Showing papers by "Monash University published in 2001"

Neural progenitors from human embryonic stem cells.

Abstract: The derivation of neural progenitor cells from human embryonic stem (ES) cells is of value both in the study of early human neurogenesis and in the creation of an unlimited source of donor cells for neural transplantation therapy. Here we report the generation of enriched and expandable preparations of proliferating neural progenitors from human ES cells. The neural progenitors could differentiate in vitro into the three neural lineages--astrocytes, oligodendrocytes, and mature neurons. When human neural progenitors were transplanted into the ventricles of newborn mouse brains, they incorporated in large numbers into the host brain parenchyma, demonstrated widespread distribution, and differentiated into progeny of the three neural lineages. The transplanted cells migrated along established brain migratory tracks in the host brain and differentiated in a region-specific manner, indicating that they could respond to local cues and participate in the processes of host brain development. Our observations set the stage for future developments that may allow the use of human ES cells for the treatment of neurological disorders.

Muscle damage from eccentric exercise: mechanism, mechanical signs, adaptation and clinical applications

Abstract: In eccentric exercise the contracting muscle is forcibly lengthened; in concentric exercise it shortens. While concentric contractions initiate movements, eccentric contractions slow or stop them. A unique feature of eccentric exercise is that untrained subjects become stiff and sore the day afterwards because of damage to muscle fibres. This review considers two possible initial events as responsible for the subsequent damage, damage to the excitation-contraction coupling system and disruption at the level of the sarcomeres. Other changes seen after eccentric exercise, a fall in active tension, shift in optimum length for active tension, and rise in passive tension, are seen, on balance, to favour sarcomere disruption as the starting point for the damage. As well as damage to muscle fibres there is evidence of disturbance of muscle sense organs and of proprioception. A second period of exercise, a week after the first, produces much less damage. This is the result of an adaptation process. One proposed mechanism for the adaptation is an increase in sarcomere number in muscle fibres. This leads to a secondary shift in the muscle's optimum length for active tension. The ability of muscle to rapidly adapt following the damage from eccentric exercise raises the possibility of clinical applications of mild eccentric exercise, such as for protecting a muscle against more major injuries.

Material fundamentals and clinical performance of plasma-sprayed hydroxyapatite coatings: A review

Abstract: The clinical use of plasma-sprayed hydroxyapatite (HA) coatings on metal implants has aroused as many controversies as interests over the last decade. Although faster and stronger fixation and more bone growth have been revealed, the performance of HA-coated implants has been doubted. This article will initially address the fundamentals of the material selection, design, and processing of the HA coating and show how the coating microstructure and properties can be a good predictor of the expected behavior in the body. Further discussion will clarify the major concerns with the clinical use of HA coatings and introduce a comprehensive review concerning the outcomes experienced with respect to clinical practice over the past 5 years. A reflection on the results indicates that HA coatings can promote earlier and stronger fixation but exhibit a durability that can be related to the coating quality. Specific relationships between coating quality and clinical performance are being established as characterization methods disclose more information about the coating.

Adaptive impulse detection using center-weighted median filters

Abstract: Previous median-based impulse detection strategies tend to work well for fixed-valued impulses but poorly for random-valued impulse noise, or vice versa. This letter devises a novel adaptive operator, which forms estimates based on the differences between the current pixel and the outputs of center-weighted median (CWM) filters with varied center weights. Extensive simulations show that the proposed scheme consistently works well in suppressing both types of impulses with different noise ratios.

A multi-national, multi-institutional study of assessment of programming skills of first-year CS students

Abstract: In computer science, an expected outcome of a student's education is programming skill. This working group investigated the programming competency students have as they complete their first one or two courses in computer science. In order to explore options for assessing students, the working group developed a trial assessment of whether students can program. The underlying goal of this work was to initiate dialog in the Computer Science community on how to develop these types of assessments. Several universities participated in our trial assessment and the disappointing results suggest that many students do not know how to program at the conclusion of their introductory courses. For a combined sample of 216 students from four universities, the average score was 22.89 out of 110 points on the general evaluation criteria developed for this study. From this trial assessment we developed a framework of expectations for first-year courses and suggestions for further work to develop more comprehensive assessments.

