921 resultados para Bottom-up processes
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This study contributes to a critical synthesis of the principle of literary warrant, initially formulated by Hulme in 1911. Hulme proposed that the terms of a classification system should be derived from the literature to be classified, rather than based on purely theoretical considerations. Founding literary warrant on literature which is actually documented rather than on scientific or philosophical classifications or on the supposed authority of the first classificationists implied a clear departure from the conceptions of Harris and Dewey, who had used the classifications of Bacon and Leibniz as models. The validity of this principle over the past century is studied by means of diverse documental data (entries in dictionaries, retrieval by Google, etc.), as it is recognized as a main methodological element for classification standards and systems. This study also discusses the situation with respect to the top-down or bottom-up methodologies of system design. Three traditional applications of literary warrant are described as well as three new applications are suggested, in light of its methodological potential. It is possible to conclude that this principle will find increasing applications in other contexts, within and beyond Information Science.
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This study aimed to analyze the composition and the ecological attributes of the zooplankton assemblages (Cladocera and Copepoda), in four marginal lagoons and in the main channel of Rosana Reservoir (SE Brazil). Fieldwork was carried out in September and November/2004 and January, March, May and August/2005. A total of 72 taxa were identifed (55 cladocerans and 17 copepods). Seasonally, a signifcant higher richness was observed during the rainy period. The lateral lagoons, compared to the reservoir, and the rainy period, compared to the dry one, showed higher zooplankton abundance. Copepods exhibited higher abundance than cladocerans. Among the copepods, there was a higher abundance of nauppli forms in the lateral lagoons and in the dry period. Calanoida dominated in relation to Cyclopoida. The most numerous cladoceran family was Bosminidae, followed by Daphniidae. The results showed that the zooplankton assemblages are infuenced by the meteorological factors, by some important nutrients (indirectly) and by the phytoplankton abundance. This pattern indicated that in the lateral lagoon system the communities are controlled by bottom-up mechanisms. The results validate the hypotheses that lateral lagoons have a prominent ecological role for the zooplankton of Rosana Reservoir and also evidenced the main driving forces infuencing the composition and ecological attributes of the assemblages. The incorporation of the reservoir lateral lagoons in regional environmental programs should be a target strategy for the conservation of the aquatic biota, mitigating the negative impact of the dam.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Chameleons are scalar fields that couple directly to ordinary matter with gravitational strength, but which nevertheless evade the stringent constraints on tests of gravity because of properties they acquire in the presence of high ambient matter density. Chameleon theories were originally constructed in a bottom-up, phenomenological fashion, with potentials and matter couplings designed to hide the scalar from experiments. In this paper, we attempt to embed the chameleon scenario within string compactifications, thus UV completing the scenario. We look for stabilized potentials that can realize a screening mechanism, and we find that the volume modulus rather generically works as a chameleon, and in fact the supersymmetric potential used by Kachru, Kallosh, Linde and Trivedi (KKLT) is an example of this type. We consider all constraints from tests of gravity, allowing us to put experimental constraints on the KKLT parameters.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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1. Although several species of Peucetia (Oxyopidae) live strictly in association with plants bearing glandular trichomes worldwide, to date little is known about whether these associations are mutualistic.2. In this study we manipulated the presence of Peucetia flava on the glandular plant Rhynchanthera dichotoma in the rainy and post-rain season, to test the strength of its effects on leaf, bud, and flower damage and plant reproductive output. In addition, we ran independent field experiments to examine whether these sticky structures improve spider fidelity to plants.3. Peucetia suppressed some species of foliar phytophages, but not others. Although spiders have reduced levels of leaf herbivory, this phenomenon was temporally conditional, i.e. occurred only in the post-rain but not in the rainy season. Floral herbivory was also reduced in the presence of spiders, but these predators did not affect plant fitness components.4. Plants that had their glandular trichomes removed retained fewer insects than those bearing such structures. Spiders remained longer on plants with glandular trichomes than on plants in which these structures had been removed. Isotopic analyses showed that spiders that fed on live and dead labelled flies adhered to the glandular hairs in similar proportions.5. Spiders incurred no costs to the plants, but can potentially increase individual plant fitness by reducing damage to reproductive tissues. Temporal conditionality probably occurred because plant productivity exceeded herbivore consumption, thus dampening top-down effects. Specialisation to live on glandular plants may have favoured scavenging behaviour in Peucetia, possibly an adaptation to periods of food scarcity.
