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711.
This paper examines the assertion that individuals with seemingly high levels of commitment to the environment at home may also be those engaged in less sustainable leisure and tourism behaviours, including a high dependency on air travel. This potential difference in environmental commitments between different consumption settings is placed within the context of recent policy developments that have seen the rise of segmentation as a commonly applied technique used to understand and encourage pro-environmental behaviours through the notion of ‘sustainable lifestyles’ and social marketing campaigns. Using data derived from a questionnaire of consumers in the UK, three distinctive, empirically-defined ‘lifestyle’ groups are identified, based on the respondents’ environmental behaviours. Significant differences emerged in reported environmental commitments according to their consumption setting. Those with higher levels of commitment in and around the home also tended to be those who flew furthest and most frequently, whilst those with moderate-to-high commitments ‘at home’ often failed to transfer these activities to their holiday environments. The paper concludes by arguing that both academics and policy-makers need to address the role of different consumption settings in which behaviours are undertaken and the ways in which these relate to underlying social practices within these settings.  相似文献   
712.
Interviews were conducted with risk managers in a case-study area in England to determine the factors influencing the choice between more traditional, engineering based, adaptation to flood risk and those focussing on vulnerability reduction. The findings of in-depth analysis of these interviews have implications for climate change adaptation as a whole. They suggest that government policies to implement a broader range of adaptation measures might be hampered by institutional cultures formed when structural, engineered approaches were the norm. Political decentralisation and the fashion for public consultation exacerbate this effect, leaving decision-makers more responsive to the influence of those directly affected by natural hazards than they are to the needs of the wider population or to policy pronouncements by government.  相似文献   
713.
The continental margin off Uruguay and northern Argentina is characterized by high fluvial input by the de la Plata River and a complex oceanographic regime. Here we present first results from RV Meteor Cruise M78/3 of May?CJuly 2009, which overall aimed at investigating sediment transport processes from the coast to the deep sea by means of hydroacoustic and seismic mapping, as well as coring using conventional tools and the new MARUM seafloor drill rig (MeBo). Various mechanisms of sediment instabilities were identified based on geophysical and core data, documenting particularly the continental slope offshore Uruguay to be locus of submarine landsliding. Individual landslides are relatively small with volumes <2km3. Gravitational downslope sediment transport also occurs through the prominent Mar del Plata Canyon and several smaller canyons. The canyons originate at a midslope position, and the absence of buried upslope continuations strongly suggests upslope erosion as main process for canyon evolution. Many other morphological features (e.g., slope-parallel scarps with scour geometries) and abundant contourites in a 35-m-long MeBo core reveal that sediment transport and erosion are controlled predominantly by strong contour currents. Despite numerous landslide events, their geohazard potential is considered to be relatively small, because of their small volumes and their occurrence at relatively deep water depths of more than 1,500?m.  相似文献   
714.
AXIOM: advanced X-ray imaging of the magnetosphere   总被引:1,自引:0,他引:1  
Planetary plasma and magnetic field environments can be studied in two complementary ways—by in situ measurements, or by remote sensing. While the former provide precise information about plasma behaviour, instabilities and dynamics on local scales, the latter offers the global view necessary to understand the overall interaction of the magnetospheric plasma with the solar wind. Some parts of the Earth’s magnetosphere have been remotely sensed, but the majority remains unexplored by this type of measurements. Here we propose a novel and more elegant approach employing remote X-ray imaging techniques, which are now possible thanks to the relatively recent discovery of solar wind charge exchange X-ray emissions in the vicinity of the Earth’s magnetosphere. In this article we describe how an appropriately designed and located X-ray telescope, supported by simultaneous in situ measurements of the solar wind, can be used to image the dayside magnetosphere, magnetosheath and bow shock, with a temporal and spatial resolution sufficient to address several key outstanding questions concerning how the solar wind interacts with the Earth’s magnetosphere on a global level. Global images of the dayside magnetospheric boundaries require vantage points well outside the magnetosphere. Our studies have led us to propose ‘AXIOM: Advanced X-ray Imaging of the Magnetosphere’, a concept mission using a Vega launcher with a LISA Pathfinder-type Propulsion Module to place the spacecraft in a Lissajous orbit around the Earth–Moon L1 point. The model payload consists of an X-ray Wide Field Imager, capable of both imaging and spectroscopy, and an in situ plasma and magnetic field measurement package. This package comprises a Proton-Alpha Sensor, designed to measure the bulk properties of the solar wind, an Ion Composition Analyser, to characterise the minor ion populations in the solar wind that cause charge exchange emission, and a Magnetometer, designed to measure the strength and direction of the solar wind magnetic field. We also show simulations that demonstrate how the proposed X-ray telescope design is capable of imaging the predicted emission from the dayside magnetosphere with the sensitivity and cadence required to achieve the science goals of the mission.  相似文献   
715.
