The technique of watching two literals per clause to determine when a clause becomes a unit clause was introduced recently in the Chaff satisfiability program. That program does not perform either equivalent-literal detection or binary-clause detection. We describe a generalization of the technique that handles the tracking necessary to support equivalent-literal detection and binary-clause det...

INTRODUCTION The epidemic of childhood obesity has been well-documented. Prevalence of obesity among students in Texas is higher than the US prevalence. Our objective was to understand the combined influence of physical activity and television viewing on weight status of students in Texas. METHODS Students in grades 4, 8, and 11 participated in the School Physical Activity and Nutrition surve...

Four puzzle boxes were used to investigate localized stimulus enhancement and object movement reenactment (OMR) in 13 pig-tailed macaques (Macaca nemestrina) and 30 human infants (Homo sapiens). Participants received contrasting demonstrations on each box. A circular lid was gripped by its rim or handle and swiveled to the left or right. A flap door was pushed or flipped. A sliding lid was push...

The bidirectional control procedure was used to determine whether pigeons (Columba livia) would imitate a demonstrator that pushed a sliding screen for food. One group of observers saw a trained demonstrator push a sliding screen door with its beak (imitation group), whereas 2 other groups watched the screen move independently (possibly learning how the environment works) with a conspecific eit...

In the present study, 12 Hereford bulls approximately 22.5 mo of age were individually introduced to a restrained nonestrous stimulus female for 15 to 30 min under four treatment conditions: (1) without prior sexual stimulation and visually isolated from male conspecifics (control), (2) being watched by another male during matings, (3) after observing the copulatory activities of another male a...