881 research outputs found

    Introduction

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    In establishing the Journal of Material Culture in 1996, the editors opened the first issue with an editorial that made the case that material culture studies is an undisciplined field of study. In framing it in this manner, they highlighted the intellectual freedom gained by drawing from multiple disciplinary insights and methodological approaches. In the 1990s, the research group was expanded, incorporating more of an archaeological influence from Cambridge, with the addition of Chris Tilley and Victor Buchli – both students of Ian Hodder. Within the anthropological attention to material culture, there has always been the critical issue of temporality as it is inscribed in the object. As Pinney reminds people, the Durkheimian tradition approaches objects as a historical record of society. Despite the many moves beyond representation, aesthetics, language, and semiotics, this chapter highlights a need to maintain these analytical registers in exploring material cultural phenomena

    A direct optical method for the study of grain boundary melting

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    The structure and evolution of grain boundaries underlies the nature of polycrystalline materials. Here we describe an experimental apparatus and light reflection technique for measuring disorder at grain boundaries in optically clear material, in thermodynamic equilibrium. The approach is demonstrated on ice bicrystals. Crystallographic orientation is measured for each ice sample. The type and concentration of impurity in the liquid can be controlled and the temperature can be continuously recorded and controlled over a range near the melting point. The general methodology is appropriate for a wide variety of materials.Comment: 8 pages, 8 figures, updated with minor changes made to published versio

    Assessing the needs of older people in urban settings : integration of emotive, physiological and built environment data

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    Design of the built environment for navigability and walkability is an increasingly important aspect of urban planning. This focus derives in part from increasing interest in lifestyles and behaviours including level of physical activity and health outcomes. Geographical Information Systems and virtual realities are playing a significant role in advancing this agenda: examples exist of integrating qualitative data (words about or visual images of places) and quantitative data (numerical descriptions of places). However there remain opportunities for exploring alternative ways of linking different types of data (physiological measurements, emotional response, street walkability and urban design quality) to address issues of urban planning and renewal. Using a case study approach this paper explores the application of geographic information science and systems to participatory approaches in built environment planning with the aim of exploring older people’s response to an unfamiliar urban environment. It examines different ways of combining temporally and spatial referenced qualitative and quantitative data. The participants in the study were a group of 44 older people (60+) from Swansea, Wales, who viewed a filmed walking route around Colchester, England. Whilst viewing the film they gave an oral commentary and physiological readings were made, which have been integrated with primary data collected on the built environment along the walking route. Proximity and inverse distance weighting approaches for combining these datasets produce complementary results in respect of older people’s physiological and emotive response to variation in the walkability and design quality of a walking route through an unfamiliar town centre. The results reveal participants experienced an elevated average heart close to Colchester Town railway station and expressed a comparatively negative emotional response to this location. Conversely participants experienced lower average heart rate, indicating reduced stress, in Brook Street where the overall Urban Design Quality score was relatively low

    Association of coronary vessel characteristics with outcome in patients with percutaneous coronary interventions with incomplete revascularization

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    © 2017 American Medical Association. All rights reserved. IMPORTANCE Many studies have compared outcomes for incomplete revascularization (IR) among patients undergoing percutaneous coronary interventions (PCI), but little is known about whether outcomes are related to the nature of the IR. OBJECTIVE To determine whether some coronary vessel characteristics are associated with worse outcomes in patients with PCI with IR. DESIGN, SETTING, AND PARTICIPANTS New York\u27s PCI registrywas used to examine mortality (median follow-up, 3.4 years) as a function of the number of vessels that were incompletely revascularized, the stenosis in those vessels, and whether the proximal left anterior descending artery was incompletely revascularized after controlling for other factors associated with mortality for patients with and without ST-elevationmyocardial infarction (STEMI). This was a multicenter study (all nonfederal PCI hospitals in New York State) that included 41 639 New York residents with multivessel coronary artery disease undergoing PCI in New York State between January 1, 2010, and December 31, 2012. EXPOSURES Percutaneous coronary interventions, with complete and incomplete revascularization. MAIN OUTCOMES AND MEASURES Medium-term mortality. RESULTS For patients with STEMI, the mean age was 62.8 years; 26.2%were women, 11.9% were Hispanic, and 81.5%were white. For other patients, the mean age was 66.6 years, 29.1%were women, 11.3%were Hispanic, and 79.1%were white. Incomplete revascularization was very common (78%among patients with STEMI and 71%among other patients). Patients with IR in a vessel with at least 90% stenosis were at higher risk than other patients with IR. This was not significant among patients with STEMI (17.18%vs 12.86%; adjusted hazard ratio [AHR], 1.16; 95%CI, 0.99-1.37) and significant among patients without STEMI (17.71% vs 12.96%; AHR, 1.15; 95%CI, 1.07-1.24). Similarly, patients with IR in 2 or more vessels had higher mortality than patients with completely revascularization and higher mortality than other patients with IR among patients with STEMI (20.37%vs 14.39%; AHR, 1.35; 95%CI, 1.15-1.59) and among patients without STEMI (20.10% vs 12.86%; AHR, 1.17; 95% CI, 1.09-1.59). Patients with proximal left anterior descending artery vessel IR had higher mortality than other patients with IR (20.09% vs 14.67%; AHR, 1.31; 95%CI, 1.04-1.64 for patients with STEMI and 20.78%vs 15.62%; AHR, 1.11; 95%CI, 1.01-1.23 for patients without STEMI). More than 20%of all PCI patients had IR of 2 or more vessels and more than 30% had IR with more than 90% stenosis. CONCLUSIONS AND RELEVANCE Patients with IR are at higher risk of mortality if they have IR with at least 90% stenosis, IR in 2 or more vessels, or proximal left anterior descending IR

