Quantitative assessment of fault tolerant precision timing for electricity substations

Advanced substation applications, such as synchrophasors and IEC 61850-9-2 sampled value process buses, depend upon highly accurate synchronizing signals for correct operation. The IEEE 1588 Precision Timing Protocol (PTP) is the recommended means of providing precise timing for future substations. This paper presents a quantitative assessment of PTP reliability using Fault Tree Analysis. Two network topologies are proposed that use grandmaster clocks with dual network connections and take advantage of the Best Master Clock Algorithm (BMCA) from IEEE 1588. The cross-connected grandmaster topology doubles reliability, and the addition of a shared third grandmaster gives a nine-fold improvement over duplicated grandmasters. The performance of BMCA mediated handover of the grandmaster role during contingencies in the timing system was evaluated experimentally. The 1 µs performance requirement of sampled values and synchrophasors are met, even during network or GPS antenna outages. Slave clocks are shown to synchronize to the backup grandmaster in response to degraded performance or loss of the main grandmaster. Slave disturbances are less than 350 ns provided the grandmaster reference clocks are not offset from one another. A clear understanding of PTP reliability and the factors that affect availability will encourage the adoption of PTP for substation time synchronization.

Adaptive radiotherapy for virally mediated head and neck cancer

Introduction: Clinical investigation has revealed a subgroup of head and neck cancers that are virally mediated. The relationship between nasopharyngeal cancer and Epstein Barr Virus (EBV) has long been established and more recently, the association between oropharyngeal cancer and Human Papillomavirus (HPV) has been revealed1,2 These cancers often present with nodal involvement and generally respond well to radiation treatment, evidenced by tumour regression1. This results in the need for treatment plan adaptation or re-planning in a subset of patients. Adaptive techniques allow the target region of the radiotherapy treatment plan to be altered in accordance with treatment-induced changes to ensure that under or over dosing does not occur3. It also assists in limiting potential overdosing of surrounding critical normal tissues4. We sought to identify a high-risk group based on nodal size to be evaluated in a future prospective adaptive radiotherapy trial. Method: Between 2005-2010, 121 patients with virally mediated, node positive nasopharyngeal (EBV positive) or oropharyngeal (HPV positive) cancers, receiving curative intent radiotherapy treatment were reviewed. Patients were analysed based on maximum size of the dominant node at diagnosis with a view to grouping them in varying risk categories to determine the need of re-planning. The frequency and timing of the re-planning scans were also evaluated. Results: Sixteen nasopharyngeal and 105 oropharyngeal tumours were reviewed. Twenty-five (21%) patients underwent a re-planning CT at a median of 22 (range, 0-29) fractions with 1 patient requiring re-planning prior to the commencement of treatment. Based on the analysis, patients were subsequently placed into risk categories; ≤35mm (Group 1), 36-45mm (Group 2), ≥46mm (Group 3). Re-planning CT’s were performed in Group 1- 8/68 (11.8%), Group 2- 4/28 (14.3%), Group 3- 13/25 (52%). Conclusion: In this series, patients with virally mediated head and neck cancer and nodal size > 46mm appear to be a high-risk group for the need of re-planning during a course of curative radiotherapy. This finding will now be tested in a prospective adaptive radiotherapy study. ‘Real World’ Implications: This research identifies predictive factors for those patients with virally mediated head and neck cancer that will benefit most from treatment adaptation. This will assist in minimising the side effects experienced by these patients thereby improving their quality of life after treatment.

Factors influencing caregiver : care receiver communication and its impact on the well-being of older care receivers

Examined communication between frail older people and their caregiving spouses (CGSs), and its relation to well-being in older care receivers. 53 community residing spousal dyads completed questionnaires about their well-being, relational satisfaction, and communication patterns. Conversations between the dyads were also videotaped and analyzed. The type of communication used by the CGSs was influenced by their sex, their earlier relationship with their spouse, and their level of well-being. CGSs who used an overly directive communication tone with their spouse were likely to be wives and CGSs who had a high degree of autonomy in their earlier relationship with their spouse. Low levels of life satisfaction and high affect balance in CGSs were associated with CGSs using a more patronizing tone. The well-being of care receivers was also related to their perceptions of their CGSs' communication. Care receivers who perceived their CGSs' communication as patronizing reported low levels of affect balance and high levels of conflict in the relationship. Findings suggest that certain characteristics of CGSs are related to the type of communication they use when conversing with their partner, although the relations are not always as expected.

