Reconciling feminist theory and gendered resource management in Indonesia     

Rebecca Elmhirst 《Area》1998,30(3):225-235

Summary This paper considers the difficulties in reconciling a fluid and ambiguous conceptualization of gender difference with policy-based efforts to define women as 'target groups' in development interventions. The issue is explored with reference to gender issues in a transmigration resettlement area in Indonesia, where the instability of gender identities is particularly marked, and where gendered resource use and control are particularly blurred.  相似文献   

Alignment and precession of a black hole with a warped accretion disc     

Rebecca G. Martin  J. E. Pringle  Christopher A. Tout 《Monthly notices of the Royal Astronomical Society》2007,381(4):1617-1624

We consider the shape of an accretion disc whose outer regions are misaligned with the spin axis of a central black hole and calculate the steady state form of the warped disc in the case where the viscosity and surface densities are power laws in the distance from the central black hole. We discuss the shape of the resulting disc in both the frame of the black hole and that of the outer disc. We note that some parts of the disc and also any companion star maybe shadowed from the central regions by the warp. We compute the torque on the black hole caused by the Lense–Thirring precession, and hence compute the alignment and precession time-scales. We generalize the case with viscosity and hence surface density independent of radius to more realistic density distributions for which the surface density is a decreasing function of radius. We find that the alignment time-scale does not change greatly but the precession time-scale is more sensitive. We also determine the effect on this time-scale if we truncate the disc. For a given truncation radius, the time-scales are less affected for more sharply falling density distributions.  相似文献   

Sea-level rise research and dialogue in North Carolina: Creating windows for policy change     

Benjamin Poulter  Rebecca L. Feldman  Mark M. Brinson  Benjamin P. Horton  Michael K. Orbach  Samuel H. Pearsall  Enrique Reyes  Stanley R. Riggs  John C. Whitehead 《Ocean & Coastal Management》2009,52(3-4):147-153

Coastal areas are among the world's most vulnerable landscapes to impacts related to climate change, including inundation from sea-level rise (SLR), increased exposure to shoreline erosion, and greater frequency and intensity of storms. The status of research on the physical, ecological, and socio-economic effects of vulnerability to SLR and progress toward planning for its consequences varies from region to region worldwide. Here, we synthesize the results of three decades of SLR research and the development of coastal management policies in North Carolina, USA. We identify the major factors responsible for opening new policy ‘windows’ that address SLR, including how stakeholders have developed an increased understanding of the risks, the extent of public dialogue about potential response strategies, and advances in political receptivity to policy change. Research and policy progress in North Carolina continue to provide a model for other regions to help guide and evaluate the development of coastal policies.  相似文献   

Hyperspectral mapping of alteration assemblages within a hydrothermal vug at the Haughton impact structure,Canada          下载免费PDF全文

Rebecca N. Greenberger  John F. Mustard  Gordon R. Osinski  Livio L. Tornabene  Alexandra J. Pontefract  Cassandra L. Marion  Roberta L. Flemming  Janette H. Wilson  Edward A. Cloutis 《Meteoritics & planetary science》2016,51(12):2274-2292

Meteorite impacts on Earth and Mars can generate hydrothermal systems that alter the primary mineralogies of rocks and provide suitable environments for microbial colonization. We investigate a calcite–marcasite‐bearing vug at the ~23 km diameter Haughton impact structure, Devon Island, Nunavut, Canada, using imaging spectroscopy of the outcrop in the field (0.65–1.1 μm) and samples in the laboratory (0.4–2.5 μm), point spectroscopy (0.35–2.5 μm), major element chemistry, and X‐ray diffraction analyses. The mineral assemblages mapped at the outcrop include marcasite; marcasite with minor gypsum and jarosite; fibroferrite and copiapite with minor gypsum and melanterite; gypsum, Fe³⁺ oxides, and jarosite; and calcite, gypsum, clay, microcline, and quartz. Hyperspectral mapping of alteration phases shows spatial patterns that illuminate changes in alteration conditions and formation of specific mineral phases. Marcasite formed from the postimpact hydrothermal system under reducing conditions, while subsequent weathering oxidized the marcasite at low temperatures and water/rock ratios. The acidic fluids resulting from the oxidation collected on flat‐lying portions of the outcrop, precipitating fibroferrite + copiapite. That assemblage then likely dissolved, and the changing chemistry and pH resulting from interaction with the calcite‐rich host rock formed gypsum‐bearing red coatings. These results have implications for understanding water–rock interactions and habitabilities at this site and on Mars.  相似文献   

