|
|
||||
|
|||||
|
|
|||||
Top Stories in Science
|
Current Issue |
| [D] Defence and security |  |
|
|
|
|
|
Bali convention The UN climate change convention in Bali reached agreement on a two-year negotiating process - the "Bali roadmap" - to secure a binding deal at the 2009 UN summit in Denmark. It recognised that deep cuts in global carbon emissions will be required to avoid dangerous climate change and decided to look at "a long-term global goal for emission reductions". Developed nations must take on commitments that are "measurable, reportable and verifiable", and "nationally appropriate". These may or may not include quantified, binding targets for all or some. Actions by developing nations must be "measurable, reportable and verifiable in the context of sustainable development, supported by technology and enabled by financing and capacity-building", meaning with Western support. There were also pledges on reducing deforestation, protecting poorer countries against climate change impacts, and scaling up the transfer of clean energy technologies from industrialised nations to the developing world.
[D][E][P][R][W][X]
Environmental security To help developing nations adapt to climate change, the UK and Netherlands have launched a 2 year study, led by the World Bank, on how governments in developing countries should take climate change into account when drawing up development plans and goals.
[D][E][X]
Flood defences Asia's massive delta cities have most to fear from catastrophic storm floods driven by climate change, according to a new OECD report. Of 136 port cities assessed around the world for their exposure to once-in-a-century coastal flooding, 38 percent are in Asia and 27 percent are located in deltas. The top 10 cities most at risk, in terms of exposed population, are Mumbai, Guangzhou, Shanghai, Miami, Ho Chi Minh City, Kolkata, Greater New York, Osaka-Kobe, Alexandria and New Orleans.
[D][E][X]
Food security The soaring cost of food is threatening millions of people in poor countries, according to the UN FAO. Food prices rose 40 percent in 2007 and many nations may be unable to cope. The FAO called for help for farmers in poor countries to buy seeds and fertiliser, and for a review of the impact of bio-fuels on food production. Thirty-seven countries currently face food crises due to conflict and disaster.
[D][E][G]
Food security According to a new report by the International Food Policy Research Institute, surging demand for food, biofuel and animal feed has recently led to drastic price increases. Between 2000 and 2006, cereal prices more than doubled and, with demand outstripping production, stocks have been heavily depleted. By 2020, global warming is projected to reduce agricultural GDP by over 20 percent in developing countries and by 16 percent worldwide, and poorer nations will face severe dangers of malnutrition, child mortality and lost livelihood. The report calls for more investment in agricultural science and technology to help increase food production, and for elimination of trade barriers so that food is distributed more equitably.
[D][E][X]
Food security According to three new reports, climate change will affect agriculture far more severely in some regions than is currently predicted. The authors say that existing projections do not take into account the seasonal extremes of heat, drought or rain, the multiplier effects of spreading diseases or weeds, and other ecological upsets that would exacerbate the agricultural decline.
[D][E][G][H][X]
Worsening armed conflict New peace strategies may be needed according to the latest annual report “States in Armed Conflict” from the Uppsala Conflict Data Programme. Following the conflict-ridden years of the early 1990s, the number of armed conflicts in the world declined year on year up to 2002. Since then, however, the number has held steady at around 30 per year and conflicts have become more protracted and extensive. This raises the question of whether the peace strategies that worked in the 1990s are no longer being carried out with the same force or effectiveness. The Middle East is the region in which peace initiatives are most wanting, particularly given the central importance of the region for the world’s oil supply and for world religions. Also, during 2007, other regional conflict complexes have emerged and worsened. The crisis in the Sudanese region Darfur is now spreading to the surrounding countries, such as Chad and the Central African Republic.
[D][X]
Fast cyanide antidote A cyanide antidote has been developed that can be administered orally and works in less than three minutes – meeting the US DOD standard for defence against cyanide agents. The antidote exploits the body's own natural pathway used to detoxify cyanide that occurs naturally in small quantities in almonds and other foods.
[D][H] |
||
| [A] Aeronautics and space | |
|
|
|
|
|
2007 in space and astronomy New Scientist has reviewed the achievements of 2007 in spaceflight, space missions and astronomy, and listed its top ten stories of the year for each.
[A][F][P][T][U]
GRAIL mission Previous lunar missions have revealed that the Moon's gravity field has much larger irregularities than Earth's. These irregularities make it harder for spacecraft to navigate and land. In preparation for returning to the Moon, NASA has announced that it will launch a mission in 2011 called GRAIL to map the Moon's gravitation field much more precisely. This mapping will also provide 100 times more sensitive measurements of how mass is distributed inside the Moon's interior and shed light on the Moon's origin and early history. Some key questions are how much of the Moon's interior is still molten, how thick the crust is and how the crust has been redistributed by major meteor impacts. GRAIL will use the same basic technology as the GRACE (Gravity Recovery and Climate Experiment) satellites that measure Earth's gravitational field.
[A][R]
Sun's mysteries The first results from Japan’s Hinode mission have has shed new light on two of the Sun's enduring mysteries: why its corona is much hotter than its surface and what produces the solar wind. The data show that the corona is swarming with Alfvén waves. These are very probably the main mechanism in heating the corona and could also be responsible for the solar wind.
[A][R]
Manned mission to Mars NASA has released details of its strategy for sending a human crew to Mars within the next few decades. It envisages despatching a "minimal" crew on a 30-month round trip in a 400 tonne spacecraft. This would be assembled in low-Earth orbit and powered by an advanced cryogenic fuel propulsion system. The cargo lander and surface habitat would be sent to Mars separately, launched before the crew ship. Estimates of the cost of the mission vary enormously, from $20bn to $450bn.
[A][P][U]
Life on Mars NASA says its robot rover Spirit has made one of its most significant discoveries on the surface of Mars. Its broken wheel dug into a patch of ground revealing silica deposits that scientists think were probably produced when hot spring water or steam came into contact with volcanic rocks. On Earth, such locations are perfect for microbial life.
[A][R][U]
Water on Mars Spacecraft orbiting Mars and roaming the Martian surface have discovered lots of sulphur minerals in the soil but almost no carbonate deposits. This has led to a novel suggestion that sulphur dioxide released by giant volcanoes, rather than carbon dioxide, could have produced sufficient greenhouse warming to support liquid water oceans early in Martian history. On Earth, sulphur dioxide from volcanoes is quickly oxidised to sulphate and removed from the atmosphere, but on early Mars, which lacked oxygen, it would have lingered in the atmosphere for much longer. Similar warming might have occurred on the early Earth when the Earth's atmosphere had almost no oxygen.
[A][E][R]
Into the heliosheath In December 2004, NASA's Voyager 1 spacecraft passed through the solar wind termination shock, crossing the boundary of a vast region called the heliosheath at the edge of the Solar System where the solar wind runs up against the thin gas between the stars. Unfortunately various reasons including instrument failure meant the event was not captured. Now Voyager 2 has also crossed the termination shock and this time with working instruments to measure directly the velocity, density and temperature of the solar wind. The shock “sloshes” back and forth like surf on a beach and the spacecraft experienced at least five shock crossings over a couple of days. The shock was not as expected. In a normal shock wave, fast-moving material slows down and forms a denser, hotter region as it encounters an obstacle. However, Voyager 2 found a temperature beyond the shock that was ten times lower than predicted. This probably indicates that the energy is being transferred to cosmic ray particles that are accelerated to high speeds at the shock.
[A][R] |
||
| [U] Unmanned vehicles and robotics | |
|
|
|
|
|
Airborne refuelling of UAVs US Air Force flight tests have demonstrated that UAVs can perform automated airborne refuelling from tanker aircrafts.
[U][A][D]
Robotic submarine A robotic submarine designed to explore the oceans thought to lie beneath the icy crust on Jupiter's moon Europa will be tested in an Antarctic lake in 2008. A previous version of the vessel has already mapped the balmier waters of a Mexican sinkhole. The submarine will survey Antarctica's West Lake Bonney, which is 4 km wide and 40 metres deep and is capped by a perennial layer of ice about 4 metres thick. The crust has kept the lake's waters pristine and virtually unexplored.
[U][A][E][R]
Flocking UAVs Researchers at the University of Colorado at Boulder have developed small uncrewed aerial vehicles (UAV) that link up to form an airborne network, allowing the planes to coordinate their behaviour independently of any central control. In trials, they used short-range radio transceivers to connect five small aircraft, weighing 250 grams each and with a wingspan of 50 cm, to fly autonomously in formation to different waypoints. Their latest aircraft now weigh about 40 grams and have 15 cm wingspan.
