scholarly journals Synergistic effect: a common theme in mixed-species litter decomposition

2019 ◽  
Author(s):  
Jun Liu ◽  
Xiaoyu Liu ◽  
Qingni Song ◽  
Fenggang Luan ◽  
Hui Wang ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Litter Decomposition ◽  
Nutrient Dynamics ◽  
Meta Analysis ◽  
Global Scale ◽  
Antagonistic Effect ◽  
Additive Effect ◽  
Systematic Evaluation ◽  
List Type ◽  
Meta Analyses

AbstractLitter decomposition plays a key role in ecosystem nutrients cycling, yet, to date science is lacking a comprehensive understanding of the non-additive effect in mixing litter decomposition.In order to fill that gap, we compiled 69 individual studies for the purpose of performing two sub-meta-analyses on the non-additive effect.Our results show that a significantly synergistic effect occurs at global scale with the average increase by 2-4% in litter mixture decomposition; In particular, low-quality litter in mixture shows a significantly synergistic effect, while no significant change is observed with high-quality species. Additionally, the synergistic effect turns into the antagonistic effect when soil fauna is absent or litter decomposition enters into humus-near stage. In contrast to temperate and tropical areas, studies in frigid area also show a significantly antagonistic effect.Our meta-analysis provides a systematic evaluation of the non-additive effect in decomposition mixed litters, which is critical for understanding and improving the carbon forecasts and nutrient dynamics.

scholarly journals Concordance and incongruence in preclinical anxiety models: systematic review and meta-analyses

2015 ◽  
Author(s):  
Farhan Mohammad ◽  
Joses Ho ◽  
Jia Hern Woo ◽  
Chun Lei Lim ◽  
Dennis Jun Jie Poon ◽  
...  
Keyword(s):  
Systematic Review ◽  
Publication Bias ◽  
Social Isolation ◽  
Gene Knockout ◽  
Meta Analysis ◽  
Receptor Gene ◽  
List Type ◽  
Clinical Use ◽  
Defense Behavior ◽  
Meta Analyses

AbstractRodent defense behavior assays have been widely used as preclinical models of anxiety to study possibly therapeutic anxiety-reducing interventions. However, some proposed anxiety-modulating factors—genes, drugs and stressors—have had discordant effects across different studies. To reconcile the effect sizes of purported anxiety factors, we conducted systematic review and meta-analyses of the literature on ten anxiety-linked interventions, as examined in the elevated plus maze, open field and light-dark box assays. Diazepam, 5-HT1A receptor gene knockout and overexpression, SERT gene knockout and overexpression, pain, restraint, social isolation, corticotropin-releasing hormone and Crhr1 were selected for review. Eight interventions had statistically significant effects on rodent anxiety, while Htr1a overexpression and Crh knockout did not. Evidence for publication bias was found in the diazepam, Htt knockout, and social isolation literatures. The Htr1a and Crhr1 results indicate a disconnect between preclinical science and clinical research. Furthermore, the meta-analytic data confirmed that genetic SERT anxiety effects were paradoxical in the context of the clinical use of SERT inhibitors to reduce anxiety.HighlightsMeta-analysis shows eight rodent anxiety factors have at least moderate effects.Publication bias affects four of the anxiety interventions.Preclinical rodent anxiety results appear disconnected from clinical efforts.Serotonin transporter gene lesion effects are paradoxical with reuptake inhibitors clinical use.

scholarly journals The global molecular epidemiology of microsporidia infection in sheep and goats with focus on Enterocytozoon bieneusi: a systematic review and meta-analysis

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Ali Taghipour ◽  
Saeed Bahadory ◽  
Ehsan Javanmard
Keyword(s):  
Systematic Review ◽  
Meta Analysis ◽  
Small Ruminants ◽  
Global Scale ◽  
Enterocytozoon Bieneusi ◽  
Control Measures ◽  
Sheep And Goats ◽  
Prevalence Studies ◽  
Global Estimate ◽  
Meta Analyses

