428 research outputs found

    The autoimmune rheumatic diseases – an introduction

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    We have brought together opinion leaders to provide up to date reviews on common autoimmune rheumatic diseases with clinically relevant diagnostic and management strategies, as well as insightful updates on pathogenesis, classification and outcomes

    The role of art education in adult prisons: The Western Australian experience

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    Incarceration costs are high; in Australia, for example, each prisoner costs an average of AUD 115,000 per year. Other countries are also feeling the fiscal pinch of high incarceration costs, and a number of jurisdictions are now closing some of their prisons. Most prison costs are non-discretionary (accommodation, meals, etc.). But some of the costs relate to discretionary activities, services and facilities (including schooling). In terms of correctional education, many prison managers try to invest any meagre correctional education resources available to them in those classes and courses which have proven to have the best results, such as improved labour market outcomes and reduced recidivism, minimising subsequent re-imprisonment. Course offers for prisoner-students include vocational training, adult basic education (ABE) and art studies. The two-tiered question this paper asks is: do art classes and courses produce these measurable outcomes and, if not, are there other reasons why they should continue to be funded? Addressing these issues, the authors argue that (1) these measurable outcomes are too narrow and do not reflect the complex but less quantifiable benefits to the individual and the community of studying art in prison, and (2) better measures of all impacts of art studies in prisons are needed, including qualitative and humanitarian aspects

    Does monitor position influence visual-motor performance during minimally invasive surgery?

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    Background: In minimally invasive surgery (MIS), the natural relationship between hand and eye is disrupted, i.e. surgeons typically control tools inserted through the patient’s abdomen while viewing the workspace on a remote monitor, which can be located in a variety of positions. This separates the location of visual feedback from the area in which a motor action is executed. Previous studies suggest that the visual display should be placed directly ahead of the surgeon (i.e. to preserve visual-motor mapping). However, the extent of the impact of this rotation on surgical performance is unknown. Methods: Eighteen participants completed an aiming task on a tablet PC within a surgical box trainer using a laparoscopic tool in a controlled simulated environment. Visual feedback was presented on a remote monitor located at 0°, ±45° and ±90°, with order randomised using the Latin Square method. Results: Movements were significantly slower when the monitor was 90° relative to midline, but spatial accuracy was unaffected by monitor position. Interestingly, the effect of reduced speed in the 90° condition was transient, decreasing over time, suggesting rapid adaptation to the rotation. Conclusions: We conclude that the angle of the visual display in the context of MIS may require a surgeon to adapt to a changed mapping between visual inputs and motor outputs. While this adaptation occurs relatively quickly, it may interfere with skilled actions (e.g. intracorporeal suturing) in complex surgical procedures

    Hot new directions for quasi-Monte Carlo research in step with applications

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    This article provides an overview of some interfaces between the theory of quasi-Monte Carlo (QMC) methods and applications. We summarize three QMC theoretical settings: first order QMC methods in the unit cube [0,1]s[0,1]^s and in Rs\mathbb{R}^s, and higher order QMC methods in the unit cube. One important feature is that their error bounds can be independent of the dimension ss under appropriate conditions on the function spaces. Another important feature is that good parameters for these QMC methods can be obtained by fast efficient algorithms even when ss is large. We outline three different applications and explain how they can tap into the different QMC theory. We also discuss three cost saving strategies that can be combined with QMC in these applications. Many of these recent QMC theory and methods are developed not in isolation, but in close connection with applications

    Preoperative imaging in patients undergoing trachelectomy for cervical cancer: validation of a combined T2- and diffusion-weighted endovaginal MRI technique at 3.0 T.

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    Aim The aim of this study is to validate high-resolution endovaginal T2- and diffusion-weighted MRI measurements (tumour size, volume and length of uninvolved cervical canal) against histology in patients undergoing trachelectomy.Patients/interventions 55 consecutive patients 25-44 years with cervical cancer being considered for trachelectomy were prospectively assessed with endovaginal T2-W and diffusion-weighted MRI. Two independent observers blinded to histology recorded maximum tumour dimension, volume and distance from the superior aspect of the tumour to the internal os. Following trachelectomy, pathologist-outlined tumour sections were photographed with a set scale and similar measurements were recorded.Results Fifteen of 45 patients subsequently treated with fertility-sparing surgery had residual tumour (median histological volume: 0.28 cm(3), IQR=0.14-1.06 cm(3)). Sensitivity, specificity, positive and negative predictive values for detecting tumour: Observer 1: 86.7%, 80.0%, 68.4%, and 92.3%, respectively; Observer 2: 86.7%, 90.0%, 81.0%, and 93.1%, respectively. Size and volume correlated between observers (r=0.96, 0.84, respectively, p<0.0001). Size correlated between each observer and histology (observer 1 r=0.91, p<0.0001; observer 2 r=0.93, p<0.0001), volume did not (observer 1: r=0.08, p=0.6; observer 2: r=0.21, p=0.16); however, differences between observer measurements and histology were not significant (size p=0.09, volume p=0.15). Differences between MRI and histology estimates of endocervical canal length were not significant (p=0.1 both observers).Conclusion In subcentimetre cervical cancers, endovaginal MRI correlates with pathology and is invaluable in assessing patients for fertility-sparing surgery

    Comparison of optimised endovaginal vs external array coil T2-weighted and diffusion-weighted imaging techniques for detecting suspected early stage (IA/IB1) uterine cervical cancer.