[U][A][R]
Autonomous seaplane Researchers at the University of Michigan have developed an autonomous seaplane that can initiate and perform its own takeoffs and landings on water. The aircraft has a 2 metre wingspan and its takeoff sequence gets it airborne in just 10 metres.
[U][A][E][R]
Robot navigation and control Snakelike robots are of interest for applications such as remote inspection, repair, and even rescue work. However, getting them to navigate independently has so far proven difficult because their mode of locomotion means their body is continually changing shape and position. Researchers in Greece have now demonstrated a control mechanism, both with computer simulation and experimentally, that allows a snake-shaped robot to safely navigate through an unfamiliar environment. In simulations, the same behaviour enables several robots with sensors along their body to form a team that can travel along together.
[U][S]
Stable robots Existing humanoid robots are very liable to topple over if they are pushed at the wrong place. Now, Japanese researchers have developed software that allows a life-size humanoid robot to stay on its feet no matter where on its body it is pushed. Its joints are never kept rigid, even when standing still, so they can yield slightly when the robot is pushed. Force sensors within each joint also work out the position and velocity of the robot's centre mass as it moves around. Control software rapidly figures out what forces the robot's feet need to exert on the ground to bring it back into balance, and tells the joints how to act. This feedback keeps the robot steady as it moves itself around and allows it to readjust to sudden, external forces.
[U][S]
Robotics in 2007 Scientific American has reviewed progress in robots in 2007, highlighting: tests of how robotic surgery can be performed on astronauts, the DARPA urban challenge, robot rescuers, autonomous bonding between robots and toddlers, progress with humanoid companion or partner robots, and using cockroach-mimicking robots to research behaviour and control in cockroach communities.
[U][T] |
||
| [P] Propulsion and energy | |
|
|
|
|
|
Reducing vehicle pollution To reduce deaths and ill-health caused by air pollution, Germany has begun banning polluting vehicles from city centres. Drivers in Berlin, Cologne and Hanover are now required to display a coloured badge showing the level of pollution their vehicle causes. Some vehicles, notably an estimated 1.7 million old diesel cars and vans, will not qualify for even the highly polluting red badge and will be totally excluded from central areas.
[P][E]
Fuel cells Polymer electrolyte membrane fuel cells (PEMFCs) have a high energy-conversion efficiency, which makes them promising for use in vehicles. One problem, however, is that they use platinum as the electrocatalyst. Now scientists in China and the US have shown that nanocrystalline chromium nitride might provide a much cheaper alternative to platinum.
[P][M][N]
Vehicle-to-grid A big problem with electricity is that is difficult and expensive to store, making it hard to cope with the peaks and troughs in generation and demand. But as millions of cars become all-electric or plug-in hybrids, their batteries will collectively add up to a huge storage capacity that might be used to back-up the electricity grid, according to researchers at the University of Delaware. They have developed a prototype vehicle-to-grid system that uses "broadband-over-power lines" to link each vehicle's computer securely via the power cables with a computer owned by the grid operator. This computer asks the car to charge up and store excess power when demand is low, for example at night. Then, when demand suddenly spikes and if the car is not then being used for travel, its battery can supply electricity back to the grid.
[P][I]
Revolutionary Li-ion battery Stanford researchers have found a way to give rechargeable lithium-ion batteries ten times more capacity, enough that they might be suitable for electric cars and to store electricity generated by rooftop solar panels and wind turbines. The capacity of a Li-ion battery is limited by how much lithium can be held in the anode. This is normally made of carbon. Silicon has a much higher absorption capacity than carbon, but unfortunately it swells during charging and shrinks during discharging and this repeated expand/shrink cycle fractures the silicon. The Stanford researchers avoided this problem by instead using a forest of tiny silicon nanowires in the anode. These inflate to four times their normal size as they soak up the lithium, but they do not fracture.
[P][M][N][U]
Quick-charge battery Toshiba has developed a battery that can be recharged in five minutes, has a very long lifetime, and can operate at temperatures as low as -30 degrees C.
[P]
Oxyfuel combustion On its list of possible breakthrough technologies for 2008, IEEE Spectrum cites oxyfuel combustion. This is one of several approaches for capturing carbon dioxide from coal-fired power stations so that it can be liquefied and sequestered. In the oxyfuel process, instead of burning coal in air, the nitrogen is first extracted from the air so that the coal can be combusted in an atmosphere of oxygen and recycled flue gases. This produces a stream of nearly pure carbon dioxide. A Swedish company is building a 30 MW oxyfuel facility to demonstrate and test the approach. The simplicity of oxyfuel combustion means that it might be retrofittable to existing power stations. The big challenge, however, is the high energy cost of separating the input oxygen from air.
[P][E][M]
IGCC carbon sequestration An alliance of 14 of the largest coal burners and miners in the world is planning a full-scale demonstration and test of carbon capture and storage using the integrated gasificationcombined cycle (IGCC) approach. IGCC turns the coal into gas, removing impurities including carbon dioxide and burning the resulting pure gas to turn turbines to produce power. The alliance plans to build a $1.5 billion power plant to begin operation in 2012 producing 275 megawatts of electricity. Some of the power generated will be used to compress the carbon dioxide and pump it deep underground to be permanently stored in saline aquifers. IGCC is a complicated process requiring a complex dedicated plant and a big question is whether it could prove too expensive.
[P][E][M]
Microbial conversion of hydrocarbons The world's gas reserves have been created over geological time by anaerobic microbes that live deep underground and convert oil and other hydrocarbons into methane. Researchers would like to use these same microbes to produce methane, or even hydrogen, from unrecoverable heavy oil and from residual oil that cannot be extracted from existing oil fields. Currently only about 35 percent of the oil can be extracted from a conventional reservoir; 65 percent remains in the ground. For a gas field, in contrast, 70 percent can be extracted. At present, microbial conversion underground happens far too slowly. Researchers are planning by 2009 to test whether they can massively boost the conversion rate in existing reservoirs by pumping in nutrient-rich wastewater to give the microbes an optimum diet.
[P][E][G]
Solar synthetic fuel Researchers at Sandia have created a machine, called a CR5 (Counter Rotating Ring Receiver Reactor Recuperator), that can break water into hydrogen and oxygen by using temperatures of over 1500 degrees C created by focusing sunlight. In a cyclic process, the high temperature is used to liberate oxygen from rust. Then the scorched rust is exposed to superheated steam, which restores the rust to its original form, yielding free hydrogen. The process can also be used to convert carbon dioxide to carbon monoxide, which can be combined with the hydrogen to make hydrocarbons such as methanol, ethanol, and even gasoline or diesel fuel. The researchers say that the machine’s maximum theoretical efficiency at turning the sun’s heat into chemical energy is 76 percent. Their aim is to build a reactor about the size of an oil drum that should be able to convert 22 kg of carbon dioxide and 18 kg of water into roughly 9.5 litres of liquid fuel each day.
[P][M]
UK wind power Under plans unveiled by the UK government, all UK homes could be powered by offshore wind farms by 2020 as part of the fight against climate change. The aim is to produce around 33 GW by 2020 from 7,000 wind turbines. About 8 GW could be in place by 2014, including the 1 GW London Array in the Greater Thames Estuary, which will be the biggest offshore wind farm in the world.
[P][E]
Low carbon technologies A survey by the World Conservation Union of 1,000 relevant professionals in 105 countries has found there is little support for first generation biofuels. Only 21 percent believed these biofuels have potential to "lower overall carbon levels in the atmosphere without unacceptable side effects" over the next 25 years. The technologies that inspired greatest confidence were solar and wind power.
[P][E][T] |
||
| [M] Materials, structures and surfaces | |
|
|
|
|
|
Magnetic shape-memory foams A new class of materials known as "magnetic shape-memory foams" has been developed by US researchers. The foam consists of a nickel-manganese-gallium alloy whose structure has small voids of space between thin, curvy "struts" of material. The struts have a bamboo-like grain structure that can lengthen up to 10 percent when a magnetic field is applied. The material retains its new shape when the field is turned off, but returns to its original structure if the field is rotated 90 degrees. The researchers say the new material is a good candidate for tiny motion control devices or biomedical pumps without moving parts, and for uses that require a large strain and light weight such as in space applications and automobiles.
