176 research outputs found

    DTN routing optimised by human routines: the HURRy protocol

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    This paper proposes the HURRy (HUman Routines used for Routing) protocol, which infers and benefits from the social behaviour of nodes in disruptive networking environments. HURRy incorporates the contact duration to the information retrieved from historical encounters among neighbours, so that smarter routing decisions can be made. The specification of HURRy is based on the outcomes of a thorough experiment, which highlighted the importance of distinguishing between short and long contacts and deriving mathematical relations in order to optimally prioritize the available routes to a destination. HURRy introduces a novel and more meaningful rating system to evaluate the quality of each contact and overcome the limitations of other routing approaches in social environments.European Commission, Horizon 2020, Grant Agreement number 645124, UMOBIL

    Density Contrast Sedimentation Velocity for the Determination of Protein Partial-Specific Volumes

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    The partial-specific volume of proteins is an important thermodynamic parameter required for the interpretation of data in several biophysical disciplines. Building on recent advances in the use of density variation sedimentation velocity analytical ultracentrifugation for the determination of macromolecular partial-specific volumes, we have explored a direct global modeling approach describing the sedimentation boundaries in different solvents with a joint differential sedimentation coefficient distribution. This takes full advantage of the influence of different macromolecular buoyancy on both the spread and the velocity of the sedimentation boundary. It should lend itself well to the study of interacting macromolecules and/or heterogeneous samples in microgram quantities. Model applications to three protein samples studied in either H2O, or isotopically enriched H218O mixtures, indicate that partial-specific volumes can be determined with a statistical precision of better than 0.5%, provided signal/noise ratios of 50–100 can be achieved in the measurement of the macromolecular sedimentation velocity profiles. The approach is implemented in the global modeling software SEDPHAT

    The long-term prediction of return to work following serious accidental injuries: A follow up study

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    Background Considerable indirect costs are incurred by time taken off work following accidental injuries. The aim of this study was to predict return to work following serious accidental injuries. Method 121 severely injured patients were included in the study. Complete follow-up data were available for 85 patients. Two weeks post trauma (T1), patients rated their appraisal of the injury severity and their ability to cope with the injury and its job-related consequences. Time off work was assessed at one (T2) and three years (T3) post accident. The main outcome was the number of days of sick leave taken due to the accidental injury. Results The patients' appraisals a) of the injury severity and b) of their coping abilities regarding the accidental injury and its job-related consequences were significant predictors of the number of sick-leave days taken. Injury severity (ISS), type of accident, age and gender did not contribute significantly to the prediction. Conclusions Return to work in the long term is best predicted by the patients' own appraisal of both their injury severity and the ability to cope with the accidental injury

    Variance components associated with long-echo-time MR spectroscopic imaging in human brain at 1.5T and 3T

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    <div><p>Object</p><p>Magnetic resonance spectroscopic imaging (MRSI) is increasingly used in medicine and clinical research. Previous reliability studies have used small samples and focussed on limited aspects of variability; information regarding 1.5T versus 3T performance is lacking. The aim of the present work was to measure the inter-session, intra-session, inter-subject, within-brain and residual variance components using both 1.5T and 3T MR scanners.</p><p>Materials and methods</p><p>Eleven healthy volunteers were invited for MRSI scanning on three occasions at both 1.5T and 3T, with four scans acquired at each visit. We measured variance components, correcting for grey matter and white matter content of voxels, of metabolite peak areas and peak area ratios.</p><p>Results</p><p>Residual variance was in general the largest component at 1.5T (8.6–24.6%), while within-brain variation was the largest component at 3T (12.0–24.7%). Inter-subject variation was around 5%, while inter- and intra-session variance were both generally small.</p><p>Conclusion</p><p>Multiple variance contributions associated with MRSI measurements were quantified and the performance of 1.5T and 3T MRI scanners compared using data from the same group of subjects. Residual error is much lower at 3T, but other variance components remain important.</p></div

    Decentralization and regional government size in Spain

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    The aim of this paper is to investigate the impact of fiscal decen- tralization on the size of regional governments in Spain, by controlling for economies of scale, interregional heterogeneity and institutional framework. We study it over 1985 to 2004 using a panel dataset of seventeen spanish regions. The results can be easily summarized. Firstly, it supports the classic public goods theory of a trade-off-between the economic benefits of size and the costs of heterogeneity. Secondly, it doesn’t reject the “Leviathan” hypoth- esis and neither does the “common pool” hypothesis. Thirdly, by contrast, the paper partly rejects the “Wallis”’ hypothesis. It argues that government size is mediated by financial resources obtained through intergovernmental grants, consistent with welfare economics and positive economic policies. We conclude that later advances in the decentralisation process must be compatible with the goal of reducing fiscal imbalances that emanate from the vertical structure of fiscal power.info:eu-repo/semantics/publishedVersio

    Rasch scaling procedures for informing development of a valid Fetal Surveillance Education Program multiple-choice assessment

