Showing papers by "RMIT University published in 2004"

Diet, nutrition and the prevention of excess weight gain and obesity

Abstract: Objective: To review the evidence on the diet and nutrition causes of obesity and to recommend strategies to reduce obesity prevalence Design: The evidence for potential aetiological factors and strategies to reduce obesity prevalence was reviewed, and recommendations for public health action, population nutrition goals and further research were made Results: Protective factors against obesity were considered to be: regular physical activity (convincing); a high intake of dietary non-starch polysaccharides (NSP)/fibre (convincing); supportive home and school environments for children (probable); and breastfeeding (probable) Risk factors for obesity were considered to be sedentary lifestyles (convincing); a high intake of energy-dense, micronutrient-poor foods (convincing); heavy marketing of energy-dense foods and fast food outlets (probable); sugar-sweetened soft drinks and fruit juices (probable); adverse social and economic conditions—developed countries, especially in women (probable) A broad range of strategies were recommended to reduce obesity prevalence including: influencing the food supply to make healthy choices easier; reducing the marketing of energy dense foods and beverages to children; influencing urban environments and transport systems to promote physical activity; developing community-wide programmes in multiple settings; increased communications about healthy eating and physical activity; and improved health services to promote breastfeeding and manage currently overweight or obese people Conclusions: The increasing prevalence of obesity is a major health threat in both low- and high income countries Comprehensive programmes will be needed to turn the epidemic around

Factors Affecting Running Economy in Trained Distance Runners

Abstract: velocity of submaximal running, and is determined by measuring the steady-state consumption of oxygen ( ˙ VO2) and the respiratory exchange ratio. Taking body mass (BM) into consideration, runners with good RE use less energy and therefore less oxygen than runners with poor RE at the same velocity. There is a strong association between RE and distance running performance, with RE being a better predictor of performance than maximal oxygen uptake ( ˙ VO2max) in elite runners

Reliability and validity of the Biodex System 3 Pro Isokinetic Dynamometer velocity, torque and position measurements

Abstract: This study quantitatively assessed the mechanical reliability and validity of position, torque and velocity measurements of the Biodex System 3 isokinetic dynamometer. Trial-to-trial and day-to-day reliability were assessed during three trials on two separate days. To assess instrument validity, measurement of each variable using the Biodex System 3 dynamometer was compared to a criterion measure of position, torque and velocity. Position was assessed at 5° increments across the available range of motion of the dynamometer. Torque measures were assessed isometrically by hanging six different calibrated weights from the lever arm. Velocity was assessed (30°/s to 500°/s) across a 70° arc of motion by manually accelerating the weighted lever arm. With the exception of a systematic decrease in velocity at speeds of 300°/s and higher, the Biodex System 3 performed with acceptable mechanical reliability and validity on all variables tested.

Exploring the relationship between knowledge management practices and innovation performance

Abstract: The process of innovation depends heavily on knowledge, and the management of knowledge and human capital should be an essential element of running any type of business Recent research indicates that organisations are not consistent in their approach to knowledge management (KM), with KM approaches being driven predominantly within an information technology (IT) or humanist framework, with little if any overlap This paper explores the relationship between KM approaches and innovation performance through a preliminary study focusing on the manufacturing industry The most significant implication that has emerged from the study is that managers in manufacturing firms should place more emphasis on human resource management (HRM) practices when developing innovation strategies for product and process innovations The study shows that KM contributes to innovation performance when a simultaneous approach of “soft HRM practices” and “hard IT practices” are implemented

The Use of Ice in the Treatment of Acute Soft-Tissue Injury: A Systematic Review of Randomized Controlled Trials

Abstract: Background: There are wide variations in the clinical use of cryotherapy, and guidelines continue to be made on an empirical basis.Study Design: Systematic review assessing the evidence base for cryotherapy in the treatment of acute soft-tissue injuries.Methods: A computerized literature search, citation tracking, and hand searching were carried out up to April 2002. Eligible studies were randomized-controlled trials describing human subjects recovering from acute soft-tissue injuries and employing a cryotherapy treatment in isolation or in combination with other therapies. Two reviewers independently assessed the validity of included trials using the Physiotherapy Evidence Database (PEDro) scale.Results: Twenty-two trials met the inclusion criteria. There was a mean PEDro score of 3.4 out of of 10. There was marginal evidence that ice plus exercise is most effective, after ankle sprain and postsurgery. There was little evidence to suggest that the addition of ice to compression had any significant effect...

