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

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

A study into the effects of gas flow inlet design of the Renishaw AM250 laser powder bed fusion machine using computational modelling

Previous work has highlighted the importance of the gas flow system in laser powder bed fusion (L-PBF) processes. Inhomogeneous gas flow experienced at the surface of the powder bed can cause variations in mechanical properties over a build platform, where insufficient removal of by-products which cause laser attenuation and redisposition of byproducts are believed to contribute to these variations. The current study analyses the gas flow experienced over a build platform in a Renishaw AM250 metal powder bed fusion machine via Hot Wire Anemometer (HWA) testing. Velocity profiles of the flow directly above the powder-bed and through the centre plane normal to the inlets have been categorized. These HWA results illustrate the inhomogeneity of the gas flow experienced over the build platform and from literature imply that there will be insufficient removal of by-products and hence variable build quality in specific areas of the build platform. A Computational Fluid Dynamics (CFD) model was created in ANSYS Fluent and validated against HWA results coupled with a Discrete Phase Model (DPM) representing the expulsion of spatter. Velocity contours of simulated against experimental are compared, where the results appear in good agreement. The multiphase CFD model was then used to explore the effects of changing inlet design parameters using a Design of Experiments (DOE) study based on an Optimal Space Filling (OSF) method. This was to understand the effect of design parameters on flow uniformity, local gas velocity over the processing area and spatter particulate accumulation within the build chamber. The initial design study found that flow uniformity could potentially be increased by 21.05% and spatter accumulation on the processing area could be reduced by 26.64%. In addition, this has given insight into important design considerations for future generation of L-PBF machines

Defining response to radiotherapy in rectal cancer using magnetic resonance imaging and histopathological scales

Aim: To define good and poor regression using pathology and MRI regression scales after neo-adjuvant chemotherapy for rectal cancer. Methods: A systematic review of all studies up to December 2015, without language restriction that were identified from MEDLINE, Cochrane Controlled Trials Register (1960–2015), and EMBASE (1991–2015). Searches were performed of article bibliographies and conference abstracts. MeSH and text words, included “tumour regression”, “mrTRG”, “poor response” and “colorectal cancers”. Clinical studies using either MRI or histopathological TRG scales to define good and poor responders were included in relation to outcomes (local (LR), distant recurrence (DR), disease free (DFS), overall survival (OS)). There was no age restriction to included patients nor stage of cancer.Data was extracted by two authors independently using pre-defined outcome measures. Results: Quantitative data (prevalence) were extracted and analysed according to meta-analytical techniques using comprehensive meta-analysis. Qualitative data (LR, DR, DFS &OS) were presented as ranges. The overall proportion of poor responders after neo-adjuvant CRT was 37.7% (CI: 30.1 to 45.8). There were 19 different reported histopathological scales and one MRI regression scale (mrTRG). Clinical studies used nine and six histopathological scales for poor and good responders respectively. All studies using MRI to define good and poor response used one scale. The most common histopathological definition for good response was the Mandard grades 1&2 or Dworak grades 3&4; Mandard 3,4&5 and Dworak 0,1&2 were used for poor response. For histopathological grades, the 5-year outcomes for poor responders were LR 3.4-4.3%, DR 14.3-20.3%, DFS 61.7-68.1% and OS 60.7-69.1. Good pathological response 5-year outcomes were LR, 0-1.8%; DR, 0-11.6%; DFS, 78.4-86.7%; and, OS, 77.4-88.2%. A poor response on MRI (mrTRG 4,5) resulted in 5-year LR 4-29%, DR 9%, DFS 31-59% and OS 27-68%. The 5-year outcomes with a good response on MRI (mrTRG 1,2 & 3) was LR 1-14%, DR 3%, DFS 64-83% and OS 72-90%. Conclusions: For histopathology regression assessment Mandard1,2/Dworak3,4 should be used for good and Mandard3,4,5/Dworak0,1,2 for poor response. MRI indicates good and poor response by mrTRG1-3 and mrTRG4-5 respectively

Do mutual funds have consistency in their performance?

Using a comprehensive data set of 714 Chinese mutual funds from 2004 to 2015, the study investigates these funds’ performance persistence by using the Capital Asset Pricing model, the Fama-French three-factor model and the Carhart Four-factor model. For persistence analysis, we categorize mutual funds into eight octiles based on their one year lagged performance and then observe their performance for the subsequent 12 months. We also apply Cross-Product Ratio technique to assess the performance persistence in these Chinese funds. The study finds no significant evidence of persis- tence in the performance of the mutual funds. Winner (loser) funds do not continue to be winner (loser) funds in the subsequent time period. These findings suggest that future performance of funds cannot be predicted based on their past performance.info:eu-repo/semantics/publishedVersio

