3,204 research outputs found

    G-38, 39 and 40: An artist's exploration of space

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    Three experiments are described which use space processing technology in the formation of and coating of bubbles and spheres to be orbited as sculptures visible from Earth. In one experiment, a 22,000 m1 sphere is to ride into orbit containing a 15 psi Earth atmosphere. Once in orbit, a controller directs a valve to open, linking the sphere to a vacuum of space. Technologies used in the fabrication of these art forms include vacuum film deposition and large bubble formation in the space environment

    A statistical analysis of multiple temperature proxies: Are reconstructions of surface temperatures over the last 1000 years reliable?

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    Predicting historic temperatures based on tree rings, ice cores, and other natural proxies is a difficult endeavor. The relationship between proxies and temperature is weak and the number of proxies is far larger than the number of target data points. Furthermore, the data contain complex spatial and temporal dependence structures which are not easily captured with simple models. In this paper, we assess the reliability of such reconstructions and their statistical significance against various null models. We find that the proxies do not predict temperature significantly better than random series generated independently of temperature. Furthermore, various model specifications that perform similarly at predicting temperature produce extremely different historical backcasts. Finally, the proxies seem unable to forecast the high levels of and sharp run-up in temperature in the 1990s either in-sample or from contiguous holdout blocks, thus casting doubt on their ability to predict such phenomena if in fact they occurred several hundred years ago. We propose our own reconstruction of Northern Hemisphere average annual land temperature over the last millennium, assess its reliability, and compare it to those from the climate science literature. Our model provides a similar reconstruction but has much wider standard errors, reflecting the weak signal and large uncertainty encountered in this setting.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS398 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Hierarchical Bayesian Modeling of Hitting Performance in Baseball

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    We have developed a sophisticated statistical model for predicting the hitting performance of Major League baseball players. The Bayesian paradigm provides a principled method for balancing past performance with crucial covariates, such as player age and position. We share information across time and across players by using mixture distributions to control shrinkage for improved accuracy. We compare the performance of our model to current sabermetric methods on a held-out season (2006), and discuss both successes and limitations

    The long-term effects of a police-school program on attitudes toward police.

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    The purpose of this study was to evaluate the effects of the Values, Influences, and Peers (VIP) program (Ministry of Education, 1984) on the attitudes of adolescents toward the police. The contributions of gender and grade (age) to the adolescents\u27 attitudes also were examined. With a view toward providing further information about the long term effects of the VIP program on attitude formation, the study also examined the attitudes of adolescents toward the police-relevant concerns of law and order problems, police programs, and personal safety. The data were obtained from Horrobin\u27s (1994) Community Youth Needs and Concerns Survey of 1,221 students enrolled in grades 9 through 13 from 15 high schools in a medium-sized southwestern Ontario metropolitan area. Multivariate analyses of variance (MANOVAs), using program (VIP/non-VIP experience), gender, and grade as independent variables, were performed on the 1,134 response scores utilized in the present study. The results were interpreted as indicating that there are meaningful attitudinal differences between VIP and non-VIP adolescents and as providing support for the continued use of VIP intervention with Grade 6 populations. (Abstract shortened by UMI.)Dept. of Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1996 .M397. Source: Masters Abstracts International, Volume: 37-01, page: 0385. Adviser: Frank Schneider. Thesis (M.A.)--University of Windsor (Canada), 1997

    ‘Subjects and Objects: Material Expressions of Love and Loyalty in Seventeenth-Century England’, in special section on ‘Loyalties and Allegiances in Early Modern England’ in Journal of British Studies Vol. 48: 4 (October, 2009)

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    This article investigates how and where the emotive relations between subject and state were forged and how these ideas were manifested in early modern England. McShane describes an affective economy of loyalty, embodied in cheap and accessible political commodities: decorated objects made of clay, metals, and paper, on which precious household resources of time, money and emotion were spent. She argues that by engendering, inculcating and insinuating codes of political love into people’s ‘emotional, sensual, representational, and communicative’ lives, ‘loyal’ goods acted as vehicles and texts for what Victoria Kahn describes as ‘the supplementary role of the passions’ in ‘forging political obligation’ and the reformulation of ‘the duty to love’ of both subject and king in 17th-century England. McShane’s research contributes to a growing theme in scholarship, namely the active consumption of politically significant goods. This essay extends the range of objects under examination to include quotidian household items, shedding light on the dissemination and construction of early modern loyalty across a much wider social scale. The research draws on an extensive survey of collections held at the V&A, the Museum of London, Ashmolean Museum, Fitzwilliam Museum and Burrell Collection. Importantly, by putting illustrated print products back together with other political commodities in the early modern home, creating a broad archive of objects and text-objects where each informs the other, McShane’s approach challenges the typical social historical methodology, which uses material culture as merely illustrative of textual sources. This article was part of a special section on loyalty and allegiance in early modern England, co-edited by McShane with Dr Ted Vallance for one of the leading scholarly journals in the field. The material was drawn from a workshop on the topic held at the University of Liverpool funded by the British Academy, University of Liverpool and the Scouloudi Foundation (2007)

    Milwaukee Parental Choice Program: Descriptive Report on Participating Schools 2010–11

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    This report is the fifth in a series of annual reports produced by the School Choice Demonstration Project (SCDP) that will provide descriptive information about the schools participating in the Milwaukee Parental Choice Program (MPCP)

    Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for the diagnosis of dementia within community dwelling populations

