94 resultados para Alphanumeric category


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We extend the theory of Quillen adjunctions by combining ideas of homotopical algebra and of enriched category theory. Our results describe how the formulas for homotopy colimits of Bousfield and Kan arise from general formulas describing the derived functor of the weighted colimit functor.

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In a recent paper Iyama and Yoshino consider two interesting examples of isolated singularities over which it is possible to classify the indecomposable maximal Cohen-Macaulay modules in terms of linear algebra data. In this paper we present two new approaches to these examples. In the first approach we give a relation with cluster categories. In the second approach we use Orlov's result on the graded singularity category. We obtain some new results on the singularity category of isolated singularities which may be interesting in their own right.

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We show that the classifying category C(T)of a dependent type theory T with axioms for identity types admits a nontrivial weak factorisation system. After characterising this weak factorisation system explicitly, we relate it to the homotopy theory of groupoids.

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This article presents and explores the axioms and core ideas, or idées-force, of the Fascist ideologies of the first third of the twentieth century. The aim is to identify the features that define the term “Classical Fascism” as a conceptual category in the study of politics and to uncover the core ideas of its political theory. This analysis requires an appraisal of both the idées-force themselves and the political use that is made of them. If these appreciations are correct, Classical Fascism is characterized by a set of ideological and political aims and methods in which ideas, attitudes and behaviours are determined by an anti-democratic palingenetic ultranationalism underpinned by a sacralized ideology; the quest for a united, indissoluble society as apolitical system and, at the same time, the collective myth that mobilizes and redeems the nation; and third, violence as a political vehicle applied unchecked against internal opposition and against external enemies who challenge the nation´s progression towards the dream of rebirth and the culmination of this progression in the form of an empire.

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We examine the proof of a classical localization theorem of Bousfield and Friedlander and we remove the assumption that the underlying model category be right proper. The key to the argument is a lemma about factoring in morphisms in the arrow category of a model category.

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We explore the relationship between polynomial functors and trees. In the first part we characterise trees as certain polynomial functors and obtain a completely formal but at the same time conceptual and explicit construction of two categories of rooted trees, whose main properties we describe in terms of some factorisation systems. The second category is the category Ω of Moerdijk and Weiss. Although the constructions are motivated and explained in terms of polynomial functors, they all amount to elementary manipulations with finite sets. Included in Part 1 is also an explicit construction of the free monad on a polynomial endofunctor, given in terms of trees. In the second part we describe polynomial endofunctors and monads as structures built from trees, characterising the images of several nerve functors from polynomial endofunctors and monads into presheaves on categories of trees. Polynomial endofunctors and monads over a base are characterised by a sheaf condition on categories of decorated trees. In the absolute case, one further condition is needed, a projectivity condition, which serves also to characterise polynomial endofunctors and monads among (coloured) collections and operads.

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Report for the scientific sojourn at the National Institute for Public Health and the Environment (RIVM), Netherlands, from 2006 to 2008. This project aimed at creating scientific elements that could help deriving an integrated testing strategy for reproductive toxicity. Part of the project focused on the use of alternative tests for regulatory purposes. An in vitro-in vivo extrapolation method for embryotoxicity was proposed and evaluated. In vitro and in vivo dose descriptors were correlated; however, the scatter in the correlation was too large to allow an accurate estimation of an in vivo dose from an in vitro dose. The in vitro-in vivo extrapolation method together with toxicokinetic data was also applied to a category of substances (phthalates). Although based on a limited number of substances, the results suggested that in vitro-in vivo extrapolation for embryotoxicity is possible within a category of compounds if adequate toxicokinetic data is available. Because of the limitations that still remain in the use of alternative tests for reproductive toxicicity, other approaches to reduce animal testing were explored. Thus, a database of reproductive toxicity studies was created to retrospectively evaluate the comparative value of some studies or elements in a particular study. When compared to the subchronic toxicity study, the rat two-generation reproductive toxicity study had a considerable impact on the identification of hazard for reproductive toxicity, but not on the overall NOAEL. Among the two-generation studies included in our database, the second generation affected neither the overall NOAEL nor the critical effect. The rat and the rabbit developmental toxicity studies were, on average, similarly sensitive. However, for certain substances the developmental study in either one of the two species appeared to be more sensitive than in the other species.

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Proyecto de investigación realizado a partir de una estancia en el Centre of Criminology de la University of Toronto, Canadà, entre 2006 y 2008. El miedo al delito como ámbito temático lleva 40 años de andadura y cuenta con cientos de investigaciones en su acervo. Dicha subdisciplina ha utilizado la expresión “miedo al delito” para referirse a un conjunto de conceptos académicos que ella misma va desarrollando, así como a lo que considera una experiencia subjetiva que pretende estudiar. Tanto el concepto como la experiencia han sido vagamente catalogados de respuesta emocional frente al delito o imágenes asociadas a éste. A pesar de los estudios más empíricos y de las teorías más positivistas, que tratan el miedo al delito como un fenómeno que puede ser medido y a cuyo conocimiento nos podemos ir aproximando cada vez con mayor precisión, con el trabajo de este proyecto se puede concluir que el miedo al delito constituye un elemento semántico-conceptual de las categorías académica y popular de delito. Los enfoques culturalistas o hermenéuticos han apuntado esta cuestión pero, simultáneamente, han seguido admitiendo la complementariedad entre enfoques. En principio, admitir el valor constitutivo del miedo al delito en la noción de delito parece que no excluye la necesidad de conocer si los temores a ser víctima de un delito han aumentado en nuestra ciudad, ni el saber por qué ello ha sido así. Apropiarse de tales saberes tal vez sea la única forma de aislar factores discretos que puedan ser manipulados en políticas públicas para erradicar el temor cuyo incremento se supone verificado con las mediciones. Sin embargo, puesto que lo registrado han sido actitudes cognitivas y no emociones, los eventuales programas de intervención deberían ser ideados en el mejor de los casos, con la misma complejidad que la propia formación de creencias lo que lo haría inoperativo. Acción bianual.

