62 resultados para Supply and demand


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The high fat content in Western diets probably affects placental function during pregnancy with potential consequences for the offspring in the short and long term. The aim of the present study was to compare genome-wide placental gene expression between rat dams fed a high-fat diet (HFD) and those fed a control diet for 3 weeks before conception and during gestation. Gene expression was measured by microarray and pathway analysis was performed. Gene expression differences were replicated by real-time PCR and protein expression was assessed by Western blot analysis. Placental and fetal weights at E17.25 were not altered by exposure to the maternal HFD. Gene pathways targeting placental growth, blood supply and chemokine signalling were up-regulated in the placentae of dams fed the HFD. The up-regulation in messenger RNA expression for five genes Ptgs2 (fatty acid cyclo-oxidase 2; COX2), Limk1 (LIM domain kinase 1), Pla2g2a (phospholipase A2), Itga1 (integrin α-1) and Serpine1 was confirmed by real-time PCR. Placental protein expression for COX2 and LIMK was also increased in HFD-fed dams. In conclusion, maternal HFD feeding alters placental gene expression patterns of placental growth and blood supply and specifically increases the expression of genes involved in arachidonic acid and PG metabolism. These changes indicate a placental response to the altered maternal metabolic environment.

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Water supply and demand planning is often conducted independently of social and economic strategies. There are presently no comprehensive life-cycle approaches to modelling urban water balances that incorporate economic feedbacks, such as tariff adjustment, which can in turn create a financing capacity for investment responses to low reservoir levels. This paper addresses this gap, and presents a system dynamics model that augments the usual water utility representation of the physical linkages of water grids, by adding inter-connected feedback loops in tariff structures, demand levels and financing capacity. The model, applied in the south-east Queensland region in Australia, enables simulation of alternatives and analysis of stocks and flows around a grid or portfolio of bulk supplies including an increasing proportion of rain-independent desalination plants. Such rain-independent water production plants complement the rain-dependent sources in the region and can potentially offer indefinite water security at a price. The study also shows how an alternative temporary drought pricing regime not only defers costly bulk supply infrastructure but actually generates greater price stability than traditional pricing approaches. The model has implications for water supply planners seeking to pro-actively plan, justify and finance portfolios of rain-dependent and rain-independent bulk water supply infrastructure. Interestingly, the modelling showed that a temporary drought pricing regime not only lowers the frequency and severity of water insecurity events but also reduces the long-run marginal cost of water supply for the region when compared to traditional reactive planning approaches that focus on restrictions to affect demand in scarcity periods.

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To assess the degree to which reimbursement prices in Australia and England differ for a range of generic drugs, and to analyse the supply- and demand-side factors that may contribute to these differences.

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Mixed-species restoration tree plantings are being established increasingly, contributing to mitigate climate change and restore ecosystems. Including nitrogen (N)-fixing tree species may increase carbon (C) sequestration in mixed-species plantings, as these species may substantially increase soil C beneath them. We need to better understand the role of N-fixers in mixed-species plantings to potentially maximize soil C sequestration in these systems. Here, we present a field-based study that asked two specific questions related to the inclusion of N-fixing trees in a mixed-species planting: 1) Do non-N-fixing trees have access to N derived from fixation of atmospheric N2 by neighbouring N-fixing trees? 2) Do soil microbial communities differ under N-fixing trees and non-N-fixing trees in a mixed-species restoration planting? We sampled leaves from the crowns, and litter and soils beneath the crowns of two N-fixing and two non-N-fixing tree species that dominated the planting. Using the 15N natural abundance method, we found indications that fixed atmospheric N was utilized by the non-N-fixing trees, most likely through tight root connections or organic forms of N from the litter layer, rather than through the decomposition of N-fixers litter. While the two N-fixing tree species that were studied appeared to fix atmospheric N, they were substantially different in terms of C and N addition to the soil, as well as microbial community composition beneath them. This shows that the effect of N-fixing tree species on soil carbon sequestration is species-specific, cannot be generalized and requires planting trails to determine if there will be benefits to carbon sequestration. © 2014 Elsevier Ltd.

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Uncertainty is known to be a concomitant factor of almost all the real world commodities such as oil prices, stock prices, sales and demand of products. As a consequence, forecasting problems are becoming more and more challenging and ridden with uncertainty. Such uncertainties are generally quantified by statistical tools such as prediction intervals (Pis). Pis quantify the uncertainty related to forecasts by estimating the ranges of the targeted quantities. Pis generated by traditional neural network based approaches are limited by high computational burden and impractical assumptions about the distribution of the data. A novel technique for constructing high quality Pis using support vector machines (SVMs) is being proposed in this paper. The proposed technique directly estimates the upper and lower bounds of the PI in a short time and without any assumptions about the data distribution. The SVM parameters are tuned using particle swarm optimization technique by minimization of a modified Pi-based objective function. Electricity price and demand data of the Ontario electricity market is used to validate the performance of the proposed technique. Several case studies for different months indicate the superior performance of the proposed method in terms of high quality PI generation and shorter computational times.

