Field trials have yielded positive results and a handful of companies hope to commercialize this plant technology.

CNN: Flower power

Safety trials of the vaccine have already been successfully completed, and tests to work out its effectiveness have also yielded positive results.

BBC: Cocaine vaccine trials progress

More recently, sampling by the U.S. Army Corps of Engineers and other federal agencies also yielded positive results in the Chicago waterways.

WSJ: Report: Asian carp may have reached Great Lakes

So far, the community-focused policing strategy has yielded positive results.

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Over the past several years, various studies have yielded conflicting results as to whether viral loads differ between HIV-positive men and women.

BBC: HIV test