UQ Theses Collection (RHD) - UQ staff and students only - UQ eSpace

THE ECONOMIC ROLE OF FORMAL AND INFORMAL INTER-FIRM NETWORKS IN THE DEVELOPMENT OF SMALL AND MEDIUM INDUSTRIAL ENTERPRISES: STUDY OF SYMBIOSIS IN THE INDONESIAN GARMENT INDUSTRY

Adam, Latif — 2008-11-21T00:00:00Z

It has been frequently argued that the formation of inter-firm networks (business cooperation) could be used as an effective means to promote SMIEs in Indonesia. However, as the majority of previous studies have concentrated largely on investigating SMIEs internal management, there has been only little detailed information available concerning the determinants and the economic role of inter-firm networks in the development of Indonesian SMIEs. This thesis discusses not only issues involving the development of SMIEs from the angle of SMIEs internal management, but also goes further to examine what are the determinants impacting on the efforts of SMIEs to develop and maintain long-term inter-firm networks, and to what extent and how have inter-firm networks contributed to the improvement in their performance. Thus, this thesis is expected to make several distinctive contributions to knowledge since it provides the first examination of the determinants and the economic role of inter-firm networks in the development of SMIEs in the Bandung garment industry, and is the first estimate of technological capabilities, competitiveness, and growth of SMIEs in Indonesia. To provide a better foundation for considering these three issues, this thesis starts by analyzing the development of both the Indonesian SMIEs and the Indonesian garment industry. Subsequently, this thesis constructs a theoretical framework by adopting a pluralistic theoretical approach. The theoretical framework emphasizes the importance of trust and competency as fundamental determinants for cementing the formation and operation of a network. The framework also highlights several advantages that SMIEs can enjoy from their involvement in a particular type of inter-firm networks. Using these initial analyses and the theoretical framework as guidance, a case study is then conducted by surveying 210 SMIEs in the garment industry in several specific locations of Bandung. The analysis outlined in this thesis indicates the important role of SMIEs in the Indonesian economy. SMIEs are able not only to create employment and generate income for both household economies and the national economy, but importantly also to contribute to Indonesias industrial exports. However, despite these important roles, the analysis of the survey (fieldwork) data also indicates that SMIEs suffer from a number of problems. It is found that most SMIEs surveyed face difficulties in securing and expanding their markets. They also have limited resources and access to capital, technology, and raw materials. The majority of SMIEs surveyed eased their problems by engaging in inter-firm networks. However, due to unfair practices, untrustworthy and incompetent partners, a significant number of them terminated and discontinued their engagement. Consistent with theoretical arguments, it is found that by developing inter-firm networks, SMIEs surveyed have an alternative solution to securing and expanding their markets. Furthermore, developing inter-firm networks provides opportunities to SMIEs to have better access to capital, technology, information, and raw materials. This suggests that inter-firm networks can be used as an important means of facilitating the development of SMIEs. Three important conditions may facilitate the preference of the majority of SMIEs surveyed to develop inter-firm networks. Firstly, entrepreneurs in the Bandung garment industry come from a similar socio-cultural background. Furthermore, Bandungs garment products are popular among many Indonesian for their up-to-date design, good quality, and competitive prices. This popularity attracts many enterprises from Bandung and other Indonesian cities to develop networks with Bandungs garment enterprises. In addition, by using a binomial logit model, it is found that several attributes of entrepreneurs, particularly educational background, correlate positively with the decision of SMIEs to develop inter-firm networks. The higher educational level of entrepreneurs, the more likely they are to develop inter-firm networks. The fact that the majority of entrepreneurs interviewed have a high level of educational background could be another reason why inter-firm networks have been adopted as a common strategy by the majority of SMIEs surveyed. This is because educational background correlates positively with the ability to build contacts and to communicate with others. The better entrepreneurs communicate with others, the more capable they are to develop inter-firm networks. In line with the theoretical argument, the analysis of the fieldwork data also indicates that trustworthiness and competency are fundamental determinants for the success of long-term inter-firm networks. Thus, to develop such networks, SMIEs need not only to build trust and competency, but also to find trustworthy and competent partners. This entailed several initial mechanisms being utilized by the SMIEs surveyed. Interestingly, the initial mechanism that SMIEs choose to develop inter-firm networks determines whether or not their networks can survive over a longer period of time. Indeed, as the estimates of the binomial logit model indicates, if entrepreneurs develop cooperation through mechanisms other than trade and industry associations and government programs, this increases the probability of long-term business cooperation. In contrast, if entrepreneurs develop business cooperation via trade and industry associations and government programs, this decreases the probability that cooperation will continue over a longer period of time. By using an ordered probit model, the analyses of the survey data also shows that inter-firm networks, together with several other variables, positively influence the performances of SMIEs surveyed. If SMIEs are involved in inter-firm networks, this increases their probability of improving their technological capabilities, expanding their markets, and accelerating their growth. However, the estimates of the ordered probit model also indicate that each type of inter-firm network brings a different positive impact. Engaging in more than one type of inter-firm network has a larger impact on improving the performances of SMIEs surveyed than involvement in one type of network. Also, entering a vertical inter-firm network (putting out and subcontracting) has a greater positive impact in enabling SMIEs to increase their business performances than entering into horizontal inter-firm network (clustering). The significant role of inter-firm networks in providing various benefits for SMIEs may in turn encourage the government to become involved in the promotion of inter-firm networks. However, by assuming SMIEs that can maintain their inter-firm networks over a longer period of time are those that succeed in developing their networks, it is found that such networks can only be developed successfully if they are based on economic and profit motivations. This suggests that the government should focus and limit its involvement in the promotion of inter-firm networks by only adopting market-oriented policy based on actual needs as articulated by SMIEs themselves. Indeed, as the SMIEs surveyed mention, instead of intervening directly, the government should pay more attention to the creation of conducive and stable legal and commercial (economic) conditions. Many SMIEs believe that such an environment is an important prerequisite not only to stimulate the development of inter-firm networks, but also to ensure that these work effectively. Without having to intervene directly, there are many ways in which the government can support the development of inter-firm networks. The first important one is to design and introduce a legal framework (laws) that can be used to solve commercial disputes of firms in a network. In addition, the government could eliminate various nuisance taxes and reduce tariffs and taxes on high quality imported inputs to enable SMIEs to develop inter-firm networks. Finally, the government should eliminate discriminatory policy against SMIEs and implement anti-monopoly laws to ensure that SMIEs and LIEs compete fairly.

The Economics of Alcohol in Australian Rural Communities

Dennis Petrie — 2010-05-13T00:00:00Z

Alcohol is a complex good which is ingrained within the social fabric of Australian culture. This is even more apparent within rural communities which are considered to have higher levels of risky alcohol consumption. While alcohol provides pleasure to many, it has devastating effects for others. Not only are individuals themselves affected, but also their families and the community at large. This thesis considers a number of the economic aspects associated with alcohol consumption in rural Australia. This thesis was completed in conjunction with a larger ongoing project: Alcohol Action in Rural Communities (AARC), which is a cost-benefit analysis of community-wide interventions to reduce alcohol-related harm in rural Australia. Given the study involves 20 rural communities in New South Wales, Australia; much of the analysis is centred around data collected from these communities. This thesis examines the amount and patterns of alcohol consumption, some of the associated harms, the value of reducing these harms, plus professionals’ and the public’s opinions on interventions, viewed as an optimal solution to reduce alcohol-related harm for the communities within this study. First, those factors which affect individuals’ decisions regarding how much alcohol to consume are examined through econometric modelling of the demand for alcohol. Moreover, a theoretical model is derived whereby individuals choose both the intensity and frequency of alcohol consumption in order to maximise their utility. This is then used to examine those factors that affect the relationship between intensity and frequency of alcohol consumption for individuals within the 20 communities of the study. Secondly, the impact that this alcohol consumption has in terms of the effect on morbidity, crime and traffic accidents within these 20 communities is analysed. The relationship between selfreported quality of life using the EQ5D (a quality of life instrument) and self-reported risky alcohol use are examined using ordered Probit and Tobit models. Also, the relationship between community levels of risky drinking and crime and traffic accidents that occur in alcohol-related times is analysed, controlling for the underlying level of crime in the community by using the rate of incidents that occur in non-alcohol-related times. It is found that rural communities in Australia are experiencing a sizeable amount of potentially avoidable harm due to risky alcohol use. Thirdly, the value of reducing alcohol-related harm in these communities, in terms of the amount households are willing to pay for these reductions, is estimated using contingent valuation methods. Individuals’ willingness to pay for a percentage reduction in alcohol-related harm is estimated using both a postal questionnaire for the 20 communities, plus a face-to-face questionnaire conducted in two of these communities. The face-to-face questionnaire is also used to conduct a double-bounded dichotomous choice experiment, to investigate the willingness of households to pay for a reduction in a number of different types of alcohol-related harm. Finally, the views on the optimal policy options to reduce alcohol-related harm for rural communities in Australia are examined for both professionals and the general public. A sample of drug and alcohol (D&A) professionals were asked to allocate a budget of $100,000 to a number of interventions in order to reduce alcohol-related harm in a hypothetical rural community. The D&A professionals most commonly selected interventions include training general practitioners (GPs), targeting high-risk groups, developing a harm-reduction code of practice, expanding social work services and the training of emergency department staff. Additionally, individuals from the general public were asked via a postal questionnaire to allocate a percentage of total funds to eight intervention areas in order to reduce alcohol-related harm in their communities. The top three intervention areas given the most funding, on average, by the public were school-based interventions, educational messages in the media, and greater police enforcement. There is no doubt that alcohol consumption causes a substantial amount of harm for rural communities within Australia. This thesis has provided information to inform the development of interventions tailored to specific communities and has derived estimates which can be used to help evaluate the cost-benefit of these interventions. There is still additional research to be done in order to obtain more accurate estimates of the exact effect alcohol has on rural communities and thus comprehensively evaluate which interventions are likely to be the most cost-effective in reducing this harm.

