USB mouse or printer identifying itself to a PC after it is plugged in. [R][A][C][E][I][P][S][T]
Imaging shock waves The recent merger of high-speed video technology with centuries-old techniques for seeing fluctuations of the air is enabling engineers to study the previously unseen, large-scale behaviour of shock waves in explosions and in aerodynamics research. [R][A][M][P][S][T] |
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| [S] Sensor devices | |
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Gamma ray detector Scientists at NIST have demonstrated the world's most accurate gamma ray detector. It can pinpoint gamma ray signatures of specific atoms with 10 times the precision of the best conventional sensors used to examine stockpiles of nuclear materials. The sensor is expected to be useful in verifying inventories of nuclear materials and detecting radioactive contamination in the environment. [S][D][E][P][R]
Mass spectrometry Desorption electrospray ionization (DESI) provides a way to produce compact portable mass spectrometers that could have numerous uses for detecting everything from cancer in the liver to explosives residues on luggage. Conventional mass spectrometers require samples that are specially prepared and placed in a vacuum chamber. The key DESI innovation is performing the ionization step in the air or directly on surfaces outside of the mass spectrometer's vacuum chamber. This is done by spraying water in the presence of an electric field, causing water molecules to become positively charged "hydronium ions," which contain an extra proton. When the positively charged droplets hit the surface of the sample being tested, the hydronium ions transfer their extra proton to molecules in the sample, turning them into ions. The ionized molecules are then vacuumed through a tube and into the mass spectrometer, where the masses of the ions are measured and the material analysed. [S][A][D][H][M]
Nanopore sensors Some proteins naturally form nanometre-scale pores that serve as channels for biochemical ions. Nanopores enable many functions in cells, such as allowing nerve cells to communicate. They are also exploited by viruses to infect cells by shooting viral RNA and DNA into the cell through the nanopore. Researchers have now shown how single biological nanopores can be used to detect and characterise individual molecules of RNA and DNA, and have demonstrated using anthrax-related nanopores in diagnosing anthrax infections and testing anti-anthrax drugs. [S][B][G][H][N]
Nanopore DNA sequencing Current DNA sequencing methods are vastly too slow and expensive to routinely sequence people's genomes to tailor medical treatments for each individual. Now, however, US researchers have shown from a detailed computer simulation of over 100,000 interacting atoms that it may be possible to speed up DNA sequencing more than 200 times by using a nanopore to detect electrical changes as a strand of DNA is passed through it. The researchers based their calculations on a pore about a nanometre in diameter made from silicon nitride surrounded by two pairs of tiny gold electrodes. The electrodes record the electrical current perpendicular to the DNA strand as it passed through the pore. Because each of the four DNA bases (A, G, C, T) is structurally and chemically different, each base creates its own distinct electronic signature. [S][G][J]
Spin-excitation spectroscopy IBM scientists have developed a powerful new technique, called spin-excitation spectroscopy, for exploring and controlling magnetism at its fundamental atomic level. Using the technique, they created chains of up to 10 manganese atoms and measured how the magnetic properties changed as each new atom was added. They found that chains with an even number of atoms had no net magnetism, while chains with an odd number of atoms showed net magnetism. The technique should make it possible to explore the limits of magnetic data storage, to determine the feasibility of spin-based wires and a spin version of the molecular-motion cascade, and to investigate how engineered spin interactions could be applied to quantum information systems, such as quantum computers. [S][C][J][N][O][R]
Frequency-comb spectroscopy Physicists at JILA have designed and demonstrated a highly sensitive new tool that allows real-time analysis of the quantity, structure and dynamics of a variety of atoms and molecules simultaneously. It works even for minuscule gas samples. The technique uses cavity ring-down spectroscopy, which identifies atoms or molecules by the way they absorb laser light as it is repeatedly reflected and dissipates inside a mirrored vacuum cavity. It combined this with an ultrafast laser-based "optical frequency comb" used as both the light source and as a ruler for precisely measuring the many different colours of light after the interactions. The technology could provide unprecedented capabilities for use in laboratories, environmental monitoring stations, security sites screening for explosives or biochemical weapons, and medical offices where patients' breath is analysed to monitor disease. [S][O][R]
Holographic microscope A new submersible holographic microscope allows scientists to form 3D images of tiny marine organisms at water depths as great as 100 metres. The device allows the recording of behavioural characteristics of zooplankton and other marine organisms in their natural environment without having to bring specimens to the surface for examination. [S][E][O]
