No description available.

No abstract available. / Thesis (Ph.D.)-University of Natal, Durban, 1973.

The current study aimed to determine the selective advantage of lateral amygdala (LA) neurons overexpressing the transcription factor CREB that enables their preferential incorporation into the fear memory trace. I hypothesized that overexpression of CREB drives the formation of dendritic spines, potentially providing these neurons with greater connectivity to sensory inputs at the time of learning. Using viral-mediated gene transfer, CREB tagged with GFP, or GFP as a control, was overexpressed in the LA of wild-type mice. Spine number and morphology were compared in homecage mice at the time when mice are normally trained in fear conditioning. Spine density was increased in neurons with CREB vector compared to neurons with GFP vector whereas spine head diameter and length was not different. Therefore, LA neurons overexpressing CREB have increased spine number at the time of learning, potentially providing these neurons with a selective advantage for incorporation into the fear memory trace.

The current study aimed to determine the selective advantage of lateral amygdala (LA) neurons overexpressing the transcription factor CREB that enables their preferential incorporation into the fear memory trace. I hypothesized that overexpression of CREB drives the formation of dendritic spines, potentially providing these neurons with greater connectivity to sensory inputs at the time of learning. Using viral-mediated gene transfer, CREB tagged with GFP, or GFP as a control, was overexpressed in the LA of wild-type mice. Spine number and morphology were compared in homecage mice at the time when mice are normally trained in fear conditioning. Spine density was increased in neurons with CREB vector compared to neurons with GFP vector whereas spine head diameter and length was not different. Therefore, LA neurons overexpressing CREB have increased spine number at the time of learning, potentially providing these neurons with a selective advantage for incorporation into the fear memory trace.

No description available.

Asthma is a heterogeneity disease that is mostly managed successfully using bronchodilators and anti-inflammatory drugs. Around 10%-15% of asthmatics however have difficult or severe asthma which is less responsive to treatments. Asthma and in particular severe asthma are now thought of a description of symptoms which may contain possible sub-groups with possible different pathologies which could be useful for targeting different drugs for different sub-groups. However little statistical work has been carried out to determine these sub-phenotypes. Studies have been carried out to partition severe asthma variables in to a number of sub-groups but the algorithms used in these studies are not based on statistical inference and it is difficult to select the number of best fitting sub-groups using such methods. It is also unclear where the clusters or sub-groups returned are actual sub-groups or reflect a bigger non-normal distribution. In the thesis we have developed a statistical model that combines factor analysis, a method used to obtain independent factors to describe processes allowing for variation over variables, and infinite mixture modelling, a process that involves determining the most probable number of mixtures or clusters thus allowing for variation over individuals. This model created is a Dirichlet process normal mixture latent variable model DPNMLVN and it is capable of determining the correct number of mixtures over each factor. The model was tested with simulations and used to analysis two severe asthma datasets and a cancer clinical trial. Sub-groups were found that reflect a high Eosinophilic group and an average eosinophilic group, a late onset older non atopic group and a highly atopic younger early onset group. In the clinical trial data 3 distinct mixtures were found relating to existing biomarkers not used in the mixture analysis.

The ongoing transition of former communist countries from planned to market economies has been one of the most important economic phenomena in the last few decades. Among these, China is one of the largest and fastest growing emerging economies in the world since the reforms initiated in the late 1980s. China’s economic growth has been phenomenal. Therefore, understanding China’s energy economy is crucial in the new millennium for politicians, businessmen and energy economists. In particular, China’s energy policy directions will bring about both challenges and opportunities to the world in terms of an increasing share of primary energy consumption and investment in the energy industry. However, after surveying the literature, it is surprising to find that a few major areas of China’s energy economics are missing and the views on China’s energy economics are already out dated. Therefore, given the size and growth of its economy and the effect of its energy consumption on global energy markets, reviewing China’s energy situation and filling the missing literatures are essential for those who are interested in and concerned about China’s economic development in the new millennium. This study was motivated after conducting a survey of the literature on the study of China’s energy economy and reviewing China’s energy situation in the new millennium. The goal of the research is focused on providing readers the most important and the newest information on China’s energy economy. The study consists of three introductory sections and three core sections. The former includes a survey of literature, China’s energy situation in the new millennium, institutional evolution and changing energy prices. The latter includes tests for the emergence of an energy market in China, factor substitution and demand for energy, and technological change and the determinants of energy intensity. The main findings are as follows. China’s energy economy is still underdeveloped. It is crucial to review China’s energy situation in the new millennium. Energy, industrial deregulation and price reforms have been fast in China since the early 1990s. Empirical investigations have found evidence for the emergence of an energy market economy in China. The estimates demonstrate that there appears to be significant substitution possibilities between energy and labor when compared with international findings. Significant effects of substitution mainly come from the adoption of labor-intensive technology. Coal and electricity are significantly substitutable, while the demand for energy is elastic, in general. Finally, decomposing energy intensity shows that the budget constraint (a kind of price effect) reduces energy intensity while technological change increases energy intensity. These findings bring us to the following major implications. Firstly, it is important to understand the potential effect of new energy regulation and pricing mechanism on the future directions of China’s energy economy, which suggests that former predictions of China’s energy demand may have to be significantly discounted, and the potential effect on the global energy markets and emissions may need to be re-evaluated. Secondly, significant substitution between energy and labor is potentially good news as China possesses some of the most abundant labor sources in the world. However, because capital more easily substitutes for energy than labor, more policy incentives are needed for labor to substitute for energy. Thirdly, significant substitution between coal-electricity suggests that the effects of environmental taxes, however, may be smaller than expected due to the fact that most primary energy coming from coal. Also any shift from coal to electricity implies more investment in transmission lines rather than railways. Fourthly, energy constraints on energy supply may only slightly impede economic growth in China because the elasticity of substitution between energy and other factors is quite large compared to internationally. Fifthly, while many factors are responsible for the inelasticity of demand for energy, rising income may be one of the most important given the high levels of energy prices. Increasing energy prices may be unable to constrain energy consumption at present. Thus other energy policies need to be considered to encourage or depress certain types of energy consumption. Finally, reducing exports of energy-intensive commodities, reducing the high-level energy-using sectors, lowering capital investment and constraining imports of second-hand and obsolete equipment, would all help reduce growth in energy intensity. Politically, however, this may be at an unacceptable cost to economic growth. Although this study has conducted a series of investigations into the institutional changes and consumption behavior of China’s energy economy, continuous updating required as more data is continually added in a highly dynamic and changing environment. JEL Classifications: D24, O33, Q41.

