Temporary Hearing Threshold Shift in Harbor Porpoises (Phocoena phocoena) Due to One-Sixth-Octave Noise Band at 32 kHz

Temporary hearing threshold shift (TTS) caused by fatiguing sounds in the 1.5 to 16 kHz range has been documented in harbor porpoises (Phocoena phocoena). To assess impacts of anthropogenic noise on porpoise hearing, TTS needs to be investigated for other frequencies, as susceptibility appears to depend on the frequency of the fatiguing sound. TTS was quantified after two porpoises (Porpoises F05 and M06) were exposed for 1 hour to a continuous one-sixth-octave noise band centered at 32 kHz, at average received sound pressure levels of 118 to 148 dB re 1 µPa, and at a sound exposure level (SEL) range of 154 to 184 dB re 1 µPa2s. Hearing thresholds for 32, 44.8, and 63 kHz tonal signals were determined before and after exposure to quantify initial TTS and recovery. Porpoise M06’s hearing was tested 1 to 4 min after exposure. At 32 kHz, the lowest SEL that resulted in significant TTS1-4 (3.4 dB) was 166 dB re 1 µPa2s. At 44.8 kHz, the lowest SEL that resulted in significant TTS1-4 (5.2 dB) was 178 dB re 1 µPa2s. The highest TTS1-4 (18.3 dB) occurred at 44.8 kHz after exposure to 184 dB SEL. Porpoise F05’s hearing was tested 12 to 16 min after exposure. At 32 kHz, the lowest SEL that resulted in significant TTS12-16 (3.5 dB) was 184 dB re 1 µPa2s. At 44.8 kHz, the lowest SEL that resulted in significant TTS12-16 (1.2 dB) was 178 dB re 1 µPa2s. The highest TTS12-16 (8.2 dB) occurred in Porpoise F05 at 44.8 kHz after exposure to 184 dB SEL. At 63 kHz, no TTS could be elicited in either animal. Considering that Porpoise F05 had more time than Porpoise M06 for recovery, the susceptibility of the two porpoises to TTS after exposure to sounds of 32 kHz was similar. In the range investigated so far (1.5 to 32 kHz), susceptibility to TTS appears to increase with increasing frequency below ~6.5 kHz, and to decrease with increasing frequency above ~6.5 kHz

Temporary hearing threshold shift in harbor seals (Phoca vitulina) due to a one-sixth-octave noise band centered at 16 kHz

Temporary hearing threshold shifts (TTSs) were investigated in two adult female harbor seals after exposure for 60 min to a continuous one-sixth-octave noise band centered at 16 kHz (the fatiguing sound) at sound pressure levels of 128-149 dB re 1 μPa, resulting in sound exposure levels (SELs) of 164-185 dB re 1 μPas. TTSs were quantified at the center frequency of the fatiguing sound (16 kHz) and at half an octave above that frequency (22.4 kHz) by means of a psychoacoustic hearing test method. Susceptibility to TTS was similar in both animals when measured 8-12 and 12-16 min after cessation of the fatiguing sound. TTS increased with increasing SEL at both frequencies, but above an SEL of 174 dB re 1 μPas, TTS was greater at 22.4 kHz than at 16 kHz for the same SELs. Recovery was rapid: the greatest TTS, measured at 22.4 kHz 1-4 min after cessation of the sound, was 17 dB, but dropped to 3 dB in 1 h, and hearing recovered fully within 2 h. The affected hearing frequency should be considered when estimating ecological impacts of anthropogenic sound on seals. Between 2.5 and 16 kHz the species appears equally susceptible to TTS

Temporary threshold shift in a second harbor porpoise (phocoena phocoena) after exposure to a one-sixth-octave noise band at 1.5 kHz and a 6.5 kHz continuous wave

