52 research outputs found

    Use of an Electrochemical Split Cell Technique to Evaluate the Influence of Shewanella oneidensis Activities on Corrosion of Carbon Steel

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    Microbially induced corrosion (MIC) is a complex problem that affects various industries. Several techniques have been developed to monitor corrosion and elucidate corrosion mechanisms, including microbiological processes that induce metal deterioration. We used zero resistance ammetry (ZRA) in a split chamber configuration to evaluate the effects of the facultatively anaerobic Fe(III) reducing bacterium Shewanella oneidensis MR-1 on the corrosion of UNS G10180 carbon steel. We show that activities of S. oneidensis inhibit corrosion of steel with which that organism has direct contact. However, when a carbon steel coupon in contact with S. oneidensis was electrically connected to a second coupon that was free of biofilm (in separate chambers of the split chamber assembly), ZRA-based measurements indicated that current moved from the S. oneidensis-containing chamber to the cell-free chamber. This electron transfer enhanced the O2 reduction reaction on the coupon deployed in the cell free chamber, and consequently, enhanced oxidation and corrosion of that electrode. Our results illustrate a novel mechanism for MIC in cases where metal surfaces are heterogeneously covered by biofilms

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Undergraduate Students Becoming Engineers: The Affordances of University-Based Makerspaces

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    In the last decade, postsecondary institutions have seen a notable increase in makerspaces on their campuses and the integration of these spaces into engineering programs. Yet research into the efficacy of university-based makerspaces is sparse. We contribute to this nascent body of research in reporting on findings from a phenomenological study on the perceptions of faculty, staff, and students concerning six university-based makerspaces in the United States. We discuss the findings using a framework of heterogeneous engineering (integration of the social and technical aspects of engineering practice). Various physical, climate, and programmatic features of makerspaces were read as affordances for students’ development of engineering practices and their continued participation and persistence in engineering. We discuss the potential of makerspaces in helping students develop knowledge, skills, and proclivities that may support their attending to especially wicked societal problems, such as issues of sustainability. We offer implications for makerspace administrators, engineering program leaders, faculty, and staff, as well as those developing and delivering professional development for faculty and staff, to better incorporate makerspaces into the university engineering curriculum

    Undergraduate Students Becoming Engineers: The Affordances of University-Based Makerspaces

    No full text
    In the last decade, postsecondary institutions have seen a notable increase in makerspaces on their campuses and the integration of these spaces into engineering programs. Yet research into the efficacy of university-based makerspaces is sparse. We contribute to this nascent body of research in reporting on findings from a phenomenological study on the perceptions of faculty, staff, and students concerning six university-based makerspaces in the United States. We discuss the findings using a framework of heterogeneous engineering (integration of the social and technical aspects of engineering practice). Various physical, climate, and programmatic features of makerspaces were read as affordances for students’ development of engineering practices and their continued participation and persistence in engineering. We discuss the potential of makerspaces in helping students develop knowledge, skills, and proclivities that may support their attending to especially wicked societal problems, such as issues of sustainability. We offer implications for makerspace administrators, engineering program leaders, faculty, and staff, as well as those developing and delivering professional development for faculty and staff, to better incorporate makerspaces into the university engineering curriculum

    Understanding Social Wellbeing and Values of Small-Scale Fisheries amongst the Sama-Bajau of Archipelagic Southeast Asia

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    The Sama-Bajau represent one of the most widely dispersed Indigenous groups in Southeast Asia. Recent estimates indicate a total population of approximately 1.1 million, with around 200,000 living in areas of high biodiversity in the islands of eastern Indonesia, 347,000 in Malaysia (Sabah) and 564,000 in the Philippines. Sama-Bajau culture is intimately connected to marine environments on which they depend for subsistence and cash income, as well as their cultural identity. Culturally defined patterns of fishing activity (including migratory expeditions) unite all sectors of Sama-Bajau communities through catching, consuming, processing and trading of marine resources. Fishing and gathering of shellfish and other strand resources provide the focus for individual and communal relations within villages and across extensive kin and trading networks. The maintenance and transmission of Indigenous language and knowledge between generations occurs through socialisation into livelihoods and related social and cultural activities. As such, customary beliefs and practices in relation to boats and sea spirits endure among the Sama-Bajau, and are primarily oriented to ensuring return on fishing effort. Sama-Bajau small-scale fisheries (SSF) across insular Southeast Asia therefore present a highly relevant case study. We will explore the dimensions of social wellbeing in the Sama-Bajau context and identify how the Sama-Bajau have responded to endogenously developed and exogenously induced drivers. Utilising our collective experience of Sama-Bajau society in diverse locations across Indonesia, Malaysia and the Philippines, we will discuss the parameters of continuity and transformation in the Sama-Bajau way of life. The case study offers the opportunity to explore how historical and contemporary drivers have contributed to the variability of Sama-Bajau social welfare, spatially and temporally
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