4,087 research outputs found

    Characterization, cloning and immunogenicity of antigens released by lung-stage larvae of Schistosoma mansoni

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    Lung-stage schistosomula are the target of protective immunity in mice vaccinated with attenuated cercariae of Schistosoma mansoni. Therefore, proteins present at this developmental stage, and in particular those which are secreted, are a potential source of novel vaccine candidates. However, little information is available about such molecules. Here we describe the cDNA clones identified by screening expression libraries with serum raised against proteins released by lung-stage schistosomula. In total, 11 different cDNA species were identified, 6 of which have been described previously in S. mansoni; these included fructose 1,6-bisphosphate aldolase and Sm21.7 which together accounted for two-thirds of all positive clones. Of the 5 newly described schistosome genes, 1 cDNA had a high degree of homology to the s5a subunit of 26S proteasomes, most significant being with the human protein. The remaining 4 clones showed no significant homologies to any genes sequenced previously. Fructose 1,6-bisphosphate aldolase, Sm21.7, the proteasome homologue and 1 unknown clone (A26) have been expressed in a bacterial expression system and serum produced against each recombinant protein. Immunolocalization showed fructose 1,6-bisphosphate aldolase, Sm21.7 and the proteasome homologue to be most abundant in muscle cells whilst clone A26 was distributed throughout many tissues, but was most abundant in the tegument. Analysis of the cellular immune responses of vaccinated mice showed 3 of the 4 expressed clones to be highly immunogenic, inducing the secretion of large quantities of the Th1-type cytokine interferon gamma

    Polarization perception device

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    A polarization perception device comprises a base and a polarizing filter having opposite broad sides and a centerline perpendicular thereto. The filter is mounted on the base for relative rotation and with a major portion of the area of the filter substantially unobstructed on either side. A motor on the base automatically moves the filter angularly about its centerline at a speed slow enough to permit changes in light transmission by virtue of such movement to be perceived as light-dark pulses by a human observer, but fast enough so that the light phase of each such pulse occurs prior to fading of the light phase image of the preceding pulse from the observer's retina. In addition to an observer viewing a scene in real time through the filter while it is so angularly moved, or instead of such observation, the scene can be photographed, filmed or taped by a camera whose lens is positioned behind the filter

    Peer-to-peer:is deviant behavior the norm on P2P file-sharing networks?

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    P2P file-sharing networks such as Kazaa, eDonkey, and Limewire boast millions of users. Because of scalability concerns and legal issues, such networks are moving away from the semicentralized approach that Napster typifies toward more scalable and anonymous decentralized P2P architectures. Because they lack any central authority, these networks provide a new, interesting context for the expression of human social behavior. However, the activities of P2P community members are sometimes at odds with what real-world authorities consider acceptable. One example is the use of P2P networks to distribute illegal pornography. To gauge the form and extent of P2P-based sharing of illegal pornography, we analyzed pornography-related resource-discovery traffic in the Gnutella P2P network. We found that a small yet significant proportion of Gnutella activity relates to illegal pornography: for example, 1.6 percent of searches and 2.4 percent of responses are for this type of material. But does this imply that such activity is widespread in the file-sharing population? On the contrary, our results show that a small yet particularly active subcommunity of users searches for and distributes illegal pornography, but it isn't a behavioral norm

    Exploring patients' engagement with web-based peer support for Inflammatory Bowel Disease: forums or Facebook?

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    Whilst the popularity of health-related peer-to-peer web-based support shows no sign of diminishing, comparatively little is known about the factors associated with engagement in alternative web-based types of support (e.g. chat rooms, discussion forums, social networking sites). In this study, 147 patients living with Inflammatory Bowel Disease (IBD) completed an online questionnaire and described their use of either IBD forums or IBD Facebook groups along with a range of socio-demographic, disease-related and psychosocial factors. The findings revealed that over half (59 per cent) of respondents accessed forums with the remaining accessing Facebook groups. Members of Facebook groups were more likely to be younger, single and achieved a higher level of educational attainment compared with forum members but there was no difference in terms of disease-related characteristics. However, differences did exist in how they used web-based support with forum members having been members for longer, accessing them more frequently and spending longer online as well as posting more messages. Taking into account these background variables, there were no differences in terms of perceived stress, perceived social support and health-related quality of life between members of these two types of support communities

