Since the mid-1990s resin composite has been used for Class II restorations in stress-bearing areas as an alternative to amalgam. Reasons for this were the patients’ fear of mercury in dental amalgam and a growing demand for aesthetic restorations. During the last decades, the use of new resin composites with more optimized filler loading have resulted in reduced clinical wear. Improved and simplified amphiphilic bonding systems have been introduced. However, one of the main problems with resin composites, its polymerization shrinkage, has not been solved yet. During the polymerization of the resin composites, they shrink as a result of the conversion of the monomers into rigid polymers by a radical addition reaction. The resulting shrinkage stresses in the bonded resin composite restorations may cause adhesive failures at the resin composite/tooth structure interface and/or cohesive failures within the tooth or the resin composite. The interfacial failures may result in post-operative sensitivity, recurrent caries or pulpal injury. This thesis evaluates different restorative and light-curing techniques that are proposed to reduce the polymerization shrinkage and also the effect of new lightcuring units, light-emitting diodes (LED) and high-power quartz tungsten halogen (QTH) light on curing depth and degree of conversion of resin composites. Two restorative techniques using a polyacid-modified resin composite or a flowable resin composite in combination with conventional resin composite in sandwich restorations were evaluated in an intraindividual comparison with a conventional resin composite restoration. The durability of the polyacid-modified resin composite sandwich technique was investigated in a three year clinical follow-up study. A scanning electron microscope replica method was used for evaluation of the interfacial adaptation in vivo of both sandwich combinations. The depth of cure of the flowable resin composite was evaluated with the use of Wallace hardness testing. Degree of conversion for resin composite cured with the new LED units was evaluated with Fourier Transform Raman spectroscopy. Major results and conclusions from the studies are: • Neither the sandwich restoration with polyacid-modified resin composite nor the flowable resin composite improved the interfacial adaptation of the restorations. • No difference in durability was found between the sandwich restorations with polyacidmodified resin composite or the resin composite restorations. A low failure rate was observed for both types of restorations after a clinical observation time of three years. • The depth of cure of the flowable resin composite was higher than the depth of cure of the resin composite. It was found that the curing time of the resin composite studied could be reduced or the increment layer thickness increased compared to earlier recommendations. • LED curing units of the latest generation were able to cure resin composites to a higher degree of conversion than the control QTH unit • The use of soft-start curing did not improve the interfacial adaptation of neither of resin composite restorations tested.

Soluble organic matter represent less than 1% of total soil organic matter (SOM) - but it contributes to many terrestrial ecosystem processes, due to its high mobility and reactivity in soil. Although it has been suggested that soluble organic matter (OM) may serve as an early indicator of soil quality changes as a result of shifts in land-use and management practices, only a few studies have addressed the dynamics of soluble OM in relation to land-use and specifically soil depth. This study focuses on two aspects of soluble OM. In the first part, I hypothesized that extractable OM obtained by aqueous solutions is a continuum of substances that depending on the extraction method can be separated into two operationally different fractions. The size and properties of these fractions may consistently differ among different land uses and at different soil depths. The objective of this part of the study was then to assess dynamics (size and properties, biodegradability and seasonality) of water extractable organic matter (WEOM) and salt extractable organic matter (SEOM) in a sequence of human dominated land-uses at topsoil and subsoil. At the second part of the study, I tested the regulatory gate hypothesis –abiotic solubilization of OM- as a primary controlling factor in soluble OM production. The objective of this study was to evaluate the impact of the microbial activity on the net production of dissolved organic matter (DOM) from the native SOM in the presence of added DOM and plant residue. For the first part of the experiment, the soil samples were collected from four land-uses under bog pine (Halocarpus