York University

About: York University is a education organization based out in Toronto, Ontario, Canada. It is known for research contribution in the topics: Population & Politics. The organization has 18899 authors who have published 43357 publications receiving 1568560 citations.

Partialed products are interactions; partialed powers are curve components.

Abstract: The fact that simple (zero-order) correlations of products (XZ) and powers (X, X*) with other variables (Y) are not invariant over linear transformations of their constituents (X, Z) has led to confusion and anxiety about their use as independent variables in the representation of interactions and curve components in general multiple regression/correlation analysis. This article demonstrates that when their constituents are linearly partialed out, products and powers are invariant with regard to both their correlations and tests of significance; further, their raw score regression coefficients are simply rescaled. Partialed products and powers are not subject to constraints of orthogonality, level of scaling, or whether data arise from experiments or observational studies.

Micronuclei as an index of cytogenetic damage: Past, present, and future

Abstract: The workshop was designed to present what is known about the production of micronuclei, what protocols are now accepted or proposed internationally, what new results have been obtained, and what new methods and protocols are likely to be forthcoming. This report is designed to convey the flavour of the workshop and to provide the essence of the new information. After the workshop an effort was made to determine what single protocol would satisfy the requirements set for the micronucleus test by as many regulatory agencies as possible. The result, reported here, includes the requirements of six regulatory authorities in Canada, the European Economic Community, the Organization for Economic Co-operation and Development, Japan, and the United States.

A comparison of propensity score methods: a case-study estimating the effectiveness of post-AMI statin use.

Abstract: There is an increasing interest in the use of propensity score methods to estimate causal effects in observational studies. However, recent systematic reviews have demonstrated that propensity score methods are inconsistently used and frequently poorly applied in the medical literature. In this study, we compared the following propensity score methods for estimating the reduction in all-cause mortality due to statin therapy for patients hospitalized with acute myocardial infarction: propensity-score matching, stratification using the propensity score, covariate adjustment using the propensity score, and weighting using the propensity score. We used propensity score methods to estimate both adjusted treated effects and the absolute and relative risk reduction in all-cause mortality. We also examined the use of statistical hypothesis testing, standardized differences, box plots, non-parametric density estimates, and quantile-quantile plots to assess residual confounding that remained after stratification or matching on the propensity score. Estimates of the absolute reduction in 3-year mortality ranged from 2.1 to 4.5 per cent, while estimates of the relative risk reduction ranged from 13.3 to 17.0 per cent. Adjusted estimates of the reduction in the odds of 3-year death varied from 15 to 24 per cent across the different propensity score methods.

Attention and Automaticity in the Processing of Self-Relevant Information

Abstract: A neglected aspect of the study of social cognition has been the way in which people select information for further processing from the vast amount available in social environments. A major contemporary model of attention holds that there are two separate types of processes that operate concurrently: a flexible but resource-limited control process that regulates the contents of conscious awareness, and a relatively inflexible automatic process that can attract attention to stimuli without conscious intent. Passive automatic processes, can either facilitate or inhibit active attentional processing, necessitating either less or more attentional effort, depending on the characteristics of the information that is currently present. On a dichotic listening task in which subjects attended to or ignored self-relevant stimuli, it was found that self-relevant information required less attentional resources when presented to the attended channel, but more when presented to the rejected channel, relative to neutral words. This differential capacity allocation occurred despite subjects' lack of awareness of the contents of the rejected channel. The results supported the existence and interaction of the two processes of attention in social information processing.