2007 Higher Education Research Data Collection - UQ eSpace

Assessing the competitiveness of loss allocation methods in a deregulated electricity market

2007-03-29T00:00:00Z

This paper critically assesses several loss allocation methods based on the type of competition each method promotes. This understanding assists in determining which method will promote more efficient network operations when implemented in deregulated electricity industries. The methods addressed in this paper include the pro rata [1], proportional sharing [2], loss formula [3], incremental [4], and a new method proposed by the authors of this paper, which is loop-based [5]. These methods are tested on a modified Nordic 32-bus network, where different case studies of different operating points are investigated. The varying results obtained for each allocation method at different operating points make it possible to distinguish methods that promote unhealthy competition from those that encourage better system operation.

Assessing the Conservation Status and Threats to Priority Plants: a threat assessment approach and case study in South-East Queensland, Australia

Lynch, AJasmyn J. og Drury, Wendy L. — 2007-08-15T00:00:00Z

bstract: During the Regional Forest Agreement (RFA) process in south-east Queensland, the conservation status of, and threats to, priority vascular plant taxa in the region was assessed. Characteristics of biology, demography and distribution were used to assess the species' intrinsic risk of extinction. In contrast, the threats to the taxa (their extrinsic risk of extinction) were assessed using a decision-support protocol for setting conservation targets for taxa lacking population viability analyses and habitat modelling data. Disturbance processes known or suspected to be adversely affecting the taxa were evaluated for their intensity, extent and time-scale. Expert opinion was used to provide much of the data and to assess the recommended protection areas. Five categories of intrinsic risk of extinction were recognised for the 105 priority taxa: critically endangered (43 taxa); endangered (29); vulnerable (21); rare (10); and presumed extinct (2). Only 6 of the 103 extant taxa were found to be adequately reserved and the majority were considered inadequately protected to survive the current regimes of threatening processes affecting them. Data were insufficient to calculate a protection target for one extant taxon. Over half of the taxa require all populations to be conserved as well as active management to alleviate threatening processes. The most common threats to particular taxa were competition from weeds or native species, inappropriate fire regimes, agricultural clearing, forestry, grazing by native or feral species, drought, urban development, illegal collection of plants, and altered hydrology. Apart from drought and competition from native species, these disturbances are largely influenced or initiated by human actions. Therefore, as well as increased protection of most of the taxa, active management interventions are necessary to reduce the effects of threatening processes and to enable the persistence of the taxa.

Assessing the efficacy of gene therapy in Rpe65(-/-) mice using photoentrainment of circadian rhythm

2007-08-14T00:00:00Z

Assessing the quality of risk factor survey data: lessons from the WHO MONICA Project

2007-08-15T00:00:00Z

Background and purpose Survey data quality is a combination of the representativeness of the sample, the accuracy and precision of measurements, data processing and management with several subcomponents in each. The purpose of this paper is to show how, in the final risk factor surveys of the WHO MONICA Project, information on data quality were obtained, quantified, and used in the analysis. Methods and results In the WHO MONICA (Multinational MONItoring of trends and determinants in CArdiovascular disease) Project, the information about the data quality components was documented in retrospective quality assessment reports. On the basis of the documented information and the survey data, the quality of each data component was assessed and summarized using quality scores. The quality scores were used in sensitivity testing of the results both by excluding populations with low quality scores and by weighting the data by its quality scores. Conclusions Detailed documentation of all survey procedures with standardized protocols, training, and quality control are steps towards optimizing data quality. Quantifying data quality is a further step. Methods used in the WHO MONICA Project could be adopted to improve quality in other health surveys.

Assessing Union Strategies in Indonesian Telecommunications Industry

Satrya, A. — 2007-08-23T00:00:00Z

This article explores the implementation of a comprehensive model of union strategy,consisting of union aims, union methods, union tactics, and level of decision-making (Gahan 1998). The analysis further employs the framework of Boxall and Haynes (1997) to assess the dominant strategy pattern of the unions. Empirical data are provided from a survey of seven national enterprise unions in the telecommunications industry in Indonesia. Research findings reveal that consultancy unionism is playing important roles in explaining the relationships among unions, workers, and employers. This pattern of strategy places more emphasis on servicing and limited partnership with employers. The stronger organising solidarity from their members may improve their partnership in the interest of union survival facing tough competition in the telecommunications business.

Assessing Union Strategy in Postal Industry: Case Studies in Malaysia and Indonesia

Satrya, Alayana og Parasuraman, Balakrishnan — 2007-08-23T00:00:00Z

Assessment for learning in physical education

Hay, P J — 2007-08-14T00:00:00Z

Assessment of epidermal cell viability by near infrared multi-photon microscopy following ballistic delivery of gold micro-particles

2007-08-15T00:00:00Z

The use of gene guns in ballistically delivering DNA vaccine coated gold micro-particles to skin can potentially damage targeted cells, therefore influencing transfection efficiencies. In this paper, we assess cell death in the viable epidermis by non-invasive near infrared two-photon microscopy following micro-particle bombardment of murine skin. We show that the ballistic delivery of micro-particles to the viable epidermis can result in localised cell death. Furthermore, experimental results show the degree of cell death is dependant on the number of micro-particles delivered per unit of tissue surface area. Micro-particles densities of 0.16 +/- 0.27 (mean +/- S.D.), 1.35 +/- 0.285 and 2.72 +/- 0.47 per 1000 mu m(2) resulted in percent deaths of 3.96 +/- 5.22, 45.91 +/- 10.89, 90.52 +/- 12.28, respectively. These results suggest that optimization of transfection by genes administered with gene guns is - among other effects - a compromise of micro-particle payload and cell death. (c) 2005 Elsevier Ltd. All rights reserved.

