Molecular epidemiology of antibiotic resistance in the commensal Escherichia coli of calves

In animals, the study of antibiotic resistance in bacteria has been focused on organisms that are pathogenic in human or animal hosts. The development of antibiotic resistance in commensal bacteria is also of concern because they may act as a reservoir ofresistance genes. This thesis aimed to determine levels of resistance to veterinary and medical antibiotics in the commensal Escherichia coli of calves, to explore the genotypic diversity of isolates, and to study the molecular mechanism and transfer dynamics ofresistance to apramycin.The antibiotic sensitivity testing of calf faecal E. coli, obtained by weekly sampling, demonstrated that there was resistance to beta-lactams, cephalosporins, streptomycin, trimethoprim, chloramphenicol, tetracycline and sulphamethoxazole. These resistance phenotypes had not been selected for on antibiotic-containing media, indicating a high prevalence of the corresponding resistance determinants.Five hundred and forty three isolates were genotyped by pulsed-field gel electrophoresis. Examination of the patterns generated by restriction with Xbal and analysed with BioNumerics software revealed a total of 55 different genotypes. Ampicillin resistant isolates were more diverse (24 genotypes) than apramycin or nalidixic acid resistant isolates (5 and 2 genotypes respectively). Apramycin resistance (aprR) was conferred by three conjugative plasmids, pUK2001, pUK2002 and pUK2003, of sizes 91, 115 and 181Kb respectively. All aprR plasmids conferred cross-resistance to the medical antibiotics tobramycin and gentamicin. Plasmids pUK2002 and pUK2003 also carried tetracycline and streptomycin resistance. Plasmid pUK2001 demonstrated very high transfer frequencies (4.12x10" during 7 hrs mating), horizontal spread to three different genotypes, and an apparent fitness advantage in vitro.This thesis shows a very high prevalence of antibiotic resistance genes in the commensal faecal flora of food-producing calves. This may have significant implications for the transmission ofresistance genes to human clinical bacteri

Jak powiedzieć, żeby nie powiedzieć (lub odwrotnie), czyli kłopoty z przekładem elegii wygnańczej Owidiusza „Ex P.” IV 12

Aside from its wealth of meaning and contexts, Ovid’s poetry seems to be sometimes difficult to translate into Polish. This paper shows such an extreme situation using the example of Ex P IV 12, where the translator is virtually helpless in the face of the poet’s subtle sense of humor and sophisticated play with a reader on the grounds of the nature of Roman elegiac distich.Aside from its wealth of meaning and contexts, Ovid’s poetry seems to be sometimes difficult to translate into Polish. This paper shows such an extreme situation using the example of Ex P IV 12, where the translator is virtually helpless in the face of the poet’s subtle sense of humor and sophisticated play with a reader on the grounds of the nature of Roman elegiac distich

Using Population-based Metaheuristics and Trend Representative Testing to Compose Strategies for Market Timing

Market Timing is the capacity of deciding when to buy or sell a given asset on a financial market. Market Timing strategies are usually composed of components that process market context and return a recommendation whether to buy or sell. The main issues with composing market timing strategies are twofold: (i) selecting the signal generating components; and (ii) tuning their parameters. In previous work, researchers usually attempt to either tune the parameters of a set of components or select amongst a number of components with predetermined parameter values. In this paper, we approach market timing as one integrated problem and propose to solve it with two variants of Particle Swarm Optimization (PSO). We compare the performance of PSO against a Genetic Algorithm (GA), the most widely used metaheuristic in the domain of market timing. We also propose the use of trend representative testing to circumvent the issue of overfitting commonly associated with step-forward testing. Results show PSO to be competitive with GA, and that trend representative testing is an effective method of exposing strategies to various market conditions during training and testing

Ecological Concept Development at the Elementary School Level

This case study of one school was designed to examine the level of knowledge and understanding elementary students (ages 9 – 13) have for key ecological concepts that are found in the Ontario 2007 science curriculum guidelines for grades 4, 6, and 8. This study utilizes the research design technique of concept analysis to investigate the level of maturity of understanding found in elementary students‟ definitions for these ecological concepts. The study revealed that a majority of students possess a limited understanding of the concepts of photosynthesis, decomposition, greenhouse gas, recycling and biodiversity. The study also found that students possess quite varied meanings for the concepts of the environment, sustainability and green. This limited understanding of concepts and the variability of meaning demonstrated that there was limited growth in concept development from grade 4 to grade 8. The results of this one study may encourage educators to consider further the importance of focusing on ecological concept development in elementary education

