11,701 research outputs found

    Investigation to develop a process for production of oxide fibers by melt draw technique Final report

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    Process for production of oxide fibers by melt draw techniqu

    The Effect of Fiscal Rules on Public Investment if Budget Deficits Are Politically Motivated

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    Uncertainty about the future preferences of the government may induce policy makers to run excessive budget deficits. As a solution to this problem, economists have proposed to impose a binding debt rule. In this paper we argue that a binding debt rule does not eliminate the distortions due to strategic behaviour of politicians. Rather, strategic manipulation shifts from public debt to public investment. As an alternative, we examine the effects of a capital borrowing rule which permits the government to run a budget deficit equal to the amount of public investment. We show that this rule effectively eliminates strategic behaviour.fiscal rules and budget deficits and public investment

    Electrical observation of a tunable band gap in bilayer graphene nanoribbons at room temperature

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    We investigate the transport properties of double-gated bilayer graphene nanoribbons at room temperature. The devices were fabricated using conventional CMOS-compatible processes. By analyzing the dependence of the resistance at the charge neutrality point as a function of the electric field applied perpendicular to the graphene surface, we show that a band gap in the density of states opens, reaching an effective value of ~sim50 meV. This demonstrates the potential of bilayer graphene as FET channel material in a conventional CMOS environment.Comment: 3 pages, 3 figure

    Analytical study of the effect of recombination on evolution via DNA shuffling

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    We investigate a multi-locus evolutionary model which is based on the DNA shuffling protocol widely applied in \textit{in vitro} directed evolution. This model incorporates selection, recombination and point mutations. The simplicity of the model allows us to obtain a full analytical treatment of both its dynamical and equilibrium properties, for the case of an infinite population. We also briefly discuss finite population size corrections

    Parametric Fokker-Planck equation

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    We derive the Fokker-Planck equation on the parametric space. It is the Wasserstein gradient flow of relative entropy on the statistical manifold. We pull back the PDE to a finite dimensional ODE on parameter space. Some analytical example and numerical examples are presented

    Quantitative insertion-site sequencing (QIseq) for high throughput phenotyping of transposon mutants

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    Genetic screening using random transposon insertions has been a powerful tool for uncovering biology in prokaryotes, where whole-genome saturating screens have been performed in multiple organisms. In eukaryotes, such screens have proven more problematic, in part because of the lack of a sensitive and robust system for identifying transposon insertion sites. We here describe quantitative insertion-site sequencing, or QIseq, which uses custom library preparation and Illumina sequencing technology and is able to identify insertion sites from both the 5' and 3' ends of the transposon, providing an inbuilt level of validation. The approach was developed using piggyBac mutants in the human malaria parasite Plasmodium falciparum but should be applicable to many other eukaryotic genomes. QIseq proved accurate, confirming known sites in >100 mutants, and sensitive, identifying and monitoring sites over a >10,000-fold dynamic range of sequence counts. Applying QIseq to uncloned parasites shortly after transfections revealed multiple insertions in mixed populations and suggests that >4000 independent mutants could be generated from relatively modest scales of transfection, providing a clear pathway to genome-scale screens in P. falciparum QIseq was also used to monitor the growth of pools of previously cloned mutants and reproducibly differentiated between deleterious and neutral mutations in competitive growth. Among the mutants with fitness defects was a mutant with a piggyBac insertion immediately upstream of the kelch protein K13 gene associated with artemisinin resistance, implying mutants in this gene may have competitive fitness costs. QIseq has the potential to enable the scale-up of piggyBac-mediated genetics across multiple eukaryotic systems

    Recombination dramatically speeds up evolution of finite populations

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    We study the role of recombination, as practiced by genetically-competent bacteria, in speeding up Darwinian evolution. This is done by adding a new process to a previously-studied Markov model of evolution on a smooth fitness landscape; this new process allows alleles to be exchanged with those in the surrounding medium. Our results, both numerical and analytic, indicate that for a wide range of intermediate population sizes, recombination dramatically speeds up the evolutionary advance

    Accounting Ethics Education: A Comparison with Buddhist Ethics Education Framework

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    Accounting educators such as Mintz and Mele have argued about the importance of virtues in moral behavior. Mele presented a conceptual model of moral behavior that integrated professional rules of conduct, moral values, and moral virtues. Moral virtues are defined as “permanent attitudes and interior strength for moral behavior.” A major shortcoming of the Mele’s model is that the model does not provide any discussion on the methodologies facilitating the cultivation of virtues. This paper describes the framework and process of Buddhist ethics education and compares the similarities and differences of the Buddhist ethics education framework with the mainstream accounting ethics education framework. Compared with the mainstream ethics education model, the Buddhist ethics education framework appears to be comprehensive and systematic. In addition, to delineate the constituent factors that contribute to moral behavior, it renders several methodological discussions on how to cultivate moral sentiment, practical wisdom, and transitive and self-mastering virtues. Its systematic nature is exhibited by the line-up or formulation of necessary steps leading to the final achievement of moral behavior. Taken as a whole, the framework provides practitioners with practical guidance for what they need to work on sequentially or simultaneously in the moral development process. We sincerely hope that our discussion and comparison of the framework benefit accounting educators who are concerned with instilling long-term values and virtues into the lives of their students

    Interferometric Astrometry of Proxima Centauri and Barnard's Star Using Hubble Space Telescope Fine Guidance Sensor 3: Detection Limits for sub-Stellar Companions

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    We report on a sub-stellar companion search utilizing interferometric fringe-tracking astrometry acquired with Fine Guidance Sensor 3 (FGS 3) on the Hubble Space Telescope. Our targets were Proxima Centauri and Barnard's Star. We obtain absolute parallax values for Proxima Cen pi_{abs} = 0.7687 arcsecond and for Barnard's Star pi_{abs} = 0.5454 arcsecond. Once low-amplitude instrumental systematic errors are identified and removed, our companion detection sensitivity is less than or equal to one Jupiter mass for periods longer than 60 days for Proxima Cen. Between the astrometry and the radial velocity results we exclude all companions with M > 0.8M_{Jup} for the range of periods 1 < P < 1000 days. For Barnard's Star our companion detection sensitivity is less than or equal to one Jupiter mass for periods long er than 150 days. Our null results for Barnard's Star are consistent with those of Gatewood (1995).Comment: 35 pages, 13 figures, to appear in August 1999 A
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