651 research outputs found

    National Opera Review discussion paper

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    On 25 September 2015, the National Opera Review Discussion Paper was released by the National Opera Review Panel.  The Discussion Paper considers the financial viability, artistic vibrancy and audience access of Australia’s four major opera companies — Opera Australia, Opera Queensland, State Opera of South Australia and West Australian Opera. Those organisations are funded by the Australian Government and relevant state governments as major performing arts companies.  Submissions are invited on the issues and options raised in the Discussion Paper. The National Opera Review Discussion Paper and a list of the key issues raised in the paper are provided at the listed website. National Opera Review Discussion Paper [PDF 4.9MB] National Opera Review Discussion Paper [DOC 3.4MB] List of Key Issues in the National Opera Review Discussion Paper [PDF 58KB] List of Key Issues in the National Opera Review Discussion Paper [DOC 26KB] Have your say The National Opera Review Panel invites you to make a submission on key issues raised in the Discussion Paper. Submissions must be received by close of business 26 October 2015

    Review of Australian higher education: discussion paper

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    The federal government\u27s review of Australia’s higher education system will examine and report on the future direction of the higher education sector, its fitness for purpose in meeting the needs of the Australian community and economy and the options for ongoing reform. This paper has been released to outline issues and invite input on the key issues identified in the review\u27s terms of reference. The paper has been structured around nine key challenges and issues for higher education in Australia over the coming decades

    Delivery Site of Perivascular Endothelial Cell Matrices Determines Control of Stenosis in a Porcine Femoral Stent Model

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    PURPOSE: High restenosis rates are a major limitation of peripheral interventions. Endothelial cells, grown within gelatin matrices and implanted onto the adventitia of injured vessels, inhibit stenosis in experimental models. To determine if this technology could be adapted for minimally invasive procedures, we compared the effects of cells in an implantable sponge to an injectable formulation and investigated the importance of delivery site in a stent model. MATERIALS AND METHODS: Stents were implanted in the femoral arteries of 30 pigs followed by perivascular implantation of sponges or injection of particles containing allogeneic endothelial cells. Controls received acellular matrices or nothing. The effects of delivery site were assessed by injecting cellular matrices into or adjacent to the perivascular tissue, or into the neighboring muscle. Animals were sacrificed after 28 days. Pre-sacrifice angiograms and tissue sections were evaluated for stenosis. RESULTS: Arteries treated with cellular matrices had a 55 – 63% decrease in angiographic stenosis (P<0.05) and a 38 – 43% reduction (P<0.05) in histologic stenoses compared to controls. Intimal area was greatest when cellular matrices were delivered into the muscle (6.35 ± 0.95 mm2) compared to into or adjacent to the perivascular tissue (4.05 ± 0.56 mm2 and 4.73 ± 0.53 mm2, respectively, P < 0.05). CONCLUSIONS: Perivascular endothelial-cell matrices reduced stenosis after stent-induced injury. The effects were not dependent on the formulation but appeared to be dependent upon delivery site. Minimally invasive injections of endothelial-cell matrices to the adventitia of arteries following peripheral interventions may decrease restenosis rates.National Institutes of Health (U.S.) (Grant GM 49039

    Free radical reactions in atherosclerosis; An EPR spectrometry study

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    The copper catalysed oxidation of homocysteine has been studied by electron paramagnetic resonance (EPR) spectroscopy and spin trapping techniques to determine the nature of free radical species formed under varying experimental conditions. Three radicals; thiyl, alkyl and hydroxyl were detected with hydroxyl being predominant. A reaction mechanism is proposed involving Fenton chemistry. Inclusion of catalase to test for intermediate generation of hydrogen peroxide showed a marked reduction in amount of hydroxyl radical generated. In contrast, the addition of superoxide dismutase showed no significant effect on the level of hydroxyl radical formed. Enhanced radical formation was observed at higher levels of oxygen, an effect which has consequences for differential oxygen levels in arterial and venous systems. Implications are drawn for a higher incidence of atherosclerotic plaque formation in arteries versus veins. © 2006 - IOS Press and the authors. All rights reserved

