132 research outputs found
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Communicative elements of fluid collective organizing
Organizational communication research has traditionally focused on the organizing processes of firmly structured conventional organizations, such as workplaces, schools, and nonprofits. However, a growing line of research is beginning to investigate more fluid, ad-hoc, ephemeral, spontaneous, and loosely structured social collectives. This dissertation draws upon interview, observational, photographic, and social media data collected over a four-year time frame to investigate how a community of bicycle motocross (BMX) riders in the Southern United States communicate and organize to build and maintain public bicycle dirt jumps, despite lacking many of the elements commonly associated with formal organizing. The dissertation explores three key areas: (1) how communication gives rise to forms of authority in this fluid social collective, (2) how the materiality of the natural environment intersects with the group’s organizing, and (3) how intermingling social, material, and performative practices negotiate the tensions inherent to this organizational setting. Findings of the first study reveal that specific communicative interactions in the form of repetitive stories and assertives scale up to form a paradoxical “authoritative text” (Kuhn, 2008) that upholds a group ethos of contribution, but fails to specify the nature of how to carry out that contribution. The paradoxical nature of this authoritative text perpetuates conflict within the space. Study two conceptualizes environmental materiality as pure natural or (re)natural—depending upon the degree of alteration at human hands—and explains how a combination of these forms of nature contribute to the group’s organizationality. Finally, study three develops a model showing how the tensions of organic/civic, inclusion/consensus, and contributing/loafing are negotiated through communicative practices to sustain a version of the space that is both material and vision flexible. Theoretical contributions of this dissertation include extending our understanding of how authoritative texts emerge outside of formal organizing, providing a stronger analytical focus on the material, and explicating the importance of the space of practice in the tensions inherent to fluid organizing. The final section provides suggestions for how organic community recreation sites might be supported through official organizations, without bureaucratic or institutional influence undermining the core characteristics of the community.Communication Studie
Neither Shoreditch nor Manhattan: Post-politics, 'soft austerity urbanism' and real abstraction in Glasgow North
Speirs Locks is being re-constructed as a new cultural quarter in Glasgow North, with urban boosters envisioning the unlikely, rundown and de-populated light industrial estate as a key site in the city's ongoing cultural regeneration strategy. Yet this creative place-making initiative, I argue, masks a post-political conjuncture based on urban speculation, displacement and the foreclosure of dissent. Post-politics at Speirs Locks is characterised by what I term ‘soft austerity urbanism’: seemingly progressive, instrumental small-scale urban catalyst initiatives that in reality complement rather than counter punitive hard austerity urbanism. Relating such processes of soft austerity urbanism to a wider context of state-led gentrification, this study contributes to post-political debates in several ways. Firstly, it questions demands for participation as a proper politics when it has become practically compulsory in contemporary biopolitical capitalism. Secondly, it demonstrates how an extreme economy of austerity urbanism remains the hard underside of post-political, soft austerity urbanism approaches. Thirdly, it illustrates how these approaches relate to wider processes of ‘real abstraction’ – which is no mere flattery of the mind, but instead is rooted in actually existing processes of commodity exchange. Such abstraction, epitomised in the financialisation and privatisation of land and housing, buttresses the same ongoing property dynamics that were so integral to the global financial crisis and ensuing austerity policies in the first place. If we aim to generate a proper politics that creates a genuine rupture with the destructive play of capital in the built environment, the secret of real abstraction must be critically addressed
Comparison of T-Cell Interferon-γ Release Assays for Mycobacterium tuberculosis-Specific Antigens in Patients with Active and Latent Tuberculosis
Through the use of QuantiFERON-TB Gold, a commercial IFN-γ assay, we compared differences in quantitative T-cell responses to Mycobacterium tuberculosis (MTB)-specific antigens [QuantiFERON TB-2G (QFT-2G)] between patients with active tuberculosis (TB) disease and those with latent TB infection (LTBI). The patient group consisted of 180 patients with active TB disease (culture-positive for MTB) and 50 screening contacts with LTBI-positive response to the QFT-2G test. We prospectively performed a tuberculin skin test (TST) and a QFT-2G test for all subjects. The median IFN-γ levels upon the application of both antigens, ESAT-6 and CFP-10, were significantly higher in patients with active TB disease than in those with LTBI. A combined positive response to both antigens occurred at a higher rate in patients with active TB disease than in those with LTBI. There were no significant relationships between the quantitative responses of IFN-γ to both antigens and the maximum induration on TST in both patient groups. We demonstrated significant differences in the quantitative responses of IFN-γ to MTB between patients with active TB disease and those with LTBI in this study. However, there was an overlap in the IFN-γ levels between active TB disease and LTBI groups. Therefore, it would be difficult to use the QFT-2G test to completely discriminate active TB disease from LTBI
Mycobacterium bovis antigens for the differential diagnosis of vaccinated and infected cattle
Effect of concrete slats, three mat types and out-wintering pads on performance and welfare of finishing beef steers
peer-reviewedBackground
The objective was to investigate the effect of placing mats on concrete slatted floors on performance, behaviour, hoof condition, dirt scores, physiological and immunological variables of beef steers, and to compare responses with animals on out-wintering pads. Continental crossbred beef steers [n = 360; mean (±SD) initial live weight 539 kg (42.2)] were blocked by breed and live weight and randomly assigned to one of five treatments; (1) Concrete slats alone, (2) Mat 1 (Natural Rubber structure) (Durapak Rubber Products), (3) Mat 2 (Natural rubber structure) (EasyFix), (4) Mat 3 (modified ethylene vinyl acetate (EVA) foam structure) and (5) Out-wintering pads (OWP’s).
