96 research outputs found

    Characterization of DP600 Steel Subject to Electrohydraulic Forming

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    Electrohydraulic forming (EHF) is a manufacturing technique that transforms electrical energy into work. In EHF, a shockwave is produced as a result of a high-voltage electrical discharge between two electrodes in a water chamber, which travels through water toward the sheet and forms it into the final shape at high velocity. Strain rates can reach 104 s-1 in EHF. DP600 dual phase steel was formed in the Nakazima test in quasi-static (QS) condition, and EHF, performed without a mating die (free forming) and using a 34° conical die (die forming). The sheets were etched with a grid prior to testing to determine strains across each specimen. Analysis of voids was carried out to investigate the micro-mechanisms of failure in DP600 steel formed in these three processes. Nakazima specimens exhibited uniform strain behaviour up to 0.65 effective strain; EHFF up to 0.45 effective strain; and EHDF up to 0.7 effective strain

    Fraudulent Tax Refunds: The Notorious Career of Harriette Walters

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    Harriette Walters embezzled more than $48 million from the District of Columbia by processing fraudulent real estate tax refunds. This paper describes the Walters scheme and discusses, from the perspective of the COSO framework, internal control weaknesses that enabled the fraud to go undetected for more than 20 years. While this analysis of the Walters fraud should be of interest to both accounting academics and audit professionals, it should be particularly helpful to students, fi nancial managers, and inexperienced auditors in understanding the importance of effective internal controls for preventing and detecting fraud in a wide variety of organizational settings

    AAC Viewfield Hard Red Spring Wheat

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    AAC Viewfield hard red spring wheat (Triticum aestivum L.) has grain yield significantly higher than the check cultivars Katepwa and Lillian and is similar to Carberry. AAC Viewfield matures significantly later than Katewpa and Lillian but is similar to Carberry. AAC Viewfield has an awned spike, a low lodging score indicative of strong straw, and significantly shorter plant stature than all checks. AAC Viewfield expressed resistance to prevalent races of yellow rust and stem rust, moderate resistance to leaf rust and common bunt, and intermediate resistance to Fusarium head blight. AAC Viewfield has quality attributes within the range of the check cultivars and is eligible for grades of Canada Western Red Spring

    Genetics and resistance/Génétique et résistance Development of EST-derived simple sequence repeat markers for wheat leaf rust fungus, Puccinia triticina Eriks Molecular markers for wheat leaf rust

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    Abstract: Gene-associated simple sequence repeat (SSR) markers were developed for Puccinia triticina through the data mining of existing EST libraries. Analysis of 7134 expressed sequence tags (ESTs) from cDNA libraries of P. triticina detected 204 EST-SSRs with a minimum of 12 repeating nucleotides. The majority of EST-SSRs contained short di-or tri-nucleotide repeats. These EST-SSRs were evaluated on 35 P. triticina isolates collected in Canada and 21 EST-SSRs were polymorphic and informative in determining intraspecific genetic diversity. A comparison of virulence and EST-SSR genotypes showed a strong correlation between virulence to Lr2a, Lr2c and Lr17a and EST-SSRs genotypes. The differentiation of the P. triticina population based on EST-SSR genotypes was comparable to that obtained with genomic SSRs, despite differences between two types of SSR markers. Eight of the 21 EST-SSRs produced the cross amplification in Puccinia coronata and Puccinia graminis, suggesting that EST-SSRs are more applicable than genomic SSRs for interspecific analysis. In summary, our study suggests that the data mining of EST databases is a feasible way to generate informative molecular markers for genetic studies of P. triticina. Keywords: population genetics, Puccinia triticina, simple sequence repeat, virulence Résumé: Des marqueurs microsatellites (SSR) associés à des gènes ont été conçus pour Puccinia triticina à partir l'exploration de données contenues dans des banques d'étiquettes de séquences exprimées (EST). L'analyse de 7134 EST issues de banques d'ADNc de P. triticina ont permis de détecter 204 EST-SSR avec un minimum de 12 répétitions de nucléotides. La majorité des EST-SSR contenaient de courtes répétitions di-ou tri-nucléotidiques. Ces EST-SSR ont été évaluées sur 35 isolats de P. triticina collectés au Canada. Parmi celles-ci, 21 étaient polymorphiques et ont fourni de l'information servant à établir la diversité génétique intraspécifique. Une comparaison de la virulence et des génotypes EST-SSR a montré une forte corrélation entre la virulence à l'égard de Lr2a, Lr2c et Lr17a ainsi qu'à l'égard des génotypes EST-SSR. La différenciation de la population de P. triticina, basée sur les génotypes EST-SSR, était comparable à celle obtenue avec les SSR génomiques, malgré les différences entre les deux types de marqueurs. Huit des 21 EST-SSR ont engendré la transférabilité chez Puccinia coronata et Puccinia graminis, ce qui suggère que les EST-SSR sont plus adaptables à l'analyse interspécifique que les SSR génomiques. En résumé, notre étude suggère que l'exploration de données des banques d'EST permet de générer des marqueurs moléculaires informatifs pour les études génétiques portant sur P. triticina

    Mapping quantitative trait loci associated with leaf rust resistance in five spring wheat populations using single nucleotide polymorphism markers

