Abstract

Heparin administration during extracorporeal procedures such as kidney dialysis and heart surgeries is a challenging problem, as under heparinisation leads to clotting and over heparinisation may cause excessive bleeding complications. Various reactor designs including the use of heparinase and poly-L-lysine.HBr hollow fiber have been proposed, however none of them have been clinically approved yet. This work presents the possibility of designing a packed bed reactor with poly-Llysine/ alginate beads. The poly-L-lysine/alginate beads have been used widely in fields of microencapsulation of cells and can be made using techniques such as the Initech encapsulation and layer by layer approach. In some cases ginipin has been used for microcapsule preparations to provide stronger cross linking. In this study, the poly-L-lysine beads are made using the encapsulation procedure patented by Chang18 (1992). Batch experiments, using saline, fetal calf serum and blood were performed to investigate the efficiency of the beads. The absorption of heparin was determined to be a first order absorption process and fits the Freundlich Isotherm. The beads were determined to be relatively safe in blood. The absorption of heparin was linked to the poly-L-lysine content in the membrane. Thus the rate of the amount of heparin absorbed could be increased by increasing the membrane thickness or by increasing the number of poly-L-lysine/alginate beads. The results were used to investigate the feasibility of using a packed bed reactor for the absorption process by adjusting the specifications of the reactor and analysing simple flow models.

Media ownership has remained an intriguing factor in understanding the news production process. Various studies have proven that ownership influence do affect how journalists cover stories. The said influence takes various forms including direct censorship and coercion of editorial staff. This study critically examines how media ownership patterns, shape content in the Kenyan media. The researcher employs the use of thematic content analysis and coding of raw data retrieved from the internet sites of two leading Kenyan newspapers as outlined in the research methodology and findings chapters. The data retrieved from the internet sites of the two newspapers is then analysed to prove how ownership patterns influence daily news coverage. Of note is also the use of two case studies – The Nation and The Standard newspapers to analyse 905 articles written during the 2002 multiparty Kenyan elections. It emerges that ownership indeed influenced news coverage in the 2002 Kenyan elections. The emerging winner in the elections was also the candidate with the most coverage in the two newspapers. Also emergent is the factor that the election was widely personality driven. The implications of the research findings is that objectivity though practiced in some instances, was widely affected by the editorial line of the said newspapers. The editorial line was largely pegged to ownership influences in most cases.

The dissertation is ccncemed with the values iasue in the South African context, a multicultural education situation. South Africa is a plu~Hstfc society. Being pluralistic, means that 1he country is rich in different cultures, belief· and value systems. Different cultures haw different value systems. If an Institution is practising multicultural education, the question is, which values are to be used? If we say Ule institution should use the values of the majority culture, wiU 1hat not disadvantage minority cultures? ff minority cultures are undennined by neglecting their cultures won't that cause conflict between minority cultures and the majority culture? Each society that Is implementing multicultural education should consider that there are common human values and partia.dar values. In multicultural education particular values are important because they show how a particulat group behaves and what its beliefs and culture are. Common values dewlap from particular values and teachers must emphasise common values without neglecting particular values, to encourage tolerance and acceptance between different groups.

Abstract

Abstract

In the past decade some 150 planets have been detected outside our Solar System, mostly via precise radial-velocity measurements of their host stars. Using an alternative method, transit searches have recently added 6 planets to the tally, and are expected to make more significant contributions in the future. The transit method is based on the detection of the tiny, periodic dip in the apparent brightness of a star when an orbiting planet passes in front of it. It requires intensive photometric monitoring of ??? 104 stars, with a precision better than ??? 1%. The 0.5 m Automated Patrol Telescope (APT) at Siding Spring Observatory, Australia, with its wide field of view and large aperture, is ideal for this task. This combination is also somewhat unique among telescopes used in transit searches. Since 2001, the APT has been semi-dedicated to a search for extrasolar planets. In this thesis work, observing, data reduction and analysis procedures were developed for the project. A significant fraction of the initial effort was focused on reaching the required photometric precision. This was achieved by implementing a new observing technique, and robust data reduction software. In the first two years of regular observations (starting in August 2002), 8 crowded Galactic fields were monitored, with photometric precision reaching 0.2% for the brightest stars. We searched the lightcurves of the brightest stars (V &lt13) and selected 5 planet candidates. Follow-up photometry and spectroscopy revealed all of these to be eclipsing binary stars. To date, no planets have been detected by this project. A detailed Monte Carlo simulation of the observations, using the currently known frequency and properties of extrasolar planets, resulted in a low calculated detection rate, consistent with the lack of detections. Using this simulation, we have investigated the observational and target star/planet parameters that determine the sensitivity of transit searches. The results highlighted the factors limiting our detection rate, and allowed us to significantly improve our observing strategy. According to the simulations, we should now detect ??? 2 planets per year. This will increase by a factor of a few when a new camera, currently under construction, is installed on the APT in early 2006.

