42,881 research outputs found

    Design Context and Nursing Roles

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    Spin 1 inversion: a Majorana tensor force for deuteron alpha scattering

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    We demonstrate, for the first time, successful S-matrix to potential inversion for spin one projectiles with non-diagonal Sll′jS^j_{ll'} yielding a TRT_{\rm R} interaction. The method is a generalization of the iterative-perturbative, IP, method. We present a test case indicating the degree of uniqueness of the potential. The method is adapted, using established procedures, into direct observable to potential inversion, fitting σ\sigma, iT11{\rm i}T_{11}, T20T_{20}, T21T_{21} and T22T_{22} for d + alpha scattering over a range of energies near 10 MeV. The TRT_{\rm R} interaction which we find is very different from that proposed elsewhere, both real and imaginary parts being very different for odd and even parity channels.Comment: 7 pages Revtex, 4 ps figure

    Belief in public efficacy, trust and attitudes to modern genetic science

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    The official published version can be accessed from the links below - Copyright @ 2007 Wiley-BlackwellGovernment and policymakers want to engage the public in a dialogue about the conduct and consequences of science and increasingly seek to actively involve citizens in decision-making processes. Implicit in this thinking is that greater transparency and public inclusion will help dispel fears associated with new scientific advancements, foster greater public trust in those accountable, and ultimately increase the acceptability of new technologies. Less understood, however, are public perceptions about such high-level involvement in science and how these map onto public trust and attitudes within a diverse population. This article uses the concept of public efficacy—the extent to which people believe that the public might be able to affect the course of decision making—to explore differences in trust, attentiveness, and attitudes toward modern genetic science. Using nationally representative data from the 2003 British Social Attitudes Survey, we begin by examining the characteristics of those who have a positive belief about public involvement in this area of scientific inquiry. We then focus on how this belief maps on to indicators of public trust in key stakeholder groups, including the government and genetic scientists. Finally, we consider the relationship between public efficacy and trust and attitudes toward different applications of genetic technology. Our findings run contrary to assumptions that public involvement in science will foster greater trust and lead to a climate of greater acceptance for genetic technology. A belief in public efficacy does not uniformly equate with more trusting attitudes toward stakeholders but is associated with less trust in government rules. Whereas trust is positively correlated with more permissive attitudes about technologies such as cloning and gene therapy, people who believe in high-level public involvement are less likely to think that these technologies should be allowed than those who do not.The support of the Economics and Social Research Council (ESRC) is acknowledged. The work arises from the ESRC Attitudes to Genomics project L145251005

    Geometric scaling in ultrahigh energy neutrinos and nonlinear perturbative QCD

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    The ultrahigh energy neutrino cross section is a crucial ingredient in the calculation of the event rate in high energy neutrino telescopes. Currently there are several approaches which predict different behaviors for its magnitude for ultrahigh energies. In this contribution is presented a summary of current predictions based on the non-linear QCD evolution equations, the so-called perturbative saturation physics. In particular, predictions are shown based on the parton saturation approaches and the consequences of geometric scaling property at high energies are discussed. The scaling property allows an analytical computation of the neutrino scattering on nucleon/nucleus at high energies, providing a theoretical parameterization.Comment: 6 pages, one figure. Presented at First Caribbean Symposium on Nuclear and Astroparticle Physics - STARS2011, La Habana, Cuba, 2011. arXiv admin note: substantial text overlap with arXiv:1011.2718 by different author

    Renormalized broken-symmetry Schwinger-Dyson equations and the 2PI-1/N expansion for the O(N) model

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    We derive the renormalized Schwinger-Dyson equations for the one- and two-point functions in the auxiliary field formulation of λϕ4\lambda \phi^4 field theory to order 1/N in the 2PI-1/N expansion. We show that the renormalization of the broken-symmetry theory depends only on the counter terms of the symmetric theory with ϕ=0\phi = 0. We find that the 2PI-1/N expansion violates the Goldstone theorem at order 1/N. In using the O(4) model as a low energy effective field theory of pions to study the time evolution of disoriented chiral condensates one has to {\em{explicitly}} break the O(4) symmetry to give the physical pions a nonzero mass. In this effective theory the {\em additional} small contribution to the pion mass due to the violation of the Goldstone theorem in the 2-PI-1/N equations should be numerically unimportant

    How to Couple from the Past Using a Read-Once Source of Randomness

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    We give a new method for generating perfectly random samples from the stationary distribution of a Markov chain. The method is related to coupling from the past (CFTP), but only runs the Markov chain forwards in time, and never restarts it at previous times in the past. The method is also related to an idea known as PASTA (Poisson arrivals see time averages) in the operations research literature. Because the new algorithm can be run using a read-once stream of randomness, we call it read-once CFTP. The memory and time requirements of read-once CFTP are on par with the requirements of the usual form of CFTP, and for a variety of applications the requirements may be noticeably less. Some perfect sampling algorithms for point processes are based on an extension of CFTP known as coupling into and from the past; for completeness, we give a read-once version of coupling into and from the past, but it remains unpractical. For these point process applications, we give an alternative coupling method with which read-once CFTP may be efficiently used.Comment: 28 pages, 2 figure

    Earth Radiation budget satellite system studies

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    The scientific objectives and the associated mission analysis, instrument definition, and data analysis methods are discussed
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