    Ultrasound-guided percutaneous delivery of tissue-engineered endothelial cells to the adventitia of stented arteries controls the response to vascular injury in a porcine model

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    Objective High restenosis rates are a limitation of peripheral vascular interventions. Previous studies have shown that surgical implantation of a tissue-engineered endothelium onto the adventitia surface of injured vessels regulates vascular repair. In the present study, we developed a particulate formulation of tissue-engineered endothelium and a method to deliver the formulation perivascular to injured blood vessels using a percutaneous, minimally invasive technique. Methods Stainless steel stents were implanted in 18 balloon-injured femoral arteries of nine domestic swine, followed by ultrasound-guided percutaneous perivascular injection of gelatin particles containing cultured allogeneic porcine aortic endothelial cells (PAE). Controls received injections of empty particles (matrix) or no perivascular injection (sham) after stent deployment. Animals were sacrificed after 90 days. Results Angiographic analysis revealed a significantly greater lumen diameter in the stented segments of arteries treated with PAE/matrix (4.72 ± 0.12 mm) compared with matrix (4.01 ± 0.20 mm) or sham (4.03 ± 0.16 mm) controls (P < .05). Similarly, histologic analysis revealed that PAE/matrix-treated arteries had the greatest lumen area (20.4 ± 0.7 mm[superscript 2]; P < .05) compared with controls (16.1 ± 0.9 mm[superscript 2] and 17.1 ± 1.0 mm[superscript 2] for sham and matrix controls, respectively) and the smallest intimal area (3.3 ± 0.4 mm[superscript 2]; P < .05) compared with controls (6.2 ± 0.5 mm[superscript 2] and 4.4 ± 0.5 mm[superscript 2] for sham and matrix controls, respectively). Overall, PAE-treated arteries had a 33% to 50% decrease in percent occlusion (P < .05) compared with controls. Histopathological analysis revealed fewer leukocytes present in the intima in the PAE/matrix group compared with control groups, suggesting that the biological effects were in part due to inhibition of the inflammatory phase of the vascular response to injury. Conclusions Minimally invasive, perivascular delivery of PAE/matrix to stented arteries was performed safely using ultrasound-guided percutaneous injections and significantly decreased stenosis. Application at the time of or subsequent to peripheral interventions may decrease clinical restenosis rates

    Crops, Rumps and Woolly Jumpers: An Innovative Extension Approach Enabling the Complexities of Mixed Farming to Be Shared and Understood

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    The sheep-wheat belt of southern Australia accounts for about 19% and 57% of total Australian beef and sheep production, respectively. Most farm businesses in this zone are family owned and contain a mix of livestock and cropping enterprises. While the focus of most research, development and extension for mixed farming systems focuses on single components of the system (lamb, wool, beef, pastures, crops), the systems are complex and dynamic and cannot be understood by analysing the components in isolation. The enterprise synergies are dependent on economic, environmental and social factors. The farmers themselves are best equipped to explain the system function and the interplay between the components. The traditional conference format with technical experts presenting their findings was deemed to be inadequate to relay the complexity of mixed farming systems, stifling two-way information flow and the opportunity for experts to acquire tacit knowledge held by farmers. This paper out-lines an innovative extension approach based on story telling, video footage and discussion, providing technical experts with an opportunity to appreciate the complexity and farmer decision processes. This approach fostered audience participation and interaction, leading to a better understanding of the complexities of mixed farming and how conflicts between diversification and specialisation may be resolved by the management team. Facilitated discussion also highlighted potential areas of research, development and extension

    Freezing plants : exploring the effects of freeze thaw cycles on macrophyte phosphorus release

