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Catherine M. Cupples M.S. ; Jarrod R. Champagne M.S. ; Kristen E. Lewis M.S. ; Tracey Dawson Cruz Ph.D. 《Journal of forensic sciences》2009,54(1):103-107
Abstract: Screening methods capable of identifying DNA samples that will not yield short tandem repeat (STR) profiles are desired. In the past, quantitation methods have not been sensitive enough for this purpose. In this study, low level DNA samples were used to assess whether Quantifiler™ has a minimum quantitation value below which STR profiles would consistently fail to be detected. Buccal swabs were obtained and the DNA extracted, quantified, and serially diluted to concentrations ranging from 0.002 to 0.250 ng/μL. Samples were analyzed once with Quantifiler™, followed by Profiler Plus™ amplification and capillary electrophoresis analysis. An absolute minimum value below which STR results were unobtainable could not be defined. From the 96 low level samples tested, STR loci (including one full profile) were successfully amplified and detected from 27% of the samples "undetected" by Quantifiler™. However, no STR alleles were detected in 73% of these "undetected" samples, indicating that Quantifiler™ data may be useful for predicting STR typing success. 相似文献
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Emma A. Levin M.Res. Ruth M. Morgan D.Phil. Lewis D. Griffin Ph.D. Vivienne J. Jones Ph.D. 《Journal of forensic sciences》2019,64(2):431-442
Image segmentation is a fundamental precursor to quantitative image analysis. At present, no standardised methodology exists for segmenting images of fluorescent proxies for trace evidence. Experiments evaluated (i) whether manual segmentation is reproducible within and between examiners (with three participants repeatedly tracing three images) (ii) whether manually defining a threshold level offers accurate and reproducible results (with 20 examiners segmenting 10 images), and (iii) whether a global thresholding algorithm might perform with similar accuracy, while offering improved reproducibility and efficiency (16 algorithms tested). Statistically significant differences were seen between examiners’ traced outputs. Manually thresholding produced good accuracy on average (within ±1% of the expected values), but poor reproducibility (with multiple outliers). Three algorithms (Yen, MaxEntropy, and RenyiEntropy) offered similar accuracy, with improved reproducibility and efficiency. Together, these findings suggest that appropriate algorithms could perform thresholding tasks as part of a robust workflow for reconstruction studies employing fluorescent proxies for trace evidence. 相似文献
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This article analyses in detail the fact that there has beenalmost no dissent in World Trade Organization (WTO) disputesettlement reports. Only a handful of articles have noted thisphenomenon, even in passing. The article first examines theempirical data with respect to dissenting and concurring opinionsat both the panel and Appellate Body levels. Fewer than 5% ofpanel reports and 2% of Appellate Body reports contain separateopinions of any kind. Second, it shows that the WTO is in factactively discouraging dissents and discusses why this mightbe the case. The article argues that dissents are valuable ingeneral and assesses whether more dissents would be a positivefor the WTO. It then reviews the few dissents that have beenpublished and demonstrates that 50% of the arguments raisedin dissents at the panel level were adopted in whole or in parton appeal by the Appellate Body, thus illustrating dissentscan and do make a difference. The article concludes that keepingthe lid on dissents may ultimately erode the strength of thedispute settlement system and hinder the ability of the WTOMembers to make appropriate changes to the Agreements. 相似文献
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