365 research outputs found

    Conduit dynamics and post-explosion degassing on Stromboli:a combined UV camera and 1 numerical modelling treatment

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    Recent gas flux measurements have shown that strombolian explosions are often followed by periods of elevated flux, or ‘gas codas’, with durations of order a minute. Here, we present UV camera data from 200 events recorded at Stromboli volcano to constrain the nature of these codas for the first time, providing estimates for combined explosion plus coda SO2 masses of ≈ 18 – 225 kg. Numerical simulations of gas slug ascent show that substantial proportions of the initial gas mass can be distributed into a train of ‘daughter bubbles’ released from the base of the slug, which we suggest, generate the codas, on bursting at the surface. This process could also cause transitioning of slugs into cap bubbles, significantly reducing explosivity. This study is the first attempt to combine high temporal resolution gas flux data with numerical simulations of conduit gas flow to investigate volcanic degassing dynamics

    Health professionals' experiences of tuberculosis cohort audit in the North West of England : a qualitative study

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    This research was supported by Public Health England and the Centre for Applied Health Research and Delivery, Liverpool School of Tropical Medicine (LSTM).Objectives. Tuberculosis cohort audit (TBCA) was introduced across the North West (NW) of England in 2012 as an ongoing, multidisciplinary, systematic case review process, designed to improve clinical and public health practice. TBCA has not previously been introduced across such a large and socioeconomically diverse area in England, nor has it undergone formal, qualitative evaluation. This study explored health professionals' experiences of the process after 1515 cases had been reviewed. Design. Qualitative study using semistructured interviews. Respondents were purposively sampled from 3 groups involved in the NW TBCA: (1) TB nurse specialists, (2) consultant physicians and (3) public health practitioners. Data from the 26 respondents were triangulated with further interviews with key informants from the TBCA Steering Group and through observation of TBCA meetings. Analysis. Interview transcripts were analysed thematically using the framework approach. Results. Participants described the evolution of a valuable 'community of practice' where interprofessional exchange of experience and ideas has led to enhanced mutual respect between different roles and a shared sense of purpose. This multidisciplinary, regional approach to TB cohort audit has promoted local and regional team working, exchange of good practices and local initiatives to improve care. There is strong ownership of the process from public health professionals, nurses and clinicians; all groups want it to continue. TBCA is regarded as a tool for quality improvement that improves patient safety. Conclusions. TBCA provides peer support and learning for management of a relatively rare, but important infectious disease through discussion in a no-blame atmosphere. It is seen as an effective quality improvement strategy which enhances TB care, control and patient safety. Continuing success will require increased engagement of consultant physicians and public health practitioners, a secure and ongoing funding stream and establishment of clear reporting mechanisms within the public health system.Publisher PDFPeer reviewe

    Detectors for the James Webb Space Telescope Near-Infrared Spectrograph I: Readout Mode, Noise Model, and Calibration Considerations

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    We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec's) detectors will be read out, and present a model of how noise scales with the number of multiple non-destructive reads sampling-up-the-ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some non-ideal behaviors that have been observed in engineering grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is: (1) very nearly noiseless and (2) can be easily calibrated out. Likewise, we show that large-amplitude RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps.Comment: 55 pages, 10 figure

    The Impossibility of a Perfectly Competitive Labor Market

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    Using the institutional theory of transaction cost, I demonstrate that the assumptions of the competitive labor market model are internally contradictory and lead to the conclusion that on purely theoretical grounds a perfectly competitive labor market is a logical impossibility. By extension, the familiar diagram of wage determination by supply and demand is also a logical impossibility and the neoclassical labor demand curve is not a well-defined construct. The reason is that the perfectly competitive market model presumes zero transaction cost and with zero transaction cost all labor is hired as independent contractors, implying multi-person firms, the employment relationship, and labor market disappear. With positive transaction cost, on the other hand, employment contracts are incomplete and the labor supply curve to the firm is upward sloping, again causing the labor demand curve to be ill-defined. As a result, theory suggests that wage rates are always and everywhere an amalgam of an administered and bargained price. Working Paper 06-0

    Digital Extended Specimens: Enabling an Extensible Network of Biodiversity Data Records as Integrated Digital Objects on the Internet

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    The early twenty-first century has witnessed massive expansions in availability and accessibility of digital data in virtually all domains of the biodiversity sciences. Led by an array of asynchronous digitization activities spanning ecological, environmental, climatological, and biological collections data, these initiatives have resulted in a plethora of mostly disconnected and siloed data, leaving to researchers the tedious and time-consuming manual task of finding and connecting them in usable ways, integrating them into coherent data sets, and making them interoperable. The focus to date has been on elevating analog and physical records to digital replicas in local databases prior to elevating them to ever-growing aggregations of essentially disconnected discipline-specific information. In the present article, we propose a new interconnected network of digital objects on the Internet—the Digital Extended Specimen (DES) network—that transcends existing aggregator technology, augments the DES with third-party data through machine algorithms, and provides a platform for more efficient research and robust interdisciplinary discovery

    A comprehensive targeted next-generation sequencing panel for genetic diagnosis of patients with suspected inherited thrombocytopenia.

