Portfolio saliency and ministerial turnover: Dynamics in Scandinavian postwar cabinets

© 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

A promising new ELISA diagnostic test for cattle babesiosis based on Babesia bigemina Apical Membrane Antigen-1.

Babesiosis due to Babesia bigemina is a relevant tick‑borne disease, affecting cattle worldwide. Many surface proteins of the pathogen including the Apical Membrane Antigen 1 (AMA‑1) ‑ have been analysed for vaccine and diagnostic purposes. This study focused on B. bigemina AMA‑1 and on its use for the assessment of diagnostic tests. After bioinformatic analyses, AMA‑1 codifying region was amplified and cloned into an expression vector used to induce protein synthesis in Escherichia coli cells. AMA‑1 was purified by affinity chromatography and used to set up the best condition for an ELISA protocol. Bovine field sera positive to B. bigemina were used to evaluate the presence of anti‑AMA‑1 antibodies. In order to verify the assay specificity, sera positive to Babesia bovis or to the piroplasm Theileria annulata were also included. Significant differences were obtained between sera negative to both B. bigemina and B. bovis and samples positive to B. bigemina, to B. bovis or to both pathogens. No significant reaction was observed with T. annulata positive sera. The results showed that AMA‑1 protein is suitable to be used as antigen in diagnostic assays for babesiosis diagnosis in cattle, as it does not show any cross reaction with anti-T. annulata antibodies

Heavily obscured AGN with SIMBOL-X

By comparing an optically selected sample of narrow lines AGN with an X-ray selected sample of AGN we have recently derived an estimate of the intrinsic (i.e. before absorption) 2-10 keV luminosity function (XLF) of Compton Thick AGNs. We will use this XLF to derive the number of Compton Thick AGN that will be found in the SIMBOL-X survey(s).Comment: Talk at the Simbol-X symposium held in Paris, 2-5 December, 2008. 6 pages, 1 figure with three panel

The distribution of meteorite finds in the Namibian desert and recovery of a highly shocked meteorite pairing group.

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The Exponential-Time Complexity of Counting (Quantum) Graph Homomorphisms

Many graph parameters can be expressed as homomorphism counts to fixed target graphs; this includes the number of independent sets and the number of k-colorings for any fixed k. Dyer and Greenhill (RSA 2000) gave a sweeping complexity dichotomy for such problems, classifying which target graphs render the problem polynomial-time solvable or #P-hard. In this paper, we give a new and shorter proof of this theorem, with previously unknown tight lower bounds under the exponential-time hypothesis. We similarly strengthen complexity dichotomies by Focke, Goldberg, and Živný (SODA 2018) for counting surjective homomorphisms to fixed graphs. Both results crucially rely on our main contribution, a complexity dichotomy for evaluating linear combinations of homomorphism numbers to fixed graphs. In the terminology of Lovász (Colloquium Publications 2012), this amounts to counting homomorphisms to quantum graphs

Geographical trends in research: a preliminary analysis on authors' affiliations

In the last decade, research literature reached an enormous volume with an unprecedented current annual increase of 1.5 million new publications. As research gets ever more global and new countries and institutions, either from academia or corporate environment, start to contribute with their share, it is important to monitor this complex scenario and understand its dynamics. We present a study on a conference proceedings dataset extracted from Springer Nature Scigraph that illustrates insightful geographical trends and highlights the unbalanced growth of competitive research institutions worldwide. Results emerged from our micro and macro analysis show that the distributions among countries of institutions and papers follow a power law, and thus very few countries keep producing most of the papers accepted by high-tier conferences. In addition, we found that the annual and overall turnover rate of the top 5, 10 and 25 countries is extremely low, suggesting a very static landscape in which new entries struggle to emerge. Finally, we highlight the presence of an increasing gap between the number of institutions initiating and overseeing research endeavours (i.e. first and last authors' affiliations) and the total number of institutions participating in research. As a consequence of our analysis, the paper also discusses our experience in working with affiliations: an utterly simple matter at first glance, that is instead revealed to be a complex research and technical challenge yet far from being solved

The Galactic population of HMXBs as seen with INTEGRAL during its four first years of activity

We collected the parameters (position, absorption, spin, orbital period, etc..), when known, of all Galactic sources detected by INTEGRAL during its four first years of activity. We use these parameters to test theoretical predictions. For example, it is clear that HMXBs tend to be found mostly in the tangential direction of the Galactic arms, while LMXBs tend to be clustered in the Galactic bulge. We then focus on HMXBs and present two possible new tools, in addition to the well-known ``Corbet-diagram'', to distinguish between Be-HMXBs and Sg-HMXBsComment: 5 pages, 3 figures proceedings of "A population explosion: the nature and evolution of X-ray binaries in diverse environments", conference held in St.Petersburg Beach, Florida; R.M.Bandyopadhyay, S.Wachter, D.Gelino, C.R.Gelino, ed

The emerging population of pulsar wind nebulae in hard X-rays

The hard X-ray synchrotron emission from pulsar wind nebulae (PWNe) probes energetic particles, closely related to the pulsar injection power at the present time. INTEGRAL has disclosed the yet poorly known population of hard X-ray pulsar/PWN systems. We summarize the properties of the class, with emphasys on the first hard X-ray bow-shock (CTB 80 powered by PSR B1951+32), and highlight some prospects for the study of Pulsar Wind Nebulae with the Simbol-X mission.Comment: Proceedings of the 2nd Simbol-X Symposium, AIP Conf. Proc. Series, Eds. P. Ferrando and J. Rodriguez (4 pages, 2 figures

On the complexity of computing the kk-restricted edge-connectivity of a graph

The \emph{$k$-restricted edge-connectivity} of a graph $G$, denoted by $\lambda_k(G)$, is defined as the minimum size of an edge set whose removal leaves exactly two connected components each containing at least $k$ vertices. This graph invariant, which can be seen as a generalization of a minimum edge-cut, has been extensively studied from a combinatorial point of view. However, very little is known about the complexity of computing $\lambda_k(G)$. Very recently, in the parameterized complexity community the notion of \emph{good edge separation} of a graph has been defined, which happens to be essentially the same as the $k$-restricted edge-connectivity. Motivated by the relevance of this invariant from both combinatorial and algorithmic points of view, in this article we initiate a systematic study of its computational complexity, with special emphasis on its parameterized complexity for several choices of the parameters. We provide a number of NP-hardness and W[1]-hardness results, as well as FPT-algorithms.Comment: 16 pages, 4 figure