Showing papers by "University of Wollongong published in 2008"
TL;DR: It is reported that chemically converted graphene sheets obtained from graphite can readily form stable aqueous colloids through electrostatic stabilization, making it possible to process graphene materials using low-cost solution processing techniques, opening up enormous opportunities to use this unique carbon nanostructure for many technological applications.
Abstract: Graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected to find a variety of applications. A prerequisite for exploiting most proposed applications for graphene is the availability of processable graphene sheets in large quantities. The direct dispersion of hydrophobic graphite or graphene sheets in water without the assistance of dispersing agents has generally been considered to be an insurmountable challenge. Here we report that chemically converted graphene sheets obtained from graphite can readily form stable aqueous colloids through electrostatic stabilization. This discovery has enabled us to develop a facile approach to large-scale production of aqueous graphene dispersions without the need for polymeric or surfactant stabilizers. Our findings make it possible to process graphene materials using low-cost solution processing techniques, opening up enormous opportunities to use this unique carbon nanostructure for many technological applications.
8,534 citations
TL;DR: It is proposed that a more measured and disinterested approach is now required to investigate ‘digital natives’ and their implications for education and it is argued that rather than being empirical and theoretically informed, the debate can be likened to an academic form of a ‘moral panic’.
Abstract: The idea that a new generation of students is entering the education system has excited recent attention among educators and education commentators. Termed ‘digital natives’ or the ‘Net generation’, these young people are said to have been immersed in technology all their lives, imbuing them with sophisticated technical skills and learning preferences for which traditional education is unprepared. Grand claims are being made about the nature of this generational change and about the urgent necessity for educational reform in response. A sense of impending crisis pervades this debate. However, the actual situation is far from clear. In this paper, the authors draw on the fields of education and sociology to analyse the digital natives debate. The paper presents and questions the main claims made about digital natives and analyses the nature of the debate itself. We argue that rather than being empirically and theoretically informed, the debate can be likened to an academic form of a ‘moral panic’. We propose that a more measured and disinterested approach is now required to investigate ‘digital natives’ and their implications for education.
2,711 citations
TL;DR: In this paper, a study was conducted to demonstrate that highly ordered graphene paper can be prepared by directional flow-induced assembly of graphene sheets that are well dispersed in solution, which can enhance its mechanical stiffness and strength, and also electrical conductivity.
Abstract: A study was conducted to demonstrate that highly ordered graphene paper can be prepared by directional flow-induced assembly of graphene sheets that are well dispersed in solution. Moderate thermal annealing can enhance its mechanical stiffness and strength, and also electrical conductivity. Scanning electron microscopy (SEM) analysis reveals that the surface of the graphene paper is quite smooth and the fracture edges of the papers exhibit a layered structure through the entire cross-section. The study has also shown the results of cell culture experiments, which indicate that graphene paper may be biocompatible and therefore suitable for biomedical applications. The combination of the exceptional mechanical strength, thermal stability, high electrical conductivity, and biocompatibility makes graphene paper a promising material for many technological applications, such as inclusion in heart valves.
1,917 citations
TL;DR: Graphene nanosheets were produced in large quantity via a soft chemistry synthetic route involving graphite oxidation, ultrasonic exfoliation, and chemical reduction in this paper.
Abstract: Graphene nanosheets were produced in large quantity via a soft chemistry synthetic route involving graphite oxidation, ultrasonic exfoliation, and chemical reduction. X-ray diffraction and transmission electron microscopy (TEM) observations show that graphene nanosheets were produced with sizes in the range of tens to hundreds of square nanometers and ripple-like corrugations. High resolution TEM (HRTEM) and selected area electron diffraction (SAED) analysis confirmed the ordered graphite crystal structure of graphene nanosheets. The optical properties of graphene nanosheets were characterized by Raman spectroscopy.
1,916 citations
TL;DR: In this article, the authors present a framework that helps researchers to design and validate both formative and reflective measurement models, drawing from the existing literature and including both theoretical and empirical considerations.
