1,075 research outputs found

    The rationale for simple approaches for sustainability assessment and management in contaminated land practice

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    AbstractThe scale of land-contamination problems, and of the responses to them, makes achieving sustainability in contaminated land remediation an important objective. The Sustainable Remediation Forum in the UK (SuRF-UK) was established in 2007 to support more sustainable remediation practice in the UK. The current international interest in ‘sustainable remediation’ has achieved a fairly rapid consensus on concepts, descriptions and definitions for sustainable remediation, which are now being incorporated into an ISO standard. However the sustainability assessment methods being used remain diverse with a range of (mainly) semi-quantitative and quantitative approaches and tools developed, or in development. Sustainability assessment is site specific and subjective. It depends on the inclusion of a wide range of considerations across different stakeholder perspectives. Taking a tiered approach to sustainability assessment offers important advantages, starting from a qualitative assessment and moving through to semi-quantitative and quantitative assessments on an ‘as required’ basis only. It is also clear that there are a number of ‘easy wins’ that could improve performance against sustainability criteria right across the site management process. SuRF-UK has provided a checklist of ‘sustainable management practices’ that describes some of these. This paper provides the rationale for, and an outline of, and recently published SuRF-UK guidance on preparing for and framing sustainability assessments; carrying out qualitative sustainability assessment; and simple good management practices to improve sustainability across contaminated land management activities

    The unusual morphology of the intragroup medium in NGC 5171

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    We present the results of a 24 ks XMM-Newton observation of the NGC 5171 group of galaxies. NGC 5171 is unusual in that it is an X-ray bright group (L > 10^42 erg/s), with irregular contours which are not centred on a bright galaxy. The global spectrum is adequately described by a single temperature APEC model with T = 0.96 +/- 0.04 keV, and Z = 0.13 +/- 0.02 Zsol, in good agreement with previous ROSAT data. We find the X-ray contours are centred on a bright ridge of emission stretching from the BGG to a nearby galaxy. Spectral mapping reveals this ridge to be both cool (T ~ 1.1 keV) and metallic (Z ~ 0.4 Zsol) in comparison to its surrounding, suggesting it is the result of a tidal interaction between the two galaxies. Optical data reveals the member galaxies to have a high velocity dispersion (sigma = 494 +/- 99 km/s), and a significantly non-Gaussian velocity distribution, suggesting the group is in the process of merging. A region of hot gas with T = 1.58 +/- 0.36 keV is found to the West of the bright central ridge, and we interpret this as shock-heating resulting from the merging. A further region of emission to the South-East of the bright central ridge, with T = 1.14 +/- 0.13 keV, is probably associated with a background group, four times more distant.Comment: 10 pages, 8 figures, to be published in MNRA

    Canalization of the evolutionary trajectory of the human influenza virus

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    Since its emergence in 1968, influenza A (H3N2) has evolved extensively in genotype and antigenic phenotype. Antigenic evolution occurs in the context of a two-dimensional 'antigenic map', while genetic evolution shows a characteristic ladder-like genealogical tree. Here, we use a large-scale individual-based model to show that evolution in a Euclidean antigenic space provides a remarkable correspondence between model behavior and the epidemiological, antigenic, genealogical and geographic patterns observed in influenza virus. We find that evolution away from existing human immunity results in rapid population turnover in the influenza virus and that this population turnover occurs primarily along a single antigenic axis. Thus, selective dynamics induce a canalized evolutionary trajectory, in which the evolutionary fate of the influenza population is surprisingly repeatable and hence, in theory, predictable.Comment: 29 pages, 5 figures, 10 supporting figure

    The discovery of potent, selective, and reversible inhibitors of the house dust mite peptidase allergen Der p 1: an innovative approach to the treatment of allergic asthma.