Oral cancer sensor Tumours in the mouth are often easily visible, but determining whether a suspicious sore is benign or potentially cancerous has remained difficult. Now researchers have developed a simple hand-held device, called a Visually Enhanced Lesion Scope, that emits a cone of blue light into the mouth, exciting fluorescence. Normal oral tissue emits a pale green fluorescence, while potentially early tumour cells appear dark green to black. [S][H][O] |
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| [O] Optoelectronics, optics and lasers | |
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Tuneable terahertz source Researchers at the University of St Andrews have developed a compact tuneable terahertz source by placing a parametric generator inside a laser. The hope is that this source could lead to practical terahertz scanners to detect and identify concealed drugs, weapons and explosives. [O][R][S]
In-fibre electronics A new technique has been developed at Penn State and Southampton University that encases semiconductor devices inside microstructured optical fibres. This opens the possibility of rapid and efficient optoelectronic devices that do not require conversion between optical and electronic signals. The resulting ability to generate and manipulate signals inside optical fibres could have applications in medicine, computing and remote sensing. The team has demonstrated a simple in-fibre transistor. [O][H][J][R][S]
1.93 micron laser Researchers at INFM Pisa and the Milan Polytechnic have developed an eye-safe laser emitting at 1.93 microns. The laser has a tuning range of 85 nm and the researchers say that it is ideal for use in both LIDAR and DIAL systems and for monitoring atmospheric gases such as water, ozone, carbon dioxide and nitrogen dioxide. It has a pulse duration of 170 ns at a repetition rate of 5Hz and a peak power of 19 kW. It could also be useful for high resolution spectroscopy and biomedicine. [O][H][R]
Optical interconnect NEC has developed a vertical-cavity surface-emitting laser (VCSEL) emitting at 1.07 micron wavelength and with an operating speed of 25 gigabits per second (Gbps) per channel. The device is seen as a major step forward in developing optical interconnects between chips to meet the needs of future supercomputers for transmission speeds of over 20 Gbps by 2010. [O][C][J]
GHz bandwidth slow light Slow light techniques have had very limited bandwidths in comparison with the requirements of optical networks. Now, however, Swiss and Japanese researchers have shown that they can achieve GHz-bandwidth slow light using a simple and inexpensive technique. They believe this may be the key to producing high-speed all-optical buffers and optical routers. [O][I]
Entanglement swapping In entanglement swapping, one particle of an entangled pair becomes entangled with a third particle, which itself becomes entangled with the other particle in the first pair, even though the two never interact. This effect can be used in quantum communications and high-speed computing. At present, quantum teleporting of information using entangled photons only works over a hundred or so miles before signal loss weakens the connection. One way to tackle signal loss is to place quantum repeaters along the quantum channel. At the repeater, a photon belonging to an entangled pair can use entanglement swapping to transfer its entangled partner to another particle nearby, and so on down the channel. Chinese scientists have demonstrated this entanglement swapping experimentally. [O][C][I]
Photonic translator Researchers at UCSD say they have used a parametric process in photonic crystal fibre to change the wavelengths of modulated optical channels from 1.55 micron to a visible light signal at half a micron. The parametric band translator means that mature telecom technology can be applied to many other wavelengths, permitting development of new applications at various bands without requiring huge investment in new infrastructure to replace what already exists. Free-space communication requires mid- and far-infrared bands, undersea communication uses visible wavelengths, and general sensing applications can occupy any band from ultraviolet to infrared. [O][I][R]
Nanophotonics The Institute of Physics has published a review of nanophotonics - a new field concerned with the generation, transport, routing and detection of light in sub-wavelength structures. Nanophotonics combines electrodynamics, solid state physics and laser physics; it draws analogies between electrons in crystals and photons in nanostructures, and it achieves strong fields not through an increase in optical power but through its concentration. From an engineering perspective, nanophotonics promises to develop optical functionality on the smallest possible size scale (thus allowing for ultra-high-density integration), at the lowest possible energy level (thus allowing for single photon all-optical devices), and on the shortest possible timescale (thus allowing for optical devices operating within a single period of an optical wave). [O][J][I][N][R][S][T]
Photonic holes Just as electronic holes act like positively charged particles in a semiconductor, so it might be possible to create photonic holes. A photon hole might, for example, be a place in an otherwise intense laser-beam wavefront where a photon had been removed, for example by passing the laser beam through vapour. It is also proposed that photon holes can be entangled, and that entangled photon-holes would be able to propagate through optical fibres just as well as entangled photons, but might be even more robust against decoherence. [O][C]
