Teachers everywhere can be heard shouting "look at me when I'm talking to you". But research presented today at the British Association's Festival of Science in Norwich, UK, suggests that they should be doing exactly the opposite.

When posed with a conundrum, it is normal for adults and older children to look away, staring in an unfocused way out of the window or at a patch of the carpet. This aimless gaze isn't necessarily thanks to an attitude of indifference or indolence, but instead might be helping the brain to concentrate.

We are so distracted by the barrage of emotional information transmitted in faces that it stops us from thinking clearly, Doherty-Sneddon says.

At least 800 volunteers will be needed for China's second and third phases of AIDS vaccine trials, health officials said Friday.

The second phase of clinical trials of China's AIDS vaccine would need at least 300 volunteers and the third phase at least 500, said Sang Guowei, director of the National Institute for the Control of Pharmaceutical and Biological Products.

The first phase of clinical trials indicates China's first AIDS vaccine is safe and possibly effective, government officials announced at the press conference after a two-month-odd assessment.

"Forty-nine healthy people who received the injection showed no severe adverse reactions after 180 days, proving the vaccine was safe," said Zhang Wei, head of the pharmaceutical registration department of the SFDA.

"The recipients appeared immune to the HIV-1 virus 15 days after the injection, indicating the vaccine worked well in stimulating the body's immunity," he told the press conference.

Scientists believe they have found a way to probe the mysterious phenomenon of feeling you have witnessed something before - deja vu.

Leeds Memory Group researchers say they have gone some way to recreating the sensation in the lab using hypnosis.

Two key processes are thought to occur when someone recognises a familiar object or scene.

First, the brain searches through memory traces to see if the contents of that scene have been observed before.

If they have, a separate part of the brain then identifies the scene or object as being familiar.

In deja vu, this second process may occur by mistake, so that a feeling of familiarity is triggered by a novel object or scene.

The technique could allow the development of sophisticated biological sensors that use functioning brain cells, the researchers say. This type of device would identify a compound - a deadly nerve agent or poison, for example - by measuring its effect on a functioning network of neurons.

Axons and dendrites carry electrical signals between neurons. The electrical activity of the neural network can easily be measured because carbon nanotubes conduct electricity and so can function as electrodes.

The process makes it possible to create more uniform neural networks, Hanein says. In experiments they last longer than other artificial networks, surviving for up to 11 weeks.

Smith says finding ways to connect to individual neurons in similar arrangements would be even more useful. "That's the holy grail," he told New Scientist. "The best labs can only really put an electrode near a neuron of interest. Finding a way to connect directly and non-invasively is much harder."

Capsaicin, which makes peppers hot, can cause prostate cancer cells to kill themselves, U.S. and Japanese researchers said on Wednesday.

Capsaicin led 80 percent of human prostate cancer cells growing in mice to commit suicide in a process known as apoptosis, the researchers said.

Lehmann estimated that the mice ate the human equivalent of 400 milligrams of capsaicin three times a week. That is about the amount found in three to eight fresh habanero peppers, depending on how hot the peppers are.

If you wanted to catch a few particles of comet dust speeding through the vacuum of space at 6 kilometers per second -- without damaging or destroying those particles -- how would you do it?

Faced with exactly this problem, scientists at the Jet Propulsion Laboratory focused on aerogel -- an extremely lightweight, porous material that is chemically identical to glass, but weighs only a little more than air.

Aerogel is the lightest solid known to science. It's also one of the most insulating materials on Earth, the most porous, and it's nearly transparent. Those last two properties made it an ideal choice for catching flecks of comet and interstellar dust on the recently-returned Stardust mission launched by NASA and JPL.

They are only a few nanometers in size, but their impact is tremendous: The tiny particles drive cancer cells to their death in no time at all. At nano tech 2006 in Japan from February 21 to 23 Fraunhofer researchers will demonstrate the great efficiency of nanoscopic particles as a vehicle for drug delivery.

Medicines that will make their own way through the body and attack precisely the diseased cells on reaching their destination – such has been the dream of physicians and pharmacists since time immemorial. Fraunhofer researchers working in the Nanotechnology Alliance have now come a little closer to reaching this goal. They have developed bio-functional nanoparticles that cause necrosis in cancer cells. "These cell-like structures have a solid nucleus surrounded by proteins that detect and destroy cancer cells," explains Dr. Günter Tovar of the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB.

A Florida schoolgirl won top prize with a science project proving toilet water is cleaner than ice in fast food restaurants.

"My hypothesis was that the fast food restaurants' ice would contain more bacteria that the fast food restaurants' toilet water," she said.

Jasmine says at each restaurant she flushed the toilet once, then used sterile gloves to gather samples.

She also collected ice from soda fountains and asked for cups of ice at drive thru windows. She then tested the samples at a lab.

Jasmine said: "I found that 70% of the time, the ice from the fast food restaurant's contain more bacteria than the fast food restaurant's toilet water."

A bright yellow slime mould that can grow to several metres in diameter has been put in charge of a scrabbling, six-legged robot.

The Physarum polycephalum slime, which naturally shies away from light, controls the robot's movement so that it too keeps out of light and seeks out dark places in which to hide itself.

Physarum polycephalum is a large single-celled organism that responds to food sources, such as bacteria and fungi, by moving towards and engulfing it. It also moves away from light and favours humid, moist places to inhabit. The mould uses a network of tiny tubes filled with cytoplasm to both sense its environment and decide how to respond to it. Zauner's team decided to harness this simple control mechanism to direct a small six-legged (hexapod) walking bot.

As the slime tried to get away from the light its movement was sensed by the circuit and used to control one of the robot's six legs. The robot then scrabbled away from bright lights as a mechanical embodiment of the mould. Eventually, this type of control could be incorporated into the bot itself rather than used remotely.

Researchers, including a BYU scientist, believe they have found a new compound that could finally kill the HIV/AIDS virus, not just slow it down as current treatments do.

While issuing a cautious caveat about his early results, Unutmaz acknowledged Monday that CSAs could be the breakthrough HIV/AIDS researchers have sought for so long.

In addition to being a potential checkmate to HIV, the compounds show indications of being just as effective against other diseases plaguing humankind - among them influenza, possibly even the dread bird flu, along with smallpox and herpes.

"We are encouraged ... that CSAs may provide a completely unique family of anti-infectives, potentially active against a wide range of viral, fungal and bacterial targets, including those resistant to current therapies," he said.