18,047 research outputs found

    Welfarism vs. extra-welfarism

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    'Extra-welfarism' has received some attention in health economics, yet there is little consensus on what distinguishes it from more conventional 'welfarist economics'. In this paper, we seek to identify the characteristics of each in order to make a systematic comparison of the ways in which they evaluate alternative social states. The focus, though this is not intended to be exclusive, is on health. Specifically, we highlight four areas in which the two schools differ: (i) the outcomes considered relevant in an evaluation; (ii) the sources of valuation of the relevant outcomes; (iii) the basis of weighting of relevant outcomes and (iv) interpersonal comparisons. We conclude that these differences are substantive. (C) 2007 Elsevier B.V. All rights reserved

    Data Mining and Quantitative Structure-Activity Relationships of Inhibitors for Treating Alzheimer's Disease

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    poster abstractAmyloid cleaving enzyme-1 (BACE1) is a target of interest for treating patients with Alzheimer’s disease (AD). As of 2007, more than 37 million people worldwide are afflicted with the disease. Incidence of the disease keeps increasing as the population ages and fewer people die of other diseases. ß-Amyloid precursor protein (APP) is a natural protein associated with neurons of the brain. In Alzheimer's disease, APP is cleaved by BACE1 at the beta-site, resulting in short 42 amino acid segments called amyloid-ß (Aß). Aggregation of Aß into plaques results in the death of neurons and is associated with AD. Inhibition of the BACE1 enzyme may prevent Aß formation and prevent the development or progression of AD. Known BACE1 inhibitors are analyzed using computational chemistry techniques, and quantitative structure-activity relationships (QSAR) are developed

    Simple Structure-Based Approach for Predicting the Activity of Inhibitors of Beta-Secretase (BACE1) Associated with Alzheimer's Disease

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    poster abstractBeta-site amyloid precursor protein cleaving enzyme-1 (BACE1) is a target of interest for treating patients with Alzheimer’s disease (AD). Inhibition of BACE1 may prevent amyloid-ß (Aß) plaque formation and the development or progression of Alzheimer’s disease. Known BACE1 inhibitors were analyzed using computational chemistry and cheminformatics techniques to search for quantitative structure− activity relationships (QSAR). A remarkable relationship was found with only two simple descriptors with a square of the linear correlation coefficient r2 of 0.75. The main descriptor is the number of hydrophobic contacts in the range 4−5 Å between the atoms of the ligand and active site. The other descriptor is the number of short (<2.8 Å) hydrogen bonds. Our approach uses readily available structural data on protein- inhibitor complexes in the Protein Data Bank (PDB) but would be equally applicable to proprietary structural biology data. The findings can aid structure-based design of improved BACE-1 inhibitors. If an inhibitor has less observed activity than predicted by our correlation, the compound should be retested because the first assay may have underestimated the compound’s true activity

    Control of Intense Laser- Atom Processes With Strong Static Fields

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    Atomic processes in the presence of intense fields continue to attract a great deal of attention [1-3]. Key goals of research in this area are to increase the intensities and frequencies of coherent light produced in these processes. In two recent works [4,5] we have demonstrated theoretically the possibility of controlling intense laser-atom interaction processes by employing strong, but experimentally feasible, static electric or magnetic fields. Thus, in Ref. [4] we demonstrated how a strong static electric field may induce a high-energy plateau for scattered x-ray photons in laser-assisted, x-ray-atom scattering in which the incident x-rays were assumed to have an energy of 50 eV. The scattered x-rays were shown to have energies up to well over 200 eV, making such a process an attractive one for realizing coherent x-rays in the water window [between the K shell absorption edges of C (284 eV) and 0 (532 eV)], which would have important applications to imaging living biological structures by means of x-ray holography [6]. In Ref. [5], we demonstrated control of high-harmonic generation (HHG) by a linearly polarized laser field using a uniform static magnetic field parallel to the laser polarization. We predicted that particular values of the magnetic field can increase harmonic intensities by orders of magnitude. Our classical orbit calculations showed that these magnetic-field-induced intensity revivals occur when the return time for laserdriven motion of the electron back to the origin is a multiple of the cyclotron period for motion perpendicular to the laser polarization direction. We present here further results [7-9] on using strong electric and magnetic fields to control these two intense laser-atom processes

    Magnetic-Field-Induced Intensity Revivals in Harmonic Generation

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    We demonstrate control of high harmonic generation by a linearly polarized laser field using a uniform static magnetic field parallel to the laser polarization. We predict that particular values of the magnetic field can increase harmonic intensities by orders of magnitude. Classical orbit calculations show that these magnetic-field-induced intensity revivals occur when the return time for laser-driven motion of the electron back to the origin is a multiple of the cyclotron period for motion perpendicular to the laser polarization direction

    Continuous Variable Quantum Key Distribution: Finite-Key Analysis of Composable Security against Coherent Attacks

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    We provide a security analysis for continuous variable quantum key distribution protocols based on the transmission of squeezed vacuum states measured via homodyne detection. We employ a version of the entropic uncertainty relation for smooth entropies to give a lower bound on the number of secret bits which can be extracted from a finite number of runs of the protocol. This bound is valid under general coherent attacks, and gives rise to keys which are composably secure. For comparison, we also give a lower bound valid under the assumption of collective attacks. For both scenarios, we find positive key rates using experimental parameters reachable today.Comment: v2: new author, technical inaccuracy corrected, new plots, v3: substantially improved key rates against coherent attacks (due to correction of an error in the numerical computation

    Real-time prediction with U.K. monetary aggregates in the presence of model uncertainty

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    A popular account for the demise of the U.K.’s monetary targeting regime in the 1980s blames the fluctuating predictive relationships between broad money and inflation and real output growth. Yet ex post policy analysis based on heavily revised data suggests no fluctuations in the predictive content of money. In this paper, we investigate the predictive relationships for inflation and output growth using both real-time and heavily revised data. We consider a large set of recursively estimated vector autoregressive (VAR) and vector error correction models (VECM). These models differ in terms of lag length and the number of cointegrating relationships. We use Bayesian model averaging (BMA) to demonstrate that real-time monetary policymakers faced considerable model uncertainty. The in-sample predictive content of money fluctuated during the 1980s as a result of data revisions in the presence of model uncertainty. This feature is only apparent with real-time data as heavily revised data obscure these fluctuations. Out-of-sample predictive evaluations rarely suggest that money matters for either inflation or real output. We conclude that both data revisions and model uncertainty contributed to the demise of the U.K.’s monetary targeting regime

    The FLIC Overlap Quark Propagator

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    FLIC overlap fermions are a variant of the standard (Wilson) overlap action, with the FLIC (Fat Link Irrelevant Clover) action as the overlap kernel rather than the Wilson action. The structure of the FLIC overlap fermion propagator in momentum space is studied, and a comparison against previous studies of the Wilson overlap propagator in quenched QCD is performed. To explore the scaling properties of the propagator for the two actions, numerical calculations are performed in Landau Gauge across three lattices with different lattice spacing aa and similar physical volumes. We find that at light quark masses the acti ons agree in both the infrared and the ultraviolet, but at heavier masses some disagreement in the ultraviolet appears. This is attributed to the two action s having different discretisation errors with the FLIC overlap providing superior performance in this regime. Both actions scale reasonably, but some scaling violations are observed
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