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    Every year following the cold winter freeze comes the spring thaw, and with it comes an influx of nutrients that can cause eutrophication problems; even in high nutrient systems. We identified a potential source of nutrients released during the winter freeze; aquatic macrophytes and aimed to determine the quantity of total phosphorus (TP) they release. Specifically, cattails and reeds (Typha and Juncus, respectively). Stalks were harvested from 3 different sites; a pond with an agriculturally dominated watershed, the beginning of a wetland used to treat effluent waste water, and a site further along in the wetland treatment process. Samples from each site were split into four different sample types: wet freeze, dry freeze, wet control, and dry control. Control and freeze samples were placed in at 1.6[degree]C and -1[degree]C respectively, and left for equal amounts of time averaging 31.375 hours (SD 10.25). After treatment, residual water samples were analyzed for total phosphorus concentrations. Results showed that freeze thaw cycles (FTCs) did not induce TP release from macrophytes tested in the lab. These results suggest that the use of macrophytes as a sink for nutrients is a beneficial practice that managers should continue to employ.Matthew Sauer, Osama Ahmed, Jeremy Leathers, Katy Nugent, Tyler Prentice, Helen Baulch, Nora Casson, Jason Venkiteswarab, Colin Whitfield and Rebecca North (University of Missouri, University of Saskatchewan, Wilfred Laurier University, University of Winnipeg

    Recombinant antigens based on toxins A and B of Clostridium difficile that evoke a potent toxin-neutralising immune response

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    AbstractInfection with the bacterium Clostridium difficile causes symptoms ranging from mild to severe diarrhoea with life-threatening complications and remains a significant burden to healthcare systems throughout the developed world. Two potent cytotoxins, TcdA and TcdB are the prime mediators of the syndrome and rapid neutralisation of these would afford significant benefits in disease management. In the present study, a broad range of non-toxic, recombinant fragments derived from TcdA and TcdB were designed for soluble expression in E. coli and assessed for their capacity to generate a potent toxin-neutralising immune response as assessed by cell-based assays. Significant differences between the efficacies of isolated TcdA and TcdB regions with respect to inducing a neutralising immune response were observed. While the C-terminal repeat regions played the principal role in generating neutralising antibodies to TcdA, in the case of TcdB, the central region domains dominated the neutralising immune response. For both TcdA and TcdB, fragments which comprised domains from both the central and C-terminal repeat region of the toxins were found to induce the most potent neutralising immune responses. Generated antibodies neutralised toxins produced by a range of C. difficile isolates including ribotype 027 and 078 strains. Passive immunisation of hamsters with a combination of antibodies to TcdA and TcdB fragments afforded complete protection from severe CDI induced by a challenge of bacterial spores. The results of the study are discussed with respect to the development of a cost effective immunotherapeutic approach for the management of C. difficile infection

    Downstream effects on human low density lipoprotein of homocysteine exported from endothelial cells in an in vitro system

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    A model system is presented using human umbilical vein endothelial cells (HUVECs) to investigate the role of homocysteine (Hcy) in atherosclerosis. HUVECs are shown to export Hcy at a rate determined by the flux through the methionine/Hcy pathway. Additional methionine increases intracellular methionine, decreases intracellular folate, and increases Hcy export, whereas additional folate inhibits export. An inverse relationship exists between intracellular folate and Hcy export. Hcy export may be regulated by intracellular S-adenosyl methionine rather than by Hcy. Human LDLs exposed to HUVECs exporting Hcy undergo time-related lipid oxidation, a process inhibited by the thiol trap dithionitrobenzoate. This is likely to be related to the generation of hydroxyl radicals, which we show are associated with Hcy export. Although Hcy is the major oxidant, cysteine also contributes, as shown by the effect of glutamate. Finally, the LDL oxidized in this system showed a time-dependent increase in uptake by human macrophages, implying an upregulation of the scavenger receptor. These results suggest that continuous export of Hcy from endothelial cells contributes to the generation of extracellular hydroxyl radicals, with associated oxidative modification of LDL and incorporation into macrophages, a key step in atherosclerosis. Factors that regulate intracellular Hcy metabolism modulate these effects. Copyright © 2005 by the American Society for Biochemistry and Molecular Biology, Inc
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