Scientific advocacy,environmental interest groups,and climate change: are climate skeptic portrayals of climate scientists as biased accurate?     

Rebecca Bromley-Trujillo  James W. Stoutenborough  Arnold Vedlitz 《Climatic change》2015,131(4):607-620

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A new chronological framework for Middle and Upper Pleistocene landscape evolution in the Sussex/Hampshire Coastal Corridor, UK     

Martin R. Bates  Rebecca M. Briant  Jean-Luc Schwenninger 《Proceedings of the Geologists' Association. Geologists' Association》2010,121(4):369-392

The unique Middle and Late Pleistocene sedimentary record preserved along the Sussex/Hampshire Coastal Corridor between Romsey and Brighton contains a wealth of deposits including highstand marine sediments associated with a variety of different aged beaches, fluvial sediments associated with rivers crossing the coastal plain and cold stage deposits accumulating above the marine and fluvial sediments. Although quarrying activity has been extensive across much of the area it has been undertaken in flooded workings due to the high level of the watertable. Consequently little is known in detail about the sequences except where they outcrop on the foreshore around the coast. This paper examines recent work from the lower coastal plain using a multi-disciplinary approach these deposits to elucidate the age of the sequences and their associated environments of deposition.OSL dates from two of the beaches, the Aldingbourne and Brighton/Norton Beaches, place both within MIS 7. Although these OSL dates cannot differentiate between sub-stages within MIS 7, coupling these results with inferences from local geography, lithology and contained microfossils it is clear that the beaches belong to two different phases within MIS 7. These two beaches are clearly divided by a major phase of erosion and downcutting associated with a fall in sea-level. Fluvial sediments from Solent Terrace 2 and Arun Terrace 4 also date within MIS 7 and are tentatively ascribed to the downcutting event between the beaches. Together this information allows us to propose, for the first time, a robust independently dated framework for the lower parts of the coastal plain integrating for the first time the marine and terrestrial record.  相似文献   

Intraspecific Variation in Growth of Marsh Macrophytes in Response to Salinity and Soil Type: Implications for Wetland Restoration     

Rebecca J. Howard 《Estuaries and Coasts》2010,33(1):127-138

Genetic diversity within plant populations can influence plant community structure along environmental gradients. In wetland habitats, salinity and soil type are factors that can vary along gradients and therefore affect plant growth. To test for intraspecific growth variation in response to these factors, a greenhouse study was conducted using common plants that occur in northern Gulf of Mexico brackish and salt marshes. Individual plants of Distichlis spicata, Phragmites australis, Schoenoplectus californicus, and Schoenoplectus robustus were collected from several locations along the coast in Louisiana, USA. Plant identity, based on collection location, was used as a measure of intraspecific variability. Prepared soil mixtures were organic, silt, or clay, and salinity treatments were 0 or 18 psu. Significant intraspecific variation in stem number, total stem height, or biomass was found in all species. Within species, response to soil type varied, but increased salinity significantly decreased growth in all individuals. Findings indicate that inclusion of multiple genets within species is an important consideration for marsh restoration projects that include vegetation plantings. This strategy will facilitate establishment of plant communities that have the flexibility to adapt to changing environmental conditions and, therefore, are capable of persisting over time.  相似文献   

Rift kinematics preserved in deep-time erosional landscape below the northern North Sea     

Thilo Wrona  Alexander C. Whittaker  Rebecca E. Bell  Robert L. Gawthorpe  Haakon Fossen  Christopher A.-L. Jackson  Marit Stokke Bauck 《Basin Research》2023,35(2):744-761