The impact of malnutrition and decreased food intake on length of stay, readmission, and mortality in acute care patients

Rationale: The Australasian Nutrition Care Day Survey (ANCDS) evaluated if malnutrition and decreased food intake are independent risk factors for negative outcomes in hospitalised patients. Methods: A multicentre (56 hospitals) cross-sectional survey was conducted in two phases. Phase 1 evaluated nutritional status (defined by Subjective Global Assessment) and 24-hour food intake recorded as 0, 25, 50, 75, and 100% intake. Phase 2 data, which included length of stay (LOS), readmissions and mortality, were collected 90 days post-Phase 1. Logistic regression was used to control for confounders: age, gender, disease type and severity (using Patient Clinical Complexity Level scores). Results: Of 3122 participants (53% males, mean age: 65±18 years) 32% were malnourished and 23% consumed�25% of the offered food. Median LOS for malnourished (MN) patients was higher than well-nourished (WN) patients (15 vs. 10 days, p<0.0001). Median LOS for patients consuming �25% of the food was higher than those consuming �50% (13 vs. 11 days, p<0.0001). MN patients had higher readmission rates (36% vs. 30%, p = 0.001). The odds ratios of 90-day in-hospital mortality were 1.8 times greater for MN patients (CI: 1.03 3.22, p = 0.04) and 2.7 times greater for those consuming �25% of the offered food (CI: 1.54 4.68, p = 0.001). Conclusion: The ANCDS demonstrates that malnutrition and/or decreased food intake are associated with longer LOS and readmissions. The survey also establishes that malnutrition and decreased food intake are independent risk factors for in-hospital mortality in acute care patients; and highlights the need for appropriate nutritional screening and support during hospitalisation. Disclosure of Interest: None Declared.

Factors that influence Chinese TEFL academics' research capacity building : an institutional case study

Research capacity building has become a prominent theme in higher education institutions across the world. To build research capacity, it is necessary to identify areas of challenges academics face within the academia. This case study focuses on Chinese teaching English as a foreign language (TEFL) academics with the purpose of identifying factors that influence their research capacity building. Six TEFL academics from a Chinese national university were interviewed and institutional research documents were analysed. Findings showed that obstacles and difficulties in conducting research were more related to departmental factors than individual characteristics. The institution was keen on developing a research culture, and encouraged research and publications. Departmental support for research was improving, but it seems that it was more generic than tailored to individual needs. The findings of this study provide implications for research administrators in further supporting TEFL academics’ research capacity building.

Mutual enlightenment : augmenting human factors research in surgical robotics

This discussion has outlined a theoretical and pragmatic framework to demonstrate that future research involving the analysis of human performance in surgical should encourage the use of phenomenology to enhance the knowledge base of this area of study. Merging experiential (first-person) and experimental (third-person) methods may possibly help improve research designs and analyses in the investigation of robotics in surgical performance. By relying solely on third-person techniques, the current methodology and interpretation used to analyze human performance in surgical robotics is limited. Recent advances in cognitive science and psychology have also recognized this limitation and have now begun to shift to neurophenomenology. Finally, discussion on recent robotics research presented here demonstrates the potential phenomenology holds for augmenting the methodological and analysis techniques currently used by researchers of human performance in surgical robotics.

A safe system-based approach to selection of clear zones, safety barriers and other roadside treatments

On average, 560 fatal run-off-road crashes occur annually in Australia and 135 in New Zealand. In addition, there are more than 14,000 run-off-road crashes causing injuries each year across both countries. In rural areas, run-off-road casualty crashes constitute 50-60% of all casualty crashes. Their severity is particularly high with more than half of those involved sustaining fatal or serious injuries. This paper reviews the existing approach to roadside hazard risk assessment, selection of clear zones and hazard treatments. It proposes a modified approach to roadside safety evaluation and management. It is a methodology based on statistical modelling of run-off-road casualty crashes, and application of locally developed crash modification factors and severity indices. Clear zones, safety barriers and other roadside design/treatment options are evaluated with a view to minimise fatal and serious injuries – the key Safe System objective. The paper concludes with a practical demonstration of the proposed approach. The paper is based on findings from a four-year Austroads research project into improving roadside safety in the Safe System context.

