26 resultados para efficient algorithms
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Exposure to chronic stress can have broad effects on health ranging from increased predisposition for neuropsychiatric disorders to deregulation of immune responses. The chronic unpredictable stress (CUS) protocol has been widely used to study the impact of stress exposure in several animal models and consists in the random, intermittent, and unpredictable exposure to a variety of stressors during several weeks. CUS has consistently been shown to induce behavioral and immunological alterations typical of the chronic stress-response. Unfortunately C57BL/6 mice, one of the most widely used mouse strains, due to the great variety of genetically modified lines, seem to be resistant to the commonly used 4-week-long CUS protocol. The definition of an alternative CUS protocol allowing the use of C57BL/6 mice in chronic stress experiments is a need. Here, we show that by extending the CUS protocol to 8?weeks is possible to induce a chronic stress-response in C57BL/6 mice, as revealed by abrogated body weight gain, increased adrenals weight, and an overactive hypothalamic-pituitary-adrenal axis with increased levels of serum corticosterone. Moreover, we also observed stress-associated behavioral alterations, including the potentiation of anxious-like and depressive-like behaviors and a reduction of exploratory behavior, as well as subtle stress-related changes in the cell population of the thymus and of the spleen. The present protocol for C57BL/6 mice consistently triggers the spectrum of CUS-induced changes observed in rats and, thus, will be highly useful to researchers that need to use this particular mouse strain as an animal model of neuropsychiatric disorders and/or immune deregulation related to CUS.
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Dissertação de mestrado em Economia Monetária, Bancária e Financeira
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We demonstrate the first example of silicon nanowire array photocathodes coupled with hollow spheres of the emerging earth-abundant cobalt phosphide catalysts. Compared to bare silicon nanowire arrays, the hybrid electrodes exhibit significantly improved photoelectrochemical performance toward the solar-driven H2 evolution reaction.
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Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e de Computadores
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Dissertação de mestrado integrado em Engenharia Mecânica
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PhD thesis in Biomedical Engineering
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Distributed data aggregation is an important task, allowing the de- centralized determination of meaningful global properties, that can then be used to direct the execution of other applications. The resulting val- ues result from the distributed computation of functions like count, sum and average. Some application examples can found to determine the network size, total storage capacity, average load, majorities and many others. In the last decade, many di erent approaches have been pro- posed, with di erent trade-o s in terms of accuracy, reliability, message and time complexity. Due to the considerable amount and variety of ag- gregation algorithms, it can be di cult and time consuming to determine which techniques will be more appropriate to use in speci c settings, jus- tifying the existence of a survey to aid in this task. This work reviews the state of the art on distributed data aggregation algorithms, providing three main contributions. First, it formally de nes the concept of aggrega- tion, characterizing the di erent types of aggregation functions. Second, it succinctly describes the main aggregation techniques, organizing them in a taxonomy. Finally, it provides some guidelines toward the selection and use of the most relevant techniques, summarizing their principal characteristics.
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Dissertação de mestrado integrado em Engenharia Civil
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[Excerpt] Lignocellulosic plant biomass is being envisioned by biorefinery industry as an alternative to current petroleum platform because of the large scale availability, low cost and environmentally benign production. The industrial bioprocessing designed to transform lignocellulosic biomass into biofuels are harsh and the enzymatic reactions may be severely compromised reducing the production of fermentable sugars from lignocellulosic biomass. Thermophilic bacteria consortium are a potential source of cellulases and hemicellulases adapted to extreme environmental conditions, which can be exploited as a new source for the development of more robust enzymatic cocktails. (...)
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The concepts involved in sustainable textile fashion, demanding good knowledge about raw materials, processes, end use properties and circuits amongst others, are able to determine the way the textile product is designed and the behavior of the consumer, regarding life style and buying decisions. The textile product`s life integrates raw materials, their processing, distribution, use by the consumer and destination of the product after useful lifetime, this is, his complete life cycle. It is very important to recognize the power of the consumer to influence parameters related to sustainability, namely when he decides how, when and why he buys and afterwards by the attitudes taken during and after use. The conscious act of consumption involves ethical, ecological and technical knowledge in which the concern is overall lifecycle of the fashion product and not exclusively aesthetic and symbolic values strongly related with its ephemeral nature. The present work proposes the classification of textile products by means of an innovative label aiming to establish a rating related to the Life of Fashion Products, by using parameters considered with especial impact in lifecycle, as textile fibers, processing conditions, generated wastes, commercialization circuits, durability and cleaning procedures. This label for sustainable fashion products aims to assist the stakeholders with informed attitudes and correct decisions in order to promote the objectives of sustainable fashion near designers, consumers and industrial experts.
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Tese de Doutoramento em Engenharia Industrial e de Sistemas.