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Coal comprises 70 per cent of China’s primary energy source and 80 per cent of China's electricity generation. This study investigates the long-run relationship between coal consumption-economic growth nexus considering both supply and demand side models in a multivariate framework over the period of 1978 and 2010. Our innovation in this paper is to include a coal-to-electricity efficiency indicator into the economic growth model ; and trade exposure in coal demand. Using Autoregressive Distributed Lag bounds testing approach, we find improvement in coal-to-efficiency indicator causes almost 35 per cent increase in real GDP in the long-run. The Toda-Yamamoto approach of causality test indicates unidirectional causality from coal consumption to economic growth; feedback effect both for coal-to-electricity efficiency indicator to economic growth and openness to coal consumption. For robustness check, using the generalised forecast error variance decomposition method we forecast the validity of causal relationships beyond the sample horizon. The paper suggests the role of advanced coal technologies will play a significant role along with other environmental and energy policies in maintaining sustainable economic growth in China .

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This thesis investigated the trends in supply and demand in the Australian housing market between 1996 and 2014.

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A qualitative study of online management education and the role of writing as an indicative measure of thinking and learning. Established educational models, such as Dale's Cone of Experience, are expanded and redeveloped to illustrate the central role of writing as a critical thinking process which appears to be increasing, rather than decreasing, with the advent of online multimedia technology. In an environment of increasing reliance on audiovisual stimulus in online education, the authors contend that tertiary educators may witness an ascendance or re-emergence of writing as central to the academic experience. This may be both supply and demand driven. Drawing on a study of two undergraduate units in the Bachelor of Commerce and applying hermeneutics to develop challenging insights, the authors present a case for educators to remain conversant with the art of teaching writing, and to promote writing to improve educational outcomes.

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Dental services in Australia are available both privately and publicly. However, access to public dental services, like access to public hospital services for non-urgent treatment, is subject to a considerable waiting period. Moreover, access to public dental services is restricted to certain categories of welfare beneficiaries who qualify for a health care card. Because of the waiting time for public treatment, there is a frequent call for more public dental resources. This paper addresses the issue of what the waiting time for public dental services represents. One view largely confirmed by our research is that state governments are using the waiting time as a way of trying to push more and more people into the private sector. We find that more and more health care card holders are using the
private sector for dental services.

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A reliable forecasting for future construction costs or prices would help to ensure the budget of a construction project can be well planned and limited resources can be allocated more appropriately in construction firms. Although many studies have been focused on the construction price modelling and forecasting, few researchers have considered the impacts of the global economic events and seasonality in price modelling and forecasting. In this study, an advanced multivariate modelling technique, namely the vector correction (VEC) model with dummy variables was employed and the impacts of the global economic event and seasonality were factored into the forecasting model for the building construction price in the Australian construction market. Research findings suggest that a long-run equilibrium relationship exists among the price, levels of supply and demand in the construction market. The reliability of forecasting models was examined by mean absolute percentage error (MAPE) and The Theil's inequality coefficient U tests. The results of MAPE and U tests suggest that the conventional VEC model and the VEC model with dummy variable are both acceptable for forecasting building construction prices, while the VEC model that considered external impacts achieves higher prediction accuracy than the conventional VEC model does.

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All over the world, electrical power systems are encountering radical change stimulated by the urgent need to decarbonize electricity supply, to swap aging resources and to make effective application of swiftly evolving information and communication technologies (ICTs). All of these goals converge toward one direction; ‘Smart Grid.’ The Smart Grid can be described as the transparent, seamless, and instantaneous two-way delivery of energy information, enabling the electricity industry to better manage energy delivery and transmission and empowering consumers to have more control over energy decisions. Basically, the vision of Smart Grid is to provide much better visibility to lower-voltage networks as well as to permit the involvement of consumers in the function of the power system, mostly through smart meters and Smart Homes. A Smart Grid incorporates the features of advanced ICTs to convey real-time information and facilitate the almost instantaneous stability of supply and demand on the electrical grid. The operational data collected by Smart Grid and its sub-systems will allow system operators to quickly recognize the best line of attack to protect against attacks, susceptibility, and so on, sourced by a variety of incidents. However, Smart Grid initially depends upon knowing and researching key performance components and developing the proper education program to equip current and future workforce with the knowledge and skills for exploitation of this greatly advanced system. The aim of this chapter is to provide a basic discussion of the Smart Grid concept, evolution and components of Smart Grid, environmental impacts of Smart Grid and then in some detail, to describe the technologies that are required for its realization. Even though the Smart Grid concept is not yet fully defined, the chapter will be helpful in describing the key enabling technologies and thus allowing the reader to play a part in the debate over the future of the Smart Grid. The chapter concludes with the experimental description and results of developing a hybrid prediction method for solar power which is applicable to successfully implement the ‘Smart Grid.’

