1,579 research outputs found

    Power and policy in floodplain management, drawing on research in Alberta, Canada

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    Floodplain management policy implementation and change involves a range of actors and opportunities for power to be exercised. Considering four conceptualizations of power envisioned by Dahl, Bachrach & Baratz, Lukes, and Emerson, this paper explores the actors and instances where power emerges in floodplain management policy implementation and change, using Alberta, Canada, as our focus. We consider which conceptualization is most reflective of the Alberta context. We conclude that all four views of behaviour are relevant here, with some power dynamics between actors more complex than others. Further, these dynamics change over time, and therefore the trade-offs to be made also change. Understanding power relations allows for clearer identification of these trade-offs and, therefore, the potential winners and losers in floodplain management policy. We describe strategies for assisting in this process of managing power relations, including information sharing, transparency and actively managing the policy process

    Surface Textures and Features Indicative of Endogenous Growth at the McCartys Flow Field, NM, as an Analog to Martian Volcanic Plains

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    Basaltic lavas typically form channels or tubes, which are recognized on the Earth and Mars. Although largely unrecognized in the planetary community, terrestrial inflated sheet flows also display morphologies that share many commonalities with lava plains on Mars. The McCartys lava flow field is among the youngest (approx.3000 yrs) basaltic flows in the continental United States. The southwest sections of the flow displays smooth, flat-topped plateaus with irregularly shaped pits and hummocky inter-plateau units that form a polygonal surface. Plateaus are typically elongate in map view, up to 20 m high and display lineations within the glassy crust. Lineated surfaces occasionally display small < 1m diameter lava coils. Lineations are generally straight and parallel each other, sometimes for over 100 meters. The boundaries between plateaus and depressions are also lineated and tilted to angles sometimes approaching vertical. Plateau-parallel cracks, sometimes containing squeeze-ups, mark the boundary between tilted crust and plateau. Some plateau depressions display level floors with hummocky surfaces, while some are bowl shaped with floors covered in broken lava slabs. The lower walls of pits sometimes display lateral, sagged lava wedges. Infrequently, pit floors display the upper portion of a tumulus from an older flow. In some places the surface crust has been disrupted forming a slabby texture. Slabs are typically on the scale of a meter or less across and no less than 7-10 cm thick. The slabs preserve the lineated textures of the undisturbed plateau crust. It appears that this style of terrain represents the emplacement of an extensive sheet that experiences inflation episodes within preferred regions where lateral spreading of the sheet is inhibited, thereby forming plateaus. Rough surfaces represent inflation-related disruption of pahoehoe lava and not a a lava. Depressions are often the result of non-inflation and can be clearly identified by lateral squeeze-outs along the pit walls that form when the rising crust exposes the still liquid core of the sheet. The plains of Tharsis and Elysium, Mars, display many analogous feature

    Agreement between prospective diary data and retrospective questionnaire report of abdominal pain and stooling symptoms in children with irritable bowel syndrome

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    BACKGROUND: In functional gastrointestinal disorders, patient recall of symptoms drives diagnostic decisions and evaluation of treatment response, and research conclusions about potential treatments. In pediatrics, parent report also impacts assessment and care. Hence, identifying methods for accurately capturing patient and parent report of irritable bowel syndrome (IBS) symptoms is important. This study evaluated correspondence between retrospective questionnaire (parent and child report) and prospective diary data for children and adolescents with IBS. METHODS: Participants included 50 children/adolescents with IBS per Rome III criteria. Children completed a 2-week pain and stool diary. Children and parents subsequently completed a 2-week recall questionnaire, reporting number of pain days, maximum pain, days without bowel movement, and days with diarrhea during the diary interval. Intraclass correlation coefficients and Bland-Altman plots assessed agreement. KEY RESULTS: For pain and days without bowel movement, overall agreement between child recall questionnaire and child diary was strong, although under conditions likely to facilitate agreement and with individual variation observed. Parent recall and child diary were less concordant, and agreement about diarrhea was poor for parent and child. Age did not significantly correlate with agreement. CONCLUSIONS & INFERENCES: Child questionnaire with short recall interval may be a reasonable approximation for diary data, although this varies by individual and replication/investigation of lengthier recall are needed. Relying on parent questionnaire does not appear a suitable proxy, and recall of stool form by both parent and child appears more problematic. These results combined with existing literature support use of diary data whenever possible

