161 research outputs found

    Field-testing of the rapid assessment of disability questionnaire

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    The Rapid Assessment of Disability (RAD) questionnaire measures the magnitude and impact of disability and aims to inform the design of disability inclusive development programs. This paper reports the psychometric evaluation of the RAD

    Order and Frustration in Chiral Liquid Crystals

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    This paper reviews the complex ordered structures induced by chirality in liquid crystals. In general, chirality favors a twist in the orientation of liquid-crystal molecules. In some cases, as in the cholesteric phase, this favored twist can be achieved without any defects. More often, the favored twist competes with applied electric or magnetic fields or with geometric constraints, leading to frustration. In response to this frustration, the system develops ordered structures with periodic arrays of defects. The simplest example of such a structure is the lattice of domains and domain walls in a cholesteric phase under a magnetic field. More complex examples include defect structures formed in two-dimensional films of chiral liquid crystals. The same considerations of chirality and defects apply to three-dimensional structures, such as the twist-grain-boundary and moire phases.Comment: 39 pages, RevTeX, 14 included eps figure

    A systematic review of the effectiveness of antimicrobial rinse-free hand sanitizers for prevention of illness-related absenteeism in elementary school children

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    BACKGROUND: Absenteeism due to communicable illness is a major problem encountered by North American elementary school children. Although handwashing is a proven infection control measure, barriers exist in the school environment, which hinder compliance to this routine. Currently, alternative hand hygiene techniques are being considered, and one such technique is the use of antimicrobial rinse-free hand sanitizers. METHODS: A systematic review was conducted to examine the effectiveness of antimicrobial rinse-free hand sanitizer interventions in the elementary school setting. MEDLINE, EMBASE, Biological Abstract, CINAHL, HealthSTAR and Cochrane Controlled Trials Register were searched for both randomized and non-randomized controlled trials. Absenteeism due to communicable illness was the primary outcome variable. RESULTS: Six eligible studies, two of which were randomized, were identified (5 published studies, 1 published abstract). The quality of reporting was low. Due to a large amount of heterogeneity and low quality of reporting, no pooled estimates were calculated. There was a significant difference reported in favor of the intervention in all 5 published studies. CONCLUSIONS: The available evidence for the effectiveness of antimicrobial rinse-free hand sanitizer in the school environment is of low quality. The results suggest that the strength of the benefit should be interpreted with caution. Given the potential to reduce student absenteeism, teacher absenteeism, school operating costs, healthcare costs and parental absenteeism, a well-designed and analyzed trial is needed to optimize this hand hygiene technique

    Light-Controlled Polymerization Kinetics for the Photostabilization of Cholesteric Fingerprint Rolls

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    We use a focused ultraviolet (UV) laser beam to photopolymerize localized polymer networks in a cholesteric liquid-crystalline host and to thereby stabilize small, light-diffracting "fingerprint'' domains within a uniform, planar-aligned sample. As we have previously described, these "microspot'' gratings are electrically switchable [1] and can be produced with diameters ranging from a few tens to hundreds of microns. Our focus in this article is to model the growth of the stabilized domain using a simple reaction-diffusion model of the photopolymerization process and to compare this model with data for networks formed both from isotropic and mesogenic monomers. In spite of an initial spatial asymmetry observed in the mesogenic case, both types of light-controlled networks develop in accordance with the fast photoreactivity/weak diffusion limit of the model
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