45 research outputs found
Averaging dependent effect sizes in meta-analysis: A cautionary note about procedures.
Sin resume
Testing Categorical Moderators in Mixed-Effects Meta-analysis in the Presence of Heteroscedasticity
Mixed-effects models can be used to examine the association between a categorical moderator and the magnitude of the effect size. Two approaches are available to estimate the residual between-studies variance, τ2res—namely, separate estimation within each category of the moderator versus pooled estimation across all categories. We examine, by means of a Monte Carlo simulation study, both approaches for τ2res estimation in combination with two methods, the Wald-type χ2 and F tests, to test the statistical significance of the moderator. Results suggest that the F test using a pooled estimate of τ2res across categories is the best option in most conditions, although the F test using separate estimates of τ2res is preferable if the residual heterogeneity variances are heteroscedastic
A methodological review of meta-analyses of the effectiveness of clinical psychology treatments
Guidelines for Reporting Systematic Reviews and Meta-analyses
Meta-analysis is an essential methodology that allows researchers to synthesize the scientific evidence available on a given research question. Due to its wide applicability in most applied research fields, it is really important that meta-analyses be written and reported appropriately. In this paper we propose some guidelines to report the results of a meta-analysis in a scientific journal as Annals of Psychology. Concretely, the structure for reporting a meta-analysis following its different stages is detailed. In addition, some recommendations related to the usual tasks when conducting a meta-analysis are provided. A recent meta-analysis focused on the psychological field is used to illustrate the guidelines proposed. Finally, some concluding remarks are presented. El meta-análisis es una metodología esencial que permite a los investigadores sintetizar la evidencia científica disponible sobre una determinada cuestión de investigación. Debido a su amplia aplicabilidad en la mayoría de los campos de investigación aplicados, es realmente importante que los meta-análisis se escriban y se reporten de manera apropiada. En este artículo proponemos pautas para reportar los resultados de un meta-análisis en una revista científica como Anales de Psicología. Concretamente, se detalla la estructura para reportar un meta-análisis siguiendo sus fases. Además, proporcionamos recomendaciones relacionadas con las tareas usuales en meta-análisis. Un meta-análisis reciente centrado en el campo de la psicología es usado para ilustrar las guías propuestas. Finalmente, presentamos algunas observaciones finales
Analysis of Categorical Moderators in Mixed-effects Meta-analysis:Consequences of Using Pooled vs. Separate Estimates of the Residual Between-studies Variances
Application of refrigeration for debittering table olives
During the process of making table olives, it is necessary to remove bitterness
caused by phenolic compounds like oleuropein. This debittering effect is achieved by degrading
these compounds into non-bitter ones that are beneficial for health due to their
antioxidant properties. One of the most used methods is alkaline debittering using NaOH
but the main drawback is the environmental impact generated by wastes and degradation
of high-value nutraceutical compounds in olives. Different olive debittering pre-treatments
followed by refrigeration storage at 5ºC during 90 days have been performed using
Ocal variety olives (Olea europaea L.) by combining heat, β- glucosidase and Lactobacillus
plantarum treatments. Oleuropein and hydroxytyrosol concentrations were determined
in olive pulp and brine. The data has been complemented with sensory tests. The treatment
with the best results was storage in refrigeration, which achieved significant debittering
and greater degradation of oleuropein, due to the action of endogenous enzymes
of the olives
Estimation of an overall standardized mean difference in random-effects meta-analysis if the distribution of random effects departs from normal
The Padua Inventory-Washington State University Revision of Obsessions and Compulsions:A Reliability Generalization Meta-analysis
A Reliability Generalization Meta-Analysis of the Padua Inventory of Obsessions and Compulsions
