Showing papers by "University of Southern Queensland published in 2011"

Doing qualitative research: a practical handbook

Abstract: Doing qualitative research: a practical handbook, by David Silverman, Los Angeles, Sage, 2010, 456 pp., AU$65.00, ISBN 978-1-84860-033-1, ISBN 978-1-94960-034-8. Available in Australia and New Zeal...

A review on the tensile properties of natural fiber reinforced polymer composites

Abstract: This paper is a review on the tensile properties of natural fiber reinforced polymer composites. Natural fibers have recently become attractive to researchers, engineers and scientists as an alternative reinforcement for fiber reinforced polymer (FRP) composites. Due to their low cost, fairly good mechanical properties, high specific strength, non-abrasive, eco-friendly and bio-degradability characteristics, they are exploited as a replacement for the conventional fiber, such as glass, aramid and carbon. The tensile properties of natural fiber reinforce polymers (both thermoplastics and thermosets) are mainly influenced by the interfacial adhesion between the matrix and the fibers. Several chemical modifications are employed to improve the interfacial matrix–fiber bonding resulting in the enhancement of tensile properties of the composites. In general, the tensile strengths of the natural fiber reinforced polymer composites increase with fiber content, up to a maximum or optimum value, the value will then drop. However, the Young’s modulus of the natural fiber reinforced polymer composites increase with increasing fiber loading. Khoathane et al. [1] found that the tensile strength and Young’s modulus of composites reinforced with bleached hemp fibers increased incredibly with increasing fiber loading. Mathematical modelling was also mentioned. It was discovered that the rule of mixture (ROM) predicted and experimental tensile strength of different natural fibers reinforced HDPE composites were very close to each other. Halpin–Tsai equation was found to be the most effective equation in predicting the Young’s modulus of composites containing different types of natural fibers.

High-carbohydrate, high-fat diet-induced metabolic syndrome and cardiovascular remodeling in rats

Abstract: The prevalence of metabolic syndrome including central obesity, insulin resistance, impaired glucose tolerance, hypertension, and dyslipidemia is increasing. Development of adequate therapy for metabolic syndrome requires an animal model that mimics the human disease state. Therefore, we have characterized the metabolic, cardiovascular, hepatic, renal, and pancreatic changes in male Wistar rats (8-9 weeks old) fed on a high-carbohydrate, high-fat diet including condensed milk (39.5%), beef tallow (20%), and fructose (17.5%) together with 25% fructose in drinking water; control rats were fed a cornstarch diet. During 16 weeks on this diet, rats showed progressive increases in body weight, energy intake, abdominal fat deposition, and abdominal circumference along with impaired glucose tolerance, dyslipidemia, hyperinsulinemia, and increased plasma leptin and malondialdehyde concentrations. Cardiovascular signs included increased systolic blood pressure and endothelial dysfunction together with inflammation, fibrosis, hypertrophy, increased stiffness, and delayed repolarization in the left ventricle of the heart. The liver showed increased wet weight, fat deposition, inflammation, and fibrosis with increased plasma activity of liver enzymes. The kidneys showed inflammation and fibrosis, whereas the pancreas showed increased islet size. In comparison with other models of diabetes and obesity, this diet-induced model more closely mimics the changes observed in human metabolic syndrome.

Rodent Models for Metabolic Syndrome Research

Abstract: Rodents are widely used to mimic human diseases to improve understanding of the causes and progression of disease symptoms and to test potential therapeutic interventions. Chronic diseases such as obesity, diabetes and hypertension, together known as the metabolic syndrome, are causing increasing morbidity and mortality. To control these diseases, research in rodent models that closely mimic the changes in humans is essential. This review will examine the adequacy of the many rodent models of metabolic syndrome to mimic the causes and progression of the disease in humans. The primary criterion will be whether a rodent model initiates all of the signs, especially obesity, diabetes, hypertension and dysfunction of the heart, blood vessels, liver and kidney, primarily by diet since these are the diet-induced signs in humans with metabolic syndrome. We conclude that the model that comes closest to fulfilling this criterion is the high carbohydrate, high fat-fed male rodent.