Negative refraction Using a full 3-dimentional negative refractive index lens, researchers at the University of Delaware have demonstrated, for the first time, electromagnetic gradient force trapping, similar to optical tweezers but at microwave frequencies. [O] |
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| [I] IT, communications, networking and secure systems | |
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Wired-wireless convergence Telecommunications providers currently supply services that are generally either all-wireless through cellular telephones or similar devices, or all-wired through DSL, cable or optical access network. As wireless providers seek to provide new bandwidth-intensive services such as video, music and high-speed Internet access, the bandwidth needs of wired and wireless services are converging. Researchers at Georgia Tech have demonstrated a new network design that would allow both ultra-high-speed wireless and wired access services from the same signals carried on a single optical fibre. Wavelength division multiplexing would allow a fibre to carry as many as 32 different channels, each providing 2.5 gigabit-per-second service. [I][O]
ENUM and the future of telephony. There are about 1 billion fixed telephone lines and 2 billion cellphones in the world. Most calls still travel across traditional systems based on proprietary software and hardware. Soon, though, they will move to networks based on voice over Internet Protocol (VoIP). Done wrong and too quickly this change could cause parts of the internet to collapse under the increased load. Done right the move will open doors to new telephone services. Openness is key if tomorrow's VoIP world is to be as open and interoperable as the Internet itself has been. Internet standards bodies have approved a new type of data record—called ENUM, for electronic number—that could accommodate the legacy information of both telephony and the Internet. ENUM will be the bridge between the two global communications networks. [I][C][K][R][T]
Future of Wimax and Wi-Fi Intel expects that cards allowing access to Wimax (Worldwide Interoperability for Microwave Access) will be rolled out this year. However, an OECD report on Wimax has concluded that regulatory, security and spectrum problems may limit the widespread use of Wimax, and that it unlikely to replace Wi-Fi and third generation mobile networks. Blanket Wi-Fi is already spreading within urban areas, and, as cheap mobile Wi-Fi devices become available, this will lead to radical changes in everyday urban life and work. Wimax, according to the OECD, may find a niche in providing broadband to rural areas and developing countries. [I][D][K][R][T]
Wi-Fi society Wi-Fi built into objects such as wine glasses may enable people to feel more together when they are geographically separated. [I][K]
P2P TV The current method of distributing television via the internet makes use of centrally located computer systems. However, another approach being demonstrated is to use peer-to-peer (P2P) systems. This would enable high bandwidth TV programmes to be broadcast at almost no cost and opens the way to new TV stations operating through the Internet. However, a big issue is how to protect the ownership of the visual material. [I]
Emergency communications Rapidly deployable interoperable communications are increasingly needed for disaster relief operations involving multinational efforts. A European Community project has developed a prototype network that could be quickly deployed in areas where there is no available communication infrastructure to support emergency or peacekeeping operations. [I][D]
RFID viruses Security researchers have shown that RFID tags can be infected by computer viruses and have warned that RFID tags could open up many different types of attacks on computer systems. The researchers showed how to get round the limited computational abilities of the smart tags to use them as an attack vector and corrupt databases holding information about what a company has in storage. They tested this with a virus that used only 127 characters. [I][D] |
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| [K] Knowledge, information and technology management | |
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e-health Future mobile phones might incorporate a virtual healthcare assistant to give the phone owner personalised advice on making healthy choices about food and lifestyle, and to prompt about taking medication and the right exercise. [K][I][H][V]
e-Health Telehealthcare, or e-care, could help in providing better care to elderly and chronically ill people in their homes. A project funded by the EU has developed an affordable and usable video-telephony system that comprises a small movable camera, a set-top box for a TV and a handheld service pad. Together, these components enable users to see, talk to or seek assistance from professional carers in real time, over the Internet, using a TV rather than a portable computer. The project concluded that home video-telephony systems of this kind need good integration, including with alarm systems or with mobile devices that register vital signs such as blood pressure. The researchers also found that Wi-Fi does not meet the needs of video telephony for stable, high-bandwidth connections. [K][I][H]
