Mass, solute (chloride), isotope (deuterium) and thermal balances were completed at Perry Lakes, two semi-permanent 'water table' lakes near Perth, Western Australia. All balance components except groundwater discharge/recharge were measured independently. These difficult to measure groundwater components of lake-aquifer interaction were estimated by integrating mass, solute and chloride data in sequential 4 day balances spanning two years. Before urbanisation, such wetlands functioned predominantly as flow-through lakes. Now, large winter storm water inputs (and summer artificial level maintenance pumped locally from groundwater) dominate. In East Lake these inputs together comprise 42% of the annual water budget; groundwater discharge is reduced to just 2%. Even under flow-through conditions, these 'non natural' inputs are so large East Lake always tends towards a recharge state and commonly becomes a local groundwater mound. Flow-through is established in both lakes over winter. Initially each lake functions separately however as winter progresses shared capture and release zones are established. Maintenance of lake levels in early summer forces East Lake back to recharge status. Sediment heat flux (Qse) is significant in these very shallow lakes. Over summer Qse was negative, with a net movement of heat from the water into the sediments which act as a seasonal heat sink. In winter Qse was positive and stored summer heat was returned to the water column. This flux at times exceeded 40 W m-2. Evaporation was determined independently by floating pan, leaving Qse as the thermal balance residual. Ignoring Qse, annual evaporation determined by thermal balance was over estimated by 7%. Over and under estimates of individual 12 day balance period evaporation exceeded 50%. Monthly Class A (Perth airport) pan coefficients varied from 0.54 (January) to 0.86 (September). Ten empirical equations for evaporation were calibrated and compared with the East Lake floating pan. Best performer was the Makkink which tracked the floating pan closely throughout all seasons. Poorest were the Penman, DeBruin-Keijman, Priestly-Taylor and Brutsaert-Stricker which grossly over estimated late winter evaporation. Transpiration from Typha orientalis, estimated using hydrograph techniques was 43% of open water evaporation in summer and 28% annually. Temperature controlled evaporation pans (tracking lake temperature) experimentally determined the local deuterium content of lake evaporate ƒÔE, required for isotopic balances. Techniques employing pans evaporated to dryness and pans evaporated at constant volume were run in tandem continuously for two years. This study singularly integrates mass, solute and isotope balances thereby allowing groundwater components to be accurately quantified. The isotope balances are unique, being the only such balances incorporating experimentally derived local deuterium values of lake evaporate. This study represents the only thermal balance, the only accurate determination of pan-lake coefficients and the first calibration of commonly used empirical evaporation equations for Swan Coastal Plain wetlands. Groundwater levels in the western suburbs of Perth have declined over 40 years and a disproportionate larger decline now seriously threatens Perry Lakes. Modelling suggests regional groundwater extraction exceeds recharge. Wetland managers can no longer maintain East Lake via local groundwater extraction. Artificial recharge using imported surface and waste water are possible future management options.

