12 resultados para 100105 Genetically Modified Field Crops and Pasture

em Aston University Research Archive


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Attitudes towards the environment can be manifest in two broad categories, namely anthropocentric and ecocentric. The former regards nature as of value only insofar as it is useful to humanity, whereas the latter assigns intrinsic value to natural entities. Industrial society can be characterised as being dominated by anthropocentrism, which leads to the assumption that a majority of people hold anthropocentric values. However, research shows the most widely held values are ecocentric, which implies that many people's actions are at variance with their values. Furthermore, policy relating to environmental issues is predominantly anthropocentric, which implies it is failing to take account of the values of the majority. Research among experts involved in policy formulation has shown that their values, often ecocentric, are excluded from the policy process. The genetic modification of food can be categorised as anthropocentric, which implies that the technique is in conflict with widely held ecocentric values. This thesis examines data collected from interviews with individuals who have an influence on the debate surrounding the introduction of genetically modified foods, and can be considered 'experts'. Each interviewee is categorised according to whether their values and actions are ecocentric or anthropocentric, and the linkages between the two and the arguments used to justify their positions are explored. Particular emphasis is placed on interviewees who have ecocentric values but act professionally in an anthropocentric way. Finally, common themes are drawn out, and the features the arguments used by the interviewees have in common are outlined.

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This report seeks to make concrete some of the ideas we have been discussing about sensible priors for winds over the ocean. In particular, random field models are reviewed, as are permissible covariance functions. The criteria which these covariance functions must satisfy in order that vorticity and divergence exist and are continuous are defined. The use of Helmholtz theorem is discussed, and possible choices for the covariances are suggested.

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In this chapter, we elaborate on the well-known relationship between Gaussian processes (GP) and Support Vector Machines (SVM). Secondly, we present approximate solutions for two computational problems arising in GP and SVM. The first one is the calculation of the posterior mean for GP classifiers using a `naive' mean field approach. The second one is a leave-one-out estimator for the generalization error of SVM based on a linear response method. Simulation results on a benchmark dataset show similar performances for the GP mean field algorithm and the SVM algorithm. The approximate leave-one-out estimator is found to be in very good agreement with the exact leave-one-out error.

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Masking is said to occur when a mask stimulus interferes with the visibility of a target (test) stimulus. One widely held view of this process supposes interactions between mask and test mechanisms (cross-channel masking), and explicit models (e.g., J. M. Foley, 1994) have proposed that the interactions are inhibitory. Unlike a within-channel model, where masking involves the combination of mask and test stimulus within a single mechanism, this cross-channel inhibitory model predicts that the mask should attenuate the perceived contrast of a test stimulus. Another possibility is that masking is due to an increase in noise, in which case, perception of contrast should be unaffected once the signal exceeds detection threshold. We use circular patches and annuli of sine-wave grating in contrast detection and contrast matching experiments to test these hypotheses and investigate interactions across spatial frequency, orientation, field position, and eye of origin. In both types of experiments we found substantial effects of masking that can occur over a factor of 3 in spatial frequency, 45° in orientation, across different field positions and between different eyes. We found the effects to be greatest at the lowest test spatial frequency we used (0.46 c/deg), and when the mask and test differed in all four dimensions simultaneously. This is surprising in light of previous work where it was concluded that suppression from the surround was strictly monocular (C. Chubb, G. Sperling, & J. A. Solomon, 1989). The results confirm that above detection threshold, cross-channel masking involves contrast suppression and not (purely) mask-induced noise. We conclude that cross-channel masking can be a powerful phenomenon, particularly at low test spatial frequencies and when mask and test are presented to different eyes. © 2004 ARVO.

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The simultaneous use of willow as a vegetation filter and an energy crop can respond both to the increasing energy demand and to the problem of the soil and water contamination. Its characteristics guarantee that the resources are used economically. As a vegetation filter, willow uptakes organic and inorganic contaminants. As a fast growing energy crop it meets the requirements of rural areas without the exploitation of existing forestry. The aim of the research was to gather knowledge on the thermal behaviour of willow, uptaking contaminants and then used as an energy crop. For this reason pyrolysis experiments were performed in two different scales. In analytical scale metal-contaminated wood was investigated and bench scale pyrolysis experiments were performed with nitrogen-enriched willow, originated from a wastewater treatment plant. Results of the pyrolysis showed that 51-81 % of the wastewater derived nitrogen of willow was captured in the char product. Char had low surface area (1.4 to 5.4 m2/g), low bulk density (0.15–0.18 g/cm3), high pH values (7.8–9.4) and high water-holding capacity (1.8 to 4.3 cm3/g) while the bioavailability of char nutrients was low. Links were also established between the pyrolysis temperature and the product properties for maximising the biochar provided benefits for soil applications. Results also showed that the metal binding capacity of wood varied from one metal ion to another, char yield increased and levoglucosan yield decreased in their presence. While char yield was mainly affected by the concentration of the metal ions, levoglucosan yield was more dependent on the type of the ionic species. Combustion experiments were also carried out with metal-enriched char. The burnout temperatures, estimated ignition indices and the conversion indicate that the metal ions type and not the amount were the determining factors during the combustion. Results presented in the Thesis provide better understanding on the thermal behaviour of nitrogen-enriched and metal contaminated biomass which is crucial to design effective pyrolysis units and combustors. These findings are relevant for pyrolysis experiments, where the goal is to yield char for energetic or soil applications.

