scholarly journals The impacts of hydropower on freshwater macroinvertebrate richness: A global meta-analysis

2021 ◽  
Author(s):  
Gabrielle Trottier ◽  
Katrine Turgeon ◽  
Daniel Boisclair ◽  
Cécile Bulle ◽  
Manuele Margni
Keyword(s):  
Variance Estimation ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Hydroelectric Dams ◽  
Freshwater Biodiversity ◽  
Mixed Effect ◽  
Large Variability ◽  
Effect Model ◽  
Hydropower Dams ◽  
Study Designs

AbstractHydroelectric dams and their reservoirs have been suggested to affect freshwater biodiversity. However, studies investigating the consequences of hydroelectric dams and reservoirs on macroinvertebrate richness have reached opposite conclusions. We carried out a meta-analysis devised to elucidate the effects of hydropower dams and their reservoirs on macroinvertebrates richness while accounting for the potential role played by moderators such as biomes, impact types, study designs, sampling seasons and gears. We used a random and mixed effect model, combined with robust variance estimation, to conduct the meta-analysis on 72 pairs of observations (i.e., impacted versus reference) extracted from 17 studies (more than one observation per study). We observed a large range of effect sizes, from very negative to very positive impacts of hydropower. However, according to this meta-analysis, hydropower dams and their reservoirs did not have an overall clear, directional and statistically significant effect on macroinvertebrate richness. We tried to account for the large variability in effect sizes using moderators, but none of the moderators included in the meta-analysis had statistically significant effect. This suggests that some other moderators, which were unavailable for the 17 studies included in this meta-analysis, might be important (e.g., temperature, granulometry, wave disturbance and macrophytes) and that macroinvertebrate richness may be driven by local, smaller scale processes. As new studies become available, it would be interesting to keep enriching this meta-analysis, as well as collecting local habitat variables, to see if we could finally draw statistically significant conclusions about the impacts of hydropower on macroinvertebrate richness.

scholarly journals Effectiveness of Chitosan as a Dietary Supplement in Lowering Cholesterol in Murine Models: A Meta-Analysis

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 26
Author(s):  
Sung-Il Ahn ◽  
Sangbuem Cho ◽  
Nag-Jin Choi
Keyword(s):  
Meta Analysis ◽  
Random Effect ◽  
Random Effect Model ◽  
Hdl Cholesterol ◽  
Effect Sizes ◽  
Murine Models ◽  
Mixed Effect ◽  
Related Disease ◽  
Effect Model ◽  
Regression Test

This study presents a meta-analysis of studies that investigate the effectiveness of chitosan administration on lifestyle-related disease in murine models. A total of 34 published studies were used to evaluate the effect of chitosan supplementation. The effect sizes for various items after chitosan administration were evaluated using the standardized mean difference. Using Cochran’s Q test, the heterogeneity of effect sizes was assessed, after which a meta-ANOVA and -regression test was conducted to explain the heterogeneity of effect sizes using the mixed-effect model. Publication bias was performed using Egger’s linear regression test. Among the items evaluated, blood triglyceride and HDL-cholesterol showed the highest heterogeneity, respectively. Other than blood HDL-cholesterol, total cholesterol, and triglyceride in feces, most items evaluated showed a negative effect size with high significance in the fixed- and random-effect model (p < 0.0001). In the meta-ANOVA and -regression test, administering chitosan and resistant starch was revealed to be most effective in lowering body weight. In addition, chitosan supplementation proved to be an effective solution for serum TNF-α inhibition. In conclusion, chitosan has been shown to be somewhat useful in improving symptoms of lifestyle-related disease. Although there are some limitations in the results of this meta-analysis due to the limited number of animal experiments conducted, chitosan administration nevertheless shows promise in reducing the risk of cholesterol related metabolic disorder.

scholarly journals Effects of Diet, Aerobic Exercise, or Both on Non-HDL-C in Adults: A Meta-Analysis of Randomized Controlled Trials

Cholesterol ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
George A. Kelley ◽  
Kristi S. Kelley
Keyword(s):  
Aerobic Exercise ◽  
Randomized Controlled Trials ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Density Lipoprotein ◽  
Control Group ◽  
Controlled Trials ◽  
Mixed Effect ◽  
Randomized Controlled ◽  
Effect Model

