891 research outputs found

    Perception and Barriers to Indoor Air Quality and Perceived Impact on Respiratory Health: An Assessment in Rural Honduras

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    Objective. The aim of this study was to identify household-specific factors associated with respiratory symptoms and to study the perceived impact of indoor air pollution (IAP) as a health issue. Methods. An IRB-approved, voluntary, anonymous 23-item survey was conducted in Spanish at a medical outreach clinic in June 2012 and at the homes of survey respondents (N = 79). Comparative analyses were performed to investigate relationships between specific house characteristics and respiratory complaints. Results. Seventy-nine surveys were completed. Respiratory symptoms were frequently reported by survey respondents: 42% stated that smoke in their household caused them to have watery eyes, 42% reported household members with coughs within the past two weeks, and 25% stated that there were currently household members experiencing difficulty in breathing. Stove location and kitchen roof construction material were significantly associated with frequency of respiratory symptoms. The vast majority used firewood as their major fuel type. Most respondents indicated that neither indoor air quality was a problem nor did it affect their daily life. Conclusions. Respiratory complaints are common in Yoro, Honduras. Stove location and kitchen roof construction material were significantly associated with frequency of respiratory symptoms; this may have implications for efforts to improve respiratory health in the region

    Ultrasound Use in Resource-limited Settings: A Systematic Review

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    Purpose: Over the past decade, ultrasound (US) machines have become smaller, less expensive, more reliable, durable and user-friendly, making ultrasonography an ideal imaging modality in resource-poor settings. We conducted a literature review to examine the use of ultrasound in resource-limited settings, with emphasis on common applications, barriers to implementation, and impact on clinical decision-making and patient disposition. Methods and Materials: Literature review. We conducted a PubMed and Cochrane Central search on the clinical use of ultrasound in the developing world. Search terms included ultrasonography, developing countries, resource limited, remote setting, poverty, and low income. Articles from 2000 to 2015 that included data on the clinical use of ultrasound in resource limited settings were eligible for inclusion. Data on country of origin, medical specialty, US modality, clinical impact, and potential barriers to implementation were recorded. Results: Fifty-eight articles were eligible for inclusion. Most studies were observational, with Africa as the most common site, accounting for 35 articles. Radiology was the most represented specialty. Cardiac and obstetric were the most commonly utilized ultrasound modalities. Most data on cardiac ultrasound pertained to its role in the diagnosis of rheumatic heart disease. Obstetric ultrasound was primarily used for pregnancy dating and diagnosing fetal abnormalities. Twelve studies examined clinical impact of ultrasound in resource-limited settings and showed that its use dramatically altered differential diagnosis and patient disposition. Common barriers to implementation were the high cost of equipment and maintenance, and lack of skilled personnel and formal training programs. A commonly cited consequence of ultrasound use in resource-poor settings was sex-selective abortions. Conclusion: Ultrasound has widespread clinical applications, particularly as a diagnostic tool in the developing world. Significant barriers exist with respect to access and training of US in resource-limited settings. Further research is needed to study its impact on medical decision-making, patient disposition and outcomes

    How technology shapes assessment design: findings from a study of university teachers

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    A wide range of technologies has been developed to enhance assessment, but adoption has been inconsistent. This is despite assessment being critical to student learning and certification. To understand why this is the case and how it can be addressed, we need to explore the perspectives of academics responsible for designing and implementing technology-supported assessment strategies. This paper reports on the experience of designing technology-supported assessment based on interviews with 33 Australian university teachers. The findings reveal the desire to achieve greater efficiencies and to be contemporary and innovative as key drivers of technology adoption for assessment. Participants sought to shape student behaviors through their designs and made adaptations in response to positive feedback and undesirable outcomes. Many designs required modification because of a lack of appropriate support, leading to compromise and, in some cases, abandonment. These findings highlight the challenges to effective technology-supported assessment design and demonstrate the difficulties university teachers face when attempting to negotiate mixed messages within institutions and the demands of design work. We use these findings to suggest opportunities to improve support by offering pedagogical guidance and technical help at critical stages of the design process and encouraging an iterative approach to design

    Drag and inertia coefficients for horizontally submerged rectangular cylinders in waves and currents

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    The results of an experimental investigation carried out to measure combined wave and current loads on horizontally submerged square and rectangular cylinders are reported in this paper. The wave and current induced forces on a section of the cylinders with breadth-depth (aspect) ratios equal to 1, 0.5, and 0.75 are measured in a wave tank. The maximum value of Keulegan-Carpenter (KC) number obtained in waves alone is about 5 and Reynolds (Re) number ranged from 6.3976103 to 1.186105. The drag (CD) and inertia (CM) coefficients for each cylinder are evaluated using measured sectional wave forces and particle kinematics calculated from linear wave theory. The values of CD and CM obtained for waves alone have already been reported (Venugopal, V., Varyani, K. S., and Barltrop, N. D. P. Wave force coefficients for horizontally submerged rectangular cylinders. Ocean Engineering, 2006, 33, 11-12, 1669-1704) and the coefficients derived in combined waves and currents are presented here. The results indicate that both drag and inertia coefficients are strongly affected by the presenceof the current and show different trends for different cylinders. The values of the vertical component inertia coefficients (CMY) in waves and currents are generally smaller than the inertia coefficients obtained in waves alone, irrespective of the current's magnitude and direction. The results also illustrate the effect of a cylinder's aspect ratio on force coefficients. This study will be useful in the design of offshore structures whose columns and caissons are rectangular sections

