244 research outputs found

    How I learned to stop worrying and love the bomb: An ethnography of speaking of a millenarian movement

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    Spin-resolved photoemission from Pd(111)

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    Schmiedeskamp B, Kessler B, Müller N, Schönhense G, Heinzmann U. Spin-resolved photoemission from Pd(111). Solid State Communications. 1988;65(7):665-670

    Spin polarized photoelectrons with unpolarized light in normal emission from Pt(110)

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    Irmer N, Frentzen F, Schmiedeskamp B, Heinzmann U. Spin polarized photoelectrons with unpolarized light in normal emission from Pt(110). Surface Science. 1994;307-309(2):1114-1117.The normally emitted photoelectrons of the reconstructed (1 x 2) surface of Pt(110) caused by off-normally incoming, unpolarized light are spin polarized. Measurements have been performed with the light of a gas discharge tube and spin polarization of up to 20% has been found for the spin polarization perpendicular to the reaction plane, defined by the momenta of incoming photon and outgoing electron beam. The polarization depends significantly on a rotation of the crystal about the surface normal. The experimental data are in good agreement with theoretical calculations of Feder's group [1] based upon the theory describing the photoemission in the one-step model

    Electronic Resonances in Rare-Gas Adsorbates Observed by Spin-Resolved Electron Spectroscopy

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    Schönhense G, Kessler B, Müller N, Schmiedeskamp B, Heinzmann U. Electronic Resonances in Rare-Gas Adsorbates Observed by Spin-Resolved Electron Spectroscopy. Physica Scripta. 1987;35(4):541-546

    Push, Pull, and Spill: A Transdisciplinary Case Study in Municipal Open Government

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    Municipal open data raises hopes and concerns. The activities of cities produce a wide array of data, data that is vastly enriched by ubiquitous computing. Municipal data is opened as it is pushed to, pulled by, and spilled to the public through online portals, requests for public records, and releases by cities and their vendors, contractors, and partners. By opening data, cities hope to raise public trust and prompt innovation. Municipal data, however, is often about the people who live, work, and travel in the city. By opening data, cities raise concern for privacy and social justice. This article presents the results of a broad empirical exploration of municipal data release in the City of Seattle. In this research, parties affected by municipal practices expressed their hopes and concerns for open data. City personnel from eight prominent departments described the reasoning, procedures, and controversies that have accompanied their release of data. All of the existing data from the online portal for the city were joined to Municipal open data raises hopes and concerns. The activities of cities produce a wide array of data, data that is vastly enriched by ubiquitous computing. Municipal data is opened as it is pushed to, pulled by, and spilled to the public through online portals, requests for public records, and releases by cities and their vendors, contractors, and partners. By opening data, cities hope to raise public trust and prompt innovation. Municipal data, however, is often about the people who live, work, and travel in the city. By opening data, cities raise concern for privacy and social justice. Results suggest the need for more comprehensive measures to manage the risk latent in opening city data. Cities should maintain inventories of data assets, produce data management plans pertaining to the activities of departments, and develop governance structures to deal with issues as they arise—centrally and amongst the various departments—with ex ante and ex post protocols to govern the push, pull, and spill of data. In addition, cities should consider conditioned access to pushed data, conduct audits and training around public records requests, and develop standardized model contracts to protect against the spill of data by third parties

    Spin echo formation in the presence of stochastic dynamics

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    Spin echo formation in magnetic field gradients in the presence of fast stochastic motion is studied for hyperpolarized He3 gas at different diffusivities. The fast translational motion leads to frequency shifts already during echo formation, which can be described analytically for a linear gradient. Despite complete signal loss at the position of the spin echo itself, considerable intensity can be preserved at an earlier time (2τ rather than 2τ, where τ is the pulse delay). Hence, the phenomenon is designated as a pseudo spin echo. © 2007 The American Physical Society.Fil: Zänker, Paul P.. Max Planck Institute For Polymer Research; AlemaniaFil: Schmidt, Jochen. Max Planck Institute For Polymer Research; AlemaniaFil: Schmiedeskamp, Jörg. Max Planck Institute For Polymer Research; AlemaniaFil: Acosta, Rodolfo Héctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Spiess, Hans W.. Max Planck Institute For Polymer Research; Alemani

    Spin polarization of the L-gap surface states on Au(111)

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    The electron spin polarization (ESP) of the L-gap surface states on Au(111) is investigated theoretically by means of first-principles electronic-structure and photoemission calculations. The surface states show a large spin-orbit induced in-plane ESP which is perpendicular to the in-plane wavevector, in close analogy to a two-dimensional electron gas with Rashba spin-orbit interaction. The surface corrugation leads to a small ESP component normal to the surface, being not reported so far. The surface-states ESP can be probed qualitatively and quantitatively by spin- and angle-resolved photoelectron spectroscopy, provided that the initial-state ESP is retained in the photoemission process and not obscured by spin-orbit induced polarization effects. Relativistic photoemission calculations provide detailed information on what photoemission set-ups allow to conclude from the photoelectron ESP on that of the surface states.Comment: 22 pages with 8 figure

    Final State Interaction Effects in pol 3He(pol e,e'p)

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    Asymmetries in quasi-elastic pol 3He(pol e,e'p) have been measured at a momentum transfer of 0.67 (GeV/c)^2 and are compared to a calculation which takes into account relativistic kinematics in the final state and a relativistic one-body current operator. With an exact solution of the Faddeev equation for the 3He-ground state and an approximate treatment of final state interactions in the continuum good agreement is found with the experimental data.Comment: 11 pages, 6 figures, submitted to Phys. Lett. B, revised version, sensitivity study to relativity and NN-potential adde

    Absence of major histocompatibility complex class II mediated immunity in pipefish, Syngnathus typhle: evidence from deep transcriptome sequencing

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    The major histocompatibility complex (MHC)-mediated adaptive immune system is the hallmark of gnathostome immune defence. Recent work suggests that cod-like fishes (Gadidae) lack important components of the MHC class II mediated immunity. Here, we report a putative independent loss of functionality of this pathway in another species, the pipefish Syngnathus typhle, that belongs to a distantly related fish family (Syngnathidae). In a deep transcriptome sequencing approach comprising several independent normalized and non-normalized expressed sequence tag (EST) libraries with approximately 7.5 × 108 reads, sequenced with two next generation platforms (454 and Illumina), we were unable to identify MHC class IIα/β genes as well as genes encoding associated receptors. Along with the recent findings in cod, our results suggest that immune systems of the Euteleosts may be more variable than previously assumed
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