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571.
African Inland Fisheries: Experiences with Co-Management and Policies of Decentralization 总被引:1,自引:1,他引:0
Roger Lewins Malloum Ousman Baba Emma Belal Steve Donda Abbagana Mamane Lamine 《社会与自然资源》2014,27(4):405-420
Most countries in Africa have promoted some form of decentralized fisheries management either as discrete co-management projects or as a component of broader decentralization processes that cut across other sectors. These initiatives were shaped by an international policy narrative that emphasises participation in decision making and development. A review of fisheries decentralization experiences in Cameroon, Niger, Nigeria, and Malawi reveals marked differences in purpose, strategy, and performance. In general, co-management projects are limited by their ability to scale up new practice and to maintain viable and representative management institutions. In other cases, the decentralization process is not well supported politically or locally or does not articulate with fisheries policy. Experiences of decentralization in other sectors provide useful lessons. Acknowledging the informal institutional environment or realpolitikof fisheries and the rural economy could provide opportunities to better manage and review the process of decentralization. 相似文献
572.
SST errors in the tropical Atlantic are large and systematic in current coupled general-circulation models. We analyse the growth of these errors in the region of the south-eastern tropical Atlantic in initialised decadal hindcasts integrations for three of the models participating in the Coupled Model Inter-comparison Project 5. A variety of causes for the initial bias development are identified, but a crucial involvement is found, in all cases considered, of ocean-atmosphere coupling for their maintenance. These involve an oceanic “bridge” between the Equator and the Benguela-Angola coastal seas which communicates sub-surface ocean anomalies and constitutes a coupling between SSTs in the south-eastern tropical Atlantic and the winds over the Equator. The resulting coupling between SSTs, winds and precipitation represents a positive feedback for warm SST errors in the south-eastern tropical Atlantic. 相似文献
573.
A combination of numeric hydrodynamic models, a large-clast inverse sediment-transport model, and extensive field measurements were used to discriminate between a tsunami and a storm striking Anegada, BVI a few centuries ago. In total, 161 cobbles and boulders were measured ranging from 1.5 to 830?kg at distances of up to 1?km from the shoreline and 2?km from the crest of a fringing coral reef. Transported clasts are composed of low porosity limestone and were derived from outcrops in the low lying interior of Anegada. Estimates of the near-bed flow velocities required to transport the observed boulders were calculated using a simple sediment-transport model, which accounts for fluid drag, inertia, buoyancy, and lift forces on boulders and includes both sliding and overturning transport mechanisms. Estimated near-bed flow velocities are converted to depth-averaged velocities using a linear eddy viscosity model and compared with water level and depth-averaged velocity time series from high-resolution coastal inundation models. Coastal inundation models simulate overwash by the storm surge and waves of a category 5 hurricane and tsunamis from a Lisbon earthquake of M 9.0 and two hypothetical earthquakes along the North America Caribbean Plate boundary. A modeled category 5 hurricane and three simulated tsunamis were all capable of inundating the boulder fields and transporting a portion of the observed clasts, but only an earthquake of M 8.0 on a normal fault of the outer rise along the Puerto Rico Trench was found to be capable of transporting the largest clasts at their current locations. Model results show that while both storm waves and tsunamis are capable of generating velocities and temporal acceleration necessary to transport large boulders near the reef crest, attenuation of wave energy due to wave breaking and bottom friction limits the capacity of storm waves to transport large clast at great inland distances. Through sensitivity analysis, we show that even when using coefficients in the sediment-transport model which yield the lowest estimated minimum velocities for boulder transport, storm waves from a category 5 hurricane are not capable of transporting the largest boulders in the interior of Anegada. Because of the uncertainties in the modeling approach, extensive sensitivity analyses are included and limitations are discussed. 相似文献
574.
The retail geography literature has long recognised the importance of spatial and catchment analysis to inform decision-making relating to store development. However, less attention has been directed to store development “in practice” and, more specifically, how location research and geographical knowledge is leveraged across the wider retail business – in particular informing the marketing function. Through the use of a semi-structured interview and focus group methodology involving approximately 40 location planning, property and marketing analysts, we find that while some larger retailers have established close links between store development and marketing functions in the exchange of catchment, customer, competitor and loyalty card data to inform local marketing, product ranging, promotional mailings and post-opening store performance reviews, this tends to be the exception rather than the rule. We suggest there is a need for location planners to develop their intra-organisational legitimacy to engender a culture of knowledge-sharing and challenge the departmentalised, silo cultures that exist within some retailers in order to better leverage geographical insights and assist in the realisation of appropriate customer propositions and marketing strategies. 相似文献
575.
Shaun Cole Will J. Percival John A. Peacock Peder Norberg Carlton M. Baugh Carlos S. Frenk Ivan Baldry Joss Bland-Hawthorn Terry Bridges Russell Cannon Matthew Colless Chris Collins Warrick Couch Nicholas J. G. Cross Gavin Dalton Vincent R. Eke Roberto De Propris Simon P. Driver George Efstathiou Richard S. Ellis Karl Glazebrook Carole Jackson Adrian Jenkins Ofer Lahav Ian Lewis Stuart Lumsden Steve Maddox Darren Madgwick Bruce A. Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2005,362(2):505-534
576.
Massimiliano Galeazzi Meng Chiao Michael R. Collier Thomas Cravens Dimitra Koutroumpa Kip D. Kuntz Susan Lepri Dan McCammon Frederick S. Porter Krishna Prasai Ina Robertson Steve Snowden Youaraj Uprety 《Experimental Astronomy》2011,32(2):83-99
The Diffuse X-rays from the Local galaxy (DXL) mission is an approved sounding rocket project with a first launch scheduled around December 2012. Its goal is to identify and separate the X-ray emission generated by solar wind charge exchange from that of the local hot bubble to improve our understanding of both. With 1,000 cm2 proportional counters and grasp of about 10 cm2 sr both in the 1/4 and 3/4 keV bands, DXL will achieve in a 5-min flight what cannot be achieved by current and future X-ray satellites. 相似文献
577.
John C. BRIDGES Mark J. BURCHELL Hitesh C. CHANGELA Nick J. FOSTER J. Alan CREIGHTON James D. CARPENTER Steve J. GURMAN Ian A. FRANCHI Henner BUSEMANN 《Meteoritics & planetary science》2010,45(1):55-72
Abstract– We have used synchrotron Fe‐XANES, XRS, microRaman, and SEM‐TEM analyses of Stardust track 41 slice and track 121 terminal area slices to identify Fe oxide (magnetite‐hematite and amorphous oxide), Fe‐Ti oxide, and V‐rich chromite (Fe‐Cr‐V‐Ti‐Mn oxide) grains ranging in size from 200 nm to ~10 μm. They co‐exist with relict FeNi metal. Both Fe‐XANES and microRaman analyses suggest that the FeNi metal and magnetite (Fe2O3FeO) also contain some hematite (Fe2O3). The FeNi has been partially oxidized (probably during capture), but on the basis of our experimental work with a light‐gas gun and microRaman analyses, we believe that some of the magnetite‐hematite mixtures may have originated on Wild 2. The terminal samples from track 121 also contain traces of sulfide and Mg‐rich silicate minerals. Our results show an unequilibrated mixture of reduced and oxidized Fe‐bearing minerals in the Wild 2 samples in an analogous way to mineral assemblages seen in carbonaceous chondrites and interplanetary dust particles. The samples contain some evidence for terrestrial contamination, for example, occasional Zn‐bearing grains and amorphous Fe oxide in track 121 for which evidence of a cometary origin is lacking. 相似文献