Our understanding of continental rifting is, in large parts, derived from the stratigraphic record. This record is, however, incomplete as it does not often capture the geomorphic and erosional signal of rifting. New 3D seismic reflection data reveal a Late Permian-Early Triassic landscape incised into the pre-rift basement of the northern North Sea. This landscape, which covers at least 542 km², preserves a drainage system bound by two major tectonic faults. A quantitative geomorphic analysis of the drainage system reveals 68 catchments, with channel steepness and knickpoint analysis of catchment-hosted palaeo-rivers showing that the landscape preserved a >2 Myr long period of transient tectonics. We interpret that this landscape records a punctuated uplift of the footwall of a major rift-related normal fault (Vette Fault) at the onset of rifting. The landscape was preserved by a combination of relatively rapid subsidence in the hangingwall of a younger fault (Øygarden Fault) and burial by post-incision sediments. As such, we show how and why erosional landscapes are preserved in the stratigraphic record, and how they can help us understand the tectono-stratigraphic evolution of ancient continental rifts.  相似文献   

Diapycnal heat flux and mixed layer heat budget within the Atlantic Cold Tongue     

Rebecca Hummels  Marcus Dengler  Peter Brandt  Michael Schlundt 《Climate Dynamics》2014,43(11):3179-3199

Sea surface temperatures (SSTs) in the eastern tropical Atlantic are crucial for climate variability within the tropical belt. Despite this importance, state-of-the-art climate models show a large SST warm bias in this region. Knowledge about the seasonal mixed layer (ML) heat budget is a prerequisite for understanding SST mean state and its variability. Within this study all contributions to the seasonal ML heat budget are estimated at four locations within the Atlantic cold tongue (ACT) that are representative for the western (0°N, 23°W), central (0°N, 10°W) and eastern (0°N, 0°E) equatorial as well as the southern (10°S, 10°W) ACT. To estimate the contribution of the diapycnal heat flux due to turbulence an extensive data set of microstructure observations collected during ten research cruises between 2005 and 2012 is analyzed. The results for the equatorial ACT indicate that with the inclusion of the diapycnal heat flux the seasonal ML heat budget is balanced. Within the equatorial region, the diapycnal heat flux is essential for the development of the ACT. It dominates over all other cooling terms in the central and eastern equatorial ACT, while it is of similar size as the zonal advection in the western equatorial ACT. In contrast, the SST evolution in the southern ACT region can be explained entirely by air-sea heat fluxes.  相似文献   

Changes to the drivers of fire weather with a warming climate – a case study of southeast Tasmania     

Michael R. Grose  Paul Fox-Hughes  Rebecca M. B. Harris  Nathaniel L. Bindoff 《Climatic change》2014,124(1-2):255-269

Projected changes to the global climate system have great implications for the incidence of large infrequent fires in many regions. Here we examine the synoptic-scale and local-scale influences on the incidence of extreme fire weather days and consider projections of the large-scale mean climate to explore future fire weather projections. We focus on a case study region with periodic extreme fire dangers; southeast Tasmania, Australia. We compare the performance of a dynamically downscaled regional climate model with Global Climate Model outputs as a tool for examining the local-scale influences while accounting for high regional variability. Many of the worst fires in Tasmania and the southeast Australian region are associated with deep cold fronts and strong prefrontal winds. The downscaled simulations reproduce this synoptic type with greater fidelity than a typical global climate model. The incidence of systems in this category is projected to increase through the century under a high emission scenario, driven mainly by an increase in the temperature of air masses, with little change in the strength of the systems. The regional climate model projected increase in frequency is smaller than for the global climate models used as input, with a large model range and natural variability. We also demonstrate how a blocking Foehn effect and topographic channelling contributed to the extreme conditions during an extreme fire weather day in Tasmania in January 2013. Effects such as these are likely to contribute to high fire danger throughout the century. Regional climate models are useful tools that enable various meteorological drivers of fire danger to be considered in projections of future fire danger.  相似文献