Since the Netflix Prize competition, latent factor models (LFMs) have become the comparison ``staples'' for many of the recent recommender methods. Meanwhile, it is still unclear to understand the impact of data preprocessing and updating algorithms on LFMs. The performance improvement of LFMs over baseline approaches, however, hovers at only low percentage numbers. Therefore, it is time for a better understanding of their real power beyond the overall root mean square error (RMSE), which as it happens, lies at a very compressed range, without providing too much chance for deeper insight. We introduce an experiment based handbook of LFMs and reveal data preprocessing and updating algorithms' power. We perform a detailed experimental study regarding the performance of classical staple LFMs on a classical dataset, Movielens 1M, that sheds light on a much more pronounced excellence of LFMs for particular categories of users and items, for RMSE and other measures. In particular, LFMs exhibit surprising and excellent advantages when handling several difficult user and item categories. By comparing the distributions of test ratings and predicted ratings, we show that the performance of LFMs is influenced by rating distribution. We then propose a method to estimate the performance of LFMs for a given rating dataset. Also, we provide a very simple, open-source library that implements staple LFMs achieving a similar performance as some very recent (2013) developments in LFMs, and at the same time being more transparent than some other libraries in wide use. / Graduate

Background: In the context of transitional Vietnam, hypertension has been shown to be one of the ten leading causes of morbidity and mortality in hospitals. However, population-based data on hypertension are to a large extent lacking. This thesis aims to characterise the current epidemiology of hypertension in the adult Vietnamese population and provide preliminary evidence for developing effective community-based hypertension management programmes nationwide. Methods: The study was conducted during 2002-2010. It includes two national surveys of the adult population aged 25 years and older, randomly selected in eight provinces in different regions of Vietnam, as well as a community-based programme on hypertension management in two communes of Bavi district. The survey on hypertension and associated risk factors, which included 9,832 adults, applied the WHO STEP-wise approach. The survey on hypertension-related knowledge and health seeking behaviour included 31,720 adults, using a structured questionnaire. For the community-based study, three-year follow-up data on 860 hypertensives was used to assess the effectiveness of the hypertension control model. Main findings: Hypertension prevalence was high (overall 25.1%, 28.3% in men and 23.1% in women). The proportions of hypertensives aware, treated and controlled were unacceptably low (48.4%, 29.6% and 10.7% respectively). Most Vietnamese adults (82.4%) had good knowledge about high blood pressure. People received their information on hypertension from mass media (newspapers, radio, and especially television). Most people would choose a commune health station (75%) if seeking health care for hypertension. The programme on hypertension control was able to run independently at the commune health station. Severity of hypertension and effectiveness of treatment were the main factors influencing people’s adherence to the programme. The hypertension control programme successfully reduced blood pressure (systolic blood pressure: -2.2 mmHg in men and -7.8 mmHg in women; diastolic blood pressure: -4.3 mmHg in men and -6.8 mmHg in women), the estimated CVD 10-year risk (-2.5% in women), and increased the proportions of treatment (22% in men and 13.6% in women) and control (11% in men and 17.3% in women) among hypertensive people. Suggestions for hypertension control: (1) Address the general population by developing community interventions, particularly salt reduction; (2) Provide interventions to individuals at high risk of a CVD event, including multi-drug treatment within patient-centred primary health care. (3) Set up a hypertension care network based in the existing health care system; (4) Improve and strengthen capacity and skills of medical staff in cardiac care, particularly staff at primary care level.

No description available.