Abstract Background Microsporidia is a zoonotic pathogen with health consequences in immunocompromised patients. Small ruminants are a potential reservoir of microsporidia for humans in their vicinity. Hence, we aimed to evaluate the molecular prevalence of microsporidian infections with emphasis on Enterocytozoon bieneusi genotypes among sheep and goats at a global scale through systematic review and meta-analysis approach. Methods The standard protocol of preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Eligible prevalence studies on small ruminant microsporidiosis, published from 1 January 2000 until 15 April 2021 were gathered using systematic literature search in PubMed, Scopus, Web of Science and Google Scholar databases. Inclusion and exclusion criteria were applied. The point estimates and 95% confidence intervals were calculated using a random-effects model. The variance between studies (heterogeneity) was quantified by I2 index. Results In total, 25 articles (including 34 datasets) were included for final meta-analysis. The pooled molecular prevalence of microsporidia in sheep and goats was estimated to be 17.4% (95% CI: 11.8–25%) and 16% (95% CI: 11.2–22.4%), respectively. Likewise, the overall prevalence of E. bieneusi was estimated to be 17.4% (95% CI: 11.8–25%) for sheep and 16.3% (95% CI: 11.3–22.8%) for goats. According to internal transcribed spacer (ITS) gene analysis, E. bieneusi with genotypes BEB6 (15 studies) and COS-1 (nine studies) in sheep, and CHG3 (six studies) and BEB6 (five studies) in goats were the highest reported genotypes. Conclusion The present results highlight the role of sheep and goats as reservoir hosts for human-infecting microsporidia. Therefore, this global estimate could be beneficial on preventive and control measures.

scholarly journals The mystery of COVID-19 reinfections: A global systematic review and meta-analysis of 577 cases

2021 ◽  
Author(s):  
Rubaid Azhar Dhillon ◽  
Mohammad Aadil Qamar ◽  
Omar Irfan ◽  
Jaleed Ahmed Gilani ◽  
Usama Waqar ◽  
...  
Keyword(s):  
Systematic Review ◽  
Assessment Tool ◽  
Meta Analysis ◽  
Case Series ◽  
Admission Rate ◽  
Global Scale ◽  
Common Symptom ◽  
Time Duration ◽  
Disease Spectrum ◽  
Meta Analyses

Background As the COVID-19 pandemic rages on, reports on disparities in vaccine roll out alongside reinfection and reactivation from previously recovered cases have been emerging. With newer waves and variants of COVID-19, we conducted a systematic review to assess the determinants and disease spectrum of COVID-19 reinfection. Methods A comprehensive search covering relevant databases was conducted for observational studies reporting Polymerase Chain Reaction (PCR) confirmed infection and reinfection cases. Quality assessment tool developed by the National Institute of Health (NIH) for assessment of case series was used. Meta-analyses were performed using RevMan 5.3 for pooled proportions of findings in first infection and reinfection with 95% confidence interval (CI). Results Eighty-one studies reporting 577 cases were included from 22 countries. The mean age of patients was 46.2±18.9 years with males accounting for 45.8% of the study population while 179 (31.0%) cases of comorbidities were reported. The average time duration between first infection and reinfection was 63.6±48.9 days. During first infection and reinfection, fever was the most common symptom (41.4% and 36.4%,respectively) whilst anti-viral therapy was the most common treatment regimen administered (44.5% and 43.0%, respectively). Overall, comparable odds of symptomatic presentation and management were reported in the two infections. However, a higher Intensive Care Unit (ICU) admission rate was observed in reinfection compared to first infection (10 vs 3). Ten deaths were reported with 565 patients fully recovering. Respiratory failure was the most common cause of death (7/10 deaths). Seventy-two studies were determined to be of good quality whilst nine studies were of fair quality. Conclusion As the first global-scale systematic review of its kind, our findings support immunization practices given increased ICU admissions and mortality in reinfections. Our cohort serves as a guide for clinicians and authorities for devising an optimal strategy for controlling the pandemic.

