Speed and Road Safety

2005 ◽  
Vol 1908 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Rune Elvik
Keyword(s):  
Power Function ◽  
Road Safety ◽  
Meta Analysis ◽  
Relevant Literature ◽  
Power Model ◽  
Extensive Review ◽  
Change In The Mean ◽  
The Mean ◽  
Relative Change ◽  
The Relationship

This paper presents a study evaluating the power model of the relationship between speed and road safety. The power model states that a given relative change in the mean speed of traffic is associated with a relative change in the number of accidents or accident victims by means of a power function. An extensive review of relevant literature has been made, and evidence from 98 studies containing 460 estimates of the relationship between changes in speed and changes in the number of accidents or accident victims has been synthesized by means of meta-analysis. The results are broadly supportive of the power model. It is concluded that speed has a major impact on the number of accidents and the severity of injuries and that the relationship between speed and road safety is causal, not just statistical.

Correlation of paretic knee extension strength with gait speed after stroke: A meta-analysis

2021 ◽  
pp. 1-5
Author(s):  
Richard W. Bohannon
Keyword(s):  
Gait Speed ◽  
Meta Analysis ◽  
Relevant Literature ◽  
Knee Extension ◽  
Bibliographic Databases ◽  
Knee Extension Strength ◽  
Extension Force ◽  
Correlational Data ◽  
Using Data ◽  
The Relationship

BACKGROUND AND OBJECTIVE: Numerous studies have addressed the relationship between paretic knee extension strength and comfortable walking speed after stroke. However, the correlations reported are highly variable. This review sought to summarize the correlational data using meta-analysis. METHODS: Relevant literature was identified via a search of 3 bibliographic databases. Articles were screened and perused for inclusion. Included articles were examined for information on the sample studied, procedures for measuring strength and gait speed, and correlations reported between the 2 variables. Meta-analysis was used to calculate a summary correlation. RESULTS: Of 299 unique articles, 18 met inclusion criteria. Articles were diverse in regard to samples studied, procedures described, and correlations reported. Meta-analysis using data from all included studies revealed a summary correlation of 0.51. For studies using hand-held or isokinetic dynamometry, the summary correlation was 0.46 and 0.59 respectively. CONCLUSIONS: This study provides a better indication of the correlation between paretic knee extension strength and comfortable gait speed than individual studies. The correlation is high enough to provide support for the routine measurement of paretic knee extension force for individuals who have experienced a stroke.

scholarly journals Relationship Between Salivary Nitric Oxide Concentration and Dental Caries in Children: A Systematic Review and Meta-Analysis

2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Nadia Elyassi ◽  
Ali Malekzadeh Shafaroudi ◽  
Pegah Nasiri ◽  
Mahmood Moosazadeh ◽  
Azam Nahvi
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Dental Caries ◽  
Meta Analysis ◽  
Control Group ◽  
Analysis Study ◽  
Oxide Concentration ◽  
The Mean ◽  
The Relationship ◽  
Nitrous Oxide Concentration

Context: Conflicting results have been reported in the literature concerning the relationship between salivary nitrous oxide concentration and dental caries in children. Metaanalysis studies aim to combine different studies and reduce the difference between the parameters by increasing the number of studies involved in the analysis process. Objectives: Accordingly, this meta-analysis study aimed at determining the relationship between salivary nitrous oxide concentration and dental caries in children. Methods: Databases were searched using the keywords “nitric oxide”, “salivary”, “Caries”, “DMFT Index”, “children”, “early childhood caries” and OR, AND and NOT operators. Quality assessment was then performed based on the Newcastle-Ottawa scale (NOS) checklist. The standardized mean difference (SMD) of DMFT, dmft, and salivary nitric oxide (NO) concentration was estimated. Results: Seven studies made a comparison between the mean salivary NO concentration in children with dental caries and that in the control group. In four studies, the mean salivary NO concentration in children with dental caries was lower, as compared to that in the control group. This difference was significant in all four studies. Also, the mean standardized difference of the salivary NO index was also estimated to be -0.11 (CI 95%: -1.77, 1.55). Conclusions: This meta-analysis study demonstrated that salivary NO concentration was not significantly related to dental caries. Moreover, since salivary NO concentration is affected by various factors, it is not sufficient to determine the likelihood of the incidence of caries.

