Investigators believe the fires are related and may be the work of radical environmentalists opposed to genetic engineering. The horticulture center develops fast-growing hybrid trees, a practice that many environmentalists dislike.
Authorities say the Oregon fire was ignited at roughly the same time as the center fire.
The Earth Liberation Front is known for conducting such attacks, and the initials ELF were scrawled at the scene of the Oregon fire. No such graffiti was found at the center. Listen as NPR's Wendy Kaufman reports on the attacks for Morning Edition . Study Labels 'Placebo Effect' As No More Than Medical Myth New research indicates the placebo effect may be no more than a medical myth. For 50 years, doctors have believed that dummy pills with no active ingredient could help some sick people get better through the power of suggestion.