13,766 research outputs found

    Very Special Relativity

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    By Very Special Relativity (VSR) we mean descriptions of nature whose space-time symmetries are certain proper subgroups of the Poincar\'e group. These subgroups contain space-time translations together with at least a 2-parameter subgroup of the Lorentz group isomorphic to that generated by Kx+JyK_{x}+J_{y} and KyJxK_{y}-J_{x}. We find that VSR implies special relativity (SR) in the context of local quantum field theory or of CP conservation. Absent both of these added hypotheses, VSR provides a simulacrum of SR for which most of the consequences of Lorentz invariance remain wholly or essentially intact, and for which many sensitive searches for departures from Lorentz invariance must fail. Several feasible experiments are discussed for which Lorentz-violating effects in VSR may be detectable.Comment: 3 pages, revte

    Getting research findings into practice : when to act on the evidence.

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    There is increasing interest in providing evidence based health care—that is, care in which healthcare professionals, provider managers, those who commission health care, the public, and policymakers consistently consider research evidence when making decisions. Purchasers, for example, should be able to influence the organisation and delivery of care (such as for cancer and stroke services) and the type and content of services (such as using chiropractic for back pain or dilatation and curettage and drug treatment for menorrhagia). Policymakers should ensure that policies on treatment reflect and are consistent with research evidence, and that the incentive structure within the health system promotes cost effective practice. They must also ensure that there is an adequate infrastructure for monitoring changes in practice and for producing, gathering, summarising, and disseminating evidence. Clinicians determine the day to day care patients receive in healthcare systems, and user groups (for example, patients, their families, and their representatives) are also beginning to play an important role in influencing healthcare decisions

    Gaussian Approximation of Collective Graphical Models

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    The Collective Graphical Model (CGM) models a population of independent and identically distributed individuals when only collective statistics (i.e., counts of individuals) are observed. Exact inference in CGMs is intractable, and previous work has explored Markov Chain Monte Carlo (MCMC) and MAP approximations for learning and inference. This paper studies Gaussian approximations to the CGM. As the population grows large, we show that the CGM distribution converges to a multivariate Gaussian distribution (GCGM) that maintains the conditional independence properties of the original CGM. If the observations are exact marginals of the CGM or marginals that are corrupted by Gaussian noise, inference in the GCGM approximation can be computed efficiently in closed form. If the observations follow a different noise model (e.g., Poisson), then expectation propagation provides efficient and accurate approximate inference. The accuracy and speed of GCGM inference is compared to the MCMC and MAP methods on a simulated bird migration problem. The GCGM matches or exceeds the accuracy of the MAP method while being significantly faster.Comment: Accepted by ICML 2014. 10 page version with appendi

    Disentangling Neutrino Oscillations

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    The theory underlying neutrino oscillations has been described at length in the literature. The neutrino state produced by a weak decay is usually portrayed as a linear superposition of mass eigenstates with, variously, equal energies or equal momenta. We point out that such a description is incomplete, that in fact, the neutrino is entangled with the other particle or particles emerging from the decay. We offer an analysis of oscillation phenomena involving neutrinos (applying equally well to neutral mesons) that takes entanglement into account. Thereby we present a theoretically sound proof of the universal validity of the oscillation formulae ordinarily used. In so doing, we show that the departures from exponential decay reported by the GSI experiment cannot be attributed to neutrino mixing. Furthermore, we demonstrate that the `Mossbauer' neutrino oscillation experiment proposed by Raghavan, while technically challenging, is correctly and unambiguously describable by means of the usual oscillation formalae.Comment: 16 page

    The Interaction of Movement and Sound

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    Senior Project submitted to The Division of Arts of Bard College

    A History of the Boone and Crockett Club: Milestones in Wildlife Conservation

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    This account covers the history of the Boone and Crockett Club up to 1954. Contents include: Introduction Chapter 1: Formation purposes and method of operating Chapter 2: National parks and monuments (History of Yellowstone Park, The Beginnings of Glacier National Park, Establishment of Mt. McKinley National Park) Chapter 3: The Forest Service (saving the Redwoods) Chapter 4: Madison Grant Forest and Elk Refuge Chapter 5: Club\u27s policies of game conservation and the national recreation conference Chapter 6: Efforts on behalf of specific game species Chapter 7: Waterfowl and other wildlife legislation Chapter 8: Alaska game law Chapter 9: Records of North American big game and North American big game competitions Chapter 10: Records of North American committee for international wildlife protection Chapter 11: The origin of the New York Zoological Society Chapter 12: Conclusion Appendix A: Books published by Boone and Crockett Club Appendix B: Chronological history of establishment of Mt. McKinley National Park Appendix C: Resolutions of National Recreation Conference Appendix D: Agreement for the restocking of the Black Gap Area of Texas and areas in Arizona with bighorn sheep Appendix E: The American Wild Fowlers, a brief history of the association Appendix F: Publications of American Committee Appendix G: Officers, by-laws and list of members of the Boone and Crockett Club - 1955https://scholarworks.umt.edu/sheldon/1000/thumbnail.jp

    LOCATION OF VERTICALLY LINKED INDUSTRIES UNDER FREE TRADE: CASE STUDIES OF ORANGE JUICE AND TOMATO PASTE IN THE WESTERN HEMISPHERE

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    The objective of this study was to determine the economic impact on the United States of removing tariff barriers on imports of concentrated orange juice and tomato paste from South America. The study highlighted an agglomeration model of industry location recognizing imperfect competition and increasing returns. The results were contrasted with those from a competitive model with conventional estimates of supply and demand elasticities. Because the assumptions of the models differed, the results also differed. The agglomeration model indicated that the United States would gain market share of production and processing with the removal of tariffs. In contrast, the competitive model indicated that the United States would lose market share in production and processing. According to the competitive model, US consumers would gain, producers would lose, and the government would lose from less tariff revenue, but the gains to consumers would offset losses elsewhere so that national income would rise. In South America, consumers would lose, producers would gain, and national incomes would rise. In the long run, countries would individually and collectively gain from freer trade in fruits and vegetables. Both models indicated that American production and processing of oranges and tomatoes would not be displaced by removing barriers to international trade.oranges, tomatoes, juice, paste, model, agglomeration, competitive, comparative advantage., Industrial Organization, International Relations/Trade,
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