Showing papers by "University of South Australia published in 2001"

Images of nanobubbles on hydrophobic surfaces and their interactions.

Abstract: Imaging of hydrophobic surfaces in water with tapping mode atomic force microscopy reveals them to be covered with soft domains, apparently nanobubbles, that are close packed and irregular in cross section, have a radius of curvature of the order of 100 nm, and a height above the substrate of 20-30 nm. Complementary force measurements show features seen in previous measurements of the long-range hydrophobic attraction, including a jump into a soft contact and a prejump repulsion. The distance of the jump is correlated with the height of the images. The morphology of the nanobubbles and the time scale for their formation suggest the origin of their stability.

Testing reciprocal relationships between job characteristics and psychological well-being: A cross-lagged structural equation model

Abstract: This article describes a two-wave panel study which was carried out to examine reciprocal relationships between job characteristics and work-related psychological well-being. Hypotheses were tested in a sample of 261 health care professionals using structural equation modelling (LISREL 8). Controlling for gender, age, and negative affectivity, the results primarily supported the hypothesis that Time 1 job characteristics influence Time 2 psychological well-being. More specifically, Time 2 job satisfaction was determined by Time 1 job demands and workplace social support, respectively. Furthermore, there was also some preliminary but weak evidence for reversed cross-lagged effects since Time 1 emotional exhaustion seemed to be the causal dominant factor with respect to Time 2 (perceived) job demands. In conclusion, this study builds on earlier cross-sectional and longitudinal findings by eliminating confounding factors and diminishing methodological deficiencies. Empirical support for the influence of job characteristics on psychological well-being affirms what several theoretical models have postulated to be the causal ordering among job characteristics and work-related psychological well-being.

Effects of backpacks on students: Measurement of cervical and shoulder posture

Abstract: The aims of this pilot study were to determine whether the weight of a backpack, its position on the spine or time carried affected adolescents' cervical and shoulder posture. Standing posture measured from the sagittal and frontal planes of 13 students was recorded photographically under several load carrying conditions. Cervical and shoulder position angles were calculated and compared. Results revealed that both backpack weight and time carried influenced cervical and shoulder posture. Forward head posture increased when carrying a backpack, especially one with a heavy load. Carrying a backpack weighing 15% of body weight appeared to be too heavy to maintain standing posture for adolescents. These findings have implications for future load carrying studies in adolescents.

Hydrolyzing metal salts as coagulants

Abstract: Aluminium and ferric salts are widely used as coagulants in water and wastewater treatment. They are effective in removing a broad range of impurities from water, including colloidal particles and dissolved organic substances. Their mode of action is broadly under- stood in terms of essentially two mechanisms: charge neutralization of negatively charged colloids by cationic hydrolysis products and incorporation of impurities in an amorphous pre- cipitate of metal hydroxide. The relative importance of these two mechanisms depends on many factors, especially pH and coagulant dosage. Alternative coagulants based on prehydrolyzed forms of aluminium or iron can be more effective than the traditional materials in many cases, but their mode of action is not completely understood, especially with regard to the role of charge neutralization and hydroxide precipitation. Basic principles of colloid stability and metal ion hydrolysis are briefly reviewed, and the action of hydrolyzing metal coagulants is then discussed, with some examples from recent experimental studies. Although it is possible to interpret results reasonably well in terms of established ideas, there are still some uncertainties that need to be resolved

Content Analysis of Secondary Data: A Study of Courage in Managerial Decision Making

Abstract: Empirical studies in business ethics often rely on self-reported data, but this reliance is open to criticism Responses to questionnaires and interviews may be influenced by the subject's view of what the researcher might want to hear, by a reluctance to talk about sensitive ethical issues, and by imperfect recall This paper reviews the extent to which published research in business ethics relies on interviews and questionnaires, and then explores the possibilities of using secondary data, such as company documents and newspaper reports, as a source for empirical studies in applied ethics A specific example is then discussed, describing the source material, the method, the development of the research questions, and the way in which reliability and validity were established In the example, content analysis was used to examine the extent to which the executive virtue of courage was observed or called for in items published in four international daily newspapers, and to explore the meaning which was attributed to "courage" in the papers

In vitro pharmacodynamic properties of colistin and colistin methanesulfonate against Pseudomonas aeruginosa isolates from patients with cystic fibrosis.

