Benefits of Meeting the Healthy People 2030 Youth Sports Participation Target.

Introduction: Healthy People 2030, a U.S. government health initiative, has indicated that increasing youth sports participation to 63.

Selective reactions to different killer whale call categories in two delphinid species.

The risk of predation is often invoked as an important factor influencing the evolution of social organization in cetaceans, but little direct information is available about how these aquatic mammals respond to predators or other perceived threats. We used controlled playback experiments to examine the behavioral responses of short-finned pilot whales () off Cape Hatteras, NC, USA, and Risso's dolphins () off the coast of Southern California, USA, to the calls of a potential predator, mammal-eating killer whales. We transmitted calls of mammal-eating killer whales, conspecifics and baleen whales to 10 pilot whales and four Risso's dolphins equipped with multi-sensor archival acoustic recording tags (DTAGs).

The effects of climate change on harp seals (Pagophilus groenlandicus).

Harp seals (Pagophilus groenlandicus) have evolved life history strategies to exploit seasonal sea ice as a breeding platform. As such, individuals are prepared to deal with fluctuations in the quantity and quality of ice in their breeding areas. It remains unclear, however, how shifts in climate may affect seal populations.

Interresponse time structures in variable-ratio and variable-interval schedules.

The interresponse-time structures of pigeon key pecking were examined under variable-ratio, variable-interval, and variable-interval plus linear feedback schedules. Whereas the variable-ratio and variable-interval plus linear feedback schedules generally resulted in a distinct group of short interresponse times and a broad distribution of longer interresponse times, the variable-interval schedules generally showed a much more continuous distribution of interresponse times. The results were taken to indicate that a log survivor analysis or double exponential fit of interresponse times may not be universally applicable to the task of demonstrating that operant behavior can be dichotomized into bouts of engagement and periods of disengagement.

Stimulus control in fixed interfood intervals.

The control exerted by various portions of fixed-time and fixed-interval schedules was assessed with a trace-conditioning procedure. The intervals were segmented into 10 bins. In all but 1 of those bins, the stimuli were presented in different random orders on each trial.