15,679 research outputs found

    Will the lessons be learned? Reflections on local authority evaluations and the use of research evidence

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    Sure Start programmes are complex, community-based initiatives - forerunners of the Children's Centres Initiative - that have been evaluated nationally and locally. Using an in-depth, retrospective case study of an evaluation of one local programme, the authors raise key issues pertinent to both practice and evaluation in the field, highlighting conflicts and dilemmas both within evaluation generally and, specifically, relating to the evaluation of this programme.We illustrate the difficulties placed on local evaluators by the lack of clear structures within which to work, and provide useful lessons as we move forward into the development and evaluations of new services for children and families

    What Do Complex Adaptive Systems Look Like and What Are the Implications for Innovation Policy?

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    This paper explores the use of complex adaptive systems theory in development policy analysis using a case study drawn from recent events in Uganda. It documents the changes that took place in the farming system in Soroti district during an outbreak of African cassava mosaic virus disease (ACMVD) and the subsequent decline in cassava production - the main staple food in the area. Resultant adaptation impacts are analysed across cropping, biological, economic and social systems each of which operate as an interlinked sub-system. The policy implications of this story suggest a policy agenda that recognises adaptation capacity as the life blood of complex adaptive systems. Since these types of systems are found in all realms of human activity, it follows that strengthening this capacity is a key developmental priority that requires linking together new configurations of actors and resources to tackle an ever-changing set of contexts.Complex Adaptive Systems, Innovation Policy, Uganda, Cassava, Adaptation Capacity, Smallholder Production, Policy

    Technology Supply Chain or Innovation Capacity?: Contrasting Experiences of Promoting Small Scale Irrigation Technology in South Asia

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    The most effective approach to agricultural technology promotion and innovation is still a source of considerable debate, and nowhere more so than in the context of agricultural engineering hardware. Contemporary perspective on agricultural innovation stress the importance of institutional change and give emphasis to the need to develop innovation capacity in systems terms rather address limitations of technology transfer mechanisms. This paper illustrates using the case of manual irrigation technology - treadle pumps -- in Bangladesh and India. It identifies 5 elements of this capacity: (i) A sector coordination mechanism; (ii) a developmental rather than technical organising principle for sector development; (iii) habits and practices (institutions) of key organisations; (iv) Interaction as a learning and knowledge transmission mechanism (v) Market demand as key an incentive for innovation; and (vi) Policies and institutional innovations to ensure adequate stakeholder participation. The paper concludes by suggesting that identifying new sources of institutional innovation is the most presses task for initiatives that seek to make more effective use of knowledge and technology in development.Agricultural Technology, Innovation Systems, Innovation Capacity, Agricultural Research, Poverty Reduction, Small Scale Irrigation, Supply Chains

    Helmet weight simulator

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    A device for providing acceleration cues to the helmet of a simulator pilot is described. Pulleys are attached to both shoulders of the pilot. A cable is attached to both sides of the helmet and extends through the pulleys to a takeup reel that is controlled by a torque motor. Control signals are applied to a servo system including the torque motor, the takeup reel and a force transducer which supplies the feedback signal. In one embodiment of the invention the force transducer is in the cable and in another it is in the takeup reel

    The role of reactive oxygen species in the gut immune response of cat fleas (Ctenocephalides felis)

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    Fleas transmit numerous deadly and debilitating diseases, including the causative agents of murine typhus and plague. Because initial entry of these infectious agents occurs while blood feeding, the immune response in the flea gut is considered to be the first line of defense against invading microbes. However, relatively few studies have identified the flea immune molecules that effectively resist or limit infection in the gut. In other hematophagous insects, an immediate immune response to imbibed pathogens is the generation of reactive oxygen species (ROS). In this study, we utilized cat fleas (Ctenocephalides felis) to investigate whether natural infections with bacteria induce ROS synthesis in the flea gut, and whether production of ROS provides a defense mechanism against microbial colonization. Specifically, we assessed the generation of ROS via quantitative peroxide assays from fleas that were given uninfected and bacteria-infected blood meals. Additionally, we treated fleas with an antioxidant before infection with bacteria, and then measured the resultant bacterial load within each flea. Our data shows that ROS levels increase in response to infection in the flea gut, and that this increase helps to strengthen the flea immune response through the microbicidal activity of ROS. Overall, these data yield significant insight into how fleas interact with pathogens in their gut lumen, as well as the challenges faced by pathogens upon entering the flea host

    Pictures are necessary but not sufficient: Using a range of visual methods to engage users about school design

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    It has been argued by both educationalists and social researchers that visual methods are particularly appropriate for the investigation of people's experiences of the school environment. The current and expected building work taking place in British schools provides an opportunity for exploration of methods, as well as a need to establish ways to achieve this involvement of a range of school users, including students. This article describes a consultation that was undertaken in a UK secondary school as part of a participatory design process centred on the rebuilding of the school. A range of visual methods, based on photographs and maps, was used to investigate the views of a diverse sample of school users, including students, teachers, technical and support staff and the wider community. Reported here is the experience of using these tools, considering the success of different visually-based methods in engaging a broad cross section of the school community and revealing useful information. Using a range of visual methods allows a complex, but coherent, understanding of the particular school environment to be constructed and developed. It is further argued that such a range of visual and spatial methods is needed to develop appropriate understanding. The study, therefore, contributes to knowledge about specific visual research methods, appreciation of the relationship between tools, and a general methodological understanding of visual methods' utility for developing understanding of the learning environment

    Diffusion in hierarchical systems: A simulation study in models of healthy and diseased muscle tissue

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    PURPOSE: To investigate the sensitivity of diffusion-MR signal to microstructural change in muscle tissue associated with pathology, and recommend optimal acquisition parameters. METHODS: We employ Monte-Carlo simulation of diffusing spins in hierarchical tissue to generate synthetic diffusion-weighted signal curves over a wide range of scan parameters. Curves are analyzed using entropy-a measure of curve complexity. Entropy change between a baseline and various microstructural scenarios is investigated. We find acquisitions that optimize entropy difference in each scenario. RESULTS: Permeability changes have a large effect on the diffusion-weighted signal curve. Muscle fiber atrophy is also important, although differentiating between mechanisms is challenging. Several acquisitions over a range of diffusion times is optimal for imaging microstructural change in muscle tissue. Sensitivity to permeability is optimized for high gradient strengths, but sensitivity to other scenarios is optimal at other values. CONCLUSIONS: The diffusion-attenuated signal is sensitive to the microstructural changes, but the changes are subtle. Taking full advantage of the changes to the overall curve requires a set of acquisitions over a range of diffusion times. Permeability causes the largest changes, but even the very subtle changes associated with fiber radius distribution change the curves more than noise alone

    Spillovers of Equal Treatment in Wage Offers

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    We analyse a labour matching model with wage posting, where re flecting institutional constraints firms cannot differentiate their wage offers within certain subsets of workers. Inter alia, we find that the presence of impersonal wage offers leads to wage compression, which propagates to the wages for high productivity workers who receive personalised offers
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