Early Versus Traditional Postoperative Feeding in Patients Undergoing Resectional Gastrointestinal Surgery A Meta-Analysis

Abstract: Background: A meta-analysis evaluating surgical outcomes following nutritional provision provided proximal to the anastomosis within 24 hours of gastrointestinal surgery compared with traditional postoperative management was conducted. Methods: Databases were searched to identify randomized controlled trials comparing the outcomes of early and traditional postoperative feeding. Trials involving gastrointestinal tract resection followed by patients receiving nutritionally significant oral or enteral intake within 24 hours after surgery were included for analysis. Results: Fifteen studies involving a total of 1240 patients were analyzed. A statistically significant reduction (45%) in relative odds of total postoperative complications was seen in patients receiving early postoperative feeding (odds ratio [OR] 0.55; confidence interval [CI], 0.35 -0.87, P = .01). No effect of early feeding was seen with relation to anastomotic dehiscence (OR 0.75; CI, 0.39-1.4, P = .39), mortality (OR 0.71; CI, 0.32-1.56, P = .39), days to passage of flatus (weighted mean difference [WMD] -0.42; CI, -1.12 to 0.28, P = .23), first bowel motion (WMD -0.28; CI, -1.20 to 0.64, P = .55), or reduced length of stay (WMD -1.28; CI, -2.94 to 0.38, P = .13); however, the direction of clinical outcomes favored early feeding. Nasogastric tube reinsertion was less common in traditional feeding interventions (OR 1.48; CI, 0.93-2.35, P = .10). Conclusions: Early postoperative nutrition is associated with significant reductions in total complications compared with traditional postoperative feeding practices and does not negatively affect outcomes such as mortality, anastomotic dehiscence, resumption of bowel function, or hospital length of stay.

Beyond the first‐year experience: the impact on attrition of student experiences throughout undergraduate degree studies in six diverse universities

Abstract: In the face of difficult economic circumstances, increased competition and student diversity, attrition and retention have become issues of great significance to higher education institutions seeking to survive. A large body of work has explored the relationship between attrition and the first‐year experience, but there has been little focus on students' experience of university in subsequent years despite the fact that later year attrition counts for approximately half of all attrition. This empirical research study examines students' experience of university in six diverse universities, across the three years of business degree studies. It finds that the factors correlated with intention to withdraw from university studies are differentiated by year of study, and further differentiated by the university attended. The implications of these findings are discussed and a framework for institutional action is subsequently used to outline the dimensions of a relevant retention program.

Mechanism of reinforcement in a nanoclay/polymer composite

Abstract: Using organomodified montmorillonite (MMT) (commonly called “Nanoclay”) to reinforce polymer-based composites have raised much attention to academic and industrial sectors due to the addition of small amount of nanoclay could substantially enhance the mechanical properties of pristine polymers. However, most of the works done previously have neglected to comprehensively study the basic reinforcing mechanism of the composites, particular the interaction between nanoclay and surrounding matrix even though high tensile strength and modulus were obtained. In this paper, uniformly-dispersed nanoclay/epoxy composite samples, based on our tailor-made experiment setup were fabricated. A tensile property test was conducted to examine the mechanical properties of the samples with different nanoclay content. It was found that the Young’s modulus and tensile strength of a composite with 5 wt.% of nanoclay increased up to 34% and 25% respectively, as compared with a pristine sample. Images obtained from scanning electron microscopy (SEM) and results extracted from transmission electron microscope (TEM) proved that interlocking and bridging effects did exist in the composites. Nanoclay clusters with the diameter of 10 nm could enhance the mechanical interlocking inside the composites and thus, breaking up the crack propagation. The formation of boundaries between the nanoclay clusters and epoxy can refine the matrix grains and further improve the flexural strength of the composites.

Electrochemical performance of a graphene polypyrrole nanocomposite as a supercapacitor electrode

Abstract: A unique nanoarchitecture has been established involving polypyrrole (PPy) and graphene nanosheets by in situ polymerization. The structural aspect of the nanocomposite has been determined by Raman spectroscopy. Atomic force microscopy reveals that the thickness of the synthesized graphene is ~ 2 nm. The dispersion of the nanometer-sized PPy has been demonstrated through transmission electron microscopy and the electrochemical performance of the nanocomposite has been illustrated by cyclic voltammetry measurements. Graphene nanosheet serves as a support material for the electrochemical utilization of PPy and also provides the path for electron transfer. The specific capacitance value of the nanocomposite has been determined to be 267 F g − 1 at a scan rate of 100 mV s − 1 compared to 137 mV s − 1 for PPy, suggesting the possible use of the nanocomposite as a supercapacitor electrode. After 500 cycles, only 10% decrease in specific capacitance as compared to initial value justifies the improved electrochemical cyclic stability of the nanocomposite.

