Genetic regulatory networks are of great importance in terms of scientific interests and practical medical importance. Since a number of high-throughput measurement devices are available, such as microarrays and sequencing techniques, regulatory networks have been intensively studied over the last decade. Based on these high-throughput data sets, statistical interpretations of these billions of bits are crucial for biologist to extract meaningful results. In this thesis, we compare a variety of existing regression models and apply them to construct regulatory networks which span trancription factors and microRNAs. We also propose an extended algorithm to address the local optimum issue in finding the Maximum A Posterjorj estimator. An E. coli mRNA expression microarray data set with known bona fide interactions is used to evaluate our models and we show that our regression networks with a properly chosen prior can perform comparably to the state-of-the-art regulatory network construction algorithm. Finally, we apply our models on a p53-related data set, NCI-60 data. By further incorporating available prior structural information from sequencing data, we identify several significantly enriched interactions with cell proliferation function. In both of the two data sets, we select specific examples to show that many regulatory interactions can be confirmed by previous studies or functional enrichment analysis. Through comparing statistical models, we conclude from the project that combining different models with over-representation analysis and prior structural information can improve the quality of prediction and facilitate biological interpretation. Keywords: regulatory network, variable selection, penalized maximum likelihood estimation, optimization, functional enrichment analysis.

This thesis attempted to determine whether precipitation at CFB Borden, Ontario Canada is derived from recycled or marine source water using δ18O and to explore the enrichment of leaf water in three temperate forest trees. The d-excess values and rainfall intensity were used as indicators of recycled water and were found to suggest that precipitation at Borden is not derived from recycled water. The leaves of ash, aspen and maple showed significant enrichment in δ18O over xylem water. Maple leaves were significantly more enriched over the leaves of ash and aspen (p-value = 0.0019), despite source water not being significantly different (p-value = 0.1782). Modelling leaf water demonstrated the need for the inclusion of the Peclet effect in the steady state model for ash and aspen leaves, however for maple, the Peclet effect is insignificant. The non-steady state model used measured values of δET, which were uncertain and lead to poor model predictions. / NSERC Strategic Project #351040

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No description available.

This study investigated the relationship between flood duration of beaver ponds in eastern Ontario and their productivity for waterfowl. The primary objective was to assess the effect of removing water from a beaver pond for one year had on the subsequent productivity of the wetland. Productivity was estimated by sampling water chemistry, standing crops of aquatic invertebrates, vertebrates, algae and vegetation composition and distribution in naturally occurring and managed beaver ponds of varying ages during 1994 and 1995. Three ponds in each of the following categories were sampled; managed ponds reflooded in 1993, managed ponds reflooded in 1991, naturally occurring beaver ponds reflooded in 1992-93, and naturally occurring old flood ponds ($>$5 years old). / Results from this study indicate that beaver pond productivity is negatively affected by flooding duration. Removal of a portion of the beaver dam on old flood ponds may be an effective means of rejuvenating the wetland. Positive effects on the productivity of the wetland should be realized for several years after reflood. Variability in results indicates that other environmental variables were also affecting the overall productivity of beaver ponds. (Abstract shortened by UMI.)

In the South African educational landscape curriculum transformation since Curriculum 2005 (C2005) to the now prevailing National Curriculum Statement (NCS) has been dramatic. In fact in the Foundation Phase and in Grade 10 a revised Curriculum and Assessment Policy (CAPS) document introduced in 2012 is presently being implemented. The continuous revision of curriculum policies is the background to the purpose of this research study, which is to understand how four experienced teachers of English Home Language (EHL) engage with changes in EHL policy and the impact this has on their identity/identities as teachers. The National Education Department often hopes that teachers are highly regulated by policies, and will thus change their practices in accordance to curriculum policy. My research project seeks to understand the complexity of the ways in which external regulations, embedded in the changing curriculum, govern teachers’ practices and consequently impacts on the identity of professionally qualified teachers. The study is framed by two critical questions: a) To what extent are the practices of experienced teachers governed by external regulation (in the form of the curriculum policy)? and b) To what extent does external regulation shape their identity as teachers? To this end, lesson observation and unstructured interviews were the data collection methods that were employed. This research is located within the interpretive paradigm. Data is gleaned from the stories told by four experienced teachers of English about their everyday classroom practices and the ways in which they translate and implement EHL policy from changing curriculum documents, as well as through observations of their teaching. These teachers work in four diverse South African educational contexts. The analytical framework that is used in this study suggests that teacher practice and identity is shaped by external regulations (such as policy requirements); internal regulations which are the contextual factors such as institutional school culture as well as core regulations such as their beliefs and values. Teachers’ sense-making of changing policy entrenched in curriculum documents; their translation of policy and its impact on teaching practices and consequent influence on a teacher’s identity are important for the answering of the research question. The findings reveal that these teachers find curriculum changes challenging and are reluctant to implement them entirely. Instead they select and adapt from the document what can fit with minimal change into their present repertoire of pedagogical practices. The impact of this on the identity of a teacher is minimal as teachers’ definition of who they are and the role they play is strong. Therefore the impact of curriculum changes on teacher identity appears to be minimal. I discovered that the four teachers in this study are resilient beings who adapt an externally regulated curriculum to fit their frame of classroom practices based on their beliefs of what constitutes effective teaching. To ameliorate the disjuncture between policy and practice would be an ideal situation. But realistically strongly regulated national policies will never be implemented as policy makers intend. Perhaps the lesson is looser regulations are thus more useful. / Thesis (M.Ed.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

C-type Natriuretic Peptide (CNP), a relatively new member of the natriuretic peptide family, is found throughout the central nervous system. Circumstantial evidence associates CNP with learning and memory, as its expression is highest in brain regions known to be involved in memory and associated with hippocampal physiology. Here, the first study housed rats in an enriched environment, regarded as providing an 'informal' learning experience, for either 14 or 28 days of housing in enrichment in six regions of interest, which was attributed to changes in the degradation of CNP. The second study examined a group of rats trained on object -recognition task – the bow-tie maze. A difference was found in CNP production in the limbic medial prefrontal cortex over repeated exposures to novel objects relative to controls that received 'yoked learning' an exposure only to the test room. CNP concentrations also tended to be lower in rats with better levels of discrimination between familiar objects. Together, these studies provide some initial evidence that CNP influences learning –induced plasticity in the intact brain.

