Reversed bias Pt/nanostructured ZnO Schottky diode with enhanced electric field for hydrogen sensing

In this paper, the effect of electric field enhancement on Pt/nanostructured ZnO Schottky diode based hydrogen sensors under reverse bias condition has been investigated. Current-voltage characteristics of these diodes have been studied at temperatures from 25 to 620 °C and their free carrier density concentration was estimated by exposing the sensors to hydrogen gas. The experimental results show a significantly lower breakdown voltage in reversed bias current-voltage characteristics than the conventional Schottky diodes and also greater lateral voltage shift in reverse bias operation than the forward bias. This can be ascribed to the increased localized electric fields emanating from the sharp edges and corners of the nanostructured morphologies. At 620 °C, voltage shifts of 114 and 325 mV for 0.06% and 1% hydrogen have been recorded from dynamic response under the reverse bias condition. © 2010 Elsevier B.V. All rights reserved.

Induction of anti-chlamydial mucosal immunity by transcutaneous immunization is enhanced by topical application of GM-CSF

Transcutaneous immunization (TCI) involves the direct application of antigen plus adjuvant to skin, taking advantage of the large numbers of Langerhans cells and other resident skin dendritic cells, that process antigen then migrate to draining lymph nodes where immune responses are initiated. We have used this form of immunization to protect mice against genital tract and respiratory tract chlamydial infection. Protection was associated with local antibody responses in the vagina, uterus and lung as well as strong Th1 responses in the lymph nodes draining the reproductive tract and lungs respectively. In this study we show that topical application of GM-CSF to skin enhances the numbers and activation status of epidermal dendritic cells. Topical application of GM-CSF also increased the immune responses elicited by TCI. GM-CSF supplementation greatly increased cytokine (IFNgamma and IL-4) gene expression in lymph node and splenic cells compared to cells from animals immunized without GM-CSF. IgG responses in serum, uterine lavage and bronchoalveolar lavage and IgA responses in vaginal lavage were also increased by topical application of GM-CSF. The studies show that TCI induces protection against genital and respiratory tract chlamydial infections and that topical application of cytokines such as GM-CSF can enhance TCI-induced antibody and cell-mediated immunity.

A case study of how primary school teachers in Papua New Guinea understand outcomes-based education

This case study explored how a group of primary school teachers in Papua New Guinea (PNG) understood Outcomes-based Education (OBE). OBE measures students. learning against specific outcomes. These outcomes are derived from a country.s vision of the kind of citizen that the education system should produce. While countries such as Australia, South Africa, New Zealand and the United States have abandoned OBE, others such as PNG have adopted it in various ways. How teachers understand OBE in PNG is important because such understandings are likely to influence how they implement the OBE curriculum. There has been no research to date which has investigated PNG primary school teachers. understandings and experiences with OBE. This study used a single exploratory case study design to investigate how twenty primary school teachers from the National Capital District (NCD) in PNG understood OBE. The study, underpinned by an intepretivist paradigm, explored the research question: How do primary school teachers understand outcomes-based education in PNG? The data comprised surveys, in-depth interviews and documents. Data were analysed thematically and using explanation building techniques. The findings revealed that OBE is viewed by teachers as a way to equip them with additional strategies for planning and programming, teaching and learning, and assessment. Teachers also described how OBE enabled both students and teachers to become more engaged and develop positive attitudes towards teaching and learning. There was also a perception that OBE enhanced students. future life skills through increased local community support. While some teachers commented on how the OBE reforms provided them with increased professional development opportunities, the greatest impediment to implementing OBE was perceived to be a lack of sufficient teaching and learning resources. The process of planning and programming classroom activities was also regarded as onerous. Some teachers indicated that they had been required to implement OBE without adequate in-service training support. The social constructivist theory of knowledge which underpins OBE.s student-centred pedagogy can cause tensions within PNG.s cultural contexts of teaching and learning. Teachers need to be aware of these tensions when conducting peer or group learning under OBE in PNG. By exploring how these PNG primary teachers understood OBE, the study highlighted how teachers engaged with OBE concepts when interpreting syllabus documents and how they applied these concepts to curriculum. Identifying differences in teacher understanding of OBE provides guidance for both the design of materials to support the implementation of OBE and for the design of in-service training. Thus, the outcomes of this study will inform educators about the implementation of OBE in PNG. In addition, the outcomes will provide much needed insight into how a mandated curriculum and pedagogical reform impacts teachers‟ practices in PNG.

