Trends in children`s physical activity and weight status in high and low socio-economic status areas of Melbourne, Victoria, 1985-2001

Objective:
To examine trends in active transport to and from school, in school sport and physical education (PE), and in weight status among children from high and low socio-economic status (SES) areas in Melbourne, Victoria, between 1985 and 2001.

Methods:
Cross-sectional survey data and measured height and weight from 1985 (n=557) and 2001 (n=926) were compared for children aged between 9–13 years within high and low SES areas.

Results:
From 1985 to 2001, the frequency of walking to or from school declined (4.38±4.3 vs. 3.61 ± 3.8 trips/wk, p<0.001), cycling to or from school also declined (1.22±2.9 vs. 0.36±1.5 trips/wk, p<0.001), and the frequency of PE lessons declined (1.64±1.1 vs. 1.18±0.9 lessons/wk, p<0.001). However, the frequency of school sport increased (0.9±1.22 vs. 1.24±0.8 sessions/wk, p<0.001). In 1985, 11.7% of children were overweight or obese compared with 28.7% in 2001 (p<0.001). Apart from walking to school and school sport, there were greater relative declines in cycling to school and PE, and increases in overweight and obesity among children attending schools in low SES areas compared with those attending schools in high SES areas.

Conclusions:
Declines in active school transport and PE have occurred at the same time as increases in overweight and obesity among Australian children.

Implications:
Promoting active school transport and maintaining school sport and PE should be important public health priorities in Australia. Current inequities in school sport and PE and in prevalence of overweight and obesity by area-level SES also need to be addressed.

Development, reliability and validity of an instrument measuring the attitudes and knowledge of emergency department staff regarding the emergency nurse practitioner role

Introduction: The Emergency Department (ED) at The Northern Hospital is currently participating in the Victorian Department of Human Services funded Emergency Nurse Practitioner Project. This project aims to develop, implement and evaluate the Emergency Nurse Practitioner role in Victorian EDs. This led to a need to develop a specific data collection tool called The Northern Emergency Nurse Practitioner Staff Survey to examine the knowledge and attitudes of ED medical and nursing staff. This paper describes the development of The Northern Emergency Nurse Practitioner Staff Survey and presents the results of reliability and validity studies. Method: Twenty-five items were developed and piloted on a sample of 58 ED medical and nursing staff. Content and face validity were established by expert panel review. Reliability was established by tests of unidimensionality, exploratory factor analysis and internal consistency. Results: Four items were discarded because of low item to total correlation. Exploratory factor analysis of the remaining items revealed five factors with eigenvalues >1 and acceptable correlation coefficients that explained 76.7% of the variance. Cronbach’s coefficent α for these items was 0.926 indicating a high degree of internal consistency. The factors were titled to reflect the content domain of the items in each factor and the factors arranged in a logical sequence to form the final version of The Northern Emergency Nurse Practitioner Survey.

Dietary counseling to increase natural folate intake: a ransomized placebo-controlled trial in free-living subjects to assess effects on serum folate and plasma total homocysteine.

BACKGROUND: The association between vascular disease and elevated plasma total homocysteine (tHcy) concentrations is caused, in part, by inadequate intakes of dietary folate. Increasing folate intake either through supplements or foods naturally rich in folates has been shown to decrease tHcy concentrations. OBJECTIVE: The aim of this study was to determine whether a similar reduction in tHcy was possible in free-living persons receiving dietary counseling. DESIGN: The study included a 4-wk placebo-controlled dietary intervention trial in which participants consumed either unfortified breakfast cereal (control group) or an extra 350 micro g folate derived from food/d (dietary group). Serum folate and tHcy concentrations in both groups were measured before and after the intervention period, and the concentrations in the dietary group were also measured 17 wk after the intervention period. RESULTS: During the 4-wk intervention, mean dietary folate intake in the dietary group increased from 263 (95% CI: 225, 307) to 618 micro g/d (535, 714), resulting in a mean increase in serum folate of 37% (15%, 63%) and a decrease in tHcy from 12.0 (10.9, 13.3) to 11.3 micro mol/L (10.2, 12.5). A further decrease in tHcy occurred in the dietary group during follow-up, with a final tHcy concentration of 9.7 micro mol/L (8.8, 10.8). CONCLUSIONS: Increasing natural folate intake improved folate status and decreased tHcy concentrations to an extent that may significantly reduce the risk of vascular disease. Dietary modification may have advantages over folic acid fortification because the altered food-consumption patterns lead to increased intakes of several vitamins and minerals and decreased intakes of saturated fatty acids.

Nucleation and growth during reactions in accumulative roll bonding of Ti/Al multilayers

A two-stage process in the formation of TiAl₃ was found in the accumulative roll bonding (ARB) Ti/Al multilayers. The distribution of layer spacing did not become broad enough to lose the main features of the double exothermal behaviour. A modified model based on thin films was set up to describe the kinetic characteristics of the formation of TiAl₃ in ARB samples.

