The researchers, from the Forsyth Institute in Boston, US, say that just 2 minutes of oral illumination with the new device every day should be enough to prevent, control or treat gum disease. The blue light emitted will be more effective at eradicating harmful bacteria than antiseptic mouthwash, they say.

鈥樷�漈he patient feels nothing when blue light is applied to the dental pocket -, the area between the teeth and the gums where dental plaque resides,'鈥� says researcher Nikos Soukos. 鈥淲e think it will be particularly beneficial to those who don鈥檛 like using a toothbrush.鈥�

Soukos鈥檚 team reports that the light kills the bacteria associated with gum disease but leaves 鈥済ood鈥� bacteria intact.

鈥淢icro-organisms called black-pigmented bacteria (BPB) such as Porphyromonas gingivalis and Prevotella intermedia have been implicated in the initiation and progression of gum disease,鈥� says Soukos. Blue light kills these bacteria because it is absorbed by specific chemical compounds within the bacteria 鈥� called iron-porphyrins 鈥� causing a cascade of reactions fatal to the organism.

Killed in seconds

In the experiments, blue light from a halogen lamp was shone onto pure cultures of BPB and onto plaque samples obtained from patients with chronic gum disease.

Bacteria in the pure culture were killed in seconds, whereas bacteria in the plaque samples were killed selectively. Those containing iron-porphyrins were most affected 鈥� a beneficial result as it is iron-porphyrins that help bacteria in harming the gums. It is the acidic environment produced by the harmful bugs that results in tooth decay.

The research stemmed from an observation by Forsyth researchers that the blue light used in tooth-whitening procedures also happened to reduce gum inflammation.

No apparent damage

In additional, as yet unpublished, research, Soukos鈥檚 group exposed micro-organisms and human cells in culture to the blue light and found that the bacteria could be eradicated with no apparent damage to the human cells.

Soukos believes the device will ultimately be more effective than mouthwash, since mouthwash cannot fully penetrate dental plaque and eliminate pathogenic species. He adds that bacteria can also become resistant to antiseptics in the mouthwash.

Denise McCarthy, a dental scientist at Trinity College Dublin in Ireland, says the approach is both novel and interesting. But she says it is too early to make a firm assessment of its usefulness: 鈥淚 do not think people should be encouraged to abandon their toothbrushes just yet.鈥�

Journal reference: Journal of Antimicrobial Agents and Chemotherapy (DOI: 10.1128/AAC.49.4.1391-1396.2005)

Called Demron, its potential applications range from lightweight full-body suits 鈥� which would allow the wearer to move unencumbered in high-radiation areas 鈥� to protective tents and radiation-proof linings for aircraft and spacecraft.

Traditional shielding relies on the presence of heavy metals, such as lead. But Demron is based on a polymer that mimics some of the electronic properties of these heavy metals, says John Hefler of Radiation Shield Technologies, the company in Miami, Florida, that is developing the material.

Its inventors claim that it provides protection comparable to the nuclear industry鈥檚 standard-issue lead vest, blocking alpha, beta, gamma radiation and X-rays. Traditional protective clothing only protects against alpha radiation.

Electron cloud

Heavy metals have large atoms, and so have large numbers of electrons. When the particles that make up alpha and beta radiation collide with these electrons, they slow down, and are absorbed by the material.

The helium nuclei that make up alpha radiation have so little energy that almost any physical barrier can stop them. Gamma rays and X-rays are highly penetrating forms of electromagnetic radiation, which can only be stopped if the electrons in a shield鈥檚 material can absorb enough of their energy.

Demron consists of a polyethylene and PVC-based polymer fused between two layers of a woven fabric. The polymer molecule has been designed so that incoming radiation will meet a large electron cloud, which will deflect or absorbed it.

鈥淭he molecules are lined up to give the illusion of the presence of large atoms,鈥� says Hefler. The electrons are capable of deflecting beta radiation or absorbing the energy of alpha radiation and X-rays.

The nuclear industry is still reserving judgement on the new material. 鈥淭he potential usefulness of the fabric will depend on the level of protection it offers against gamma and X-rays, and how it reacts and degrades when subjected to radiation,鈥� says Janine Claber of British Nuclear Fuels.

Researchers in Canada and Australia have shown that since the drug was introduced in 1998, worldwide trade in parts of some species has fallen by more than 70 per cent.

The reason for Viagra鈥檚 popularity is clear, says Frank von Hippel of the University of Alaska: 鈥淰iagra is cheaper than many animal products and its action is pronounced, immediate and effective.鈥�

Von Hippel and his brother William at the University of New South Wales, Sydney, analysed data on three legally traded species used in traditional medicines: Alaskan reindeer, which are hunted for antler velvet, hooded seals and harp seals, which are both hunted for their genitalia.

Antler sales fell by 72 per cent from $700,000 in 1997 to $200,000 in 1998. The number of seal penises being traded fell from around 40,000 in 1996 to 20,000 in 1998. The decline in the trade of harp seal penises has also been documented by Canada鈥檚 Department of Fisheries and Oceans, who reported the price per organ had dropped from $100 to $15 by 1999.

