1,715 research outputs found

    Late onset of Huntington's disease

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    Twenty-five patients with late-onset Huntington's disease were studied; motor impairment appeared at age 50 years or later. The average age at onset of chorea was 57.5 years, with an average age at diagnosis of 63.1 years. Approximately 25% of persons affected by Huntington's disease exhibit late onset. A preponderance of maternal transmission was noted in late-onset Huntington's disease. The clinical features resembled those of mid-life onset Huntington's disease but progressed more slowly. Neuropathological evaluation of two cases reveal less severe neuronal atrophy than for mid-life onset disease

    Finite size giant magnons in the SU(2) x SU(2) sector of AdS_4 x CP^3

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    We use the algebraic curve and Luscher's mu-term to calculate the leading order finite size corrections to the dispersion relation of giant magnons in the SU(2) x SU(2) sector of AdS_4 x CP^3. We consider a single magnon as well as one magnon in each SU(2). In addition the algebraic curve computation is generalized to give the leading order correction for an arbitrary multi-magnon state in the SU(2) x SU(2) sector.Comment: 19 pages; v2, v3: references added, typos fixe

    Case Studies in Forensic Geotechnical and Foundation Engineering

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    Forensics in the geo-domain encompasses an extensive array of topics with specific emphasis in geotechnical related fields. A new discipline known as forensic geotechnical engineering (FGE) has been created to deal with investigations of soil-interaction related failures of engineered facilities or structures. A practicing geotechnical engineer cannot provide services without the fear of a lawsuit. Services of geotechnical engineers experienced in jurisprudence system are commissioned to investigate such failures. This paper presents two case histories where forensic geotechnical engineering was effectively utilized to identify, investigate, and remediate the problem as well assist in litigation. The first case history identifies a request from an office building owner for a forensic geotechnical engineering review of an extensive distress settlement cracking claim. The claim resulted in discovery of a relic sinkhole with neither collapse nor an injury combined with deficient foundation and slab design. The second case history illustrates how a forensic geotechnical investigation was undertaken to identify causative factors of the slope failure and to address the extent of damage. In both cases, the project owner(s) were able to recover a major portion of the loss and litigation cost from the insurance company

    Population policies and education: exploring the contradictions of neo-liberal globalisation

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    The world is increasingly characterised by profound income, health and social inequalities (Appadurai, 2000). In recent decades development initiatives aimed at reducing these inequalities have been situated in a context of increasing globalisation with a dominant neo-liberal economic orthodoxy. This paper argues that neo-liberal globalisation contains inherent contradictions regarding choice and uniformity. This is illustrated in this paper through an exploration of the impact of neo-liberal globalisation on population policies and programmes. The dominant neo-liberal economic ideology that has influenced development over the last few decades has often led to alternative global visions being overlooked. Many current population and development debates are characterised by polarised arguments with strongly opposing aims and views. This raises the challenge of finding alternatives situated in more middle ground that both identify and promote the socially positive elements of neo-liberalism and state intervention, but also to limit their worst excesses within the population field and more broadly. This paper concludes with a discussion outling the positive nature of middle ground and other possible alternatives

    The low-energy limit of AdS(3)/CFT2 and its TBA

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    We investigate low-energy string excitations in AdS3 × S3 × T4. When the worldsheet is decompactified, the theory has gapless modes whose spectrum at low energies is determined by massless relativistic integrable S matrices of the type introduced by Al. B. Zamolodchikov. The S matrices are non-trivial only for excitations with identical worldsheet chirality, indicating that the low-energy theory is a CFT2. We construct a Thermodynamic Bethe Ansatz (TBA) for these excitations and show how the massless modes’ wrapping effects may be incorporated into the AdS3 spectral problem. Using the TBA and its associated Y-system, we determine the central charge of the low-energy CFT2 to be c = 6 from calculating the vacuum energy for antiperiodic fermions — with the vacuum energy being zero for periodic fermions in agreement with a supersymmetric theory — and find the energies of some excited states

