Listening under pressure : the downside of motivation

The desire for self-improvement is critical to human performance and learning outcomes. Paradoxically, however, being subjected to increased performance pressure can also result in “choking under pressure”. No studies have experimentally examined the extent to which motivation impacts native speech processing. This dissertation manipulated performance pressure in listeners, and systematically examined its impact on three speech-processing experiments. Sixty adult native English listeners and 45 non-native listeners with poorer English proficiency completed three speech processing experiments, twice – once to establish a baseline, and again to measure changes in performance. In these experiments using native English speech, listeners detected (illusionary) sound changes, categorized phonemes under lexical interference, and recognized words in noises. After baseline testing, half of the participants in each language group were instructed to work, with a fictitious partner, towards a performance-contingent monetary reward; the other half, as controls, simply performed the tasks a second time. This study demonstrated a negative impact of performance pressure on native listeners in all experiments. Relative to the controls, the motivation group were more susceptible to illusions, failed to ignore lexical interference despite prior exposure, and recognized fewer words in cognitively-demanding listening situations. Unexpectedly, relative to native listeners, non-native listeners perceived it as less important to perform well, and those who were in the high performance-pressure group requested significantly greater amount of money for improvement. These language-group differences in task-related attitudes might be a confounding factor that moderate the effect of motivation. By illustrating a complex interaction among motivation, listener status, and performance-induced demands, this dissertation highlights the importance of motivation in speech science.Communication Sciences and Disorder

