629 research outputs found

    Vaccination of Cattle with the N Terminus of LppQ of Mycoplasma mycoides subsp. mycoides Results in Type III Immune Complex Disease upon Experimental Infection

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    Contagious bovine pleuropneumonia (CBPP) is a serious respiratory disease of cattle caused by Mycoplasma mycoides subsp. mycoides. Current vaccines against CBPP induce short-lived immunity and can cause severe postvaccine reactions. Previous studies have identified the N terminus of the transmembrane lipoprotein Q (LppQ-N') of M. mycoides subsp. mycoides as the major antigen and a possible virulence factor. We therefore immunized cattle with purified recombinant LppQ-N' formulated in Freund's adjuvant and challenged them with M. mycoides subsp. mycoides. Vaccinated animals showed a strong seroconversion to LppQ, but they exhibited significantly enhanced postchallenge glomerulonephritis compared to the placebo group (P = 0.021). Glomerulonephritis was characterized by features that suggested the development of antigen-antibody immune complexes. Clinical signs and gross pathological scores did not significantly differ between vaccinated and placebo groups. These findings reveal for the first time the pathogenesis of enhanced disease as a result of antibodies against LppQ during challenge and also argue against inclusion of LppQ-N' in a future subunit vaccine for CBPP

    Energy benchmarks for water clusters and ice structures from an embedded many-body expansion

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    We show how an embedded many-body expansion (EMBE) can be used to calculate accurate \emph{ab initio} energies of water clusters and ice structures using wavefunction-based methods. We use the EMBE described recently by Bygrave \emph{et al.} (J. Chem. Phys. \textbf{137}, 164102 (2012)), in which the terms in the expansion are obtained from calculations on monomers, dimers, etc. acted on by an approximate representation of the embedding field due to all other molecules in the system, this field being a sum of Coulomb and exchange-repulsion fields. Our strategy is to separate the total energy of the system into Hartree-Fock and correlation parts, using the EMBE only for the correlation energy, with the Hartree-Fock energy calculated using standard molecular quantum chemistry for clusters and plane-wave methods for crystals. Our tests on a range of different water clusters up to the 16-mer show that for the second-order M\o{}ller-Plesset (MP2) method the EMBE truncated at 2-body level reproduces to better than 0.1 mEhE_{\rm h}/monomer the correlation energy from standard methods. The use of EMBE for computing coupled-cluster energies of clusters is also discussed. For the ice structures Ih, II and VIII, we find that MP2 energies near the complete basis-set limit reproduce very well the experimental values of the absolute and relative binding energies, but that the use of coupled-cluster methods for many-body correlation (non-additive dispersion) is essential for a full description. Possible future applications of the EMBE approach are suggested

    The future of social is personal: the potential of the personal data store

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    This chapter argues that technical architectures that facilitate the longitudinal, decentralised and individual-centric personal collection and curation of data will be an important, but partial, response to the pressing problem of the autonomy of the data subject, and the asymmetry of power between the subject and large scale service providers/data consumers. Towards framing the scope and role of such Personal Data Stores (PDSes), the legalistic notion of personal data is examined, and it is argued that a more inclusive, intuitive notion expresses more accurately what individuals require in order to preserve their autonomy in a data-driven world of large aggregators. Six challenges towards realising the PDS vision are set out: the requirement to store data for long periods; the difficulties of managing data for individuals; the need to reconsider the regulatory basis for third-party access to data; the need to comply with international data handling standards; the need to integrate privacy-enhancing technologies; and the need to future-proof data gathering against the evolution of social norms. The open experimental PDS platform INDX is introduced and described, as a means of beginning to address at least some of these six challenges

    Antiretroviral Therapy outcomes among adolescents and youth in rural Zimbabwe

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    Around 2 million adolescents and 3 million youth are estimated to be living with HIV worldwide. Antiretroviral outcomes for this group appear to be worse compared to adults. We report antiretroviral therapy outcomes from a rural setting in Zimbabwe among patients aged 10-30 years who were initiated on ART between 2005 and 2008. The cohort was stratified into four age groups: 10-15 (young adolescents) 15.1-19 years (adolescents), 19.1-24 years (young adults) and 24.1-29.9 years (older adults). Survival analysis was used to estimate rates of deaths and loss to follow-up stratified by age group. Endpoints were time from ART initiation to death or loss to follow-up. Follow-up of patients on continuous therapy was censored at date of transfer, or study end (31 December 2008). Sex-adjusted Cox proportional hazards models were used to estimate hazard ratios for different age groups. 898 patients were included in the analysis; median duration on ART was 468 days. The risk of death were highest in adults compared to young adolescents (aHR 2.25, 95%CI 1.17-4.35). Young adults and adolescents had a 2-3 times higher risk of loss to follow-up compared to young adolescents. When estimating the risk of attrition combining loss to follow-up and death, young adults had the highest risk (aHR 2.70, 95%CI 1.62-4.52). This study highlights the need for adapted adherence support and service delivery models for both adolescents and young adults

    Nothing Ventured — Nothing Gained? Empirical Evidence on Venture Capital Financing in Switzerland

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    This paper analyses the Determinants of Venture Capital Staging and Syndication in Switzerland. I find that among the different affiliations of VC investors in Switzerland especially independent investors make more extensive use of staged capital infusions. Moreover, the results suggest that staging is employed as a tool for mitigating risks in VC financing. In addition, I find that Syndication can serve as an entrance strategy for foreign VC providers. Furthermore, I find evidence that firms, which realize the benefit of staging, do also become conscious of the value added in financing Start Ups by involving partners. Consequently, VC firms that make use of staging are also more open to syndication. With respect to the value-added of Co-Investment behavior, I show that syndication positively impacts the success rate of a VC provider, whereas VC firms that are more locally embedded do exhibit lower success rates for their investment portfolio

    Entrepreneurial knowledge and aspirations of dentistry students in South Africa

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    An investigation of the intentions and knowledge of entrepreneurship of final-year university dentistry students is reported, with particular regard to the factors of gender and race. A questionnaire survey was used with final-year dentistry students, over two years, at the University of the Western Cape in South Africa. The findings show that dentistry students across race and gender groups believed that entrepreneurship education was important. At least half of the students showed an interest in starting a business practice soon after their graduation and completion of a mandatory one-year internship, with more male students indicating an interest in starting a business than female students. More Black African students indicated interest compared to other race groups (Coloureds, Whites and Indians). There were no significant differences between male and female students with regard to knowledge of entrepreneurship, but there were significant differences with regard to race in the scores for knowledge of entrepreneurship, with White students scoring the highest and African students the lowest. The authors conclude that entrepreneurship education should be included in the curriculum in the final year of dentistry studies to encourage business practice start-up soon after the one-year internship period, with the aim of contributing to growth in employment.Department of HE and Training approved lis

    Image Classification using non-linear Support Vector Machines on Encrypted Data

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    In image processing, algorithms for object classification are typically based around machine learning. From the algorithm developer\u27s perspective, these can involve a considerable amount of effort and expertise to develop, which makes them commercially valuable. On the other hand, other parties may want to make use of these algorithms to classify their images, while protecting the privacy of their data. In this paper, we show how non-linear Support Vector Machines (SVMs) can be practically used for image classification on data encrypted with a Somewhat Homomorphic Encryption (SHE) scheme. Previous work has shown how an SVM with a linear kernel can be computed on encrypted data, but this only has limited applicability. By enabling SVMs with polynomial kernels, a much larger class of applications are possible with more accuracy in classification results
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