Property enhancement of a carbon fiber/epoxy composite by using carbon nanotubes

Abstract: We investigated the effect of carbon nanotube (CNT) modifications on the flexural and wear behaviors of multiscale carbon/CNT/epoxy composites in this study. Carbon/epoxy woven composites and two types of multiscale carbon/CNT/epoxy composites were fabricated by incorporating woven-type carbon fibers into epoxy matrices modified with 2 wt% acid-treated and silane-treated multi-walled carbon nanotubes (MWCNTs). Three-point bending and ball-on-disk wear tests were performed on the three composites. The results showed that the flexural moduli and strengths of carbon/CNT/epoxy composites were greater than those of carbon/epoxy composites, regardless of CNT modification. Specifically, the flexural modulus and strength of the silane-treated specimens were 10% and 15% greater, respectively, than those of the acid-treated samples. The results also showed that the wear properties of carbon/epoxy composites are improved by the addition of CNTs. In addition, the wear properties of silane-treated samples were superior to those of acid-treated samples. Scanning electron microscopic examination of fractured and worn surfaces showed that the improvement in the flexural and wear properties of the silane-treated carbon/CNT/epoxy composites was attributed to the improved dispersion of CNTs in the epoxy and the better interfacial characteristics caused by the silanization of the CNTs.

Putting plant resistance traits on the map: a test of the idea that plants are better defended at lower latitudes

Abstract: • It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods from a wide range of latitudes. • We quantified the relationship between latitude and a broad range of chemical and physical traits across 301 species from 75 sites world-wide. • Six putative resistance traits, including tannins, the concentration of lipids (an indicator of oils, waxes and resins), and leaf toughness were greater in high-latitude species. Six traits, including cyanide production and the presence of spines, were unrelated to latitude. Only ash content (an indicator of inorganic substances such as calcium oxalates and phytoliths) and the properties of species with delayed greening were higher in the tropics. • Our results do not support the hypothesis that tropical plants have higher levels of resistance traits than do plants from higher latitudes. If anything, plants have higher resistance toward the poles. The greater resistance traits of high-latitude species might be explained by the greater cost of losing a given amount of leaf tissue in low-productivity environments.

The International Atmospheric Circulation Reconstructions over the Earth (ACRE) Initiative

Abstract: In 2006, climate applications scientists in Queensland, Australia, asked the lead author if a longer and more complete historical weather record could be created and fed directly into various crop, pasture, and production models. Existing dynamical reanalyses were steps toward such a product, but they spanned only the last six decades and had well-known shortcomings. To meet the needs of application scientists, new reanalyses would have to extend much further back in time while maintaining accuracy with limited observations. They would also need to be disseminated in a way that is easy to use directly and to downscale to small regions.

Rutin Attenuates Metabolic Changes, Nonalcoholic Steatohepatitis, and Cardiovascular Remodeling in High-Carbohydrate, High-Fat Diet-Fed Rats

Abstract: Metabolic syndrome (obesity, diabetes, and hypertension) increases hepatic and cardiovascular damage This study investigated preventive or reversal responses to rutin in high-carbohydrate, high-fat diet-fed rats as a model of metabolic syndrome Rats were divided into 6 groups: 2 groups were fed a corn starch-rich diet for 8 or 16 wk, 2 groups were fed a high-carbohydrate, high-fat diet for 8 or 16 wk, and 2 groups received rutin (16 g/kg diet) in either diet for the last 8 wk only of the 16-wk protocol Metabolic changes and hepatic and cardiovascular structure and function were then evaluated in these rats The corn starch-rich diet contained 68% carbohydrate (mainly cornstarch) and 07% fat, whereas the high-carbohydrate, high-fat diet contained 50% carbohydrate (mainly fructose) and 24% fat (mainly beef tallow) along with 25% fructose in drinking water (total 68% carbohydrate using mean food and water intakes) The high-carbohydrate, high-fat diet produced obesity, dyslipidemia, hypertension, impaired glucose tolerance, hepatic steatosis, infiltration of inflammatory cells in the liver and the heart, higher cardiac stiffness, endothelial dysfunction, and higher plasma markers of oxidative stress with lower expression of markers for oxidative stress and apoptosis in the liver Rutin reversed or prevented metabolic changes such as abdominal fat pads and glucose tolerance, reversed or prevented changes in hepatic and cardiovascular structure and function, reversed oxidative stress and inflammation in the liver and heart, and normalized expression of liver markers These results suggest a non-nutritive role for rutin to attenuate chronic changes in metabolic syndrome

Institutional Investor Influence on Global Climate Change Disclosure Practices

Abstract: Using a stakeholder engagement perspective, we investigate the collective influence of institutional investors on a comprehensive set of climate change disclosures for a global sample of large companies. The proposition tested in this paper is that the influence of these powerful stakeholders is positively associated with climate change disclosure via corporate communications channels. We find that the extent and quality of climate change disclosures to be associated with three indicators of corporate responsiveness to institutional investor expectations about the disclosure of this information. These are completion and publication of the Carbon Disclosure Project (CDP) questionnaire on CDP’s website, indications in corporate communications that CDP activities have influenced climate change disclosures, and the extent and quality of climate change information provided in CDP questionnaire responses.

