13 research outputs found

    The virtues of small grain size: Potential pathways to a distinguishing feature of Asian wheats

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    Increase in grain/seed size recurrently features as a key element in the ‘domestication syndrome’ of plants (cf. Zohary and Hopf 2000; Fuller et al. 2014). In the context of its spread across Eurasia, however, the grain size of one of the world's major crop species underwent a substantial reduction. Between the fifth and second millennia BC, the grain length in a number of species of Triticum, collectively known as free-threshing wheat, decreased by around 30%. In order to understand and help account for this trend, we have obtained direct radiocarbon measurements from 51 charred wheat grains and measured the dimensions of several hundred grains from Asia to establish when and where that size diminution occurred. Our results indicate that the pace of a eastward/southward spread was interrupted around 1800 BC on the borders of the distinct culinary zone recognized by Fuller and Rowlands (2011), but regained pace around 200–300 years later in central-east China with a diminished grain size. We interpret this as evidence of a period of active crop selection to suit culinary needs, and consider whether it constitutes a distinct episode in the general character of genetic intervention in domesticated species.Financial support was provided by the European Research Council, under grant 249642 (FOGLIP), UKIERI – UK & India Collaborative Educational Research Initiative, and the International Center for Advanced Renewable Energy and Sustainability, Washington University in St. Louis

    Do patients with osteoporosis have an increased prevalence of periodontal disease? A cross-sectional study

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    The study examined if women with osteoporosis were at increased risk of periodontal disease. Three hundred eighty females aged 45-65 years with recent dual-energy X-ray absorptiometry (DXA) scans of the spine and proximal femur agreed to a dental examination. No association was established between the presence of severe periodontal disease and osteoporosis. Introduction: The purpose of this study is to determine whether patients with osteoporosis have an increased severity and extent of periodontal disease, taking full account of confounding factors. Methods: Volunteer dentate women (45-65 years), who had undergone recent DXA of the femur and lumbar spine, received a clinical examination of their periodontal tissues by a single trained operator who was blind to the subject's osteoporosis status. Clinical examinations were performed within 6 months of the DXA. Basic Periodontal Examination score, gingival bleeding score, periodontal pocket depth, recession and calculus were the periodontal outcome measures. Potential confounding factors were recorded. Logistic regression was performed for the dichotomous outcome measure of severe periodontal disease (present or absent) with osteoporotic status, adjusting for confounding factors. Results: There were 380 dentate participants for whom DXA data were available. Of these, 98 had osteoporosis. When compared with osteoporotic subjects, those with normal bone mineral density were significantly younger (p = 0.01), had a higher body mass index (p = 0.03) and had more teeth (p = 0.01). The prevalence of severe periodontal disease in the sample was 39 %. The unadjusted odds ratio for the association between osteoporosis and severe periodontal disease was 1.21 (0.76 to 1.93). The adjusted odds ratio analysis including other covariates (age, smoking, hormone replacement therapy, alcohol) was 0.99 (0.61 to 1.61). Conclusion: No association was established between the presence of severe periodontal disease and osteoporosis. © 2012 International Osteoporosis Foundation and National Osteoporosis Foundation

    Proposal of a Quality-Index or Metric for Soft Copy Display Systems: Contrast Sensitivity Study

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    In addition to the inherent qualities of a digital image, the qualities of the monitor and graphics control card as well as the viewing conditions will affect the perceived quality of an image that is displayed on a soft copy display (SD) system. With the implementation of picture archiving and communication systems (PACS), many diagnoses are being made based on images displayed on SD devices, and consequently SD quality may affect the accuracy of diagnosis. Unlike the traditional film-on-lightbox display, optimal SD system parameters are not well defined, and many issues remain unsettled. In this article, the human observer performance, as measured by contrast sensitivity, for several SD devices including an active matrix liquid crystal flat panel monitor is reported. Contrast sensitivities were measured with various display system configurations. Experimental results showed that contrast sensitivity depends on many factors such as the type of monitor, the monitor brightness, and the gamma settings of the graphics card in a complex manner. However, there is a clear correlation between the measured contrast thresholds and the gradient of the display device’s luminance response curve. Based on this correlation, it is proposed to use the gradient of luminance response curve as a quality-index or metric for SD devices
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