A consequence of antimicrobial use in food production systems is the potential for antimicrobial resistant (AMR) bacteria to develop and transfer to the human population via the food chain. Integrons have been identified as critical factors in the development of AMR. Despite Australia being amongst the world’s largest exporters of beef, there is a general lack of data on the prevalence of AMR in bacteria from Australian beef cattle. Consequently, the aim of this study has been to contribute to research strategies and knowledge of AMR by investigating integron-associated antimicrobial resistance in Australian beef cattle production systems. This study developed a protocol that targets resistance integrons. The protocol was trialled on 50 bovine faecal samples with a total of 39 integron-containing isolates recovered. Characterisation of the integrons was performed and it was determined that the majority of integrons harboured genes encoding resistance to trimethoprim (dfr) and streptomycin / spectinomycin (aad). The protocol provides an opportunity to rapidly interrogate populations of bacteria within a defined sample for resistance integrons. The protocol was used to investigate integron-associated AMR in Australian beef cattle production systems. Each production system was investigated for resistance integrons to determine if production practices were impacting on the prevalence and types of AMR present. The investigation found that the prevalence of integron-containing bacteria was higher in lot-fed cattle than grass-fed cattle which in turn were higher than organically produced cattle. However, the types of AMR differed very little across production systems and suggested that the higher prevalence of integrons in lot-fed samples may be a function of the intensive nature of this type of production system rather than a result of selective pressure caused by antibiotic use. Although there appeared to be no obvious trends in the types of gene cassettes carried by integrons from differing production systems, if lot-fed cattle continually arrive at slaughter with a higher prevalence of integron-containing bacteria then these cattle may be more likely to contribute to contamination of the final product. Samples from lot-fed, grass-fed and organically produced cattle at slaughter were collected. Despite the apparent unrelatedness of the cattle herds, there was little difference in the PCR prevalence of class 1 and class 2 integrase, the gene cassettes harboured by the integrons, and the host organism for the integron. Genes encoding resistance to streptomycin and chloramphenicol (catB8) dominated the majority of arrays regardless of production system, although two novel arrays were identified. One of the arrays, cmlA5-blaoxa-10-aadA1, was found in A. veronii biovar Sobria isolates from organic cattle thereby confirming the ability of multi-resistant integrons to persist in environments that have no obvious antimicrobial selection. The abattoir study revealed an unusually high prevalence of Aeromonas isolates carrying integrons. It appeared to implicate the abattoir environment as a direct contributor to the presence of integron-containing bacteria in each herd. Characterisation of each Aeromonas isolate determined that the isolates were not clonal in nature and not a result of persistent contamination at the abattoir. It seemed more probable that the Aeromonas isolates were present in the cattle prior to arrival and may have been acquired from the environment. To explore this further, soil samples from cattle associated and non-cattle associated areas were tested for the presence of resistance integrons. The prevalence of class 1 integrons was higher in cattle-associated soil samples than in non-cattle-associated soil samples, however the diversity of gene cassettes harboured by the integrons was greater in non-cattle-associated samples than cattle-associated samples. An array harbouring blaoxa-30 was isolated from a non-cattle-associated soil sample. Its presence continues to highlight the potential for multi-resistant integrons to exist in environments with no obvious antimicrobial selection pressure.The detection of seldom reported class 1 integron arrays in this study indicates the potential of the developed protocol to interrogate populations of bacteria for resistance integrons. This is highlighted further by the isolation of a novel class 2 integron. This novel class 2 integron from Providencia stuartii possesses a class 2 integrase that is predicted to be fully functional and has a variable region comprising nine ORFs that do not encode AMR genes. Overall, this study demonstrated that integrons are present in all cattle production systems employed in Australia and although the prevalence of integrons appeared to align with the anticipated use of antimicrobials in each system, differences in the integrons from each production system were not evident. As the similarities observed between integrons extend to isolates from organically produced cattle and from non-cattle associated soil samples it is suggested that the majority of integrons identified in this study are not present as a direct result of antimicrobial use in cattle production. Nevertheless, the potential of integrons to capture AMR genes remains and their presence in beef cattle highlights the need for the continued prudent use of antimicrobials.

