604 research outputs found

    Infectious bronchitis virus infections of chickens in Belgium : an epidemiological survey

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    Between April 2012 and July 2015, cloacal and/or tracheal swab samples were collected from four hundred and twenty-four Belgian chicken broiler, breeder and layer flocks. All flocks were kept for production purposes and presented clinical signs suggestive of an infectious bronchitis virus (IBV) infection. The samples were analyzed by real-time polymerase chain reaction (RT-qPCR) to detect the presence of ribonucleic acid (RNA) of IBV. When positive, approximately four hundred base pairs (bp) encoding for the hypervariable region of the IBV S1 protein were sequenced. Sequencing results, cycle threshold (Ct) values and vaccination history were used as criteria to try and distinguish vaccine strains from field strains. Of all samples examined, 22.4% was negative. In 16.4% of the samples that did contain RNA from IBV, the genotype could not be determined. In most cases, this was due to the recovery of RNA quantities below the lower limit of detection of the sequencing PCR. The remaining positive submissions predominantly revealed RNA from IBV strains that belonged to the 4/91-793B (46.8%), D388-QX (25.2%), D274-D207 (5.8%) and Massachusetts (4.0%) genotypes. Estimations indicated that approximately 58%, 11%, 37% and 46% of these detections, respectively, were vaccine strains. Infections with types CK/CH/Guandong/Xindadi/0903, Ukr/27/2011, NGA/295/2006 and Q1 were observed sporadically. The results indicate that IBV infections are highly prevalent in Belgian chickens and that at least eight different IBV types were circulating during the monitored period. This underlines the necessity of providing flocks with a strong and broad protective immunity against IBV

    Robust surface electronic properties of topological insulators: Bi2Te3 films grown by molecular beam epitaxy

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    The surface electronic properties of the important topological insulator Bi2Te3 are shown to be robust under an extended surface preparation procedure which includes exposure to atmosphere and subsequent cleaning and recrystallization by an optimized in-situ sputter-anneal procedure under ultra high vacuum conditions. Clear Dirac-cone features are displayed in high-resolution angle-resolved photoemission spectra from the resulting samples, indicating remarkable insensitivity of the topological surface state to cleaning-induced surface roughness.Comment: 3 pages, 3 figure

    Grid Workflow Modelling Using Grid-Specific BPEL Extensions

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    This paper discusses problems of Grid service composition using BPEL4WS. In particular, difficulties concerning the invocation of WSRF-based services are elucidated. A solution to this problem is presented by extending the BPEL specification, and an implementation based on the ActiveBPEL workflow enactment engine is described

    Hypertiling -- a high performance Python library for the generation and visualization of hyperbolic lattices

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    Hypertiling is a high-performance Python library for the generation and visualization of regular hyperbolic lattices embedded in the Poincar\'e disk model. Using highly optimized, efficient algorithms, hyperbolic tilings with millions of vertices can be created in a matter of minutes on a single workstation computer. Facilities including computation of adjacent vertices, dynamic lattice manipulation, refinements, as well as powerful plotting and animation capabilities are provided to support advanced uses of hyperbolic graphs. In this manuscript, we present a comprehensive exploration of the package, encompassing its mathematical foundations, usage examples, applications, and a detailed description of its implementation.Comment: 52 pages, 20 figure

    Application of Respondent Driven Sampling to Collect Baseline Data on FSWs and MSM for HIV Risk Reduction Interventions in Two Urban Centres in Papua New Guinea

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    The need to obtain unbiased information among hard–to-reach and hidden populations for behavioural and biological surveillance, epidemiological studies, and intervention program evaluations has led researchers to search for a suitable sampling method. One method that has been tested among IDU and MSM recently is respondent-driven sampling (RDS). We used RDS to conduct a behavioural survey among FSWs and MSM in two urban centres in Papua New Guinea (PNG). In this paper we present the lessons learned implementing RDS in a developing country setting. We also present comparisons of RDSAT-adjusted versus unadjusted crude estimates of some key socio-demographic indicators as well as comparisons between the estimates from RDS and a hypothetical time–location sample (TLS). Overall, the use of RDS among the MSM and FSWs in PNG had numerous advantages in terms of collecting a required sample size in a short time period, minimizing costs and maximising security for staff and respondents. Although there were a few problems these were easily remedied and we would recommend RDS for other similar studies in PNG and other developing countries

    Coming out with the media: the ritualization of self-disclosure in the Dutch television program Uit de Kast

