20 research outputs found

    A satellite view of spatial points in conversation 1

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    It can be difficult for external analysts without knowledge of the local environment to understand what conversationalists are talking about when they point to locations outside their immediate environment. Our geospatial framework for analysing directional points provides the external analyst with a panoramic view of the conversational setting, so that the world which members inhabit can be seen from space. By rotating the satellite imagery to align with bearing of the video cameras, the locations being pointed to and spoken about can be visualised within the context of the topography that surrounds the setting of the talk. We demonstrate these procedures using data from conversations conducted in the remote Australian outback, in Australian English, and in three distantly related Aboriginal languages

    A satellite view of spatial points in conversation 1

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    It can be difficult for external analysts without knowledge of the local environment to understand what conversationalists are talking about when they point to locations outside their immediate environment. Our geospatial framework for analysing directional points provides the external analyst with a panoramic view of the conversational setting, so that the world which members inhabit can be seen from space. By rotating the satellite imagery to align with bearing of the video cameras, the locations being pointed to and spoken about can be visualised within the context of the topography that surrounds the setting of the talk. We demonstrate these procedures using data from conversations conducted in the remote Australian outback, in Australian English, and in three distantly related Aboriginal languages

    CHARACTERIZATION OF COPPER IN LEACHATES FROM ACQ- AND MCQ-TREATED WOOD AND ITS EFFECT ON BASIDIOSPORE GERMINATION

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    The unpenetrated interior of wood with a shell of preservative treatment may be exposed when the wood is cut or when checks open up. Mobile copper from wood shell-treated with chromated copper arsenate (CCA) has been shown to protect cut ends and checks against basidiospore germination. However, recent observations found that leachates from alkaline copper quat (ACQ)-treated wood failed to prevent basidiospore germination on untreated wood although copper levels were higher than toxic thresholds previously identified. It was hypothesized that the copper in leachate from ACQ-treated wood may be coordinated with monoethanolamine and/or lignin-based ligands and that this may result in poorer performance against basidiospores. In this study, electron paramagnetic resonance spectroscopy was used to determine the form of copper in leachates from ACQ, micronized copper quat (MCQ), and coppersulfate-treated wood. Leachates from ACQ-treated wood contained at least some degree of coordination with a nitrogen- and oxygen-containing ligand, probably monoethanolamine. This was not detected in leachates from MCQ and copper-sulfate-treated wood. These leachates were further evaluated for their ability to inhibit germination of Tyromyces palustris basidiospores. At low concentrations of copper, the CuSO4 and MCQ leachates were more effective than the ACQ leachate. At high concentrations CuSO4 and MCQ, leachates prevented germination in all samples, whereas ACQ leachates prevented germination in all but one sample

    Modelling the Material Resistance of Wood—Part 3: Relative Resistance in above- and in-Ground Situations—Results of a Global Survey

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    Durability-based designs with timber require reliable information about the wood properties and how they affect its performance under variable exposure conditions. This study aimed at utilizing a material resistance model (Part 2 of this publication) based on a dose–response approach for predicting the relative decay rates in above-ground situations. Laboratory and field test data were, for the first time, surveyed globally and used to determine material-specific resistance dose values, which were correlated to decay rates. In addition, laboratory indicators were used to adapt the material resistance model to in-ground exposure. The relationship between decay rates in- and above-ground, the predictive power of laboratory indicators to predict such decay rates, and a method for implementing both in a service life prediction tool, were established based on 195 hardwoods, 29 softwoods, 19 modified timbers, and 41 preservative-treated timbers

    Modeling the material resistance of wood—part 2:Validation and optimization of the meyer-veltrup model

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    Service life planning with timber requires reliable models for quantifying the effects of exposure-related parameters and the material-inherent resistance of wood against biotic agents. The Meyer-Veltrup model was the first attempt to account for inherent protective properties and the wetting ability of wood to quantify resistance of wood in a quantitative manner. Based on test data on brown, white, and soft rot as well as moisture dynamics, the decay rates of different untreated wood species were predicted relative to the reference species of Norway spruce (Picea abies). The present study aimed to validate and optimize the resistance model for a wider range of wood species including very durable species, thermally and chemically modified wood, and preservative treated wood. The general model structure was shown to also be suitable for highly durable materials, but previously defined maximum thresholds had to be adjusted (i.e., maximum values of factors accounting for wetting ability and inherent protective properties) to 18 instead of 5 compared to Norway spruce. As expected, both the enlarged span in durability and the use of numerous and partly very divergent data sources (i.e., test methods, test locations, and types of data presentation) led to a decrease in the predictive power of the model compared to the original. In addition to the need to enlarge the database quantity and improve its quality, in particular for treated wood, it might be advantageous to use separate models for untreated and treated wood as long as the effect of additional impact variables (e.g., treatment quality) can be accounted for. Nevertheless, the adapted Meyer-Veltrup model will serve as an instrument to quantify material resistance for a wide range of wood-based materials as an input for comprehensive service life prediction software

    Identification of Small Molecule Inhibitors of Pseudomonas aeruginosa Exoenzyme S Using a Yeast Phenotypic Screen

