235,844 research outputs found

    Collaborating to develop an online resource for parents

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    Background The development and evaluation of Online Parent Information and Support (OPIS) involved the creation of a web resource for parents who needed support for the home-based management of their child's chronic kidney disease (CKD)

    Sound separation probe

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    Probe separates sound waves from turbulent flow pressure fluctuations in ducted airstreams by using principle that sound waves and turbulent flow pressure perturbations travel at different velocities

    Design and Focused Ion Beam Fabrication of Single Crystal Diamond Nanobeam Cavities

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    We present the design and fabrication of nanobeam photonic crystal cavities in single crystal diamond for applications in cavity quantum electrodynamics. First, we describe three-dimensional finite-difference time-domain simulations of a high quality factor (Q ~ 10^6) and small mode volume (V ~ 0.5 ({\lambda}/n)^3) device whose cavity resonance corresponds to the zero-phonon transition (637nm) of the Nitrogen-Vacancy (NV) color center in diamond. This high Q/V structure, which would allow for strong light-matter interaction, is achieved by gradually tapering the size of the photonic crystal holes between the defect center and mirror regions of the nanobeam. Next, we demonstrate two different focused ion beam (FIB) fabrication strategies to generate thin diamond membranes and nanobeam photonic crystal resonators from a bulk crystal. These approaches include a diamond crystal "side-milling" procedure as well as an application of the "lift-off" technique used in TEM sample preparation. Finally, we discuss certain aspects of the FIB fabrication routine that are a challenge to the realization of the high-Q/V designs

    Statistics of statisticians: Critical mass of statistics and operational research groups in the UK

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    Using a recently developed model, inspired by mean field theory in statistical physics, and data from the UK's Research Assessment Exercise, we analyse the relationship between the quality of statistics and operational research groups and the quantity researchers in them. Similar to other academic disciplines, we provide evidence for a linear dependency of quality on quantity up to an upper critical mass, which is interpreted as the average maximum number of colleagues with whom a researcher can communicate meaningfully within a research group. The model also predicts a lower critical mass, which research groups should strive to achieve to avoid extinction. For statistics and operational research, the lower critical mass is estimated to be 9 ±\pm 3. The upper critical mass, beyond which research quality does not significantly depend on group size, is about twice this value

    GLM permutation - nonparametric inference for arbitrary general linear models

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    Introduction: Permutation methods are finding growing use in neuroimag- ing data analyses (e.g. randomise in FSL, SnPM in SPM, XBAMM/BAMM/CAMBA, etc). These methods provide ex- act control of false positives, make only weak assumptions, and allow nonstandard types of statistics (e.g. smoothed variance t- test). With fast and inexpensive computing, there would seem few reasons not to use nonparametric methods. A significant limitation of these methods, however, is the lack of flexibility with respect to the experimental design and nuisance variables. Each specific design dictates the type of exchange- ability of null data, and hence how to permute. Nuisance effects (e.g. age) render data non-exchangeable even when the effect of interest is null. Hence, even something as simple as ANCOVA has no exact permutation test. Recently there has been an active literature on approximate– but accurate–permutation tests for 2-variable regression, one effect of interest, one nuisance (see review by Anderson & Robinson [1]). Here we extend and evaluate these methods for use with an arbitrary General Linear Model (GLM)

    Surface core excitons in III-V semiconductors

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    Recent experiments have shown that the cation core excitons on the (110) surface of many III-V semiconductors have very large binding energies.(^1) They are sometimes reported to be bound by as much as ≳0.8 eV, tightly bound compared to bulk binding energies of ≾0.1 eV. To explore this phenomenon, we have calculated the binding energies and oscillator strengths of core excitons on the (110) surface of GaAs, GaSb, GaP, and InP

    Retrospective study of more than 9000 feline cutaneous tumours in the UK: 2006–2013

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    The aim of the study was to utilise a large database available from a UK-based, commercial veterinary diagnostic laboratory to ascertain the prevalence of different forms of cutaneous neoplasia within the feline population, and to detect any breed, sex or age predilections for the more common tumours

    A functional analysis of change propagation

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    A thorough understanding of change propagation is fundamental to effective change management during product redesign. A new model of change propagation, as a result of the interaction of form and function is presented and used to develop an analysis method that determines how change is likely to propagate. The analysis produces a Design Structure Matrix, which clearly illustrates change propagation paths and highlights connections that could otherwise be ignored. This provides the user with an in-depth knowledge of product connectivity, which has the potential to support the design process and reduce the product's susceptibility to future change
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