The UC Research Repository digital repository system captures, stores, indexes, preserves, and distributes digital research material. http://ir.canterbury.ac.nz:80 2012-02-23T00:51:25Z 2012-02-23T00:51:25Z Armstrong, Mark James http://hdl.handle.net/10092/4509 2011-12-07T11:46:10Z 2000-01-01T00:00:00Z

Title: Geomorphological and geophysical investigation of the effects of active tectonic deformation on the hydrogeology of North Culverden Basin, North Canterbury Authors: Armstrong, Mark James Abstract: This thesis examines the complex interaction between the tectonic evolution of Culverden Basin and the Late Quaternary sediments, which form the aquifer-bearing deposits, using geological and geomorphological mapping as well as near-surface geophysical investigations. Along the eastern margin of Culverden Basin, the deformation associated with the actively widening Australian-Pacific plate boundary zone, has resulted in the evolution of Culverden Basin and the progressive inversion of the basin floor. The eastern margin of the basin is structurally controlled by a NE trending, complexly segmented range-front fault system and associated thrust-propagated anticlines forming the basin boundary. Basin inversion is driven by the westward propagation of footwall imbricate thrusts and associated folds. The inversion of the basin floor lead to the creation of sub-basins within the larger basin, which have controlled the distribution and architecture of the Late Quaternary stratigraphy. The Late Quaternary sedimentary record documents periods of climatically induced aggradation during cold conditions and degradation in the intervening warmer times. The interaction between the sedimentation and ongoing tectonic deformation has resulted in complex lithological relationships between the locally sourced alluvial fans and the glacial outwash deposits of the major rivers entering the basin. The architecture of the aquifers is therefore controlled by the changing fluvial regime and its interaction with the evolving sub-basins. The progressive evolution of the sub-basins leads to increasing complexities in the facies relationships and to the confinement of the deposits into progressively smaller portions of the sub-basins. Once the basin boundaries become emergent, the basin becomes isolated, and potentially cut-off from its groundwater recharge source. Leonard Mound is an actively evolving imbricate thrust system along the eastern margin of Culverden Basin that has isolated the Wynyard sub-basin from the central portion of Culverden Basin, during the Late Pleistocene and present. The emergence of Leonard Mound is preventing the recharge to the Wynyard sub-basin from the high yielding aquifers of the central portion of the basin. In the central portion of Culverden Basin, high natural recharge combined with an irrigation scheme has allowed for transformation of the basin into a major dairy farming centre. In contrast, the Wynyard sub-basin is still subjected to frequent summer droughts, making it desirable to find a better source of groundwater for the eastern margin of the basin. The hydrogeological model provided by the Culverden Basin almost certainly has wider implications to the groundwater resources of other basins in similar active tectonic settings.

2000-01-01T00:00:00Z Sundaresan, A. Chase, J.G. Hann, C.E. Shaw, G.M. http://hdl.handle.net/10092/6313 2012-02-22T23:10:06Z 2011-01-01T00:00:00Z