The contribution of emotional satisfaction to consumer loyalty

Abstract: Many customer satisfaction studies have concluded that there is a significant relationship between customer satisfaction and loyalty, but this finding has been questioned in that most of the studies focus on measuring the cognitive component of customer satisfaction. This study includes the cognitive component, but focuses on the affective component. It explores the role of emotions in satisfaction, and then compares the predictive ability of the cognitive and affective elements. Key findings are that both positive and negative emotions, and the cognitive component of satisfaction correlate with loyalty. Regression analysis indicates that the affective component serves as a better predictor of customer loyalty than the cognitive component. Further, the best predictor of both overall loyalty and the most reliable dimension of loyalty, positive word of mouth, is positive emotions. Thhe theoretical and practical implications of these findings are discussed.

Trends in extreme daily rainfall and temperature in Southeast Asia and the South Pacific: 1961–1998

Abstract: Trends in extreme daily temperature and rainfall have been analysed from 1961 to 1998 for Southeast Asia and the South Pacific. This 38-year period was chosen to optimize data availability across the region. Using high-quality data from 91 stations in 15 countries, significant increases were detected in the annual number of hot days and warm nights, with significant decreases in the annual number of cool days and cold nights. These trends in extreme temperatures showed considerable consistency across the region. Extreme rainfall trends were generally less spatially coherent than were those for extreme temperature. The number of rain days (with at least 2 mm of rain) has decreased significantly throughout Southeast Asia and the western and central South Pacific, but increased in the north of French Polynesia, in Fiji, and at some stations in Australia. The proportion of annual rainfall from extreme events has increased at a majority of stations. The frequency of extreme rainfall events has declined at most stations (but not significantly), although significant increases were detected in French Polynesia. Trends in the average intensity of the wettest rainfall events each year were generally weak and not significant. Copyright © 2001 Royal Meteorological Society.

SME marketing in practice

Abstract: Acknowledges that SMEs (small to medium‐sized enterprises) cannot do conventional marketing because of the limitations of resources which are inherent to all SMEs and also because SME owner/managers behave and think differently from conventional marketing decision‐making practices in large companies. In this context the discussion focuses on SME characteristics and how these impact upon marketing characteristics within SMEs. In a search for “alternative” marketing approaches, the inherent existence of the owner/manager’s “network” in its various guises such as personal contact networks, social networks, business networks and industry and marketing networks and how these networks are used is considered. Some evidence from an empirical study carried out simultaneously in Northern Ireland and Australia is presented which illustrates how and why networking is used by SME owner/managers as a tool or approach for carrying out meaningful marketing.

Differential production of IL-12, IFN-alpha, and IFN-gamma by mouse dendritic cell subsets.

Abstract: Dendritic cells (DC) not only stimulate T cells effectively but are also producers of cytokines that have important immune regulatory functions. In this study we have extended information on the functional differences between DC subpopulations to include differences in the production of the major immune-directing cytokines IL-12, IFN-alpha, and IFN-gamma. Splenic CD4(-)8(+) DC were identified as the major IL-12 producers in response to microbiological or T cell stimuli when compared with splenic CD4(-)8(-) or CD4(+)8(-) DC; however, all three subsets of DC showed similar IL-12 regulation and responded with increased IL-12 p70 production if IL-4 was present during stimulation. High level CD8 expression also correlated with extent of IL-12 production for DC isolated from thymus and lymph nodes. By using gene knockout mice we ruled out any role for CD8alpha itself, or of priming by T cells, on the superior IL-12-producing capacity of the CD8(+) DC. Additionally, CD8(+) DC were identified as the major producers of IFN-alpha compared with the two CD8(-) DC subsets, a finding that suggests similarity to the human plasmacytoid DC lineage. In contrast, the CD4(-)8(-) DC produced much more IFN-gamma than the CD4(-)8(+) or the CD4(+)8(-) DC under all conditions tested.