1,032 citations
01 Jan 2008
TL;DR: The general public becomes rapidly jaded with such ‘bold predictions’ that fail to live up to their original hype, and which ultimately render the zealots’ promises as counter-productive.
Abstract: The Artificial Intelligence field continues to be plagued by what can only be described as ‘bold promises for the future syndrome’, often perpetrated by researchers who should know better. While impartial assessment can point to concrete contributions over the past 50 years (such as automated theorem proving, games strategies, the LISP and Prolog high-level computer languages, Automatic Speech Recognition, Natural Language Processing, mobile robot path planning, unmanned vehicles, humanoid robots, data mining, and more), the more cynical argue that AI has witnessed more than its fair share of ‘unmitigated disasters’ during this time – see, for example [3,58,107,125,186]. The general public becomes rapidly jaded with such ‘bold predictions’ that fail to live up to their original hype, and which ultimately render the zealots’ promises as counter-productive.
846 citations
TL;DR: A structured group education programme for patients with newly diagnosed type 2 diabetes resulted in greater improvements in weight loss and smoking cessation and positive improvements in beliefs about illness but no difference in haemoglobin A1c levels up to 12 months after diagnosis.
Abstract: Objective To evaluate the effectiveness of a structured group education programme on biomedical, psychosocial, and lifestyle measures in people with newly diagnosed type 2 diabetes Design Multicentre cluster randomised controlled trial in primary care with randomisation at practice level Setting 207 general practices in 13 primary care sites in the United Kingdom Participants 824 adults (55% men, mean age 595 years) Intervention A structured group education programme for six hours delivered in the community by two trained healthcare professional educators compared with usual care Main outcome measures Haemoglobin A 1c levels, blood pressure, weight, blood lipid levels, smoking status, physical activity, quality of life, beliefs about illness, depression, and emotional impact of diabetes at baseline and up to 12 months Main results Haemoglobin A 1c levels at 12 months had decreased by 149% in the intervention group compared with 121% in the control group After adjusting for baseline and cluster, the difference was not significant: 005% (95% confidence interval −010% to 020%) The intervention group showed a greater weight loss: −298 kg (95% confidence interval −354 to −241) compared with 186 kg (−244 to −128), P=0027 at 12 months The odds of not smoking were 356 (95% confidence interval 111 to 1145), P=0033 higher in the intervention group at 12 months The intervention group showed significantly greater changes in illness belief scores (P=0001); directions of change were positive indicating greater understanding of diabetes The intervention group had a lower depression score at 12 months: mean difference was −050 (95% confidence interval −096 to −004); P=0032 A positive association was found between change in perceived personal responsibility and weight loss at 12 months (β=012; P=0008) Conclusion A structured group education programme for patients with newly diagnosed type 2 diabetes resulted in greater improvements in weight loss and smoking cessation and positive improvements in beliefs about illness but no difference in haemoglobin A 1c levels up to 12 months after diagnosis Trial registration Current Controlled Trials ISRCTN17844016
745 citations
TL;DR: Metal electrode materials used in active implantable devices are often associated with poor long-term stimulation and recording performance and modification of these materials with conducting polymer coatings has been suggested as an approach for improving the neural tissue-electrode interface and increasing the effective lifetime of these implants.
612 citations
TL;DR: The influences on the physical activity behaviors of preschool children are multidimensional and further research is required to enhance an understanding of these influences.
556 citations
TL;DR: The concept of the spin gapless semiconductor in which both electron and hole can be fully spin polarized is proposed, and its possibility is presented on the basis of first-principles electronic structure calculations.
Abstract: The concept of the spin gapless semiconductor in which both electron and hole can be fully spin polarized is proposed, and its possibility is presented on the basis of first-principles electronic structure calculations. Possible new physics and potential applications in spintronic devices based on the spin gapless semiconductors are discussed.
545 citations
TL;DR: A comprehensive literature review of rural-urban health status differentials within Australia, New Zealand, Canada, the USA, the UK, and a variety of other western European nations was undertaken to understand the differences in life expectancy and cause-specific morbidity and mortality.
