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71.
Communicated by G. Lallement 相似文献
72.
73.
Click-evoked otoacoustic emissions (CEOAEs) were previously shown to be significantly less strong in homosexual and bisexual females than in heterosexual females. Here it is reported that the spontaneous otoacoustic emissions (SOAEs) of those same 60 homosexual and bisexual females were less numerous and weaker than those in 57 heterosexual females. That is, the SOAEs of the homosexual and bisexual females were intermediate to those of heterosexual females and heterosexual males. The SOAE and CEOAE data both suggest that the cochleas of homosexual and bisexual females have been partially masculinized, possibly as part of some prenatal processes that also masculinized whatever brain structures are responsible for sexual orientation. For males of all sexual orientation, the SOAEs were less numerous and weaker than for the females, and there were no significant differences among the 56 heterosexual, 51 homosexual, and 11 bisexual males. All subjects passed a hearing screening test. When all SOAEs above 3000 Hz were excluded (as a control against incipient, undetected hearing loss) the same results were obtained as with the full range of data (550-9000 Hz). The differential use of oral contraceptives by the heterosexual and nonheterosexual females also could not explain the differences in their OAEs. 相似文献
74.
Waveforms that yield comodulation masking release (CMR) when they are presented simultaneously with a signal were used in a standard forward-masking procedure. The signal was a 25-ms sample of a 2500-Hz tone. The masker was a band of noise centered at 2500 Hz, 100 Hz in width, and 200 ms in duration. Presented with the masker were two or four cue bands, each 100 Hz wide and centered at various distances from the masker band. These cue bands either all had the same temporal envelope as the masker band (correlated condition) or their common envelope was different from that of the masker band (uncorrelated condition). In the initial experiments, (1) detectability of the tonal signal was 7-18 dB better when the masker band was accompanied by cue bands than when it was not--an effect that would be expected from past research on lateral suppression--but further, (2) the signal was about 3 dB more detectable in the correlated conditions than in the uncorrelated conditions. In follow-up experiments, these CMR-like differences between the correlated and uncorrelated conditions were substantially reduced (although not eliminated) by presenting a contralateral, wideband noise that was gated synchronously with the masker and/or cue bands. The implications are that the initial results were attributable in part to the "confusion effects" known to exist in certain temporal-masking situations, and that listeners are able to obtain greater information about the temporal extent of a masker band from correlated cue bands than from uncorrelated bands.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
75.
76.
Abstract. Let n and r be positive integers with 1 < r < n and let K(n,r) consist of all transformations on X
n
= {1,···,n} having image size less than or equal to r . For 1 < r < n , there exist rank-r elements of K(n,r) which are not the product of two rank-r idempotents. With this limitation in mind, we prove that for fixed r , and for all n large enough relative to r , that there exists a minimal idempotent generating set U of K(n,r) such that all rank-r elements of K(n,r) are contained in U
3
. Moreover, for all n> r>1 , there exists a minimal idempotent generating set W for K(n,r) such that not every rank-r element is contained in W
3
. 相似文献
77.
[formula: see text] A new and efficient asymmetric synthesis of naturally occurring (5R)-thiolactomycin (1) using D-alanine as the source of chirality is described. 相似文献
78.
79.
Aspirin abolishes spontaneous oto-acoustic emissions 总被引:1,自引:0,他引:1
Spontaneous oto-acoustic emissions (OAEs) were measured prior to, during, and following administration of aspirin. The dose schedule was three 325-mg tablets every 6 h for a total of 16 doses (3.75 days). In every subject studied, all spontaneous OAEs gradually diminished and then disappeared during the drug regimen. Emissions that were initially small disappeared within 14-20 h of beginning the drug regimen (3-4 doses), while initially large emissions took 40-70 h (7-12 doses) to disappear completely. In contrast, the initial size of an emission appeared unrelated to the time required for it to recover to full strength once drug administration ceased. The recovery process was highly idiosyncratic, with the emissions of some subjects returning to full strength within 24 h, while for other subjects, full recovery required several days. In two subjects having multiple emissions in the same ear, the relative sizes of the different emissions often changed greatly during the disappearance and recovery phases. When small frequency shifts appeared for these subjects, they appeared--and were in the same direction--for each of the multiple emissions. In a related experiment, the spontaneous emission was unchanged in one subject who took a drug that inhibits the intracellular entry of calcium ions (verapamil). 相似文献
80.
Two-photon high resolution sequential spectroscopy has been used to excite iodine monochloride from X1Σ+ ground state to the intermediate A3Π1 state and thence to a final electronic state at 4.82 eV. Vibrational and rotational analyses of this state have been carried out for both isotopic species. For I35Cl, Te = 38916.0 cm?1 ωe = 168.99 cm?1, ωexe = 0.357 cm?1 and Be = 0.05685 cm?1. The state probably has Ω = 1 in case (c) coupling approximation. It is also shown how to two-photon technique enables rotational line structure of the A ← X transition to be selectively excited for either isotopic species at a resolution of 500000, from an absorption mixture containing natural iodine monochloride plus its iodine dissociation product at equilibrium vapour pressure. 相似文献