Towards learner autonomy : an assessment for learning approach

Using Assessment for Learning (AfL) may develop learner autonomy however, very often AfL is reduced to a set of strategies that do not always achieve the desired outcome. This research adopted a different approach that examined AfL as a cultural practice, situated within influential social relationships that shape learner identity. The study addressed the question “What are the qualities of the teacher-student relationship that support student learning autonomy in an AfL context?” Three case studies of the interactions of Queensland middle school teachers and their classes of Year 7, 8 and 9 were developed over one year. Data were collected from field notes and video recordings of classroom interactions and individual and focus group interviews with teachers and students. The analysis began with a close look at the field data. Interpretations that emerged from a sociocultural theoretical understanding were helpful in informing the process of analysis. Themes and patterns of interrelationships were identified through thematic coding using a constant comparative approach. Validation was achieved through methodological triangulation. Four findings that inform an understanding of AfL and the development of learner autonomy emerged. Firstly, autonomy is theorised as a context-specific identity mediated through the teacher-student relationship. Secondly, it was observed that learners negotiated their identities as knowers through AfL practices in various tacit, explicit, group and individual ways in a ‘generative dance’ of knowing in action (Cook & Brown, 2005). Thirdly, teachers and learners negotiated their participation by drawing from identities in multiple communities of practice. Finally it is proposed that a new participative identity or narrative for assessment is needed. This study contributes to understandings about teacher AfL practices that can help build teacher assessment capacity. Importantly, autonomy is understood as an identity that is available to all learners. This study is also significant as it affirms the importance of teacher assessment to support learners in developing autonomy, a focus that challenges the singular assessment policy focus on measuring performance. Finally this study contributes to a sociocultural theoretical understanding of AfL.

Assessment policy change in relation to English language teaching and learning in China : a study of perspectives from two universities

In response to concerns about the quality of English Language Learning (ELL) education at tertiary level, the Chinese Ministry of Education (CMoE) launched the College English Reform Program (CERP) in 2004. By means of a press release (CMoE, 2005) and a guideline document titled College English Curriculum Requirements (CECR) (CMoE, 2007), the CERP proposed two major changes to the College English assessment policy, which were: (1) the shift to optional status for the compulsory external test, the College English Test Band 4 (CET4); and (2) the incorporation of formative assessment into the existing summative assessment framework. This study investigated the interactions between the College English assessment policy change, the theoretical underpinnings, and the assessment practices within two Chinese universities (one Key University and one Non-Key University). It adopted a sociocultural theoretical perspective to examine the implementation process as experienced by local actors of institutional and classroom levels. Systematic data analysis using a constant comparative method (Merriam, 1998) revealed that contextual factors and implementation issues did not lead to significant differences in the two cases. Lack of training in assessment and the sociocultural factors such as the traditional emphasis on the product of learning and hierarchical teacher/students relationship are decisive and responsible for the limited effect of the reform.

