91 research outputs found

    Layered Xerogel Films Incorporating Monolayer Protected Cluster Networks on Platinum Black Modified Electrodes for Enhanced Sensitivity in 1st Generation Uric Acid Biosensing

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    Amperometric uric acid (UA) biosensing schemes incorporating networks of alkanethiolate‐protected gold nanoparticles, monolayer protected clusters (MPCs), and platinum black (Pt‐B) electrode modification through the layer‐by‐layer construction of xerogels are investigated. MPC doping and Pt‐B augmentation are implemented within hydroxymethyltriethoxysilane xerogel bilayers at platinum electrodes. The first xerogel adlayer is doped with an MPC network and houses uricase for the enzymatic reaction required for first‐generation schemes. Polyluminol–aniline and polyurethane are used as selective/stabilizing interfacial layers. The sensing performance with and without Pt‐B and/or MPC doping is assessed by amperometry with standardized UA injections. The use of each individual material results in an enhancement of UA sensitivity compared with analogous films without these materials. The use of Pt‐B and MPC doping in concert results in a biosensor design with the highest observed UA sensitivity (0.97 μA mm−1) and fast, linear responses over physiologically relevant UA concentrations. Enhancement is attributed to Pt‐B providing increased electrode surface area and integration into the xerogel for greater electronic coupling of the MPC network and more efficient reporting of H2O2 oxidation. The findings have implications for advancing clinical in vivo sensing devices that require scalability or additional biocompatibility layering, both of which would benefit from signal enhancement strategies

    ADOPT: a tool for predicting adoption of agricultural innovations

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    A wealth of evidence exists about the adoption of new practices and technologies in agriculture but there does not appear to have been any attempt to simplify this vast body of research knowledge into a model to make quantitative predictions across a broad range of contexts. This is despite increasing demand from research, development and extension agencies for estimates of likely extent of adoption and the likely timeframes for project impacts. This paper reports on the reasoning underpinning the development of ADOPT (Adoption and Diffusion Outcome Prediction Tool). The tool has been designed to: 1) predict an innovation‘s likely peak extent of adoption and likely time for reaching that peak; 2) encourage users to consider the influence of a structured set of factors affecting adoption; and 3) engage R, D & E managers and practitioners by making adoptability knowledge and considerations more transparent and understandable. The tool is structured around four aspects of adoption: 1) characteristics of the innovation, 2) characteristics of the population, 3) actual advantage of using the innovation, and 4) learning of the actual advantage of the innovation. The conceptual framework used for developing ADOPT is described.Adoption, Diffusion, Prediction, Research and Development/Tech Change/Emerging Technologies,

    Functionalized Carbon Nanotube Adsorption Interfaces for Electron Transfer Studies of Galactose Oxidase

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    Modified electrodes featuring specific adsorption platforms able to access the electrochemistry of the copper containing enzyme galactose oxidase (GaOx) were explored, including interfaces featuring nanomaterials such as nanoparticles and carbon nanotubes (CNTs). Electrodes modified with various self-assembled monolayers (SAMs) including those with attached nanoparticles or amide-coupled functionalized CNTs were examined for their ability to effectively immobilize GaOx and study the redox activity related to its copper core. While stable GaOx electrochemistry has been notoriously difficult to achieve at modified electrodes, strategically designed functionalized CNT-based interfaces, cysteamine SAM-modified electrode subsequently amide-coupled to carboxylic acid functionalized single wall CNTs, were significantly more effective with high GaOx surface adsorption along with well-defined, more reversible, stable (≥ 8 days) voltammetry and an average ET rate constant of 0.74 s-1 in spite of increased ET distance - a result attributed to effective electronic coupling at the GaOx active site. Both amperometric and fluorescence assay results suggest embedded GaOx remains active. Fundamental ET properties of GaOx may be relevant to biosensor development targeting galactosemia while the use functionalized CNT platforms for adsorption/electrochemistry of electroactive enzymes/proteins may present an approach for fundamental protein electrochemistry and their future use in both direct and indirect biosensor schemes

    Rescue of DNA damage after constricted migration reveals a mechano-regulated threshold for cell cycle.

