2,819 research outputs found

    Overruling Opinions in the Supreme Court

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    Despite its vaunted reputation for rectitude, the United States Supreme Court has been the first to deny its own judicial infallibility. For in at least ninety decisions, dating as far back as 1810 and as recent as its 1956 Term, the Supreme Court has made public confession of error by overruling its previous determinations. This is a study of those ninety decisions-a statistical accounting of overruling cases and cases overruled, and a listing of the judges who agreed and disagreed with what was said and done. And this is a study of the right to be wrong -an inquiry into when and under what circumstances the Supreme Court should overrule its prior dictates

    The Potential Uses of Operational Earthquake Forecasting

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    This article reports on a workshop held to explore the potential uses of operational earthquake forecasting (OEF). We discuss the current status of OEF in the United States and elsewhere, the types of products that could be generated, the various potential users and uses of OEF, and the need for carefully crafted communication protocols. Although operationalization challenges remain, there was clear consensus among the stakeholders at the workshop that OEF could be useful

    Ethnic variations in sexual behaviour in Great Britain and risk of sexually transmitted infections: a probability survey.

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    BACKGROUND: Ethnic variations in the rate of diagnosed sexually transmitted infections (STIs) have been reported in many developed countries. We used data from the second British National Survey of Sexual Attitudes and Lifestyles (Natsal 2000) to investigate the frequency of high-risk sexual behaviours and adverse sexual health outcomes in five ethnic groups in Great Britain. METHODS: We did a stratified probability sample survey of 11161 men and women aged 16-44 years, resident in Great Britain, using computer-assisted interviews. Additional sampling enabled us to do more detailed analyses for 949 black Caribbean, black African, Indian, and Pakistani respondents. We used logistic regression to assess reporting of STI diagnoses in the past 5 years, after controlling for demographic and behavioural variables. FINDINGS: We noted striking variations in number of sexual partnerships by ethnic group and between men and women. Reported numbers of sexual partnerships in a lifetime were highest in black Caribbean (median 9 [IQR 4-20]) and black African (9 [3-20]) men, and in white (5 [2-9]) and black Caribbean (4 [2-7]) women. Indian and Pakistani men and women reported fewer sexual partnerships, later first intercourse, and substantially lower prevalence of diagnosed STIs than did other groups. We recorded a significant association between ethnic origin and reported STIs in the past 5 years with increased risk in sexually active black Caribbean (OR 2.74 [95% CI 1.22-6.15]) and black African (2.95 [1.45-5.99]) men compared with white men, and black Caribbean (2.41 [1.35-4.28]) women compared with white women. Odds ratios changed little after controlling for age, number of sexual partnerships, homosexual and overseas partnerships, and condom use at last sexual intercourse. INTERPRETATION: Individual sexual behaviour is a key determinant of STI transmission risk, but alone does not explain the varying risk across ethnic groups. Our findings suggest a need for targeted and culturally competent prevention interventions

    Pseudo-prospective Evaluation of UCERF3-ETAS Forecasts During the 2019 Ridgecrest Sequence

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    The 2019 Ridgecrest sequence provides the first opportunity to evaluate Uniform California Earthquake Rupture Forecast v.3 with epidemic‐type aftershock sequences (UCERF3‐ETAS) in a pseudoprospective sense. For comparison, we include a version of the model without explicit faults more closely mimicking traditional ETAS models (UCERF3‐NoFaults). We evaluate the forecasts with new metrics developed within the Collaboratory for the Study of Earthquake Predictability (CSEP). The metrics consider synthetic catalogs simulated by the models rather than synoptic probability maps, thereby relaxing the Poisson assumption of previous CSEP tests. Our approach compares statistics from the synthetic catalogs directly against observations, providing a flexible approach that can account for dependencies and uncertainties encoded in the models. We find that, to the first order, both UCERF3‐ETAS and UCERF3‐NoFaults approximately capture the spatiotemporal evolution of the Ridgecrest sequence, adding to the growing body of evidence that ETAS models can be informative forecasting tools. However, we also find that both models mildly overpredict the seismicity rate, on average, aggregated over the evaluation period. More severe testing indicates the overpredictions occur too often for observations to be statistically indistinguishable from the model. Magnitude tests indicate that the models do not include enough variability in forecasted magnitude‐number distributions to match the data. Spatial tests highlight discrepancies between the forecasts and observations, but the greatest differences between the two models appear when aftershocks occur on modeled UCERF3‐ETAS faults. Therefore, any predictability associated with embedding earthquake triggering on the (modeled) fault network may only crystalize during the presumably rare sequences with aftershocks on these faults. Accounting for uncertainty in the model parameters could improve test results during future experiments.Maximilian J. Werner and Warner Marzocchi received funding from the European Union's Horizon 2020 research and innovation program (Number 821115, RISE: Real‐Time Earthquake Risk Reduction for a Resilient Europe). This research was supported by the Southern California Earthquake Center (SCEC; Contribution Number 10082). SCEC is funded by National Science Foundation (NSF) Cooperative Agreement EAR‐1600087 and the U.S. Geological Survey (USGS) Cooperative Agreement G17AC00047