[M][A][N][P][S]
Shape-memory rubber Researchers at the University of Rochester have developed a shape-memory rubber that may have applications for biomedical implants, conformal face-masks, self-sealing sutures, and “smart” labels. Unlike conventional shape-memory polymers, the new material is transparent, rubbery, and the speed at which it returns to its original shape can be controlled. Other shape memory polymers use crystallization to hold a temporary shape, which often makes them opaque, hard, and brittle in their frozen states, limiting their usefulness.
[M][H]
Bamboo composite A novel type of bridge with horizontal beams made from a bamboo composite has proved strong enough to support even heavy trucks in tests. The bamboo beams are cheaper and more environmentally friendly to make than steel or concrete, yet offer comparable structural strength.
[M]
High temperature superconductivity In most high temperature superconductors, the supercurrent is carried by holes. Research has shown that phonons are involved in this superconductivity and may be the “glue” that produces the pairing. However, researchers have now used scanning tunnelling microscopy (STM) to look at a high temperature superconductor called PLCCO in which the supercurrent is formed of electrons. These STM measurements have revealed a signature of excitations that might originate from spins rather than lattice vibrations, giving the first experimental support for theories that suggest spin excitations are actually the “glue” in high temperature superconductivity.
[M][F][P][S]
Superexchange Using an optical lattice, researchers can place atoms at points in the lattice and control and understand their interactions. In this way, German and US researchers have been able to observe superexchange in a 1-dimensional lattice of rubidium atoms. The superexchange interaction involves “virtual hopping” of electrons from one lattice site to another. The likelihood of this happening is governed by the relative orientations of the spins of the electrons, and superexchange can produce both ferromagnetic and antiferromagnetic alignments. The researchers were able to switch their 1-D lattice between these alignments. The next step is to produce a 2D lattice - high temperature superconductors consist of stacked 2D layers and are known to have magnetic properties related to superexchange. The ability to fine-tune superexchange between atoms in an optical lattice might also be used to create logical components for quantum computers.
[M][C][O]
Ultracold polar molecules Physicists at the University of Rochester have combined an atom-chiller with a molecule trap to generate and trap huge numbers of ultracold polar molecules. This has potential for making a stable quantum computer. The ultracold temperature reduces the problem of decoherence and the strong polarity of the molecules allows them to interact with each other over large distances. The stronger the interaction, the faster a quantum computer can perform certain operations. Ultracold polar molecules might also provide a way to determine whether electrons are really point particles or have finite size, with a precision sufficient to test between the Standard Model of elementary particles and various alternative models.
[M][C][F]
Antibacterial polymers The immune system includes peptides that apparently work by carpeting and disrupting the membrane of an invading pathogen. By mimicking the chemical structure of these peptide using different forms of nylon polymer, researchers at the University of Wisconsin have developed easy-to-produce antibacterial material that might be used for clothing and coatings for stents, catheters and other biomedical devices. The polymers appear to be attracted to the bacteria's negatively charged membranes and then reshape themselves and punch holes in the membrane. Animal cells, on the other hand, are generally neutrally charged and appear not to be attacked by the polymers. The researchers found that the polymer could quite readily kill dangerous drug-resistant bacteria, such as vancomycin-resistant MRSA.
[M][H]
Liquid-repellent surfaces Researchers in New Jersey have developed a surface than can be electrically switched between being highly liquid-repellent to highly wettable. The surface, which exploits silicon "nanonails", appears to work with virtually any liquid including water and oils. Potential applications include contamination-resistant and self-cleaning surfaces, reduced-drag ships, and advanced electrical batteries.
[M][A][E][N][P]
Oleophobic material MIT engineers have designed a class of material structures that can repel oils. Unlike water, oils and hydrocarbons have very low surface tension and can therefore easily spread over surfaces. The researchers overcame the surface-tension problem by designing a material composed of specially prepared microfibres that essentially cushion droplets of liquid, allowing them to sit, intact, just above the surface. The material can be applied as a flexible surface coating and could have applications in aviation, space travel and hazardous waste cleanup. For example, it could be used to help protect parts of aircraft or rockets that are vulnerable to damage from being soaked in fuel, such as rubber gaskets and o-rings.
[M][A][E][P] |
||
| [E] Environment, transport and marine | |
|
|
|
|
|
Environment in 2007 In 2007, environmental science has been dominated by global warming and climate change, including melting of ice sheets and glaciers, the opening of the North-West passage, controversy over biofuels, the growing list of endangered species, and other indications that, as Al Gore pronounced at the World Economic Forum, humanity is facing an unprecedented planetary emergency.
[E][D][P][T][X]
Greenhouse gas trends UN statistics for changes in greenhouse gas emissions by country from 1990 to 2005 show that emissions of 25 EU members (not counting Cyprus and Malta) fell by 10.2 percent from 1990 to 2005 whilst US emissions increased by 16.3 percent. The individual countries, such as Denmark and the UK, that have been most vocal in support of Kyoto have especially reduced their emissions, but recently emissions have been rising sharply among many EU members in southern and eastern Europe.
[E][P]
Mitigating climate change Peat is the largest and most efficient land-based store of carbon, and the world's second largest carbon store after the oceans. Peat bogs store on average 10 times more carbon per hectare than any other ecosystem, including forests. Burning, draining, and degrading of peat bogs currently produces carbon dioxide emissions equivalent to more than one tenth of the global emissions released from burning fossil fuels, according to a new report published by the UN Environment Programme in collaboration with Wetlands International. The emissions could be prevented quite easily by blocking the man-made channels that drain peatlands to make way for agriculture. This is among the most cost-effective options for mitigating climate change, according to the report.
[E]
Rising sea levels The Intergovernmental Panel on Climate Change (IPCC) concluded that the rise in sea level would be not more than 81 cm in this century. However a new study suggests the maximum could be as high as 163 cm. This is based on what happened in the so-called interglacial period, some 124,000 to 119,000 years ago, when a different configuration of the Earth's orbit around the Sun made Greenland 3C to 5C warmer than now - similar to the warming expected in Greenland over the next 50 to 100 years. The researchers found that average sea level rose about 1.6 metres each century during the interglacial period, reaching a peak of 6 metres above present levels.
[E][X]
Northeastern Greenland Ice Stream Recent melting of the ice sheet in northeast Greenland is especially worrisome to scientists. The region had no known ice streams until 1991, when satellites spied one for the first time. Now it carries ice nearly 400 miles, from the deepest interior of the island out to the Greenland Sea. The worrying question is how an ice stream can form in the middle of the ice sheet. By combining gravity measurements of the area with airborne radar measurements researchers have now found a possible answer. Underneath the ice stream there is a thin spot in Earth's crust. Heat from underground magma could be melting the base of the ice enough to lubricate the ice flow, adding to the effect of global warming.
[E][R]
Clouds and rain New findings from NASA's CloudSat and other spacecraft in NASA's "A-Train" constellation of five Earth observing satellites suggest that an important factor in the record melting of the Greenland ice sheet in 2007 has been reduced cloud cover. Over the western Arctic, where most of the ice loss occurred, the total cloud cover was 16 percent less in the 2007 melt season than in 2006. CloudSat data is also showing that rainfall, at least over oceans, is considerably greater than previously thought. This is important for modelling the Earth's water cycle and estimating how climate change may affect future rainfall.
[E][R][X]
China's glaciers A survey covering roughly one third of China's glaciers has found that they are melting at an alarming rate. On average they were 7.4 percent smaller in 2007 than in 2002. A glacier along the upper reaches of the Brahmaputra River on the Tibetan plateau had shrunk by more than 18 percent, as had other glacial areas in China's far northwest Xinjiang region. China's glaciers in the west of the country feed many of Asia's greatest and most vital rivers, including the Yangtze, Mekong, Yellow and Ganges, as well as the Brahmaputra.
[E][D][X] |
||
| [R] Remote sensing and sensor systems | |
|
|
|
|
|
Extra-solar planets Two teams of astronomers have made the first ground-based detection of the atmosphere of a planet outside the Solar System. One team extracted polarised light to enhance the faint reflected starlight ‘glare’ from the exoplanet, enabling them to infer the size of its atmosphere. The other team was able to detect the presence of large amounts of sodium vapour in its atmosphere. They did this by repeatedly observing the transit of the planet in front of the star as seen from Earth. At the precise wavelengths of strong atomic transitions in sodium, the light blocked was about 6 percent larger than at other wavelengths. The hope for the future it to be able to observe the atmospheres of potentially habitable planets and to detect molecules that might indicate conditions suitable for life. Of the more than 250 extra-solar planets so far discovered, most are Jupiter-mass, probably gaseous, planets unlikely to harbour life. However, some recently discovered planets appear to be much smaller and rocky like Earth, and at least two of these might be habitable.
