Air travel has long been suspected of playing a role in flu's gradual spread around the globe each year, but yesterday, Boston researchers said they finally have documented it: The drop in air travel after the September 11, 2001, terrorist attacks seemed to delay that winter's flu season by about two weeks.

"This is the first time that a study has been able to show a direct link between the numbers of people traveling and the rate of spread of a virus," said John Brownstein, an epidemiologist at Children's Hospital of Boston, who led the research.

Other scientists stress that the study doesn't prove that restricting air travel helps in the long run -- there was no drop in the number of deaths, just a delay. So if a pandemic were to strike, the question is whether a mere two-week delay would outweigh the economic chaos of severe travel restrictions.

"You wouldn't want to have people look at this and say, 'Ah, this is overwhelming evidence that if the pandemic occurs, we should shut down air travel,'" said Dr. Anthony Fauci of the National Institutes of Health, the government's chief influenza specialist.

"What does it buy you? That's the real critical issue."

Added Dr. William Schaffner of Vanderbilt University, who advises the government on flu issues: "We're all sure that airlines play a role. ... Leaping from this sort of analysis to interdiction of air travel I think is provocative, and we have to be very careful about that."

It's not that a lot of people catch the flu from sneezy fellow passengers, although that's possible. Instead, Mr. Brownstein says, travelers who may start a trip before flu's symptoms kick in infect the people they're visiting -- or they catch the virus in one city and carry it back home.

People easily spread the flu through coughs, sneezes and germs on their hands. But scientists don't understand how a community outbreak ripples outward until each winter's flu strain spreads across countries. Plus, every few decades, a new and virulent flu strain causes a worldwide epidemic. Better understanding of those geographic patterns might help stem the next such pandemic.

Previous studies suggest that young children who bring the flu home to older relatives spark community outbreaks, which spread among U.S. cities and states when the sick go to work instead of recuperating at home.

The study appeared yesterday in the online science journal PLoS Medicine.

Merck & Co Inc. withdrew Vioxx from the market in September 2004 after a three-year study showed it doubled the risk of heart attack and strokes in patients taking it for at least 18 months.

A second report from the University of Newcastle, New South Wales, Australia, said a look at 23 studies confirms findings of an increased risk of heart problems with Vioxx that could be found "during the first 30 days of treatment. This conclusion is consistent with a recent reanalysis ... which contradicts the original suggestion that the vascular risk was only seen after 18 months."

The studies were published in this week's Journal of the American Medical Association (JAMA) along with an editorial from David Graham, a physician who works for the U.S. Food and Drug Administration but whose comments were labeled as his own views and not those of the regulatory agency.

Merck is facing more than 11,500 product liability lawsuits from people claiming to have been harmed by Vioxx.

"What the studies are going to do is provide substantial support for the opinions being expressed by the plaintiffs' experts, and that will serve to increase their credibility and persuasiveness to juries," said Frank McClellan, professor at Temple University's Beasley School of Law.

"Those studies will also be used to cross-examine and impeach Merck's experts who testify that there is no link between the drug and the injuries," McClellan said. "The impact could be profound in the outcomes of the trials."

Merck said it still believes the data confirm the increased heart risk begins only after the medicine had been taken for 18 months.

Merck said in a statement the observations in the JAMA articles and opinions expressed in an accompanying editorial regarding potential increased risks with short-term Vioxx use "are not supported by the current weight of clinical data."

The Australian analysis also found that celecoxib -- sold as Celebrex by Pfizer Inc. -- was not associated with heart problems at a dose no greater than 200 milligrams a day.

It said that its review "raises serious questions about the safety of diclofenac, an older (analgesic) drug" which is sold more in Europe than the United States.

"In conclusion ... diclofenac seems to share this risk and, unlike celecoxib, it appears to be harmful at commonly used doses. We believe there are grounds for reviewing its regulatory status," the report added.

In his editorial, Graham said the studies demonstrate that Vioxx "increases the risk of acute myocardial infarction at low and high doses" and that "there is no initial 18-month period of immunity from risk."

He said Celebrex increases heart risk at doses higher than 200 milligrams per day and several other non-steroidal anti-inflammatory drugs (NSAIDs) increase risk, including diclofenac, meloxicam, indomethacin and "probably" ibuprofen, while studies agree naproxen is "neutral" for heart attack risk.

