11,239 research outputs found
El descubrimiento de España de Fernando Iwasaki: la conquista del humor
En la presente investigación se mostrará cómo Fernando Iwasaki (Lima, 1961) consigue mediante la hibridación genérica implícita en El descubrimiento de España desatar la sonrisa de los lectores, acercarlos a su particular hallazgo del país a través de la música, de la anécdota y de su propio trabajo como historiador. Se analizarán como fundamentales los deslindamientos genéricos, culturales y geográficos. Pese a su temprana publicación en 1996, en la obra ya se perfilan los rasgos que caracterizan la escritura del hispanoperuano: la ironía, la parodia, la autoficción y las intertextualidades. Se subrayará el crescendo en los recursos formales y temáticos, desde los capítulos iniciales en los que prevalecen el extrañamiento y la mirada pueril hasta la crítica sarcástica en la que posteriormente un Iwasaki adulto ahonda en el orgullo castizo. Asimismo, se destacará la relevancia de la música en este descubrimiento, donde el autor recurre a las canciones más populares —y a menudo, kitsch— del panorama español para fomentar la conquista del humor.The present investigation will demonstrate how Fernando Iwasaki (Lima, 1961), through the implicit generic hybridation found in El descubrimiento de España, manages to make the reader smile and feel closer to his special discovery of this country, made through music, the anecdotic and his own work as historian. It will also analyze the demarcations in gender, culture and geography that are fundamental to the novel. Despite its early publishing in 1996, this book already shows the characteristic writing of the Hispanic-Peruvian author: irony, parody, autofiction and intertextuality. It is important to note the crescendo in formal and thematic resources, from the estrangement and childlike vision of the first chapters to the sarcasm with which an adult Iwasaki critics the concept of Spanish pride. It will also be noted the importance of music in this discovery, since the writer appeals to the most popular —and often, kitsch— songs of the Spanish scene to promote the conquest of humor
The Implementation of the Pronunciation Techniques through the Warming Up Stage
Después de analizar el contexto colombiano en la enseñanza del inglés, se concluyó que la pronunciación en este idioma no era tenida en cuenta en la enseñanza del inglés en los colegios y la actividad de los primeros diez minutos (warming up stage), eran utilizados de una manera inapropiada. Este proyecto de aula pretende integrar técnicas de pronunciación a través de actividades en los primeros minutos de la clase, para promover y fortalecer la pronunciación en inglés como lengua extranjera en el aula. Este proyecto de aula presenta los resultados en tres grandes categorías. Primero, desarrollo profesional, segundo; resultados en lingüística y tercero respuesta de los estudiantes. Luego del análisis de la información consignada en el diario y el formato de observación, cada categoría arrojó unos resultados específicos que fueron descritos en retos y fortalezas, lo cual ayuda a tener una mejor comprensión del tema. Para concluir, se identificó que el proyecto tiene un impacto positivo en la promoción de la pronunciación en ingles en los estudiantes, al igual que un mejoramiento en el desarrollo profesional del docente. Adicionalmente, este tipo de proyectos ofrecen una alternativa para el desarrollo de la clase de inglés en el contexto colombiano
Implicaciones humanitarias de la contratación de empresas militares privadas (PMC) por parte de los Estados. Estudio de caso; Estados Unidos y Blackwater en Irak (2003-2007)
La presente investigación tiene como finalidad analizar las implicaciones humanitarias de la participación de las Compañías Militares Privadas (PMC) contratadas por los Estados en escenarios de conflicto, a partir del caso de Blackwater y Estados Unidos en Irak (2003-2007), con el fin de mostrar a través de algunos hechos específicos como el acaecido en la plaza Al Nisour los vacíos existentes en la regulación de sus actividades. Frente a estos hechos se muestra como la Comunidad Internacional ha tratado de avanzar en la creación de un régimen internacional que las controle, sin embargo, como se evidencia a lo largo de este escrito la falta de compromiso por parte de los Estados ha hecho que esta tarea se vea obstaculizada y por lo tanto la actuación de estas compañías se encuentra aún en una zona jurídica gris.This investigation aims to analyze Private Military Companies’ participation in conflict sceneries, using the specific case of Blackwater in Irak hired by the United States (2003-2007). Achieving the goal of trying to explain the blank spaces in current law regulations trough some incidents such as the one developed in Al Nisour square. According to this, the article also reflects the efforts made by the international community and the lack of States solid participation, turning this into a difficult to solve situation that carries many grey jurisdiction areas.Universidad del Rosari
Synthesis of Planar Microwave Circuits based on Metamaterial Concepts through Aggressive Space Mapping
RF and microwave applications represent one of the fastest-growing segments of
the high performance electronics market, where ongoing innovation is critical.
