17,761 research outputs found

    "The American Jewish Committee’s Annual Opinion Surveys: An Assessment of Sample Quality"

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    The American Jewish Committee (AJC) surveys of Jewish opinion are unique both in being conducted annually and in the subject matter covered. This paper assesses the quality of these samples. I first summarize my earlier findings on the implications of limiting a sample to respondents who answered “Jewish” when asked a screening question about their religion. I then explore how well the AJC samples actually represent the chosen target population of Jews by religion. That exploration rests on public use datasets available for five recent AJC survey years. Outcomes from these five datasets can be compared to one another as well as to outcomes from public use datasets of two other recent national surveys of Jews, especially on the demographic characteristics of the respondents. The paper finds some larger-than-expected differences among AJC samples, and between these and the other two types of datasets. Finally, the paper considers the extent to which these differences matter for the substantive analysis of American Jewish opinion.

    LGSQE: Lightweight Generated Sample Quality Evaluatoin

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    Despite prolific work on evaluating generative models, little research has been done on the quality evaluation of an individual generated sample. To address this problem, a lightweight generated sample quality evaluation (LGSQE) method is proposed in this work. In the training stage of LGSQE, a binary classifier is trained on real and synthetic samples, where real and synthetic data are labeled by 0 and 1, respectively. In the inference stage, the classifier assigns soft labels (ranging from 0 to 1) to each generated sample. The value of soft label indicates the quality level; namely, the quality is better if its soft label is closer to 0. LGSQE can serve as a post-processing module for quality control. Furthermore, LGSQE can be used to evaluate the performance of generative models, such as accuracy, AUC, precision and recall, by aggregating sample-level quality. Experiments are conducted on CIFAR-10 and MNIST to demonstrate that LGSQE can preserve the same performance rank order as that predicted by the Frechet Inception Distance (FID) but with significantly lower complexity

    Ensuring sample quality for biomarker discovery studies - Use of ict tools to trace biosample life-cycle

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    The growing demand of personalized medicine marked the transition from an empirical medicine to a molecular one, aimed at predicting safer and more effective medical treatment for every patient, while minimizing adverse effects. This passage has emphasized the importance of biomarker discovery studies, and has led sample availability to assume a crucial role in biomedical research. Accordingly, a great interest in Biological Bank science has grown concomitantly. In biobanks, biological material and its accompanying data are collected, handled and stored in accordance with standard operating procedures (SOPs) and existing legislation. Sample quality is ensured by adherence to SOPs and sample whole life-cycle can be recorded by innovative tracking systems employing information technology (IT) tools for monitoring storage conditions and characterization of vast amount of data. All the above will ensure proper sample exchangeability among research facilities and will represent the starting point of all future personalized medicine-based clinical trials

    Statistical Evaluation of Geochemical Au Sample Quality

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    Exploration and mining activities are based on anomalous occurrence of minerals. The basic concept governing this high risk venture is ‘no ore, no mining’. Hence, the quality of anomalous sample or its accurate determination is of great concern to exploration and mining operations. Regarding erratic mineralisation such as gold (Au), anomalous pattern of no significance whatsoever may appear in geochemical sample data as a result of poor sampling, improper sample handling or error in analytical techniques among other causes. To prevent the frequency of these occurrences, quality control checks coupled with classical statistical probe can form an integral part of the checklist to eliminate these errors. Although duplicate results have often accompanied original Au assays in most analytical reports submitted by laboratories, it is not immediately known upon what b asis the results need to be accepted or rejected. Often, some geologists accept results upon quick sight comparison. A total of three hundred and ninety (390) geochemical soil samples from the Sefwi-Bibiani belt of Ghana together with some blanks and standards were subjected to statistical analysis after following rigorous quality control sampling protocols. The statistical models employed include outlier test, distribution and correlation analysis. The original and duplicate samples were then statistically compared using simple nested One –Way Analysis of Variance (ANOVA), the Chi Square Test and the Student’s t –Test.The ANOVA and the t–Tests revealed no significant analytical error. However, the other tests indicated multimodality of the populations as well as batch effect which culminates into significant procedural error. The investigation concludes that these systematic procedural errors if unchecked could mask true geochemical distribution

    NMR for sample quality assessment in metabolomics.

