2,376 research outputs found

    An economic analysis of trading on private information by external administrators: international comparisons

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    This paper examines the regulation of trades in listed securities by external administrators (EAs), such as trustees in bankruptcy, liquidators, receivers, and administrators on the basis of private information. We consider the economic policy issues associated with such trades. The principal considerations counsel in favour of taking a permissive approach. These are: the difficulties of associating trades with insider information, given the EA's necessarily short expected holding period, the asymmetric application of the insider trading prohibition to sales (rather than decisions not to sell), the market incentives not to misuse private information that apply to EAs, and the unlikelihood that the EA has monopolistic access to the information in question. We consider these considerations by reference to a number of hypothetical scenarios. The paper argues that the law should regulate the subject by coupling a broad exemption for EAs with a "goiod faith" proviso, a continuous disclosure obligation, and a requirement to sell "all or nothing" of a holding of listed securities

    Monolithically integrated InAsSb-based nBnBn heterostructure on GaAs for infrared detection

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    High operating temperature i nfrared photo detectors with multi -color function that are capable of monolithic integration are of increasing importance in developing the next generation of mid -IR imag e sensors. Applications of these sensors include defense, medical diagnosis, environmental and astronomical observations. We have investigated a novel InAsSb -based nBnBn heterostructure that combines a state -of-art InAsSb nBn detector with an InAsSb/GaSb heterojuncti on detector . At room temperature, r educti on in the dark current density of more than an order of magnitude was achieved compared to previously investigated InAsSb/GaSb heterojunction dete ctors . Electrical characterization from cryogenic temperatures to roo m temperature confirmed that the nBnBn device was diffusion limited for temperature s above 150K. O ptical measurements demonstrated that the nBnBn detector was sensitive in both the SWIR and MWIR wavelength range at room temperature . The specific detectivity (D*) of the competed nBnBn devices was calculated to be 8.6 × 10 8 cm · Hz 1/2 W -1 at 300K and approximately 1.0 × 10 10 cm · Hz 1/2 W -1 when cooled down to 200K (with 0.3V reverse bias and 1550nm illumination ). In addition, all photodetector layers were grown monolithically on GaAs active layers u sing the interfacial misfit array growth mode . Our results therefore pave the way for the development of new active pixel designs for monolithically integrated mid -IR imaging arrays

    Automatic classification of facial morphology for medical applications

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    Facial morphology measurement and classification play important role in the face anthropometry of many medical applications. This usually involves the investigation of medical abnormalities where specific facial features are studied by taking a number of measurements of the facial area under investigation. The measurements are often obtained from the three-dimensional (3D) scans of the faces; however, the measurements are often made manually, which is tedious and time consuming process. Moreover, in gene related studies thousands of measurements may be necessary in order to find statistically significant relationships between facial features and genes. Normative studies, from which typical populous models can be built, also require many measurements. Thus an automatic method to extract morphological measurements and interpret them is desirable. In this article, an automatic method for classification of facial morphology on the basis of a number of geometric measurements obtained automatically from 3D facial scans is presented. Among different facial features the philtrum, which is the vertical groove extending from the nose to the upper lip and the lip area, plays an important role in defining the interaction between the genes and craniofacial anomalies such as, for example, cleft lip and palate. In this paper, geometric features are analysed for their suitability to classify philtrum into three classes previously proposed by medical experts. Moreover, further analysis is conducted to assess the best number of classes to model the underlying data distribution from the point of view of classification accuracy. The obtained classification results are compared with the ground truth manual labelling of 3D face meshes provided by a medical expert. The dataset used for this research is taken from ALSPAC dataset and consists of 1000 3D face meshes. The proposed method achieves classification accuracy of 97% for this data set using the Mean, Minimum and Maximum curvature features in combination

    Eddy Cancellation of the Ekman Cell in Subtropical Gyres

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    The presence of large-scale Ekman pumping associated with the climatological wind stress curl is the textbook explanation for low biological activity in the subtropical gyres. Using an idealized, eddy-resolving model, it is shown that Eulerian-mean Ekman pumping may be opposed by an eddy-driven circulation, analogous to the way in which the atmospheric Ferrel cell and the Southern Ocean Deacon cell are opposed by eddy-driven circulations. Lagrangian particle tracking, potential vorticity fluxes, and depth–density streamfunctions are used to show that, in the model, the rectified effect of eddies acts to largely cancel the Eulerian-mean Ekman downwelling. To distinguish this effect from eddy compensation, it is proposed that the suppression of Eulerian-mean downwelling by eddies be called “eddy cancellation.