Chaos synchronization of general complex dynamical networks

Abstract: Recently, it has been demonstrated that many large-scale complex dynamical networks display a collective synchronization motion. Here, we introduce a time-varying complex dynamical network model and further investigate its synchronization phenomenon. Based on this new complex network model, two network chaos synchronization theorems are proved. We show that the chaos synchronization of a time-varying complex network is determined by means of the inner coupled link matrix, the eigenvalues and the corresponding eigenvectors of the coupled configuration matrix, rather than the conventional eigenvalues of the coupled configuration matrix for a uniform network. Especially, we do not assume that the coupled configuration matrix is symmetric and its off-diagonal elements are nonnegative, which in a way generalizes the related results existing in the literature.

Reevaluation of prognostic factors for survival after liver resection in patients with hepatocellular carcinoma in a Japanese nationwide survey.

Abstract: BACKGROUND Advances in the diagnosis and surgical treatment of hepatocellular carcinoma (HCC) have improved the prognosis for patients with HCC who undergo liver resection. The objective of this study was to evaluate prognostic predictors for patients with HCC who underwent liver resection in a Japanese nationwide data base. METHODS In this study, the authors analyzed 12,118 patients with HCC in a Japanese nationwide data base who underwent liver resection between 1990 and 1999 and compared them with a previous analysis of patients between 1982 and 1989. All patients were evaluated for prognostic factors. RESULTS During the last decade, the increases in patients who were without hepatitis B virus surface antigen, who had small tumors, and who had portal vein invasion were noted. The 5-year overall survival rates for patients with HCC improved to 50.5%, compared with < 40% in the previous analysis. A multivariate analysis using a stratified Cox proportional hazards model according to associated liver disease indicated that age, degree of liver damage, α-fetoprotein level, maximal tumor dimension, number of tumors, intrahepatic extent of tumor, extrahepatic metastasis, portal vein invasion, hepatic vein invasion, surgical curability, and free surgical margins were independent prognostic predictors for patients with HCC. Operative mortality decreased from 2.3% in 1990–1991 to 0.6% in 1998–1999. CONCLUSIONS Outcomes and operative mortality rates in patients with HCC improved during the last decade. Age, degree of liver damage, α-fetoprotein level, maximal tumor dimension, number of tumors, intrahepatic extent of tumor, extrahepatic metastasis, portal vein invasion, hepatic vein invasion, surgical curability, and free surgical margins were prognostic factors for patients with HCC who underwent liver resection. Cancer 2004. © 2004 American Cancer Society.

Interleukin-6 Is a Novel Factor Mediating Glucose Homeostasis During Skeletal Muscle Contraction