Towards the biofortification of banana fruit for enhanced micronutrient content

In Uganda, vitamin A deficiency (VAD) and iron deficiency anaemia (IDA) are major public health problems with between 15-32% of children under 5 years of age showing VAD and 73% being anaemic. This is largely due to the fact that the staple food crop of the country, banana, is low in pro-vitamin A and iron, therefore leading to dietary deficiencies. Although worldwide progress has been made to control VAD and IDA through supplementation, food fortification and diet diversification, their long term sustainability and impact in developing countries such as Uganda is limited. The approach taken by researchers at Queensland University of Technology (QUT), Australia, in collaboration with the National Agricultural Research Organization (NARO), Uganda, to address this problem, is to generate consumer acceptable banana varieties with significantly increased levels of pro-vitamin A and iron in the fruit using genetic engineering techniques. Such an approach requires the use of suitable, well characterised genes and promoters for targeted transgene expression. Recently, a new banana phytoene synthase gene (APsy2a) involved in the synthesis of pro-vitamin A (pVA) carotenoids was isolated from a high â-carotene banana (F’ei cv Asupina). In addition, sequences of banana ferritin, an iron storage protein, have been isolated from Cavendish banana. The aim of the research described in this thesis was to evaluate the function of these genes to assess their suitability for the biofortification of banana fruit. In addition, a range of banana-derived promoters were characterised to determine their suitability for controlling the expression of transgenes in banana fruit. Due to the time constraints involved with generating transgenic banana fruit, rice was used as the model crop to investigate the functionality of the banana-derived APsy2a and ferritin genes. Using Agrobacterium-mediated transformation, rice callus was transformed with APsy2a +/- the bacterial-derived carotene desaturase gene (CrtI) each under the control of the constitutive maize poly-ubiquitin promoter (ZmUbi) or seed-specific rice glutelin1 (Gt1) promoter. The maize phytoene synthase (ZmPsy1) gene was included as a control. On selective media, with the exception of ZmUbi-CrtI-transgenic callus, all antibiotic resistant callus displayed a yellow-orange colour from which the presence of â-carotene was demonstrated using Raman spectroscopy. Although the regeneration of plants from yellow-orange callus was difficult, 16 transgenic plants were obtained and characterised from callus transformed with ZmUbi-APys2a alone. At least 50% of the T1 seeds developed a yellow-orange coloured callus which was found to contain levels of â-carotene ranging from 4.6-fold to 72-fold higher than that in non-transgenic rice callus. Using the seed-specific Gt1 promoter, 38 transgenic rice plants were generated from APsy2a-CrtI-transformed callus while 32 plants were regenerated from ZmPsy1-CrtI-transformed callus. However, when analysed for presence of transgene by PCR, all transgenic plants contained the APsy2a, ZmPsy1 or CrtI transgene, with none of the plants found to be co-transformed. Using Raman spectroscopy, no â-carotene was detected in-situ in representative T1 seeds. To investigate the potential of the banana-derived ferritin gene (BanFer1) to enhance iron content, rice callus was transformed with constitutively expressed BanFer1 using the soybean ferritin gene (SoyFer) as a control. A total of 12 and 11 callus lines independently transformed with BanFer1 and SoyFer, respectively, were multiplied and transgene expression was verified by RT-PCR. Pearl’s Prussian blue staining for in-situ detection of ferric iron showed a stronger blue colour in rice callus transformed with BanFer1 compared to SoyFer. Using flame atomic absorption spectrometry, the highest mean amount of iron quantified in callus transformed with BanFer1 was 30-fold while that obtained using the SoyFer was 14-fold higher than the controls. In addition, ~78% of BanFer1-transgenic callus lines and ~27% of SoyFer-transgenic callus lines had significantly higher iron content than the non-transformed controls. Since the genes used for enhancing micronutrient content need to be expressed in banana fruit, the activity of a range of banana-derived, potentially fruit-active promoters in banana was investigated. Using uidA (GUS) as a reporter gene, the function of the Expansin1 (MaExp1), Expansin1 containing the rice actin intron (MaExp1a), Expansin4 (MaExp4), Extensin (MaExt), ACS (MaACS), ACO (MaACO), Metallothionein (MaMT2a) and phytoene synthase (APsy2a) promoters were transiently analysed in intact banana fruit using two transformation methods, particle bombardment and Agrobacterium-mediated infiltration (agro-infiltration). Although a considerable amount of variation in promoter activity was observed both within and between experiments, similar trends were obtained using both transformation methods. The MaExp1 and MaExp1a directed high levels of GUS expression in banana fruit which were comparable to those observed from the ZmUbi and Banana bunchy top virus-derived BT4 promoters that were included as positive controls. Lower levels of promoter activity were obtained in both methods using the MaACO and MaExt promoters while the MaExp4, MaACS, and APsy2a promoters directed the lowest GUS activity in banana fruit. An attempt was subsequently made to use agro-infiltration to assess the expression of pVA biosynthesis genes in banana fruit by infiltrating fruit with constructs in which the ZmUbi promoter controlled the expression of APsy2a +/- CrtI, and with the maize phytoene synthase gene (ZmPsy1) included as a control. Unfortunately, the large amount of variation and inconsistency observed within and between experiments precluded any meaningful conclusions to be drawn. The final component of this research was to assess the level of promoter activity and specificity in non-target tissue. These analyses were done on leaves obtained from glasshouse-grown banana plants stably transformed with MaExp1, MaACO, APsy2a, BT4 and ZmUbi promoters driving the expression of the GUS gene in addition to leaves from a selection of the same transgenic plants which were growing in a field trial in North Queensland. The results from both histochemical and fluorometric GUS assays showed that the MaExp1 and MaACO promoters directed very low GUS activities in leaves of stably transformed banana plants compared to the constitutive ZmUbi and BT4 promoters. In summary, the results from this research provide evidence that the banana phytoene synthase gene (APsy2a) and the banana ferritin gene (BanFer1) are functional, since the constitutive over-expression of each of these transgenes led to increased levels of pVA carotenoids (for APsy2a) and iron content (for BanFer1) in transgenic rice callus. Further work is now required to determine the functionality of these genes in stably-transformed banana fruit. This research also demonstrated that the MaExp1 and MaACO promoters are fruit-active but have low activity in non-target tissue (leaves), characteristics that make them potentially useful for the biofortification of banana fruit. Ultimately, however, analysis of fruit from field-grown transgenic plants will be required to fully evaluate the suitability of pVA biosynthesis genes and the fruit-active promoters for fruit biofortification.

