328 research outputs found

    How does the Market View Share Repurchases: Five Possible Book Values in the Fama-French 3 Factor Model

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    Share repurchase activity has grown significantly over the past twenty years and has emerged as the most popular technique for returning cash to shareholders. Current U.S. generally accepted accounting principles treat share repurchases as a return of capital to shareholders, recording the repurchased shares at market prices and offsetting them against contributed capital accounts. This treatment reduces the recorded book value of the equity of companies. Of course, companies can reissue these shares to fulfill stock option contracts, as consideration in acquisitions, and/or in secondary offerings. These economically relevant uses of repurchased shares suggest that the market may treat share repurchases differently than GAAP-based accounting. This study employs the Fama-French 3-Factor Model to test five potential views on repurchased shares: 1) a permanent return of capital to shareholders; 2) a prepaid cash expense related to stock-options; 3) the monetization of internally generated goodwill; 4) a prepaid asset that can be used as consideration in a future acquisition; and 5) a put option on company shares. Results suggest that the current accounting treatment is as good or better than all other possibilities for diversified portfolios, but we do find support for other treatments in certain industries

    Evaluating the impact and use of Transparent Reporting of Evaluations with Non-randomised Designs (TREND) reporting guidelines.

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    notes: PMCID: PMC3533093Freely available Open Access paper. Cite published version at: doi:10.1136/bmjopen-2012-002073INTRODUCTION: Accurate and full reporting of evaluation of interventions in health research is needed for evidence synthesis and informed decision-making. Evidence suggests that biases and incomplete reporting affect the assessment of study validity and the ability to include this data in secondary research. The Transparent Reporting of Evaluations with Non-randomised Designs (TREND) reporting guideline was developed to improve the transparency and accuracy of the reporting of behavioural and public health evaluations with non-randomised designs. Evaluations of reporting guidelines have shown that they can be effective in improving reporting completeness. Although TREND occupies a niche within reporting guidelines, and despite it being 8 years since publication, no study yet has assessed its impact on reporting completeness or investigated what factors affect its use by authors and journal editors. This protocol describes two studies that aim to redress this. METHODS AND ANALYSIS: Study 1 will use an observational design to examine the uptake and use of TREND by authors, and by journals in their instructions to authors. A comparison of reporting completeness and study quality of papers that do and do not use TREND to inform reporting will be made. Study 2 will use a cross-sectional survey to investigate what factors inhibit or facilitate authors' and journal editors' use of TREND. Semistructured interviews will also be conducted with a subset of authors and editors to explore findings from study 1 and the surveys in greater depth. ETHICS AND DISSEMINATION: These studies will generate evidence of how implementation and dissemination of the TREND guideline has affected reporting completeness in studies with experimental, non-randomised designs within behavioural and public health research. The project has received ethics approval from the Research Ethics Committee of the Peninsula College of Medicine and Dentistry, Universities of Exeter and Plymouth

    Preventing unintentional injuries to children under 15 years in the outdoors: A systematic review of the effectiveness of educational programs

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    Introduction Unintentional injuries to children in the outdoors have a significant impact on child mortality, development and healthcare costs. This paper presents the findings of a systematic review about the effectiveness of programs that provided information, advice or education about the prevention of unintentional injuries to children under 15 years during outdoor play and leisure. Methods A structured search strategy was conducted in a range of databases. All report titles and abstracts were screened using pre-defined criteria. Included reports were quality appraised using a modified Graphical Appraisal Tool for Epidemiological studies (GATE) tool. All quality appraisals and data extraction were checked by a second reviewer. If not provided in the original reports, ORs and mean differences were calculated, where sufficient data were available. Results Twenty-three studies met the inclusion criteria. There was a paucity of robust study designs. The majority of studies only reported a short-term follow-up of intermediate outcome measures. Only two studies measured injury rates; both reported a reduction, but both studies also had considerable methodological weaknesses. The five studies that measured the use of protective equipment reported mixed results, although there is some evidence that suggests that more extensive educational programs (such as health fairs and media campaigns) increase their use. The 20 studies that measured behaviour, attitude or knowledge outcomes reported highly mixed results. Discussion Methodological weaknesses of the included studies limit support for a particular course of action. To better inform policy and practice, future research should (1) use robust study designs and (2) not rely on short-term proxy outcome measures

    Are interventions to reduce the impact of arsenic contamination of groundwater on human health in developing countries effective? A systematic review