    Superconducting Cosmc Strings and Primordial Magnetic Fields

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    We consider grand unified theories with superconducting cosmic strings and which admit the mechanism for generating primordial magnetic fields recently discussed by Vachaspati. We show that these models are severely constrained by cosmological arguments. Quite generically, either stable springs or vortons will form. Provided the mass per unit length of the strings is sufficiently large, these stable configurations will overclose the Universe.Comment: BROWN-HET-830, 14 pages, use phyzz

    Assessing direct contributions of morphological awareness and prosodic sensitivity to children’s word reading and reading comprehension

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    We examined the independent contributions of prosodic sensitivity and morphological awareness to word reading, text reading accuracy, and reading comprehension. We did so in a longitudinal study of English-speaking children (N = 70). At 5 to 7 years of age, children completed the metalinguistic measures along with control measures of phonological awareness and vocabulary. Children completed the reading measures two years later. Morphological awareness, but not prosodic sensitivity made a significant independent contribution to word reading, text reading accuracy and reading comprehension. The effects of morphological awareness on reading comprehension remained after controls for word reading. These results suggest that morphological awareness needs to be considered seriously in models of reading development and that prosodic sensitivity might have primarily indirect relations to reading outcomes. Keywords: Morphological Awareness; Prosody; Word Reading; Reading Comprehension

    Development and validation of a visual grading scale for assessing image quality of AP pelvis radiographic images

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    OBJECTIVE: Apply psychometric theory to develop and validate a visual grading scale for assessing visual perception of AP pelvis digital image quality. METHODS: Psychometric theory was used to guide scale development. Seven phantom and 7 cadaver images of visually and objectively predetermined quality were used to help assess scale reliability and validity. 151 volunteers scored phantom images; 184 volunteers scored cadaver images. Factor analysis and Cronbach’s alpha were used to assess scale validity and reliability. RESULTS: A 24 item scale was produced. Aggregated mean volunteer scores for each image correlated with the rank order of the visually and objectively predetermined image qualities. Scale items had good inter-item correlation (≥0.2) and high factor loadings (≥0.3). Cronbach's alpha (reliability) revealed that the scale has acceptable levels of internal reliability for both phantom and cadaver images (α= 0.8 and 0.9, respectively). Factor analysis suggested the scale is multidimensional (assessing multiple quality themes). CONCLUSION: This study represents the first full development and validation of a visual image quality scale using psychometric theory. It is likely that this scale will have clinical, training and research applications. ADVANCES IN KNOWLEDGE: This article presents data to create and validate visual grading scales for radiographic examinations. The visual grading scale, for AP pelvis examinations, can act as a validated tool for future research, teaching and clinical evaluations of image quality

    Medicated sex in Britain: evidence from the third National Survey of Sexual Attitudes and Lifestyles.

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    OBJECTIVES: To describe the prevalence of medication use to assist sexual performance in Britain and to identify associated factors. METHODS: Cross-sectional probability sample, undertaken in 2010-2012, of 15 162 people aged 16-74 years, resident in Britain, of whom, 5617 men and 8095 women reported sexual experience (ever) and 4817 men were sexually-active (reported sex in the last year). RESULTS: Ever use of medication to assist sexual performance (medicated sex) was more commonly reported by men than women (12.9% (95% CI 11.9% to 13.9%) vs 1.9% (95% CI 1.7% to 2.3%)) and associated with older age in men and younger age in women. It was associated with reporting smoking, and use of alcohol and recreational drugs, as well as unsafe sex (≥2 partners and no condom use in the last year) in both men and women. Among men, the proportion reporting medicated sex in the last year was higher among those reporting erectile difficulties (ED) than those not doing so (28.4% (95% CI 24.4% to 32.8%) vs 4.1% (95% CI 3.4% to 4.9%)). In all men, medicated sex was associated with more frequent sexual activity, meeting a partner on the internet, unsafe sex and recent sexually transmitted infections diagnosis; associations that persisted after adjusting for same-sex behaviour and ED. However, there were significant interactions with reporting ED, indicating that among men with ED, medicated sex is not associated with same-sex behaviour and ever use of recreational drugs. CONCLUSIONS: A substantial minority of people in Britain report medicated sex, and the association between medicated sex and risky sexual behaviour is not confined to high-risk groups
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