The relationship between teacher efficacy and students' academic achievement: A meta-analysis

2018 ◽  
Vol 46 (4) ◽  
pp. 529-540 ◽  
Author(s):  
Kyung Ryung Kim ◽  
Eun Hee Seo
Keyword(s):  
Academic Achievement ◽  
Teacher Efficacy ◽  
Classroom Management ◽  
Meta Analysis ◽  
Teaching Experience ◽  
Student Academic Achievement ◽  
Years Of Teaching Experience ◽  
Efficacy Measures ◽  
The Mean ◽  
The Relationship

We conducted a meta-analysis by synthesizing the results of 16 studies involving 4,130 teachers to explore whether or not the relationship between teacher efficacy and students' academic achievement was influenced by the scale used to measure teacher efficacy, and/or by the subfactors of teacher efficacy, length of teaching experience, location of the school, or the students' educational level. The results showed that the mean relationship between teacher efficacy and students' academic achievement was significant but the effect size was small. The results also indicated that the relationship was influenced by some teacher efficacy measures and subfactors, and by length of teaching experience. In studies in which the measure used was Gibson and Dembo's scale, in regard to classroom management, and in the case of teachers with fewer than 11 years of teaching experience, the relationship between teacher efficacy and student academic achievement was nonsignificant.

scholarly journals The association between systemic lupus erythematosus and dementia A meta-analysis

2018 ◽  
Vol 12 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Zhuoxian Zhao ◽  
Natalia P. Rocha ◽  
Haitham Salem ◽  
Breno S. Diniz ◽  
Antonio L. Teixeira
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Cognitive Impairment ◽  
Cognitive Dysfunction ◽  
Lupus Erythematosus ◽  
Meta Analysis ◽  
Relevant Literature ◽  
Systemic Lupus ◽  
Increased Risk ◽  
Relationship Of ◽  
The Relationship

Abstract A growing body of evidence indicates that systemic lupus erythematosus (SLE) is associated with increased risk of cognitive impairment and dementia. However, to date, no studies have been conducted to quantitatively summarize and evaluate the consistency of data. Objective: To quantitatively evaluate the relationship of SLE and antiphospholipid antibodies (aPL) with cognitive dysfunction and dementia. Methods: All relevant literature was retrieved from Pubmed, Scopus, and PsycINFO databases. The meta-analysis was performed using effect estimates and 95% confidence intervals (CIs) to calculate pooled risk estimates. The heterogeneity among studies was also examined. Results: The meta-analysis included 11 original studies involving a total of 81,668 patients with dementia and 407 patients with cognitive dysfunction. There were significant associations on fixed-effect models between SLE and dementia (3 studies; RR=1.50; 95% CI=1.37-1.64), SLE and cognitive dysfunction (4 studies; OR=2.97; 95% CI=1.72-5.15), and aPL and cognitive dysfunction (5 studies, OR=1.97; 95% CI=1.55-2.52). We also combined cognitive dysfunction and dementia outcomes as they both represented cognitive impairment. There were significant associations between aPL and cognitive impairment (6 studies; OR=2.03; 95% CI=1.62-2.55), and SLE and cognitive impairment (7 studies; OR=1.83; 95% CI=1.42-2.35). Moderate heterogeneity (I2=45.7%) was found in the association between SLE and cognitive impairment, low heterogeneity (I2=21.8%) in the association between SLE and dementia, and near zero heterogeneity for the other three main analyses. Conclusion: Both SLE and aPL are associated with cognitive impairment.

Associations of Volume and Thyroidectomy Outcomes

2016 ◽  
Vol 155 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Tsung-Jung Liang ◽  
Shiuh-Inn Liu ◽  
King-Tong Mok ◽  
Hon-Yi Shi
Keyword(s):  
Hospital Mortality ◽  
Meta Analysis ◽  
Relevant Literature ◽  
Survival Rates ◽  
High Volume ◽  
Mortality Rates ◽  
Surgeon Volume ◽  
The Mean ◽  
Low Volume ◽  
Mean Cost

Objective This study explored how different hospital volumes and surgeon volumes affect thyroidectomy outcomes in terms of length of stay (LOS), costs, and in-hospital mortality. Data Sources MEDLINE and EMBASE databases. Review Methods This study retrospectively analyzed a cohort of 125,037 thyroidectomy patients treated at Taiwan hospitals from 1996 to 2010. Relationships between hospital/surgeon volume and patient outcomes were retrospectively analyzed by propensity score matching. In conjunction with the retrospective study, a systematic review and meta-analysis of the relevant literature also were performed. Results The mean LOS for all thyroidectomies performed during the study period was 3.3 days, and the mean cost was $1193.5. Both high-volume hospitals and high-volume surgeons were associated with significantly shorter LOS and lower costs compared with their low-volume counterparts ( P < .001). Different volume groups had similar in-hospital mortality rates. The meta-analysis results consistently showed that the benefits of high-volume hospitals/surgeons are reduced LOS and costs. However, low in-hospital mortality rates were associated with high-volume surgeons but not with high-volume hospitals. Conclusions This meta-analysis showed that patients who received thyroidectomies performed by high-volume hospitals and surgeons had shorter LOS and lower costs compared with those treated by low-volume hospitals and surgeons. In addition, in-hospital survival rates were better in patients treated by high-volume surgeons. Further research is needed to define the learning curve for thyroidectomy and to clarify how hospital volume and surgeon volume affect its success rate.

