Background: People with COPD have significant balance impairments and an increased risk of falls. The psychometric properties of short balance screening tests to inform fall risk assessment in COPD have not been studied. The objective of this study was to compare the validity of four short balance tests suitable for fall risk screening to identify the most optimal screening tool(s). Methods: Participants at least 60 years old with COPD attended a single physical assessment with completion of questionnaires. Correlation coefficients were used to describe relationships between the Brief Balance Evaluation Systems Test (Brief BESTest), Single-Leg Stance (SLS), Timed Up and Go (TUG) and Timed Up and Go Dual-Task (TUG-DT) tests, and other measures of balance, measures of muscle strength, exercise tolerance, functional limitation, disability and prognosis. Independent t-tests or Mann-Whitney U tests were used to examine differences between groups with respect to fall risk. Receiver operating characteristic curves were plotted to examine the ability to of the screening tests to identify individuals with previous falls. Results: Seventy-three participants with COPD completed the study (age 73.0 ± 6.9 years; FEV1 47.0 ± 19.8% predicted). All balance screening tests demonstrated moderate to strong correlations with the Berg Balance Scale (r= 0.47 to 0.80, p<0.05) and Activities-specific Balance Confidence scale (r= 0.44 to 0.61, p<0.05). The Brief BESTest and SLS showed the strongest correlations with other balance measures and demonstrated the most consistent ability to discriminate between fall risk groups. The Brief BESTest was the only screening test that identified individuals who reported a previous fall with acceptable accuracy (AUC= 0.7). Conclusions: The Brief BESTest and SLS show the most promise as balance screening tools for fall risk assessment in older adults with COPD. These results will need to be prospectively confirmed with a larger sample size. / Thesis / Master of Science Rehabilitation Science (MSc)

Obesity is associated with an increased risk of falls and subsequent injury. Previous studies have shown weight loss and strength training to be beneficial to balance, but knowing which is more beneficial will allow researchers to design interventions to maximize the benefits in terms of balance and reducing risk of falls. Therefore, the purpose of the first study was to evaluate the effects of weight loss and strength training on balance recovery using a combination of laboratory experiments and mathematical modeling. Nine male subjects with BMI 30.1 to 36.9 kg/m² were released from a forward lean and attempted to recover balance using an ankle strategy. Lean angle was increased until subjects required a step or hip flexion to recover balance. The maximum lean angle, θ_max, was used as the measure of balance recovery capability. Experimental data were used as inputs to an inverted pendulum model of balance recovery. Multiple simulations were used to determine the effects of strength (maximum ankle torque and ankle torque generation rate) and weight loss on θ_max. Changes in weight and strength were linearly related to changes in θ_max. A 6.6 ± 0.4% decrease in weight or 6.9 ± 0.9% increase in strength were estimated as required to improve (increase) θ_max by 1 degree. Based on these results, balance recovery using an ankle strategy can improve with either reductions in weight or increases in strength. In addition, weight loss may be a more effective intervention than strength gain at improving balance recovery capability. The purpose of the second study was to quantify changes in body segment inertial parameters (BSIPs) with weight loss. These data were needed to alter BSIPs in the first study to mimic changes with weight loss. Both before and after weight loss, magnetic resonance imaging scans were acquired along the length of the body and were used to calculate segment masses, COM positions, and radii of gyration. A number of significant changes in BSIPs occurred with weight loss. / Master of Science

