901 research outputs found

    Media events, spectacles and risky globalization: a critical review and possible avenues for future research

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    We review the research conducted to date on media events and media spectacles. We posit that the main phenomena challenging the current conceptualizations of media event and media spectacle are (1) the understanding of risk, (2) the context of disasters and (3) globalization and the mediation of news in the context of transnational and transitional societies. We suggest that more research on disruptive events is needed. In the context of the new media landscape in particular, the ritual researcher may need to take into account the concepts of temporality and unpredictability as inherent features of media events and rituals – the traumatic events researcher may benefit from the concept of global risk society. Finally, we argue that more research needs to be carried out on transitional societies, as we need to learn more about the role of mediation, events and spectacles in democratization processes and in contemporary revolutions. Overall, our findings indicate that in the context of global risk society, constant disruptions and unplanned events, together with the changes in news transmission, need to be taken as a starting point also in the research frames used to understand the mediation of events in contemporary society

    The non-linear behavior of aqueous model ice in downward flexure

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    As aqueous model ice is used extensively in ice tanks tests on the performance of ship hulls in sheet ice, it is imperative that such model ice replicate the main flexural strength behavior of sheets of sea ice and freshwater ice. Ice tanks use various types of aqueous model ice types, each of which contain brine dopants to scale-reduce ice-sheet strength. Dopants, though, introduce non-linear trends in the scaled flexural behavior of model ice sheets, and can affect ice loads and ice-rubble at ship-hulls and structures. This paper analyzes the non-linear behavior of model ices, and shows that all types behave non-linearly in flexure independent from crystal structure or chemical dopant. Such behavior is attributable to plasticity and vertical variations in stiffness and strength through sheets of model ice. Additionally, the problematic formation of a top layer in model ice sheets is shown to have a greater impact of sheet behavior than the literature reports heretofore. There remains a significant knowledge gap regarding the freezing and movement of brine dopants within ice sheets and their impact on the non-linear behavior. Additionally, it is found that the Hertz method for estimating the Cauchy number of model ice does not reflect the actual deformation behavior of model ice and should be revised.Comment: 45 pages, 20 figure

    Evidenzbasierte Diagnostik hereditärer Netzhautdystrophien 2009 = Evidence-Based Diagnostic Approach to Inherited Retinal Dystrophies 2009

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    Hintergrund: Hereditäre Netzhautdystrophien bilden eine heterogene Gruppe erblicher Erkrankungen mit einem sehr variablen klinischen Erscheinungsbild und multiplen assoziierten Genen. Diagnostik und Differenzialdiagnostik sind daher schwierig. Ziel dieser Arbeit ist es, Leitlinien für eine effektive Diagnostik zu geben. Methoden: Literaturrecherche und Auswertung eigener Erfahrungen mit klinischer (n = 3200) und molekulargenetischer (n = 4050) Diagnostik von Patienten mit Netzhautdystrophien. Ergebnisse: Für eine frühzeitige Diagnosestellung von Netzhautdystrophien ist deren Einbeziehung in die Differenzialdiagnose unklarer Sehstörungen von wesentlicher Bedeutung. Wichtigster diagnostischer Test ist das Ganzfeld-Elektroretinogramm (ERG), mit welchem generalisierte Netzhautdystrophien nachgewiesen werden können. Bei einem normalen ERG-Befund ist ein multifokales ERG zur Abklärung von Makuladystrophien indiziert. Fundusautofluoreszenz, Nah-Infrarot-Autofluoreszenz und hochauflösende optische Kohärenztomografie verbessern die Frühdiagnose, da morphologische Veränderungen bereits vor ophthalmoskopisch sichtbaren Veränderungen nachweisbar sein können. Darüber hinaus stellen diese nichtinvasiven bildgebenden Verfahren neue Phänomene dar, die für die Differenzialdiagnose, Verlaufskontrolle und das Verständnis der Pathogenese von Netzhautdystrophien wesentlich sind. Für eine zunehmende Anzahl hereditärer Netzhauterkrankungen besteht heute die Möglichkeit einer routinemäßigen molekulargenetischen Diagnostik. Eine möglichst genaue klinische Diagnosestellung ist hierbei unentbehrlich, um gezielt nach Mutationen in ausgewählten Genen suchen zu können. Ist eine genetische Untersuchung indiziert, empfiehlt sich die Kontaktaufnahme zu einem Humangenetiker vor Ort, um eine genetische Beratung der Familie einzuleiten sowie den konkreten Untersuchungsablauf und die Voraussetzungen für eine Kostenübernahme der Krankenkassen zu besprechen. Im Rahmen der humangenetischen Beratung wird in der Regel auch die molekulargenetische Diagnostik veranlasst und gegebenenfalls die Untersuchung weiterer Familienmitglieder koordiniert. Schlussfolgerungen: Die Kombination von elektrophysiologischer Diagnostik, bildgebenden Verfahren und molekulargenetischer Analyse erlaubt eine differenzierte Diagnose von Netzhautdystrophien und eine adäquate Beratung der Patienten. Bei Verdacht auf eine Netzhautdystrophie ist eine Überweisung des Patienten an ein Schwerpunktzentrum für Netzhautdystrophien zu empfehlen