Gene database The COSMIC database developed at the Sanger Institute, Cambridge, was created in 2004 to provide free up to the minute genetic data to scientific communities and to prevent the duplication of research. The data in COSMIC has expanded to include data on 538 genes, and 124,367 tumours with 23,157 mutations. Recently, information about patients lifestyle, ethnicity and tumour characteristics has also been incorporated into tables. Two genes BRCA1 and BRCA2 have been identified that account for approximately 20 percent of the familial risk of breast cancer. The hope is to soon find the genes responsible for the remaining 80 percent, and for other cancers. [K][C][G][H]
Intelligent search In many fields of research it is very hard for researchers to keep track of the huge volume of publications. In response to this, an EU project has developed a new type of search tool that presents search results in a way that is specifically linked to the interests of a particular research group. It classifies and files unstructured information in a 'knowledge grid' and can not only search and find documents, but also answer questions based on its database. [K][C][G][H]
Personalisation A newly launched tool, called Boxxet, may be a step forward for creating personalised web pages. The site asks web surfers to come up with any subject they are interested in and to submit links to their five favourite news articles, blogs or photos on that subject. It then automatically creates a webpage on that topic. The site’s algorithm starts by reading through the web pages submitted by the user. It calculates the frequency of unique words and which words these unique words are likely to be adjacent to. It also notes the number of images and which news organisation or blogger created those pages. It uses this data to filter its index of web pages and RSS feeds, depositing anything highly relevant in the Boxxet. The Boxxet is constantly updated as new stories appear, and the type of information is also modified by ratings provided by new visitors to the site. [K][I][V]
Assessment of UK science The UK Office of Science and Technology has published the results of the latest study into the outputs and outcomes from UK science. This shows that the UK produces 9 percent of the world’s scientific papers and has a citation share of 12 percent - second highest to the US. The UK continues to strengthen its share - 13 percent - of the world's most influential papers. [K] |
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| [C] Computing, supercomputing, modelling and simulation | |
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Heterogeneous supercomputers Different applications run best on different types of processors, but high-performance computers typically offer only one type of processor. Cray has announced that its next generation of supercomputers will instead be adaptable for particular computing chores by plugging special-purpose circuit boards, known as blades, into a standard chassis. Software then will direct computing jobs to be handled by the most suitable blades. [C]
Simulating a complete lifeform The complete structure of a simple virus has been simulated on a computer. This is the first computer simulation of an entire life form. The simulation was able to briefly follow the life of the virus, and elucidated the key physical properties of the viral particle as well as providing crucial information on its assembly. [C][G]
Galactic simulation In one of the biggest simulations ever performed in astrophysics, Japanese and US scientists have calculated how galaxies evolved from just 300 million years after the Big Bang to the present day. They used a powerful 3D hydrodynamic code combined with a "spectral synthesis" code for an astrophysical plasma in order to represent both the dynamical and chemical evolution of a primordial galaxy. The results show that galaxies may have evolved much faster than currently believed. [C][A][F] |
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| [W] Whole life engineering, manufacture and testing | |
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Design for safety Motor vehicles are highly manoeuvrable and to replicate this movement in a controlled environment has been extremely challenging without the use of heavy, expensive equipment to replicate the sensations of movement. This has made driving simulators expensive to build and operate, and unrealistic to use. A joint Dutch, French and UK EUREKA project has developed a sophisticated lightweight system that is claimed to be accurate and relatively cheap, yet gives a realistic experience to the user. The system is designed to be used for testing modifications to car design and how these will influence safety. [W][C][X]
Tensegrity design Scientists at the UCSD have devised two mathematical tools for the optimal design of a new generation of deformable bridges, buildings, shape-controllable airplane wings, radio antennas, and other alternatives to current structural technologies. The deformable characteristic is made possible with strong, ultra-light truss-like arrangements of rods suspended by strings or wires. The resulting structure incorporates tensegrity, a combination of “tension” and “integrity.”. [W][A][E][I][M] |
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| [X] Systems, complexity and risk | |
