1,207 research outputs found
Presence of Salmonella and Campylobacter spp. in Wild Small Mammals on Organic Farms
The presence of Salmonella and Campylobacter spp. in rodents and insectivores (n 282) was investigated
on organic farms. Infections were encountered in house mice (8 of 83 Campylobacter positive and 1 of 83
Salmonella sp. strain Livingstone positive) and brown rats (1 of 8 Campylobacter positive) but not in other
species. No shared Campylobacter genotypes were found between rodent and pig manure isolates. Effective
on-farm rodent management is recommended
Hawking radiation in different coordinate settings: Complex paths approach
We apply the technique of complex paths to obtain Hawking radiation in
different coordinate representations of the Schwarzschild space-time. The
coordinate representations we consider do not possess a singularity at the
horizon unlike the standard Schwarzschild coordinate. However, the event
horizon manifests itself as a singularity in the expression for the
semiclassical action. This singularity is regularized by using the method of
complex paths and we find that Hawking radiation is recovered in these
coordinates indicating the covariance of Hawking radiation as far as these
coordinates are concerned.Comment: 18 pages, 2 figures, Uses IOP style file; final version; accepted in
Class. Quant. Gra
If you say so:A mixed-method study of hospital mergers and quality of care
Background: Despite a lack of supporting evidence, hospitals continue to merge in pursuit of quality improvements. Purpose: We seek to develop a more thorough understanding of the quality effects of hospital mergers by integrating various theoretical perspectives using a mixed-methods design. Methodology: Quantitatively, we tested the quality effect of all consummated hospital mergers in the Netherlands between 2008 and 2014 on 15 quality indicators (with 82 measurements at hospital, department, and disease levels) using a difference-in-difference approach with Bonferroni correction. Qualitatively, we conducted three comparative case studies to examine how hospital executives, managers, and medical professionals perceive the quality impact of hospital mergers. Results: Our quantitative results reveal few significant effects of hospital mergers on quality of care at all levels. After applying Bonferroni correction, two quality indicators are negatively associated with hospital mergers. However, the qualitative results indicate that hospital staff have positive perceptions of the mergers’ quality implications, resulting from scale and shock effects. Conclusion: The perceptions of hospital staff regarding mergers diametrically oppose their measurable effects. However, the operationalization of quality by hospital staff members differs considerably from the way it is quantitatively measured. The positive perceptions of hospital staff toward mergers could further contribute to the institutionalization of mergers as a quality improvement strategy. Practice Implications: Hospital managers seeking measurable quality improvements should be wary of merging, despite potential positive perceptions toward it within the organization. In case they do decide to merge, mitigating difficulties in the postmerger integration processes seem most pertinent to achieve measurable effects
Nietzsche, Sin and Redemption
In this thesis, I use the work of Friedrich Nietzsche to offer a detailed account of existential sin. I show that existential sin as a form of self-understanding is deeply embedded in the Christian theological tradition, and that Nietzsche’s account of existential sin should be understood as part of this same tradition. In my reading of On the Genealogy of Morality I show that we need to place sin in close relation to bad conscience, guilt and the genealogical method itself. However, despite being grounded in Christian thought and dependent upon the figure of the Christian God in its origin and emergence, I follow Nietzsche in positing that existential sin continues to exist after the death of God. It is by considering sin as not only a form of self-understanding, but also as a cultural memory, that we can make sense of this claim.