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    BackgroundWithin developing countries, groundwater provides an alternative drinking source to polluted surface water. However, the presence of arsenic in some groundwater sources has resulted in chronic worldwide poisoning. The aim of this review was to determine the effectiveness of field-based technologies for the removal of arsenic from groundwater in developing countries.MethodsA structured search strategy was conducted in a range of databases. Titles, abstracts and full texts were screened using pre-defined inclusion criteria. Included studies were quality appraised prior to data extraction. The primary outcome was the percentage of effluent water samples meeting WHO guidelines for arsenic concentrations (≀0.01 mg/L). Secondary outcomes included: (a) arsenic concentrations in effluent water samples meeting the national guideline limit (≀0.05 mg/L), (b) arsenic concentrations in human tissue, and (c) knowledge and attitudes related to the interventions.ResultsFifty-one reports, evaluating 50 different technologies, were included. Sixty-seven percent (n = 34) of studies were conducted in Bangladesh. Fifty of the included reports were appraised as ‘weak’, with one ‘strong’ report of a randomised-controlled trial.In summary, the effectiveness of the oxidation and filtration interventions is poor, while the evidence for coagulation, co-precipitation and filtration, subterranean and membrane and electrolytic methods is mixed. Evidence regarding adsorption and zero valent iron interventions is more persuasive with most results suggesting good evidence of effectiveness (i.e. ≄95% of samples with arsenic concentrations ≀0.01 mg/L). In particular, activated alumina and sono/three-kolshi/gagri/pitcher filters have ≄95% of samples meeting national guidelines. Disappointingly, only one study reports excellent evidence of effectiveness: BRAC (2000) for activated alumina (i.e. ≄95% of samples with arsenic concentrations ≀0.01 mg/L).The success of each technology was highly dependent on context, especially their acceptability to users, a sense of ownership and expectations of women’s roles in society.ConclusionsMost studies were poorly conducted and reported. Consequently, although some technologies met national guidelines, the evidence-base for decision-making regarding arsenic mitigation technologies at household- and community-level is weak. To improve this situation, primary research needs to be commissioned with adequate sample sizes, testing the impact of key contextual factors, using valid tools for analysis, and meeting standards for completeness of reporting

    Meta-analyses of randomized controlled trials show suboptimal validity of surrogate outcomes for overall survival in advanced colorectal cancer

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    Objectives: To quantify and compare the treatment effects on three surrogate end points, progression-free survival (PFS), time to progression (TTP), and tumor response rate (TR) vs. overall survival (OS) based on a meta-analysis of randomized controlled trials (RCTs) of drug interventions in advanced colorectal cancer (aCRC). Study Design and Setting: We systematically searched for RCTs of pharmacologic therapies in aCRC between 2003 and 2013. Trial characteristics, risk of bias, and outcomes were recorded based on a predefined form. Univariate and multivariate random-effects meta-analyses were used to estimate pooled summary treatment effects. The ratio of hazard ratios (HRs)/odds ratios (ORs) and difference in medians were used to quantify the degree of difference in treatment effects on the surrogate end points and OS. Spearman ρ, surrogate threshold effect (STE), and R2 were also estimated across predefined trial-level covariates. Results: We included 101 RCTs. In univariate and multivariate meta-analyses, we found larger treatment effects for the surrogates than for OS. Compared with OS, treatment effects were on average 13% higher when HRs were measured and 3% to 45% higher when ORs were considered; differences in median PFS/TTP were higher than on OS by an average of 0.5 month. Spearman ρ ranged from 0.39 to 0.80, mean R2 from 0.06 to 0.65, and STE was 0.8 for HRPFS, 0.64 for HRTTP, or 0.28 for ORTR. The stratified analyses revealed high variability across all strata. Conclusion: None of the end points in this study were found to achieve the level of evidence (ie, mean R2trial > 0.60) that has been set to select high or excellent correlation levels by common surrogate evaluation tools. Previous surrogacy relationships observed between PFS and TTP vs. OS in selected settings may not apply across other classes or lines of therapy

    Beyond Food Security: Understanding Access to Cultural Food for Urban Indigenous People in Winnipeg as Indigenous Food Sovereignty