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1-dimensional system Physicists at Penn State University have performed the first laboratory experiment with a system of many colliding particles whose motion never becomes chaotic. The system used interfering beams of laser light to form an array of thousands of parallel, tube-shaped traps that forced atoms to stay in one dimension. The atoms collided like a quantum version of a Newton's cradle, but even after each atom had collided thousands of times their momentum profile was completely unchanged. The researchers say the work provides a deeper understanding of conditions that govern the boundary between order and chaos in physical systems. It is also potentially important for high precision gyroscopes. Trapped atoms also can be used as precise force sensors, which can be limited in their sensitivity by collisions. [X][I][R][S]
Arctic ecosystem The northern Bering Sea provides critical habitat for large populations of sea ducks, grey whales, bearded seals and walruses, all of which depend on small bottom-dwelling creatures for sustenance. These bottom-dwellers, in turn, are accustomed to colder water temperatures and long periods of extensive sea ice cover. Change from arctic to sub-arctic conditions could profoundly affect this ecosystem and the people who depend on it. [X][E]
Insect infrastructure Insects play some highly valuable economic roles, but many wild insect species are facing extinction or are in deep decline. US scientists have estimated that four insect activities - processing cattle dung, controlling pests, pollinating plants and serving as food for wildlife - contribute at least $57 billion a year to the US economy. The analysis excluded the value of services provided by domesticated insects such as honey bees, by mass-reared biological control agents, and by commercially raised insects. [X][E]
Loss of biodiversity The newly published Global Biodiversity Outlook (GBO) paints a very gloomy picture of how biodiversity is being rapidly lost. The GBO sets out 15 indicators of progress towards the 2010 target of the UN Convention on Biological Diversity. These indicators range from trends in the extent of wildlife habitats to the build-up of nutrients such as nitrogen which can harm aquatic life. Only one of the 15 indicators - the area of the world's surface officially protected for wildlife - is moving in the right direction for biodiversity. [X][E][G]
Eco-efficiency and sustainability The challenge for sustainability is to simultaneously satisfy the rising consumption and aspirations for affluence in the world's population and the attainment of a reasonable environmental quality. However, relations between economy and environment are not self-evident, not at a micro level and not at the macro level resulting from micro-level decisions for society as a whole. Eco-efficiency analysis seeks to provide a framework for dealing with this. [X][D][E][T]
Risk of Bay Area earthquake The devastation of New Orleans by hurricane Katrina is focusing minds on the potential for a massive earthquake catastrophe in the Bay Area. The huge San Francisco earthquake in 1906, estimated at magnitude 7.9, released the strain on all of the parallel faults in the Bay Area. However, continuing plate movement means there is now a probability of at least 62 percent of a quake of magnitude 6.7 or greater on a Bay Area fault before 2032, according to scientists at the USGS who have reconstructed the region's seismic history since 1600. A quake is most likely to occur on the Hayward fault that runs under Oakland or on the San Andreas fault under San Francisco. It is not just the seismic energy that does the damage, but also the speed at which the fault ruptures. That speed can be so great that the seismic waves form an intense pressure pulse analogous to a sonic boom in the air. [X][C][D][E][T]
Climate change and malaria risk Since the 1970s, the highlands of East Africa have witnessed a surge in malaria outbreaks. Because the mosquitoes that carry the disease do not thrive in cooler climes some researchers have suggested a link between this rise and climate change. A 2002 study found no such connection, but a new analysis of the data, including five more years of records, seems to show that just a 1 degree C rise in local temperature from one year to the next can mean a 30 to 40 percent increase in mosquito abundance. [X][E][H] |
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| [V] Virtuality and human-machine interface | |
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Virtual humans It is now possible to produce extremely realistic "virtual humans" featuring intricate anatomy and physiology, integrating detailed knowledge of the forces produced by specific human muscles, the ways muscles wrap around bones and the ways nerves communicate and co-ordinate with muscles, and of how the brain generates and controls movement. Virtual humans have many potential applications, ranging from health, stamina, medicine and surgery to the design of body armour, emergency escape, seating, machinery and work environments. [V][B][C][D][H][T][W]
Virtual worlds and gaming A recent UK survey highlighted that 82 percent of 9 to 19-year-olds have at least one games console and 70 percent play computer games online. A study by Brunel University has concluded that this is not necessarily damaging from an educational perspective and that the complexity and structure of most games means that teenage gamers are actually learning vital skills and becoming more socially accomplished. Gaming worlds can offer young people the chance to explore all sorts of experiences that would otherwise be closed to them, and to develop wider relationships and important social and cultural skills which carry significance for real life, and also for the future cyber society. [V][C][K]
