On the fringes of Interstate 85, where the highway snakes through Atlanta's inner city, researchers from Emory University came to study the off-road behaviour of long-haul truckers.
There, amid the empty lots, nudie bars and by-the-hour motels, they set up their living lab -- and landed in one of the ugly morality debates dogging American science.
The project was inspired by research in Africa, where the mix of truckers and sex workers on the Kinshasa Highway is infamous for spreading AIDS along the continent's spine. Emory's experts wondered if the same would be true in North America.
Preliminary field work showed that long-haul truckers (close to four million in the United States, including half a million Canadians) are at the centre of a desperate network of truck-stop hustlers.
Prostitutes, drug dealers and truck chasers -- gay or bisexual men who idolize truckers as "the last of the cowboys" -- vie to eke out a living off the drivers, who may bring home something worse than cargo.
In 2002, the U.S. National Institutes of Health, the government's prime funder of medical research, agreed it was worth learning more. It awarded the Emory scientists a $1.1-million (U.S.) grant.
But a year later an official called to warn them their project was on an ominous list circulating in Washington.
The Traditional Values Coalition, which lobbies on behalf of 43,000 U.S. churches, spotted the study on the NIH website: "Wait until you see how angry the American people get," its president wrote to Democratic Rep. Henry Waxman, "when they discover that NIH have been using federal tax dollars to study 'lot lizards' -- prostitutes who service truckers in parking lots."
The group deemed the project and 200 others an immoral or "nonsensical" waste.
With Congress threatening action, the NIH undertook a review of all its behaviour-related studies. Although attempts to strip funding failed, the episode spawned a chill that shows no sign of thaw.
With the re-election of President George W. Bush and the Republican congressional majority, scientists across the United States have found themselves in a surreal era of self-censorship. Conservatives used key-word Internet searches to compile their watch lists, so researchers are hunting for euphemisms for homosexuals and prostitutes (replaced with "high-risk population").
"Many STD/HIV researchers who are seeking federal funding are reconsidering details down to the level of how they title their grants, so as not to draw unwanted --ideologically and certainly not intellectually driven -- scrutiny," said Jeanne Marrazzo, who researches sexually transmitted diseases at Washington State University. "It's scary."
Such measures might sound more like Soviet-era paranoia than modern American science. But there is no mistaking the degree of mistrust many U.S. researchers feel in this political climate. "I think folks are worried this smacks of McCarthyism 50 years later," said David Celentano, an AIDS researcher at Johns Hopkins University.
Dr. Celentano described grant-review hearings attended by religious-group members and political appointees. He said it was the NIH that has advised researchers to take projects "underground" -- to replace lesbians, for example, with "prospective mothers."
NIH officials would not discuss the policy on the record. But a recent article in the Johns Hopkins alumni magazine included comments from an unnamed official pressed to explain the ambiguous-language directive. "Don't make me speak to you about this in public," she said. "There are spies everywhere!"
Politics and science have clashed before in the United States, and around the world, on issues such as nuclear arms or, most recently, stem cells.
But never before has the U.S. scientific community been embroiled in such a broad, sustained battle with political leaders.
The government ignored the protests of its top geologists in 2003 when it decided to allow the sale of a book at Grand Canyon National Park claiming that Noah's biblical flood created the chasm 4,500 years ago -- an estimate scientists suggest is short by six million years.
Most publicly, even Congress intervened to prolong the life of Terri Schiavo, a Florida woman who had lived in a "persistent vegetative state" for 15 years. Despite medical evidence of severe brain damage and no hope of recovery, religious groups took up the case as a right-to-life issue.
Mr. Bush interrupted his Texas vacation to sign the bill, and his brother Jeb, the governor of Florida, sought to have the state take custody of Ms. Schiavo's care. The U.S. Supreme Court six times turned down requests to consider the case before she died on March 31.
Controversy over the treatment of science has erupted around national security, myriad environmental issues and endangered-species programs. Medical research in particular has been caught in the crossfire. Whenever it involves issues of sexuality, such as STD prevention, AIDS policies or reproductive issues, critics charge, morality trumps medical evidence.