48 research outputs found

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

    Get PDF
    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Evolving the narrative for protecting a rapidly changing ocean, post‐COVID‐19

    Get PDF
    The ocean is the linchpin supporting life on Earth, but it is in declining health due to an increasing footprint of human use and climate change. Despite notable successes in helping to protect the ocean, the scale of actions is simply not now meeting the overriding scale and nature of the ocean's problems that confront us. Moving into a post-COVID-19 world, new policy decisions will need to be made. Some, especially those developed prior to the pandemic, will require changes to their trajectories; others will emerge as a response to this global event. Reconnecting with nature, and specifically with the ocean, will take more than good intent and wishful thinking. Words, and how we express our connection to the ocean, clearly matter now more than ever before. The evolution of the ocean narrative, aimed at preserving and expanding options and opportunities for future generations and a healthier planet, is articulated around six themes: (1) all life is dependent on the ocean; (2) by harming the ocean, we harm ourselves; (3) by protecting the ocean, we protect ourselves; (4) humans, the ocean, biodiversity, and climate are inextricably linked; (5) ocean and climate action must be undertaken together; and (6) reversing ocean change needs action now. This narrative adopts a ‘One Health’ approach to protecting the ocean, addressing the whole Earth ocean system for better and more equitable social, cultural, economic, and environmental outcomes at its core. Speaking with one voice through a narrative that captures the latest science, concerns, and linkages to humanity is a precondition to action, by elevating humankind's understanding of our relationship with ‘planet Ocean’ and why it needs to become a central theme to everyone's lives. We have only one ocean, we must protect it, now. There is no ‘Ocean B’

    Immune modulation in pemphigus vulgaris: Role of CD28 and IL-10

    No full text
    Pemphigus vulgaris (PV) is an autoimmune bullous skin disease characterized by Abs to the desmosomal cadherin desmoglein-3. Although the autoantibodies have been shown to be pathogenic, the role of the cellular immune system in the pathology of pemphigus-induced acantholysis is unclear. To further delineate the potential role of T cell-signaling pathways in the pathogenesis of PV, we performed passive transfer experiments with PV IgG in gene-targeted mutant mice. Our results demonstrated that CD28-deficient mice (lacking a costimulatory signal for T cell activation) are 5-fold more sensitive to the development of PV than wild-type mice. To evaluate whether the higher incidence of disease was due to an impairment in intercellular adhesion of keratinocytes, we performed an in vitro acantholysis, using CD28(-/-) mice keratinocytes. No alteration in in vitro adhesion was detected in CD28(-/-)-type keratinocytes. Because the CD28 molecule plays a pivotal role in the induction of Th2 cytokines, we examined the levels of a prototypic Th2 cytokine (IL-10) in CD28(-/-) mice. Lower levels of IL-10 mRNA were found in lesions from CD28(-/-) mice. To determine whether pemphigus susceptibility in CD28(-/-) was related to IL-10 deficiency, we performed passive transfer experiments in IL-10(-/-) mice that demonstrated increased blisters compared with controls. To confirm that IL-10 is involved in the pathogenesis, rIL-10 was given with PV IgG. IL-10 significantly suppressed the disease activity. These data suggest a potential role of IL-10 in PV

    Immune modulation in pemphigus vulgaris: Role of CD28 and IL-10

    No full text
    Pemphigus vulgaris (PV) is an autoimmune bullous skin disease characterized by Abs to the desmosomal cadherin desmoglein-3. Although the autoantibodies have been shown to be pathogenic, the role of the cellular immune system in the pathology of pemphigus-induced acantholysis is unclear. To further delineate the potential role of T cell-signaling pathways in the pathogenesis of PV, we performed passive transfer experiments with PV IgG in gene-targeted mutant mice. Our results demonstrated that CD28-deficient mice (lacking a costimulatory signal for T cell activation) are 5-fold more sensitive to the development of PV than wild-type mice. To evaluate whether the higher incidence of disease was due to an impairment in intercellular adhesion of keratinocytes, we performed an in vitro acantholysis, using CD28(-/-) mice keratinocytes. No alteration in in vitro adhesion was detected in CD28(-/-)-type keratinocytes. Because the CD28 molecule plays a pivotal role in the induction of Th2 cytokines, we examined the levels of a prototypic Th2 cytokine (IL-10) in CD28(-/-) mice. Lower levels of IL-10 mRNA were found in lesions from CD28(-/-) mice. To determine whether pemphigus susceptibility in CD28(-/-) was related to IL-10 deficiency, we performed passive transfer experiments in IL-10(-/-) mice that demonstrated increased blisters compared with controls. To confirm that IL-10 is involved in the pathogenesis, rIL-10 was given with PV IgG. IL-10 significantly suppressed the disease activity. These data suggest a potential role of IL-10 in PV

    Wider access and progression among full-time students

    No full text
    By 2010 the UK government intends to widen access and provide experience of higher education to half of those aged up to 30. Unlike many institutions, University of Paisley (UP) has exceeded its individual target on access. It has done this by providing entry routes for students with ‘non-traditional’ qualifications. It is feared that low entry qualifications will adversely influence performance and progression statistics as wider access is pursued. Drawing on a student-attrition theory, performance and progression are investigated using data for students enrolling at UP for the first time in 2000. At UP non-traditional entry coincided with the enrolment of many students over 21. The relationships between age and performance and between age and progression are nonlinear and involve interactions with gender. Also, there are interactions between entry qualification and field of study. These relationships and interactions could complicate the important task of translating wider access into academic success

    Social water assessment protocol: a step towards connecting mining, water and human rights

    Get PDF
    The human right to water has recently been recognized by both the United Nations General Assembly and the Human Rights Council. As the mining industry interacts with water on multiple levels, it is important that these interactions respect the human right to water. Currently, a disconnect exists between mine site water management practices and the recognition of water from a human rights perspective. It has been argued that the Minerals Council of Australia Water Accounting Framework can be used to strengthen the connection between water management and human rights. This article extends this connection through the use of a Social Water Assessment Protocol (SWAP). The SWAP is a scoping tool consisting of a set of questions classified into taxonomic themes under leading topics with suggested sources of data that enable mine sites to better understand the local water context in which they operate. Three of the themes contained in the SWAP - gender, Indigenous peoples and health - are discussed to demonstrate how the protocol may be useful in assisting mining companies to consider their impacts on the human right to water
    corecore