Assessment of insight and self-awareness in older drivers

Pachana, Nancy A. og Petriwskyj, Andrea M. — 2007-08-15T00:00:00Z

Assessment of playfulness in children with autistic disorder: A comparison of the children's playfulness scale and the test of playfulness

2007-08-15T00:00:00Z

Asset Price Instability and Policy Responses: The Legacy of Liberalization

Bell, Stephen og Quiggin, John — 2007-08-15T00:00:00Z

The problem of asset price bubbles, and more generally of instability in the financial system, has been a matter of concern since the 1980s but has only recently moved to the center of the macroeconomic policy debate. The main concern with bubbles arises when they burst, imposing losses on investors holding the bubble assets and potentially on the financial institutions that have extended credit to them. Asset price volatility is an inevitable consequence of financial market liberalization and, in extreme cases, generates asset price bubbles, the bursting of which can impose substantial economic and social costs. Policy responses within the existing liberalized financial system face daunting levels of uncertainty and risk. Given the pattern of increasing asset market volatility over recent decades and the policy issues highlighted in this paper, the future looks uncertain. Another significant cycle of asset price movements, especially in one of the major economies, could see a fundamental revision of thinking about the costs and benefits of liberalized financial systems.

Association between agent orange and birth defects: systematic review and meta-analysis

2008-01-02T00:00:00Z

Association of asthma with a functional promoter polymorphism in the IL16 gene

2008-01-25T00:00:00Z

Association of Cardiovascular Risk Factors and Disease With Depression in Later Life

2007-08-16T00:00:00Z

Association of subclinical right ventricular dysfunction with obesity

2007-08-15T00:00:00Z

OBJECTIVES The purpose of this research was to identify the determinants of right ventricular (RV) dysfunction in overweight and obese subjects. BACKGROUND Right ventricular dysfunction in obese subjects is usually ascribed to comorbid diseases, especially obstructive sleep apnea. We used tissue Doppler imaging to identify the determinants of RV dysfunction in overweight and obese subjects. METHODS Standard and tissue Doppler echocardiography was performed in 112 overweight (body mass index [BMI] 25 to 29.9 kg/m(2)) or obese (BMI >30 kg/m(1)) subjects and 36 referents (BMI <25 kg/m(2)), including 22 with obstructive sleep apnea but no obesity. Tissue Doppler was used to measure RV systolic (s(m)) and diastolic (e(m)) velocities and strain indexes. 2 RESULTS Obese subjects with BMI >35 kg/m(2) had reduced RV function compared with referent subjects, evidenced by reduced s(m) (6.5 +/- 2.4 cm/s vs. 10.2 +/- 1.5 cm/s, p < 0.001), peak strain (-21 +/- 4% vs. -28 +/- 4%, p < 0.001), peak strain rate (-1.4 +/- 0.4 s(-1) vs. -2.0 +/- 0.5 s(-1), p < 0.001), and e(m) (6.8 +/- 2.4 cm/s vs. -10.3 +/- 2.5 cm/s, p < 0.001), irrespective of the presence of sleep apnea. Similar but lesser degrees of reduced systolic function (p < 0.05) were present in overweight (BMI 25 to 29.9 kg/m(2)) and mildly obese (BMI 30 to 35 kg/m(2)) groups. Differences in RV e(m), s(m), and strain indexes were demonstrated between the severely versus overweight and mildly obese groups (p < 0.05). Body mass index remained independently related to RV changes after adjusting for age, log insulin, and mean arterial pressures. In obese patients, these changes were associated with reduced exercise capacity but not the duration of obesity and presence of sleep apnea or its severity. CONCLUSIONS Increasing BMI is associated with increasing severity of RV dysfunction in overweight and obese subjects without overt heart disease, independent of sleep apnea.

Associations between the use of common medications and sleep architecture in patients with untreated obstructive sleep apnea

2007-08-15T00:00:00Z

Association study of the dystrobrevin-binding gene with schizophrenia in Australian and Indian samples

2007-08-15T00:00:00Z

Assortative Mating for Cigarette Smoking and for Alcohol Consumption in Female Australian Twins and their Spouses

2007-08-15T00:00:00Z

Background Non-random mating affects population variation for substance use and dependence. Developmentally, mate selection leading to positive spousal correlations for genetic similarity may result in increased risk for substance use and misuse in offspring. Mate selection varies by cohort and thus, assortative mating in one generation may produce marked changes in rates of substance use in the next. We aim to clarify the mechanisms contributing to spousal similarity for cigarette smoking and alcohol consumption. Methods Using data from female twins and their male spouses, we fit univariate and bivariate twin models to examine the contribution of primary assortative mating and reciprocal marital interaction to spousal resemblance for regular cigarette smoking and nicotine dependence, and for regular alcohol use and alcohol dependence. Results We found that assortative mating significantly influenced regular smoking, regular alcohol use, nicotine dependence and alcohol dependence. The bivariate models for cigarette smoking and alcohol consumption also highlighted the importance of primary assortative mating on all stages of cigarette smoking and alcohol consumption, with additional evidence for assortative mating across the two stages of alcohol consumption. Conclusions Women who regularly used, and subsequently were dependent on cigarettes or alcohol were more likely to marry men with similar behaviors. After mate selection had occurred, one partner's cigarette or alcohol involvement did not significantly modify the other partner's involvement with these psychoactive substances.