Algae as a sustainable energy source for biofuel production in Iran: A case study

Abstract: Algae can be converted directly into energy, such as biodiesel, bioethanol and biomethanol and therefore can be a source of renewable energy. There is a growing interest for biodiesel production from algae because of its higher yield non-edible oil production and its fast growth that does not compete for land with food production. About 50% of algae weight is oil that this lipid oil can be used to make biodiesel. Algae is capable of yielding 30 times more oil per acre than the crops currently used in biodiesel production. Processes for biodiesel production from algae-oil are similar to food and non-food crops derived biodiesel processes. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Iran has high biofuel energy potential. The Iranian government is considerable attention to the utilization of renewable energy, especially biofuels. Iran has enough land in order to algae cultivation that does not compete with food production. A salt lake (Lake Orumieh) in Iran's West Azarbaijan province, Maharlu salt lake in Iran's Fars province, Qom salt lake in Iran's Qom province have given rise to a new species of algae for biofuel. Algae are frequent in the shallow-marine lime stones in Zagros Mountains in north of Fars province. Greenish blooms of algae can be seen in the Persian Gulf and Caspian Sea, south and north of Iran respectively. This study presents a brief introduction to the resource, status and prospect of algae as a sustainable energy source for biodiesel production in Iran. The main advantages of using algae for biodiesel production in Iran are described.

The power of problem-based learning in developing critical thinking skills: preparing students for tomorrow's digital futures in today's classrooms

Abstract: This article describes problem‐based learning as a powerful pedagogical approach and an aligned teaching and learning system to explicitly and directly teach critical thinking skills in a broad range of disciplines. Problem‐based learning is argued to be a powerful pedagogical approach as it explicitly and actively engages students in a learning and teaching system, characterised by reiterative and reflective cycles of learning domain‐specific knowledge and doing the thinking themselves. At the same time, students are guided and coached by the problem‐based learning teacher, who models critical thinking skills in the acquisition of the domain‐specific knowledge. This article will explore what critical thinking actually means. What are critical thinking skills? How best to teach such skills? What is the potential role of problem‐based learning in teaching critical thinking skills? Finally, the article reflects on how critical thinking can be developed through problem‐based learning as a pedagogical approac...

From face-to-face teaching to online teaching: Pedagogical transitions

Abstract: This paper will share the experiences of two instructors as they moved from teaching in a face-to-face environment to blended teaching and then to online teaching. It will describe the four year journey and shed light on the issues, perspectives and practices as the instructors reflected on the changes to their pedagogical practice and the resulting online student engagement. Data included three 1-hour interviews and an analysis of online discussion postings. The instructors reflected on their values, beliefs and assumptions about teaching and learning. As higher education has embraced online education as a way to reduce costs, increase flexibility, and enhance access to students it is important to gain an understanding of the perceptions of instructors moving into online teaching. This study found a change in the beliefs and teaching presence of the instructors from their initial resistance to online teaching to an approach which is mindful of the student experience and promotes a dialogical approach to online learning.

Privacy-aware access control with trust management in web service

Abstract: With the significant development of mobile commerce, privacy becomes a major concern for both customers and enterprises. Although data generalization can provide significant protection of an individual's privacy, over-generalized data may render data of little value or useless. In this paper, we devise generalization boundary techniques to maximize data usability while, minimizing disclosure of privacy. Inspired by the fact that the permissible generalization level results in a much finer level access control, we propose a privacy-aware access control model in web service environments. We also analyze how to manage a valid access process through a trust-based decision and ongoing access control policies. The extensive experiments on both real-world and synthetic data sets show that the proposed privacy aware access control model is practical and effective.

Assessing Environmental Stewardship Motivation

Abstract: Environmental stewardship networks flourish across Australia. Although the environment benefits, this article looks to identify what volunteers draw from their stewardship. The authors adapted 16 questions that purport- edly tap environmental stewardship motivation and administered them to a convenience sample of 318 university students and then to 88 people living in rural Australia, who were either active members of environmental groups or voiced concern about local environmental issues. The results suggest that the measure consisting of these questions demonstrates acceptable internal consistency. Factor analyses support three relatively independent aspects of environmental stewardship motivation: (a) developing a sense of belonging, (b) caretaking the environment, and (c) expanding personal learning. Scores on the scale were not strongly correlated with well-being, suggesting that the scale measures more than general feelings of positive affect. Discussion focuses on the benefits of being able to reliably assess environmental stew- ardship motivation and areas for further development of the scale.