Results
Animals on the OWPs had a greater (P 0.05) as the other treatments. Animals on the OWPs had reduced lying percentage time compared with all the other treatments. Dry matter (DM) intake was greater for animals on the OWPs compared with all the other treatments. Carcass weight, kill out proportion, carcass fat score, carcass composition score, FCR and physiological responses were similar (P > 0.05) among treatments. No incidence of laminitis was observed among treatments. The number of hoof lesions was greater on all mat types (P < 0.05) compared with concrete slats and OWP treatments. Dirt scores were greater (P < 0.05) for animals on OWPs when measured on days 42, 84, 105, 126 and 150 compared with animals on slats.
Conclusions
Under the conditions adopted for the present study, there was no evidence to suggest that animals housed on bare concrete slats were disadvantaged in respect of animal welfare compared with animals housed on other floor types. It is concluded that the welfare of steers was not adversely affected by slats compared with different mat types or OWPs
Inflammasome activation in ruminant cells infected with Chlamydia abortus
Chlamydia abortus is the most common known infectious cause of ovine abortion
worldwide but is rarely linked with bovine abortion. The reasons for this differential
pathogenesis are unknown but may involve differences in innate immune recognition
and immune responsiveness. This is supported by the observation that chlamydial
abortion in sheep is associated with an inflammatory cytokine/chemokine cascade
that is not commonly observed in cattle. Studies with other Chlamydia species have
demonstrated that innate inflammatory pathways including inflammasome activation
contribute to both pathogen clearance and pathology. Pattern recognition receptors
(PRRs) activate these innate immune signalling pathways but are relatively poorly
characterized in ruminants. We hypothesize that the ruminant hosts differ in their
ability to innately sense C. abortus infection and activate the inflammasome. The
main aims of this project were to: analyse PRR expression in innate immune cells;
assess cytokine production from innate immune cells in response to C. abortus;
investigate the role of PRRs in the induction of innate immune responses to C.
abortus; and, conduct RNA-seq analysis on macrophages following infection with C.
abortus to identify important immune signalling pathways.
Ruminant oro-nasal turbinate cells, monocyte derived dendritic cells (MDDCs) and
monocyte derived macrophages (MDMs) express the cell-surface PRRs TLR2 and
TLR4 and also the intracellular PRRs NOD 1 and NLRP3. Oro-nasal turbinate cells
produce CXCL8 late into the chlamydial developmental cycle independent of IL-1β.
In contrast, ruminant MDMs and MDDCs secrete early IL-1β in response to C.
abortus infection. In MDMs and MDDCs, live and UV-inactivated C. abortus
induced TNF-α and CXCL8 but live infection was required for IL-1β secretion.
