15 research outputs found
Final Report of the Task Force to Promote Equity of Opportunity for Women in the Public School System
Summary of the Final Report of the Task Force to Promote Equity of Opportunity for Women in the Public School System
TESS Discovery of a Transiting Super-Earth in the Mensae System
We report the detection of a transiting planet around Mensae (HD
39091), using data from the Transiting Exoplanet Survey Satellite (TESS). The
solar-type host star is unusually bright (V=5.7) and was already known to host
a Jovian planet on a highly eccentric, 5.7-year orbit. The newly discovered
planet has a size of and an orbital period of 6.27
days. Radial-velocity data from the HARPS and AAT/UCLES archives also displays
a 6.27-day periodicity, confirming the existence of the planet and leading to a
mass determination of . The star's proximity and
brightness will facilitate further investigations, such as atmospheric
spectroscopy, asteroseismology, the Rossiter--McLaughlin effect, astrometry,
and direct imaging.Comment: Accepted for publication ApJ Letters. This letter makes use of the
TESS Alert data, which is currently in a beta test phase. The discovery light
curve is included in a table inside the arxiv submissio
Adjusting for multiple prognostic factors in the analysis of randomised trials
Background: When multiple prognostic factors are adjusted for in the analysis of a randomised trial, it is unclear (1) whether it is necessary to account for each of the strata, formed by all combinations of the prognostic factors (stratified analysis), when randomisation has been balanced within each stratum (stratified randomisation), or whether adjusting for the main effects alone will suffice, and (2) the best method of adjustment in terms of type I error rate and power, irrespective of the randomisation method.
Methods: We used simulation to (1) determine if a stratified analysis is necessary after stratified randomisation, and (2) to compare different methods of adjustment in terms of power and type I error rate. We considered the following methods of analysis: adjusting for covariates in a regression model, adjusting for each stratum using either fixed or random effects, and Mantel-Haenszel or a stratified Cox model depending on outcome.
Results: Stratified analysis is required after stratified randomisation to maintain correct type I error rates when (a) there are strong interactions between prognostic factors, and (b) there are approximately equal number of patients in each stratum. However, simulations based on real trial data found that type I error rates were unaffected by the method of analysis (stratified vs unstratified), indicating these conditions were not met in real datasets. Comparison of different analysis methods found that with small sample sizes and a binary or time-to-event outcome, most analysis methods lead to either inflated type I error rates or a reduction in power; the lone exception was a stratified analysis using random effects for strata, which gave nominal type I error rates and adequate power.
Conclusions: It is unlikely that a stratified analysis is necessary after stratified randomisation except in extreme
scenarios. Therefore, the method of analysis (accounting for the strata, or adjusting only for the covariates) will not generally need to depend on the method of randomisation used. Most methods of analysis work well with large
sample sizes, however treating strata as random effects should be the analysis method of choice with binary or
time-to-event outcomes and a small sample size
Focus on the Environment piece on the Land for Maine\u27s Future (LMF) program, w
Focus on the Environment piece on the Land for Maine\u27s Future (LMF) program, which since 1987 has backed land conservation efforts. LMF\u27s existing funds are fully committed, and because of the Legislature\u27s failure to send a new bond issue to the voters this fall, the forward momentum of the program is threatened. There is the risk that important opportunities to conserve land will be lost in the hot real estate market. LMF\u27s rails-to-trails project in Aroostook County has attracted thousands of snowmobilers and given the county an economic boost. Breaking up the millions of acres comprising Maine\u27s timber basket in the north woods could compromise production, a challenge that LMF has addressed
Evaluating the Economic Benefits of Land Conservation in Maine, June 2011
https://digitalmaine.com/lmf_docs/1000/thumbnail.jp
Evaluating the Economic Benefits of Land Conservation in Maine, June 2011
https://digitalmaine.com/lmf_docs/1000/thumbnail.jp