In vitro cytotoxicity of binary TI alloys for bone implants

Interest in using titanium (Ti) alloys as load-bearing implant materials has increased due to their high strength to weight ratio, lower elastic modulus, and superior biocompatibility and enhanced corrosion resistance compared to conventional metals such as stainless steel and Co-Cr alloys. In the present study, the in vitro cytotoxicity of five binary titanium alloys, Ti15Ta, Ti15Nb, Ti15Zr, Ti15Sn and Ti15Mo, was assessed using human osteosarcoma cell line, SaOS-2 cells. The Cell proliferation and viability were determined, and cell adhesion and morphology on the surfaces of the binary Ti alloys after cell culture were observed by SEM. Results indicated that the Ti binary alloys of Ti15Ta, Ti15Nb and Ti15Zr exhibited the same level of excellent biocompatibility; Ti15Sn alloy exhibited a moderate biocompatibility while Ti15Mo alloy exhibited a moderate cytotoxicity. The SaOS-2 osteoblast-like cells had flattened and spread across the surfaces of the Ti15Ta, Ti15Nb, Ti15Zr and Ti15Sn groups; however, the cell shapes on the Ti15Mo alloy was shrinking and unhealthy. These results indicated that the Mo contents should be limited to a certain level in the design and development of new Ti alloys for implant material applications.

Effect of structure relaxation on the plastic deformation behaviour in a Zr-based BMG under indenter

Vickers and nano indentations were performed on a structurally relaxed Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5 bulk metallic glass (BMG), and the evolution of the shear bands in the relaxed BMG was investigated and compared to that in the as-cast alloy. Results indicate that the plastic deformation in the BMG with structure relaxation is accommodated by the semicircular (primary) and radial (secondary) as well as tertiary shear bands. Quantitatively, the shear band density in the relaxed alloy was much lower than that in the as-cast alloy. The annihilation of free volume caused by the annealing was responsible for the embrittlement of the sample with structure relaxation.

Bioactive hydroxyapatite coating on titanium-niobium alloy through a sol-gel process

Hydroxyapatite (HA) was coated on the surface of a titanium-niobium (Ti-Nb) alloy by a sol-gel process. Triethyl phosphite and calcium nitrate were used as the phosphorus (P) and calcium (Ca) precursors respectively to prepare a Ca/P sol solution. The Ti-Nb alloy was dip-coated in the sol and heated at 600°C for 30 minutes. X-ray diffraction (XRD) analysis indicated the major phase constituent of the coating after heat treatment was HA. Scanning electron microscopy (SEM) observation showed that a few cracks were distributed on the HA coating. The in-vitro bioactivity of the HA coated Ti-Nb alloy was assessed using a cell culture of SaOS-2 osteoblast-like cells. The density of cell attachment was determined by MTT assay; the cell morphology was observed by SEM. Results indicated that the density of cell attachment on the surface of the Ti-Nb alloy was significantly increased by HA coating. Cell morphology observation showed that cells attached, spread and grew well on the HA coated surface. It can be concluded that the HA coating improved the in-vitro bioactivity of Ti-Nb alloy effectively.

Biomimetic coating on pure titanium submitted to different surface treatments

Titanium (Ti) plates were firstly treated to form various types of oxide layers on the surface and then immersed into simulated body fluid (SBF) to evaluate the apatite forming ability. The surface morphology and roughness of the different oxide layers were measured by atomic force microscopy (AFM), and the surface energies were determined based on the Owens-Wendt (OW) methods. It was found that Ti samples after Alkali-Heat treatment (AH) achieved the best apatite formation after soaking in SBF for 3 weeks, compared to those without treatment, thermal or H₂O₂ oxidation. Furthermore, contact angle measurement revealed that the oxide layer on the alkali-heat treated Ti samples possessed the highest surface energy. The results indicate that the apatite inducing ability of a titanium oxide layer is linked to its surface energy. Apatite nucleation is easier on a surface with a higher surface energy.

The Challenge of inhomogeneous deformation in magnesium and its alloys

It is shown that wrought magnesium alloys display a number of significant types of deformation inhomogeneities. These are influenced by the variation in the ease of basal slip amongst grains, micro-textures, shear banding, twinning and grain boundary sliding. Key features of each of these effects are examined and their engineering consequences and challenges are identified.

Effect of grain size on the performance of extruded magnesium alloy tubes in three-point bending

The performance of extruded AZ31, AZ61 and AM-EX1 tubes was examined in three-point bending. Different extrusion temperatures were used to investigate the effect of grain size on the load-carrying capacity, energy absorption and fracture propensity of the tubes. Results showed that while the peak load increased with a smaller average recrystallised grain size, the retention of large elongated un-recrystallised grains in the microstructure reduced the load. The presence of the large elongated grains also appeared detrimental to the ability of the tube to deform before fracture.

