1,609 research outputs found

    No-go for Partially Massless Spin-2 Yang-Mills

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    There are various no-go results forbidding self-interactions for a single partially massless spin-2 field. Given the photon-like structure of the linear partially massless field, it is natural to ask whether a multiplet of such fields can interact under an internal Yang-Mills like extension of the partially massless symmetry. We give two arguments that such a partially massless Yang-Mills theory does not exist. The first is that there is no Yang-Mills like non-abelian deformation of the partially massless symmetry, and the second is that cubic vertices with the appropriate structure constants do not exist.Comment: 18 pages. v2 small corrections and ref

    Imaging and Imagining Taiwan: Identity representation and cultural politics

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    Since the 1990s the issue of identity has been one of the most prominent and hotly-debated topics in Taiwan Studies. A rich corpus of literature has been produced in various fields in the attempt to address this problematic issue, examining questions of Taiwanese identity from political, social and cultural perspectives. Imaging and Imagining Taiwan takes a fresh approach to this important topic, examining Taiwanese identity from a visual perspective and exploring the ways in which the island is presented and imagined. In contrast to those studies that seek to address the issue of identity from an essentialist position, Imaging and Imagining Taiwan offers a new contextualization of identity, investigating the ways in which Taiwan has been represented in films, fine art, advertising, sport, and social spaces at different periods in history. Covering a diverse range of topics, the book aims to capture the fluidity, changeability, fragmentation and dynamism of Taiwanese identity as an imaginary and encompassing whole. Through seven case studies the book focuses on the ways in which Taiwan is represented, how this relates to identity politics, and how the island is imaged and imagined visually, socially, and symbolically. The essays comprising this collection are grouped into three sections, each of which focuses on a particular approach to the topic of Taiwanese identity. The first of these —Colonial Representation —deals with colonial subjectivity and traumatic experience. The second, entitled Imaging Difference, examines cultural practices in film, TV advertisements and fine art, and explores the boundaries between the inside and the outside, the difference marked by the process of othering, and the anxiety and alienation of the excluded. The third section—Identity and Place—focuses on the relationship between identity and the social construction of place, and examines the role of place-making in the new Taiwanese nation-building process. Interrogating the complex issue of Taiwanese identity from various standpoints, the seven contributors write from a range of disciplinary backgrounds (Literature, History, Film Studies, Linguistics, Anthropology and Cultural Studies) and geographical contexts (Taiwan, Europe and America). This combination of fresh perspectives and a range of disciplinary approaches offers a set of diverse yet complementary insights into how Taiwan has been envisioned and imagined, and how the Taiwanese have positioned and identified themselves at different times. By combining different themes and disciplinary approaches together in one publication, Imaging and Imagining Taiwan brings both nuance and depth to the discussion of the representation of Taiwanese identity. The book articulates and examines the complexity of identity, avoiding essentialist approaches to the topic, instead illustrating identity's multi-faceted nature and dynamic messiness. Thus, the book argues, the politics of identity is not only a politics of representation, but also a politics of positioning, whereby identity is formulated both by the construction of sameness and the inscription of difference. The interdisciplinary approach adopted by this book makes the discussion of Taiwanese identity of interest to those both studying and working in a range of subject disciplines, not limited to Taiwan Studies, but also in History, Film, Linguistics, Literary Studies, Nationalism Studies, and Urban Studies

    Interventions for Challenging Behaviours of Students with Autism Spectrum Disorders and Developmental Disabilities: A Synthesis Paper

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    This synthesis paper summarizes research literature addressing challenging be-haviours in children and youth with autism spectrum disorders and developmental disabilities in school settings. We conducted a comprehensive literature review to identify relevant peer-reviewed articles published between the years 2000 and 2011. The methodological quality of all studies was screened following a stan-dard quality assessment checklist. Intervention effects were assessed quantitatively. Results of quality analysis and intervention effectiveness were in-tegrated to identify interventions with strong support and evidence of effectiveness. We discuss results in terms of implications for intervention choice and implementation in school settings, limitations, and directions for future re-search

    Artemisinin-based combination therapy in pregnant women in Zambia: efficacy, safety and risk of recurrent malaria.

