9,214 research outputs found

    Green cities and health: a question of scale?

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    <p><b>Background:</b> Cities are expanding and accommodating an increasing proportion of the world's population. It is important to identify features of urban form that promote the health of city dwellers. Access to green space has been associated with health benefits at both individual and neighbourhood level. We investigated whether a relationship between green space coverage and selected mortality rates exists at the city level in the USA.</p> <p><b>Methods:</b> An ecological cross-sectional study. A detailed land use data set was used to quantify green space for the largest US cities (n=49, combined population of 43 million). Linear regression models were used to examine the association between city-level ‘greenness’ and city-level standardised rates of mortality from heart disease, diabetes, lung cancer, motor vehicle fatalities and all causes, after adjustment for confounders.</p> <p><b>Results:</b> There was no association between greenness and mortality from heart disease, diabetes, lung cancer or automobile accidents. Mortality from all causes was significantly higher in greener cities.</p> <p><b>Conclusions:</b> While considerable evidence suggests that access to green space yields health benefits, we found no such evidence at the scale of the American city. In the USA, greener cities tend also to be more sprawling and have higher levels of car dependency. Any benefits that the green space might offer seem easily eclipsed by these other conditions and the lifestyles that accompany them. The result merits further investigation as it has important implications for how we increase green space access in our cities.</p&gt

    The Girl Who Threw Me Down

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    https://digitalcommons.library.umaine.edu/mmb-vp/5180/thumbnail.jp

    Dynamic Animations of Journal Maps: Indicators of Structural Changes and Interdisciplinary Developments

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    The dynamic analysis of structural change in the organization of the sciences requires methodologically the integration of multivariate and time-series analysis. Structural change--e.g., interdisciplinary development--is often an objective of government interventions. Recent developments in multi-dimensional scaling (MDS) enable us to distinguish the stress originating in each time-slice from the stress originating from the sequencing of time-slices, and thus to locally optimize the trade-offs between these two sources of variance in the animation. Furthermore, visualization programs like Pajek and Visone allow us to show not only the positions of the nodes, but also their relational attributes like betweenness centrality. Betweenness centrality in the vector space can be considered as an indicator of interdisciplinarity. Using this indicator, the dynamics of the citation impact environments of the journals Cognitive Science, Social Networks, and Nanotechnology are animated and assessed in terms of interdisciplinarity among the disciplines involved

    Vector-Tensor multiplet in N=2 superspace with central charge

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    We use the four-dimensional N=2 central charge superspace to give a geometrical construction of the Abelian vector-tensor multiplet consisting, under N=1 supersymmetry, of one vector and one linear multiplet. We derive the component field supersymmetry and central charge transformations, and show that there is a super-Lagrangian, the higher components of which are all total derivatives, allowing us to construct superfield and component actions.Comment: LaTeX2e with AMS-LaTeX, 12 page

    How environmental protection agencies can promote eco-innovation: The prospect of voluntary reciprocal legitimacy

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    Abstract This paper examines the \{UK\} and Irish Environmental Protection Agencies (EPAs) ability to move beyond regulatory compliance to support and promote sustainable environmental innovation, in short “eco-innovation”. To do so would require them to overcome the perception that they face, often being perceived as ‘policemen’ by the regulated business community. We propose a new empirically-derived theoretical construct called Voluntary Reciprocal Legitimacy (VRL), defined as the development of mutual trust between the regulator and business resulting in arrangements which generate eco-innovation benefits for the regulator, the regulated business communities and society at large. \{VRL\} adds a new category to Suchman's (1995) theory of moral legitimacy as well as highlights how \{EPAs\} can build trust between themselves and regulated business, allowing a shift of the ‘beyond compliance’ legislative boundary. Such an approach supports eco-innovation whilst simultaneously protecting the natural environment

    The Ten-dimensional Effective Action of Strongly Coupled Heterotic String Theory

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    We derive the ten-dimensional effective action of the strongly coupled heterotic string as the low energy limit of M-theory on S^1/Z_2. In contrast to a conventional dimensional reduction, it is necessary to integrate out nontrivial heavy modes which arise from the sources located on the orbifold fixed hyperplanes. This procedure, characteristic of theories with dynamical boundaries, is illustrated by a simple example. Using this method, we determine a complete set of R^4, F^2R^2, and F^4 terms and the corresponding Chern-Simons and Green-Schwarz terms in ten dimensions. As required by anomaly cancelation and supersymmetry, these terms are found to exactly coincide with their weakly coupled one-loop counterparts.Comment: 18 pages, Latex2e with amsmath, corrected some typo

    Вчені України — лауреати міжнародних премій і нагород

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    Рецензія на книгу: Абліцов В.Г. «Вчені України — лауреати міжнародних премій і нагород» (Серія «Наука України у світовому інформаційному просторі». Вип. 4) Київ: Академперіодика, 2011. — 192 с

    Sediment and fluvial particulate carbon flux from an eroding peatland catchment

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    Erosion and the associated loss of carbon is a major environmental concern in many peatlands and remains difficult to accurately quantify beyond the plot scale. Erosion was measured in an upland blanket peatland catchment (0.017 km2) in northern England using Structure‐from‐Motion (SfM) photogrammetry, sediment traps and stream sediment sampling at different spatial scales. A net median topographic change of –27 mm yr–1 was recorded by SfM over the 12‐month monitoring period for the entire surveyed area (598 m2). Within the entire surveyed area there were six nested catchments where both SfM and sediment traps were used to measure erosion. Substantial amounts of peat were captured in sediment traps during summer storm events after two months of dry weather where desiccation of the peat surface occurred. The magnitude of topographic change for the six nested catchments determined by SfM (mean value: 5.3 mm, standard deviation: 5.2 mm) was very different to the areal average derived from sediment traps (mean value: –0.3 mm, standard deviation: 0.1 mm). Thus direct interpolation of peat erosion from local net topographic change into sediment yield at the catchment outlet appears problematic. Peat loss measured at the hillslope scale was not representative of that at the catchment scale. Stream sediment sampling at the outlet of the research catchment (0.017 km2) suggested that the yields of suspended sediment and particulate organic carbon were 926.3 t km–2 yr–1 and 340.9 t km–2 yr–1 respectively, with highest losses occurring during the autumn. Both freeze–thaw during winter and desiccation during long periods of dry weather in spring and summer were identified as important peat weathering processes during the study. Such weathering was a key enabler of subsequent fluvial peat loss from the catchment

    Membranes and Three-form Supergravity

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    We discuss membranes in four-dimensional N=1 superspace. The kappa-invariance of the Green-Schwarz action implies that there is a dual version of N=1 supergravity with a three-form potential. We formulate this new supergravity in terms of a three-form superfield in curved superspace, giving the relevant constraints on the field strength. We find the corresponding membrane soliton in the new supergravity and discuss how the extended supersymmetry algebra emerges from the symmetries of the flat superspace background.Comment: 34 pages, Latex2
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