Towards a more holistic approach to quality improvements in aluminium die casting

This work evaluates the feasibility of using a holistic approach, based on dynamical system theory,
to reduce porosity defects in high pressure aluminum die casting. Quality improvements, from a
dynamical system perspective mean the ability to move the die casting process out of its natural
equilibrium to a more beneficial state and the ability to maintain this new process state. This more beneficial state may be achieved in several ways. One way is to increase the amount of forcing to overcome natural process resistance. This forcing approach is represented by typical continuous intervention policy, with modifications in die/part design and/or process parameters. An alternative approach is to reduce the amount of natural process resistance, in particular the amount of process disturbance, allowing the process to move out of its natural equilibrium with much less forcing. This alternative uses the self-regulating ability of dynamical systems thus decreasing the amount of human intervention required. In this respect, the influence of vacuum on time on chattering at the first stage of the casting shot was identified as a good process candidate for testing using dynamical system theory. A significant reduction in porosity defects was achieved, which also set the process on a path of slow but consistent self-improvement.

Simultaneously enhanced strength and ductility of titanium via multimodal grain structure

Commercial Ti with a multimodal grain structure was successfully produced using cryorolling, followed by low-temperature annealing. This multimodal grain structure Ti exhibited a combination of high yield strength (926 MPa), a uniform elongation of 11% and a failure elongation of 23%. The strength enhancement was mainly derived from the ultrafine equiaxed grains, while the improved ductility originated from the large fraction of high-angle grain boundaries and the multimodal grain structure.

Difficult times, difficult students? Teaching students with learning difficulties to be teachers

The last decade of Australian higher education has witnessed significant expansion in the provision of student places, relative to the Australian population, with student enrolment figures for undergraduate award courses in 1993 totalling 453,926, compared with 287,713 in 1983. Such expansion has raised considerable speculation amongst academics about the quality of students now entering university and their ability to successfully negotiate academic learning environments, particularly since the mid 1990s when unmet demand for higher education began to diminish; the assumption often being that lower entry scores are indicative of future academic problems. This is a significant issue for Australian regional universities, which historically have struggled to attract students with high entry scores and which are likely to experience even greater competition from metropolitan universities given the prospect of 'vouchers', a possibility (re)floated by the West Review, which will enable students to be more selective in their university of choice. Moreover, these 'problems' seem compounded for teacher educators who are required to deliver greater numbers of graduates to satisfy a current shortage of teachers in many Australian States and also to 'soak up' government funded places within their institutions that other faculties have been unable to fill, while drawing from a diminishing pool of high entry-scoring applicants. Within this context, this paper addresses the possibility for teacher educators of facing classes with increasing numbers of students with learning difficulties and learning disabilities, estimated in the early 1980s by Sykes (1982) to be about 5% of university students. In raising these issues, the paper makes two broad contributions. First, it engages with the discussion within the literature concerning competing definitions of university students' learning difficulties and learning disabilities, suggesting that the debate is unhelpful and that the differences are not that important when consideration is given to how they are experienced by students. Secondly, and flowing logically from this, the paper argues that rather than simply defining learning difficulty as intrinsic to students, academic learning environments, and those who construct them, are also implicated in the determination of how difficult (or otherwise) they are for students to access.

Pandemic (H1N1) 2009 influenza in Australia : absenteeism and redeployment of emergency medicine and nursing staff

Objective: The aim of the present study was to examine the impact of Pandemic (H1N1) 2009 Influenza on the Australian emergency nursing and medicine workforce, specifically absenteeism and deployment.

Methods: Data were collected using an online survey of 618 members of the three professional emergency medicine or emergency nursing colleges.

Results: Despite significant increases in emergency demand during the Pandemic (H1N1) 2009 Influenza, 56.6% of emergency nursing and medicine staff reported absenteeism of at least 1 day and only 8.5% of staff were redeployed. Staff illness with influenza-like illness was reported by 37% of respondents, and 87% of respondents who became ill were not tested for the Pandemic (H1N1) 2009 Influenza. Of the respondents who became ill, 43% (n = 79) reported missing no days of work and only 8% of respondents (n = 14) reported being absent for more than 5 days. The mean number of days away from work was 3.73 (standard deviation = 3.63). Factors anecdotally associated with staff absenteeism (caregiver responsibilities, concern about personal illness, concern about exposing family members to illness, school closures, risk of quarantine, stress and increased workload) appeared to be of little or no relevance. Redeployment was reported by 8% of respondents and the majority of redeployment was for operational reasons.

Conclusion: Future research related to absenteeism, redeployment during actual pandemic events is urgently needed. Workforce data collection should be an integral part of organizational pandemic planning.