Abstract: The mechanisms that mediate the tightly controlled production and clearance of glucose during muscular work are unclear, and it has been suggested that an unidentified "work factor" exists that influences the contraction-induced increase in endogenous glucose production (EGP). The cytokine interleukin (IL)-6 is released from skeletal muscle during contraction. Here we show that IL-6 contributes to the contraction-induced increase in EGP. Six men performed 2 h of bicycle exercise on three separate occasions, at a relatively high intensity (HI) or at a low intensity with (LO + IL-6) or without (LO) an infusion of recombinant human IL-6 that matched the circulating concentration of IL-6 seen in HI exercise. The stable isotope 6,6 (2)H(2) glucose was infused to calculate EGP (rate of glucose appearance [R(a)]), whole-body glucose disposal (rate of glucose disappearance [R(d)]), and metabolic clearance rate (MCR) of glucose. Glucose R(a), R(d), and MCR were higher (P < 0.05) at HI than at LO. Throughout exercise at LO + IL-6, glucose R(a) and R(d) were higher (P < 0.05) than LO, even though the exercise intensity was identical. In addition, MCR was higher (P < 0.05) at LO + IL-6 than at LO at 90 min. Insulin, glucagon, epinephrine, norepinephrine, cortisol, and growth hormone were identical when comparing LO + IL-6 with LO. These data suggest that IL-6 influences glucose homeostasis during exercise. Our results provide potential new insights into factors that mediate glucose production and disposal and implicates IL-6 in the so-called "work factor."

Reducing the global burden of depression: population-level analysis of intervention cost-effectiveness in 14 world regions.

Abstract: Background International evidence on the cost and effects of interventions for reducing the global burden of depression remain scarce. Aims To estimate the population-level cost-effectiveness of evidence-based depression interventions and their contribution towards reducing current burden. Method Primary-care-based depression interventions were modelled at the level of whole populations in 14 epidemiological subregions of the world. Total population-level costs (in international dollars or I$) and effectiveness (disability adjusted life years (DALYs) averted) were combined to form average and incremental cost-effectiveness ratios. Results Evaluated interventions have the potential to reduce the current burden of depression by 10–30%. Pharmacotherapy with older antidepressant drugs, with or without proactive collaborative care, are currently more cost-effective strategies than those using newer antidepressants, particularly in lower-income subregions. Conclusions Even in resource-poor regions, each DALYaverted by efficient depression treatments in primary care costs less than 1 year of average per capita income, making such interventions a cost-effective use of health resources. However, current levels of burden can only be reduced significantlyif there is a substantialincrease substantial increase intreatment coverage.

Effects of dietary omega-3 polyunsaturated fatty acids on brain gene expression

Abstract: Polyunsaturated fatty acids (PUFA) are essential structural components of the central nervous system. Their role in controlling learning and memory has been well documented. A nutrigenomic approach with high-density microarrays was used to reveal brain gene-expression changes in response to different PUFA-enriched diets in rats. In aged rats fed throughout life with PUFA-enriched diets, genes with altered expressions included transthyretin, α-synuclein, and calmodulins, which play important roles in synaptic plasticity and learning. The effect of perinatal omega-3 PUFA supply on gene expression later in life also was studied. Several genes showed similar changes in expression in rats fed omega-3-deficient diets in the perinatal period, regardless of whether they or their mothers were fed omega-3 PUFA-sufficient diets after giving birth. In this experiment, among the down-regulated genes were a kainate glutamate receptor and a DEAD-box polypeptide. Among the up-regulated genes were a chemokine-like factor, a tumor necrosis factor receptor, and cytochrome c. The possible involvement of the genes with altered expression attributable to different diets in different brain regions in young and aged rats and the possible mode of regulatory action of PUFA also are discussed. We conclude that PUFA-enriched diets lead to significant changes in expression of several genes in the central nervous tissue, and these effects appear to be mainly independent of their effects on membrane composition. The direct effects of PUFA on transcriptional modulators, the downstream developmentally and tissue-specifically activated elements might be one of the clues to understanding the beneficial effects of the omega-3 PUFA on the nervous system.

