3,771 research outputs found

    Culture-based artefacts to inform ICT design: foundations and practice

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    Cultural aspects frame our perception of the world and direct the many different ways people interact with things in it. For this reason, these aspects should be considered when designing technology with the purpose to positively impact people in a community. In this paper, we revisit the foundations of culture aiming to bring this concept in dialogue with design. To inform design with cultural aspects, we model reality in three levels of formality: informal, formal, and technical, and subscribe to a systemic vision that considers the technical solution as part of a more complex social system in which people live and interact. In this paper, we instantiate this theoretical and methodological view by presenting two case studies of technology design in which culture-based artefacts were employed to inform the design process. We claim that as important as including issues related to culture in the ICT design agenda—from the conception to the development, evaluation, and adoption of a technology—is the need to support the design process with adequate artefacts that help identifying cultural aspects within communities and translating them into sociotechnical requirements. We argue that a culturally informed perspective on design can go beyond an informative analysis, and can be integrated with the theoretical and methodological framework used to support design, throughout the entire design process

    Simulaçao numérica do escoamento de fluido no-newtoniano em duto parcialmente bloqueado

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    Complications with Controlling Insect Eggs

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    Eggs are difficult to kill because of the unique structure of the eggshell, comprised of multiple layers that have evolved to allow the embryo to breathe while simultaneously limiting water loss. The eggshell has been shown to be an excellent barrier to insecticides, fungal pathogens, and some fumigants. The insect eggshell contains only a few areas that could allow penetration of insecticides, the aeropyles and micropyles, which seem to be either so few in number or small in size that they do not allow a sufficient amount of insecticide through the eggshell. Resistance is also a contributing factor to control failures of insect eggs. Resistance in eggs has been documented in several insect species and a few studies have shown that some insect eggs produce elevated numbers of enzymes to break down insecticides. This chapter focuses on the structure and respiration of the insect eggshell as a barrier to insecticides and also covers various management strategies against insect eggs. Lastly, we discuss the few documentations of resistance in insect eggs thus far

    Anatomical Characteristics and Leaf Blade Digestibility of Five \u3cem\u3ePanicum\u3c/em\u3e Genotypes under Integrated Crop-Livestock-Forest System

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    Integrated crop-livestock-forest systems (ICLF) are intended to increase land use efficiency and to harvest benefits from interactions among the components involved. Thus, cattle husbandry success on such systems depends on the suitability and adaptability of the forages used. Shadow causes stress to plants growing in the understory of ICLF systems due to limitation of photo synthetically active radiation, whose intensity varies with location, time of the year and the tree component. Reduction of light incidence on forage leads to limited growth rates as a function of energy restriction necessary to the photosynthetic processes, requiring a number of morphological, physiological, structural and anatomical adaptations from the plant, called acclimatization (Gobbi et al., 2011). In this context, this work aimed to evaluate anatomical characteristics of tropical Panicum grasses under an ICLF system in the Brazilian Cerrado