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    <b>Background</b><p></p> Various tools exist for initial assessment of possible dementia with no consensus on the optimal assessment method. Instruments that use collateral sources to assess change in cognitive function over time may have particular utility. The most commonly used informant dementia assessment is the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE).<p></p> A synthesis of the available data regarding IQCODE accuracy will help inform cognitive assessment strategies for clinical practice, research and policy.<p></p> <b>Objectives</b><p></p> Our primary objective was to determine the diagnostic accuracy of the informant based questionnaire IQCODE, for detection of all cause (undifferentiated) dementia in community-dwelling adults with no previous cognitive assessment. We sought to describe the accuracy of IQCODE (the index test) against a clinical diagnosis of dementia (the reference standard).<p></p> Our secondary objective was to describe the effect of heterogeneity on the summary estimates. We were particularly interested in the traditional 26-item scale versus the 16-item short form; and language of administration. We explored the effect of varying the threshold IQCODE score used to define 'test positivity'.<p></p> <b>Search methods</b><p></p> We searched the following sources on 28 January 2013: ALOIS (Cochrane Dementia and Cognitive Improvement Group), MEDLINE (OvidSP), EMBASE (OvidSP), PsycINFO (OvidSP), BIOSIS Previews (ISI Web of Knowledge), Web of Science with Conference Proceedings (ISI Web of Knowledge), LILACS (BIREME). We also searched sources relevant or specific to diagnostic test accuracy: MEDION (Universities of Maastrict and Leuven); DARE (York University); ARIF (Birmingham University). We used sensitive search terms based on MeSH terms and other controlled vocabulary.<p></p> <b>Selection criteria</b><p></p> We selected those studies performed in community settings that used (not necessarily exclusively) the IQCODE to assess for presence of dementia and, where dementia diagnosis was confirmed, with clinical assessment. Our intention with limiting the search to a 'community' setting was to include those studies closest to population level assessment. Within our predefined community inclusion criteria, there were relevant papers that fulfilled our definition of community dwelling but represented a selected population, for example stroke survivors. We included these studies but performed sensitivity analyses to assess the effects of these less representative populations on the summary results.<p></p> <b>Data collection and analysis</b><p></p> We screened all titles generated by the electronic database searches and abstracts of all potentially relevant studies were reviewed. Full papers were assessed for eligibility and data extracted by two independent assessors. For quality assessment (risk of bias and applicability) we used the QUADAS 2 tool. We included test accuracy data on the IQCODE used at predefined diagnostic thresholds. Where data allowed, we performed meta-analyses to calculate summary values of sensitivity and specificity with corresponding 95% confidence intervals (CIs). We pre-specified analyses to describe the effect of IQCODE format (traditional or short form) and language of administration for the IQCODE.<p></p> <b>Main results</b><p></p> From 16,144 citations, 71 papers described IQCODE test accuracy. We included 10 papers (11 independent datasets) representing data from 2644 individuals (n = 379 (14%) with dementia). Using IQCODE cut-offs commonly employed in clinical practice (3.3, 3.4, 3.5, 3.6) the sensitivity and specificity of IQCODE for diagnosis of dementia across the studies were generally above 75%.<p></p> Taking an IQCODE threshold of 3.3 (or closest available) the sensitivity was 0.80 (95% CI 0.75 to 0.85); specificity was 0.84 (95% CI 0.78 to 0.90); positive likelihood ratio was 5.2 (95% CI 3.7 to 7.5) and the negative likelihood ratio was 0.23 (95% CI 0.19 to 0.29).<p></p> Comparative analysis suggested no significant difference in the test accuracy of the 16 and 26-item IQCODE tests and no significant difference in test accuracy by language of administration. There was little difference in sensitivity across our predefined diagnostic cut-points.<p></p> There was substantial heterogeneity in the included studies. Sensitivity analyses removing potentially unrepresentative populations in these studies made little difference to the pooled data estimates. The majority of included papers had potential for bias, particularly around participant selection and sampling. The quality of reporting was suboptimal particularly regarding timing of assessments and descriptors of reproducibility and inter-observer variability.<p></p> <b>Authors' conclusions</b><p></p> Published data suggest that if using the IQCODE for community dwelling older adults, the 16 item IQCODE may be preferable to the traditional scale due to lesser test burden and no obvious difference in accuracy. Although IQCODE test accuracy is in a range that many would consider 'reasonable', in the context of community or population settings the use of the IQCODE alone would result in substantial misdiagnosis and false reassurance. Across the included studies there were issues with heterogeneity, several potential biases and suboptimal reporting quality

    Design of elastomer coatings for concrete impact damage mitigation

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    Practical, cost-effective strategies are of interest for the protection of vulnerable infrastructure against dynamic load events such as blast and fragment impact. Recent research has established that spray-on elastomer coatings can provide a significant impact mitigating effect when applied to concrete structural elements [1]. However, to date, no practical design guidelines exist to support efficient implementation of this retrofit solution. In this work, an analytical model is proposed for the impact indentation of an elastomer-coated concrete structural element. Design maps are produced, predicting the critical projectile impact velocities for elastomer failure and concrete failure, taking the coating thickness and elastomer modulus as the key design variables. The analytical predictions provide a close match to experimental and finite element analysis (FEA) results [1,2]. Spanning a realistic range of elastomer moduli, representative of typical spray application polymers, a regime change is predicted that depends only on the elastomer modulus, Ee. For Ee &lt; 50 MPa, elastomer failure is predicted to occur first. In this regime, there is a much higher sensitivity to Ee compared with the elastomer thickness, he. For Ee &gt; 50 MPa, the concrete is predicted to fail first and in this regime, the critical velocities are most sensitive to he compared with Ee.</p
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