[R][A]
Observing Earth-like planets As the Earth rotates, sunlight falls on different surface features such as forests, deserts and seas, and the total brightness of the planet seen by a distant observer will vary. Astronomers estimate that this type of signal might enable them to determine some degree of detail of any Earth-like planets that lie up to 20 or 30 light years away, even though such planets are too small and distant to be imaged directly.
[R][A]
Rare Moon How the Earth got its Moon is not certain. But it is generally thought that the Moon was created by the young Earth colliding with an object the size of Mars and that the massive collision threw a huge plume of Earth's mantle into space. Most of this would have then coalesced to form the Moon, with the remainder continuing to circle round the Sun until it was cleaned up by gravity and the solar wind. Astronomers are interested in estimating how common such massive collisions are in young solar systems. A survey of the cluster NGC 2547, which is only 30 million years old and in the process of forming solar systems, has found that out of about 400 stars in the cluster, only one shows evidence of dust from a massive impact. Such rarity might reduce the chance of finding any life in neighbouring solar systems, since it is thought that the heavy tidal mixing driven by the Moon’s gravity may have played an important role in making conditions favourable for life to originate on Earth.
[R][A]
Star dust NASA has selected three teams of scientists to begin studying disks of dust around nearby stars starting in February 2008, using the new Keck Interferometer in Mauna Kea, Hawaii. This sophisticated new system combines the observing power of the two large Keck telescopes into a single mega-telescope.
[R][A]
Remote sensing with muons Ground-penetrating radar can reach only 30 metres below the surface under ideal conditions. In contrast, muons that constantly rain down on Earth from cosmic rays striking the atmosphere can penetrate far deeper and are being used to study active volcanoes, detect nuclear materials, and look for hidden chambers inside pyramids.
[R][D][E][T]
Molecular imaging of skin Using an advanced microscopy technique known as cryo-electron tomography, scientists from the European Molecular Biology Laboratory (EMBL) have made the first ever three-dimensional images of human skin at molecular resolution. The images reveal how proteins called cadherins bind skin cells together making skin so strong. The researchers found that each cadherin binds twice: once to a molecule from the juxtaposed cell, and once to its next-door neighbour. This works somewhat like Velcro and establishes very tight contacts between cells.
[R][M][N]
Super-resolution With more efficient algorithms, super-resolution is being used to improve the resolution of medical x-ray images without increasing the x-ray dose to the patient.
[R][C][H]
Wavelength-on-demand Quantum Cascade Laser chip Harvard engineers have demonstrated a highly versatile, compact and portable Quantum Cascade Laser spectrometer. It uses an array of 32 lasers, each designed to emit at a specific wavelength and all fabricated on a single chip by standard semiconductor processing techniques. Together the lasers cover the full spectrum from 8.7 to 9.4 microns, the so-called 'molecular fingerprint region' where most molecules have their characteristic absorption spectrum. The researchers say that the spectrometer can detect in parallel an extremely large number of trace gases, in concentrations of parts per billion.
[R][O] |
||
| [S] Sensor devices | |
|
|
|
|
|
Nanopore DNA reader Personalized medicine is currently inhibited by the cost and practicality of developing personalised drugs and by the high cost of genetic testing. For the latter, a key goal is to develop sensors that can directly read the sequence of a DNA molecule. Teams at IBM and the University of Illinois have proposed that this could be done by driving the DNA molecule back and forth through a nanopore capacitor or transistor in a semiconductor chip. As the DNA molecule moves through the nanopore, its electric field induces sequence-specific electrostatic potentials that can be detected. The Illinois team has computer simulated the process and has also demonstrated experimentally that voltage signals can be measured from DNA movement through such nanopores.
[S][G][H][N]
Biochip testing of drugs If specialist and personalised drugs are to be financially viable, much cheaper ways are needed to test their safety. One approach is to use biochip sensors that mimic what the body does when it ingests a drug. The chip is dotted with tiny droplets containing human liver enzymes, and the toxicity of compounds can be tested by introducing them into the droplets and seeing how they react. Alternatively the droplets can contain cell cultures from the bladder, kidney or liver. A chemical's safety is tested by putting drops of it onto the slide and measuring the culture's growth or shrinkage over time.
[S][G][H][J][T]
Nanorod pH sensor A new type of intracellular pH sensor made from zinc oxide (ZnO) nanorods has been developed by researchers in Sweden. The device is highly sensitive and can probe individual chemical species in specific locations within a single cell. The instrument might even be used to distinguish between healthy and diseased cells.
[S][G][H][N]
Sensing bacteria MEMS sensors have been developed to detect bacteria. But, because they rely on bacteria sticking to tiny vibrating cantilevers and changing their oscillation frequency, they are not suitable for detecting bacteria in a liquid. For this, researchers at the University of Michigan have developed a technique that uses a 2-µm diameter magnetic sphere, which is rotated in the liquid by an external magnetic field. The sphere is coated with antibodies that grab hold of certain bacteria. If the sphere is spun fast enough, it is no longer synchronized with the rotation of the external field. This "asynchronous rotation rate" is highly sensitive to small changes in the drag, and when a bacterium attaches to the sphere, the rotation slows down measurably.
[S][D][G][H][J][N]
Sensing viruses Scientists at the University of Rochester have created a nanoscale device that is capable of detecting one quadrillionth of a gram of biological matter, about the mass of certain viruses. In the future, the sensor may be able to detect influenza, severe acute respiratory syndrome (SARS), bird flu, and other viruses. The sensor is a hexagonal array of tiny cavities, each 240 nm in diameter, carved into a very thin slab of silicon by using an electron beam. When a laser beam is directed into the crystal, it interacts with the crystal such that only a particular part of the light's spectrum is transmitted. But when a particle is trapped in one of the nanocavities, the transmitted spectrum changes detectably.
[S][D][G][H][J][N][O] |
||
| [O] Optoelectronics, optics and lasers | |
|
|
|
|
|
Wakefield synchrotron radiation source The first synchrotron radiation source small enough to fit in a university laboratory has been built at Strathclyde University. Instead of needing a huge particle accelerator, it uses wakefield acceleration in which a high-intensity laser beam creates waves inside a plasma. Electrons "surf" these waves and are accelerated to close to the speed of light. They then pass through an arrangement of fixed magnets called an undulator that causes them to emit synchrotron radiation. By adjusting the undulators, the output wavelength can be precisely specified from the teraHertz spectrum up to x-rays. This makes synchrotron radiation invaluable for a wide range of applications. As well as being much more compact, a wakefield accelerator produces electron pulses much shorter than in a conventional accelerator. So the synchrotron can produce femtosecond pulses for studying ultra-fast processes.
[O][G][M][N][P][R]
Supercontinuum generation A photonic crystal fibre can convert a pulse of light with a narrow range of wavelengths into a supercontinuum hundreds of times broader, spanning from visible to the infra-red. Being able to generate a supercontinuum so easily has many exciting applications, including in optical clocks and for optical processing and telecommunications using multiple wavelengths. Researchers at the University of Bath have now discovered that the broadening is produced by an interaction between conventional pulse of lights and solitons. The solitons slow down as they move along the fibre and trap the light pulses, shortening their wavelengths. At the same time the solitons' wavelengths become longer.
[O][I][R]
3D photonic crystal waveguide Physicists in the US have found how to create a true 3D waveguide in a photonic crystal. Such waveguides could be used to process optical signals in telecommunications, or to serve as small laser cavities that only require a low power to start lasing.
[O][C][I]
Invisibility cloak Researchers at the University of Maryland have used plasmon technology to create the world's first invisibility cloak for visible light and to build a superlens microscope that give nanoscale resolution. The cloaking device is a two-dimensional pattern of concentric rings created in a thin, transparent acrylic plastic layer on a gold film. The plastic and gold each have different refractive properties. The structured plastic on gold in different areas of the cloak creates negative refraction effects, which bend plasmons around the cloaked region and release the light on the other side so that it appears as if it had gone straight through ring. The cloak only works in 2 dimensions and over a limited spectral range.
