Objectives Many randomised trials use stratified permuted blocks or minimisation to balance key prognostic variables between treatment groups. It is widely argued in the statistical literature that any balancing variables should be adjusted for in the analysis, however a review of major medical journals shows that this is not commonly done. Our objective was to determine the effects of an unadj...

Gauge theory is a theory with constraints and, for that reason, the space of physical states is not a manifold but a stratified space (orbifold) with singularities. The classification of strata for smooth (and generalized) connections is reviewed as well as the formulation of the physical space as the zero set of a momentum map. Several important features of nongeneric strata are discussed and ...

The present study examines how the use of social network sites (SNS) increases the potential of experiencing psychological, reputational and physical vulnerability online. From our theoretical perspective, concerns over the use of social network sites and online vulnerability stem from the ease with which users can amass large and diverse sets of online social connections and the associated mai...

This study investigates the relationships between predictors (i.e., personal traits and mobile activities) of smartphone dependency and its impacts on improper phone use, academic performance and perceived sociability. Using a stratified sampling method, a web survey obtained data from 438 undergraduate smartphone users in Singapore. PLS results show that improper phone use is a critical factor...

Stratified medicine requires identifying predictive markers to determine differential treatment effects for subgroups. Ideally, these markers are then validated in prospective randomised trials. However, many of the methods for the analysis and validation of markers are based on there being a single marker. For example, a biomarker stratified trial design typically stratifies on a single binary...

A national web-based survey was administered to 700 undergraduate computer science programs in the United States as part of a stratified random sample of 797 undergraduate computer science programs. The 251 program responses (36% response rate) regarding social and professional issues are presented. This article describes the demographics of the respondents, presents results concerning whether ...

These notes are part of the first chapter of a series of lectures given by the author in the spring of 1970. The ultimate aim of these notes will be to prove the theorem that the set of topologically stable mappings form a dense subset of C∞(N,P ) for any finite dimensional manifolds N and P where N is compact. The first chapter is a study of Thom–Whitney theory of stratified sets and stratifie...

Business performance is affected by the quality management practices of the organization. Holistic programs, including the national quality award programs, six-sigma initiatives, and enterprise resource planning (ERP) applications may characterize the highest level of quality initiatives. Arguably, the most popular quality initiative is the ISO 9000 program. The effect of different levels of qu...

Approximately every 10 years the fixed market basket of commodities and services supporting the Consumer Price Index is updated in a process referred to as a revision of the index. Samples of specific items in the fixed market basket are selected within a newly designed, stratified sample of geographic areas on a continuing rotation basis. The prices of the specific items are quoted every month...

The present longitudinal study described developmental patterns of perceived psychological need satisfaction (PNS) from the end of elementary school to the end of high school and their contribution to school adjustment at the end of high school. The first goal thus consisted in estimating whether developmental trajectories of perceived PNS were homogeneous (i.e., all students reported similar d...