3,828 research outputs found

    Short Interest and Stock Returns

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    Using a longer time period and both NYSE-Amex and Nasdaq stocks, this paper examines short interest and stock returns in more detail than any previous study and finds that many documented patterns are not robust. While equally weighted high short interest portfolios generally underperform, value weighted portfolios do not. In addition, there is a negative correlation between market returns and short interest over our whole period. Finally, inferences from short time periods, such as 1988-1994 when the underperformance of high short interest stocks was exceptional or 1995-2002, when high short interest Nasdaq stocks did not underperform, are misleading.

    Predictors of Creativity in Young People: Using Frequentist and Bayesian Approaches in Estimating the Importance of Individual and Contextual Factors

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    © 2020 American Psychological Association. The development of creativity in young children has been studied extensively, but relatively few studies have examined the period of adolescence and emerging adulthood in relation to creative potential. The present study uses a combination of frequentist and Bayesian analyses to evaluate the impact of individual factors (e.g., IQ) and contextual factors (e.g., pursuit of creative hobbies) on creative ideation in three cohorts of young people aged 14-20 years. Measures of divergent thinking, specifically the Alternate Uses Task (AUT) and the Overcoming Knowledge Constraints Task, were used to this end. Openness to aesthetic and imaginative experience was the strongest predictor of creative potential for the 3 AUT measures. Moreover, Bayesian hypothesis testing revealed that the best predictive model for AUT ideational fluency and AUT overall originality was one that included only Openness, whereas the best predictive model for AUT peak originality, or the propensity to generate highly original responses, included Openness, as well as IQ and Engagement in Creative Hobbies. No group differences in creative potential were found between the three age cohorts (aged 14-15, 16-17, and 18-20). The study not only confirms the importance of openness to aesthetic and imaginative experience as a predictor of creative potential in adolescents and young adults, but also indicates the necessity to consider the combined and differentiated impact of individual and contextual factors in different facets of creative ideation

    Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

    Assessing changes in the internal worlds of early- and late-adopted children using the Story Stem Assessment Profile (SSAP)

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    A growing body of literature has consistently shown how adopted children often have previous history of trauma and neglect, and in turn develop negative representations of the self and others. This study assesses the internal representations of three groups of children, as measured by the Story Stem Assessment Profile (SSAP). These were: (1) a maltreated, late-adopted (MLA) sample (n = 63); (2) a non-maltreated, early-adopted (EA) sample (n = 48); and (3) a non-maltreated community sample (COMM) (n = 80). In addition, it examined whether MLA and EA adopted children’s attachment and internal representations changed over time. Results showed that children in the MLA sample significantly displayed more disorganised, avoidant and negative representations and fewer representations characteristic of ‘secure’ attachment when compared with EA and, especially, COMM children. Longitudinal follow-up of both MLA and EA samples demonstrated significant changes over a two-year period in SSAP representation; secure representations increased while the avoidant and disorganised ones diminished. These findings are discussed and the limitations and implications of the study presented

    Explicit kinetic heterogeneity: mechanistic models for interpretation of labeling data of heterogeneous cell populations

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    Estimation of division and death rates of lymphocytes in different conditions is vital for quantitative understanding of the immune system. Deuterium, in the form of deuterated glucose or heavy water, can be used to measure rates of proliferation and death of lymphocytes in vivo. Inferring these rates from labeling and delabeling curves has been subject to considerable debate with different groups suggesting different mathematical models for that purpose. We show that the three models that are most commonly used are in fact mathematically identical and differ only in their interpretation of the estimated parameters. By extending these previous models, we here propose a more mechanistic approach for the analysis of data from deuterium labeling experiments. We construct a model of "kinetic heterogeneity" in which the total cell population consists of many sub-populations with different rates of cell turnover. In this model, for a given distribution of the rates of turnover, the predicted fraction of labeled DNA accumulated and lost can be calculated. Our model reproduces several previously made experimental observations, such as a negative correlation between the length of the labeling period and the rate at which labeled DNA is lost after label cessation. We demonstrate the reliability of the new explicit kinetic heterogeneity model by applying it to artificially generated datasets, and illustrate its usefulness by fitting experimental data. In contrast to previous models, the explicit kinetic heterogeneity model 1) provides a mechanistic way of interpreting labeling data; 2) allows for a non-exponential loss of labeled cells during delabeling, and 3) can be used to describe data with variable labeling length

    The Market for Borrowing Corporate Bonds

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    This paper describes the market for borrowing corporate bonds using a comprehensive dataset from a major lender. The cost of borrowing corporate bonds is comparable to the cost of borrowing stock, between 10 and 20 basis points per year. Factors that increase borrowing costs are loan size, percentage of inventory lent, rating, and borrower identity. Trading strategies based on cost or amount of borrowing do not yield excess returns. Bonds with corresponding CDS contracts are more actively lent than those without. Finally, the 2007 Credit Crunch did not affect average borrowing cost or loan volume, but increased borrowing cost variance.

    1,2,6-thiadiazinones as novel narrow spectrum calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) inhibitors

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    We demonstrate for the first time that 4H-1,2,6-thiadiazin-4-one (TDZ) can function as a chemotype for the design of ATP-competitive kinase inhibitors. Using insights from a co-crystal structure of a 3,5-bis(arylamino)-4H-1,2,6-thiadiazin-4-one bound to calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2), several analogues were identified with micromolar activity through targeted displacement of bound water molecules in the active site. Since the TDZ analogues showed reduced promiscuity compared to their 2,4-dianilinopyrimidine counter parts, they represent starting points for development of highly selective kinase inhibitors

    Reconciling Estimates of Cell Proliferation from Stable Isotope Labeling Experiments.

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    Stable isotope labeling is the state of the art technique for in vivo quantification of lymphocyte kinetics in humans. It has been central to a number of seminal studies, particularly in the context of HIV-1 and leukemia. However, there is a significant discrepancy between lymphocyte proliferation rates estimated in different studies. Notably, deuterated (2)H2-glucose (D2-glucose) labeling studies consistently yield higher estimates of proliferation than deuterated water (D2O) labeling studies. This hampers our understanding of immune function and undermines our confidence in this important technique. Whether these differences are caused by fundamental biochemical differences between the two compounds and/or by methodological differences in the studies is unknown. D2-glucose and D2O labeling experiments have never been performed by the same group under the same experimental conditions; consequently a direct comparison of these two techniques has not been possible. We sought to address this problem. We performed both in vitro and murine in vivo labeling experiments using identical protocols with both D2-glucose and D2O. This showed that intrinsic differences between the two compounds do not cause differences in the proliferation rate estimates, but that estimates made using D2-glucose in vivo were susceptible to difficulties in normalization due to highly variable blood glucose enrichment. Analysis of three published human studies made using D2-glucose and D2O confirmed this problem, particularly in the case of short term D2-glucose labeling. Correcting for these inaccuracies in normalization decreased proliferation rate estimates made using D2-glucose and slightly increased estimates made using D2O; thus bringing the estimates from the two methods significantly closer and highlighting the importance of reliable normalization when using this technique

    Reviews

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    The following publications have been reviewed by the mentioned authors;Design and technology education exhibition  - reviewed by John EgglestonProject 2045 - The Design CouncilBeginning Teaching: Beginning Learning - reviewed by Bridget A. EganThe World of Chocolate - reviewed by Richard AgerSteel & Motorways Curriculum Pack - reviewed by Robert BowenDesign and Technology in Action Teacher's pack - reviewed by Robert Bowenthings: thinking things through with 7-11 year olds - reviewed by Marion RutlandD&T Challenges - reviewed by Tim FulfordSTEP Key Stage 3 Teacher's Handbook 2nd Ed. - reviewed by John HansonDesign and Technology Projects for Secondary Schools - reviewed by George Asquith
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