Ecotourism: impacts, potentials and possibilities

Abstract: Ecotourism: impacts, potentials and possibilities (2nd ed.), by Stephen Wearing and John Neil, Oxford, UK, Butterworth-Heinemann, 2009, v + 286 pp., ISBN 978-0-9506-6249-9 I was looking forward to ...

Lone Wolf Terrorism

Abstract: The purpose of this paper is to investigate the insights that might be generated into the nature of 'lone wolf terrorism' through the application of economic analysis. Orthodox approaches, particularly (standard) expected utility analysis and game theoretical analysis, are discussed. These tools prove useful in developing preliminary or 'first order' insights. The lone wolf terrorist exhibits a number of idiosyncrasies that present challenges to both economic analysis and government security policy. An alternative analytical framework is constructed wherein a terroristic agent makes choices on the basis of a preference ordering constructed over two moments of the distribution (measured in terms of fatalities generated by terrorist attacks). Seven predictions are yielded from the mean-variance theoretical framework and numerical estimates are computed as preliminary steps towards the full exploration of the implications of the framework. Most importantly, depending on their level of risk aversion (or risk seeking behaviour), lone wolves are expected to predominantly choose assassination, armed attack, bombing, hostage taking or unconventional attacks. Furthermore, within a range of between one and two standard deviations from the mean, it is possible that the quadratic utility function will reach a maximum. Following attacks of a certain magnitude (in terms of fatalities), it might be expected that the lone wolf will withdraw from activity for a period of time. This analytical approach may assist governments and security agencies facing the threat of lone wolf terrorism.

QTL mapping of stripe, leaf and stem rust resistance genes in a Kariega × Avocet S doubled haploid wheat population

Abstract: Adult plant resistance to stripe (yellow) rust in the wheat cultivar Kariega has previously been ascribed to a major quantitative trait locus (QTL) on each of chromosomes 2B and 7D, along with a number of minor QTL. We have extended both the size of the cv. Kariega × cv. Avocet S mapping population, and the marker coverage within it, by assembling a set of Diversity Array Technology (DArT) markers. This has allowed for the analysis of the genetic basis of the adult plant and seedling resistances to stripe, leaf and stem rust present in the two mapping population parents. The stripe rust reactions of the segregating material were assessed in both field (three scoring dates) and greenhouse experiments. The chromosome 2B QTL became more important than the Lr34/Yr18 complex on chromosome 7D as the plants aged. As the infection progressed, the two QTL explained an increasing proportion of the variance for percentage leaf area infected. The cv. Kariega allele at the minor chromosome 4A QTL had a consistent effect on the severity of stripe rust infection and the overall plant reaction at the earlier scoring dates, but lost importance as the disease progressed. Several rust resistances were detected using an improved greenhouse-based test.

Exploring programming assessment instruments: a classification scheme for examination questions

Abstract: This paper describes the development of a classification scheme that can be used to investigate the characteristics of introductory programming examinations. We describe the process of developing the scheme, explain its categories, and present a taste of the results of a pilot analysis of a set of CS1 exam papers. This study is part of a project that aims to investigate the nature and composition of formal examination instruments used in the summative assessment of introductory programming students, and the pedagogical intentions of the educators who construct these instruments.

In vitro biodegradation behavior of magnesium and magnesium alloy

Abstract: Magnesium has the potential to be used as degradable metallic biomaterial. For magnesium and its alloys to be used as biodegradable implant materials, their degradation rates should be consistent with the rate of healing of the affected tissue, and the release of the degradation products should be within the body's acceptable absorption levels. Conventional magnesium degrades rapidly, which is undesirable. In this study, biodegradation behaviors of high purity magnesium and commercial purity magnesium alloy AZ31 in both static and dynamic Hank's solution are systematically investigated. The in vitro test results show that magnesium purification and selective alloying are effective approaches to reduce the degradation rate of magnesium. In the static condition, the corrosion products accumulate on the materials surface as a protective layer, which results in a lower degradation rate than the dynamic condition. Anodized coating can significantly further reduce the degradation rate of magnesium. This study strongly indicates that magnesium can be used as degradable implant material as long as the degradation is controlled at a low rate. Magnesium purification, selective alloying, and anodized coating are three effective approaches to reduce the rate of degradation.