The Economics of Developing a Long-Distance Walking Track in North Queensland

Cook, Averil — 2008-11-21T00:00:00Z

Walking tracks with provision for overnight stays exist in many countries. They are a tourism drawcard and some (e.g. the Milford Track in New Zealand) have icon status. In Australia, long-distance tracks exist in most states but had not until recently been developed in north Queensland. The working hypothesis for this thesis is that a new long-distance walking track in the tropical rainforest environment could be a valuable recreation asset for the region, and a major tourism attractor. Since a long-distance walking track in a natural environment would be situated in a rural region away from major cities, there is potential for tourism expenditure by long-distance hikers to contribute positively to the economy of remote towns. It is proposed that a walking track can be created relatively easily in the rainforests if disused former logging roads are used as the basis. The new walking track on a logging road base could be developed at moderate cost, and with minimal ecological and environmental disturbance. A new track created within a protected natural area is usually regarded as a public good and most associated costs may be considered to be appropriately funded through the taxation system. However, it may be argued that the recreational use of a long-distance walking track provides benefits to those who use it, and that hikers should contribute towards the recovery of managerial costs. An appropriate level of user fee may be obtained from a market model. In this thesis, an annual market model is estimated for the recreation service which provides a short-term efficient price. A long-distance walking track is an investment in recreation infrastructure the benefits of which are intergenerational. Thus efficiency in the long-term is also an important consideration. Both a static analysis and cost-benefit dynamic analysis are presented in this thesis. When a track does not exist (as was the case in north Queensland when this thesis commenced) or when it is under construction (as when the thesis was nearing completion), direct evaluation is not possible and so demand (consumer surplus) and supply (marginal cost of recreation service) estimates for a new track must be obtained from other sources. A key original contribution in this thesis is the application of economic transfer to derive a market model for a proposed recreation service infrastructure item, and a further application of economic transfer involves the use of the benefit level from the market model as an input into the cost-benefit analysis. Demand estimates have been obtained from surveys of visitors on two other walking tracks in north Queensland. Zonal travel cost methodology has been applied to the survey data to develop demand curves for these long-distance hiking opportunities and measures of value in terms of consumer surplus. Zonal rather than individual travel cost was necessary since most respondents were walking the particular track for the first time. Since the Centenary of Federation in Australia in 2001, when seed funding was made available, some new long-distance walking tracks have been developed in the Queensland Wet Tropics World Heritage Area. One of these has been selected as the case study developing track for this thesis. Demand and cost estimates for the new trail have been transferred, with appropriate adjustments, from the studies conducted on the two other trails. An interesting feature in this transfer process is that close substitutes exist for the target walking track but not for either of the two source walking tracks. An innovation in this thesis is the development of a market model for the new track. Two market models are derived, one from each of the source tracks, and are used to determine the socially efficient price and visitation levels. These may be used by management as a basis for the setting of user fees. The equilibrium values obtained from the static analysis have also been incorporated into the dynamic analysis together with the consumer surplus estimates from the travel cost demand curve. The equilibrium quantities provide the basis for an estimate of the visitation level expected for the new track on which many of the continuing management costs depend. Two scenarios (with and without hut infrastructure) have been investigated in cost-benefit analyses. Both scenarios were found to be economically worthwhile.

The economics of developing water resource projects in the Ethiopian Nile River basin : their environmental, and transboundary implications

Mekonnen, Kefyalew. — 2011-09-14T00:00:00Z

The economics of interstate freight transport regulation and competition in West Malaysia

Gan, Saiu-Chiew. — 2011-07-11T00:00:00Z

THE ECONOMICS OF RENEWABLE ENERGY POLICY WITH SPECIAL REFERENCE TO AUSTRALIA

Ivanova, Galina — 2008-11-21T00:00:00Z

This thesis examines some aspects of the economics of the Australian Federal Governments Mandatory Renewable Energy Target (MRET) policy with a special reference to Queensland. The objective of this policy is to increase the market share of renewable energy technologies in the Electricity Supply Industry (ESI) in Australia. The Renewable Energy Certificates (RECs) market was established to achieve the desired market share of renewable energy technologies. These certificates are issued to renewable energy generators for each megawatt hour of eligible renewable electricity produced by generators. In Australia, electricity retailers and other large consumers of electricity have to buy a certain amount of RECs and then surrender RECs to the renewable energy regulator in order to comply with the policy. If retailers and other large consumers of electricity do not have the required amount of RECs by a certain day they have to pay a specified penalty. Renewable energy technologies are less emission intensive than conventional fossil-fuel electricity generation technologies. Therefore, the increased market share of renewable energy technologies is expected to result in reduced emissions from the electricity industry and corresponding improvements in environmental quality. The problem, however, is that private costs of producing electricity from renewable energy technologies are in general more expensive than private costs of producing electricity from conventional fossil-fuel generation technologies. Further, the recent structural reforms of the Australian electricity sector and removal of legal barriers to entry in generation have contributed to the private cost advantage which fossil - fuel electricity generation has in general over renewable technologies. This thesis investigates the options available to policymakers to internalise externalities in the ESI, the cost of emissions from the ESI, and benefits of increasing the market share of renewable energy technologies. It also looks at the renewable energy policies adopted in various countries. The thesis presents simulation models examining the impact of the MRET policy as if it were a state based scheme adopted by the state of Queensland. Models also illustrate how a carbon tax can change the merit order of the Queensland ESI. It highlights the advantages and disadvantages of the MRET policy. This thesis looks at the supply side by examining main components and effects of the Australian MRET policy including, using the methodology of experimental economics, the effects of the penalty for non-compliance in the context of a specific market structure. Increasing the market share of the renewable energy technologies is also approached from the demand side. This thesis examines consumers willingness to pay (WTP) to protect the environment. Important influences on WTP higher prices in order to protect the environment were analysed on the international and Australian levels using the 1993 and 2000 International Social Survey Programme (ISSP) data and the Australian data from the 2003 Australian Survey of Social Attitudes (AuSSA). This thesis also employs a contingent valuation survey that was developed to determine the extent to which consumers are willing to pay to protect the environment, to support the MRET policy and to pay for electricity generated from renewable energy. The contingent valuation survey was administered in Queensland. The simulation results indicated that there were enough available low cost renewable energy resources (such as biomass) in Queensland if the state were to adopt the Federal Governments MRET scheme policy objectives and policy instruments (such as RECs market and a penalty for non-compliance) as a state scheme. However, it is unlikely that all these resources will be employed due to several factors (e.g., the seasonal nature of some of the biomass resources, such as waste from sugar mills). Therefore the price of RECs could be quite high and just below the penalty. It was also concluded that the presence of a penalty for non-compliance in the RECs market can lead to a high RECs price. Wrong market price signals could lead to inefficient investments in renewable energy technologies. Several important results emerged from the analysis of WTP for the protection of the environment: 1) in most countries considered, marginal willingness to pay to protect the environment was less in 2000, than in 1993; 2) respondents were more inclined to state that they were willing to pay higher prices in order to protect the environment than they were to pay higher taxes; 3) respondents were more reluctant to pay for an environmental good if the good is provided on a very large scale, such as the global environment, compared with an environmental good provided on a small scale which impacts mainly the local environment; 4) WTP to protect the environment is associated strongly with perceptions of the risk of environmental destruction; and 5) although there are many similarities among the characteristics of the consumers in different countries who are willing to pay more for environmental protection, the country specific research is required to account for local specifics. The analysis of the data obtained by the Queensland survey showed that the demand side can support some investments in low cost renewable energy technologies. Consumers indicated a strong preference for voluntary support of support renewable energy technologies compared with the mandatory support as required by the MRET policy. Policy recommendations are presented.

The economics of the church-firm : a case study of Churches of Christ in New South Wales : a non-profit organisation

Fiedler, Mervyn Rupert George. — 2010-11-02T00:00:00Z

The Effect and Efficacy of E-government administration

Amy Cooper — 2011-11-30T00:00:00Z

Determining the optimum form of administration is the ideal of public administration theory. This thesis begins by acknowledging the long-standing debate between public administration theorists over the best way for governments to organise and manage for successful outcomes. E-government administration is a more recent entrant into this debate. This thesis determines the effect and efficacy of e-government administration by pursuing answers to the following three research questions: 1: What causes divergence between traditional and e-government administration structures? 2: How has e-government administration affected traditional public administration? 3: Which e-government administration style produces the best e-government outcome? Asking what caused the divergence between virtual and traditional administration structures results in two conclusions. First, the OECD e-government administration classifications provide a very useful framework and classified each case study’s e-government administration to show if and how they differed from traditional public administration structures. Second, the formal and informal institutions at play in a given country are the single greatest influence on the development of its particular e-government administration style. Next, the effect of e-government administration on public administration was researched in the context of two leading theories on the subject. Fountain’s (2001; 2006) Technology Enactment Framework suggests how e-government could affect public administration (Fountain 2001; 2006). Dunleavy et al.’s (2005; 2006) Digital Era Governance suggests the effect of this change has been to move governance beyond New Public Management trends to a new era of digital governance. Case study data supports both theories. This thesis contributes significantly to and modifies Fountain’s work, which until now has been most often tested on US data. Having three additional countries reflect Fountain’s Framework greatly assists its usefulness as an explanatory tool to illustrate how technology (here, e-government) affects institutional structures (or public administration). This research also contributes to Dunleavy et al. Though their theory had been tested in each case study country, the level of analysis was particularly deep in this research and yet remains in support of their proposition. Collectively, this research provides a pool of evidence in support of each theory that is too significant to allow either to be considered as significantly flawed. To provide a mechanism in which both can be considered accurate, it is argued that Fountain’s TEF provides the logisitical framework through which Dunleavy et al.’s DEG is able to take root. This line of argument also contributes to the broader public administration literature. The two dominant theories provided by Fountain and Dunleavy have not previously been tested in conjunction with one another. The argument that each supports the other has provided an alternate explanation to the usual juxtaposition of the two as contrasting viewpoints. Lastly, asking which e-government administration produces the best e-government outcome was designed to advance the field of public administration by testing centralisation theory. The question was designed to assist in the debate over the best way to organise and manage for successful outcomes. Researching its answer followed a logical progression that demonstrates no significant flaw and in fact works hard to dispel any concerns on that front. It was found that centralised administrations did not produce better e-government outcomes on a municipal, national nor global scale. The overwhelming indication of these results is that there is no causal relationship between centralised administrations and good e-government outcomes. This is not an insignificant finding. The pursuit of excellence in public administration, however defined, remains a key concern in developed countries. The OECD is even now in “talks with the producers of the major global e-government surveys with a view to launching new e-government indicators that focus on public sector performance” (Hicks 2010). For countries seeking public administration excellence in their online application of e-government, these results demonstrate that organising and managing e-government administration in a centralised fashion has not produced top quality e-government outcomes. In sum, this research has made the effect and efficacy of e-government administration clear. The efficacy of e-government is not tied to the centrality of its administration and its effect, brought about by how civil servants use and perceive technology, has been to usher in a new era of digital governance.

The effectiveness of CBT in the treatment of depression and anxiety occurring both in isolation and in conjunction with other serious psychiatric conditions as seen within a community mental health service.

Katherine Macdonald — 2009-10-15T00:00:00Z

Abstract Background: Cognitive Behaviour Therapy, (CBT) is well established as an effective treatment for depression. Its applicability in routine public mental health practice is however unknown, as most published studies excluded participants with suicide risk or if co-morbid with other disorders such as schizophrenia or bipolar affective disorder. Clients of public mental health services are characterised by symptom severity, chronic course of illness, treatment resistance and / or co-morbidity. In order to determine whether CBT has utility in routine public mental health practice, it is important to find out whether symptoms of depression (and anxiety) in this client population will respond to a course of CBT provided as part of standard care. Aims and Hypotheses: This effectiveness study aimed to ascertain if CBT is effective in treating depressed and/or anxious symptoms when such symptoms exist within the clinically more complex population found within Community Mental Health Services / Settings, (CMHSs). It was hypothesised that clients receiving CBT would show reliable and clinically significant improvement in symptoms of depression and anxiety but that the amount of improvement would be less than that reported in efficacy studies with less complex client groups. Method: This was a repeated measures, uncontrolled intervention study with results benchmarked against published data. Forty six adult clients of the Inner North Brisbane Mental Health Service (INBMHS) with diagnoses of Depression and / or Anxiety, in isolation or in conjunction with Schizophrenia, Bipolar affective disorder, or a Personality Disorder were treated with an eight (8) session manualised CBT program as part of routine clinical care. Standardised measures of depression, anxiety and stress were taken at time of referral, time of the commencement of treatment, time of treatment completion and at six-month post completion of treatment. Results: Participants showed reliable and statistically significant improvement in self reported symptoms from commencement to completion of treatment. Gains were retained at follow-up. Effect sizes were in the moderate to large range and improvements were clinically significant for approximately one third of the participants. Conclusions: CBT seems to be an effective treatment for depression and anxiety where such symptoms exist within a mental health population. Further research addressing the limitations of this study would add strength to the argument that the mental health population could benefit from the broad availability of such treatment.