Abstract: The in vitro pharmacodynamic properties of colistin and colistin methanesulfonate were investigated by studying the MICs, time-kill kinetics, and postantibiotic effect (PAE) against mucoid and nonmucoid strains of Pseudomonas aeruginosa isolated from patients with cystic fibrosis. Twenty-three clinical strains, including multiresistant strains, and one type strain were selected for MIC determination. Eleven strains were resistant; MICs for these strains were >128 mg/liter. For the susceptible strains, MICs of colistin ranged from 1 to 4 mg/liter, while the MICs of colistin methanesulfonate were significantly higher and ranged from 4 to 16 mg/liter. The time-kill kinetics were investigated with three strains at drug concentrations ranging from 0.5 to 64 times the MIC. Colistin showed extremely rapid killing, resulting in complete elimination at the highest concentrations within 5 min, while colistin methanesulfonate killed more slowly, requiring a concentration of 16 times the MIC to achieve complete killing within 24 h. Colistin exhibited a significant PAE of 2 to 3 h at 16 times the MIC against the three strains after 15 min of exposure. For colistin methanesulfonate, PAEs were shorter at the concentrations tested. Colistin methanesulfonate had lower overall bactericidal and postantibiotic activities than colistin, even when adjusted for differences in MICs. Our data suggest that doses of colistin methanesulfonate higher than the recommended 2 to 3 mg/kg of body weight every 12 h may be required for the effective treatment of P. aeruginosa infections in cystic fibrosis patients.

Assessing the performance of brand loyalty measures

Abstract: There has long been a requirement for researchers to relate different loyalty measures in one paper and to compare measures across markets. Explores the performance of a number of loyalty measures in two service markets, namely a telecommunications market, and a credit card market. Also explores the performance of a number of measures across market types. The results indicate that all eight measures can be considered as indicators of brand loyalty in service markets. Two distinct concepts of loyalty were apparent in the telecommunications market. A third possible concept, termed differentiation loyalty, was also evident in the analysis conducted. This suggests that distinguishing between concepts does matter, specifically in service markets where a decrease in behavioral loyalty results in a customer defection. There is no difference in the performance of brand loyalty measures in service markets when compared with a repeat‐purchase market.

A brand for all seasons? A discussion of brand loyalty approaches and their applicability for different markets

Abstract: Seeks to enhance our understanding of the suitability of loyalty measurement techniques by proposing a classification of brand loyalty based on varying market types. Distinguishing between market types is important because the very nature of markets indicates that the measures used to capture loyalty should be very different. This paper, in effect, argues against a single brand loyalty measure for all market types. Marketing practitioners wishing to predict future levels of loyalty would need to use different loyalty measures. In consumable markets where the market is stable and where there is high switching and low involvement and risk, behavioral measures are appropriate for predicting future brand loyalty levels. However where the market is not stable, there is a propensity towards sole brands and attitudinal measures may be better predictors of future behavior in such cases.

Occupational stress in university staff.

Abstract: 2A survey was conducted of all staff members of an established Australian metropolitan university. The overall response rate for noncasual staff was 72% (77% for general staff and 65% for academic staff) resulting in a sample of N = 2,040. High levels of psychological stress were observed, despite the fact that trait anxiety and job satisfaction were normal. Psychological distress was highest and job satisfaction lowest among academic staff engaged in both teaching and research. In general, university staff reported high levels of autonomy and social support from colleagues. However those engaged in both teaching and research reported increased pressure arising from funding cuts to universities, resulting in heavier teaching loads and greater difficulty in securing research funds, as well as a decline in facilities and support for both teaching and research. The results are discussed in relation to the Demand–Control and Person–Environment Fit models of job stress.

Morphological evolution of athletes over the 20th century: causes and consequences.

