7,351 research outputs found

    African-American patients with cancer Talking About Clinical Trials (TACT) with oncologists during consultations: evaluating the efficacy of tailored health messages in a randomised controlled trial—the TACT study protocol

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    Introduction Low rates of accrual of African-American (AA) patients with cancer to therapeutic clinical trials (CTs) represent a serious and modifiable racial disparity in healthcare that impedes the development of promising cancer therapies. Suboptimal physician–patient consultation communication is a barrier to the accrual of patients with cancer of any race, but communication difficulties are compounded with AA patients. Providing tailored health messages (THM) to AA patients and their physician about CTs has the potential to improve communication, lower barriers to accrual and ameliorate health disparities. Objective (1) Demonstrate the efficacy of THM to increase patient activation as measured by direct observation. (2) Demonstrate the efficacy of THM to improve patient outcomes associated with barriers to AA participation. (3) Explore associations among preconsultation levels of: (A) trust in medical researchers, (B) knowledge and attitudes towards CTs, (C) patient-family member congruence in decision-making, and (D) involvement/information preferences, and group assignment. Methods and analysis First, using established methods, we will develop THM materials. Second, the efficacy of the intervention is determined in a 2 by 2 factorial randomised controlled trial to test the effectiveness of (1) providing 357 AA patients with cancer with THM with 2 different ‘depths’ of tailoring and (2) either providing feedback to oncologists about the patients\u27 trial THM or not. The primary analysis compares patient engaged communication in 4 groups preconsultation and postconsultation. Ethics and dissemination This study was approved by the Virginia Commonwealth University Institutional Review Board. To facilitate use of the THM intervention in diverse settings, we will convene ‘user groups’ at 3 major US cancer centres. To facilitate dissemination, we will post all materials and the implementation guide in publicly available locations

    Resource use data by patient report or hospital records: Do they agree?

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    Background: Economic evaluations alongside clinical trials are becoming increasingly common. Cost data are often collected through the use of postal questionnaires; however, the accuracy of this method is uncertain. We compared postal questionnaires with hospital records for collecting data on physiotherapy service use. Methods: As part of a randomised trial of orthopaedic medicine compared with orthopaedic surgery we collected physiotherapy use data on a group of patients from retrospective postal questionnaires and from hospital records. Results: 315 patients were referred for physiotherapy. Hospital data on attendances was available for 30% (n = 96), compared with 48% (n = 150) of patients completing questionnaire data (95% Cl for difference = 10% to 24%); 19% (n = 59) had data available from both sources. The two methods produced an intraclass correlation coefficient of 0.54 (95% Cl 0.31 to 0.70). However, the two methods produced significantly different estimates of resource use with patient self report recalling a mean of 1.3 extra visits (95% Cl 0.4 to 2.2) compared with hospital records. Conclusions: Using questionnaires in this study produced data on a greater number of patients compared with examination of hospital records. However, the two data sources did differ in the quantity of physiotherapy used and this should be taken into account in any analysi

    Hamiltonians for Reduced Gravity

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    A generalised canonical formulation of gravity is devised for foliations of spacetime with codimension n≄1n\ge1. The new formalism retains n-dimensional covariance and is especially suited to 2+2 decompositions of spacetime. It is also possible to use the generalised formalism to obtain boundary contributions to the 3+1 Hamiltonian.Comment: 18 pages, revtex, 3 postscript figures include

    Molecular weight effects on chain pull-out fracture of reinforced polymeric interfaces

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    Using Brownian dynamics, we simulate the fracture of polymer interfaces reinforced by diblock connector chains. We find that for short chains the interface fracture toughness depends linearly on the degree of polymerization NN of the connector chains, while for longer chains the dependence becomes N3/2N^{3/2}. Based on the geometry of initial chain configuration, we propose a scaling argument that accounts for both short and long chain limits and crossover between them.Comment: 5 pages, 3 figure

    Otolithic receptor mechanisms for vestibular-evoked myogenic potentials: A review