Autofocusing spectacles Spectacles that can automatically adjust their focus depending on what the wearer is viewing could become possible as a result of the development of a lens whose focusing power can be changed electronically. The lens consists of a flat, 5-micron thick layer of liquid crystal sandwiched between two layers of glass that are coated with concentric rings of transparent indium-tin-oxide electrodes. [V][O]
White light organic LED Researchers from UCS and Princeton have succeeded in making a prototype white-light organic LED (OLED). The researchers previously invented efficient single-colour OLED displays, soon to be used in next-generation cell phones. But subsequent attempts by several groups to create white-light OLEDs hit problems, particularly fast burnout time of the phosphorescent blue component. The new technology overcomes this by using a fluorescent blue dye instead. Almost any surface in a home, whether flat or curved, could become an OLED light source, and since OLEDs are transparent when turned off, they could be installed as windows or skylights to mimic the feel of natural light after dark. [V][E][J][P]
Brain interconnect chip A specialised microchip that could communicate with thousands of individual brain cells has been developed by European scientists. The device will help researchers examine the workings of interconnected brain cells, and might one day enable them to develop computers that use live neurons for memory. The chip is capable of receiving signals from more than 16,000 mammalian brain cells, and sending messages back to several hundred cells. Previous neuron-computer interfaces have either connected to far fewer individual neurons, or to groups of neurons clumped together. [V][B][C][J] |
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| [B] Brain research and human science | |
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Brain communication Brain cells do not communicate strictly by a digital code, as generally believed, but use a mix of analogue and digital coding, according to research at Yale. The study reveals that the brain is very sophisticated in its operation, using a code that is more efficient than previously appreciated. [B][I]
The olfactory brain One of the puzzling aspects of the sense of smell is how the perception of an odour can evolve over multiple sniffs. US researchers have discovered that the olfactory bulb, which processes the signals from the millions of olfactory sensor neurones in the nose, contains a type of cell called a Blanes cell. This is one of six named but hitherto unstudied types of brain cells in the olfactory bulb. Blanes cells have a unique ability to maintain their activity between sniffs, and although there are relatively few Blanes cells in the brain, they appear to play a critical role, magnifying hundreds of times the output signals leaving the olfactory bulb by the specific pattern of connections they make with other cell types. The researchers also found that the memory mechanism in the olfactory bulb is the same as that in the cortex, which is involved in Alzheimer's disease. [B][V]
Culture and intelligence Studies of orang-utans in Sumatra suggest that the most important driver in the evolution of human and primate intelligence has been the survival advantage of being able to share innovations and to pass knowledge on to future generations. This does not exclude that other factors may also play a part: such as, the ability to figure out how to skilfully extract hidden nourishment or the capacity to remember the perennially shifting locations of critical food items, or the Machiavellian ability to recognise situations and to decide, for example, whether to come to the aid of an ally attacked by another animal. However, the evidence suggests that the survival advantage of cultural knowledge and learning is paramount. [B][K][T]
Development of high IQ People with exceptionally high IQ do not have larger brains but may differ in the way their brains develop, according to MRI studies at NIMH. The study followed 307 children and teens as they grew up. It found that in those who developed exceptionally high IQ, the cerebral cortex thickened more rapidly during childhood and reached its peak later than normal, and also then thinned faster during the late teens. This may reflect a longer developmental window for high-level cognitive circuitry followed by a withering of unused neural connections as the brain streamlines its operations. The NIMH researchers are following-up with a search for gene variants that might be linked to how the cortex matures. However, they expect that any effects of genes will depends on interactions with environmental events, so that the determinants of intelligence will likely prove to be a very complex mix of nature and nurture. [B][K]
Intelligence and family size Many past studies have reported that older children are generally more intelligent than their younger siblings. However, research has now shown that this is flawed, and that birth order really does not have an effect on intelligence. Researchers have now shown that the reason that later-born siblings seem to have lower intelligence has to do with the fact that they come from larger families that may have different home environments than smaller families. [B][K]
Male and female brains Researchers have found that the amygdala, a key part of the brain involved in processing emotionally influenced memories, acts differently in men and women, even when they are at rest. The findings may have implications for certain psychiatric and mental disorders. For example, one of the brain areas communicating with the amygdala in women is implicated in disorders such as depression and irritable bowel syndrome, which predominantly affect women. [B][H]
