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Ideas of complexity theory – including self-organized criticality – are being applied to the study of turbulence and astroplasmas in the solar system. An RAS MIST meeting in London brought together researchers from different disciplines to compare established paradigms with more recent ideas. Sandra Chapman , Mervyn Freeman and Sean Oughton report. 相似文献
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D. Berggren Kleja W. Standring D.H. Oughton K. Fifield 《Geochimica et cosmochimica acta》2005,69(22):5263-5277
The solubility of aluminium (Al) in many acidic soils is controlled by complexation reactions with soil organic matter. In such soils, Al solubility is theoretically a function of the pool size of “active” Al, i.e., the total amount of Al that equilibrates with the soil solution within a defined period of time. To date, no reliable measurements of “active” Al in soil materials exist. In this study, we determined the isotopically exchangeable pool of Al (EAl) as an operationally defined assessment of “active” Al in acidic mineral soils. The suitability of CuCl2 and pyrophosphate (Na4P2O7) as extractants for “active” Al was also evaluated. Eleven samples, mostly from spodic B horizons, were spiked with carrier-free 26Al and equilibrated for different time periods (1-756 h). The size of the Al pool with which the 26Al tracer exchanged increased with time during the whole experimental period. Thus, contact time between solid and solution phases needs to be defined when assessing the “active” Al pool. Values of EAl obtained after 1 to 5 d of equilibration were equal to the amount of CuCl2 extractable Al, but considerably smaller than the Na4P2O7-extractable pool. Equilibration times greater than 5 d resulted in CuCl2 extractable Al concentrations that under-estimated the “active” Al pool. Three of the investigated samples were rich in imogolite-type materials (ITM). In these samples, 30-50 % of the added 26Al rapidly became associated with soil constituents in forms that could not be extracted by Na4P2O7, indicating that a part of ITM may be in a dynamic state. 相似文献
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Antonio B. S. Poléo Sigurd A. Øxnevad Kjartan Østbye Ronny A. Andersen Deborah H. Oughton Leif A. Vøllestad 《Aquatic Sciences - Research Across Boundaries》1995,57(4):350-359
Crucian carp were exposed to three combinations of pH and inorganic aluminium concentrations for 25 days. Mortality, plasma chloride and haematocrit, and gill aluminium content were investigated. No mortality was observed in any of the three exposures. Crucian carp survived acidic Al-rich water (pH 5.17) with a high concentration of low-molecular weight inorganic Al species (242 µgl–1) for 25 days. These fish had lowered plasma chloride levels and high amounts of aluminium on their gills compared to fish exposed to acidic Al-poor water (pH 5.16 and 12 µgl–1 Ali) and control water (pH 6.29 and 4 µgl–1 Ali). Haematocrit was the same in all three exposures. Because aluminium was not acutely toxic to the anoxia tolerant crucian carp, the present results give support to the hypothesis that Al polymerization with subsequent hypoxia is of high importance for the mechanism of acute Al toxicity to fish. 相似文献
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Bracken L. J. Oughton E. A. Donaldson A. Cook B. Forrester J. Spray C. Cinderby S. Passmore D. Bissett N. 《Natural Hazards》2016,82(2):217-240
River flooding is a serious hazard in the UK with interest driven by recent widespread events. This paper reviews different approaches to flood risk management and the borders (physical, conceptual and organisational) that are involved. The paper showcases a multi-method approach to negotiating flood risk management interventions. We address three fundamental issues around flood risk management: differences and similarities between a variety of approaches; how different approaches work across borders between professionals, lay people, organisations and between different planning regimes; and, whether the science evidence base is adequate to support different types of flood risk management. We explore these issues through a case study on the River Tweed using Q methodology, community mapping and focus groups, participatory GIS, and interviews, which enabled co-production of knowledge around possible interventions to manage flooding. Our research demonstrated that excellent networks of practice exist to make decisions about flood risk management in the Scottish–English borders. Physical and organisational borders were continually traversed in practice. There was an overwhelming desire from professional flood managers and local communities for an alternative to simply structural methods of flood management. People were keen to make use of the ability of catchments to store water, even if land needed to be sacrificed to do so. There was no difference in the desire to embrace natural flood management approaches between people with different roles in flood management, expertise, training or based in different locations. Thus conceptual borders were also crossed effectively in practice. 相似文献
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Interdisciplinary research: framing and reframing 总被引：1，自引：0，他引：1
Framing encompasses the processes of identifying and bounding the area of research and based on our own experiences as academics we have found significant differences in the ways that researchers establish and frame a disciplinary, compared to an interdisciplinary, research project. In this paper we have attempted to contribute to the development of the conceptual framework underpinning interdisciplinary research through analysis of interviews with a number of academics already working in an interdisciplinary manner. Successful projects are able to identify and support the processes that allow the communication and negotiation that is necessary, not just for the initial framing of a research funding proposal but to be able to maintain negotiation. Self awareness and continual reflexivity and a willingness to be questioned by others are essential to this process. 相似文献
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