Search PubMed⌕ Search

Biomedical subjects

R L Snyder

Publications and source records attributed to R L Snyder.

75 records · Page 5Linked to original sources
PubMedDate not supplied

Behavioral and neurophysiological thresholds for electrical cochlear stimulation in the deaf cat.

Psychophysical detection thresholds for unmodulated electrical pulse trains or for sinusoidally amplitude-modulated (SAM) pulse trains were estimated in deaf juvenile cats using a conditioned avoidance paradigm. Biphasic current pulses (0.2 ms/phase) were delivered by scala tympani electrodes consisting of 4-8 electrode contacts driven as bipolar pairs. Electrical auditory brainstem response (EABR) thresholds were obtained periodically, and at the conclusion of behavioral training, response thresholds were obtained for neurons in the inferior colliculus (IC) and the primary auditory cortex (A1) in acute physiological experiments in the same animals. The results of the study include: (1) detection thresholds for unmodulated pulse trains and for SAM pulse trains were virtually identical; (2) EABR thresholds and behavioral thresholds were significantly correlated, although EABR thresholds consistently overestimated behavioral thresholds; (3) the lowest thresholds in the IC and the A1 were significantly correlated with behavioral thresholds, and (4) mean lowest thresholds in the IC and the A1 were essentially the same as the mean psychophysical detection threshold in the trained deaf cats.

Animals↗
PubMedDate not supplied

Years of potential life lost among a Native American population.

The determination of years of potential life lost (YPLL) can aid in monitoring changes in premature mortality among various population groups. While premature mortality has been shown to differ among blacks and whites, patterns of YPLL have not been well established among other racial groups. The Seneca Nation of Indians (SNI) is a Native American group residing primarily in western New York State (NYS). A review of SNI necrology records revealed that 55 percent (510 of 924) of the deaths between 1955 and 1984 occurred before 65 years of age. The proportion of premature deaths among males exceeded the proportion in females. SNI males demonstrated an increased risk of premature death (odds ratio = 1.43) relative to SNI females. Both the percentage of premature deaths and the number of YPLL per death were greater among SNI members compared with NYS residents. Almost one-half of all YPLL among the SNI were attributable to accidents and injuries. Heart disease, digestive diseases, and malignant neoplasms also represented important contributors to YPLL for both SNI males and females. This investigation identifies important causes of premature death among a Native American population and underscores the preventable nature of premature loss of life.

Age Factors↗