5,787 research outputs found

    Bootstrap Technique to Study Correlation Between Neutron Skin Thickness and the Slope of Symmetry Energy in Atomic Nuclei

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    We examine the proposed correlation between the neutron skin thickness and the slope of the symmetry energy for two doubly-magic nuclei (Sn-100 and Sn-132) and find that a statistically significant correlation appears to exist for Sn-132 whilst no such correlation appears to exist for Sn-100. Additionally, we present a new statistical tool based on random sampling to assess the confidence interval of Pearson's and Spearman's correlation coefficients in order to examine the aforementioned correlation. These estimators are then used to quantify the statistical correlations among the neutron skin thickness of atomic nuclei and the slope of the symmetry energy in the infinite nuclear medium.Peer reviewe

    Transforming learning of programming: A mentoring project

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    Programming is central to Computer Science and cognate disciplines, and poses early-learning challenges in problem-solving and coding. Since the recent past the School of Computer Science & Information Technology (RMIT University) has provided a student mentoring service to assist novice student programmers with their programming, indeed, to build up their confidence in programming. The service has received favourable feedback from students and, as an interesting aside, has had the added benefit of increasing mentors' confidence and improving mentors' communication skills. Mentors volunteer their services under a University leadership initiative, and are not paid to assist students. In light of such success, we secured a University action-research teaching and learning grant, to investigate aspects of the service delivered to date. While mentoring has been shown to be helpful for novice student programmers to learn and improve their programming, less recognised, but of equal importance, is the value to mentors through the skills and experience they gain. This paper reports early findings of a dual-purpose research investigation into the mentoring service. The research project seeks to discover ways to improve the mentoring service for novice student programmers, as well as to enhance a range of qualities in mentors

    Attitudes and impressions of participants in a study of the causes of childhood cancer

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    Researchers and ethics committees are increasingly concerned about the perceived emotional impact on individuals following participation in epidemiologic studies. This attitudinal survey was designed to investigate this issue among 751 of the parents who had already given an interview in the UK Childhood Cancer Study (UKCCS), one of the largest case-control studies ever undertaken to investigate the aetiology of cancer in children. Information was collected by postal questionnaire on their reasons for agreeing to take part in the UKCCS, on whether questions had caused distress or difficulty and what their feelings were immediately after the interview and at the time of this survey. Parents were asked if they felt they had benefited in any way by taking part and control parents were asked if they would have taken part without prior consent of their doctor. 90% of both cases and controls felt glad to have taken part immediately after the interview and few reported any anxiety at having done so; 95% of both cases and controls felt satisfied that they had made a worthwhile contribution. Although 18% of cases felt tense and 14% felt unhappy after the interview, over 90% of them felt glad that they had taken part a few weeks later. Of particular interest is that 38% of cases and 24% of controls said they had positively benefited from taking part in the UKCCS and 96% of control mothers did not mind their family doctor giving permission for them to be contacted. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Blaming Bill Gates AGAIN! Misuse, overuse and misunderstanding of performance data in sport

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    Recently in Sport, Education and Society, Williams and Manley (2014) argued against the heavy reliance on technology in professional Rugby Union and elite sport in general. In summary, technology is presented as an elitist, ‘gold standard’ villain that management and coaches use to exert control and by which players lose autonomy, identity, motivation, social interactions and expertise. In this article we suggest that the sociological interpretations and implications offered by Williams and Manley may be somewhat limited when viewed in isolation. In doing so, we identify some core methodological issues in Williams and Manley’s study and critically consider important arguments for utilising technology; notably, to inform coach decision making and generate player empowerment. Secondly, we present a different, yet perhaps equally concerning, practice-oriented interpretation of the same results but from alternative coaching and expertise literature. Accordingly, we suggest that Williams and Manley have perhaps raised their alarm prematurely, inappropriately and on somewhat shaky foundations. We also hope to stimulate others to consider contrary positions, or at least to think about this topic in greater detail. More specifically, we encourage coaches and academics to think carefully about what technology is employed, how and why, and then the means by which these decisions are discussed with and, preferably, sold to players. Certainly, technology can significantly enhance coach decision making and practice, while also helping players to optimise their focus, empowerment and independence in knowing how to achieve their personal and collective goals

    Bathymetry and Sediment Geochemistry of Lake Hazen (Quttinirpaaq National Park, Ellesmere Island, Nunavut)