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    Growing resistant wheat (Triticum aestivum L) varieties is an important strategy for the control of leaf rust, caused by Puccinia triticina Eriks. This study sought to identify the chromosomal location and effects of leaf rust resistance loci in five Canadian spring wheat cultivars. The parents and doubled haploid lines of crosses Carberry/AC Cadillac, Carberry/Vesper, Vesper/Lillian, Vesper/Stettler and Stettler/Red Fife were assessed for leaf rust severity and infection response in field nurseries in Canada near Swift Current, SK from 2013 to 2015, Morden, MB from 2015 to 2017 and Brandon, MB in 2016, and in New Zealand near Lincoln in 2014. The populations were genotyped with the 90K Infinium iSelect assay and quantitative trait loci (QTL) analysis was performed. A high density consensus map generated based on 14 doubled haploid populations and integrating SNP and SSR markers was used to compare QTL identified in different populations. AC Cadillac contributed QTL on chromosomes 2A, 3B and 7B (2 loci), Carberry on 1A, 2B (2 loci), 2D, 4B (2 loci), 5A, 6A, 7A and 7D, Lillian on 4A and 7D, Stettler on 2D and 6B, Vesper on 1B, 1D, 2A, 6B and 7B (2 loci), and Red Fife on 7A and 7B. Lillian contributed to a novel locus QLr.spa-4A, and similarly Carberry at QLr.spa-5A. The discovery of novel leaf rust resistance QTL QLr.spa-4A and QLr.spa-5A, and several others in contemporary Canada Western Red Spring wheat varieties is a tremendous addition to our present knowledge of resistance gene deployment in breeding. Carberry demonstrated substantial stacking of genes which could be supplemented with the genes identified in other cultivars with the expectation of increasing efficacy of resistance to leaf rust and longevity with little risk of linkage drag

    Genetic mapping of leaf rust (Puccinia triticina Eriks) resistance genes in six Canadian spring wheat cultivars

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    The Canada Western Red Spring wheat (Triticum aestivum L.) cultivars AAC Concord, AAC Prevail, CDC Hughes, Lillian, Glenlea, and elite line BW961 express a spectrum of resistance to leaf rust caused by Puccinia triticina Eriks. This study aimed to identify and map the leaf rust resistance of the cultivars using three doubled haploid populations, AAC Prevail/BW961 (PB), CDC Hughes/AAC Concord (HC), and Lillian/Glenlea (LG). The populations were evaluated for seedling resistance in the greenhouse and adult plant disease response in the field at Morden, MB for 3 years and genotyped with the 90K wheat Infinium iSelect SNP array. Genetic maps were constructed to perform QTL analysis on the seedling and field leaf rust data. A total of three field leaf rust resistance QTL segregated in the PB population, five in the HC, and six in the LG population. In the PB population, BW961 contributed two QTL on chromosomes 2DS and 7DS, and AAC Prevail contributed a QTL on 4AL consistent across trials. Of the five QTL in HC, AAC Concord contributed two QTL on 4AL and 7AL consistent across trials and a QTL on 3DL.1 that provided seedling resistance only. CDC Hughes contributed two QTL on 1DS and 3DL.2. Lillian contributed four QTL significant in at least two of the three trials on 2BS, 4AL, 5AL, and 7AL, and Glenlea two QTL on 4BL and 7BL. The 1DS QTL from CDC Hughes, the 2DS from BW961, the 4AL from the AAC Prevail, AAC Concord, and Lillian, and the 7AL from AAC Concord and Lillian conferred seedling leaf rust resistance. The QTL on 4AL corresponded with Lr30 and was the same across cultivars AAC Prevail, AAC Concord, and Lillian, whereas the 7AL corresponding with LrCen was coincident between AAC Concord and Lillian. The 7DS and 2DS QTL in BW961 corresponded with Lr34 and Lr2a, respectively, and the 1DS QTL in CDC Hughes with Lr21. The QTL identified on 5AL could represent a novel gene. The results of this study will widen our knowledge of leaf rust resistance genes in Canadian wheat and their utilization in resistance breeding

    ANSI/NISO Z39.99-2017 ResourceSync Framework Specification

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    This ResourceSync specification describes a synchronization framework for the web consisting of various capabilities that allow third-party systems to remain synchronized with a server’s evolving resources. The capabilities may be combined in a modular manner to meet local or community requirements. This specification also describes how a server should advertise the synchronization capabilities it supports and how third-party systems may discover this information. The specification repurposes the document formats defined by the Sitemap protocol and introduces extensions for them

    Evolutionary Epidemiology of Drug-Resistance in Space

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    The spread of drug-resistant parasites erodes the efficacy of therapeutic treatments against many infectious diseases and is a major threat of the 21st century. The evolution of drug-resistance depends, among other things, on how the treatments are administered at the population level. “Resistance management” consists of finding optimal treatment strategies that both reduce the consequence of an infection at the individual host level, and limit the spread of drug-resistance in the pathogen population. Several studies have focused on the effect of mixing different treatments, or of alternating them in time. Here, we analyze another strategy, where the use of the drug varies spatially: there are places where no one receives any treatment. We find that such a spatial heterogeneity can totally prevent the rise of drug-resistance, provided that the size of treated patches is below a critical threshold. The range of parasite dispersal, the relative costs and benefits of being drug-resistant compared to being drug-sensitive, and the duration of an infection with drug-resistant parasites are the main factors determining the value of this threshold. Our analysis thus provides some general guidance regarding the optimal spatial use of drugs to prevent or limit the evolution of drug-resistance
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