1,467 research outputs found

    Ductile mandrel and parting compound facilitate tube drawing

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    Refractory tubing is warm drawn over a solid ductile mandrel with a powder parting compound packed between mandrel and the tubes inner surface. This method applies also to the coextrusion of a billet and a ductile mandrel

    True and False Foodplants of \u3ci\u3eCallosamia Promethea\u3c/i\u3e (Lepidoptera: Saturniidae) in Southern Michigan

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    A survey in 1980 of the associations of over 400 cocoons of Callosamia promethea Drury in vegetation along and adjacent to southern Michigan roadsides gave evidence for seven species of true larval foodplants (not including two others known in the area from other studies) and 17 species of false foodplants, the latter determined by the (1) rarity of their association with cocoons, (2) only one or two cocoons per plant, and (3) their proximity to a well known true foodplant. Three species, sassafras, black cherry, and buttonbush, are evidently the most important true foodplants in this area. Comparisons are made of the foodplants in terms of past literature, geography, and taxonomic relationships

    Urban and Rural—Population and Energy Consumption Dynamics in Local Authorities within England and Wales

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    The formulation of feasible and pragmatic policies that mitigate climate change would require a thorough understanding of the interconnectivity that exists between environment, energy, and the composition of our settlements both urban and rural. This study explores the patterns of energy consumption in England and Wales by investigating consumption behavior within domestic and transport sectors as a function of city characteristics, such as population, density, and density distribution for 346 Local Authority Units (LAU). Patterns observed linking energetic behavior of these LAUs to their respective population and area characteristics highlight some distinctly contrasting consumption behaviors within urban and rural zones. This provides an overview of the correlation between urban/rural status, population, and energy consumption and highlights points of interest for further research and policy intervention. The findings show that energy consumption across cities follows common power law scaling increasing sub-linearly with their population regardless of their urban/rural classification. However, when considering per capita and sector specific consumptions, decreasing per capita consumption patterns are observed for growing population densities within more uniformly populated urban LAUs. This is while rural and sparsely populated LAUs exhibit sharply different patterns for gas, electricity, and transport per capita consumption

    Analysis of regulatory protease sequences identified through bioinformatic data mining of the Schistosoma mansoni genome

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    <p>Abstract</p> <p>Background</p> <p>New chemotherapeutic agents against <it>Schistosoma mansoni</it>, an etiological agent of human schistosomiasis, are a priority due to the emerging drug resistance and the inability of current drug treatments to prevent reinfection. Proteases have been under scrutiny as targets of immunological or chemotherapeutic anti-<it>Schistosoma </it>agents because of their vital role in many stages of the parasitic life cycle. Function has been established for only a handful of identified <it>S. mansoni </it>proteases, and the vast majority of these are the digestive proteases; very few of the conserved classes of regulatory proteases have been identified from <it>Schistosoma </it>species, despite their vital role in numerous cellular processes. To that end, we identified protease protein coding genes from the <it>S. mansoni </it>genome project and EST library.</p> <p>Results</p> <p>We identified 255 protease sequences from five catalytic classes using predicted proteins of the <it>S. mansoni </it>genome. The vast majority of these show significant similarity to proteins in KEGG and the Conserved Domain Database. Proteases include calpains, caspases, cytosolic and mitochondrial signal peptidases, proteases that interact with ubiquitin and ubiquitin-like molecules, and proteases that perform regulated intramembrane proteolysis. Comparative analysis of classes of important regulatory proteases find conserved active site domains, and where appropriate, signal peptides and transmembrane helices. Phylogenetic analysis provides support for inferring functional divergence among regulatory aspartic, cysteine, and serine proteases.</p> <p>Conclusion</p> <p>Numerous proteases are identified for the first time in <it>S. mansoni</it>. We characterized important regulatory proteases and focus analysis on these proteases to complement the growing knowledge base of digestive proteases. This work provides a foundation for expanding knowledge of proteases in <it>Schistosoma </it>species and examining their diverse function and potential as targets for new chemotherapies.</p

    Aromatic ring cleavage of a β-biphenyl ether dimer catalyzed by lignin peroxidase of phanerochaete chrysosporium