For Nietzsche existential sin is at its root a mistaken understanding of human nature that has taken hold of us through Christianity. However, I argue that we need to consider existential sin as a socio-historical answer to the ontological problem of meaningless suffering. Existential sin responds to a fundamental experience of the human condition. With this in mind, in the final chapter of the thesis I examine possible avenues of redemption from post-Christian sin. What options are open to the person suffering from post-Christian sin-consciousness if she cannot turn to religious narratives? I argue that Nietzsche’s redemptive method of genealogy is not sufficient, and that life-affirmation is too demanding. However, a weaker version of life-affirmation in which meaningless suffering is affirmed as necessary, but not desired, does provide a promising alternative answer to the problem of meaningless suffering
Orbital and spin physics in LiNiO2 and NaNiO2
We derive a spin-orbital Hamiltonian for a triangular lattice of e_g orbital
degenerate (Ni^{3+}) transition metal ions interacting via 90 degree
superexchange involving (O^{2-}) anions, taking into account the on-site
Coulomb interactions on both the anions and the transition metal ions. The
derived interactions in the spin-orbital model are strongly frustrated, with
the strongest orbital interactions selecting different orbitals for pairs of Ni
ions along the three different lattice directions. In the orbital ordered
phase, favoured in mean field theory, the spin-orbital interaction can play an
important role by breaking the U(1) symmetry generated by the much stronger
orbital interaction and restoring the threefold symmetry of the lattice. As a
result the effective magnetic exchange is non-uniform and includes both
ferromagnetic and antiferromagnetic spin interactions. Since ferromagnetic
interactions still dominate, this offers yet insufficient explanation for the
absence of magnetic order and the low-temperature behaviour of the magnetic
susceptibility of stoichiometric LiNiO_2. The scenario proposed to explain the
observed difference in the physical properties of LiNiO_2 and NaNiO_2 includes
small covalency of Ni-O-Li-O-Ni bonds inducing weaker interplane superexchange
in LiNiO_2, insufficient to stabilize orbital long-range order in the presence
of stronger intraplane competition between superexchange and Jahn-Teller
coupling.Comment: 33 pages, 12 postscript figures, uses iopams.sty . This article
features in New Journal of Physics as part of a Focus Issue on Orbital
Physics - all contributions may be freely accessed at
(http://stacks.iop.org/1367-2630/6/i=1/a=E05). The published version of this
article may be found at http://stacks.iop.org/1367-2630/7/12
Delayed relaxation of highly excited naphthalene cations
The efficiency of energy transfer in ultrafast electronic relaxation of molecules depends strongly on the complex interplay between electronic and nuclear motion. In this study we use wavelength-selected XUV pulses to induce relaxation dynamics of highly excited cationic states of naphthalene. Surprisingly, the observed relaxation lifetimes increase with the cationic excitation energy. We propose that this is a manifestation of a quantum mechanical population trapping that leads to delayed relaxation of molecules in the regions with a high density of excited states. © 2019 Published under licence by IOP Publishing Ltd
Endoscopic tri-modal imaging for surveillance in ulcerative colitis: randomised comparison of high-resolution endoscopy and autofluorescence imaging for neoplasia detection; and evaluation of narrow-band imaging for classification of lesions
Background: Endoscopic tri-modal imaging (ETMI) incorporates white light endoscopy (WLE), autofluorescence imaging (AFI) and narrow-band imaging (NBI). Aims: To assess the value of ETMI for the detection and classification of neoplasia in patients with longstanding ulcerative colitis. Design: Randomised comparative trial of tandem colonoscopies. Setting: Academic Medical Centre Amsterdam, Netherlands. Patients and methods: Fifty patients with ulcerative colitis underwent surveillance colonoscopy with ETMI. Each colonic segment was inspected twice, once with AFI and once with WLE, in random order. All detected lesions were inspected by NBI for Kudo pit pattern analysis and additional random biopsies were taken. Main outcome measures: Neoplasia miss-rates of AFI and WLE, and accuracy of the Kudo classification by NBI. Results: Among patients assigned to inspection with AFI first (n = 25), 10 neoplastic lesions were primarily detected. Subsequent WLE detected no additional neoplasia. Among patients examined with WLE first (n = 25), three neoplastic lesions were detected; subsequent inspection with AFI added three neoplastic lesions. Neoplasia miss-rates for AFI and WLE were 0% and 50% (p = 0.036). The Kudo classification by NBI had a sensitivity and specificity of 75% and 81%; however, all neoplasia was coloured purple on AFI (sensitivity 100%). No additional patients with neoplasia were detected by random biopsies. Conclusion: Autofluorescence imaging improves the detection of neoplasia in patients with ulcerative colitis and decreases the yield of random biopsies. Pit pattern analysis by NBI has a moderate accuracy for the prediction of histology, whereas AFI colour appears valuable in excluding the presence of neoplasia. Trial registration number: ISRCTN0527274
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