544 research outputs found

    Using AI/expert system technology to automate planning and replanning for the HST servicing missions

    Get PDF
    This paper describes a knowledge-based system that has been developed to automate planning and scheduling for the Hubble Space Telescope (HST) Servicing Missions. This new system is the Servicing Mission Planning and Replanning Tool (SM/PART). SM/PART has been delivered to the HST Flight Operations Team (FOT) at Goddard Space Flight Center (GSFC) where it is being used to build integrated time lines and command plans to control the activities of the HST, Shuttle, Crew and ground systems for the next HST Servicing Mission. SM/PART reuses and extends AI/expert system technology from Interactive Experimenter Planning System (IEPS) systems to build or rebuild time lines and command plans more rapidly than was possible for previous missions where they were built manually. This capability provides an important safety factor for the HST, Shuttle and Crew in case unexpected events occur during the mission

    The architectures of media power: editing, the newsroom, and urban public space

    Get PDF
    This paper considers the relation of the newsroom and the city as a lens into the more general relation of production spaces and mediated publics. Leading theoretically from Lee and LiPuma’s (2002) notion of ‘cultures of circulation’, and drawing on an ethnography of the Toronto Star, the paper focuses on how media forms circulate and are enacted through particular practices and material settings. With its attention to the urban milieus and orientations of media organizations, this paper exhibits both affinities with but also differences to current interests in the urban architectures of media, which describe and theorize how media get ‘built into’ the urban experience more generally. In looking at editing practices situated in the newsroom, an emphasis is placed on the phenomenological appearance of media forms both as objects for material assembly as well as more abstracted subjects of reflexivity, anticipation and purposiveness. Although this is explored with detailed attention to the settings of the newsroom and the city, the paper seeks to also provide insight into the more general question of how publicness is material shaped and sited

    Scheduling science on television: A comparative analysis of the representations of science in 11 European countries

    Get PDF
    While science-in-the-media is a useful vehicle for understanding the media, few scholars have used it that way: instead, they look at science-in-the-media as a way of understanding science-in-the-media and often end up attributing characteristics to science-in-the-media that are simply characteristics of the media, rather than of the science they see there. This point of view was argued by Jane Gregory and Steve Miller in 1998 in Science in Public. Science, they concluded, is not a special case in the mass media, understanding science-in-the-media is mostly about understanding the media (Gregory and Miller, 1998: 105). More than a decade later, research that looks for patterns or even determinants of science-in-the-media, be it in press or electronic media, is still very rare. There is interest in explaining the media’s selection of science content from a media perspective. Instead, the search for, and analysis of, several kinds of distortions in media representations of science have been leading topics of science-in-the-media research since its beginning in the USA at the end of the 1960s and remain influential today (see Lewenstein, 1994; Weigold, 2001; Kohring, 2005 for summaries). Only a relatively small amount of research has been conducted seeking to identify factors relevant to understanding how science is treated by the mass media in general and by television in particular. The current study addresses the lack of research in this area. Our research seeks to explore which constraints national media systems place on the volume and structure of science programming in television. In simpler terms, the main question this study is trying to address is why science-in-TV in Europe appears as it does. We seek to link research focussing on the detailed analysis of science representations on television (Silverstone, 1984; Collins, 1987; Hornig, 1990; Leon, 2008), and media research focussing on the historical genesis and current political regulation of national media systems (see for instance Hallin and Mancini, 2004; Napoli, 2004; Open Society Institute, 2005, 2008). The former studies provide deeper insights into the selection and reconstruction of scientific subject matters, which reflect and – at the same time – reinforce popular images of science. But their studies do not give much attention to production constraints or other relevant factors which could provide an insight into why media treat science as they do. The latter scholars inter alia shed light on distinct media policies in Europe which significantly influence national channel patterns. However, they do not refer to clearly defined content categories but to fairly rough distinctions such as information versus entertainment or fictional versus factual. Accordingly, we know more about historical roots and current practices of media regulation across Europe than we do about the effects of these different regimes on the provision of specific content in European societies

    Substantiating a political public sphere in the Scottish press : a comparative analysis

    Get PDF
    This article uses content analysis to characterize the performance of the media in a national public sphere, by setting apart those qualities that typify internal press coverage of a political event. The article looks at the coverage of the 1999 devolved Scottish election from the day before the election until the day after. It uses a word count to measure the election material in Scottish newspapers the Herald, the Press and Journal and the Scotsman, and United Kingdom newspapers the Guardian, the Independent and The Times, and categorizes that material according to discourse type, day and page selection. The article finds a number of qualities that typify the Scottish sample in particular, and might be broadly indicative of a political public sphere in action. Firstly, and not unexpectedly, it finds that the Scottish newspapers carry significantly more election coverage. Just as tellingly, though, the article finds that the Scottish papers offer a greater proportion of advice and background information, in the form of opinion columns and feature articles. It also finds that the Scottish papers place a greater concentration of both informative and evaluative material in the period before the vote, consistent with their making a contribution to informed political action. Lastly, the article finds that the Scottish sample situates coverage nearer the front of the paper and places a greater proportion on recto pages. The article therefore argues that the Scottish papers display features that distinguish them from the UK papers, and are broadly consistent with their forming part of a deliberative public sphere, and suggests that these qualities might be explored as a means of judging future media performance

    Vertical Structure of the Outer Accretion Disk in Persistent Low-Mass X-Ray Binaries