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    Migration through 3D constrictions can cause nuclear rupture and mislocalization of nuclear proteins, but damage to DNA remains uncertain, as does any effect on cell cycle. Here, myosin II inhibition rescues rupture and partially rescues the DNA damage marker γH2AX, but an apparent block in cell cycle appears unaffected. Co-overexpression of multiple DNA repair factors or antioxidant inhibition of break formation also exert partial effects, independently of rupture. Combined treatments completely rescue cell cycle suppression by DNA damage, revealing a sigmoidal dependence of cell cycle on excess DNA damage. Migration through custom-etched pores yields the same damage threshold, with ∼4-µm pores causing intermediate levels of both damage and cell cycle suppression. High curvature imposed rapidly by pores or probes or else by small micronuclei consistently associates nuclear rupture with dilution of stiff lamin-B filaments, loss of repair factors, and entry from cytoplasm of chromatin-binding cGAS (cyclic GMP-AMP synthase). The cell cycle block caused by constricted migration is nonetheless reversible, with a potential for DNA misrepair and genome variation

    Crop Updates 2000 - Weeds

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    This session covers thirty six papers from different authors: INTRODUCTION, Vanessa Stewart Agriculture Western Australia INTEGRATED WEED MANAGEMENT Effect of seeding density, row spacing and Trifluralin on the competitive ability of Annual Ryegrass in a minimum tillage system, David Minkey, Abul Hashem, Glen Riethmuller and Martin Harries, Agriculture Western Australia High wheat seeding rates coupled with narrow row spacing increases yield and suppresses grass, Peter Newman1 and Cameron Weeks2,1Agronomist, Elders Limited 2Mingenew/Irwin Group Resistant ryegrass management in a wheat – lupin rotation, Abul Hashem, Harmohinder S. Dhammu, Aik Cheam, David Bowran and Terry Piper, Agriculture Western Australia Integrated weed management – Will it work with my rotation? Alexandra Wallace, Agriculture Western Australia Long term herbicide resistance trial – Mingenew, Peter Newman Elders, Cameron Weeks Mingenew-Irwin Group Is two years enough? Bill Roy, Agricultural Consulting and Research Services The fate of ryegrass seed when sheep graze chaff cart heaps, Keith L. Devenish1 and Lisa J. Leaver2 1 Agriculture Western Australia, 2Curtin University of Technology, Muresk Institute of Agriculture Can blanket wiping and crop topping prevent seed set of resistant wild radish and mustard? StAbul Hashem, Harmohinder Dhammu, Vanessa Stewart, Brad Rayner and Mike Collins, Agriculture Western Australia The value of green manuring in the integrated management of ryegrass, Marta Monjardino1,2, David Pannell2, Stephen Powles1 ,1Western Australia Herbicide Resistance Initiative, 2Agricultural and Resource Economics, University of Western Australia Some ways of increasing wheat competitiveness against ryegrass,, Mike Collins Centre for Cropping Systems, Agriculture Western Australia WEED BIOLOGY Understanding and driving weed seed banks to very low levels, Sally Peltzer, Agriculture Western Australi HERBICIDE RESISTANCE Cross resistance of chlorsulfuron-resistant wild radish to imidazolinones, Abul Hashem, Harmohinder Dhammu and David Bowran, Agriculture Western Australia Investigation of suspected triazine resistant ryegrass populations for cross-resistance and multiple resistance to herbicides, Michael Walsh, Charles Boyle and Stephen Powles, Western Australian Herbicide Resistance Initiative, University of Western Australia Genetics and fitness of glyphosate resistant ryegrass, S. Powles1, P. Neve1, D. Lorraine-Colwill2, C. Preston2 ,1WAHRI, University of Western Australia 2 CRC Weed Management Systems, University of Adelaide Managing herbicide resistance – the effect of local extinction of resistance genes, Art Diggle1, Paul B. Neve2, Stephen B. Powles2 ,1Agriculture Western Australia, 2WAHRI, Faculty of Agriculture, University of Western Australia The double knock - the best strategy for conserving glyphosate susceptibility? Paul B. Neve1, Art Diggle2, Stephen B. Powles1,1WAHRI, Faculty of Agriculture, University of Western Australia, 2Agriculture Western Australia Wild radish had evolved resistance to triazines, Abul Hashem, Harmohinder S. Dhammu, David Bowran and Aik Cheam, Agriculture Western Australia Ryegrass resistance in Western Australia – where and how much? Rick Llewellyn and Stephen Powles, Western Australian Herbicide Resistance Initiative, Faculty of Agriculture, University of Western Australia Wild radish herbicide resistance survey, Michael Walsh, Ryan Duane and Stephen Powles, Western Australian Herbicide Resistance Initiative, University of Western Australia Knockdown resistance in the Western Australian wheatbelt – a proposed survey, Paul B. Neve1, Abul Hashem2, Stephen B. Powles1,1Western Australian Herbicide Resistance Initiative, University of Western Australia, 2Agriculture Western Australia Diflufenican resistant wild radish, Aik Cheam, Siew Lee, David Bowran, David Nicholson and Abul Hashem, Agriculture Western Australi Multiple resistance to triazines and diflufenican further complicates wild radish control, Aik Cheam, Siew Lee, David Bowran, David Nicholson and Abul Hashem, Agriculture Western Australia HERBICIDE TOLERANCE 25. Herbicide tolerance of lupins, Terry Piper, Weed Science Group, Agriculture Western Australia 26. Tanjil lupins will tolerate metribuzin under the right conditions, Peter Newman, Agronomist Elders Limited and Cameron Weeks, Mingenew/Irwin Group 27. Herbicide damage does not mean lower yield in Lupins, Peter Carlton, Trials Coordinator, Elders Limited 28. Herbicide tolerance of new pea varieties, Dr Terry Piper, Agriculture Western Australia 29. Herbicide tolerance of (waterlogged) wheat, Dr Terry Piper, Agriculture Western Australia 30. Wheat tolerance trials – Mingenew 1999, Peter Newman1, Cameron Weeks2 and Stewart Smith3,1Elders, Mingenew, 2Mingenew-Irwin Group,3Agriculture Western Australia ISSUES OF TRIFLURALIN USE 31. Trifluralin works better on ryegrass when no-tilling into thick wheat stubbles as granules, or mixed with limesand, Bill Crabtree, WANTFA Scientific Officer 32. Increasing trifluralin rate did not compensate for delaying incorporation, Bill Crabtree, WANTFA Scientific Officer 33. Poor emergence survey, 1999, Terry Piper, Weed Science Group, Agriculture Western Australia HERBICIDES – ISSUES AND OPTIONS 34. AFFINITY 400DF – A new herbicide with a new mode of action (Group G) for Broadleaf Weed Control in Cereals, Gordon Cumming, Technical Officer, Crop Care Australasia 35 Herbicide screening for Marshmallow, David Minkey1 and David Cameron2,1Agriculture Western Australia, 2Elders Ltd, Merredin 36. The control of Capeweed in Clearfield Production System for Canola, Mike Jackson and Scott Paton, Cyanamid Agriculture Pty Ltd 37.Effect of herbicides Tordonä 75D and Lontrelä,used for eradication of Skeleton Weed, on production of Lupins I the following seasons, John R. Peirce and Brad J. Rayner, Agriculture Western Australia INDUSTRY PROTECTION 38. Graingaurd – Opportunities for agribusiness to help protect the West Australian grains industry, Greg Shea, Executive Officer, GrainGuard Agriculture Western Australi