Re-counting the determinant factors of human development: a review of the literature

Humanomics ◽  
2016 ◽  
Vol 32 (2) ◽  
pp. 205-226
Author(s):  
Ibrahim Abiodun Oladapo ◽  
Asmak Ab Rahman
Keyword(s):  
Human Development ◽  
Relevant Literature ◽  
Demographic Variables ◽  
Extensive Review ◽  
Capital Theory ◽  
Content Type ◽  
Determinant Factors ◽  
And Gender ◽  
Policy Direction ◽  
The Relationship

Purpose This paper aims to examine the basic determinant factors of human development using the theory of Maqasid al Shari’ah (TMS). It also identifies relevant demographic variables that may likely moderate the relationship among the identified factors. Design/methodology/approach An in-depth review of the TMS and human capital theory literature was conducted, with a specific attention on their impact to human development. Findings The extensive review of the relevant literature shows that human development is not only determined by education, health, income, human rights and social justice but also influenced by some demographic variables like educational attainment and gender composition. Originality/value This paper is a novel attempt whereby an extensive review on the factors of human development is conducted using TMS and identifying the narrowness in the existing framework. The paper will help researchers to better their understanding in this context. It will also provide the policymakers with adequate information on the important factors of human development with the aim to chart a comprehensive policy direction.

scholarly journals Positive Psychology’s Character Strengths in Addiction-Spirituality Research: A Qualitative Systematic Literature Review

2015 ◽  
Author(s):  
Sahaya Selvam
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Character Strengths ◽  
Meta Analysis ◽  
Relevant Literature ◽  
Numerical Data ◽  
Exclusion Criteria ◽  
Academic Literature ◽  
Underlying Mechanisms ◽  
The Relationship

There is an increasing interest in the scientific study of the association between spirituality and recovery from addiction. While most of these studies have provided evidence for a possible relationship, others have explored the underlying mechanisms and meditators in the relationship. However, generally, many studies and reviews have not approached the issue within a specific theoretical framework of mainstream psychology. In an attempt to fill this gap, the review being reported here undertook a Qualitative Systematic Literature Review (QSLR) of addiction-spirituality literature. QSLR is an orderly manner of searching for academic literature, selecting relevant literature following a set of inclusion/exclusion criteria, qualitatively analysing the selected literature, and reporting the findings in such a way as to generate a set of hypotheses. QSLR focusses on literary data, rather than on numerical data as the tradition Systematic Literature Review and Meta-analysis do. Working within the framework of positive psychology, the present review attempted to identify the character strengths relevant to addiction and recovery by carrying out a QSLR on 53 selected peer-reviewed articles. Among the 24 character strengths, the following emerged as salient: wisdom, integrity, vitality, humility, forgiveness, kindness, love, hope and spirituality. On this basis, a hypothetical conclusion is suggested.

Which Behaviors Do Attitudes Predict? Meta-Analyzing the Effects of Social Pressure and Perceived Difficulty

2005 ◽  
Vol 9 (3) ◽  
pp. 214-227 ◽  
Author(s):  
David S. Wallace ◽  
René M. Paulson ◽  
Charles G. Lord ◽  
Charles F. Bond
Keyword(s):  
Standard Deviation ◽  
Meta Analysis ◽  
Social Pressure ◽  
Perceived Difficulty ◽  
Theoretical Hypothesis ◽  
The Mean ◽  
Attitude Behavior ◽  
And Behavior ◽  
Attitudes And Behavior ◽  
The Relationship

A meta-analysis of 797 studies and 1,001 effect sizes tested a theoretical hypothesis that situational constraints, such as perceived social pressure and perceived difficulty, weaken the relationship between attitudes and behavior. This hypothesis was confirmed for attitudes toward performing behaviors and for attitudes toward issues and social groups. Meta-analytic estimates of attitude-behavior correlations served to quantify these moderating effects. The present results indicated that the mean attitude-behavior correlation was .41 when people experienced a mean level of social pressure to perform a behavior of mean difficulty. The mean correlation was .30 when people experienced social pressure 1 standard deviation above the mean to perform a behavior that was 1 standard deviation more difficult than the mean. The results suggest a need for increased attention to the “behavior” side of the attitude-behavior equation. Attitudes predict some behaviors better than others.