bidwillii) woodland, tussock grassland (Festuca novae-zelandiae and Heiracium pilosella), cropland (Medicago sativa) and plantation forest (Pinus nigra). The selected land uses were located in the Mackenzie Basin, Canterbury, New Zealand and occurring on the same soils, topography and experienced similar climates. Soil samples were obtained from topsoil (0-20 cm) and subsoil (60-80 cm) at the end of each season (November, February, May and August) during 2007-2008. The sampled soils were adjusted to the same water status prior to extraction. While WEOM was obtained during a mild extraction procedure and using 0.01M CaCl2, SEOM was extracted with 0.5M K2SO4 at high temperature (75οC for 90 min). Both extracts were filtered through a 0.45 μm filter size. In the first part of the study, I assessed the biodegradation dynamics of WEOM and SEOM (spring samples), using a double-exponential decay model. The WEOM and SEOM were inoculated and incubated at 22°C for 90d under aerobic conditions. Subsamples were removed on days 1, 3, 7, 12, 16, 30, 42, 60, 75, and 90, filtered (0.22 μm), and analyzed for organic C and N content, UV absorption, and 13C natural abundance (δ13C). The results of the biodegradation experiment indicated a similar pattern for both C and N of SEOM and WEOM as that of previously shown for soil DOM. However, C and N mineralization rate were considerably larger in the WEOM than SEOM. The parameters of the double-exponential model suggested that regardless of the land-use and soil depth, both the WEOM and SEOM can be modeled in two biological pools, with a largely similar “fast decomposable” but different “slowly decomposable” pools. However, since the extraction was not sequentially followed, a very small portion of the SEOM was comprised of the WEOM and given the greater observed biodegradability of the WEOM, the overall biodegradable portion of the SEOM would be lower than the observed. Despite a greater biodegradability of the organic N than C of both WEOM and SEOM; mainly due to a longer HL of the slowly biodegradable pool of C; the C/N ratio of the samples did not change very much during the biodegradation. This led us to conclude that the biodegradation of soluble OM may occur as a function of N availability. Parallel to C and N loss, a considerable increase in SUVA254 of SEOM, and particularly WEOM occurred during the incubation period. The greater increase in the proportion of aromatic compounds (assessed by SUVA) in the WEOM than SEOM, implied consumption of simple compounds (vs. very humified) during decomposition and further supported the observed faster biodegradation rate of the WEOM. The data indicated a relatively strong correlation (R2=0.66 and 0.74 for the WEOM and SEOM, respectively) between the amount of biodegraded C and the increase in SUVA254. This suggested that SUVA254 can be used as a simple, low-cost but reliable approach for describing the biodegradability of soluble OM, as previously suggested by others. At the end of the bioassay, the 13C natural abundance of the WEOM was significantly depleted, and showed a clear relationship with the proportion of the biodegraded C. This confirmed the previously suggested preferential biodegradation of simple organic constituents (13C enriched), resulting in the accumulation of more depleted 13C compounds (often recalcitrant compounds). Moreover, the results of the δ13C technique revealed that the relatively greater 13C enrichment of the WEOM obtained from subsoil, seems to be due to the presence of root exudates (often highly 13C enriched). In contrast, a proportionally greater 13C depletion observed in the SEOM particularly at subsoil samples, suggests that there is a close relationship between the SEOM and the typically 13C depleted humified SOM. The results of the biodegradation model (half-life of both C and N), in addition to dynamics of SUVA254 and δ13C of the WEOM and SEOM were very comparable between top and subsoil samples. This implied that the potential biodegradability of soluble OM under laboratory conditions does not necessary reflect the reported lower in situ biodegradability at soil depth, in agreement with recent evidence suggested by others. Instead, this may be largely due to the lack of optimum conditions (oxygen, nutrients, and moisture) for the decomposer community at soil depth. Although there was a tendency for a generally greater biodegradability of the samples from the soils under the crop land (both WEOC and SEOC), along with relatively greater increase in SUVA, there was not a consistent trend of the effect of land use on the biodegradation of either WEOM or SEOM. The lower C/N ratio of the soils under the crop land seemed to be related with the observed proportionally greater biodegradability of these