Animals are confronted with potential stressors at zoos compared to in the wild, such as visitors and lack of environmental stimulation. This study included two projects conducted on the drills at Parken Zoo in Eskilstuna where I investigated: 1) the effect of visual barriers on the behaviour of the drills and if the visual barriers can moderate the visitor effect on the drills and 2) how outdoor-only access together with feeding enrichment (frozen fruit and tube feeders) affects the behaviour of the drills. 1/0- sampling method was used when observing the behaviours of the drills with 1 minute-intervals. Resting/Sleeping increased, while social agonistic behaviour and stereotypies decreased with visual barriers. A moderated visitor effect was shown in resting/sleeping and social affiliative behaviour in the drills with visual barriers. However, social agonistic behaviour and visitor interaction were still affected by visitors after the installation of the visual barriers, implying that the drills still find visitors stressful to some extent and that further alterations on the observation area viewing the indoor enclosure is recommended for the welfare of the drills. With outdoor-only access together with feeding enrichment, locomotion, foraging/eating and body-shaking increased, while resting/sleeping, social affiliative and agonistic behaviour, stereotypies, visitor interaction, scratching and self-grooming decreased. This suggests that outdoor-only access and feeding enrichment improve the behaviour of the drills and would be a valid option during summer season for the drills at Parken Zoo.

This study analyses certain controversial issues commonly arising when a claim for restitution is brought against a bank. Chapter 1 considers the equitable claim traditionally labelled ‘knowing receipt’. Three issues are discussed: (i) the basis in principle of the claim for ‘knowing receipt’; (ii) whether the claim requires proof of fault on the part of the recipient; and (iii) whether the claim can be brought in relation to the receipt by a bank of a mortgage or guarantee offered to the bank in breach of trust or fiduciary duty. The conclusions are (i) that ‘knowing receipt’ is often a claim in unjust enrichment, though the dishonest recipient will also be liable for an equitable wrong; (ii) that when the unjust enrichment version of ‘knowing receipt’ is in issue, the claim should be one of strict liability; and (iii) a claim in unjust enrichment can be brought against a bank to defeat its interest in a mortgage or guarantee offered in breach of trust. Chapters 2 to 4 concern a concept within the law of unjust enrichment that has come to be called ministerial receipt. A ministerial receipt is a receipt of money or property by an agent on behalf of his or her principal. Banks often receive money as agents on behalf of account holders. Chapters 2 and 3 analyse that concept as it is dealt with at common law and in equity respectively. At common law, ministerial receipt is a defence which exists only if the agent pays over the money in question before receiving notive of the right of the plaintiff to restitution. By contrast, ministerial receipt in equity operates to restrict a right to restitution which would otherwise arise. A claim for 'knowing receipt' cannot be brought against an agent in equity. Chapter 4 argues that the equitable tratement of agents is correct as a matter of principle, and that no common law claim in unjust enrichment should be maintainable against a person who receives as agent. Special attention is given to banks. Chapter 5 analyses three other defences which a bank can plead in answer to restitutionary claims: 'good consideration', bona fide purchase and set off. It is concluded that there is no general defence of 'good consideration'; that the bank can plead bona fide purchase in relation to money deposited into an account in credit; and that in the context of combining two or more bank accounts set off is merely a species of bona fide purchase.

A method for the selective concentrating of DNA targets using capillary affinity gel electrophoresis is presented. Complementary ssDNA targets are retained through hybridization with oligonucleotide probes immobilized within polyacrylamide gels while non-complementary targets are removed. The captured DNA targets were concentrated by step elution, where a localized thermal zone was applied in small steps along the capillary. Evaluation of the selective capture of a 150 nt DNA target in a complicated mixture was carried out by factorial analysis. Gels with a smaller average pore size were found to retain a higher amount of complementary targets. This was thought to be due to the ssDNA target migrating through the gel by reptation, eliminating hairpin structures, making the complementary region of the target available for hybridization. This method was applied to a series of DNA targets of different lengths, 19 nt, 150 nt, 250 nt and 400 nt. The recovery of the method ranged from 0.5 to 4% for the PCR targets, and 13 to 18% for the 19 nt oligonucleotide target. The purity was calculated to be up to 44% for the PCR targets and up to 86% for the 19 nt target. This was an improvement in purity of up to 15 times and 1100 times in comparison to the original samples for the PCR targets and 19 nt oligonucleotide, respectively. The 19 nt targets were selective concentrated and delivered into a microfluidic based DNA biosensing platform. The purity of the sample improved from 0.01% to 50% while recovery decreased from 100% to 20% for a sample with 0.5 nM complementary and 1 μM non-complementary targets. An improvement in the response of the sensing platform was demonstrated on 19 nt oligonucleotide targets delivered by selective concentration versus concentration alone into the microfluidic biosensing system.