    Hereditäre Netzhautdystrophien

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    Der Begriff „hereditäre Netzhautdystrophien“ fasst eine genetisch und phänotypisch sehr heterogene Gruppe erblicher Netzhauterkrankungen zusammen, deren gemeinsames Charakteristikum eine fortschreitende Verschlechterung der Sehfunktionen ist. Klinisch werden etwa 100 zum Teil extrem seltene Krankheitsbilder unterschieden. Die hohe phänotypische Variabilität und die insbesondere in frühen Krankheitsstadien oft unspezifischen Netzhautveränderungen und subjektiven Symptome erschweren dem Augenarzt die Diagnosestellung. Umgekehrt ist jedoch für den Patienten eine frühzeitige Diagnosestellung von immenser Bedeutung für die weitere Lebensplanung. Diese Fortbildung fokussiert daher vorwiegend auf eine praxisorientierte Strategie zur adäquaten Diagnostik hereditärer Netzhautdystrophien, jedoch nicht auf die detaillierte Differenzialdiagnose der Netzhautdystrophien. Für den Patienten ist die Einbeziehung hereditärer Netzhautdystrophien in die Differenzialdiagnose einer unklaren Sehstörung von großer Relevanz

    X-linked juvenile retinoschisis: clinical diagnosis, genetic analysis, and molecular mechanisms

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    X-linked juvenile retinoschisis (XLRS, MIM 312700) is a common early onset macular degeneration in males characterized by mild to severe loss in visual acuity, splitting of retinal layers, and a reduction in the b-wave of the electroretinogram (ERG). The RS1 gene (MIM 300839) associated with the disease encodes retinoschisin, a 224 amino acid protein containing a discoidin domain as the major structural unit, an N-terminal cleavable signal sequence, and regions responsible for subunit oligomerization. Retinoschisin is secreted from retinal cells as a disulphide-linked homo-octameric complex which binds to the surface of photoreceptors and bipolar cells to help maintain the integrity of the retina. Over 190 disease-causing mutations in the RS1 gene are known with most mutations occurring as non-synonymous changes in the discoidin domain. Cell expression studies have shown that disease-associated missense mutations in the discoidin domain cause severe protein misfolding and retention in the endoplasmic reticulum, mutations in the signal sequence result in aberrant protein synthesis, and mutations in regions flanking the discoidin domain cause defective disulphide-linked subunit assembly, all of which produce a non-functional protein. Knockout mice deficient in retinoschisin have been generated and shown to display most of the characteristic features found in XLRS patients. Recombinant adeno-associated virus (rAAV) mediated delivery of the normal RS1 gene to the retina of young knockout mice result in long-term retinoschisin expression and rescue of retinal structure and function providing a ‘proof of concept’ that gene therapy may be an effective treatment for XLRS

    Model studies of lantibiotic biogenesis

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    A six residue polypeptide has been synthesized to study the proposed biosynthesis of lanthionine. It is shown that this peptide spontaneously cyclizes in a biomimetic fashion via a completely stereoselective intramolecular Michael addition to form (2s, 6R)-lanthionine, as found in naturally occurring lantibiotics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30395/1/0000014.pd