[O]
Nanolaser A nanolaser that can focus light with a power of over 200?nW into a spot just 35?nm across has been developed by US researchers. This means that data storage beyond 10? Terabits per square inch could now be possible. The researchers say that the nanolaser technology could be scaled down to a spot size as small as 10 ?nm.
[O][N]
Optically-driven femtosecond shutter Researchers have found that a vanadium oxide film can switch from transparent to reflective and back to transparent again in less than 100 femtoseconds, making this the fastest phase transition ever measured. Using 12 femtosecond laser pulses to “strobe” the vanadium dioxide transition they found that no heating or cooling is involved. The energy in the laser beam goes directly into the crystal lattice of the vanadium oxide, driving it to shift from its transparent, crystalline form to its more compact and symmetric metallic configuration.
[O][M]
Ultra-compact modulator IBM has developed a silicon Mach-Zehnder electro-optic modulator that is hundreds of times smaller than previously demonstrated modulators of its kind. It operates at 10 Gbits/second and its tiny size paves the way for integrating many modulators on a single silicon chip to optically link cores in multicore processors. The eventual aim is to optically network hundreds or thousands of cores together on a single chip. Compared with metal wires, the optical network could transmit data 100 times faster using 10 times less power.
[O][C][I][J][N]
Storing optical signals as sound A problem in developing optical computer networks is how to store information. Researchers have now demonstrated that stimulated Brillouin scattering can be used to transfer information from a laser beam into sound waves. They showed that the sound wave could retain the data for as long as 12 nanoseconds and that it could be transferred from sound to light again by shining a third laser beam through the fibre. Nanosecond storage times are long enough to be useful for optical communication networks.
[O][C][I]
Terabit/second optical switching In a high-performance optical communication network the most critical components are the switches that control data flows and prevent congestion. A four-year project by IBM and Corning has now demonstrated an optical packet switch that transmits 2.5 Terabits per second. It combines 64 optical data links, each running at 40 Gigabit per second. Such powerful switches are needed for optical interconnect systems to scale supercomputing beyond the petaflop range. One of the main challenges in developing the switch was the lack of optical memory. The researchers overcame this by adopting a hybrid electro-optical approach using electronics to buffer and schedule data and optics.
[O][C][I][J]
Optical signal regeneration As light travels along an optical fibre, the information it carries gradually decays and has to be regenerated. Currently, this is done electrically, which involves converting the optical signals into electrical ones and then back again. But if the regeneration could be done purely optically, this could be cheaper and allow higher data rates to be transmitted. For this one needs a strongly non-linear optical effect in order to boost light pulses much more strongly than noise. Four-wave mixing has been shown to be suitable, but has required using a 100 metre length of a special type of fibre optic cable. Now, researchers have shown that regeneration by four-wave mixing can be done much more compactly using a silicon nanowire as a waveguide. The nanowire was 500 nm x 300 nm in cross-section and only 1.8 cm long.
[O][I][N] |
||
| [I] IT, communications, networking and secure systems | |
|
|
|
|
|
Super-fast broadband Broadband speeds vary greatly between countries. Fibre optic networks capable of speeds of up to 100Mbps are already commonplace in Japan and South Korea and are starting to be rolled out in countries such as the US, France and Germany. In the UK, the next generation of ADSL (ADSL2) is being rolled out from April 2008 and will provide up to 24 Mbits/sec (Mps) over copper wire to the home. VDSL (Very High Speed Digital Subscriber Line), which is a combination of fibre optics and a final copper stage to the home, could provide 50 Mbps. WiMAX could deliver speeds of up to 70Mbps and operate over distances of up to 50km, although not concurrently. In some developing countries WiMAX will be the dominant infrastructure for broadband access. At present, however, there are few high volume applications that need such high speeds and it is not clear how soon there will be enough demand to make super-fast broadband commercially viable.
[I][C][K][T]
IT sector carbon emissions With more than 1 billion computers on the planet, the global IT sector is responsible for about 2 percent of human carbon dioxide emissions each year, according to a report by a UK environmental organisation. Moreover, the data storage is growing very rapidly: in 2006, 48 percent more data storage capacity was sold in the UK than in 2005.
[I][C][E][J][K]
Privacy protection The increasing prevalence of GPS and other wireless location-based technologies on cell phones and other mobile devices raises the spectre of an Orwellian world in which everyone is being watched. One way to enable mobile users to protect their privacy and still enjoy the benefits of location based information services is to bundle up requests for information with other requests from users in the same locality using a trusted intermediary. This provides a degree of anonymity that can be tailored by bundling together more requests or fewer requests.
[I][K] |
||
| [K] Knowledge, information and technology management | |
|
|
|
|
|
Web 3.0 The so-called Web 2.0 revolution has transformed the Web in recent years, bringing explosive growth of blogs, wikis, and social networking sites and other online communities. Now, according to a review article in IEEE Computer, Web 3.0 is on the horizon, exploiting the convergence of Semantic Web capabilities to embed increasing amounts of reasoning into large-scale Web applications. Emerging Web 3.0 companies are combining the Web data resources, standard languages, ever-better tools, and ontologies into semantic applications that can, for example, help web users to organise, link and retrieve their web information more easily and effectively.
[K][I][T][U][V][W]
Google knol project Google has launched a project to create an authoritative store of information about any and every topic. Unlike Wikipedia, it will be authored by experts rather than written by an open community. The system will centre around authored articles created with a tool Google has dubbed "knol" - the word denotes a unit of knowledge - that will make webpages with a distinctive livery to identify them as authoritative. A knol on a particular topic is meant to be the first thing someone who searches for this topic for the first time will want to read. The knol pages will get search rankings to reflect their usefulness. Knols will also come with tools that readers can use to rate the information, add comments, and suggest edits or additional content. Critics, however, are concerned that the knol project could undermine Wikipedia.
[K]
Social networking Social network sites are moving to make it much easier for software developers to write add-ons that will allow users to add extras, such as video and music clips, to the personal profiles they maintain. Bebo has unveiled partnerships with more than 40 developers and its interface tools will work with Facebook's already announced development system, allowing many developers who have written applications for Facebook to use their code almost unchanged for the Bebo network. Bebo is also supporting Google's Open Social initiative, which aims to create a unified system of tools that can be used on any and every social network site. MySpace and Friendster are backing Google's initiative, whilst Meebo is supporting Facebook's system.
[K][W]
Health benefit of creative work Employees who have more control over their daily activities and do challenging work they enjoy are likely to be in better health, according to a new study from The University of Texas. The most important finding is that people, whether employed or voluntary, who do creative activity that is non-routine, enjoyable and provides opportunity for learning and for solving problems feel healthier and have fewer physical problems. The health advantage of being somewhat above average in creative work (in the 60th percentile) versus being somewhat below average (in the 40th percentile) was estimated to be equivalent on average to being 6.7 years younger.
[K][H][W] |
||
| [C] Computing, supercomputing, modelling and simulation | |
|
|
|
|
|
Simulating the universe One of the largest ever supercomputer simulations of the universe has modelled how a region comprising 2.5 percent of the visible universe is likely to have evolved, as matter collapsed to form cosmic filaments and galaxy structures. The study supports the conjecture that much of the 40 percent of normal matter that is so far unaccounted for lies in the cosmic filaments connecting galaxy clusters. These filaments are hidden in enormous gas clouds in intergalactic space, known as the Warm-Hot Intergalactic Medium (WHIM). The researchers say that, with the new generation of telescopes now under construction, .it may be possible to detect these filaments and the WHIM.
[C][A][F][R]
Two-way seismic supercomputing Large reserves of oil and gas lie in deep waters, but drilling for them is extremely challenging and hugely expensive. It is vital to pinpoint the precise target before drilling. But seismic imaging methods using air-gun blasts that work well in shallow continental shelf waters cannot accurately image complex deep water structures that produce multiple ricocheting echoes. The ideal is to be able to solve the so-called two-way wave equation. This involves first building a detailed model of the subsurface structures and then simulating the actual path of the echoes by running the wave equation backwards in time from the signals received by survey hydrophones. The resulting grid of echo data is then compared with the grid of in-going waves from calculating the propagation forward in time from the air gun blast. Wherever the in-going and outgoing waves intersect, an echo originated at that point and these intersections reveal the contours and interfaces of the surveyed volume. Although this method is stupendously computationally intensive, advances in supercomputers and algorithms are now making it possible.