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    BACKGROUND: In Zambia, malaria is one of the leading causes of morbidity and mortality, especially among under five children and pregnant women. For the latter, the World Health Organization recommends the use of artemisinin-based combination therapy (ACT) in the second and third trimester of pregnancy. In a context of limited information on ACT, the safety and efficacy of three combinations, namely artemether-lumefantrine (AL), mefloquine-artesunate (MQAS) and dihydroartemisinin-piperaquine (DHAPQ) were assessed in pregnant women with malaria. METHODS: The trial was carried out between July 2010 and August 2013 in Nchelenge district, Luapula Province, an area of high transmission, as part of a multi-centre trial. Women in the second or third trimester of pregnancy and with malaria were recruited and randomized to one of the three study arms. Women were actively followed up for 63 days, and then at delivery and 1 year post-delivery. RESULTS: Nine hundred pregnant women were included, 300 per arm. PCR-adjusted treatment failure was 4.7% (12/258) (95% CI 2.7-8.0) for AL, 1.3% (3/235) (95% CI 0.4-3.7) for MQAS and 0.8% (2/236) (95% CI 0.2-3.0) for DHAPQ, with significant risk difference between AL and DHAPQ (p = 0.01) and between AL and MQAS (p = 0.03) treatments. Re-infections during follow up were more frequent in the AL (HR: 4.71; 95% CI 3.10-7.2; p < 0.01) and MQAS (HR: 1.59; 95% CI 1.02-2.46; p = 0.04) arms compared to the DHAPQ arm. PCR-adjusted treatment failure was significantly associated with women under 20 years [Hazard Ratio (HR) 5.35 (95% CI 1.07-26.73; p = 0.04)] and higher malaria parasite density [3.23 (95% CI 1.03-10.10; p = 0.04)], and still women under 20 years [1.78, (95% CI 1.26-2.52; p < 0.01)] had a significantly higher risk of re-infection. The three treatments were generally well tolerated. Dizziness, nausea, vomiting, headache and asthenia as adverse events (AEs) were more common in MQAS than in AL or DHAPQ (p < 0.001). Birth outcomes were not significantly different between treatment arms. CONCLUSION: As new infections can be prevented by a long acting partner drug to the artemisinins, DHAPQ should be preferred in places as Nchelenge district where transmission is intense while in areas of low transmission intensity AL or MQAS may be used

    Nur77 controls tolerance induction, terminal differentiation, and effector functions in semi-invariant natural killer T cells

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    Semi-invariant natural killer T (iNKT) cells are self-reactive lymphocytes, yet how this lineage attains self-tolerance remains unknown. iNKT cells constitutively express high levels of Nr4a1-encoded Nur77, a transcription factor that integrates signal strength downstream of the T cell receptor (TCR) within activated thymocytes and peripheral T cells. The function of Nur77 in iNKT cells is unknown. Here we report that sustained Nur77 overexpression (Nur77^(tg)) in mouse thymocytes abrogates iNKT cell development. Introgression of a rearranged Vα14-Jα18 TCR-α chain gene into the Nur77^(tg) (Nur77^(tg);Vα14^(tg)) mouse rescued iNKT cell development up to the early precursor stage, stage 0. iNKT cells in bone marrow chimeras that reconstituted thymic cellularity developed beyond stage 0 precursors and yielded IL-4–producing NKT2 cell subset but not IFN-γ–producing NKT1 cell subset. Nonetheless, the developing thymic iNKT cells that emerged in these chimeras expressed the exhaustion marker PD1 and responded poorly to a strong glycolipid agonist. Thus, Nur77 integrates signals emanating from the TCR to control thymic iNKT cell tolerance induction, terminal differentiation, and effector functions

    Nur77 controls tolerance induction, terminal differentiation, and effector functions in semi-invariant natural killer T cells