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    Blocking the bioactivity of allergens is conceptually attractive as a small-molecule therapy for allergic diseases but has not been attempted previously. Group 1 allergens of house dust mites (HDM) are meaningful targets in this quest because they are globally prevalent and clinically important triggers of allergic asthma. Group 1 HDM allergens are cysteine peptidases whose proteolytic activity triggers essential steps in the allergy cascade. Using the HDM allergen Der p 1 as an archetype for structure-based drug discovery, we have identified a series of novel, reversible inhibitors. Potency and selectivity were manipulated by optimizing drug interactions with enzyme binding pockets, while variation of terminal groups conferred the physicochemical and pharmacokinetic attributes required for inhaled delivery. Studies in animals challenged with the gamut of HDM allergens showed an attenuation of allergic responses by targeting just a single component, namely, Der p 1. Our findings suggest that these inhibitors may be used as novel therapies for allergic asthma

    The Development and Use of Sustainability Criteria in SuRF-UK’s Sustainable Remediation Framework

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    Sustainability considerations have become widely recognised in contaminated land management and are now accepted as an important component of remediation planning and implementation around the world. The Sustainable Remediation Forum for the UK (SuRF-UK) published guidance on sustainability criteria for consideration in drawing up (or framing) assessments, organised across 15 “headline” categories, five for the environment element of sustainability, five for the social, and five for the economic. This paper describes how the SuRF-UK indicator guidance was developed, and the rationale behind its structure and approach. It describes its use in remediation option appraisal in the UK, and reviews the international papers that have applied or reviewed it. It then reviews the lessons learned from its initial use and the opinions and findings of international commentators, and concludes with recommendations on how the indicator categories might be further refined in the future. The key findings of this review are that the SuRF-UK framework and indicator guidance is well adopted into practice in the UK. It is widely recognised as the most appropriate mechanism to support sustainability-based decision making in contaminated land decision making. It has influenced the development of other national and international guidance and standards on sustainable remediation. However, there is room for some fine tuning of approach based on the lessons learned during its application

    Silicic volcanism on Mars evidenced by tridymite in high-SiO2 sedimentary rock at Gale crater

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    Tridymite, a SiO2 mineral that crystallizes at low pressures and high temperatures (>870 °C) from high-SiO2 materials, was detected at high concentrations in a sedimentary mudstone in Gale crater, Mars. Mineralogy and abundance were determined by X-ray diffraction using the Chemistry and Mineralogy instrument on the Mars Science Laboratory rover Curiosity. Terrestrial tridymite is commonly associated with silicic volcanism where high temperatures and high-silica magmas prevail, so this occurrence is the first in situ mineralogical evidence for martian silicic volcanism. Multistep processes, including high-temperature alteration of silica-rich residues of acid sulfate leaching, are alternate formation pathways for martian tridymite but are less likely. The unexpected discovery of tridymite is further evidence of the complexity of igneous petrogenesis on Mars, with igneous evolution to high-SiO2 compositions

    First observations of separated atmospheric nu_mu and bar{nu-mu} events in the MINOS detector

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    The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of nuµ and [overline nu ]µ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field nuµ and [overline nu ]µ interactions are separated. The ratio of [overline nu ]µ to nuµ events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving R[overline nu ][sub mu]/nu[sub mu]data/R[overline nu ][sub mu]/nu[sub mu]MC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for nuµ and [overline nu ]µ

    Reef fishes at all trophic levels respond positively to effective marine protected areas

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    Marine Protected Areas (MPAs) offer a unique opportunity to test the assumption that fishing pressure affects some trophic groups more than others. Removal of larger predators through fishing is often suggested to have positive flow-on effects for some lower trophic groups, in which case protection from fishing should result in suppression of lower trophic groups as predator populations recover. We tested this by assessing differences in the trophic structure of reef fish communities associated with 79 MPAs and open-access sites worldwide, using a standardised quantitative dataset on reef fish community structure. The biomass of all major trophic groups (higher carnivores, benthic carnivores, planktivores and herbivores) was significantly greater (by 40% - 200%) in effective no-take MPAs relative to fished open-access areas. This effect was most pronounced for individuals in large size classes, but with no size class of any trophic group showing signs of depressed biomass in MPAs, as predicted from higher predator abundance. Thus, greater biomass in effective MPAs implies that exploitation on shallow rocky and coral reefs negatively affects biomass of all fish trophic groups and size classes. These direct effects of fishing on trophic structure appear stronger than any top down effects on lower trophic levels that would be imposed by intact predator populations. We propose that exploitation affects fish assemblages at all trophic levels, and that local ecosystem function is generally modified by fishing
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