Sustainability and Economics of Aviation Industry

Aviation draws people attention, not only because it is a dream of human race to fly or the association to vacations, but its role in our modern economies. It is, first of all, an incredible investment, such as building airports, buying aircrafts, lands, control systems…etc. There are great business opportunities as well as risks. Moreover, the operation of airports, airlines or aircraft manufacturing generate tremendous incomes and jobs, often vital to cities heavily relay on these business. Furthermore, politic issues, such as regulations, agreements, ownerships and business decisions in company level, are shaping the market. Last but not least, enhanced by aviation, the connectivity and attractiveness of city induce economic benefit in tourism, business and so on, are very seductive to governors hoping to exploit its economic potential. However, just like any aspect of economics, there are externalities, which is not always captured nor considered by decision makers. Externality is always the first question I ask. To quantify and internalize them will enhance market efficiency and the fairness of society. Furthermore, the trend and abnormality are crucial in this uncertain world if we want to predict the future. Focusing on econometrics, i.e. applying statistical tools on economic data to spot estimators and to set models, reference points for discussion or decision could be provided while arousing the awareness of less-acknowledged matters by including them in the models. Three papers are presented in this report. First of all, as the fastest growing transport mode, aviation sustainability and environmental costs are generally concerned. We tried to address the noise and emission of the global aircraft fleet and to argue the current technology progress is not vigorous enough, while examining the trade off of these externalities. We find a statistically significant impact of incremental technical progress on all environmental externalities. Substantial innovation is found to have positive effect on per-passenger externalities. These results point to the need for incentives in aviation technical progress. Secondly, the blooming of passenger traffic, particularly contributed by low cost airlines across Europe is shaping the air transport market, regulations and policies. By observing the carbon dioxide footprint of flights departing from Lombardy region, we find distinguished characteristics of LCC and also capture the impact of air traffic policies of government and airlines. we found that European non-environmental-oriented policies brought environmental benefits: Low cost carriers, their entrance as a consequence of liberalization, perform 18.24% to 24.50% better in terms of emission efficiency; Italian aviation policies (traffic distribution rule on Linate airport) have no significant effect while a drop of 2.61% CO2 level is observed, ceteris paribus, after the dehubbing of the national airline from Malpensa airport. We also confirm the annual improvement of aviation technology to be 1.9% while such effect is outweighed by the growth of traffic volume. Last but not least, air transport generates economic benefit to airlines, airports, local areas and countries. While the movement of people is well studied, we explore the benefit of movement of goods by air cargo, which is playing an essential role in new economies characterized by high-cost and time sensitive goods. We conclude that one percentage increase in total value export of good induces 0.47% increase in cargo volume. The marginal impact of an additional destination to cargo volume is 1.4%. We also provide evidence in the relationship of growth in air cargo volume with increasing online purchase in Europe.Aviation draws people attention, not only because it is a dream of human race to fly or the association to vacations, but its role in our modern economies. It is, first of all, an incredible investment, such as building airports, buying aircrafts, lands, control systems…etc. There are great business opportunities as well as risks. Moreover, the operation of airports, airlines or aircraft manufacturing generate tremendous incomes and jobs, often vital to cities heavily relay on these business. Furthermore, politic issues, such as regulations, agreements, ownerships and business decisions in company level, are shaping the market. Last but not least, enhanced by aviation, the connectivity and attractiveness of city induce economic benefit in tourism, business and so on, are very seductive to governors hoping to exploit its economic potential. However, just like any aspect of economics, there are externalities, which is not always captured nor considered by decision makers. Externality is always the first question I ask. To quantify and internalize them will enhance market efficiency and the fairness of society. Furthermore, the trend and abnormality are crucial in this uncertain world if we want to predict the future. Focusing on econometrics, i.e. applying statistical tools on economic data to spot estimators and to set models, reference points for discussion or decision could be provided while arousing the awareness of less-acknowledged matters by including them in the models. Three papers are presented in this report. First of all, as the fastest growing transport mode, aviation sustainability and environmental costs are generally concerned. We tried to address the noise and emission of the global aircraft fleet and to argue the current technology progress is not vigorous enough, while examining the trade off of these externalities. We find a statistically significant impact of incremental technical progress on all environmental externalities. Substantial innovation is found to have positive effect on per-passenger externalities. These results point to the need for incentives in aviation technical progress. Secondly, the blooming of passenger traffic, particularly contributed by low cost airlines across Europe is shaping the air transport market, regulations and policies. By observing the carbon dioxide footprint of flights departing from Lombardy region, we find distinguished characteristics of LCC and also capture the impact of air traffic policies of government and airlines. we found that European non-environmental-oriented policies brought environmental benefits: Low cost carriers, their entrance as a consequence of liberalization, perform 18.24% to 24.50% better in terms of emission efficiency; Italian aviation policies (traffic distribution rule on Linate airport) have no significant effect while a drop of 2.61% CO2 level is observed, ceteris paribus, after the dehubbing of the national airline from Malpensa airport. We also confirm the annual improvement of aviation technology to be 1.9% while such effect is outweighed by the growth of traffic volume. Last but not least, air transport generates economic benefit to airlines, airports, local areas and countries. While the movement of people is well studied, we explore the benefit of movement of goods by air cargo, which is playing an essential role in new economies characterized by high-cost and time sensitive goods. We conclude that one percentage increase in total value export of good induces 0.47% increase in cargo volume. The marginal impact of an additional destination to cargo volume is 1.4%. We also provide evidence in the relationship of growth in air cargo volume with increasing online purchase in Europe

Non-adaptive probabilistic group testing with noisy measurements: Near-optimal bounds with efficient algorithms

We consider the problem of detecting a small subset of defective items from a large set via non-adaptive "random pooling" group tests. We consider both the case when the measurements are noiseless, and the case when the measurements are noisy (the outcome of each group test may be independently faulty with probability q). Order-optimal results for these scenarios are known in the literature. We give information-theoretic lower bounds on the query complexity of these problems, and provide corresponding computationally efficient algorithms that match the lower bounds up to a constant factor. To the best of our knowledge this work is the first to explicitly estimate such a constant that characterizes the gap between the upper and lower bounds for these problems

Use of antibiotics by primary care doctors in Hong Kong

© 2009 Lam et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Fuzzy rule based multiwavelet ECG signal denoising

