Fischer et al. Respond

Clayton et al. respond.

Lusk et al. respond.

We thank Schimek for his thoughtful letter. We agree that the American Association of State Highway and Transportation Officials (AASHTO) encourages bike paths; however, AASHTO’s definition of a bike path is a shared use path for pedestrians, skaters, wheelchair users, joggers, and other nonmotorized users. AASHTO discourages bicycle-only cycle tracks because, as noted by Schimek, AASHTO discou...

Reply to Fischer et al.

We welcome the correspondence from Fischer and colleagues regarding our recent paper on vocal learning in chimpanzee food grunts [1]. Fischer et al. make two challenges to our paper's conclusions, which we address here.

Nanotoxicology: Gangwal et al. Respond

Gangwal et al. (2011) addressed an important topic for nanotoxicology about assessing the toxicity of inhaled nano materials by recom mending relevant concentrations for in vitro toxicity testing. Their efforts to select in vitro concentrations based on reported occupational exposure levels of inhaled nano materials are, indeed, laudable. Their under lying conceptual approach is logical, involv...

“Phthalates”: Kelley et al. Respond