scholarly journals Contributions of Hedgerows to People: A Global Meta-Analysis

2021 ◽  
Vol 2 ◽  
Author(s):  
David García de León ◽  
José M. Rey Benayas ◽  
Enrique Andivia
Keyword(s):  
Ecosystem Services ◽  
Meta Analysis ◽  
Natural Habitat ◽  
Global Scale ◽  
Agricultural Landscapes ◽  
Agricultural Fields ◽  
Climate Type ◽  
Scale Field ◽  
Meta Analyses ◽  
Provisioning Services

Hedgerows are linear landscape features of woody vegetation usually located around agricultural fields. An increasing number of studies have addressed the effects of hedgerows on biodiversity and ecosystem services. This study is aimed to synthesize these effects and compare the levels of biodiversity and ecosystem services in farmland with hedgerows and (1) farmland without hedgerows and (2) nearby natural habitat at the global scale. We hypothesized that farmland with hedgerows (1) enhances biodiversity and ecosystem services as compared to farmland without hedgerows but (2) supports lower levels of biodiversity and ecosystem services than natural habitat. Our systematic literature review retained 835 observations from 170 primary studies, which were analyzed following the standard methodology in meta-analyses. Our results partially support both hypotheses. Farmland with hedgerows exhibited higher levels of biodiversity and provisioning services than farmland without hedgerows (H1). Farmland with hedgerows provided similar levels of biodiversity (edge effects) but lower levels of ecosystem services than natural habitat (H2). The effects of hedgerows on biodiversity and ecosystem services depended on control ecosystem type (grassland/meadow or forest/woodland) but were largely independent of climate type (temperate or tropical) and the focus of spatial scale (field or landscape). In conclusion, conservation and restoration of hedgerows contribute to people in several ways by enhancing biodiversity and multifunctionality in agricultural landscapes.

scholarly journals Factors underpinning discrepant findings from reviews on the same topic: A systematic analysis of Cochrane and non-Cochrane reviews

2019 ◽  
Author(s):  
Claudia Hacke ◽  
David Nunan
Keyword(s):  
Systematic Reviews ◽  
Methodological Quality ◽  
Data Extraction ◽  
Meta Analysis ◽  
List Type ◽  
Eligibility Criteria ◽  
Cochrane Reviews ◽  
And Performance ◽  
Meta Analyses

AbstractObjectiveTo explore factors underpinning discrepancies in reported pooled effect estimates from Cochrane and non-Cochrane systematic reviews answering the same question.Study Design and SettingWe observed discrepant pooled effects in 23 out of 24 pairs of meta-analyses from Cochrane and non-Cochrane systematic reviews answering the same question. Here we present the results of a systematic assessment of methodological quality and factors that explain the observed quantitative discrepancies. Methodological quality of each review was assessed using AMSTAR (Assessing the Methodological Quality of Systematic Reviews). Matched pairs were contrasted at the macro- (review methodology), meso- (application of methodology) and micro- (data extraction) level and reasons for differences were derived.ResultsAll Cochrane reviews had high methodological quality (AMSTAR 8-11), whereas the majority (87.5%) of non-Cochrane reviews were classified as moderate (AMSTAR 4-7). Only one pair included exactly the same studies for their respective meta-analyses but there was still a discrepancy in the pooled estimate due to differences in data extraction. One pair did not include any study of its match and for one pair the same effect estimates were reported despite inclusion of different studies. The remaining pairs included at least one study in their match. Due to insufficient reporting (predominantly affecting non-Cochrane reviews) we were only able to completely ascertain the reasons for discrepancies in all included studies for 9/24 (37.5%) pairs. Across all pairs, differences in pre-defined methods (macro-level) including search strategy, eligibility criteria and performance of dual screening could possibly explain mismatches in included studies. Study selection procedures (meso-level) including disagreements in the interpretation of pre-defined eligibility criteria (14 matches) were identified as reasons underpinning discrepant review findings. Comparison of data extraction from primary studies (micro-level) was not possible in 13/24 pairs as a result of the non-Cochrane review providing insufficient details of the studies included in their meta-analyses. Two out of 24 pairs completely agreed on the numerical data presented for the same studies in their respective meta-analysis. Both review types provided sufficient information to check the accuracy of data extraction for 8 pairs (45 studies) where there were discrepancies. An assessment of 50% (22 studies) of these showed that reasons for differences in extracted data could be identified in 15 studies. We found examples for both types of review where data presented were discrepant from that given in the source study without a plausible explanation.ConclusionMethodological and author judgements and performance are key aspects underpinning poor overlap of included studies and discrepancies in reported pooled effect estimates between topic-matched reviews. Though caution must be taken when extrapolating, our findings raise the question as to what extent the entire meta-analysis evidence-base accurately reflects the available primary research both in terms of volume and data. Reinforcing awareness of the application of guidelines for systematic reviews and meta-analyses may help mitigate some of the key issues identified in our analysis.What is new?Key findings Non-Cochrane reviews were of a lower overall methodological quality compared with Cochrane reviews. Discrepant results of meta-analyses on the same topic can be attributed to differences in included studies based on review author decision, judgements and performance at different stages of the review process.What this adds to what was known?This study provides the most robust analysis to date of the potential methodological factors underpinning discrepant review findings between matched meta-analyses answering the same question. Assessing differences between reviews at the macro-, meso-, and micro-levels is a useful method to identify reasons for discrepant meta-analyses at key stages of the review process.What is the implication and what should change now?There is a need for a standardised approach to performing matched-pair analysis of meta-analyses and systematic reviews answering the same question. Our paper provides a base for this that can be refined by replication and expert consensus.