Since different multiwavelets, pre- and post-filters have different impulse responses and frequency responses, different multiwavelets, pre- and post-filters should be selected and applied at different noise levels for signal denoising if signals are corrupted by additive white Gaussian noises. In this paper, some fuzzy rules are formulated for integrating different multiwavelets, pre- and post-filters together so that expert knowledge on employing different multiwavelets, pre- and post-filters at different noise levels on denoising performances is exploited. When an ECG signal is received, the noise level is first estimated. Then, based on the estimated noise level and our proposed fuzzy rules, different multiwavelets, pre- and post-filters are integrated together. A hard thresholding is applied on the multiwavelet coefficients. According to extensive numerical computer simulations, our proposed fuzzy rule based multiwavelet denoising algorithm outperforms traditional multiwavelet denoising algorithms by 30%

Executive and Language Control in the Multilingual Brain

Neuroimaging studies suggest that the neural network involved in language control may not be specific to bi-/multilingualism but is part of a domain-general executive control system. We report a trilingual case of a Cantonese (L1), English (L2), and Mandarin (L3) speaker, Dr. T, who sustained a brain injury at the age of 77 causing lesions in the left frontal lobe and in the left temporo-parietal areas resulting in fluent aphasia. Dr. T\u27s executive functions were impaired according to a modified version of the Stroop color-word test and the Wisconsin Card Sorting Test performance was characterized by frequent perseveration errors. Dr. T demonstrated pathological language switching and mixing across her three languages. Code switching in Cantonese was more prominent in discourse production than confrontation naming. Our case suggests that voluntary control of spoken word production in trilingual speakers shares neural substrata in the frontobasal ganglia system with domain-general executive control mechanisms. One prediction is that lesions to such a system would give rise to both pathological switching and impairments of executive functions in trilingual speakers

Verifiable wage offers and recontracting: effect on wage and consumption profiles

Abstract This paper analyzes the effect of recontracting and matching verifiable wage offers on the intertemporal structure of contract wage and consumption profile for a two-period economy. A contract firm provides specific training for a worker during the first period, which increases his productivity if he stays in the second period, but the worker may quit to accept an alternative wage offer after a successful search. Wage offers are private to the worker but can be presented to the contract firm for matching. This paper shows that when capital markets are imperfect and wage offers are verifiable, the contract firm recontracts and matches any wage offers the worker receives up to the second-period productivity. The ex ante contract wage profile will be flat. Inefficient quits will be eliminated and there will be complete ex ante consumption smoothing. It is significant to note that the result of rising wage profile derived in numerous contract models is fragile with respect to assumptions on mechanism of interfirm labor mobility.

Improvement of myocardial perfusion reserve detected by cardiovascular magnetic resonance after direct endomyocardial implantation of autologous bone marrow cells in patients with severe coronary artery disease

<p>Abstract</p> <p>Background</p> <p>Recent studies suggested that bone marrow (BM) cell implantation in patients with severe chronic coronary artery disease (CAD) resulted in modest improvement in symptoms and cardiac function. This study sought to investigate the functional changes that occur within the chronic human ischaemic myocardium after direct endomyocardial BM cells implantation by cardiovascular magnetic resonance (CMR).</p> <p>Methods and Results</p> <p>We compared the interval changes of left ventricular ejection fraction (LVEF), myocardial perfusion reserve and the extent of myocardial scar by using late gadolinium enhancement CMR in 12 patients with severe CAD. CMR was performed at baseline and at 6 months after catheter-based direct endomyocardial autologous BM cell (n = 12) injection to viable ischaemic myocardium as guided by electromechanical mapping. In patients randomized to receive BM cell injection, there was significant decrease in percentage area of peri-infarct regions (-23.6%, <it>P </it>= <it>0.04</it>) and increase in global LVEF (+9.0%, <it>P </it>= <it>0.02</it>), the percentage of regional wall thickening (+13.1%, <it>P= 0.04</it>) and MPR (+0.25%, <it>P </it>= <it>0.03</it>) over the target area at 6-months compared with baseline.</p> <p>Conclusions</p> <p>Direct endomyocardial implantation of autologous BM cells significantly improved global LVEF, regional wall thickening and myocardial perfusion reserve, and reduced percentage area of peri-infarct regions in patients with severe CAD.</p