Therefore, intracellular C. abortus multiplication is necessary to stimulate the IL-1β
processing pathway within these cells. In order to determine PRR function, NOD1
and NLRP3 were knocked down in ruminant MDMs using siRNA. In both ovine and
bovine MDMs, NOD1 was identified as a factor in C. abortus mediated IL-1β
production. NLRP3 knockdown in bovine but not ovine MDMs also reduced IL-1β
production, indicating species-specific differences in C. abortus recognition. The
RNA-seq analysis of ruminant MDMs identified novel pathways of immune
activation by C. abortus and potentially important species-specific differences. An
improved understanding of the innate immune pathways activated in susceptible and
resistant hosts following C. abortus infection will inform on disease pathogenesis
and could contribute to novel chlamydial vaccine design
Protection against Tuberculosis in Eurasian Wild Boar Vaccinated with Heat-Inactivated Mycobacterium bovis
Tuberculosis (TB) caused by Mycobacterium bovis and closely related members of the Mycobacterium tuberculosis complex continues to affect humans and animals worldwide and its control requires vaccination of wildlife reservoir species such as Eurasian wild boar (Sus scrofa). Vaccination efforts for TB control in wildlife have been based primarily on oral live BCG formulations. However, this is the first report of the use of oral inactivated vaccines for controlling TB in wildlife. In this study, four groups of 5 wild boar each were vaccinated with inactivated M. bovis by the oral and intramuscular routes, vaccinated with oral BCG or left unvaccinated as controls. All groups were later challenged with a field strain of M. bovis. The results of the IFN-gamma response, serum antibody levels, M. bovis culture, TB lesion scores, and the expression of C3 and MUT genes were compared between these four groups. The results suggested that vaccination with heat-inactivated M. bovis or BCG protect wild boar from TB. These results also encouraged testing combinations of BCG and inactivated M. bovis to vaccinate wild boar against TB. Vaccine formulations using heat-inactivated M. bovis for TB control in wildlife would have the advantage of being environmentally safe and more stable under field conditions when compared to live BCG vaccines. The antibody response and MUT expression levels can help differentiating between vaccinated and infected wild boar and as correlates of protective response in vaccinated animals. These results suggest that vaccine studies in free-living wild boar are now possible to reveal the full potential of protecting against TB using oral M. bovis inactivated and BCG vaccines
Genome-wide transcriptional profiling of peripheral blood leukocytes from cattle infected with Mycobacterium bovis reveals suppression of host immune genes
Background
Mycobacterium bovis is the causative agent of bovine tuberculosis (BTB), a pathological infection with significant economic impact. Recent studies have highlighted the role of functional genomics to better understand the molecular mechanisms governing the host immune response to M. bovis infection. Furthermore, these studies may enable the identification of novel transcriptional markers of BTB that can augment current diagnostic tests and surveillance programmes. In the present study, we have analysed the transcriptome of peripheral blood leukocytes (PBL) from eight M. bovis-infected and eight control non-infected age-matched and sex-matched Holstein-Friesian cattle using the Affymetrix® GeneChip® Bovine Genome Array with 24,072 gene probe sets representing more than 23,000 gene transcripts.
Results
Control and infected animals had similar mean white blood cell counts. However, the mean number of lymphocytes was significantly increased in the infected group relative to the control group (P = 0.001), while the mean number of monocytes was significantly decreased in the BTB group (P = 0.002). Hierarchical clustering analysis using gene expression data from all 5,388 detectable mRNA transcripts unambiguously partitioned the animals according to their disease status. In total, 2,960 gene transcripts were differentially expressed (DE) between the infected and control animal groups (adjusted P-value threshold ≤ 0.05); with the number of gene transcripts showing decreased relative expression (1,563) exceeding those displaying increased relative expression (1,397). Systems analysis using the Ingenuity® Systems Pathway Analysis (IPA) Knowledge Base revealed an over-representation of DE genes involved in the immune response functional category. More specifically, 64.5% of genes in the affects immune response subcategory displayed decreased relative expression levels in the infected animals compared to the control group.
Conclusions
This study demonstrates that genome-wide transcriptional profiling of PBL can distinguish active M. bovis-infected animals from control non-infected animals. Furthermore, the results obtained support previous investigations demonstrating that mycobacterial infection is associated with host transcriptional suppression. These data support the use of transcriptomic technologies to enable the identification of robust, reliable transcriptional markers of active M. bovis infection.This work was supported by Investigator Grants from Science Foundation Ireland (Nos: SFI/01/F.1/B028 and SFI/08/IN.1/B2038), a Research Stimulus Grant from the Department of Agriculture, Fisheries and Food (No: RSF 06 405) and a European Union Framework 7 Project Grant (No: KBBE-211602-MACROSYS). KEK is supported by the Irish Research Council for Science, Engineering and Technology (IRCSET) funded Bioinformatics and Systems Biology PhD Programme http://bioinfo-casl.ucd.ie/PhD
Parameter estimation and use of gamma interferon assay for the diagnosis of bovine tuberculosis in Brazil
Ocorrência e caracterização da tuberculose em caprinos leiteiros criados no estado de Pernambuco
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