soils. During the second part of the study, I assessed seasonal variations of the size and properties of the previously defined WEOM and SEOM, collected from top-and subsoil from the land-uses. I observed that 10-year after conversion of the degraded tussock grassland to cropland or plantation, the total C stock of topsoil (0-20 cm) when above- and below-ground plant biomass is excluded; has remained unchanged. This was attributed to the limited biomass production of the region, more likely as a result of low productivity of the soil, but also harsh climatic conditions. Not only soil depth, but land-use affected both C concentration and C/N ratio of soil organic matter (SOM), with the greatest C concentration of soils under grassland and plantation in topsoil and subsoil, respectively. Despite the WEOM, the size of SEOM was largely unaffected by land-use and soil depth; instead, the properties of SEOM was more consistent with the effect of soil depth. Given the observed large temporal and spatial variability of the WEOM, the study suggests that the SEOM more consistently reflects the influence of land use and soil depth. No consistent effect of seasonality was observed in terms of size or properties of the SOM and the WEOM and SEOM. Overall comparison of the size and properties of the WEOM and SEOM indicated that OM extraction efficiency may vary largely, depending on extraction conditions. Using more concentrated salt solutions consistently yielded greater amount of OM (N, and especially C) release from soil with properties resembling more those of total soil OM (more humified) compared to the WEOM. The SEOM was also less variable by time and space. The last part of the study was aimed to assess biotic vs. non-biotic solubilization of OM in the presence of added plant residue. Given the need to recognize the source of the solubilized OM during the experiment, I used enriched (13C) plant residue as the source of fresh OM. The above-ground part of ryegrass was added to soil either as plant residue or residue extract (extracted with CaCl2 followed by 0.45μm filtration) -termed DOM. These two forms of added OM (residue/DOM) were conceived to represent two levels of bioavailability for the decomposer community for further assessing possible biotic solubilization of OM. Two soils similar in their OM content and other properties, but different in mineralogy were selected for the experiment. Soils were incubated for 90d under sterilized vs. non-sterile conditions and leached regularly with a dilute aqueous solution (0.05M CaCl2). Plant residue was added to soil (1:100, residue: soil, w/w) prior to the start of the incubation, but DOM was frequently applied to the soils along with each leaching experiment. The greater C and N concentration in the leachates of both sterilized residue-amended and DOM-amended soils compared to that of living soils, indicated a high microbial activity, as determined by CO2 loss, in the living soils. However, the proportion of the solubilized C (determined by 13C) from sterilized soils was largely comparable to that of living soils. This supports the recently suggested “regulatory gate” hypothesis, stating that solubilisation of OM largely occurs independent of the size or community structure of microorganisms. In addition, I observed that even with the presence of adequate amount of added fresh OM (ryegrass residue), about 70% of the solubilized C consistently originated from the humified soil OM, highlighting the role of native soil OM as the source of soluble OM in soil. In addition, in the DOM-amended soils, there was strong evidence, indicating that in the sterilized soils, the added DOM was exchanged with the humified soil OM as observed by an increase in SUVA, and humification index (HI) of the leached OM. Although the results of the study did not show a considerable difference in the solubilisation rate of added OM as a function of biological activity (either in the residue- or DOM-amended soils), there was clear evidence that the presence of microbial activity has resulted in further decomposition of the solubilised OM through biological transformations. Together, the results suggested that the proposed fractionation method can be used to separate two operationally defined pools of soluble OM with consistent differences in their size (C and N), properties (δ13C, SUVA254, and C/N ratio) and biodegradability across the land-uses and soil depth. The second part of the study supported the primary role of abiotic factors on the production of soluble OM from native soil OM. Although the abiotic mechanisms involved in the solubilization remain to be addressed by future studies. Cons and pros of the methods with some suggestions for further works have been mentioned in the last chapter.