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Hacia fines del siglo XX, en Latinoamérica se publica una gran producción de novelas calificadas como históricas, notable cuantitativa y cualitativamente. Sus novedosas propuestas y las diferencias que guarda respecto a las características tradicionales del género, provocan un cuestionamiento crítico respecto a la categoría de novela histórica. En general, las producciones recientes problematizan las posibilidades del conocimiento histórico, como también las posibilidades del lenguaje para expresar ese conocimiento. Además, contienen una fuerte crítica hacia el discurso historiográfico oficial y recurren a la historia, no como producto acabado o dato, sino como procedimiento narrativo y cognoscitivo. Esto les permite trascender la referencia histórica local –sin excluirla – para remitir de manera más amplia a la historiografía y a la historia como portadores de la verdad sobre el pasado. La investigación analiza un corpus de novelas argentinas de finales del siglo pasado indagando los conceptos de historia y ficción propuestos por los textos.

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This article presents a way to associate a Grothendieck site structure to a category endowed with a unique factorisation system of its arrows. In particular this recovers the Zariski and Etale topologies and others related to Voevodsky's cd-structures. As unique factorisation systems are also frequent outside algebraic geometry, the same construction applies to some new contexts, where it is related with known structures dened otherwise. The paper details algebraic geometrical situations and sketches only the other contexts.

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Boar taint is the off-odour or off flavour of cooked pork. Currently, the most common method of controlling boar taint is surgical castration. However, immunocastration has been used in some parts of the world as an alternative to surgical castration. The aim of this study was to evaluate the sensory acceptability of meat from immunocastrated pigs (IM) compared with meat from females (FE), surgically castrated (CM) and entire males (EM). Twenty animals of each type were evaluated by 201 consumers in 20 sessions. Longissimus thoracis muscle of the different animals was cooked in an oven at 180 °C for 10 min. Consumers scored the odour and the flavour of the meat in a 9-point category scale without an intermediate level. There were no significant differences in consumer’s evaluation of meat from IM, CM, and FE. In contrast, EM meat presented a higher percentage of dissatisfied scores and was significantly (P & 0.05) less accepted than meat from CM, IM and FE. Consumers’ acceptability of EM meat was always lower, independently of its androstenone levels. However meat with low levels of androstenone was more accepted that meat with medium or high levels of this substance. It can be concluded that immunocastration produced pork that was accepted by the consumers, and was indistinguishable from pork from CM or FE.

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We study polynomial functors over locally cartesian closed categories. After setting up the basic theory, we show how polynomial functors assemble into a double category, in fact a framed bicategory. We show that the free monad on a polynomial endofunctor is polynomial. The relationship with operads and other related notions is explored.

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We extend the basic concepts of Street's formal theory of monads from the setting of 2-categories to that of double categories. In particular, we introduce the double category Mnd(C) of monads in a double category C and dene what it means for a double category to admit the construction of free monads. Our main theorem shows that, under some mild conditions, a double category that is a framed bicategory admits the construction of free monads if its horizontal 2-category does. We apply this result to obtain double adjunctions which extend the adjunction between graphs and categories and the adjunction between polynomial endofunctors and polynomial monads.

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El objetivo de la presente investigación es analizar el tratamiento que algunos de los diccionarios generales monolingües del español aparecidos en los últimos diez años han dado al fenómeno de las colocaciones léxicas, a saber, aquellas combinaciones de palabras que, desde el punto de vista de la norma, presentan ciertas restricciones combinatorias, esencialmente de carácter semántico, impuestas por el uso (Corpas: 1996). Los repertorios objeto de análisis han sido: el "Diccionario Salamanca de la lengua española", dirigido por Juan Gutiérrez (1996); el "Diccionario del español actual", de Manuel Seco, Olimpia Andrés y Gabino Ramos (1999); la vigésima segunda edición del diccionario de la RAE (2001); y el "Gran diccionario de uso del español actual. Basado en el corpus Cumbre", dirigido por Aquilino Sánchez (2001). Nuestro estudio se ha fundamentado en un corpus de 52 colocaciones léxicas confeccionado a partir del análisis de las subentradas contenidas en la letra "b" de cada uno de los diccionarios seleccionados. Posteriormente, hemos examinado las entradas correspondientes a cada uno de los elementos que constituyen la colocación (base y colocativo) con el fin de observar si los diccionarios estudiados dan cuenta de estas mismas combinaciones en otras partes del artículo lexicográfico, como son las definiciones o los ejemplos. A la hora de analizar la información lexicográfica hemos centrado nuestra atención en cuatro aspectos: a) la información contenida en las páginas preliminares de cada una de las obras; b) la ubicación de las colocaciones en el artículo lexicográfico; c) la asignación de la colocación a un artículo determinado; y d) la marcación gramatical.

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We describe a model structure for coloured operads with values in the category of symmetric spectra (with the positive model structure), in which fibrations and weak equivalences are defined at the level of the underlying collections. This allows us to treat R-module spectra (where R is a cofibrant ring spectrum) as algebras over a cofibrant spectrum-valued operad with R as its first term. Using this model structure, we give sufficient conditions for homotopical localizations in the category of symmetric spectra to preserve module structures.