4,091 research outputs found

    Serum amyloid P aids complement-mediated immunity to Streptococcus pneumoniae

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    The physiological functions of the acute phase protein serum amyloid P (SAP) component are not well defined, although they are likely to be important, as no natural state of SAP deficiency has been reported. We have investigated the role of SAP for innate immunity to the important human pathogen Streptococcus pneumoniae. Using flow cytometry assays, we show that SAP binds to S. pneumoniae, increases classical pathway–dependent deposition of complement on the bacteria, and improves the efficiency of phagocytosis. As a consequence, in mouse models of infection, mice genetically engineered to be SAP-deficient had an impaired early inflammatory response to S. pneumoniae pneumonia and were unable to control bacterial replication, leading to the rapid development of fatal infection. Complement deposition, phagocytosis, and control of S. pneumoniae pneumonia were all improved by complementation with human SAP. These results demonstrate a novel and physiologically significant role for SAP for complement-mediated immunity against an important bacterial pathogen, and provide further evidence for the importance of the classical complement pathway for innate immunity

    A study to examine the operation and function of a virtual UK environmental specimen bank (UK-ESB). Final report

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    Executive Summary: 1. Environmental specimen banking is recognised internationally as an integral part of long-term environmental research and monitoring. Analysis of preserved environmental samples is often needed to detect and quantify patterns and rate of environmental change, and the emergence and progression of environmental hazards and risks. 2. National Environmental Specimen Banks have been established in several countries; they vary in scope and breadth. There are a few specialised environmental specimen holdings in the UK but no national-scale catalogue of holdings, despite an estimated annual spend of £16 million to store specimens. This lack of information results in under-exploitation of archived specimens and is a lost opportunity to facilitate world-class science and identify emerging pressures and threats on the environment. 3. An earlier project had identified key stakeholder organisations either engaged in archiving nationally important environmental specimens or who wished to utilise such specimens. These stakeholders had agreed there was a need for a national metadata catalogue of environmental specimens (subsequently termed a virtual UK-ESB). The objective of the current project was to further develop a virtual UK-ESB. Specifically, the aim was to work with stakeholders to establish the correct metadata entry fields, the search capabilities, the functionality and the nature of the hosting website of a virtual UK-ESB. 4. More than 80 stakeholder organisations that had previously expressed an interest in a UK-ESB were approached to provide feedback either electronically or by attending a stakeholder workshop. Thirty eight organisations responded. All remained interested in the UK-ESB concept and seventeen answered the survey questions. 5. Mock-ups of data entry screens, search screens and ideas around the functionality of a UK-ESB were developed by the CEH project team. These were mailed to stakeholders for feedback. Initial feedback was incorporated into the mock-ups which were then presented for discussion at a workshop comprising 15 attendees from across the specimen archiving community, CEH and the UK-EOF. 6. Workshop participants reviewed and agreed the format of 23 mandatory or optional data-entry fields for a virtual UK-ESB that, in the absence of standard for material samples and archives, were aligned with ISO19115 (geospatial metadata standard) and DublinCore (metadata standard). These fields were sub-divided into the following headings: Sample description, Categorisation, keywords and links, Storage Information and Contact information. Workshop participants also made a number of recommendations as to the format of the data entry screens and inclusion of extra fields. 7. Workshop participants reviewed options for search capabilities and made recommendations as to simple and advanced searching methods and their formats. It was also recommended that search facilities of the ESBs of other countries be examined to determine what is used, ease of use, and how they match the recommendations from the workshop. 8. Workshop participants reviewed options for functionality and agreed a detailed list of prioritised requirements. 9. Workshop participants agreed that a virtual UK-ESB should be hosted through a dedicated website that would also provide wider information, such as recently updated or added specimen holdings, most downloaded information, links to other groups, standard operating procedures, etc. 10. The next step for the development of a virtual UK-ESB is to implement the design and development ideas captured in the current report and build a test version of a virtual UK-ESB. This would be tested and refined, and could then be launched on a specifically designed website. This would need to be accompanied by a communication strategy. There is potential to link and co-brand a virtual UK-ESB with the UK-Environmental Observation Framework (UK-EOF)

    Making academia more accessible

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    Academia can be a challenging place to work and academics who have a disability, neurodiversity or chronic illness are further disadvantaged, as non-stereotypical ways of working are not necessarily supported or catered for. The remit of this paper is to provide practical ideas and recommendations to address accessibility issues in events and conferences as a first step to improving existing working conditions. We start with providing a brief overview of and background to the issues of ableism, disabilities, chronic illnesses and neurodiversities in academia. We then offer a detailed description of the organisational and developmental strategies relating to the Ableism in Academia conference to practically demonstrate how accessibility can be achieved. Despite vast literature available on theorisations of reasonable adjustments and some individual handbooks on conference accessibility, noted the absence of a systematic write-up of a case study that would demonstrate the thought processes required for the organisation of a fully accessible and inclusive event. This paper provides almost a step-by-step rationale and rundown of the decisions that had to be taken in order to facilitate an accessible event. After a brief consideration of challenges we encountered along the way, we share personal reflections regarding the event and future developments