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    Background: Inherited thrombocytopenias (ITs) are a heterogeneous group of disorders characterized by low platelet counts and often disproportionate bleeding with over 30 genes currently implicated. Previously the UK-GAPP study using whole exome sequencing (WES) identified a pathogenic variant in 19 of 47 (40%) patients of which 71% had variants in genes known to cause IT. Aims: To employ a targeted next-generation sequencing platform to improve efficiency of diagnostic testing and reduce overall costs. Methods: We have developed an IT-specific gene panel as a pre-screen for patients prior to WES using the Agilent SureSelectQXT transposon-based enrichment system. Results: Thirty-one patients were analyzed using the panel-based sequencing, of which; 10% (3/31) were identified with a classified pathogenic variant, 16% (5/31) were identified with a likely pathogenic variant, 51% (16/31) were identified with variants of unknown significance, and 23% (7/31) were identified with either no variant or a benign variant. Discussion and Conclusion: Although requiring further clarification of the impact of the genetic variations, the application of an IT-specific next generation sequencing panel is an viable method of pre-screening patients for variants in known IT-causing genes prior to WES. With an added benefit of distinguishing IT from idiopathic thrombocytopenic purpura (ITP) and the potential to identify variants in genes known to have a predisposition to hematological malignancies, it could become a critical step in improving patient clinical management

    Tales from the Drop Zone: roles, risks and dramaturgical dilemmas

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    This paper critically revisits conventional understandings of ethnographic fieldwork roles, arguing that representations of the covert insider as heroic and adventurous are often idealistic and unrealistic. Drawing on one of the authors’ experiences of being both a covert and overt researcher in an ethnographic study of skydiving, we identify some of the dramaturgical dilemmas that can unexpectedly affect relations with participants throughout the research process. Our overall aim is to highlight how issues of trust, betrayal, exposure and vulnerability, together with the practical considerations of field research, combine to shape the researcher’s interactional strategies of identity work

    Novel sulI binary vectors enable an inexpensive foliar selection method in Arabidopsis

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    <p>Abstract</p> <p>Background</p> <p>Sulfonamide resistance is conferred by the <it>sul</it>I gene found on many <it>Enterobacteriaceae </it>R plasmids and Tn21 type transposons. The <it>sul</it>I gene encodes a sulfonamide insensitive dihydropteroate synthase enzyme required for folate biosynthesis. Transformation of tobacco, potato or <it>Arabidopsis </it>using <it>sul</it>I as a selectable marker generates sulfadiazine-resistant plants. Typically <it>sul</it>I-based selection of transgenic plants is performed on tissue culture media under sterile conditions.</p> <p>Findings</p> <p>A set of novel binary vectors containing a <it>sul</it>I selectable marker expression cassette were constructed and used to generate transgenic <it>Arabidopsis</it>. We demonstrate that the <it>sul</it>I selectable marker can be utilized for direct selection of plants grown in soil with a simple foliar spray application procedure. A highly effective and inexpensive high throughput screening strategy to identify transgenic <it>Arabidopsis </it>without use of tissue culture was developed.</p> <p>Conclusion</p> <p>Novel <it>sul</it>I-containing <it>Agrobacterium </it>binary vectors designed to over-express a gene of interest or to characterize a test promoter in transgenic plants have been constructed. These new vector tools combined with the various beneficial attributes of sulfonamide selection and the simple foliar screening strategy provide an advantageous alternative for plant biotechnology researchers. The set of binary vectors is freely available upon request.</p

    Charisma and the Clinic

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    Here we argue that ‘charisma’, a concept widely taken up within geography and the environmental humanities, is of utility to the social studies of medicine. Charisma, we suggest, draws attention to the affective dimensions of medical work, the ways in which these affective relations are structured, and the manner in which they are intimately tied to particular material-discursive contexts. The paper differentiates this notion of charisma from Weber’s analyses of the ‘charismatic leader’ before detailing three forms of charisma - ecological (which relates to the affordances an entity has), corporeal (related to bodily interaction) and aesthetic (pertaining to an entity’s initial visual and emotional impact). Drawing on interview data we then show how this framework can be used to understand the manner in which psychologists and neuroscientists have come to see and act on autism. We conclude the article by suggesting that examining charisma within healthcare settings furthers the concept, in particular by drawing attention to the discursive features of ecologies and the ‘non-innocence’ of charisma
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