152 research outputs found

    Prevention of immunodeficiency virus induced CD4+ T-cell depletion by prior infection with a non-pathogenic virus

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    AbstractImmune dysregulation initiated by a profound loss of CD4+ T-cells is fundamental to HIV-induced pathogenesis. Infection of domestic cats with a non-pathogenic lentivirus prevalent in the puma (puma lentivirus, PLV or FIVpco) prevented peripheral blood CD4+ T-cell depletion caused by subsequent virulent FIV infection. Maintenance of this critical population was not associated with a significant decrease in FIV viremia, lending support to the hypothesis that direct viral cytopathic effect is not the primary cause of immunodeficiency. Although this approach was analogous to immunization with a modified live vaccine, correlates of immunity such as a serum-neutralizing antibody or virus-specific T-cell proliferative response were not found in protected animals. Differences in cytokine transcription profile, most notably in interferon gamma, were observed between the protected and unprotected groups. These data provide support for the importance of non-adaptive enhancement of the immune response in the prevention of CD4+ T-cell loss

    Infrared spectroscopy of phytochrome and model pigments

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    Fourier-transform infrared difference spectra between the red-absorbing and far-red-absorbing forms of oat phytochrome have been measured in H2O and 2H2O. The difference spectra are compared with infrared spectra of model compounds, i.e. the (5Z,10Z,15Z)- and (5Z,10Z,15E)-isomers of 2,3,7,8,12,13,17,18-octaethyl-bilindion (Et8-bilindion), 2,3-dihydro-2,3,7,8,12,13,17,18-octaethyl-bilindion (H2Et8-bilindion), and protonated H2Et8-bilindion in various solvents. The spectra of the model compounds show that only for the protonated forms can clear differences between the two isomers be detected. Since considerable differences are present between the spectra of Et8-bilindion and H2Et8-bilindion, it is concluded that only the latter compound can serve as a model system of phytochrome. The 2H2O effect on the difference spectrum of phytochrome supports the view that the chromophore in red-absorbing phytochrome is protonated and suggests, in addition, that it is also protonated in far-red-absorbing phytochrome. The spectra show that protonated carboxyl groups are influenced. The small amplitudes in the difference spectra exclude major changes of protein secondary structure

    Cyber security fear appeals:unexpectedly complicated

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    Cyber security researchers are starting to experiment with fear appeals, with a wide variety of designs and reported efficaciousness. This makes it hard to derive recommendations for designing and deploying these interventions. We thus reviewed the wider fear appeal literature to arrive at a set of guidelines to assist cyber security researchers. Our review revealed a degree of dissent about whether or not fear appeals are indeed helpful and advisable. Our review also revealed a wide range of fear appeal experimental designs, in both cyber and other domains, which confirms the need for some standardized guidelines to inform practice in this respect. We propose a protocol for carrying out fear appeal experiments, and we review a sample of cyber security fear appeal studies, via this lens, to provide a snapshot of the current state of play. We hope the proposed experimental protocol will prove helpful to those who wish to engage in future cyber security fear appeal research

    Sport in the city: measuring economic significance at the local level

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    In many cities throughout Europe, sport is increasingly being used as a tool for economic revitalisation. While there has been a growth in literature relating to the specific economic impacts of sports-led development, including professional sport facilities, teams, and sport events, limited research has been undertaken on the contribution of the whole sport sector to output and employment. In the United Kingdom (UK), studies have focused on evaluating sport-related economic activity at the national level, yet despite the increasing use of sport for local economic development little research has been undertaken at the city level. To address this situation, this article uses the National Income Accounting framework to measure the economic importance of sport in Sheffield, UK. It shows that the value-added in 1996/97 was 165.61m or 4.11% of Gross Domestic Product (GDP), approximately twice the amount predicted from current national estimates. It is argued that this can primarily be explained by previous studies under-estimating the economic importance of sport, largely due to methodological differences. It goes on to suggest that future research on the significance of sport should be undertaken at the local level to provide policymakers with information at the spatial level where regeneration programmes are being implemented.</p

    Accessory Genomes Drive Independent Spread of Carbapenem- Resistant Klebsiella pneumoniae Clonal Groups 258 and 307 in Houston, TX

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    Carbapenem-resistant Klebsiella pneumoniae (CRKp) is an urgent public health threat. Worldwide dissemination of CRKp has been largely attributed to clonal group (CG) 258. However, recent evidence indicates the global emergence of a CRKp CG307 lineage. Houston, TX, is the first large city in the United States with detected cocirculation of both CRKp CG307 and CG258. We sought to characterize the genomic and clinical factors contributing to the parallel endemic spread of CG258 and CG307. CRKp isolates were collected as part of the prospective, Consortium on Resistance against Carbapenems in Klebsiella and other Enterobacterales 2 (CRACKLE-2) study. Hybrid short-read and long-read genome assemblies were generated from 119 CRKp isolates (95 originated from Houston hospitals). A comprehensive characterization of phylogenies, gene transfer, and plasmid content with pan-genome analysis was performed on all CRKp isolates. Plasmid mating experiments were performed with CG307 and CG258 isolates of interest. Dissection of the accessory genomes suggested independent evolution and limited horizontal gene transfer between CG307 and CG258 lineages. CG307 contained a diverse repertoire of mobile genetic elements, which were shared with other non-CG258 K. pneumoniae isolates. Three unique clades of Houston CG307 isolates clustered distinctly from other global CG307 isolates, indicating potential selective adaptation of particular CG307 lineages to their respective geographical niches. CG307 strains were often isolated from the urine of hospitalized patients, likely serving as important reservoirs for genes encoding carbapenemases and extendedspectrum b-lactamases. Our findings suggest parallel cocirculation of high-risk lineages with potentially divergent evolution

    At Home with “Real Americans”: Communicating Across the Urban/Rural and Black/White Divides in the 2008 Presidential Election

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    This ethnographic story seeks to reveal the complexity in talking across the urban/rural and Black/White divide in the 2008 Presidential Election.The story shows the tensions between feeling that an attempt to understand the other might help perpetuate the very intolerance we want to break through and feeling a responsibility to reach out and try to fashion a way out of prejudices and values with which we disagree. Is there a possibility for transformative dialogue and appreciative inquiry, where the four participants in this story might envision and generate a new, coconstructed reality, that all of them could believe in? Should that be our goal
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