3,304 research outputs found

    Whiplash: the possible impact of context on diagnosis

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    This study explores the importance of context when diagnosing Whiplash Associated Disorders (WAD). Whiplash is a complex injury and there is considerable variation in its diagnosis and treatment. Research has focussed on RTAs, whilst there is a paucity of evidence relating to WAD in sport. It is unclear whether WAD is simply not occurring in sport, or if such injuries are occurring but are not identified as WAD. In the current study, 87 postgraduate physiotherapists were asked to classify an injury reported in a short vignette. Two parallel vignettes were used, which were identical except for the context of the injury (one being an RTA and the other being within sport). Each participant responded to only one of these. It was found that, even within a sample of experienced physiotherapists, the injury environment impacted on diagnosis, despite the symptoms being identical. A significantly higher proportion of therapists diagnosed WAD within the RTA context than within the sporting context. Additionally, there were differences between the two context groups in relation to the diagnostic terminology used by participants. Most respondents had heard of the CSP whiplash guidelines but only a minority had actively used these. The majority of respondents were also aware of the litigation aspects of RTAs

    Nitric Oxide Bioavailability and Its Potential Relevance to the Variation in Susceptibility to the Renal and Vascular Complications in Patients With Type 2 Diabetes

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    OBJECTIVE—We compared the renal and systemic vascular (renovascular) response to a reduction of bioavailable nitric oxide (NO) in type 2 diabetic patients without nephropathy and of African and Caucasian heritage. RESEARCH DESIGN AND METHODS—Under euglycemic conditions, renal blood flow was determined by a constant infusion of paraminohippurate and changes in blood pressure and renal vascular resistance estimated before and after an infusion of l-Ng-monomethyl-l-arginine. RESULTS—In the African-heritage group, there was a significant fall in renal blood flow (Δ−46.0 ml/min per 1.73 m(2); P < 0.05) and rise in systolic blood pressure (Δ10.0 mmHg [95% CI 2.3–17.9]; P = 0.017), which correlated with an increase in renal vascular resistance (r(2) = 0.77; P = 0.004). CONCLUSIONS—The renal vasoconstrictive response associated with NO synthase inhibition in this study may be of relevance to the observed vulnerability to renal injury in patients of African heritage

    Rotorcraft convertible engine study

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    The objective of the Rotorcraft Convertible Engine Study was to define future research and technology effort required for commercial development by 1988 of convertible fan/shaft gas turbine engines for unconventional rotorcraft transports. Two rotorcraft and their respective missions were defined: a Fold Tilt Rotor aircraft and an Advancing Blade Concept (ABC) rotorcraft. Sensitivity studies were conducted with these rotorcraft to determine parametrically the influence of propulsion characteristics on aircraft size, mission fuel requirements, and direct operating costs (DOC). The two rotorcraft were flown with conventional propulsion systems (separate lift/cruise engines) and with convertible propulsion systems to determine the benefits to be derived from convertible engines. Trade-off studies were conducted to determine the optimum engine cycle and staging arrangement for a convertible engine. Advanced technology options applicable to convertible engines were studied. Research and technology programs were identified which would ensure technology readiness for commercial development of convertible engines by 1988

    Z-Spec: A MM-Wave Spectrometer For Measuring Redshifts Of Submillimeter Galaxies

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    We are building a background-limited, broadband millimeter-wave spectrometer (Z-Spec) for observations of CO rotational transitions from high-redshift dusty galaxies. The large instantaneous bandwidth (195 to 310 GHz) will enable redshifts of dust obscured galaxies to be unambiguously measured. Z-Spec uses a waveguide-coupled grating architecture in which the light propagation is confined within a parallel-plate waveguide. The grating is extremely compact compared to a classical free-space system. An array of silicon nitride bolometers cooled to 100 mK will provide background-limited performance. Z-Spec serves as a technology demonstration for a future space-borne far-infrared grating spectrometer

    Size dependence of volume and surface nucleation rates for homogeneous freezing of supercooled water droplets

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    The relative roles of volume and surface nucleation were investigated for the homogeneous freezing of pure water droplets. Experiments were carried out in a cryogenic laminar aerosol flow tube using supercooled water aerosols with maximum volume densities at radii between 1 and 3 μm. Temperature- and size-dependent values of volume- and surface-based homogeneous nucleation rates between 234.8 and 236.2 K were derived using a microphysical model and aerosol phase compositions and size distributions determined from infrared extinction measurements in the flow tube. The results show that the contribution from nucleation at the droplet surface increases with decreasing droplet radius and dominates over nucleation in the bulk droplet volume for droplets with radii smaller than approximately 5 μm. This is interpreted in terms of a lowered free energy of ice germ formation in the surface-based process. The implications of surface nucleation for the parameterization of homogeneous ice nucleation in numerical models are considered

    An effective approach to improve the performance of PC-based superplasticizer in alkali-activated slag