Assumption-free estimation of heritability from genome-wide identity-by-descent sharing between full siblings

2007-08-15T00:00:00Z

The study of continuously varying, quantitative traits is important in evolutionary biology, agriculture, and medicine. Variation in such traits is attributable to many, possibly interacting, genes whose expression may be sensitive to the environment, which makes their dissection into underlying causative factors difficult. An important population parameter for quantitative traits is heritability, the proportion of total variance that is due to genetic factors. Response to artificial and natural selection and the degree of resemblance between relatives are all a function of this parameter. Following the classic paper by R. A. Fisher in 1918, the estimation of additive and dominance genetic variance and heritability in populations is based upon the expected proportion of genes shared between different types of relatives, and explicit, often controversial and untestable models of genetic and non-genetic causes of family resemblance. With genome-wide coverage of genetic markers it is now possible to estimate such parameters solely within families using the actual degree of identity-by-descent sharing between relatives. Using genome scans on 4,401 quasi-independent sib pairs of which 3,375 pairs had phenotypes, we estimated the heritability of height from empirical genome-wide identity-by-descent sharing, which varied from 0.374 to 0.617 (mean 0.498, standard deviation 0.036). The variance in identity-by-descent sharing per chromosome and per genome was consistent with theory. The maximum likelihood estimate of the heritability for height was 0.80 with no evidence for non-genetic causes of sib resemblance, consistent with results from independent twin and family studies but using an entirely separate source of information. Our application shows that it is feasible to estimate genetic variance solely from within- family segregation and provides an independent validation of previously untestable assumptions. Given sufficient data, our new paradigm will allow the estimation of genetic variation for disease susceptibility and quantitative traits that is free from confounding with non-genetic factors and will allow partitioning of genetic variation into additive and non-additive components.

A standardized method for analysis of Medicago truncatula phenotypic development

2007-08-15T08:19:03Z

A state-of-practice questionnaire on verification and validation for concurrent programs

Wojcicki, M. A. og Strooper, P A — 2007-08-23T00:00:00Z

Research in verification and validation (V&V) for concurrent programs can be guided by practitioner information. A survey was therefore run to gain state-of-practice information in this context. The survey presented in this paper collected state-of-practice information on V&V technology in concurrency from 35 respondents. The results of the survey can help refine existing V&V technology by providing a better understanding of the context of V&V technology usage. Responses to questions regarding the motivation for selecting V&V technologies can help refine a systematic approach to V&V technology selection.

A statistical analysis of the Delogne-Kasa method for fitting circles

Zelniker, Emanuel E. og Clarkson, I. Vaughan, L. — 2006-05-05T00:00:00Z

In this paper, we examine the problem of fitting a circle to a set of noisy measurements of points on the circle's circumference. Delogne (Proc. IMEKO-Symp. Microwave Measurements 1972, 117-123) has proposed an estimator which has been shown by Kasa (IEEE Trans. Instrum. Meas. 25, 1976, 8-14) to be convenient for its ease of analysis and computation. Using Chan's circular functional model to describe the distribution of points, we perform a statistical analysis of the estimate of the circle's centre, assuming independent, identically distributed Gaussian measurement errors. We examine the existence of the mean and variance of the estimator for fixed sample sizes. We find that the mean exists when the number of sample points is greater than 3 and the variance exists when this number is greater than 4. We also derive approximations for the mean and variance for fixed sample sizes when the noise variance is small. We find that the bias approaches zero as the noise variance diminishes and that the variance approaches the Cramer-Rao lower bound.

A stochastic metapopulation model accounting for habitat dynamics

Ross, JV — 2007-08-15T00:00:00Z

A stochastic metapopulation model accounting for habitat dynamics is presented. This is the stochastic SIS logistic model with the novel aspect that it incorporates varying carrying capacity. We present results of Kurtz and Barbour, that provide deterministic and diffusion approximations for a wide class of stochastic models, in a form that most easily allows their direct application to population models. These results are used to show that a suitably scaled version of the metapopulation model converges, uniformly in probability over finite time intervals, to a deterministic model previously studied in the ecological literature. Additionally, they allow us to establish a bivariate normal approximation to the quasi-stationary distribution of the process. This allows us to consider the effects of habitat dynamics on metapopulation modelling through a comparison with the stochastic SIS logistic model and provides an effective means for modelling metapopulations inhabiting dynamic landscapes.

A straightforward wet-chemical route to the nanocomposites of general layered clays and metal sulfides

2007-08-15T00:00:00Z

The nanocomposites of general layered clays and metal sulfides could be produced from reactions of the layered clay aqueous suspensions and water-soluble metal-thiourea complexes. The clay could be saponite, montmorillonite, hectorite and laponite, while the metal sulfide could be cobalt sulfide, nickel sulfide, zinc sulfide, cadmium sulfide, and lead sulfide. In the nanocomposites, the clay could be incorporated with the metal sulfide pillars and metal sulfide nanoparticles. (c) 2006 Elsevier B.V. All rights reserved.