Abstract: We reviewed evidence of any apparently significant 'rural-urban' health status differentials in developed countries, to determine whether such differentials are generic or nation-specific, and to explore the nature and policy implications of determinants underpinning rural-urban health variations. A comprehensive literature review of rural-urban health status differentials within Australia, New Zealand, Canada, the USA, the UK, and a variety of other western European nations was undertaken to understand the differences in life expectancy and cause-specific morbidity and mortality. While rural location plays a major role in determining the nature and level of access to and provision of health services, it does not always translate into health disadvantage. When controlling for major risk determinants, rurality per se does not necessarily lead to rural-urban disparities, but may exacerbate the effects of socio-economic disadvantage, ethnicity, poorer service availability, higher levels of personal risk and more hazardous environmental, occupational and transportation conditions. Programs to improve rural health will be most effective when based on policies which target all risk determinants collectively contributing to poor rural health outcomes. Focusing solely on 'area-based' explanations and responses to rural health problems may divert attention from more fundamental social and structural processes operating in the broader context to the detriment of rural health policy formulation and remedial effort.
TL;DR: Age ages for nine sites from varied climatic and ecological zones across southern Africa show that both industries were short-lived (5000 years or less), separated by about 7000 years, and coeval with genetic estimates of population expansion and exit times.
Abstract: The expansion of modern human populations in Africa 80,000 to 60,000 years ago and their initial exodus out of Africa have been tentatively linked to two phases of technological and behavioral innovation within the Middle Stone Age of southern Africa-the Still Bay and Howieson's Poort industries-that are associated with early evidence for symbols and personal ornaments. Establishing the correct sequence of events, however, has been hampered by inadequate chronologies. We report ages for nine sites from varied climatic and ecological zones across southern Africa that show that both industries were short-lived (5000 years or less), separated by about 7000 years, and coeval with genetic estimates of population expansion and exit times. Comparison with climatic records shows that these bursts of innovative behavior cannot be explained by environmental factors alone.
TL;DR: This contribution reviews the current situation of integrative ecological assessment worldwide, by presenting several examples from each of the continents: Africa, Asia, Australia, Europe and North America.
TL;DR: These findings indicate that heavy daily cannabis use across protracted periods exerts harmful effects on brain tissue and mental health.
Abstract: Context Cannabis is the most widely used illicit drug in the developed world. Despite this, there is a paucity of research examining its long-term effect on the human brain. Objective To determine whether long-term heavy cannabis use is associated with gross anatomical abnormalities in 2 cannabinoid receptor–rich regions of the brain, the hippocampus and the amygdala. Design Cross-sectional design using high-resolution (3-T) structural magnetic resonance imaging. Setting Participants were recruited from the general community and underwent imaging at a hospital research facility. Participants Fifteen carefully selected long-term (>10 years) and heavy (>5 joints daily) cannabis-using men (mean age, 39.8 years; mean duration of regular use, 19.7 years) with no history of polydrug abuse or neurologic/mental disorder and 16 matched nonusing control subjects (mean age, 36.4 years). Main Outcome Measures Volumetric measures of the hippocampus and the amygdala combined with measures of cannabis use. Subthreshold psychotic symptoms and verbal learning ability were also measured. Results Cannabis users had bilaterally reduced hippocampal and amygdala volumes ( P = .001), with a relatively (and significantly [ P = .02]) greater magnitude of reduction in the former (12.0% vs 7.1%). Left hemisphere hippocampal volume was inversely associated with cumulative exposure to cannabis during the previous 10 years ( P = .01) and subthreshold positive psychotic symptoms ( P P = .048). Although cannabis users performed significantly worse than controls on verbal learning ( P Conclusions These results provide new evidence of exposure-related structural abnormalities in the hippocampus and amygdala in long-term heavy cannabis users and corroborate similar findings in the animal literature. These findings indicate that heavy daily cannabis use across protracted periods exerts harmful effects on brain tissue and mental health.