scholarly journals Association between the MMP-1-1607 1G/2G Polymorphism and Osteoarthritis Risk: A Systematic Review and Meta-Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Jiankun Liu ◽  
Guangye Wang ◽  
Zhan Peng
Keyword(s):  
Meta Analysis ◽  
Relevant Literature ◽  
Cartilage Degeneration ◽  
Common Disease ◽  
Bonferroni Correction ◽  
Matrix Metalloproteinase 1 ◽  
The Matrix ◽  
The Relationship ◽  
Articular Cartilage Degeneration ◽  
Control Study

Background. Osteoarthritis (OA) is a common disease characterized by articular cartilage degeneration and secondary hyperosteogenesis. Genetic factors are associated with the occurrence of OA. While several studies have shown that the matrix metalloproteinase-1- (MMP-1-) 1607 1G/2G (rs1799750) polymorphism may be related to the occurrence and development of OA, there is inconsistency in the literature. To better estimate the relationship between the MMP-1 gene polymorphism and OA, a comprehensive meta-analysis of relevant literature was carried out. Results. In total, seven studies comprising 1245 OA patients and 1230 controls were included in this meta-analysis. The combined results revealed no significant association between the MMP-1-1607 1G/2G polymorphism and risk of OA in the five genetic models. However, after Bonferroni correction, the results of subgroup analysis revealed a significant correlation between the MMP-1-1607 1G/2G polymorphism and OA susceptibility in the temporomandibular joint (TMJ) OA subgroup (allelic: 2G vs. 1G: OR=1.575, 95%CI=1.259–1.972, P<0.01; recessive: 2G2G vs. 1G1G+1G2G: OR=2.411, 95%CI=1.658–3.504, P<0.01; and homozygote: 2G2G vs. 1G1G: OR=2.313, 95%CI=1.341, 3.991, P=0.003), the younger subgroup (aged less than 60 years; allelic: 2G vs. 1G: OR=1.635, 95%CI=1.354, 1.974, P<0.01; dominant: 2G1G+2G2G vs. 1G1G: OR=1.622, 95%CI=1.158, 2.271, P=0.005; recessive: 2G2G vs. 1G1G+1G2G: OR=2.209, 95%CI=1.718, 2.840, P<0.01; and homozygote: 2G2G vs. 1G1G: OR=2.578, 95%CI=1.798, 3.696, P<0.01), the larger subgroup (N>300), and the hospital-based case-control study (HCC) subgroup. The sensitivity analysis suggested that the results of the meta-analysis were stable and reliable. Begg’s funnel plot and Egger’s test indicated that there was no publication bias in this study. Conclusion. Our meta-analysis indicated that although the MMP-1-1607 1G/2G polymorphism was not significantly associated with OA susceptibility among the whole sample, it played a key role in the etiology and development of TMJ OA and OA in people aged less than 60 years.

scholarly journals A Meta-Analysis of Open-Path Eddy Covariance Observations of Apparent CO2 Flux in Cold Conditions in FLUXNET

2017 ◽  
Vol 34 (11) ◽  
pp. 2475-2487 ◽  
Author(s):  
Liming Wang ◽  
Xuhui Lee ◽  
Wei Wang ◽  
Xufeng Wang ◽  
Zhongwang Wei ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Meta Analysis ◽  
Sensible Heat Flux ◽  
Co2 Flux ◽  
Systematic Bias ◽  
Open Path ◽  
The Mean ◽  
Linear Slope ◽  
The Relationship ◽  
Negative Linear Relationship

AbstractOpen-path eddy covariance systems are widely used for measuring the CO2 flux between land and atmosphere. A common problem is that they often yield negative fluxes or physiologically unreasonable CO2 uptake fluxes in the nongrowing season under cold conditions. In this study, a meta-analysis was performed on the eddy flux data from 64 FLUXNET sites and the relationship between the observed CO2 flux and the sensible heat flux was analyzed. In theory, these two fluxes should be independent of each other in cold conditions (air temperature lower than 0°C) when photosynthesis is suppressed. However, the results show that a significant and negative linear relationship existed between these two fluxes at 37 of the sites. The mean linear slope value is −0.008 ± 0.001 µmol m−2 s−1 per W m−2 among the 64 sites analyzed. The slope value was not significantly different among the three gas analyzer models (LI-7500, LI-7500A, IRGASON/EC150) used at these sites, indicating that self-heating may not be the only reason for the apparent wintertime net CO2 uptake. These results suggest a systematic bias toward larger carbon uptakes in the FLUXNET sites that deploy open-path eddy covariance systems.

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