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    Semi-invariant natural killer T (iNKT) cells are self-reactive lymphocytes, yet how this lineage attains self-tolerance remains unknown. iNKT cells constitutively express high levels of Nr4a1-encoded Nur77, a transcription factor that integrates signal strength downstream of the T cell receptor (TCR) within activated thymocytes and peripheral T cells. The function of Nur77 in iNKT cells is unknown. Here we report that sustained Nur77 overexpression (Nur77^(tg)) in mouse thymocytes abrogates iNKT cell development. Introgression of a rearranged Vα14-Jα18 TCR-α chain gene into the Nur77^(tg) (Nur77^(tg);Vα14^(tg)) mouse rescued iNKT cell development up to the early precursor stage, stage 0. iNKT cells in bone marrow chimeras that reconstituted thymic cellularity developed beyond stage 0 precursors and yielded IL-4–producing NKT2 cell subset but not IFN-γ–producing NKT1 cell subset. Nonetheless, the developing thymic iNKT cells that emerged in these chimeras expressed the exhaustion marker PD1 and responded poorly to a strong glycolipid agonist. Thus, Nur77 integrates signals emanating from the TCR to control thymic iNKT cell tolerance induction, terminal differentiation, and effector functions

    Border patrol gone awry: Lung NKT cell activation by Francisella tularensis exacerbates tularemia-like disease

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    The respiratory mucosa is a major site for pathogen invasion and, hence, a site requiring constant immune surveillance. The type I, semi-invariant natural killer T (NKT) cells are enriched within the lung vasculature. Despite optimal positioning, the role of NKT cells in respiratory infectious diseases remains poorly understood. Hence, we assessed their function in a murine model of pulmonary tularemia--because tularemia is a sepsis-like proinflammatory disease and NKT cells are known to control the cellular and humoral responses underlying sepsis. Here we show for the first time that respiratory infection with Francisella tularensis live vaccine strain resulted in rapid accumulation of NKT cells within the lung interstitium. Activated NKT cells produced interferon-Îł and promoted both local and systemic proinflammatory responses. Consistent with these results, NKT cell-deficient mice showed reduced inflammatory cytokine and chemokine response yet they survived the infection better than their wild type counterparts. Strikingly, NKT cell-deficient mice had increased lymphocytic infiltration in the lungs that organized into tertiary lymphoid structures resembling induced bronchus-associated lymphoid tissue (iBALT) at the peak of infection. Thus, NKT cell activation by F. tularensis infection hampers iBALT formation and promotes a systemic proinflammatory response, which exacerbates severe pulmonary tularemia-like disease in mice

    New VVV Survey Globular Cluster Candidates in the Milky Way Bulge

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    © 2017 The American Astronomical Society. All rights reserved.It is likely that a number of Galactic globular clusters remain to be discovered, especially toward the Galactic bulge. High stellar density combined with high and differential interstellar reddening are the two major problems for finding globular clusters located toward the bulge. We use the deep near-IR photometry of the VISTA Variables in the Vía Láctea (VVV) Survey to search for globular clusters projected toward the Galactic bulge, and hereby report the discovery of 22 new candidate globular clusters. These objects, detected as high density regions in our maps of bulge red giants, are confirmed as globular cluster candidates by their color-magnitude diagrams. We provide their coordinates as well as their near-IR color-magnitude diagrams, from which some basic parameters are derived, such as reddenings and heliocentric distances. The color-magnitude diagrams reveal well defined red giant branches in all cases, often including a prominent red clump. The new globular cluster candidates exhibit a variety of extinctions (0.06 < A Ks < 2.77) and distances (5.3 < D < 9.5 kpc). We also classify the globular cluster candidates into 10 metal-poor and 12 metal-rich clusters, based on the comparison of their color-magnitude diagrams with those of known globular clusters also observed by the VVV Survey. Finally, we argue that the census for Galactic globular clusters still remains incomplete, and that many more candidate globular clusters (particularly the low luminosity ones) await to be found and studied in detail in the central regions of the Milky Way.Peer reviewedFinal Accepted Versio
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