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    Air-conducted sound and bone-conduced vibration activate otolithic receptors and afferent neurons in both the utricular and saccular maculae, and trigger small electromyographic (EMG) responses [called vestibular-evoked myogenic potentials (VEMPs)] in various muscle groups throughout the body. The use of these VEMPs for clinical assessment of human otolithic function is built on the following logical steps: (1) that high-frequency sound and vibration at clinically effective stimulus levels activate otolithic receptors and afferents, rather than semicircular canal afferents, (2) that there is differential anatomical projection of otolith afferents to eye muscles and neck muscles, and (3) that isolated stimulation of the utricular macula induces short latency responses in eye muscles, and that isolated stimulation of the saccular macula induces short latency responses in neck motoneurons. Evidence supports these logical steps, and so VEMPs are increasingly being used for clinical assessment of otolith function, even differential evaluation of utricular and saccular function. The proposal, originally put forward by Curthoys in 2010, is now accepted: that the ocular vestibular-evoked myogenic potential reflects predominantly contralateral utricular function and the cervical vestibular-evoked myogenic potential reflects predominantly ipsilateral saccular function. So VEMPs can provide differential tests of utricular and saccular function, not because of stimulus selectivity for either of the two maculae, but by measuring responses which are predominantly determined by the differential neural projection of utricular as opposed to saccular neural information to various muscle groups. The major question which this review addresses is how the otolithic sensory system, with such a high density otoconial layer, can be activated by individual cycles of sound and vibration and show such tight locking of the timing of action potentials of single primary otolithic afferents to a particular phase angle of the stimulus cycle even at frequencies far above 1,000 Hz. The new explanation is that it is due to the otoliths acting as seismometers at high frequencies and accelerometers at low frequencies. VEMPs are an otolith-dominated response, but in a particular clinical condition, semicircular canal dehiscence, semicircular canal receptors are also activated by sound and vibration, and act to enhance the otolith-dominated VEMP responses

    Angle-independent microwave absorption by ultrathin microcavity arrays

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    Copyright © 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 104 (2008) and may be found at http://link.aip.org/link/?JAPIAU/104/043105/1The resonant absorption of microwave radiation by thin, two-dimensional microcavity arrays has been studied. Resonant modes associated with these structures, formed from copper-clad FR4 laminates, exhibit both an azimuthal and polar angle independent electromagnetic response. The experimental data agree well with the predictions of a finite element method computer model, which has been utilized to explore the electromagnetic character of the resonant modes supported

    Evolution of speckle during spinodal decomposition

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    Time-dependent properties of the speckled intensity patterns created by scattering coherent radiation from materials undergoing spinodal decomposition are investigated by numerical integration of the Cahn-Hilliard-Cook equation. For binary systems which obey a local conservation law, the characteristic domain size is known to grow in time τ\tau as R=[Bτ]nR = [B \tau]^n with n=1/3, where B is a constant. The intensities of individual speckles are found to be nonstationary, persistent time series. The two-time intensity covariance at wave vector k{\bf k} can be collapsed onto a scaling function Cov(ÎŽt,tˉ)Cov(\delta t,\bar{t}), where ÎŽt=k1/nBâˆŁÏ„2−τ1∣\delta t = k^{1/n} B |\tau_2-\tau_1| and tˉ=k1/nB(τ1+τ2)/2\bar{t} = k^{1/n} B (\tau_1+\tau_2)/2. Both analytically and numerically, the covariance is found to depend on ÎŽt\delta t only through ÎŽt/tˉ\delta t/\bar{t} in the small-tˉ\bar{t} limit and ÎŽt/tˉ1−n\delta t/\bar{t} ^{1-n} in the large-tˉ\bar{t} limit, consistent with a simple theory of moving interfaces that applies to any universality class described by a scalar order parameter. The speckle-intensity covariance is numerically demonstrated to be equal to the square of the two-time structure factor of the scattering material, for which an analytic scaling function is obtained for large tˉ.\bar{t}. In addition, the two-time, two-point order-parameter correlation function is found to scale as C(r/(Bnτ12n+τ22n),τ1/τ2)C(r/(B^n\sqrt{\tau_1^{2n}+\tau_2^{2n}}),\tau_1/\tau_2), even for quite large distances rr. The asymptotic power-law exponent for the autocorrelation function is found to be λ≈4.47\lambda \approx 4.47, violating an upper bound conjectured by Fisher and Huse.Comment: RevTex: 11 pages + 12 figures, submitted to PR

    Virtua Walker '87

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    Virtua Walker ’87 is an experimental VR installation that explores current nostalgia for period game technologies and consumer electronics. Virtua Walker ’87 is a playable critique of audience assumptions about VR and the walking simulator genre, informed by Hutcheon’s theory of parody (1989).In the game, players are tasked with walking along a virtual recreation of a real Scottish beach. They control their movement by physically walking on the spot, barefoot inside a custom, sand-filled controller. Player steps are captured by two force sensitive resistors that serve as inputs for the VR-based game. The game world is presented to the player in 2-bit colour (reminiscent of the Nintendo Game Boy), with 8-bit audio and purposefully constrained gameplay. Interaction is limited to walking and looking, with few points of interest along the 4-kilometer stretch of beach. As a practice-based research project, Virtua Walker ’87 sought to explore a number of ideas around virtual reality and walking as a mechanic, including: how contemporary VR can be understood as a form of technostalgia; why VR as a technology often falls short of user expectations in terms of affordances and player control; and how the act of walking is understood and appreciated by players within the wider context of a videogame. Importantly, Virtua Walker ’87 aimed to explore dissonant aesthetics in games, contrasting rich tactile experience (the act of walking barefoot on natural materials) with the disenchantment that results from antiquated sound and graphics and a monotonous ludic interface.<br/
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