41,979 research outputs found

    The place where curses are manufactured : four poets of the Vietnam War

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    The Vietnam War was unique among American wars. To pinpoint its uniqueness, it was necessary to look for a non-American voice that would enable me to articulate its distinctiveness and explore the American character as observed by an Asian. Takeshi Kaiko proved to be most helpful. From his novel, Into a Black Sun, I was able to establish a working pair of 'bookends' from which to approach the poetry of Walter McDonald, Bruce Weigl, Basil T. Paquet and Steve Mason. Chapter One is devoted to those seemingly mismatched 'bookends,' Walt Whitman and General William C. Westmoreland, and their respective anthropocentric and technocentric visions of progress and the peculiarly American concept of the "open road" as they manifest themselves in Vietnam. In Chapter, Two, I analyze the war poems of Walter McDonald. As a pilot, writing primarily about flying, his poetry manifests General Westmoreland's technocentric vision of the 'road' as determined by and manifest through technology. Chapter Three focuses on the poems of Bruce Weigl. The poems analyzed portray the literal and metaphorical descent from the technocentric, 'numbed' distance of aerial warfare to the world of ground warfare, and the initiation of a 'fucking new guy,' who discovers the contours of the self's interior through a set of experiences that lead from from aerial insertion into the jungle to the degradation of burning human feces. Chapter Four, devoted to the thirteen poems of Basil T. Paquet, focuses on the continuation of the descent begun in Chapter Two. In his capacity as a medic, Paquet's entire body of poems details his quotidian tasks which entail tending the maimed, the mortally wounded and the dead. The final chapter deals with Steve Mason's JohnnY's Song, and his depiction of the plight of Vietnam veterans back in "The World" who are still trapped inside the interior landscape of their individual "ghettoes" of the soul created by their war-time experiences

    Miniaturización de antenas tipo microstrip mediante recubrimientos con materiales ferroeléctricos

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    La limitación en el espacio donde se dispone la antena dentro de un dispositivo electrónico ha promovido la investigación de alternativas que permitan el desarrollo de antenas miniaturizadas con una amplia capacidad de emisión y recepción, siendo los materiales ferroeléctricos una de las opciones más acertadas para reducir el tamaño de las antenas sin generar cambios significativos en el diseño. Adicionalmente, estos materiales pueden ser obtenidos por diferentes técnicas, dentro de las que sobresale sol-gel por su flexibilidad en deposición de película. Por ello, el presente trabajo se centra en la evaluación del factor de miniaturización de antenas de parche microstrip recubiertas con materiales ferroeléctricos tales como titanato de estroncio (STO), titanato de bario-estroncio (BSTO), y titanato de bario (BTO), obtenidos vía sol-gel y depositados mediante spin coating a 3000 rpm (20 s) con tratamiento térmico a 700 °C (1 h, 1 °C/min). Estas antenas fueron diseñadas y simuladas dentro de un rango de frecuencia entre 1 y 8.5 GHz; se fabricaron por fotolitografía usando substratos de alúmina de 635 m con metalización en oro (3.0 m) y capa de adherencia de níquel-cromo (0.2 m), para ser caracterizadas con el uso de un analizador vectorial de red (VNA). La ejecución de esta investigación se verificó mediante difracción de rayos X, mostrando la presencia de estructuras cristalinas en fase perovskita cúbica, con parámetros de red para STO, BSTO y BTO de 3.9012 ± 0.0049 Å, 3.9631 ± 0.0055 Å, y 4.0268 ± 0.0119 Å, respectivamente. La caracterización microestructural y morfológica permitió establecer las condiciones de deposición y de tratamiento térmico de la película que permitieran uniformidad, homogeneidad y adherencia aceptable de la capa con poca presencia de defectos superficiales. Por su parte, la espectroscopía de rayos X de energía dispersa cuantificó composiciones elementales para STO de 1.48 ± 0.13 % wt Sr, y 0.54 ± 0.07 % wt Ti; BSTO: 0.69 ± 0.22 % wt Ba, 1.22 ± 0.12 % wt Sr, 0.63 ± 0.09 % wt Ti, y 6.05 ± 0.85 % wt O; y para BTO de 1.28 ± 0.23 % wt Ba, 0.74 ± 0.09 % wt Ti, y 7.28 ± 0.92 % O; todos estos materiales analizados en forma de película cristalizada y depositada sobre Al2O3/Ni-Cr/Au. Los espesores obtenidos para las películas de STO, BSTO, y BTO fueron: 2.8130, 4.1070, y 3.9217 m; con constante dieléctrica de 92, 136, y 232; tangente de pérdida de 0.0112, 0.0104, y 0.0080, con operación en 4.116 GHz (-12.6000 dB), 4.0800 GHz (-10.0900 dB), y 4.0200 GHz (-10.0900 dB), respectivamente para STO, BSTO y BTO. Por otro lado, las antenas recubiertas con STO, BSTO y BTO evidenciaron tasas de miniaturización de 4.7 %, 7.0 %, y 15.6 %, con frecuencia de operación en 2.5925 GHz, 2.5300 GHz, y 2.2950 GHz, respectivamente. De este modo se comprobó dentro de las instalaciones de la Universidad EAFIT la aplicabilidad de las películas ferroeléctricas en los procesos de miniaturización de antenas

