RESUMEN
A psychophysical procedure was used to measure pure-tone detection thresholds for a killer whale (Orcinus orca) as a function of both signal frequency and signal duration. Frequencies ranged between 1 and 100 kHz and signal durations ranged from 50 µs to 2 s, depending on the frequency. Detection thresholds decreased with an increase in signal duration up to a critical duration, which represents the auditory integration time. Integration times ranged from 4 ms at 100 kHz and increased up to 241 ms at 1 kHz. The killer whale data are similar to other odontocete species that have participated in similar experiments. The results have implications for noise impact predictions for signals with durations less than the auditory integration time.
Asunto(s)
Orca , Animales , Ruido/efectos adversosRESUMEN
OBJECTIVE: To determine a learning curve for radical perineal prostatectomy after formal training in radical retropubic prostatectomy. METHODS: Using the William Beaumont Hospital Prostatectomy database, we analyzed peri-operative data from two surgeons performing radical perineal prostatectomies from their initial 96 cases to determine a learning curve. RESULTS: Over time, data between the first and last quarters showed consistent, excellent results in terms of skin time (143 SD ± 22 and 136 SD ± 24 min), blood loss (310 SD ± 120 and 335 ± 216 cc), and length of stay (1.3 SD ± 0.6 and 1.2 SD ± 0.5 days), without significant change. However, only two positive margins were obtained in the 4th quartile representing a significant change and possibly representing a learning curve. CONCLUSIONS: These data show that excellent, reproducible results can be obtained using basic surgical principles, without incorporating expensive technology and resources.