Purpose. To use the meta-analytic approach to examine the effects of diet (D), aerobic exercise (E), or both (DE) on non-high-density lipoprotein cholesterol (non-HDL-C) in adults. Methods. Randomized controlled trials in adults ≥18 years of age were included. A mixed-effect model was used to combine effect size (ES) results within each subgroup and to compare subgroups (Qb). Heterogeneity was examined using the Q and I2 statistics, and 95% confidence intervals (CI) were also calculated. Statistical significance was set at P≤0.05, while a trend for statistical significance was set between P>0.05, and ≤0.10. Results. A statistically significant exercise minus control group decrease in non-HDL-C was found for DE (7 ESs, 389 participants, x¯=-11.1 mg/dL, 95%  CI=−21.7 to −0.6, P=0.04, Q=2.4, P=0.88, I2=0%), a trend for the D group (7 ESs, 402 participants, x¯=−8.5 mg/dL, 95%  CI=−18.6 to 1.6, P=0.10, Q=0.76, P=0.99, I2=0%), and no change for the E group (7 ESs, 387 participants, x¯=3.0 mg/dL, 95%   CI=−7.1 to 13.1, P=0.56, Q=0.78, P=0.99, I2=0%). Overall, no statistically significant between-group differences were found (Qb=4.1, P=0.12). Conclusions. Diet combined with aerobic exercise may reduce non-HDL-C among adults in some settings.

Test Frequency, Stakes, and Feedback in Student Achievement: A Meta-Analysis

2019 ◽  
Vol 43 (3-4) ◽  
pp. 111-151 ◽  
Author(s):  
Richard P. Phelps
Keyword(s):  
Student Achievement ◽  
Early Childhood ◽  
Effect Size ◽  
English Language ◽  
Variance Estimation ◽  
Meta Analysis ◽  
The United States ◽  
Research Literature ◽  
Effect Sizes ◽  
Test Frequency

Background: Test frequency, stakes associated with educational tests, and feedback from test results have been identified in the research literature as relevant factors in student achievement. Objectives: Summarize the separate and joint contribution to student achievement of these three treatments and their interactions via multivariable meta-analytic techniques using a database of English-language studies spanning a century (1910–2010), comprising 149 studies and 509 effect size estimates. Research design: Analysis employed robust variance estimation. Considered as potential moderators were hundreds of study features comprising various test designs and test administration, demographic, and source document characteristics. Subjects: Subjects were students at all levels, from early childhood to adult, mostly from the United States but also eight other countries. Results: We find a summary effect size of 0.84 for the three treatments collectively. Further analysis suggests benefits accrue to the incremental addition of combinations of testing and feedback or stakes and feedback. Moderator analysis shows higher effect sizes associated with the following study characteristics: more recent year of publication, summative (rather than formative) testing, constructed (rather than selected) item response formats, alignment of subject matter between pre- and posttests, and recognition/recall (rather than core subjects, art, or physical education). Conversely, lower effect sizes are associated with postsecondary students (rather than early childhood–upper secondary), special education population, larger study population, random assignment (rather than another sampling method), use of shadow test as outcome measure, designation of individuals (rather than groups) as units of analysis, and academic (rather than corporate or government) research.

P2482Sex-based differences in cardioprotective role of SGLT-2 inhibitors in patients with type 2 diabetes mellitus

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
N Madan ◽  
S Sohal ◽  
B Parapid ◽  
L Sperling ◽  
J L Januzzi ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Meta Analysis ◽  
Mixed Effect ◽  
Pooled Data ◽  
Major Cardiovascular Events ◽  
Effect Model

Abstract Background Randomized studies have shown that sodium-glucose cotransporter-2 inhibitors (SGLT2i) reduce major cardiovascular events in patients with type 2 diabetes mellitus. However, it is not known whether there are significant sex-based differences in the cardioprotective role of SGLT-2 inhibitors. Purpose To investigate whether sex differences exist in reduction of major cardiovascular events (MACE)in patients with type 2 diabetes mellitus when treated with SGLT2i. Methods A comprehensive PubMed search was conducted using keywords, (“Diabetes” AND (“Dapagliflozin” OR “Empagliflozin” OR “Canagliflozin” OR “Ertugliflozin”) AND “Outcomes”) that resulted in a total of 221 studies. Studies were included in our meta-analysis if they were randomized controlled trials, placebo-controlled, reported MACE as the primary outcome and reported sex-based subgroup analyses of these outcomes. Only 2 RCTs (EMPA-REG and DECLARE-TIMI 58) met our inclusion criteria.The sex-based event data for both trials was pooled to calculate risk ratios (RR) with 95% confidence intervals (CI). Analyses was performed using Comprehensive Meta-analysis (CMA) software. Fixed effect models, random effect models and mixed effect models were used. Results Pooled datafrom the 2 RCTs (EMPA-REG and DECLARE-TIMI 58) resulted in a total of 24,180 patients who were included in our primary analysis. Of these, 2331 patients were reported to have MACE. In our pooled data, SGLT2i reduced MACE in patients with diabetes with an overall risk ratio of 0.92 (0.85–0.99), p=0.03 (I2=0, p=0.31)using fixed effect model (Table 1). We also performed subgroup analysis of the pooled data categorizing by sex and using mixed effect model. Our subgroup analysis by sex showed a Q statistic of 1.88 with p-value of 0.17 suggesting that there is no significant difference in MACE reduction between men and women with diabetes when treated with SGLT2i. However, on further analyzing the sex differences in the individual trials, we found that women may have greater reduction in MACE compared with their male counterparts (RR in females: 0.66 (0.42–1.04); RR in males: 0.92 (0.84–1.00)), however this finding did not meet statistical significance (Table 2). Conclusion Our meta-analysis included the pooled data from 2 major RCTs (EMPA-REG and DECLARE-TIMI 58) assessing the cardioprotective role of SGLT2i in diabetic patients and shows that SGLT2i significantly reduce the risk of major adverse CV events in patients with type 2 diabetes mellitus. However, we did not find any significant sex-based differences in reduction of MACE between men and women with diabetes when treated with SGLT2i.

