428 research outputs found

    Acid-yield measurements of the gas-phase ozonolysis of ethene as a function of humidity using Chemical Ionisation Mass Spectrometry (CIMS)

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    Gas-phase ethene ozonolysis experiments were conducted at room temperature to determine formic acid yields as a function of relative humidity (RH) using the integrated EXTreme RAnge chamber-Chemical Ionisation Mass Spectrometry technique, employing a CH<sub>3</sub>I ionisation scheme. RHs studied were <1, 11, 21, 27, 30 % and formic acid yields of (0.07±0.01) and (0.41±0.07) were determined at <1 % RH and 30 % RH respectively, showing a strong water dependence. It has been possible to estimate the ratio of the rate coefficient for the reaction of the Criegee biradical, CH<sub>2</sub>OO with water compared with decomposition. This analysis suggests that the rate of reaction with water ranges between 1×10<sup>−12</sup>–1×10<sup>−15</sup> cm<sup>3</sup> molecule<sup>−1</sup> s<sup>−1</sup> and will therefore dominate its loss with respect to bimolecular processes in the atmosphere. Global model integrations suggest that this reaction between CH<sub>2</sub>OO and water may dominate the production of HC(O)OH in the atmosphere

    Is the Insect Apocalypse upon us? How to Find Out

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    In recent decades, entomologists have documented alarming declines in occurrence, taxonomic richness, and geographic range of insects around the world. Additionally, some recent studies have reported that insect abundance and biomass, often of common species, are rapidly declining, which has led some to dub the phenomenon an “Insect Apocalypse”. Recent reports are sufficiently robust to justify immediate actions to protect insect biodiversity worldwide. We caution, however, that we do not yet have the data to assess large-scale spatial patterns in the severity of insect trends. Most documented collapses are from geographically restricted studies and, alone, do not allow us to draw conclusions about insect declines on continental or global scales, especially with regards to future projections of total insect biomass, abundance, and extinction. There are many challenges to understanding insect declines: only a small fraction of insect species have had any substantial population monitoring, millions of species remain unstudied, and most of the long-term population data for insects come from human-dominated landscapes in western and northern Europe. But there are still concrete steps we can take to improve our understanding of potential declines. Here, we review the challenges scientists face in documenting insect population and diversity trends, including communicating their findings, and recommend research approaches needed to address these challenges

    Outdoor learning spaces: the case of forest school

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    © 2017 The Author. Area published by John Wiley & Sons Ltd on behalf of Royal Geographical Society (with the Institute of British Geographers). This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.This paper contributes to the growing body of research concerning use of outdoor spaces by educators, and the increased use of informal and outdoor learning spaces when teaching primary school children. The research takes the example of forest school, a form of regular and repeated outdoor learning increasingly common in primary schools. This research focuses on how the learning space at forest school shapes the experience of children and forest school leaders as they engage in learning outside the classroom. The learning space is considered as a physical space, and also in a more metaphorical way as a space where different behaviours are permitted, and a space set apart from the national curriculum. Through semi-structured interviews with members of the community of practice of forest school leaders, the paper seeks to determine the significance of being outdoors on the forest school experience. How does this learning space differ from the classroom environment? What aspects of the forest school learning space support pupils’ experiences? How does the outdoor learning space affect teaching, and the dynamics of learning while at forest school? The research shows that the outdoor space provides new opportunities for children and teachers to interact and learn, and revealed how forest school leaders and children co-create a learning environment in which the boundaries between classroom and outdoor learning, teacher and pupil, are renegotiated to stimulate teaching and learning. Forest school practitioners see forest school as a separate learning space that is removed from the physical constraints of the classroom and pedagogical constraints of the national curriculum to provide a more flexible and responsive learning environment.Peer reviewe

    Project MOSI: rationale and pilot-study results of an initiative to help protect zoo animals from mosquito-transmitted pathogens and contribute data on mosquito spatio–temporal distribution change

