1,253 research outputs found

    Determining The Cost Effectiveness Of Solutions To Diffuse Pollution: Developing A Model To Assess In-Field Mitigation Options for Phosphorous and Sediment Loss

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    The European Union Water Framework Directive requires governments to set water quality objectives based on good ecological status. This includes specific requirements to control diffuse pollution. Diffuse phosphorous (P) pollution plays a pivotal role in influencing water quality with losses of P associated with soil particles often linked to soil erosion. The Mitigation Options for Phosphorus and Sediment (MOPS) project, using three case study sites, is investigating the cost effectiveness of specific control measures in terms of mitigating sediment and P loss from combinable crops. The analysis is conducted at the farm level using a simple spreadsheet model. Further development of the model will allow the results to be extrapolated to generic regional farm typologies. Results from the initial farm level analysis suggest that some mitigation options may not be cost effective in reducing diffuse pollution, however, that other options may be very cost effective.Resource /Energy Economics and Policy,

    GeneLink: a database to facilitate genetic studies of complex traits

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    BACKGROUND: In contrast to gene-mapping studies of simple Mendelian disorders, genetic analyses of complex traits are far more challenging, and high quality data management systems are often critical to the success of these projects. To minimize the difficulties inherent in complex trait studies, we have developed GeneLink, a Web-accessible, password-protected Sybase database. RESULTS: GeneLink is a powerful tool for complex trait mapping, enabling genotypic data to be easily merged with pedigree and extensive phenotypic data. Specifically designed to facilitate large-scale (multi-center) genetic linkage or association studies, GeneLink securely and efficiently handles large amounts of data and provides additional features to facilitate data analysis by existing software packages and quality control. These include the ability to download chromosome-specific data files containing marker data in map order in various formats appropriate for downstream analyses (e.g., GAS and LINKAGE). Furthermore, an unlimited number of phenotypes (either qualitative or quantitative) can be stored and analyzed. Finally, GeneLink generates several quality assurance reports, including genotyping success rates of specified DNA samples or success and heterozygosity rates for specified markers. CONCLUSIONS: GeneLink has already proven an invaluable tool for complex trait mapping studies and is discussed primarily in the context of our large, multi-center study of hereditary prostate cancer (HPC). GeneLink is freely available at

    Evaluation of random forests performance for genome-wide association studies in the presence of interaction effects

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    Random forests (RF) is one of a broad class of machine learning methods that are able to deal with large-scale data without model specification, which makes it an attractive method for genome-wide association studies (GWAS). The performance of RF and other association methods in the presence of interactions was evaluated using the simulated data from Genetic Analysis Workshop 16 Problem 3, with knowledge of the major causative markers, risk factors, and their interactions in the simulated traits. There was good power to detect the environmental risk factors using RF, trend tests, or regression analyses but the power to detect the effects of the causal markers was poor for all methods. The causal marker that had an interactive effect with smoking did show moderate evidence of association in the RF and regression analyses, suggesting that RF may perform well at detecting such interactions in larger, more highly powered datasets

    A pre-post study testing a lung cancer screening decision aid in primary care

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    Abstract Background The United States Preventive Services Task Force (USPSTF) issued recommendations for older, heavy lifetime smokers to complete annual low-dose computed tomography (LDCT) scans of the chest as screening for lung cancer. The USPSTF recommends and the Centers for Medicare and Medicaid Services require shared decision making using a decision aid for lung cancer screening with annual LDCT. Little is known about how decision aids affect screening knowledge, preferences, and behavior. Thus, we tested a lung cancer screening decision aid video in screening-eligible primary care patients. Methods We conducted a single-group study with surveys before and after decision aid viewing and medical record review at 3 months. Participants were active patients of a large US academic primary care practice who were current or former smokers, ages 55–80 years, and eligible for screening based on current screening guidelines. Outcomes assessed pre-post decision aid viewing were screening-related knowledge score (9 items about screening-related harms of false positives and overdiagnosis, likelihood of benefit; score range = 0–9) and preference (preferred screening vs. not). Screening behavior measures, assessed via chart review, included provider visits, screening discussion, LDCT ordering, and LDCT completion within 3 months. Results Among 50 participants, knowledge increased from pre- to post-decision aid viewing (mean = 2.6 vs. 5.5, difference = 2.8; 95% CI 2.1, 3.6, p < 0.001). Preferences across the overall sample remained similar such that 54% preferred screening at baseline and 50% after viewing; however, 28% of participants changed their preference (to or away from screening) from baseline to after viewing. We assessed screening behavior for 36 participants who had a primary care visit during the 3-month period following enrollment. Eighteen of 36 preferred screening after decision aid viewing. Of these 18, 10 discussed screening, 8 had a test ordered, and 6 completed LDCT. Among the 18 who preferred no screening, 7 discussed screening, 5 had a test ordered, and 4 completed LDCT. Conclusions In primary care patients, a lung cancer screening decision aid improved knowledge regarding screening-related benefits and harms. Screening preferences and behavior were heterogeneous. Trial registration This study is registered at www.clinicaltrials.gov . NCT03077230 (registered retrospectively,November 22, 2016)

    Identification of tag single-nucleotide polymorphisms in regions with varying linkage disequilibrium

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    We compared seven different tagging single-nucleotide polymorphism (SNP) programs in 10 regions with varied amounts of linkage disequilibrium (LD) and physical distance. We used the Collaborative Studies on the Genetics of Alcoholism dataset, part of the Genetic Analysis Workshop 14. We show that in regions with moderate to strong LD these programs are relatively consistent, despite different parameters and methods. In addition, we compared the selected SNPs in a multipoint linkage analysis for one region with strong LD. As the number of selected SNPs increased, the LOD score, mean information content, and type I error also increased
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