TL;DR: In this paper, the as-prepared MnO 2 nanowire/CNT composite paper (MNCCP) was used as a flexible electrode for electrochemical supercapacitors.
30 Jun 2008
TL;DR: This paper addresses two important issues of a PEKS scheme, "removing secure channel" and "refreshing keywords", and points out the inefficiency of the original PE KS scheme due to the use of the secure channel.
Abstract: The public key encryption with keyword search (PEKS) scheme, proposed by Boneh, Di Crescenzo, Ostrovsky and Persiano, enables one to search for encrypted keywords without compromising the security of the original data. In this paper, we address two important issues of a PEKS scheme, "removing secure channel" and "refreshing keywords", which have not been considered in Boneh et al.'s paper. We point out the inefficiency of the original PEKS scheme due to the use of the secure channel. We resolve this problem by constructing an efficient PEKS scheme that removes a secure channel. We then argue that care must be taken when keywords are used frequently in the PEKS scheme as this situation might contradict the security of PEKS.
TL;DR: The functionality of the Flexmix package was enhanced and concomitant variable models as well as varying and constant parameters for the component specific generalized linear regression models can be fitted.
Abstract: flexmix provides infrastructure for flexible fitting of finite mixture models in R using the expectation-maximization (EM) algorithm or one of its variants. The functionality of the package was enhanced. Now concomitant variable models as well as varying and constant parameters for the component specific generalized linear regression models can be fitted. The application of the package is demonstrated on several examples, the implementation described and examples given to illustrate how new drivers for the component specific models and the concomitant variable models can be defined.
TL;DR: In this paper, a mesoporous carbon (S-C) composites were tested in a novel ionic liquid electrolyte consisting of 1-ethyl-3methylimidazolium bis(trifluoromethanesulfonyl)imide and lithium bistrifluorsulfonimidate.
TL;DR: The impact of not only specific parameters of cannabis use in the manifestation of memory dysfunction, but also such factors as age, neurodevelopmental stage, IQ, gender, various vulnerabilities and other substance-use interactions are considered, in the context of neural efficiency and compensatory mechanisms.
Abstract: Memory problems are frequently associated with cannabis use, in both the short- and long-term. To date, reviews on the long-term cognitive sequelae of cannabis use have examined a broad range of cognitive functions, with none specifically focused on memory. Consequently, this review sought to examine the literature specific to memory function in cannabis users in the nontoxicated state with the aim of identifying the existence and nature of memory impairment in cannabis users and appraising potentially related mediators or moderators. Literature searches were conducted to extract well-controlled studies that investigated memory function in cannabis users outside of the acute intoxication period, with a focus on reviewing studies published within the past 10 years. Most recent studies have examined working memory and verbal episodic memory and cumulatively, the evidence suggests impaired encoding, storage, manipulation and retrieval mechanisms in long-term or heavy cannabis users. These impairments are not dissimilar to those associated with acute intoxication and have been related to the duration, frequency, dose and age of onset of cannabis use. We consider the impact of not only specific parameters of cannabis use in the manifestation of memory dysfunction, but also such factors as age, neurodevelopmental stage, IQ, gender, various vulnerabilities and other substance-use interactions, in the context of neural efficiency and compensatory mechanisms. The precise nature of memory deficits in cannabis users, their neural substrates and manifestation requires much further exploration through a variety of behavioural, functional brain imaging, prospective and genetic studies.
TL;DR: It is argued that the most parsimonious explanation for patterns of multiple paternity is that it represents the combined effect of mate‐encounter frequency and conflict over mating rates between males and females driven by large male benefits and relatively small female costs, with only weak selection via indirect benefits.
