97 research outputs found

    What we learn when designing with marginalised children

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    Designing with marginalised children often produces detailed insights about their lives and communities. Whilst it is possible to extract methodological and artefact-centred knowledge from existing design cases, it can be difficult to utilise and build on some of the more complex and multifaceted issues that these generate, for instance, how researcher decisions inform design outcomes. In this workshop, we invite researchers to reflect on the insights design case studies with marginalized children offer to the larger Children-Computer Interaction (CCI) community. Our goals are to reflect on what kinds of insights are generated; what we as design researchers and practitioners would have wanted to know prior to undertaking such work, and; to identify ways of communicating these insights

    Case-oriented computer-based-training in radiology: concept, implementation and evaluation

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    BACKGROUND: Providing high-quality clinical cases is important for teaching radiology. We developed, implemented and evaluated a program for a university hospital to support this task. METHODS: The system was built with Intranet technology and connected to the Picture Archiving and Communications System (PACS). It contains cases for every user group from students to attendants and is structured according to the ACR-code (American College of Radiology) [2]. Each department member was given an individual account, could gather his teaching cases and put the completed cases into the common database. RESULTS: During 18 months 583 cases containing 4136 images involving all radiological techniques were compiled and 350 cases put into the common case repository. Workflow integration as well as individual interest influenced the personal efforts to participate but an increasing number of cases and minor modifications of the program improved user acceptance continuously. 101 students went through an evaluation which showed a high level of acceptance and a special interest in elaborate documentation. CONCLUSION: Electronic access to reference cases for all department members anytime anywhere is feasible. Critical success factors are workflow integration, reliability, efficient retrieval strategies and incentives for case authoring

    On the barrier properties of the cornea: a microscopy study of the penetration of fluorescently labeled nanoparticles, polymers, and sodium fluorescein

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    Overcoming the natural defensive barrier functions of the eye remains one of the greatest challenges of ocular drug delivery. Cornea is a chemical and mechanical barrier preventing the passage of any foreign bodies including drugs into the eye, but the factors limiting penetration of permeants and nanoparticulate drug delivery systems through the cornea are still not fully understood. In this study, we investigate these barrier properties of the cornea using thiolated and PEGylated (750 and 5000 Da) nanoparticles, sodium fluorescein, and two linear polymers (dextran and polyethylene glycol). Experiments used intact bovine cornea in addition to bovine cornea de-epithelialized or tissues pretreated with cyclodextrin. It was shown that corneal epithelium is the major barrier for permeation; pretreatment of the cornea with β-cyclodextrin provides higher permeation of low molecular weight compounds, such as sodium fluorescein, but does not enhance penetration of nanoparticles and larger molecules. Studying penetration of thiolated and PEGylated (750 and 5000 Da) nanoparticles into the de-epithelialized ocular tissue revealed that interactions between corneal surface and thiol groups of nanoparticles were more significant determinants of penetration than particle size (for the sizes used here). PEGylation with polyethylene glycol of a higher molecular weight (5000 Da) allows penetration of nanoparticles into the stroma, which proceeds gradually, after an initial 1 h lag phase

    sFlt Multivalent Conjugates Inhibit Angiogenesis and Improve Half-Life In Vivo

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    We would like to thank Jonathan Winger and Xiao Zhu for guidance with the insect cell protein expression system and providing reagents. We would like to acknowledge Ann Fischer for help with expressing the sFlt protein in the Tissue Culture Facility at UC Berkeley and Dawn Spelke and Anusuya Ramasubramanian for help optimizing protein purification from insect cells. We are also grateful for the help from Leah Byrne and John Flannery at in the Helen Wills Neuroscience Institute at UC Berkeley for aiding us in the development of the rat intravitreal residence time model and for allowing us to use their facilities.Current anti-VEGF drugs for patients with diabetic retinopathy suffer from short residence time in the vitreous of the eye. In order to maintain biologically effective doses of drug for inhibiting retinal neovascularization, patients are required to receive regular monthly injections of drug, which often results in low patient compliance and progression of the disease. To improve the intravitreal residence time of anti-VEGF drugs, we have synthesized multivalent bioconjugates of an anti-VEGF protein, soluble fms-like tyrosine kinase-1 (sFlt) that is covalently grafted to chains of hyaluronic acid (HyA), conjugates that are termed mvsFlt. Using a mouse corneal angiogenesis assay, we demonstrate that covalent conjugation to HyA chains does not decrease the bioactivity of sFlt and that mvsFlt is equivalent to sFlt at inhibiting corneal angiogenesis. In a rat vitreous model, we observed that mvsFlt had significantly increased intravitreal residence time compared to the unconjugated sFlt after 2 days. The calculated intravitreal half-lives for sFlt and mvsFlt were 3.3 and 35 hours, respectively. Furthermore, we show that mvsFlt is more effective than the unconjugated form at inhibiting retinal neovascularization in an oxygen-induced retinopathy model, an effect that is most likely due to the longer half-life of mvsFlt in the vitreous. Taken together, our results indicate that conjugation of sFlt to HyA does not affect its affinity for VEGF and this conjugation significantly improves drug half-life. These in vivo results suggest that our strategy of multivalent conjugation could substantially improve upon drug half-life, and thus the efficacy of currently available drugs that are used in diseases such as diabetic retinopathy, thereby improving patient quality of life.Yeshttp://www.plosone.org/static/editorial#pee

    Water Fingering Into an Oil-Wet Porous Medium Saturated with Oil At Connate Water Saturation Digitation de l'eau dans un milieu poreux mouillable à l'huile saturée en eau connée

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    The effect that connate water has on fingers of water penetrating into an oil-wet porous medium is examined. In this context, the connate water appears to have no influence on the width of fingers, but instead causes the fingers to be more irregular than fingers in similar experiments without connate water. The surface wettability, in contrast, does have a marked effect on finger widths. On examine dans cet article les effets de l'eau connée sur la digitation de l'eau dans un milieu poreux mouillable à l'huile. Dans ce contexte l'eau connée ne semble avoir aucune influence sur la largeur des digitations mais rend ces dernières plutôt plus irrégulières que dans le cas des expériences effectuées en absence d'eau connée. Par contre, la mouillabilité de la surface a un effet important sur la largeur des digitations

    Water Fingering Into an Oil-Wet Porous Medium Saturated with Oil At Connate Water Saturation

    No full text
    The effect that connate water has on fingers of water penetrating into an oil-wet porous medium is examined. In this context, the connate water appears to have no influence on the width of fingers, but instead causes the fingers to be more irregular than fingers in similar experiments without connate water. The surface wettability, in contrast, does have a marked effect on finger widths

    Automatic, Template-Based Run-Time Specialization: Implementation and Experimental Study

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    : Specializing programs with respect to run-time values is an optimization strategy that has been shown to drastically improve code performance on realistic programs ranging from operating systems to graphics. Recently, various approaches to specializing code at run-time have been proposed. However, these approaches still suffer from shortcomings that limit their applicability: they are either manual, require programs to be written in a dedicated language, or are too expensive to be widely applied. We solve these problems by introducing new techniques to implement run-time specialization. The key to our approach is the use of code templates. Templates are automatically generated from ordinary programs. These templates are compiled and optimized before run time, thus minimizing the time to generate code at run time. Because templates can be compiled by an optimizing compiler, the code generated is of high quality. Experimental results obtained on scientific and graphics code indicate th..
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