280 research outputs found

    RIDGE and InterRidge: Cooperative interdisciplynary studies of mid-ocean ridges

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    RIDGE (gidge mer-Oisciplinary Boba1 bperiments) is a major research initiative in the United States designed to complement existing research on spreading centers. RIDGE has been designed to integrate exploration, expenment and theory into a major, decade-long effort to understand one of the pnmary processes that have shaped the evolution of our planet. Its objectives are twofold: (1) to provide a focus for a coordinated, interdisciplinary research program directed at geological, hydrothermal and biological processes associated with the formation of oceanic cmst, and (2) to provide a framework within which a rich diversity of investigator-initiated research can be undertaken. The RIDGE initiative has led to parallel efforts in other nations which have recently joined together to form InterRidge, an intemational collaboration of some sixteen countries focused on ridge crest studies

    Design study of magnetic eddy-current vibration suppression dampers for application to cryogenic turbomachinery

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    Cryogenic turbomachinery used to pump high pressure fuel (liquid H2) and oxidizer (liquid O2) to the main engines of the Space Shuttle have experienced rotor instabilities. Subsynchronous whirl, an extremely destructive instability, has caused bearing failures and severe rubs in the seals. These failures have resulted in premature engine shutdowns or, in many instances, have limited the power level to which the turbopumps could be operated. The feasibility of using an eddy current type of damping mechanism for the Space Shuttle Main Engine is outlined

    Mineral carbonation of peridotite fueled by magmatic degassing and melt impregnation in an oceanic transform fault

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    Most of the geologic CO2 entering Earth's atmosphere and oceans is emitted along plate margins. While C-cycling at mid-ocean ridges and subduction zones has been studied for decades, little attention has been paid to degassing of magmatic CO2 and mineral carbonation of mantle rocks in oceanic transform faults. We studied the formation of soapstone (magnesite-talc rock) and other magnesite-bearing assemblages during mineral carbonation of mantle peridotite in the St. Paul's transform fault, equatorial Atlantic. Clumped carbonate thermometry of soapstone yields a formation (or equilibration) temperature of 147 ± 13 °C which, based on thermodynamic constraints, suggests that CO2(aq) concentrations of the hydrothermal fluid were at least an order of magnitude higher than in seawater. The association of magnesite with apatite in veins, magnesite with a δ13C of -3.40 ± 0.04‰, and the enrichment of CO2 in hydrothermal fluids point to magmatic degassing and melt-impregnation as the main source of CO2. Melt-rock interaction related to gas-rich alkali olivine basalt volcanism near the St. Paul's Rocks archipelago is manifested in systematic changes in peridotite compositions, notably a strong enrichment in incompatible elements with decreasing MgO/SiO2. These findings reveal a previously undocumented aspect of the geologic carbon cycle in one of the largest oceanic transform faults: Fueled by magmatism in or below the root zone of the transform fault and subsequent degassing, the fault constitutes a conduit for CO2-rich hydrothermal fluids, while carbonation of peridotite represents a vast sink for the emitted CO2

    Cross-sectional evaluation of a longitudinal consultation skills course at a new UK medical school

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    Background: Good communication is a crucial element of good clinical care, and it is important to provide appropriate consultation skills teaching in undergraduate medical training to ensure that doctors have the necessary skills to communicate effectively with patients and other key stakeholders. This article aims to provide research evidence of the acceptability of a longitudinal consultation skills strand in an undergraduate medical course, as assessed by a cross-sectional evaluation of students' perceptions of their teaching and learning experiences. Methods: A structured questionnaire was used to collect student views. The questionnaire comprised two parts: 16 closed questions to evaluate content and process of teaching and 5 open-ended questions. Questionnaires were completed at the end of each consultation skills session across all year groups during the 2006-7 academic year (5 sessions in Year 1, 3 in Year 2, 3 in Year 3, 10 in Year 4 and 10 in Year 5). 2519 questionnaires were returned in total. Results: Students rated Tutor Facilitation most favourably, followed by Teaching, then Practice & Feedback, with suitability of the Rooms being most poorly rated. All years listed the following as important aspects they had learnt during the session: • how to structure the consultation • importance of patient-centredness • aspects of professionalism (including recognising own limits, being prepared, generally acting professionally). All years also noted that the sessions had increased their confidence, particularly through practice. Conclusions: Our results suggest that a longitudinal and integrated approach to teaching consultation skills using a well structured model such as Calgary-Cambridge, facilitates and consolidates learning of desired process skills, increases student confidence, encourages integration of process and content, and reinforces appreciation of patient-centredness and professionalism

    Globally aligned photomosaic of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37°18.5′N) : release of georeferenced data, mosaic construction, and viewing software