Attention-Based Machine Vision Models and Techniques for Solar Wind Speed Forecasting Using Solar EUV Images

Abstract: Extreme ultraviolet images taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory make it possible to use deep vision techniques to forecast solar wind speed—a difficult, high‐impact, and unsolved problem. At a 4 day time horizon, this study uses attention‐based models and a set of methodological improvements to deliver an 11.1% lower RMSE and a 17.4% higher prediction correlation compared to the previous work testing on the period from 2010 to 2018. Our analysis shows that attention‐based models combined with our pipeline consistently outperform convolutional alternatives. Our study shows a large performance improvement by using a 30 min as opposed to a daily sampling frequency. Our model has learned relationships between coronal holes' characteristics and the speed of their associated high‐speed streams, agreeing with empirical results. Our study finds a strong dependence of our best model on the phase of the solar cycle, with the best performance occurring in the declining phase

Attention-Based Machine Vision Models and Techniques for Solar Wind Speed Forecasting Using Solar EUV Images

Abstract: Extreme ultraviolet images taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory make it possible to use deep vision techniques to forecast solar wind speed—a difficult, high‐impact, and unsolved problem. At a 4 day time horizon, this study uses attention‐based models and a set of methodological improvements to deliver an 11.1% lower RMSE and a 17.4% higher prediction correlation compared to the previous work testing on the period from 2010 to 2018. Our analysis shows that attention‐based models combined with our pipeline consistently outperform convolutional alternatives. Our study shows a large performance improvement by using a 30 min as opposed to a daily sampling frequency. Our model has learned relationships between coronal holes' characteristics and the speed of their associated high‐speed streams, agreeing with empirical results. Our study finds a strong dependence of our best model on the phase of the solar cycle, with the best performance occurring in the declining phase

Relative commutants of strongly self-absorbing C*-algebras

The relative commutant $A'\cap A^{\mathcal{U}}$ of a strongly self-absorbing algebra $A$ is indistinguishable from its ultrapower $A^{\mathcal{U}}$. This applies both to the case when $A$ is the hyperfinite II$_1$ factor and to the case when it is a strongly self-absorbing C*-algebra. In the latter case we prove analogous results for $\ell_\infty(A)/c_0(A)$ and reduced powers corresponding to other filters on $\bf N$. Examples of algebras with approximately inner flip and approximately inner half-flip are provided, showing the optimality of our results. We also prove that strongly self-absorbing algebras are smoothly classifiable, unlike the algebras with approximately inner half-flip.Comment: Some minor correction

Quantized reduction as a tensor product

Symplectic reduction is reinterpreted as the composition of arrows in the category of integrable Poisson manifolds, whose arrows are isomorphism classes of dual pairs, with symplectic groupoids as units. Morita equivalence of Poisson manifolds amounts to isomorphism of objects in this category. This description paves the way for the quantization of the classical reduction procedure, which is based on the formal analogy between dual pairs of Poisson manifolds and Hilbert bimodules over C*-algebras, as well as with correspondences between von Neumann algebras. Further analogies are drawn with categories of groupoids (of algebraic, measured, Lie, and symplectic type). In all cases, the arrows are isomorphism classes of appropriate bimodules, and their composition may be seen as a tensor product. Hence in suitable categories reduction is simply composition of arrows, and Morita equivalence is isomorphism of objects.Comment: 44 pages, categorical interpretation adde

The three-prong method: a novel assessment of residual stress in laser powder bed fusion

Residual stress is a major problem for most metal-based laser powder bed fusion (L-PBF) components. Residual stress can be reduced by appropriate build planning and post-process heat treatments; however, it is not always avoidable and can lead to build failures due to distortion and cracking. Accurate measurement of residual stress levels can be difficult due to high equipment set-up costs and long processing times. This paper introduces a simple but novel method of measuring residual stresses via a three-pronged cantilever component, the three-prong method (TPM). The method allows for a quick and easy characterisation of residual stress for a wide range of machine parameters, build strategies and materials. Many different cantilever designs have been used to indicate residual stress within additive manufacturing techniques. All of which share the same shortcoming that they indicate stress in one direction. If the principal component of stress is not aligned with the beam geometry, it will underestimate peak stress values. A novel three-prong design is proposed which covers two dimensions by utilising three adjoined cantilever beams, a configuration which echoes that of hole-drilling where three measurements are used to calculate the stress field around a drilled hole. Each arm of the component resembles a curved bridge-like structure; one end of each bridge is cut away from the base plate leaving the centre intact. Deformation of the beams is then measured using a co-ordinate measurement machine. Stress profiles are then estimated using finite element analysis by meshing the deflected structure and forcing it back to its original shape. In this paper, the new TPM is used to compare the residual stress levels of components built in Ti–6Al–4V with different hatch patterns, powers and exposure times