The effectiveness of dialectical behaviour therapy in routine public mental health settings: an Australian controlled trial

Pasieczny, Nathan — 2013-03-11T12:38:22Z

THE EFFECTIVENESS OF KIKUYU PASTURES IN THE CAPTURE OF NITROGEN FROM DAIRY EFFLUENT ON THE ATHERTON TABLELANDS

Silver, Bradley Allan — 2008-11-21T00:00:00Z

Pressure on dairy farmers to remain viable since the industry was deregulated in July 2000 has accelerated the rate of production intensification. Milk is still produced on a year round basis in Queensland but now decreased milk price and increasing production costs are requiring farmers to intensify to a greater extent. The industry is still primarily pasture based but there is an increasing trend to feed larger numbers of cows in some form of purpose built intensive feeding system. Increased intensification results in an increased reliance on supplementary feeding, a greater need to ensure peak pasture production with fertiliser and more pressure on the waste management system. A common waste management system on the Atherton Tablelands of northern Queensland requires storage of all effluent in a single long term storage pond. This waste is then applied to pasture in the dry season through a sprinkler system. Alternatively effluent may be applied on a twice daily basis as yards are cleaned after milking. Although tropical grass can use large amounts of nutrient, potential loss of nutrients by run-off and leaching can occur in the wet season of tropical north Queensland when effluent is applied daily. This study was designed to test the management strategy of applying dairy effluent to a tropical pasture in summer when the pasture growth and therefore nutrient requirement is at its highest. The objective was to determine nutrient use efficiency of kikuyu and to determine leaching losses of nitrogen and therefore the potential environmental hazard. Stored dairy effluent was applied through the irrigation system at 0, 18.5, 42.4, 56.0 and 74.6 kg TKN ha‾¹ over the wet season to a kikuyu (Pennisetum clandestenin) dominant pasture which had been sown to annual ryegrass (Lolium multiflorum) the previous autumn. Irrigation water was applied at rates which were in inverse proportions to dairy effluent. Pasture yield was measured every three weeks over a 107 day period. No significant difference in total pasture dry matter yield, pasture growth rate, plant nitrogen percent or total plant nitrogen yield was measured. Total pasture yields were 5243, 5808, 6213, 6035 and 5836 kg DM ha‾¹ over 5 harvests. Pasture growth rate ranged from 33.4 to 78.9 kg DM day‾¹. Mean plant nitrogen yield was 161.8, 178.2, 194.2, 197.5 and 196.9 kg ha‾¹. There was no significant difference in soil N and soil cation concentration (except sodium) to a depth of 80 cm at the completion of the trial period. At 50 to 80 cm soil depths treatments 1, 4 and 5 were significantly different to treatments 2 and 3 in sodium concentration. There was no difference in soil N levels to a depth of 20 cm prior to or after the treatment application. Following extensive measurement and sampling of leachate it was calculated that 29.1 and 86.8 kg ha‾¹ of total N was leached to 50 cm from treatments 1 and 5 respectively. Measurements of soil N, plant N and leachate N indicate that there was a gain of 20 kg N ha‾¹ in the N budget for treatment 1 and a gain of 55 kg N ha‾¹ from the system during the trial period for treatment 5. Possible reasons for these results are discussed. The results indicate that it is difficult to apply dairy effluent to pastures during the summer wet season on the Atherton Tablelands without nitrogen losses through leaching. However given the large amounts of organic N and the potential for high rates of mineralisation, substantial N losses can occur without any additional N application. The results also suggest that the yield of a tropical pasture, which follows a well fertilised annual temperate pasture such as ryegrass, is not enhanced by the application of dairy effluent during this time. However, pasture quality may be improved by the application of dairy effluent.

The effect of aestivation on the musculo-skeletal system of the green striped burrowing frog, Cyclorana alboguttata

Hudson, Nicholas J. — 2007-08-24T00:00:00Z

The effect of alloy composition and microstructure on the hot cracking of vertical direct chill cast aluminium alloy billet

Instone, Stephen S — 2011-12-14T00:00:00Z

The effect of Australian gudgeon (Hypseleotris spp.) on phytoplankton in a subtropical reservoir, and implications for food web manipulation

Hunt, Richard Joseph — 2007-08-24T00:00:00Z

The effect of cadmium on benzo[a]pyrene-induced DNA damage and repair in Sprague-Dawley rats

Peng, Cheng. — 2007-08-24T17:52:15Z

The effect of case conferences between general practitioners and palliative care specialist teams on the quality of life of dying people

Geoffrey Keith Mitchell — 2007-08-24T00:00:00Z

The effect of cell hydrodynamics on flotation kinetics

Tabosa, Erico Oliveira — 2012-10-18T00:00:00Z

THE EFFECT OF CHRONIC LOW BACK PAIN ON THE SIZE AND ACTIVATION OF THE LUMBAR MULTIFIDUS MUSCLE

Wallwork, Tracy Leigh — 2008-11-21T00:00:00Z

The lack of control of lumbar stability is thought to be a major factor in the aetiology and chronicity of low back pain. The lumbar multifidus muscle is considered to play a significant role in maintaining lumbar stability and stiffness. The aim of this study was to use clinical measures to compare lumbar multifidus muscle in chronic low back pain patients and unimpaired subjects. Sixteen subjects with chronic low back pain and 16 unimpaired subjects were assessed in the study. Cross-sectional area (CSA) and contraction size of multifidus were measured on both sides and at individual vertebral levels, from L2 L5, using realtime ultrasound. The differences between the chronic back pain and unimpaired groups were statistically significant for both cross-sectional area and contraction size measures. In the unimpaired group, the contraction size of multifidus was greatest at the L5 segmental level, and then decreased in size at higher lumbar levels. In the chronic low back pain group, the contraction size was the same at L4 and L5 levels and contractions were less at these levels than those at L2 and L3. Three way interactions showed a significant interaction (p<0.05) between vertebral levels, change in thickness and group. Contrasts revealed a significant difference (p<0.05) between upper lumbar levels (L2 and L3) and lower lumbar levels (L4 and L5) across groups. In the unimpaired group, the contraction size of multifidus was greater at lower lumbar levels (L4 and L5) than upper lumbar levels (L2 and L3), while in the low back pain group, the contraction size was less at lower lumbar levels than upper lumbar levels. A similar pattern occurred with multifidus CSAs. In the unimpaired group, CSA was greatest at L5 and gradually reduced at higher lumbar levels. In the chronic back pain group, CSAs were the same at L5 and L4 and only slightly greater than L3. Two way interactions showed a highly significant difference (p<0.01) between groups across vertebral levels. There was a significant difference between upper lumbar levels (L2and L3) and lower lumbar levels (L4 and L5). Lower lumbar levels were less in the chronic low back pain group than the unimpaired group, when compared to upper lumbar levels. Estimated marginal means showed that CSA at L5 was significantly less in the chronic low back pain group (confidence interval >95%). Results of the study indicate that chronic low back pain patients have poorer muscle activation and greater muscle wasting of multifidus muscle at the lower lumbar levels compared with higher lumbar levels, than normal subjects. Clinical programmes should aim to restore multifidus muscle activation and size, in patients with chronic low back pain.

The Effect of Chronic Stress on Cellular Immunity: A Possible Alleviation by Praescent™

Neville Hartley — 2012-02-27T00:00:00Z

It is well known that chronic stress affects the immune system which is often suppressed during chronic stress affecting both cellular and humoral components of immunity. During chronic stress excessive reactive oxygen species (ROS) are also produced which contribute to cellular damage, inflammation, cancer, and immune dysfunction. This project investigates whether Praescent™, a mixture of plant derived chemicals; cis-3-hexen-1-ol (0.03%), trans-2-hexenal (0.03%) and alpha-pinene (0.015%), can alleviate the negative effects of chronic stress on cellular immunity. In addition it explores whether there is a correlation between high levels of ROS and immune suppression. To answer these questions C57BL/6 mice were restrained for 35 consecutive days (4 h/day), injected with an antigen (ovalbumin) and exposed aromatically to Praescent™. Stress hormones were determined by radioimmunoassay (RIA) measuring the total and free compartments of corticosterone within the blood plasma, and adrenals were weighed as a percentage of body weight to determine the physiological effects of chronic stress. The immunological response was evaluated using enzyme-linked immunosorbent assay’s (ELISAs) to quantify immunoglobulin-gamma (IgG) antibodies, and their subtypes IgG1 and IgG2a, and the ratio of IgG1 to IgG2a was also evaluated. Leukocyte numbers were determined by microscopy. The oxidative status was evaluated using 2′,7′-dichloro- fluorescin diacetate (DCFH-DA), a sensor of ROS. During chronic stress high levels of ROS were detected accompanied by a corresponding decrease in the number of leukocytes. In addition, there was a shift from cell-mediated immunity toward antibody-mediated immunity as evident by an increase in the IgG1 to IgG2a ratio. Praescent™ significantly reduced ROS levels and prevented the reduction of leukocytes following chronic stress; however it did not prevent the stress-induced shift toward an antibody-mediated immunity. Furthermore, Praescent™ prevented the stress-induced increase in adrenal weights. These results suggest that Praescent™ is an effective agent alleviating oxidative stress and preventing stress-induced alterations to the immune system.

The Effect of Comminution Mechanism on Particle Properties: Consequences for Downstream Flotation Performance

Timothy Vizcarra — 2011-03-31T00:00:00Z

Many particle properties critical to the flotation process originate from the comminution stage. A better understanding of how these properties are affected by the methods of particle size reduction used will help determine whether current strategies for comminuting ores can be modified to further enhance particle floatabilities. This thesis investigates how different comminution mechanisms affect the properties of ore and mineral particles and assesses how changes to these properties subsequently affect flotation performance downstream. Three ores were selected for this study: Northparkes (a low-grade, copper porphyry ore); Ernest Henry (an iron-oxide hosted copper-gold ore); and Century (a high-grade strataform zinc ore). These were each comminuted to various particle size distributions using a hammer mill and a piston-die compression unit (simulating the breakage mechanisms used by high pressure grinding rolls). Progeny particles were then characterised using the JKMRC’s mineral liberation analyser (MLA) on a size-by-size basis. It was found that size-by-size liberation properties were independent of both the mechanism used to comminute the ore samples, as well as the final size distribution of the progeny particles. This was observed for both valuable and gangue mineral phases. Variations in the liberation properties of a mineral in a given size fraction were explained in terms of the effect of mineral grade upon the statistical uncertainties of liberation measurements. Rather than being dependent on the method of breakage used to comminute an ore, liberation properties were instead found to be dependent on the mechanical properties of associated mineral phases. Where large differences existed between the mechanical properties of associated minerals, the “harder” mineral was found to be conserved during the breakage process, deporting directly to high-grade liberation classes upon size reduction without forming composite particles. These effects were not observed for “softer” minerals. The mechanism of comminution used was not found to have any effect on the liberation properties of the discharge particles. However, relationships were found between the shape properties of particles (quantified using the MLA) and the breakage devices from which they were discharged. Samples comminuted in the hammer mill were found to be comparatively more round than those discharged from the piston-die compression unit which, conversely, were more angular. This was attributed to rebreakage events during the hammer mill grinding process whereby topographical features on particle surfaces (such as sharp edges and corners) were chipped away, resulting in the production of round, spherical particles. The effect of particle angularity on flotation performance was subsequently tested by floating sized, fully liberated chalcopyrite particles that were comminuted in either the hammer mill or piston-die compression unit, and retrospectively analysing the angularity properties of the timed concentrates. It was found that, in the absence of collector, angular chalcopyrite particles exhibited faster flotation kinetics than comparatively round particles, likely due to the enhancement of particle-bubble adhesion mechanics as hypothesised by past studies. Additionally, surface chemistry analysis conducted in collaboration with the Ian Wark Research Institute also showed that the comparatively angular concentrates also had higher degrees of surface coverage by hydrophobic polysulphide species, and this is also likely to have contributed to their faster flotation kinetics. The results of this thesis clearly show that mineral liberation properties cannot be controlled by the method of breakage used. However, it is expected that the results will aid in the development of both empirical as well as fundamental mineral liberation models. Additionally, it is shown that a potential method of enhancing particle floatability during the comminution stage is through the manipulation of particle shape properties. This has important implications for the development of property-based flotation models as well as for the eventual integration of comminution and flotation models.