    Patterns of engagement with inflammatory bowel disease online support groups: comparing posters and lurkers

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    Little is known about the varying patterns of member engagement within inflammatory bowel disease online support groups. The aim of the study was, therefore, to compare posters and lurkers (i.e., those who read messages but choose not to post) in terms of engagement and motives for accessing online groups as well as to explore reasons why lurkers do not make an active contribution through posting messages. The findings revealed that those who posted messages visited groups more often and spent longer periods of time accessing them. However, there was no difference between posters and lurkers in terms of length of time as a group member. Furthermore, posters were more inclined to access online support groups to both seek and provide emotional, informational, and experiential support. Finally, four main reasons were described by lurkers for not posting messages and these focused on personal factors, illness severity, being helpful, and new member. For those healthcare professionals or patient volunteers who are involved in supporting inflammatory bowel disease online support groups, there are a number of practical strategies arising from these results which can be implemented to help integrate and encourage active participation by all members

    A holistic approach to the evaluation of sustainable housing

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    Residential housing is often evaluated against single or at best a limited number of similar criteria. These include quantifiable indicators such as energy use and its associated greenhouse gas emissions. It might also include material consumption from an embodied energy or resource use perspective. Social factors or qualitative indicators may be evaluated but are rarely placed or juxtaposed alongside these quantifiable indicators. A one-dimensional approach will be limiting because sustainable development includes both environmental and social factors. This paper describes the methodologies that have been developed to assess housing developments against five quite different criteria. These are: energy use, resource use, neighbourhood character, neighbourhood connectedness and diversity. In each case, high and low sustainability practice has been identified so that ranking is possible. These methodologies have then been tested by evaluating a typical precinct (approximately 400 m by 400 m) of a 1970-80s housing development in a suburb of Geelong. The rankings of the particular precinct have then been combined in a visual way to assist in the evaluation of the housing in a more holistic way. The results of this evaluation method are presented, along with a discussion of the strengths and weaknesses of the methodologies. The research is the outcome of collaboration by a cross-disciplinary group of academics within Deakin’s School of Architecture and Building

    The western blue groper (Achoerodus gouldii), a protogynous hermaphroditic labrid with exceptional longevity, late maturity, slow growth, and both late maturation and sex change

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    The western blue groper (Achoerodus gouldii) is shown to be a temperate protogynous hermaphrodite, which spawns between early winter and mid-spring. Because A. gouldii changes body color at about the time of sex change, its color can be used as a proxy for sex for estimating the size and age at sex change and for estimating growth when it is not possible to use gonads for determining the sex of this fish. The following characteristics make A. gouldii highly susceptible to overfishing: 1) exceptional longevity, with a maximum age (70 years) that is by far the greatest yet estimated for a labrid; 2) slow growth for the first 15 years and little subsequent growth by females; and 3) late maturation at a large total length (TL50 = 653 mm) and old age (~17 years) and 4) late sex change at an even greater total length (TL50 = 821 mm) and age (~35 years). The TL50 at maturity and particularly at sex change exceeded the minimum legal total length (500 mm) of A. gouldii and the lengths of many recreationally and commercially caught fish. Many of these characteristics are found in certain deep-water fishes that are likewise considered susceptible to overfishing. Indeed, although fishing effort for A. gouldii in Western Australia is not particularly high, per-recruit analyses indicate that this species is already close to or fully exploited

    A thematic analysis of messages posted by moderators within health-related asynchronous online support forums

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    Objective: To identify and describe the activities performed by online support community moderators. Methods: A total of 790 messages were downloaded for analysis. Messages were written by 59 moderators from 6 forums that represent a diverse range of conditions (arthritis, complex regional pain syndrome, Crohn’s disease, depression, diabetes and Huntington’s disease). Results:Thematic analysis revealed four themes: supportive tasks supportive tasks involve providing help to members, moderators sharing experiences shows how they use forums to fulfil their own personal support needs, making announcements about new discoveries and upcoming events, and administrative tasks such as enforcing rules and deleting spam. Conclusion: These results are consistent with the helper-therapy principle and provide a new insight into the diverse and varied range of activities carried out by moderators. Practice implications: Moderators perform many roles, including using forums for their own support needs
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