1,352 research outputs found

    Lagrangian analysis of alignment dynamics for isentropic compressible magnetohydrodynamics

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    After a review of the isentropic compressible magnetohydrodynamics (ICMHD) equations, a quaternionic framework for studying the alignment dynamics of a general fluid flow is explained and applied to the ICMHD equations.Comment: 12 pages, 2 figures, submitted to a Focus Issue of New Journal of Physics on "Magnetohydrodynamics and the Dynamo Problem" J-F Pinton, A Pouquet, E Dormy and S Cowley, editor

    Developing a partcipatory approach to seed production and varietal selection

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    The performance of UK winter wheat varieties was tested under organic conditions involving farmer participation. Three breadmaking varieties (Hereward, Solstice and Xi19) and their mixture (1:1:1) were grown at 19 UK farms in 2003/04 and 2004/05. The variability of productivity on organic farms was illustrated with more variation among farm sites than among varieties. Seed health was generally high over all sites. Although the trials were successful, more time was needed at project initiation to improve farmer involvement. Some farmers expected more researcher visits, and were reticent about assessing the trials themselves. In contrast, some participants valued the variety performance data on their farms particularly when related to that of other growers. The balance between the goals of the researchers relative to the farmers needs to be defined at project initiation

    The Victoria west: Earliest prepared core technology in the acheulean at canteen kopje and implications for the cognitive evolution of early hominids

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    Prepared core technology illustrates in-depth planning and the presence of a mental template during the core reduction process. This technology is, therefore, a significant indicator in studying the evolution of abstract thought and the cognitive abilities of hominids. Here, we report on Victoria West cores excavated from the Canteen Kopje site in central South Africa, with a preliminary age estimate of approximately 1Ma (million years ago) for these cores. Technological analysis shows that the VictoriaWest cores bear similarities to the ‘Volumetric Concept’ as defined for the Levallois, a popular and widely distributed prepared core technology from at least 200 ka (thousand years ago). Although these similarities are present, several notable differences also occur that make the Victoria West a unique and distinctive prepared core technology; these are: elongated and convergent core shapes, consistent blow directions for flake removal, a predominance of large side-struck flakes, and the use of these flakes to make Acheulean large cutting tools. This innovative core reduction strategy at Canteen Kopje extends the roots of prepared core technology to the latter part of the Early Acheulean and clearly demonstrates an increase in the cognitive abilities and complexities of hominids in this time period.EM201

    Biodigital publics: personal genomes as digital media artifacts

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    The recent proliferation of personal genomics and direct-to-consumer (DTC) genomics has attracted much attention and publicity. Concern around these developments has mainly focused on issues of biomedical regulation and hinged on questions of how people understand genomic information as biomedical and what meaning they make of it. However, this publicity amplifies genome sequences which are also made as internet texts and, as such, they generate new reading publics. The practices around the generation, circulation and reading of genome scans do not just raise questions about biomedical regulation, they also provide the focus for an exploration of how contemporary public participation in genomics works. These issues around the public features of DTC genomic testing can be pursued through a close examination of the modes of one of the best known providers—23andMe. In fact, genome sequences circulate as digital artefacts and, hence, people are addressed by them. They are read as texts, annotated and written about in browsers, blogs and wikis. This activity also yields content for media coverage which addresses an indefinite public in line with Michael Warner’s conceptualisation of publics. Digital genomic texts promise empowerment, personalisation and community, but this promise may obscure the compliance and proscription associated with these forms. The kinds of interaction here can be compared to those analysed by Andrew Barry. Direct-to-consumer genetics companies are part of a network providing an infrastructure for genomic reading publics and this network can be mapped and examined to demonstrate the ways in which this formation both exacerbates inequalities and offers possibilities for participation in biodigital culture

    Identity, community and care in online accounts of hereditary colorectal cancer syndrome

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    Sociological literature has explored how shifts in the point at which individuals may be designated as diseased impact upon experiences of ill health. Research has shown that experiences of being genetically “at risk” are shaped by and shape familial relations, coping strategies, and new forms of biosociality. Less is known about how living with genetic risk is negotiated in the everyday and over time, and the wider forms of identity, communities and care this involves. This article explores these arrangements drawing on online bloggers’ accounts of Familial Adenomatous Polyposis (FAP). We show how accounts of genetic risk co-exist with more palpable experiences of FAP in everyday life, notably the consequences of prophylactic surgeries. We consider how the act of blogging represents but also constitutes everyday experiences of hereditary cancer syndrome as simultaneously ordinary and exceptional, and reflect on the implications of our analysis for understanding experiences of genetic cancer risk

    Introduction. Public Health Genomics: anthropological interventions in the quest for molecular medicine

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    We introduce this special issue of Medial Anthropology Quarterly on public health genomics by exploring both the unique contribution of ethnographic sensibility that medical anthropologists bring to the study of genomics and some of the key insights offered by the essays in this collection. As anthropologists, we are concerned with the power dynamics and larger cultural commitments embedded in practices associated with public health. We seek to understand, first, the broad significance of genomics as a cultural object and, second, the social action set into motion as researchers seek to translate genomic knowledge and technology into public health benefits

    A participatory methodology for large scale field trials in the UK

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    Farmer participation was essential in developing a uniquely useful set of wheat variety trials data on a wide range of organic farms over two years. Although the trials were successful, it became clear that some of the participating farmers felt there were some limitations in the process. These included a lack of ownership in the project and a concern for more researcher help. It was clear that a greater time in-vestment was needed at the start of the project to help with farmer understanding and ownership. De-spite the negative comments, farmers appreciated their involvement, particularly in contrasting their own views and information with that from the wider scene. Farmer participation is essential for systems-level research and this project helped to develop a small core of trained farmers and researchers

    Lagrangian particle paths and ortho-normal quaternion frames

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    Experimentalists now measure intense rotations of Lagrangian particles in turbulent flows by tracking their trajectories and Lagrangian-average velocity gradients at high Reynolds numbers. This paper formulates the dynamics of an orthonormal frame attached to each Lagrangian fluid particle undergoing three-axis rotations, by using quaternions in combination with Ertel's theorem for frozen-in vorticity. The method is applicable to a wide range of Lagrangian flows including the three-dimensional Euler equations and its variants such as ideal MHD. The applicability of the quaterionic frame description to Lagrangian averaged velocity gradient dynamics is also demonstrated.Comment: 9 pages, one figure, revise
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