Abstract: Over the course of the past century it has become increasingly difficult to find athletes of the size and shape required to compete successfully at the highest level. Sport is Darwinian in that only the 'fittest' reach the highest level of participation. Not every physical characteristic could be expected to play a role in this selection process, but two that are important and for which substantial data assemblies exist, are height and mass. Measurements of elite athlete sizes were obtained from a variety of sources as far back as records allowed. We charted the shift in these anthropometric characteristics of elite sportspeople over time, against a backdrop of secular changes in the general population. Athletes in many sports have been getting taller and more massive over time; the rates of rise outstripping those of the secular trend. In open-ended sports, more massive players have an advantage. Larger players average longer careers and obtain greater financial rewards. In some sports it is equally difficult to find athletes small enough to compete. In contrast, there are sports that demand a narrow range of morphological characteristics. In these sports the size of the most successful athletes over the century has remained constant, despite the drift in the population characteristics from which they are drawn. A number of social factors both drive and are driven by the search for athletes of increasingly rare morphology. These include globalisation and international recruitment, greater financial and social incentives, and the use of special training methods and artificial growth stimuli. In many sports the demand for a specific range in body size reinforces the need to adopt questionable and illegal behaviours to reach the required size and shape to compete at the top level. Future scenarios also include 'gene-farming' through assortative mating and athlete gamete banks.

Adaptive filtering algorithms with selective partial updates

Abstract: In some applications of adaptive filtering such as active noise reduction, and network and acoustic echo cancellation, the adaptive filter may be required to have a large number of coefficients in order to model the unknown physical medium with sufficient accuracy. The computational complexity of adaptation algorithms is proportional to the number of filter coefficients. This implies that, for long adaptive filters, the adaptation task can become prohibitively expensive, ruling out cost-effective implementation on digital signal processors. The purpose of partial coefficient updates is to reduce the computational complexity of an adaptive filter by adapting a block of the filter coefficients rather than the entire filter at every iteration. In this paper, we develop a selective-partial-update normalized least-mean-square (NLMS) algorithm, and analyze its stability using the traditional independence assumptions and error-energy bounds. Selective partial updating is also extended to the affine projection (AP) algorithm by introducing multiple constraints. The new algorithms appear to have good convergence performance as attested to by computer simulations with real speech signals.

In the flesh or online? Exploring qualitative research methodologies

Abstract: This article discusses the use of computer-mediated research techniques in a research project which investigates how people with disabilities engage with and use computer technologies. Identifying the rationale, process and experiences involved in the decision to engage in electronic research in this particular research topic will illuminate some limitations in traditional methods of qualitative data collection more generally. In responding to the opportunities presented by the information age, electronic research methods will substantially enhance the development of a more participatory research process. While incorporative research is imperative to the disability research agenda, the issue is no less critical to other aspects of the research enterprise.

Effect of removing user fees on attendance for curative and preventive primary health care services in rural South Africa.

Abstract: User fees are used to recover costs and discourage unnecessary attendance at primary care clinics in many developing countries. In South Africa, user fees for children aged under 6 years and pregnant women were removed in 1994, and in 1997 all user fees at all primary health care clinics were abolished. The intention of these policy changes was to improve access to health services for previously disadvantaged communities. We investigated the impact of these changes on clinic attendance patterns in Hlabisa health district. Average quarterly new registrations and total attendances for preventive services (antenatal care, immunization, growth monitoring) and curative services (treatment of ailments) at a mobile primary health care unit were studied from 1992 to 1998. Regression analysis was undertaken to assess whether trends were statistically significant. There was a sustained increase in new registrations (P = 0.0001) and total attendances (P = 0.0001) for curative services, and a fall in new registrations (P = 0.01) and total attendances for immunization and growth monitoring (P = 0.0002) over the study period. The upturn in demand for curative services started at the time of the first policy change. The decreases in antenatal registrations (P = 0.07) and attendances (P = 0.09) were not statistically significant. The number of new registrations for immunization and growth monitoring increased following the first policy change but declined thereafter. We found no evidence that the second policy change influenced underlying trends. The removal of user fees improved access to curative services but this may have happened at the expense of some preventive services. Governments should remain vigilant about the effects of new health policies in order to ensure that objectives are being met.