A comparison of the Assessment of Quality of Life (AQoL) with four other generic utility instruments

Abstract: As part of the validation of the Assessment of Quality of Life (AQoL) instrument comparisons were made between five multiattribute utility (MAU) instruments, each purporting to measure health-related quality of life (HRQoL). These were the AQoL, the Canadian Health Utilities Index (HUI) 3, the Finnish 15D, the EQ-5D (formerly the EuroQoL) and the SF6D (derived from the SF-36). The paper compares absolute utility scores, instrument sensitivity, and incremental differences in measured utility between different instruments predicted by different individuals. The AQoL predicted utilities are similar to those from the HUI3 and EQ-5D. By contrast the 15D and SF6D predict systematically higher utilities, and the differences between individuals are significantly smaller. There is some evidence that the AQoL has greater sensitivity to health states than other instruments. It is concluded that at present no single MAU instrument can claim to be the 'gold standard', and that researchers should select an instrument sensitive to the health states they are investigating. Caution should be exercised in treating any of the instrument scores as representing a trade-off between length of life and HRQoL.

Genetic Organization of Pasteurella multocida cap Loci and Development of a Multiplex Capsular PCR Typing System

Abstract: Current serotyping methods classify Pasteurella multocida into five capsular serogroups (serogroups A, B, D, E, and F) and 16 somatic serotypes (serotypes 1 to 16). In the present study, we have developed a multiplex PCR assay as a rapid alternative to the conventional capsular serotyping system. The serogroup-specific primers used in this assay were designed following identification, sequence determination, and analysis of the capsular biosynthetic loci of each capsular serogroup. The entire capsular biosynthetic loci of P. multocida A:1 (X-73) and B:2 (M1404) have been cloned and sequenced previously (J. Y. Chung, Y. M. Zhang, and B. Adler, FEMS Microbiol. Lett. 166:289-296, 1998; J. D. Boyce, J. Y. Chung, and B. Adler, Vet. Microbiol. 72:121-134, 2000). Nucleotide sequence analysis of the biosynthetic region (region 2) from each of the remaining three serogroups, serogroups D, E, and F, identified serogroup-specific regions and gave an indication of the capsular polysaccharide composition. The multiplex capsular PCR assay was highly specific, and its results, with the exception of those for some serogroup F strains, correlated well with conventional serotyping results. Sequence analysis of the strains that gave conflicting results confirmed the validity of the multiplex PCR and indicated that these strains were in fact capsular serogroup A. The multiplex PCR will clarify the distinction between closely related serogroups A and F and constitutes a rapid assay for the definitive classification of P. multocida capsular types.

Critical success factors in agile supply chain management ‐ An empirical study

Abstract: This paper analyses results from a survey of 962 Australian manufacturing companies in order to identify some of the factors critical for successful agile organizations in managing their supply chains. Analysis of the survey results provided some interesting insights into factors differentiating “more agile” organizations from “less agile” organizations. “More agile” companies from this study can be characterized as more customer focused, and applying a combination of “soft” and “hard” methodologies in order to meet changing customer requirements. They also see the involvement of suppliers in this process as being crucial to their ability to attain high levels of customer satisfaction. The “less agile” group, on the other hand, can be characterized as more internally focused with a bias toward internal operational outcomes. They saw no link between any of the independent variables and innovation, and appear to see technology as more closely linked to the promotion of these operational outcomes than to customer satisfaction. The role of suppliers for this group is to support productivity and process improvement rather than to promote customer satisfaction.

Relaxing music prevents stress-induced increases in subjective anxiety, systolic blood pressure, and heart rate in healthy males and females

Abstract: Previous research suggests that while subjective anxiety is reduced by relaxing music, the effect of music on physiological stress indices is less consistent. In the current study, the effect of relaxing music on participants' subjective and physiological response to stress was explored, with attention paid to methodological factors and mediating variables that might have contributed to inconsistencies in previous studies. Undergraduate students (43 females & 44 males) were exposed to a cognitive stressor task involving preparation for an oral presentation either in the presence of Pachelbel's Canon in D major, or in silence. Measures of subjective anxiety, heart rate, blood pressure, cortisol, and salivary IgA were obtained during rest and after presentation of the stressor. The stressor caused significant increases in subjective anxiety, heart rate, and systolic blood pressure in male and female controls. These stress-induced increases were each prevented by exposure to music, and this effect was independent of gender. Music also enhanced baseline salivary IgA levels in the absence of any stress-induced effects. These findings provide experimental support for claims that music is an effective anxiolytic treatment, the robustness of which is demonstrated by retention of the effect in the presence of a range of potentially mediating variables.