    Higher spin AdS_3 holography with extended supersymmetry

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    We propose a holographic duality between a higher spin AdS_3 gravity with so(p) extended supersymmetry and a large N limit of a 2-dimensional Grassmannian-like model with a specific critical level k=N and a non-diagonal modular invariant. As evidence, we show the match of one-loop partition functions. Moreover, we construct symmetry generators of the coset model for low spins which are dual to gauge fields in the supergravity. Further, we discuss a possible relation to superstring theory by noticing an N=3 supersymmetry of critical level model at finite k,N. In particular, we examine BPS states and marginal deformations. Inspired by the supergravity side, we also propose and test another large N CFT dual obtained as a Z_2 automorphism truncation of a similar coset model, but at a non-critical level.Comment: 44 pages, published versio

    Single impurity operators at critical wrapping order in the beta-deformed N=4 SYM

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    We study the spectrum of one single magnon in the superconformal beta-deformed N=4 SYM theory in the planar limit. We compute the anomalous dimensions of one-impurity operators O_{1,L}= tr(phi Z^{L-1}), including wrapping contributions at their critical order L.Comment: LaTeX, feynmf, Metapost, 20 pages, 11 figures, v2: results up to 11 loops completed, appendix on integral calculation extende

    Broader niches revealed by fossil data don’t reduce estimates of range loss and fragmentation of African montane trees

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The data supporting the results already exists and is freely available in the Global Biodiversity Information Facility (GBIF) and the African Pollen Database (APD).Aim: Many species’ climate tolerances are broader than those estimated from current native ranges. Indeed, some Afromontane trees’ niches are up to 50% larger after incorporating fossil data. This expansion could reduce estimates of species’ future range loss due to climate change but also implies strong non-climatic limitations on species’ current ranges. One such limitation is land use, which fossil data suggest influences Afromontane tree distribution, preventing these trees from occupying warmer conditions than they currently do. We aim to assess the degree to which the broader climatic tolerances revealed by fossil data buffers projected range loss from climate and land use for Afromontane trees. Location: Africa. Time period: Last 21,000 years. Major taxa studied: Afromontane trees. Methods: We used species distribution models informed by both current and fossil distributions to project future ranges under climate and land-use projections. Results: We found that projected range reductions are only slightly ameliorated by incorporating fossil distributions and these improvements diminish further under severe land use or climate change scenarios. Taxa that are less impacted by climate are more impacted by intense land use. Depending on the severity of climate and land use, the geographic extent of Afromontane tree species’ ranges will contract by 40-85% and the trees will completely be lost from large portions of Africa. We projected that the surviving species’ ranges will become increasingly fragmented. Main conclusions: Maintaining Afromontane ecosystems will require mitigation of both climate and land-use change and protecting areas to optimize connectivity. Our findings caution that species with climate tolerances broader than their current range might not necessarily fare better under strong changes in climate or land use

    Classical integrability and quantum aspects of the AdS(3) x S(3) x S(3) x S(1) superstring

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    In this paper we continue the investigation of aspects of integrability of the type IIA AdS(3) x S(3) x S(3) x S(1) and AdS(3) x S(3) x T(4) superstrings. By constructing a one parameter family of flat connections we prove that the Green-Schwarz string is classically integrable, at least to quadratic order in fermions, without fixing the kappa-symmetry. We then compare the quantum dispersion relation, fixed by integrability up to an unknown interpolating function h(lambda), to explicit one-loop calculations on the string worldsheet. For AdS(3) x S(3) x S(3) x S(1) the spectrum contains heavy, as well as light and massless modes, and we find that the one-loop contribution differs depending on how we treat these modes showing that similar regularization ambiguities as appeared in AdS(4)/CFT(3) occur also here.Comment: 29 pages; v2: updated references and acknowledgmen
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