Dimension reduction and mixed-effects model for microarray meta-analysis of cancer

10.2741/2878 ◽  
2008 ◽  
Vol 13 (13) ◽  
pp. 2714 ◽  
Author(s):  
Tianwei Yu
Keyword(s):  
Dimension Reduction ◽  
Meta Analysis ◽  
Mixed Effects ◽  
Mixed Effects Model

A meta-analysis using a logit non-linear mixed effects model for ‘Hass’ avocado postharvest performance data

2013 ◽  
Vol 86 ◽  
pp. 134-140 ◽  
Author(s):  
Jeremy Burdon ◽  
Patrick Connolly ◽  
Nihal de Silva ◽  
Nagin Lallu ◽  
Jonathan Dixon ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Mixed Effects ◽  
Performance Data ◽  
Mixed Effects Model ◽  
Linear Mixed Effects Model ◽  
Linear Mixed Effects ◽  
Non Linear ◽  
Hass Avocado

scholarly journals Heterogeneous Heterogeneity by Default: Testing Categorical Moderators in Random-effects Meta-Analysis

2021 ◽  
Author(s):  
Josue E. Rodriguez ◽  
Donald Ray Williams ◽  
Paul - Christian Bürkner
Keyword(s):  
Statistical Power ◽  
Type I Error ◽  
Meta Analysis ◽  
Mixed Effects ◽  
Error Rates ◽  
Mixed Effects Model ◽  
Scale Model ◽  
Type I ◽  
Sample Sizes ◽  
Unequal Variances

Categorical moderators are often included in mixed-effects meta-analysis to explain heterogeneity in effect sizes. An assumption in tests of moderator effects is that of a constant between-study variance across all levels of the moderator. Although it rarely receives serious thought, there can be drastic ramifications to upholding this assumption. We propose that researchers should instead assume unequal between-study variances by default. To achieve this, we suggest using a mixed-effects location-scale model (MELSM) to allow group-specific estimates for the between-study variances. In two extensive simulation studies, we show that in terms of Type I error and statistical power, nearly nothing is lost by using the MELSM for moderator tests, but there can be serious costs when a mixed-effects model with equal variances is used. Most notably, in scenarios with balanced sample sizes or equal between-study variance, the Type I error and power rates are nearly identical between the mixed-effects model and the MELSM. On the other hand, with imbalanced sample sizes and unequal variances, the Type I error rate under the mixed-effects model can be grossly inflated or overly conservative, whereas the MELSM excellently controlled the Type I error across all scenarios. With respect to power, the MELSM had comparable or higher power than the mixed-effects model in all conditions where the latter produced valid (i.e., not inflated) Type 1 error rates. Altogether, our results strongly support that assuming unequal between-study variances is preferred as a default strategy when testing categorical moderators

scholarly journals A flexible nonlinear mixed effects model for HIV viral load rebound after treatment interruption

2020 ◽  
Vol 39 (15) ◽  
pp. 2051-2066 ◽  
Author(s):  
Rui Wang ◽  
Ante Bing ◽  
Cathy Wang ◽  
Yuchen Hu ◽  
Ronald J. Bosch ◽  
...  
Keyword(s):  
Viral Load ◽  
Treatment Interruption ◽  
Mixed Effects ◽  
Mixed Effects Model ◽  
Nonlinear Mixed Effects ◽  
Hiv Viral Load ◽  
Nonlinear Mixed Effects Model ◽  
Viral Load Rebound

scholarly journals The state of Spanish /s/ variation in Concepción, Chile: Linguistic and social trends

2020 ◽  
Vol 6 (1) ◽  
pp. 132-153
Author(s):  
Brandon M. A. Rogers
Keyword(s):  
Social Factors ◽  
Central City ◽  
Mixed Effects ◽  
The State ◽  
Mixed Effects Model ◽  
Proportional Odds ◽  
Random Factor ◽  
Social Trends ◽  
Southern Central ◽  
Social Demographics

AbstractThe current study examines /s/ variation in the southern-central city of Concepción, Chile and its relation to a variety of linguistic and social factors. A proportional-odds mixed effects model, with the random factor of “speaker”, was used to treat the categorically coded data on a continuum of acoustical variation ([s] > [h] > ∅). The results presented show that contrary to the previous assertions, heavy sibilant reduction, especially elision, in Concepción, Chile is the rule, rather than the exception, to the extent that it is no longer a marker of certain social demographics as has been reported previously. Furthermore, based on the trends reported, it is likely that this has been the case for several decades. Finally, the overall observed trends are indicative that the rates of /s/ elision will continue to increase across social demographics and different phonetic and phonological contexts in Concepción, Chile.

Sign in / Sign up

Export Citation Format

Share Document