On the Tidal Inflation of Short-Period Extrasolar Planets*

Abstract: We examine the consequences of tidal interaction between eccentric short-period extrasolar planets and their host stars and of secular perturbations between planets in a given system If the planet is within 005 AU of the star, the dissipation of the stellar tidal disturbance within the planet provides a significant energy source, which causes the planet to inflate as it adjusts to a thermal equilibrium We determine the planetary size as a function of the tidal dissipation rate with or without the presence of a core Inflation intensifies the star-planet tidal interaction and accelerates the pace of the planet's spin synchronization and orbital circularization We apply our results to three systems with short-period planets: HD 209458, Ups And, and Tau Boo

Cost-effectiveness analysis and the consistency of decision making: evidence from pharmaceutical reimbursement in australia (1991 to 1996).

Abstract: Objective: The principle aim of this study was to generate a league table of drugs considered by the Australian Pharmaceutical Benefits Advisory Committee (PBAC) for reimbursement. The table was used to test the hypothesis that decisions made by the PBAC are consistent with the maxim of economic efficiency. In addition, we explored whether the past decisions by the PBAC revealed a threshold incremental cost-effectiveness ratio beyond which the PBAC is not prepared to recommend reimbursement of a drug. Methods: All 355 submissions made to the PBAC between January 1991 and June 1996 were reviewed. Submissions using cost per life-year gained (26 submissions) or the cost per quality adjusted life-year (QALY) gained (9 submissions) were ranked in a league table and compared with advice given by the PBAC about that drug. The confidentiality restrictions for the submissions require that the individual drug details cannot be revealed in this article. Results: There was a statistically significant difference between the cost per life-year gained for drugs that were recommended for listing and those that were not, suggesting that the PBAC has been broadly consistent with the use of economic efficiency as a criterion for decision making. We did not find an explicit threshold beyond which the PBAC was unwilling to pay for additional life years gained. However, between 1992 and 1996 the PBAC appears to have been unlikely to recommend a drug for listing if the additional cost per life-year exceeded 76 000 Australian dollars [$AU] (1998/1999 values) and was unlikely to reject a drug for which the additional cost per life-year gained was less than $AU42 000. The cost-effectiveness ratio was not the only factor determining the reimbursement decision. Conclusions: The results of this preliminary study indicate that decisions to recommend a drug for listing by the PBAC in the last few years have, by and large, been consistent with the notion of economic efficiency.

Incidence of Malignant Disease in Biopsy-Proven Inflammatory Myopathy: A Population-Based Cohort Study

Abstract: The risk for malignant disease is increased in biopsy-proven dermatomyositis and polymyositis and also appears to be increased in inclusion-body myositis.

The distribution and strength of riparian tree roots in relation to riverbank reinforcement

Abstract: The main influences of plants on the mass stability of riverbanks are those that affect the strength of bank sediments. Plants enhance bank strength by reducing pore-water pressures and by directly reinforcing bank material with their roots. In this paper we do not consider bank hydrology but focus on quantifying increases in sediment strength due to root reinforcement. Root reinforcement is a function of root strength, interface friction between the roots and the soil, and the distribution of roots within the soil. Field and laboratory studies of Australian riparian trees, river red gum (Eucalyptus camaldulensis) and swamp paperbark (Melaleuca ericifolia), indicate that bank reinforcement, due to the roots of these species, decreases exponentially with depth below the soil surface and distance away from the trees. Differences in the spatial distribution of root reinforcement are illustrated by a comparison of the apparent cohesion due to roots (cr) with the effective cohesion of the saturated bank material (15 kPa). Directly below the river red gum, root reinforcement is equal to effective cohesion at 1·7 m depth. At the dripline (17 m from the trunk), root reinforcement is equal to material strength at 0·4 m depth. For the swamp paperbark, cr=15 kPa at 1·1 m depth beneath surface, at the trunks, and at 0·4 m depth at the dripline (2·5 m from the trunk). A description of the spatial distribution of root reinforcement is important in the riverbank context. We find that interspecies differences in the strength of living roots have less significance for bank reinforcement than interspecies differences in root distribution. Copyright © 2001 John Wiley & Sons, Ltd.