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    Using the media to disclose one’s sexual identity has become an increasingly salient practice in recent years. Yet little is known about the reasons for the emergence of this form of self-disclosure. Based on an analysis of the Dutch television programme Uit de Kast (‘Out of the Closet’), this article relates the rise of mediated coming out practices to the ritualizing power of the media: we argue that media plays a quintessential role in transforming the socially unscripted act of coming out into a patterned, culturally meaningful performance. Our analysis reveals that the ritual work of the programme is embedded in the ways 1) the generic format of the show structures the self-disclosures, 2) the authority of the media is deployed to channel the coming out process, and 3) the programme, while controlling diversity, reinforces dominant societal values and ideologies. The case not only highlights how unprecedented ritual forms come to flourish in the current era of ‘participatory’ media culture, but also demonstrates how ritualization supports and naturalizes the claim that media is an effective agent to create order in everyday, ordinary lives

    Tandem Phosphorothioate Modifications for DNA Adsorption Strength and Polarity Control on Gold Nanoparticles

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see Zhou, W., Wang, F., Ding, J., & Liu, J. (2014). Tandem Phosphorothioate Modifications for DNA Adsorption Strength and Polarity Control on Gold Nanoparticles. ACS Applied Materials & Interfaces, 6(17), 14795–14800. https://doi.org/10.1021/am504791bUnmodified DNA was recently used to functionalize gold nanoparticles via DNA base adsorption. Compared to thiolated DNA, however, the application of unmodified DNA is limited by the lack of sequence generality, adsorption polarity control and poor adsorption stability. We report that these problems can be solved using phosphorothioate (PS) DNA. PS DNA binds to gold mainly via the sulfur atom and is thus less sequence dependent. The adsorption affinity is ranked to be thiol > PS > adenine > thymine. Tandem PS improves adsorption strength, allows tunable DNA density, and the resulting conjugates are functional at a low cost.University of Waterloo || Natural Sciences and Engineering Research Council || Foundation for Shenghua Scholar of Central South University || National Natural Science Foundation of China || Grant No. 2130119

    Tamoxifen enhances the cytotoxic effects of nelfinavir in breast cancer cells

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    Introduction: The HIV protease inhibitor nelfinavir is currently under investigation as a new anti-cancer drug. Several studies have shown that nelfinavir induces cell cycle arrest, endoplasmic reticulum stress, autophagy, and apoptosis in cancer cells. In the present article, the effect of nelfinavir on human breast cancer cells is examined and potential combination treatments are investigated. Methods: The effects of nelfinavir and tamoxifen on the human breast cancer cell lines MCF7, T47 D, MDA-MB-453, and MDA-MB-435 were tested by analysing their influence on cell viability (via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay), apoptosis (annexin binding, poly(ADP-ribose) polymerase cleavage), autophagy (autophagy marker light chain 3B expression), endoplasmic reticulum stress (binding protein and activating transcription factor 3 expression), and the occurrence of oxidative stress (intracellular glutathione level). Results: Nelfinavir induced apoptosis in all four breast cancer cell lines tested, although the extent of autophagy and endoplasmic reticulum stress varied among the cell lines. The concentration of nelfinavir needed for an efficient induction of apoptosis in breast cancer cells could be reduced from 15 mu g/ml to 6 mu g/ml when combined with tamoxifen. At a concentration of 6 mu g/ml, tamoxifen substantially enhanced the endoplasmic reticulum stress reaction in those cell lines that responded to nelfinavir with binding protein (BiP) upregulation (MCF7, T47D), and enhanced autophagy in cell lines that responded to nelfinavir treatment with autophagy marker light chain 3B upregulation (MDA-MB-453). Although tamoxifen has been described to be able to induce oxidative stress at concentrations similar to those applied in this study (6 mu g/ml), we observed that nelfinavir but not tamoxifen reduced the intracellular glutathione level of breast cancer cells within hours of application by up to 32%, suggesting the induction of oxidative stress was an early event and an additional cause of the apoptosis induced by nelfinavir. Conclusions: The results demonstrate that nelfinavir may be an effective drug against breast cancer and could be combined with tamoxifen to enhance its efficacy against breast cancer cells. Moreover, the cytotoxic effect of a tamoxifen and nelfinavir combination was independent of the oestrogen receptor status of the analysed breast cancer cells, suggesting a potential benefit of a combination of these two drugs even in patients with no hormone-responsive tumours. We therefore recommend that clinical studies on nelfinavir with breast cancer patients should include this drug combination to analyse the therapeutic efficacy as well as the safety and tolerability of this potential treatment option

    Mind the (yield) gap(s)

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    This paper explores the origin of the notion of “yield gap” and its use as a framing device for agricultural policy in sub-Saharan Africa. The argument is that while the yield gap of policy discourse provides a simple and powerful framing device, it is most often used without the discipline or caveats associated with the best examples of its use in crop production ecology and microeconomics. This argument is developed by examining how yield gap is used in a selection of recent and influential agricultural policy documents. The message for policy makers and others is clear: “mind the (yield) gap(s)”, for they are seldom what they appear
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