3,541 research outputs found

    Use of domesticated pigs by Mesolithic hunter-gatherers in northwestern Europe

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    Acknowledgements We thank the Archaeological State Museum Schleswig-Holstein, the Archaeological State Offices of Brandenburg, Lower Saxony and Saxony and the following individuals who provided sample material: Betty Arndt, Jo¨rg Ewersen, Frederick Feulner, Susanne Hanik, Ru¨diger Krause, Jochen Reinhard, Uwe Reuter, Karl-Heinz Ro¨hrig, Maguerita Scha¨fer, Jo¨rg Schibler, Reinhold Schoon, Regina Smolnik, Thomas Terberger and Ingrid Ulbricht. We are grateful to Ulrich Schmo¨lcke, Michael Forster, Peter Forster and Aikaterini Glykou for their support and comments on the manuscript. We also thank many institutions and individuals that provided sample material and access to collections, especially the curators of the Museum fu¨r Naturkunde, Berlin; Muse´um National d0 Histoire Naturelle, Paris; Smithsonian Institution, National Museum of Natural History, Washington D.C.; Zoologische Staatssammlung, Mu¨nchen; Museum fu¨r Haustierkunde, Halle; the American Museum of Natural History, New-York. This work was funded by the Graduate School ‘Human Development in Landscapes’ at Kiel University (CAU) and supported by NERC project Grant NE/F003382/1. Radiocarbon dating was carried out at the Leibniz Laboratory, CAU. This work is licensed under a Creative Commons AttributionNonCommercial-NoDerivs 3.0 Unported License.Peer reviewedPublisher PD

    Reduced order models for control of fluids using the Eigensystem Realization Algorithm

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    In feedback flow control, one of the challenges is to develop mathematical models that describe the fluid physics relevant to the task at hand, while neglecting irrelevant details of the flow in order to remain computationally tractable. A number of techniques are presently used to develop such reduced-order models, such as proper orthogonal decomposition (POD), and approximate snapshot-based balanced truncation, also known as balanced POD. Each method has its strengths and weaknesses: for instance, POD models can behave unpredictably and perform poorly, but they can be computed directly from experimental data; approximate balanced truncation often produces vastly superior models to POD, but requires data from adjoint simulations, and thus cannot be applied to experimental data. In this paper, we show that using the Eigensystem Realization Algorithm (ERA) \citep{JuPa-85}, one can theoretically obtain exactly the same reduced order models as by balanced POD. Moreover, the models can be obtained directly from experimental data, without the use of adjoint information. The algorithm can also substantially improve computational efficiency when forming reduced-order models from simulation data. If adjoint information is available, then balanced POD has some advantages over ERA: for instance, it produces modes that are useful for multiple purposes, and the method has been generalized to unstable systems. We also present a modified ERA procedure that produces modes without adjoint information, but for this procedure, the resulting models are not balanced, and do not perform as well in examples. We present a detailed comparison of the methods, and illustrate them on an example of the flow past an inclined flat plate at a low Reynolds number.Comment: 22 pages, 7 figure

    On the α−\alpha-decay of deformed actinide nuclei

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    α−\alpha-decay through a deformed potential barrier produces significant mixing of angular momenta when mapped from the nuclear interior to the outside. Using experimental branching ratios and either semi-classical or coupled-channels transmission matrices, we have found that there is a set of internal amplitudes which are essentially constant for all even--even actinide nuclei. These same amplitudes also give good results for the known anisotropic α−\alpha-particle emission of the favored decays of odd nuclei in the same mass region. PACS numbers: 23.60.+e, 24.10.Eq, 27.90.+bComment: 5 pages, latex (revtex style), 2 embedded postscript figures uuencoded gz-compressed .tar file To appear in Physical Review Letter

    Developing a framework for the analysis of power through depotentia

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    Stakeholder participation in tourism policy-making is usually perceived as providing a means of empowerment. However participatory processes drawing upon stakeholders from traditionally empowered backgrounds may provide the means of removing empowerment from stakeholders. Such an outcome would be in contradiction to the claims that participatory processes improve both inclusivity and sustainability. In order to form an understanding of the sources through which empowerment may be removed, an analytical perspective has been developed deriving from Lukes�s views of power dating from 1974. This perspective considers the concept of depotentia as the removal of �power to� without speculating upon the underlying intent and also provides for the multidimensionality of power to be examined within a single study. The application of this analytical perspective has been tested upon findings of the government-commissioned report of the Countryside and Community Research Unit in 2005. The survey and report investigated the progress of Local Access Forums in England created in response to the Countryside and Rights of Way Act 2000. Consideration of the data from this perspective permits the classification of individual sources of depotentia which can each be addressed and potentially enable stakeholder groups to reverse loss of empowerment where it has occurred

    Stationary Flows of the Parabolic Potential Barrier in Two Dimensions

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    In the two-dimensional isotropic parabolic potential barrier V(x,y)=V0−mγ2(x2+y2)/2V(x, y)=V_0 -m\gamma^2 (x^2+y^2)/2, though it is a model of an unstable system in quantum mechanics, we can obtain the stationary states corresponding to the real energy eigenvalue V0V_0. Further, they are infinitely degenerate. For the first few eigenstates, we will find the stationary flows round a right angle that are expressed by the complex velocity potentials W=±γz2/2W=\pm\gamma z^2/2.Comment: 12 pages, AmS-LaTeX, 4 figure

