Responder Identification in Clinical Trials with Censored Data

We present a newly developed technique for identification of positive and negative responders to a new treatment which was compared to a classical treatment (or placebo) in a randomized clinical trial. This bump-hunting-based method was developed for trials in which the two treatment arms do not differ in survival overall. It checks in a systematic manner if certain subgroups, described by predictive factors do show difference in survival due to the new treatment. Several versions of the method were discussed and compared in a simulation study. The best version of the responder identification method employs martingale residuals to a prognostic model as response in a stabilized through bootstrapping bump hunting procedure. On average it recognizes 90% of the time the correct positive responder group and 99% of the time the correct negative responder group

On the Total Amount of Neutral Hydrogen in the Upper Atmosphere of the Earth

Total neutral hydrogen in earths upper atmospher

Observations of Scattered L Alpha Emission in the Vicinity of the Earth and in the Interplanetary Medium

Ultraviolet photometer measurements in earth vicinity, and in interplanetary medium onboard interplanetary space prob

SN Shock Evolution in the Circumstellar Medium surrounding SN 1987A

We study the structure of the circumstellar medium surrounding SN 1987A in the equatorial plane. Furthermore, we study the evolution of the SN shock within this medium during the first 25 years, and the resulting hard X-ray and radio emission from the remnant.Comment: 5 pages, 3 Figures. To be published in the proceedings of the conference on "Supernova 1987A: 20 Years After: Supernovae and Gamma-Ray Bursters" AIP, New York, eds. S. Immler, K.W. Weiler, and R. McCra

HAVE INCENTIVE BASED POLICIES BEEN OVERSOLD?

Comparisons of alternative pollution control instruments over the past thirty years show quite disparate results for seemingly comparable situations. This research demonstrates how the magnitude of the estimated cost savings associated with incentive-based instruments is influenced by two important factors: (i) separability assumptions between emissions and output, and (ii) participation criteria.Environmental Economics and Policy,