OBJECTIVES To find evidence, either corroborating or refuting, for many persisting beliefs regarding the feasibility of carrying out surgical randomised controlled trials with a placebo arm, with emphasis on the challenges related to recruitment, funding, anaesthesia or blinding. DESIGN Systematic review. DATA SOURCES AND STUDY SELECTION The analysis involved studies published between 1959 ...

Context. The current generation of X-ray observatories like Chandra allows studies with very fine spatial details. It is now possible to resolve X–ray point sources projected into the cluster diffuse emission and exclude them from the analysis to estimate the " correct " X–ray observables. Aims. We wish to verify the incidence of point sources on the cluster thermal emission and to evaluate the...

OBJECTIVES To describe the characteristics of randomised controlled trials supported by the main non-commercial sources of funding in the United Kingdom between 1980 and 2002. DESIGN Descriptive survey. SETTING Randomised controlled trials funded by the Medical Research Council, NHS research and development programme, Department of Health, Chief Scientist Office in Scotland, and medical res...

introduction water quality trading (wqt) is an economically incentive-based strategy that focuses on finding the optimal discharge permit market for surface water quality management. the amounts of traded discharge permits determine the interactions of emission sources in the market. pollutantsthat are able to provide extra permits can satisfy the demands of other participants for credits. find...

Dimensional Finite Element Model for Pollutant A Two Transport out of Dumped Disposal sites