Naval Submarine Medical Research Laboratory

About: Naval Submarine Medical Research Laboratory is a facility organization based out in Groton, Connecticut, United States. It is known for research contribution in the topics: Poison control & Population. The organization has 164 authors who have published 186 publications receiving 2949 citations. The organization is also known as: NSMRL.

Incremental validity of the frame-of-reference effect in personality scale scores: a replication and extension.

Abstract: Context-specific personality items provide respondents with a common frame of reference unlike more traditional, noncontextual personality items. The common frame of reference standardizes item interpretation and has been shown to reduce measurement error while increasing validity in comparison to noncontextual items (M. J. Schmit, A. M. Ryan. S. L. Stierwalt. & S. L. Powell, 1995). Although the frame-of-reference effect on personality scales scores has been well investigated (e.g., M. J. Schmit et al., 1995), the ability of this innovation to obtain incremental validity above and beyond the well-established, noncontextual personality scale scores has yet to be examined. The current study replicates and extends work by M. J. Schmit et al. (1995) to determine the incremental validity of the frame-of-reference effect. The results indicate that context-specific personality items do indeed obtain incremental validity above and beyond both noncontextual items and cognitive ability, and in spite of socially desirable responding induced by applicant instructions. The implications of these findings for personnel selection are discussed.

Low-level otoacoustic emissions may predict susceptibility to noise-induced hearing loss.

Abstract: In a longitudinal study with 338 volunteers, audiometric thresholds and otoacoustic emissions were measured before and after 6 months of noise exposure on an aircraft carrier. While the average amplitudes of the otoacoustic emissions decreased significantly, the average audiometric thresholds did not change. Furthermore, there were no significant correlations between changes in audiometric thresholds and changes in otoacoustic emissions. Changes in transient-evoked otoacoustic emissions and distortion-product otoacoustic emissions were moderately correlated. Eighteen ears acquired permanent audiometric threshold shifts. Only one-third of those ears showed significant otoacoustic emission shifts that mirrored their permanent threshold shifts. A Bayesian analysis indicated that permanent threshold shift status following a deployment was predicted by baseline low-level or absent otoacoustic emissions. The best predictor was transient-evoked otoacoustic emission amplitude in the 4-kHz half-octave frequency band, with risk increasing more than sixfold from approximately 3% to 20% as the emission amplitude decreased. It is possible that the otoacoustic emissions indicated noise-induced changes in the inner ear, undetected by audiometric tests. Otoacoustic emissions may therefore be a diagnostic predictor for noise-induced-hearing-loss risk.

Novel Electrodes for Underwater ECG Monitoring

Abstract: We have developed hydrophobic electrodes that provide all morphological waveforms without distortion of an ECG signal for both dry and water-immersed conditions. Our electrode is comprised of a mixture of carbon black powder (CB) and polydimethylsiloxane (PDMS). For feasibility testing of the CB/PDMS electrodes, various tests were performed. One of the tests included evaluation of the electrode-to-skin contact impedance for different diameters, thicknesses, and different pressure levels. As expected, the larger the diameter of the electrodes, the lower the impedance and the difference between the large sized CB/PDMS and the similarly-sized Ag/AgCl hydrogel electrodes was at most 200 kΩ, in favor of the latter. Performance comparison of CB/PDMS electrodes to Ag/AgCl hydrogel electrodes was carried out in three different scenarios: a dry surface, water immersion, and postwater immersion conditions. In the dry condition, no statistical differences were found for both the temporal and spectral indices of the heart rate variability analysis between the CB/PDMS and Ag/AgCl hydrogel (p > 0.05) electrodes. During water immersion, there was significant ECG amplitude reduction with CB/PDMS electrodes when compared to wet Ag/AgCl electrodes kept dry by their waterproof adhesive tape, but the reduction was not severe enough to obscure the readability of the recordings, and all morphological waveforms of the ECG signal were discernible even when motion artifacts were introduced. When water did not penetrate tape-wrapped Ag/AgCl electrodes, high fidelity ECG signals were observed. However, when water penetrated the Ag/AgCl electrodes, the signal quality degraded to the point where ECG morphological waveforms were not discernible.