[C][E][P][R][T]
Computing crystal structure Being able to predict crystal structure computationally from first principles without experimental input has been described as the Holy Grail of crystallography. Success would revolutionise the design of materials with novel properties, particularly of polymorphic drugs that need to be crystallised in a specific form with rigorously consistency. Until recently the progress in crystal structured prediction was discouragingly slow. Now, however, the latest international blind test challenge has demonstrated a major advance, showing that the crystal structures of small organic molecules can now be predicted reliably. The next big challenge is to be able to predict the relative stability of polymorphs as a function of crystallisation conditions.
[C][G][H][M][N][R][W]
Computer design of explosives Researchers from Lawrence Livermore and MIT have created the first quantum molecular dynamics simulation of a shocked explosive near detonation conditions, revealing what happens at the microscopic scale. This could lead to being able to use computer simulations to predict the detonation properties of new, yet-to-be synthesized designer explosives.
[C][D][M][N][P][W] |
||
| [W] Whole life engineering, manufacture and testing | |
|
|
|
|
|
Open-source mathematics tools Open-source software is increasingly used in everyday applications such as Firefox, Linux and Open Office. Now, open source mathematical tools are emerging. More than a hundred mathematicians from around the world have collaborated to build a tool called Sage that combines powerful number-crunching with new features, such as collaborative online worksheets. Importantly, as well as being free, the open tools make it possible to scrutinize the code to see how a computer-based calculation has arrived at a result; with proprietary tools this is often obscure .
[W][C]
Nanorobot design One of the major factors for successfully developing nanorobots is to bring together interdisciplinary professionals from chemistry, materials engineering, electronics, computing, physics, mechanics, photonics, pharmaceutics, and medicine technologies. To help this, researchers have developed a virtual reality simulator that enables interdisciplinary designers to explore how nanorobots might operate inside the human body.
[W][C][G][H][J][N][S][U][V] |
||
| [X] Systems, complexity and risk | |
|
|
|
|
|
Traffic congestion Many traffic jams leave drivers baffled as they finally reach the end of a tail-back to find no visible cause for their delay. The jam arises because traffic breaking generates a backward propagating wave in which vehicles slow slightly more than those in front until eventually the traffic comes to a standstill. Modelling by mathematicians from the Universities of Exeter, Bristol and Budapest shows that a jam can be caused by a single driver braking excessively in heavy traffic, usually through late reaction to a problem ahead. One factor in causing late reaction could be use of mobile phones, according to research at the University of Utah. Their experiments with driving simulators show that drivers talking on mobile phones, whether handheld or hands-free, have much slower reaction times and are as impaired as if they were drink-driving (800 ppm blood alcohol level). They also drive more slowly and adapt less flexibly to traffic conditions.
[X][B][C][E][I][U][V]
Movement in complex systems Researchers in Tel Aviv and Paris have developed an analytical model that calculates the average arrival time of a randomly-moving object in a complex environment, such as biological cells, the human body or the World Wide Web. Previous models have only been able to handle movement in a homogenous environment, such as a vacuum or water. The researchers say their method, which needs to be validated experimentally, can be applied to a wide range of concepts in nature and mathematics.
[X][B][C][D][E][G][H][I]
Hazards of aquaculture Parasitic sea lice infestations caused by salmon farms are driving nearby populations of wild salmon toward extinction, according to a Canadian study. The affected pink salmon populations have been rapidly declining for four years and the study predicts a 99 percent collapse in another four years, or two salmon generations, if the infestations continue. This would have a very serious ecosystem impact, according to the researchers. Sea lice are natural parasites of wild salmon that are transmitted by a tiny free-swimming larval stage. Open-net salmon farms are a haven for these parasites. Adult salmon can survive a small number of lice, but juvenile wild salmon heading from the river to the sea past the fish farms are very vulnerable.
[X][E]
Biodiversity and ecosystem functioning Recent investigations on land have warned that biodiversity loss might impair the functioning and sustainability of ecosystems. However, the data needed to evaluate the consequences of biodiversity loss on the ocean floor has been completely lacking, despite the fact that the deep sea covers 65 percent of the Earth and is by far the most important ecosystem for the cycling of carbon, nitrogen, and phosphorus of the biosphere. The deep ocean supports the largest “biomass” of living things, including a large proportion of undiscovered species. Researchers have now examined the biodiversity of nematode worms and several independent indicators of ecosystem functioning and efficiency at 116 deep-sea sites. They found that sites with a higher diversity of nematodes support exponentially higher rates of ecosystem processes and an increased efficiency with which those processes are performed. This suggests that conserving biodiversity may be even more crucial in the deep ocean than on land, where studies show a linear relationship between diversity and ecosystem functioning.
[X][E]
Biodiversity and ecosystem value Healthy ecosystems that provide people with essential natural goods and services often overlap with regions rich in biological diversity, underscoring that conserving one also protects the other, according to a new study. The value of ecosystem services in the 7 percent of the planet of greatest biodiversity conservation priority was more than double the global average. Overall, the annual value of the world’s ecosystem services is estimated at $33 trillion, or greater than the gross national product of all nations combined.
[X][E]
Carbon sequestration by northern ecosystems Many northern terrestrial ecosystems currently lose carbon dioxide in response to autumn warming, offsetting 90 percent of the increased carbon dioxide uptake during spring. Researchers have examined how global warming will affect this. Using computer modelling to integrate forest canopy measurements and remote satellite data, they found warmer spring temperatures accelerate growth more than soil decomposition and thereby enhance carbon uptake. But the autumn warming greatly increases soil decomposition, and the net effect is that global warming is reducing the carbon uptake by northern ecosystems. This means that stabilizing atmospheric carbon dioxide concentrations will be even harder than currently predicted.
[X][C][E][P]
Rogue events By launching laser pulses into photonic-crystal fibres, researchers in the US and Germany have created optical rogue waves that may be the equivalent of the giant rogue waves, 30 metres high, that are occasionally observed in the ocean. From computer simulations of the optical system, the researchers suggest that optical rogue waves, and therefore oceanic rogue waves, are seeded by noise.
[X][C][D][E][O] |
||
| [V] Virtuality and human-machine interface | |
|
|
|
|
|
Transparent electrodes Transparent electrodes on liquid crystal displays and solar cells are normally made of indium tin oxide. The world's reserves of indium are now running out, but graphene may provide an alternative according to researchers at Max Planck. They found that graphene electrodes just 10 graphene layers thick (roughly 5 nm) are about 80 percent transparent in the visible and completely transparent in the infrared light, which is beneficial for solar cells.
[V][M][N][P]
Whole-body interface Researchers at MIT and ETH in Zurich and MIT have developed a wearable sensor system that can track the movement of a each part of a wearer's entire body in a fairly wide range of situations including skiing and biking. It uses small, cheap, off-the-shelf sensors. These detect movement in two different ways: accelerometers and gyroscopes measure motion, and ultrasonic beepers and receivers measure distances. Such small, cheap wearable systems could lead to "whole-body interfaces" for controlling computers or playing games.
[V][H][J][R][S]
Visualising medical information A research team at IBM’s Zurich Research Lab has demonstrated a prototype system that will allow doctors to view their patients’ electronic health record using three-dimensional images of the human body. Clicking on a particular part of the image retrieves the relevant information from the patient’s record, including text entries, lab results, and medical images. The doctor can zoom in on the image to retrieve selective information or narrow the search parameters by time or other factors. This graphical representation of medical information has been found to help many doctors to use the information more effectively to identify what is going on with a patient, to check possible diagnoses against the evidence and to explain complex medical information to the patient.
[V][B][H][K]
Review of brain-computer interface research According to a review by the World Technology Evaluation Center, brain-computer interface (BCI) research is now approaching a level of first-generation medical practice and is also expected to rapidly accelerate in nonmedical arenas, particularly in the gaming, automotive, and robotics industries. Research on invasive BCIs, where electrodes are inserted directly into the cortex, is very largely centred in North America. Research on noninvasive BCI systems, where electrodes are placed on the scalp and use electroencephalography or electrocorticography, is primarily in Europe and Asia. Asian researchers are also championing the integration of BCIs and robotics systems. The report covers sensor technologies, the abiotic-biotic interface, interface modelling and signal processing, hardware implementation, functional electrical stimulation and rehabilitation applications of BCIs, non-invasive communication systems, cognitive and emotional neuroprostheses, and the commercialisation of BCI technology. The report also describes major BCI research programmes in Europe and Asia.