scholarly journals Effectiveness of probiotics in irritable bowel syndrome: methodological quality of meta-analyses and systematic reviews

2019 ◽  
Vol 6 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Yuan Jia ◽  
Li-Min Guo ◽  
Si-Yuan Yang ◽  
Qian Wu ◽  
Fan-Jie Meng
Keyword(s):  
Irritable Bowel Syndrome ◽  
Systematic Reviews ◽  
Methodological Quality ◽  
Meta Analysis ◽  
Quality Standards ◽  
Systematic Evaluation ◽  
Future Research ◽  
Irritable Bowel ◽  
Meta Analyses

Abstract Objective This study assessed the methodological quality of systematic reviews/meta-analysis of the effectiveness of probiotics against irritable bowel syndrome (IBS) using the accepted methodological quality assessment scale AMSTAR and explored the factors that influenced the quality of methodology. It was designed to provide a reference for future research and systematic reviews/metaanalysis. Methods The methodological quality of existing systematic reviews/meta-analysis was evaluated using the AMSTAR scale. Influencing factors of methodological quality were statistically analyzed using RevMan 5.3 software. The included systematic reviews/metaanalysis must include the following characteristics: (1) methods using systematic evaluation/meta-analysis, (2) probiotic intervention, and (3) language limitation to Chinese and English. Results The AMSTAR score was 5–9 (7.42 ± 1.22), and the quality is above average. The factors affecting the methodological quality are the number of authors and whether they cooperate with the institution. Conclusions Studies have shown that current systematic reviews/meta-analysis of the effectiveness of probiotics on IBS does not fully comply with methodological quality standards, and therefore the methodological quality of research in this area needs to be strengthened. To better clarify how probiotics affect IBS, future systematic reviews and meta-analyses should not only follow methodological quality standards but also include more effective outcome measures, and they should focus more on the discussion of research results. We look forward to the development of higher-quality randomized controlled trials in the future.

scholarly journals PERIPHERAL BLOOD AS TOOL TO DETERMINE GENE EXPRESSION PATTERNS IN PATIENTS WITH PSYCHIATRIC, NEUROLOGICAL AND OTHER COMMON DISORDERS: A SYSTEMATIC REVIEW AND META-ANALYSIS PROTOCOL

