At least 166 people have died and WHO says it is aware of 372 other cases.

Specialist laboratories in Gabon and Atlanta in the US confirmed Ebola from blood samples, saying they also showed the presence of Shigella dysentery.

Ebola is highly contagious. People contracting the disease suffer severe stomach pain and internal bleeding.

The fatality rate for Ebola, which has no known cure, is as high as 90%.

WHO and Medecins sans Frontieres have despatched medical personnel to help the Congolese contain the outbreak.

Yamabiru, or land leeches, have become a problem in 29 of Japan's 47 prefectures, according to the Institute for Environmental Culture, a private research facility in Chiba prefecture, east of Tokyo.

The little suckers are riding into towns and villages, hitching lifts on deer and boar whose numbers have grown due to re-forestation and dwindling rural populations.

Once there, the leeches, which measure in at about 1.5 cms before a meal, take to feasting on warm human flesh.

"Yamabiru will climb into people's socks and stay for about an hour, growing five to 10 times in size. Unlike with water leeches, people don't immediately realise they've been bitten. Only later when they see their blood-soaked feet, do they realise what has happened," said Shigekazu Tani, the institute's director.

"The real problem is that the bleeding won't stop and the affected area swells up and really itches," he added.

With radiating waves, a skull and crossbones and a running person, a new ionizing radiation warning symbol is being introduced to supplement the traditional international symbol for radiation, the three cornered trefoil.

The new symbol is being launched today by the IAEA and the International Organization for Standardization (ISO) to help reduce needless deaths and serious injuries from accidental exposure to large radioactive sources. It will serve as a supplementary warning to the trefoil, which has no intuitive meaning and little recognition beyond those educated in its significance.

"I believe the international recognition of the specific expertise of both organizations will ensure that the new standard will be accepted and applied by governments and industry to improve the safety of nuclear applications, protection of people and the environment," said Ms. Eliana Amaral, Director, Division of Radiation, Transport and Waste Safety, IAEA.

The new symbol is aimed at alerting anyone, anywhere to the potential dangers of being close to a large source of ionizing radiation, the result of a five-year project conducted in 11 countries around the world. The symbol was tested with different population groups - mixed ages, varying educational backgrounds, male and female - to ensure that its message of "danger - stay away" was crystal clear and understood by all.

Researchers at Manchester University say while beauty is in the eye of the beer-holder, the amount of alcohol consumed is not the only factor.

Additional factors include the level of light in the pub or club, the drinker's own eyesight and the room's smokiness.

The distance between two people is also a factor.

They all add up to make the aesthetically-challenged more attractive, according to the formula.

The formula can work out a final score, ranging from less than one - where there is no beer goggle effect - to more than 100.

An = number of units of alcohol consumed
S = smokiness of the room (graded from 0-10, where 0 clear air; 10 extremely smoky)
L = luminance of 'person of interest' (candelas per square metre; typically 1 pitch black; 150 as seen in normal room lighting)
Vo = Snellen visual acuity (6/6 normal; 6/12 just meets driving standard)
d = distance from 'person of interest' (metres; 0.5 to 3 metres)

Scientists have discovered a dramatic variation in the genetic make-up of humans that could lead to a fundamental reappraisal of what causes incurable diseases and could provide a greater understanding of mankind.

The discovery has astonished scientists studying the human genome - the genetic recipe of man. Until now it was believed the variation between people was due largely to differences in the sequences of the individual " letters" of the genome.

It now appears much of the variation is explained instead by people having multiple copies of some key genes that make up the human genome.

The findings mean that instead of humanity being 99.9 per cent identical, as previously believed, we are at least 10 times more different between one another than once thought - which could explain why some people are prone to serious diseases.

The studies published today have found that instead of having just two copies of each gene - one from each parent - people can carry many copies, but just how many can vary between one person and the next.

What have scientists discovered today?

They have found that each of us is more different genetically than we previously believed. Instead of being 99.9 per cent identical, it may turn out to be more like 99 per cent identical - enough of a difference to explain many variations in human traits. Instead of having just two copies of every gene - one from each parent - we have some genes that are multiplied several times. Furthermore these "multiple copy numbers" differ from one person to another, which could explain human physical and even mental variation.

US biotech firm Allerca says it has managed to selectively breed them by reducing a certain type of protein that triggers allergic reactions.