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    Access to safe, affordable and nutritious food is an obstacle facing many Indigenous people in the inner city of Winnipeg, which is known for having vast food deserts. While food security is an urgent social, economic, cultural and health issue for Indigenous people in urban areas, and particularly those living in inner city areas, there are some unique elements of food security related to cultural values. Access to cultural food in urban communities is a challenge for Indigenous people. This paper discusses the results of some preliminary research conducted which explored the experiences and meanings associated with Indigenous cultural food for Indigenous people living in urban communities and the larger goals of what is being called “Indigenous Food Sovereignty” (IFS) with regards to cultural food specifically. When Indigenous people have the skills to practice IFS, a whole range of positive benefits to their social and economic well-being can unfold. Three themes which emerged from this research include (1) growing, harvesting, preparing and eating cultural food as ceremony, (2) cultural food as a part of connection to land through reciprocity and (3) re-learning IFS to address food insecurity in the city."Th is project was generously funded by the Urban Aboriginal Knowledge Network (SSHRC), Manitoba Research Alliance (SSHRC), Government of Manitoba Ministry of Indigenous Aff airs, University of Winnipeg Major Research Award, University of Winnipeg Partnership Development Grant, and the University of Winnipeg Discretionary Grant."http://cjur.uwinnipeg.ca/index.php/cjur/article/view/

    Population-Based Assessment of a Biomarker-Based Screening Pathway to Aid Diagnosis of Monogenic Diabetes in Young-Onset Patients

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    This is the author accepted manuscript. The final version is available from the American Diabetes Association via the DOI in this record.Objective: Monogenic diabetes, a young-onset form of diabetes, is often misdiagnosed as Type 1 diabetes, resulting in unnecessary treatment with insulin. A screening approach for monogenic diabetes is needed to accurately select suitable patients for expensive diagnostic genetic testing. We used C-peptide and islet autoantibodies, highly sensitive and specific biomarkers for discriminating Type 1 from non-Type 1 diabetes, in a biomarker screening pathway for monogenic diabetes. Research Design and Methods: We studied patients diagnosed ≀30y, currently <50y, in two UK regions with existing high detection of monogenic diabetes. The biomarker screening pathway comprised 3 stages: 1) Assessment of endogenous insulin secretion using urinary C-peptide/creatinine ratio (UCPCR); 2) If UCPCR≄0.2nmol/mmol, measurement of GAD and IA2 islet autoantibodies; 3) If negative for both autoantibodies, molecular genetic diagnostic testing for 35 monogenic diabetes subtypes. Results: 1407 patients participated (1365 no known genetic cause, 34 monogenic diabetes, 8 cystic-fibrosis-related diabetes). 386/1365(28%) had UCPCR≄0.2nmol/mmol. 216/386(56%) of these patients were negative for GAD and IA2 and underwent molecular genetic testing. 17 new cases of monogenic diabetes were diagnosed (8 common MODY (Sanger sequencing), 9 rarer causes (next generation sequencing)) in addition to the 34 known cases (estimated prevalence of 3.6% (51/1407) (95%CI: 2.7-4.7%)). The positive predictive value was 20%, suggesting a 1-in-5 detection rate for the pathway. The negative predictive value was 99.9%. Conclusions: The biomarker screening pathway for monogenic diabetes is an effective, cheap, and easily implemented approach to systematically screening all young-onset patients. The minimum prevalence of monogenic diabetes is 3.6% of patients diagnosed ≀30y.This study was funded by the Department of Health and Wellcome Trust Health Innovation Challenge Award (HICF-1009-041; WT-091985). ATH and SE are Wellcome Trust Senior Investigators. ATH is an NIHR Senior Investigator. BS, ATH, MH, SE, and BK are core members of the NIHR Exeter Clinical Research Facility. EP is a Wellcome Trust New Investigator. TM is supported by NIHR CSO Fellowship. JP is partly funded by the NIHR Collaboration for Leadership in Applied Health Research and Care for the South West (PenCLAHRC)

    A community convention for ecological forecasting: output files and metadata

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    This document summarizes the open community standards developed by the Ecological Forecasting Initiative (EFI) for the common formatting and archiving of ecological forecasts and the metadata associated with these forecasts. Such open standards are intended to promote interoperability and facilitate forecast adoption, distribution, validation, and synthesis. For output files EFI has adopted a three-tiered approach reflecting trade-offs in forecast data volume and technical expertise. The preferred output file format is netCDF following the Climate and Forecast Convention for dimensions and variable naming, including an ensemble dimension where appropriate. The second-tier option is a semi-long CSV format, with state variables as columns and each row representing a unique issue date time, prediction date time, location, ensemble member, etc. The third-tier option is similar to option 2, but each row represents a specific summary statistic (mean, upper/lower CI) rather than individual ensemble members. For metadata, EFI expands upon the Ecological Metadata Language (EML), using additional Metadata tags to store information designed to facilitate cross-forecast synthesis (e.g. uncertainty propagation, data assimilation, model complexity) and setting a subset of base EML tags (e.g. temporal resolution, output variables) to be required. To facilitate community adoption we also provides a R package containing a number of vignettes on how to both write and read in the EFI standard, as well as a metadata validator tool.First author draf
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