195,138 research outputs found

    Bihomogeneity of solenoids

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    Solenoids are inverse limit spaces over regular covering maps of closed manifolds. M.C. McCord has shown that solenoids are topologically homogeneous and that they are principal bundles with a profinite structure group. We show that if a solenoid is bihomogeneous, then its structure group contains an open abelian subgroup. This leads to new examples of homogeneous continua that are not bihomogeneous.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol2/agt-2-1.abs.htm

    Anticommuting Variables, Fermionic Path Integrals and Supersymmetry

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    (Replacement because mailer changed `hat' for supercript into something weird. The macro `\sp' has been used in place of the `hat' character in this revised version.) Fermionic Brownian paths are defined as paths in a space para\-metr\-ised by anticommuting variables. Stochastic calculus for these paths, in conjunction with classical Brownian paths, is described; Brownian paths on supermanifolds are developed and applied to establish a Feynman-Kac formula for the twisted Laplace-Beltrami operator on differential forms taking values in a vector bundle. This formula is used to give a proof of the Atiyah-Singer index theorem which is rigorous while being closely modelled on the supersymmetric proofs in the physics literature.Comment: 18 pages, KCL-TH-92-

    Effect of sacubitril/valsartan on recurrent events in the prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure trial (PARADIGM-HF)

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    Aims: Recurrent hospitalizations are a major part of the disease burden in heart failure (HF), but conventional analyses consider only the first event. We compared the effect of sacubitril/valsartan vs. enalapril on recurrent events, incorporating all HF hospitalizations and cardiovascular (CV) deaths in PARADIGM-HF, using a variety of statistical approaches advocated for this type of analysis. Methods and results: In PARADIGM-HF, a total of 8399 patients were randomized and followed for a median of 27 months. We applied various recurrent event analyses, including a negative binomial model, the Wei, Lin and Weissfeld (WLW), and Lin, Wei, Ying and Yang (LWYY) methods, and a joint frailty model, all adjusted for treatment and region. Among a total of 3181 primary endpoint events (including 1251 CV deaths) during the trial, only 2031 (63.8%) were first events (836 CV deaths). Among a total of 1195 patients with at least one HF hospitalization, 410 (34%) had at least one further HF hospitalization. Sacubitril/valsartan compared with enalapril reduced the risk of recurrent HF hospitalization using the negative binomial model [rate ratio (RR) 0.77, 95% confidence interval (CI) 0.67–0.89], the WLW method [hazard ratio (HR) 0.79, 95% CI 0.71–0.89], the LWYY method (RR 0.78, 95% CI 0.68–0.90), and the joint frailty model (HR 0.75, 95% CI 0.66–0.86) (all P < 0.001). The effect of sacubitril/valsartan vs. enalapril on recurrent HF hospitalizations/CV death was similar. Conclusions: In PARADIGM-HF, approximately one third of patients with a primary endpoint (time-to-first) experienced a further event. Compared with enalapril, sacubitril/valsartan reduced both first and recurrent events. The treatment effect size was similar, regardless of the statistical approach applied

    Fresnel concentrating collector

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    An advanced point focusing solar technology demonstrated potential for near term commercialization as a renewable energy technology. The design features combine to produce a highly efficient, low cost, safe, adaptable, durable system which is simple to manufacture, install and maintain

    Capturing CFLs with Tree Adjoining Grammars

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    We define a decidable class of TAGs that is strongly equivalent to CFGs and is cubic-time parsable. This class serves to lexicalize CFGs in the same manner as the LCFGs of Schabes and Waters but with considerably less restriction on the form of the grammars. The class provides a normal form for TAGs that generate local sets in much the same way that regular grammars provide a normal form for CFGs that generate regular sets.Comment: 8 pages, 3 figures. To appear in proceedings of ACL'9

    "James Joyce en su laberinto" ["James Joyce in His Labyrinth"] by Antonio Marichalar, translated by Gayle Rogers

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    A translation of the first full-length study of James Joyce in Spanish, along with partial translations of Ulysses, by Antonio Marichalar. Published in 1924 in the journal Revista de Occidente [Review of the West], edited by José Ortega y Gasset, the most influential magazine of interwar Spain and in the Hispanophone world. Translated by Gayle Rogers, Department of English

    The Impact of Climate Change on Coastal Fog Hours of California\u27s Central Coast

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    This study used observations and downscaled model output from the Coupled Model Intercomparison Project 5 to investigate diurnal temperature differences and their relationship to the number of fog hours in the future along California’s central coast. The study area extended north-south from Bodega Bay to the Santa Lucia Range and east-west from the coast of California to the western flank of the Sierra Nevada Mountains. Analyses of Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5 showed that most of California’s central coast will likely see minimal changes in the number of fog hours per day through the turn of the century. However, fog hours in the northern portion of the study area showed a reduction of up to an hour and a half per day, while southern areas showed an increase by more than an hour and a half per day by the turn of the century. The implications of these changes will vary depending on the timing of the increase or decrease. Further research is needed to look at timing of fog events

    The motivational pull of video game feedback, rules, and social interaction: Another self-determination theory approach

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    This paper argues that most video game enjoyment can be understood in terms of the type of feedback used, the rules set out by the game and the social elements of the game - concepts that have been identified as critical to video games. Self-determination theory (SDT) is used as a lens for understanding the mechanism by which these traits might lead to enjoyment. Specifically, the argument is that feedback, rules, and social elements of games will fulfill the dimensions of SDT - competence autonomy, and relatedness. Then, the dimensions of SDT will predict enjoyment. Participants were presented with a game that emphasized feedback, rules, or social elements. Games that emphasized flexible rules led to feelings of competence while games that emphasized social elements led to feelings of relatedness. Competence and elatedness then led to feelings of enjoyment. In doing so, this study identifies key elements of video games while illuminating ways to understand video game enjoyment
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