OBJECTIVE The performance of association tests based on case-control or case-parents substudy alone can be improved by jointly using genetic data from two substudies. However, genetic data from different sources may not be combinable due to population stratification. We propose a two-stage association test based on using combinability tests in stage 1 and association tests in stage 2. METHODS...

For large data sets, it can be difficult or impossible to fit models with random effects using standard algorithms due to memory limitations or high computational burdens. In addition, it would be advantageous to use the abundant information to relax assumptions, such as normality of random effects. Motivated by data from an epidemiologic study of childhood growth, we propose a 2-stage method f...

One strategy for reducing the primary cesarean surgery rate and length of labor is using a peanut-shaped exercise ball for women laboring under epidural analgesia. A randomized, controlled study was conducted to determine whether use of a "peanut ball" decreased length of labor and increased the rate of vaginal birth. Women who used the peanut ball (n = 107) versus those who did not (n = 91) de...

The impossibility result by Jehiel and Moldovanu says that in a setting with interdependent valuations, any efficient and ex-post incentive compatible mechanism must be a constant mechanism. Mezzetti circumvents this problem by designing a two stage mechanism where the decision of allocation and payment are split over the two stages. This mechanism is elegant, however keeps a major weakness. In...

It is often assumed that a two-stage filter-process is involved in the coding of visual contours. In the first stage the contour is coded by localized luminance filters selective for, among other dimensions, orientation and spatial frequency. A second stage then integrates the outputs of these local luminance filters over space. In the experiments described here we address the issue of which sp...

Traditional drug development consists of a sequence of independent trials organized in different phases. Full development typically involves (i) a learning phase II trial and (ii) one or two confirmatory phase III trial(s). For example, in the phase II trials several doses of the new compound might be compared to a control and/or placebo with the goal of deciding whether to stop or continue dev...

Two-stage randomized trials are growing in importance in developing adaptive treatment strategies, i.e. treatment policies or dynamic treatment regimes. Usually, the first stage involves randomization to one of the several initial treatments. The second stage of treatment begins when an early nonresponse criterion or response criterion is met. In the second-stage, nonresponding subjects are re-...

Mexico has engaged in many trade agreements that have left unaffected internal competition, being one of the most trade-opened countries in the world is also one of the most restrictive regarding product market competition. For developing countries, this is a field to study that still need to be undertaken. This paper relates informality in the Mexican labor markets outcomes with market competi...

BACKGROUND This study aims to remodel the Broselow Pediatric Emergency Tape for the Indian pediatric population. The Broselow tape overestimates the heights of the Indian pediatric population and remits inaccurate predicted weights for all color zones with varying degrees and could result in overresuscitation of Indian children in emergency settings. The Indian children are underweight for thei...

Object recognition relies on a series of transformations among which only the first cortical stage is relatively well understood. Already at the second stage, the visual area V2, the complexity of the transformation precludes a clear understanding of what specifically this area computes. Previous work has found multiple types of V2 neurons, with neurons of each type selective for multi-edge fea...