Mycobacterium ulcerans infection : factors influencing diagnostic delay

Objective: To document the epidemiology, clinical characteristics and diagnosis of an outbreak of Mycobacterium ulcerans infection (Bairnsdale or Buruli ulcer [BU]) during the period 1998–2006, and compare delays in diagnosis between residents of endemic and non-endemic regions.

Design and setting: Retrospective case study of patients identified through infectious disease physicians on the Bellarine Peninsula and the Victorian Department of Human Services notifiable diseases database.

Main outcome measures: Description of events leading to diagnosis of BU.

Results: Eighty-five BU patients recalled their experience. Fifty-three patients were older than 60 years, and 61 permanently resided on the Bellarine Peninsula. The onset of symptoms occurred most frequently in mid winter. Twenty-eight patients had lesions on the arm and 51 on the leg. The median time between onset of symptoms and first medical contact was shorter for those living in the endemic area (3.0 weeks; interquartile range [IQR], 1.0–5.0 weeks) compared with non-endemic areas (5.3 weeks; IQR, 2.0–9.5 weeks) (P = 0.05). Patients who resided in the endemic area had a shorter median time from their first medical appointment to diagnosis (1.0 week; IQR, 0.0–3.9 weeks) than those who resided in non-endemic areas (5.0 weeks; IQR, 1.3–8.0 weeks) (P = 0.001).

Conclusion: Delay in presentation and time to diagnosis of BU are longer in non-endemic than endemic areas. Measures should be taken to raise awareness of the disease in non-endemic areas.

Robust-diagnostic regression : a prelude for inducing reliable knowledge from regression

Regression lies heart in statistics, it is the one of the most important branch of multivariate techniques available for extracting knowledge in almost every field of study and research. Nowadays, it has drawn a huge interest to perform the tasks with different fields like machine learning, pattern recognition and data mining. Investigating outlier (exceptional) is a century long problem to the data analyst and researchers. Blind application of data could have dangerous consequences and leading to discovery of meaningless patterns and carrying to the imperfect knowledge. As a result of digital revolution and the growth of the Internet and Intranet data continues to be accumulated at an exponential rate and thereby importance of detecting outliers and study their costs and benefits as a tool for reliable knowledge discovery claims perfect attention. Investigating outliers in regression has been paid great value for the last few decades within two frames of thoughts in the name of robust regression and regression diagnostics. Robust regression first wants to fit a regression to the majority of the data and then to discover outliers as those points that possess large residuals from the robust output whereas in regression diagnostics one first finds the outliers, delete/correct them and then fit the regular data by classical (usual) methods. At the beginning there seems to be much confusion but now the researchers reach to the consensus, robustness and diagnostics are two complementary approaches to the analysis of data and any one is not good enough. In this chapter, we discuss both of them under the unique spectrum of regression diagnostics. Chapter expresses the necessity and views of regression diagnostics as well as presents several contemporary methods through numerical examples in linear regression within each aforesaid category together with current challenges and possible future research directions. Our aim is to make the chapter self-explained maintaining its general accessibility.

Attributes of champion female tennis players and challenges faced by aspirants

As part of a larger study on talent development in tennis1, 10 Australian top ranked Australian female professional tennis players responded to a questionnaire about the attributes of a champion recalling the major challenges faced in pursuing a tennis career and strategies adopted to address these challenges. To analyse the data, a series of three inductive content analyses were conducted. The results highlighted the importance of psychological attributes and skills in a player’s journey to become a champion. The study’s implications for coaches and sport psychologists are also highlighted.

Variation in the whiteness and brightness of white Australian cashmere associated with farm of origin and fibre attributes

While white cashmere is preferred by processors, its whiteness and brightness is affected by country of origin, amino acid composition, nutrition and cashmere production of goats. This work aimed to quantify the factors which affect the whiteness and brightness of 36 batches of processed Australian white cashmere sourced from nine different farms. The cashmere was tested for tristimulus values brightness (Y) and whiteness, as measured by yellowness (Y-Z). Linear models, relating Y and Y-Z were fitted to farm of origin and other objective measurements. Mean attributes (range) were: mean fibre diameter, 16.9 µm (13.9–20.4 μm); fibre curvature, 45°/mm (31–59°/mm); clean washing yield, 91.3% (79.5–97.3%); Y, 78.7 (74.7–82.2); Y-Z, 11.9 (10.3–13.6). Farm alone accounted for 72% of the variation in Y and 65% of the variation in Y-Z (P < 0.001). Once farm had been taken into account only fibre curvature (P = 0.003) was significant in predicting Y and only clean washing yield (P = 0.047) affected Y-Z. Neither the proportion of the fleece present as guard hair (clean cashmere yield) nor cashmere staple length was a significant determinant of Y or Y-Z. For each 10°/mm increase in fibre curvature Y increased 1.3 units. For each 10% increase in clean washing yield Y-Z declined 0.9 units. Variations in Y and Y-Z among farms were probably related to differences in geographic and climatic conditions and were significantly correlated to cashmere production. The effect of clean washing yield was probably related to a reduction in suint content.

