Fitting Linear Mixed-Effects Models Using lme4
TLDR
In this article, a model is described in an lmer call by a formula, in this case including both fixed-and random-effects terms, and the formula and data together determine a numerical representation of the model from which the profiled deviance or the profeatured REML criterion can be evaluated as a function of some of model parameters.Abstract:
Maximum likelihood or restricted maximum likelihood (REML) estimates of the parameters in linear mixed-effects models can be determined using the lmer function in the lme4 package for R. As for most model-fitting functions in R, the model is described in an lmer call by a formula, in this case including both fixed- and random-effects terms. The formula and data together determine a numerical representation of the model from which the profiled deviance or the profiled REML criterion can be evaluated as a function of some of the model parameters. The appropriate criterion is optimized, using one of the constrained optimization functions in R, to provide the parameter estimates. We describe the structure of the model, the steps in evaluating the profiled deviance or REML criterion, and the structure of classes or types that represents such a model. Sufficient detail is included to allow specialization of these structures by users who wish to write functions to fit specialized linear mixed models, such as models incorporating pedigrees or smoothing splines, that are not easily expressible in the formula language used by lmer.read more
Citations
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Breaking the prejudice habit: Mechanisms, timecourse, and longevity.
TL;DR: The results suggest that the habit-breaking intervention produces enduring changes in peoples' knowledge of and beliefs about race-related issues, and it is argued that these changes are even more important for promoting long-term behavioral change than are changes in implicit bias.
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Biochemical Screening for Nonadherence Is Associated With Blood Pressure Reduction and Improvement in Adherence.
Pankaj Gupta,Prashanth Patel,Prashanth Patel,Prashanth Patel,Branislav Štrauch,Florence Lai,Artur Akbarov,Gaurav S Gulsin,Alison Beech,Věra Marešová,Peter S. Topham,Adrian G. Stanley,Herbert Thurston,Paul R. Smith,Rob Horne,Jiří Widimský,Bernard Keavney,Anthony M. Heagerty,Nilesh J. Samani,Bryan Williams,Maciej Tomaszewski +20 more
TL;DR: Data show that nonadherent hypertensive patients respond to liquid chromatography–tandem mass spectrometry-based biochemical analysis with improved adherence and significant BP drop, and such repeated biochemical analyses should be considered as a therapeutic approach in nonadherence hypertensive Patients.
Journal ArticleDOI
Assessing uncertainties in land cover projections
Peter Alexander,Peter Alexander,Reinhard Prestele,Peter H. Verburg,Almut Arneth,Claudia Baranzelli,Filipe Batista e Silva,Calum Brown,Adam Butler,Katherine Calvin,Nicolas Dendoncker,Jonathan C. Doelman,Robert Dunford,Kerstin Engström,David A. Eitelberg,Shinichiro Fujimori,Paula A. Harrison,Tomoko Hasegawa,Petr Havlik,Sascha Holzhauer,Florian Humpenöder,Chris Jacobs-Crisioni,Atul K. Jain,Tamás Krisztin,Page Kyle,Carlo Lavalle,Timothy M. Lenton,Jiayi Liu,Prasanth Meiyappan,Alexander Popp,Tom Powell,Ronald D. Sands,Rüdiger Schaldach,Elke Stehfest,Jevgenijs Steinbuks,Andrzej Tabeau,Hans van Meijl,Marshall Wise,Mark Rounsevell +38 more
TL;DR: A higher degree of uncertainty exists in land use projections than currently included in climate or earth system projections, and it is recommended to use a diverse set of models and approaches when assessing the potential impacts of land cover change on future climate.
Journal ArticleDOI
Violating the normality assumption may be the lesser of two evils
Ulrich Knief,Wolfgang Forstmeier +1 more
TL;DR: In this article, Monte Carlo simulations were used to explore the pros and cons of fitting Gaussian models to non-normal data in terms of risk of type I error, power and utility for parameter estimation.
Journal ArticleDOI
Fading positive effect of biochar on crop yield and soil acidity during five growth seasons in an Indonesian Ultisol.
Gerard Cornelissen,Gerard Cornelissen,Jubaedah,Neneng L. Nurida,Sarah E. Hale,Vegard Martinsen,Ludovica Silvani,Jan Mulder +7 more
TL;DR: The fading effectiveness after multiple growth seasons, possibly due to leaching of the biochar-associated alkalinity, indicates that 15tha-1 of cocoa shell biochar needs to be applied approximately every third season in order to maintain positive effects on yield.
References
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TL;DR: Linear Mixed-Effects and Nonlinear Mixed-effects (NLME) models have been studied in the literature as mentioned in this paper, where the structure of grouped data has been used for fitting LME models.
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