Contribution of take-out food consumption to socioeconomic differences in fruit and vegetable intake : a mediation analysis

Lower fruit and vegetable intake among socioeconomically disadvantaged groups has been well documented, and may be a consequence of a higher consumption of take-out foods. This study examined whether, and to what extent, take-out food consumption mediated (explained) the association between socioeconomic position and fruit and vegetable intake. A cross-sectional postal survey was conducted among 1500 randomly selected adults aged 25–64 years in Brisbane, Australia in 2009 (response rate = 63.7%, N = 903). A food frequency questionnaire assessed usual daily servings of fruits and vegetables (0 to 6), overall take-out consumption (times/week) and the consumption of 22 specific take-out items (never to ≥once/day). These specific take-out items were grouped into “less healthy” and “healthy” choices and indices were created for each type of choice (0 to 100). Socioeconomic position was ascertained by education. The analyses were performed using linear regression, and a bootstrap re-sampling approach estimated the statistical significance of the mediated effects. Mean daily serves of fruits and vegetables was 1.89 (SD 1.05) and 2.47 (SD 1.12) respectively. The least educated group were more likely to consume fewer serves of fruit (B= –0.39, p<0.001) and vegetables (B= –0.43, p<0.001) compared with the highest educated. The consumption of “less healthy” take-out food partly explained (mediated) education differences in fruit and vegetable intake; however, no mediating effects were observed for overall and “healthy” take-out consumption. Regular consumption of “less healthy” take-out items may contribute to socioeconomic differences in fruit and vegetable intake, possibly by displacing these foods.

New variational Bayesian approaches for statistical data mining : with applications to profiling and differentiating habitual consumption behaviour of customers in the wireless telecommunication industry

This thesis investigates profiling and differentiating customers through the use of statistical data mining techniques. The business application of our work centres on examining individuals’ seldomly studied yet critical consumption behaviour over an extensive time period within the context of the wireless telecommunication industry; consumption behaviour (as oppose to purchasing behaviour) is behaviour that has been performed so frequently that it become habitual and involves minimal intentions or decision making. Key variables investigated are the activity initialised timestamp and cell tower location as well as the activity type and usage quantity (e.g., voice call with duration in seconds); and the research focuses are on customers’ spatial and temporal usage behaviour. The main methodological emphasis is on the development of clustering models based on Gaussian mixture models (GMMs) which are fitted with the use of the recently developed variational Bayesian (VB) method. VB is an efficient deterministic alternative to the popular but computationally demandingMarkov chainMonte Carlo (MCMC) methods. The standard VBGMMalgorithm is extended by allowing component splitting such that it is robust to initial parameter choices and can automatically and efficiently determine the number of components. The new algorithm we propose allows more effective modelling of individuals’ highly heterogeneous and spiky spatial usage behaviour, or more generally human mobility patterns; the term spiky describes data patterns with large areas of low probability mixed with small areas of high probability. Customers are then characterised and segmented based on the fitted GMM which corresponds to how each of them uses the products/services spatially in their daily lives; this is essentially their likely lifestyle and occupational traits. Other significant research contributions include fitting GMMs using VB to circular data i.e., the temporal usage behaviour, and developing clustering algorithms suitable for high dimensional data based on the use of VB-GMM.

The impact of taxes on optimal portfolio choice : an Australian study

Taxes are an important component of investing that is commonly overlooked in both the literature and in practice. For example, many understand that taxes will reduce an investment’s return, but less understood is the risk-sharing nature of taxes that also reduces the investment’s risk. This thesis examines how taxes affect the optimal asset allocation and asset location decision in an Australian environment. It advances the model of Horan & Al Zaman (2008), improving the method by which the present value of tax liabilities are calculated, by using an after-tax risk-free discount rate, and incorporating any new or reduced tax liabilities generated into its expected risk and return estimates. The asset allocation problem is examined for a range of different scenarios using Australian parameters, including different risk aversion levels, personal marginal tax rates, investment horizons, borrowing premiums, high or low inflation environments, and different starting cost bases. The findings support the Horan & Al Zaman (2008) conclusion that equities should be held in the taxable account. In fact, these findings are strengthened with most of the efficient frontier maximising equity holdings in the taxable account instead of only half. Furthermore, these findings transfer to the Australian case, where it is found that taxed Australian investors should always invest into equities first through the taxable account before investing in super. However, untaxed Australian investors should invest their equity first through superannuation. With borrowings allowed in the taxable account (no borrowing premium), Australian taxed investors should hold 100% of the superannuation account in the risk-free asset, while undertaking leverage in the taxable account to achieve the desired risk-return. Introducing a borrowing premium decreases the likelihood of holding 100% of super in the risk-free asset for taxable investors. The findings also suggest that the higher the marginal tax rate, the higher the borrowing premium in order to overcome this effect. Finally, as the investor’s marginal tax rate increases, the overall allocation to equities should increase due to the increased risk and return sharing caused by taxation, and in order to achieve the same risk/return level as the lower taxation level, the investor must take on more equity exposure. The investment horizon has a minimal impact on the optimal allocation decision in the absence of factors such as mean reversion and human capital.

