81 research outputs found

    anchors: Software for Anchoring Vignette Data

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    When respondents use the ordinal response categories of standard survey questions in different ways, the validity of analyses based on the resulting data can be biased. Anchoring vignettes is a survey design technique intended to correct for some of these problems. The anchors package in R includes methods for evaluating and choosing anchoring vignettes, and for analyzing the resulting data.

    anchors: Software for Anchoring Vignette Data

    Get PDF
    When respondents use the ordinal response categories of standard survey questions in different ways, the validity of analyses based on the resulting data can be biased. Anchoring vignettes is a survey design technique intended to correct for some of these problems. The anchors package in R includes methods for evaluating and choosing anchoring vignettes, and for analyzing the resulting data

    Phylodynamics of HIV-1 Subtype B among the Men-Having-Sex-with-Men (MSM) Population in Hong Kong

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    The men-having-sex-with-men (MSM) population has become one of the major risk groups for HIV-1 infection in the Asia Pacific countries. Hong Kong is located in the centre of Asia and the transmission history of HIV-1 subtype B transmission among MSM remained unclear. The aim of this study was to investigate the transmission dynamics of HIV-1 subtype B virus in the Hong Kong MSM population. Samples of 125 HIV-1 subtype B infected MSM patients were recruited in this study. Through this study, the subtype B epidemic in the Hong Kong MSM population was identified spreading mainly among local Chinese who caught infection locally. On the other hand, HIV-1 subtype B infected Caucasian MSM caught infection mainly outside Hong Kong. The Bayesian phylogenetic analysis also indicated that 3 separate subtype B epidemics with divergence dates in the 1990s had occurred. The first and latest epidemics were comparatively small-scaled; spreading among the local Chinese MSM while sauna-visiting was found to be the major sex partner sourcing reservoir for the first subtype B epidemic. However, the second epidemic was spread in a large-scale among local Chinese MSM with a number of them having sourced their sex partners through the internet. The epidemic virus was estimated to have a divergence date in 1987 and the infected population in Hong Kong had a logistic growth throughout the past 20 years. Our study elucidated the evolutionary and demographic history of HIV-1 subtype B virus in Hong Kong MSM population. The understanding of transmission and growth model of the subtype B epidemic provides more information on the HIV-1 transmission among MSM population in other Asia Pacific high-income countries

    The effects of centralising electoral management board design

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    The public administration of elections frequently fails. Variation in the performance of electoral management boards around the world has been demonstrated, illustrated by delays in the count, inaccurate or incomplete voter registers, or severe queues at polling stations. Centralising the management of the electoral process has often been proposed as a solution. There has been little theorisation and no empirical investigations into the effects that centralising an already decentralised system would have, however. This article addresses this lacuna by conceptualising centralisation through the literature on bureaucratic control and discretion. It then empirically investigates the effects through a case study of centralisation in two UK referendums. Semi-structured interviews were used with those who devised the policy instrument and those who were subject to it. The introduction of central directions had some of the desired effects such as producing more consistent services and eliminating errors. It also had side effects, however, such as reducing economic efficiency in some areas and overlooking local knowledge. Furthermore, the reforms caused a decline of staff morale, job satisfaction and souring of relations among stakeholder organisations. The process of making organisational change therefore warrants closer attention by policy makers and future scholarship on electoral integrity

    Voting Technology, Vote-by-Mail, and Residual Votes in California, 1990-2010

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    This paper examines how the growth in vote-by-mail and changes in voting technologies led to changes in the residual vote rate in California from 1990 to 2010. We find that in California’s presidential elections, counties that abandoned punch cards in favor of optical scanning enjoyed a significant improvement in the residual vote rate. However, these findings do not always translate to other races. For instance, find that the InkaVote system in Los Angeles has been a mixed success, performing very well in presidential and gubernatorial races, fairly well for ballot propositions, and poorly in Senate races. We also conduct the first analysis of the effects of the rise of vote-by-mail on residual votes. Regardless of the race, increased use of the mails to cast ballots is robustly associated with a rise in the residual vote rate. The effect is so strong that the rise of voting by mail in California has mostly wiped out all the reductions in residual votes that were due to improved voting technologies since the early 1990s

    Characterization of homologous sphingosine-1-phosphate lyase isoforms in the bacterial pathogen Burkholderia pseudomallei

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Sphingolipids (SLs) are ubiquitous elements in eukaryotic membranes and are also found in some bacterial and viral species. As well as playing an integral structural role, SLs also act as potent signalling molecules involved in numerous cellular pathways and have been linked to many human diseases. A central SL signalling molecule is sphingosine-1-phosphate (S1P) whose breakdown is catalysed by sphingosine-1-phosphate lyase (S1PL), a pyridoxal 5 '-phosphate (PLP) dependent enzyme that catalyses the cleavage of S1P to (2E)-hexadecenal (2E-HEX) and phosphoethanolamine (PE). Here we show the pathogenic bacterium Burkholderia pseudomallei K96243 encodes two homologous proteins (S1PL2021 and S1PL2025) that display moderate sequence identity to known eukaryotic and prokaryotic S1PLs. Using an established mass spectrometry-based methodology we show that recombinant S1PL2021 is catalytically active. Using recombinant human fatty aldehyde dehydrogenase (FALDH) we developed a spectrophotometric, enzyme-coupled assay to detect 2E-HEX formation and measure the kinetic constants of the two B. pseudomallei S1PL isoforms. Furthermore, we determined the x-ray crystal structure of the PLP-bound form of S1PL2021 at 2.1 Ã… resolution revealing the enzyme displays a conserved structural fold and active site architecture comparable with known S1PLs. The combined data suggest that B. pseudomallei has the potential to degrade host SLs in a S1PL-dependent manner.The authors thanks the following for funding: The Biotechnology and Biological Sciences Research Council (BBSRC) for an EastBio Doctoral Training Programme PhD studentship award to C McLean (BB/J01446X/1) and a grant awarded to DJ Campopiano (BB/I013687/1) that supported J Lowther and DJ Clarke. R Custodio was supported by the Defence Science and Technology Laboratory under contract DSTLX-1000060221 (WP1). We thank the staff of the Diamond Light Source, UK for help with data collection. The authors thank Prof. John RW Govan (University of Edinburgh) for his suggestions regarding Burkholderia strains and enthusiastic support of this work. We also thanks Dr. Kevin Ralston for help in the synthesis of 2E-HEX. The data associated with this paper is available to download (http://dx.doi.org/10.7488/ds/1412)
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