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Additions to the aggregate housing stock are a broad measure of the state of an economy and overall level of confidence in a particular region over a designated period. This is due to the direct and indirect effect (e.g. employment in the housing construction industry) upon on the local economy and is linked to the confidence of local households in the future direction of housing investment, the level of housing affordability by households as related to employment levels and the relationship between supply and demand in each region. Another consideration is the ability of the government to monitor and successfully intervene in the operation of the household market (e.g. mortgage interest rates) with the intent of restricting an over-supply situation which may take years to fully recover. The analysis in this section examines new housing commencements for Scotland, Australia, USA and Canada over an extended time period with the specific focus placed on the periods before, during and after the high profile global financial crisis in 2007-2008. The graph in Figure 1 was adapted from data sourced from The Scottish Government (2013) and covers the 15-year period between 1998 and 2012. With the exception of 1999 there were been relatively few years with substantial additions to the housing market. However, the effect of the GFC can clearly be observed post 2007 although by 2012 there was relatively change from the previous year.

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Construction price forecasting is an essential component to facilitate decision-making for construction contractors, investors and related financial institutions. Construction economists are increasingly interested in seeking a more analytical method to forecast construction prices. Although many studies have focused on construction price modelling and forecasting, few have considered the impacts of large-scale economic events and seasonality. In this study, an advanced multivariate modelling technique, namely the vector correction (VEC) model with dummy variables, was employed. The impacts of global economic events and seasonality are factored into the model to forecast the construction price in the Australian construction market. Research findings suggest that both long-run and dynamic short-term causal relationships exist among the price and levels of supply and demand in the construction market. These relationships drive the construction price and supply and demand, which interact with one another as a loop system. The reliability of forecasting models was examined by the mean absolute percentage error (MAPE) and the Theil's inequality coefficient U tests. The test results suggest that the conventional VEC model and the VEC model with dummy variable are both acceptable for forecasting the construction price, while the VEC model considering external impacts achieves higher prediction accuracy than the conventional VEC model. © 2014 © 2014 Taylor & Francis.

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Developing sustainable e-learning requires a better understanding of the perceptions and preferences of e-learning providers and e-learners on the four crucial dimensions for elearning success including pedagogies, technologies, learning resources and management of learning resources. There is, however, little research on evaluating whether these critical dimensions are perceived as critical by e-learning providers and e-learners. To address this issue, this study investigates the gap between e-learners’ and e-learning providers’ perceptions and preferences on these critical dimensions for e-learning effectiveness. Such an investigation paves the way for developing appropriate measures to reduce the gap between the supply and the demand for sustainable e-learning.

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In this research, skills for sustainability are broadly conceived as including skills for social, economic and environmental sustainability – a triple bottom-line approach. Since 2009 Australian governments have been implementing an agreement that embeds skills for sustainability into vocational education and training, despite scant information about the actual levels of demand for, and supply of these skills. This study provides evidence on the actual depth and breadth of the take-up of these skills within Australian training organisations and workplaces. The demand studied in this research is that expressed by the primary consumers of Australian Vocational Education and Training (VET) services, students who engage in VET studies, this is known in the literature as social demand for education. VET students and teachers responded to two survey instruments that explored the sustainability values, behaviours, learning and teaching of Australian apprentices, trainees and their teachers. The results of this study show ‘a social demand’ for skills for sustainability. In summary, the results show that: •Apprentices, trainees and their teachers cared a great deal about social, economic and environmental sustainability; •Supply was closely aligned to social demand for skills for sustainability so that demand for skills for sustainability from VET students was almost entirely met; •There are important differences in the teaching, learning and utilisation of skills for sustainability that are related to gender and age; and •In-class learning of environmental skills has increased over time and now slightly outweighs learning of these skills at work, however community learning of these skills outweighs both. The findings suggest that: •Further action is required to embed green skills into the VET system, especially in the areas of energy efficiency and supply chains; •The VET system plays an important role in supporting community cohesion and economic literacy, especially for women; •It is important that social sustainability is properly considered in analysis informing VET policy; and •Gender differences in values and behaviours and gender and age differences in learning skills for sustainability have important implications for the design of future skills for sustainability programs. VET students and their teachers have unique insights into the supply of and demand for skills for sustainability, and this viewpoint can contribute, now and in the future, to the further development of skills for sustainability in Australia.