![]() Gas liquid chromatography was used to detect hydrocarbons present at different depths in the sediment, while low resolution mass spectrometry was employed to measure concentrations of paraffins, cycloparaffins, aromatics and polynuclear aromatics. It has been demonstrated that 75 to 95% of Pb can be removed across the cell, in which a significant amount of the removed Pb can be electroplated at the cathode. Preliminary laboratory data demonstrate the feasibility of removing Pb, Cr, Cd, Ni, Cu, Zn, As, TCE, BTEX compounds, and phenol from soils (clays and sandy clayey deposits, and dredged sediments) using EO technology. Instead, the DMC must remain alert to react to surprises, turning a fundamentally hypothesis-generating ("data dredging") exercise into somewhat of a hypothesis-testing framework. While one can, and should, specify precisely the number of outcomes to evaluate for efficacy, by definition one carmot specify the number of hypotheses relevant to safety. Problems of multiplicity abound-many outcomes and many looks conspire to muddle the sample space and therefore make probabilities ill defined. In looking for safety signals, the DMC searches for the unknown, the rare unexpected event. Monitoring for safety presents statistically difficult problems. It is essentially a quantitative signal detection method. It is a systematic screening for drug- event combinations that are being reported disproportionately. ![]() ĭata mining does not equal data dredging. Failure to adequately define end-points prospectively, and retrospective data dredging.
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