The In Vivo Fate of Hydroxytyrosol and Tyrosol, Antioxidant Phenolic Constituents of Olive Oil, after Intravenous and Oral Dosing of Labeled Compounds to Rats

Abstract: In vitro studies have shown phenolics in olive oil to be strong radical scavengers. The absorption and elimination of two radiolabeled phenolic constituents of olive oil, hydroxytyrosol and tyrosol were studied in vivo using rats. Compounds were administered intravenously (in saline) and orally (in oil- and water-based solutions). For both compounds, the intravenously and orally administered oil-based dosings resulted in significantly greater elimination of the phenolics in urine within 24 h than the oral, aqueous dosing method. There was no significant difference in the amount of phenolic compounds eliminated in urine between the intravenous dosing method and the oral oil-based dosing method for either tyrosol or hydroxytyrosol. Oral bioavailability estimates of hydroxytyrosol when administered in an olive oil solution and when dosed as an aqueous solution were 99% and 75%, respectively. Oral bioavailability estimates of tyrosol, when orally administered in an olive oil solution and when dosed as an aqueous solution were 98% and 71%, respectively. This is the first study that has used a radiolabeled compound to study the in vivo biological fates of hydroxytyrosol and tyrosol.

Intuition: an important tool in the practice of nursing.

Abstract: Intuition: an important tool in the practice of nursing Aim. The aim of the study reported here was to evaluate the role of intuition, to examine nurses’ understanding of intuition and their perceptions of their use of intuition, and to assess the impact of intuition on nursing practice. Background. When we read the dictionary definition of intuition, we have a sense of the meaning but there is also a sense of something still not quite defined. Yet we instinctively know what intuition is. That is, of course, an example of intuition in itself: an understanding of the concept based on our feelings, knowledge and experience. Intuition is a concept neither clearly articulated nor adequately theorized in nursing. There is evidence to suggest that practising nurses use intuition and that its use can change outcomes for patients. Because of its influence on patient well being, it needs to be recognized as an important tool in the practice of nursing. The very nature of intuition determines that there will be little agreement on a precise definition and little empirical evidence to support its existence or worth. Neither of these issues detracts from the fact that intuition is an important part of nursing. Methods. Grounded theory was used as the overarching theoretical and methodological framework for this study. Using focus group interviews and the Delphi survey technique, data were collected from 262 Registered Nurses who volunteered to take part in the study. Findings. The theory that emerged from this study provides nurses with a way of articulating their understanding of intuition and their perceptions of its use in nursing practice. Conclusions. Intuition is not some mystical power that appears from nowhere, with no rational explanation or basis. The findings from this study show that it is a product of the synergy that occurs as a result of the interaction of a number of factors.

Cramer-Rao lower bounds for QAM phase and frequency estimation

Abstract: In this paper, we present the true Cramer-Rao lower bounds (CRLBs) for the estimation of phase offset for common quadrature amplitude modulation (QAM), PSK, and PAM signals in AWGN channels. It is shown that the same analysis also applies to the QAM, FSK, and PAM CRLBs for frequency offset estimation. The ratio of the modulated to the unmodulated CRLBs is derived for all QAM, PSK, and PAM signals and calculated for specific cases of interest. This is useful to determine the limiting performance of synchronization circuits for coherent receivers without the need to simulate particular algorithms. The hounds are compared to the existing true CRLBs for an unmodulated carrier wave (CW), BPSK, and QPSK. We investigated new and existing QAM phase estimation algorithms in order to verify the new phase CRLB. This showed that new minimum distance estimator performs close to the QAM bound and provides a large improvement over the power law estimator at moderate to high signal-to-noise ratios.

Mass gathering medicine: a predictive model for patient presentation and transport rates.

Abstract: Introduction This paper reports on research into the influence of environmental factors (including crowd size, temperature, humidity, and venue type) on the number of patients and the patient problems presenting to first-aid services at large, public events in Australia. Regression models were developed to predict rates of patient presentation and of transportation-to-a-hospital for future mass gatherings. Objective To develop a data set and predictive model that can be applied across venues and types of mass gathering events that is not venue or event specific. Data collected will allow informed event planning for future mass gatherings for which health care services are required. Methods Mass gatherings were defined as public events attended by in excess of 25,000 people. Over a period of 12 months, 201 mass gatherings attended by a combined audience in excess of 12 million people were surveyed throughout Australia. The survey was undertaken by St. John Ambulance Australia personnel. The researchers collected data on the incidence and type of patients presenting for treatment and on the environmental factors that may influence these presentations. A standard reporting format and definition of event geography was employed to overcome the event-specific nature of many previous surveys. Results There are 11,956 patients in the sample. The patient presentation rate across all event types was 0.992/1,000 attendees, and the transportation-to-hospital rate was 0.027/1,000 persons in attendance. The rates of patient presentations declined slightly as crowd sizes increased. The weather (particularly the relative humidity) was related positively to an increase in the rates of presentations. Other factors that influenced the number and type of patients presenting were the mobility of the crowd, the availability of alcohol, the event being enclosed by a boundary, and the number of patient-care personnel on duty. Three regression models were developed to predict presentation rates at future events. Conclusions Several features of the event environment influence patient presentation rates, and that the prediction of patient load at these events is complex and multifactorial. The use of regression modeling and close attention to existing historical data for an event can improve planning and the provision of health care services at mass gatherings.