The effect of deeply subducted oceanic slabs and associated sediment on the chemical evolution of the mantle and on mantle-derived melts

Murphy, David Thomas. — 2011-07-11T00:00:00Z

The effect of developmental temperature on muscle morphology and growth of mangrove jack Lutjanus argentimaculatus, silver perch Bidyanus bidyanus and barramundi Lates calcarifer

Carey, Geoff — 2008-11-21T00:00:00Z

The early growth and development of fish muscle is highly temperature dependent. Changes in the thermal regimes of developing fish embryos can induce differences in the number and size of muscle fibres (muscle cellularity) in just hatched larvae. These differences show considerable variation, with the complex pattern of magnitude and longevity of myogenic change showing high species-specificity. Myogenic responses to early temperature in several fish species studied so far show no inter-species/genus patterns, although responses are repeatable within species/genus. In some species, a higher than normal incubation temperature increases muscle cellularity, whereas in others, a lower incubation temperature increases muscle cellularity. As early muscle cellularity can be a strong predictor of future growth patterns in fish, this response has prompted considerable scientific interest. Early muscle cellularity may also influence recruitment success, locomotor ability, and ultimately fitness, and as such it is important to improve understanding in this area. In this study, just fertilised eggs of mangrove jack Lutjanus argentimaculatus, silver perch Bidyanus bidyanus and barramundi Lates calcarifer were introduced to three different incubation temperatures, to assess the effects on early muscle growth and development. The thermal regimes applied to each species corresponded to an ambient (spawning) temperature, a warm temperature, and a cool temperature, all within the particular thermal tolerances of that species. Larvae of B. bidyanus and L. calcarifer were on-grown to assess subsequent effects of incubation temperature. Additionally, five day old larvae of L. calcarifer were transferred from the high and low temperatures back to ambient temperature to ascertain the effects on muscle parameters, growth rates and locomotory ability. These species were chosen as ideal candidates for examination in this study as they are important aquaculture species both in Australia and internationally, and all have well established hatchery protocols offering a reliable supply of fertilised eggs. Also they allow the examination of early thermal effects on both salt-water spawning (L. argentimaculatus, L. calcarifer) and fresh-water spawning (B. bidyanus) species. After retrieval from spawning tanks, fertilised eggs of L. argentimaculatus were incubated till hatch at 26°C (cool), 29°C (ambient) and 32°C (warm); those of B. bidyanus were incubated at 22°C, 25°C and 28°C; and those of L. calcarifer were incubated at 26°C, 29°C and 31°C. Warmer incubation temperatures hastened hatching in all three species, whereas cooler incubation temperatures delayed hatching. Average time to 50% hatch of L. argentimaculatus incubated at 26, 29 and 32°C was 19, 17.5 and 13 hours, respectively; of B. bidyanus incubated at 22, 25 and 28°C was 37, 34 and 30 hours, respectively; and of L. calcarifer incubated at 26, 29 and 31°C was 19, 15 and 13 hours, respectively. Incubation temperature had a significant effect on the length of just-hatched B. bidyanus, with incubation at 22°C producing shorter larvae (3.49 ± 0.09 mm) than those incubated at 25°C (4.18 ± 0.09 mm) or 28°C (4.39 ± 0.09 mm). By 12 days post-hatch, however, those incubated and grown at the warm (28°C) temperature were significantly longer (6.73 ± 0.14 mm) than those grown at 25°C (5.92 ± 0.22 mm). The length of just hatched L. argentimaculatus or L. calcarifer was unaffected by incubation temperature, although by nine days post-hatch barramundi incubated and grown at the warm (31°C) temperature were significantly longer (4.90 ± 0.18 mm) than those incubated and grown at 29°C (4.22 ± 0.23 mm), 26°C (3.95 ± 0.13 mm), or transferred from the warm (3.98 ± 0.25 mm) or cool (4.01 ± 0.21 mm) temperatures. Transverse sections of just hatched larvae from all incubation temperatures showed muscle components at an immature stage of development, revealing myotubes yet to differentiate to mature inner (white) muscle fibres. Incubation temperature had a significant effect on the number of immature inner muscle fibres in just hatched L. argentimaculatus and L. calcarifer, with incubation at the warm temperature increasing fibre number in L. argentimaculatus (315.60 ± 13.07 for those incubated at 32°C, 275.00 ± 16.90 for those incubated at 29°C, 253.00 ± 13.80 for those incubated at 26°C); and incubation at the cool temperature increasing fibre number in L. calcarifer (350.00 ± 14.21 for those incubated at 26°C, 327 ± 11.44 for those incubated at 29°C, 292.00 ± 14.49 for those incubated at 31°C). Conversely, inner muscle fibre area significantly increased at the warm incubation temperature in L. calcarifer (12.23 ± 0.66 µm2 for those incubated at 31°C, 9.75 ± 0.45 µm2 for those incubated at 29°C, 10.33 ± 0.75 µm2 for those incubated at 26°C), whereas incubation at the cooler incubation temperatures increased inner muscle fibre area in L. argentimaculatus, although not significantly (P = 0.09). Inner muscle fibre cellularity of just hatched B. bidyanus was unaffected by incubation temperature. The total area of superficial (red) muscle fibres and the proportion of superficial to total fibre area in just-hatched L. calcarifer were significantly affected by incubation temperature, with incubation at the cool temperature (26°C) increasing both the total area (1816.23 ± 136.16 µm2) and proportion (0.21 ± 0.01) of superficial muscle fibres compared with incubation at 29°C (974.95 ± 108.42 µm2 and 0.14 ± 0.01 for total superficial fibre area and proportion of superficial to total muscle fibre area, respectively) and 31°C (1049.09 ± 70.60 µm2 and 0.13 ± 8.7 x 10-3). These parameters were unaffected by incubation temperature in L. argentimaculatus and B. bidyanus. By nine days post-hatch, differences in the total superficial fibre area between non-transferred and transferred treatment groups of L. calcarifer were no longer significant, whereas differences in the proportion of superficial to total muscle fibre area still were, with those hatched and grown at the warm (31°C) temperature having a significantly reduced proportion of superficial muscle area (0.05 ± 6.66 x 10-3) compared with those incubated and grown at 29°C (0.08 ± 7.77 x 10-3) and 26°C (0.09 ± 5.66 x 10-3), and those incubated at 26°C and transferred to 29°C (0.07 ± 5.31 x 10-3), and incubated at 31°C and transferred to 29°C (0.06 ± 6.91 x 10-3). Growth rates of L. calcarifer from the five treatment groups were assessed over a 12 week trial. Differences in mass and standard length increase between treatment groups were not significant (P = 0.060, P = 0.071 for mass and standard length after twelve weeks, respectively). However, differences between treatment groups increased between six and 12 weeks (P = 0.075, P = 0.100 for differences in mass and standard length after six weeks, respectively), indicating that a longer period of testing may have resulted in significant growth differences between treatment groups. Additionally, mass increased considerably more in the group incubated at the coolest temperature and transferred to the control temperature (26/29°C), than in any other treatment group (37.10 % more than the 26/26°C group, 23.80 % more than the 29/29°C group, 21.00 % more than the 31/29°C). It is proposed that the superior mass increase seen in this treatment group may have been imprinted on the myogenic program of L. calcarifer after incubation at the cool (26°C) temperature, which resulted in an increase in inner muscle fibres at hatch, and a subsequently improved growth rate. There was no evidence that incubation temperature affected the burst (Umax) or sustained (Ucrit) swimming ability of L. calcarifer. However, barramundi incubated and reared at the cool (26°C) temperature performed significantly better at 26°C test temperature (101.76 ± 3.70 cm.s-1) than those of other treatment groups (83.22 ± 6.29 cm.s-1 for the 29/29°C group, 85.40 ± 9.70 cm.s-1 for the 31/31°C group, 87.30 ± 4.10 cm.s-1 for the 26/29°C group, 76.42 ± 5.93 cm.s-1 for the 31/29°C group), indicating the ability of L. calcarifer to thermally acclimate burst swimming. Additionally, swimming ability was significantly affected by the test temperature, with Umax of fish from all treatments highest at 29°C test temperature, and the swim speeds of all treatment groups combined significantly lower at 26°C for Umax (86.90 ± 2.80 cm.s-1 at 26°C, 103.20 ± 3.40 cm.s-1 at 29°C, 96.90 ± 3.90 cm.s-1 at 31°C) and Ucrit (58.89 ± 8.90 cm.s-1 at 26°C, 60.90 ± 6.50 cm.s-1 at 29°C, 62.40 ± 6.20 cm.s-1at 31°C). Lower test temperature therefore tended to depress both burst and sustained swimming ability in L. calcarifer. The positive results from this study indicate that the growth rate of L. argentimaculatus and L. calcarifer may be enhanced by the application of thermal manipulation in the hatchery phase of development. Additionally, there was a demonstrated affect of early thermal regimes on the subsequent swimming ability of L. calcarifer. Possible implications and future directions for this research are discussed.