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    Objective To compare sensitivity and specificity of endovaginal versus external-array coil T2-W and T2-W + DWI for detecting and staging small cervical tumours.Methods Optimised endovaginal and external array coil MRI at 3.0-T was done prospectively in 48 consecutive patients with stage Ia/Ib1 cervical cancer. Sensitivity/specificity for detecting tumour and parametrial extension against histopathology for a reading radiologist were determined on coronal T2-W and T2W + DW images. An independent radiologist also scored T2-W images without and with addition of DWI for the external-array and endovaginal coils on separate occasions >2 weeks apart. Cohen's kappa assessed inter- and intra-observer agreement.Results Median tumour volume in 19/38 cases positive on subsequent histology was 1.75 cm(3). Sensitivity, specificity, PPV, NPV were: reading radiologist 91.3 %, 89.5 %, 91.3 %, 89.5 %, respectively; independent radiologist T2-W 82.6 %, 73.7 %, 79.1 %, 77.8 % for endovaginal, 73.9 %, 89.5 %, 89.5 %, 73.9 % for external-array coil. Adding DWI improved sensitivity and specificity of endovaginal imaging (78.2 %, 89.5 %); adding DWI to external-array imaging improved specificity (94.7 %) but reduced sensitivity (66.7 %). Inter- and intra-observer agreement on T2-W + DWI was good (kappa = 0.67 and 0.62, respectively).Conclusion Endovaginal coil T2-W MRI is more sensitive than external-array coil for detecting tumours <2 cm(3); adding DWI improves specificity of endovaginal imaging but reduces sensitivity of external-array imaging.Key points • Endovaginal more accurate than external-array T2-W MRI for detecting small cervical cancers. • Addition of DWI improves sensitivity and specificity of endovaginal T2-W imaging. • Addition of DWI substantially reduces sensitivity of external-array T2-W imaging

    Endovaginal magnetic resonance imaging of stage 1A/1B cervical cancer with A T2- and diffusion-weighted magnetic resonance technique: effect of lesion size and previous cone biopsy on tumor detectability.

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    Objective To evaluate the effects of previous cone biopsy and lesion size on detectability of stage 1a/1b cervical cancer using endovaginal T2- and diffusion-weighted magnetic resonance imaging.Methods One hundred and thirteen patients with cervical tumor were imaged using an endovaginal coil with T2-weighted (T2-W) and diffusion-weighted single-shot echo-planar sequences; 85 managed surgically (58 with prior cone biopsy/LLETZ) were evaluated. T2-W images and ADC maps viewed simultaneously were scored positive or negative for tumor and compared with histology at surgery. MRI tumor volumes, maximum radiological and histological dimensions were recorded. ROC analysis determined the MRI volume with optimal sensitivity/specificity for identifying tumor in those without and with prior cone biopsy/LLETZ and the maximum histological dimension for correctly identifying tumor with MRI. Mean apparent diffusion coefficients (ADCs) from tumor and adjacent normal epithelium were compared.Results Sensitivity and specificity for detecting tumor in those without (100%; 100% respectively) and with (80%; 78.9% respectively) prior cone biopsy/LLETZ were significantly different (p<0.001). Following cone biopsy/LLETZ, MRI tumor volume of 83 mm3 detected tumor with 80% sensitivity, 94.7% specificity; a 5.3mm maximal histological dimension was detected on MRI with 100% sensitivity, 100% specificity. Tumor ADCs were significantly lower (p<0.001) than paired normal epithelial tissue (median, 988×10(-6) mm2/s vs. 1564×10(-6) mm2/s) but neither tumor nor epithelial ADCs differed significantly between patients with or without prior cone biopsy/LLETZ (p=0.48 and 0.15, respectively).Conclusions Endovaginal MRI with T2- and diffusion-weighted sequences has significantly lower sensitivity and specificity for tumor detection following cone biopsy/LLETZ

    The holographic principle

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    There is strong evidence that the area of any surface limits the information content of adjacent spacetime regions, at 10^(69) bits per square meter. We review the developments that have led to the recognition of this entropy bound, placing special emphasis on the quantum properties of black holes. The construction of light-sheets, which associate relevant spacetime regions to any given surface, is discussed in detail. We explain how the bound is tested and demonstrate its validity in a wide range of examples. A universal relation between geometry and information is thus uncovered. It has yet to be explained. The holographic principle asserts that its origin must lie in the number of fundamental degrees of freedom involved in a unified description of spacetime and matter. It must be manifest in an underlying quantum theory of gravity. We survey some successes and challenges in implementing the holographic principle.Comment: 52 pages, 10 figures, invited review for Rev. Mod. Phys; v2: reference adde

    Greater incidence of depression with hypnotic use than with placebo

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    Abstract Background Although it has been claimed that insomnia causes an increased risk for depression, adequate controlled trials testing this hypothesis have not been available. This study contrasted the incidence of depression among subjects receiving hypnotics in randomized controlled trials versus those receiving placebo. Methods The incidence of depression among patients randomized to hypnotic drugs or placebo was compiled from prescribing information approved by the United States Food and Drug Administration (FDA) and from FDA New Drug Application documents. Available data for zolpidem, zaleplon, eszopiclone, and ramelteon were accessed. Results Data for 5535 patients randomized to a hypnotic and for 2318 randomized to placebo were compiled. The incidence of depression was 2.0% among participants randomized to hypnotics as compared to 0.9% among those randomized in parallel to placebo (p Conclusion Modern hypnotics were associated with an increased incidence of depression in data released by the FDA. This suggests that when there is a risk of depression, hypnotics may be contra-indicated. Preventive treatments such as antidepressant drugs, cognitive-behavioral therapy, or bright light might be preferred. Limitations in the FDA data prevented a formal meta-analysis, and there was a lack of information about drop-out rates and definitions of depression. Trials specifically designed to detect incident depression when treating insomnia with hypnotic drugs and better summarization of adverse events in trials submitted to the FDA are both necessary.</p
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