A Practical Guide to Calculating Cohen’s f2, a Measure of Local Effect Size, from PROC MIXED

Reporting effect sizes in scientific articles is increasingly widespread and encouraged by journals; however, choosing an effect size for analyses such as mixed-effects regression modeling and hierarchical linear modeling can be difficult. One relatively uncommon, but very informative, standardized measure of effect size is Cohen’s f2, which allows an evaluation of local effect size, i.e., one variable’s effect size within the context of a multivariate regression model. Unfortunately, this measure is often not readily accessible from commonly used software for repeated-measures or hierarchical data analysis. In this guide, we illustrate how to extract Cohen’s f2 for two variables within a mixed-effects regression model using PROC MIXED in SAS® software. Two examples of calculating Cohen’s f2 for different research questions are shown, using data from a longitudinal cohort study of smoking development in adolescents. This tutorial is designed to facilitate the calculation and reporting of effect sizes for single variables within mixed-effects multiple regression models, and is relevant for analyses of repeated-measures or hierarchical/multilevel data that are common in experimental psychology, observational research, and clinical or intervention studies

Internally-Developed Teen Smoking Cessation Programs: Characterizing the Unique Features of Programs Developed by Community-Based Organizations

We have compared the unique features of teen tobacco cessation programs developed internally by community-based organizations (N=75) to prepackaged programs disseminated nationally (N=234) to expand our knowledge of treatment options for teen smokers. Internally-developed programs were more likely offered in response to the sponsoring organization’s initiative (OR=2.16, p<0.05); had fewer trained cessation counselors (OR=0.31, p<0.01); and were more likely found in urban areas (OR=2.89, p=0.01). Internally-developed programs more often provided other substance-abuse treatment services than prepackaged programs and addressed other youth-specific problem behaviors (p≤0.05). Studies that examine the effectiveness of internally-developed programs in reducing smoking and maintaining cessation for teen smokers are warranted

Communications Biophysics

Contains reports on six research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-02

Neutrality of Molecules by the Pulsed Gas Flow Method

Contains an introduction and a description on one research project.F.L. Friedman Chai

Structure-Guided Molecular Grafting Of A Complex Broadly Neutralizing Viral Epitope

Antigenic variation and viral evolution have thwarted traditional influenza vaccination strategies. The broad protection afforded by a “universal” influenza vaccine may come from immunogens that elicit humoral immune responses targeting conserved epitopes on the viral hemagglutinin (HA), such as the receptor-binding site (RBS). Here, we engineered candidate immunogens that use noncirculating, avian influenza HAs as molecular scaffolds to present the broadly neutralizing RBS epitope from historical, circulating H1 influenzas. These “resurfaced” HAs (rsHAs) remove epitopes potentially targeted by strain-specific responses in immune-experienced individuals. Through structure-guided optimization, we improved two antigenically different scaffolds to bind a diverse panel of pan-H1 and H1/H3 cross-reactive bnAbs with high affinity. Subsequent serological and single germinal center B cell analyses from murine prime-boost immunizations show that the rsHAs are both immunogenic and can augment the quality of elicited RBS-directed antibodies. Our structure-guided, RBS grafting approach provides candidate immunogens for selectively presenting a conserved viral epitope

Communications Biophysics

Contains reports on four research projects.National Institutes of Health (Grant MH-04737-03)National Science Foundation (Grant G-16526)National Aeronautics and Space Administration (Grant NsG-496