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We deployed depth-specific drifters in the western and eastern parts of the South Arm basin of Lake Opeongo and collected zooplankton samples at west and east fixed stations and at additional up- and downwind locations at three depths of the epilimnion under a range of wind conditions. Water currents had highest association with the immediate wind direction and the direction they travelled was dependent on wind strength. Along the main west-east fetch large zooplankton resided high in the epilimnion and were transported eastwards by strong surface currents where they accumulated. Small zooplankton were more uniformly distributed with depth and their accumulation patterns and transport mechanisms are less clear. Along shorter fetches oriented off-angle with the main one accumulations of zooplankton occurred at all downwind locations under heavy winds although the patterns are more variable and complex. These downwind accumulations likely create high quality habitat for warm water fish.

3D representation nowadays has attracted much more public attention than ever before. One of the most important techniques in this field is depth extraction. In this thesis, we first introduce a well-known stereo matching method using color segmentation and belief propagation, and make an implementation of this framework. The color-segmentation based stereo matching method performs well recently, since this method can keep the object boundaries accurate, which is very important to depth map. Based on the implemented framework of segmentation based stereo matching, we proposed a color segmentation based 2D-to-3D video conversion method using high quality motion information. In our proposed scheme, the original depth map is generated from motion parallax by optical flow calculation. After that we employ color segmentation and plane estimation to optimize the original depth map to get an improved depth map with sharp object boundaries. We also make some adjustments for optical flow calculation to improve its efficiency and accuracy. By using the motion vectors extracted from compressed video as initial values for optical flow calculation, the calculated motion vectors are more accurate within a shorter time compared with the same process without initial values. The experimental results shows that our proposed method indeed gives much more accurate depth maps with high quality edge information. Optical flow with initial values provides good original depth map, and color segmentation with plane estimation further improves the depth map by sharpening its boundaries.

Additive manufacturing methods have been developed from rapid prototyping techniques and are now being considered as alternatives to conventional techniques of manufacturing. Stereolithography is one of the main additive methods and is considered highly accurate and consistent. Polymers are used as stereolithography materials and exhibit features such as high strength-to-weight ratio, corrosion resistance, ease of manufacturing and good thermal and electrical resistance properties. However, they are sensitive to environmental factors such as temperature, moisture and UV light, with moisture being identified as one of the most important factors that affect their properties. Moisture generally has an adverse effect on the mechanical properties of polymers. Investigation of the effects of moisture on polymers can be carried out using a number of experimental techniques; however, the benefits of the depth sensing indentation method over bulk tests include its ability to characterise various mechanical properties in a single test from only a small volume of material and the investigation of spatial variation in mechanical properties near the surface. The aim of this research was to investigate the effects of varying relative humidity on the indentation behaviour of stereolithography polymers and to develop a modelling methodology that can predict this behaviour under various humidities. It was achieved by a combination of experimental and numerical methods. Depth sensing indentation experiments were carried out at 33.5 %, 53.8 %, 75.3 % and 84.5 % RH (relative humidity) and 22.5 °C temperature to investigate the effects of varying humidity on the micron scale properties of the stereolithography resin, Accura 60. In order to minimise the effects of creep on the calculated properties, appropriate loading and unloading rates with suitable dwell period were selected and indentation data was analysed using the Oliver and Pharr method (1992). A humidity control unit fitted to the machine was used to condition the samples and regulate humidity during testing. Samples were also preconditioned at 33.5 %, 53.8 %, 75.3 % and 84.5 % RH using saturated salt solutions and were tested at 33.5 % RH using humidity control unit. It was seen that properties such as indentation depth increased and contact iv hardness and contact modulus decreased with increasing RH. The samples conditioned and tested using the humidity control unit at high RH showed a greater effect of moisture than the preconditioned samples tested at 33.5 % RH. This was because the samples preconditioned at high RH exhibited surface desorption of moisture when tested at ambient RH, resulting in some recovery of the mechanical properties. In order to investigate these further, tests were performed periodically on saturated samples after drying. Ten days drying of samples conditioned for five days at 84.5 % RH provided significant, though not complete, recovery in the mechanical properties. These tests confirmed that Accura 60 is highly hygroscopic and its mechanical properties are a function of RH and removal of moisture leads to a significant recovery of the original mechanical properties.