A study of large-bowel volvulus in urban Australia

2007-08-15T00:00:00Z

Background: Large-bowel volvulus is a rare cause of bowel obstruction in the industrialized world. We analyzed the presentation and outcome of 49 patients at the Princess Alexandra Hospital, Brisbane, Australia, who received a diagnosis of colonic volvulus from 1991 to 2001. Methods: A retrospective chart study was carried out. Results: Twenty-nine patients had sigmoid volvulus (59%), 19 patients had cecal volvulus (39%) and 1 patient had a transverse colon volvulus (2%). The diagnosis of sigmoid volvulus was made accurately on plain abdominal radiography or contrast enema in 90% of cases (n = 26), compared with only 42% of cases (n = 8) of cecal volvulus. Twenty-two patients with sigmoid volvulus were treated initially with endoscopic decompression. The success rate was 64% (n = 14). There was a high early recurrence rate of sigmoid volvulus for those treated by endoscopic decompression alone (43%) during a mean period of 32 days. Of the 14 patients with cecal volvulus who were treated with right hemicolectomy, 12 had primary anastomosis and 2 had end ileostomy with mucous fistula formation. There was no anastomotic leak following right hemicolectomy with primary anastomosis, even though 6 of these patients had an ischemic cecum. Conclusions: Endoscopic decompression of the sigmoid volvulus was safe and effective as an initial treatment but has a high early recurrence rate. Any patient who is fit enough to undergo operation should have a definitive procedure during the same admission to avoid recurrence. Cecal volvulus is associated with a higher incidence of gangrene and is treated effectively by right hemicolectomy with or without anastomosis. The need for swift operative intervention is emphasized.

A study of the effects of postcure treatments on polyester-melamine coating matrices

2007-08-15T00:00:00Z

The effect of postcure high energy (gamma), ultraviolet (UV) and thermal treatment on the properties of polyester-melamine clearcoats of a range of compositions has been investigated. Two initial cure conditions were used, of which one was '' optimally '' cured and the other undercured. It was found that postcure treatments, particularly gamma and UV, led to coatings of similar mechanical and thermal properties irrespective of initial cure, although the change in properties on postcure treatment was greater for the under-cured samples. The results were interpreted in terms of the effect of the treatments on the structure of the crosslinked matrices. The study suggests the possibility of the development of a dual-cure process for polyester-melamines, whereby cure optimization and property improvement can be achieved. This could also be used to '' correct '' for small variations in thermal cure levels brought about by adventitious online fluctuations in cure oven conditions.

A study of the evolution of the representational capabilities of process modeling grammars

2007-08-23T00:00:00Z

A plethora of process modeling techniques has been proposed over the years. One way of evaluating and comparing the scope and completeness of techniques is by way of representational analysis. The purpose of this paper is to examine how process modeling techniques have developed over the last four decades. The basis of the comparison is the Bunge-Wand-Weber representation model, a benchmark used for the analysis of grammars that purport to model the real world and the interactions within it. This paper presents a comparison of representational analyses of several popular process modeling techniques and has two main outcomes. First, it provides insights, within the boundaries of a representational analysis, into the extent to which process modeling techniques have developed over time. Second, the findings also indicate areas in which the underlying theory seems to be over-engineered or lacking in specialization.

A study of the lagged relationships among safety climate, safety motivation, safety behavior, and accidents at the individual and group levels

Neal, A. og Griffin, M. A. — 2007-08-15T00:00:00Z

The authors measured perceptions of safety climate, motivation, and behavior at 2 time points and linked them to prior and subsequent levels of accidents over a 5-year period. A series of analyses examined the effects of top-down and bottom-up processes operating simultaneously over time. In terms of top-down effects, average levels of safety climate within groups at I point in time predicted subsequent changes in individual safety motivation. Individual safety motivation, in turn, was associated with subsequent changes in self-reported safety behavior. In terms of bottom-up effects, improvements in the average level of safety behavior within groups were associated with a subsequent reduction in accidents at the group level. The results contribute to an understanding of the factors influencing workplace safety and the levels and lags at which these effects operate.

A survey of regular ecstasy users' knowledge and practices around determining pill content and purity: Implications for policy and practice.

2007-08-15T00:00:00Z

Objective: To examine the methods used by a sample of regular ecstasy users to determine the content and purity of ecstasy pills, their knowledge of the limitations of available pill testing methods, and how pill test results would influence their drug use behaviour. Method: Data were collected from regular ecstasy users (n = 810) recruited from all eight capital cities of Australia. Data were analysed using multiple logistic regression and chi-square (chi(2)) tests of association. Open-ended responses were coded for themes. Results: The majority of the sample(84%) reported attempting to find out the content and purity of ecstasy at least some of the time, most commonly asking friends or dealers. Less than one quarter (22%) reported personal use of testing kits. There was a moderate level of awareness of the limitations of testing kits among those who reported having used them. Over half (57%) of those reporting personal use of testing kits reported that they would not take a pill if test results indicated that it contained ketamine and over three quarters (76%) reported that they would not take an "unknown" pill (producing no reaction in a reagent test). Finally, a considerable majority (63%) expressed interest in pill testing should it be more widely available. Conclusions: The majority of regular ecstasy users sampled in this Australian study report previous attempts to determine the content and purity of pills sold as ecstasy. Although only a small proportion have used testing kits, many report that they would do so if they were more widely available. The results of pill tests may influence drug use if they indicate that pills contain substances which ecstasy users do not want to ingest or are of unknown content. More detailed research examining ways in which pill testing may influence drug use is required to inform evidence-based policy. (c) 2006 Elsevier B.V. All rights reserved.

