783 research outputs found

    Collaborative public procurement: Institutional explanations of legitimised resistance

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    This paper reports on the barriers to regional collaborative procurement developed from an action research study of five UK public authorities in the emergency services sector. Despite political pressure to procure collaboratively, strategic avoidance responses of institutional logics and symbolic tick boxing legitimise stakeholder resistance to isomorphic forces and entrench operational barriers. The prevailing institutional logics are that regional collaborative procurement is unsuitable and risky, derived from procurement's lack of status and the emotive nature of the emergency services. Symbolic tick boxing is seen through collaboration that is limited to high profile spend categories, enabling organisations to demonstrate compliance while simultaneously retaining local decision-making for less visible, but larger areas of spend. The findings expose choice mechanisms in public procurement by exploring tensions arising from collaborative procurement strategies within, and between, organisations. Multiple stakeholders' perspectives add to current thinking on how organisations create institutional logics to avoid institutional pressure to procure collaboratively and how stakeholders legitimise their actions

    Cerebrovascular carbon dioxide reactivity in sheep: Effect of propofol or isoflurane anaesthesia

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    Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsPropofol and isoflurane are commonly used in neuroanaesthesia. Some published data suggest that the use of these agents is associated with impaired cerebral blood flow/carbon dioxide (CO₂) reactivity. Cerebrovascular CO₂ reactivity was therefore measured in three cohorts of adult merino sheep: awake (n=6), anaesthetized with steady-state propofol (15 mg/min; n=6) and anaesthetized with 2% isoflurane (n=6). Changes in cerebral blood flow were measured continuously from changes in velocities of blood in the sagittal sinus via a Doppler probe. Alterations in the partial pressure of carbon dioxide in arterial blood (PaCO₂) over the range 18-63 mmHg were achieved by altering either the inspired CO₂ concentration or the rate of mechanical ventilation. Cerebral blood flow/CO₂ relationships were determined by linear regression analysis, with changes in cerebral blood flow expressed as a percentage of the value for a PaCO₂ of 35 mmHg. Propofol decreased cerebral blood flow by 55% relative to pre-anaesthesia values (P=0.0001), while isoflurane did not significantly alter cerebral blood flow (88.45% of baseline, P=0.39). Significant linear relationships between cerebral blood flow and CO₂ tension were determined in all individual studies (r2 ranged from 0.72 to 0.99). The slopes of the lines were highly variable between individuals for the awake cohort (mean 4.73, 1.42-7.12, 95% CI). The slopes for the propofol (mean 2.67, 2.06-3.28, 95% CI) and isoflurane (mean 2.82, 2.19-3.45, 95% CI) cohorts were more predictable. However, there was no significant difference between these anaesthetic agents with respect to the CO₂ reactivity of cerebral blood flow.J. A. Myburgh, R. N. Upton, G. L. Ludbrook, A. Martinez, C. Granthttp://www.aaic.net.au/Article.asp?D=200137

    Perceived barriers towards healthy eating and their association with fruit and vegetable consumption

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    Acknowledgements The authors would like to thank the anonymous reviewer, staff at the Health Economics Research Unit and the Rowett Institute of Nutrition and Health for helpful comments on the manuscript. Funding This work was supported by the Scottish Government Rural and Environment Science and Analytical Services (RESAS) division.Peer reviewedPostprin

    Na2IrO3 as a spin-orbit-assisted antiferromagnetic insulator with a 340 meV gap

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    We study Na2IrO3 by ARPES, optics, and band structure calculations in the local-density approximation (LDA). The weak dispersion of the Ir 5d-t2g manifold highlights the importance of structural distortions and spin-orbit coupling (SO) in driving the system closer to a Mott transition. We detect an insulating gap {\Delta}_gap = 340 meV which, at variance with a Slater-type description, is already open at 300 K and does not show significant temperature dependence even across T_N ~ 15 K. An LDA analysis with the inclusion of SO and Coulomb repulsion U reveals that, while the prodromes of an underlying insulating state are already found in LDA+SO, the correct gap magnitude can only be reproduced by LDA+SO+U, with U = 3 eV. This establishes Na2IrO3 as a novel type of Mott-like correlated insulator in which Coulomb and relativistic effects have to be treated on an equal footing.Comment: Accepted in Physical Review Letters. Auxiliary and related material can be found at: http://www.phas.ubc.ca/~quantmat/ARPES/PUBLICATIONS/articles.htm

    Determining the Surface-To-Bulk Progression in the Normal-State Electronic Structure of Sr2RuO4 by Angle-Resolved Photoemission and Density Functional Theory

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    In search of the potential realization of novel normal-state phases on the surface of Sr2RuO4 - those stemming from either topological bulk properties or the interplay between spin-orbit coupling (SO) and the broken symmetry of the surface - we revisit the electronic structure of the top-most layers by ARPES with improved data quality as well as ab-initio LDA slab calculations. We find that the current model of a single surface layer (\surd2x\surd2)R45{\deg} reconstruction does not explain all detected features. The observed depth-dependent signal degradation, together with the close quantitative agreement with LDA+SO slab calculations based on the LEED-determined surface crystal structure, reveal that (at a minimum) the sub-surface layer also undergoes a similar although weaker reconstruction. This points to a surface-to-bulk progression of the electronic states driven by structural instabilities, with no evidence for Dirac and Rashba-type states or surface magnetism.Comment: 4 pages, 4 figures, 1 table. Further information and PDF available at: http://www.phas.ubc.ca/~quantmat/ARPES/PUBLICATIONS/articles.htm

    Rashba spin-splitting control at the surface of the topological insulator Bi2Se3

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    The electronic structure of Bi2Se3 is studied by angle-resolved photoemission and density functional theory. We show that the instability of the surface electronic properties, observed even in ultra-high-vacuum conditions, can be overcome via in-situ potassium deposition. In addition to accurately setting the carrier concentration, new Rashba-like spin-polarized states are induced, with a tunable, reversible, and highly stable spin splitting. Ab-initio slab calculations reveal that these Rashba state are derived from the 5QL quantum-well states. While the K-induced potential gradient enhances the spin splitting, this might be already present for pristine surfaces due to the symmetry breaking of the vacuum-solid interface.Comment: A high-resolution version can be found at http://www.physics.ubc.ca/~quantmat/ARPES/PUBLICATIONS/Articles/BiSe_K.pd
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