On a global basis over A$450 billion is invested each year in foreign direct investment and aid with a view to supporting development. Developing countries themselves allocate significant sums out of their own budgets in order to stimulate development. Development is concomitantly a major goal and enterprise of the global economy. Developed countries through aid (Official Development Assistance) spend large sums purportedly to improve the development status of developing countries. Recently voices from within the developed world???s establishment have derided the performance of aid and by default the performance of state organisations charged with managing aid delivery. Australia has not been immune from this criticism. Its aid program while modest by global standards still consumes A$1.5 billion in taxpayers money each year. Australian aid is delivered primarily by the Australian International Aid Agency (AusAID) with smaller contributions through the Department of Foreign Affairs, Department of Defence and Australian Federal Police. AusAID has recently faced severe criticism over failure of the aid investment in the South Pacific to engender development. Most South Pacific countries (excluding Fiji and Samoa) have failed to show desired development. A number have faced bankruptcy (Naru, Solomon Islands), while others have increasing lawlessness (Papua New Guinea). It is important in the above milieu to examine the delivery mechanisms of Australian aid through its chosen vehicle (AusAID) and determine whether aid has really been effective or not. This thesis reviews the development effectiveness of Australian aid in one Pacific island nation ??? Samoa. In this context, the effectiveness of Australian development assistance is reviewed in terms of the results of four case studies of project aid to Samoa. The four case studies cover a range of project activity in differing sectors and offer specific insights into aid policy and delivery and the effects other variables such as culture, history and development status have on development outcomes. The thesis tests the hypothesis that Australian aid to Samoa has resulted in only limited development success and then in ways that are not generally sustainable. In confirming the hypothesis, this thesis identifies that while variables such as the procedural and policy underpinnings of the Australian aid program, aid design/delivery and management, and the history, culture and development status of Samoa impact on the development outcomes, they do not prohibit development. This thesis concludes that development outcomes will be maximised when there are good macro policies present, sound sector policies and real commitments of the government and people to development. Moreover, this thesis finds that while development theories inform the debate over aid none successfully encapsulates the actual development process.

Australia is a multicultural society with an ageing population. Diseases such as dementia, which affect older age groups, are therefore becoming increasingly important health issues. Brief cognitive assessment instruments are used to screen older patients for dementia. Many of these instruments have been developed for use in English speaking populations and are not culture-fair or easily translated for use with non-English speakers. To ensure that people from all cultural backgrounds receive optimal health care, primary health care workers need a quick, reliable, and non-threatening dementia screening tool that is valid across cultures and easy to administer in a wide range of settings. This thesis explores the philosophical, scientific, and social antecedents of current approaches to measuring cognition. It argues that these have led to the treatment of culture as an intrinsic human attribute rather than one which describes variations in human experience. The consequences for approaches to the assessment of cognition in people from diverse cultural backgrounds are discussed and a model is presented to provide theoretical support for the development of a multicultural cognitive screening test for dementia. Following a literature review of brief cognitive screening instruments, clock drawing tests, and cross-cultural cognitive tests, two studies are presented. The first study tests the hypothesis that clock drawing is a useful multicultural screening instrument. There were no significant differences between six clock scoring methods for predicting dementia in a sample of 93 patients from non-English speaking backgrounds. While the Wolf-Klein clock scoring method produced the best trade-off between sensitivity (78%) and specificity (58%), this was insufficient to recommend clock drawing as a useful screening test for dementia in a multicultural population. The second study provides support for the hypothesis that a cognitive screening test with good predictive accuracy can be developed and used to screen for dementia in a multicultural population. This study reports the development, pilot, and validation stages of a multicultural cognitive test with excellent diagnostic accuracy (Area under the ROC curve = 0.95) and 89% sensitivity and 98% specificity for detecting dementia. This research has important implications for current clinical practice and the potential to improve public health for many Australians.

Conventional perceptual coding algorithms do not normally exploit the temporal masking property of the human auditory system. These algorithms rely only on simultaneous masking models to calculate the masking threshold. This work proposes the use of a temporal masking model, combined with a simultaneous masking model, in wavelet packet-based audio coding. The result is a reduction in bit rate of approximately 25 kbps while preserving the transparent perceptual quality of audio signals, at a sampling rate of 16 kHz. This is achieved by a more accurate calculation of the combined auditory masking threshold. Another proposed approach of calculating the masking threshold accurately is by oversampling in the discrete wavelet transform. Most of the current wavelet based perceptual coders use the critically sampled discrete wavelet transform. The problem with this transform is aliasing, resulting from the down sampling process after each decomposition. This aliasing is cancelled in the decoding process, however the masking threshold calculation is done using aliased wavelet coefficients. Oversampling in the discrete wavelet transform is proposed in this work to avoid aliasing. The results show that by oversampling in the discrete wavelet transform, a reduction in a bit rate of up to 16 kbps can be achieved for audio signal, at a sampling rate of 44.1 kHz. The two approaches are then used in scalable audio coding in developing a fixed bit rate audio coder. The bit rate saving from the two approaches is used in scalable audio coding to include additional frequency content at the target bit rate.