Internal audit attributes and external audit's reliance on internal audit : implications for audit fees

This study aims to examine two aspects of internal audit quality, namely internal audit competency and internal audit contribution to financial statement audits. Consistent with the substitution view, this study predicts a negative relationship between the competency aspects of internal audit (the tenure of the existence of internal audit in the organization, internal audit staff expertise in IT and computer skills, training hours, internal audit staff professional certifications in accounting and auditing, and internal audit staff experience in auditing) and audit fees. Second, this study tests whether the contribution of internal auditors to financial statement audit reduces audit fees. The data analysis is based on a cross-sectional regression model with observations of 73 public-listed firms in Malaysia, which include publicly available data matched with survey responses from their internal and external auditors. The results of the study suggest that the competency of internal audit, namely the tenure of the existence of internal audit in the organization, training, internal audit staff prior experience in auditing and accounting, and certifications are associated with lower audit fees. Our findings for both aspects of internal audit quality (competency and internal audit contribution) lend support to the substitution view for explaining the links between internal audit quality and audit fees.

Little evidence that condition, stress indicators, sex ratio, or homozygosity are related to landscape or habitat attributes in declining woodland birds

Habitat loss, fragmentation and degradation are drivers of major declines in biodiversity and species extinctions. The actual causes of species population declines following habitat change are more difficult to discern and there is typically high covariation among the measures used to infer the causes of decline. The causes of decline may act directly on individual fitness and survival, or through disruption of population processes. We examined the relationships among configuration, extent and status of native vegetation and three commonly used indicators of individual body condition and chronic stress (haemoglobin level, haematocrit, residual body mass condition index) in 13 species of woodland-dependent birds in south-eastern Australia. We also examined two measures of changes to population processes (sex ratio and individual homozygosity) in ten species and alleic richness in five species. We found little support for relationships between site or landscape characteristics and individual or population response variables, notwithstanding that our simulations showed we had sufficient power to detect relatively small effects. We discuss possible causes of the absence of detectable habitat effects in this system and the implications for the usefulness of individual body condition and easily measured haematological indices as indicators of the response of avian populations to habitat change. © 2012 The Authors.

Identifying attributes contributing to environmental sustainability of public-private partnership infrastructure projects

Due to increasing demands for new infrastructure and an aim to reduce initial public investment, Australian government agencies are increasingly using public-private partnerships (PPPs) as a form of delivery for infrastructure projects. Environmentally, there is growing pressure for the building industry in general to become more sustainable. Moreover, as the built environment continues to grow each year, the performance of buildings as a whole will need to continually improve purely for national energy consumption to remain stable. Based on a systematic and extensive review on relevant literature, this paper has identified the key attributes that will influence the environmental sustainability of infrastructure completed through a PPP. The key attributes are grouped into five groups defined by whom or what has the majority of control over the attribute. Meanwhile, the key attributes are explored and their influence on environmental sustainability justified. This paper was able to not only identify significant factors involved in creating environmental sustainability in infrastructure PPPs, but also trends of the key attributes. It has been found that (1) the longevity of the contract in a PPP project allows greater innovation into environmental sustainability than traditional methods of procurement, (2) innovation is a requirement for the improving upon environmental performance in the built environment, (3) improvements to environmental sustainability relies upon a positive relationship between economic and environmental benefits, and (4) the key attributes for PPP projects are decided upon relatively early in the contract. Due to space limit, detailed discussion on each of the identified attributes is not provided in this paper. Nonetheless, further research direction is discussed.

Variation in the whiteness and brightness of mohair associated with farm, season, and mohair attributes

This work aimed to quantify factors affecting the reflectance attributes of Australian white mohair sourced from five different farms and to evaluate the effect of season and year on mohair grown by goats of known genetic origin in a replicated study. For the season study the mohair was harvested every three months for two years. All goats and their fleeces were weighed. Mid-side samples were tested for fibre diameter attributes, clean washing yield (CWY), staple length (SL) and for tristimulus values X, Y, Z and Y-Z. For the farm study (n = 196), linear models, relating Y, Z and Y-Z were fitted to farm of origin and other objective measurements. For the season and year study (n = 176), data were analysed by ANOVA and then by linear analysis. The variation accounted for by farm alone was: X, 22%; Y, 24%; Z, 12%; Y-Z, 30% (P < 0.001). Once farm had been taken into account, the regression models for X, Y and Z had similar significant terms: mean fibre diameter (MFD), CWY, SL and fibre diameter CV; and correlation coefficients (057–0.65). For Y-Z, in addition to farm only MFD was significant (P = 1.8 × 10−9). While X, Y, Z and Y-Z were significantly associated with clean fleece weight (CFwt), CFwt was not significant in any final model. Season affected mohair Y (P = 2.5 × 10−24), Z (P = 2.3 × 10−20) and Y-Z (P = 6.8 × 10−22). Autumn grown mohair had higher Y and Z, and summer grown mohair had lower Z than mohair grown in other seasons. This resulted in summer grown mohair having the highest Y-Z and winter grown mohair having the lowest Y-Z than mohair grown in other seasons. The differences between years in Y, Z and Y-Z were significant but not large. When Y, Z and Y-Z were modeled with season and other mohair attributes, MFD, CWY, CFwt, incidence of medullated fibre (Med) and sire were also significant terms. This model accounted for 62.1% of the variance. Over the range of Med (0.3–4.2%), Y-Z increased by 11 T units. Increasing CFwt 0.5 kg was associated with a decline in Y-Z of 7.5 T units. The variation in Y, Z and Y-Z associated with sire effects were respectively 2.66, 3.77, and 1.04 T units. In the farm and the season studies increasing MFD was associated with lower Y and Z and higher Y-Z. The extent of the differences in tristimulus values between seasons and years, were unlikely to be of commercial importance. The extent of the differences between farms, and to variations in MFD and Med were large enough to be of commercial importance. Clean mohair colour was artefactually biased by MFD.