The effect of developmental vitamin D3 deficiency on brain development, behaviour and immune function in the Sprague-Dawley rat

Louise Harvey — 2009-03-23T00:00:00Z

Epidemiological evidence from season of birth and migrant studies has led to the proposal that developmental vitamin D3 (DVD) deficiency may be a risk factor for schizophrenia. Concurrently, there has been recent intense interest in vitamin D3 as a modifying factor in the development of immune responses. However, the effects of DVD deficiency on immune function remains unknown. Thus, a model of DVD deficiency has been developed in Sprague-Dawley rats. Briefly, female rats were maintained on a vitamin D3 deficient diet prior to and during gestation. At birth dams were returned to a vitamin D3 replete diet. Post-weaning their offspring, the DVD-deficient rats, were maintained on a vitamin D3 replete diet. Therefore, this model represents a transient, prenatal vitamin D3 deficiency. A number of structural and cellular changes have been described in the DVD-deficient rat brain, including ventriculomegaly, decreased growth factor expression, and increased rates of mitosis. These changes are correlated with altered adult behaviour in the DVD-deficient rat, including a locomotor sensitivity to novelty. This thesis will focus on extending these findings and characterising immune function in the DVD-deficient rat. Vitamin D3 can affect cellular differentiation and is anti-proliferative and pro-apoptotic in many tissues including the brain. The effect of DVD deficiency on brain development has been restricted to neuronal cells in vivo and in vitro. However, the effect of this exposure on glial cell maturation and phenotype was unknown. The experiments reported in this thesis demonstrated that primary cortical glial cell cultures from DVD-deficient rat neonates displayed a similar phenotype and maturational status compared with cells from control rats. Learning and memory was examined in this model by exploring the phenomenon of latent inhibition. DVD-deficient rats displayed normal latent inhibition, however, they exhibited a subtle performance acquisition deficit during the early stages of the conditioned avoidance learning task. Extended handling and pre-exposure were able to ameliorate this deficit, though with this treatment normal latent inhibition was also abolished in both control and DVD-deficient rats. Ultrasonic vocalization and nociceptive threshold testing confirmed that alterations in peripheral sensation could not explain this performance acquisition deficit. The results suggested that anxiety or attentional mechanisms may have contributed to this rate of learning deficit. Finally, as vitamin D3 is a powerful immunoregulator, there is the potential for a transient DVD deficiency to induce a persistent alteration in the development and function of the immune system. This hypothesis was supported by findings that showed DVD deficiency resulted in a primed immune system, as indicated by an enlarged spleen, thymus and peripheral lymph tissue as well as increased pro-inflammatory cytokine production in response to an in vitro stimulation. However, these findings did not lead to an alteration in cell mediated immune response in vivo. The results from the research reported in this thesis indicate that a transient, prenatal vitamin D3 deficiency had a subtle yet significant effect on the immune system and behaviour of the adult rat. These findings add further weight to the body of evidence that link prenatal vitamin D3 status to various adverse health outcomes. The DVD-deficient rat model is an integral step in understanding prenatal vitamin D3 deficiency as a potential environment risk factor in the development of immune and psychiatric disorders.

The effect of elevated temperature on the ability to preserve disused muscle during metabolic depression in the aestivating ectotherm, Cyclorana alboguttata

Young, Karen Melissa — 2012-11-06T00:00:00Z

The effect of enacted capabilities on adoption and utilisation of innovative information systems : a study of small- and medium-sized enterprises.

Salleh, Noor Akma Mohd — 2008-11-21T00:00:00Z

This thesis is motivated by the need to establish a model covering innovative information systems (IS) adoption behaviours within small and medium-sized enterprises (SMEs). Studies on adoption behaviour related to innovative IS are devoting increasing attention to SMEs. Most prior studies, however, have still relied on models developed from studies of large firms. The applicability to SMEs of findings and models developed from large firm studies is not without question as SMEs are not miniature versions of large firms. SMEs face different challenges and opportunities from large firms. This thesis empirically examined issues on the adoption behaviours of innovative IS by SMEs. In line with this objective, two research questions were established. First, what are the critical determinants that allow SMEs to overcome inhibiting factors and adopt an innovative IS? Second, what are the critical determinants that ultimately activate and stimulate them to become enabled and actively utilise an innovative IS? The conceptualisation of enacted capabilities, adapted from the resource-based view of the firm is introduced. This thesis postulates that appropriate enacted capabilities facilitate SMEs to become enabled and actively utilise an innovative IS. These enacted capabilities include the level of IT skills and knowledge of the enterprises members, trust in technology, trust in trading partners, external experts support, and organisational culture Models incorporating aspects of the theory underlying the technology acceptance model (Davis, 1989), the diffusion of innovation theory (Rogers, 1995), and the resource-based view of the firm (Barney, 1991) were developed to describe the causal linkages between the determinants that activate and stimulate innovative IS adoption behaviour (i.e., from adopting to enabling to utilising innovative IS). One model was developed for the adoption stage and a second for the enablement and utilisation stages. The adoption stage model contains three main hypotheses. The first two hypotheses propose that enacted capabilities have a positive direct effect on both perceived net benefits and attitude towards adoption from a competitive advantage perspective. The third hypothesis proposes that perceived net benefits have a positive effect on attitude towards adoption form a competitive advantage perspective. The enablement and utilisation stages model contains four main hypotheses. The first two hypotheses propose that enacted capabilities and attitude have positive effects on perceived net benefits. The last two hypotheses propose that perceived net benefits and attitude towards adoption from a competitive advantage perspective have positive effects on the extent of enablement and usage of innovative IS. The hypotheses are tested using data obtained via a survey and follow-up interview. Responses were received from 206 SMEs of varying industries and sizes from the survey. Out of these 206 SMEs, follow-up interviews were conducted with twenty-one SMEs. The interviews utilise a combination of both open and closed questions. The questions for the follow-up interviews were based on findings derived from the survey. The innovative IS examined was the Malaysian governments electronic procurement system, known as ePerolehan. All government suppliers must register for the system and become enabled for use before they can start utilising the system. The results indicate that enacted capabilities possessed by SMEs affect perceived net benefits at all stages of adoption behaviours of SMEs (i.e., adoption, enablement and utilisation). More significantly, two aspects of enacted capabilities, top management IS skills and knowledge and trust in trading partners dominate the effect on perceived net benefits. Support from external experts dominates the effect on attitude at the adoption stage. Top management IS skills and knowledge and trust in technology have a negative effect on attitude at the time of adoption. Enacted capabilities also contribute to the extent of enablement and usage within SMEs. Furthermore, different categories of adopters differ in the set of enacted capabilities underlying their innovative IS adoption behaviour. Results also indicate that when SMEs perceived higher net benefits in adopting innovative IS, they have a positive attitude. The positive attitude generated at the time of adoption has a direct effect on the extent of enablement and usage. The influence of perceived net benefits differs at the different stages of adoption behaviour. At the utilisation stage, usage is affected by perceived net benefits, however, perceived net benefits do not affect the extent of enablement at the enablement stage. In conclusion, this thesis found that enacted capabilities display important roles as antecedents to perceived net benefits, and that perceived net benefits act as a mediator from enacted capabilities to attitude at the adoption stage. Enacted capabilities also display important roles as stimulators of the extent of enablement and usage. Thus, apart from requiring good ideas and financial resources, SMEs also require appropriate enacted capabilities when adopting, enabling and utilising innovative IS.

The Effect of Exercise on Cancer Risk Factors in Males with Barrett's Oesophagus

Brooke Maree Winzer — 2012-06-18T00:00:00Z

The incidence of oesophageal adenocarcinoma is rising faster than any other cancer. Overweight and obese males are at a particularly high risk of this cancer, especially those with the pre-malignant lesion, Barrett's oesophagus. If Barrett's oesophagus does progress to adenocarcinoma, prognosis is poor with a 5 year survival rate of 10-15%. At present there is a lack of evidenced-based interventions aimed at reducing oesophageal cancer risk in persons with Barrett's oesophagus. Oesophageal adenocarcinoma and Barrett's oesophagus have strong links with gastro-oesophageal reflux disease, overall body fatness and more specifically, abdominal obesity. Mechanisms mediating the positive relationship between adiposity and oesophageal adenocarcinoma may include the exacerbation of gastro-oesophageal reflux disease through mechanical factors, however metabolic mechanisms related to obesity may also be involved including altered concentrations of a number of obesity-related hormones. Exercise may be beneficial for those with Barrett's oesophagus due to its effects on reducing adiposity and improving levels of some obesity-related hormones; and possibly via reducing gastro-oesophageal reflux. Therefore exercise may be a suitable and feasible lifestyle treatment to lower oesophageal adenocarcinoma risk. However no trials have been conducted to date in adults with Barrett's oesophagus to evaluate the effect of exercise on mechanisms or "biomarkers" implicated in oesophageal adenocarcinoma development. The overall aim of this thesis is therefore to further understand the capacity of exercise to modulate oesophageal adenocarcinoma risk. To address this aim, two studies were undertaken: a systematic literature review and a randomised controlled trial. A systematic literature review was conducted to appraise previous trials evaluating the effect of exercise interventions on candidate biomarkers associated with cancer development. Findings of the review were used to inform the development of an exercise trial in persons with Barrett's oesophagus. A randomised controlled trial of exercise versus stretching was conducted in inactive males with Barrett's oesophagus (n = 33), aged 18 to 70 years, who were overweight or obese (body mass index 25.0 - 34.9 kg/m2). Participants were randomised to receive either a 24-week, moderate-intensity aerobic and resistance exercise intervention (60 min, 5 sessions/week) or stretching (45 min, 5 sessions/week). Outcomes were measured at baseline, 12-weeks and 24-weeks and included body composition (bio-impedance spectroscopy), abdominal adiposity (waist circumference), gastro-oesophageal reflux symptoms (Gastro-oesophageal Reflux Disease Impact Scale) and circulating concentrations of leptin, adiponectin (total, high molecular weight), C-reactive protein, interleukin-6, tumour necrosis factor-alpha, insulin and glucose. Insulin resistance was determined using homeostasis model assessment (HOMA) score. An intention-to-treat analysis was conducted as the primary analysis using generalised linear models. In addition, per-protocol and dose-response analyses were performed as an exploratory exercise. In total, 32 men (97%) completed the study. Men in the intervention group exercised an average of 4.2 hours/week. Compared to the control group, the exercise group recorded larger improvements in fitness and strength following 12- and 24-weeks of intervention, indicating good levels of adherence. From baseline to 24-weeks, reductions in waist circumference were greater in the exercise group compared with the control group (adjusted intervention effect -4.5 [95% CI -7.5, -1.4] cm; p < 0.01). Reductions in fat mass were also greater in the exercise group than the control group however the difference was non-significant (adjusted intervention effect -1.7 [95% CI -4.9, 1.7] kg; p = 0.32). Compared with controls, the exercise group recorded greater reductions in leptin levels (adjusted intervention effect -3.0 [95% CI -6.4, 0.5] ng/mL; p = 0.09). Changes in gastro-oesophageal reflux symptoms, C-reactive protein, interleukin-6, tumour necrosis factor-a and adiponectin levels did not differ between the groups, however levels of C-reactive protein, insulin and total adiponectin significantly decreased within both groups (p < 0.05). This novel and exploratory exercise trial found beneficial changes in a number of candidate biomarkers associated with oesophageal adenocarcinoma risk in males with Barrett's oesophagus including abdominal obesity, fat mass, leptin, insulin and insulin resistance. These findings, along with those from previous exercise trials in populations with a number of risk factors for breast and colon cancer, suggest that exercise can modulate various metabolic and hormonal pathways implicated in cancer development.