The company says the animals will not cause the red eyes, sneezing and even asthma triggered by cat allergy, except in the most acute cases.

Despite costing $3,950 (£2,104), there is already a waiting list to get one.

Allerca first started taking orders for hypoallergenic cats back in 2004.

Within minutes, our left eye was swollen shut, puffy, red and horrifically itchy. It took four days for the swelling to go down, although our opthamologist (after he stopped laughing, the swine) informed us that we had suffered no serious ocular damage.

The House passed the measure nearly a year ago with support from 50 Republicans. Supporters contend government funding of the budding science could someday cure diseases suffered by millions of people. Opponents argue that harvesting such stem cells amounts to abortion because an embryo is destroyed in the process.

President Bush in 2001 ordered sharp restrictions on federal funding of embryonic stem cell research, allowing it only for stem cells created before Aug. 9 of that year.

His veto threat stands, according to White House spokesman Ken Lisaius. Neither chamber of Congress has demonstrated the two-thirds support required to overcome a veto.

Mrs. Reagan's letter and a firming up of plans to tackle the issue this summer before the November elections mark a major step forward for the bill in the Senate. All 435 House seats and a third of the 100-member Senate are up for re-election at a time when Bush's approval ratings are at an all-time low.

The embryonic stem cell debate is one issue where parting with the president is unlikely to hurt senators. An overwhelming majority of the public supports the bill, including such pro-life constituencies represented by Hatch and Frist, a heart transplant surgeon.

Russell Foster, a circadian biologist at Imperial College London, said: "The more we understand about the body's 24-hour clock the more we will be able to override it.

"In 10 to 20 years we'll be able to pharmacologically turn sleep off. Mimicking sleep will take longer, but I can see it happening."

Neil Stanley, head of sleep research at the Human Psychopharmacology Research Unit at the University of Surrey, countered: "I think that would be the most hideous thing to happen to society."

Scientists are hoping to build on the success of the drug Modafinil, a stimulant launched seven years ago which allows people to wake up refreshed after four hours of sleep.

The results from testing stations at the Atomic Weapons Establishment (AWE) in Aldermaston and four other stations within a 10-mile radius were obtained by Chris Busby, of Liverpool University’s department of human anatomy and cell biology.

Each detector recorded a significant rise in uranium levels during the Gulf war bombing campaign in March 2003. The reading from a park in Reading was high enough for the Environment Agency to be alerted.

Busby, who has advised the government on radiation and is a founder of Green Audit, the environmental consultancy, believes "uranium aerosols" from Iraq were widely dispersed in the atmosphere and blown across Europe.

"This research shows that rather than remaining near the target as claimed by the military, depleted uranium weapons contaminate both locals and whole populations hundreds to thousands of miles away," he said.

"As far as regenerating parts of the brain that have degenerated, such as in Parkinson's disease, it would have major impact," said Dr. Eric Holland, a brain expert at Memorial Sloan-Kettering Cancer Center in New York.

The team also hopes that one day patients could be given a drug that enables their brain to regenerate itself.

But the biological co-mingling of animal and human is now evolving into even more exotic and unsettling mixes of species, evoking the Greek myth of the monstrous chimera, which was part lion, part goat and part serpent.

In the past two years, scientists have created pigs with human blood, fused rabbit eggs with human DNA and injected human stem cells to make paralyzed mice walk.

Particularly worrisome to some scientists are the nightmare scenarios that could arise from the mixing of brain cells: What if a human mind somehow got trapped inside a sheep's head?

Scientists have not figured out exactly how either critter works, but quite a bit is known. Maggots eat dead and infected tissue and other infectious organisms, which are later killed in maggots' guts. They secrete enzymes that break down dead tissue, turning it into a mush they can then slurp up.

Leech saliva is made up of a potent cocktail of more than 30 different proteins that, among other things, helps to numb pain, reduce swelling and keep blood flowing.

Taken together, the bacteria in our guts contain 100 times more genes than our human cells do. The ecosystems they form are the densest known in nature. Our feces are about half bacteria by weight. Yet we know more about the microbes of the soil and the seas than we know about these intimate companions, said Lora Hooper, an immunologist at the University of Texas Southwest Medical Center. Gordon said the report, published Thursday in the online edition of the journal Science, is the first comprehensive inventory of a microbial community so vast that it is "mind-boggling." When the gut microbes are in balance, they help keep us well. Thrown out of balance, they may contribute to disease.