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The control of cellular tyrosine phosphorylation levels is of great importance in many biological systems. Among the kinases and phosphatases that modulate these levels, the LAR-RPTPs have been suggested to act in several key aspects of neural development, and in a dysfunctional manner in various pathologies from diabetes to cancer. The aim of this thesis is to describe the physiological functions of one of the members of this subfamily of RPTPs, namely RPTPsigma. First, we showed that glucose homeostasis is altered in RPTPsigma null mice. They are hypoglycemic and more sensitive to exogenous insulin and we proposed that the insulin hypersensitivity observed in RPTPsigma-null mice is likely secondary to their neuroendocrine dysplasia and GH/IGF-1 deficiency. In addition to regulating nervous system development, RPTPsigma was previously shown to regulate axonal regeneration after injury. In the absence of RPTPsigma, axonal regeneration in the sciatic, facial and optical nerves was enhanced following nerve crush. However, myelin-associated growth inhibitory proteins and components of the glial scar such as CSPGs (chondroitin sulfate proteoglycans) have long been known to inhibit axonal regeneration in the CNS, making spinal cord injury irreversible. In collaboration with Dr Samuel David, we unveiled that RPTPsigma null mice are able to regenerate their corticospinal tract following spinal cord hemisections as opposed to their WT littermates. We then isolated primary neurons from both sets of animals and found that the absence of RPTPsigma promotes the ability of the neurons to adhere to certain inhibitory substrates. Finally, in order to better understand the physiological role of RPTPsigma, we used a yeast substrate-trapping approach, to screen a murine embryonic library for new substrates. This screen identified the RhoGAP p250GAP as a new substrate, suggesting a downstream role for RPTPsigma in RhoGTPase signaling. We also identified p130Cas and Fyn as new binding partners. All these proteins have clear functional links to neurite extension. The characterization of RPTPsigma and its signaling partners is essential for understanding its role in neurological development and may one day translate into treatments of neural diseases and injuries.

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Today there are no requirements on burglary protection in the building regulation “Boverketsbyggregler”. Instead SSF Stöldskyddsföreningen has developed norms for physical security.SSF 200:5 is a norm that treats burglary protection in buildings and business premises, and isused as a basis for the insurance companies own description of security classification.The main purpose of the report is to get an increased understanding of what requirementsregarding burglary protection there are, and who is demanding them. The report also aims toexplore how people in the industry deal with security related work in the design stage.The questions at issue are all related to burglary protection. To answer these questions threemethods have been used. Interviews/surveys, physical tests, and a comparison between SSF200:5 and the insurance companies description of security classification.The interviews show that the burglary protection can vary depending on who the claimant is.It shines a light on a problem that occurs in the construction process, that is, discussingsecurity related questions too late. This can lead to compromised burglar security andincreased construction costs.The comparison shows that SSF 200:5 is not fully comparable with the insurance companiesdescription of security classification. Easy measures like door and window locks can beequated, meanwhile more complicated measures like wall constructions, can not.Using the test results, alternative wall constructions that satisfy the norm have been presented.Also improvements of SSF 200:5 have been discussed in favor of the whole industry.

This master thesis introduces innovative approach to teaching practice at Waldorf schools, the so called movable classroom. This model originates in German Waldorf schools, primarily from Rudolf Steiner Schule in Bochum. Its main specific is furnishing the classroom with movable equipment, which creates the possibility for greater variability in organizing the space by implementation of weekly outdoor learning and change in the timing set up of teaching units. The research question of this work is meaningfulness of the movable classroom model, it specifically concerns itself with the question, whether it is possible to observe the benefits of movable classroom model for physical, psychological, social and cognitive development of children, while teacher simultaneously takes into account the current limitations of this model. Following observation in the classrooms, which work according to this model and researching contemporary literature, individual categories of both benefits and risks have been specified. Through follow up interviews with teachers, these categories are verified and exactified through actual situations, the research question is answered and further possibilities for working with this model in Czech Waldorf schools are explored.