353 research outputs found

    Papilionidae and pieridae butterflies (lepidoptera, papilionoidea) of the state of Guanajuato, México

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    An annotated list of butterflies of the families of Papilionidae and Pieridae (Lepidoptera: Papilionoidea) of the state of Guanajuato, Mexico, is presented for the first time. The list is the result of systematic monitoring of these taxa in a few localities of the state (mainly, in the vicinities of León and Guanajuato City) during 1998-2004, as well as from specimens at the Mexican National Collection of Insects. We report 12 species of Papilionidae (4 new records for the state), and 27 species of Pieridae (15 first records for Guanajuato). Therefore, at least about 30% and 50% of species of, respectively, Papilionidae and Pieridae, are registered as new state records. Some distributional and ecological observations for the butterflies are addressed as well.Presentamos, por primera vez, una lista anotada de las familias Papilionidae y Pieridae (Lepidoptera: Papilionoidea) para el estado de Guanajuato. Esta lista es el resultado de muestreos sistemáticos de estos taxones en un conjunto de localidades del estado (principalmente en las cercanías de León y la Ciudad de Guanajuato) durante 1998-2004, así como de especímenes depositados en la Colección Nacional de Insectos. Se registran 12 de Papilionidae y 27 especies de Pieridae, de las cuales 4 y 15 respectivamente son nuevos registros para el estado. Por lo anterior 30% de las especies de Papilionidae y 50% Pieridae constituyen nuevos registros estatales. Se presentan algunas observaciones de la ecología y distribución de los taxones encontrados

    Immunity and simplicity in relativizations of probabilistic complexity classes

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    The existence of immune and simple sets in relativizations of the probabilistic polynomial time bounded classes is studied. Some techniques previously used to show similar results for relativizations of P and NP are adapted to the probabilistic classes. Using these results, an exhaustive settling of all possible strong separations among these relativized classes is obtained.On étudie les relativisations des classes de complexité probabiliste polynômiale. On adapte aux classes probabilistes des techniques déjà utilisées pour établir des résultats similaires pour les relativisations de P et NP. On obtient à partir de ces résultats une classification de toutes les propriétés de séparation forte pour ces classes relativisées.Peer ReviewedPostprint (published version

    Exponential Separation of Quantum and Classical Online Space Complexity

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    Although quantum algorithms realizing an exponential time speed-up over the best known classical algorithms exist, no quantum algorithm is known performing computation using less space resources than classical algorithms. In this paper, we study, for the first time explicitly, space-bounded quantum algorithms for computational problems where the input is given not as a whole, but bit by bit. We show that there exist such problems that a quantum computer can solve using exponentially less work space than a classical computer. More precisely, we introduce a very natural and simple model of a space-bounded quantum online machine and prove an exponential separation of classical and quantum online space complexity, in the bounded-error setting and for a total language. The language we consider is inspired by a communication problem (the set intersection function) that Buhrman, Cleve and Wigderson used to show an almost quadratic separation of quantum and classical bounded-error communication complexity. We prove that, in the framework of online space complexity, the separation becomes exponential.Comment: 13 pages. v3: minor change

    Asymptotics and zeros of Sobolev orthogonal polynomials on unbounded supports

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    In this paper we present a survey about analytic properties of polynomials orthogonal with respect to a weighted Sobolev inner product such that the vector of measures has an unbounded support. In particular, we are focused in the study of the asymptotic behaviour of such polynomials as well as in the distribution of their zeros. Some open problems as well as some new directions for a future research are formulated.Comment: Changed content; 34 pages, 41 reference

    Microfluidics in Membraneless Fuel Cells

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    In the 1990s, the idea of developing miniaturized devices that integrate functions other than what normally are carried out at the laboratory level was conceived, and the so-called “lab-on-a-chip” (LOC) devices emerged as one of the most important research areas. LOC devices exhibit advantages related to the use of microfluidic channels such as small sample and reagent consumption, portability, low-power consumption, laminar flow, and higher surface area/volume ratio that enhances both thermal dissipation and electrochemical kinetics. Fuel cells are electrochemical devices that convert chemical energy to electrical energy. These are considered as one of the greener ways to generate electricity because typical fuel cells produce water and heat as the main reaction byproducts. The technical challenges to develop systems at the microscale and the advantages of microfluidics exhibited an important impact on fuel cells for several reasons, mainly related to avoid inherent problems of gaseous-based fuel cells. As a result, the birth of a new type of fuel cells as microfluidic fuel cells (MFCs) took place. The first microfluidic fuel cell was reported in 2002. This MFC was operated with liquid fuel/oxidant and had the advantage of the low laminar flow generated using a “Y” microfluidic channel to separate the anodic and cathodic streams, resulting in an energy conversion device that did not require a physical barrier to separate both streams. This electrochemical system originated a specific type of MFCs categorized as membraneless also called colaminar microfluidic fuel cells. Since that year, numerous works focused on the nature of fuels, oxidants and anodic/cathodic electrocatalysts, and cell designs have been reported. The limiting parameters of this kind of devices toward their use in portable applications are related to their low cell performances, small mass activity, and partial selectivity/durability of electrocatalysts. On the other hand, it has been observed that the cell design has a high effect on the cell performance due to internal cell resistances and the crossover effect. Furthermore, current technology is growing faster than last centuries and new microfabrication technologies are always emerging, allowing the development of smaller and more powerful microfluidic energy devices. In this chapter, the application of microfluidics in membraneless fuel cells is addressed in terms of evolution of cell designs of miniaturized microfluidic fuel cells as a result of new discoveries in microfabrication technology and the use of several fuels and electrocatalysts for specific and selective applications