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We propose - as a modification of the optical (RF) pilot scheme -a balanced phase modulation between two polarizations of the optical signal in order to generate correlated equalization enhanced phase noise (EEPN) contributions in the two polarizations. The method is applicable for n-level PSK system. The EEPN can be compensated, the carrier phase extracted and the nPSK signal regenerated by complex conjugation and multiplication in the receiver. The method is tested by system simulations in a single channel QPSK system at 56 Gb/s system rate. It is found that the conjugation and multiplication scheme in the Rx can mitigate the EEPN to within 1/2 orders of magnitude. Results are compared to using the Viterbi-Viterbi algorithm to mitigate the EEPN. The latter method improves the sensitivity more than two orders of magnitude. Important novel insight into the statistical properties of EEPN is identified and discussed in the paper. © 2013 Optical Society of America.

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This work studied the drying kinetics of the organic fractions of municipal solid waste (MSW) samples with different initial moisture contents and presented a new method for determination of drying kinetic parameters. A series of drying experiments at different temperatures were performed by using a thermogravimetric technique. Based on the modified Page drying model and the general pattern search method, a new drying kinetic method was developed using multiple isothermal drying curves simultaneously. The new method fitted the experimental data more accurately than the traditional method. Drying kinetic behaviors under extrapolated conditions were also predicted and validated. The new method indicated that the drying activation energies for the samples with initial moisture contents of 31.1 and 17.2 % on wet basis were 25.97 and 24.73 kJ mol−1. These results are useful for drying process simulation and industrial dryer design. This new method can be also applied to determine the drying parameters of other materials with high reliability.

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Plasmonic resonant cavities are capable of confining light at the nanoscale, resulting in both enhanced local electromagnetic fields and lower mode volumes. However, conventional plasmonic resonant cavities possess large Ohmic losses at metal-dielectric interfaces. Plasmonic near-field coupling plays a key role in a design of photonic components based on the resonant cavities because of the possibility to reduce losses. Here, we study the plasmonic near-field coupling in the silver nanorod metamaterials treated as resonant nanostructured optical cavities. Reflectance measurements reveal the existence of multiple resonance modes of the nanorod metamaterials, which is consistent with our theoretical analysis. Furthermore, our numerical simulations show that the electric field at the longitudinal resonances forms standing waves in the nanocavities due to the near-field coupling between the adjacent nanorods, and a new hybrid mode emerges due to a coupling between nanorods and a gold-film substrate. We demonstrate that this coupling can be controlled by changing the gap between the silver nanorod array and gold substrate.

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The emergence of the counter-globalisation movement in France has been accompanied by an apparent diversification of social protest repertoires. Protest events carried out by groups associated with a wide array of issues have been remarkable for their use of spectacular and novel actions, while civil disobedience campaigns have been prominent features of environmental and civil rights protests in particular. Drawing on a number of examples of contemporary environmental and global justice campaigns, opposing advertising, four-wheeled drive vehicles, nuclear energy and, especially, open field trials of genetically modified crops, this article discusses the rise of such new forms of protest, placing them in the wider context of transformations in protest repertoires in France. It identifies key examples of innovation, before discussing the twin processes of diffusion and domestication that shape them. It is argued that, although transnational agents and processes are key determinants of repertoire innovation, it is vital to identify the national, movement and sectoral contexts and discourses which enable the naturalisation and legitimisation of new action forms.

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This article compares the tactic of trashing genetically modified crops in activist campaigns in Britain and France. In Britain, most crop trashing was carried out covertly, while in France most activists undertook open, public actions. In seeking an explanation for this, the article shows that the analysis of political opportunities, dominant in comparative studies of social movements, can only take us so far. While it helps explain the occurrence of direct action, it is much less useful in explaining the tactical differences between each country. It is argued that a fuller explanation requires an understanding of how action was shaped by different activist traditions. In France, action was staged as a demonstration of serious, responsible, collective Republican citizenship; in the United Kingdom, activists combined a sceptical view of legality developing from anarchist individualism with an explicitly non-threatening, playful, ethos. The article concludes that a focus on activist traditions can provide an effective bridge between structural and cultural approaches to understanding the determinants of social movement action.

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Investigating the recent direct action campaigns against genetically modified crops in France and the United Kingdom, the authors set out to understand how contrasting judicial systems and cultures affect the way that activists choose to commit ostensibly illegal actions and how they negotiate the trade-offs between effectiveness and public accountability. The authors find evidence that prosecution outcomes across different judicial systems are consistent and relatively predictable and consequently argue that the concept of a “judicial opportunity structure” is useful for developing scholars’ understanding of social movement trajectories. The authors also find that these differential judicial opportunities cannot adequately account for the tactical choices made by activists with respect to the staging of covert or overt direct action; rather, explanations of tactical choice are better accounted for by movement ideas, cultures, and traditions.