1,045 research outputs found

    Performance of a quality assurance program for assessing dental health in methamphetamine users.

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    BackgroundSystematic characterization of the dental consequences of methamphetamine (MA) abuse presupposes a rigorous quality assurance (QA) program to ensure the credibility of the data collected and the scientific integrity and validity of the clinical study. In this report we describe and evaluate the performance of a quality assurance program implemented in a large cross-sectional study of the dental consequences of MA use.MethodsA large community sample of MA users was recruited over a 30 month period during 2011-13 and received comprehensive oral examinations and psychosocial assessments by site examiners based at two large community health centers in Los Angeles. National Health and Nutrition Examination Survey (NHANES) protocols for oral health assessments were utilized to characterize dental disease. Using NHANES oral health quality assurance guidelines, examiner reliability statistics such as Cohen's Kappa coefficients and inter-class correlation coefficients were calculated to assess the magnitude of agreement between the site examiners and a reference examiner to ensure conformance and comparability with NHANES practices.ResultsApproximately 9% (n = 49) of the enrolled 574 MA users received a repeat dental caries and periodontal examination conducted by the reference examiner. There was high concordance between the reference examiner and the site examiners for identification of untreated dental disease (Kappa statistic values: 0.57-0.75, percent agreement 83-88%). For identification of untreated caries on at least 5 surfaces of anterior teeth, the Kappas ranged from 0.77 to 0.87, and percent agreement from 94 to 97%. The intra-class coefficients (ICCs) ranged from 0.87 to 89 for attachment loss across all periodontal sites assessed and the ICCs ranged from 0.79 to 0.81 for pocket depth. For overall gingival recession, the ICCs ranged from 0.88 to 0.91. When Kappa was calculated based on the CDC/AAP case definitions for severe periodontitis, inter-examiner reliability for site examiners was low (Kappa 0.27-0.67).ConclusionOverall, the quality assurance program confirmed the procedural adherence of the quality of the data collected on the distribution of dental caries and periodontal disease in MA-users. Examiner concordance was higher for dental caries but lower for specific periodontal assessments

    Supplementary Material for a Functional Classification of Hawaiian Curved-Edge Adzes and Gouges

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    This document describes 24 Hawaiian adzes from the collection of B.P. Bishop Museum in Honolulu, Hawaiʻi. It supplements and partially reproduces an article by the authors entitled ”Functional classification of Hawaiian curved-edge adzes and gouges” that was published in the Journal of Pacific Archaeology

    Supplementary Material for States Without Archaeological Correlates? A Report from Hawai‘i James M. Bayman, Thomas S. Dye, and Timothy M. Rieth

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    This file contains links to the OxCal input files used to create Figures 1–3 in the paper, "States Without Archaeological Correlates? A Report from Hawai‘i" (table 1). It also includes source code for the R statistical software routines used to produce the graphic files for the figures.This file contains links to the OxCal input files used to create Figures 1–3 in the paper, "States Without Archaeological Correlates? A Report from Hawai‘i" (table 1). It also includes source code for the R statistical software routines used to produce the graphic files for the figures

    Interface characteristics in an {\alpha}+{\beta} titanium alloy

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    The alpha/beta interface in Ti-6Al-2Sn-4Zr-6Mo (Ti-6246) is investigated via centre of symmetry analysis, both as-grown and after 10% cold work. Semi-coherent interface steps are observed at a spacing of 4.5 +/-1.13 atoms in the as-grown condition, in good agreement with theory prediction (4.37 atoms). Lattice accommodation is observed, with elongation along [-1 2 -1 0]alpha and contraction along [1 0 -1 0]alpha . Deformed alpha exhibited larger, less coherent steps with slip bands lying in {110}beta. This indicates dislocation pile-up at the grain boundary, a precursor to globularisation, offering insight into the effect of deformation processing on the interface, which is important for titanium alloy processing route design.Comment: Revised after revie

    Characterizing degradation gradients through land cover change analysis in rural Eastern Cape, South Africa