Evidence that 2-aminoethyl diphenylborate is a novel inhibitor of store-operated Ca2+ channels in liver cells, and acts through a mechanism which does not involve inositol trisphosphate receptors

Abstract: The compound 2-aminoethyl diphenylborate (2-APB), an inhibitor of Ins(1,4,5)P(3) receptor action in some cell types, has been used to assess the role of Ins(1,4,5)P(3) receptors in the activation of store-operated Ca2+ channels (SOCs) [Ma, Patterson, van Rossum, Birnbaumer, Mikoshiba and Gill (2000) Science 287, 1647-1651]. In freshly-isolated rat hepatocytes, 2-APB inhibited thapsigargin- and vasopressin-stimulated Ca2+ inflow (measured using fura-2) with no detectable effect on the release of Ca2+ from intracellular stores. The concentration of 2-APB which gave half-maximal inhibition of Ca2+ inflow was approx. 10 microM. 2-APB also inhibited Ca2+ inflow initiated by a low concentration of adenophostin A but had no effect on maitotoxin-stimulated Ca2+ inflow through non-selective cation channels. The onset of the inhibitory effect of 2-APB on thapsigargin-stimulated Ca2+ inflow was rapid. When 2-APB was added to rat hepatocytes in the presence of extracellular Ca2+ after a vasopressin-induced plateau in the cytoplasmic free Ca2+ concentration ([Ca2+](cyt)) had been established, the kinetics of the decrease in [Ca2+](cyt) were identical with those induced by the addition of 50 microM Gd(3+) (gadolinium). 2-APB did not inhibit the release of Ca2+ from intracellular stores induced by the addition of Ins(1,4,5)P(3) to permeabilized hepatocytes. In the H4-IIE rat hepatoma cell line, 2-APB inhibited thapsigargin-stimulated Ca2+ inflow (measured using fura-2) and, in whole-cell patch-clamp experiments, the Ins(1,4,5)P(3)-induced inward current carried by Ca2+. It was concluded that, in liver cells, 2-APB inhibited SOCs through a mechanism which involved the binding of 2-APB to either the channel protein or an associated regulatory protein. 2-APB appeared to be a novel inhibitor of SOCs in liver cells with a mechanism of action which, in this cell type, is unlikely to involve an interaction of 2-APB with Ins(1,4,5)P(3) receptors. The need for caution in the use of 2-APB as a probe for the involvement of Ins(1,4,5)P(3) receptors in the activation of SOCs in other cell types is briefly discussed.

Using Involvement and Brand Equity to Develop a Wine Tourism Strategy

Abstract: Wine tourism is a major public relations medium and for many wineries a major source of revenue. This article uses theories of brand equity to develop cellar door strategies. These theories are supported by previous research into product involvement with wine, which shows that high and low involvement wine buyers behave differently. The two segments must be catered for differently if a winery is to build its overall reputation and brand equity. Wineries can enhance their long‐term market‐based assets through building customer relationships at cellar door. Strategies and examples are provided.

The evolution of physique in male rugby union players in the twentieth century.

