31 research outputs found

    Geodesic rewriting systems and pregroups

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    In this paper we study rewriting systems for groups and monoids, focusing on situations where finite convergent systems may be difficult to find or do not exist. We consider systems which have no length increasing rules and are confluent and then systems in which the length reducing rules lead to geodesics. Combining these properties we arrive at our main object of study which we call geodesically perfect rewriting systems. We show that these are well-behaved and convenient to use, and give several examples of classes of groups for which they can be constructed from natural presentations. We describe a Knuth-Bendix completion process to construct such systems, show how they may be found with the help of Stallings' pregroups and conversely may be used to construct such pregroups.Comment: 44 pages, to appear in "Combinatorial and Geometric Group Theory, Dortmund and Carleton Conferences". Series: Trends in Mathematics. Bogopolski, O.; Bumagin, I.; Kharlampovich, O.; Ventura, E. (Eds.) 2009, Approx. 350 p., Hardcover. ISBN: 978-3-7643-9910-8 Birkhause

    Digestibility energy and amino acids of canola meal from two species (Brassica juncea and Brassica napus) fed to distal ileum cannulated grower pigs

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    Yellow-seeded Brassica juncea is a novel canola species targeted to grow in the southern Canadian prairies where thermotolerance, disease resistance, and adaptation to dry agronomic conditions are required. The support of its cultivation needs nutritional evaluation of its coproduct. The B. juncea canola meal (CM) contains less fiber than conventional, dark-seeded Brassica napus CM but also slightly less Lys. In a 6 × 6 Latin square, 6 distal ileum cannulated pigs (47 kg BW) were fed 6 diets to determine the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA, AID and apparent total tract digestibility (ATTD) of energy, and VFA content in digesta and feces. Pigs were fed 6 diets: basal [46% wheat (Triticum aestivum) and corn (Zea mays) starch], 4 diets with 46% wheat and either B. juncea or B. napus CM at 25 or 50%, and a N-free diet based on corn starch. The B. juncea CM had higher (P <0.05) ATTD of energy than B. napus CM (68.6 vs. 60.3%) likely due to its lower fiber content. Ileal total VFA was lower (P <0.001) in pigs fed B. juncea than B. napus CM diets. In pigs fed B. juncea CM, the molar ratio in digesta was lower (P <0.001) for acetate and butyrate whereas the propionate ratio was lower (P <0.001) in feces than in pigs fed B. napus CM diets. The CM species did not affect the AID of energy, SID of AA, and feces VFA content. The DE value was higher (P <0.05) and content of SID Lys was lower (P <0.05) for B. juncea than B. napus CM. In conclusion, availability of B. juncea CM, a coproduct of a canola species grown in Canadian prairie land, will increase flexibility in swine feed formulation

    Digestibility and intestinal fermentability of canola meal from Brassica juncea and Brassica napus fed to ileal-cannulated grower pigs

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    Yellow-seeded Brassica (B.) juncea is a novel canola species. Therefore, its meal co-product requires feed quality evaluation and comparison to conventional, dark-seeded B. napus canola meal for pigs. The B. juncea canola meal contains less fibre than B. napus canola meal (190 vs. 260 g NDF/kg, as is), but also less lysine (20.3 vs. 22.1 g/kg). Nutrient digestibility and fermentibility of B. juncea and B. napus canola meal were assessed in a 2 × 2factorial arrangement. Six ileal-cannulated pigs (47 kg BW) were fed six diets in a 6 × 6 Latin square: basal diet (460 g wheat/kg and corn starch), 4 diets with 460 g wheat/kg and either B. juncea or B. napus canola meal at 250 or 500 g/kg replacing corn starch, sugar and canola oil, and an N-free diet based on corn starch. The B. juncea canola meal had greater (P < 0.05) CATTD of gross energy than B. napus canola meal (0.70 vs. 0.63) most likely due to its lower fibre content. Ileal total VFA concentration was lower (P < 0.001) in pigs fed B. juncea than B. napus canola meal diets (15.2 vs. 20.8 μmol/g of wet digesta). In pigs fed B. juncea canola meal instead of B. napus canola meal diets, the molar ratio was greater (P < 0.01) for digesta propionate and faecal acetate, but lower (P < 0.05) for digesta and faecal butyrate. Canola meal species did not affect the CAID of gross energy, CSID of amino acid and faecal VFA content. The digestible energy (DE) value was greater (P < 0.01; 12.1 vs. 10.9 MJ/kg, standardised to 100 g/kg moisture) for B. juncea than B. napus canola meal. Increasing dietary inclusion of canola meal up to 500 g/kg reduced (P < 0.01) diet digestibility of gross energy but not amino acids and decreased (P < 0.05) intestinal fermentability of B. napus but not B. juncea. In conclusion, B. juncea canola meal had greater fermentability and ATTD of gross energy than B. napus canola meal, but digestibility of amino acids did not differ. Increasing dietary inclusion of canola meal up to 500 g/kg reduced digestibility of gross energy but not digestibility of AA. Fermentability of B. napus canola meal but not B. juncea canola meal decreased in the pig intestine with increased dietary inclusion. Hence, yellow-seeded B. juncea canola meal had a greater DE value, similar amino acid digestibility as conventional dark-seed B. napus canola meal and may limit protein fermentation in the pig intestine

    Aspects of urinary tract infections and antimicrobial resistance in hospitalized urology patients in Asia: 10-Year results of the Global Prevalence Study of Infections in Urology (GPIU)

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    10.1016/j.jiac.2017.11.013Journal of Infection and Chemotherapy244278-283JICH
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