Two years after Rachel Weiss began working at Emory?s Yerkes National Primate Research Center as an animal care technician in 1994, she left the center disgusted by the animals? living conditions.

?Those monkeys ? their housing conditions were atrocious,? Weiss said. ?They lived in single cages and a lot of them were crazy. [It was] really abnormal behavior.?

Today, Weiss is the president and co-founder of the Laboratory Primate Advocacy Group (LPAG), a coalition of former laboratory workers who support animal rights.

LPAG is one of many animal rights groups that have criticized Yerkes for its research on primates.

In recent years, Weiss said, animal rights groups have stepped up their opposition to Yerkes. The center is now among the top targets in the nation for animal rights activists.

As a result, she said, Yerkes and other primate research centers have become less responsive to the concerns of animal rights groups.

?What I think [our education has] done is made Yerkes less communicative than they?ve ever been before,? Weiss said.

For example, Weiss said she recently tried to talk with someone at Yerkes about the chimpanzees she used to work with, but no one would speak with her.

Weiss said that she used to be able speak on the telephone with Tom Insel, who directed Yerkes while she worked there, even after he knew she opposed animal research.

Other animal rights groups have reported a similar lack of cooperation from Yerkes.

?Nobody ever gets any response from Yerkes at all because Emory is private and they hide behind that,? said Jean Barnes, director of the Primate Freedom Project.

Thomas Gordon, the associate director for scientific programs at Yerkes, said the center?s response to the Primate Freedom Project has changed throughout the years.

?In early days we responded point by point,? he said. ?It soon became clear that this was a group that was deeply committed philosophically, and there was nothing we could say to change their mind.?

Gordon said the center also takes ?enormous efforts? to make information about the research its scientists conduct available to the public.

?We publish the results of everything we do in open journals,? he said.

Kathleen Conlee, director of program management in animal research issues at the Humane Society of the United States, said her organization is particularly concerned with the way Yerkes treats primates used in AIDS research.

?Yerkes does a fair amount of invasive research for HIV,? Conlee said.

Invasive research involves tests that cause more than momentary pain for the animals involved.

Weiss said that she does not believe that scientists can perform worthwhile research while also properly protecting an animal?s welfare.

?I don?t think they try to act cruelly, but they?re job is to make money and do research. They?re not there to take care of animals,? Weiss said. ?That?s not their job.?

Yerkes? research on an AIDS vaccine has not produced results, Barnes said.

Yerkes last published a press release about progress in AIDS research in January 2003. The press release stated that a vaccine developed in a collaboration between Yerkes and several other research institutions would begin a Phase I clinical trial during the week of Jan. 23, 2003.