3,798 research outputs found

    Practising the Space Between: Embodying Belief as an Evangelical Anglican Student

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    This article explores the formation of British evangelical university students as believers. Drawing on ethnographic fieldwork conducted with a conservative evangelical Anglican congregation in London, I describe how students in this church come to embody a highly cognitive, word-based mode of belief through particular material practices. As they learn to identify themselves as believers, practices of reflexivity and accountability enable them to develop a sense of narrative coherence in their lives that allows them to negotiate tensions that arise from their participation in church and broader social structures. I demonstrate that propositional belief – in contexts where it becomes an identity marker – is bound up with relational practices of belief, such that distinctions between “belief in” and “belief that” are necessarily blurred in the lives of young evangelicals

    Serum dioxin concentrations and endometriosis: a cohort study in Seveso, Italy.

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    Dioxin, a ubiquitous contaminant of industrial combustion processes including medical waste incineration, has been implicated in the etiology of endometriosis in animals. We sought to determine whether dioxin exposure is associated with endometriosis in humans. We conducted a population-based historical cohort study 20 years after the 1976 factory explosion in Seveso, Italy, which resulted in the highest known population exposure to 2,3,7,8-tetrachlorodibenzo-(italic)p(/italic)-dioxin (TCDD). Participants were 601 female residents of the Seveso area who were (3/4) 30 years old in 1976 and had adequate stored sera. Endometriosis disease status was defined by pelvic surgery, current transvaginal ultrasound, pelvic examination, and interview (for history of infertility and pelvic pain). "Cases" were women who had surgically confirmed disease or an ultrasound consistent with endometriosis. "Nondiseased" women had surgery with no evidence of endometriosis or no signs or symptoms. Other women had uncertain status. To assess TCDD exposure, individual levels of TCDD were measured in stored sera collected soon after the accident. We identified 19 women with endometriosis and 277 nondiseased women. The relative risk ratios (RRRs) for women with serum TCDD levels of 20.1-100 ppt and >100 ppt were 1.2 [90% confidence interval (CI) = 0.3-4.5] and 2.1 (90% CI = 0.5-8.0), respectively, relative to women with TCDD levels (3/4) 20 ppt. Tests for trend using the above exposure categories and continuous log TCDD were nonsignificant. In conclusion, we report a doubled, nonsignificant risk for endometriosis among women with serum TCDD levels of 100 ppt or higher, but no clear dose response. Unavoidable disease misclassification in a population-based study may have led to an underestimate of the true risk of endometriosis

    The Statistical Mechanics of Membranes

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    The fluctuations of two-dimensional extended objects membranes is a rich and exciting field with many solid results and a wide range of open issues. We review the distinct universality classes of membranes, determined by the local order, and the associated phase diagrams. After a discussion of several physical examples of membranes we turn to the physics of crystalline (or polymerized) membranes in which the individual monomers are rigidly bound. We discuss the phase diagram with particular attention to the dependence on the degree of self-avoidance and anisotropy. In each case we review and discuss analytic, numerical and experimental predictions of critical exponents and other key observables. Particular emphasis is given to the results obtained from the renormalization group epsilon-expansion. The resulting renormalization group flows and fixed points are illustrated graphically. The full technical details necessary to perform actual calculations are presented in the Appendices. We then turn to a discussion of the role of topological defects whose liberation leads to the hexatic and fluid universality classes. We finish with conclusions and a discussion of promising open directions for the future.Comment: 75 LaTeX pages, 36 figures. To appear in Physics Reports in the Proceedings of RG2000, Taxco, 199

    Beyond element-wise interactions: identifying complex interactions in biological processes

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    Background: Biological processes typically involve the interactions of a number of elements (genes, cells) acting on each others. Such processes are often modelled as networks whose nodes are the elements in question and edges pairwise relations between them (transcription, inhibition). But more often than not, elements actually work cooperatively or competitively to achieve a task. Or an element can act on the interaction between two others, as in the case of an enzyme controlling a reaction rate. We call “complex” these types of interaction and propose ways to identify them from time-series observations. Methodology: We use Granger Causality, a measure of the interaction between two signals, to characterize the influence of an enzyme on a reaction rate. We extend its traditional formulation to the case of multi-dimensional signals in order to capture group interactions, and not only element interactions. Our method is extensively tested on simulated data and applied to three biological datasets: microarray data of the Saccharomyces cerevisiae yeast, local field potential recordings of two brain areas and a metabolic reaction. Conclusions: Our results demonstrate that complex Granger causality can reveal new types of relation between signals and is particularly suited to biological data. Our approach raises some fundamental issues of the systems biology approach since finding all complex causalities (interactions) is an NP hard problem

    The engine reformer: Syngas production in an engine for compact gas-to-liquids synthesis

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    Methane (CH[subscript 4]) reforming was carried out in an internal combustion engine (an “engine reformer”). We successfully produced syngas from the partial oxidation of natural gas in the cylinder of a diesel engine that was reconfigured to perform spark ignition. Performing the reaction in an engine cylinder allows some of the exothermicity to be captured as useful work. Intake conditions of 110 kPa and up to 480 °C allowed low cycle-to-cycle variability (COV[subscript nimep]  2.4, but < 1 mg/L below these equivalence ratios. These results demonstrate that the engine reformer could be a key component of a compact gas-to-liquids synthesis plant by highlighting the operating conditions under which high gas conversion, high H[subscript 2]-to-CO ratios close to 2.0, and low soot production are possible.United States. Advanced Research Projects Agency-Energy (Award DE-AR0000506)Research Triangle InitiativeMIT Energy InitiativeMassachusetts Institute of Technology. Tata Center for Technology and Desig

    The evolution problem for the 1D nonlocal Fisher-KPP equation with a top hat kernel. Part 2. The initial-boundary value problem on a finite domain

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    In the second part of this series of papers, we address the same evolution problem that was considered in part 1 (see [16]), namely the nonlocal Fisher-KPP equation in one spatial dimension, ut=Duxx+u(1−ϕ∗u),     where ϕ∗u is a spatial convolution with the top hat kernel, ϕ(y)≡H(1/4−y2), except that now we modify this to an associated initial-boundary value problem on the finite spatial interval [0, a] rather than the whole real line. Boundary conditions are required at the end points of the interval, and we address the situations when these are of either Dirichlet or Neumann type. This model is a natural extension of the classical Fisher-KPP model, with the introduction of the simplest possible nonlocal effect into the saturation term. Nonlocal reaction-diffusion models arise naturally in a variety of (frequently biological or ecological) contexts, and as such it is of fundamental interest to examine their properties in detail, and to compare and contrast these with the well known properties of the classical Fisher-KPP model
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