Arbeitsbericht (Working Paper) Nr. 2011-07, Dezember 2011

Ilmenauer Beiträge zur Wirtschaftsinformatik Nr. 2011-07 / Technische Universität Ilmenau, Fakultät für Wirtschaftswissenschaften, Institut für Wirtschaftsinformatik ISSN 1861-9223 ISBN 978-3-938940-40-2Abstract: Sub-daily personnel planning, which is the focus of our work offers considerable productivity reserves for companies in certain industries, such as logistics, retail and call centers. However, it also creates complex challenges for the planning software. We compare particle swarm optimisation (PSO), the evolution strategy (ES) and a constructive agentbased heuristic on a set of staff scheduling problems derived from a practical case in logistics. All heuristics significantly outperform conventional manual full-day planning, demonstrating the value of sub-daily scheduling heuristics. PSO delivers the best overall results in terms of solution quality and is the method of choice, when CPU-time is not limited. The approach based on artificial agents is competitive with ES and delivers solutions of almost the same quality as PSO, but is vastly quicker. This suggests that agents could be an interesting method for real-time scheduling or re-scheduling tasks

Building Market Timing Strategies Using Trend Representative Testing and Computational Intelligence Metaheuristics

Market timing, one of the core deciding when to buy or sell an asset of interest on a financial market. Market timing strategies can be built by using a collection of components or functions that process market context and return a recommendation on the course of action to take. In this chapter, we revisit the work presented in [20] on the application of Genetic Algorithms (GA) and Particle Swarm Optimization (PSO) to the issue of market timing while using a novel approach for training and testing called Trend Representative Testing. We provide more details on the process of building trend representative datasets, as well as, introduce a new PSO variant with a different approach to pruning. Results show that the new pruning procedure is capable of reducing solution length while not adversely affecting the quality of the solutions in a statistically significant manner

Studi Karakteristik Serat Rosela, Serat Pisang, Serat Enceng Gondok Sebagai Substitusi Konstruksi Pelat FRP Pada Pembangunan Kapal

Sifar material komposil yang ringan rahan rerhadap korosi menjadilcan materia ini dijadikan sebagai alternatif pengganti baja pada pembangunan lcapal Fiberglass Reinforced Plastic (FRP) adalah salah satu jenis material komposi yang biasa digunakan. Penggunaan sera/ penguat dari bahan a/am, Naturaljibe Reinforced Plastic (NRP) dewasa ini banyak diminati. Pada penelitian ini mencoba menggali karakteristik dari Natura/fiber Reinforce Plastic (NRP). Material pengujian yang digunakan adalah komposit dengan sera penguat sera/ karung (Hibiscus Cannabius), abaka (Musa Texti//is Nee) da enceng gondok (Eicchornia Crassipes) yang dianyam tegak lurus. Pengujian yan dilakukan adalah pengujian tarik dan tekuk menggunakan standar pengujia ASTM D 3039/D 3039 M, 1993 dan ASTM D 790-91, 1993. Hasi/ yang diperoleh menunjuklwn bahwa NRP dengan sera/ penguar sera karung mempunyai kekuaran tarik lebih tinggi 18.6 % dibanding NRP dengan sera! penguat abaka dan lebih tinggi 870 . .J % dibanding NRP dengan sera penguat enceng gondok. Sementara itu untuk kuat tekuk NRP dengan sera penguat serar karung mempunyai kekuaran rekuk .J2 % febih tinggi dibandh ,\RP dengan sera/ penguar abaka dan -126 % lebih tinggi dibanding NRP denga sera! penguat enceng gondok. Untuk penerapan pada pembangunan lcapal pengunaan NRP demgan sera/ penguat serat karung memif.:ki ketebafan terkeci dibanding dengan NRP berserat penguar abaka dan enceng gondok denga peningkatan leba/ 51.3% dibanding FRP. Berat konstruksi NRP sebagai pela kulit kapal masih febih berat dibandingkan dengan FRP