14,197 research outputs found

    A Hidden Broad-Line Region in the Weak Seyfert 2 Galaxy NGC 788

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    We have detected a broad H alpha emission line in the polarized flux spectrum of the Seyfert 2 galaxy NGC 788, indicating that it contains an obscured Seyfert 1 nucleus. While such features have been observed in ~15 other Seyfert 2s, this example is unusual because it has a higher fraction of galaxy starlight in its spectrum, a lower average measured polarization, and a significantly lower radio luminosity than other hidden Seyfert 1s discovered to date. This demonstrates that polarized broad-line regions can be detected in relatively weak classical Seyfert 2s, and illustrates why well-defined, reasonably complete spectropolarimetric surveys at H alpha are necessary in order to assess whether or not all Seyfert 2s are obscured Seyfert 1s.Comment: 10 pages using (AASTEX) aaspp4.sty and 4 postscript figures. Publications of the Astronomical Society of the Pacific, Research Notes, in pres

    Resonance absolute quantum reflection at selected energies

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    The possibility of the resonance reflection (100 % at maximum) is revealed. The corresponding exactly solvable models with the controllable numbers of resonances, their positions and widths are presented.Comment: 5 pages, 2 figure

    Compassion fatigue among nurses working with older adults

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    Nurses who care for older patients are exposed to significant suffering and loss that can lead to the development of compassion fatigue and burnout. An exploratory descriptive study was conducted to assess compassion fatigue, burnout, and compassion satisfaction in a group of 42 nurses who worked on a geriatric medicine unit using the Professional Quality of Life (ProQOL) compassion satisfaction and compassion fatigue 5 scale. Nurses reported average levels of compassion fatigue, burnout, and compassion satisfaction. However, new nurses reported higher levels of compassion fatigue (p < .01) and burnout (p = .02) than experienced nurses. Findings suggest the need to purposely build a supportive environment that focuses on new nurses to reduce compassion fatigue and burnout while enhancing compassion satisfaction

    Functional renormalization group at large N for random manifolds

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    We introduce a method, based on an exact calculation of the effective action at large N, to bridge the gap between mean field theory and renormalization in complex systems. We apply it to a d-dimensional manifold in a random potential for large embedding space dimension N. This yields a functional renormalization group equation valid for any d, which contains both the O(epsilon=4-d) results of Balents-Fisher and some of the non-trivial results of the Mezard-Parisi solution thus shedding light on both. Corrections are computed at order O(1/N). Applications to the problems of KPZ, random field and mode coupling in glasses are mentioned

    Degree of quantum correlation required to speed up a computation

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    The one clean qubit model of quantum computation (DQC1) efficiently implements a computational task that is not known to have a classical alternative. During the computation, there is never more than a small but finite amount of entanglement present, and it is typically vanishingly small in the system size. In this paper, we demonstrate that there is nothing unexpected hidden within the DQC1 model -- Grover's Search, when acting on a mixed state, provably exhibits a speed-up over classical with guarantees as to the presence of only vanishingly small amounts of quantum correlations (entanglement and quantum discord) -- while arguing that this is not an artefact of the oracle-based construction. We also present some important refinements in the evaluation of how much entanglement may be present in DQC1, and how the typical entanglement of the system must be evaluated.Comment: 7 pages, 3 figure
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