A land cover map of South America

Abstract: A digital land cover map of South America has been produced using remotely sensed satellite data acquired between 1995 and the year 2000 The mapping scale is defined by the 1 km spatial resolution of the map grid-cell In order to realize the product, different sources of satellite data were used, each source providing either a particular parameter of land cover characteristic required by the legend, or mapping a particular land cover class The map legend is designed both to fit requirements for regional climate modelling and for studies on land cover change The legend is also compatible with a wider, global, land cover mapping exercise, which seeks to characterize the world's land surface for the year 2000 As a first step, the humid forest domain has been validated using a sample of high-resolution satellite images The map demonstrates both the major incursions of agriculture into the remaining forest domains and the extensive areas of agriculture, which now dominate South America's grasslands

Adaptively Choosing Neighbourhood Bests Using Species in a Particle Swarm Optimizer for Multimodal Function Optimization

Abstract: This paper proposes an improved particle swarm optimizer using the notion of species to determine its neighbourhood best values, for solving multimodal optimization problems. In the proposed species- based PSO (SPSO), the swarm population is divided into species sub- populations based on their similarity. Each species is grouped around a dominating particle called the species seed. At each iteration step, species seeds are identified from the entire population and then adopted as neig- hbourhood bests for these individual species groups separately. Species are formed adaptively at each step based on the feedback obtained from the multimodal fitness landscape. Over successive iterations, species are able to simultaneously optimize towards multiple optima, regardless of if they are global or local optima. Our experiments demonstrated that SPSO is very effective in dealing with multimodal optimization functions with lower dimensions.

Design and analysis of multiscroll chaotic attractors from saturated function series

Abstract: This paper initiates a saturated function series approach for chaos generation. The systematic saturated function series methodology developed here can create multiscroll chaotic attractors from a three-dimensional (3D) linear autonomous system with a simple saturated function series controller, including one-directional n-scroll, two-directional n/spl times/m-grid scroll, and 3-D n/spl times/m/spl times/l-grid scroll chaotic attractors. The dynamical behaviors and chaos generation mechanism of multiscroll systems are further investigated by analyzing the system trajectories. In particular, a two-dimensional (2D) Poincare/spl acute/ return map is rigorously derived for verifying the chaotic behaviors of the double-scroll chaotic attractor, which is a basic generator of various multiscroll chaotic attractors investigated in the paper.

Sustainability in tertiary curricula: what is stopping it happening?

Abstract: The concepts of environmental education and education for sustainability have been acknowledged by many tertiary institutions for over a decade. An appreciable number of institutions have signed agreements to educate students in all disciplines about sustainability. Although several Australian institutions of higher education have signed the Talloire Declaration, a recent survey finds little indication that their curricula have been changed to include sustainability education. Despite the apparent widespread support for the concept of student education in sustainability, there is little implementation. The experience of Royal Melbourne Institute of Technology (RMIT) University suggests that those concerned about education and environment/sustainability need more than conviction and vision. A strategic approach – based on change management and supported by staff development – is needed to implement these sorts of changes. Rather than attempting to outline a grand plan or model for implementation, this paper identifies key issues and looks into the current experience associated with implementation approaches.

Solving rotated multi-objective optimization problems using differential evolution

Abstract: This paper demonstrates that the self-adaptive technique of Differential Evolution (DE) can be simply used for solving a multi-objective optimization problem where parameters are interdependent The real-coded crossover and mutation rates within the NSGA-II have been replaced with a simple Differential Evolution scheme, and results are reported on a rotated problem which has presented difficulties using existing Multi-objective Genetic Algorithms The Differential Evolution variant of the NSGA-II has demonstrated rotational invariance and superior performance over the NSGA-II on this problem.

Exercise as a therapeutic intervention for the prevention and treatment of insulin resistance.

