4,418 research outputs found

    Conservation banking and the economization of nature : an institutional analysis

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    During the last decade, conservation banking mechanisms have emerged in the environmental discourse as new market instruments to promote biodiversity conservation. Compensation was already provided for in environmental law in many countries, as the last step of the mitigation hierarchy. The institutional arrangements developed in this context have been redefined and reshaped as market-based instruments (MBIs). As such, they are discursively disentangled from the complex legal-economic nexus they are part of. Monetary transactions are given prominence and tend to be presented as stand alone agreements, whereas they take place in the context of prescriptive regulations. The pro-market narrative featuring conservation banking systems as market-like arrangements as well as their denunciation as instances of nature commodification tend to obscure their actual characteristics. The purpose of this paper is to describe the latter, adopting an explicitly analytical stance on these complex institutional arrangements and their performative dimensions. Beyond the discourse supporting them and notwithstanding the diversity of national policies and regulatory frameworks for compensation, the constitutive force of these mechanisms probably lies in their ability to redefine control, power and the distribution of costs and in their impacts in terms of land use rather than in their efficiency

    Searches for resonant production of top anti-top quarks at the Tevatron

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    A review of the measurements pertaining to searches for resonant production of top and anti-top quarks from the CDF and D0 Collaborations is presented, using different methods to reconstruct the top anti-top quark invariant mass

    Les marchés de la biodiversité

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    Depuis la fin des annĂ©es 1980, l’essor des biotechnologies et l’extension des brevets sur le vivant ont laissĂ© entrevoir des possibilitĂ©s d’utilisations lucratives des substances naturelles, notamment dans les secteurs de la pharmacie, de la cosmĂ©tique, de l’agroalimentaire... Pour concilier la conservation de la biodiversitĂ© et les revendications des populations autochtones gardiennes de ces ressources, la Convention sur la diversitĂ© biologique, signĂ©e lors du Sommet de Rio en 1992, a prĂ©conisĂ© l’institution de marchĂ©s. Il s’agissait aussi d’en finir avec la bio-piraterie et d’assurer « le partage juste et Ă©quitable des avantages tirĂ©s de l’exploitation des ressources gĂ©nĂ©tiques ». Ces « marchĂ©s de la biodiversitĂ© », soutenus par la vague du libĂ©ralisme Ă©conomique, ont Ă©tĂ© l’objet de toutes les spĂ©culations. Mais au-delĂ  du slogan, qu’en est-il aujourd’hui de la marchandisation du vivant ? Comment se dĂ©cline-t-elle du Nord au Sud ? Le cadre juridique et politique de la Convention n’est-il pas dĂ©jĂ  dĂ©passĂ© par l’évolution des connaissances et des techniques, et peu adaptĂ© Ă  la complexitĂ© des situations observĂ©es ? Pour rĂ©pondre Ă  ces questions, Ă©conomistes, juristes, sociologues, anthropologues et biochimistes apportent ici un Ă©clairage nouveau, documentĂ© et critique, sur le modĂšle de conservation de la biodiversitĂ© fondĂ© sur son exploitation commerciale

    Report of the Topical Group on Environmental and Societal Impacts of Particle Physics for Snowmass 2021

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    We report on the work of the Topical Group on Environmental and Societal Impacts of Particle Physics for the Snowmass 2021 Community Summer Study. Topics include impacts on climate, impacts on local communities, and impacts on non-proliferation.Comment: arXiv admin note: substantial text overlap with arXiv:2203.1238

    Surface diffusion coefficients by thermodynamic integration: Cu on Cu(100)

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    The rate of diffusion of a Cu adatom on the Cu(100) surface is calculated using thermodynamic integration within the transition state theory. The results are found to be in excellent agreement with the essentially exact values from molecular-dynamics simulations. The activation energy and related entropy are shown to be effectively independent of temperature, thus establishing the validity of the Arrhenius law over a wide range of temperatures. Our study demonstrates the equivalence of diffusion rates calculated using thermodynamic integration within the transition state theory and direct molecular-dynamics simulations.Comment: 4 pages (revtex), two figures (postscript

    Upstream-binding factor is sequestered into herpes simplex virus type 1 replication compartments

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    Previous reports have shown that adenovirus recruits nucleolar protein upstream-binding factor (UBF) into adenovirus DNA replication centres. Here, we report that despite having a different mode of viral DNA replication, herpes simplex virus type 1 (HSV-1) also recruits UBF into viral DNA replication centres. Moreover, as with adenovirus, enhanced green fluorescent protein-tagged fusion proteins of UBF inhibit viral DNA replication. We propose that UBF is recruited to the replication compartments to aid replication of HSV-1 DNA. In addition, this is a further example of the role of nucleolar components in viral life cycle

    Self-diffusion of adatoms, dimers, and vacancies on Cu(100)

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    We use ab initio static relaxation methods and semi-empirical molecular-dynamics simulations to investigate the energetics and dynamics of the diffusion of adatoms, dimers, and vacancies on Cu(100). It is found that the dynamical energy barriers for diffusion are well approximated by the static, 0 K barriers and that prefactors do not depend sensitively on the species undergoing diffusion. The ab initio barriers are observed to be significantly lower when calculated within the generalized-gradient approximation (GGA) rather than in the local-density approximation (LDA). Our calculations predict that surface diffusion should proceed primarily via the diffusion of vacancies. Adatoms are found to migrate most easily via a jump mechanism. This is the case, also, of dimers, even though the corresponding barrier is slightly larger than it is for adatoms. We observe, further, that dimers diffuse more readily than they can dissociate. Our results are discussed in the context of recent submonolayer growth experiments of Cu(100).Comment: Submitted to the Physical Review B; 15 pages including postscript figures; see also http://www.centrcn.umontreal.ca/~lewi

    Effect of strain on surface diffusion in semiconductor heteroepitaxy

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    We present a first-principles analysis of the strain renormalization of the cation diffusivity on the GaAs(001) surface. For the example of In/GaAs(001)-c(4x4) it is shown that the binding of In is increased when the substrate lattice is expanded. The diffusion barrier \Delta E(e) has a non-monotonic strain dependence with a maximum at compressive strain values (e 0) studied. We discuss the consequences of spatial variations of both the binding energy and the diffusion barrier of an adatom caused by the strain field around a heteroepitaxial island. For a simplified geometry, we evaluate the speed of growth of two coherently strained islands on the GaAs(001) surface and identify a growth regime where island sizes tend to equalize during growth due to the strain dependence of surface diffusion.Comment: 10 pages, 8 figures, LaTeX2e, to appear in Phys. Rev. B (2001). Other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm