1,861 research outputs found
The Deep Poincare Map: A Novel Approach for Left Ventricle Segmentation
Precise segmentation of the left ventricle (LV) within cardiac MRI images is a prerequisite for the quantitative measurement of heart function. However, this task is challenging due to the limited availability of labeled data and motion artifacts from cardiac imaging. In this work, we present an iterative segmentation algorithm for LV delineation. By coupling deep learning with a novel dynamic-based labeling scheme, we present a new methodology where a policy model is learned to guide an agent to travel over the image, tracing out a boundary of the ROI – using the magnitude difference of the Poincaré map as a stopping criterion. Our method is evaluated on two datasets, namely the Sunnybrook Cardiac Dataset (SCD) and data from the STACOM 2011 LV segmentation challenge. Our method outperforms the previous research over many metrics. In order to demonstrate the transferability of our method we present encouraging results over the STACOM 2011 data, when using a model trained on the SCD dataset
Clinical features and management of erythromelalgia: long term follow-up of 46 cases
OBJECTIVES: To review our clinical experience of this rare condition and describe the clinical features and response to therapy in a cohort of patients with erythromelalgia (EM), a rare condition, characterised by paroxysmal hyperthermia of the extremities with erythema, pain and intense burning. METHODS: A review was made of the electronic and paper medical records of patients with the diagnosis of EM, with a telephone interview to verify and complete clinical information relating treatment and outcome. RESULTS: 46 patients (41 females) were included in this study. Mean age was 57 years and mean duration of symptoms was 16 years. Raynaud's phenomenon was present in 36 patients (80%) and 4 patients (9%) had systemic sclerosis. Smoking (current or previous) was identified as a possible risk factor in 26 cases and exposure to chronic vibration in 3 cases. Overall, the effect on quality of life was mild in 15% of cases, moderate in 30% and severe in 48%. The most common symptoms were burning (96%), heat (93%), pain (87%), and redness (83%). Symptoms affected the lower limbs in 98% of cases, upper limbs in 76%, face in 20% and trunk in 11%. Triggers included heat (85%), exercise (78%) and time of day (76%). Various medications were tried, showing poor effect in most cases. Intravenous iloprost was given to 27 patients, with benefit in 17 patients (63%). CONCLUSIONS: Erythromelalgia is a rare chronic debilitating condition. Exercise, heat and night time are common triggers. Current medical therapies are seldom effective and further research is sorely needed
Beyond motivation: Job and work design for development, health, ambidexterity, and more
Much research shows it is possible to design motivating work, which has positive consequences for individuals and their organizations. This article reviews research that adopts this motivational perspective on work design, and it emphasizes that it is important to continue to refine motivational theories. In light of continued large numbers of poor-quality jobs, attention must also be given to influencing practice and policy to promote the effective implementation of enriched work designs. Nevertheless, current and future work-based challenges mean that designing work for motivation is necessary but insufficient. This review argues that work design can be a powerful vehicle for learning and development, for maintaining and enhancing employees' physical and mental health, and for achieving control and flexibility simultaneously (for example, in the form of ambidexterity); all these outcomes are important given the challenges in today's workplaces. The review concludes by suggesting methodological directions
Sperm design and variation in the New World blackbirds (Icteridae)
Post-copulatory sexual selection (PCSS) is thought to be one of the evolutionary forces responsible for the rapid and divergent evolution of sperm design. However, whereas in some taxa particular sperm traits are positively associated with PCSS, in other taxa, these relationships are negative, and the causes of these different patterns across taxa are poorly understood. In a comparative study using New World blackbirds (Icteridae), we tested whether sperm design was influenced by the level of PCSS and found significant positive associations with the level of PCSS for all sperm components but head length. Additionally, whereas the absolute length of sperm components increased, their variation declined with the intensity of PCSS, indicating stabilizing selection around an optimal sperm design. Given the diversity of, and strong selection on, sperm design, it seems likely that sperm phenotype may influence sperm velocity within species. However, in contrast to other recent studies of passerine birds, but consistent with several other studies, we found no significant link between sperm design and velocity, using four different species that vary both in sperm design and PCSS. Potential reasons for this discrepancy between studies are discussed
Ultrasound-guided core-needle biopsy of breast lesions
Ultrasound-guided CNB has proven to be a reliable technique for performing a biopsy for breast lesions that can be clearly seen on ultrasoun
Spatially Explicit Data: Stewardship and Ethical Challenges in Science
Scholarly communication is at an unprecedented turning point created in part by the increasing saliency of data stewardship and data sharing. Formal data management plans represent a new emphasis in research, enabling access to data at higher volumes and more quickly, and the potential for replication and augmentation of existing research. Data sharing has recently transformed the practice, scope, content, and applicability of research in several disciplines, in particular in relation to spatially specific data. This lends exciting potentiality, but the most effective ways in which to implement such changes, particularly for disciplines involving human subjects and other sensitive information, demand consideration. Data management plans, stewardship, and sharing, impart distinctive technical, sociological, and ethical challenges that remain to be adequately identified and remedied. Here, we consider these and propose potential solutions for their amelioration
Satellite mapping in cities and below cities: how good is it now?
