We report a case of Cockayne syndrome with several atypical features. The patient displayed many of the typical features, including cachectic bird-headed dwarfism, photodermatitis, normal pressure hydrocephalus, and extraphyramidal and pyramidal tract signs. However, she also displayed the unusual and previously unreported features of late age at onset, relative stability until age 19, and fertility, with a successful pregnancy. Brain biopsy showed hypomyelination, no active demyelination, and fibrillary gliosis.

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A general calculation of the spatial correlation function due to a distributed acoustic source near the water surface has been done by others using normal-mode theory. In this article, a multiple-ray-path analysis is used to calculate the acoustic ambient vertical directivity function. Multipath propagation and ambient directional functions are physically intuitive concepts in underwater acoustic theory, and direct application of these notions has advantages in the interpretation of data. Existing procedures and computer codes are used to expand the received pressure field, from a distributed source, into a sum of terms interpreted as multiple propagation paths. Standard forms for the source function and a geometric transformation are used to convert the pressure field to a solid-angle density function. Surface roughness, bottom geoacoustic parameters, and sound velocity-depth profiles measured in the Tongue of the Ocean in the Bahamas are used in the calculations to predict hydrophone array performance in that area. Directivity function versus elevation angle and frequency are displayed for observers above and below a seasonal thermocline. A path-by-path contribution to the vertical distribution of energy is discussed.

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While wave breaking is continually occurring at the sea surface, its transient and sporadic nature makes it difficult to measure. Experimental results are presented that show how acoustic methods can be used as a remote sensor of this fundamental process. Sea surface-generated acoustic radiation (40 to 4000 Hz) is directly related to a quantitative measure of the boundary dynamics; i.e., the Toba variable. The frequency spectrum of the radiation remains remarkably unchanged over a wide range of environmental conditions but the correlation between the sound pressure level and the Toba variable undergoes an abrupt change when spilling breakers start to occur. Results support the use of acoustics to remotely measure the rate of energy being dissipated by wave breaking and the wavelength of the dominant gravity wave component. Theoretical studies have related the field measurements to analytical and laboratory results cited in the literature indicating that remote monitoring of the rate of occurrence and size distribution of ‘‘infant’’ (freshly entrained) bubbles may be possible if splashes on the surface do not radiate significant sound. Signal processing algorithms for the remote measurements discussed above are enhanced by eigenstructure analysis of the measured cross-spectral density matrix. [Work sponsored by ONR and NUSC.]