Abstract: During the past half-century, there has been a dramatic increase in the incidence of obesity, insulin resistance and type 2 diabetes. A hallmark feature of these conditions is impaired glucose tolerance (IGT). Cross-sectional and retrospective epidemiological studies have provided direct evidence that a lack of physical activity is strongly associated with IGT. Indeed, physical inactivity is an independent risk factor for insulin resistance and type 2 diabetes. The primary defect(s) in the development of whole-body insulin resistance remain unclear. However, during the past decade significant progress has been made towards an understanding of the molecular basis underlying the beneficial effects of exercise training in stimulating the entry of glucose into insulin-sensitive tissues. Accordingly, it is now well accepted that regular physical exercise offers an effective therapeutic intervention to improve insulin action in skeletal muscle in insulin-resistant individuals. This review provides evidence that physical inactivity is significantly associated with IGT and directly contributes to the cascade of events that lead to the expression of the 'exercise-deficient phenotype' associated with insulin resistance and type 2 diabetes. In contrast, exercise training will be shown to significantly reduce the risk of developing insulin resistance by improving glucose tolerance and insulin action in individuals predisposed to develop type 2 diabetes. Several putative mechanisms for enhanced glucose uptake after exercise training will be discussed. A determination of the underlying biological mechanisms that result from exercise training is essential in order to define the precise variations in physical activity that result in the most desired effects on targeted risk factors, and to aid in the development of such interventions.

Supplementation with vitamins C and E inhibits the release of interleukin‐6 from contracting human skeletal muscle

Abstract: Contracting human skeletal muscle is a major contributor to the exercise-induced increase of plasma interleukin-6 (IL-6). Although antioxidants have been shown to attenuate the exercise-induced increase of plasma IL-6, it is unknown whether antioxidants inhibit transcription, translation or translocation of IL-6 within contracting human skeletal muscle. Using a single-blind placebo-controlled design with randomization, young healthy men received an oral supplementation with either a combination of ascorbic acid (500 mg day(-1)) and RRR-alpha-tocopherol (400 i.u. day(-1)) (Treatment, n= 7), or placebo (Control, n= 7). After 28 days of supplementation, the subjects performed 3 h of dynamic two-legged knee-extensor exercise at 50% of their individual maximal power output. Muscle biopsies from vastus lateralis were obtained at rest (0 h), immediately post exercise (3 h) and after 3 h of recovery (6 h). Leg blood flow was measured using Doppler ultrasonography. Plasma IL-6 concentration was measured in blood sampled from the femoral artery and vein. The net release of IL-6 was calculated using Fick's principle. Plasma vitamin C and E concentrations were elevated in Treatment compared to Control. Plasma 8-iso-prostaglandin F(2alpha), a marker of lipid peroxidation, increased in response to exercise in Control, but not in Treatment. In both Control and Treatment, skeletal muscle IL-6 mRNA and protein levels increased between 0 and 3 h. In contrast, the net release of IL-6 from the leg, which increased during exercise with a peak at 3.5 h in Control, was completely blunted during exercise in Treatment. The arterial plasma IL-6 concentration from 3 to 4 h, when the arterial IL-6 levels peaked in both groups, was approximately 50% lower in the Treatment group compared to Control (Treatment versus Control: 7.9 pg ml(-1), 95% confidence interval (CI) 6.0-10.7 pg ml(-1), versus 19.7 pg ml(-1), CI 13.8-29.4 pg ml(-1), at 3.5 h, P < 0.05 between groups). Moreover, plasma interleukin-1 receptor antagonist (IL-1ra), C-reactive protein and cortisol levels all increased after the exercise in Control, but not in Treatment. In conclusion, our results show that supplementation with vitamins C and E attenuated the systemic IL-6 response to exercise primarily via inhibition of the IL-6 protein release from the contracting skeletal muscle per se.

Skeletal myocytes are a source of interleukin-6 mRNA expression and protein release during contraction: evidence of fiber type specificity