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    Pseudomonas aeruginosa is an opportunistic human pathogen that is a key factor in the mortality of cystic fibrosis patients, and infection represents an increased threat for human health worldwide. Because resistance of Pseudomonas aeruginosa to antibiotics is increasing, new inhibitors of pharmacologically validated targets of this bacterium are needed. Here we demonstrate that a cell-based yeast phenotypic assay, combined with a large-scale inhibitor screen, identified small molecule inhibitors that can suppress the toxicity caused by heterologous expression of selected Pseudomonas aeruginosa ORFs. We identified the first small molecule inhibitor of Exoenzyme S (ExoS), a toxin involved in Type III secretion. We show that this inhibitor, exosin, modulates ExoS ADP-ribosyltransferase activity in vitro, suggesting the inhibition is direct. Moreover, exosin and two of its analogues display a significant protective effect against Pseudomonas infection in vivo. Furthermore, because the assay was performed in yeast, we were able to demonstrate that several yeast homologues of the known human ExoS targets are likely ADP-ribosylated by the toxin. For example, using an in vitro enzymatic assay, we demonstrate that yeast Ras2p is directly modified by ExoS. Lastly, by surveying a collection of yeast deletion mutants, we identified Bmh1p, a yeast homologue of the human FAS, as an ExoS cofactor, revealing that portions of the bacterial toxin mode of action are conserved from yeast to human. Taken together, our integrated cell-based, chemical-genetic approach demonstrates that such screens can augment traditional drug screening approaches and facilitate the discovery of new compounds against a broad range of human pathogens

    Advancing Eucalyptus genomics: identification and sequencing of lignin biosynthesis genes from deep-coverage BAC libraries

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    <p>Abstract</p> <p>Background</p> <p><it>Eucalyptus </it>species are among the most planted hardwoods in the world because of their rapid growth, adaptability and valuable wood properties. The development and integration of genomic resources into breeding practice will be increasingly important in the decades to come. Bacterial artificial chromosome (BAC) libraries are key genomic tools that enable positional cloning of important traits, synteny evaluation, and the development of genome framework physical maps for genetic linkage and genome sequencing.</p> <p>Results</p> <p>We describe the construction and characterization of two deep-coverage BAC libraries EG_Ba and EG_Bb obtained from nuclear DNA fragments of <it>E. grandis </it>(clone BRASUZ1) digested with <it>Hind</it>III and <it>BstY</it>I, respectively. Genome coverages of 17 and 15 haploid genome equivalents were estimated for EG_Ba and EG_Bb, respectively. Both libraries contained large inserts, with average sizes ranging from 135 Kb (Eg_Bb) to 157 Kb (Eg_Ba), very low extra-nuclear genome contamination providing a probability of finding a single copy gene ≥ 99.99%. Libraries were screened for the presence of several genes of interest <it>via </it>hybridizations to high-density BAC filters followed by PCR validation. Five selected BAC clones were sequenced and assembled using the Roche GS FLX technology providing the whole sequence of the <it>E. grandis </it>chloroplast genome, and complete genomic sequences of important lignin biosynthesis genes.</p> <p>Conclusions</p> <p>The two <it>E. grandis </it>BAC libraries described in this study represent an important milestone for the advancement of <it>Eucalyptus </it>genomics and forest tree research. These BAC resources have a highly redundant genome coverage (> 15×), contain large average inserts and have a very low percentage of clones with organellar DNA or empty vectors. These publicly available BAC libraries are thus suitable for a broad range of applications in genetic and genomic research in <it>Eucalyptus </it>and possibly in related species of <it>Myrtaceae</it>, including genome sequencing, gene isolation, functional and comparative genomics. Because they have been constructed using the same tree (<it>E. grandis </it>BRASUZ1) whose full genome is being sequenced, they should prove instrumental for assembly and gap filling of the upcoming <it>Eucalyptus </it>reference genome sequence.</p

    Security of Energy Supply: Comparing Scenarios from a European Perspective

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    Characterization of pacific silver fir impregnated with extractives from western redcedar

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    Alternative and higher value uses are needed for residual materials generated from wood products processing. Western redcedar sawdust contains an array of unique chemicals and has the potential to be used to alter the appearance, stability and durability of non-durable timbers. Here it was hypothesized that impregnation of Western redcedar heartwood extractives into Pacific silver fir would decrease shrinkage, hygroscopicity, and susceptibility to decay. Western redcedar hot water extracts were obtained from sawdust and used to pressure-treat Pacific silver fir blocks. Extractive impregnation enhanced the wood’s appearance and gave it a more cedar-like brown colour. Impregnated samples had reduced shrinkage, but were not as dimensionally stable as Western redcedar heartwood. Pacific silver fir blocks impregnated with water-soluble extractives were also highly susceptible to leaching, and leached samples had similar shrinkage values to untreated controls. In contrast, leaching had little effect on the hygroscopicity of the Western redcedar heartwood. Extractive-impregnated Pacific silver fir blocks had increased resistance to decay by two brown-rot fungi, and showed resistance similar to that of Western redcedar heartwood. However, leached blocks did not have the same decay resistance

    Characterization of pacific silver fir impregnated with extractives from western redcedar

    Get PDF
    Alternative and higher value uses are needed for residual materials generated from wood products processing. Western redcedar sawdust contains an array of unique chemicals and has the potential to be used to alter the appearance, stability and durability of non-durable timbers. Here it was hypothesized that impregnation of Western redcedar heartwood extractives into Pacific silver fir would decrease shrinkage, hygroscopicity, and susceptibility to decay. Western redcedar hot water extracts were obtained from sawdust and used to pressure-treat Pacific silver fir blocks. Extractive impregnation enhanced the wood’s appearance and gave it a more cedar-like brown colour. Impregnated samples had reduced shrinkage, but were not as dimensionally stable as Western redcedar heartwood. Pacific silver fir blocks impregnated with water-soluble extractives were also highly susceptible to leaching, and leached samples had similar shrinkage values to untreated controls. In contrast, leaching had little effect on the hygroscopicity of the Western redcedar heartwood. Extractive-impregnated Pacific silver fir blocks had increased resistance to decay by two brown-rot fungi, and showed resistance similar to that of Western redcedar heartwood. However, leached blocks did not have the same decay resistance
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