Title: Dynamic functional residual capacity can be estimated using a stress-strain approach Authors: Sundaresan, A.; Chase, J.G.; Hann, C.E.; Shaw, G.M. Abstract: Background Acute Respiratory Distress Syndrome (ARDS) results in collapse of alveolar units and loss of lung volume at the end of expiration. Mechanical ventilation is used to treat patients with ARDS or Acute Lung Injury (ALI), with the end objective being to increase the dynamic functional residual capacity (dFRC), and thus increasing overall functional residual capacity (FRC). Simple methods to estimate dFRC at a given positive end expiratory pressure (PEEP) level in patients with ARDS/ALI currently does not exist. Current viable methods are time-consuming and relatively invasive. Methods Previous studies have found a constant linear relationship between the global stress and strain in the lung independent of lung condition. This study utilizes the constant stress–strain ratio and an individual patient's volume responsiveness to PEEP to estimate dFRC at any level of PEEP. The estimation model identifies two global parameters to estimate a patient specific dFRC, ß and mß. The parameter ß captures physiological parameters of FRC, lung and respiratory elastance and varies depending on the PEEP level used, and mß is the gradient of ß vs. PEEP. Results dFRC was estimated at different PEEP values and compared to the measured dFRC using retrospective data from 12 different patients with different levels of lung injury. The median percentage error is 18% (IQR: 6.49) for PEEP = 5 cm H2O, 10% (IQR: 9.18) for PEEP = 7 cm H2O, 28% (IQR: 12.33) for PEEP = 10 cm H2O, 3% (IQR: 2.10) for PEEP = 12 cm H2O and 10% (IQR: 9.11) for PEEP = 15 cm H2O. The results were further validated using a cross-correlation (N = 100,000). Linear regression between the estimated and measured dFRC with a median R2 of 0.948 (IQR: 0.915, 0.968; 90% CI: 0.814, 0.984) over the N = 100,000 cross-validation tests. Conclusions The results suggest that a model based approach to estimating dFRC may be viable in a clinical scenario without any interruption to ventilation and can thus provide an alternative to measuring dFRC by disconnecting the patient from the ventilator or by using advanced ventilators. The overall results provide a means of estimating dFRC at any PEEP levels. Although reasonable clinical accuracy is limited to the linear region of the static PV curve, the model can evaluate the impact of changes in PEEP or other mechanical ventilation settings. Description: Invited. Available online 9 June 2010.

2011-01-01T00:00:00Z McAuliffe, M.J. Wilding, P.J. Rickard, N.A. O'Beirne, G.A. http://hdl.handle.net/10092/6312 2012-02-22T23:04:55Z 2012-01-01T00:00:00Z

Title: Effect of speaker age on speech recognition and perceived listening effort in older adults with hearing loss Authors: McAuliffe, M.J.; Wilding, P.J.; Rickard, N.A.; O'Beirne, G.A. Abstract: Purpose: Older adults exhibit difficulty understanding speech that has been experimentally degraded. Age-related changes to the speech mechanism lead to natural degradations in signal quality. We tested the hypothesis that older adults with hearing loss would exhibit declines in speech recognition when listening to the speech of older adults, compared with the speech of younger adults, and would report greater amounts of listening effort in this task. Methods: Nineteen individuals with age-related hearing loss completed speech recognition and listening effort scaling tasks. Both were conducted in quiet, when listening to high and low predictability phrases produced by younger and older speakers respectively. Results: No significant difference in speech recognition existed when stimuli were derived from younger or older speakers. However, perceived effort was significantly higher when listening to speech from older adults, as compared to younger adults. Conclusions: For older individuals with hearing loss, natural degradations in signal quality may require greater listening effort. However, they do not interfere with speech recognition – at least in quiet. Follow-up investigation of the effect of speaker age on speech recognition and listening effort under more challenging noise conditions appears warranted. Description: Published online January 2012

2012-01-01T00:00:00Z Collins, Andrew Elliott Egerton http://hdl.handle.net/10092/6311 2012-02-22T22:36:46Z 2011-01-01T00:00:00Z

Title: Saving State-Building: EU Contributions to Security Sector Reform in Afghanistan Authors: Collins, Andrew Elliott Egerton Abstract: State failure represents one of the most pressing concerns for international security in the 21st century, and Afghanistan represents one of the most concerted efforts ever witnessed to address this phenomenon in a lasting and sustainable way. This thesis takes the position that part of the difficulty in finding a remedy for state failure relates to the contradictions and dilemmas inherent within the state-building enterprise itself. The trade-offs required by certain fundamental aspects of state-building must be better understood if they are to be effectively managed, and these trade-offs cannot be understood without critically analysing the basic assumptions of state-building. To come to grips with these assumptions in concrete terms, this paper examines the European Union’s involvement in Afghanistan as a case study to apply and develop the analytical framework of “dilemma analysis.” The first major goal of this research will be to outline the tensions within state-building, and to assess their usefulness for explaining some of the difficulties facing state-builders in general terms. The second goal will be to analyse the significance of the specific combination of dilemmas relevant to the case of Afghanistan, in order to show how those dilemmas interact with each other to constrain the EU’s options for effective state-building. The third goal is to identify ways in which the EU and the international community in general can benefit from dilemma analysis when conducting state-building interventions in the future.

2011-01-01T00:00:00Z