A survey of the intestinal transcriptomes of the hookworms, Necator americanus and Ancylostoma caninum, using tissues isolated by laser microdissection microscopy

2007-08-15T00:00:00Z

The gastrointestinal tracts of multi-cellular blood-feeding parasites are targets for vaccines and drugs. Recently, recombinant vaccines that interrupt the digestion of blood in the hookworm gut have shown efficacy, so we explored the intestinal transcriptomes of the human and canine hookworms, Necator americanus and Ancylostoma caninum, respectively. We used Laser Microdissection Microscopy to dissect gut tissue from the parasites, extracted the RNA and generated cDNA libraries. A total of 480 expressed sequence tags were sequenced from each library and assembled into contigs, accounting for 268 N. americanus genes and 276 A. caninum genes. Only 17% of N. americanus and 36% of A. caninum contigs were assigned Gene Ontology classifications. Twenty-six (9.8%) N. americanus and 18 (6.5%) A. caninum contigs did not have homologues in any databases including dbEST-of these novel clones, seven N. americanus and three A. caninum contigs had Open Reading Frames with predicted secretory signal peptides. The most abundant transcripts corresponded to mRNAs encoding cholesterol-and fatty acid-binding proteins, C-type lectins, Activation-Associated Secretory Proteins, and proteases of different mechanistic classes, particularly astacin-like metallopeptidases. Expressed sequence tags corresponding to known and potential recombinant vaccines were identified and these included homologues of proteases, anti-clotting factors, defensins and integral membrane proteins involved in cell adhesion. (c) 2006 Australian Society for Parasitology Inc Published by Elsevier Ltd. All fights reserved.

Asymmetric page split generalized index search trees for formal concept analysis

Martin, B. og Eklund, P. — 2007-08-14T00:00:00Z

Formal Concept Analysis is an unsupervised machine learning technique that has successfully been applied to document organisation by considering documents as objects and keywords as attributes. The basic algorithms of Formal Concept Analysis then allow an intelligent information retrieval system to cluster documents according to keyword views. This paper investigates the scalability of this idea. In particular we present the results of applying spatial data structures to large datasets in formal concept analysis. Our experiments are motivated by the application of the Formal Concept Analysis idea of a virtual filesystem [11,17,15]. In particular the libferris [1] Semantic File System. This paper presents customizations to an RD-Tree Generalized Index Search Tree based index structure to better support the application of Formal Concept Analysis to large data sources.

Asymmetric polychromatic tripartite entanglement from interlinked χ(2) parametric interactions

Olsen, M. K. og Bradley, A. S. — 2007-08-15T00:00:00Z

Asymptomatic bacteriuria Escherichia coli strain 83972 carries mutations in the foc locus and is unable to express F1C fimbriae

2007-08-15T00:00:00Z

Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infection (UTI), very little is known about the mechanisms by which these strains colonize the urinary tract. Bacterial adhesion conferred by specific surface-associated adhesins is normally considered as a prerequisite for colonization of the urinary tract. The prototype ABU E coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. This study characterized the molecular status of one of the primary adhesion factors known to be associated with UTI, namely F1C fimbriae, encoded by the foc gene cluster. F1C fimbriae recognize receptors present in the human kidney and bladder. Expression of the foc genes was found to be up-regulated in human urine. It was also shown that although strain 83972 contains a seemingly intact foc gene cluster, F1C fimbriae are not expressed. Sequencing and genetic complementation revealed that the focD gene, encoding a component of the F1C transport and assembly system, was non-functional, explaining the inability of strain 83972 to express this adhesin. The data imply that E. coli 83972 has lost its ability to express this important colonization factor as a result of host-driven evolution. The ancestor of the strain seems to have been a pyelonephritis strain of phylogenetic group B2. Strain 83972 therefore represents an example of bacterial adaptation from pathogenicity to commensalism through virulence factor loss.

Asymptomatic long-term survivors of coronary artery bypass surgery enjoy a quality of life equal to the general population

2007-08-15T00:00:00Z

Background Health-related quality of life (HRQOL) among long-term survivors of coronary artery bypass surgery is an important outcome that has been little studied at the population level. Methods A postal survey was conducted in 1999 to 2000 in patients 6 to 20 years after coronary artery bypass graft (CABG) surgery in Western-Australia. A random stratified sample of 2500 was drawn from 8910 patients who had their first CABG surgery in 1980 to 1993. Health-related quality of life was measured with Short Form 36 and EuroQol visual analogue scale. Results Response was 82% (n = 2061). Health-related quality of life declined with age and was similar for men and women, although scores for women were worse for physical functioning. Compared with Australian population norms, the age- and sex-standardized scores of survivors of CABG were generally worse, mainly in the physical domain. Reported angina at the time of follow-up (33%), symptoms of heart failure equivalent to New York Heart Association (NYHA) classes II to IV (34%), and comorbidities such as diabetes and hypertension were associated with poorer HRQOL. For both men and women without angina or heart failure at follow-up, HRQOL was no different from that of the general population. Conclusion Overall, the quality of life among long-term survivors of CABG is worse than that of the general population, the difference being mainly attributable to recurrent symptoms and comorbidities. Quality of life for those without angina or heart failure at follow-up was equivalent to the population norms, providing an incentive to maximize efforts to abolish angina and ameliorate heart failure symptoms.

