RESUMEN
Dissolved organic carbon (DOC) is a significant organic carbon reservoir in many ecosystems, and its characteristics and sources determine many aspects of ecosystem health and water quality. Fluorescence spectroscopy methods can quantify and characterize the subset of the DOC pool that can absorb and re-emit electromagnetic energy as fluorescence and thus provide a rapid technique for environmental monitoring of DOC in lakes and rivers. Using high resolution fluorescence techniques, we characterized DOC in the Tualatin River watershed near Portland, Oregon, and identified fluorescence parameters associated with effluent from two wastewater treatment plants and samples from sites within and outside the urban region. Using a variety of statistical approaches, we developed and validated a multivariate linear regression model to predict the amount of wastewater in the river as a function of the relative abundance of specific fluorescence excitation/emission pairs. The model was tested with independent data and predicts the percentage of wastewater in a sample within 80% confidence. Model results can be used to develop in situ instrumentation, inform monitoring programs, and develop additional water quality indicators for aquatic systems.
Asunto(s)
Monitoreo del Ambiente/métodos , Ríos , Eliminación de Residuos Líquidos , Carbono/análisis , Ciudades , Modelos Lineales , Oregon , Espectrometría de Fluorescencia , Contaminantes del Agua/análisisRESUMEN
A case is reported of spontaneous coronary dissection in a 55-year-old patient with an anterior myocardial infarction treated by intravenous thrombolysis. The angiographic appearance was highly characteristic with successive opacification of the true then the false channel involving the entire distal third of the anterior interventricular artery. The outcome was immediately favourable. Spontaneous dissection of coronary arteries is rare. The etiology is discussed and there is not standard management approach.