Abstract: In this study, we aimed to determine whether skeletal muscle cells per se are a source of interleukin (IL)-6 during contraction and whether IL-6 production is fiber type specific. Muscle biopsy samples were collected from seven males before (PRE) and after (POST) completing 120 min of continuous bicycle ergometry. Biopsies were sectioned and analyzed for the following: IL-6 protein detected by immunohistochemistry (IHC), IL-6 mRNA content detected by in situ hybridization, fiber type measured by either IHC or myofibrillar ATPase activity stain, and glycogen content measured by periodic acid schiff (PAS) assay. Fibers were qualitatively categorized according to glycogen content to one of five groups (1-5), with 1 being very low (LOW) and 5 being very high (HIGH) glycogen. Total fluorescence (PRE vs. POST) and glycogen-dependent fluorescence (LOW vs. HIGH) of IL-6 protein were quantitated using Metamorph software. Total IL-6 protein was elevated from PRE to POST exercise (P<0.05). At PRE, IL-6 protein was evenly distributed across all fibers at low levels, consistent with glycogen distribution. At POST, IL-6 protein was greater (P<0.05) in HIGH compared with LOW glycogen fibers, which coincided with type 2 fibers. IL-6 mRNA was distributed peripherally in all fibers at PRE. At POST, however, IL-6 mRNA appeared predominantly in type 2 fibers, which also had higher glycogen content (P<0.05). These data demonstrate that myocytes per se are a source of IL-6 produced during contraction. Our data also suggest that type 2 fibers predominantly produce IL-6 during muscle contractile activity.

Dietary Composition of Pregnant Women Is Related to Size of the Baby at Birth

Abstract: The fetal origins theory of adult disease suggests that term infants who are small for their gestational age have an increased susceptibility to chronic disease in adulthood as a consequence of physiologic adaptations to undernutrition during fetal life. Consistent evidence for an influence of women's dietary composition during pregnancy on growth of their babies is lacking, despite robust effects in animal experiments. We undertook a prospective observational study of 557 women aged 18-41 y, living in Adelaide, South Australia. Diet was assessed in early and late pregnancy using an FFQ. In early pregnancy, medians for energy intake, the proportion of energy derived from protein and from carbohydrate were 9.0 MJ, 17 and 48%, respectively. In late pregnancy the corresponding medians were 9.2 MJ, 16 and 49%. In early pregnancy, the percentage of energy derived from protein was positively associated with birth weight (P = 0.02) and placental weight (P = 0.07), independently of energy intake and weight gain during pregnancy, and after adjustment for potential confounders, including maternal age, parity, and smoking. Effects were stronger among women (n = 429) who had reliable data, based on prespecified criteria including the plausibility of dietary data when referenced against estimated energy expenditure. In addition, for this subgroup, the percentage of energy from carbohydrate in early and late pregnancy was negatively associated with ponderal index of the baby, and a specific effect of protein from dairy sources was identified. These data support the proposition that maternal dietary composition has an effect on fetal growth. Maternal diet in Western societies may therefore be important for the long-term health of the child.

Comparing agent-oriented methodologies

Abstract: Numerous methodologies for developing agent-based systems have been proposed in the literature. However, their application is still limited due to their lack of maturity. Evaluating methodologies’ strengths and weaknesses plays an important role in improving them and in developing the “next-generation” of methodologies. This paper presents a comparison of three prominent agent-oriented methodologies: MaSE, Prometheus and Tropos. It is performed based upon an attribute-based framework which addresses four major areas: concepts, modelling language, process and pragmatics. The objectivity of the comparison is increased by including inputs from the authors of the methodologies using a questionnaire and by conducting an experimental evaluation of the methodologies.

The national market impact of sovereign rating changes

Abstract: This study investigates the aggregate stock market impact of sovereign rating changes. Consistent with evidence pertaining to company credit rating changes, we report that rating downgrades have a negative wealth impact on market returns. Moreover, we find that a downgrade impacts negatively on both the domestic stock market and the dollar value of the country’s currency. Interestingly, of the four credit rating agencies examined, only Standard & Poors and Fitch rating downgrades result in significant market falls. Finally, we can find no evidence that emerging markets are particularly sensitive to rating changes or that markets react more severely to multiple rating changes.

Real-time RT-PCR analysis of housekeeping genes in human skeletal muscle following acute exercise.

Abstract: Studies examining gene expression with RT-PCR typically normalize their mRNA data to a constitutively expressed housekeeping gene. The validity of a particular housekeeping gene must be determined ...