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    Abstract The EU Framework 7 project SPIDIA was the occasion for development of NMR approaches to evaluate the impact of different pre-analytical treatments on the quality of biological samples dedicated to metabolomics. Systematic simulation of different pre-analytical procedures was performed on urine and blood serum and plasma. Here we review the key aspects of these studies that have led to the development of CEN technical specifications, to be translated into ISO/IS in the course of the EU Horizon 2020 project SPIDIA4P. Inspired by the SPIDIA results, follow-up research was performed, extending the analysis to different sample types and to the different effects of long-term storage. The latter activity was in conjunction with the local European da Vinci Biobank. These results (which partially contributed to the ANNEX of CEN/TS 16945"MOLECULAR IN VITRO DIAGNOSTIC EXAMINATIONS - SPECIFICATIONS FOR PRE-EXAMINATION PROCESSES FOR METABOLOMICS IN URINE, VENOUS BLOOD SERUM AND PLASMA") are presented in detail

    A- and B-Exciton Photoluminescence Intensity Ratio as a Measure of Sample Quality for Transition Metal Dichalcogenide Monolayers

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    The photoluminescence (PL) in monolayer transition metal dichalcogenides (TMDs) is dominated by recombination of electrons in the conduction band with holes in the spin-orbit split valence bands, and there are two distinct emission features referred to as the A-peak (ground state exciton) and B-peak (higher spin-orbit split state). The intensity ratio of these two features varies widely and several contradictory interpretations have been reported. We analyze the room temperature PL from MoS2, MoSe2, WS2, and WSe2 monolayers and show that these variations arise from differences in the non-radiative recombination associated with defect densities. Hence, the relative intensities of the A- and B-emission features can be used to qualitatively asses the non-radiative recombination, and thus the quality of the sample. A low B/A ratio is indicative of low defect density and high sample quality. Emission from TMD monolayers is governed by unique optical selection rules which make them promising materials for valleytronic operations. We observe a notably higher valley polarization in the B-exciton relative to the A-exciton. The high polarization is a consequence of the shorter B-exciton lifetime resulting from rapid relaxation of excitons from the B-exciton to the A-exciton of the valence band.Comment: Final version is published online at APL Material

    Sample quality control documents for local CPA firms

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    https://egrove.olemiss.edu/aicpa_guides/1280/thumbnail.jp

    Effect of annealing on the specific heat of Ba(Fe1-xCox)2As2

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    We report on the effect of annealing on the temperature and field dependencies of the low temperature specific heat of the electron-doped Ba(Fe1x_{1-x}Cox_{x})2_{2}As2_{2} for under-(x = 0.045), optimal- (x = 0.08) and over-doped (x = 0.105 and 0.14) regimes. We observed that annealing significantly improves some superconducting characteristics in Ba(Fe1x_{1-x}Cox_{x})2_{2}As2_{2}. It considerably increases TcT_{c}, decreases γ0\gamma_{0} in the superconducting state and suppresses the Schottky-like contribution at very low temperatures. The improved sample quality allows for a better identification of the superconducting gap structure of these materials. We examine the effects of doping and annealing within a self-consistent framework for an extended s-wave pairing scenario. At optimal doping our data indicates the sample is fully gapped, while for both under and overdoped samples significant low-energy excitations possibly consistent with a nodal structure remain. The difference of sample quality offers a natural explanation for the variation in low temperature power laws observed by many techniques.Comment: 9 pages: added references, two figures and supplementary information; Accepted to Physical Review B (Jan 10, 2010
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