During exercise water and electrolytes are lost in sweat. There is a large variation in both sweat rate and sweat composition and as a consequence sweat electrolyte loss can be large, especially for sodium, the primary cation in sweat. The loss of large amounts of sodium in sweat has been linked with hyponatraemia and muscle cramps. Sodium intake is encouraged in some athletes and in some exercise situations, which is in direct contrast to guidelines aimed at the general population aimed at reducing average sodium intakes to 2.4g of sodium per day (6g salt/day). Dietary sodium intakes have been determined by numerous methods, including weighed dietary records and 24h urine collections. As dietary sodium intake in excess of basal requirement is primarily excreted in the urine in non-sweating individuals, and the basal requirement for sodium is small, 24h urine collections can provide an accurate estimate of dietary sodium intake. In Chapter 3, 24h urinary sodium excretion was measured in eighteen subjects on 4 separate occasions. Subjects consumed their normal diet with the exception of a 5g creatine supplement and 500ml of water, which was part of a separate investigation. The relationship between urine sodium excretion in each 24h collection period was weak, but on average males excreted 200 ± 48mmol of sodium per day and females excreted 157 ± 33mmol of sodium per day, which is equivalent to 4.6g and 3.6g of sodium, respectively. This is in excess of the current recommended intake. In chapter 4, the variation in sodium excretion was determined in eight subjects who consumed the same diet for 5 consecutive days. Despite the similar intake of sodium each day, a day to day variation in sodium excretion of 13% was still observed. This was not related to either sodium intake or potassium intake. In chapter 5, nine subjects consumed their normal diet for 5 consecutive days but weighed and recorded all food and drink consumed. During this period, 24h urine samples were also collected. No strenuous exercise was permitted apart from an exercise task on day 4. This involved intermittent cycling in the heat until 2% body mass (BM) was lost. Sweat was collected from four absorbent patches placed on the back, chest, forearm and thigh. Sweat sodium concentration was adjusted to account for the 35% over-estimation using this regional collection method. Subjects lost 1.51 ± 0.19L of sweat and 66 ± 16mmol (range 32 86mmol) of sodium. There was no difference in sodium balance between each 24h period due to a significant decrease in urine sodium excretion on the day of exercise (day 4). In chapter 6, the effect of prior exercise on sweat composition during a second exercise bout completed later that same day was determined. Eight healthy males cycled for 40 minutes in the heat on one or two occasions. A period of 5h elapsed between exercise bouts when two exercise sessions were performed. Sweat was collected using a whole body washdown method and by 4 absorbent patches placed on the back, chest, forearm and thigh. The main finding was that prior exercise did not affect sweat rate or sweat sodium, potassium and chloride concentrations in the second exercise bout when using the whole body washdown method. Chapter 7 determined the effects of two exercise sessions completed on the same day on electrolyte balance. Nine subjects followed their normal dietary behaviour but weighed and recorded all food and drink consumed during 5 consecutive days. During this period 24h urine samples were also collected. No strenuous exercise was permitted during this period apart from two exercise tasks on day 4. During exercise sweat was collected using a whole body washdown technique. Sweat rate and sweat sodium, potassium and chloride concentrations during the second exercise bout were found to be similar to the first exercise bout. Subjects lost 2.64L (range 1.80 3.48L) of sweat and 138 ± 106mmol of sodium (range 32 287mmol). Sodium balance was not significantly affected on the day of exercise, but urine sodium was lower than dietary sodium intake on the day of exercise (Day 4) and the day following exercise (day 5), indicating significant sodium conservation by the kidney. In contrast, no change in sodium intake was observed. In chapter 8, the effect of skimmed milk and a sports drink in restoring fluid balance was examined following exercise-induced dehydration. Seven physically active males cycled intermittently in the heat until 2% BM was lost. During a 1h rehydration period a sports drink (23mmol Na+/L) or skimmed milk (32mmol Na+/L) was consumed in a volume equivalent to 150% of BM loss. Fluid balance at the end of the 3h recovery period tended to be more positive when milk was consumed. Despite this, no difference in exercise capacity in the heat was observed. This thesis shows that exercise did not increase sodium intake, but this may be due to the already high dietary sodium intake of individuals. Sodium balance was maintained in the majority of individuals due to a significant conservation of sodium by the kidneys. When sweat sodium losses are large, urine sodium conservation may not be sufficient to prevent a negative sodium balance. When no food is consumed in the acute period post-exercise, the higher sodium content of skimmed milk than a sports drink may be partly responsible for the increased retention of the ingested fluid. But this did not enhance subsequent performance in the heat.