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    Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q12009, doi:10.1029/2008GC002204.We present a georeferenced photomosaic of the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37°18′N). The photomosaic was generated from digital photographs acquired using the ARGO II seafloor imaging system during the 1996 LUSTRE cruise, which surveyed a ∼1 km2 zone and provided a coverage of ∼20% of the seafloor. The photomosaic has a pixel resolution of 15 mm and encloses the areas with known active hydrothermal venting. The final mosaic is generated after an optimization that includes the automatic detection of the same benthic features across different images (feature-matching), followed by a global alignment of images based on the vehicle navigation. We also provide software to construct mosaics from large sets of images for which georeferencing information exists (location, attitude, and altitude per image), to visualize them, and to extract data. Georeferencing information can be provided by the raw navigation data (collected during the survey) or result from the optimization obtained from image matching. Mosaics based solely on navigation can be readily generated by any user but the optimization and global alignment of the mosaic requires a case-by-case approach for which no universally software is available. The Lucky Strike photomosaics (optimized and navigated-only) are publicly available through the Marine Geoscience Data System (MGDS, http://www.marine-geo.org). The mosaic-generating and viewing software is available through the Computer Vision and Robotics Group Web page at the University of Girona (http://eia.udg.es/∼rafa/mosaicviewer.html).This work has been supported by the EU Marie Curie RTNs MOMARNet (OD, RG, JE, LN, JF, NG) and FREESUBNet (RG, NG, XC), the Spanish Ministry of Science and Innovation (grant CTM2007–64751; RG, JE), CNRS and ANR (grant ANR NT05–3_42212, JE), ICREA (LN), and by the Generalitat de Catalunya (JE, RG). JF has been funded by MICINN under FPI grant BES-2006-12733 and NG has been supported by MICINN under the ‘‘Ramon y Cajal’’ program

    Mini-AFTERc: a controlled pilot trial of a nurse-led psychological intervention for fear of breast cancer recurrence

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    Objectives To determine the feasibility and acceptability of implementing the Mini-AFTERc intervention. Design Non-randomised cluster-controlled pilot trial. Setting Four NHS out-patient breast cancer centres in Scotland. Participants Ninety-two women who had successfully completed primary treatment for breast cancer were screened for moderate levels of fear of cancer recurrence (FCR). Forty-five were eligible (17 intervention and 28 control) and 34 completed 3-month follow-up (15 intervention and 21 control). Intervention Mini-AFTERc, a single brief (30 min) structured telephone discussion with a specialist breast cancer nurse (SBCN) trained to target the antecedents of FCR. Outcomes Feasibility and acceptability of Mini-AFTERc and the study design were assessed via recruitment, consent, retention rates, patient outcomes (measured at baseline, 2, 4, and 12 weeks), and post-study interviews with participants and SBCNs, which were guided by Normalisation Process Theory. Results Mini-AFTERc was acceptable to patients and SBCNs. SBCNs believe the implementation of Mini-AFTERc to be feasible and an extension of discussions that already happen routinely. SBCNs believe delivery, however, at the scale required would be challenging given current competing demands for their time. Recruitment was impacted by variability in the follow-up practices of cancer centres and COVID-19 lockdown. Consent and follow-up procedures worked well, and retention rates were high. Conclusions The study provided invaluable information about the potential challenges and solutions for testing the Mini-AFTERc intervention more widely where limiting high FCR levels is an important goal following recovery from primary breast cancer treatment

    Migration, Racism and the Hostile Environment: Making the Case for the Social Sciences

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    Cite as: Social Scientists Against the Hostile Environment (SSAHE)(2020). Migration, racism and the hostile environment : Making the case for the social sciences. London. https://acssmigration.wordpress.com/report/

    Utilization of the ART approach in a group of public oral health operators in South Africa: a 5-year longitudinal study

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    Contains fulltext : 80990.pdf (publisher's version ) (Open Access)BACKGROUND: A significant increase in the proportion of restorations to the number of tooth extractions was reported after the introduction of ART in an academic mobile dental service in South Africa. The changes were ascribed to its less threatening procedure. Based on these findings, ART was subsequently introduced into the public oral health service of Ekurhuleni district in the South African province of Gauteng. This article reports on the 5-year restorative treatment pattern of operators in the Ekurhuleni district, who adopted the ART approach into their daily dental practice. METHODS: Of the 21 trained operators, 11 had placed more than 10% of restorations using ART at year 1 and were evaluated after 5 years. Data, including number of restored and extracted teeth and type of restoration, were drawn from clinical records 4 months before, and up to 5 years after training. The restoration/extraction ratio (REX score) and the proportion of ART restorations to the total number of restorations were calculated. The paired sample t-test and linear regression analysis were applied. RESULTS: The mean percentage of ART restorations after 1 year was 24.0% (SE 7.2) and significantly increased annually to 42.7% (SE 9.2) after 5 years in permanent dentitions. In primary dentitions the mean percentage of ART restorations after 1 year was 80.6% (SE 4.9) and 72.6% (SE 8.8) after 5 years. The mean REX score before ART training was 0.08 (SE 0.03) and 0.07 (SE 0.04) for permanent and primary teeth, respectively and 0.11 (SE 0.03) and 0.17 (SE 0.05) after 5 years. CONCLUSION: Five years after training, ART had been used consistently in this selected group of operators as the predominant restorative treatment used for primary teeth and showed a significant annual increase in permanent teeth. However, this change had not resulted in an increase in the REX score in both dentitions
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