Background: Concussion assessments rely on a multifaceted approach where evaluation of balance and postural control plays an important role. Following a concussion, 67% of individuals report dizziness as a persistent symptom and 30% experience balance impairments. Studies incorporating the common Balance Error Scoring System (BESS) tool suggest that these impairments return to pre-injury baselines within ten days of incident. In contrast, however, studies incorporating more advanced posturography methods observe significant differences in balance up to one year following injury. While the BESS is consistently associated with low sensitivity and poor reliability scores, advanced posturography systems using force plates are not practical or accessible in most recreational sports environments. Recently, the Wii Balance Board (WBB) has been identified as a potential force plate proxy. Research confirms that the WBB is both valid and reliable in collecting center of pressure data. Thus, the WBB may be useful for investigating post-concussion balance deficits. Objective: The purpose of this study was to investigate the potential utility of a customized WBB program to assess postural balance in an athletic population. The study aimed to assess change in postural balance using the clinical BESS and WBB assessment tools to evaluate balance at fixed intervals during a regular athletic season and following concussion. Design: Prospective partial cohort. Methods: Balance was assessed at baseline, mid-, and post-season. Individuals who sustained a concussion during the study period were further assessed weekly for four weeks post-injury. Results: No significant differences were observed in raw BESS scores across regular season or post-concussion time points. In contrast, significant differences in several WBB outcome measures were observed. In the single stance condition, COPML worsened by 24% and COPT worsened by 9% between baseline and post-season time points (p=.002 and p=.007). In contrast, participants improved by 14% on a timed dynamic task (p=.003) between baseline and post-season time points. Following concussion, only the WBB dynamic outcome measures were found to be statistically significant. A positive trend was observed post-concussion, suggesting that a learning effect exists with the dynamic WBB program. Conclusion: Study results emphasize the importance of considering the progression of athletic season when interpreting baseline and post-concussion balance measurements. Study results support the use of a quantitative balance assessment, such as with a WBB, to improve measurement of static and dynamic postural balance. / Graduate / 0566 / hilarymcullen@gmail.com

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Balance dysfunction and the resultant falls and injuries, loss of confidence, alternations lifestyle and the overall costs are a major problem to older people in Australia. The studies in this thesis investigate discrete but inter-linked aspects of the problems of falls among community dwelling older people, including measurement issues, prediction of fallers, types of dysfunction related to clinical diagnoses, and the effect of multidisciplinary intervention. Preliminary studies of older people from both healthy and clinical samples identified high retest reliability for the dynamic balance tests on the Chattecx Balance System, high retest reliability and concurrent validity for a new clinical test of dynamic standing balance, and high retest reliability and predictive validity for an expanded scale to measure fear of falling. (For complete abstract open document)

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

M.Comm. (Economic Development and Policy Issues) / The response of the trade balance to changes in currency movements has gained increasing interest among researchers, especially since the fall of the Bretton Woods system. Previous empirical studies that examined the response of the trade balance to exchange rate changes in South Africa employed aggregate trade data and provided mixed results. This dissertation uses disaggregated data with specific focus on the manufacturing sector. The purpose is to investigate the short and long run effects of the real exchange rate of the rand on the South African manufacturing trade balance by adopting the elasticity approach of balance of payments adjustment. Using quarterly data from 1995 to 2010, the study seeks to test the existence of the J-curve effect and to show whether the Marshal–Lerner condition holds in the manufacturing sector. Johansen cointegration and vector error correction modelling techniques are employed in attaining the objectives of this study. In addition, impulse response functions are used to determine how the manufacturing trade balance responds following shocks in its main determinants. The results show that real effective exchange rate (REER), real domestic and foreign income levels are important long run determinants of the manufacturing trade balance, and that a long run equilibrium relationship exists among these variables. A long run negative relationship was found between the trade balance and the REER and between the trade balance and real domestic income. In contrast, real foreign income was found to be positively related to the domestic manufacturing trade balance in the long run. The short run model reveals that a depreciation in the domestic currency results in a deterioration in the manufacturing trade balance. This, together with the long run findings, suggests evidence of the existence of the J-curve in the South African manufacturing trade balance. The long run dynamics suggest that the Marshal–Lerner condition holds. This dissertation found evidence that a depreciation of the rand is necessary to improve the manufacturing trade balance.

