Young adults' survival rate resembles that reported for all patients with head and neck cancer stage for stage. Tobacco and alcohol abuse prevention among young people is imperative. Health care providers who encounter a young patient with a suspicious head or neck lesion must include malignancy in their differential diagnosis.

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Eighteen Peking ducklings were imprinted and tested for their tendency to emit distress calls during the presentation and withdrawal of the imprinted stimulus. A subsequent arrangement in which each distress vocalization led to a 5-second presentation of the imprinted stimulus resulted in an enhanced tendency to emit distress calls.

The effects of total darkness on DRL schedule control were studied with pigeons under two lighting conditions. Increased DRL schedule control is indicated by decreased response and response/reinforcer rates and by increased reinforcer rates. Four pigeons with prior training on DRL schedules were conditioned to keypeck in total darkness. There were five blocks of sessions. In Blocks 1-4, subjects were trained on four alternating blocks of sessions under dark and light conditions (ABAB design). Block 5 consisted of four alternating sessions of dark and light conditions (ABAB design). Comparison of the dark with the light condition showed 3 subjects with decreased response and response/reinforcer rates and increased reinforcer rates in the dark condition. The results indicate increased control with DRL schedules under conditions of total darkness and are in agreement with Robinson and Shelley's (1974) study in which increased control was demonstrated for FI, VI, FR, and VR schedules.

No abstract