88 research outputs found

    bRing: An observatory dedicated to monitoring the β\beta Pictoris b Hill sphere transit

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    Aims. We describe the design and first light observations from the β\beta Pictoris b Ring ("bRing") project. The primary goal is to detect photometric variability from the young star β\beta Pictoris due to circumplanetary material surrounding the directly imaged young extrasolar gas giant planet \bpb. Methods. Over a nine month period centred on September 2017, the Hill sphere of the planet will cross in front of the star, providing a unique opportunity to directly probe the circumplanetary environment of a directly imaged planet through photometric and spectroscopic variations. We have built and installed the first of two bRing monitoring stations (one in South Africa and the other in Australia) that will measure the flux of β\beta Pictoris, with a photometric precision of 0.5%0.5\% over 5 minutes. Each station uses two wide field cameras to cover the declination of the star at all elevations. Detection of photometric fluctuations will trigger spectroscopic observations with large aperture telescopes in order to determine the gas and dust composition in a system at the end of the planet-forming era. Results. The first three months of operation demonstrate that bRing can obtain better than 0.5\% photometry on β\beta Pictoris in five minutes and is sensitive to nightly trends enabling the detection of any transiting material within the Hill sphere of the exoplanet

    Playing with the future: social irrealism and the politics of aesthetics

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    In this paper we wish to explore the political possibilities of video games. Numerous scholars now take seriously the place of popular culture in the remaking of our geographies, but video games still lag behind. For us, this tendency reflects a general response to them as imaginary spaces that are separate from everyday life and 'real' politics. It is this disconnect between abstraction and lived experience that we complicate by defining play as an event of what Brian Massumi calls lived abstraction. We wish to short-circuit the barriers that prevent the aesthetic resonating with the political and argue that through their enactment, video games can animate fantastical futures that require the player to make, and reflect upon, profound ethical decisions that can be antagonistic to prevailing political imaginations. We refer to this as social irrealism to demonstrate that reality can be understood through the impossible and the imagined

    Depauperate Avifauna in Plantations Compared to Forests and Exurban Areas

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    Native forests are shrinking worldwide, causing a loss of biological diversity. Our ability to prioritize forest conservation actions is hampered by a lack of information about the relative impacts of different types of forest loss on biodiversity. In particular, we lack rigorous comparisons of the effects of clearing forests for tree plantations and for human settlements, two leading causes of deforestation worldwide. We compared avian diversity in forests, plantations and exurban areas on the Cumberland Plateau, USA, an area of global importance for biodiversity. By combining field surveys with digital habitat databases, and then analyzing diversity at multiple scales, we found that plantations had lower diversity and fewer conservation priority species than did other habitats. Exurban areas had higher diversity than did native forests, but native forests outscored exurban areas for some measures of conservation priority. Overall therefore, pine plantations had impoverished avian communities relative to both native forests and to exurban areas. Thus, reports on the status of forests give misleading signals about biological diversity when they include plantations in their estimates of forest cover but exclude forested areas in which humans live. Likewise, forest conservation programs should downgrade incentives for plantations and should include settled areas within their purview

    Formal and Informal Financing Decisions of Small Businesses

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    This study investigates small businesses’ financing decisions. Drawing upon asymmetric information theory, institutional theory and relevant literature on cognitive financial constraints, human capital and social capital, we propose a theoretical framework in which financing determinants come from three dimensions: entrepreneurs’ individual factors, organisational (firm-level) factors and contextual (institutional) factors. We employ this model to distinguish four types of firms: (1) firms that use no external finance, (2) firms that use informal finance only, (3) firms that use formal finance only and (4) firms that use both formal and informal finance. An empirical test on Vietnamese small businesses shows that factors from all three dimensions are important in understanding small businesses’ financing decisions

    A Genetic Basis of Susceptibility to Acute Pyelonephritis

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    For unknown reasons, urinary tract infections (UTIs) are clustered in certain individuals. Here we propose a novel, genetically determined cause of susceptibility to acute pyelonephritis, which is the most severe form of UTI. The IL-8 receptor, CXCR1, was identified as a candidate gene when mIL-8Rh mutant mice developed acute pyelonephritis (APN) with severe tissue damage.We have obtained CXCR1 sequences from two, highly selected APN prone patient groups, and detected three unique mutations and two known polymorphisms with a genotype frequency of 23% and 25% compared to 7% in controls (p<0.001 and p<0.0001, respectively). When reflux was excluded, 54% of the patients had CXCR1 sequence variants. The UTI prone children expressed less CXCR1 protein than the pediatric controls (p<0.0001) and two sequence variants were shown to impair transcription.The results identify a genetic innate immune deficiency, with a strong link to APN and renal scarring

    The Gothenburg Traffic Control Area

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