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    Mosquito-borne pathogens pose major threats to both wildlife and human health and, largely as a result of unintentional human-aided dispersal of their vector species, their cumulative threat is on the rise. Anthropogenic climate change is expected to be an increasingly significant driver of mosquito dispersal and associated disease spread. The potential health implications of changes in the spatio-temporal distribution of mosquitoes highlight the importance of ongoing surveillance and, where necessary, vector control and other health-management measures. The World Association of Zoos and Aquariums initiative, Project MOSI, was established to help protect vulnerable wildlife species in zoological facilities from mosquito-transmitted pathogens by establishing a zoo-based network of fixed mosquito monitoring sites to assist wildlife health management and contribute data on mosquito spatio-temporal distribution changes. A pilot study for Project MOSI is described here, including project rationale and results that confirm the feasibility of conducting basic standardized year-round mosquito trapping and monitoring in a zoo environment

    Infrainguinal arterial reconstruction for claudication: Is it worth the risk? An analysis of 409 procedures

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    AbstractPurpose: Infrainguinal reconstruction traditionally has been reserved for patients with limb-threatening ischemia. Surgery for debilitating claudication, however, has been discouraged as a result of the perceived fear of bypass graft failure, limb loss, and significant perioperative complications that may be worse than the natural history of the disease. In this study, the results of infrainguinal reconstructions for claudication performed during the past 10 years were evaluated for bypass graft patency, limb loss, and long-term survival rates. Methods: Data were collected and reviewed from the vascular registry, the office charts, and the hospital records for patients who underwent infrainguinal bypass grafting for claudication. Results: From 1987 to 1997, 409 infrainguinal reconstructions were performed for claudication (9% of all infrainguinal reconstructions in our unit). The patient population had the following demographics: 73% men, 28% with diabetes, 54% smokers, and an average age of 64 years (range, 24 to 91 years). Inflow was from the following arteries: iliac artery/graft, 10%; common femoral artery, 52%; superficial femoral artery, 19%; profunda femoris artery, 16%; and popliteal artery, 2%. The outflow vessels were the following arteries: 165 above-knee popliteal arteries (40%), 150 below-knee popliteal arteries (37%), and 94 tibial vessels (23%). The operative mortality rate was 0%, and one limb was lost in the series from distal embolization. The primary patency rates were 62%, 77%, and 86% for above-knee popliteal artery, below-knee popliteal artery, and tibial vessel reconstructions at 4 years, and the secondary patency rates were 64%, 81%, and 90%, respectively. Cumulative patient survival rates were 93% and 80% at 4 and 6 years as compared with 65% and 52%, respectively, for infrainguinal reconstructions performed for limb salvage. Conclusion: Infrainguinal arterial reconstruction for disabling claudication is a safe and durable procedure in selected patients. These data indicate that concern for limb loss, death, and limited life span of the patients with this disease may not be warranted. (J Vasc Surg 1999;29:259-69.

    Diffusion of e-health innovations in 'post-conflict' settings: a qualitative study on the personal experiences of health workers.

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    BACKGROUND: Technological innovations have the potential to strengthen human resources for health and improve access and quality of care in challenging 'post-conflict' contexts. However, analyses on the adoption of technology for health (that is, 'e-health') and whether and how e-health can strengthen a health workforce in these settings have been limited so far. This study explores the personal experiences of health workers using e-health innovations in selected post-conflict situations. METHODS: This study had a cross-sectional qualitative design. Telephone interviews were conducted with 12 health workers, from a variety of cadres and stages in their careers, from four post-conflict settings (Liberia, West Bank and Gaza, Sierra Leone and Somaliland) in 2012. Everett Roger's diffusion of innovation-decision model (that is, knowledge, persuasion, decision, implementation, contemplation) guided the thematic analysis. RESULTS: All health workers interviewed held positive perceptions of e-health, related to their beliefs that e-health can help them to access information and communicate with other health workers. However, understanding of the scope of e-health was generally limited, and often based on innovations that health workers have been introduced through by their international partners. Health workers reported a range of engagement with e-health innovations, mostly for communication (for example, email) and educational purposes (for example, online learning platforms). Poor, unreliable and unaffordable Internet was a commonly mentioned barrier to e-health use. Scaling-up existing e-health partnerships and innovations were suggested starting points to increase e-health innovation dissemination. CONCLUSIONS: Results from this study showed ICT based e-health innovations can relieve information and communication needs of health workers in post-conflict settings. However, more efforts and investments, preferably driven by healthcare workers within the post-conflict context, are needed to make e-health more widespread and sustainable. Increased awareness is necessary among health professionals, even among current e-health users, and physical and financial access barriers need to be addressed. Future e-health initiatives are likely to increase their impact if based on perceived health information needs of intended users

    Mechanisms of Hormone Action

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