Risk factors for moderate and severe microbial keratitis in daily wear contact lens users

Objective: To establish risk factors for moderate and severe microbial keratitis among daily contact lens (CL) wearers in Australia. Design: A prospective, 12-month, population-based, case-control study. Participants: New cases of moderate and severe microbial keratitis in daily wear CL users presenting in Australia over a 12-month period were identified through surveillance of all ophthalmic practitioners. Case detection was augmented by record audits at major ophthalmic centers. Controls were users of daily wear CLs in the community identified using a national telephone survey. Testing: Cases and controls were interviewed by telephone to determine subject demographics and CL wear history. Multiple binary logistic regression was used to determine independent risk factors and univariate population attributable risk percentage (PAR%) was estimated for each risk factor.; Main Outcome Measures: Independent risk factors, relative risk (with 95% confidence intervals [CIs]), and PAR%. Results: There were 90 eligible moderate and severe cases related to daily wear of CLs reported during the study period. We identified 1090 community controls using daily wear CLs. Independent risk factors for moderate and severe keratitis while adjusting for age, gender, and lens material type included poor storage case hygiene 6.4× (95% CI, 1.9-21.8; PAR, 49%), infrequent storage case replacement 5.4× (95% CI, 1.5-18.9; PAR, 27%), solution type 7.2× (95% CI, 2.3-22.5; PAR, 35%), occasional overnight lens use (<1 night per week) 6.5× (95% CI, 1.3-31.7; PAR, 23%), high socioeconomic status 4.1× (95% CI, 1.2-14.4; PAR, 31%), and smoking 3.7× (95% CI, 1.1-12.8; PAR, 31%). Conclusions: Moderate and severe microbial keratitis associated with daily use of CLs was independently associated with factors likely to cause contamination of CL storage cases (frequency of storage case replacement, hygiene, and solution type). Other factors included occasional overnight use of CLs, smoking, and socioeconomic class. Disease load may be considerably reduced by attention to modifiable risk factors related to CL storage case practice.

Socioeconomic inequalities in cardiovascular mortality and the role of childhood socioeconomic conditions and adulthood risk factors : a prospective cohort study with 17-years of follow up

Background The mechanisms underlying socioeconomic inequalities in mortality from cardiovascular diseases (CVD) are largely unknown. We studied the contribution of childhood socioeconomic conditions and adulthood risk factors to inequalities in CVD mortality in adulthood. Methods The prospective GLOBE study was carried out in the Netherlands, with baseline data from 1991, and linked with the cause of death register in 2007. At baseline, participants reported on adulthood socioeconomic position (SEP) (own educational level), childhood socioeconomic conditions (occupational level of respondent’s father), and a broad range of adulthood risk factors (health behaviours, material circumstances, psychosocial factors). This present study is based on 5,395 men and 6,306 women, and the data were analysed using Cox regression models and hazard ratios (HR). Results A low adulthood SEP was associated with increased CVD mortality for men (HR 1.84; 95% CI: 1.41-2.39) and women (HR 1.80; 95%CI: 1.04-3.10). Those with poorer childhood socioeconomic conditions were more likely to die from CVD in adulthood, but this reached statistical significance only among men with the poorest childhood socioeconomic circumstances. About half of the investigated adulthood risk factors showed significant associations with CVD mortality among both men and women, namely renting a house, experiencing financial problems, smoking, physical activity and marital status. Alcohol consumption and BMI showed a U-shaped relationship with CVD mortality among women, with the risk being significantly greater for both abstainers and heavy drinkers, and among women who were underweight or obese. Among men, being single or divorced and using sleep/anxiety drugs increased the risk of CVD mortality. In explanatory models, the largest contributor to adulthood CVD inequalities were material conditions for men (42%; 95% CI: −73 to −20) and behavioural factors for women (55%; 95% CI: -191 to −28). Simultaneous adjustment for adulthood risk factors and childhood socioeconomic conditions attenuated the HR for the lowest adulthood SEP to 1.34 (95% CI: 0.99-1.82) for men and 1.19 (95% CI: 0.65-2.15) for women. Conclusions Adulthood material, behavioural and psychosocial factors played a major role in the explanation of adulthood SEP inequalities in CVD mortality. Childhood socioeconomic circumstances made a modest contribution, mainly via their association with adulthood risk factors. Policies and interventions to reduce health inequalities are likely to be most effective when considering the influence of socioeconomic circumstances across the entire life course and in particular, poor material conditions and unhealthy behaviours in adulthood.

