227 research outputs found

    Extruded Monofilament and Multifilament Thermoplastic Stitching Yarns

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    Carbon fibre reinforced polymer composites offer significant improvement in overall material strength to weight, when compared with metals traditionally used in engineering. As a result, they are replacing metals where overall weight is a significant consideration, such as in the aerospace and automotive industries. However, due to their laminate structure, delamination is a prime concern. Through-thickness stitching has been shown to be a relatively simple method of improving resistance to delamination. In this paper, monofilament and multifilament fibres of a similar overall diameter were characterised and their properties compared for their suitability as stitching yarns. Dissimilar to other published works which rely on commercially available materials, such as polyparaphenylene terephthalamide, criteria were produced on the required properties and two potentially promising polymers were selected for extrusion. It was found that although the multifilament fibres had a greater ultimate tensile strength, they began to yield at a lower force than their monofilament equivalent

    Pure iterative reconstruction improves image quality in computed tomography of the abdomen and pelvis acquired at substantially reduced radiation doses in patients with active Crohn disease

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    Objective: We assessed diagnostic accuracy and image quality of modified protocol (MP) computed tomography (CT) of the abdomen and pelvis reconstructed using pure iterative reconstruction (IR) in patients with Crohn disease (CD). Methods: Thirty-four consecutive patients with CD were referred with suspected extramural complications. Two contemporaneous CT datasets were acquired in all patients: standard protocol (SP) and MP. The MP and SP protocols were designed to impart radiation exposures of 10% to 20% and 80% to 90% of routine abdominopelvic CT, respectively. The MP images were reconstructed with model-based IR (MBIR) and adaptive statistical IR (ASIR). Results: The MP-CT and SP-CT dose length product were 88 (58) mGy.cm (1.27 [0.87] mSv) and 303 [204] mGy.cm (4.8 [2.99] mSv), respectively (P < 0.001). Median diagnostic acceptability, spatial resolution, and contrast resolution were significantly higher and subjective noise scores were significantly lower on SP-ASIR 40 compared with all MP datasets. There was perfect clinical agreement between MP-MBIR and SP-ASIR 40 images for detection of extramural complications. Conclusions: Modified protocol CT using pure IR is feasible for assessment of active CD

    Young children’s impressionable use of teleology: the influence of question wording and questioned topic on teleological explanations for natural phenomena

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    There is a significant body of research on children's preconceptions concerning scientific concepts and the impact this has upon their science education. One active issue concerns the extent to which young children's explanations for the existence of natural kinds rely on a teleological rationale: for example, rain is for watering the grass, or tigers’ stripes are for camouflage. It has been argued that this teleological tendency hampers children's ability to learn about causality in the natural world. This paper investigates two factors (question wording and topic) which it is argued have led to a misestimation of children's teleological tendencies within the area natural phenomena: i.e., those that are time-constrained, natural events or process such as snow, clouds or night. Sixty-six (5- to 8-years-old) children took part in a repeated-measures experiment, answering both open- and leading-questions across 10 topics of natural phenomena. The findings indicate that children's teleological reasoning may have been overestimated as open question forms significantly reduced their tendency to answer teleologically. Moreover, the concept of teleology is more nuanced than often suggested. Consequently, young children may be more able to learn about causal explanations for the existence of natural phenomena than the literature implies

    Monitoring and evaluation of breast cancer screening programmes : Selecting candidate performance indicators

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    In the scope of the European Commission Initiative on Breast Cancer (ECIBC) the Monitoring and Evaluation (M&E) subgroup was tasked to identify breast cancer screening programme (BCSP) performance indicators, including their acceptable and desirable levels, which are associated with breast cancer (BC) mortality. This paper documents the methodology used for the indicator selection. The indicators were identified through a multi-stage process. First, a scoping review was conducted to identify existing performance indicators. Second, building on existing frameworks for making well-informed health care choices, a specific conceptual framework was developed to guide the indicator selection. Third, two group exercises including a rating and ranking survey were conducted for indicator selection using pre-determined criteria, such as: relevance, measurability, accurateness, ethics and understandability. The selected indicators were mapped onto a BC screening pathway developed by the M&E subgroup to illustrate the steps of BC screening common to all EU countries. A total of 96 indicators were identified from an initial list of 1325 indicators. After removing redundant and irrelevant indicators and adding those missing, 39 candidate indicators underwent the rating and ranking exercise. Based on the results, the M&E subgroup selected 13 indicators: screening coverage, participation rate, recall rate, breast cancer detection rate, invasive breast cancer detection rate, cancers > 20 mm, cancers ≤10 mm, lymph node status, interval cancer rate, episode sensitivity, time interval between screening and first treatment, benign open surgical biopsy rate, and mastectomy rate. This systematic approach led to the identification of 13 BCSP candidate performance indicators to be further evaluated for their association with BC mortality

    The Internet and HIV study: design and methods

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    BACKGROUND: The Internet provides a new meeting ground, especially for gay men, that did not exist in the early 1990s. Several studies have found increased levels of high risk sexual behaviour and sexually transmissible infections (STI) among gay men who seek sex on the Internet, although the underlying processes are not fully understood. Research funded by the UK Medical Research Council (2002–2004) provided the opportunity to consider whether the Internet represents a new sexual risk environment for gay and bisexual men living in London. METHODS: The objectives of the Internet and HIV study are to: (i) measure the extent to which gay men living in London seek sexual partners on the Internet; (ii) compare the characteristics of London gay men who do and do not seek sex on the Internet; (iii) examine whether sex with Internet-partners is less safe than with other sexual partners; (iv) compare use of the Internet with other venues where men meet sexual partners; (v) establish whether gay men use the Internet to actively seek partners for unprotected anal intercourse; (vi) determine the potential for using the Internet for HIV prevention. These objectives have been explored using quantitative and qualitative research methods in four samples of London gay men recruited and interviewed both online and offline. The four samples were: (i) gay men recruited through Internet chat rooms and profiles; (ii) HIV positive gay men attending an NHS hospital outpatients clinic; (iii) gay men seeking an HIV test in an NHS HIV testing or sexual health clinic; (iv) gay men recruited in the community. RESULTS: Quantitative data were collected by means of confidential, anonymous self-administered questionnaires (n>4000) completed on-line by the Internet sample. Qualitative data were collected by means of one-to-one interviews (n = 128) conducted either face-to-face or on-line. CONCLUSION: The strength of the Internet and HIV study is its methodological plurality, drawing on both qualitative and quantitative research among online and offline samples, as well as taking advantage of recent advances in web survey design. The study's findings will help us better understand the role of the Internet in relation to gay men's sexual practic

    Embedding open and reproducible science into teaching: A bank of lesson plans and resources

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    Recently, there has been a growing emphasis on embedding open and reproducible approaches into research. One essential step in accomplishing this larger goal is to embed such practices into undergraduate and postgraduate research training. However, this often requires substantial time and resources to implement. Also, while many pedagogical resources are regularly developed for this purpose, they are not often openly and actively shared with the wider community. The creation and public sharing of open educational resources is useful for educators who wish to embed open scholarship and reproducibility into their teaching and learning. In this article, we describe and openly share a bank of teaching resources and lesson plans on the broad topics of open scholarship, open science, replication, and reproducibility that can be integrated into taught courses, to support educators and instructors. These resources were created as part of the Society for the Improvement of Psychological Science (SIPS) hackathon at the 2021 Annual Conference, and we detail this collaborative process in the article. By sharing these open pedagogical resources, we aim to reduce the labour required to develop and implement open scholarship content to further the open scholarship and open educational materials movement
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