217 research outputs found

    Effect of the Orbital Level Difference in Doped Spin-1 Chains

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    Doping of a two-orbital chain with mobile S=1/2 Fermions and strong Hund's rule couplings stabilizing the S=1 spins strongly depends on the presence of a level difference among these orbitals. By DMRG methods we find a finite spin gap upon doping and dominant pairing correlations without level-difference, whereas the presence of a level difference leads to dominant charge density wave (CDW) correlations with gapless spin-excitations. The string correlation function also shows qualitative differences between the two models.Comment: 4 pages, 4 figure

    Rethinking the social impacts of the arts

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    The paper presents a critical discussion of the current debate over the social impacts of the arts in the UK. It argues that the accepted understanding of the terms of the debate is rooted in a number of assumptions and beliefs that are rarely questioned. The paper goes on to present the interim findings of a three‐year research project, which aims to rethink the social impact of the arts, with a view to determining how these impacts might be better understood. The desirability of a historical approach is articulated, and a classification of the claims made within the Western intellectual tradition for what the arts “do” to people is presented and discussed

    Practice Parameter: Therapies for Benign Paroxysmal Positional Vertigo (An Evidence-Based Review): Report of the Quality Standards Subcommittee of the American Academy of Neurologysymbol Symbol

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    American Academy of Neurology; BPPV = benign paroxysmal positional vertigo; CONSORT = Consolidated Standards of Reporting Trials; CRP = canalith repositioning procedure; NNT = number needed to treat

    Analysis of end-to-end multi-domain management and orchestration frameworks for software defined infrastructures: An architectural survey

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    Over the last couple of years, industry operators' associations issued requirements towards an end-to-end management and orchestration plane for 5G networks. Consequently, standard organisations started their activities in this domain. This article provides an analysis and an architectural survey of these initiatives and of the main requirements, proposes descriptions for the key concepts of domain, resource and service slicing, end-to-end orchestration and a reference architecture for the end-to-end orchestration plane. Then, a set of currently available or under development domain orchestration frameworks are mapped to this reference architecture. These frameworks, meant to provide coordination and automated management of cloud and networking resources, network functions and services, fulfil multi-domain (i.e. multi-technology and multi-operator) orchestration requirements, thus enabling the realisation of an end-to-end orchestration plane. Finally, based on the analysis of existing single-domain and multi-domain orchestration components and requirements, this paper presents a functional architecture for the end-to-end management and orchestration plane, paving the way to its full realisatio

    Analysis of end-to-end multi-domain management and orchestration frameworks for software defined infrastructures: An architectural survey

    Get PDF
    Over the last couple of years, industry operators' associations issued requirements towards an end-to-end management and orchestration plane for 5G networks. Consequently, standard organisations started their activities in this domain. This article provides an analysis and an architectural survey of these initiatives and of the main requirements, proposes descriptions for the key concepts of domain, resource and service slicing, end-to-end orchestration and a reference architecture for the end-to-end orchestration plane. Then, a set of currently available or under development domain orchestration frameworks are mapped to this reference architecture. These frameworks, meant to provide coordination and automated management of cloud and networking resources, network functions and services, fulfil multi-domain (i.e. multi-technology and multi-operator) orchestration requirements, thus enabling the realisation of an end-to-end orchestration plane. Finally, based on the analysis of existing single-domain and multi-domain orchestration components and requirements, this paper presents a functional architecture for the end-to-end management and orchestration plane, paving the way to its full realisation

    Quantifying probabilities of eruption at a well-monitored active volcano: an application to Mount Etna (Sicily, Italy).

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    At active volcanoes, distinct eruptions are preceded by complex and different precursory patterns; in addition, there are precursory signals which do not necessarily lead to an eruption. The main purpose of this paper is to present an unprecedented application of the recently developed code named BET_EF (Bayesian Event Tree_Eruption Forecasting) to the quantitative estimate of the eruptive hazard at Mt. Etna volcano. We tested the model for the case history of the July-August 2001 flank eruption. Anomalies in geophysical, geochemical and volcanological monitoring parameters were observed more than a month in advance of the effective onset of the eruption. As a consequence, eruption probabilities larger than 90% were estimated. An important feature of the application of BET_EF to Mt. Etna was the probabilistic estimate of opening vent locations. The methodology allowed a clear identification of assumptions and monitoring parameter thresholds and provided rational means for their revision if new data or information are incoming

    Genomic and dietary transitions during the Mesolithic and Early Neolithic in Sicily