A case for economy grid architecture for service oriented grid computing

Abstract: Computational Grids are a promising platform for executinglarge-scale resource intensive applications. However, resource management and scheduling in the Grid environment is a complex undertaking as resources are (geographically) distributed, heterogeneous in nature, owned by different individuals or organizations with their own policies, have different access and cost models, and have dynamically varying loads and availability. This introduces a number of challenging issues such as site autonomy, heterogeneous interaction, policy extensibility, resource allocation or co-allocation, online control, scalability, transparency, resource brokering, and "computational economy".A number of Grid systems (such as Globus and Legion)have addressed many of these issues with exception of acomputational economy. We argue that a computationaleconomy is required in order to create a real world scalableGrid because it provides a mechanism for regulating the Gridresources demand and supply. It offers incentive for resourceowners to be part of the Grid and encourages consumers tooptimally utilize resources and balance timeframe and accesscosts. We propose a 'computational economy framework' thatbuilds on the existing Grid middleware systems and offers aninfrastructure for resource management and trading in theGrid environment. We discuss the usage economic models forresource trading in the Nimrod/G resource broker and presentdeadline and cost-based scheduling experimental results onthe Grid.

Simplified technique for differential staining of inner cell mass and trophectoderm cells of mouse and bovine blastocysts

Abstract: Histological staining and counting of blastocyst inner cell mass (ICM) and trophectoderm (TE) cells differentially with chromatin-specific dyes is a more accurate indicator of cultured blastocyst quality and normality than total cell number assessment. The aim of this study was to test the effectiveness of a simplified method of chemically-defined differential blastocyst staining. The TE of cultured mouse and bovine blastocysts of different developmental stages was stained when blastocysts were treated with a permeabilizing solution containing the ionic detergent Triton X-100 and the fluorochrome propidium iodide. Blastocysts were then incubated in a second solution containing 100% ethanol (for fixation) and the secondary fluorochrome bisbenzimide. Fixed and stained whole blastocysts were mounted and assessed for cell number using ultraviolet fluorescent microscopy. Using this method, in-vitro cultured mouse blastocysts (day 4.5) were shown to have an ICM:TE ratio of 1:2.63 with an average total cell count of 75.3 ± 3. While day 7 and 8 in-vitro produced bovine blastocysts were shown to have an ICM:TE ratio of 1:3.42 and 1:3.36 with an average total cell count of 151.3 ± 5.48 and 217.8 ± 8.75 respectively. Blastocyst staining patterns indicate that this modified technique represents a simple and reliable alternative to current bichromatic blastocyst staining techniques for the differential assessment of cell numbers and may be useful for the assessment of blastocysts derived from in-vitro maturation, novel culture systems and advanced reproductive technologies such as cloning.

The validity of self-reported weight in US adults: a population based cross-sectional study

Abstract: Investigating the validity of the self-reported values of weight allows for the proper assessment of studies using questionnaire-derived data. The study examined the accuracy of gender-specific self-reported weight in a sample of adults. The effects of age, education, race and ethnicity, income, general health and medical status on the degree of discrepancy (the difference between self-reported weight and measured weight) are similarly considered. The analysis used data from the US Third National Health and Nutrition Examination Survey. Self-reported and measured weights were abstracted and analyzed according to sex, age, measured weight, self-reported weight, and body mass index (BMI). A proportional odds model was applied. The weight discrepancy was positively associated with age, and negatively associated with measured weight and BMI. Ordered logistic regression modeling showed age, race-ethnicity, education, and BMI to be associated with the degree of discrepancy in both sexes. In men, additional predictors were consumption of more than 100 cigarettes and the desire to change weight. In women, marital status, income, activity level, and the number of months since the last doctor's visit were important. Predictors of the degree of weight discrepancy are gender-specific, and require careful consideration when examined.

Status in Markets

Abstract: This project tests for the effect of social status in a laboratory experimental market. We consider a special ''box design" market in which a vertical overlap in supply and demand ensure that there are multiple equilibrium prices. We manipulate the relative social status of our subjects by awarding high status to a subset of the group based on one of two procedures. In the first, a subject's score on a trivia quiz determines his or her status; in another, subjects are assigned randomly to a higher-status or lower-status group. In both treatments we find that average prices are higher in markets where higher-status sellers face lower status buyers, and lower when buyers have higher status than sellers. Across all sessions, the higher-status side of the market captures a greater share of the surplus, earning significantly more than their lower-status counterparts.

