2,418 research outputs found

    QED in external fields from the spin representation

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    Systematic use of the infinite-dimensional spin representation simplifies and rigorizes several questions in Quantum Field Theory. This representation permutes ``Gaussian'' elements in the fermion Fock space, and is necessarily projective: we compute its cocycle at the group level, and obtain Schwinger terms and anomalies from infinitesimal versions of this cocycle. Quantization, in this framework, depends on the choice of the ``right'' complex structure on the space of solutions of the Dirac equation. We show how the spin representation allows one to compute exactly the S-matrix for fermions in an external field; the cocycle yields a causality condition needed to determine the phase.Comment: 32 pages, Plain TeX, UCR-FM-01-9

    On the ultraviolet behaviour of quantum fields over noncommutative manifolds

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    By exploiting the relation between Fredholm modules and the Segal-Shale-Stinespring version of canonical quantization, and taking as starting point the first-quantized fields described by Connes' axioms for noncommutative spin geometries, a Hamiltonian framework for fermion quantum fields over noncommutative manifolds is introduced. We analyze the ultraviolet behaviour of second-quantized fields over noncommutative 3-tori, and discuss what behaviour should be expected on other noncommutative spin manifolds.Comment: 10 pages, RevTeX version, a few references adde

    Exploring Neighborhood Influences on Small-Area Variations in Intimate Partner Violence Risk: A Bayesian Random-Effects Modeling Approach

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    This paper uses spatial data of cases of intimate partner violence against women (IPVAW) to examine neighborhood-level influences on small-area variations in IPVAW risk in a police district of the city of Valencia (Spain). To analyze area variations in IPVAW risk and its association with neighborhood-level explanatory variables we use a Bayesian spatial random-effects modeling approach, as well as disease mapping methods to represent risk probabilities in each area. Analyses show that IPVAW cases are more likely in areas of high immigrant concentration, high public disorder and crime, and high physical disorder. Results also show a spatial component indicating remaining variability attributable to spatially structured random effects. Bayesian spatial modeling offers a new perspective to identify IPVAW high and low risk areas, and provides a new avenue for the design of better-informed prevention and intervention strategies

    The uses of Connes and Kreimer's algebraic formulation of renormalization theory

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    We show how, modulo the distinction between the antipode and the "twisted" or "renormalized" antipode, Connes and Kreimer's algebraic paradigm trivializes the proofs of equivalence of the (corrected) Dyson-Salam, Bogoliubov-Parasiuk-Hepp and Zimmermann procedures for renormalizing Feynman amplitudes. We discuss the outlook for a parallel simplification of computations in quantum field theory, stemming from the same algebraic approach.Comment: 15 pages, Latex. Minor changes, typos fixed, 2 references adde

    Gambaran Eritrosit Urin Pada Pasien Tuberkulosis Paru Dewasa Di RSUP Prof. Dr. R. D. Kandou Manado

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    : Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. Tuberculosis remains a major global health problem and ranks as the second leading cause of death from an infectious disease worldwide. Anti-tuberculosis drugs, such as streptomycin and rifampicin are nephrotoxic. If the kidney function decreased, especially the glomerulus there can be found blood cells in the urine. A small number of erythrocytes may be found in normal urine, about 0-2 cells per HPF (High Power Field). But more than three erythrocytes per HPF is generally considered hematuria. This study aims to describe about how the urine erythrocytes in adult pulmonary tuberculosis patients at RSUP Prof. Dr. R. D. Kandou Manado. Research design used is descriptive observational research. Samples were urine samples of all pulmonary tuberculosis patients that suit to inclusion criteria. This study was conducted from October to November 2016. The results of chemical urinalysis of urine erythrocytes are negative in 20 patients and positive in 10 patients, while the results of microscopic urinalysis of urine erythrocytes are normal in 26 patients and hematuria in 4 patients. Conclusion: Hematuria mostly found in males, age 56-65 years old, default tuberculosis type, the first category of anti-tuberculosis drugs, the duration of therapy about 3-4 months, and in patients with comorbid disease