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    Southern Italy is a key region for understanding the agricultural transition in the Mediterranean due to its central position. We present a genomic transect for 19 prehistoric Sicilians that covers the Early Mesolithic to Early Neolithic period. We find that the Early Mesolithic hunter-gatherers (HGs) are a highly drifted sister lineage to Early Holocene western European HGs, whereas a quarter of the Late Mesolithic HGs ancestry is related to HGs from eastern Europe and the Near East. This indicates substantial gene flow from (south-)eastern Europe between the Early and Late Mesolithic. The Early Neolithic farmers are genetically most similar to those from the Balkan and Greece, and carry only a maximum of ~7% ancestry from Sicilian Mesolithic HGs. Ancestry changes match changes in dietary profile and material culture, except for two individuals who may provide tentative initial evidence that HGs adopted elements of farming in Sicily

    Genomic and dietary discontinuities during the Mesolithic and Neolithic in Sicily

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    Summary Sicily is a key region for understanding the agricultural transition in the Mediterranean, due to its central position. Here, we present genomic and stable isotopic data for 19 prehistoric Sicilians covering the Mesolithic to Bronze Age periods (10,700-4,100 yBP). We find that Early Mesolithic hunter-gatherers (HGs) from Sicily are a highly drifted lineage of the Early Holocene western European HGs, while Late Mesolithic HGs carry ∌20% ancestry related to northern and (south)eastern European HGs, indicating substantial gene flow. Early Neolithic farmers are genetically most similar to farmers from the Balkans and Greece, with only ∌7% ancestry from local Mesolithic HGs. The genetic discontinuities during the Mesolithic and Early Neolithic match changes in material culture and diet. Three outlying individuals dated to ∌8,000 yBP, however, suggest that hunter-gatherers interacted with incoming farmers at Grotta dell’Uzzo, resulting in a mixed economy and diet for a brief interlude at the Mesolithic-Neolithic transition.- Introduction - Results -- Genetically-distinct groups of prehistoric Sicilians -- Genomic and dietary transitions in Sicily during the Mesolithic and Early Neolithic -- Did Sicilian Late Mesolithic foragers adopt some aspects of early farming? - Discussion -- Limitations of the stud

    Institutional creativity and pathologies of potential space: The modern university

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    This paper proposes the applicability of object relations psychoanalytic conceptions of dialogue (Ogden, 1986, 1993) to thinking about relationships and relational structures and their governance in universities. It proposes that: the qualities of dialogic relations in creative institutions are the proper index of creative productivity; that is of, as examples, ’thinking’ (Evans, 2004), ’emotional learning’ (Salzberger-Wittenburg et al., 1983) or ’criticality’ (Barnett, 1997); contemporary institutions’ explicit preoccupation in assuring, monitoring and managing creative ’dialogue’ can, in practice, pervert creative processes and thoughtful symbolic productivity, thus inhibiting students’ development and the quality of ’thinking space’ for teaching and research. In this context the paper examines uncanny and perverse connections between Paulo Freire’s (1972) account of educational empowerment and dialogics (from his Pedagogy of the oppressed) to the consumerist (see, for example, Clarke & Vidler, 2005) rhetoric of student empowerment, as mediated by some strands of managerialism in contemporary higher education. The paper grounds its critique of current models of dialogue, feedback loops, audit and other mechanisms of accountability (Power, 1997; Strathern, 2000), in a close analysis of how creative thinking emerges. The paper discusses the failure to maintain a dialogic space in humanities and social science areas in particular, exploring psychoanalytic conceptions from Donald Winnicott (1971), Milner (1979), Thomas Ogden (1986) and Csikszentmihalyi (1997). Coleridge’s ideas about imagination as the movement of thought between subjective and objective modes are discussed in terms of both intra- and inter-subjective relational modes of ’dialogue’, which are seen as subject to pathology in the pathologically structured psychosocial environment. Current patterns of institutional governance, by micromanaging dialogic spaces, curtail the ’natural’ rhythms and temporalities of imagination by giving an over-emphasis to the moment of outcome, at the expense of holding the necessary vagaries of process in the institutional ’mind’. On the contrary, as this paper argues, creative thinking lies in sporadic emergences at the conjunction of object/(ive) outcome and through (thought) processes

    A creative industries perspective on creativity and culture

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    The chapter considers changing definitions of creativity in relation to UK cultural policy and practice in the creative industries. Three perspectives are introduced, beginning with the notion of creativity as a product of individual creativity and talent, popularised by the UK government’s 1998 Creative Industries Mapping Document. This perspective is contrasted with an older model of creativity as a collective expression of shared values, as emphasised in earlier cultural industries policies of the 1970s and 1980s. Finally, the chapter considers contemporary views of creativity in the creative industries as participatory, user-generated, remixed and ‘democratized’. The chapter concludes that there is value in all three perspectives—the challenge for policy makers, managers and practitioners in the creative industries is connecting together individual self-expression with collective cultural values
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