    Community Insurgency: Constituency, School Choice, and the Common Good

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    This study explores the ways in which the democratic notion of the people may be enacted in the school choice arena. Through an investigation of a charter school movement in a rural and segregated district in the Deep South, we explore themes of the constituent paradox that enabled the community to move beyond individual interests towards an expression of the common good. It is argued that for the people to be invoked via the democratic claim, they must identify more deeply than the institutions of their representation and recognize an expanded form of individualism defined through participation over consumption

    Post-operative atrial fibrillation is influenced by beta-blocker therapy but not by pre-operative atrial cellular electrophysiology

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    We investigated whether post-cardiac surgery (CS) new-onset atrial fibrillation (AF) is predicted by pre-CS atrial cellular electrophysiology, and whether the antiarrhythmic effect of beta-blocker therapy may involve pre-CS pharmacological remodeling. Atrial myocytes were obtained from consenting patients in sinus rhythm, just prior to CS. Action potentials and ion currents were recorded using whole-cell patch-clamp technique. Post-CS AF occurred in 53 of 212 patients (25%). Those with post-CS AF were older than those without (67 ± 2 vs 62 ± 1 years, P = 0.005). In cells from patients with post-CS AF, the action potential duration at 50% and 90% repolarization, maximum upstroke velocity, and effective refractory period (ERP) were 13 ± 4 ms, 217 ± 16 ms, 185 ± 10 V/s, and 216 ± 14 ms, respectively (n = 30 cells, 11 patients). Peak L-type Ca2+ current, transient outward and inward rectifier K+ currents, and the sustained outward current were −5.0 ± 0.5, 12.9 ± 2.4, −4.1 ± 0.4, and 9.7 ± 1.0 pA/pF, respectively (13-62 cells, 7-19 patients). None of these values were significantly different in cells from patients without post-CS AF (P > 0.05 for each, 60-279 cells, 29-86 patients), confirmed by multiple and logistic regression. In patients treated >7 days with a beta-blocker pre-CS, the incidence of post-CS AF was lower than in non-beta-blocked patients (13% vs 27%, P = 0.038). Pre-CS beta-blockade was associated with a prolonged pre-CS atrial cellular ERP (P = 0.001), by a similar degree (∼20%) in those with and without post-CS AF. Conclusion: Pre-CS human atrial cellular electrophysiology does not predict post-CS AF. Chronic beta-blocker therapy is associated with a reduced incidence of post-CS AF, unrelated to a pre-CS ERP-prolonging effect of this treatment

    An investigation of music analysis by the application of grammar-based compressors

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    Many studies have presented computational models of musical structure, as an important aspect of musicological analysis. However, the use of grammar-based compressors to automatically recover such information is a relatively new and promising technique. We investigate their performance extensively using a collection of nearly 8000 scores, on tasks including error detection, classification, and segmentation, and compare this with a range of more traditional compressors. Further, we detail a novel method for locating transcription errors based on grammar compression. Despite its lack of domain knowledge, we conclude that grammar-based compression offers competitive performance when solving a variety of musicological tasks

    Improved Learning in U.S. History and Decision Competence with Decision-Focused Curriculum

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    Decision making is rarely taught in high school, even though improved decision skills could benefit young people facing life-shaping decisions. While decision competence has been shown to correlate with better life outcomes, few interventions designed to improve decision skills have been evaluated with rigorous quantitative measures. A randomized study showed that integrating decision making into U.S. history instruction improved students' history knowledge and decision-making competence, compared to traditional history instruction. Thus, integrating decision training enhanced academic performance and improved an important, general life skill associated with improved life outcomes. © 2012 Jacobson et al

    Copper Mining in the Bronze Age at Mynydd Parys, Anglesey, Wales

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    Acknowledgements This article was researched and written by David Jenkins. The final editing was undertaken by Andrew Davidson and Jane Kenney (Gwynedd Archaeological Trust) and Dr Simon Timberlake (Early Mines Research Group and McDonald Institute, University of Cambridge), who contributed additional background information. Further contributions and corrections were provided by Peter Marshall (Historic England) and Tim Mighall (University of Aberdeen) who oversaw the palaeoenvironmental study. Cadw generously funded the work through grant aid. The suggestion to edit and publish the article came from John Llywelyn Williams, who has worked closely with David Jenkins on this and a number of other significant projects. The editors are also very grateful for the help and encouragement provided by Paul Jenkins (David’s son). Members of the Parys Underground Group, particularly Oliver Burrows, and the Early Mines Research Group have helped source illustrations, provided corrections and comments, and supported the work. Thanks also to Anglesey Mining plc.Peer reviewedPostprin
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