Implementable efficient time and energy consumption trajectories design for an autonomous underwater vehicle

In this paper we consider the implementation of time and energy efficient trajectories onto a test-bed autonomous underwater vehicle. The trajectories are losely connected to the results of the application of the maximum principle to the controlled mechanical system. We use a numerical algorithm to compute efficient trajectories designed using geometric control theory to optimize a given cost function. Experimental results are shown for the time minimization problem.

The ghrelin signalling system is involved in the consumption of sweets

The gastric-derived orexigenic peptide ghrelin affects brain circuits involved in energy balance as well as in reward. Indeed, ghrelin activates an important reward circuit involved in natural- as well as drug-induced reward, the cholinergic-dopaminergic reward link. It has been hypothesized that there is a common reward mechanism for alcohol and sweet substances in both animals and humans. Alcohol dependent individuals have higher craving for sweets than do healthy controls and the hedonic response to sweet taste may, at least in part, depend on genetic factors. Rat selectively bred for high sucrose intake have higher alcohol consumption than non-sucrose preferring rats and vice versa. In the present study a group of alcohol-consuming individuals selected from a population cohort was investigated for genetic variants of the ghrelin signalling system in relation to both their alcohol and sucrose consumption. Moreover, the effects of GHS-R1A antagonism on voluntary sucrose- intake and operant self-administration, as well as saccharin intake were investigated in preclinical studies using rodents. The effects of peripheral grelin administration on sucrose intake were also examined. Here we found associations with the ghrelin gene haplotypes and increased sucrose consumption, and a trend for the same association was seen in the high alcohol consumers. The preclinical data show that a GHS-R1A antagonist reduces the intake and self-administration of sucrose in rats as well as saccharin intake in mice. Further, ghrelin increases the intake of sucrose in rats. Collectively, our data provide a clear indication that the GHS-R1A antagonists reduces and ghrelin increases the intake of rewarding substances and hence, the central ghrelin signalling system provides a novel target for the development of drug strategies to treat addictive behaviours. © 2011 Landgren et al.

Socio-economic differences in takeaway food consumption among adults

To examine socioeconomic differences in the frequency and types of takeaway foods consumed. Cross-sectional postal survey. Participants were asked about their usual consumption of overall takeaway food (< four times a month, or ≥ four times a month) and 22 specific takeaway food items (< once a month, or ≥ once a month): these latter foods were grouped into “healthy” and “less healthy” choices. Socioeconomic position was measured using education and equivalised household income and differences in takeaway food consumption were assessed by calculating prevalence ratios using log binomial regression. Adults aged 25–64 years from Brisbane, Australia were randomly selected from the electoral roll (N = 903, 63.7% response rate). Compared with their more educated counterparts, the least educated were more regular consumers of overall takeaway food, fruit/vegetable juice, and less regular consumers of sushi. For the “less healthy” items, the least educated more regularly consumed potato chips, savoury pies, fried chicken, and non-diet soft drinks; however, the least educated were less likely to consume curry. Household income was not associated with overall takeaway consumption. The lowest income group were more regular consumers of fruit/vegetable juice compared with the highest income group. Among the “less healthy” items, the lowest income group were more regular consumers of fried fish, ice-cream, and milk shakes, while curry was consumed less regularly. The frequency and types of takeaway foods consumed by socioeconomically disadvantaged groups may contribute to inequalities in overweight/obesity and chronic disease.

