59,746 research outputs found

    Introduction: Protistan Biology, Horizontal Gene Transfer, and Common Descent Uncover Faulty Logic in Intelligent Design

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    THE International Society of Protistologists (ISOP) organized a pre-meeting workshop entitled ‘‘Horizontal Gene Transfer and Phylogenetic Evolution Debunk Intelligent Design,’’ as part of the 1st North American Section meeting held June 11–13, 2009, at Roger Williams University, Bristol, RI, USA. This workshop focused on the acceptance of Darwinian evolution in the United States and the role of intelligent design (ID) in the ongoing controversy between scientific knowledge and popular belief. Intelligent design, a doctrine born in the 1980s, proposes that a ‘‘Designer’’ is responsible for the complexity in biological systems and that Darwinism cannot explain holistically the origin and evolution of the natural world, nor the intricate chemical assemblage of most organic structures (Forrest and Gross 2007; Padian and Matzke 2009). The workshop emphasized how to communicate evolutionary principles to student and public audiences by using examples of protistan evolution

    Governance for sustainability: learning from VSM practice

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    Purpose – While there is some agreement on the usefulness of systems and complexity approaches to tackle the sustainability challenges facing the organisations and governments in the twenty-first century, less is clear regarding the way such approaches can inspire new ways of governance for sustainability. The purpose of this paper is to progress ongoing research using the Viable System Model (VSM) as a meta-language to facilitate long-term sustainability in business, communities and societies, using the “Methodology to support self-transformation”, by focusing on ways of learning about governance for sustainability. Design/methodology/approach – It summarises core self-governance challenges for long-term sustainability, and the organisational capabilities required to face them, at the “Framework for Assessing Sustainable Governance”. This tool is then used to analyse capabilities for governance for sustainability at three real situations where the mentioned Methodology inspired bottom up processes of self-organisation. It analyses the transformations decided from each organisation, in terms of capabilities for sustainable governance, using the suggested Framework. Findings – Core technical lessons learned from using the framework are discussed, include the usefulness of using a unified language and tool when studying governance for sustainability in differing types and scales of case study organisations. Research limitations/implications – As with other exploratory research, it reckons the convenience for further development and testing of the proposed tools to improve their reliability and robustness. Practical implications – A final conclusion suggests that the suggested tools offer a useful heuristic path to learn about governance for sustainability, from a VSM perspective; the learning from each organisational self-transformation regarding governance for sustainability is insightful for policy and strategy design and evaluation; in particular the possibility of comparing situations from different scales and types of organisations. Originality/value – There is very little coherence in the governance literature and the field of governance for sustainability is an emerging field. This piece of exploratory research is valuable as it presents an effective tool to learn about governance for sustainability, based in the “Methodology for Self-Transformation”; and offers reflexions on applications of the methodology and the tool, that contribute to clarify the meaning of governance for sustainability in practice, in organisations from different scales and types

    Vacuum Stability and the Higgs Boson

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    The discovery of the Higgs boson at the LHC, and especially the determination of its mass around 125 GeV, together with the absence of any trace of new physics make it conceivable that we live in a metastable (but long-lived) electroweak vacuum. I will describe the state-of-the-art calculation that leads to this conclusion, elaborate on possible implications as well as cures of this instability of the Higgs potential and discuss some possible lines of attack for lattice studies of such metastability.Comment: 15 pages. Proceedings of the 31st International Symposium on Lattice Field Theory - LATTICE 201

    A Fresh Look at the Calculation of Tunneling Actions including Gravitational Effects

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    Recently, the calculation of tunneling actions, that control the exponential suppression of the decay of metastable vacua, has been reformulated as an elementary variational problem in field space. This paper extends this formalism to include the effect of gravity. Considering tunneling potentials Vt(ϕ)V_t(\phi) that go from the false vacuum ϕ+\phi_+ to some ϕ0\phi_0 on the stable basin of the scalar potential V(ϕ)V(\phi), the tunneling action is the minimum of the functional SE[Vt]=6π2mP4ϕ+ϕ0(D+Vt)2/(Vt2D)dϕS_E[V_t]=6 \pi^2m_P^4\int_{\phi_+}^{\phi_0}(D+V_t')^2/(V_t^2D)d\phi , where D[(Vt)2+6(VVt)Vt/mP2]1/2D\equiv [(V_t')^2+6(V-V_t)V_t/m_P^2]^{1/2}, Vt=dVt/dϕV_t'=dV_t/d\phi and mPm_P is the reduced Planck mass. This one-line simple result applies equally to AdS, Minkowski or dS vacua decays and reproduces the Hawking-Moss action in the appropriate cases. This formalism provides new handles for the theoretical understanding of different features of vacuum decay in the presence of gravity.Comment: 12 pages in double-column format. 8 figures. Small changes, errata fixe

    Electroweak Baryogenesis with Cosmic Strings ?

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    I report on a critical analysis of the scenario of electroweak baryogenesis mediated by nonsuperconducting cosmic strings. This mechanism relies upon electroweak symmetry restoration in a region around cosmic strings, where sphalerons would be unsuppressed. I discuss the various problems this scenario has to face, presenting a careful computation of the sphaleron rates inside the strings, of the chemical potential for chiral number and of the efficiency of baryogenesis in different regimes of string networks. The conclusion is that the asymmetry in baryon number generated by this scenario is smaller than the observed value by at least 10 orders of magnitude.Comment: 5 pages, uses sprocl.sty. Talk given at SEWM98, Dec.98, Copenhage
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