Inaug.-diss.--Göttingen. / Lebenslauf. "Quellenverzeichnis": p. [1]-2.

Inaug.-diss.--Göttingen. / Lebenslauf. "Quellenverzeichnis": p. [1]-2.

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.

Advances in our understanding of osteoarthritis (OA) have made development of sensitive measurement tools a priority. The literature review in this thesis found that one of the measurement tools, arthroscopy, had not been fully evaluated. This body of work evaluated the performance of arthroscopic assessments of articular cartilage (AC) in early OA with specific reference to the OMERACT filter. Preliminary studies in plastic knee arthroscopy simulation models found that estimates of AC lesion area had poor accuracy and reliability. Measurements of lesion diameter were greatly improved by the use of specially designed measurement probes but these did not prove feasible in vivo. Ovine studies evaluated discriminant and criterion validity. Biomechanical assessments served as the gold standard for AC stiffness while macroscopic, thickness and histologic assessments were used for gross structural damage. An hybrid gold standard assessment was devised to validate arthroscopic estimates of Severity and Extent of chondropathy. Arthroscopic global assessments discriminated between normal and very early OA but discrimination between different states of OA was less impressive. Assessments of the Severity of chondropathy had acceptable accuracy and moderate reliability. While arthroscopy could not examine the entire articular surface and estimates of Extent of chondropathy were subject to very large error they broadly resembled those of the hybrid gold standard assessment and they enhanced composite score performance. Composite score validity was further improved by inclusion of estimates of chondro-osteophyte. An empirical approach to composite algorithm weighting to optimise discriminant validity was developed. This approach compared favourably with previously described methods. Composite scores proved best at discriminating between normal and very early OA but were also capable of detecting small changes in OA. Arthroscopic asessments of AC damage meet the OMERACT filter criteria of Truth and Discrimination. Assessments using current arthroscopic technology should include estimates of the Extent of all grades of chondropathy. The optimal scoring algorithm should be determined empirically. Arthroscopic assessments using existing technology may be used to validate noninvasive assessments of the Severity chondropathy but not of Extent. Future efforts to improve arthroscopic assessments of AC should focus on reducing random error associated with estimates of extent.

The iron content of industrial minerals can be reduced by physical and chemical processing. Chemical processing is very efficient to achieve a high degree of iron removal at minimum operating cost. Both inorganic acids and organic acids have been used for clay refining. However, due to environmental pollution and contamination of products with the SO42- and Cl-, inorganic acids should be avoided as much as possible. This research investigated the use of oxalic acid to dissolve iron oxides and the dissolution characteristics of natural iron oxides. The dissolution of iron oxides in oxalic acid was found to be very slow at temperatures ranging from 25??? to 60???, but increased rapidly at a temperature above 90oC with increasing oxalic acid concentration, whereas the pH caused the reaction rate to decrease at pH&gt2.5 and improved the rate from pH 1 to pH 2.5. The iron oxides such as goethite (??-FeOOH), lepidocrocite (??-FeOOH) and iron hydroxide (Fe(OH)3) can be dissolved faster at the presence of magnetite which exhibits an induction period at the initial stage and showed the bell-shaped curves for the dissolution. In titration tests, however, the increase of temperature causes an increase in solubility of the oxalate complexes, resulting in an increased stability of ionized species in solution. During the addition of NaOH, NaHC2O4???H2O was precipitated without forming Na2C2O4???H2O, but it was re-dissolved at pH&gt4.0. On the other hand with NH4OH, NH4HC2O4???H2O and (NH4) 2C2O4???H2O co-precipitated at pH 0.93, but also re-dissolved at over pH 2.03. The reaction temperature was found not to affect the removal of iron from the ferric oxalate complex solution using lime. Iron is removed as iron hydroxide and calcium oxalate is then precipitated during the iron removal step. The formation of Fe(OH)3 in the solution was affected by the dissociation of Ca(OH)2. The thermodynamics of sodium, ammonium and iron oxalate complexes were investigated and the standard free energy, ??Go was calculated using thermodynamic data and solubility products. The dissolution of pure hematite by oxalate was found to follow a shrinking core model of which the kinetic step of the reaction is the controlled mechanism.

