4,518 research outputs found
Short Interest and Stock Returns
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.
End of the World: New Zealand’s Local Government and COVID-19
The book provides a global perspective of local government response towards the COVID-19 pandemic through the analysis of a sample of countries in all continents.fals
A queer criminal career
Since the publication of Moffitt’s (1993) important research on adolescence-limited andlife-course-persistent offending, there has been a renewal of the often tacit goal ofcriminology of identifying the individual factors that facilitate and inhibit deviant behaviour.In focusing on early childhood biological, genetic and psychological development, andconsidering social environment only as a mediating factor, these approaches miss some of thequeer pathways to crime. We argue that examining offending by queer people inevitablydestabilises taken-for-granted ideas about offending and desistance from offending.Moreover, given the increasing numbers of young people identifying as queer, and that theyare more likely to be sanctioned by criminal processing systems, we highlight the importanceof exploring the experiences of queer young people. A queer criminological lens can offer upan alternative, queer criminal career, which starts not with bio-psychological dysfunctioning,but with social exclusion and criminalisation of identit
Predictors of Creativity in Young People: Using Frequentist and Bayesian Approaches in Estimating the Importance of Individual and Contextual Factors
© 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
The Rules of Human T Cell Fate in vivo.
The processes governing lymphocyte fate (division, differentiation, and death), are typically assumed to be independent of cell age. This assumption has been challenged by a series of elegant studies which clearly show that, for murine cells in vitro, lymphocyte fate is age-dependent and that younger cells (i.e., cells which have recently divided) are less likely to divide or die. Here we investigate whether the same rules determine human T cell fate in vivo. We combined data from in vivo stable isotope labeling in healthy humans with stochastic, agent-based mathematical modeling. We show firstly that the choice of model paradigm has a large impact on parameter estimates obtained using stable isotope labeling i.e., different models fitted to the same data can yield very different estimates of T cell lifespan. Secondly, we found no evidence in humans in vivo to support the model in which younger T cells are less likely to divide or die. This age-dependent model never provided the best description of isotope labeling; this was true for naïve and memory, CD4+ and CD8+ T cells. Furthermore, this age-dependent model also failed to predict an independent data set in which the link between division and death was explored using Annexin V and deuterated glucose. In contrast, the age-independent model provided the best description of both naïve and memory T cell dynamics and was also able to predict the independent dataset
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
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)
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
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
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.
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