[V][B][C][H][I][J][K][N][R][S][T][U] |
||
| [B] Brain research and human science | |
|
|
|
|
|
Power of a single neuron It is generally thought that, at least in higher animals, processing is done by networks of neurons. However, new research suggests that even individual neurons are quite powerful. Researchers in Germany and the Netherlands stimulated single neurons in rats and found this was enough to trigger a behavioural response when their whiskers were touched. US researchers have found that within a single neuron the synapses are able to act independently of each other and could be storing or processing completely different bits of information.
[B][C]
Synaptic processes By exploiting recent advances in fluorescent 'tagging' of molecules and new microscopy technologies, researchers have been able to watch the exocytosis/endocytosis process by which information is transmitted between synapses. Exocytosis involves the packaging, transport and delivery of neurotransmitter chemicals in sac-like structures called vesicles. These vesicles move from the interior of the cell to the cell membrane, where they deliver their information-rich cargo to the synapse. Endocytosis involves a similar function in the reverse direction, with incoming vesicles being transported into the cell's interior. An important early result from watching the process has been to confirm that, upon delivering its cargo, the vesicle fragments and is then rebuilt for reuse rather than just being refilled.
[B][N][S]
Complement system and neurodegeneration As a child's brain develops, its neural circuits are refined by eliminating synapses that are not needed. Stanford researchers have now found that this elimination uses the body's complement system - a chemical multiplication process involving more than 20 small proteins in the blood. Complement is part of the immune system: an invading parasite activates the first complement protein C1q, which activates the second, which in turn activates a third in a cascade in which each stage multiplies the response. The researchers found that C1q together with another complement protein called C3 are also used to tag synapses for elimination. Synapse elimination ceases when a child is about ten, but the researchers found it becomes reactivated again very early in neurodegeneration associated with glaucoma. In fact, C1q and C3 are drastically up-regulated in nearly every neurodegenerative disease that has been examined, and this suggests that synapse elimination may be involved in all of them. If this is the case, then blocking the complement cascade might be a way to treat diseases such as Alzheimer's, autism, ALS, MS and Parkinson's.
[B][H]
Photographic memory A Japanese study has shown that young chimpanzees can substantially outperform adult humans in a task involving remembering numbers and their location. The findings suggest that young chimps use a kind of photographic memory to do this. Human children also sometimes display a similar kind of photographic memory, but it is very rare. The researchers think that early humans may have lost this photographic memory as they acquired new memory-related skills such as symbolic representation and hierarchical organisation.
[B]
Short term memory Scientists have found that when electrical impulses are passed from one neuron to another, they not only strengthen the synapse between them but also give a boost to neighbouring synapses, priming them to learn more quickly and easily. This boost lasts 5 to 10 minutes and could be key to short term memory.
[B]
Ageing brain Comparisons of the brains of young and old people have revealed that normal aging may cause cognitive decline due to deterioration of the connections among large-scale brain systems. The researchers linked the deterioration to a decrease in the integrity of the brain’s white matter. This is the tissue containing myelinated nerve cell processes, or axons, which connect various gray matter areas (the locations of nerve cell bodies) of the brain to each other and carry nerve impulses between neurons.
[B][H]
Spinal repair Canadian researchers have found that a reason it is so difficult to regenerate nerve cells following spinal cord injury is that stem cells that might effect a repair are actually repelled away from the site of the injury by the release of a protein called netrin-1. This protein acts in the developing nervous system as a repulsive or attractive signal, guiding nerve cells to their proper targets. Another problem in spinal cord repair, according to researchers at Georgia Tech, is that neural activity is required to stimulate nerve regeneration. They demonstrated that neural activity can be stimulated using degradable biopolymers incorporating acetylcholine-like neurotransmitters. This caused growth of new neuron protrusions called neurites and promoted formation and strengthening of synapses on these neurites.
[B][H][M]
Irrelevance filter Working memory gives a mental workspace in which the brain can hold information whilst mentally engaged in other relevant tasks. Its capacity is limited and seems to vary from person to person - not only because of memory size but also because of differences in how effectively irrelevant items are kept out of memory. Researchers at the Karolinksa Institute found using fMRI that two areas of the brain - the basal ganglia and the prefrontal cortex - appear to be involved in filtering out irrelevant information. Greater activity in a specific part of the basal ganglia - the globus pallidus - correlated with less unnecessary storage in another part of the brain, the posterior parietal cortex, which is sensitive to the amount of information held in memory. The findings could help explain why some people are better at remembering things than others and could also aid the understanding of attention deficit hyperactivity disorder (ADHD).
[B][H] |
||
| [H] Healthcare and medicine | |
|
|
|
|
|
Resveratrol mimic Resveratrol is the chemical found in red wine that provides protection against fatty diets and resultant cell degeneration that occurs in the aging process. It is believed resveratrol activates a protein Sirt1 that effects metabolism. US researchers searching for drugs that might mimic and enhance this effect have discovered one, called SRT 1720, that appears from experiments on rodents to be about a thousand times more potent than resveratrol.
[H][G]
Reducing bad cholesterol In its first clinical trial, a new kind of drug to cut the risk of cardiovascular disease has been found safe and effective at dropping levels of “bad” low density lipoprotein (LADLE) cholesterol by as much as 40 percent. High levels of LDL increase the risk for heart attack and stroke. The drug mimics the action of thyroid hormone and safely accelerates the hormone’s natural ability to rid the body of LDL.
[H]
Reversing heart attack damage The tissue damage caused by a heart attack makes the heart susceptible to ventricular arrhythmias that are highly dangerous or fatal. Researchers have found in experiments on mice that implanting embryonic heart cells into the cardiac tissue reverses this susceptibility, protecting the damaged heart against arrhythmias. They discovered that the transplanted embryonic heart cells produce a protein called connexin43 that improves the conduction of electrical signals within the damaged tissue. By engineering skeletal muscle to express connexin43 they showed they could achieve the same restorative results without needing to use embryonic cells.
[H][G]
Immune system control Three molecules known as TAM receptor tyrosine kinases keep the immune system in check so that it mounts a proportionate response against invading pathogens, Salk researchers have found. Without these critical molecules, patrolling immune cells would ceaselessly activate the immune system once they found an alien microbe. The findings suggest that a drug that temporarily inhibits TAMs could enhance the effectiveness of a therapeutic vaccines against infection or cancer cells by increasing the immune response. Conversely, TAMs might be engaged to treat chronic autoimmune diseases.
[H][G]
Inherited allergies Allergies are often inherited and this shows that genes are involved. It is known that regulatory T-cells play a key role in limiting the immune system response to harmless allergens. Now, research at Imperial College and the Swiss Institute of Allergy and Asthma Research has found that two genes called FOXP3 and GATA-3 may play a crucial role. FOXP3 helps produce regulatory T-cells but is blocked by overexpression of GATA-3. The researchers showed that mice engineered to overexpress GATA-3 produced far fewer regulatory T-cells and suffered allergy attacks. In the long term, therapies that target GATA-3 might help to prevent or cure serious allergies.
[H][G]
Evading the immune system Researchers at Imperial College have identified markers on the surface of human sperm that prevent them being attacked by the female immune system. The same markers are also found on cancer cells and HIV-infected blood cells and may help these diseases to hide from the immune system.
[H][G]
Viral cancer therapy In experiments on mice, an international research team has designed a technique that combines a virus and the immune system T-cells to destroy cancer cells that have spread from primary tumours to the lymphatic system. The researchers first removed T-cells from a mouse and loaded them with a virus called the vesicular stomatitis virus, which targets and destroys cancer cells while leaving normal cells unharmed. Then they injected the T-cells back into the mouse. When the T-cells returned to the lymph nodes and the spleen, the viruses detached themselves, found the tumour cells, selectively replicated within them and eliminated the tumour cells in the lymph nodes and spleen. Because the cancer cells were killed actually within the lymph nodes, this triggered a strong immune response to the cancer cells, and this might work as a cancer vaccination to prevent recurrence.
[H]
Cancer stem cell marker Researchers at the University of Michigan have found a marker that can be used to identify stem cells in breast tumours, suggesting a potential simple test that could help determine the best treatment for breast cancer. The findings provide strong support for the hypothesis that cancer stem cells play a key role in the spread of cancer and also suggest that cancer stem cells arise from normal stem cells.
