849 research outputs found

    Ramps first – interpreting thrust nucleation in multilayers

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    Acknowledgements The work contained in this paper was conducted during a PhD study undertaken as part of the Centre for Doctoral Training (CDT) in Geoscience and the Low Carbon Energy Transition (NERC Grant Code RG15727-10). It is sponsored by Aberdeen University, via their GeoNetZero 502 CDT Studentship, whose support is gratefully acknowledged. Many thanks to Magda Chmielewska for assistance with the virtual outcrop model processing and to Elizabeth Unsworth and Jack Connors for assistance with drone piloting in the field. The virtual outcrop is available at: https://sketchfab.com/3d-models/st-brides-haven506 pembrokeshire-d9808f4cd1ca46e8aef549f2300913b4. We thank Bob Holdsworth and an anonymous reviewer for their critical reviews of an earlier draft of this paper, though the views and any remaining errors remain the responsibility of the authors.Peer reviewe

    Experimental phage therapy of burn wound infection : difficult first steps

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    Antibiotic resistance has become a major public health problem and the antibiotics pipeline is running dry. Bacteriophages (phages) may offer an ‘innovative’ means of infection treatment, which can be combined or alternated with antibiotic therapy and may enhance our abilities to treat bacterial infections successfully. Today, in the Queen Astrid Military Hospital, phage therapy is increasingly considered as part of a salvage therapy for patients in therapeutic dead end, particularly those with multidrug resistant infections. We describe the application of a well-defined and quality controlled phage cocktail, active against Pseudomonas aeruginosa and Staphylococcus aureus, on colonized burn wounds within a modest clinical trial (nine patients, 10 applications), which was approved by a leading Belgian Medical Ethical Committee. No adverse events, clinical abnormalities or changes in laboratory test results that could be related to the application of phages were observed. Unfortunately, this very prudent ‘clinical trial’ did not allow for an adequate evaluation of the efficacy of the phage cocktail. Nevertheless, this first ‘baby step’ revealed several pitfalls and lessons for future experimental phage therapy and helped overcome the psychological hurdles that existed to the use of viruses in the treatment of patients in our burn unit

    Effects of long-term removal of sheep grazing on the seedbanks of high-level grasslands and blanket bogs

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    Many areas of vegetation in the British uplands have reduced species diversity as a result of sheep overgrazing. It has been suggested that abandonment or re-wilding strategies might be used to reverse this. A likely first step would be the removal or reduction of grazing livestock from upland areas, with a presumption that this would lead to a recovery in species richness. However, we do not know if this would work, or the timescales involved. One of the important areas where more knowledge is needed is information on the size and composition of soil seedbanks as regeneration from zseed is a likely pathway of recovery. Here, we compared seedbanks in both grazed and ungrazed plots in five experiments at Moor House NNR in the northern Pennines; these sheep grazing exclusion experiments were started 52 and 63/64 years ago. Soil samples (n=10) were collected from both grazed and ungrazed plots in each experiment, and seed emergence counted in glasshouse trials. We detected only seeds of common species and very few dicotyledonous species. This suggests that the soil seedbank is unlikely to be a reliable source of the less common species for ecological restoration in these upland communities, suggesting an extinction debt. Therefore, seed addition and the creation of suitable safe-sites for germination may be needed in conjunction with grazing controls to allow the establishment of plants that will increase the species richness of the vegetation. However, this interventionist restoration approach remains to be tested

    Understanding System Complexity in the Non-Destructive Testing of Advanced Composite Products

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    Non-destructive testing (NDT) is a quality control measure designed to ensure the safety of products according to established variability thresholds. With the development of advanced technologies and a lack of formalised knowledge of the state-of-the-art, the National Composites Centre, Bristol, has identified that the increasing complexity of composite products will lead to some severe inspection challenges. To address the apparent knowledge gap and understand system complexity, a formulaic approach to introduce intelligence and improve the robustness of NDT operations is presented. The systemic development of a high-fidelity knowledge base (KB) involves the establishment of a capability matrix that maps material, component, and defect configuration to the capabilities and limitations of selected detection methods. Population and validation are demonstrated through the experimental testing of reference standards and evaluated against an assessment criteria. System complexity in ultrasonic testing operations focusses on capturing the inherent risks in inspection and the designation of evidence-based path plans for automation platforms. Anticipated deployment of the validated applicability data within the KB will allow for road-mapping of the inspection technique development and will provide opportunities for knowledge-based decision making. Moreover, the KB highlights the need for Design for Inspection, providing measurable data that the methodology should not be ignored

    It’s time to talk: Voluntary action, the state and welfare provision

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    1. The 1940s and the 2010s were significant periods of transformation in the shape and direction of social welfare services across England. In both periods assumptions about the responsibilities of citizens, the state, voluntary action and the private sector became open to debate. 2. Both decades were also transformational times for the voluntary movement, involving coming to terms with new realities and rethinking its part in welfare provision. 3. Comprehensive discussion in the 1940s about the new role and responsibilities of the state in social welfare has not been matched in the 2010s. 4. In the 1940s the voluntary movement and the Labour government consolidated a pragmatic partnership that overcame initial suspicion on both sides, while the 2010s were marked by a more antagonistic relationship between government and the voluntary sector. 5. It’s time to talk. A national conversation, which tackles the issues and seeks to build consensus on our welfare future, is needed. 6. We invite you to be part of this new debate, by reflecting upon, sharing and acting on this research and its implications

    Ten Simple Rules for Reproducible Research in Jupyter Notebooks

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    Reproducibility of computational studies is a hallmark of scientific methodology. It enables researchers to build with confidence on the methods and findings of others, reuse and extend computational pipelines, and thereby drive scientific progress. Since many experimental studies rely on computational analyses, biologists need guidance on how to set up and document reproducible data analyses or simulations. In this paper, we address several questions about reproducibility. For example, what are the technical and non-technical barriers to reproducible computational studies? What opportunities and challenges do computational notebooks offer to overcome some of these barriers? What tools are available and how can they be used effectively? We have developed a set of rules to serve as a guide to scientists with a specific focus on computational notebook systems, such as Jupyter Notebooks, which have become a tool of choice for many applications. Notebooks combine detailed workflows with narrative text and visualization of results. Combined with software repositories and open source licensing, notebooks are powerful tools for transparent, collaborative, reproducible, and reusable data analyses

    Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

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    We gratefully acknowledge the National Science Foundation’s Paleoclimatic Perspectives on Climatic Change (P2C2) grant nos. AGS 1159430, AGS 1502186, AGS 1502150, and PLR 15-04134.Ring-width (RW) records from the Gulf of Alaska (GOA) have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD) proxy, the blue intensity (BI) parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI) from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana) sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv) or delta BI (DB) can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June–September, which may have implications for studying ocean–atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th–19th century temperatures ca. 0.5 °C cooler than the 20th–21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per site (> 20) and compiling more sites to overcome site-specific factors affecting climate response and using subfossil material to extend the record. Although LWBinv captures the inter-annual climate signal more strongly than DB, DB appears to better capture long-term secular trends that agree with other proxy archives in the region. Great care is needed, however, when implementing different detrending options and more experimentation is necessary to assess the utility of DB for different conifer species around the Northern Hemisphere.Publisher PDFPeer reviewe
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