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91.
This paper explores the relationship between interdisciplinary studies and research and researchers’ positionalities, both within and beyond geography. The profound degree to which researchers’ assumptions, expectations and attitudes (which in turn are affected by their personal backgrounds, training, location, etc.) influences the very notion of interdisciplinarity, and what it involves and consists of, is often neither noted nor appreciated. This paper will illustrate, particularly through personal examples, how positionality is part of the circuit of knowledge production, informing academic research, employment and publishing to no small extent. The boundaries of interdisciplinary research are shown to be under constant negotiation, still far from mutual understanding or consensus, a fact which explains the often uneasy identification and negotiation of oneself as an interdisciplinary scholar. The paper concludes by making recommendations at individual and institutional level on how to overcome some of the constraints imposed by researchers’ positionalities to the promotion of interdisciplinary research. 相似文献
92.
Stacy D. Jupiter Graham Epstein Natalie C. Ban Sangeeta Mangubhai Margaret Fox Michael Cox 《社会与自然资源》2017,30(9):1096-1111
Locally managed marine areas (LMMAs) are often recommended as a strategy to achieve conservation and fisheries management, though few studies have evaluated their performance against these objectives. We assessed the effectiveness of eight periodically harvested closures (PHCs), the most common form of management within Fijian LMMAs, focusing on two outcomes: protection of resource units and biodiversity conservation. Of the eight PHCs, only one provided biodiversity benefits, whereas three were moderately successful in protecting resource units (targeted fish biomass). Protection of resource units was more likely when PHCs were harvested less frequently, less recently, and when total fish biomass in open areas was lower. Our findings further suggest that monitoring, enforcement, and clearly defined boundaries are critical, less frequent harvesting regimes are advised, and culturally appropriate management incentives are needed. Although PHCs have some potential to protect resource units, they are not recommended as a single strategy for broad-scale biodiversity conservation. 相似文献
93.
Paul Docherty Ron Silva Satish Singh Zhong-Min Song Margaret Wood 《Geophysical Prospecting》1997,45(5):865-878
Migration velocity analysis, a method for determining long wavelength velocity structure, is a critical step in prestack imaging. Solution of this inverse problem is made difficult by a multimodal objective function; a parameter space often vast in extent; and an evaluation procedure for candidate solutions, involving the calculation of depth-migrated image gathers, that can be prohibitively expensive. Recognizing the global nature of the problem, we employ a genetic algorithm (GA) in the search for the optimum velocity model. In order to describe a model efficiently, regions of smooth variation are identified and sparsely parametrized. Region boundaries are obtained via map migration of events picked on the zero-offset time section. Within a region, which may contain several reflectors, separate components describe long and short wavelength variations, eliminating from the parameter space, models with large velocity fluctuations. Vital to the success of the method is rapid model evaluation, achieved by generating image gathers only in the neighbourhood of specific reflectors. Probability of a model, which we seek to maximize, is derived from the flatness of imaged events. Except for an initial interpretation of the zero-offset time section, our method is automatic in that it requires no picking of residual moveout on migrated gathers. Using an example data set from the North Sea, we show that it is feasible to solve for all velocity parameters in the model simultaneously: the method is global in this respect also. 相似文献
94.
Margaret Alston Kerri Whittenbury Deb Western Aaron Gosling 《The Australian geographer》2016,47(1):49-64
Concerns for river health in the Murray-Darling Basin (MDB) area and shifting priorities for water use have led to a significant process of water reform over the last decade. The MDB area, also known as the food bowl of Australia, produces much of the country's food and is home to a significant portion of the population. A long-term drought, historical over-allocation of water for irrigation and climate variability have led to mounting concerns about the long-term viability of the rivers. While the reform process has resulted in the Commonwealth government taking control of the rivers from the States, it has also been influenced by changes in governments and consequent shifts in water allocation priorities from a privileging of agriculture to a broader approach encompassing economic, environmental and social concerns. This had led to uncertainty for the people and communities in the Basin and some confusion between the various layers of governance structures. This paper presents the results of exploratory research conducted with key, high-level stakeholders involved in water reform to examine their perceptions of the evolving water policy process. Despite agreement amongst stakeholders that returning water to the environment to ensure river health is critical, our research reveals significant tensions between stakeholders concerning the evolving process, particularly centred on the potential social outcomes and fairness and equity. This suggests the need for more integrated and transparent governance structures, attention to levels of trust between partners and a common vision that incorporates environmental, economic and social goals. 相似文献
95.
