Manchester Metropolitan University

About: Manchester Metropolitan University is a education organization based out in Manchester, Manchester, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 5435 authors who have published 16202 publications receiving 442561 citations. The organization is also known as: Manchester Polytechnic & MMU.

Situated evaluation for cooperative systems

Abstract: This paper discusses an evaluation of the MEAD prototype, a multi-user interface generator tool particularly for use in the context of Air Traffic Control (ATC). The procedures we adopted took the form of opportunistic and informal evaluation sessions with small user groups, including Air Traffic Controllers (ATCOs). We argue that informal procedures are a powerful and cost effective method for dealing with specific evaluation issues in the context of CSCW but that wider issues are more problematic. Most notably, identifying the “validity” or otherwise of CSCW systems requires that the context of use be taken seriously, necessitating a fundamental re-appraisal of the concept of evaluation.

Posthuman disability studies

Abstract: This article explores the human through critical disability studies and the theories of Rosi Braidotti. We ask: What does it mean to be human in the twenty-first century and in what ways does disability enhance these meanings? In addressing this question we seek to work through entangled connections of nature, society, technology, medicine, biopower and culture to consider the extent to which the human might be an outdated phenomenon, replaced by Braidotti’s posthuman condition. We then introduce disability as a political category, an identity and a moment of relational ethics. Critical disability studies, we argue, are perfectly at ease with the posthuman because disability has always contravened the traditional classical humanist conception of what it means to be human. Disability also invites a critical analysis of the posthuman. We examine the ways in which disability and posthuman work together, enhancing and complicating one another in ways that raise important questions about the kinds of life and death we value. We consider three of Braidotti’s themes in relation to disability: (i) Life beyond the self: Rethinking enhancement; (ii) Life beyond the species: Rethinking animal; (iii) Life beyond death: Rethinking death. We conclude by advocating a posthuman disability studies that responds directly to contemporary complexities around the human while celebrating moments of difference and disruption.

Does elevated nitrogen deposition or ecosystem recovery from acidification drive increased dissolved organic carbon loss from upland soil? A review of evidence from field nitrogen addition experiments

Abstract: Dissolved organic carbon (DOC) concentrations have risen in upland waters across large areas of Europe and North America. Two proposed drivers of these increases are (1) deposition of atmospheric pollutant nitrogen (N) with consequent effects on plant and decomposer carbon dynamics, and (2) soil recovery from acidification associated with decreasing sulphur deposition. Examination of 12 European and North American field N addition experiments showed inconsistent (positive, neutral, and negative) responses of DOC to N addition. However, responses were linked to the form of N added and to resulting changes in soil acidity. Sodium nitrate additions consistently increased DOC, whereas ammonium salts additions usually decreased DOC. Leachate chemistry was used to calculate an index of “ANC forcing” of the effect of fertilization on the acid-base balance, which showed that DOC increased in response to all de-acidifying N additions, and decreased in response to all but three acidifying N additions. Exceptions occurred at two sites where N additions caused tree mortality, and one experiment located on an older, unglaciated soil with high anion adsorption capacity. We conclude that collectively these experiments do not provide clear support for the role of N deposition as the sole driver of rising DOC, but are largely consistent with an acidity-change mechanism. It is however possible that the unintended effect of acidity change on DOC mobility masks genuine effects of experimental N enrichment on DOC production and degradation. We suggest that there is a need, more generally, for interpretation of N manipulation experiments to take account of the effects that experimentally-induced changes in acidity, rather than elevated N per se, may have on ecosystem biogeochemistry.

How difficult is it to recover from dangerous levels of global warming

Abstract: Climate models provide compelling evidence that if greenhouse gas emissions continue at present rates, then key global temperature thresholds (such as the European Union limit of two degrees of warming since pre-industrial times) are very likely to be crossed in the next few decades. However, there is relatively little attention paid to whether, should a dangerous temperature level be exceeded, it is feasible for the global temperature to then return to safer levels in a usefully short time. We focus on the timescales needed to reduce atmospheric greenhouse gases and associated temperatures back below potentially dangerous thresholds, using a state-of-the-art general circulation model. This analysis is extended with a simple climate model to provide uncertainty bounds. We find that even for very large reductions in emissions, temperature reduction is likely to occur at a low rate. Policy-makers need to consider such very long recovery timescales implicit in the Earth system when formulating future emission pathways that have the potential to 'overshoot' particular atmospheric concentrations of greenhouse gases and, more importantly, related temperature levels that might be considered dangerous.