A synchronous multimedia annotation system for secure collaboratories

2007-01-25T00:00:00Z

In this paper, we describe the Vannotea system - an application designed to enable collaborating groups to discuss and annotate collections of high quality images, video, audio or 3D objects. The system has been designed specifically to capture and share scholarly discourse and annotations about multimedia research data by teams of trusted colleagues within a research or academic environment. As such, it provides: authenticated access to a web browser search interface for discovering and retrieving media objects; a media replay window that can incorporate a variety of embedded plug-ins to render different scientific media formats; an annotation authoring, editing, searching and browsing tool; and session logging and replay capabilities. Annotations are personal remarks, interpretations, questions or references that can be attached to whole files, segments or regions. Vannotea enables annotations to be attached either synchronously (using jabber message passing and audio/video conferencing) or asynchronously and stand-alone. The annotations are stored on an Annotea server, extended for multimedia content. Their access, retrieval and re-use is controlled via Shibboleth identity management and XACML access policies.

A systematic review of successes and failures in home telehealth: preliminary results

2007-08-15T00:00:00Z

We conducted a systematic review of the literature to identify studies in home telehealth that compared a home telehealth intervention with a non-telehealth standard/usual care alternative in terms of administrative changes, patient management decisions, patient outcomes, caregiver outcomes, economic impact or social impact on patients. A search of various databases produced 6643 references. Of these 769 papers were selected for more detailed investigation. These papers, combined with hand searching of relevant telehealth journals and cross-referencing of citations in identified publications, resulted in 138 papers referring to 130 projects for review. In this preliminary analysis we used a quality appraisal approach that took into account the study design. An additional analysis of patient numbers was then used to calculate a net evidence score. A large proportion of studies (80%) were randomised controlled trials. Only 22 projects (17%) reported economic data deemed to be sufficient for appraisal. Evidence exists for the clinical effectiveness of home telehealth in diabetes, the general area of mental health, high risk pregnancy monitoring, heart failure and cardiac disease.

A systematic review of topical skin care in aged care facilities

Hodgkinson, B og Nay, R. og Wilson, J. — 2007-08-15T00:00:00Z

This systematic review aimed to evaluate the best available evidence regarding the effectiveness of topical skin care interventions for residents of aged care facilities. Introduction. Natural changes to skin, as well as increased predisposition to pressure sores and incontinence, means residents of aged care facilities readily require topical skin care. A range of interventions exist that aim to maintain or improve the integrity of skin of older adults. Methods. Pubmed, Embase, Current Contents, CINAHL and The Cochrane Library databases were searched, as well as Health Technology Assessment websites up to April 2003. Systematic reviews and randomized or non-randomized controlled trials were evaluated for quality and data were independently extracted by two reviewers. Results. The effectiveness of topical skin interventions was variable and dependent on the skin condition being treated. Studies examined the effectiveness of washing products on incontinence irritated skin. Disposable bodyworns may prevent deterioration of skin condition better than non-disposable underpads or bodyworns. Clinisan, a no-rinse cleanser may reduce the incidence of incontinence associated pressure ulcers when compared with soap and water. Conclusion. In general the quality of evidence for interventions to improve or maintain the skin condition in the older person was poor and more research in this area is needed. Relevance to Clinical Practice. Skin care is a major issue for nurses working with older people. On the basis of this review no clear recommendations can be made. This lack of strong evidence for nurses to base effective practice decisions is problematic. However, the 'best' evidence suggests that disposable bodyworns are a good investment in the fight against skin deterioration. No rinse cleansers are to be preferred over soap and the use of the bag bath appears to be a useful practice to reduce the risk of dry skin ( a risk factor for breaches in skin integrity).

A Test of Performance of Breast MRI Interpretation in a Multicentre Screening Study

2007-08-15T00:00:00Z

Objectives: The aim of this study was to assess the consistency and performance of radiologists interpreting breast magnetic resonance imaging (MRI) examinations. Materials and Methods: Two test sets of eight cases comprising cancers, benign disease, technical problems and parenchymal enhancement were prepared from two manufacturers' equipment (X and Y) and reported by 15 radiologists using the recording form and scoring system of the UK MRI breast screening study [(MAgnetic Resonance Imaging in Breast Screening (MARIBS)]. Variations in assessments of morphology, kinetic scores and diagnosis were measured by assessing intraobserver and interobserver variability and agreement. The sensitivity and specificity of reporting performances was determined using receiver operating characteristic (ROC) curve analysis. Results: Intraobserver variation was seen in 13 (27.7%) of 47 of the radiologists' conclusions (four technical and seven pathological differences). Substantial interobserver variation was observed in the scores recorded for morphology, pattern of enhancement, quantification of enhancement and washout pattern. The overall sensitivity of breast MRI was high [88.6%, 95% confidence interval (CI) 77.4-94.7%], combined with a specificity of 69.2% (95% CI 60.5-76.7%). The sensitivities were similar for the two test sets (P=.3), but the specificity was significantly higher for the Manufacturer X dataset (P <.001). ROC curve analysis gave an area under the curve of 0.85 (95% CI 0.79-0.92) Conclusions: Substantial variation in all elements of the scoring system and in the overall diagnostic conclusions was observed between radiologists participating in MARIBS. High overall sensitivity was achieved with moderate specificity. Manufacturer-related differences in specificities possibly occurred because the numerical thresholds set for the scoring system were not optimised for both equipment manufacturers. Scoring systems developed on one equipment software may not be transferable to other manufacturers. (c) 2006 Elsevier Inc. All rights reserved

