8,383 research outputs found

    Dual turbopump liquid hydrogen feed system experience

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    Design and development of dual turbopump liquid hydrogen feed syste

    Exploring the role of voluntary disease schemes on UK farmer bio-security behaviours: Findings from the Norfolk-Suffolk Bovine Viral Diarrhoea control scheme

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    The article describes the influence of a disease control scheme (the Norfolk-Suffolk Bovine Viral Diarrhoea Disease (BVD) Eradication scheme) on farmers' bio-security attitudes and behaviours. In 2010, a survey of 100 cattle farmers (53 scheme members vs. 47 out of scheme farmers) was undertaken among cattle farmers residing in Norfolk and Suffolk counties in the UK. A cross-sectional independent measures design was employed. The main analytical tool was content analysis. The following variables at the farmer-level were explored: the specific BVD control measures adopted, livestock disease priorities, motivation for scheme membership, wider knowledge acquisition, biosecurity behaviours employed and training course attendance. The findings suggest that participation in the BVD scheme improved farmers' perception of the scheme benefits and participation in training courses. However, no association was found between the taking part in the BVD scheme and livestock disease priorities or motivation for scheme participation, or knowledge about BVD bio-security measures employed. Equally importantly, scheme membership did appear to influence the importance accorded specific bio-security measures. Yet such ranking did not appear to reflect the actual behaviours undertaken. As such, disease control efforts alone while necessary, are insufficient. Rather, to enhance farmer bio-security behaviours significant effort must be made to address underlying attitudes to the specific disease threat involved

    Bringing Hope to the Harbor

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    Wavefront shaping of a Bessel light field enhances light sheet microscopy with scattered light

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    The project was supported by the UK Engineering and Physical Sciences Research Council, RS MacDonald Charitable Trust, SULSA, and the St. Andrews 600th anniversary BRAINS appeal. K. D. is a Royal Society Wolfson Merit Award holder.Light sheet microscopy has seen a resurgence as it facilitates rapid, high contrast, volumetric imaging with minimal sample exposure. Initially developed for imaging scattered light, this application of light sheet microscopy has largely been overlooked but provides an endogenous contrast mechanism which can complement fluorescence imaging and requires very little or no modification to an existing light sheet fluorescence microscope. Fluorescence imaging and scattered light imaging differ in terms of image formation. In the former the detected light is incoherent and weak whereas in the latter the coherence properties of the illumination source, typically a laser, dictate the coherence of detected light, but both are dependent on the quality of the illuminating light sheet. Image formation in both schemes can be understood as the convolution of the light sheet with the specimen distribution. In this paper we explore wavefront shaping for the enhancement of light sheet microscopy with scattered light. We show experimental verification of this result, demonstrating the use of the propagation invariant Bessel beam to extend the field of view of a high resolution scattered light, light sheet microscope and its application to imaging of biological super-cellular structures with sub-cellular resolution. Additionally, complementary scattering and fluorescence imaging is used to characterize the enhancement, and to develop a deeper understanding of the differences of image formation between contrast mechanisms in light sheet microscopy.Publisher PD

    A Study of Innovative Alkali-Activated Binders for Soil Stabilisation in the Context of Engineering Sustainability and Circular Economy

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    In the context of sustainability in the civil engineering industry, chemical ground improvement is becoming increasingly used, as a generally more sustainable alternative to replacing and landfilling unsuitable for construction ground. However, traditional soil stabilisers such as Portland cement or lime are not environmentally impact-free; international research effort is thus focusing on the development of innovative cementing agents. This paper presents results from a feasibility study on the development of suitable alkali-activated slag cements for the stabilisation of two soils. A number of alkali-activators were considered, comprising potassium hydroxide, a range of alkali salts, as well as a material retrieved from waste (Paper Sludge Ash, PSA) which contains free lime. Indicative results of an extensive parametric study in terms of unconfined compressive strength (UCS) are shown, followed by results of ongoing oedometer tests to determine soil compressibility and some preliminary tests on selected soil/binder mixes to observe the durability to wetting-drying cycles. Overall, all alkali-activated cement mixes increased the UCS and stiffness of the soil. Carbonates and Na 2 SiO 3 used on their own gave lower strength increases. The highest strengths were achieved from AAC with KOH and Ca(OH) 2 from PSA, which showed similar strength gain. The latter material has shown consistently a lot of promise in terms of strength, stiffness and volumetric stability of the soil as well as treatment durability. Ongoing research focuses on further mix optimisation and a comprehensive mechanical and durability property testing supported by material analysis (mineralogical, chemical and microstructural) to gain a better understanding of the complex mechanisms involved