Postural instability is one of the hallmarks of Parkinson's disease (PD), currently evaluated using several subjective tools. However, the nature and degree of the resulting balance deficit is not well specified by these tools. Computerized dynamic posturography (CDP) provides an objective assessment by isolating and quantifying sensory and motor contributions to balance control. The purpose of this study was to compare balance in individuals with PD to a control group using CDP (NeuroCom Smart Balance Master® system). Testing took place at the Southeast Parkinson's disease Research Education and Clinical Center (PADRECC), an interdisciplinary center of excellence for people with PD within a Veterans Affairs Medical Center. The 51 PD patients (mean age = 72.18 ± 6.98 years;) were compared to 55 age-matched controls supplied by the CDP manufacturer. Subjects were assessed with three test scales defined by the Smart Balance Master® system: Sensory Organization Test (SOT), Adaptation Test (ADT), and Limits of Stability Test (LOS). All PD population CDP scores were significantly different (a=0.05) than those of a healthy population, except for the SOT Somatosensory subscale (p=0.28), LOS Directional Control subscale (p=0.08), ADT Toes Up subscale (p=0.16) and ADT Toes Down subscale (p=0.23). The Smart Balance Master® system's LOS Movement Velocity, Endpoint Excursion, Maximum Excursion, and Reaction Time subscores and the SOT Composite, Visual, and Vestibular subscores uniquely describe the varying symptoms of the disease. These disease specific abnormalities may provide insight into focused treatment intervention strategies.

The aim of this thesis is to evaluate the ERM II mechanism and to explain it's positives and negatives for the internal and external economic balance. In the first part of this thesis the author engages in the ERM II system and other applied exchange mechanisms. Further he focuses in detail on the theory of internal and external economic balance. In the analytic part of the work the author uses chosen indicators to monitor the influence of ERM II mechanism on the internal and external balance of three selected countries - Malta, Cyprus and Latvia. In the closing part the author summarizes the outcome of the analysis.

本文扩展了由Chari, Kehoe和McGrattan最初开创的Business Cycle Accounting 方法，利用两国开放经济模型研究中国经常账波动的根源。本文从模型得出的五个一阶条件方程和两个产出方程中，量化衡量了代表不同市场扭曲程度的7个变量。其中包括两国分别的生产力扭曲程度、劳动市场扭曲程度、资本市场扭曲程度，以及两国风险共担的程度。本文通过将得出的代表市场扭曲程度的变量逐一逆向回代入模型中，进一步分解了各个变量对中国经常账波动的贡献度。利用1978年至2010年中国和美国的数据，本文得出结论认为中国的经常账波动与劳动力市场扭曲具有最密切的关系，其次是资本市场扭曲。生产力的提高和中美两国的风险共担程度对中国经常账的影响甚微。同时结果表明，中美两国的真实利率差距也对中国经常账有显著影响，中国的真实利率相对美国而言较高。 / This paper extends the original Business Cycle Accounting exercise developed by Chari, Kehoe, and McGrattan to a two-country open economy model. To identify the sources of China’s current account fluctuations, I measure seven wedges from five first-order conditions and two productivity functions, including the productivity wedges, labor wedges, and investment wedges in both China and the US, as well as the risk sharing wedge between the two countries. Then I incorporate the measured wedges back into the model to decompose their contributions to the behavior of real current account. With the use of real data (beginning 1978) on China and the US, the accounting procedures suggest that the behavior of China’s current account is best explained by labor wedges, followed by investment wedges. The productivity wedges and risk sharing wedge between the two countries impose minor effects. Results also indicate that the spread of real interest rates in China and the US significantly influences China’s current account surplus, and that the real interest rates in China is relatively higher than those of the United States. / Detailed summary in vernacular field only. / Yuan, Xiaochuan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 71-76). / Abstracts also in Chinese. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgements --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Literature on the Current Account of China --- p.3 / Chapter 2.1 --- Saving and investment --- p.4 / Chapter 2.2 --- Financial imperfections --- p.5 / Chapter 2.3 --- Exchange rate --- p.7 / Chapter 2.4 --- Income and growth --- p.9 / Chapter 2.5 --- Multiple reasons --- p.10 / Chapter 2.6 --- Improvement policies --- p.11 / Chapter 3 --- Facts on China’s Current Account --- p.13 / Chapter 4 --- Two-Country Open Economy Model --- p.19 / Chapter 4.1 --- Household --- p.19 / Chapter 4.2 --- Firm --- p.20 / Chapter 4.3 --- Government --- p.21 / Chapter 4.4 --- Two-country problem --- p.21 / Chapter 4.5 --- Definitions of the wedges --- p.23 / Chapter 5 --- Measuring the Wedges --- p.25 / Chapter 6 --- Accounting Procedure --- p.32 / Chapter 7 --- Further Implications --- p.38 / Chapter 8 --- Conclusions --- p.41 / Chapter 9 --- Data Appendix --- p.46 / Chapter 9.1 --- Data source --- p.46 / Chapter 9.2 --- Variables --- p.46 / Chapter 9.3 --- Parameters --- p.49 / Chapter 9.4 --- Robust check --- p.50 / Chapter 10 --- References --- p.71