A thermal shocker: The polar foehn of the Victoria Valley, McMurdo Dry Valleys, Antarctica

McGowan, H A og Speirs, J. — 2007-08-23T00:00:00Z

ATM and the DNA damage response - Workshop on ataxia-telangiectasia and related syndromes

Lavin, M. F. og Delia, D. og Chessa, L. — 2007-08-15T00:00:00Z

Atmospheric corrosion of copper and the colour, structure and composition of natural patinas on copper

2007-08-15T00:00:00Z

This paper describes the results of atmospheric corrosion testing and of an examination of patina samples from Brisbane, Denmark, Sweden, France, USA and Austria. The aim was threefold: (1) to determine the structure of natural patinas and to relate their structure to their appearance in service and to the atmospheric corrosion of copper; (2) to understand why a brown rust coloured layer forms on the surface of some copper patinas; (3) to understand why some patinas are still black in colour despite being of significant age. During the atmospheric corrosion of copper, a two-layer patina forms on the copper surface. Cuprite is the initial corrosion product and cuprite is always the patina layer in contact with the copper. The growth laws describing patina formation indicate that the decreasing corrosion rate with increasing exposure time is due to the protective nature of the cuprite layer. The green patinas were typically characterised by an outer layer of brochantite, which forms as individual crystals on the surface of the cuprite layer, probably by a precipitation reaction from an aqueous surface layer on the cuprite layer. Natural patinas come in a variety of colours. The colour is controlled by the amount of the patina and its chemical composition. Thin patinas containing predominantly cuprite were black. If the patina was sufficiently thick, and the [Fe]/[Cu] ratio was low, then the patina was green, whereas if the [Fe]/[Cu] ratio was approximately 10 at%, then the patina is rust brown in colour. The iron was in solid solution in the brochantite, which might be designated as a (copper/iron) hydroxysulphate. In the brown patinas examined, the iron was distributed predominately in the outermost part of the patina. (c) 2005 Elsevier Ltd. All rights reserved.

Atoll lagoon flushing forced by waves

2007-08-15T00:00:00Z

Water level and current measurements from two virtually enclosed South Pacific atolls, Manihiki and Rakahanga, support a new lagoon flushing mechanism which is driven by waves and modulated by the ocean tide for virtually enclosed atolls. This is evident because the lagoon water level remains above the ocean at all tidal phases (i.e., ruling out tidal flushing) and because the average lagoon water level rises significantly during periods with large waves. Hence, we develop a model by which the lagoons are flushed by waves pumping of ocean water into the lagoon and gravity draining water from the lagoon over the reef rim. That is, the waves on the exposed side push water into the lagoon during most of the tidal cycle while water leaves the lagoon on the protected side for most of the tidal cycle. This wave-driven through flow flushing is shown to be more efficient than alternating tidal flushing with respect to water renewal. Improved water quality should therefore be sought through enhancement of the natural wave pumping rather than by blasting deep channels which would change the system to an alternating tide-driven one.

Atom counting in ultracold gases using photoionization and ion detection

2007-08-15T00:00:00Z

We analyze photoionization and ion detection as a means of accurately counting ultracold atoms. We show that it is possible to count clouds containing many thousands of atoms with accuracies better than N-1/2 with current technology. This allows the direct probing of sub-Poissonian number statistics of atomic samples. The scheme can also be used for efficient single-atom detection with high spatiotemporal resolution. All aspects of a realistic detection scheme are considered, and we discuss experimental situations in which such a scheme could be implemented.

Atomic composition profile change of SiGe islands during Si capping

2007-08-15T00:00:00Z

The 6% Ge isocomposition profile change of individual SiGe islands during Si capping at 640 degrees C is investigated by atomic force microscopy combined with a selective etching procedure. The island shape transforms from a dome to a {103}-faceted pyramid at a Si capping thickness of 0.32 nm, followed by the decreasing of pyramid facet inclination with increasing Si capping layer thickness. The 6% Ge isocomposition profiles show that the island with more highly Si enriched at its one base corner before Si capping becomes to be more highly Si intermixed along pyramid base diagonals during Si capping. This Si enrichment evolution inside an island during Si capping can be attributed to the exchange of capped Si atoms that aggregated to the island by surface diffusion with Ge atoms from inside the island by both atomic surface segregation and interdiffusion rather than to the atomic interdiffusion at the interface between the island and the Si substrate. In addition, the observed Si enrichment along the island base diagonals is attempted to be explained on the basis of the elastic constant anisotropy of the Si and Ge materials in (001) plane. (c) 2006 American Institute of Physics.

Atom probe field ion microscope measurements of carbon segregation at an a:a grain boundary and service failures by intergranular stress corrosion cracking

2007-08-15T00:00:00Z

This work reports on a critical measurement to understand the intergranular stress corrosion cracking (IGSCC) of pipeline steels: the atom probe field ion microscope (APFIM) measurement of the carbon concentration at a grain boundary (GB). The APFIM measurement was related to the microstructure and to IGSCC observations. The APFIM indicated that the GB carbon concentration of X70 was similar to 10 at% or less, which correlated with a high resistance to IGSCC for X70. (C) 2005 Elsevier Ltd. All rights reserved.