The effects of linguistic factors on student performance on economics multiple choice questions

This paper proposes a framework to analyse performance on multiple choice questions with the focus on linguistic factors. Item Response Theory (IRT) is deployed to estimate ability and question difficulty levels. A logistic regression model is used to detect Differential Item Functioning questions. Probit models testify relationships between performance and linguistic factors controlling the effects of question construction and students’ background. Empirical results have important implications. The lexical density of stems affects performance. The use of non-Economics specialised vocabulary has differing impacts on the performance of students with different language backgrounds. The IRT-based ability and difficulty help explain performance variations.

Inflammation, hepatic enzymes and resistance training in individuals with metabolic risk factors

AIMS: Increases in inflammatory markers, hepatic enzymes and physical inactivity are associated with the development of the metabolic syndrome (MetS). We examined whether inflammatory markers and hepatic enzymes are correlated with traditional risk factors for MetS and studied the effects of resistance training (RT) on these emerging risk factors in individuals with a high number of metabolic risk factors (HiMF, 2.9 +/- 0.8) and those with a low number of metabolic risk factors (LoMF, 0.5 +/- 0.5). METHODS: Twenty-eight men and 27 women aged 50.8 +/- 6.5 years (mean +/- sd) participated in the study. Participants were randomized to four groups, HiMF training (HiMFT), HiMF control (HiMFC), LoMF training (LoMFT) and LoMF control (LoMFC). Before and after 10 weeks of RT [3 days/week, seven exercises, three sets with intensity gradually increased from 40-50% of one repetition maximum (1RM) to 75-85% of 1RM], blood samples were obtained for the measurement of pro-inflammatory cytokines, C-reactive protein (CRP), gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT). RESULTS: At baseline, HiMF had higher interleukin-6 (33.9%), CRP (57.1%), GGT (45.2%) and ALT (40.6%) levels, compared with LoMF (all P < 0.05). CRP, GGT and ALT correlated with the number of risk factors (r = 0.48, 0.51 and 0.57, respectively, all P < 0.01) and with other anthropometric and clinical measures (r range from 0.26 to 0.60, P < 0.05). RT did not significantly alter inflammatory markers or hepatic enzymes (all P > 0.05). CONCLUSIONS: HiMF was associated with increased inflammatory markers and hepatic enzyme concentrations. RT did not reduce inflammatory markers and hepatic enzymes in individuals with HiMF.

Factors affecting the stability analysis of earth dam slopes subjected to reservoir drawdown

The drawdown of reservoirs can significantly affect the stability of upstream slopes of earth dams. This is due to the removal of the balancing hydraulic forces acting on the dams and the undrained condition within the upstream slope soils. In such scenarios, the stability of the slopes can be influenced by a range of factors including drawdown rates, slope inclination and soil properties. This paper investigates the effects of drawdown rate, saturated hydraulic conductivity and unsaturated shear strength of dam materials on the stability of the upstream slope of an earth dam. In this study, the analysis of pore-water pressure changes within the upstream slope during reservoir drawdown was coupled with the slope stability analysis using the general limit equilibrium method. The results of the analysis suggested that a decrease in the reservoir water level caused the stability of the upstream slope to decrease. The dam embankment constructed with highly permeable soil was found to be more stable during drawdown scenarios, compared to others. Further, lower drawdown rates resulted in a higher safety factor for the upstream slope. Also, the safety factor of the slope calculated using saturated shear strength properties of the dam materials was slightly higher than that calculated using unsaturated shear strength properties. In general, for all the scenarios analysed, the lowest safety factor was found to be at the reservoir water level of about 2/3 of drawdown regime.