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    The lack of workability has hindered the industriallisation of alkali-activated slag (AAS) - a novel, low carbon cementitious building material. In order to address this main barrier, adding superplasticiser (SP) is essential. The main reason causing the dysfunction of current commercial SP in AAS has been identified as competitive adsorption between the SPs and the activators. The separate SP addition methods (adding SP and activator separately) offers the potentials to tackle the above issue. In this paper, the effects of separate addition methods of 134 lignosulfonate superplasticiser (LS) in AAS activated by NaOH were investigated. The adsorption between the LS and the slag was examined to understand the interaction between the SP and the slag. The workability and rheological properties of fresh NaOH-activated slag and the compressive strength of hardened NaOH-activated slag were also investigated. The results indicated that the separate addition methods reduced the competitive adsorption between the SPs and the NaOH activator, leading to a higher adsorption of the SPs on the slag. Consequently, the workability and rheological properties of NaOH-activated slag was enhanced by separate addition methods without reducing the compressive strength of hardened NaOH-activated slag

    A Monolithic Time Stretcher for Precision Time Recording

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    Identifying light mesons which contain only up/down quarks (pions) from those containing a strange quark (kaons) over the typical meter length scales of a particle physics detector requires instrumentation capable of measuring flight times with a resolution on the order of 20ps. In the last few years a large number of inexpensive, multi-channel Time-to-Digital Converter (TDC) chips have become available. These devices typically have timing resolution performance in the hundreds of ps regime. A technique is presented that is a monolithic version of ``time stretcher'' solution adopted for the Belle Time-Of-Flight system to address this gap between resolution need and intrinsic multi-hit TDC performance.Comment: 9 pages, 15 figures, minor corrections made, to appear as JINST_008

    Homotopy types of stabilizers and orbits of Morse functions on surfaces

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    Let MM be a smooth compact surface, orientable or not, with boundary or without it, PP either the real line R1R^1 or the circle S1S^1, and Diff(M)Diff(M) the group of diffeomorphisms of MM acting on C∞(M,P)C^{\infty}(M,P) by the rule h⋅f↦f∘h−1h\cdot f\mapsto f \circ h^{-1}, where h∈Diff(M)h\in Diff(M) and f∈C∞(M,P)f \in C^{\infty}(M,P). Let f:M→Pf:M \to P be a Morse function and O(f)O(f) be the orbit of ff under this action. We prove that πkO(f)=πkM\pi_k O(f)=\pi_k M for k≥3k\geq 3, and π2O(f)=0\pi_2 O(f)=0 except for few cases. In particular, O(f)O(f) is aspherical, provided so is MM. Moreover, π1O(f)\pi_1 O(f) is an extension of a finitely generated free abelian group with a (finite) subgroup of the group of automorphisms of the Reeb graph of ff. We also give a complete proof of the fact that the orbit O(f)O(f) is tame Frechet submanifold of C∞(M,P)C^{\infty}(M,P) of finite codimension, and that the projection Diff(M)→O(f)Diff(M) \to O(f) is a principal locally trivial S(f)S(f)-fibration.Comment: 49 pages, 8 figures. This version includes the proof of the fact that the orbits of a finite codimension of tame action of tame Lie group on tame Frechet manifold is a tame Frechet manifold itsel

    Automorphisms of graphs of cyclic splittings of free groups

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    We prove that any isometry of the graph of cyclic splittings of a finitely generated free group FNF_N of rank N≥3N\ge 3 is induced by an outer automorphism of FNF_N. The same statement also applies to the graphs of maximally-cyclic splittings, and of very small splittings.Comment: 22 pages, 5 figures. Small modifications. To appear in Geometriae Dedicat

    PNF 2.0? Initial evidence that gamification can increase the efficacy of brief, web-based personalized normative feedback alcohol interventions

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    Gamified interventions exploit the motivational characteristics of a game in order to provide prevention information and promote behavior change. Despite the modest effect sizes observed in increasingly popular web-based personalized normative feedback (PNF) alcohol interventions for college students, previous research has yet to consider how gamification might be used to enhance efficacy. This study examines whether a novel, gamified PNF intervention format, which includes a point-based reward system, the element of chance, and personal icons to visually represent users, is more effective in reducing short-term alcohol use than the standard web-based style of PNF currently used on college campuses. Two-hundred and thirty-seven college students were randomly assigned to receive either a standard brief, web-based PNF alcohol intervention or the same alcohol intervention components delivered within a Facebook-connected social game called CampusGANDR (Gamified Alcohol Norm Discovery and Readjustment). In both study conditions participants answered identical questions about their perceptions of peer drinking norms and own drinking and then received the same PNF slides. Two weeks following PNF delivery, participants again reported their perceptions of peers\u27 alcohol use and own drinking. Students in the CampusGANDR condition reported significantly reduced peer drinking norms and alcohol use at the two-week follow-up relative to students who received identical PNF delivered by standard online survey. Further, a mediation model demonstrated that this effect was driven by larger reductions in perceived drinking norms among participants assigned to receive CampusGANDR, relative to control. As web-based PNF is becoming an increasingly universal prevention strategy, findings from this study suggest gamification may represent one method by which intervention efficacy could be substantially improved. The potential methodological and economic benefits associated with gamified PNF interventions are emphasized and directions for future research are discussed
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