Coupled Scholte modes supported by soft elastic plates in water.

Localized acoustic surface waves supported by a "soft" elastic plate in water are explored. Unlike many materials, such as aluminum, for soft interfaces the Scholte wave, a localized interface wave, has a speed well below that of sound in water, and the energy of the Scholte wave is no longer mainly localized to the water. We note that the Scholte velocity is largely independent of Poisson's ratio in the solid, and rather than the bulk speeds of sound, the ratio between the Young's modulus and the density of the solid may better indicate whether an interface is soft. The behavior of the coupled Scholte modes along a thin plate with soft interfaces are investigated. It is demonstrated, and experimentally verified using acrylic plates underwater, that for soft interfaces, the symmetric coupled Scholte mode exhibits dispersive behavior, and deviates from the Scholte and the fluid velocities at low frequencies.

Excess risk of kidney disease in a population living near industrial plants.

Runcorn has been a site of chemical industry activity for over a century, where tons of toxic chemicals are released annually to air and water. Excess kidney disease mortality (nephritis, nephrotic syndrome, and nephrosis) was found in the population living within 2 km of the industrial plants (standardised mortality ratio (SMR) in males 131 (95% CI 90 to 185) and females 161 (95% CI 118 to 214)) compared to a reference population (northwest England)). Risk of hospital admissions for kidney disease in Halton (comprising the towns of Runcorn and Widnes) was higher than in the less industrial, nearby town of Warrington. The standardised admission ratio (SAR) in Halton was 115 (95% CI 107 to 124) for males and 126 (95% CI 117 to 137) for females; and in Warrington 91 (95% CI 85 to 97) for males and 84 (95% CI 78 to 91) for females compared to the Warrington and Halton area as a whole. The excess risk of kidney disease in the Runcorn area requires further investigation.

Land contamination and urinary abnormalities: cause for concern?

AIMS: To determine the prevalence of proteinuira and enzymuria among a cohort of subjects exposed to hexachlorobutadiene (HCBD) in their homes and to determine whether there was a change in observed effects when exposure ceased. METHODS: Residents underwent a health check, which included a panel of urinary markers of both glomerular and tubular origin, within two months of cessation of long term exposure to HCBD and again at least 10 months after exposure ceased. Analysis of the results was performed to determine if there was any early evidence of renal effects, and to ascertain whether changes in these parameters occurred after exposure to HCBD ceased. RESULTS: Tubular proteinuria and enzymuria were increased in the initial health check and significantly decreased after the residents had left their homes for about 10 months. As the early renal tubular markers improved when exposure ceased it is anticipated that the long term nephrotoxic risk will be minimal, but the carcinogenic risk remains unknown. CONCLUSIONS: Results show there was a renal effect which improved when subjects left their homes. This suggests there was a local environmental factor responsible for the observations. This is consistent with the predicted toxicological effects of HCBD from animal studies.

Improving clinical processes: one dialysis facility's experiences.

Northeast Louisiana Dialysis Center implemented continuous quality improvement (CQI) to improve the quality of care delivered to end stage renal disease (ESRD) patients treated by hemodialysis in their facility. The unit chose to address normalization of calcium and phosphorus and parathyroid hormone (PTH), anemia, nutrition, adequacy of dialysis and dialyzer reuse as well as performance benchmarks by the Health Care Financing Administration (HCFA) core indicators. This article presents the results obtained and the methodology used in this improvement effort. The article also presents nine principles the authors believe necessary for a successful CQI program.

Lenticular chalcosis--electron microscopic and microprobe analysis. A case report.

A patient with a retained intra-ocular foreign body had a lens extraction for lenticular chalcosis. The lens capsule, examined under an electron microscope, showed copper particles deposited in the basement membrane. The lens capsule and foreign body were examined with an electron microprobe beam. This method proved to be an efficient method of qualitative and quantitative analysis of the contents of the foreign body.