El Balance Scorecard es una herramienta de gestión propuesta en la década de los noventa por Kaplan Y Norton, quienes al verificar que los indicadores financieros no eran confiables para una organización en un medio altamente competitivo, ampliaron el manejo y visión de la gerencia, considerando perspectivas de igual importancia para la organización. Es decir, mediante este enfoque teórico, los autores señalaban que el gerente o gerencia no pueden guiarse solo por los resultados económicos, porque podrían ser engañosos para la organización, principalmente porque no se podía medir las acciones que la organización realizaba por ejemplo en desarrollo y tecnología dentro de los procesos internos. La herramienta de gestión Balance Scorecard, proporciona beneficios en toda organización, pero estos pueden ser variables, por lo que su implementación no tiene los mismos resultados en todas las organizaciones. Motivo por el cual es necesario seguir investigando sobre la implementación de esta herramienta de gestión, aun mas cuando las estrategias propuestas para las organizaciones no siempre tienen resultados satisfactorios o esperados.

Background: Over the past decade obesity has doubled in children aged 6-11 and tripled among adolescents aged 12-19. One trend that has coincided with this increased obesity prevalence is decreased meal frequency, which may impact blood sugar, meal size, cortisol release, insulin release, and appetite controls that include the release of leptin and ghrelin. Ultimately, these changes may result in a simultaneous lowering of the metabolic (i.e., fat-free) mass and a rising of the fat mass. Purpose: To assess food/beverage intake in a way that would determine if large deviations in energy balance (EB) during the day were related to body fat percent (BF%). Methods: Using an IRB-approved protocol, male and female children were assessed using NutriTiming® (NutriTiming LLC, 2011) software, which simultaneously assesses energy intake from consumed foods and beverages and energy expenditure from activities with different intensities. A 24-hour recall questionnaire and interview, with at least one parent present, was used to obtain data, which represented a typical school day. BF% was assessed using an 8-mode bioelectrical impedance segmental body composition analyzer (Tanita, Model BC-418). Statistical analysis was performed with SPSS (ver. 18). Results: A total of 16 children ranging in age from 8-14 years were interviewed. Due to incomplete data on 4 subjects, 12 subjects (6 boys; 6 girls ranging in age from 9-14 years; mean=11.41 ± 1.5) were included in the data analysis. Energy intakes averaged 1,984 ± 510 kcal; and energy expenditure averaged 1,689 ± 351 kcal. Average BF% was 24.3 ± 4.9. Using Spearman correlation and independent group t-test (with the mean energy balance as the cut-point) traditional end-of-day energy balance (24-hr energy in vs. 24-hr energy out) was not statistically associated with body fat %, and there was no difference in BF% between those above and below the end-of-day EB mean. However, more hours spent in an energy surplus (EB > 0) was significantly associated with lower body fat % (r=-0.914; PP

In the Kebnekaise Massif, Northern Sweden, the west facing glacier, Rabots glaciär, is loosing volume at a significantly higher rate than east facing, Storglaciären. By analyzing data from automatic weather stations situated on the ablation area on the glaciers we investigated the effect of meteorological differences on ablation. There was a difference in micro-climate between Rabots glaciär and Storglaciären. Generally Storglaciären had slightly warmer and drier air, had less or a thinner cloud layer but more precipitation. On both glaciers a glacier wind is dominant but high wind velocities were common especially on Storglaciären indicating a larger influence from the synoptic system. There was a good correlation for temperature and vapor pressure between the glaciers that indicate that both glaciers are strongly affected by the synoptic system. The meteorological parameters have similar effect on the ablation on the glaciers. Temperature, vapor pressure and the turbulent heat fluxes are the only meteorological parameters that suggest a linear affect on ablation. Net shortwave radiation contribute with the greatest amount of energy for ablation but decreased in relative importance as the temperature increased. Shortwave radiation, sensible and latent heat contributed with a total 184Wm-2 on Rabots glaciär and 222Wm-2 on Storglaciären. Rabots glaciär seem to have a significantly greater relative importance of the turbulent heat fluxes than Storglaciären. Although the differences in micro-climate were not great, using the ablation for Storglaciären to estimate ablation on Rabots glaciär would over estimate the ablation with 0.5m w.e..

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