71 research outputs found

    Collaborating with the enemy? A view from Down Under on GM research partnerships

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    Abstract This chapter explores the distribution of funding and approvals for GM crops in Australia in order to determine if private interests dominate public research in agricultural biotechnology and if public interests can be served by collaborations with private organizations. Although a highly detailed analysis is not possible given the available data, it is contended that the Australian setting provides a different perspective on the potential for various forms of public-private collaborations in GM research, as well as an excellent test bed for assessing effects of diverse types of funding and institutional arrangements. Three brief GM case studies from the Australian context are presented to explore key issues arising and underlying complexities associated with GM research: (i) drought-tolerant wheat; (ii) high-amylose wheat; and (iii) Vitamin A-enhanced 'super banana'.Rachel A. Ankeny, Heather J. Bray, Kelly A. McKinle

    Spectrum of antibacterial activity and mode of action of a novel tris-stilbene bacteriostatic compound

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    The spectrum of activity and mode of action of a novel antibacterial agent, 135C, was investigated using a range of microbiological and genomic approaches. Compound 135C was active against Gram-positive bacteria with MICs for Staphylococcus aureus ranging from 0.12–0.5 μg/ml. It was largely inactive against Gram-negative bacteria. The compound showed bacteriostatic activity in time-kill studies and did not elicit bacterial cell leakage or cell lysis. Checkerboard assays showed no synergy or antagonism when 135C was combined with a range of other antibacterials. Multi-step serial passage of four S. aureus isolates with increasing concentrations of 135C showed that resistance developed rapidly and was stable after drug-free passages. Minor differences in the fitness of 135C-resistant strains and parent wildtypes were evident by growth curves, but 135C-resistant strains did not show cross-resistance to other antibacterial agents. Genomic comparison of resistant and wildtype parent strains showed changes in genes encoding cell wall teichoic acids. 135C shows promising activity against Gram-positive bacteria but is currently limited by the rapid resistance development. Further studies are required to investigate the effects on cell wall teichoic acids and to determine whether the issue of resistance development can be overcome

    Measurement precision and evaluation of the diameter profiles of single wool fibers

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    A recent model of the Single Fiber Analyzer 3001 (SIFAN3001) was firstly employed to obtain the single wool fiber diameter profiles (SfFDPs) at multiple orientations. The results showed that using SIFAN3001 to measure fiber diameter at four orientations for 50 single fibers randomly sub-sampled from each mid-side sample can produce average fiber diameter profiles (AS fFDPs) of fibers within staples. Within the testing regime used, the precision estimates for the total samples were &plusmn;1.3 &micro;m for the mean fiber diameter of staples and 1.4 &micro;m for the average fiber diameter of the AS fFDPs at each scanned step in the diameter profile. The mean diameter ratio (ellipticity) obtained from the four orientations was 1.08&plusmn;0.01, confirming that the Merino wool fibers under review were elliptical rather than circular. The elliptical morphology of wool fibers and the precision of the fiber diameter measurement at each point along a fiber will be considered in the development of a mechanical model of Staple Strength testing.<br /

    Mass Loss Due to Sputtering and Thermal Processes in Meteoroid Ablation

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    Conventional meteoroid theory assumes that the dominant mode of ablation is by evaporation following intense heating during atmospheric flight. In this paper we consider the question of whether sputtering may provide an alternative disintegration process of some importance.For meteoroids in the mass range from 10^-3 to 10^-13 kg and covering a meteor velocity range from 11 to 71 km/s, we numerically modeled both thermal ablation and sputtering ablation during atmospheric flight. We considered three meteoroid models believed to be representative of asteroidal (3300 kg m^-3 mass density), cometary (1000 kg m^-3) and porous cometary (300 kg m^-3) meteoroid structures. Atmospheric profiles which considered the molecular compositions at different heights were used in the sputtering calculations. We find that while in many cases (particularly at low velocities and for relatively large meteoroid masses) sputtering contributes only a small amount of mass loss during atmospheric flight, in some cases sputtering is very important. For example, a 10^-10 kg porous meteoroid at 40 km/s will lose nearly 51% of its mass by sputtering, while a 10^-13 kg asteroidal meteoroid at 60 km/s will lose nearly 83% of its mass by sputtering. We argue that sputtering may explain the light production observed at very great heights in some Leonid meteors. The impact of this work will be most dramatic for very small meteoroids such as those observed with large aperture radars.Comment: in pdf form, 48 pgs incl figures and table

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

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    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Association between peri-operative angiotensin-converting enzyme inhibitors and angiotensin-2 receptor blockers and acute kidney injury in major elective non-cardiac surgery: a multicentre, prospective cohort study

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    The peri-operative use of angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers is thought to be associated with an increased risk of postoperative acute kidney injury. To reduce this risk, these agents are commonly withheld during the peri-operative period. This study aimed to investigate if withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers peri-operatively reduces the risk of acute kidney injury following major non-cardiac surgery. Patients undergoing elective major surgery on the gastrointestinal tract and/or the liver were eligible for inclusion in this prospective study. The primary outcome was the development of acute kidney injury within seven days of operation. Adjusted multi-level models were used to account for centre-level effects and propensity score matching was used to reduce the effects of selection bias between treatment groups. A total of 949 patients were included from 160 centres across the UK and Republic of Ireland. From this population, 573 (60.4%) patients had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers withheld during the peri-operative period. One hundred and seventy-five (18.4%) patients developed acute kidney injury; there was no difference in the incidence of acute kidney injury between patients who had their angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers continued or withheld (107 (18.7%) vs. 68 (18.1%), respectively; p = 0.914). Following propensity matching, withholding angiotensin-converting enzyme inhibitors or angiotensin-2 receptor blockers did not demonstrate a protective effect against the development of postoperative acute kidney injury (OR (95%CI) 0.89 (0.58–1.34); p = 0.567)

    Microbiological effects on the Cavern-Extended Storage (CES) repository for radioactive waste : a quantitative evaluation

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    The recently developed Cavern Extended Storage (CES) repository design for radioactive waste combines some of the advantages of the flexibility provided by long-term interim storage with the safety of deep geological disposal. It is also of particular interest where demands are made for long periods of institutional control and monitoring (or staged implementation) of repositories or where a desire exists to keep options open for possible retrieval with regard to spent fuel reprocessing. In this concept, large steel casks containing vitrified High Level Waste (HLW) and/or spent fuel are stored in large rock caverns at depths 500 to 1000 m below surface for approximately 300 years before backfilling to transform this ‘store’ into a final ‘repository’. However, the extreme environmental conditions of a HLW repository cannot guarantee sterility. As a result, the humid, ventilated caverns could provide many potential niches for microbial growth, which could influence both the integrity of the storage casks (and any associated infrastructure) and the subsequent long-term performance of the sealed repository. The storage period is likely to provide the optimum period for microbial colonisation and growth, with the casks and rock walls exposed to constantly circulating air, which would provide oxygen for aerobic microbial processes. In addition, nutrients and energy sources will be introduced from the surface during operational and monitoring procedures. The duration of this storage period may be extended or shortened, depending on changing institutional requirements and it is thus particularly important to know the effects of microbial activity during this time. Simple models of the constraints on such growth can be used to scope the potential for activity to influence repository performance, particularly in relation to changing storage times, and to compare the CES design with conventional repository concepts

    Evidence that N2O is a stronger oxidizing agent than O2 for the post-deposition annealing of Ta2O5 on Si capacitors

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    Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers362661-666JAPN
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