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    Arctic lakes can provide a long-term perspective on environmental change, including trends in long-range atmospheric transport and deposition of contaminants, inferred from studies of sediment cores. In this study, we conducted the first detailed bathymetric survey of Lake Hazen (Quttinirpaaq National Park, Ellesmere Island, Nunavut), the world’s largest lake north of 74˚ latitude. With these data we were able to determine optimal locations for sediment coring and to collect and analyze profundal sediment cores. A bathymetric map of Lake Hazen was developed on the basis of 362 spot soundings obtained with GPS-coupled sounding equipment placed directly on the ice combined with additional soundings from a small boat. The deepest point in the lake (81˚49.5Êč N; 70˚42.8Êč W) was found to be 267 m deep. The lake volume was estimated to be 5.14 × 1010 m3, about 10% larger than previous estimates. Using estimates of the discharge of Lake Hazen from the Water Survey of Canada, we estimated the water retention time to be 89 years. Sediment cores were dated using 210Pb and 137Cs. Sedimentation rates at the deep point, estimated using the Constant Rate of Supply model for excess 210Pb, were relatively high (1260 g m-2yr-1) in the period 2005 – 1963 and lower (650 ± 100 g m-2yr-1) in horizons dated to 1950 – 1880. The majority of elements measured in sediment (24 of 29 consistently above detection limits), as well as organic carbon, showed less than 20% variation in concentrations in the top 10 cm (compacted depth), which represent deposition over approximately 140 years. Geochemical characteristics of the sediment suggest that erosional inputs from annual glacial melting are the major source of essentially all elements and that anthropogenic inputs from long-range transport of toxic metals such as mercury and lead are very low.Les lacs de l’Arctique peuvent fournir une perspective Ă  long terme en matiĂšre de changement environnemental, notamment en ce qui a trait aux tendances relatives au transport atmosphĂ©rique et au dĂ©pĂŽt de contaminants sur de longues pĂ©riodes, tendances infĂ©rĂ©es Ă  partir d’études de carottes de sĂ©diments. Dans le cadre de la prĂ©sente Ă©tude, nous avons effectuĂ© le premier levĂ© bathymĂ©trique dĂ©taillĂ© du lac Hazen (parc national Quttinirpaaq, Ăźle d’Ellesmere, Nunavut), le plus grand lac de la planĂšte situĂ© au nord de 74˚ de latitude. GrĂące aux donnĂ©es prĂ©levĂ©es, nous avons rĂ©ussi Ă  dĂ©terminer les meilleurs emplacements pour le prĂ©lĂšvement de carottes de sĂ©diments de mĂȘme que pour la collecte et l’analyse de carottes de sĂ©diments profonds. Une carte bathymĂ©trique du lac Hazen a Ă©tĂ© dressĂ©e en fonction de 362 sondages obtenus au moyen de matĂ©riel d’appareils phoniques dotĂ©s de GPS placĂ©s directement sur la glace et supplĂ©mentĂ©s par des sondages recueillis Ă  partir d’un petit bateau. Le point le plus profond du lac (81˚49,5Êč N; 70˚42,8Êč O) a Ă©tĂ© trouvĂ© Ă  267 m de profondeur. Le volume du lac a Ă©tĂ© Ă©valuĂ© Ă  5,14 × 1010 m3, soit 10 % de plus que les Ă©valuations prĂ©cĂ©dentes. À l’aide d’estimations du dĂ©versement du lac Hazen obtenues auprĂšs de la Division des relevĂ©s hydrologiques du Canada, nous avons Ă©valuĂ© que la durĂ©e de rĂ©tention de l’eau Ă©tait de 89 ans. La datation des carottes de sĂ©diments a Ă©tĂ© faite Ă  l’aide de 210Pb et de 137Cs. Les taux de sĂ©dimentation au point profond, estimĂ©s en s’appuyant sur le modĂšle CRS (Constant Rate of Supply) pour l’excĂ©dent 210Pb, Ă©taient relativement Ă©levĂ©s (1260 g m-2an-1) pour la pĂ©riode allant de 2005 Ă  1963, et moins Ă©levĂ©s (650 ± 100 g m-2an-1) pour la pĂ©riode de 1950 Ă  1880. La majoritĂ© des Ă©lĂ©ments mesurĂ©s dans les sĂ©diments (24 sur 29 Ă©taient uniformĂ©ment au-dessus des seuils de dĂ©tection) ainsi que dans le carbone organique ont produit une variation de concentrations de moins de 20 % dans les 10 cm supĂ©rieurs (profondeur compactĂ©e), ce qui reprĂ©sente des dĂ©pĂŽts s’échelonnant sur environ 140 ans. Les caractĂ©ristiques gĂ©ochimiques des sĂ©diments laissent prĂ©sumer que les matiĂšres d’érosion dĂ©coulant de la fonte glaciaire annuelle constituent la source principale de sensiblement tous les Ă©lĂ©ments, et que les matiĂšres anthropiques provenant du transport Ă  grande distance de mĂ©taux toxiques, tels que le mercure et le plomb, sont trĂšs faibles
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