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Michael E Field

Publications and source records attributed to Michael E Field.

3 recordsLinked to original sources
PubMed2006

Quantity, composition, and source of sediment collected in sediment traps along the fringing coral reef off Molokai, Hawaii.

Sediment traps were used to evaluate the frequency, cause, and relative intensity of sediment mobility/resuspension along the fringing coral reef off southern Molokai (February 2000-May 2002). Two storms with high rainfall, floods, and exceptionally high waves resulted in sediment collection rates>1000 times higher than during non-storm periods, primarily because of sediment resuspension by waves. Based on quantity and composition of trapped sediment, floods recharged the reef flat with land-derived sediment, but had a low potential for burying coral on the fore reef when accompanied by high waves. The trapped sediments have low concentrations of anthropogenic metals. The magnetic properties of trapped sediment may provide information about the sources of land-derived sediment reaching the fore reef. The high trapping rate and low sediment cover indicate that coral surfaces on the fore reef are exposed to transient resuspended sediment, and that the traps do not measure net sediment accumulation on the reef surface.

Animals↗
PubMed2006

Right ventricular dysfunction and adverse outcome in patients with advanced heart failure.

BACKGROUND: In patients with heart failure (HF) from left ventricular systolic dysfunction, the presence of coexistent right ventricular (RV) dysfunction is associated with poor exercise capacity and reduced survival. We sought to determine whether a simple measure of RV function, the RV myocardial performance index (RV MPI), is associated with adverse outcome in a population of advanced heart failure patients selected to receive cardiac resynchronization therapy (CRT). METHODS AND RESULTS: The RV MPI was measured on 77 consecutive preimplantation echocardiograms. The relationship between RV MPI and the end point of all-cause mortality, transplantation, or ventricular assist device placement was evaluated. The end point occurred in 28 patients (36%) during a median follow-up of 21 months. The median RV MPI was 0.73 (interquartile range 0.51-0.89). Worse RV function, as demonstrated by a higher RV MPI, was seen in those patients who reached the end point compared with those who did not (0.83 vs. 0.69, P = .004). The highest tercile of RV MPI was associated with a 3.3-fold increased risk of poor outcome (95% CI 1.3-8.5). Each 0.1 unit increase in RV MPI was associated with a 16% increased risk (95% CI 8-26). After adjusting for other echocardiographic variables, RV MPI remained significantly associated with the outcome. CONCLUSION: In a population of advanced HF patients selected to receive CRT, RV dysfunction, as assessed by the RV MPI, is associated with adverse outcome. Wider use of this simple nongeometric parameter may help to identify patients for whom options for further intervention should be carefully evaluated.

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