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    <p>Abstract</p> <p>Background</p> <p>It is widely recognised that deficiencies in fetal surveillance practice continue to contribute significantly to the burden of adverse outcomes. This has prompted the development of evidence-based clinical practice guidelines by the Royal Australian and New Zealand College of Obstetricians and Gynaecologists and an associated Fetal Surveillance Education Program to deliver the associated learning. This article describes initial steps in the validation of a corresponding multiple-choice assessment of the relevant educational outcomes through a combination of item response modelling and expert judgement.</p> <p>Methods</p> <p>The Rasch item response model was employed for item and test analysis and to empirically derive the substantive interpretation of the assessment variable. This interpretation was then compared to the hierarchy of competencies specified a priori by a team of eight subject-matter experts. Classical Test Theory analyses were also conducted.</p> <p>Results</p> <p>A high level of agreement between the hypothesised and derived variable provided evidence of construct validity. Item and test indices from Rasch analysis and Classical Test Theory analysis suggested that the current test form was of moderate quality. However, the analyses made clear the required steps for establishing a valid assessment of sufficient psychometric quality. These steps included: increasing the number of items from 40 to 50 in the first instance, reviewing ineffective items, targeting new items to specific content and difficulty gaps, and formalising the assessment blueprint in light of empirical information relating item structure to item difficulty.</p> <p>Conclusion</p> <p>The application of the Rasch model for criterion-referenced assessment validation with an expert stakeholder group is herein described. Recommendations for subsequent item and test construction are also outlined in this article.</p

    Comparison of In vitro Nanoparticles Uptake in Various Cell Lines and In vivo Pulmonary Cellular Transport in Intratracheally Dosed Rat Model

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    In present study, the potential drug delivery of nanoformulations was validated via the comparison of cellular uptake of nanoparticles in various cell lines and in vivo pulmonary cellular uptake in intratracheally (IT) dosed rat model. Nanoparticles were prepared by a bench scale wet milling device and incubated with a series of cell lines, including Caco-2, RAW, MDCK and MDCK transfected MDR1 cells. IT dosed rats were examined for the pulmonary cellular uptake of nanoparticles. The processes of nanoparticle preparation did not alter the crystalline state of the material. The uptake of nanoparticles was observed most extensively in RAW cells and the least in Caco-2 cells. Efflux transporter P-gp did not prevent cell from nanoparticles uptake. The cellular uptake of nanoparticles was also confirmed in bronchoalveolar lavage (BAL) fluid cells and in bronchiolar epithelial cells, type II alveolar epithelial cells in the intratracheally administrated rats. The nanoparticles uptake in MDCK, RAW cells and in vivo lung epithelial cells indicated the potential applications of nanoformulation for poorly soluble compounds. The observed limited direct uptake of nanoparticles in Caco-2 cells suggests that the improvement in oral bioavailability by particle size reduction is via increased dissolution rate rather than direct uptake

    Neue linguistische Methoden und arbeitstechnische Verfahren in der Erschliessung der ägyptischen Grammatik

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    15 páginas, 1 tabla, 6 figuras.Does diversity beget diversity? Diversity includes a diversity of concepts because it is linked to variability in and of life and can be applied to multiple levels. The connections between multiple levels of diversity are poorly understood. Here, we investigated the relationships between genetic, bacterial, and chemical diversity of the endangered Atlanto-Mediterranean sponge Spongia lamella. These levels of diversity are intrinsically related to sponge evolution and could have strong conservation implications. We used microsatellite markers, denaturing gel gradient electrophoresis and quantitative polymerase chain reaction, and high performance liquid chromatography to quantify genetic, bacterial, and chemical diversity of nine sponge populations. We then used correlations to test whether these diversity levels covaried. We found that sponge populations differed significantly in genetic, bacterial, and chemical diversity. We also found a strong geographic pattern of increasing genetic, bacterial, and chemical dissimilarity with increasing geographic distance between populations. However, we failed to detect significant correlations between the three levels of diversity investigated in our study. Our results suggest that diversity fails to beget diversity within a single species and indicates that a diversity of factors regulates a diversity of diversities, which highlights the complex nature of the mechanisms behind diversityResearch funded by grants from the Agence Nationale de la Recherche (ECIMAR), from the Spanish Ministry of Science and Technology SOLID (CTM2010-17755) and Benthomics (CTM2010-22218-C02-01) and the BIOCAPITAL project (MRTN-CT-2004-512301) of the European Union. This is a contribution of the Consolidated Research Group ‘‘Grupo de Ecologı´a Bento´nica,’’ SGR2009-655.Peer reviewe

    The EHEC Type III Effector NleL Is an E3 Ubiquitin Ligase That Modulates Pedestal Formation

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    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes hemorrhagic colitis and may result in potentially fatal hemolytic uremia syndrome in humans. EHEC colonize the intestinal mucosa and promote the formation of actin-rich pedestals via translocated type III effectors. Two EHEC type III secreted effectors, Tir and EspFu/TccP, are key players for pedestal formation. We discovered that an EHEC effector protein called Non-LEE-encoded Ligase (NleL) is an E3 ubiquitin ligase. In vitro, we showed that the NleL C753 residue is critical for its E3 ligase activity. Functionally, we demonstrated that NleL E3 ubiquitin ligase activity is involved in modulating Tir-mediated pedestal formation. Surprisingly, EHEC mutant strain deficient in the E3 ligase activity induced more pedestals than the wild-type strain. The canonical EPEC strain E2348/69 normally lacks the nleL gene, and the ectopic expression of the wild-type EHEC nleL, but not the catalytically-deficient nleL(C753A) mutant, in this strain resulted in fewer actin-rich pedestals. Furthermore, we showed that the C. rodentium NleL homolog is a E3 ubiquitin ligase and is required for efficient infection of murine colonic epithelial cells in vivo. In summary, our study demonstrated that EHEC utilizes NleL E3 ubiquitin ligase activity to modulate Tir-mediated pedestal formation.National Institutes of Health (U.S.) (grant AI078092)National Institutes of Health (U.S.) (grant AI068655
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