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Technology IMPLANTS that encourage bone regrowth could one day be printed using ink-jet technology. In the current edition of the journal Advanced Materials (http://tinyurl.com/2ydraj) a team at McGill University in Montreal, Canada, reveal how it can be done. They “print” droplets of a tricalcium phosphate suspension, layer by layer on a hydroxyapatite surface. These minerals reacts to form brushite, a calcium phosphate that hardens into a porous 3D scaffold. This slowly dissolves in the body to be replaced by real bone. Better still, the team, led by Jake Barralet, has successfully encouraged a network of blood vessels to grow in their implants. When an implant was tested in mice, the use of a growth factor called VEGF caused extensive vascularisation. EVER heard of the ruthenium rush, the bismuth bonanza or the indium stampede? Demand for cellphones and flat-screen TVs is depleting global supplies of a host of uncommon metals. Indium is built into a billion consumer devices a year, for instance in phone displays, and prices have soared. Some estimates say reserves could run 30 thousand Estonians, or 3.5 per cent of the country’s voters, cast their ballot online last week in the world’s first internet election Brake lights warn that a car in front is slowing down but they give no indication of how sharply it is braking. Respond too slowly and you could slam straight into it. To try to prevent this, particularly at night and in poor weather, Zhonghai Li and Paul Milgram at the University of Toronto in Canada propose fitting cars with brake lights that grow larger the harder the driver brakes. They began by experimenting with novel brake-light configurations in driving simulators, to see what changes would indicate most clearly how heavily a vehicle is braking. The arrangement they eventually decided on was a triangle, with an upper brake light placed slightly above two lights on either side. When the driver just touches the brakes, the lights form a small triangle close to the centre of the car. As braking gets heavier, all three lights get bigger, and those to the left and right also move outwards in proportion to the braking force. With the brakes fully applied, the lights get larger still and move right out to the edge of the car. In simulator tests with 40 volunteer drivers, the scheme showed the biggest benefits in very poor visibility, the researchers will report in an upcoming edition of the International Journal of Human-Computer Studies. Rear-end collisions accounted for 30 per cent of all US road crashes in 2003, including 5 per cent of fatal collisions, according to government figures. Shape-shifting brake lights could be built into cars using low-power LED arrays, say the researchers, who hope to interest car makers in the idea. TAIL LIGHTS GROW IN THE DARK out within five years. Bismuth, used in lead-free solder, has doubled in price in two years, while the price of ruthenium, used in resistors and disc drives, has risen sevenfold in a year. To meet demand, tech firms must mine the growing mountains of electronic waste to recover the materials, says Rüdiger Kühr of the United Nations University in Tokyo, which this week launched a global e-waste initiative. “The recycling of trace metals is essential to ongoing production,” he says. Fatal bushfires in Australia have had scientists calling for virtual reality systems that would let people “experience” the conflagrations and react more rationally in the face of their soaring flames and booming noise. Now the University of Nevada, Reno, has developed such a system, called VRFire, which lets users wearing position trackers and surrounded by video screens explore 3D bush terrain with realistic visuals and the sound of spreading wildfires (http://tinyurl.com/36lumm). A gadget that shrieks if a driver begins to doze at the wheel has been developed by Revex of Japan. The firm’s $10 Drowse Prevention Alarm is built into a small earpiece and contains a tilt sensor and an audio alarm. If the wearer’s head tilts forward just 10 degrees, the sensor activates the alarm in case they are nodding off. GIZMO In US Department of Homeland Security field trials 10 of the 14 robots tested experienced communication problems due to radio interference from other robots ROBOT INTERFERENCE Conflicting radio signals between robots could hamper urban search and rescue operations Journalist Noam Cohen on the anger amongst Wikipedia editors after the unmasking of “Essjay”, a trusted editor who had claimed to be a tenured university lecturer in religion. In fact he is a 24-year-old ex-student with a close interest in Justin Timberlake’s musical career (The New York Times, 5 March) “The wisdom of the crowd became the fury of the crowd” CREATAS SOURCE: AFP SOURCE: NIST Bone up with an ink-jet printer TVs put squeeze on minor metals www.newscientist.com 10 March 2007 | NewScientist | 25 –Safer braking ahead–