Abstract: The evolution of female promiscuity poses an intriguing problem as benefits of mating with multiple males often have to arise via indirect, genetic, effects. Studies on birds have documented that multiple paternity is common in natural populations but strong evidence for selection via female benefits is lacking. In an attempt to evaluate the evidence more broadly, we review studies of multiple paternity in natural populations of all major groups of nonavian reptiles. Multiple paternity has been documented in all species investigated so far and commonly exists in over 50% of clutches, with particularly high levels in snakes and lizards. Marine turtles and lizards with prolonged pair-bonding have relatively low levels of multiple paternity but levels are nevertheless higher than in many vertebrates with parental care. There is no evidence that high levels of polyandry are driven by direct benefits to females and the evidence that multiple paternity arises from indirect genetic benefits is weak. Instead, we argue that the most parsimonious explanation for patterns of multiple paternity is that it represents the combined effect of mate-encounter frequency and conflict over mating rates between males and females driven by large male benefits and relatively small female costs, with only weak selection via indirect benefits. A crucial step for researchers is to move from correlative approaches to experimental tests of assumptions and predictions of theory under natural settings, using a combination of molecular techniques and behavioural observations.
01 Jun 2008-Epidemiologia E Psichiatria Sociale-an International Journal for Epidemiology and Psychiatric Sciences
TL;DR: Development of recovery-focussed mental health services internationally is reviewed, and two innovative, generalisable and empirically investigated examples of implementing a focus on personal recovery are given.
Abstract: SUMMARY. Aims – To review developments in recovery-focussed mental health services internationally. Methods – Two forms of ‘recovery’ which have been used in the literature are considered, and international examples of recovery-focussed initiatives reviews. A ‘litmus test’ for a recovery-focussed service is proposed. Results – ‘Clinical recovery’ has emerged from professional literature, focuses on sustained remission and restoration of functioning, is invariant across individuals, and has been used to establish rates of recovery. ‘Personal recovery’ has emerged from consumer narratives, focuses on living a satisfying, hopeful and contributing life even with limitations caused by the illness, varies across individuals, and the empirical evidence base relates to stages of change more than overall prevalence rates. Clinical and personal recovery are different. Two innovative, generalisable and empirically investigated examples are given of implementing a focus on personal recovery: the Collaborative Recovery Model in Australia, and Trialogues in German-speaking Europe. The role of medication is an indicator: services in which all service users are prescribed medication, in which the term ‘compliance’ is used, in which the reasoning bias is present of attributing improvement to medication and deterioration to the person, and in which contact with and discussion about the service user revolves around medication issues, are not personal recovery-focussed services. Conclusions – The term ‘Recovery’ has been used in different ways, so conceptual clarity is important. Developing a focus on personal recovery is more than a cosmetic change – it will entail fundamental shifts in the values of mental health services. Declaration of Interest: None.
TL;DR: These results suggest dysfunctional integration of frontal and posterior brain regions in autistics along with a pattern of neural underconnectivity consistent with other EEG, MRI and fMRI research suggesting that neural connectivity anomalies are a major deficit leading to autistic symptomatology.
TL;DR: In this article, the electrochemical properties of 1D SnO2 nanomaterials, nanotubes, nanowires, and nanopowders are compared to define the most favorable morphology when used as the electrode material for lithium-ion batteries.
Abstract: The electrochemical performances of 1D SnO2 nanomaterials, nanotubes, nanowires, and nanopowders, are compared to define the most favorable morphology when SnO2 nanomaterials are adopted as the electrode material for lithium-ion batteries. Changes in the morphology of SnO2 are closely related with its electrochemical performance. Some SnO2 nanomaterials feature not only an increased energy density but also enhanced Li+ transfer. The correlation between the morphological characteristics and the electrochemical properties of SnO2 nanomaterials is discussed. The interesting electrochemical results obtained here on SnO2 nanomaterials indicate the possibility of designing and fabricating attractive nanostructured materials for lithium-ion batteries.
TL;DR: In this paper, the authors examined the contribution of movement-related potentials (MRPs) to the Go/NoGo N2 and P3 "inhibitory" effects.
TL;DR: In this paper, a review of the typical characteristics of the loading conditions for railway track structures, in particular, impact loads due to the wheel/rail interaction, is presented, with particular emphasis on the typical shapes of the impact load waveforms generally found on railway tracks.