    Get PDF
    We have investigated the influence of X-ray irradiation on the vertical structure of the outer accretion disk in low-mass X-ray binaries by performing a self-consistent calculation of the vertical structure and X-ray radiation transfer in the disk. Penetrating deep into the disk, the field of scattered X-ray photons with energy E10E\gtrsim10\,keV exerts a significant influence on the vertical structure of the accretion disk at a distance R1010R\gtrsim10^{10}\,cm from the neutron star. At a distance R1011R\sim10^{11}\,cm, where the total surface density in the disk reaches Σ020\Sigma_0\sim20\,g\,cm2^{-2}, X-ray heating affects all layers of an optically thick disk. The X-ray heating effect is enhanced significantly in the presence of an extended atmospheric layer with a temperature Tatm(2÷3)×106T_{atm}\sim(2\div3)\times10^6\,K above the accretion disk. We have derived simple analytic formulas for the disk heating by scattered X-ray photons using an approximate solution of the transfer equation by the Sobolev method. This approximation has a 10\gtrsim10\,% accuracy in the range of X-ray photon energies E<20E<20\,keV.Comment: 19 pages, 8 figures, published in Astronomy Letter

    Comparing international coverage of 9/11 : towards an interdisciplinary explanation of the construction of news

    Get PDF
    This article presents an interdisciplinary model attempting to explain how news is constructed by relying on the contributions of different fields of study: News Sociology, Political Communications, International Communications, International Relations. It is a first step towards developing a holistic theoretical approach to what shapes the news, which bridges current micro to macro approaches. More precisely the model explains news variation across different media organization and countries by focusing on the different way the sense of newsworthiness of journalists is affected by three main variables: national interest, national journalistic culture, and editorial policy of each media organization. The model is developed on the basis of an investigation into what shaped the media coverage of 9/11 in eight elite newspapers across the US, France, Italy and Pakistan

    Carcinogenic Effects in a Phenylketonuria Mouse Model

    Get PDF
    Phenylketonuria (PKU) is a metabolic disorder caused by impaired phenylalanine hydroxylase (PAH). This condition results in hyperphenylalaninemia and elevated levels of abnormal phenylalanine metabolites, among which is phenylacetic acid/phenylacetate (PA). In recent years, PA and its analogs were found to have anticancer activity against a variety of malignancies suggesting the possibility that PKU may offer protection against cancer through chronically elevated levels of PA. We tested this hypothesis in a genetic mouse model of PKU (PAHenu2) which has a biochemical profile that closely resembles that of human PKU. Plasma levels of phenylalanine in homozygous (HMZ) PAHenu2 mice were >12-fold those of heterozygous (HTZ) littermates while tyrosine levels were reduced. Phenylketones, including PA, were also markedly elevated to the range seen in the human disease. Mice were subjected to 7,12 dimethylbenz[a]anthracene (DMBA) carcinogenesis, a model which is sensitive to the anticancer effects of the PA derivative 4-chlorophenylacetate (4-CPA). Tumor induction by DMBA was not significantly different between the HTZ and HMZ mice, either in total tumor development or in the type of cancers that arose. HMZ mice were then treated with 4-CPA as positive controls for the anticancer effects of PA and to evaluate its possible effects on phenylalanine metabolism in PKU mice. 4-CPA had no effect on the plasma concentrations of phenylalanine, phenylketones, or tyrosine. Surprisingly, the HMZ mice treated with 4-CPA developed an unexplained neuromuscular syndrome which precluded its use in these animals as an anticancer agent. Together, these studies support the use of PAHenu2 mice as a model for studying human PKU. Chronically elevated levels of PA in the PAHenu2 mice were not protective against cancer

    Scandinavian Flagship Universities: an Appraisal of Leading National Universities in the European Context

    Get PDF
    In the immediate post-Sputnik era, Clark Kerr saw America’s breed of universities as “multiversities,” characterized by growing enrollment, an increasingly diversified academic community, and as the emerging driver of knowledge production and innovation (Kerr 2001: xi). This is now a widely shared vision throughout the world. Governments have provided additional funding, fueling further growth in academic programs and attracting talent. One result: the number of perceived stakeholders has increased, along with their expectations

    The Kafkaesque Pursuit of ‘World Class’: Audit Culture and the Reputational Arms Race in Academia

    Get PDF
    Since the 1980s universities have been subjected to a seemingly continuous process of policy reforms designed to make them more economical, efficient and effective, according to yardsticks defined by governments and university managers. The pursuit of ‘excellence’, ‘international standing’ and ‘world class’ status have become key drivers of what Hazelkorn (High Educ Pol 21(2):193–215, 2008) has termed the ‘rankings arms race’ that now dominates the world of academia. These policies are changing the mission and meaning of the public university and, more profoundly, the culture of academia itself. While some authors have sought to capture and analyse these trends in terms of ‘academic capitalism’ and the ‘enterprise university model’, we suggest they might also be usefully understood theoretically as illustrations of the rise of audit culture in higher education and its effects. Drawing on ethnographic examples from the UK, Denmark and New Zealand, we ask: how are higher education institutions being reconfigured by these new disciplinary regimes of audit? How are ranking and performance indicators changing institutional behaviour and transforming academic subjectivities? What possibilities are there for alternative university futures? And what insights can anthropology offer to address these questions
    corecore