Manufacturers compete intensively to meet market needs with reduced cost,
size, weight and many other performance criteria demands. Under this scenario,
transmission lines based on metamaterial concepts can be considered a very
interesting alternative to the conventional transmission lines. They are more
compact (compatible with planar manufacturing processes) and present higher
degrees of design flexibility. Furthermore, metamaterial transmission lines can
also provide many other unique properties not achievable with ordinary
transmission lines, such as dispersion or impedance engineering. Nevertheless,
the impact in the industry is still not relevant, mostly due to the complexity of
the related synthesis and design procedures. These procedures are mainly based
on the engineer’s experience, with the help of costly full-wave electromagnetic
(EM) simulators and parameter extraction methods.
The aim of this thesis is to contribute to simplify and speed up the synthesis
and design procedures of artificial transmission lines. In particular, the lines
obtained by periodically loading a conventional transmission line with
electrically small resonators, such as split ring resonators (SSRs) or its
complementary particle (CSRR). The design procedure is automated by using
Space Mapping techniques. In contrast to other alternative methods, real
synthesis is found from the circuit schematic (that provides a given target
response) and without need of human intervention. Some efforts to make the
method practical and useful have been carried out. Given a certain target
response, it is determined whether it can be physically implemented with a
chosen technology, and hence proceeding next to find the synthesis, or not. For
this purpose, a two-step Aggressive Space Mapping approach is successfully
proposed.
In contrast to other methods, the real synthesis is found from certain target
circuit values (corresponding to the equivalent circuit model that characterizes
the structure to be synthesized). Different efforts have been carried out in order
to implement a useful and practical method. Some of them were focused to determine if, given certain circuit parameters (which determine the target
response) and certain given technology specifications (permittivity and height of
the substrate, technology limits), that response is physically realizable
(convergence region). This technique was successfully formulated and it is
known as “Two-Step Aggressive Space Mapping Approach”.
In this work, the latest improvements made till date, from the synthesis of
basic unit cells until different applications and kinds of metamaterial-based
circuits, are presented. The results are promising and prove the validity of the
method, as well as its potential application to other basic cells and more complex
designs. The general knowledge gained from these cases of study can be
considered a good base for a coming implementation in commercial software
tools, which can help to improve its competitiveness in markets, and also
contribute to a more general use of this technology.Rodríguez Pérez, AM. (2014). Synthesis of Planar Microwave Circuits based on Metamaterial Concepts through Aggressive Space Mapping [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48465TESI
Comprensión de textos en la escuela: ¿aún es importante la aplicación de organizadores gráficos para desarrollarla?