    Índice de qualidade de água usando análise fatorial multivariada

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    The evaluation of environmental effects generated by agricultural production on water quality became essential in Brazil after the creation of policies for the use and conservation of water resources. For such, water quality indices have been considered with the purpose of showing the spatial and temporal variation of water quality in a watershed. The objective of this study was to develop a water quality index (WQI) applying the Multivariate Factorial Analysis (MFA) statistical technique, which could indicate the influence of agricultural activities in the quality of water resources. Water in a predominantly farm watershed was monitored from Sept. 2003 to Sept. 2004. Monthly water collections were carried out at six sample points, and eight parameters were analyzed: nitrate, ammoniacal nitrogen, ammonia, total phosphorus, electrical conductivity, pH, suspended solids and turbidity, which were considered important due to the agricultural management adopted in the region. Results indicated a contamination of agricultural origin along the basin. Factorial analysis showed that ammonia, ammoniacal nitrogen and nitrate parameters were the ones that most contributed in determining the WQI.A avaliação dos impactos gerados pela agricultura sobre a qualidade da água tornou-se primordial no Brasil após o estabelecimento das políticas de uso e conservação dos recursos hídricos, razão por que índices de qualidade de água são propostos com o intuito de se mostrar a evolução da qualidade da água no tempo e no espaço. O objetivo primeiro neste estudo, foi desenvolver um índice de qualidade de água (IQA), utilizando-se a técnica estatística da Análise Fatorial Multivariada, avaliando-se a influência das atividades agrícolas na qualidade dos recursos hídricos; realizou-se, para se atingir o proposto, um monitoramento da qualidade da água em uma bacia hidrográfica de uso predominantemente agrícola, no período de set/03 a set/04. Realizaram-se, também, coletas mensais de água em seis pontos, analisando-se oito variáveis (nitrato, nitrogênio amoniacal, amônia, fósforo total, condutividade elétrica, pH, turbidez e sólidos suspensos), julgadas importantes pelo manejo agrícola adotado na região. Os resultados obtidos indicaram uma contaminação de origem agrícola ao longo da bacia, sendo que, pela análise fatorial, amônia, nitrogênio amoniacal e nitrato foram as variáveis que mais contribuíram na determinação do IQA.51752

    The loop-quantum-gravity vertex-amplitude

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    Spinfoam theories are hoped to provide the dynamics of non-perturbative loop quantum gravity. But a number of their features remain elusive. The best studied one -the euclidean Barrett-Crane model- does not have the boundary state space needed for this, and there are recent indications that, consequently, it may fail to yield the correct low-energy nn-point functions. These difficulties can be traced to the SO(4) -> SU(2) gauge fixing and the way certain second class constraints are imposed, arguably incorrectly, strongly. We present an alternative model, that can be derived as a bona fide quantization of a Regge discretization of euclidean general relativity, and where the constraints are imposed weakly. Its state space is a natural subspace of the SO(4) spin-network space and matches the SO(3) hamiltonian spin network space. The model provides a long sought SO(4)-covariant vertex amplitude for loop quantum gravity.Comment: 6page

    Susceptibility of \u3ci\u3eAedes aegypti, Culex quinquefasciatus\u3c/i\u3e Say, and \u3ci\u3eAnopheles quadrimaculatus\u3c/i\u3e Say to 19 Pesticides with Different Modes of Action

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    To access the relative potency of pesticides to control adult mosquitoes, 19 pesticides with various modes of action were evaluated against Aedes aegypti, Culex quinquefasciatus Say, and Anopheles quadrimaculatus Say. On the basis of 24-h LD50 values after topical application, the only pesticide that had higher activity than permethrin was fipronil, with LD50 values lower than permethrin for 107-, 4,849-, and 2-fold against Ae. aegypti, Cx. quinquefasciatus Say, and An. quadrimaculatus Say, respectively. Abamectin, imidacloprid, spinosad, diazinon, and carbaryl showed slightly lower activity than permethrin (\u3c20-fold). However, bifenazate showed very low activity against the three mosquito species tested, with LD50 values higher than permthrin for \u3e1000-fold. On the basis of 24-h LD50 values, Cx. quinquefasciatus was the least susceptible species to nine pesticides tested (DNOC, azocyclotin, chlorfenapyr, carbaryl, spinosad, imidaclorid, diazinon, abamectin, and permethrin), whereas Ae. aegypti was the least susceptible species to six pesticides tested (dicofol, amitraz, propargite, hydramethylnon, cyhexatin, and diafenthiuron), and An. quadrimaculatus was the least susceptible species to four pesticides tested (bifenazate, pyridaben, indoxacarb, and fipronil). Our results revealed that different species of mosquitoes had different susceptibility to pesticides, showing the need to select the most efficacious compounds for the least susceptible mosquito species to achieve successful mosquito control
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