Abstract: Train and track interactions during services normally generate substantial forces on railway tracks. Such forces are transient by nature and of relatively large magnitude and are referred to as impact loading. There has been no comprehensive review of the typical characteristics of the loading conditions for railway track structures, in particular, impact loads due to the wheel/rail interaction, published in the literature. This paper presents a review of basic design concepts for railway tracks, abnormalities on tracks, and a variety of typical dynamic impact loadings imparted by wheel/rail interaction and irregularities. The characteristics of typical impact loads due to wheel and rail irregularities, e.g. rail corrugation, wheel flats and shells, worn wheel and rail profiles, bad welds or joints, and track imperfections, are presented with particular emphasis on the typical shapes of the impact load waveforms generally found on railway tracks. Copyright © 2007 John Wiley & Sons, Ltd.
TL;DR: In this paper, the morphology and substrate characteristics of reef islands on Indo-Pacific atolls, and summarises their topography are reviewed, and three effects are inferred: erosion of the shoreline, inundation of low-lying areas, and saline intrusion into the freshwater lens.
TL;DR: In this article, a review of the literature on sustainable tourism and ecotourism is presented, highlighting that researchers still have only a limited understanding of what tourist behaviour can be considered as sustainable, and little consensus about who environment-friendly tourists (EFTs) actually are.
Abstract: Sustainable tourism and ecotourism have now been researched in depth for some years. This paper highlights that researchers still have only a limited understanding of what tourist behaviour can be considered as sustainable, and little consensus about who environment-friendly tourists (EFTs) actually are. This study reviews theoretical and empirical studies by tourism researchers, and explores work done on environment-friendly behaviour in other disciplines. Results indicate that operationalisations of EFTs are inconsistent and, at times, do not ensure that EFTs are actually studied, thus jeopardising the quality of cumulative knowledge on this critical issue. There is little insight into who EFTs are. Suggestions for future work are made, which would develop more reliable and generalisable insights into EFT profiles.
TL;DR: In this article, a series of structure transformations depend upon the doping level of Bi1−xLaxFeO3 ceramics with x=0, 0.8La0.2 and Bi0.7La 0.3 have been synthesized by solid state reaction starting from metal oxides.
Abstract: Bi1−xLaxFeO3 ceramics with x=0, 0.1, 0.2, and 0.3 have been synthesized by solid state reaction, starting from metal oxides. A series of structure transformations is found to depend upon the doping level. Below 10% La doping, Bi1−xLaxFeO3 maintains the rhombohedral structure of BiFeO3. However, for Bi0.8La0.2FeO3 and Bi0.7La0.3FeO3, the structures change to the orthorhombic and tetragonal, respectively. La doping significantly reduces electric leakage and leads to successful observation of electrical polarization hysteresis loops. Doping with La also enhances the ferromagnetic moment, due to the broken cycloid spin structure caused by the changes in the crystalline structure.
01 Jun 2008
TL;DR: In this article, the authors investigated productivity growth in 35 Australian universities using non-parametric frontier techniques over the period 1998-2003 and found that annual productivity growth averaged 3.3% across all universities, with a range from -1.8% to 13.0%, and was largely attributable to technological progress.
Abstract: In this study, productivity growth in 35 Australian universities is investigated using non-parametric frontier techniques over the period 1998–2003. The five inputs included in the analysis are full-time equivalent academic and non-academic staff, non-labour expenditure and undergraduate and postgraduate student load while the six outputs are undergraduate, postgraduate and Ph.D. completions, national competitive and industry grants and publications. Using Malmquist indices, productivity growth is decomposed into technical efficiency and technological change. The results indicate that annual productivity growth averaged 3.3% across all universities, with a range from -1.8% to 13.0%, and was largely attributable to technological progress. However, separate analyses of research-only and teaching-only productivity indicate that most of this gain was attributable to improvements in research-only productivity associated with pure technical and some scale efficiency improvements. While teaching-only productivity also contributed, the largest source of gain in that instance was technological progress offset by a slight fall in technical efficiency.