    The Atmospheric Impact of the 1991 Mount Pinatubo Eruption

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    The 1991 eruption of Pinatubo produced about 5 cubic kilometers of dacitic magma and may be the second largest volcanic eruption of the century. Eruption columns reached 40 kilometers in altitude and emplaced a giant umbrella cloud in the middle to lower stratosphere that injected about 17 megatons of SO2, slightly more than twice the largest yielded by the 1982 eruption of El Chichon, Mexico. The SO2 formed sulfate aerosols that produced the largest perturbation to the stratospheric aerosol layer since the eruption of Krakatau in 1883. The aerosol cloud spread rapidly around the Earth in about 3 weeks and attained global coverage by about 1 year after the eruption. Peak local midvisible optical depths of up to 0.4 were measured in late 1992, and globally averaged values were about 0.1 to 0.15 for 2 years. The large aerosol cloud caused dramatic decreases in the amount of net radiation reaching the Earth's surface, producing a climate forcing that was two times stronger than the aerosols of El Chichon. Effects on climate were an observed surface cooling in the northern hemisphere of up to 0.5 to 0.6 C, equivalent to a hemispheric-wide reduction in net radiation of 4 watts per square meter and a cooling of perhaps as large as -0.4 C over large parts of the earth in 1992-93. Climate models seem to have predicted the cooling with a reasonable degree of accuracy. The Pinatubo climate forcing was stronger than the opposite warming of either the El Nino event or anthropogenic greenhouse gases in the period 1991-93. As a result of the presence of the aerosol particles, midlatitude ozone concentrations reached their lowest levels on record during 1992-93, the southern hemisphere 'ozone hole' increased in 1992 to an unprecedented size and ozone depletion rates were observed to be faster than ever before recorded. The atmospheric impact of the Pinatubo eruption has been profound, and it has sparked a lively interest in the role that volcanic aerosols play in climate change. This event has shown that a powerful eruption providing a 15 to 20 megaton release of SO2 into the stratosphere can produce sufficient aerosols to offset the present global warming trends and severely impact the ozone budget

    On the linear stability of solitons and hairy black holes with a negative cosmological constant: the odd-parity sector

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    Using a recently developed perturbation formalism based on curvature quantities, we investigate the linear stability of black holes and solitons with Yang-Mills hair and a negative cosmological constant. We show that those solutions which have no linear instabilities under odd- and even- parity spherically symmetric perturbations remain stable under odd-parity, linear, non-spherically symmetric perturbations.Comment: 26 pages, 1 figur

    Swarm-based adaptation: wayfinding support for lifelong learners

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    Please refer to the orinigal publication in: Tattersall, C. Van den Berg, B., Van Es, R., Janssen, J., Manderveld, J., Koper, R. (2004). Swarm-based adaptation: wayfinding support for lifelong learners. In P. de Bra & W. Nejdl, Adaptive Hypermedia and Adaptive Web-Based Systems (LNCS3137), (pp. 336-339). Heidelberg: Springer. http://www.springerlink.com/index/UW0DUG7KHTU0KBX9.This article introduces an approach to adaptive wayfinding support for lifelong learners based on self-organisation theory. It describes an architecture which supports the recording, processing and presentation of collective learner behaviour designed to create a feedback loop informing learners of successful paths towards the attainment of their learning objectives. The approach is presented as an alternative to methods of achieving adaptation in hypermedia-based learning environments which involve learner modelling

    Trust and Credibility in Web-Based Health Information: A Review and Agenda for Future Research

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    Background: Online sources are becoming increasingly important in health information seeking, such that they may have a significant effect on health care decisions and outcomes. Hence, given the wide range of different sources of online health information from different organisations and individuals, it is important to understand how information seekers evaluate and select the sources that they use, and, more specifically how they assess their credibility and trustworthiness. Objectives: This article reviews empirical studies on trust and credibility in the use of online health information. The article seeks to present a profile of the research conducted on trust and credibility in online health information seeking, to identify the factors that impact judgements of trustworthiness and credibility, and to explore the role of demographic factors affecting trust formation. On this basis, it aims to identify the gaps in current knowledge and to propose an agenda for future research. Methods: A systematic literature review was conducted. Searches were conducted using a variety of combinations of the terms: online health information, trust, credibility, and their variants, in four multi-disciplinary and four health-oriented databases. Articles selected were published in English from 2000 onwards; this process generated 3827 unique records. After the application of exclusion criteria, this was reduced to a final dataset of 73 articles, which was analysed in full. Results: Interest in this topic has persisted over the last 15 years, with articles being published in medicine, social science and computer science, and focussing mostly on the USA and the UK. Documents in the dataset fell into three categories: those using trust or credibility as a dependent variable, those using trust or credibility as an independent variable, and studies of the demographic factors that influence the role of trust or credibility in online health information seeking. There is a consensus that in terms of website design, clear layout and design, interactive features and the authority of the owner have a positive effect on trust or credibility, whilst advertising has a negative effect. With regard to content features, authority of the author, ease of use and content have a positive effect on trust or credibility formation. Demographic factors influencing trust formation are age, gender and perceived health status. Conclusions: There is considerable scope for further research. This includes: increased clarity of the interaction between the variables associated with health information seeking; increased consistency on the measurement of trust and credibility; a greater focus on specific online health information sources; and, enhanced understanding of the impact of demographic variables on trust and credibility judgement

    Swarm-based adaptation:wayfinding support for lifelong learners

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    Please refer to the orinigal publication in: Tattersall, C. Van den Berg, B., Van Es, R., Janssen, J., Manderveld, J., Koper, R. (2004). Swarm-based adaptation: wayfinding support for lifelong learners. In P. de Bra & W. Nejdl, Adaptive Hypermedia and Adaptive Web-Based Systems (LNCS3137), (pp. 336-339). Heidelberg: Springer. http://www.springerlink.com/index/UW0DUG7KHTU0KBX9.This article introduces an approach to adaptive wayfinding support for lifelong learners based on self-organisation theory. It describes an architecture which supports the recording, processing and presentation of collective learner behaviour designed to create a feedback loop informing learners of successful paths towards the attainment of their learning objectives. The approach is presented as an alternative to methods of achieving adaptation in hypermedia-based learning environments which involve learner modelling
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