    Eicosapentaenoic acid and oxypurinol in the treatment of muscle wasting in a mouse model of cancer cachexia

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    Cancer cachexia is a wasting condition, driven by systemic inflammation and oxidative stress. This study investigated eicosapentaenoic acid (EPA) in combination with oxypurinol as a treatment in a mouse model of cancer cachexia. Mice with cancer cachexia were randomized into 4 treatment groups (EPA (0.4 g/kg/day), oxypurinol (1 mmol/L ad-lib), combination, or control), and euthanized after 29 days. Analysis of oxidative damage to DNA, mRNA analysis of pro-oxidant, antioxidant and proteolytic pathway components, along with enzyme activity of pro- and antioxidants were completed on gastrocnemius muscle. The control group displayed earlier onset of tumor compared to EPA and oxypurinol groups (P&lt;0.001). The EPA group maintained body weight for an extended duration (20 days) compared to the oxypurinol (5 days) and combination (8 days) groups (P&lt;0.05). EPA (18.2&plusmn;3.2 pg/ml) and combination (18.4&plusmn;3.7 pg/ml) groups had significantly higher 8-OH-dG levels than the control group (12.9&plusmn;1.4 pg/ml, P&le;0.05) indicating increased oxidative damage to DNA. mRNA levels of GPx1, MURF1 and MAFbx were higher following EPA treatment compared to control (P&le;0.05). Whereas oxypurinol was associated with higher GPx1, MnSOD, CAT, XDH, MURF1, MAFbx and UbB mRNA compared to control (P&le;0.05). Activity of total SOD was higher in the oxypurinol group (32.2&plusmn;1.5 U/ml) compared to control (27.0&plusmn;1.3 U/ml, P&lt;0.01), GPx activity was lower in the EPA group (8.76&plusmn;2.0 U/ml) compared to control (14.0&plusmn;1.9 U/ml, P&lt;0.05), and catalase activity was lower in the combination group (14.4&plusmn;2.8 U/ml) compared to control (20.9&plusmn;2.0 U/ml, P&lt;0.01). There was no change in XO activity. The increased rate of weight decline in mice treated with oxypurinol indicates that XO may play a protective role during the progression of cancer cachexia, and its inhibition is detrimental to outcomes. In combination with EPA, there was little significant improvement from control, indicating oxypurinol is unlikely to be a viable treatment compound in cancer cachexia.<br /

    Moccasin Confluence: Occupation and Settlement in the Lower Fredericksburg Basin of the Edwards Plateau

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    During the summer of 1982 the eastern half of Lyndon B. Johnson State Historical Park was surveyed and sites tested. The work was sponsored by the Texas Parks and Wildlife Department and performed by Center for Archaeological Research and the Division of Behavioral and Cultural Sciences, The University of Texas at San Antonio. The Principal Investigator was Joel D. Gunn. The field work was conducted by the field course in archaeology from the University of Texas at San Antonio. Members (listed in the Acknowledgments section) of the Anthropology Laboratory class assisted the Principal Investigator with laboratory analysis. Most of the sites were shallow or deflated and of limited information value except for their location in the overall settlement pattern. Excavation of 41GL21, Hop Hill (Gunn and Mahula 1977a), was completed. An old stream channel was found in the bedrock under the site. It was filled with occupation debris from the Late Archaic. The site may have been used as an overlook to an adjacent ford in the Pedernales River. At the confluence of the Pedernales River and Williams Creek (Moccasin Confluence) at the east end of the park a very important site was found. Moccasin Confluence consists of two segments divided by Williams Creek. The west segment (41BC71) is a deeply stratified alluvial site with a Holocene sequence. Whether the sequence is continuous through the Holocene remains to be determined. The levels are extremely thick in the Middle and Early Holocene. The location, at three sources of varying sediments, indicates that the site could be a very sensitive geological barometer of Holocene climate, a hypothesis that seems to have merit based on analysis of sediment grain size composition and IPF analysis of sediment chemistry. The site is very rich in chronological diagnostics and is of great potential for studying environmental and cultural process in the Edwards Plateau region. Analysis of artifact wear patterns, points, flake size and frequencies, and mollusks indicates the site was inhabited over long periods of time, sometimes with a fair amount of intensity. Nomads apparently visited the site at the beginning of each cultural period and eventually settled there until their culture was disrupted. The site is recommended for nomination to the National Register of Historic Places. The site (41BC63) on the east bank of Williams Creek outside the park, considered to be the eastern segment of Moccasin Confluence, was tested enough to show that it has a dense burned rock midden. It is assumed to represent a shift of occupation locus to the east side of the creek during the Middle Archaic
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