    Mapping Super-Relaxed States of Myosin Heads in Sarcomeres using Oblique Angle Fluorescent Microscopy

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    We have utilised modern methods of super-resolution fluorescent microscopy to spatially map fluorescently labelled ATP molecules in relaxed rabbit psoas skeletal muscles. For our imaging process, we have labelled ATP molecules with Rhodamine and Z-lines with Alexa488. Data from imaging these fluorophores have been collected using oblique angle fluorescent microscopy and further analysed to map super relaxed states (SRX) of myosin heads on the thick filament. Our experiments have concluded that most SRX of myosin heads were found in the C-zone of the thick filament, while other zones of thick filament had smaller populations of SRX. Further introduction of mavacamten (MAVA) to our imaging system has revealed an increase in SRX in both D and P zones, while the C zone population of SRX had remained constant. Further experiments must be conducted to establish a clear pattern and further proof our findings

    Hybrid Perovskite Thin Film

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    Hybrid perovskite thin film offers diverse advantages like low cost deposition techniques, less material consumption and superior optoelectronic properties. These merits including high voltage and high efficiency performance in a wide range of high light intensity are sufficient to distinguish perovskite thin films/devices from their contenders as a thin film technology with greater potential for industrial applications. Perovskite thin film technology demonstrates potency in a variety of applications in optoelectronic devices especially photovoltaic applications. The National Renewable Energy Laboratory (NREL) of the USA categorizes a number of thin films technologies including perovskite thin film, as emerging photovoltaics with the bulk of them yet to be commercially applied but are still in the research or developmental stage. In this chapter, various processing methods and material combinations as well as current trends in this technology are subjects of discussion

    NOMA Transmission Systems: Overview of SIC Design and New Findings

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    Non-Orthogonal Multiple Access (NOMA) has been recently proposed as a good alternative to meet 5G and beyond requirements in terms of high spectral efficiency, massive connectivity, and low latency. It has been demonstrated that the use of NOMA in downlink has superior performance in terms of throughput, whereas the use in uplink outperforms OMA techniques in terms of fairness. A distinctive feature of NOMA is the presence of excessive multiple-access interference due to the case of usage of power domain to multiplex signals, thus the functional implementation of NOMA implies Successive Interference Cancelation (SIC) to combat this interference. Therefore, SIC design becomes the main point in the effectiveness of NOMA systems. On the other hand, hybrid schemes, NOMA/OMA, have been recently proposed to reduce the drawbacks of pure NOMA systems. However, in these schemes, it becomes necessary to distinguish NOMA and OMA users. Cognitive Radio techniques turn to be a good option to effectively separate NOMA/OMA users as well as to distinguish NOMA users. In this chapter, a brief overview of NOMA techniques related to Cognitive Radio technology (CR-NOMA) and SIC design reported in the literature is presented. Also, new findings about NOMA/OMA users’ recognition are described

    Unraveling the effect of sex on human genetic architecture

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    Sex is arguably the most important differentiating characteristic in most mammalian species, separating populations into different groups, with varying behaviors, morphologies, and physiologies based on their complement of sex chromosomes, amongst other factors. In humans, despite males and females sharing nearly identical genomes, there are differences between the sexes in complex traits and in the risk of a wide array of diseases. Sex provides the genome with a distinct hormonal milieu, differential gene expression, and environmental pressures arising from gender societal roles. This thus poses the possibility of observing gene by sex (GxS) interactions between the sexes that may contribute to some of the phenotypic differences observed. In recent years, there has been growing evidence of GxS, with common genetic variation presenting different effects on males and females. These studies have however been limited in regards to the number of traits studied and/or statistical power. Understanding sex differences in genetic architecture is of great importance as this could lead to improved understanding of potential differences in underlying biological pathways and disease etiology between the sexes and in turn help inform personalised treatments and precision medicine. In this thesis we provide insights into both the scope and mechanism of GxS across the genome of circa 450,000 individuals of European ancestry and 530 complex traits in the UK Biobank. We found small yet widespread differences in genetic architecture across traits through the calculation of sex-specific heritability, genetic correlations, and sex-stratified genome-wide association studies (GWAS). We further investigated whether sex-agnostic (non-stratified) efforts could potentially be missing information of interest, including sex-specific trait-relevant loci and increased phenotype prediction accuracies. Finally, we studied the potential functional role of sex differences in genetic architecture through sex biased expression quantitative trait loci (eQTL) and gene-level analyses. Overall, this study marks a broad examination of the genetics of sex differences. Our findings parallel previous reports, suggesting the presence of sexual genetic heterogeneity across complex traits of generally modest magnitude. Furthermore, our results suggest the need to consider sex-stratified analyses in future studies in order to shed light into possible sex-specific molecular mechanisms
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