748 research outputs found

    Physics and Performance Evaluation Group

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    We summarize the objectives and results of the ``international scoping study of a future neutrino factory and superbeam facility'' (ISS) physics working group. Furthermore, we discuss how the ISS study should develop into a neutrino factory design study (IDS-NF) from the point of view of physics and performance evaluation.Comment: 3 pages, 1 figure. Plenary talk given at the NuFact 07 conferenc

    On the improvement of the low energy neutrino factory

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    The low energy neutrino factory has been proposed as a very sensitive setup for future searches for CP violation and matter effects. Here we study how its performance is affected when the experimental specifications of the setup are varied. Most notably, we have considered the addition of the 'platinum' nu_{mu} -> nu_{e} channel. We find that, whilst theoretically the extra channel provides very useful complementary information and helps to lift degeneracies, its practical usefulness is lost when considering realistic background levels. Conversely, an increase in statistics in the 'golden' nu_{e} -> nu_{mu} channel and, to some extent, an improvement in the energy resolution, lead to an important increase in the performance of the facility, given the rich energy dependence of the 'golden' channel at these energies. We show that a low energy neutrino factory with a baseline of 1300 km, muon energy of 4.5 GeV, and either a 20 kton totally active scintillating detector or 100 kton liquid argon detector, can have outstanding sensitivity to the neutrino oscillation parameters theta13, delta and the mass hierarchy. For our estimated exposure of 2.8 x 10^{23} kton x decays per muon polarity, the low energy neutrino factory has sensitivity to theta13 and delta for sin^{2}(2theta13) > 10^{-4} and to the mass hierarchy for sin^{2}(2theta13) > 10^{-3}.Comment: 13 pages, 8 eps figures. Version published in PRD - experimental section with preliminary results removed, abstract and conclusions re-written accordingly, title changed, author list amended

    A Spatiotemporal Analysis of Climatic Drivers for Observed Changes in Sahelian Vegetation Productivity (1982–2007)

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    Linear trend analysis and seasonal trend analysis are performed on gridded data of vegetation, rainfall, solar radiation flux, and air temperature, in order to examine the influence of the past three decades of climate variability and change on the Sahelian vegetation dynamics. Per-pixel correlation analyses are conducted on annual and monthly data, and analyses of change in the potential climatic constraints to the natural vegetation development from 1982–2007 are performed. The results reveal two distinct periods: (a) 1982–1994 marked by large increases in vegetation productivity and rainfall and little change in average air temperatures and solar radiation and (b) 1995–2007 characterized by no distinct trends in vegetation productivity and rainfall and increase in average air temperatures and decrease in solar radiation flux. Correlations between vegetation productivity and climatic constraints were found to be statistically significant only for rainfall explaining only a moderate degree of observed NDVI variation, indicating that nonclimatic factors are also important for the Sahelian vegetation dynamics

    Estimation of latent variable models for ordinal data via fully exponential Laplace approximation

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    Latent variable models for ordinal data represent a useful tool in different fields of research in which the constructs of interest are not directly observable. In such models, problems related to the integration of the likelihood function can arise since analytical solutions do not exist. Numerical approximations, like the widely used Gauss Hermite (GH) quadrature, are generally applied to solve these problems. However, GH becomes unfeasible as the number of latent variables increases. Thus, alternative solutions have to be found. In this paper, we propose an extended version of the Laplace method for approximating the integrals, known as fully exponential Laplace approximation. It is computational feasible also in presence of many latent variables, and it is more accurate than the classical Laplace method

    Carbonic Acid Revisited: Vibrational Spectra, Energetics and the Possibility of Detecting an Elusive Molecule

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    We calculate harmonic frequencies of the three most abundant carbonic acid conformers. For this, different model chemistries are investigated with respect to their benefits and shortcomings. Based on these results we use perturbation theory to calculate anharmonic corrections at the {\omega}B97XD/aug-cc-pVXZ, X=D,T,Q, level of theory and compare them with recent experimental data and theoretical predictions. A discrete variable representation method is used to predict the large anharmonic contributions to the frequencies of the stretching vibrations in the hydrogen bonds in the carbonic acid dimer. Moreover, we re-investigate the energetics of the formation of the carbonic acid dimer from its constituents water and carbon dioxide using a high-level extrapolation method. We find that the {\omega}B97XD functional performs well in estimating the fundamental frequencies of the carbonic acid conformers. Concerning the reaction energetics, the accuracy of {\omega}B97XD is even comparable to the high-level extrapolation method. We discuss possibilities to detect carbonic acid in various natural environments such as Earth's and Martian atmospheres.Comment: 22 pages, 2 figures, 5 tables. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. The following article appeared in AIP Advances 2, 032180 (2012) and may be found at http://link.aip.org/link/?ADV/2/03218

    Farmer opinion on the process of health and welfare planning in Austria, Denmark, Germany, Norway and Switzerland

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    This report serves as a deliverable from the ANIPLAN project, with the original title ‘Evaluation report on state of the art regarding animal health and welfare planning in the participating countries’ (Deliverable 5.1). We chose to focus on the farmers’ perspective in each country, and ask the farmers who had participated in our project how they perceived the process of animal health and welfare planning. We did that using a questionnaire which each participant used in an interview with the farmer, asking some specific questions with the aim to evaluate how the farmers had experienced the ANIPLAN approach. We found that this focus was important as a supplement to other outcomes from the project, such as reduction of medicines (Ivemeyer et al., 2011) and improvement of animal based parameters (Gratzer et al., 2011). Furthermore potential scenarios for implementation of this concept into practice can be developed from the farmers responses

    Animal health and welfare planning in organic dairy cattle farms

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    Continuous development is needed within the farm to reach the goal of good animal health and welfare in organic livestock farming. The very different conditions between countries call for models that are relevant for different farming types and can be integrated into local practice and be relevant for each type of farming context. This article reviews frameworks, principles and practices for animal health and welfare planning which are relevant for organic livestock farming. This review is based on preliminary analyses carried out within a European project (acronym ANIPLAN) with participants from seven countries. The process begins with gathering knowledge about the current status within a given herd as background for making decisions and planning future improvements as well as evaluating already implemented improvements. Respectful communication between the owner of the herd and other farmers as well as animal health and welfare professionals (veterinarians and advisors) is paramount. This paper provides an overview of some current animal health and welfare planning initiatives and explains the principles of animal health and welfare planning which are being implemented in ANIPLAN partner countries, in collaboration with groups of organic farmers and organisations

    Farmer groups for animal health and welfare planning in European organic dairy herds

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    A set of common principles for active animal health and welfare planning in organic dairy farming has been developed in the ANIPLAN project group of seven European countries. Health and welfare planning is a farmer‐owned process of continuous development and improvement and may be practised in many different ways. It should incorporate health promotion and disease handling, based on a strategy where assessment of current status and risks forms the basis for evaluation, action and review. Besides this, it should be 1) farm-specific, 2) involve external person(s) and 3) external knowledge, 4) be based on organic principles, 5) be written, and 6) acknowledge good aspects in addition to targeting the problem areas in order to stimulate the learning process. Establishing farmer groups seems to be a beneficial way of stimulating a dynamic development on the farms towards continuous improvement, as in this case with focus on animal health and welfare planning. Various factors influence the process in different contexts, e.g. geographical, cultural, traditional factors, and a proper analysis of the situation as well as the purpose of the group is necessary, and can relevantly be negotiated and co‐developed with farmers as well as facilitators before being implemented. Farmer groups based on farmer‐to‐farmer advice and co‐development need a facilitator who takes on the role of facilitating the process and ‘decodes’ him‐ or herself from being ‘expert’
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