Search results for "Meta-"
showing 10 items of 1069 documents
Review of the impact of biogas digestates on the microbiological quality of agricultural soils
2023
The global production of biogas has increased threefold during the last decade to partly replace fossil fuels, yet biogas production by anaerobic digestion generates substantial amounts of by-products named digestates. These biogas digestates can be recycled in soils to fertilize crops and to sequester carbon. However, the impact of digestates on the soil biological is actually poorly known. Here we reviewed the impact of digestates published in 56 articles reporting 23 microbial parameters. Half of the articles show neutral effects of biogas digestates and 7% showed negative effects. 25% of the articles show more stimulation of biogas digestates for the soil microbial quality, compared to …
Programs' Efficacy to Develop Employable Skills for People With Functional Diversity: A Meta-Analysis
2021
Purpose: Promoting the labour integration of people with functional diversity is a key element to achieve their social inclusion. This meta-analysis aims to examine the effectiveness of experimental programs in developing employable skills for people with disabilities. Methods: Literature searches up to June 2019 were conducted in four databases (Web of Science, Scopus, PsycINFO and ERIC). Studies that met the following criteria were selected: (1) The program should develop employable skills; (2) the participants should be people with functional diversity; (3) the study should have a design with an experimental group and a control group as well as pretest and posttest measurements; (4) the …
Outcomes of hepatocellular carcinoma patients treated with sorafenib: a meta-analysis of Phase III trials
2019
Aim: To benchmark overall survival (OS) and time to radiological progression (TTP) of patients enrolled in randomized controlled trials (RCTs) assessing sorafenib in advanced hepatocellular carcinoma using individual participant survival data, and to meta-analyze prognostic factors for OS and TTP. Methods: RCTs were identified through literature search until December 2018. Individual participant survival was reconstructed with an algorithm from published Kaplan–Meier curves. Results: Ten RCTs were included. Median OS was 10.0 months (95% CI: 9.6–10.5), and median TTP was 4.1 months (95% CI: 3.8–4.3). Multivariable analyses showed HCV positivity, absence of macrovascular invasion and extra-…
Genome-wide association analysis identifies six new loci associated with forced vital capacity
2014
Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P <5 x 10(-8)) with FVC in or near EFEMP1, BMP6, MIR129-2-HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispani…
Testing for homogeneity in meta-analysis I. The one-parameter case: standardized mean difference.
2010
Meta-analysis seeks to combine the results of several experiments in order to improve the accuracy of decisions. It is common to use a test for homogeneity to determine if the results of the several experiments are sufficiently similar to warrant their combination into an overall result. Cochran's Q statistic is frequently used for this homogeneity test. It is often assumed that Q follows a chi-square distribution under the null hypothesis of homogeneity, but it has long been known that this asymptotic distribution for Q is not accurate for moderate sample sizes. Here, we present an expansion for the mean of Q under the null hypothesis that is valid when the effect and the weight for each s…
Assessing the quality of studies in meta-research: Review/guidelines on the most important quality assessment tools
2020
Systematic reviews and meta-analyses pool data from individual studies to generate a higher level of evidence to be evaluated by guidelines. These reviews ultimately guide clinicians and stakeholders in health-related decisions. However, the informativeness and quality of evidence synthesis inherently depend on the quality of what has been pooled into meta-research projects. Moreover, beyond the quality of included individual studies, only a methodologically correct process, in relation to systematic reviews and meta-analyses themselves, can produce a reliable and valid evidence synthesis. Hence, quality of meta-research projects also affects evidence synthesis reliability. In this overview…
A multi-local optimization algorithm
1998
The development of efficient algorithms that provide all the local minima of a function is crucial to solve certain subproblems in many optimization methods. A “multi-local” optimization procedure using inexact line searches is presented, and numerical experiments are also reported. An application of the method to a semi-infinite programming procedure is included.
Comments on "Identifying inconsistency in network meta-analysis: Is the net heat plot a reliable method?"
2021
One of the biggest challenges for network meta‐analysis is inconsistency, which occurs when the direct and indirect evidence conflict. Inconsistency causes problems for the estimation and interpretation of treatment effects and treatment contrasts. Krahn and colleagues proposed the net heat approach as a graphical tool for identifying and locating inconsistency within a network of randomized controlled trials. For networks with a treatment loop, the net heat plot displays statistics calculated by temporarily removing each design one at a time, in turn, and assessing the contribution of each remaining design to the inconsistency. The net heat plot takes the form of a matrix which is displaye…
Assessing covariate imbalance in meta-analysis studies.
2010
The main goal of meta-analysis is to combine data across studies or data sets to obtain summary estimates. In this paper, the novelty is to propose a statistical tool to assess a possible covariate imbalance in baseline variables to investigate similarity of trials. We conducted the detection of the covariate imbalance, first, through some graphical comparison of the empirical cumulative distribution functions or ECDFs, which are built by putting together arms or trials according to some risk factor, and second, through some non-parametric tests such as the Kolmogorov–Smirnov and the Anderson–Darling tests. To overcome the huge presence of ties, we conducted the statistical tests on perturbe…
A meta-analysis of distributed leadership from 2002 to 2013 : Theory development, empirical evidence and future research focus
2015
This article provides a meta-analysis of research conducted on distributed leadership from 2002 to 2013. It continues the review of distributed leadership commissioned by the English National College for School Leadership (NCSL) ( Distributed Leadership: A Desk Study, Bennett et al., 2003), which identified two gaps in the research during the 1996–2002 period. The review found that the studies had been unable to conceptualise distributed leadership or empirically outline its application. The two research gaps identified by Bennett et al. (2003) constitute the focus of the present review, which attempts to determine whether recent research has been able to fill these gaps. Based on the find…