43,664 research outputs found
Cultural activism and the politics of place-making
No full textIn this paper, we explore the relationship between creative practice, activism, and urban place-making by considering the role they play in the construction of meaning in urban spaces. Through an analysis of two activist groups based in Stokes Croft, Bristol (UK), we argue that cultural activism provides new political prospects within the wider context of global capitalism through the cultivation of a shared aesthetics of protest. By cultivating aspects of shared history and a mutual enthusiasm for creative practice as a form of resistance, Stokes Croft has emerged as a ‘space of nurturance’ for creative sensibilities. However, we note how Stokes Croft as an autonomous space remains open-ended and multiple for activists interested in promoting different visions of social justice
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Activated STAT4 and a functional role for IL-12 in human Peyer's patches
No full textT cells in the Peyer’s patches (PP) of the human ileum are exposed to a myriad of dietary and bacterial Ags from the gut lumen. Recall proliferative responses to common dietary Ags are readily demonstrable by PP T cells from healthy individuals, and the cytokine response is dominated by IFN-{gamma}. Consistent with Th1 skewing, PP cells spontaneously secrete IL-12p70, and IL-12p40 protein can be visualized underneath the PP dome epithelium. In this study, we have analyzed IL-12 signaling in PP and investigated whether IL-12 plays a functional role. CD3+ T lymphocytes isolated from PP and adjacent ileal mucosa spontaneously secrete IFN-{gamma} with negligible IL-4 or IL-5. RNA transcripts for IL-12R{beta}2, the signaling component of the IL-12R, are present in purified CD4+ and CD8+ T PP lymphocytes. Active STAT4, a transcription factor essential for IL-12-mediated Th1 differentiation, is readily detectable in biopsies from PP and ileal mucosa and STAT4-DNA binding activity is demonstrable by EMSA. Nuclear proteins from CD3+ T PP lymphocytes contain STAT4 and T-bet, a transcription factor selectively expressed in Th1 cells. Stimulation of freshly isolated PP cells with staphylococcal enterotoxin B dramatically enhanced the production of IFN-{gamma}, an effect which was largely inhibited by neutralizing anti-IL-12 Ab. These data show that IL-12 in human PP is likely to be responsible for the Th1-dominated cytokine response of the human mucosal immune system
Wave turbulence of a rotating array of quantized vortices in the T → 0 temperature limit
No full textThe dynamics of quantized vortices in the zero temperature limit is currently of great interest, particularly in the case of the Fermi superfluid He-B. Here we study wave turbulence, generated by the librating motion of a rotating cylindrical container filled with He-B, in the limit of vanishing viscous forces at temperatures . The polarization of the quantized vortices with respect to the axis of rotation is measured using non-invasive NMR techniques. We observe a decrease of the polarization when the librating motion is started, and a two-stage relaxation process when the modulation of the rotation velocity is stopped. The first relaxation process is associated with the dissipation of large-scale flow stored in inertial waves and the solid body rotation of the vortex array. From the decay of these energy reservoirs we determine the rate of energy dissipation of large-scale flow. The later second process is related to the relaxation of Kelvin waves on individual vortices. This process is monitored by the recovery of the polarization. The existence of a Kelvin wave cascade at the lowest temperatures is currently a central open question. We supply some evidence for the cascade
Health status in patients awaiting hip replacement for osteoarthritis
No full textBackground: Hip osteoarthritis is a major cause of pain and disability, especially in the elderly. As part of a study investigating factors that could be associated with advanced osteoarthritis of the hip, we compared the health status of patients awaiting arthroplasty for hip osteoarthritis with controls. We further investigated the interaction of hip osteoarthritis with other variables (age, gender, social class and concurrent pain) in relation to health status. Methods: A case–control study was performed in two English health districts (Portsmouth and North Staffordshire) during 1993–1995. A total of 611 patients (210 men and 401 women) listed for hip replacement because of osteoarthritis over an 18-month period formed the case group and were compared with an equal number of controls selected from the general population and individually matched for age, gender and general practice. Cases and controls completed a structured interviewer-administered questionnaire, which included queries about their medical condition, occupation (from which a measure of social class was derived), and general health status using the SF36. Results: Physical function (t=32.1, P<0.001), social function (t=16.8, P<0.001) and perceived general health (t=4.1, P<0.001) were worse in the case group, but energy/vitality and mental health showed little difference between cases and controls. Cases were more likely to report knee pain than controls, but case–control status was not associated with pain in the fingers or shoulders, or with social class. However, differences in physical and social function between cases and controls did vary with socio-demographic factors and concurrent knee pain status. Conclusion: Patients awaiting hip-replacement because of osteoarthritis were more likely to be restricted in their physical and social life than adults in the general population, but mental state and vitality appear unimpaired in this group. This contrasts with findings from other chronic pain disorders. Manual social class is not linked to being on a waiting list for osteoarthritic hip replacement but does add to the burden on health status, particularly social functioning in those with osteoarthritis of the hip
The development of rail-head acoustic roughness
No full textA model of the development of rail-head acoustic roughness on tangent track has been formulated. The model consists of a two-dimensional time domain wheel-rail interaction force calculation, with the normal force used as the input to a two-dimensional rolling contact and wear model. The possibility of multiple wear mechanisms arising from stress concentrations is considered by using a wear coefficient that can vary with the conditions
at each point in the contact. The contact model is based on a variational technique, taking account of non-Hertzian and transient effects. A novel feature of the rolling contact model
is the introduction of a velocity-dependent friction coefficient. In rolling contact this leads to a high frequency stick-slip oscillation in the slip zone at the trailing edge. Roughness development depends on the dynamics of the track. Roughness growth
has often been linked to the pinned-pinned frequency and other resonances of the coupled track and vehicle system. Here the effect of different vehicle and track parameters on track
dynamics, wear and roughness development has been examined. Rail dampers are studied as they change the dynamic response of the track. Results are presented in the form of roughness growth rate functions both for individual vehicle types and for mixed traffic. The model parameters match those at a site used for measurements of roughness
development taken by Deutsche Bahn AG as part of the EU project Silence. The study shows that it is important to include non-Hertzian effects when studying roughness with wavelengths shorter than 100 mm. With a non-Hertzian contact model, no
mechanism has been found for consistently increasing roughness levels. The model predicts that roughness wavelengths shorter than the contact length will wear away. Rail
dampers are shown to reduce the pinned-pinned frequency and smooth the peaks and troughs in the track receptance. Rail dampers also reduce the dynamic wheel-rail
interaction forces, especially around the pinned-pinned resonance, and shift the force spectrum to lower frequencies or longer wavelengths. However, rail dampers are not
predicted to affect roughness growth rates significantly
E-book : Industrial Transformation In The Developing World (author: Michael T. Rock & David P. Angel)
No full textArsip Kuliah Online 2010: E-book : Industrial Transformation In The Developing World (author: Michael T. Rock & David P. Angel
Letter from Carl Hayden to P. J Moran
No full textLetter from Carl T. Hayden to P. J. Moran concerning the alignment of the road to Bright Angel Trail
E-book : "industrial Transformations In The Developing World (author: Michael T. Rock & David. P Angel)
No full textArsip Kuliah Online 2010: E-book : "industrial Transformations In The Developing World (author: Michael T. Rock & David. P Angel
Letter from P. J. Moran to Carl Hayden
No full textLetter from P. J. Moran to Carl T. Hayden inquiring when construction will begin on the approach road to Bright Angel Trai
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