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© 2019 Informa UK Limited, trading as Taylor & Francis Group. Introduction: Various pressures exist for curricular change, including economic forces, burgeoning knowledge, broadening learning outcomes, and improving quality and outcomes of learning experiences. In an Australian 5-year undergraduate medical course, staff were asked to reduce teaching hours by 20% to alleviate perceived overcrowded preclinical curriculum, achieve operating efficiencies and liberate time for students’ self-directed learning. Methods: A case study design with mixed methods was used to evaluate outcomes. Results: Teaching hours were reduced by 198 hours (14%) overall, lectures by 153 hours (19%) and other learning activities by 45 hours (7%). Summative assessment scores did not change significantly after the reductions: 0.4% increase, 1.5% decrease and 1.7% increase in Years 1, 2 and 3, respectively. The percentage of students successfully completing their academic year did not change significantly: 94.4% before and 93.3% after the reductions. Student evaluations from eVALUate surveys changed little, except workload was perceived to be more reasonable. Conclusions: Teaching hours, particularly lectures, can be moderately reduced with little impact on student learning outcomes or satisfaction with an undergraduate medical course.

The principal aim of this thesis is to explore the relationship between trace elements in the tooth enamel of children from the Destitute Children’s Asylum (DCA), who died in the mid-to-late nineteenth century and their health, diet and environment, as determined from historical records and osteological stress markers. The secondary aim is to explore the validity of trace element analysis in archaeological populations in relation to paleodiet and health status. The major issue surrounding the use of trace element analysis in archaeological samples has been the impact of diagenesis, that is where the bone chemistry is altered post-mortem. Although it is generally considered that enamel is more stable than bone, the degree to which tooth enamel may be affected by the post-mortem environment is not clear. The possibility that the enamel of the teeth from the DCA was affected by diagenesis was examined using a number of techniques including microprobe analysis. The DCA was set up in 1852 to care for children whose parents were unable or ‘unfit’ to care for them. In 1995, the cemetery, which operated from 1863 until 1891, was excavated and 65 burials were found and it is the analysis of these remains that forms the basis of this thesis. The techniques used for trace element analysis in this thesis were Proton Induced X-ray Emission (PIXE) and Gamma-ray Emission (PIGE) analysis. PIXE/PIGE allows for multi—element analysis and can be performed without destruction of the sample, a particular advantage for archaeological samples. The examination of trace elements in different teeth allows the trace element exposure of the Asylum children to be examined over three time periods, in utero, before entry to the Asylum and after entry to the Asylum. Extensive analysis of both intra- and inter-tooth variation of trace elements was performed in order to investigate the replicability of trace element analysis using PIGE/PIXE and to determine the extent to which tooth surface selection and tooth type affected the outcome. The relationships between trace element concentrations in the Asylum teeth and osteological stress markers were examined. It is thought that osteological stress markers may occur as a result of malnutrition and/or illness, suggesting that stress indicators may be associated with lower levels of essential elements and possibly a higher toxic element load. The use of PIGE/PIXE to analyse tooth enamel was found to have a number of limitations, most importantly the possible presence of systematic error which impacted on the interpretation of the results. The selection of tooth surface was found to be important and the averaging of the results from a number of teeth of the same type gave the best view of each child’s trace element load. In terms of the children no significant relationships were found between trace elements and the diet of the children either before or after entry to the Asylum. This contradicts the historical records, which suggest the children would have come from a background of malnutrition with improved diet on entry to the Asylum. However, a major finding in this thesis was that iron and zinc, the two most commonly deficient elements in humans, had been altered in the tooth enamel by the post-mortem environment. The other major finding in this thesis was the significant relationship between the high concentration of lead in the Asylum teeth and the degree of cribra orbitalia. The relationship between lead and cribra orbitalia was strongest in the teeth representing life before entry to the Asylum. However other signs of stress such as Harris lines and enamel hypoplasias showed no relationship with lead or any other trace elements. In the future there is clearly value in using trace element analysis to examine the health of the population, particularly in relation to toxic elements. However, it must not be assumed that archaeological teeth are free from post-mortem alteration and it is recommended that future researchers select the elements for analysis with care and examine their samples for post-mortem alteration using a multitude of techniques.

The logic of theory change models the way a knowledge system would respond to various forms of new information. Alchourron, Gardenfors and Makinson have developed and investigated a set of rationality postulates and various constructive models which appear to capture much of what is required of an ideal rational system of theory change, we refer to their approach as the AGM paradigm. In this thesis we focus on the following; constructions for theory change operators, constructions for theory base change operators, and iterated theory change operators. The GMA postulates describe a class of theory change operators, however they do not provide a constructive way of defining such an operator. We provide new constructive modeling for theory change operators based on nice preorders on models, and further we give explicit conditions under which a nice preorder on models, and two well known constructions represent the same theory change operator. Recently, there has been considerable interest in change operators for theory bases, rather than entire theories. Clearly, such operators would be useful in supporting computer-based implementations of knowledge system revision. However, a perceived problem associated with known theory base change operators is their sensitivity to the syntax of the theory base used. Although it has been argued that this sensitivity should simply reflect a higher level of commitment to sentences in the theory base as opposed to sentences derivable from the theory base. We develop a logic of theory base change, using an ensconcement ordering of a theory base. We show whenever two theory bases have equivalent ensconcements, the logical closure of their theory base revisions are identical. Moreover, we give explicit relationships associating theory base revision and theory base contraction, and show explicit relationships between theory base operations and theory operations. We argue that these relationships show that our theory base revision and theory base contraction operators exhibit desirable behaviour. Finally, the principal constructions for theory change operators rely on some form of underlying preference relation. These operators require that the preference relation be predetermined or given at the outset. Although this property provides desirable theoretical freedom, it leads to difficulties in designing a computer-based knowledge revision system. In order to accommodate subsequent informational changes such a system will require guidance in revising its preference relation. We call the process of changing the underlying preference relation a transmutation, and we address the problem of iterated theory change by generalizing Spohn’s approach, in particular we formalize a transmutation to be a transformation of preference relations that preserves the behaviour of theory change operators within the AGM paradigm.