The effect of harvest date on the composition and quality of macadamia nuts

Netiwaranon, Siriwan. — 2007-08-24T18:01:21Z

The effect of heifer dietary protein intake during gestation on fetal and postnatal development of their progeny: attention to the circulatory IGF-axis and the autocrine IGF-axis of skeletal muscle and adipose tissue

Gina Micke — 2011-10-13T00:00:00Z

The beef producing northern pastoral and southern agricultural zones of Australia share an inherent seasonal pattern of pasture quantity and quality. Protein deficiency is a feature of dry season pastures in the northern pastoral zone, whilst protein oversupply is a feature of improved and legume based pastures in the southern agricultural zone. Maternal nutrient intake during gestation has been linked to perturbations to the postnatal growth pathway, the body composition and the metabolism of their progeny. This thesis investigates the effect of heifer (n = 120) protein intake during the first two trimesters of gestation on fetal (n = 71) growth; dystocia and progeny (n = 68) postnatal growth. It also investigates this effect on the circulatory, skeletal muscle and adipose tissue insulin-like growth factor (IGF) axes of the progeny. The study was based at Goondiwindi, Australia (latitude 28.52S, longitude 150.33E) and consisted of a two-by-two factorial design. On the day of artificial insemination (AI), heifers were allocated by stratification by weight and genotype to one of four treatment groups. Treatment groups were defined by the amount of crude protein (CP) fed to each heifer during the first (AI to 93 days of gestation (gd)) and second (94 to 180 gd) trimesters of gestation (HH: first trimester = 1.4 kg CP/d and 76.3 MJ ME/d, second trimester = 1.4 kg CP/d and 82.4 MJ ME; HL: first trimester = 1.4 kg CP/d and 76.3 MJ ME/d, second trimester = 0.4 kg CP/d and 63.1 MJ ME/d; LH: first trimester = 0.4 kg CP/d and 62.5 MJ ME/d, second trimester = 1.4kg CP/d and 82.4 MJ ME/d; LL: first trimester = 0.4kg CP/d and 62.5 MJ ME/d, second trimester = 0.4 kg CP/d and 63.1 MJ ME/d). All heifers were fed 1.06 kg CP/d and 71.45 MJ ME/d from 181 gd until parturition. Progeny remained with their mothers until weaning at 191 days of age (d). From weaning until 401 d they were managed as a single group grazing native pastures at Goondiwindi. From 401 d they were managed as part of a larger group of yearling cattle at Surat, Queensland (27°16′S, 149°07′E) before commencing an intensive feedlot finishing program at 541 d at Dalby, Queensland (27°18′S, 151°26′E). They were commercially slaughtered at 680 d. Heifers fed low compared to high protein diets during the first trimester of gestation had smaller fetuses at 39 gd and progeny with greater expression of IGF-IR mRNA in their SC adipose tissue at 680 d. There were further sex-specific effects of heifer diet during the first trimester of gestation. Male progeny exposed to maternal diets low in protein during the first trimester of gestation were heavier and leaner during the post-weaning period and had greater cross-sectional areas of their semitendinosus and longissimus dorsi muscles when compared to their high protein exposed counterparts. These changes were accompanied by greater IGF-I and IGF-II mRNA expression in their semitendinosus muscle and lower LEP mRNA expression in their PR adipose tissue at 680 d. In contrast, female progeny exposed to maternal diets low in protein during the first trimester of gestation were lighter and of smaller stature during the post-weaning period which resulted in them having lighter carcasses at 680 d. In addition they had greater expression of IGF-IIR mRNA in their semitendinosus muscle but decreased expression of IGF-I mRNA in PR adipose tissue at 680 d when compared to their high protein exposed counterparts. In comparison, heifers fed low protein diets during the second trimester of gestation had lower birthweight calves, an effect that persisted to 29 d, in addition to having calves with greater plasma NEFA concentration at birth than those that were fed high protein diets during the same period. These progeny went on to have greater cross-sectional area of their longissimus dorsi muscle at slaughter; greater expression of IGF-IR mRNA in their semitendinosus muscle, IGF-II mRNA in PR adipose tissue and LEP mRNA in OM adipose tissue, but lesser expression of IGF-IR, IGF-II and IGF-IIR mRNA in their omental adipose tissue at 680 d when compared to their high protein exposed counterparts. A change to maternal diet from high to low protein, or visa versa, at the end of the first trimester of gestation resulted in a male offspring with greater plasma IGF-I concentrations during the postnatal period compared to their counterparts exposed to a constant plane of nutiriton. Importantly, pelvic area measurements obtained prior to conception remained valid in their assessement of the relationship between pelvic area and the likelihood of dystocia occurring in the event of changing maternal nutrient intake during gestation. Heifer protein intake during gestation has a permanent sex-specific effects on: fetal and postnatal growth; the endocrine IGF-axis of progeny; and the autocrine/paracrine IGF-axes of skeletal muscle and adipose tissue of the progeny. These findings may assist cattle producers to optimise both welfare and financial outcomes for the heifer herd.

The effect of infestation with the Australian paralysis tick, Ixodes holocyclus, on thermoregulation and respiration in the dog

Fearnley, C. E. A. (Cecily E. A.) — 2008-11-21T00:00:00Z

The effect of intra-muscular components of oxidative phosphorylation on the rate of phosphocreatine resynthesis following intense exercise

McMahon, Shaun A.J. — 2010-10-29T00:00:00Z

The Effect of Mental Workload on Decision Making in Air Traffic Control

Selina Fothergill — 2010-08-23T00:00:00Z

The aim of the present research was to examine the impact of mental workload on conflict resolution decision making in air traffic control (ATC). While previous studies have examined the effect of workload on performance (Averty, 2004; Kopardekar & Magyrits, 2002) and conflict detection (Mogford, 1997; Seamster, Redding, Cannon, Ryder & Purcell, 1993), limited research examines the effect of workload on conflict resolution decisions. The aim of the first study was to gain an initial understanding of how controllers manage their airspace. Results demonstrated that controllers scan repetitively, in a clockwise and top-bottom pattern; group aircraft with similar characteristics and use at least five lateral and eight vertical conflict resolution heuristics. Study two examined the effect of conflict type on conflict resolution under different levels of workload. Under moderate workload controllers used a mix of solutions, while under high workload, solutions became more conservative. Study three examined the effect of other contextual factors on conflict resolution. Results again suggested conflict type affects conflict resolution decisions and also that other contextual parameters, such as aircraft performance may play a role in solution preferences. Study four examined the effect of workload on conflict resolution using a realistic ATC task. Workload not only impacted on controllers’ performance scores, but interacted with conflict type to determine whether an efficient solution was preferred over a less efficient solution. This research identifies some of the heuristics experts use when competing priorities are present and provides an understanding of how conflict type, contextual factors and workload affect decisions. Findings contribute to the naturalistic decision making (NDM) literature by demonstrating how the situation can influence decision making.

The effect of particle size collector coverage and liberation on the floatability of galena particles in an ore

Vianna, Sérgio Maurício S. M. — 2007-08-24T00:00:00Z

THE EFFECT OF PREHARVEST NUTRITION AND CROP LOAD ON FRUIT QUALITY AND POSTHARVEST DISEASE IN MANGO (Mangifera indica L.)

Bally, Ian Stephen Edward — 2008-11-21T00:00:00Z

The aim of this thesis was to investigate how preharvest calcium (Ca) and nitrogen (N) nutrition, and low crop load during fruit development affect fruit quality and postharvest disease of Keitt mangoes (Mangifera indica L). Calcium, N and crop load were chosen because previous research and Gower reports implicate them as major factors in internal disorders, poor colour development, and postharvest disease in mangoes grown in the Mareeba district of Queensland. The symptoms and incidence of the internal fruit disorders seen in Keitt mangoes growing in Queensland were investigated to determine their similarity to other forms of internal disorders, and to develop a severity rating scale to assess fruit in later experiments. While the observed disorder in Keitt shared some symptoms with other named forms of disorders, not all symptoms were similar. The typical symptoms of patches of watery translucent flesh that breakdown and discharge cellular fluids in the more severe cases, are referred to as watery-pulp breakdown throughout this thesis. Watery-pulp breakdown-affected fruit had lower mesocarp Ca concentrations (0.05% dw) than healthy fruit (0.10% dw), but not N, K, P, and Mg concentrations. The severity of symptoms increased as maturity of the fruit increased, and early harvest may be a useful strategy to minimise the disorder. The first nutrition experiment investigated the effects of Ca, N and crop load on fruit quality in 6-year-old Keitt trees, between 1997 and 2000. Trees were fertilised with high (>1 kg Ca tree-1 and >300 g N tree-1) or nil concentrations of Ca and N, and natural or 70%-reduced crop loads. Fruit were assessed for watery-pulp breakdown, fruit colour, postharvest disease, fruit firmness, yield and average fruit weight. Although Ca was applied above the normal industry rates, there were no significant increases in fruit-Ca or leaf- Ca concentrations, or response in any of the fruit quality parameters measured. The factors influencing Ca concentrations in mesocarp were shown to be changes in dry matter accumulation and periodic reductions in Ca supply. Fruit from the high N treatment had significantly (p < 0.05) greater incidence and severity of postharvest side disease lesions (mainly anthracnose) but not stem lesions (mainly stem-end rot). The high N treatments also significantly (p < 0.05) reduced the percentage of yellow skin, and the percentage and intensity of red blush colour in ripe fruit. Watery-pulp breakdown, fruit firmness and average fruit weight were not significantly affected by the high N treatments. Reducing the crop load throughout fruit development significantly (p<0.05) increased the average fruit weights and the incidence of watery-pulp breakdown, but did not significantly affect the other fruit quality parameters measured. Further studies on Ca uptake and distribution were carried out in 3 additional experiments. The effects of Ca supply on fruit quality were investigated in a similar manner to the first experiment, by varying soil-applied Ca. Increased rates (1726 g tree-1 Ca) and more frequent applications (fortnightly) of gypsum were used to overcome leaching. Although soil Ca concentrations at harvest (0 - 30 cm deep) were increased by the Ca treatment, no significant effects were observed on fruit quality. The effect of leaf transpiration on leaf and fruit Ca concentrations was investigated by reducing leaf transpiration with an anti-transpirant throughout flowering and fruit development. Reduced leaf transpiration did not significantly affect mesocarp or leaf Ca, N, P, Mg, K, B concentrations, indicating the balance of transpiration mass flow between leaves and fruit is not a major factor in mango fruit Ca accumulation. Temporal changes in uptake and distribution of Ca during flowering and fruit development were studied using elemental strontium (Sr) as a Ca analogue. Sr and Ca concentrations were not similar during the experiment making prediction of Ca uptake and distribution based on Sr uptake and partitioning unsuitable. The effect of high N in increasing postharvest fruit disease in the first experiment was further studied to confirm the earlier results and to identify the mechanisms involved in this relationship. Fruit with a range of N concentrations were produced from trees fertilised with a range of N rates (0 417 g tree-1). The incidence and severity of postharvest anthracnose (C. gloeosporioides) increased as fruit-N increased, with significant relationships between anthracnose severity and exocarp-N concentration (anthracnose severity in sprung fruit = 163.18x2 151.85x + 36.987, r2 = 0.97**). High N had a similar effect on the incidence of Penicillium sp., Rhizopus sp., Guibnardia sp., or Epicoccum sp., but not Dothiorella sp. (stem-end rot). The antifungal compounds 5-n-pentadecyl resorcinol and 5-n-heptadecenyl resorcinol were influenced by exocarp-N in two ways. Resorcinol concentrations were lower in fruit with high exocarp-N than low-N fruit, and concentrations decreased faster in ripening fruit with high exocarp-N. The differences in resorcinol concentrations between high- and low-N fruit was strongest in the sprung stage of ripeness, and positive exponential relationships were found between exocarp-N and concentrations of 5-n-pentadecyl resorcinol (p=0.006. r2= 0.92) and 5-n-heptadecenyl resorcinol (p=0.016, r2=0.82). There were also positive relationships between anthracnose severity and 5-n-pentadecyl resorcinol (p=0.003, r2=0.86) and 5-n-heptadecenyl resorcinol (p=0.003, r2 =0.87). No significant differences were observed in exocarp morphology to explain the N effect on postharvest disease incidence or severity. The effect of timing of application of N on fruit quality and disease was investigated in a field experiment on 8-year-old Keitt mango trees on which N was applied at flowering, at mid fruit development, 2 weeks pre-harvest, or not applied (control). N applied at flowering and mid fruit development, significantly increased the severity of postharvest Colletotrichum sp. (p<0.05) Penicillium sp., Rhizopus sp., Guibnardia sp., and Epicoccum sp. (p<0.01) in ripe fruit. N applied 2 weeks prior to harvest did not significantly affect postharvest diseases, with fruit having similar anthracnose severity and incidence to the nil-N (control) treatment. Fruit Ca concentrations were not able to be manipulated by imposing field treatments. The inability to easily manipulate fruit Ca concentrations indicates it is unlikely to be an effective tool to manipulate fruit quality in mango. Nitrogen was shown to greatly influence fruit quality, having a major influence on postharvest disease, skin colour and sunburn susceptibility, but not watery-pulp breakdown. Increased N was also shown to reduce concentrations of natural antifungal resorcinol compounds as fruit ripened, making fruit more susceptible to postharvest rots. The sensitivity of fruit quality to N makes management of N a critical tool in managing fruit quality and disease susceptibility. Reduced crop load had a major effect on the incidence and severity of watery-pulp breakdown, indicating tree management practices to maximise crop load will also reduce the severity of watery-pulp breakdown.