    GRAVITY: getting to the event horizon of Sgr A*

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    We present the second-generation VLTI instrument GRAVITY, which currently is in the preliminary design phase. GRAVITY is specifically designed to observe highly relativistic motions of matter close to the event horizon of Sgr A*, the massive black hole at center of the Milky Way. We have identified the key design features needed to achieve this goal and present the resulting instrument concept. It includes an integrated optics, 4-telescope, dual feed beam combiner operated in a cryogenic vessel; near infrared wavefront sensing adaptive optics; fringe tracking on secondary sources within the field of view of the VLTI and a novel metrology concept. Simulations show that the planned design matches the scientific needs; in particular that 10 microarcsecond astrometry is feasible for a source with a magnitude of K=15 like Sgr A*, given the availability of suitable phase reference sources.Comment: 13 pages, 11 figures, to appear in the conference proceedings of SPIE Astronomical Instrumentation, 23-28 June 2008, Marseille, Franc

    The first bite: Imaginaries, promotional publics and the laboratory grown burger

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    In this paper we analyse a 2013 press conference hosting the world’s first tasting of a laboratory grown hamburger. We explore this as a media event: an exceptional performative moment in which common meanings are mobilised and a connection to a shared centre of reality is offered. We develop our own theoretical contribution – the promotional public – to characterise the affirmative and partial patchwork of carefully selected actors invoked during the burger tasting. Our account draws upon three areas of analysis: interview data with the scientists who developed the burger, media analysis of the streamed press conference itself, and media analysis of the social media tail during and following the event. We argue that the call to witness an experiment is a form of promotion but that such promotional material also offers an address that invokes a public with its attendant tensions.The research leading to this publication has received funding from the European Community’s Seventh Framework Programme (FP7/2007–2013) under grant agreement number 288971 (EPINET). Neil Stephens’ involvement has also received the support of the Economic and Social Research Council (ESRC). His work is part of the Research Programme of the ESRC Genomics Network at Cesagen (ESRC Centre for Economic and Social Aspects of Genomics). Neil Stephens’ work was also supported by the Wellcome Trust (WT096541MA) and a visiting scholarship to CGS Centre for Society and Genomics in The Netherlands, May to July 2011. This support is gratefully acknowledge

    Mutation Spectrum of the ABCA4 Gene in 335 Stargardt Disease Patients From a Multicenter German Cohort-Impact of Selected Deep Intronic Variants and Common SNPs

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    PURPOSE. Stargardt disease (STGD1) is an autosomal recessive retinopathy, caused by mutations in the retina-specific ATP-binding cassette transporter (ABCA4) gene. To establish the mutational spectrum and to assess effects of selected deep intronic and common genetic variants on disease, we performed a comprehensive sequence analysis in a large cohort of German STGD1 patients. METHODS. DNA samples of 335 STGD1 patients were analyzed for ABCA4 mutations in its 50 coding exons and adjacent intronic sequences by resequencing array technology or next generation sequencing (NGS). Parts of intron 30 and 36 were screened by Sanger chain-terminating dideoxynucleotide sequencing. An in vitro splicing assay was used to test selected variants for their splicing behavior. By logistic regression analysis we assessed the association of common ABCA4 alleles while a multivariate logistic regression model calculated a genetic risk score (GRS). RESULTS. Our analysis identified 148 pathogenic or likely pathogenic mutations, of which 48 constitute so far unpublished ABCA4-associated disease alleles. Four rare deep intronic variants were found once in 472 alleles analyzed. In addition, we identified six risk-modulating common variants. Genetic risk score estimates suggest that defined common ABCA4 variants influence disease risk in carriers of a single pathogenic ABCA4 allele. CONCLUSIONS. Our study adds to the mutational spectrum of the ABCA4 gene. Moreover, in our cohort, deep intronic variants in intron 30 and 36 likely play no or only a minor role in disease pathology. Of note, our findings demonstrate a possible modifying effect of common sequence variants on ABCA4-associated disease
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