Optimal sampling locations to reduce uncertainty in contamination extent in water distribution systems.

Drinking water utilities rely on samples collected from the distribution system to provide assurance of water quality. If a water contamination incident is suspected, samples can be used to determine the source and extent of contamination. By determining the extent of contamination, the percentage of the population exposed to contamination, or areas of the system unaffected can be identified. Using water distribution system models for this purpose poses a challenge because significant uncertainty exists in the contamination scenarios (e.g., injection location, amount, duration, customer demands, contaminant characteristics). This article outlines an optimization framework to identify strategic sampling locations in water distribution systems. The framework seeks to identify the best sampling locations to quickly determine the extent of the contamination while considering uncertainty with respect to the contamination scenarios. The optimization formulations presented here solve for multiple optimal sampling locations simultaneously and efficiently, even for large systems with a large uncertainty space. These features are demonstrated in two case studies.

Menkes' syndrome: an updated review.

Menkes' syndrome is an X-linked recessive multisystem disease which is usually fatal prior to 5 years of age. Though originally felt to be a disorder of copper deficiency, it now appears to be a copper storage disease, with the observed defects resulting from inappropriate systemic copper distribution. Disorders in the metabolism of metallothionein, a metalloprotein involved in cellular copper transport, may be the primary defect in this syndrome. This review summarizes the relevant clinical and pathologic findings seen in this condition to date. It also describes some of the abnormalities in the metabolism of copper and metallothionein in these infants.

Measurement of speech thresholds of Spanish-speaking children by non-Spanish speaking clinicians.

This study investigated the feasibility of a prerecorded speech threshold procedure that was used in a picture-pointing format, and was administered to Spanish-speaking children by non-Spanish-speaking clinicians. The derived Spanish word list was compared for equivalency to English spondees on a group of bilingual adults. The test, administered to 16 children ages three to six years, resulted in good agreement between SRT and pure-tone average. The test was found to be feasible, rapid, and reliable.