Treating depression Whether or not cognitive behaviour therapy will help a person recover from depression can be predicted through brain imaging, according to research results published by the University of Pittsburgh School of Medicine. A problem in treating depression is that there is no single medication or therapy that has been found to work as a primary treatment for most patients. Brain scans may provide a better way than trial and error for finding the right treatment. [B][H]
Reducing fear When people with a phobia are exposed to what they fear, they experience a surge in stress hormones known as glucocorticoids. These compounds help prepare the body for action, whether fight or flight. Now researchers have found that giving people glucocorticoid pills to raise the levels of stress hormones in the body can actually reduce the level of fear. [B]
Treating dementia US researchers have, for the first time, identified a substance in the brain that is proven to cause memory loss. The substance is an amyloid-beta protein that is distinct from the protein in the plaques associated with Alzheimer's disease. It could now give drug developers a target for creating drugs to treat memory loss in patients with Alzheimer's and other dementia. The researchers say that the results together with earlier work show that neither the tau tangles nor the amyloid plaques are major causes of memory loss in Alzheimer's disease. [B][H]
Neonate pain perception From brain scans taken while babies were having blood tests, scientists at UCL have found that premature babies are likely to experience 'true' pain rather than simply displaying reflex reactions. Pain information is transmitted to the preterm infant cortex from 25 weeks, and there is the potential for pain experience to influence brain development as the brain is highly malleable at this stage of development. Estimates show that in intensive care a premature baby is subjected to an average of 14 procedures per day, many of which are considered by clinical staff to be painful. [B][H] |
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| [H] Healthcare and medicine | |
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Restoring sight Scientists have prompted mouse-eye cells that are not normally light sensitive to respond to light. This strategy could lead to new treatments for retinitis pigmentosa and related diseases, which cause blindness in 1 in 3,000 people worldwide. These diseases destroy the light sensitive rods and cones in the eye, but other cells in the eye are not affected. These spared cells include inner retinal neurons, nerve cells that process information from rods and cones before sending it to the brain. The scientists showed that these cells can be made light-sensitive using a green algae protein, called channelrhodopsin-2 (ChR2), inserted into the cell membranes. [H][G][B]
Asthma and antibiotics The increasing prevalence of asthma may be related to antibiotic use in early childhood. A study covering 12,082 children has found that those exposed to at least one course of antibiotics in their first year of life were twice as likely as untreated children to develop asthma. In a dose-response analysis, researchers analysed the data from 27,167 children (3,392 asthma cases) from five studies to determine the effect that multiple courses of antibiotics in infants would have on the development of asthma. For each additional course of antibiotics taken during the first year of life, results showed a significant overall odds ratio of 1.16, suggesting that additional courses of antibiotics appeared to further increase the risk for asthma development. [H]
New understanding of asthma A newly recognised type of immune cell, known as natural-killer T cells (NKT cells), may play an important role in causing asthma. This may explain why current asthma therapies based on corticosteroids are sometimes ineffective. Previous research in mice has shown that NKT cells have a direct causative role in asthma. Now the researchers have found that NKT cells are abundant in the lungs of patients with asthma, but virtually absent in the lungs of healthy people. Previously, it was thought that a type of conventional T-cell, specifically type 2 helper cells (Th2 cells), were causing the asthma inflammatory process. Corticosteroids target these Th2 cells, along with other inflammatory cells, but appear to have little effect on NKT cells. Drugs to inhibit NKT cells may therefore prove more effective for treating asthma. Also, past research on how asthma is triggered has focused on protein antigens that activate Th2 cells. However, NKT cells are triggered instead by glycolipid antigens. Identifying these antigens and how they activate NKT cells could open up many opportunities for better therapies. [H][G]
Alcohol and cancer Researchers have developed a mouse model of how alcohol consumption may be linked to cancer. When alcohol is consumed, cells increase metabolic activity to break it down, and may deplete themselves of oxygen. This oxygen-depletion (hypoxia) indirectly induces overproduction of vascular endothelial growth factor (VEGF). VEGF, in turn, stimulates the growth of new blood vessels to meet the increased oxygen demand. At the same time it helps small tumours to develop blood vessels and grow. The findings may make it possible to block the VEGF overproduction. [H]