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    AbstractUnder aerobic conditions homogeneous lignin peroxidase catalyzed the oxidation of 1-(4'-methoxyphenyl)-2-(2″,5′-dimethoxy-4″-phenylphenoxy)-1,3-dihydroxypropane (I) to yield four products: 1-(4'-methoxy-phenyl)-1,2,3-trihydroxypropane (X), 4-[α-hydroxy-α-(4'-methoxyphenyl)-methyl]-1,3-dioxolane-2-one (V), 4-(4'-methoxyphenyl)-5-hydroxymethyl-1,3-dioxolane-2-one (VI) and 5-hydroxy-5-carbomethoxy-4-phenyl-oxol-3-en-2-one (VIII). V, VI and VIII are all products of ring opening reactions. When the reaction was conducted under anaerobic conditions, the substrate was oxidized but no ring-cleaved products were detected. During the oxidation of I, 4 atoms of 18O from 18O2 were incorporated into the lactol product VIII

    Reduced Genetic Variation in Populations of Black Cherry (Prunus serotina subsp. serotina, Rosaceae) at Its Western Range Limit in Kansas

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    Citation: Beck, J. B., Ferguson, C. J., Mayfield, M. H., & Shaw, J. (2015). Reduced Genetic Variation in Populations of Black Cherry (Prunus serotina subsp. serotina, Rosaceae) at Its Western Range Limit in Kansas. Northeastern Naturalist, 21(3), 472-478. doi:10.1656/045.021.0313We compared genetic variation at five nuclear simple sequence repeat loci between three populations of Black Cherry (Prunus serotina subsp. serotina) at the edge of its western range in Kansas to four populations from within the range interior. Although within-population expected heterozygosity did not differ between edge and core populations, allelic richness was significantly lower in the edge populations. This finding is consistent with a loss of rare alleles due to genetic drift in demographically unstable edge populations

    On the use of random graphs in analysing resource utilization in urban systems

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    Urban resource models increasingly rely on implicit network formulations. Resource consumption behaviours documented in the existing empirical studies are ultimately by-products of the network abstractions underlying these models. Here, we present an analytical formulation and examination of a generic demand-driven network model that accounts for the effectiveness of resource utilization and its implications for policy levers in addressing resource management in cities. We establish simple limiting boundaries to systems' resource effectiveness. These limits are found not to be a function of system size and to be simply determined by the system's average ability to maintain resource quality through its transformation processes. We also show that resource utilization in itself does not enjoy considerable size efficiencies with larger and more diverse systems only offering increased chances of finding matching demand and supply between existing sectors in the system

    Predictive risk mapping of an environmentally-driven infectious disease using spatial Bayesian networks: A case study of leptospirosis in Fiji

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    Introduction Leptospirosis is a zoonotic disease responsible for over 1 million severe cases and 60,000 deaths annually. The wide range of animal hosts and complex environmental drivers of transmission make targeted interventions challenging, particularly when restricted to regression-based analyses which have limited ability to deal with complexity. In Fiji, important environmental and socio-demographic factors include living in rural areas, poverty, and livestock exposure. This study aims to examine drivers of transmission under different scenarios of environmental and livestock exposures. Methods Spatial Bayesian networks (SBN) were used to analyse the influence of livestock and poverty on the risk of leptospirosis infection in urban compared to rural areas. The SBN models used a combination of spatially-explicit field data from previous work and publically available census information. Predictive risk maps were produced for overall risk, and for scenarios related to poverty, livestock, and urban/rural setting. Results While high, rather than low, commercial dairy farm density similarly increased the risk of infection in both urban (12% to 18%) and rural areas (70% to 79%), the presence of pigs in a village had different impact in rural (43% to 84%) compared with urban areas (4% to 24%). Areas with high poverty rates were predicted to have 26.6% and 18.0% higher probability of above average seroprevalence in rural and urban areas, respectively. In urban areas, this represents >300% difference between areas of low and high poverty, compared to 43% difference in rural areas. Conclusions Our study demonstrates the use of SBN to provide valuable insights into the drivers of leptospirosis transmission under complex scenarios. By estimating the risk of leptospirosis infection under different scenarios, such as urban versus rural areas, these subgroups or areas can be targeted with more precise interventions that focus on the most relevant key drivers of infection
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