AbstractThe Padua Inventory (PI) of obsessions and compulsions is one of the most usually applied tests to assess obsessive-compulsive symptomatology in research contexts as well as for clinical and screening purposes. A reliability generalization meta-analysis was accomplished to estimate the average reliability of the PI scores and to search for characteristics of the samples and studies that can explain the variability among reliability estimates. An exhaustive literature search enabled us to select 39 studies (53 independent samples) that reported alpha and/or test-retest coefficients with the data at hand for the PI total score and subscales. An excellent average coefficient alpha was found for the PI total score (M= .935; 95%CI = .922–.949) and for Impaired Mental Control subscale (M= .911; 95%CI = .897–.924), being good for Contamination (M= .861; 95%CI = .841–.882) and Checking (M= .880; 95%CI = .856–.903), and fair for Urges and Worries (M= .783; 95%CI = .745–.822). The average test-retest reliability for PI total score was also satisfactory (M= .835; 95%CI = .782–.877). Moderator analyses showed larger coefficients alpha for larger standard deviation of the PI total scores (p= .0005;R2= .46), for adapted versions of the test (p= .002;R2= .32), and for samples composed of clinical participants (p= .066;R2= .10). The practical implications of these results are discussed as well as the need for researchers to report reliability estimates with the data at hand.</jats:p
Revisión y Control del Plan de Vigilancia Ambiental de las obras de dragado del Puerto de Maó
Se integra información hidrográfica, geomorfológica, sedimentológica y biológica, para la caracterización de los ecosistemas marinos en el punto de vertido y área adyacente previa al inicio de las obras de dragado del Puerto de Maó.RESUMEN: En este documento se presentan los trabajos científicos realizados por el Instituto Español de Oceanografía, dentro del Plan de Vigilancia Ambiental del dragado del Puerto de Maó (Menorca, Islas Baleares), para la caracterización de los ecosistema marino en el punto de vertido y área adyacente, previa al inicio de las obras. Se incluyen los resultados y las conclusiones de los estudios realizados por diversos grupos de investigación, principalmente en Enero-Marzo 2014, en relación al fondo marino, la hidrodinámica, las praderas de Posidonia oceanica y el molusco bivalvo Pinna nobilis, el macro-bentos de los fondos circalitorales blandos y los contaminantes en agua, sedimentos y biota, así como en especies de interés comercial para el consumo humano. Este informe se contempla en el contrato entre la Autoridad Portuaria de Baleares y el Instituto Español de Oceanografía, suscrito el 5 Febrero 2014, para los trabajos de asistencia técnica para la revisión y control del Plan de Vigilancia Ambiental del dragado del Puerto de Maó.RESUM: En aquest document es presenten els treballs científics realitzats per l’Instituto Español de Oceanografía, dins del Pla de Vigilància Ambiental del dragat del Port de Maó (Menorca, Illes Balears), per a la caracterització dels ecosistemes marins en el punt de vessament i àrea adjacent, prèvia a l’inici de les obres. S’inclouen els resultats i les conclusions del estudis realitzats per diversos grups de recerca, principalment durant Gener-Març 2014, en relació al fons marí, la hidrodinàmica, les praderies de Posidonia oceanica i el mol•lusc bivalve Pinna nobilis, el macro-bentos dels fons circalitorals tous i els contaminants en aigua, sediments i biota, així com en espècies d’interès comercial pel consum humà. Aquest informe es contempla en el contracte entre l’Autoritat Portuària de Balears i el Instituto Español de Oceanografía, subscrit el 5 Febrer 2014, pels treballs d’assistència tècnica per a la revisió i control del Pla de Vigilància Ambiental del dragat de Port de Maó.ABSTRACT: This document presents the scientific actions developed by the Instituto Español de Oceanografía within the Environmental Monitoring Plan of the works of dredging the Port of Maó (Minorca, Balearic Islands), for the characterization of the marine ecosystems in the point of discharge of dredged material and adjacent area, before the beginning of the dredging. The results and conclusions of the studies developed by several research groups, mainly in January-March 2014, in relation to the bottom, hydrodynamics, Posidonia oceanica meadows, and the bivalve mollusc Pinna nobilis, the macro-benthos of the circalittoral soft bottoms and the contaminants in water, sediments and biota, as well as in commercial species for human consumption, are included. This report is contemplated within the contract between the Autoridad Portuaria de Baleares and the Instituto Español de Oceanografía, signed on 5 February 2014, for the technical assistance activities to review and control the Environmental Monitoring Plan of the works of dredging the Port of Maó.Autoridad Portuaria de Baleare