Research on graphic organizers and reading comprehension has taken up new reins in the knowledge about the reader's mental processes, but it has been avoided to understand the levels in the reading process. The importance of organizers often focuses on the power they demonstrate to allow the reader to analyze and map ideas, especially concept maps and mind maps. In this study, we propose to determine the effects of graphic organizers on text comprehension at the school stage. The study is quantitative of quasi-experimental design. It was developed in 42 students from the primary level of Callao, Peru. The results allow concluding that the graphic organizers improved the comprehension of texts in general. The evidences remit significant differences with scores compared at the literal level. The results of inferential understanding presented data that revealed improvement, although it was minimal at this level. This shows that graphic organizers can make improvements but are unlikely during the inferencing process. This shows that graphic organizers can make improvements but are unlikely during the inference-making process as in critical construction. Their contribution is essential in the literal processes, but it is suggested to replicate the study analyzing the processes of understanding at a higher level, with tests of greater complexity, to overcome the limitations obtained here.La investigación sobre organizadores gráficos y comprensión lectora ha retomado nuevas riendas en el conocimiento sobre los procesos mentales del lector, pero se ha obviado comprender los niveles en el proceso de lectura. La importancia de los organizadores suele centrarse en el poder que demuestran para permitir al lector analizar y esquematizar ideas, en especial los mapas conceptuales y mapas mentales. En este estudio, se propone determinar los efectos de los organizadores gráficos en la comprensión de textos en la etapa escolar. El estudio es cuantitativo de diseño cuasiexperimental. Se desarrolló en 42 estudiantes del nivel primaria del Callao, Perú. Los resultados permiten concluir en que los organizadores gráficos mejoraron la comprensión de textos en general. Las evidencias remiten diferencias significativas con puntuaciones comparadas en el nivel literal. Los resultados de la comprensión inferencial presentaron datos que revelaron la mejora, aunque fue ínfima en este nivel. Esto pone de manifiesto que los organizadores gráficos pueden establecer mejoras pero resultan improbables durante el proceso de hacer inferencias. Su aporte es esencial en los procesos literales, pero se sugiere replicar el estudio analizando los procesos de comprensión a nivel superior, con pruebas de mayor complejidad, para superar las limitaciones aquí obtenidas
Novel stabilisation of emulsions with polyelectrolyte complexes
The concept of a novel stabiliser of oil-water emulsions has been put forward, being the polyelectrolyte complex (PEC) formed between oppositely charged water-soluble polymers in cases where either polymer alone is incapable of stabilising an emulsion. Four oppositely charged synthetic polyelectrolytes (strong and weak) are selected, which allowed four polymer mixtures to be studied. The behaviour of their mixtures in water is correlated with that of emulsions after addition of oil.Aqueous polymer mixtures are investigated via dynamic light scattering to determine the size of the aggregates. Moreover, various optical techniques are used to identify the type of associative phase separation (precipitation or complex coacervation) and their shape. The effects of polyelectrolyte (PEL) mixing ratio, pH, [PEL] and salt content are studied in detail. In general, PEC particles are obtained as a result of a strong electrostatic interaction while complex coacervates arise from weak interactions. Around equal mole fractions of the two polymers, the zeta potential of the aggregates reverses in sign. Spherical complexes of diameters of few hundreds nanometres are obtained at low polyelectrolyte concentration. However, by increasing the initial [PEL], primary particles aggregate. Aggregated PEC particles have an irregular shape while coacervate droplets, which contain high amounts of water, are spherical and have no special internal structure, as observed from TEM images. Under specific conditions, coacervate droplets completely coalesce giving rise to the formation of the so-called coacervate phase. The effect of increasing the salt concentration is comparable in both PEC precipitates and coacervates and causes an initial destabilisation of the aqueous dispersion due to complex aggregation, followed by dissolution of the electrostatic complex at high salt concentrations.For the emulsion study, the same parameters as for aqueous PEC dispersions are evaluated, as well as the oil volume fraction (ϕo). The complete study is carried out with dodecane despite oils of different chemistry and polarity have also been considered throughout this thesis. The most stable emulsions to both creaming and coalescence are prepared with aqueous PEC dispersions containing complexes of almost neutral charge. By increasing the polyelectrolyte concentration, emulsions become more stable. However, at high [PEL], aggregation levels are relatively high and emulsion stability is slightly worse as big particles can easily be dislodged from the oil-water interface compared to smaller ones. From cryo-SEM images, close-packed particle layers are detected at drop interfaces as well as particle aggregation in the continuous phase. By increasing the oil volume fraction