By elucidating the origins of the banlieue rouge, a belt of communist-dominated suburbs surrounding Paris that arose during the interwar years and reached its apogee under the Fourth Republic, this thesis addresses the problem of why twentieth-century France was home to a pro-Soviet communist party with mass support. Specifically, a local study of the PCF in Arcueil and Cachan, two neighbouring communes south of Paris with divergent political evolutions since World War I, is used to discern how and why the Parti communiste fran??ais (PCF) came to exert hegemony in the working-class suburbs of Paris. After surveying the historiography of communism in France and beyond, this thesis concludes that the communist banlieue rouge was born of working-class alienation from bourgeois society that was nourished by a communist counter-society that was contingent upon the PCF???s capacity to adapt and respond to local circumstances. Using archival sources and statistical analysis, it demonstrates that in Arcueil and Cachan rapid suburbanisation and an attendant proletarianisation created the pre-conditions for the rise of the PCF. This study finds that during the interwar period the PCF rapidly emerged as an electoral force in both suburbs as it set about laying the foundations of a communist counter-society, especially in Arcueil where it won control of local government in 1935. In Arcueil, the PCF spearheaded the local Resistance movement during World War II and then under the Fourth Republic went on to consolidate a nascent communist communal identity, while in Cachan its influence fell victim to Cold War politics. The pre-conditions for the rise of communism were apparent earlier and to a greater degree in Arcueil, an industrialised, working-class suburb with long-standing radical traditions, than in the traditionally conservative Cachan. In Arcueil, the PCF was more successful than its counterpart in Cachan at exploiting an alienation that was not only part of the deep-seated historical traditions of the French working class but was also part of everyday life f or workers forced to live in miserable conditions. In suburbs such as Arcueil, suburban working-class pride at being a social outcast was conflated with communism to create a durable communist communal identity.

Ectomycorrhizal fungi are able to ameliorate heavy metal stress to host trees in polluted soils. Their sensitivity or tolerance to heavy metals is usually examined based on growth and proliferation on heavy metal amended media. However, there are no data on cellular effects of heavy metals and detoxification in live cells of these fungi. Organelle morphology has recently been recognized as an indication of cellular health and its changes can be used to assess cytotoxicity. The aim of this study was, therefore, to investigate short term effects of common heavy metal pollutants, Zn2+ and Ni2+ on the morphology of vacuoles, mitochondria and microtubules in hyphal tip cells of two Paxillus involutus strains. Vacuoles, mitochondria and microtubules were labeled with Oregon Green?? 488 carboxylic acid diacetate, 3,3'-dihexyloxacarbocyanine iodide ((DiOC6(3)) and anti-??- tubulin antibodies, respectively. They were treated with 0-1 mmol L-1 NiSO4 or 0-100 mmol L-1 ZnSO4 or K2SO4 (SO4 2- control) and examined by fluorescence microscopy. Vacuoles and mitochondria in untreated hyphal tip cells of strain P2 which originated from a heavy metal-rich soil were motile and tubular forming networks. Exposure to the metals caused tubular vacuole thickening and vesiculation as well as fragmentation of tubular mitochondria in living hyphal tip cells. The highest K2SO4 concentration also had severe effects on mitochondria. These effects were metal, concentration and exposure time dependent. NiSO4 caused these effects at a hundred fold lower concentration than ZnSO4 and induced severe microtubule disruption. Vacuole tubularity recovered after removal of the metal solutions depending on the metal, concentration and exposure time. Mitochondrial tubularity recovered to pretreatment morphology in a shorter time and even during exposure to the highest metal concentration. Vacuoles of strain P46 which originated from a non-polluted soil were pleomorphic, but mainly spherical with occasional tubular interconnections. The vacuoles were too sensitive to UV light exposure required for fluorescence microscopy to investigate their response to heavy metals. The mitochondrial network and microtubules resembled those of strain P2. The highest ZnSO4 and NiSO4 concentrations caused similar trends in response of mitochondria and microtubules of the two strains. However, mitochondria of strain P46 were less sensitive at lower metal concentrations. The highest K2SO4 concentration had more severe effects on mitochondria of strain P46 than in strain P2 from which tubularity was not recovered. This investigation is the first to reveal that heavy metals affect organelle morphology in two strains of an ectomycorrhizal fungus. Nickel effects on the organelles are likely to result from microtubule disruption. Metal induced mitochondrial fragmentation is possibly an apoptotic response and the recovery of tubular organelle networks suggests cellular detoxification.