Graham added that for most patients with arthritis or other conditions requiring chronic pain relief "naproxen appears to be the safest NSAID choice from a cardiovascular perspective." Naproxen is commonly sold as Aleve by Bayer Corp..

Even coffee mugs, pens and other trinkets doled out by drug companies can't be accepted anymore.

Yale University and the University of Pennsylvania have announced similar policies and several other institutions are considering gift bans as they grapple with conflict of interest concerns and rising health care costs.

"In recent years we have witnessed an erosion of the public trust in the profession of medicine and even in the value of science," said Dr. Philip Pizzo, Stanford's medical school dean. "Part of that is related to the market forces that have increasingly converted medicine from a profession to a business, but a significant factor has also been the perception that physicians and scientists may be accepting gifts and gratuities from industry at the very time that the cost of drugs is skyrocketing."

In January, an article in the Journal of the American Medical Association said current relations with pharmaceutical representatives created conflicts of interest and urged academic medical centers to take the lead in adopting reforms. The article said the drug industry spends about $19 billion annually marketing to doctors.

"Gift giving creates a reciprocal obligation that is a powerful force, and pharmaceutical companies know this very well," said David Magnus, director of the Stanford Center for Biomedical Ethics who helped write the new policy. "So we're discouraging it from happening anywhere at the medical center."

The industry's trade group, the politically influential Pharmaceutical Research and Manufacturers of America, blasted Stanford's new policy as draconian and argued that cutting down on doctors and sales representatives meetings would actually hamper health care.

"The sales representatives are typically very well trained and have quite a bit of information," said Scott Lassman, a lawyer for the trade group. "They are cutting doctors off from very useful information that they can use to help treat their patients."

Lassman said the trade group instituted its own gift policy in 2002 that prohibits lavish gift giving.

"Lavish, expensive meals, tickets to ball games and golf outings are really inappropriate," Lassman said. "But if I was concerned that my doctor was influenced by a pen or a slice of pizza, I would find another doctor."

House sparrows, chaffinches and goldfinches are affected, and there have been outbreaks of the disease in Scotland, Wales, south-western England and the Midlands. Vets said there was no link to avian flu, and the parasite posed no risk to human health.

It is thought that the sharing of feeders and baths leads to the spread of infection between the garden birds.

The RSPB has emphasised the importance of good hygiene, saying birdbaths and feeders should be regularly washed and moved around the garden to prevent infection.

Spokesman Andre Farrar said: "It is an unusually large outbreak. Trichomoniasis usually affects pigeons and doves, but this summer it seems to have affected finches and house sparrows.

"There is no human health risk but, as always when handling birds, people must take care. We are not sure what the reason is for the high number of deaths this year, but wildlife vets are investigating."

One factor may be the unusually hot weather in Britain this year, which may have helped diseases to spread, the spokesman said.

It is thought the cases of trichomoniasis are concentrated in the Midlands and the south-west of England, with a large number also reported in Wales. So far, relatively few cases have been found in the east of England.

Vets from the Garden Bird Health Initiative, a three-year project at the Institute of Zoology, are currently collating the number of deaths from across the country.

"Since children's brains are still developing, they cannot adjust as full-grown adults can, to the effects of ever more rapid technological and cultural change," the letter said.

"They need what developing human beings have always needed, including real food (as opposed to processed "junk"), real play (as opposed to sedentary, screen based entertainment), first hand experience of the world they live in and regular interaction with the real-life significant adults in their lives."

The letter was circulated by Sue Palmer, an ex-head teacher and author of a book entitled "Toxic Childhood," and Dr Richard House, a senior lecturer at the Research Center for Therapeutic Education at Roehampton University.

"Children's development is being drastically affected by the kind of world they are brought up in," Palmer told the Daily Telegraph. "It is shocking."

"A child's physical and psychological growth cannot be accelerated. It changes in biological time, not at electrical speed. Childhood is not a race."

The experts condemned Britain's increasingly "target-driven" education system and urged the government to recognize children's need for more time and space to develop, demanding an urgent public debate on child-rearing in the 21st century.

"Our society rightly takes great pains to protect children form physical harm, but sees to have lost sight of their emotional and social needs," they said.

"Two member states, France and Sweden, have found, by their own methods, positive samples of GMO, these remain to be verified by the Commission's testing methods," the official said.

In France, seven samples out of 20 tested were found to include the unauthorized strain (GMO LL601), he said, on condition of anonymity.