[H][G]
Regenerative medicine By using a nanogrooved template, MIT researchers have succeeded in getting stem cells to produce capillary blood vessels, a key step for growing replacement tissue.
[H][B][G][J][M][N]
2007 in medicine and biology According to New Scientists, in medicine and biology the year 2007 will be remembered for the arrival of totally drug resistant TB, for the great progress made in stem cell research, for understanding the many links between obesity and various diseases, and for evidence that children are damaged by watching too much television.
[H][B][G][K][T][V] |
||
| [G] Genomics, biotechnology and bioinformatics | |
|
|
|
|
|
Human genome Science Magazine and the AAAS have nominated as the top scientific breakthrough of 2007 the progress in understanding the complexity of the human genome and appreciating how the dazzling range of genome differences from one human to another relate to diseases and personal traits. During 2007, genome-wide association studies have provided insight into many diseases, including atrial fibrillation, autoimmune disease, bipolar disorder, breast cancer, colorectal cancer, type 1 and 2 diabetes, heart disease, hypertension, multiple sclerosis and rheumatoid arthritis. Biologists have also discovered that within DNA’s billions of bases, thousands to millions of them can get lost, added or copied in ways that can change genetic activity within a few generations.
[G][B][H][T][X]
Culture driving human evolution About 10,000 years ago, humanity made the transition from living off the land to actively raising crops and domesticated animals. Since then the human population has increased from around 5 million to 6.5 billion. The change has also increased selection pressure from new diseases, diet, lifestyle, work, and cultural and social competition. Researchers comparing the amount of genetic differentiation between humans and chimpanzees say that the recent rate of human evolution has accelerated to 10 to 100 times the average long-term rate.
[G][B][H][K][X]
Epigenetic inheritance As an embryo develops, it experiences wave upon wave of epigenetic changes regulating gene activity. This was thought to be a fixed process, but evidence now suggests it could be subject to external influences. This enables a developing animal to adapt to its environment, but could also be detrimental to the animal and future generations. This means that environmental factors such as stress and diet could be affecting the genes of future generations leading to increased rates of obesity, heart disease and diabetes.
[G][H][T]
How cells store fat In all animal species, from yeasts to humans, fat is stored by packaging it into lipid droplets. Researchers at Yeshiva University have now identified two genes that are responsible for this packaging. They have called the genes FIT1 and FIT2 (for Fat-Inducing Transcripts 1 and 2). Through experiments on cells and whole animals they have confirmed that fat accumulation is totally dependent on these two genes. They also found that the amino acid sequences of the FIT proteins do not resemble any other known proteins found in any species, indicating that the FIT genes comprise a novel gene family. The hope is to develop drugs that can regulate the expression of FIT1 and FIT2 in order to treat obesity and alleviate related diseases including type 2 diabetes and heart disease.
[G][H]
MicroRNA cancer therapy Current cancer therapy assumes that all tumour cells can metastasize. Hence, it aims to destroy as many tumour cells as possible. However, many researchers now suspect that many, if not all, cancers are in fact produced by cancer stem cells. These are highly resistant to chemotherapy or other current treatments. Indeed, chemotherapy can actually enrich the cancer stem cells in a tumour. By exploiting this enrichment, researchers can now generate large numbers of human breast cancer stem cells in mice so that their properties can be studied. This has revealed that the cells contain low amounts of several microRNAs compared to more mature tumour cells or stem cells that have differentiated in culture. The researchers found that a microRNA called let-7 switches off two cancer-related genes and this causes the cells to start differentiating and to become less able to form tumours or metastasize. The discovery that microRNAs can regulate cancer stem cells means that microRNAs such as let-7 might lead to a cancer therapy that is able to eliminate the cancer stem cells.
[G][H]
Role of microRNAs Researchers at Ohio State have shown that microRNAs can sometimes directly control a protein’s function - not just whether or not the protein is made by the cell, as had been thought. They also found that by controlling protein function, a microRNA called miR-328 may play a critical role in preventing the progression of chronic myeloid leukaemia (CML) from its more treatable chronic phase to a life-threatening phase, called blast crisis.
[G][H]
Induced pluripotent stem cells Researchers at the Whitehead Institute have cured sickle cell anaemia in mice using induced pluripotent stem (IPS) cells derived from adult mouse skin cells. This is further striking evidence that IPS cells have the same potential for therapy as embryonic stem cells, with the bonus of not only avoiding the ethical and practical problems of using ESCs but also that IPS cells can be derived from the patient's own skin cells, avoiding any risk of rejection. The hope is that IPS cells can be transformed into any cell in the body to replace damaged or diseased cells, tissues and organs. Only four genes need to be changed to turn the skin cell back into a stem cell. But the researchers caution that, despite this simplicity, major challenges must be overcome before clinical use of IPS cells is safe in humans. The first is to find a way to change the genes without using retroviruses, which integrate into the genome and disrupt and activate other genes in ways that are far too random and dangerous to risk in humans. Several teams have so far created IPS cells from skin cells, all using the same method.
[G][H]
Hydrogen sulphide and longevity It has previously been shown that hydrogen sulphide puts mice into a state of reversible metabolic hibernation. In an effort to understand this effect, researchers have now found that in nematode worms the hydrogen sulphide does not induce hibernation but does substantially increases life span and heat tolerance, by up to a factor of eight. Most genes that influence life span in nematode worms act on one of three genetic pathways - controlling insulin/IGF signalling, mitochondrial function or the effects of dietary restriction. The researchers found that hydrogen sulphide did not influence any of these pathways. One possibility is that it regulates the activity of the SIR-2.1 gene, which has been shown to influence life span in many organisms, including the nematode.
[G][H]
Plant circadian clock In both plants and animals, the operation of the circadian clock within the cell consists of feedback loops of gene expression in which a series of genes activate or repress one another in a cyclical manner that takes 24 hours. Scientists from the University of Cambridge have found that a specific molecule, known to be important for environmental stress signalling in plants, also regulates the plants' circadian clock and may govern how the clock responds to environmental changes. The findings could be important for agriculture. Experiments have shown that correct operation of the plant circadian clock may double plant productivity by increasing the rate of photosynthesis. The circadian clock also regulates the seasonal timing of flowering and seed production.
[G][E]
Regulation of circadian clock Researchers at UC Irvine have identified the chemical switch that triggers the genetic mechanism regulating the body's internal clock. They found surprisingly that, although complex genes regulate circadian rhythms they are activated by a single amino acid in a protein produced by a gene BMAL1. Because the triggering action is so specific, it provides a promising target for new drugs to treat sleep disorders and related ailments. Disruption of circadian rhythms has been linked to insomnia, depression, heart disease, cancer and neurodegenerative disorders. In mammals, the circadian pacemaker in the hypothalamus and the sleep/wake cycle are synchronised with a 24 hour day by non-visual sensors in the eye that respond to blue light.
[G][B][H] |
||
| [N] Nanotechnology and molecular technology | |
|
|
|
|
|
Nuclear pores The nuclear DNA inside a cell's nucleus is protected by a membrane that contains hundreds to thousands of nuclear pores. These regulate the material that goes to and from a cell’s DNA and the signals that tell a cell what to do and how to do it. The pore is very complex with 450 component proteins and is large and flexible, making it very difficult to determine its structure. Now, by using computer simulation to find structures that fully satisfy the thousands of restraints provided by experimental data, researchers have assembled the first complete molecular picture of the pore's structure. As well as helping to unravel how nuclear pores function, the results also give insight into the early evolution of eukaryotic cells.
[N][C][G]
Biologically produced nanotubes US and Korean researchers have found that nanotubes can be produced biologically as well as chemically. This discovery might lead to cheaper and more environmentally friendly ways to produce nanomaterials. The researchers showed that the bacterium Shewanella produces arsenic-sulphide nanotubes that have unique physical and chemical properties not produced by chemical agents. They behave as metals with electrical and photoconductive properties that may be useful in future nano- and electro-optic devices.
[N][G][J][M][O][S] Nanowire labels Researchers at Northwestern University have used on-wire lithography to create nanoscopic "barcodes" that could be used to label biological molecules and to authenticate valuable products. On-wire lithography turns nickel nanowires into readable tags by chemically depositing pairs of gold beads at precise locations along the wire. The sequence of paired beads can be read using surface-enhanced Raman spectrosco | ||