49,949 research outputs found

    Portfolio saliency and ministerial turnover: Dynamics in Scandinavian postwar cabinets

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    © 2013 The Author(s) Scandinavian Political Studies © 2013 Nordic Political Science Association. This is the accepted version of the following article: Hansen, M. E., Klemmensen, R., Hobolt, S. B. and Bäck, H. (2013), Portfolio Saliency and Ministerial Turnover: Dynamics in Scandinavian Postwar Cabinets. Scandinavian Political Studies, 36: 227–248, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/1467-9477.12004/abstract.Why do certain ministers remain in their post for years while others have their time in office cut short? Drawing on the broader literature on portfolio allocation, this article argues that the saliency of individual portfolios shapes ministerial turnover. The main argument is that ministerial dismissals are less likely to occur the higher the saliency attributed to the ministerial portfolio since ministers appointed to important posts are more likely to have been through extensive screening before appointment. Importantly, it is also posited in the article that the effect of portfolio salience is conditioned by government approval ratings: when government ratings are on the decline, prime ministers are less likely to reshuffle or fire important ministers than when approval ratings are improving. To test these claims, Cox proportional hazards models are applied to a new dataset on ministerial turnover in Scandinavia during the postwar period. The results strongly support the proposition that portfolio saliency matters for ministerial survival, and that this effect is moderated by government popularity

    Identification and characterization of thermophilic Synechococcus spp. isolates from Asian geothermal springs

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    Two thermophilic cyanobacterial strains, Ts and Bs, collected from Asian geothermal springs were identified morphologically and phylogenetically as Synechococcus in the order Chroococcales and were isolated into axenic cultures. In addition to the high similarities between their full 16S rRNA gene sequences, both strains also shared similar pigment profiles and fatty acid compositions but with varied ratios. Strain Ts had elevated levels of photoprotective pigments such as carotenoid and scytonemin even after prolonged culture under identical laboratory conditions, whereas strain Bs produced more chlorophyll a per unit cell volume, perhaps resulting from UV adaptation in the natural habitats. In addition, strain Ts had more content than strain Bs in terms of the total fatty acids and the proportion of unsaturated fatty acids. Neither isolate was able to fix nitrogen, and they had zero susceptibility to ampicillin and streptomycin. Š 2007 NRC.published_or_final_versio

    Anchoring climate change communications

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    Verbal probability expressions (VPEs) are frequently used to communicate risk and uncertainty. The Intergovernmental Panel on Climate Change attempts to standardise the use and interpretation of these expressions through a translation scale of numerical ranges to VPEs. A common issue in interpreting VPEs is the tendency for individuals to interpret VPEs around the mid-point of the scale (i.e., around 50%). Previous research has shown that compliance with the IPCC’s standards can be improved if the numerical translation is presented simultaneously with the VPE, reducing the regressiveness of interpretations. We show that an explicit statement of the lower or upper bound implied by the expression (e.g., 0-33%; 66-100%) leads to better differentiated estimates of the probability implied by ‘likely’ and ‘unlikely’ than when the bound is not explicitly identified (e.g., less than 33%; greater than 66%)

    Hybrid fluid–structure interaction modelling of dynamic brittle fracture in steel pipelines transporting CO2 streams

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    Pressurised steel pipelines are considered for long-distance transportation of dense-phase CO2 captured from fossil fuel power plants for its subsequent sequestration in a Carbon Capture and Storage (CCS) chain. The present study develops a hybrid fluid–structure methodology to model the dynamic brittle fracture of buried pressurised CO2 pipeline. The proposed model couples the fluid dynamics and the fracture mechanics of the deforming pipeline exposed to internal and back-fill pressures. To simulate the state of the flow in the rupturing pipeline a compressible one-dimensional Computational Fluid Dynamics (CFD) model is applied, where the fluid properties are evaluated using rigorous thermodynamic model. In terms of the fracture model, an eXtended Finite Element Method (XFEM)-based cohesive segment technique is used to model the dynamic brittle fracture behaviour of pipeline steel. Using the proposed model, a study is performed to evaluate the rate of brittle fracture propagation in a real-scale 48 in. diameter API X70 steel pipeline. The model was verified by comparing the obtained numerical results against available semi-empirical approaches from the literature. The simulated results are found to be in good correlation with the simulations using a simple semi-empirical model accounting for the fracture toughness, indicating the capability of the proposed approach to predict running brittle fracture in a CO2 pipeline

    Neural superposition and oscillations in the eye of the blowfly

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    Neural superposition in the eye of the blowfly Calliphora erythrocephala was investigated by stimulating single photoreceptors using corneal neutralization through water immersion. Responses in Large Monopolar Cells (LMCs) in the lamina were measured, while stimulating one or more of the six photoreceptors connected to the LMC. Responses to flashes of low light intensity on individual photoreceptors add approximately linearly at the LMC. Higher intensity light flashes produce a maximum LMC response to illumination of single photoreceptors which is about half the maximum response to simultaneous illumination of the six connecting photoreceptors. This observation indicates that a saturation can occur at a stage of synaptic transmission which precedes the change in the post-synaptic membrane potential. Stimulation of single photoreceptors yields high frequency oscillations (about 200 Hz) in the LMC potential, much larger in amplitude than produced by simultaneous stimulation of the six photoreceptors connected to the LMC. It is discussed that these oscillations also arise from a mechanism that precedes the change in the postsynaptic membrane potential.

    Cleaning of viscous drops on a flat inclined surface using gravity-driven film flows

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    We investigate the fluid mechanics of cleaning viscous drops attached to a flat inclined surface using thin gravity-driven film flows. We focus on the case where the drop cannot be detached from the surface by the mechanical forces exerted by the cleaning fluid on the drop surface. The fluid in the drop dissolves into the cleaning film flow, which then transports it away. To assess the impact of the drop on the velocity of the cleaning fluid, we have developed a novel experimental technique based on particle image velocimetry. We show the velocity distribution at the film surface in the situations both where the film is flowing over a smooth surface, and where it is perturbed by a solid obstacle representing a very viscous drop. We find that at intermediate Reynolds numbers the acceleration of the starting film is overestimated by a plane model using the lubrication approximation. In the perturbed case, the streamwise velocity is strongly affected by the presence of the obstacle. The upstream propagation of the disturbance is limited, but the disturbance extends downstream for distances larger than 10 obstacle diameters. Laterally, we observe small disturbances in both the streamwise and lateral velocity, owing to stationary capillary waves. The flow also exhibits a complex three-dimensional converging pattern immediately below the obstacle.J. R. Landel acknowledges financial support from Magdalene College, Cambridge, through a Nevile Research Fellowship in Applied Mathematics. This material is based upon work supported by the Defense Threat Reduction Agency under Contract No. HDTRA1-12-D- 0003-0001.This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0960308514001175
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