To determine whether susceptibility to noise-induced temporary hearing threshold shift (TTS) differs between individual harbor poipoises (Phocoena phocoena), studies with an 8-year-old male (M02) were repeated by exposing a 9-year-old female (F05) to similar fatiguing sounds. F05 was exposed for one hour to a continuous one-sixth-octave noise band (NB) centered at 1.5 kHz at six sound pressure levels (SPLs; resulting sound exposure level [SEL] range: 180 to 201 dB re 1 μPas), and to a 6.5 kHz continuous wave (CW) at 4 to 10 SPLs (resulting SEL range: 139 to 184 dB re 1 μPas). To quantify TTS, hearing thresholds for 1.5,2.1,3,6.5,9.2, and 13 kHz signals were determined before and after exposures. After exposure to the NB at 1.5 kHz, the lowest SELs resulting in significant TTS were 186 dB re 1 μPas for 1.5 kHz (1.0 dB), 194 dB re 1 μPas for 2.1 kHz (4.7 dB), and 190 dB re 1 [μPas for 3 kHz (1.5 dB). The highest TTSw was 9.3 dB, measured at 2.1 kHz after exposure to SEL 201 dB re 1 [pipe]μPas. After exposure to the 6.5 kHz CW, the lowest SELs resulting in significant TTS were 145 dB re 1 [μPas for 6.5 kHz (2.9 dB), 178 dB re 1 μPas for 9.2 kHz (7.3 dB), and 180 dB re 1 μPas for 13 kHz (6.4 dB). Six dB TTS was elicited in F05 at 2.1 kHz after exposure to the NB at 1.5 kHz at SEL 198 dB re 1 μPas, and in M02 at 1.5 kHz after exposure to 1 to 2 kHz downsweeps at SEL ~190 dB re 1 fμPas. The difference in susceptibility to TTS may be due to individual differences in TTS susceptibility and/or differences in the fatiguing sounds (i.e., sweeps, CWs, and NBs). Susceptibility to TTS was similar in both poipoises after exposure to a 6.5 kHz CW: 6 dB TTS was elicited at 9.2 kHz in both animals after exposure to SEL ~176 dB re 1 μPas

Temporary hearing threshold shift in harbor seals (Phoca vitulina) due to a one-sixth-octave noise band centered at 40 kHz

As part of a series of studies to determine frequency-dependent susceptibility to temporary hearing threshold shifts (TTS), two female harbor seals (F01 and F02) were exposed for 60 min to a one-sixth-octave noise band centered at 40 kHz at mean sound pressure levels ranging from 126 to 153 dB re 1 mu Pa [mean received sound exposure level (SEL) range: 162-189 dB re 1 mu Pa(2)s]. TTSs were quantified at 40, 50, and 63 kHz within 1-4 min of the exposure for F02 and within 12-16 min of the exposure for F01. In F02, significant TTS1-4 (1-4 min post exposure) occurred at 40 kHz with SELs of >= 183 dB re 1 mu Pa(2)s and at 50 kHz with SELs of >= 174 dB re 1 mu Pa(2)s. At 63 kHz, TTS1-4 occurred with SELs >= 186 dB re 1 mu Pa(2)s. In F01, significant TTS12-16 (12-16 min post exposure) occurred only at 50 kHz with SELs of >= 177 dB re 1 mu Pa(2)s. The highest TTSs (27.5 dB in F02, 29.8 dB in F01) occurred at 50 kHz, one-third of an octave above the fatiguing sound's center frequency (SEL = 189 dB re 1 mu Pa(2)s); recovery took 2 days in F02 and 4 days in F01. In most other cases, recovery was within 1 h. The seals have a similar susceptibility to TTS from 4 to 40 kHz

Prediction of BRCA1 Status in Patients with Breast Cancer Using Estrogen Receptor and Basal Phenotype

Purpose: To investigate the proportion of breast cancers arising inpatients with germ line BRCA1 and BRCA2 mutations expressing basal markers and developing predictive tests for identification of high-risk patients. Experimental Design: Histopathologic material from 182 tumors in BRCA1 mutation carriers, 63 BRCA2 carriers, and 109 controls, collected as part of the international Breast Cancer Linkage Consortium were immunohistochemically stained for CK14, CK5/6, CK17, epidermal growth factor receptor (EGFR), and osteonectin. Results: All five basal markers were commoner in BRCA1 tumors than in control tumors (CK14: 61% versus 12%; CK5/6: 58% versus 7%; CK17: 53% versus 10%; osteonectin: 43% versus 19%; EGFR: 67% versus 21%; P < 0.0001 in each case). In a multivariate analysis, CK14, CK5/6, and estrogen receptor (ER) remained significant predictors of BRCA1 carrier status. In contrast, the frequency of basal markers in BRCA2 tumors did not differ significant from controls. Conclusion: The use of cytokeratin staining in combination with ER and morphology provides a more accurate predictor of BRCA1 mutation status than previously available, that may be useful in selecting patients for BRCA1 mutation testing. The high percentage of BRCA1 cases positive for EGFR suggests that specific anti-tyrosine kinase therapy may be of potential benefit in these patients