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The inadequate land use in the low course of the river Acaraú is speeding up processes of erosion in some degrees. This process is accented in the areas where caatinga was removed for implantation of pastures and agriculture. Concomitantly, the plain of flooding of the river Acaraú an accumulation of sand with the carry of these sediments, resulting in the widening of the fluvial plain and reduction of the shape water, with increase of the evapotranspiration and consequence salinization, proceeding from the local substratum. This paper aimed at the crossing of diverse space information (geomorfology, soil, declivity, geology and land use) in environment SIG, for determination of the susceptible areas to the erosion and an accumulation of sand in the low course of the Acaraú river, north of the State of the Ceará, Brazil. The results allow to evaluate the application of this tool in the planning and management of the environment, from the crossing of the type of use with the used environment and the consequent impact to the ecosystem.
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Includes bibliography
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Includes bibliography
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Educação - IBRC
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The Bahamas is at great risk and vulnerability given its geographical features as a low-lying, sea encircled country. If projected sea level rise is reached by 2050, between 10-12% of territory will be lost, especially in coastal zones where the main tourism assets are located. Vulnerability could also be manifested if flight carbon emission taxes are established in the main source markets, representing an economic threat to the tourism sector for the islands. The impact of climate change on main tourism demand variables will cause some losses to the country‟s income and government revenues. This would be acting conjointly with some local threats to tourism assets and trends in future global tourism demand. The second and no less important threat is tropical cyclones, which may be associated with raising sea level. Estimations posited the amount of losses in excess of 2400 million US$ for the four decades under examination. It is to be pointed out that there is still a lack of comparatively accurate data collection and analysis on this subject, a point deserving more attention in order to deepen the understanding of, and to extract better lessons from these extreme events. In the same period, total estimated impacts of progressive climate change are between 17 and 19 billions of B$ with estimated discount rates applied. The Bahamas is a Small Island Developing State with low growth on GHG emissions (second in Latin America), as well as a relative short capacity to lower emissions in the future. The country has a relative delay in the application of renewable energy systems, a solution that, provided documented studies on-site, might turn out to be fundamental in the country‟s efforts to establish mitigation related policies. The Bahamas currently has institutions and organizations that deal with climate change-related issues and an important number of measures and courses of action have been set up by the government. Nevertheless, more coordination among them is needed and should include international institutions. This coordination is essential even for the first steps, i.e. to conduct studies with a bottom-up approach in order to draw more accurate programs on adaptation and mitigation. It is fundamental for tourism to keep track of potential losses in tourist attractions (and to act accordingly), related to correspondent losses in biodiversity, water resources and coastal erosion. Also, actions to fight climate change impacts might improve the islands security standards, quality of living and protect cultural and heritage assets. These elements may definitely shape the future of the country‟s competitiveness as a tourism destination. It is possible and necessary to decide about the options with good cost-benefit ratio and reasonable payback periods, notwithstanding that cost-benefit analysis requires more refined and accurate data to provide precise and locally adapted options.
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Pós-graduação em Geociências e Meio Ambiente - IGCE
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Analisa quantitativa e qualitativamente a avaliação da compreensão leitora do Espanhol Língua Estrangeira em provas de vestibular da região norte do Brasil, para assim evidenciar os tipos de operações e, dessa maneira, os tipos de modelos de leitura privilegiados nos testes analisados; estabelecer uma relação entre as provas coletadas e as concepções didáticas subjacentes; identificar problemas nos itens das provas com base em uma série de parâmetros de qualidade; analisar a validade dos testes selecionados; e detectar possíveis diferenças entre as provas elaboradas por Instituições de Ensino Superior públicas e privadas. Essa análise evidencia, por um lado, a tendência a se priorizarem, nessas provas, modelos ascendentes de leitura, com valorização das operações cognitivas de baixo nível e de aspectos léxico-gramaticais da língua, como conseqüência de uma concepção didática de leitura baseada em um enfoque estruturalista. Por outro lado, o estudo empreendido mostra a existência de sérias deficiências nos itens das provas de vestibular, afetando assim sua validade.