4,930 research outputs found

    Nuclear quantum optics with x-ray laser pulses

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    The direct interaction of nuclei with super-intense laser fields is studied. We show that present and upcoming high-frequency laser facilities, especially together with a moderate acceleration of the target nuclei, do allow for resonant laser-nucleus interaction. These direct interactions may be utilized for the optical measurement of nuclear properties such as the transition frequency and the dipole moment, thus opening the field of nuclear quantum optics. As ultimate goal, one may hope that direct laser-nucleus interactions could become a versatile tool to enhance preparation, control and detection in nuclear physics.Comment: 5 pages, 3 eps figures, revised versio

    How to Conduct Store Observations of Tobacco Marketing and Products

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    As tobacco companies continue to heavily market their products at the point of sale, tobacco control groups seek strategies to combat the negative effects of this marketing. Store observations, which have been widely used by researchers and practitioners alike, are an excellent surveillance tool. This article provides a guide for public health practitioners interested in working in the tobacco retail environment by detailing the steps involved in conducting store observations of tobacco marketing and products including 1) obtaining tobacco product retailer lists, 2) creating measures, 3) selecting a mode of data collection, 4) training data collectors, and 5) analyzing data. We also highlight issues that may arise while in the field and provide information on disseminating results of store observations, including the potential policy implications

    Proposal to inform European institutions regarding the regulation of conscientious objection to abortion.

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    The aim of this paper is to define a set of proposals to inform European institutions in the regulation of Conscientious Objection to abortion. The board of the European Society of Contraception and Reproductive Health Care (ESC) was informed on the elements that should in the opinion of the authors be included in a future regulation of Conscientious Objection to abortion in Europe. These elements are outlined in this paper and the debate about them could form the basis for recommendations to the international scientific community and the European institutions. As current measures governing the principle of conscientious objection result in negative consequences regarding women's access to sexual and reproductive health services, they should be changed. Healthcare services should adopt measures to guarantee that a woman's right to voluntary abortion is not limited by the practitioner's stance on the principle of conscientious objection. In the countries where conscientious objection is allowed, the regulation must clearly delineate the extent of the duties and the exemptions of professionals based on the principles of established social consensus. The recommendations included in this document specify measures on the rights of women, the rights and duties of the practitioner, the role of institutions and the role of professional associations

    Gravity a la Born-Infeld

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    A simple technique for the construction of gravity theories in Born-Infeld style is presented, and the properties of some of these novel theories are investigated. They regularize the positive energy Schwarzschild singularity, and a large class of models allows for the cancellation of ghosts. The possible correspondence to low energy string theory is discussed. By including curvature corrections to all orders in alpha', the new theories nicely illustrate a mechanism that string theory might use to regularize gravitational singularities.Comment: 21 pages, 2 figures, new appendix B with corrigendum: Class. Quantum Grav. 21 (2004) 529

    P01-029 – Microscopic hematuria in FMF

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    Ultrahigh frequency oscillations and multimode dynamics in vertical cavity surface emitting lasers

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    Includes bibliographical references (page 187).We report the observation of ultrahigh frequency oscillations of up to 240 GHz in optically gain switched vertical cavity surface emitting lasers. These oscillations are shown to be produced by multimode emission through mode competition (10-30 GHz) or mode beating (above 100 GHz). Although these oscillations are not related to the intrinsic modulation bandwidth, some of them could be mistaken for relaxation oscillations, calling for careful interpretation of the results of this type of experiments. The highest frequencies observed for single mode relaxation oscillations were about 9 GHz in agreement with values of modulation bandwidth reported in the literature

    Transverse mode dynamics in vertical cavity surface emitting lasers excited by fast electrical pulses

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    Includes bibliographical references (page 592).We report measurements of the transient multimode dynamics of vertical cavity surface emittin glasers excited by short (100-200 ps rise times, 1 ns duration) electrical pulses. Fast changes on the spatial distribution of the output power and strong mode competition are observed. Numerical simulations show that the observed dynamics are due to the partial overlap of the different transverse modes through spatial hole burning

    The nuclear AC-Stark shift in super-intense laser fields

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    The direct interaction of super-intense laser fields in the optical frequency domain with nuclei is studied. As main observable, we consider the nuclear AC-Stark shift of low-lying nuclear states due to the off-resonant excitation by the laser field. We include the case of accelerated nuclei to be able to control the frequency and the intensity of the laser field in the nuclear rest frame over a wide range of parameters. We find that AC-Stark shifts of the same order as in typical quantum optical systems relative to the respective transition frequencies are feasible with state-of-the-art or near-future laser field intensities and moderate acceleration of the target nuclei. Along with this shift, we find laser-induced modifications to the proton root-mean-square radii and to the proton density distribution. We thus expect direct laser-nucleus interaction to become of relevance together with other super-intense light-matter interaction processes such as pair creation.Comment: 10 pages, 2 eps figure

    German macro: how it's different and why that matters. EPC Discussion Paper, May 2016

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    Do the macroeconomics of the German political establishment really differ from standard western macroeconomics? That question was the starting point for the seminar on ‘German macro: How it’s Different and Why that Matters’, which was held at Heriot-Watt University in December 2015, with financial support from the Scottish Institute for Research in Economics (SIRE) and the Money, Macro & Finance Research Group (MMF). This ebook, edited by George Bratsiotis and David Cobham, is the result of that exercise; six of the papers were presented at the seminar in earlier versions, and the editors sought some additional papers to complete the range of perspectives offered. The authors all sought out to discover whether or not there is something unique about German macroeconomics, and in what ways it differs from standard western macroeconomics; is it true that the former neglects demand management (although it may be quite interventionist in other ways), rejects debt relief and emphasises structural reform designed to improve competitiveness as the (only) key to economic growth? How much of whatever difference exists is due to a well worked out set of ideas in the form of Ordoliberalism? In what way does it relate to Germany’s own experiences in different periods? And how far is this the result of political preferences and how much do the idiosyncrasies of these German views matter, for the development of the Eurozone and indeed the health of the German economy
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