    Framework for contextualized learning ecosystems

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    Proceedings of: 6th European Conference of Technology Enhanced Learning, EC-TEL 2011, Palermo, Italy, September 20-23, 2011Using mobile personal devices to interact with pervasive smart learning objects and services that create contextualized learning ecosystems can enhance both the learning outcomes and the motivational states of students. This paper defines and analyzes several pervasive learning ecosystems in which students at the Carlos III University of Madrid interact with contextualized learning objects and services. The technology defining the contextualized learning environments is first introduced and later used in two user experiments. These experiments provide data both about the learning outcomes for students after interacting with smart learning objects and services and about the motivational impact that the use of these technologies have on themThe research leading to these results has been partially funded by the ARTEMISA project TIN2009-14378-C02-02 within the Spanish "Plan Nacional de I+D+I", the Madrid regional community projects S2009/TIC-1650 and CCG10-UC3M/TIC-4992 and the SOLITE CYTED Program 508AC0341. Thanks to INNOVISION for providing the NFC tags for this experiment. Gustavo Ramirez- Gonzalez is funded by the EU Programme Alban, scholarship number E06D101768CO and by the Universidad del Cauca

    Statistical Mechanics of Nonuniform Magnetization Reversal

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    The magnetization reversal rate via thermal creation of soliton pairs in quasi-1D ferromagnetic systems is calculated. Such a model describes e.g. the time dependent coercivity of elongated particles as used in magnetic recording media. The energy barrier that has to be overcome by thermal fluctuations corresponds to a soliton-antisoliton pair whose size depends on the external field. In contrast to other models of first order phase transitions such as the phi^4 model, an analytical expression for this energy barrier is found for all values of the external field. The magnetization reversal rate is calculated using a functional Fokker-Planck description of the stochastic magnetization dynamics. Analytical results are obtained in the limits of small fields and fields close to the anisotropy field. In the former case the hard-axis anisotropy becomes effectively strong and the magnetization reversal rate is shown to reduce to the nucleation rate of soliton-antisoliton pairs in the overdamped double sine-Gordon model. The present theory therefore includes the nucleation rate of soliton-antisoliton pairs in the double sine-Gordon chain as a special case. These results demonstrate that for elongated particles, the experimentally observed coercivity is significantly lower than the value predicted by the standard theories of N\'eel and Brown.Comment: 21 pages RevTex 3.0 (twocolumn), 6 figures available on request, to appear in Phys Rev B, Dec (1994

    Effective action for scalar fields and generalised zeta-function regularisation

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    Motivated by the study of quantum fields in a Friedman-Robertson-Walker (FRW) spacetime, the one-loop effective action for a scalar field defined in the ultrastatic manifold R×H3/ΓR\times H^3/\Gamma, H3/ΓH^3/\Gamma being the finite volume, non-compact, hyperbolic spatial section, is investigated by a generalisation of zeta-function regularisation. It is shown that additional divergences may appear at one-loop level. The one-loop renormalisability of the model is discussed and making use of a generalisation of zeta-function regularisation, the one-loop renormalisation group equations are derived.Comment: Latex, 16 pages, no figures; Latex mistakes corrected; accepted for publication in Physical Review

    Results from a Prospective Study of Widowhood

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142735/1/Brown-Nesse-Religion-PSPB-2004.pd

    Fast Algorithm for Partial Covers in Words

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    A factor uu of a word ww is a cover of ww if every position in ww lies within some occurrence of uu in ww. A word ww covered by uu thus generalizes the idea of a repetition, that is, a word composed of exact concatenations of uu. In this article we introduce a new notion of α\alpha-partial cover, which can be viewed as a relaxed variant of cover, that is, a factor covering at least α\alpha positions in ww. We develop a data structure of O(n)O(n) size (where n=wn=|w|) that can be constructed in O(nlogn)O(n\log n) time which we apply to compute all shortest α\alpha-partial covers for a given α\alpha. We also employ it for an O(nlogn)O(n\log n)-time algorithm computing a shortest α\alpha-partial cover for each α=1,2,,n\alpha=1,2,\ldots,n

    One-loop Quantum Corrections to the Entropy for an Extremal Reissner-Nordstr\"om Black Hole

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    The first quantum corrections to the entropy for an eternal 4-dimensional extremal Reissner-Nordstr\"om black hole is investigated at one-loop level, in the large mass limit of the black hole, making use of the conformal techniques related to the optical metric. A leading cubic horizon divergence is found and other divergences appear due to the singular nature of the optical manifold. The area law is shown to be violated.Comment: 10 pages, LaTe

    An exploration of concepts of community through a case study of UK university web production

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    The paper explores the inter-relation and differences between the concepts of occupational community, community of practice, online community and social network. It uses as a case study illustration the domain of UK university web site production and specifically a listserv for those involved in it. Different latent occupational communities are explored, and the potential for the listserv to help realize these as an active sense of community is considered. The listserv is not (for most participants) a tight knit community of practice, indeed it fails many criteria for an online community. It is perhaps best conceived as a loose knit network of practice, valued for information, implicit support and for the maintenance of weak ties. Through the analysis the case for using strict definitions of the theoretical concepts is made
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