87 research outputs found

    Standard survey methods for estimating colony losses and explanatory risk factors in Apis mellifera

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    This chapter addresses survey methodology and questionnaire design for the collection of data pertaining to estimation of honey bee colony loss rates and identification of risk factors for colony loss. Sources of error in surveys are described. Advantages and disadvantages of different random and non-random sampling strategies and different modes of data collection are presented to enable the researcher to make an informed choice. We discuss survey and questionnaire methodology in some detail, for the purpose of raising awareness of issues to be considered during the survey design stage in order to minimise error and bias in the results. Aspects of survey design are illustrated using surveys in Scotland. Part of a standardized questionnaire is given as a further example, developed by the COLOSS working group for Monitoring and Diagnosis. Approaches to data analysis are described, focussing on estimation of loss rates. Dutch monitoring data from 2012 were used for an example of a statistical analysis with the public domain R software. We demonstrate the estimation of the overall proportion of losses and corresponding confidence interval using a quasi-binomial model to account for extra-binomial variation. We also illustrate generalized linear model fitting when incorporating a single risk factor, and derivation of relevant confidence intervals

    The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions

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    Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∼120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella

    Evaluating the role of quality assessment of primary studies in systematic reviews of cancer practice guidelines

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    BACKGROUND: The purpose of this study was to evaluate the role of study quality assessment of primary studies in cancer practice guidelines. METHODS: Reliable and valid study quality assessment scales were sought and applied to published reports of trials included in systematic reviews of cancer guidelines. Sensitivity analyses were performed to evaluate the relationship between quality scores and pooled odds ratios (OR) for mortality and need for blood transfusion. RESULTS: Results found that that whether trials were classified as high or low quality depended on the scale used to assess them. Although the results of the sensitivity analyses found some variation in the ORs observed, the confidence intervals (CIs) of the pooled effects from each of the analyses of high quality trials overlapped with the CI of the pooled odds of all trials. Quality score was not predictive of pooled ORs studied here. CONCLUSIONS: Had sensitivity analyses based on study quality been conducted prospectively, it is highly unlikely that different conclusions would have been found or that different clinical recommendations would have emerged in the guidelines

    Primary biliary cirrhosis and autoimmune cholangitis are not associated with coeliac disease in Crete

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    BACKGROUND: An increased prevalence of coeliac disease in patients with primary biliary cirrhosis has been recently reported. However, in other studies the association has not been confirmed. There have been no formal attempts to systematically evaluate patients with autoimmune cholangitis for coeliac disease. METHODS: Sera from 62 patients with primary biliary cirrhosis, 17 with autoimmune cholangitis and 100 blood donors were screened for anti-gliadin, anti-endomysial, anti-reticulin, and IgA class antibodies to guinea pig liver-derived tissue transglutaminase. Eighteen untreated coeliacs served as methodological controls. Analyses were performed by using the χ(2) and Fischer's exact tests. RESULTS: Anti-gliadin antibodies were detected in 21% of patients with primary biliary cirrhosis, 35% of patients with autoimmune cholangitis, and 3% of controls (p < 0.001). IgA class gliadin antibodies positivity was more pronounced in patients with Scheuer's stage III-IV disease (p < 0.05). Anti-transglutaminase antibodies were detected in 10% and in 18% of patients with primary biliary cirrhosis and autoimmune cholangitis respectively (p < 0.001). Anti-reticulin and anti-endomysial antibodies were negative in all patients. Duodenal biopsies were performed in 59% and 71% of patients with primary biliary cirrhosis and autoimmune cholangitis respectively, tested positive for at least one antibody class. No histological features of coeliac disease were found. CONCLUSIONS: We were unable to demonstrate an increased risk of coeliac disease in patients with primary biliary cirrhosis and autoimmune cholangitis. Our results confirm the previously reported high prevalence of false-positive anti-gliadin and guinea pig liver-derived anti-tissue transglutaminase antibodies in patients with chronic liver disease

    Beyond national narratives? : centenary histories, the First World War and the Armenian Genocide

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    In April 2015 the centenary of the Armenian Genocide was commemorated. Just like the First World War centenary, this anniversary has provoked a flurry of academic and public interest in what remains a highly contested history. This article assesses the state of the current historiography on the fate of the Ottoman Armenians. It focuses on the possibilities for moving beyond the national narratives which continue to dominate the field, in particular through connecting the case of the Armenian Genocide to what has been termed a ‘transnational turn’ in the writing of the history of the First World War

    Scalable whole-exome sequencing of cell-free DNA reveals high concordance with metastatic tumors

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    Whole-exome sequencing of cell-free DNA (cfDNA) could enable comprehensive profiling of tumors from blood but the genome-wide concordance between cfDNA and tumor biopsies is uncertain. Here we report ichorCNA, software that quantifies tumor content in cfDNA from 0.1× coverage whole-genome sequencing data without prior knowledge of tumor mutations. We apply ichorCNA to 1439 blood samples from 520 patients with metastatic prostate or breast cancers. In the earliest tested sample for each patient, 34% of patients have ≥10% tumor-derived cfDNA, sufficient for standard coverage whole-exome sequencing. Using whole-exome sequencing, we validate the concordance of clonal somatic mutations (88%), copy number alterations (80%), mutational signatures, and neoantigens between cfDNA and matched tumor biopsies from 41 patients with ≥10% cfDNA tumor content. In summary, we provide methods to identify patients eligible for comprehensive cfDNA profiling, revealing its applicability to many patients, and demonstrate high concordance of cfDNA and metastatic tumor whole-exome sequencing
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