878 research outputs found

    Metals in the diffuse gas around high-redshift galaxies

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    The gas around galaxies provides fuel for star formation, playing a crucial role in the formation and evolution of galaxies. However, because the gas is very diffuse, it is difficult to observe in emission, so in this work we examine it by analyzing absorption lines in the spectra of bright background sources. Our observational results are also compared with current cosmological simulations.GalaxiesInterstellar matter and star formatio

    NIREX petrological samples archive

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    This report describes archival curation of petrological samples and related digital records arising from past investigations undertaken by the BGS under the Nirex Site Investigations Programmes at Sellafield and, to a lesser extent, Dounreay. This consisted of the following tasks: 1. Log all relevant samples and subsamples in order to verify which can be readily made available for future investigations. 2. Record their present storage locations within the BGS site at Keyworth. 3. Determine the extent of electronic records relating to these samples and held on the Apple Mac databases within the (former) Mineralogy and Petrology Group. 4. Transfer these databases into the BGS data architecture. 5. Prepare a report recording these activities and metadata necessary to locate the samples/subsamples and records for subsequent use. The collections and electronic records were assembled during a series of investigations carried out mostly by the Mineralogy and Petrology Group (MPG) of the British Geological Survey in the early to mid 1990s, and some carried out by field staff of BGS. These investigations formed part of the Site Investigations carried out by Nirex in seeking a site acceptable for construction of a repository for low and medium level radioactive waste

    Can forest management based on natural disturbances maintain ecological resilience?

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    Given the increasingly global stresses on forests, many ecologists argue that managers must maintain ecological resilience: the capacity of ecosystems to absorb disturbances without undergoing fundamental change. In this review we ask: Can the emerging paradigm of natural-disturbance-based management (NDBM) maintain ecological resilience in managed forests? Applying resilience theory requires careful articulation of the ecosystem state under consideration, the disturbances and stresses that affect the persistence of possible alternative states, and the spatial and temporal scales of management relevance. Implementing NDBM while maintaining resilience means recognizing that (i) biodiversity is important for long-term ecosystem persistence, (ii) natural disturbances play a critical role as a generator of structural and compositional heterogeneity at multiple scales, and (iii) traditional management tends to produce forests more homogeneous than those disturbed naturally and increases the likelihood of unexpected catastrophic change by constraining variation of key environmental processes. NDBM may maintain resilience if silvicultural strategies retain the structures and processes that perpetuate desired states while reducing those that enhance resilience of undesirable states. Such strategies require an understanding of harvesting impacts on slow ecosystem processes, such as seed-bank or nutrient dynamics, which in the long term can lead to ecological surprises by altering the forest's capacity to reorganize after disturbance

    Personal identity (de)formation among lifestyle travellers: A double-edged sword?

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    This article explores the personal identity work of lifestyle travellers – individuals for whom extended leisure travel is a preferred lifestyle that they return to repeatedly. Qualitative findings from in-depth semi-structured interviews with lifestyle travellers in northern India and southern Thailand are interpreted in light of theories on identity formation in late modernity that position identity as problematic. It is suggested that extended leisure travel can provide exposure to varied cultural praxes that may contribute to a sense of social saturation. Whilst a minority of the respondents embraced a saturation of personal identity in the subjective formation of a cosmopolitan cultural identity, several of the respondents were paradoxically left with more identity questions than answers as the result of their travels
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