83 research outputs found

    Proposed specifications of a mobile operating room for far-forward surgery

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    Provision of initial surgery to casualties within one hour of injury is associated with better survival. Where evacuation options are limited, surgery within the “golden hour” may have to occur close to the point of injury. Interventions close to the point of injury are limited by the adverse environment. Far-forward surgery has a long history going back to Dominique Larrey of the Napoleonic Army. We reviewed previous reports and used our own experience of far- forward surgery to describe the specifications of the ideal mobile operating room that would address some of these environmental barriers

    Langerhans cell histiocytosis of the sternum

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    We report a rare case of Langerhans cell histiocytosis involving the sternum. The patient was a 12-year-old girl presenting with anterior chest pain and swelling. Radiographs and computed tomography showed an osteolytic lesion in the sternum. Technetium bone scintigraphy revealed increased uptakes in the sternum, the greater trochanter of the right femur, and the right distal tibia. Incisional biopsy for the sternum lesion was performed, and the histopathologic diagnosis was Langerhans cell histiocytosis. She was treated with chemotherapy and the symptoms disappeared

    Nutrients cause grassland biomass to outpace herbivory

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    Human activities are transforming grassland biomass via changing climate, elemental nutrients, and herbivory. Theory predicts that food-limited herbivores will consume any additional biomass stimulated by nutrient inputs ('consumer-controlled'). Alternatively, nutrient supply is predicted to increase biomass where herbivores alter community composition or are limited by factors other than food ('resource-controlled'). Using an experiment replicated in 58 grasslands spanning six continents, we show that nutrient addition and vertebrate herbivore exclusion each caused sustained increases in aboveground live biomass over a decade, but consumer control was weak. However, at sites with high vertebrate grazing intensity or domestic livestock, herbivores consumed the additional fertilization-induced biomass, supporting the consumer-controlled prediction. Herbivores most effectively reduced the additional live biomass at sites with low precipitation or high ambient soil nitrogen. Overall, these experimental results suggest that grassland biomass will outstrip wild herbivore control as human activities increase elemental nutrient supply, with widespread consequences for grazing and fire risk

    The outlook of building information modeling for sustainable development

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    As human needs evolve, information technologies and natural environments require a wider perspective of sustainable development, especially when examining the built environment that impacts the central of social-ecological systems. The objectives of the paper are (a) to review the status and development of building information modeling (BIM) in regards to the sustainable development in the built environment, and (b) to develop a future outlook framework that promotes BIM in sustainable development. Seven areas of sustainability were classified to analyze forty-four BIM guidelines and standards. This review examines the use of BIM in sustainable development, focusing primarily on certain areas of sustainability, such as project development, design, and construction. The developed framework describes the need for collaboration with the multiple disciplines for the future adoption and use of BIM for the sustainable development. It also considers the integration between “BIM and green assessment criteria”; and “BIM and renewable energy” to address the shortcomings of the standards and guidelines

    Analysis of ecological thresholds in a temperate forest undergoing dieback.

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    Positive feedbacks in drivers of degradation can cause threshold responses in natural ecosystems. Though threshold responses have received much attention in studies of aquatic ecosystems, they have been neglected in terrestrial systems, such as forests, where the long time-scales required for monitoring have impeded research. In this study we explored the role of positive feedbacks in a temperate forest that has been monitored for 50 years and is undergoing dieback, largely as a result of death of the canopy dominant species (Fagus sylvatica, beech). Statistical analyses showed strong non-linear losses in basal area for some plots, while others showed relatively gradual change. Beech seedling density was positively related to canopy openness, but a similar relationship was not observed for saplings, suggesting a feedback whereby mortality in areas with high canopy openness was elevated. We combined this observation with empirical data on size- and growth-mediated mortality of trees to produce an individual-based model of forest dynamics. We used this model to simulate changes in the structure of the forest over 100 years under scenarios with different juvenile and mature mortality probabilities, as well as a positive feedback between seedling and mature tree mortality. This model produced declines in forest basal area when critical juvenile and mature mortality probabilities were exceeded. Feedbacks in juvenile mortality caused a greater reduction in basal area relative to scenarios with no feedback. Non-linear, concave declines of basal area occurred only when mature tree mortality was 3-5 times higher than rates observed in the field. Our results indicate that the longevity of trees may help to buffer forests against environmental change and that the maintenance of old, large trees may aid the resilience of forest stands. In addition, our work suggests that dieback of forests may be avoidable providing pressures on mature and juvenile trees do not pass critical thresholds

    Synergistic Interactions between the NS3hel and E Proteins Contribute to the Virulence of Dengue Virus Type 1

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    Dengue virus constitutes a significant public health problem in tropical regions of the world. Despite the high morbidity and mortality of this infection, no effective antiviral drugs or vaccines are available for the treatment or prevention of dengue infections. The profile of clinical signs associated with dengue infection has changed in recent years with an increase in the number of episodes displaying unusual signs. We use reverse genetics technology to engineer DENV-1 viruses with subsets of mutations previously identified in highly neurovirulent strains to provide insights into the molecular mechanisms underlying dengue neuropathogenesis. We found that single mutations affecting the E and NS3hel proteins, introduced in a different genetic context, had a synergistic effect increasing DENV replication capacity in human and mosquito derived cells in vitro. We also demonstrated correlations between the presence of these mutations and viral replication efficiency, viral loads, the induction of innate immune response genes and pathogenesis in a mouse model. These results should improve our understanding of the DENV-host cell interaction and contribute to the development of effective antiviral strategies
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