    Redundancy, Deduction Schemes, and Minimum-Size Bases for Association Rules

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    Association rules are among the most widely employed data analysis methods in the field of Data Mining. An association rule is a form of partial implication between two sets of binary variables. In the most common approach, association rules are parameterized by a lower bound on their confidence, which is the empirical conditional probability of their consequent given the antecedent, and/or by some other parameter bounds such as "support" or deviation from independence. We study here notions of redundancy among association rules from a fundamental perspective. We see each transaction in a dataset as an interpretation (or model) in the propositional logic sense, and consider existing notions of redundancy, that is, of logical entailment, among association rules, of the form "any dataset in which this first rule holds must obey also that second rule, therefore the second is redundant". We discuss several existing alternative definitions of redundancy between association rules and provide new characterizations and relationships among them. We show that the main alternatives we discuss correspond actually to just two variants, which differ in the treatment of full-confidence implications. For each of these two notions of redundancy, we provide a sound and complete deduction calculus, and we show how to construct complete bases (that is, axiomatizations) of absolutely minimum size in terms of the number of rules. We explore finally an approach to redundancy with respect to several association rules, and fully characterize its simplest case of two partial premises.Comment: LMCS accepted pape

    An evaluation of the prevalence of vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) in hospital food

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    Los artículos que componen este libro ilustran desde múltiples puntos de vista el concepto de patrimonio biocultural. El contenido de la publicación se estructura en tres espacios sintetizados en las problemáticas asociadas al patrimonio biológico y cultural, el territorio y las disputas territoriales, la construcción identitaria y los problema de carácter socio-históricos de las comunidades afro indoamericanas. Ello permite, por un lado, obtener una aproximación contrastante, holística y compleja de la realidad latinoamericana y por otra lado sumar aportes a un concepto en construcción que no esconde su intencionalidad emancipadora.Agradecimientos; Introducción; PATRIMONIO BIOCULTURAL: Juan Pohlenz Córdova / La disputa por el patrimonio biocultural. Un acercamiento desde Mesoamérica; León Enrique Ávila Romero / La disputa por el patrimonio biocultural, la economía verde y sus impactos en los pueblos indígenas; Bernardo Javier Tobar / Lugares de vida y registros de la memoria biocultural en el Pacífico sur-colombiano; Iskra García Vázquez, Rocío Becerra Montané y Gimena Pérez Ortega / Uso, aprovechamiento social y conservación de las plantas medicinales en México; Kelly Giovanna Muñoz Balcázar / Transformaciones del territorio y el patrimonio biocultural a partir del proceso de industrialización. Recuperación de la finca tradicional en el municipio de Corinto, vereda La Paila; TERRITORIO: Johnny L. Ledezma Rivera / Reflexiones sobre las concepciones y visiones de lo que se entiende por territorio; Sindy Hernández Bonilla / ¿Justicia o legalidad para los q’eqchi’es? Agustín Ávila Romero / Turismo y pueblos indígenas de México: despojo y veredas de apropiación comunitaria; SOCIEDADES AFROINDOAMERICANAS EN MOVIMIENTO Johnny L. Ledezma Rivera / Construcción e implementación de las autonomías indígenas en Bolivia: avances y retrocesos; Stefano Claudio Sartorello / Educar para el arraigo sociocultural. El perfil de egreso de alumn@s indígenas en una propuesta educativa intercultural y bilingüe en Chiapas; Elena Pareja y Virginia Cornalino / La cultura afrodescendiente en la constitución del Estado-nación (1870-1900). La reconstrucción de los mapas de identidad en la frontera uruguayo-brasileña; Karla Chagas y Natalia Stalla / Mano de obra negra en el Estado Oriental: una mirada del trabajo esclavo y libre a través del análisis de casos; Diego E. Piñeiro y Joaquín Cardeillac / Los afro-descendientes en el campo uruguayo; Soledad Figueredo y Matías Carámbula Pareja / Puntos en el mapa: ensayo sobre identidad, inmovilidad y cultura de la población afrodescendiente en el medio rural uruguayo

    El pH de la carne de cobayo (Cavia porcellus) para consumo humano en los andes centrales del Perú

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    El objetivo del presente estudio fue evaluar el pH de la carne de cobayos faenados en los andes centrales del Perú. Se determinó el pH de 60 canales al terminar el proceso de sacrificio y a la 1, 6, 12, y 24 h posteriores. Los pH fueron de 6,79 ± 0,3, 6,74 ± 0,34, 6,59 ± 0,28, 6,45 ± 0,35 y 5,96 ± 0,11, a las horas 0, 1, 6, 12 y 24 post sacrificio respectivamente. La ecuación que explica el comportamiento del pH fue Y=6.7765-0.0231X-0.0005X2 (R2 =0.996). La ausencia de un adecuado descenso del pH muscular incide negativamente en la calidad de la carne debido a la proliferación de microrganismos perjudiciales. Para mejorar la calidad y prolongar la vida útil de la carne de cobayo se requieren estudios que evalúen las repercusiones de las deficiencias constatadas durante el sacrificio, dado que no se observó descanso, ducha ante mortem ni aturdimient

    Prioridades de investigación y asignación de recursos en agricultura : el caso Colombiano

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    Reunión: Asignación de recursos para la Investigación Agrícola, 8-10 jun. 1981, Singapore, SGEn IDL-239
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