scholarly journals The Efficacy of Recasts in Language Intervention: A Systematic Review and Meta-Analysis

2015 ◽  
Vol 24 (2) ◽  
pp. 237-255 ◽  
Author(s):  
Patricia L. Cleave ◽  
Stephanie D. Becker ◽  
Maura K. Curran ◽  
Amanda J. Owen Van Horne ◽  
Marc E. Fey
Keyword(s):  
Systematic Review ◽  
Research Evidence ◽  
Meta Analysis ◽  
Language Intervention ◽  
Effect Sizes ◽  
Study Quality ◽  
Average Effect ◽  
Grammatical Development ◽  
Meta Analyses ◽  
Study Designs

Purpose This systematic review and meta-analysis critically evaluated the research evidence on the effectiveness of conversational recasts in grammatical development for children with language impairments. Method Two different but complementary reviews were conducted and then integrated. Systematic searches of the literature resulted in 35 articles for the systematic review. Studies that employed a wide variety of study designs were involved, but all examined interventions where recasts were the key component. The meta-analysis only included studies that allowed the calculation of effect sizes, but it did include package interventions in which recasts were a major part. Fourteen studies were included, 7 of which were also in the systematic review. Studies were grouped according to research phase and were rated for quality. Results Study quality and thus strength of evidence varied substantially. Nevertheless, across all phases, the vast majority of studies provided support for the use of recasts. Meta-analyses found average effect sizes of .96 for proximal measures and .76 for distal measures, reflecting a positive benefit of about 0.75 to 1.00 standard deviation. Conclusion The available evidence is limited, but it is supportive of the use of recasts in grammatical intervention. Critical features of recasts in grammatical interventions are discussed.

The Effectiveness of Direct Instruction Curricula: A Meta-Analysis of a Half Century of Research

2018 ◽  
Vol 88 (4) ◽  
pp. 479-507 ◽  
Author(s):  
Jean Stockard ◽  
Timothy W. Wood ◽  
Cristy Coughlin ◽  
Caitlin Rasplica Khoury
Keyword(s):  
Direct Instruction ◽  
Mixed Models ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Single Subject ◽  
Affective Outcomes ◽  
Half Century ◽  
Study Designs ◽  
Single Subject Designs

Quantitative mixed models were used to examine literature published from 1966 through 2016 on the effectiveness of Direct Instruction. Analyses were based on 328 studies involving 413 study designs and almost 4,000 effects. Results are reported for the total set and subareas regarding reading, math, language, spelling, and multiple or other academic subjects; ability measures; affective outcomes; teacher and parent views; and single-subject designs. All of the estimated effects were positive and all were statistically significant except results from metaregressions involving affective outcomes. Characteristics of the publications, methodology, and sample were not systematically related to effect estimates. Effects showed little decline during maintenance, and effects for academic subjects were greater when students had more exposure to the programs. Estimated effects were educationally significant, moderate to large when using the traditional psychological benchmarks, and similar in magnitude to effect sizes that reflect performance gaps between more and less advantaged students.

scholarly journals Meta-analysis of metabolites involved in bioenergetic pathways reveals a pseudohypoxic state in Down syndrome

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Laszlo Pecze ◽  
Elisa B. Randi ◽  
Csaba Szabo
Keyword(s):  
Down Syndrome ◽  
Meta Analysis ◽  
Experimental Therapy ◽  
Mixed Effect ◽  
Functional Deficits ◽  
Clinical Observations ◽  
Effect Model ◽  
Acid Succinate ◽  
The Difference ◽  
And Control

