Guidelines for analysis and reporting of clinical trials in oncology.

When analyzing and reporting the results of clinical trials, investigators should follow a simple approach. The purpose of a trial is to estimate an effect or treatment difference, which if present would have clinical utility when treating new patients. Procedures or methods that do not facilitate precisely and impartially estimating and reporting the treatment effect are likely to mislead investigators. Most often in clinical trials, investigators are interested in estimates of risk ratios (specifically odds or hazard ratios) between the treatment groups or levels of a prognostic factor. These simple ideas suggest that the most useful results from clinical trials will be estimated risk ratios and their confidence limits. Especially in cancer, where disease progression, recurrence, and death are common events following treatment, estimates of risk difference are very relevant. Hypothesis tests and associated P-values, although often (or exclusively) reported, are of lesser utility because they do not fully summarize the data. These recommendations may be seen by some investigators to be contrary to accepted practice. It is true that they are somewhat contrary to common practice but their general acceptance is evident in many journals and presentations by clinical trial methodologists. Despite some disagreement among statisticians regarding the need for adjustment of analyses for imbalanced prognostic factors, it is helpful to see if treatment effects change after accounting for imbalances. When this occurs, it may be of clinical interest. Although we discourage analyses that exclude any patients who meet the eligibility criteria, some circumstances will require that this be done (e.g., when a patient refuses to participate after randomization). Investigators should report, and emphasize as primary, those analyses that include all eligible patients. It is our hope and belief that analysis and reporting of trial results along the guidelines suggested here will result in impartial and useful information for journal readers

Cosmic Chemical Evolution

Numerical simulations of standard cosmological scenarios have now reached the degree of sophistication required to provide tentative answers to the fundamental question: Where and when were the heavy elements formed? Averaging globally, these simulations give a metallicity that increases from 1% of the solar value at $z=3$ to 20% at present. This conclusion is, in fact, misleading, as it masks the very strong dependency of metallicity on local density. At every epoch higher density regions have much higher metallicity than lower density regions. Moreover, the highest density regions quickly approach near solar metallicity and then saturate, while more typical regions slowly catch up. These results are much more consistent with observational data than the simpler picture (adopted by many) of gradual, quasi-uniform increase of metallicity with time.Comment: ApJ(Letters) in press, 15 latex pages and 4 figure

Spin-dependent observables in surrogate reactions

Observables emitted from various spin states in compound U nuclei are investigated to validate usefulness of the surrogate reaction method. It was found that energy spectrum of cascading $\gamma$-rays and their multiplicities, spectrum of evaporated neutrons, and mass-distribution of fission fragments show clear dependence on the spin of decaying nuclei. The present results indicate that they can be used to infer populated spin distributions which significantly affect the decay branching ratio of the compound system produced by the surrogate reactions

Optical Spatial integration methods for ambiguity function generation

A coherent optical spatial integration approach to ambiguity function generation is described. It uses one dimensional acousto-optic Bragg cells as input tranducers in conjunction with a space variant linear phase shifter, a passive optical element, to generate the two dimensional ambiguity function in one exposure. Results of a real time implementation of this system are shown