The effect of relocation on the health of the brushtail possum Trichosurus vulpecula

Baker, Michelle Louise. — 2011-10-05T00:00:00Z

The effect of resuscitation fluids on beta lactam antibiotic pharmacokinetics in interstitial tissue in acute thermal injury

Kanchanamala Ranasinghe — 2010-06-29T00:00:00Z

Advantages and disadvantages of administration of resuscitation fluids in burns patients have been discussed at length. However, the effect of resuscitation fluids on tissue physiological endpoints and tissue antibiotic distribution is scarcely reported, yet clinically crucial. The preliminary studies of this thesis involved evaluation of the literature and the development of a non - recovery anaesthetized rat model of burn injury suitable for the study of plasma and tissue physiological changes and antibiotic pharmacokinetics (PK). Therefore, the first series of the studies for this thesis was designed to examine the relative effects of a range of crystalloid and colloid-containing resuscitation fluids on tissue pH following burn injury in a rat model. The secondary aims were to examine the effects of these fluids on tissue blood flow, plasma protein extravasation (PPE) and evaporative water loss (EWL). In these studies we confirmed that the burn injury and fluid resuscitation were accompanied by a tissue acidosis. Administration of Lactated Ringers’ Albumin (LRA) and Lactated Ringers’ Dextran (LRD) effectively attenuated the degree of tissue acidosis in the thermally injured and non injured sites for 180 minutes post burn and the transepidermal water loss (TEWL) on the non injured sites during the first 60 minutes of the acute phase of burn injury. The second phase of the work was designed to assess the changes in antibiotic distribution with the administration of these different fluids in plasma as well as in interstitial tissues in the burn and the non burn sites. This study showed that for cephalothin (4g/kg body weight, administered intravenously (IV)), Lactated Ringers solution (LR) and Hypertonic Saline (HS) showed similar plasma PK with Time > Minimum inhibitory concentration (MIC) (> 180 minutes) in plasma. However, the antibiotic tissue distribution was more skewed towards lower levels for HS when compared with LR. For piperacillin (18g/kg body weight, administered IV), Time > MIC was considerably low comparatively, being only 55 min for both LR and HS. Antibiotic concentrations did not reach the MIC with LRA resuscitation. When considering the interstitial tissues, Time > MIC for cephalothin was lower than HS with LR on both the burn and the non burn sites. T > MIC for piperacillin was zero for all fluids in both burn and non burn sites. The major finding of this study was that with LRA resuscitation, antibiotic distribution was significantly lower than seen with LR and HS for both antibiotics studied in the interstitial tissue fluid space in both the burn and non burn sites. The final phase of the work was designed to study the apparent permeability co efficient of Keratinocytes (KC) to antibiotics in the presence of simulated pH changes observed in burn tissue in thermal injury using colloids and crystalloids. This study found that there was no significant difference between the basolateral and apical concentrations of antibiotics observed neither with the different pH values nor with time. However, there was definitely a significant difference in the apparent permeability of the cells with LR vs LRA and that the permeability was higher with LR than LRA. This study confirmed that the presence of LR allows greater permeation of the antibiotic into the KC, and also that with LRA resuscitation, the antibiotic tends to stay at higher concentrations in the interstitial compartment. These studies demonstrate that choice of resuscitation fluid following burn injury can affect both changes in tissue physiology and antibiotic distribution, warranting further study in both animal models and patient populations.

The effect of structure on optoelectronic and charge transport properties in dendrimers

Chen, Simon Sheng Yen — 2013-03-12T22:52:10Z

The effect of the environment in Papua and New Guinea on the growth and reproduction of cattle

Leonard Anderson, James — 2012-11-10T00:00:00Z

The effect of traumatic brain injury on drivers' hazard perception

Preece, Megan Haf Wyn — 2012-11-22T00:00:00Z

The effect of X-ray irradiation on the developing hard tissues of the mandible.

Adkins, Kenneth Francis. — 2010-07-20T00:00:00Z

The effect of yttrium substitution and surface modification on BSCF perovskites

Haworth, Patrick Francis — 2012-11-14T00:00:00Z

The effect on bacterial biofilms of endoscopic sinus surgery and long term low-dose macrolide antibiotics for chronic rhinosinusitis

Vu Thanh Hai Phan — 2010-03-19T00:00:00Z

Abstract: The role of bacterial biofilms in patients with persistent CRS is of growing concern. The limited efficacy of some medical and surgical treatments for CRS illustrates the need for further progress in this area. The current treatments of chronic rhinosinusitis are concentrated on medical +/- surgical therapy. In this thesis, we consider two methods performed in chronic rhinosinusitis, endoscopic sinus surgery and long term low-dose macrolide therapy, and consider how they can affect bacterial biofilms. The effect of endoscopic sinus surgery on bacterial biofilms and the clinical impact of this condition on CRS patients may be far more profound than we can currently understand. To understand the impact of ESS on bacterial biofilms, we have performed the first prospective study to evaluate the effect of ESS on bacterial biofilms in patients with CRS and patients’ clinical outcomes after 3 months follow-up. We have shown that ESS results in a statistically significant improvement in QoL, subjective and objective outcome measures. In terms of bacterial biofilms, the mean OD630nm of isolates was significantly reduced after 3 months follow-up (p=0.043). No correlations between the reduction of bacterial biofilms with any of the objective, subjective and QoL outcomes were seen in our study. Macrolides have demonstrated their anti-inflamatory effects in the treatment of diffuse panbronchiolitis, asthma, cystis fibrosis and chronic rhinosinusitis. In recent years, there are a number of in vitro studies supporting the anti-biofilm effects of macrolide antibiotics, especially at sub-MICs level. These have shown that macrolides alter the outer membrane, lipopolysaccharide of biomass and inhibit the expression of other bacterial virulence factors which may disrupt the adherence of bacteria to form biofilms. Long term low dose macrolide therapy, therefore, may transform bacterial biofilms from the protected organized form into the plantonic form. In this thesis, we also report the first in vivo efficacy of long term low dose macrolides on bacterial biofilms in patients with CRS. Patients receiving oral macrolide showed significant improvements in subjective, objective and QoL scores following a 12 week course. Nasal swabs were taken from CRS patients at the first visit and 3 months after macrolide therapy. Using the microtiter biofilm assay, these swabs showed a reduction in the mean OD630nm of isolates in 8/12 patients. While it is well-known that bacterial biofilms are established in CRS patients, the relationship between the improvement of clinical symptoms and the severity of bacterial biofilm is less clear.

The effects of abnormal items and extraordinary items on Australian CEO's remuneration

Chng, Chee Kiong. — 2010-12-15T00:00:00Z

The effects of Advanced Paternal Age (APA) on behavioural and brain structural phenotypes in C57BL/6J mice.

Claire J Foldi — 2012-06-01T00:00:00Z

Advanced paternal age (APA) is associated with an increased risk of adverse health outcomes in offspring, including autism and schizophrenia. With respect to biological mechanisms for this association, most attention to date has focussed on the effects of aging on the integrity of germ cells. This is because there are many more germline cell divisions in the life history of a sperm relative to that of an oocyte. Each time these cells divide, the replication of the genome increases susceptibility to copy error mutations such that there is more opportunity for accumulation of copy error in germ cells from older fathers. Evidence also suggests that epigenetic patterning in the sperm from older men is altered. Rodent models provide an experimental platform to examine the association between APA and brain development. We have previously investigated structure-function relationships in the adult offspring of young (3 month-old; Control) and old (12-18 month-old; APA) C57Bl/6J sires. Mice underwent a comprehensive behavioural test battery and their brains were subsequently examined ex vivo using high resolution MRI (Foldi et al., 2010). Other APA models have been published with relevance to intermediate phenotypes related to neuropsychiatric disorders. All three existing mouse models vary in key features creating a lack of consistency with respect to behavioural phenotypes. Our published model showed increased anxiety-related and exploratory behaviours and a decrease in ventricular volume, which corresponded to an increase in rostral cortical volume. Another study demonstrated reduced social behaviour (Smith et al., 2009), while the third was associated with reductions in avoidance learning and locomotion (Garcia-Palomares et al., 2009b). In this thesis, I have carefully considered several potential modifers of APA effects in the mouse and probed the phenotypic instability by investigating the effects of breeding programme and APA sire age range on behavioural phenotypes in offspring. I have demonstrated that length of prenatal sire exposure does not contribute to offspring outcomes. We have also conducted a ‘proof of principle’ exploration of the genomic correlates of phenotypes by exploring the association between copy number variation (CNV) load and behavioural and neuroanatomical outcomes. Here, we show that particular CNV expansions, only found in APA mice, are correlated with changes in specific behavioural domains. In addition, increasing the APA sire age to 24 months was shown to be associated with increased anxiety-related behaviour in the offspring, and indicated that increasing APA sire age produced a more robust hypoexplorative phenotype. Thus, variation in CNV load and APA sire age could explain the phenotypic variability in APA mouse models. Ultimately, the results of these studies demonstrate that mouse models of APA are valuable for elucidating the mechanisms by which APA influences brain-related outcomes.

The effects of aestivation and re-feeding on the structure and function of the gut in the green-striped burrowing frog, Cyclorana alboguttata

Cramp, Rebecca L. — 2012-08-24T00:00:00Z

The effects of aphids (Aphis gossypii) Glover on photosynthesis in cotton (Gossypium hirsutum)

Heimoana, Simone Charlotte — 2012-11-05T00:00:00Z

The effects of biological waste treatment by acidogenic fermentation on certain pathogens

Harris, Ivor E. — 2007-08-24T00:00:00Z

The effects of cisplatin treatment on tumourigenic potential of head and neck cancer cells.