Free drugs

A collapse in the Asian economy at about the same time might partly explain why sales dropped so significantly. But von Hippel points out that the US and Canada are major markets for traditional medicines, and these countries did not experience economic decline during this period. Sales of deer antlers remained low in Asia even when the economy started to recover, he adds.

鈥淚 doubt the availability of Viagra will completely end the trade of any species,鈥� he says. 鈥淪ome people will undoubtedly still use traditional cures to treat impotence. But even a modest reduction is important.鈥�

Von Hippel thinks there is also scope for Viagra to help endangered species in Africa: 鈥淧eople there cannot afford Viagra, but offering free impotence drugs could go a long way to reduce the poaching of wild species.鈥�

David Cowdry of WWF UK says that although Viagra is having a positive impact on trade in animal parts for use in traditional medicines, that trade is still rife. 鈥淭here is an elitism associated with these medicines and we are fighting against thousands of years of tradition,鈥� he says.

鈥淭his ball is 25 per cent more precise and 10 per cent faster than Tricolore, the 1998 match ball,鈥� according to Gunther Pfau at the Adidas football laboratory in Scheinfeld, Germany.

Kicking tests with robotic legs showed that, at a distance of 20 to 25 metres, the Fevernova can repeatedly strike an area just 20 centimetres across. 鈥淎nd, five times out of 10, it will hit dead centre,鈥� adds Pfau. It can travel at speeds of up to 130 km/h (81 mph).

The ball鈥檚 performance results from a new combination of materials that improves the transfer of force from the footballer鈥檚 foot and retains the roundness of the ball better.

However Guy Osborn at University of Westminster says: 鈥淚鈥檓 not sure the 鈥榩erfect鈥� football would make the game any better. There are so many aspects to football, for example, the free kick specialist wants the ball to bend more but the goalkeeper wants it to be better for handling.鈥�

Gas bubbles

The Fevernova ball has a polymer outer skin under which is a layer of foam. Under the foam is a new knitted textile mesh that in turn covers the latex bladder.

The mesh provides strength that limits the initial deformation when the ball is kicked and helps the ball remain spherical in flight. Distorting the round shape leads to an uneven airflow around the ball, making it veer off course. The ability of players to swerve the ball will not be affected as this is done by imparting spin.

The foam is key to transferring the foot鈥檚 force. It contains a regular pattern of gas-filled bubbles, meaning the applied force is faithfully transferred to the ball. The bubbles are also highly elastic, meaning the ball is soft enough to be kicked comfortably but absorbs very little energy. As a result, more of the applied energy goes into propelling the ball forward, so it travels faster.

The ball also has a weight advantage. A large, light ball would tend to wobble like a balloon if kicked hard. So Fevernova has been created near FIFA鈥檚 lower limit of circumference and upper limit of weight. 鈥淗eavier, smaller balls have the most accurate trajectory,鈥� says Pfau.

The influence of the new ball on the games remains to be seen, but sports writer Liam Ryan of the Irish Times says: 鈥淵ou can definitely see drastic differences in the number of goals scored from free kicks as new balls become available.鈥�

Pfau adds that the new ball will not allow players to be less skilful, as the ball鈥檚 鈥渟weet spot鈥� is small. He says the ball is like a Formula One car 鈥� difficult to drive, but powerful when used by highly talented performers.

鈥淭here are as many as 200,000 visitors to the resort every day during the skiing season and they produce about one million litres of waste water every day,鈥� says David Westphalen, manager at the Mount Buller resort near Melbourne.

鈥淲ater is a scarce commodity in Australia so we have developed a system that can take this waste water, clean it and turn it into snow that is indistinguishable from normal snow. I see it as a way to minimise waste,鈥� he says.

A trial system is in place but it will probably be at least three years before a full-scale plant is operational on the slopes. This would process 70 to 80 per cent of the 150 million litres of waste water produced during the skiing season. Currently a total of 300m litres of water is taken from lakes each year to make snow.

Kill and filter

The trial system consists of a three-part disinfection system and snow-making process. First, biologicals, such as bacteria, viruses and spores, are killed by adding chlorine. These are then removed, along with any suspended matter, by ultra-filtration through a membrane with tiny 0.01-micron pores.

Finally, an activated carbon system, similar to that used in military respirators to filter out nerve gas and other chemicals, removes chemicals from the water. The resultant water is crystal clear and, according to Westphalen, tests have shown that bacteria and viruses are effectively removed.

Once cleaned, the water is released into a local stream and flows into a dam, where it cools down the temperature need to make snow.

No worries

The idea of recycled sewage being spread over their skiing slopes does not trouble local people. 鈥淭he community have been aware that we have been conducting a trial, and it doesn鈥檛 seem to bother them,鈥� says Westphalen.

鈥淎lthough using sewage to make snow is a new concept, reclaimed water has been used on golf courses and playing fields for years and is widely accepted,鈥� he says.

A spokesperson from Watling Hope, environmental engineering consultants, in Warwickshire, UK, says that normally you would not even feed your vegetables with water from a treatment plant.

鈥滻t wouldn鈥檛 do for a skier to fall and cut themselves on snow made from this water if there was any chance of infection. But assuming that the water is sterile and has been given extra treatment, it should be safe to use,鈥� she says.