1,976 research outputs found

    Macrofossil extinction patterns at Bay of Biscay Cretaceous-Tertiary boundary sections

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    Researchers examined several K-T boundary cores at Deep Sea Drilling Project (DSDP) core repositories to document biostratigraphic ranges of inoceramid shell fragments and prisms. As in land-based sections, prisms in the deep sea cores disappear well before the K-T boundary. Ammonites show a very different extinction pattern than do the inoceramids. A minimum of seven ammonite species have been collected from the last meter of Cretaceous strata in the Bay of Biscay basin. In three of the sections there is no marked drop in either species numbers or abundance prior to the K-T boundary Cretaceous strata; at the Zumaya section, however, both species richness and abundance drop in the last 20 m of the Cretaceous, with only a single ammonite specimen recovered to date from the uppermost 12 m of Cretaceous strata in this section. Researchers conclude that inoceramid bivalves and ammonites showed two different times and patterns of extinction, at least in the Bay of Biscay region. The inoceramids disappeared gradually during the Early Maestrichtian, and survived only into the earliest Late Maestrichtian. Ammonites, on the other hand, maintained relatively high species richness throughout the Maestrichtian, and then disappeared suddenly, either coincident with, or immediately before the microfossil extinction event marking the very end of the Cretaceous

    Issues and indicators of acceptable change : a study of visitors’ and stakeholders’ concerns about three natural attractions in the Paparoa area, West Coast, South Island, New Zealand

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    This report presents results from visitor surveys and stakeholder interviews at three natural attractions in the Paparoa National Park. The sites were the Pancake Rocks (Dolomite Point), the Fox River caves, and the Westland Black Petrel colony. Questions in the surveys and interviews were based on the Limits of Acceptable Change (LAC) framework to identify potential indicators of change at the site, and were developed from previous studies using this system. The surveys gathered information on visitors' experience of the Pancake Rocks and Fox River caves, and people's sensitivity to impacts encountered at the sites. This was done using self-administered questionnaires on-site immediately after the visit. Stakeholders were interviewed about their issues and concerns for all three sites, and were asked to provide a list of potential indicators of acceptable change

    Large-Scale Goodness Polarity Lexicons for Community Question Answering

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    We transfer a key idea from the field of sentiment analysis to a new domain: community question answering (cQA). The cQA task we are interested in is the following: given a question and a thread of comments, we want to re-rank the comments so that the ones that are good answers to the question would be ranked higher than the bad ones. We notice that good vs. bad comments use specific vocabulary and that one can often predict the goodness/badness of a comment even ignoring the question, based on the comment contents only. This leads us to the idea to build a good/bad polarity lexicon as an analogy to the positive/negative sentiment polarity lexicons, commonly used in sentiment analysis. In particular, we use pointwise mutual information in order to build large-scale goodness polarity lexicons in a semi-supervised manner starting with a small number of initial seeds. The evaluation results show an improvement of 0.7 MAP points absolute over a very strong baseline and state-of-the art performance on SemEval-2016 Task 3.Comment: SIGIR '17, August 07-11, 2017, Shinjuku, Tokyo, Japan; Community Question Answering; Goodness polarity lexicons; Sentiment Analysi

    Reflections on 15 years in the global tobacco trenches

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    This paper is based on my 2017 Research Laureate Presentation at the annual scientific meeting of the American Academy of Health Behavior in Tucson, Arizona. It provides a brief overview of the history of the smoking epidemic, and describes my work in global tobacco control, focusing on my experiences over the last 15 years as a co-founder and intervention director of the Syrian Center for Tobacco Studies (SCTS) in Aleppo, Syria. The SCTS is an NIH-funded research center that draws on a broad range of complementary expertise and resources from developed and developing nations to address the tobacco epidemic in the Arab World. The SCTS strives to serve as a model of scientific excellence and commitment to the health of people in the Middle East and beyond. Major research streams using qualitative, epidemiological, clinical lab, and intervention methodologies are reviewed, along with some of the successes and challenges encountered since the SCTS’s founding

    A Turn to Politics: Sanford Levinson\u27s Our Undemocratic Constitution and Debates in Contemporary Constitutional Theory

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    In the last generation, politics has replaced philosophy as constitutional theory\u27s center of gravity. While theorists once focused on judicial authority and looked to philosophy to validate the principles of justice that judges enforced, they now tend to consider how judges fit into the broader political process that defines constitutional doctrine. This essay considers how the change obscures important questions about the nature of democratic government. It does so by examining Sanford Levinson\u27s recent book, Our Undemocratic Constitution--an attempt to bridge academic theory to the practice of politics that is emblematic of constitutional theory\u27s emphasis of politics over philosophy

    Free Speech and the Development of Liberal Virtues: An Examination of the Controversies Involving Flag-Burning and Hate Speech

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    Colour reconnection in e+e- -> W+W- at sqrt(s) = 189 - 209 GeV

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    The effects of the final state interaction phenomenon known as colour reconnection are investigated at centre-of-mass energies in the range sqrt(s) ~ 189-209 GeV using the OPAL detector at LEP. Colour reconnection is expected to affect observables based on charged particles in hadronic decays of W+W-. Measurements of inclusive charged particle multiplicities, and of their angular distribution with respect to the four jet axes of the events, are used to test models of colour reconnection. The data are found to exclude extreme scenarios of the Sjostrand-Khoze Type I (SK-I) model and are compatible with other models, both with and without colour reconnection effects. In the context of the SK-I model, the best agreement with data is obtained for a reconnection probability of 37%. Assuming no colour reconnection, the charged particle multiplicity in hadronically decaying W bosons is measured to be (nqqch) = 19.38+-0.05(stat.)+-0.08 (syst.).Comment: 30 pages, 9 figures, Submitted to Euro. Phys. J.
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