in the emulsion, the droplet diameter increases constantly up until a point where oil droplets appear to be deformed and the viscosity of the emulsion increases substantially. This suggests the formation of high internal phase emulsions (HIPEs), which is rare in particle-stabilised systems, where catastrophic phase inversion is the usual outcome. Taking advantage of the intrinsic fluorescence of the used PEL, confocal microscopy turns out to be a useful technique to visualise where PEC particles are placed upon homogenisation. At high oil volume fractions, particles are only detected around oil droplets, whereas at low oil volume fractions, excess particles remain at the continuous aqueous phase providing extra stability against coalescence. As for aqueous PEC dispersions, the concentration of salt has a remarkable effect on emulsion stability. For emulsions stabilised with PEC particles, by increasing the aggregation level, emulsions become completely unstable. However, at a relatively high salt content, emulsions re-stabilise due to adsorption of uncharged individual polymer molecules. Emulsions with coacervate droplets can be prepared by the addition of oil stepwise and multiple homogenisation steps. However, unlike PEC particles, the system is sensible to the oil type. The feasibility of the coacervate phase to spread at the oil-water interface is discussed in terms of the relevant spreading coefficients and predictions are compared with experiments for a range of oils. We encounter oils whose drops become engulfed by the coacervate phase as well as oils where no engulfing occurs.Therefore, from the findings obtained from four different polyelectrolyte combinations, we can claim that emulsion stability is given by the presence of PEC at the oil-water interface as individual PEL are not surface-active on their own. Despite this work being a complete starting point for the basic understanding of emulsions stabilised by mixtures of oppositely charged polymers, we are not yet in a position to predict definite rules of behaviour in both aqueous PEC dispersions and emulsions containing them. Further investigation of other polyelectrolyte combinations is required to develop a better understanding of this area
Genetic engineering of plant volatiles in fleshy fruits: pest repellency and disease resistance through D-limonene downregulation in transgenic orange plants
Los terpenos constituyen el mayor grupo de metabolitos secundarios, siendo
componentes de las glándulas de aceites esenciales, de las flores y de las resinas defensivas
de plantas aromáticas, a los que proporcionan sus aromas y sabores característicos. Los
terpenos volátiles se asocian a la defensa de muchas especies de plantas, animales y
microorganismos contra depredadores, patógenos y competidores. Por otra parte, estos
compuestos parecen servir como señales para atraer a los polinizadores y agentes dispersores
de semillas, así como a depredadores de plagas. El estudio de compuestos orgánicos volátiles
emitidos durante el desarrollo del fruto y después del desafío con diferentes agentes bióticos
puede ayudar a conocer las interacciones de los frutos carnosos no sólo con vertebrados
dispersores y depredadores, sino también con insectos y microorganismos.
Los frutos carnosos son particularmente ricos en volátiles. En los frutos cítricos, los
monoterpenos son los principales componentes de las glándulas del aceite esencial de la
cáscara (flavedo), siendo el D-limoneno el más abundante (hasta 95% en la naranja). Esta
característica hace que los cítricos sean un buen sistema modelo para el estudio de la función
de los terpenos en los frutos. La biología molecular moderna permite la realización de
experimentos para comprobar la función de terpenos por medio del uso de organismos
transformados genéticamente en los que se han manipulado los niveles de acumulación de
dichos compuestos. En este trabajo, se ha utilizado un plásmido que alberga el cDNA completo
del gen de una limoneno sintasa de cítricos (CiTMTSE1) en orientación antisentido (AS) o
sentido (S) para modificar la expresión y la acumulación de D-limoneno en plantas de naranjo
dulce (Citrus sinensis L. Osb.). La acumulación de D-limoneno en las frutas AS se redujo
drásticamente pero la acumulación de otros terpenos también se modificó, afectando a
compuestos tales como alcoholes monoterpenos, cuya concentración se incrementó en la
cáscara de las frutas. Las plantas transformadas fueron morfológicamente indistinguibles de las
plantas control (WT) y de las plantas transformadas con el vector vacío (EV).
Los frutos transgénicos fueron desafiados con un insecto plaga y con diferentes
patógenos para probar si la alteración de los niveles de acumulación de estos volátiles daba
como resultado una mejora en la respuesta del flavedo frente a plagas y patógenos. Los
machos de la mosca mediterránea de la fruta (Ceratitis capitata) expuestos a las frutas AS y EV
en ensayos en túnel de viento fueron significativamente más atraídos por el aroma de los frutos
control EV. En otros experimentos de desafío con el hongo de la podredumbre verde
Penicillium digitatum y la bacteria causante de la cancrosis de los cítricos Xanthomonas
axonopodis subsp. citri, las frutas transgénicas con un contenido reducido de D-limoneno
mostraron elevada resistencia a estos patógenos. El alto contenido en D-limoneno en la
cáscara de naranjas maduras puede ser una señal para la atracción de plagas y
microorganismos que podrían estar involucrados en la facilitación del acceso a la pulpa de los
frugívoros dispersores de semillas.