Abstract: Data on 1420 high-standard rugby union players measured between 1905 and 1999 were collated to chart the evolution of body size and shape in rugby union football. Individual data were available for 843 players. Where only summary statistics were presented, Monte Carlo simulation was used to generate pseudo-data. Anthropometric variables included height, body mass, body mass index (BMI) and somatotype where available. The rates of increase in body mass (2.6 kg per decade) and BMI (0.4 kg x m(-2) per decade) were well above those of the general population of young males. The increase in height (1.0 cm per decade) was comparable to the secular increase. The increases in body mass and BMI since 1975 have been three to four times those between 1905 and 1975. Since 1975, players have been less endomorphic (-0.3 units per decade) and less ectomorphic (-0.4 units per decade), but much more mesomorphic (+1.1 units per decade) than before. There is a close association between body size and success. Final ranking in the 1999 World Cup showed significant correlations with the average mass of the squads.

International Relations: The Key Concepts

Abstract: Preface Introduction List of Key Concepts Key Concepts A-Z Appendix: International Relations Website Bibliography Index

Evaluation of brand equity measures: further empirical results

Abstract: Presents further empirical results on the convergent and predictive ability of a selection of consumer based brand equity measures. An underlying assumption in this study was that choice was an indicator of brand equity. It is a replication and extension of work carried out by Agarwal and Rao in 1996. Their work is the only study that has attempted to consolidate existing research on consumer based brand equity. Overall, the results generally concurred with those of Agarwal and Rao. Most of the measures were found to be convergent, and to estimate choice. The results mean that managers should now have more confidence in selecting from a range of brand equity measures, many of which can be collected easily and at minimal cost. More empirical studies, however, need to be carried out in a range of different markets to assess the wider performance of these brand equity measures.

Rate-splitting multiple access for discrete memoryless channels

Abstract: It is shown that the encoding/decoding problem for any asynchronous M-user discrete memoryless multiple-access channel can be reduced to corresponding problems for at most 2M-1 single-user discrete memoryless channels. This result, which extends a similar result for Gaussian channels, reduces the seemingly hard task of finding good multiple-access codes to the much better understood task of finding good codes for single-user channels. As a by-product, some interesting properties of the capacity region of M-user asynchronous discrete memoryless channels are derived.

Genetic and environmental contributions to variation in human tooth size

Abstract: Human dental crowns are complex structures without simple genetic or environmental determination, but mathematical modelling of data from family studies is now providing a more complete picture of their ontogeny. Mesiodistal (MD) and buccolingual (BL) dental crown diameters were recorded from almost 600 monozygotic and dizygotic twins, and univariate biometrical models were fitted to the data for 28 permanent teeth (excluding third molars). All 56 variables showed significant contributions of additive genetic variation, varying from 56 to 92% of phenotypic variation, with most being over 80%. The effects of individual or unique environment ranged from 8 to 29%. A significant effect of the environment shared by twins — either uterine or early childhood — was found for MD and BL diameters of maxillary first molars (22–27%). There were also significant levels of non-additive genetic variation in MD diameters of canines and first premolars, which is consistent with selective pressures acting on these teeth at some stage in human evolution.

Perineal massage in labour and prevention of perineal trauma: randomised controlled trial

Abstract: Objective To determine the effects of perineal massage in the second stage of labour on perineal outcomes. Design Randomised controlled trial. Participants At 36 weeks’ gestation, women expecting normal birth of a singleton were asked to join the study. Women became eligible to be randomised in labour if they progressed to full dilatation of the cervix or 8 cm or more if nulliparous or 5 cm or more if multiparous. 1340 were randomised into the trial. Intervention Massage and stretching of the perineum during the second stage of labour with a water soluble lubricant. Main outcome measures Primary outcomes: rates of intact perineum, episiotomies, and first, second, third, and fourth degree tears. Secondary outcomes: pain at three and 10 days postpartum and pain, dyspareunia, resumption of sexual intercourse, and urinary and faecal incontinence and urgency three months postpartum. Results Rates of intact perineums, first and second degree tears, and episiotomies were similar in the massage and the control groups. There were fewer third degree tears in the massage group (12 (1.7%) v 23 (3.6%); absolute risk 2.11, relative risk 0.45; 95% confidence interval 0.23 to 0.93, P < 0.04), though the trial was underpowered to measure this rarer outcome. Groups did not differ in any of the secondary outcomes at the three assessment points. Conclusions The practice of perineal massage in labour does not increase the likelihood of an intact perineum or reduce the risk of pain, dyspareunia, or urinary and faecal problems.