2019 ◽  
Author(s):  
Alana Castro Panzenhagen ◽  
Alexsander Alves-Teixeira ◽  
Martina Schroeder Wissmann ◽  
Carolina Saibro Girardi ◽  
Lucas Santos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Systematic Review ◽  
Peripheral Blood ◽  
Complex Traits ◽  
Meta Analysis ◽  
Expression Patterns ◽  
List Type ◽  
Common Diseases ◽  
Robust Statistical Method ◽  
Meta Analyses

ABSTRACTIntroductionCommon diseases are influenced by a variety of factors that can enhance one person’s susceptibility to developing a specific condition. Complex traits have been investigated in several biological levels. One that reflects the high interconnectivity and interaction of genes, proteins and transcription factors is the transcriptome. In this study, we disclose the protocol for a systematic review and meta-analysis aiming at summarizing the available evidence regarding transcriptomic gene expression levels of peripheral blood samples comparing subjects with psychiatric, neurological and other common disorders to healthy controls.Methods and analysisThe investigation of the transcriptomic levels in the peripheral blood enables the unique opportunity to unravel the etiology of common diseases in patients ex-vivo. However, the experimental results should be minimally consistent across studies for them to be considered as the best approximation of the true effect. In order to test this, we will systematically identify all transcriptome studies that compared subjects with common disorders to their respective control samples. We will apply meta-analyses to assess the overall differentially expressed genes throughout the studies of each condition.Ethics and disseminationThe data that will be used to conduct this study are available online and have already been published following their own ethical laws. Therefore this study requires no further ethical approval. The results of this study will be published in leading peer-reviewed journals of the area and also presented at relevant national and international conferences.Strengths and limitations of this study➣We present a new and systematically centered method to assess the overall effect of transcriptomic levels in the blood of subjects with common conditions.➣Meta-analyses are a robust statistical method to assess effect sizes across studies.➣The analysis is limited by the availability of studies, as well as their quality and comprehensiveness.➣Subgroup and meta-regression analyses will be also limited by the amount and quality of sample characterization variables made available by original studies.

scholarly journals Is OR “portable” in meta-analysis? Time to consider bivariate generalized linear mixed model

2020 ◽  
Author(s):  
Mengli Xiao ◽  
Yong Chen ◽  
Stephen Cole ◽  
Richard MacLehose ◽  
David Richardson ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Meta Analysis ◽  
Generalized Linear Mixed Model ◽  
Baseline Risk ◽  
Marginal Effect ◽  
List Type ◽  
Effect Measure ◽  
Meta Analyses

AbstractObjectivesA recent paper by Doi et al. advocated completely replacing the relative risk (RR) with the odds ratio (OR) as the effect measure used to report the association between a treatment and a binary outcome in clinical trials and meta-analyses. Besides some practical advantages of RR over OR and the well-known issue of the OR being non-collapsible, Doi et al.’s key assumption that the OR is “portable” in the meta-analysis, i.e., study-specific ORs are likely not correlated with baseline risks, was not well justified.Study designs and settingsWe summarized the Spearman’s rank correlation coefficient between study-specific OR and the baseline risk in 40,243 meta-analyses from the Cochrane Database of Systematic Reviews (CDSR).ResultsStudy-specific ORs are negatively correlated with baseline risk of disease (i.e., higher ORs tend to be observed in studies with lower baseline risks of disease) for most meta-analyses in CDSR. Using a meta-analysis comparing the effect of oral sumatriptan (100 mg) versus placebo on mitigating the acute headache at 2 hours after drug administration, we demonstrate that there is a strong negative correlation between OR (RR or RD) with the baseline risk and the conditional effects notably vary with baseline risks.ConclusionsReplacing RR or RD with OR is currently unadvisable in clinical trials and meta-analyses. It is possible that no effect measure is “portable” in a meta-analysis. In cases where portability of the effect measure is challenging to satisfy, we suggest presenting the conditional effect based on the baseline risk using a bivariate generalized linear mixed model. The bivariate generalized linear mixed model can be used to account for correlation between the effect measure and baseline disease risk. Furthermore, in addition to the overall (or marginal) effect, we recommend that investigators also report the effects conditioning on the baseline risk.What is New?Key findingsIn most meta-analyses in Cochrane Database of Systematic Reviews, there is notable negative correlation between ORs and baseline risks.When such a correlation is not negligible, the OR is not “portable” across studies with different baseline risks.When an effect measure is not “portable”, one may derive the effects conditioning on the baseline risk from a bivariate generalized linear mixed model.What this study adds to what was knownThe recommendation to replace the RR with the OR in clinical trials and meta-analyses is misguided.The OR is not a better effect summary than RR and RD in a single study or in meta-analyses; the noncollapsibility of OR can lead to misleading results in a single study and the OR is generally not portable in the meta-analysis.In addition to reporting effect measures such as the OR, RR or RD, it is also important to present the baseline risk.What is the implication and what should change now?When none of the effects are “portable” in a meta-analysis, in addition to report the overall (or marginal) effect, one should also report the effects conditioning on the baseline risk, regardless of the measure of choice.

