Cinefluorographic study of prosthetic cardiac valves.
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Biomedical subjects
Publications and source records attributed to W J Wilson.
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Respiratory rate, respiration amplitude, and vocal responses were recorded in cats of different ages during classic conditioning. Vocal responses to the conditional stimulus (CS) appeared first in 8-week-old kittens, and became prominent at older ages. An increase in respiration rate occurred after the onset of the CS in cats of all ages. Similarly, the decrease of respiration amplitude was observed at all ages, but only in 8-week-old and older subjects did this response resemble an adult pattern. In 4-week-old kittens the response was characterized by an early and brief peak, suggesting an alpha conditional response (CR). Clear and significant discrimination between a warning and a safety signal was present in both respiratory and vocal responses after the age of 8 weeks.
Heart rate and motor responses were recorded in cats of different ages during classical conditioning. A deceleratory-acceleratory heart rate pattern observed during the CS-US interval in one- and four-week-old kittens is an alpha conditioned response, a potentiated original response to the CS. At eight weeks of age two new distinct patterns of pure acceleration or pure deceleration are acquired during conditioning and in the absence of motor learning. At 12 weeks of age and in adult subjects, heart rate patterns during the CS-US interval become more complex and conditioned motor responses can be observed. A covariance of HR acceleration and motor responses during the CS-US interval is absent in eight-week-old subjects, but quite high in 12-week-old subjects and adult cats. The data are interpreted as suggesting separate elicitatory mechanisms of HR and motor responses which may show synchrony later in ontogeny.
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