113 research outputs found

    Designing a visual component of communication within 3D avatar virtual worlds

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    Merged with duplicate record 10026.1/2600 on 08.20.2017 by CS (TIS)Over the last few years 3D avatar virtual worlds (AVW) have emerged on the Internet. These are computer generated, multi-user, graphical spaces within which people meet, form social groups and interact with each other in real time, typically through the exchange of text or audio messages. Each user is represented within the space by a digital image known as an avatar, which is usually humanoid in form, and is predominantly under the control of the person it represents. This thesisd escribesa creativep roject that is concernedw ith aspectso f social communication between users of "Ws. In particular, an avatar is designed that is capable of performing body language, and a set of useful gestures are implemented that support aspects of social interaction and integrate with verbal discourse in a meaningful way. In addition to this, a number of scenic properties are derived that enable better comprehension of the non verbal communication, e. g. spatial arrangement, camera position and lighting effects. The research consists of a number of interrelated design activities which include reviewing the literature on avatar design in order to locate goals and variety of the project, therefore building on the on the work of others; a comparative review of three popular 3D AVWs to explore the design problem; a study that aims to gain an understanding of the social dynamics involved; the adaptation of a diagrammatic technique for the purpose of modelling social interaction; the development of 2D and 3D prototype techniques exploring the application of the social interaction modelling technique; a body of creative work developing ideas for conveying non verbal communication and the appraisal of the effectiveness of this creative work. The research contributes to the field of avatar design in a number of ways. Firstly, it develops our understanding of social dynamics in virtual worlds. Secondly, it postulates modes of non verbal communication for both individuals and social groups that supports multi-participatory social discourse. Additionally, a number of useful research techniques have been devised, such as a linear diagramming technique that can be used to represent the structure of conversation thereby facilitating the exploration and understanding of the dynamics of AVW social discourse. The work is of interest to those working in the field of avatar and multi-user virtual world design. It may also be of interest to anyone thinking of using an avatar virtual world for the application of collaborative leaming, collaborative games and conferencing

    Targeted control of pneumolysin production by a mobile genetic element in Streptococcus pneumoniae

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    Streptococcus pneumoniae is a major human pathogen that can cause severe invasive diseases such as pneumonia, septicaemia and meningitis. Young children are at a particularly high risk, with an estimated 3–4 million cases of severe disease and between 300 000 and 500 000 deaths attributable to pneumococcal disease each year. The haemolytic toxin pneumolysin (Ply) is a primary virulence factor for this bacterium, yet despite its key role in pathogenesis, immune evasion and transmission, the regulation of Ply production is not well defined. Using a genome-wide association approach, we identified a large number of potential affectors of Ply activity, including a gene acquired horizontally on the antibiotic resistance-conferring Integrative and Conjugative Element (ICE) ICESp23FST81. This gene encodes a novel modular protein, ZomB, which has an N-terminal UvrD-like helicase domain followed by two Cas4-like domains with potent ATP-dependent nuclease activity. We found the regulatory effect of ZomB to be specific for the ply operon, potentially mediated by its high affinity for the BOX repeats encoded therein. Using a murine model of pneumococcal colonization, we further demonstrate that a ZomB mutant strain colonizes both the upper respiratory tract and lungs at higher levels when compared to the wild-type strain. While the antibiotic resistance-conferring aspects of ICESp23FST81 are often credited with contributing to the success of the S. pneumoniae lineages that acquire it, its ability to control the expression of a major virulence factor implicated in bacterial transmission is also likely to have played an important role

    SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

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    Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types

    The 2021 WHO catalogue of Mycobacterium tuberculosis complex mutations associated with drug resistance: a genotypic analysis.

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    Background: Molecular diagnostics are considered the most promising route to achievement of rapid, universal drug susceptibility testing for Mycobacterium tuberculosis complex (MTBC). We aimed to generate a WHO-endorsed catalogue of mutations to serve as a global standard for interpreting molecular information for drug resistance prediction. Methods: In this systematic analysis, we used a candidate gene approach to identify mutations associated with resistance or consistent with susceptibility for 13 WHO-endorsed antituberculosis drugs. We collected existing worldwide MTBC whole-genome sequencing data and phenotypic data from academic groups and consortia, reference laboratories, public health organisations, and published literature. We categorised phenotypes as follows: methods and critical concentrations currently endorsed by WHO (category 1); critical concentrations previously endorsed by WHO for those methods (category 2); methods or critical concentrations not currently endorsed by WHO (category 3). For each mutation, we used a contingency table of binary phenotypes and presence or absence of the mutation to compute positive predictive value, and we used Fisher's exact tests to generate odds ratios and Benjamini-Hochberg corrected p values. Mutations were graded as associated with resistance if present in at least five isolates, if the odds ratio was more than 1 with a statistically significant corrected p value, and if the lower bound of the 95% CI on the positive predictive value for phenotypic resistance was greater than 25%. A series of expert rules were applied for final confidence grading of each mutation. Findings: We analysed 41 137 MTBC isolates with phenotypic and whole-genome sequencing data from 45 countries. 38 215 MTBC isolates passed quality control steps and were included in the final analysis. 15 667 associations were computed for 13 211 unique mutations linked to one or more drugs. 1149 (7·3%) of 15 667 mutations were classified as associated with phenotypic resistance and 107 (0·7%) were deemed consistent with susceptibility. For rifampicin, isoniazid, ethambutol, fluoroquinolones, and streptomycin, the mutations' pooled sensitivity was more than 80%. Specificity was over 95% for all drugs except ethionamide (91·4%), moxifloxacin (91·6%) and ethambutol (93·3%). Only two resistance mutations were identified for bedaquiline, delamanid, clofazimine, and linezolid as prevalence of phenotypic resistance was low for these drugs. Interpretation: We present the first WHO-endorsed catalogue of molecular targets for MTBC drug susceptibility testing, which is intended to provide a global standard for resistance interpretation. The existence of this catalogue should encourage the implementation of molecular diagnostics by national tuberculosis programmes. Funding: Unitaid, Wellcome Trust, UK Medical Research Council, and Bill and Melinda Gates Foundation

    A first update on mapping the human genetic architecture of COVID-19

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