96.
We have observed infrared brightenings near the poles of Jupiter at 8 μm in early 1980. We suspect they are nonthermal in origin. These brightenings are apparently related to the auroral zones which are determined by the magnetic mapping of the magnetotail onto the atmosphere, rather than by the Io flux tube. They were present in both hemispheres in January, present only in the north in February, and probably absent in the south in March. When visible, they were only seen in the hemisphere where the auroral zone was oriented toward the Earth and absent otherwise. 相似文献
97.
Microbial mats were collected from a variety of sites near hydrocarbon vents along the slope in the northern Gulf of Mexico and, for comparison, from Warm Mineral Springs, Florida, USA. A predominant microorganism in each of the mats was the giant bacterium,Beggiatoa. Diameters of the bacterial filaments ranged from about 6 µm to approximately 200 µm. The latter organisms are the largest prokaryotic organisms yet found. All filaments over about 10 µm in diameter contained a large central vacuole, producing a cell with the cytoplasm as a cylindrical tube underlying the cytoplasmic membrane. Sulfur globules were confined to this peripheral layer. Push cores often contained pyrite tubules whose appearance is suggestive of aBeggiatoa origin. Determinations of
13C inBeggiatoa mats from vents along the Louisiana slope yielded values in the range of –26.6 to –27.9 (PDB), suggesting an unusually high degree of isotope fractionation (–24.9) relative to the carbon source in the ambient seawater, which is typical of sulfur-oxidizing chemoautotrophs. The presence of SO (elemental sulfur) within cells ofBeggiatoa resulting from oxidation of H2S supports the importance of bacterial sulfate reduction processes in the underlying vents for the sustenance of theBeggiatoa mats. 相似文献
98.
Margaret M. Krahn Lewey J. Kittle Jr William D. MacLeod Jr 《Marine environmental research》1986,20(4)
On March 19, 1984, more than 170000 gallons of oil were spilled into the Columbia River. We had recently developed analytical methods for estimating the exposure of fish to aromatic compounds by measuring the concentrations of metabolites of these contaminants in fish bile. The oil spill provided an opportunity to field test our methods in assessing the exposure of fish to petroleum aromatic compounds from the spilled oil. Our findings indicated that, within 5 days after the spill, mean concentrations of metabolites of aromatic compounds in the bile of white sturgeon (Acipenser transmontanus) captured 57 miles downstream from the spill were significantly higher than those of sturgeon caught upriver. 相似文献
99.
Spatio-temporal distribution of dissolved inorganic carbon and net community production in the Chukchi and Beaufort Seas 总被引:2,自引:0,他引:2
Nicholas R. Bates Margaret H.P. Best Dennis A. Hansell 《Deep Sea Research Part II: Topical Studies in Oceanography》2005,52(24-26):3303
As part of the 2002 Western Arctic Shelf–Basin Interactions (SBI) project, spatio-temporal variability of dissolved inorganic carbon (DIC) was employed to determine rates of net community production (NCP) for the Chukchi and western Beaufort Sea shelf and slope, and Canada Basin of the Arctic Ocean. Seasonal and spatial distributions of DIC were characterized for all water masses (e.g., mixed layer, halocline waters, Atlantic layer, and deep Arctic Ocean) of the Chukchi Sea region during field investigations in spring (5 May–15 June 2002) and summer (15 July–25 August 2002). Between these periods, high rates of phytoplankton production resulted in large drawdown of inorganic nutrients and DIC in the Polar Mixed Layer (PML) and in the shallow depths of the Upper Halocline Layer (UHL). The highest rates of NCP (1000–2850 mg C m−2 d−1) occurred on the shelf in the Barrow Canyon region of the Chukchi Sea and east of Barrow in the western Beaufort Sea. A total NCP rate of 8.9–17.8×1012 g for the growing season was estimated for the eastern Chukchi Sea shelf and slope region. Very low inorganic nutrient concentrations and low rates of NCP (<15–25 mg C m−2 d−1) estimated for the mixed layer of the adjacent Arctic Ocean basin indicate that this area is perennially oligotrophic. 相似文献
100.