Abstract Clinical observations and preclinical studies both suggest that Down syndrome (DS) may be associated with significant metabolic and bioenergetic alterations. However, the relevant scientific literature has not yet been systematically reviewed. The aim of the current study was to conduct a meta-analysis of metabolites involved in bioenergetics pathways in DS to conclusively determine the difference between DS and control subjects. We discuss these findings and their potential relevance in the context of pathogenesis and experimental therapy of DS. Articles published before July 1, 2020, were identified by using the search terms “Down syndrome” and “metabolite name” or “trisomy 21” and “metabolite name”. Moreover, DS-related metabolomics studies and bioenergetics literature were also reviewed. 41 published reports and associated databases were identified, from which the descriptive information and the relevant metabolomic parameters were extracted and analyzed. Mixed effect model revealed the following changes in DS: significantly decreased ATP, CoQ10, homocysteine, serine, arginine and tyrosine; slightly decreased ADP; significantly increased uric acid, succinate, lactate and cysteine; slightly increased phosphate, pyruvate and citrate. However, the concentrations of AMP, 2,3-diphosphoglycerate, glucose, and glutamine were comparable in the DS vs. control populations. We conclude that cells of subjects with DS are in a pseudo-hypoxic state: the cellular metabolic and bio-energetic mechanisms exhibit pathophysiological alterations that resemble the cellular responses associated with hypoxia, even though the supply of the cells with oxygen is not disrupted. This fundamental alteration may be, at least in part, responsible for a variety of functional deficits associated with DS, including reduced exercise difference, impaired neurocognitive status and neurodegeneration.

scholarly journals A Meta-Analysis of Single-Case Research on Word-Problem Instruction for Students With Learning Disabilities

2020 ◽  
pp. 074193252096491
Author(s):  
Mikyung Shin ◽  
Diane P. Bryant ◽  
Sarah R. Powell ◽  
Pyung-Gang Jung ◽  
Min Wook Ok ◽  
...  
Keyword(s):  
Learning Disabilities ◽  
Word Problem ◽  
Variance Estimation ◽  
Single Case ◽  
Meta Analysis ◽  
Estimation Method ◽  
Implementation Fidelity ◽  
Effect Sizes ◽  
Future Research ◽  
Students With Learning Disabilities

In this meta-analysis of single-case designs, the researchers investigated the effects of word-problem instruction for students with learning disabilities in Grades 1 through 12, as reported in 20 peer-reviewed articles published between 1975 and 2020. A two-level multilevel model with a robust variance estimation method was implemented to calculate the effect sizes. A significant overall effect of word-problem instruction for students with learning disabilities was found, and the results indicate that studies meeting all three quality indicators of implementation fidelity (i.e., adherence, dosage, and regularity) showed greater effects. The average weighted effect sizes of word-problem instruction varied depending on the content and practice standards of the Common Core State Standards for Mathematics. Limitations and future research directions are also discussed.

Efficacy of TNFα blockers in patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis: a meta-analysis

2014 ◽  
Vol 74 (6) ◽  
pp. 1241-1248 ◽  
Author(s):  
Johanna Callhoff ◽  
Joachim Sieper ◽  
Anja Weiß ◽  
Angela Zink ◽  
Joachim Listing
Keyword(s):  
Ankylosing Spondylitis ◽  
Disease Activity ◽  
Effect Size ◽  
Axial Spondyloarthritis ◽  
Activity Index ◽  
Meta Analysis ◽  
Disease Activity Index ◽  
Effect Sizes ◽  
Double Blind ◽  
Mixed Effect

ObjectivesThis meta-analysis investigates the efficacy of tumour necrosis factor α (TNFα) blockers versus placebo for the treatment of ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA).MethodsA systematic literature search was conducted independently by two reviewers. Double-blind randomised controlled trials (RCTs) investigating the efficacy of adalimumab, certolizumab, etanercept, golimumab or infliximab in approved dosages in comparison with placebo were included. The use of concomitant non-steroidal antirheumatic drugs was allowed. The outcome parameters were improvement in disease activity and function measured by the Bath AS disease activity index (BASDAI), Bath AS functional index (BASFI) and ASAS40 response. The effect sizes of the changes in BASDAI/BASFI between TNFα blocker and placebo comparator groups were calculated. Mixed effect models were applied separately for RCTs with AS and nr-axSpA patients and differences between those groups were evaluated in a joint model.Results20 studies with data from 3096 patients were included in the analysis: 15 studies with AS patients, four with nr-axSpA patients and one with both. For AS patients, TNFα blockers showed better efficacy than placebo for BASDAI (effect size 1.00), BASFI (effect size 0.67) and ASAS40 response (OR 4.7). For nr-axSpA patients, the differences were smaller (effect sizes 0.73, 0.57; OR 3.6). However, after adjustment for the year of publication as a proxy for disease severity, no differences in the effect sizes between the AS and nr-axSpA trials were observed.ConclusionsCompared with placebo, TNFα blockers improve disease activity and functional capacity clinically meaningful for both AS and nr-axSpA patients.

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