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    CITATION: Munch, Z., et al. 2017. Characterizing degradation gradients through land cover change analysis in rural Eastern Cape, South Africa. Geosciences, 7(1):7, doi:10.3390/geosciences7010007.The original publication is available at http://www.mdpi.comLand cover change analysis was performed for three catchments in the rural Eastern Cape, South Africa, for two time steps (2000 and 2014), to characterize landscape conversion trajectories for sustained landscape health. Land cover maps were derived: (1) from existing data (2000); and (2) through object-based image analysis (2014) of Landsat 8 imagery. Land cover change analysis was facilitated using land cover labels developed to identify landscape change trajectories. Land cover labels assigned to each intersection of the land cover maps at the two time steps provide a thematic representation of the spatial distribution of change. While land use patterns are characterized by high persistence (77%), the expansion of urban areas and agriculture has occurred predominantly at the expense of grassland. The persistence and intensification of natural or invaded wooded areas were identified as a degradation gradient within the landscape, which amounted to almost 10% of the study area. The challenge remains to determine significant signals in the landscape that are not artefacts of error in the underlying input data or scale of analysis. Systematic change analysis and accurate uncertainty reporting can potentially address these issues to produce authentic output for further modelling.http://www.mdpi.com/2076-3263/7/1/7Publisher's versio

    Elastic precursor of the transformation from glycolipid-nanotube to -vesicle

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    By the combination of optical tweezer manipulation and digital video microscopy, the flexural rigidity of single glycolipid "nano" tubes has been measured below the transition temperature at which the lipid tubules are transformed into vesicles. Consequently, we have found a clear reduction of the rigidity obviously before the transition as temperature increasing. Further experiments of infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) have suggested a microscopic change of the tube walls, synchronizing with the precursory softening of the nanotubes.Comment: 9 pages, 6 figure

    Relative performance evaluation contracts and asset market equilibrium

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    We analyse the equilibrium consequences of performance-based contracts for fund managers. Managerial remuneration is tied to a fund's absolute and relative performance. Investors choose whether or not to delegate their investment to better-informed fund managers; if they delegate they choose the optimal contract subject to the fund manager's participation constraint. We find that the impact of relative performance evaluation on the equilibrium equity premium and on portfolio herding critically depends on whether the participation constraint is binding. Simple numerical examples suggest that the increased importance of delegation and relative performance evaluation may lower the equity premium

    Breaking new ground in mapping human settlements from space -The Global Urban Footprint-

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    Today 7.2 billion people inhabit the Earth and by 2050 this number will have risen to around nine billion, of which about 70 percent will be living in cities. Hence, it is essential to understand drivers, dynamics, and impacts of the human settlements development. A key component in this context is the availability of an up-to-date and spatially consistent map of the location and distribution of human settlements. It is here that the Global Urban Footprint (GUF) raster map can make a valuable contribution. The new global GUF binary settlement mask shows a so far unprecedented spatial resolution of 0.4 arcsec (12m\sim12 m) that provides - for the first time - a complete picture of the entirety of urban and rural settlements. The GUF has been derived by means of a fully automated processing framework - the Urban Footprint Processor (UFP) - that was used to analyze a global coverage of more than 180,000 TanDEM-X and TerraSAR-X radar images with 3m ground resolution collected in 2011-2012. Various quality assessment studies to determine the absolute GUF accuracy based on ground truth data on the one hand and the relative accuracies compared to established settlements maps on the other hand, clearly indicate the added value of the new global GUF layer, in particular with respect to the representation of rural settlement patterns. Generally, the GUF layer achieves an overall absolute accuracy of about 85\%, with observed minima around 65\% and maxima around 98 \%. The GUF will be provided open and free for any scientific use in the full resolution and for any non-profit (but also non-scientific) use in a generalized version of 2.8 arcsec (84m\sim84m). Therewith, the new GUF layer can be expected to break new ground with respect to the analysis of global urbanization and peri-urbanization patterns, population estimation or vulnerability assessment
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