Kim Poth — 2010-10-15T00:00:00Z

Head and neck cancer is the sixth most common cancer, with increasing incidence and a 5-year survival rate that has remained at 55% for several decades despite advances in diagnosis and treatment. It comprises up to 40% of diagnosed malignancies in countries such as India and Brazil, and approximately 50% of patients will relapse following initial treatment. Over 90% of head and neck cancers are squamous cell carcinomas (HNSCC), which are treated using a multimodal approach comprising combinations of surgical resection, radiation therapy and chemotherapy. Platinum-based drugs such as cisplatin are the mainstay of chemotherapeutic treatment for HNSCC. Systemic chemotherapies offer the best chance of combating the occurrence of loco-regional and distant metastatic disease, since surgery and radiation can only target local disease. However, despite improvements to dosing and scheduling, drug resistance and loco-regional and distant failure remain common. Furthermore, compliance with therapies such as cisplatin, which has severe dose limiting toxicities, is low in patients with poor performance status. Many HNSCC patients fall into this category, resulting in sub-optimal dosing of cisplatin in many patients. In order to better understand the role of drug resistance and sub-optimal treatment in disease recurrence this thesis has examined the role of cisplatin treatment on tumourigenic potential of surviving HNSCC cells. Use of xenograft models and in vitro assays of cisplatin-induced cytotoxicity demonstrated that significantly lower numbers of cisplatin treated cells were able to initiate tumours compared to untreated cells. Furthermore, this increased tumourigenic potential was a transient phenomenon associated with a distinct phenotype of small cell size and significantly enhanced expression of Interleukin-6 (IL-6), as well as significant differential expression of several other genes. Preliminary data suggests that IL-6 may be causally involved viii in mediating tumourigenesis by cisplatin treated cells. The increased tumourigenic potential mediated by cisplatin was not associated with significant changes in any known cancer stem cell markers. Furthermore, clonal analysis indicated that virtually all cells within the cell lines examined were capable of tumour initiation with varying efficiencies. Studies of cells cultured long-term following treatment indicated persisting effects of a single cisplatin treatment, such as abnormal morphology and growth characteristics, while tumourigenic potential returned to similar levels to the parental (untreated) cell lines, demonstrating that the effects of cisplatin varied with time post-exposure. Taken together, the data in this study demonstrate that cisplatin acts via a complex, stochastic mechanism to induce transient changes in tumourigenic potential in HNSCC cells, likely involving overexpression of IL-6. These results are clinically significant as they underline the need for well-tolerated, targeted systemic therapies for HNSCC and present IL-6 as a promising novel drug target to improve survival of HNSCC patients.

The Effects of Closing Watering Points on Populations of Large Macropods and Landscape Rehabilitation in a Semi-arid National Park

Fukuda, Yuki — 2008-11-21T00:00:00Z

Many national parks in Australian rangelands were formerly grazing properties. Even after domestic stock has been removed, the landscapes, especially those near artificial watering points, remained degraded with little or no regeneration of native plants. Congregating large macropods have often been blamed for impeding regeneration of plant communities and rehabilitation of these degraded landscapes. Following a severe drought which reduced densities of large macropods very significantly in Idalia National Park, central-western Queensland, I investigated whether closure of watering points would hamper their recolonisation and influence their grazing distribution and forage selection in the park. I also determined the spatial and temporal pattern of degradation around the watering points, using a suite of indicators. A BACI (Before After Control Impact) type experiment was conducted using two replicate watering points each for impact (fenced) and control (unfenced) treatments. Two watering points were fenced off behind a kangaroo-proof fence in August and December 2002, respectively, in the deepening drought. Walked 4 km line transects were used to estimate densities of red kangaroos (Macropus rufus) and wallaroos (M. robustus) in areas within a 4 km radius of each watering point. The accumulation of dung pellets was used to estimate the grazing distribution of large macropods around water. Abundance and composition of vegetation were monitored on fixed transects using a 0.5 * 0.5 m quadrat 0.5 to 4 km from each watering point. Herbivore offtake was monitored using a movable cage technique. Measures of landscape function (stability, infiltration and nutrient rating) and ant composition were monitored at various distances from each watering point. Monitoring was commenced two to six months before the closure of watering points and completed 21 and 25 months following the closure, every two to five monthly to follow changes in large macropod densities and vegetation communities. Prior to the drought, densities up to 130 large macropods km-2 were recorded in the park. The average density of wallaroos declined by 97.7% during the drought whereas that of red kangaroos declined by 83.8%. The first substantial rain fell in January 2003, but rainfall throughout the study period continued to be much lower than the long-term median, except for January 2004 when more than half the average annual rainfall fell, causing major flooding. Closure of watering points coincident with the drought inhibited red kangaroo recolonisation by 40% in the areas surrounding fenced watering points for up to 21 months following the closure, with distances to alternative watering points being 3.8-6.6 km. Red kangaroos in an area surrounding one of the unfenced watering point recovered to the pre-drought average density. The grazing distribution of large macropods within 4 km from the watering points, however, was determined primarily by where plentiful food resources were, not by the location of water. Large macropods in the areas without access to water did not select forage with higher water contents, compared to those in the areas with water access. Differences in their forage preference between the two areas appeared to reflect the difference in vegetation composition between the areas. Sida filiformis, Cynodon dactylon and Tragus australianus, were identified as grazing sensitive plant species. In some cases, closing watering points helped these plants to increase their abundance following the drought. Most indicators (the percentage of bare soil, biomasses of perennial grasses and round-leaved chenopods, ant functional groups and the measures of landscape function) showed that the exclusion of mammalian grazing for more than a decade from long-term exclosures had facilitated regeneration of perennial grasses and landscape rehabilitation at least at some sites. At one long-term exclosure, where topsoil and seed bank had presumably been lost already, no regeneration occurred. When several indicators were used to determine land conditions around watering points, their responses were not always consistent. Nevertheless, the overall spatial patterns of degradation did not match the spatial pattern of grazing distribution by large macropods around water. Therefore, the current degradation appears to be a legacy of the livestock overgrazing that had continued for more than 100 years prior to the park establishment. The large drought-induced reduction in the large macropod densities did not result in any conspicuous reversal of the patterns of degradation around the watering points.

The effects of cocaine exposure during early life on rat brain development

Mohd Ismail, Zul Izhar — 2012-02-16T00:00:00Z

The Effects of Cognitive Remediation on Functional Outcomes Among People With Schizophrenia- a Randomized Controlled Study

Bhing Leet Tan — 2012-06-01T00:00:00Z

Background Cognitive impairment is a common feature among people with schizophrenia, as they typically perform between one and a half to two standard deviations below normal population (Bilder et al., 1995; Goldberg & Gold, 1995; Goldberg & Green, 2008). This has huge impact on aspects of daily life such as vocational functioning and community living skills. This is due to impairment in the ability to plan, organize and engage in functional tasks required in daily life. Cognitive remediation is an intervention to overcome the effects of cognitive difficulties through re-training and use of compensatory strategies. Although randomized studies have been conducted to show the positive effect of cognitive remediation on cognitive skills (McGurk, Twamley, Sitzer, McHugo, & Mueser, 2007; Twamley, Jeste, & Bellack, 2003; Wykes, Huddy, Cellard, McGurk, & Czobor, 2011), many of their control arms consist of intervention that are non-therapeutic in nature and are liable to allegiance effects. Hence, this study aimed to test if cognitive remediation will improve neurocognition and functioning of people with schizophrenia, using physical exercise as the control arm, as physical exercise has been shown to benefit people with psychiatric disorders (Richardson et al., 2005). Efforts were also made to minimize allegiance effects by appropriate blinding and training of therapists. This study will also shed light on the effectiveness of cognitive remediation in an English speaking Asian population. Methodology The Occupational Therapy Department at the Institute of Mental Health, Singapore, runs an outpatient day rehabilitation program as well as an outpatient vocational training program. Patients with DSM-IV diagnoses of schizophrenia or schizoaffective disorders were invited to participate in this study. Upon obtaining informed consent, participants were randomized to receive either Cognitive Remediation (CR) or Physical Exercise (PE) treatment. Cognitive Remediation consisted of: 1. Computer-assisted cognitive exercises for up to five hours each week for 12 weeks. 2. Cognitive-based counseling, based on application of cognitive strategies learned in cognitive exercises to their vocational training or day rehabilitation program. Physical exercise consisted of: 1. Physical exercise program for up to five hours each week for 12 weeks. 2. Physical exercise-based counseling, based on application of physical strategies learned during physical endurance exercise to their vocational training or day rehabilitation program. To minimize allegiance effects, both interventions had the same amount of treatment intensity and therapist-participant contact time. All therapists and participants were told that physical exercise was also a potentially beneficial intervention to be investigated for its effectiveness. In addition, this study was double blinded. Neuroognitive function and physical fitness were measured at baseline, upon completion of the program and at six month and one year follow-up. Among the day rehabilitation participants, their community abilities were also measured at the above intervals, while employment outcomes were charted among those in the vocational training program. The hypotheses of this study were: 1. Participants from the cognitive remediation group would show significantly more improvement in neurocognition than participants from the physical exercise group at the end of treatment and over the course of the one-year follow-up. 2. Participants who underwent cognitive remediation would achieve better overall functional outcomes, ie: longer employment hours or more improvement in Multnomah Community Ability Scale (MCAS scores) than participants in the physical exercise group. 3. Improved functional outcome would be associated with reduced symptom severity as measured by the Positive and Negative Syndrome Scale (PANSS). 4. There would be an association between improved functional outcomes and better quality of life among the participants. Results Results showed that cognitive remediation was able to produce significant differential improvement in all neurocognitive measures. Besides that, the cognitive remediation group achieved better attainment of vocational or independent living skills at post-intervention. Moreover, this group displayed better vocational and community ability outcomes at the end of one year follow-up. Repeated Measures analysis also showed better overall and negative symptoms improvement amongst the cognitive remediation group. In addition, improvements in certain neurocognitive functions predicted improvements in functional outcomes, symptoms and quality of life. Better functional outcomes were found to predict overall symptoms as well as negative symptoms recovery. On the other hand, negative symptoms were also shown to partially mediate the pathway between changes in neurocognition and changes in functional outcomes. However, improved functional outcome was not associated with better quality of life. Conclusion When compared against a credible intervention such as physical exercise, cognitive remediation was able to show significant positive effects on both neurocognition and functional outcomes among the Asian population of schizophrenia patients. References Bilder, R. M., Bogerts, B., Ashtari, M., Wu, H., Alvir, J. M., Jody, D., et al. (1995). Anterior Hippocampal Volume Reductions Predict Frontal Lobe Dysfunction In First Episode Schizophrenia Schizophrenia Research, 17(1), 47-58. Goldberg, T. E., & Gold, J. M. (1995). Neurocognitive Functioning in Patients with Schizophrenia: an Overview. In F. E. Bloom & D. J. Kufler (Eds.), Psychopharmacology: the Fourth Generation of Progress (pp. 1171-1183). New York: Raven Press. Goldberg, T. E., & Green, M. F. (2008). Neurocognitive Functioning in Patients With Schizophrenia: an Overview. In American College of Neuropsychopharmacology (Ed.), Neuropsychopharmacology-5th Generation of Progress. Brentwood: American College of Neuropsychopharmacology. McGurk, S. R., Twamley, E. W., Sitzer, D. I., McHugo, G. J., & Mueser, K. T. (2007). A Meta-Analysis of Cognitive Remediation in Schizophrenia. American Journal of Psychiatry, 164, 1791–1802. Richardson, C. R., Faulkner, G., Mcdevitt, J., Skrinar, G. S., Hutchinson, D. S., & Piette, J. D. (2005). Integrating Physical Activity Into Mental health Services for Persons With Serious Mental Illness. Psychiatric Services, 56(3), 324-331. Twamley, E. W., Jeste, D. V., & Bellack, A. S. (2003). A Review of Cognitive Training in Schizophrenia. Schizophrenia Bulletin, 29(2), 359-382. Wykes, T., Huddy, V., Cellard, C., McGurk, S. R., & Czobor, P. (2011). A Meta-Analysis of Cognitive Remediation for Schizophrenia: Methodology and Effect Sizes. American Journal of Psychiatry, 168(5), 472-485.