Impact of early intervention on outcome after mild traumatic brain injury in children.

Abstract: Objectives. The impact of mild head injury or mild traumatic brain injury (TBI) in children is variable, and determinants of outcome remain poorly understood. There have been no previous attempts to evaluate the impact of interventions to improve outcome. Results of previous intervention studies in adults have been mixed. This study aimed to evaluate the impact of providing information on outcome measured in terms of reported symptoms, cognitive performance, and psychological adjustment in children 3 months after injury. Methods. A total of 61 children with mild TBI were assessed 1 week and 3 months after injury, and 58 children with mild TBI were assessed 3 months after injury only. They were compared with 2 control groups (N = 45 and 47) of children with minor injuries not involving the head. Participants completed measures of preinjury behavior and psychological adjustment, postconcussion symptoms, and tests of attention, speed of information processing, and memory. Children with mild TBI seen at 1 week were also given an information booklet outlining symptoms associated with mild TBI and suggested coping strategies. Those seen 3 months after injury only did not receive this booklet. Results. Children with mild TBI reported more symptoms than controls at 1 week but demonstrated no impairment on neuropsychological measures. Initial symptoms had resolved for most children by 3 months after injury, but a small group of children who had previous head injury or a history of learning or behavioral difficulties reported ongoing problems. The group not seen at 1 week and not given the information booklet reported more symptoms overall and was more stressed 3 months after injury. Conclusions. Providing an information booklet reduces anxiety and thereby lowers the incidence of ongoing problems.

Dietary soy has both beneficial and potentially adverse cardiovascular effects: a placebo-controlled study in men and postmenopausal women.

Abstract: To address the cardiovascular effects of dietary soy containing phytoestrogens, we measured blood pressure (BP), lipids, vascular function (systemic arterial compliance and pulse wave velocity), and endothelial function (flow-mediated vasodilation) in a randomized, double-blind trial. Two hundred thirteen healthy subjects (108 men and 105 postmenopausal women), 50-75 yr old, received either soy protein isolate (40 g soy protein, 118 mg isoflavones) or casein placebo for 3 months. There were 34 withdrawals (16%), with 179 subjects (96 men and 83 women) completing the protocol. After intervention in the soy group, compared with casein placebo, urinary phytoestrogens increased, accompanied by a significant fall in BP reflected by the BP model (P < 0.01) encompassing mean change (+/-SEM) in systolic (-7.5 +/- 1.2 vs. -3.6 +/- 1.1 mm Hg, P < 0.05), diastolic (-4.3 +/- 0.8 vs. -1.9 +/- 0.7 mm Hg, P < 0.05), and mean BP (-5.5 +/- 1 vs. -0.9 +/- 1 mm Hg, P < 0.008). In the lipid model, soy induced greater changes, compared with placebo (P < 0.001). On individual analysis, significant contributors included a reduction in the low- to high-density lipoprotein ratio (-0.33 +/- 0.1 vs. 0.04 +/- 0.1 mmol/L, P < 0.05) and triglycerides (-0.2 +/- 0.05 vs. -0.01 +/- 0.05 mol/L, P < 0.05) and an increase in Lp(a) lipoprotein (+/- 95% confidence interval) [42 (range, 17-67) vs. 4 (range, -22-31) mg/L, P < 0.05], whereas total, low-density lipoprotein, and high-density lipoprotein cholesterol improved in both groups; but no treatment effect was demonstrated. The arterial functional model demonstrated no difference between groups; although again, overall function improved in both groups. On individual analysis, peripheral PWV (reflecting peripheral vascular resistance) improved with soy (P < 0.01), whereas flow-mediated vasodilation (reflecting endothelial function) declined (in males only), compared with casein placebo (P < 0.02). No effect of treatment on the hypothalamic-pituitary-gonadal axis was noted in males or females. In normotensive men and postmenopausal women, soy improved BP and lipids but, overall, did not improve vascular function. Potential adverse effects were noted, with a decline in endothelial function (in males only) and an increase in Lp(a). Further research in hypertensive and hyperlipidemic populations is needed.