Linking perceived value of mobile marketing with the experiential consumption of mobile phones

Purpose – This study examines the nature of consumers’ perceptions of the value they derive from the everyday experiential consumption of mobile phones and how mobile marketing (m-marketing) can potentially enhance these value perceptions. Methodology – Q methodology is used to examine how consumers’ subjective perceptions and opinions are shared at a collective level. Forty participants undertook two Q sorts and the data was analysed using PQ-method. Findings – The first Q sort identified three profiles of perceived value: the Mobile Pragmatists, the Mobile Connectors and the Mobile Revellers. The second Q sort identified two profiles of perceived value of m-marketing: one emerging from the shared opinions of the Mobile Pragmatists and the Mobile Connectors, and the second from the Mobile Revellers. Implications/limitations – The findings show how consumers can be segmented based on their contextualised perceived value of consuming mobile phones and how the potential for m-marketing is perceived in ways that can enhance these value perceptions. Limitations relate to deriving statements for the Q sorts and the generalisability of the results. Practical implications – The findings highlight ways to tailor m-marketing strategies to complement consumers’ perceptions of the value offered through their mobile phones. Originality/value of paper – The study contributes to the literature through using Q methodology to examine two subjective areas of consumer behaviour, experiential consumption and consumer perceived value. Keywords mobile phones, mobile phone marketing, consumer perceived value, Q methodology, experiential consumption Classification Research paper

The value of smart metering household electricity consumption

Smart metering presents opportunities for business model creation. However the viability of many potential business models in a smart metering scenario may be dictated by privacy regulation and data sharing arrangements. An understanding by businesses of customers’ preferences for the visualisation of their electricity consumption and the degree to which they are willing to share it, is valuable. We present results from two interviews exploring data visualisation and willingness to share personal electricity consumption information. Participants displayed a high willingness to share and a preference for access to additional information when visualising their electricity consumption.

Vertical vegetation design decisions and their impact on energy consumption in subtropical cities

Vertical vegetation is vegetation growing on, or adjacent to, the unused sunlit exterior surfaces of buildings in cities. Vertical vegetation can improve the energy efficiency of the building on which it is installed mainly by insulating, shading and transpiring moisture from foliage and substrate. Several design parameters may affect the extent of the vertical vegetation's improvement of energy performance. Examples are choice of vegetation, growing medium geometry, north/south aspect and others. The purpose of this study is to quantitatively map out the contribution of several parameters to energy savings in a subtropical setting. The method is thermal simulation based on EnergyPlus configured to reflect the special characteristics of vertical vegetation. Thermal simulation results show that yearly cooling energy savings can reach 25% with realistic design choices in subtropical environments. Heating energy savings are negligible. The most important parameter is the aspect of walls covered by vegetation. Vertical vegetation covering walls facing north (south for the northern hemisphere) will result in the highest energy savings. In making plant selections, the most significant parameter is Leaf Area Index (LAI). Plants with larger LAI, preferably LAI>4, contribute to greater savings whereas vertical vegetation with LAI<2 can actually consume energy. The choice of growing media and its thickness influence both heating and cooling energy consumption. Change of growing medium thickness from 6cm to 8cm causes dramatic increase in energy savings from 2% to 18%. For cooling, it is best to use a growing material with high water retention, due to the importance of evapotranspiration for cooling. Similarly, for increased savings in cooling energy, sufficient irrigation is required. Insufficient irrigation results in the vertical vegetation requiring more energy to cool the building. To conclude, the choice of design parameters for vertical vegetation is crucial in making sure that it contributes to energy savings rather than energy consumption. Optimal design decisions can create a dramatic sustainability enhancement for the built environment in subtropical climates.