    Romantic Partnerships and the Dispersion of Social Ties: A Network Analysis of Relationship Status on Facebook

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    A crucial task in the analysis of on-line social-networking systems is to identify important people --- those linked by strong social ties --- within an individual's network neighborhood. Here we investigate this question for a particular category of strong ties, those involving spouses or romantic partners. We organize our analysis around a basic question: given all the connections among a person's friends, can you recognize his or her romantic partner from the network structure alone? Using data from a large sample of Facebook users, we find that this task can be accomplished with high accuracy, but doing so requires the development of a new measure of tie strength that we term `dispersion' --- the extent to which two people's mutual friends are not themselves well-connected. The results offer methods for identifying types of structurally significant people in on-line applications, and suggest a potential expansion of existing theories of tie strength.Comment: Proc. 17th ACM Conference on Computer Supported Cooperative Work and Social Computing (CSCW), 201

    Exploring the utility of grids for analysing long term population change

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    This paper details an innovative approach which enables the analysis of small area population change across four decades. Population surfaces are generated using small area data (enumeration districts or output areas) for each Census from 1971 to 2011 inclusive. The paper details the methods used in the creation of these surfaces, and discusses the rationale behind this approach, arguing that grids represent the most appropriate model for assessing population distributions. Methods for grid creation are tested using pre-existing population grids for Northern Ireland as a benchmark. The method developed is then applied to create population grids for the rest of the UK for 1971, 1981, 1991, 2001 and 2011. The changing population structures of small areas across these five time points are explored here to illustrate the value of this approach. The publically-available data resource – the final product of the ‘PopChange’ project – will facilitate exploration of long-term changes in populations over small areas. The paper argues that maximum advantage could be taken of the ‘big data revolution’ if such data were gridded in a similar way, allowing them to be placed in a longer-term historical context, using tools made available through the PopChange project

    Suppression of force fluctuations in flow past an aerofoil

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    A comparative analysis of the skilled use of automated feedback tools through the lens of teacher feedback literacy

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    Effective learning depends on effective feedback, which in turn requires a set of skills, dispositions and practices on the part of both students and teachers which have been termed feedback literacy. A previously published teacher feedback literacy competency framework has identified what is needed by teachers to implement feedback well. While this framework refers in broad terms to the potential uses of educational technologies, it does not examine in detail the new possibilities of automated feedback (AF) tools, especially those that are open by offering varying degrees of transparency and control to teachers. Using analytics and artificial intelligence, open AF tools permit automated processing and feedback with a speed, precision and scale that exceeds that of humans. This raises important questions about how human and machine feedback can be combined optimally and what is now required of teachers to use such tools skillfully. The paper addresses two research questions: Which teacher feedback competencies are necessary for the skilled use of open AF tools? and What does the skilled use of open AF tools add to our conceptions of teacher feedback competencies? We conduct an analysis of published evidence concerning teachers’ use of open AF tools through the lens of teacher feedback literacy, which produces summary matrices revealing relative strengths and weaknesses in the literature, and the relevance of the feedback literacy framework. We conclude firstly, that when used effectively, open AF tools exercise a range of teacher feedback competencies. The paper thus offers a detailed account of the nature of teachers’ feedback literacy practices within this context. Secondly, this analysis reveals gaps in the literature, signalling opportunities for future work. Thirdly, we propose several examples of automated feedback literacy, that is, distinctive teacher competencies linked to the skilled use of open AF tools

    Reframing assessment research: through a practice perspective

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    Assessment as a field of investigation has been influenced by a limited number of perspectives. These have focused assessment research in particular ways that have emphasised measurement, or student learning or institutional policies. The aim of this paper is to view the phenomenon of assessment from a practice perspective drawing upon ideas from practice theory. Such a view places assessment practices as central. This perspective is illustrated using data from an empirical study of assessment decision-making and uses as an exemplar the identified practice of ‘bringing a new assessment task into being’. It is suggested that a practice perspective can position assessment as integral to curriculum practices and end separations of assessment from teaching and learning. It enables research on assessment to de-centre measurement and take account of the wider range of people, phenomena and things that constitute it

    Coarse-to-Fine Annotation Enrichment for Semantic Segmentation Learning

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    Rich high-quality annotated data is critical for semantic segmentation learning, yet acquiring dense and pixel-wise ground-truth is both labor- and time-consuming. Coarse annotations (e.g., scribbles, coarse polygons) offer an economical alternative, with which training phase could hardly generate satisfactory performance unfortunately. In order to generate high-quality annotated data with a low time cost for accurate segmentation, in this paper, we propose a novel annotation enrichment strategy, which expands existing coarse annotations of training data to a finer scale. Extensive experiments on the Cityscapes and PASCAL VOC 2012 benchmarks have shown that the neural networks trained with the enriched annotations from our framework yield a significant improvement over that trained with the original coarse labels. It is highly competitive to the performance obtained by using human annotated dense annotations. The proposed method also outperforms among other state-of-the-art weakly-supervised segmentation methods.Comment: CIKM 2018 International Conference on Information and Knowledge Managemen
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