    Terahertz generation by optical rectification in uniaxial birefringent crystals

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    The angular dependence of terahertz (THz) emission from birefringent crystals can differ significantly from that of cubic crystals. Here we consider optical rectification in uniaxial birefringent materials, such as chalcopyrite crystals. The analysis is verified in (110)-cut ZnGeP_2 and compared to (zincblende) GaP. Although the crystals share the same nonzero second-order tensor elements, the birefringence in chalcopyrite crystals cause the pump pulse polarization to evolve as it propagates through the crystal, resulting in a drastically different angular dependence in chalcopyrite crystals. The analysis is extended to {012}- and {114}-cut chalcopyrite crystals and predicts more efficient conversion for the {114} crystal cut over the {012}- and {110}-cuts.Comment: 6 pages, 3 figure, online journal articl

    Strengths and limitations of a tool for monitoring and evaluating First Peoples' health promotion from an ecological perspective

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    Background: An ecological approach to health and health promotion targets individuals and the environmental determinants of their health as a means of more effectively influencing health outcomes. The approach has potential value as a means to more accurately capture the holistic nature of Australian First Peoples’ health programs and the way in which they seek to influence environmental, including social, determinants of health. Methods: We report several case studies of applying an ecological approach to health program evaluation using a tool developed for application to mainstream public health programs in North America – Richard’s ecological coding procedure. Results: We find the ecological approach in general, and the Richard procedure specifically, to have potential for broader use as an approach to reporting and evaluation of health promotion programs. However, our experience applying this tool in academic and community-based program evaluation contexts, conducted in collaboration with First Peoples of Australia, suggests that it would benefit from cultural adaptations that would bring the ecological coding procedure in greater alignment with the worldviews of First Peoples and better identify the aims and strategies of local health promotion programs. Conclusions: Establishing the cultural validity of the ecological coding procedure is necessary to adequately capture the underlying program activities of community-based health promotion programs designed to benefit First Peoples, and its collaborative implementation with First Peoples supports a human rights approach to health program evaluation.Kevin Rowley, Joyce Doyle, Leah Johnston, Rachel Reilly, Leisa McCarthy, Mayatili Marika, Therese Riley, Petah Atkinson, Bradley Firebrace, Julie Calleja and Margaret Carg

    An exploratory study looking at the relationship marketing techniques used in the music festival industry

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    There are current issues and trends in the music festival market, which may affect the success of an event, and market saturation is at the forefront of these issues. Previous literature, maintaining the need for a marketing approach to festivals, identifi es the need for maintaining strong stakeholder relationships in order to succeed in a business environment; attention has been focused to the theory of relationship marketing (RM) because of the recognition that this practice is complementary to the marketing of festivals. The very nature of the music festival as an annual, usually, 4-day event means that effective marketing is needed to keep connections with the consumer throughout the year. This article focuses on the RM techniques utilised within the music festival industry from the viewpoint of the festival organiser in an attempt to establish how festival organisations value and monitor organisational relationships. This article explores the extent to which these relationships are valued and managed; furthermore, the variations between these intricate relationships are considered by focusing on those held with the organisation ’ s consumers and sponsors, the results of which have provided the ability to establish the importance and relevance of RM to the industry and further identify the marketing communication methods employed to establish and maintain such relationships. In-depth, convergent interviews have been conducted with a segment of music festival organisers from a range of events. The results have been integrated with the study of current literature to best exemplify these issues. It has been established that RM has a strong role in today ’ s commercial and independent music festival industry; technological advances are enabling the organiser to support online relationships further and increase consumer loyalty. There is a need to expand the research further because of the complexity of organisational relationships and the varying categories of festivals

    Standard Model Contributions to the Neutrino Index of Refraction in the Early Universe

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    With the standard electroweak interactions, the lowest-order coherent forward scattering amplitudes of neutrinos in a CP symmetric medium (such as the early universe) are zero, and the index of refraction of a propagating neutrino can only arise from the expansion of gauge boson propagators, from radiative corrections, and from new physics interactions. Motivated by nucleosynthesis constraints on a possible sterile neutrino (suggested by the solar neutrino deficit and a possible 17 keV17\ keV neutrino), we calculate the standard model contributions to the neutrino index of refraction in the early universe, focusing on the period when the temperature was of the order of a few MeVMeV. We find sizable radiative corrections to the tree level result obtained by the expansion of the gauge boson propagator. For νe+e(eˉ)→νe+e(eˉ)\nu_e+e(\bar{e})\to \nu_e+e(\bar{e}) the leading log correction is about +10%+10\%, while for νe+νe(νˉe)→νe+νe(νˉe)\nu_e+\nu_e(\bar{\nu}_e)\to \nu_e+\nu_e(\bar{\nu}_e) the correction is about +20%+20\%. Depending on the family mixing (if any), effects from different family scattering can be dominated by radiative corrections. The result for ν+γ→ν+γ\nu+\gamma\to\nu+\gamma is zero at one-loop level, even if neutrinos are massive. The cancellation of infrared divergence in a coherent process is also discussed.Comment: 46pp, 13 figures (not included), UPR-0495

    SU(16) grandunification: breaking scales, proton decay and neutrino magnetic moment

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    We give a detailed renormalization group analysis for the SU(16) grandunified group with general breaking chains in which quarks and leptons transform separately at intermediate energies. Our analysis includes the effects of Higgs bosons. We show that the grandunification scale could be as low as ∼108.5\sim 10^{8.5} GeV and give examples where new physics could exist at relatively low energy (∼250\sim 250 GeV). We consider proton decay in this model and show that it is consistent with a low grandunification scale. We also discuss the possible generation of a neutrino magnetic moment in the range of 10−1110^{-11} to 10−10μB10^{-10}\mu_B with a very small mass by the breaking of the embedded SU(2)ν_\nu symmetry at a low energy.Comment: (16 pages in REVTEX + 6 figures not included) OITS-49
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