    Emotional intelligence and creativity in first- and second-year primary school children

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    The objective of this study was to describe emotional intelligence and creativity in Primary Education schoolchildren. These two constructs were evaluated in first- and second-year Primary Education schoolchildren who went to different schools in the Spanish Autonomous Community of Aragon. The study sample was formed by 631 schoolchildren (313 boys and 318 girls) aged 6-7 years. The results showed differences in emotional intelligence for gender, but the differences obtained for creativity were not significant. Finally, a cluster analysis was done to analyse how the different variables were grouped according to clusters, where differences were found for creativity levels, but not for emotional intelligence levels. This research indicated how emotional intelligence did not influence our pupils'' creativity as the cluster with the highest creativity level had the lowest level of elaboration (quantity of details in responses). This indicated that, despite being creative, these pupils were concise and pragmatic when responding. This situation should make schools reflect on what type of students we are training. As future research lines, work should be done with programmes that include creativity and emotional intelligence, and that investigate the way positive emotions and creativity can be combined

    Twisted Covariant Noncommutative Self-dual Gravity

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    A twisted covariant formulation of noncommutative self-dual gravity is presented. The formulation for constructing twisted noncommutative Yang-Mills theories is used. It is shown that the noncommutative torsion is solved at any order of the θ\theta-expansion in terms of the tetrad and some extra fields of the theory. In the process the first order expansion in θ\theta for the Pleba\'nski action is explicitly obtained.Comment: 23+1 pages, no figures, corrected typos, references and Appendix B is adde

    Intra-abdominal pressure and its relationship with markers of congestion in patients admitted for acute decompensated heart failure

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    Systemic congestion is one of the mechanisms involved in acute decompensated heart failure (ADHF). Increased intra-abdominal pressure (IAP), elicited by abdominal congestion, has been related to acute kidney injury and prognosis. Nonetheless, the link between diuretic response, surrogate markers of congestion and renal function remains poorly understood. We measured IAP in 43 patients from a non-interventional, exploratory, prospective, single center study carried out in patients admitted for ADHF. IAP was measured with a calibrated electronic manometer through a catheter inserted in the bladder. Normal IAP was defined as 12 mmHg at 72 h. In patients with ADHF, higher IAP at admission is associated with poorer baseline renal function and impaired diuretic response. The persistence of IAP at 72 h above 12 mmHg associates to longer length of hospital stay and higher 1-year all-cause mortality

    An anti-islanding protection based on RoCoF compliant with ENTSO-E and IEC 62116

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    In case of unintentional islanding, distributed generation units must be able to detect it and disconnect from the grid in less than 2 seconds. In this work, a Rate of Change of Frequency (RoCoF) method has been developed for islanding detection. Since these algorithms are conditioned by the requirements of grid codes, ENTSO-E network code and IEC 62116 have been taken into account. The RoCoF anti-islanding algorithm has been developed in MATLAB-Simulink and implemented through rapid prototyping techniques in an FPGA ALTERA Cyclone V. To check the proposed protection algorithm, simulation tests have been carried out. Finally, the RoCoF anti-islanding protection has been validated using FPGA in the loop and experimentally in a real 20-kW inverter. © 2022, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved

    Un conjunto de estructuras de combustión en la H.88/21 del poblado protohistórico del Alto de la Cruz (Cortes de Navarra)

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    La secuencia cronoestratigráfica del poblado de la Primera Edad del Hierro del Alto de la Cruz (Cortes de Navarra) constituye un punto de referencia básico para la estructuración del poblamiento en el valle medio del Ebro. Se analiza el tipo constructivo de la fase más antigua del mismo y, en especial, un conjunto de estructuras de combustión documentadas en la H.88/21.The cronostratigraphyc sequency of the Early Iron Age town of Alto de la Cruz (Cortes de Navarra) is a basic reference point for the structure of settlement in the middle walley of Ebro. This paper studies the constructive tipes of the most early occupational phase and, specially, a fireplace' s group of the H.88/21
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