Over the last two decades public service broadcasting (PSB) around the world has faced increasing pressures from accelerating commercialisation and the fragmentation of the broadcasting landscape. This has led a number of media commentators in the system's traditional heartlands to ask whether the idea has now outlived its usefulness. Against the grain of this international trend, Taiwan has moved in the opposite direction, democratising its state-owned television system and introducing a form of public broadcasting for the first time. Against the grain of growing enthusiasm for a privatised solution supporters presented PSB as a necessary counter to the perceived deficiencies of the existing system, in serving a society moving from authoritarian to competitive party rule. This study sets out to explore how the expansion of PSB in Taiwan has been socially defined and constructed, and by whom. The various constructions in play were mapped through in-depth interviews with a range of claim-makers involved in the process. A systematic content analysis of the mainstream Taiwanese press was then conducted to explore the ways contending positions and issues were presented in the public domain and to identify the key voices given a public platform. This analysis demonstrated that the opinions and concerns of the general public were largely missing from a debate dominated by political and academic elites. Against the grain of their own claims to be representing the public key actors constructed public debate as a series of monologues, advancing their own sectional and paternalistic interpretations of the public interest. These findings point to the supremely ironic conclusion that a process ostensibly dedicated to reconstructing broadcasting as key element in a new, democratic, public sphere, excluded the public from active participation and relegated them to the role of spectators.

This thesis addresses the dissection and characterisation of quantitative trait loci (QTL) affecting production traits in sheep. Firstly, the association between specific genetic polymorphisms and complex variation in weight, muscle and fat depositions was investigated. Research concentrated on assessing the presence, correspondence and significance of two single nucleotide polymorphisms (SNPs) in the GDF8 region of ovine chromosome 2, reportedly affecting muscle production. Commercial populations of British Texel, Suffolk and Charollais sheep were studied. The SNPs were absent in Suffolk and almost fixed in Texel breeds. In the Charollais population, the SNPs segregated at intermediate frequencies and a significant association was found between these polymorphisms and muscle depth. The previously proposed causative allele at one of the loci resulted in increased muscle depth and, at allele frequency of 0.5, this locus would explain one third of the additive genetic variance for the trait. Partial recessive allelic expression is proposed by genotypic value predictions and is consistent with the previously postulated molecular mechanism by which it gives rise to muscle changes. Secondly, the thesis focused on detection of QTL associated with growth. Live weight is a composite of growth rates over time, with inter-age genetic correlations for live weight decreasing as time between weight measurements increases. To explore whether observed genetic correlation patterns translate into distinct loci acting on weight at different growth stages, a novel method was developed and the applicability of a second proposed method was explored. Both methods allowed simultaneous analysis of multiple live weights per animal, while accounting differently for the correlation among measurements ordered in time. In the first approach, a growth curve technique was developed and employed to map growth QTL for curve parameters and predicted growth descriptors. A study of actual live weights identified significant QTL at different ages on distinct chromosomes, with QTL significance and variance changing over time. Further application of this technique on a simulated dataset validated its effectiveness in detecting age-dependent QTL. An extension of the procedure resulted in a novel technique for genomic evaluation of longitudinal traits. In the second method examined, random regression (RR) models were applied for dissection of growth QTL. Systematic model selection and inclusion of relevant random effects resulted in apparently significant QTL, but the method was computationally demanding, model choice proved challenging and the results were questioned. To further explore the method, RR models were applied to various simulated growth phenotypes composed of time-dependent QTL trajectories, polygenic and environmental effects. Statistically optimal RR models succeeded in identifying significant QTL and predicting the simulated time-dependence for most scenarios. However, the issue of model choice was again prominent, as suboptimal models resulted in unreliable QTL variance trajectories and pronounced confounding between different time-dependent effects. Thus, the growth curve approach appeared to be the more flexible and robust process for analysing longitudinal data to map agedependent QTL.