Observers misperceive the orientation of a vertical rod when it is viewed in the context of a tilted frame (the rod and frame illusion, or RFI). The pitch and roll of the surrounding surfaces have independent influences on this illusion (Nelson and Prinzmetal, 2003). Experiment 1 measured the RFI when the pitch and roll of the floor that supported the observer was varied, and the observer was e...

Preharvest herbicide treatment of undesirable and unmerchantable v getation was compared to postharvest felling. Ten years after the clearcut harvesting, the preharvest treatment had increased the number and proportion of desirable stems and decreased the number and proportion of undesirable sprouts in the dominant stand. Stands that developed after the preharvest herb•cide treatment are domina...