El análisis de la expresión génica global en el flavedo de las frutas transgénicas vinculó
la disminución de D-limoneno y la reducción de la expresión de genes del metabolismo de
monoterpenos con la activación de la expresión de genes implicados en inmunidad innata,
incluyendo factores de transcripción, genes de quinasas implicadas en la entrada de Ca2+ en la
célula y genes implicados en la activación de las cascadas de MAPKs, con la consiguiente
activación de la ruta de señalización de ácido jasmónico (JA), lo que provocó la activación del
metabolismo de JA y un aumentó drástico de la acumulación de JA en la cáscara de la naranja
tras el desafío con P. digitatum, lo que explicaría la resistencia al menos a hongos necrotrofos
observada en las frutas.
Estos resultados indican que la acumulación de D-limoneno en la cáscara de la naranja
estaría implicada en la interacción trófica entre las frutas, insectos y microorganismos, lo cual
proporciona una visión mucho más amplia de las funciones de los terpenos en la naturaleza.
También representa una alternativa muy prometedora para incrementar la resistencia o
tolerancia de las plantas frente a patógenos y plagas.Terpenes, the largest group of secondary metabolites, are well known as constituents of essential oils, floral scents and defensive resins of aromatic plants, to which they impart their characteristic aromas and flavors. Terpene volatiles defend many species of plants, animals and microorganisms against predators, pathogens and competitors. Moreover, those compounds seem to serve as advertisements to attract pollinators and seed-dispersal agents as well as pest predators. The study of VOCs emitted during fruit development and after challenge with different biotic agents may help to determine the interactions of fleshy fruits not only with legitimate vertebrate dispersers and predators, but also with insects and microorganisms.
Fleshy fruits are particularly rich in volatiles. In citrus fruits, monoterpenes are the main components of the essential oil glands of the peel, being D-limonene the most abundant one (up to 95% in orange fruits). This characteristic makes citrus a good model system for studying the function of terpenes in plants. Modern molecular biology now enable experiments to test terpenoid function by the use of genetically transformed organisms in which terpene levels have been manipulated. In this work, a plasmid harboring the complete cDNA of a citrus limonene synthase gene (CiTMTSE1) in antisense (AS) or sense (S) orientation was used to modify the expression and accumulation of D-limonene of sweet orange (Citrus sinensis L. Osb) plants. D-limonene accumulation in AS fruits was dramatically reduced but the accumulation of other terpenoids was also modified, such as monoterpene alcohols, whose concentration increased in the peel of fruits. Genetically transformed plants were morphologically indistinguishable from wild-type (WT) and empty vector (EV) control plants.
Transgenic fruits were challenged against a pest and different pathogens to test whether volatile profile alteration results in an improvement in the response of the fruit flavedo against them. Males of the Mediterranean fruit fly (Ceratitis capitata) exposed to AS fruits versus EV in wind tunnel assays were significantly more attracted to the odor of EV control fruits. In separate experiments with the green mould rot of citrus fruits and citrus canker caused by Penicillium digitatum and Xanthomonas axonopodis subsp. citri, respectively, transgenic fruits with a reduced content in D-limonene showed resistance to both pathogens. High D-limonene content in mature orange peels may be a signal for attractiveness of pests and microorganisms which might be likely involved in facilitating the access to the pulp of seed dispersal frugivores.
A global gene expression analysis of the flavedo of AS transgenic fruits linked the decrease of D-limonene and monoterpene metabolism to the up-regulation of genes involved in the innate immunity response, including transcription factors together with Ca2+ entry into the cell and activation of MAPK cascades, contributing to activation of jasmonic acid (JA) signaling, which triggered the up-regulation of JA metabolism and drastically increased the accumulation of JA in orange peels upon fungal challenge, explaining the resistance to necrotrophic fungi observed in AS fruits.
These results indicate that limonene accumulation in the peel of citrus fruit appears to be involved in the successful trophic interaction between fruits, insects, and microorganisms and provide a much more comprehensive view of roles of terpenes in nature. It also represents a very promising alternative for increasing resistance or tolerance of plants to pathogens.Rodríguez Baixauli, AM. (2013). Genetic engineering of plant volatiles in fleshy fruits: pest repellency and disease resistance through D-limonene downregulation in transgenic orange plants [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31655TESI
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