169 research outputs found

    Marketable Pollution Permits: Their Values, Theory, and Application

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    The Economic Council of Canada recently expressed interest in exploring alternatives to the traditional command and control model of pollution control. The marketable pollution permit (MPP) scheme proposed by Dales is one such alternative.\u27 This idea will be examined to assess its potential for practical application. I conclude that the MPP idea has little potential for widespread application. It is not suited to replace the command and control model. There is potential for the supporting principles of the scheme to provide a useful adjunct to current regulatory controls. The issue will be discussed in three sections. The first section will emphasize the value laden nature of the pollution control debate. The values incorporated in basic micro-economic analysis will be highlighted. I state my own views on what values are appropriate. Specific attention will then be given to the implicit values of an MPP scheme and cost benefit analysis. I end the discussion with the conclusion that there is good reason to be concerned about the values contained in these tools

    In/Visibility in the Internet’s Third Age

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    Current research (see, for example, Cheong, Martin and Macfadyen, 2012) on patterns of global and intercultural new media penetration and use nevertheless reveal the thinness of earlier utopian hopes for a technologically mediated “global village.” Nevertheless, new media are transforming local, political and cultural landscapes. What has (and who have) been made newly in/visible by new media and technologies? Participants in this panel will present\ud and discuss aspects of their current research that shed light, in different ways, on questions of in/visibility in this, the Internet’s ‘Third Age’ (Wellman, 2011)

    A cross-scale approach for abundance estimation of invasive alien plants in a large protected area

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    Efficient management of invasive alien plants requires robust and cost-efficient methods for measuring the abundance and spatial structure of inva- sive alien plants with sufficient accuracy. Here, we present such a monitoring method using ad hoc presence-absence records that are routinely collected for various management and research needs in Kruger National Park, South Africa. The total and local abundance of all invasive alien plants were estimated using the area-of-occupancy model that depicts a power-law scaling pattern of species occupancy across scales and a detection-rate-based Poisson model that allows us to estimate abundance from the occupancy, respectively. Results from these two models were consistent in predicting a total of about one million invasive alien plant records for the park. The accuracy of log-transformed abundance estimate improved significantly with the increase of sampling effort. However, estimating abundance was shown to be much more difficult than detecting the spatial structure of the invasive alien plants. Since management of invasive species in protected areas is often hampered by limited resources for detailed surveys and monitoring, relatively simple and inexpensive monitoring strategies are important. Such data should also be appropriate for multiple purposes. We therefore recommend the use of the scaling pattern of species distribution as a method for rapid and robust monitoring of invasive alien plants in protected areas. Not only do these approaches provide valuable tools for managers and biologists in protected areas, but this kind of data, which can be collected as part of routine activities for a protected area, provides excellent opportunities for researchers to explore the status of aliens as well as their assemblage patterns and functions

    Comparative Energy-Landscape Integrated Analysis (ELIA) of past and present agroecosystems in North America and Europe from the 1830s to the 2010s

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    Along the last century there has been an unprecedented growth in both global food production and related socioecological impacts. The objective of this paper is to analyse the effects of long-term metabolic patterns of agrarian systems on land use and cover changes (LUCC) (...

    The High-Metallicity Explosion Environment of the Relativistic Supernova 2009bb

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    We investigate the environment of the nearby (d ~ 40Mpc) broad-lined Type Ic supernova SN 2009bb. This event was observed to produce a relativistic outflow likely powered by a central accreting compact object. While such a phenomenon was previously observed only in long-duration gamma-ray bursts (LGRBs), no LGRB was detected in association with SN 2009bb. Using an optical spectrum of the SN 2009bb explosion site, we determine a variety of ISM properties for the host environment, including metallicity, young stellar population age, and star formation rate. We compare the SN explosion site properties to observations of LGRB and broad-lined SN Ic host environments on optical emission line ratio diagnostic diagrams. Based on these analyses, we find that the SN 2009bb explosion site has a very high metallicity of ~2x solar, in agreement with other broad-lined SN Ic host environments and at odds with the low-redshift LGRB host environments and recently proposed maximum metallicity limits for relativistic explosions. We consider the implications of these findings and the impact that SN 2009bb's unusual explosive properties and environment have on our understanding of the key physical ingredient that enables some SNe to produce a relativistic outflow.Comment: 7 pages, 4 figures, 1 table; accepted for publication in ApJ Letters (replaced to include missing figure

    Post-Newtonian SPH calculations of binary neutron star coalescence. II. Binary mass ratio, equation of state, and spin dependence

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    Using our new Post-Newtonian SPH (smoothed particle hydrodynamics) code, we study the final coalescence and merging of neutron star (NS) binaries. We vary the stiffness of the equation of state (EOS) as well as the initial binary mass ratio and stellar spins. Results are compared to those of Newtonian calculations, with and without the inclusion of the gravitational radiation reaction. We find a much steeper decrease in the gravity wave peak strain and luminosity with decreasing mass ratio than would be predicted by simple point-mass formulae. For NS with softer EOS (which we model as simple Γ=2\Gamma=2 polytropes) we find a stronger gravity wave emission, with a different morphology than for stiffer EOS (modeled as Γ=3\Gamma=3 polytropes as in our previous work). We also calculate the coalescence of NS binaries with an irrotational initial condition, and find that the gravity wave signal is relatively suppressed compared to the synchronized case, but shows a very significant second peak of emission. Mass shedding is also greatly reduced, and occurs via a different mechanism than in the synchronized case. We discuss the implications of our results for gravity wave astronomy with laser interferometers such as LIGO, and for theoretical models of gamma-ray bursts (GRBs) based on NS mergers.Comment: RevTeX, 38 pages, 24 figures, Minor Corrections, to appear in Phys. Rev.
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