    Transcriptome Analysis and SNP Development Can Resolve Population Differentiation of Streblospio benedicti, a Developmentally Dimorphic Marine Annelid

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    Next-generation sequencing technology is now frequently being used to develop genomic tools for non-model organisms, which are generally important for advancing studies of evolutionary ecology. One such species, the marine annelid Streblospio benedicti, is an ideal system to study the evolutionary consequences of larval life history mode because the species displays a rare offspring dimorphism termed poecilogony, where females can produce either many small offspring or a few large ones. To further develop S. benedicti as a model system for studies of life history evolution, we apply 454 sequencing to characterize the transcriptome for embryos, larvae, and juveniles of this species, for which no genomic resources are currently available. Here we performed a de novo alignment of 336,715 reads generated by a quarter GS-FLX (Roche 454) run, which produced 7,222 contigs. We developed a novel approach for evaluating the site frequency spectrum across the transcriptome to identify potential signatures of selection. We also developed 84 novel single nucleotide polymorphism (SNP) markers for this species that are used to distinguish coastal populations of S. benedicti. We validated the SNPs by genotyping individuals of different developmental modes using the BeadXPress Golden Gate assay (Illumina). This allowed us to evaluate markers that may be associated with life-history mode

    What is housing affordability? The case for the residual income approach

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    This article seeks to increase the awareness of and support for the residual income approach to housing affordability indicators and standards, especially in the United States. It begins with an overview of various semantic, substantive, and definitional issues relating to the notion of affordability, leading to an argument supporting the conceptual soundness of the residual income approach. The concept is then briefly set into the historical context of U.S. and British debates on affordability measures. This description is followed by a discussion of two of the principal issues involved in crafting an operational residual income standard: the selection of a normative standard for non-housing items and the treatment of taxes. The article concludes by considering some of the potential implications of the residual income paradigm for the analysis of housing problems and needs, for housing subsidy policy, and for mortgage underwriting practice
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