Global navigation satellite systems (GNSS) have existed since the launch of the US global positioning system constellation in 1978. There is an increasing need for better maps in the digital age, particularly for buried utilities. One of the most convenient methods for creating accurate maps is the use of navigation satellites for positioning. However, built-up urban areas are not ideal for the use of this positioning technology. This paper provides an update on the situation regarding GNSS and assesses how new satellites and signals are contributing to better positioning availability by carrying out a test in a controlled environment. The results show that using combined satellite systems improves availability in urban canyons in some cases, but not in all scenarios. In addition, pipeline mapping technology has been tested and been shown to be an effective means of mapping pipes deep under the ground over short distances
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Enriched job design, high involvement management and organizational performance: The mediating roles of job satisfaction and well-being
The relationship between organizational performance and two dimensions of the 'high performance work system' - enriched job design and high involvement management (HIM) - is widely assumed to be mediated by worker well-being. We outline the basis for three models: mutual-gains, in which employee involvement increases well-being and this mediates its positive relationship with performance; conflicting outcomes, which associates involvement with increased stress for workers, accounting for its positive performance effects; and counteracting effects, which associates involvement with increased stress and dissatisfaction, reducing its positive performance effects. These are tested using the UK's Workplace Employment Relations Survey 2004. Job satisfaction mediates the relationship between enriched job design and four performance indicators, supporting the mutual gains model; but HIM is negatively related to job satisfaction and this depresses a positive relationship between HIM and the economic performance measures, supporting a counteracting effects model. Finally, HIM is negatively related to job-related anxiety-comfort and enriched job design is unrelated to it. © The Author(s) 2012
Conceptualizing pathways linking women's empowerment and prematurity in developing countries.
BackgroundGlobally, prematurity is the leading cause of death in children under the age of 5. Many efforts have focused on clinical approaches to improve the survival of premature babies. There is a need, however, to explore psychosocial, sociocultural, economic, and other factors as potential mechanisms to reduce the burden of prematurity. Women's empowerment may be a catalyst for moving the needle in this direction. The goal of this paper is to examine links between women's empowerment and prematurity in developing settings. We propose a conceptual model that shows pathways by which women's empowerment can affect prematurity and review and summarize the literature supporting the relationships we posit. We also suggest future directions for research on women's empowerment and prematurity.MethodsThe key words we used for empowerment in the search were "empowerment," "women's status," "autonomy," and "decision-making," and for prematurity we used "preterm," "premature," and "prematurity." We did not use date, language, and regional restrictions. The search was done in PubMed, Population Information Online (POPLINE), and Web of Science. We selected intervening factors-factors that could potentially mediate the relationship between empowerment and prematurity-based on reviews of the risk factors and interventions to address prematurity and the determinants of those factors.ResultsThere is limited evidence supporting a direct link between women's empowerment and prematurity. However, there is evidence linking several dimensions of empowerment to factors known to be associated with prematurity and outcomes for premature babies. Our review of the literature shows that women's empowerment may reduce prematurity by (1) preventing early marriage and promoting family planning, which will delay age at first pregnancy and increase interpregnancy intervals; (2) improving women's nutritional status; (3) reducing domestic violence and other stressors to improve psychological health; and (4) improving access to and receipt of recommended health services during pregnancy and delivery to help prevent prematurity and improve survival of premature babies.ConclusionsWomen's empowerment is an important distal factor that affects prematurity through several intervening factors. Improving women's empowerment will help prevent prematurity and improve survival of preterm babies. Research to empirically show the links between women's empowerment and prematurity is however needed
Dispersal: an alternative mating tactic conditional on sex ratio and body size
Small male milkweed beetles are less successful at obtaining mates than are larger males. Larger males usually win fights and prevent smaller males from obtaining mates and from choosing larger more fecund females as mates. When sex ratios are male-biased, smaller males are particularly likely to experience these mating disadvantages. It follows that smaller males should be especially responsive to their local competitive environment and behave so as to minimize the mating disadvantages of their smaller size. This paper tests the hypothesis that smaller males disperse from host plant patches with male-biased sex ratios and remain in patches with female-biased sex ratios more readily than larger males.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46883/1/265_2004_Article_BF00299931.pd
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