Immune response to cancer Mayo Clinic researchers have identified a new signalling mechanism by which natural killer (NK) cells initiate a toxic response against cancers and viruses. When an NK cell encounters a new tumour developing, it may generate signals that will kill the tumour and clear it from the body. However, depending on the signals it receives, it may also generate signals that block the destruction of the tumour. Understanding which signal is effective in causing tumour destruction means new strategies can be generated for enhancing this. [H][G]
Screening for lung cancer In a group of high-risk patients, a test that examined DNA from cells expelled in sputum for evidence of "silenced" genes correctly identified the majority of patients who were later diagnosed with lung cancer. The test is unique in looking for genes that have been turned off in contrast with more traditional "biomarker" assays that look for increased gene activity. It may provide the first effective way to detect lung cancer at a very early stage in high risk people, particularly those with a history of smoking and chronic obstructive pulmonary disease. The test may also be useful for future therapy that turns silenced genes back on. [H][G][S]
Treating HIV Scientists have discovered a previously unknown mechanism that cells use to fight off HIV. Two proteins that normally help repair cellular DNA were found also to destroy DNA made by HIV after it enters a human cell, DNA which HIV requires to survive. It is hoped this could lead to a new type of treatment for HIV to which the virus might be less able to adapt. [H][G]
Calorie restriction and longevity Calorie restriction is known to increase lifespan in experimental animals. A six month US trial involving 48 volunteers has now found indications that caloric restriction might have somewhat similar effects in humans. Volunteers on a caloric restriction diets of 890 calories per day lost 10 percent or more of body weight and had reduced fasting levels of the hormone insulin, a trait associated with longevity in animal research. Volunteers who restricted their caloric intake by 25 percent or achieved similar results by cutting calories and increasing exercise levels had a reduced average core body temperature at the conclusion of the six month trial. Lower body temperatures are also associated with longevity. [H][G]
Statins Further evidence of the benefit of statins has come from a new US study, which examined patients with heart disease at 53 centres across the US, Canada, Europe and Australia. The study found that rosuvastatin has gone further than other statins, and not only improved the balance of cholesterol, but also unblocked fatty arterial thickening or atherosclerosis, and lowered 'bad' cholesterol and raised 'good' cholesterol by unprecedented amounts. [H] |
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| [G] Genomics, biotechnology and bioinformatics | |
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How viruses jump species An important issue in the context of avian flu is how quickly a virus can evolve once it has crossed a species barrier. Research at Oxford University, has traced how a virus called feline panleukopenia virus (FPLV), crossed species from cats to dogs in around 1970 and then mutated rapidly to spread as a lethal infection among healthy dogs. The researchers used Bayesian Markov Chain-Monte Carlo analysis to explore models of the evolutionary dynamics of the virus. The results showed that FPLV had been infecting cats for over a century, but once it began to infect canines, the virus, now a canine virus, quickly accumulated additional changes in individual DNA building blocks enabling it to transfer from an infected dog to a healthy dog. This rapid evolution contradicts conventional wisdom, which says that DNA viruses do not mutate rapidly. [G][D][H]
Antibiotic resistance German researchers have shown that for salmonella-related illness (diarrhoea and typhoid) there are far fewer possible points of attack for developing new antibiotics than had been expected. The researchers identified all the proteins involved in Salmonella metabolic pathways during an infection. They then knocked out individual genes to test the effect of disrupting a particular protein with antibiotics. This revealed that Salmonella is surprisingly unaffected by the blockade of several central metabolic pathways. The reason for this is redundant enzymes, as well as the host offering a wide range of nutrients, which means Salmonella does not depend on its own biosynthetic abilities. This result shows that as Salmonella and other bacteria become increasingly resistant to current antibiotics, it is necessary to find new principles for attacking them. [G][H]
Antibiotic resistance Although there a many paths by which genes can mutate, most paths are dead ends because evolution requires each step in a chain of mutations to individually improve survival fitness. This fortunately makes it much harder for microbes to develop antibiotic resistance. [G][H]
Embryonic stem cells All existing colonies of human embryonic stem cells (ESCs) have been derived from surplus human embryos. A team in Germany has now successfully grown mouse ESC-like cells from spermatagonial stem cells which normally turn into sperm. The ESC-like cells can be grown into all tissues of the mouse body, suggesting that if the same could be done in men, it would provide patients with a source of tissue-matched cells for repairing any damaged organs or tissue. [G][H] Eggs and sperm An Australian research team has solved one of biology's most fundamental questions – why males produce sperm and females produce eggs. The ce | |||