A tool for a formal pattern modeling language

Kim, Soon-Kyeong og Carrington, David — 2007-08-23T00:00:00Z

This paper presents a formal but practical approach for defining and using design patterns. Initially we formalize the concepts commonly used in defining design patterns using Object-Z. We also formalize consistency constraints that must be satisfied when a pattern is deployed in a design model. Then we implement the pattern modeling language and its consistency constraints using an existing modeling framework, EMF, and incorporate the implementation as plug-ins to the Eclipse modeling environment. While the language is defined formally in terms of Object-Z definitions, the language is implemented in a practical environment. Using the plug-ins, users can develop precise pattern descriptions without knowing the underlying formalism, and can use the tool to check the validity of the pattern descriptions and pattern usage in design models. In this work, formalism brings precision to the pattern language definition and its implementation brings practicability to our pattern-based modeling approach.

A total electron content space weather study of the Nighttime Weddell Sea Anomaly of 1996/97 southern summer with TOPEX/Poseidon radar altimetry

Horvath, Ildiko — 2007-08-15T00:00:00Z

This paper reports on a total electron content space weather study of the nighttime Weddell Sea Anomaly, overlooked by previously published TOPEX/Poseidon climate studies, and of the nighttime ionosphere during the 1996/1997 southern summer. To ascertain the morphology of spatial TEC distribution over the oceans in terms of hourly, geomagnetic, longitudinal and summer-winter variations, the TOPEX TEC, magnetic, and published neutral wind velocity data are utilized. To understand the underlying physical processes, the TEC results are combined with inclination and declination data plus global magnetic field-line maps. To investigate spatial and temporal TEC variations, geographic/magnetic latitudes and local times are computed. As results show, the nighttime Weddell Sea Anomaly is a large (∼1,600(°)2; ∼22 million km2 estimated for a steady ionosphere) space weather feature. Extending between 200°E and 300°E (geographic), it is an ionization enhancement peaking at 50°S–60°S/250°E–270°E and continuing beyond 66°S. It develops where the spacing between the magnetic field lines is wide/medium, easterly declination is large-medium (20°–50°), and inclination is optimum (∼55°S). Its development and hourly variations are closely correlated with wind speed variations. There is a noticeable (∼43%) reduction in its average area during the high magnetic activity period investigated. Southern summer nighttime TECs follow closely the variations of declination and field-line configuration and therefore introduce a longitudinal division of four (Indian, western/eastern Pacific, Atlantic). Northern winter nighttime TECs measured over a limited area are rather uniform longitudinally because of the small declination variation. TOPEX maps depict the expected strong asymmetry in TEC distribution about the magnetic dip equator.

A traffic simulation approach to evaluating the benefits of incident management programs

Dia, H F og Gondwe, W. W. og Panwai, S. — 2007-08-23T00:00:00Z

A Transdiagnostic Approach to Understanding Eating Disorders

2007-08-15T00:00:00Z

Categorical models dominate the eating disorder field, but the tandem use of categorical and dimensional models has been proposed. A transdiagnostic dimensional model, number of lifetime eating disorder behaviors (LEDB), was examined with respect to (1) its relationship to a variety of indicators of the individual's functioning, (2) the degree to which it was influenced by genetic and environmental risk factors, and (3) exposure to specific environmental risk factors. Data from self-report and interview from 1002 female twins (mean age = 34.91 years, SD = 2.09) were examined. While 15.4% women met criteria for a lifetime eating disorder, 29% had at least one LEDB. The dimensional measure provided an indicator of associated functioning, and was influenced primarily by the nonshared environment. The number of LEDB was associated with the degree of impaired functioning. This impairment was associated with conflict between parents and criticism from parents when growing up.

Attachment of Shiga toxigenic Escherichia coli to beef muscle and adipose tissue

Rivas, L og Dykes, GA og Fegan, N — 2007-08-15T00:00:00Z

Shiga toxigenic Escherichia coli (STEC) serotypes are important foodborne pathogens that cause gastrointestinal disease worldwide. An understanding of how STEC strains attach to surfaces may provide insight into the potential persistence of and contamination with STEC in food environments. The initial attachment of a selection of STEC serotypes to beef muscle and adipose tissue was evaluated for isolates grown in planktonic and sessile culture. Initial experiments were performed to determine whether attachment differed among STEC strains and between the two modes of growth. Viable counts were obtained for loosely and strongly attached cells, and the strength of attachment (S-r) was calculated. All bacterial isolates grown in sessile culture attached in higher numbers to muscle and adipose tissue than did bacteria in planktonic cultures. For all attachment assays performed, mean concentrations for loosely attached cells were consistently higher than concentrations for strongly attached cells. The mean concentrations for strongly attached bacteria for planktonic and sessile cultures were significantly higher (P < 0.05) on adipose than on muscle tissue. However, some strains of STEC, particularly those from sessile culture, did not differ in their attachment to muscle or adipose tissue. S-r values were not significantly different (P > 0.05) among STEC isolates for all assays. No correlation was found between bacterial hydrophobicity and surface charge values (previously determined) and production of surface structures, viable counts, and S-r values. STEC grown in planktonic and sessile culture seems to behave differently with respect to attachment to muscle and adipose tissue. Cells in sessile culture may have a greater potential to strongly attach to meat surfaces.