A history of decompression and metasomatism is preserved in a suite of highly chromian, garnet-rich peridotitic xenoliths from the diamondiferous Newlands and Bobbejaan kimberlites, South Africa. A high proportion of the garnets and chromites in these rocks plot in the diamond-facies fields on Cr2O3–CaO and Cr2O3–MgO wt% plots, and Cr-rich compositions are found in both the harzburgitic and lherzolitic fields. Petrographic evidence suggests that the earliest known mineralogies were those of olivine-bearing, garnet-rich rocks. These were modified by a decompression event that caused recrystallization of garnets and led to orientated spinel and pyroxene inclusions in garnet. Chemical zonation within garnet is divided into (1) external re-equilibration between garnet and matrix; (2) internal re-equilibration between garnet and its inclusions; and (3) metasomatically induced zoning between garnet core and a metasomatic rim. The compositional trajectories associated with zonations (1) and (2) in Ca–Cr plots may be closely modelled by means of sliding, garnet–spinel transition reactions whose slopes vary with bulk Ca composition; at intermediate Ca compositions, the trajectories closely match the slope of the lherzolite line or harzburgite/lherzolite boundary. The decreasing Cr/(Cr + Al) of the garnet in these zonations is in agreement with the evidence for decompression given by the petrographic recrystallization features, and overall decompression of probably 10–20 kb is indicated. We speculate on the age of these events, and consider the possibility of their association with major orogenic events documented by South African crustal rocks at 2.9–2.7 Ga, and events evidenced by peridotite-xenolith Re–Os model ages at 2.8–2.7 Ga.  相似文献   
716.
Tim Butler  Chris Hamnett 《Geoforum》2012,43(6):1242-1253
The article discusses research undertaken in East London into perceptions of educational choice amongst a group of middle-class parents drawn from all the main ethnic groups. It focuses on the way in which faith schools are slowly being drawn into the mainstream discourse of choice and how many groups are now beginning to regard such schools as their fall back of choice when it becomes apparent that they are unlikely to get their child into a preferred non-selective secondary school (and increasingly a preferred primary school). This mainstreaming of faith schooling is driven by the attractions to such parents of these schools’ ethos, their perception of them as having a favourable social mix of ‘people like us’ and their generally high record of attainment. It is argued that this increase in demand for faith schools is leading to changes in the recruitment patterns away from primarily faith-based criteria to ones based around a more diffuse (and middle-class) ethos and educational potential. In addition, where such schools once served a wider East London geographical area, there is some evidence that they are now becoming more focused around a local ‘catchment area’ in ways similar to the same popular non-selective schools to which the same group of parents aspired.  相似文献   
717.
Effectively managing and reducing high suspended sediment loads in rivers requires an understanding of the magnitude of major sediment sources as well as erosion and transport processes that deliver excess fine sediments to the channel network. The focus of this research is to determine the magnitude of erosion from tall bluffs, a primary sediment source in the 2880 km2 Le Sueur watershed, Minnesota, USA. We coupled analyses of seven decades of aerial photographs with four years of repeat terrestrial laser scanning (TLS) to determine erosion rates on bluffs. Together, these datasets provide decadal‐scale retreat rates throughout the entire watershed and high‐resolution geomorphic change detection on a subset of bluffs to both constrain erosion rates and document how environmental conditions affect bluff retreat. Erosion rates from aerial photographs and TLS were extrapolated from 243 and 15 measured bluffs, respectively, to all 480 bluffs in the Le Sueur watershed using multiple techniques to obtain estimates of sediment loading from these features at the watershed‐scale. Despite different spatial and temporal measurement scales, the aerial photograph and TLS estimates yielded similar results for bluff retreat rate and total mass of sediment derived from bluffs, with bluffs in the Le Sueur watershed yielding 135 000 ± 39 000 Mg/yr of fine sediment. Comparing this value to the average annual total suspended solids (TSS) load determined from gauging from 2000 to 2010, we determined that bluffs comprise 57 ± 16% of the total TSS load, making bluffs the single most abundant fine sediment source in the basin. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
718.
Current approaches to the discovery of scientific resources (publications, data sets and web services) are dominated by keyword search. These approaches do not allow scientists to search on the deeper semantics of scientific resources, or to discover resources on the basis of the scientific approaches taken. This article evaluates a user interface that allows users to discover scientific resources through structured knowledge in the form of ontologies describing the domain and the scientific knowledge inherent within the scientific resource, and also through informal user tags. These combined capabilities provide scientists with new and powerful options for resource discovery. A qualitative user evaluation explored how scientists felt about the approach for resource discovery in the context of their scientific work. The study showed that marine scientists were enthusiastic about the capabilities of such an approach and appreciated the ability to browse the visual structure of the knowledge and query on scientific method but, overall, preferred the use of tags over ontologies. The exploratory nature of the user study was used to identify future directions for such improvements.  相似文献   
719.
Two fundamental pillars of what it is to be a contemporary NGO and ‘do’ development work are being a part of and promoting civil society, and extending ‘good governance’. This article will provide insights into how supposedly universally applicable concepts and models for NGOs to ‘improve’ post-conflict ‘developing countries’ are incorporated into different social and cultural landscapes. Ethnographic fieldwork highlights some of the particularities of governance, as well as everyday challenges of doing NGO work in a remote province of north-eastern Cambodia. In the context of an authoritarian government, where kinship relations cross-cut all aspects of society, NGOs can be understood as embedded in neo-patrimonial networks rather than as a separate and autonomous realm of society as classic liberal theory understands ‘civil society’. Fear also plays a significant role in configuring peoples’ attitude towards authority and is rarely acknowledged in the project of ‘good governance’ which simplistically tends to see post-colonial governments situated on a linear trajectory which will eventually, with significant NGO interventions, reach advanced liberal democracy status.  相似文献   
720.
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