Ranked critical factors in PPP briefings

Public-private partnerships (PPPs) are increasingly used to procure Australian infrastructure projects. As with all construction projects, the early briefing stages are often the most crucial in determining a successful outcome. There is, however, a lack of systematic research on the type and nature of the critical factors affecting the effectiveness and efficiency of PPP during this period. A literature review is presented of PPP usage in Australia, in which four main categories of factors (procurement, stakeholder, risk, and finance) are identified, each with several subfactors. A questionnaire survey involving state government stakeholders is also described, and a mathematical model that ranks the factors involved is developed. This is followed by an examination of the potential of the factors to help improve the PPP briefing stage for both public and private sectors.

Examination of factors affecting caring efficacy, job satisfaction in Australian registered nurses

Research Question: What relationships exist between general self efficacy, locus of control and the nursing practice environment and caring efficacy and job satisfaction? Background: Important characteristics of current nursing practice include nurses having the ability to develop and continue therapeutic relationships with patients, nurses having autonomy and control over the practice environment and nurses having more involvement in decision making. In addition, employee satisfaction is enhanced when organisations offer access to authority. Despite this, nurses continue to complain of feeling powerless in their ability to make decisions. Sample: The study population and criteria for selection included Registered Nurses in Australia who were at the time members of an Australian professional and industrial organisation. Methods: A cross-sectional survey was undertaken. Data analysis was conducted using descriptive and bivariate statistics, and structural equation modelling. Results: The model fit the data well (χ² = 2.3594, χ²/df = 2.3594 and CFI = 0.9987). Twenty four percent of variation in caring efficacy (CE) can be accounted for by general self-efficacy (GSE); work locus of control (WLC) and practice environment (PE) and 62% of the variation in job satisfaction (JS) can be accounted for by GSE, WLC and PE. All pathways were found to be significant except PE to CE. GSE positively explained CE (β = 0.38). WLC was negatively related to CE i.e., as CE scores increased WLC scores decreased (β = -0.23). Further testing of the model found CE was positively related to GSE (βZ = 0.38, p < 0.001) and negatively related to WLC (βZ = - 0.23, p = 0.001). PE was not significantly associated with CE (βZ = - 0.01, p = 0.85). JS was explained by PE, which was positively related (βZ = 0.69, p = < 0.001); GSE which was negatively related (βZ - 0 .09, p < 0.001) and WLC, which was also negatively related (βZ = - 0.20, p < 0.001). Implications for Practice Nursing and organisational leaders should ensure the development of strategies for professional development and orientation programmes which may enhance nurses’ ability to develop caring relationships and express caring behaviours to their patients and as a result improve organisational and patient outcomes. Nursing shortages and turnover rates are associated with job satisfaction and the nursing practice environment. Improving the nursing environment can produce benefits to the health system such as better job satisfaction, improved workforce retention and better patient outcomes.

Classification of railway bridges based on criticality and vulnerability factors

Bridges are currently rated individually for maintenance and repair action according to the structural conditions of their elements. Dealing with thousands of bridges and the many factors that cause deterioration, makes this rating process extremely complicated. The current simplified but practical methods are not accurate enough. On the other hand, the sophisticated, more accurate methods are only used for a single or particular bridge type. It is therefore necessary to develop a practical and accurate rating system for a network of bridges. The first most important step in achieving this aim is to classify bridges based on the differences in nature and the unique characteristics of the critical factors and the relationship between them, for a network of bridges. Critical factors and vulnerable elements will be identified and placed in different categories. This classification method will be used to develop a new practical rating method for a network of railway bridges based on criticality and vulnerability analysis. This rating system will be more accurate and economical as well as improve the safety and serviceability of railway bridges.