956 research outputs found

    Neutral Particles and Super Schwinger Terms

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    Z_2-graded Schwinger terms for neutral particles in 1 and 3 space dimensions are considered.Comment: 13 page

    A procedure for standardization of color infrared film response

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    Various problems with color infrared film used for remote sensing applications which relate to the instability or variability of the relative sensitivities of the dye layers within the film and the resultant variations in color balance are indicated. A procedure developed and utilized to optimize film response and to achieve more consistent results is described. The procedure establishes a sensitometric aim point with which all new batches of film are compared. Through the use of color compensation filters and change in basic exposure, the new film is exposed to produce imagery with the response characteristics of the aim curves

    Género y capacidades directivas en cooperativas de trabajo asociado. Estudio exploratorio en CTAS valencianas

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    In the last two decades, much research has been done regarding gender differences and leadership styles. This paper presents some of the organizational implications of cooperative firms (Coops) and how their characteristics affect the leadership style of managers. Also, from a gender perspective, we study the management style associated with gender differences in Coops in Valencia (Spain).The results suggest that the nature of the work done by women managers, and their vision of management, responds to a more contemporary leadership style, and fits better in the organizational context of coops, which are characterized by equal relations.Son numerosas las investigaciones que desde hace más de dos décadas han investigado posibles influencias de género en el comportamiento en la empresa y en los estilos de dirección. Sin embargo, en el análisis no se han contemplado los aspectos institucionales y organizativos, que juegan un papel relevante en el comportamiento y en el trabajo de los directivos.Atendiendo a lo anterior, este trabajo muestra las implicaciones organizativas que tiene la forma institucional Cooperativa de trabajo asociado (CTA) y cómo afectan al trabajo directivo. Asimismo, y desde una perspectiva de género, se investigan en CTAs valencianas las capacidades directivas vinculadas a diferencias de género.Los resultados obtenidos sugieren que la naturaleza del trabajo que realizan las directivas (mujeres) así como su visión del trabajo directivo, responde a un estilo directivo contemporáneo, y tienen un mayor “encaje” con el contexto organizativo de la CTA caracterizado por relaciones entre iguales

    A four-season prospective study of muscle strain reoccurrences in a professional football club

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    The aim of this investigation was to characterise muscle strain reinjuries and examine their impact on playing resources in a professional football club. Muscle strains and reoccurrences were prospectively diagnosed over four seasons in first-team players (n = 46). Altogether, 188 muscle strains were diagnosed with 44 (23.4%) of these classed as reinjuries, leading to an incidence of 1.32 strain reoccurrences per 1,000 hours exposure (95% Confidence Interval [CI], 0.93–1.71). The incidence of recurrent strains was higher in match-play compared with training (4.51, 95% CI, 2.30–6.72 vs 0.94, 95% CI, 0.59–1.29). Altogether, 50.0% of players sustained at least 1 reoccurrence of a muscle strain, leading to approximately 3 days lost and 0.4 matches missed per player per season. The incidence of recurrent strains was highest in centre-forwards (2.15, 95% CI, 1.06–3.24), peaked in May (3.78, 95% CI, 0.47–7.09), and mostly affected the hamstrings (38.6% of all reoccurrences). Mean layoff for nonreoccurrences and recurrences was similar: ∼7.5 days. These results provide greater insight into the extent of the problem of recurrent muscle strains in professional football

    Longitudinal membrane function in functionally anuric patients treated with APD: Data from EAPOS on the effects of glucose and icodextrin prescription

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    Longitudinal membrane function in functionally anuric patients treated with APD: Data from EAPOS on the effects of glucose and icodextrin prescription. Background: Peritoneal dialysis is associated with changes in membrane function that can lead eventually to ultrafiltration (UF) failure. Factors driving these changes are thought to include hypertonic glucose exposure, but previously reported associations are confounded by the presence of residual renal function. Methods: Longitudinal membrane function (solute transport and UF capacity) were measured annually in a prospective cohort of 177 functionally anuric patients as part of the European Automated Peritoneal Dialysis Outcomes Study (EAPOS). Subgroup analysis was performed according to glucose exposure and icodextrin use at baseline. Results: The whole cohort experienced an increase in solute transport and reduction in UF capacity at 12 and 24 months that could not be explained by informative censoring. These changes were accelerated and more severe in patients using either 2.27% or 3.86% glucose, or those not using icodextrin at baseline. These differences could not be explained by age, comorbidity score, previous time spent on renal replacement, differential dropout from the study, peritonitis rates, or, by definition, residual renal function. Patients using icodextrin at baseline had worse membrane function and were more likely to be diabetic. There was an association between membrane function changes and achieved 24-hour ultrafiltration over the 2-year study period. Conclusion: Anuric automated peritoneal dialysis (APD) patients experience significant detrimental changes in membrane function over a relatively short time period. Glucose appears to enhance these changes independent of residual renal function. Icodextrin use in these circumstances is associated with less deterioration in membrane functio

    Large N limit of SO(N) gauge theory of fermions and bosons

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    In this paper we study the large N_c limit of SO(N_c) gauge theory coupled to a Majorana field and a real scalar field in 1+1 dimensions extending ideas of Rajeev. We show that the phase space of the resulting classical theory of bilinears, which are the mesonic operators of this theory, is OSp_1(H|H )/U(H_+|H_+), where H|H refers to the underlying complex graded space of combined one-particle states of fermions and bosons and H_+|H_+ corresponds to the positive frequency subspace. In the begining to simplify our presentation we discuss in detail the case with Majorana fermions only (the purely bosonic case is treated in our earlier work). In the Majorana fermion case the phase space is given by O_1(H)/U(H_+), where H refers to the complex one-particle states and H_+ to its positive frequency subspace. The meson spectrum in the linear approximation again obeys a variant of the 't Hooft equation. The linear approximation to the boson/fermion coupled case brings an additonal bound state equation for mesons, which consists of one fermion and one boson, again of the same form as the well-known 't Hooft equation.Comment: 27 pages, no figure

    Chiral de Rham complex on Riemannian manifolds and special holonomy

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    Interpreting the chiral de Rham complex (CDR) as a formal Hamiltonian quantization of the supersymmetric non-linear sigma model, we suggest a setup for the study of CDR on manifolds with special holonomy. We show how to systematically construct global sections of CDR from differential forms, and investigate the algebra of the sections corresponding to the covariantly constant forms associated with the special holonomy. As a concrete example, we construct two commuting copies of the Odake algebra (an extension of the N=2 superconformal algebra) on the space of global sections of CDR of a Calabi-Yau threefold and conjecture similar results for G_2 manifolds. We also discuss quasi-classical limits of these algebras.Comment: 49 pages, title changed, major rewrite with no changes in the main theorems, published versio
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