26 to 1.55; results were more biased when making these adjustments than when using the misclassified exposure values (ROR = 0.91). Conclusions: Making an incorrect
assumption about nondifferential or differential exposure misclassification in bias analyses can lead to more biased results than if no adjustment is performed. In our analyses, incorporating see more uncertainty using probabilistic bias analysis was not sufficient to overcome this problem.”
“Two methods are developed for constructing randomization-based confidence sets for the average effect of a treatment on a binary outcome. The methods are nonparametric and require no assumptions about random sampling from a larger population. Both of the resulting 1 – alpha confidence Selleckchem PLX4032 sets are exact in the sense that the probability of containing the true treatment effect is at least 1
– alpha. Both types of confidence sets are also guaranteed to have width no greater than one. In contrast, a previously proposed asymptotic confidence interval is not exact and may have width greater than 1. The first approach combines Bonferroni-adjusted prediction sets for the attributable effects in the treated and untreated. The second method entails inverting a permutation test. Simulations are presented comparing the two randomization-based confidence sets with the asymptotic interval as well as the standard Wald confidence interval and a commonly used exact interval for the difference in binomial proportions. Results show for small to moderate sample sizes that the permutation confidence set attains the narrowest width on average among the methods that CDK inhibitor maintain nominal coverage. Extensions that allow for stratifying on categorical baseline covariates are also discussed.
Copyright (C) 2014 John Wiley & Sons, Ltd.”
“Peatland carbon dioxide (CO2) exchange can vary spatially over a few meters because of the heterogeneity in plant communities, differing responses to environmental conditions, and the presence of pools in patterned peatlands. In contrast to the plant communities comprising a peatland’s vegetated surface, permanent pools that are characteristic of peatlands in temperate to subarctic regions are net sources of CO2 to the atmosphere. Measurements of net ecosystem CO2 exchange using the eddy covariance (EC) technique over peatlands without permanent pools do not show the smaller plant scale spatial heterogeneity in fluxes because the atmosphere mixes the variations in fluxes over the EC tower source area. However, if different vegetation communities and pools approach the spatial scale that they form a significant proportion of an EC tower’s source area, such as might be the case in peatlands with pools, they should be able to be discriminated if the surface fluxes by cover type are significantly different.