A Meta-Analysis of Interviews and Cognitive Ability

2013 ◽  
Vol 12 (4) ◽  
pp. 157-169 ◽  
Author(s):  
Philip L. Roth ◽  
Allen I. Huffcutt
Keyword(s):  
Cognitive Ability ◽  
Meta Analysis ◽  
Incremental Validity ◽  
Employment Interviews ◽  
Moderator Analysis ◽  
The Future ◽  
Research Questions ◽  
Meta Analyses ◽  
The Relationship

The topic of what interviews measure has received a great deal of attention over the years. One line of research has investigated the relationship between interviews and the construct of cognitive ability. A previous meta-analysis reported an overall corrected correlation of .40 ( Huffcutt, Roth, & McDaniel, 1996 ). A more recent meta-analysis reported a noticeably lower corrected correlation of .27 ( Berry, Sackett, & Landers, 2007 ). After reviewing both meta-analyses, it appears that the two studies posed different research questions. Further, there were a number of coding judgments in Berry et al. that merit review, and there was no moderator analysis for educational versus employment interviews. As a result, we reanalyzed the work by Berry et al. and found a corrected correlation of .42 for employment interviews (.15 higher than Berry et al., a 56% increase). Further, educational interviews were associated with a corrected correlation of .21, supporting their influence as a moderator. We suggest a better estimate of the correlation between employment interviews and cognitive ability is .42, and this takes us “back to the future” in that the better overall estimate of the employment interviews – cognitive ability relationship is roughly .40. This difference has implications for what is being measured by interviews and their incremental validity.

Power-Enhanced Funnel Plots for Meta-Analysis

2020 ◽  
Vol 228 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Michael Kossmeier ◽  
Ulrich S. Tran ◽  
Martin Voracek
Keyword(s):  
Statistical Power ◽  
Meta Analysis ◽  
Relevant Information ◽  
Selective Reporting ◽  
Graphical Display ◽  
Funnel Plot ◽  
Evidential Value ◽  
Graphical Displays ◽  
Funnel Plots ◽  
Meta Analyses

Abstract. Currently, dedicated graphical displays to depict study-level statistical power in the context of meta-analysis are unavailable. Here, we introduce the sunset (power-enhanced) funnel plot to visualize this relevant information for assessing the credibility, or evidential value, of a set of studies. The sunset funnel plot highlights the statistical power of primary studies to detect an underlying true effect of interest in the well-known funnel display with color-coded power regions and a second power axis. This graphical display allows meta-analysts to incorporate power considerations into classic funnel plot assessments of small-study effects. Nominally significant, but low-powered, studies might be seen as less credible and as more likely being affected by selective reporting. We exemplify the application of the sunset funnel plot with two published meta-analyses from medicine and psychology. Software to create this variation of the funnel plot is provided via a tailored R function. In conclusion, the sunset (power-enhanced) funnel plot is a novel and useful graphical display to critically examine and to present study-level power in the context of meta-analysis.

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