scholarly journals The demand impacts of train punctuality in great britain: systematic review, meta-analysis and some new econometric insights

2021 ◽  
Author(s):  
Mark Wardman ◽  
Richard Batley
Keyword(s):  
Systematic Review ◽  
Great Britain ◽  
Dynamic Models ◽  
Meta Analysis ◽  
Late Time ◽  
Meta Model ◽  
Passenger Rail ◽  
Long Run ◽  
Rail Industry ◽  
Econometric Evidence

AbstractThis paper updates and extends the systematic review and meta-analysis of Wardman and Batley (Transportation 41:1041–1069, 2014), which hitherto was the most comprehensive study of the impacts of punctuality on passenger rail demand in the literature. Whereas the 2014 paper covered 51 elasticities from 6 studies in Great Britain published between 2003 and 2011, this updated paper adds 11 subsequent British studies yielding a further 201 observations. The meta-model recovers a range of significant effects, relating to whether the elasticity was short versus long run, flow type and distance, season versus nonseason tickets, the relevant measure of lateness, and whether the purpose of the study was specifically the estimation of late time elasticities. Allowance was also made for study quality-related issues. The data indicated that, despite dynamic models being commonplace, there is some uncertainty as to how long the long run is. Alongside the meta-model, the paper also reports new econometric evidence that addresses some gaps in existing evidence and knowledge, especially in relation to functional form and non-linearity of effects. Findings from both strands of analysis would seem to suggest that rail industry guidance has tended to overstate the demand impacts of punctuality.

scholarly journals Root resorption in patients treated with self-ligating or conventional brackets: A systematic review

2020 ◽  
Author(s):  
Jiye Xie ◽  
Kang Yin ◽  
Xin Wen ◽  
Wei He ◽  
Yanhua Xu
Keyword(s):  
Systematic Review ◽  
Root Resorption ◽  
Meta Analysis ◽  
Cochrane Library ◽  
Controlled Trials ◽  
Manual Search ◽  
Long Run ◽  
Significant Difference ◽  
Conventional Brackets ◽  
Made In

Abstract Background: To compare the degree of external apical root resorption (EARR) in patients using self-ligating brackets with conventional brackets in a long run. Methods: Electronic search was made in databases including PubMed, OVID, the Cochrane Library, EMBASE, FMRS, CBM, CNKI, VIP and WanFang Data until November 2019 to retrievalled randomized controlled trials and clinical controlled trials that compared the EARR between patients using self-ligating or conventional brackets. What’s more, manual search was made in NLM, SIGLE, Campbell library, WHOLIS, Chinese Journal of Evidence-based Medicine and the Journal of Orthodontics. Literature filtering, data extraction and methodological quality evaluation were finished independently by two researchers and disagreements were solved by a third reviewer. Original outcome data, if possible, were subjected to statistical pooling by Review Manager 5.3 for Meta analysis.Results: Through a predefined search strategy, ten studies were included in the systematic review and nine eligible studies were pooled in meta-analysis. There was a significant difference between self-ligating and conventional brackets in terms of the value of EARR in maxillary central incisors (P=0.01; SMD: -0.42mm; 95%CI: -0.76, -0.09) in a long run. No significant difference in maxillary lateral incisors (P=0.07; SMD: -0.17; 95%CI: −0.35, 0.01), mandibular central incisors (P=0.69; SMD: 0.04; 95%CI: −0.17, 0.26) and mandibular lateral incisors (P=0.38; SMD: −0.10; 95%CI: −0.32, 0.12).Conclusions: Self-ligating brackets have a long-term effect in protecting maxillary central incisors from the EARR compared to conventional brackets. However, self-ligating brackets were not superior to conventional brackets in reducing the EARR of maxillary lateral incisors, mandible central incisors and mandible lateral incisors.

The effects of low-ratio n-6/n-3 PUFA on biomarkers of inflammation: a systematic review and meta-analysis

2021 ◽  
Author(s):  
Yali Wei ◽  
Yan Meng ◽  
Na Li ◽  
Qian Wang ◽  
Liyong Chen
Keyword(s):  
Systematic Review ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acid ◽  
Meta Analysis ◽  
Chain Polyunsaturated Fatty Acid ◽  
Inflammation Markers ◽  
Pufa Supplementation ◽  
Long Chain

The purpose of the systematic review and meta-analysis was to determine if low-ratio n-6/n-3 long-chain polyunsaturated fatty acid (PUFA) supplementation affects serum inflammation markers based on current studies.

The association between dietary inflammatory index and risk of central obesity in adults: An updated systematic review and meta-analysis

2020 ◽  
Vol 90 (5-6) ◽  
pp. 535-552 ◽  
Author(s):  
Mahdieh Abbasalizad Farhangi ◽  
Mahdi Vajdi
Keyword(s):  
Systematic Review ◽  
Observational Studies ◽  
Central Obesity ◽  
Assessment Tool ◽  
Weighted Mean Difference ◽  
Meta Analysis ◽  
Dietary Factors ◽  
Cross Sectional ◽  
Inflammatory Status ◽  
Obesity Indices

Abstract. Backgrounds: Central obesity, as a pivotal component of metabolic syndrome is associated with numerous co-morbidities. Dietary factors influence central obesity by increased inflammatory status. However, recent studies didn’t evaluate the association between central obesity and dietary inflammation index (DII®) that give score to dietary factors according to their inflammatory potential. In the current systematic review and meta-analysis, we summarized the studies that investigated the association between DII® with central obesity indices in the general populations. Methods: In a systematic search from PubMed, SCOPUS, Web of Sciences and Cochrane electronic databases, we collected relevant studies written in English and published until 30 October 2019. The population of included studies were apparently healthy subjects or individuals with obesity or obesity-related diseases. Observational studies that evaluated the association between DII® and indices of central obesity including WC or WHR were included. Results: Totally thirty-two studies were included; thirty studies were cross-sectional and two were cohort studies with 103071 participants. Meta-analysis of observational studies showed that higher DII® scores were associated with 1.81 cm increase in WC (Pooled weighted mean difference (WMD) = 1.813; CI: 0.785–2.841; p = 0.001). Also, a non-significant increase in the odds of having higher WC (OR = 1.162; CI: 0.95–1.43; p = 0.154) in the highest DII category was also observed. In subgroup analysis, the continent, dietary assessment tool and gender were the heterogeneity sources. Conclusion: The findings proposed that adherence to diets with high DII® scores was associated with increased WC. Further studies with interventional designs are necessary to elucidate the causality inference between DII® and central obesity indices.

Sign in / Sign up

Export Citation Format

Share Document