The boreal forest forms a band that stretches across the continents of the northern hemisphere. Wildfire disturbances have helped transform this forest into stands of varying ages with varying soil drainage. It is well known that the boreal forest contributes greatly to the global water cycle, but less is known as to how variable these water fluxes are throughout the forest mosaic. Throughout the growing seasons of 2006 and 2007, meteorological measurements were taken during the growing season from three different aged black spruce stands near Thompson, MB. The stands that were burned in 1930 and 1964 each included upland and lowland sites with independent measurements. The stand burned in 1850 had measurements taken only from an upland site. Evapotranspiration (ET) was calculated from the residual energy after net radiation (Rn), sensible heat flux (H) and ground heat flux were measured. We sought to investigate whether ET varied with stand age and topographic location. Results indicate that there is a significant increase in Rn, H, and ET as forests age. ET levels range from being 4% to 19% lower for younger stands. It is assumed that the depth of the organic layer at older sites allows for mosses to more effectively wick up available moisture through capillary rise, and have higher transpiration levels. The larger tree density at the 1964 sites compared to the 1930 sites may account for a portion of the observed increase in ET for these ages. Differences in drainage between the 1930 and 1850 sites may also account for a portion of the increase in ET observed between these two ages. Wetland sites had H and ET that were significantly less than for the upland sites. ET rates were 11 to 20% higher at the upland sites than the wetland sites; part of this difference is thought to be due to the presence of larger trees, with an increased capacity to transpire water at upland sites. As the number of forest fires has been predicted to increase substantially in the future, the prospect of the boreal forest average stand age being younger would affect the boreal’s water and energy budgets. Our data helps to describe water and energy budgets for forest stands with different drainage capabilities, for stands between the ages of 45 and 160 years. This knowledge will be used to help predict the degree and speed of climate change that will be experienced in the boreal forest. / October 2008

published_or_final_version / Statistics / Master / Master of Social Sciences

Recent research indicates the need for a functional balance assessment in cardiac rehabilitation (CR) programs. One assessment technique that may be appropriate is the Community Balance and Mobility Scale (CBMS). The purpose of this study was to investigate psychometric properties of the CBMS when testing patients with cardiovascular disease (CVD). Thirty-one participants from community CR programs were recruited to perform the CBMS and measures of computerized dynamic posturography. Convergent validities between the measures were investigated using correlation coefficients, and floor and ceiling effects of the CBMS were analysed. The results indicated that the CBMS was moderately correlated with all computerized posturography variables, with no floor or ceiling effects present. Analysis of posturography results indicated that CR patients have decreased movement characteristics in the anterior and posterior directions. These findings indicate that the CBMS is a suitable tool to assess and monitor balance in a CR population.

The boreal forest forms a band that stretches across the continents of the northern hemisphere. Wildfire disturbances have helped transform this forest into stands of varying ages with varying soil drainage. It is well known that the boreal forest contributes greatly to the global water cycle, but less is known as to how variable these water fluxes are throughout the forest mosaic. Throughout the growing seasons of 2006 and 2007, meteorological measurements were taken during the growing season from three different aged black spruce stands near Thompson, MB. The stands that were burned in 1930 and 1964 each included upland and lowland sites with independent measurements. The stand burned in 1850 had measurements taken only from an upland site. Evapotranspiration (ET) was calculated from the residual energy after net radiation (Rn), sensible heat flux (H) and ground heat flux were measured. We sought to investigate whether ET varied with stand age and topographic location. Results indicate that there is a significant increase in Rn, H, and ET as forests age. ET levels range from being 4% to 19% lower for younger stands. It is assumed that the depth of the organic layer at older sites allows for mosses to more effectively wick up available moisture through capillary rise, and have higher transpiration levels. The larger tree density at the 1964 sites compared to the 1930 sites may account for a portion of the observed increase in ET for these ages. Differences in drainage between the 1930 and 1850 sites may also account for a portion of the increase in ET observed between these two ages. Wetland sites had H and ET that were significantly less than for the upland sites. ET rates were 11 to 20% higher at the upland sites than the wetland sites; part of this difference is thought to be due to the presence of larger trees, with an increased capacity to transpire water at upland sites. As the number of forest fires has been predicted to increase substantially in the future, the prospect of the boreal forest average stand age being younger would affect the boreal’s water and energy budgets. Our data helps to describe water and energy budgets for forest stands with different drainage capabilities, for stands between the ages of 45 and 160 years. This knowledge will be used to help predict the degree and speed of climate change that will be experienced in the boreal forest.