701 research outputs found

    Seed selection for information cascade in multilayer networks

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    Information spreading is an interesting field in the domain of online social media. In this work, we are investigating how well different seed selection strategies affect the spreading processes simulated using independent cascade model on eighteen multilayer social networks. Fifteen networks are built based on the user interaction data extracted from Facebook public pages and tree of them are multilayer networks downloaded from public repository (two of them being Twitter networks). The results indicate that various state of the art seed selection strategies for single-layer networks like K-Shell or VoteRank do not perform so well on multilayer networks and are outperformed by Degree Centrality

    Contrasting spatial heterogeneity of sessile organisms within mussel (Perna perna L.) beds in relation to topographic variability

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    We examined the spatial heterogeneity in three sessile rocky shore organisms, the mussel Perna perna, the barnacle Octomeris angulosa (Sowerby) and the red alga Gelidium pristoides (Turn.) at a range of continuous local scales along horizontal transects within mid- and upper mussel beds of South African shores. We also examined the relationships between variability of organisms and topographic features (rock depressions, slope, aspect), and between mussel, barnacle and algal variability over the same scales. To estimate spatial heterogeneity, we analyzed scaling properties of semivariograms using a fractal approach. Relationships between different variables at the different scales were examined by cross-semivariograms. Spatial dependence of P. perna variability increased with spatial dependence of topographic variability, so that scaling regions of mussel and topographic distributions corresponded well. This relationship often improved with larger local scales (mussel cover increased with depressions, steeper slope and aspect towards waves), while at smaller spatial scales, variability in mussel cover was less well explained by variability in topography. The variability of the barnacle O. angulosa exhibited spatial dependence, even on topographically unstructured shores. In contrast, the distribution of the alga G. pristoides revealed high fractal dimensions, showing spatial independence on topographically unstructured shores. Algae also showed a very strong negative relationship with mussels at most local scales, and a negative relationship with barnacles in upper zones, especially at larger local scales. Barnacles may show clear spatial dependence because of hydrodynamics (at larger local scales) and the need to find a future mate in close proximity (at smaller local scales), while algae may show a strong negative relationship with mussels because of competition for space

    Molecular Dynamics Simulations of Dynamic Force Microscopy: Applications to the Si(111)-7x7 Surface

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    Molecular dynamics simulations have been performed to understand true atomic resolution, which has been observed on the Si(111)-7×\times7 surface by dynamic force microscopy in ultra high vacuum(UHV). Stable atomic-scale contrast is reproduced in simulations at constant mean height above a critical tip-sample separation when monitoring the interaction force between tip and sample. Missing or additional adatoms can be recognized in such scans, although they are less well resolved than native adatoms. The resonance frequency shift, as well as arbitrary scans, e.g. at constant force can be computed from a series of force-distance characteristics. By means of dynamic simulations we show how energy losses induced by interaction with an oscillating tip can be monitored and that they occur even in the non-contact range.Comment: 5 pages, 5 figures, accepted publication in Applied Surface Scienc

    Citrullinated proteins in arthritis: presence in joints and effects on immunogenicity

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    Contains fulltext : 60098.pdf (publisher's version ) (Open Access

    Motion-corrected reconstruction of parametric images from dynamic PET data with the Synergistic Image Reconstruction Framework (SIRF)

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    Motion correction has been added to a PET-MR reconstruction tool, SIRF, by incorporating a registration package, NiftyReg. New functionality has been demonstrated in the context of estimating kinetic parameters in the left temporal lobe, comparing direct and indirect reconstructions and evaluating the impact of using motion correction.Principal component analysis was used to detect motion and to determine time frames, while STIR's parametric-OSEM was used to perform the motion-corrected direct parametric reconstruction.It was found that the variance in the left temporal lobe decreased when motion correction was performed, and the same was true of direct reconstructions compared to indirect.With SIRF, the entirety of the demonstrated functionality can be performed from a single Matlab or Python script

    Expression of Concern: Redox modification of cysteine residues regulates the cytokine activity of high mobility group box-1 (HMGB1) (Molecular Medicine (2012) 18 (250-259) DOI: 10.2119/molmed.2011.00389)

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    © The Author(s). 2020. The Editors-in-Chief would like to alert readers that this article (Yang et al. 2012) is part of an investigation being conducted by the journal following the conclusions of an institutional enquiry at the University of Liverpool with respect to the quantitative mass spectrometrygenerated results regarding acetylated and redox-modified HMGB1. Appropriate editorial action will be taken once the investigation is concluded. Huan Yang, Peter Lundbäck, Lars Ottosson, Helena Erlandsson-Harris, Emilie Venereau, Marco E. Bianchi, Yousef Al-Abed, Ulf Andersson, and Kevin J. Tracey agree to this editorial expression of concern. Daniel J. Antoine has not responded to any correspondence from the editor/publisher about this editorial expression of concern

    Modelling the impact of injection time on the bolus shapes in PET-MRI AIF Conversion

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    Strengthening the integration of midwifery in health systems; a leader-to-leader collaboration

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    Barriers and facilitators for quality midwifery care exist on different levels in the health systems. After decades of challenges and varied degrees of success, a stakeholder leader-to-leader collaboration could provide added value through knowledge sharing on how to integrate the midwifery cadre into an existing health system. Initiated by The Midwifery Society of Nepal, Dalarna University Sweden and MAMTA - Health Institute for Mother and Child India, a research network focusing midwifery has been formed. The background, purpose and activities of this network has been described in this News and Events paper
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