    A Belief System's Organization Based on a Computational Model of the Dynamic Context: First Approximation

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    In this article we present a model of organization of a belief system based on a set of binary recursive functions that characterize the dynamic context that modifies the beliefs. The initial beliefs are modeled by a set of two-bit words that grow, update, and generate other beliefs as the different experiences of the dynamic context appear. Reason is presented as an emergent effect of the experience on the beliefs. The system presents a layered structure that allows a functional organization of the belief system. Our approach seems suitable to model different ways of thinking and to apply to different realistic scenarios such as ideologies

    Helicity-dependent cross sections and double-polarization observable E in η photoproduction from quasifree protons and neutrons

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    Precise helicity-dependent cross sections and the double-polarization observable E were measured for η photoproduction from quasifree protons and neutrons bound in the deuteron. The η → 2γ and η → 3π0 → 6γ decay modes were used to optimize the statistical quality of the data and to estimate systematic uncertainties. The measurement used the A2 detector setup at the tagged photon beam of the electron accelerator MAMI in Mainz. A longitudinally polarized deuterated butanol target was used in combination with a circularly polarized photon beam from bremsstrahlung of a longitudinally polarized electron beam. The reaction products were detected with the electromagnetic calorimeters Crystal Ball and TAPS, which covered 98% of the full solid angle. The results show that the narrow structure observed earlier in the unpolarized excitation function of η photoproduction off the neutron appears only in reactions with antiparallel photon and nucleon spin (σ1/2). It is absent for reactions with parallel spin orientation (σ3/2) and thus very probably related to partial waves with total spin 1/2. The behavior of the angular distributions of the helicity-dependent cross sections was analyzed by fitting them with Legendre polynomials. The results are in good agreement with a model from the Bonn-Gatchina group, which uses an interference of P11 and S11 partial waves to explain the narrow structure

    Target and beam-target spin asymmetries in exclusive pion electroproduction for Q2>1GeV2 . I. ep→eπ+n

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    Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π + electroproduction reaction γ ∗ p → n π + . The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic range covered is 1.1 < W < 3 GeV and 1 < Q 2 < 6 GeV 2 . Results were obtained for about 6000 bins in W ,   Q 2 ,   cos ( θ ∗ ) , and ϕ ∗ . Except at forward angles, very large target-spin asymmetries are observed over the entire W region. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but very large differences are seen at higher values of W . A generalized parton distributions (GPD)-based model is in poor agreement with the data. When combined with cross-sectional measurements, the present results provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q 2 , for resonances with masses as high as 2.4 GeV

    Light scattering from an isotropic layer between uniaxial crystals

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    We develop a model for the reflection and transmission of plane waves by an isotropic layer sandwiched between two uniaxial crystals of arbitrary orientation. In the laboratory frame, reflection and transmission coefficients corresponding to the principal polarization directions in each crystal are given explicitly in terms of the c-axis and propagation directions. The solution is found by first deriving explicit expressions for reflection and transmission amplitude coefficients for waves propagating from an arbitrarily oriented uniaxial anisotropic material into an isotropic material. By combining these results with Lekner's (1991) earlier treatment of waves propagating from isotropic media to anisotropic media and employing a matrix method we determine a solution to the general form of the multiple reflection case. The example system of a wetted interface between two ice crystals is used to contextualize the results.Comment: 18 pages, 9 figures,updated with changes made to published versio
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