Socioeconomic differences in takeaway food consumption among adults

Background In Australia and other developed countries, there are consistent and marked socioeconomic inequalities in health. Diet is a major contributing factor to the poorer health of lower socioeconomic groups: the dietary patterns of disadvantaged groups are least consistent with dietary recommendations for the prevention of diet-related chronic diseases compared with their more advantaged counterparts. Part of the reason that lower socioeconomic groups have poorer diets may be their consumption of takeaway foods. These foods typically have nutrient contents that fail to comply with the dietary recommendations for the prevention of chronic disease and associated risk factors. A high level of takeaway food consumption, therefore, may negatively influence overall dietary intakes and, consequently, lead to adverse health outcomes. Despite this, little attention has focused on the association between socioeconomic position (SEP) and takeaway food consumption, with the limited number of studies showing mixed results. Additionally, studies have been limited by only considering a narrow range of takeaway foods and not examining how different socioeconomic groups make choices that are more (or less) consistent with dietary recommendations. While a large number of earlier studies have consistently reported socioeconomically disadvantaged groups consume a lesser amount of fruit and vegetables, there is limited knowledge about the role of takeaway food in socioeconomic variations in fruit and vegetable intake. Furthermore, no known studies have investigated why there are socioeconomic differences in takeaway food consumption. The aims of this study are to: examine takeaway food consumption and the types of takeaway food consumed (healthy and less healthy) by different socioeconomic groups, to determine whether takeaway food consumption patterns explain socioeconomic variations in fruit and vegetable intake, and investigate the role of a range of psychosocial factors in explaining the association between SEP and takeaway food consumption and the choice of takeaway food. Methods This study used two cross-sectional population-based datasets: 1) the 1995 Australian National Nutrition Survey (NNS) which was conducted among a nationally representative sample of adults aged between 25.64 years (N = 7319, 61% response rate); and 2) the Food and Lifestyle Survey (FLS) which was conducted by the candidate and was undertaken among randomly selected adults aged between 25.64 years residing in Brisbane, Australia in 2009 (N = 903, 64% response rate). The FLS extended the NNS in several ways by describing current socioeconomic differences in takeaway food consumption patterns, formally assessing the mediated effect of takeaway food consumption to socioeconomic inequalities in fruit and vegetable intake, and also investigating whether (and which) psychosocial factors contributed to the observed socioeconomic variations in takeaway food consumption patterns. Results Approximately 32% of the NNS participants consumed takeaway food in the previous 24 hours and 38% of the FLS participants reported consuming takeaway food once a week or more. The results from analyses of the NNS and the FLS were somewhat mixed; however, disadvantaged groups were likely to consume a high level of �\less healthy. takeaway food compared with their more advantaged counterparts. The lower fruit and vegetable intake among lower socioeconomic groups was partly mediated by their high consumption of �\less healthy. takeaway food. Lower socioeconomic groups were more likely to have negative meal preparation behaviours and attitudes, and weaker health and nutrition-related beliefs and knowledge. Socioeconomic differences in takeaway food consumption were partly explained by meal preparation behaviours and attitudes, and these factors along with health and nutrition-related beliefs and knowledge appeared to contribute to the socioeconomic variations in choice of takeaway foods. Conclusion This thesis enhances our understanding of socioeconomic differences in dietary behaviours and the potential pathways by describing takeaway food consumption patterns by SEP, explaining the role of takeaway food consumption in socioeconomic inequalities in fruit and vegetable intake, and identifying the potential impact of psychosocial factors on socioeconomic differences in takeaway food consumption and the choice of takeaway food. Some important evidence is also provided for developing policies and effective intervention programs to improve the diet quality of the population, especially among lower socioeconomic groups. This thesis concludes with a discussion of a number of recommendations about future research and strategies to improve the dietary intake of the whole population, and especially among disadvantaged groups.

The creative cities discourse : production and/or consumption?

The already considerable debate about what constitutes a 'creative' city becomes ever more critical as the world urbanizes at a rapid pace. In this chapter the author argues that the key tensions in discussions over what makes cities more conducive to and supportive of creativity revolve around perspectives that are either production-centric or consumption-centric. Scholars are increasing prepared to claim priority for the city-region over the nation-state as an economic and cultural agent in the contemporary world, but are they ready to deal with major changes in the nature of cultural production and consumption themselves? A number of examples of new challenges for the creative cities 'discourse' rounds out the chapter.

Delta opioid-receptor function in the dorsal striatum plays a role in high levels of ethanol consumption in rats

Binge-like patterns of excessive drinking during young adulthood increase the propensity for alcohol use disorders (AUDs) later in adult life; however, the mechanisms that drive this are not completely understood. Previous studies showed that the δ-opioid peptide receptor (DOP-R) is dynamically regulated by exposure to ethanol and that the DOP-R plays a role in ethanol-mediated behaviors. The aim of this study was to determine the role of the DOP-R in high ethanol consumption from young adulthood through to late adulthood by measuring DOP-R-mediated [(35)S]GTPγS binding in brain membranes and DOP-R-mediated analgesia using a rat model of high ethanol consumption in Long Evans rats. We show that DOP-R activity in the dorsal striatum and DOP-R-mediated analgesia changes during development, being highest during early adulthood and reduced in late adulthood. Intermittent access to ethanol but not continuous ethanol or water from young adulthood leads to an increase in DOP-R activity in the dorsal striatum and DOP-R-mediated analgesia into late adulthood. Multiple microinfusions of naltrindole into the dorsal striatum or multiple systemic administration of naltrindole reduces ethanol consumption, and following termination of treatment, DOP-R activity in the dorsal striatum is attenuated. These findings suggest that DOP-R activity in the dorsal striatum plays a role in high levels of ethanol consumption and suggest that targeting the DOP-R is an alternative strategy for the treatment of AUDs.