Assessment of retinal structure and visual function in association with diabetic peripheral neuropathy

Diabetes is an increasingly prevalent disease worldwide. Providing early management of the complications can prevent morbidity and mortality in this population. Peripheral neuropathy, a significant complication of diabetes, is the major cause of foot ulceration and amputation in diabetes. Delay in attending to complication of the disease contributes to significant medical expenses for diabetic patients and the community. Early structural changes to the neural components of the retina have been demonstrated to occur prior to the clinically visible retinal vasculature complication of diabetic retinopathy. Additionally visual functionloss has been shown to exist before the ophthalmoscopic manifestations of vasculature damage. The purpose of this thesis was to evaluate the relationship between diabetic peripheral neuropathy and both retinal structure and visual function. The key question was whether diabetic peripheral neuropathy is the potential underlying factor responsible for retinal anatomical change and visual functional loss in people with diabetes. This study was conducted on a cohort with type 2 diabetes. Retinal nerve fibre layer thickness was assessed by means of Optical Coherence Tomography (OCT). Visual function was assessed using two different methods; Standard Automated Perimetry (SAP) and flicker perimetry were performed within the central 30 degrees of fixation. The level of diabetic peripheral neuropathy (DPN) was assessed using two techniques - Quantitative Sensory Testing and Neuropathy Disability Score (NDS). These techniques are known to be capable of detecting DPN at very early stages. NDS has also been shown as a gold standard for detecting 'risk of foot ulceration'. Findings reported in this thesis showed that RNFL thickness, particularly in the inferior quadrant, has a significant association with severity of DPN when the condition has been assessed using NDS. More specifically it was observed that inferior RNFL thickness has the ability to differentiate individuals who are at higher risk of foot ulceration from those who are at lower risk, indicating that RNFL thickness can predict late-staged DPN. Investigating the association between RNFL and QST did not show any meaningful interaction, which indicates that RNFL thickness for this cohort was not as predictive of neuropathy status as NDS. In both of these studies, control participants did not have different results from the type 2 cohort who did not DPN suggesting that RNFL thickness is not a marker for diagnosing DPN at early stages. The latter finding also indicated that diabetes per se, is unlikely to affect the RNFL thickness. Visual function as measured by SAP and flicker perimetry was found to be associated with severity of peripheral neuropathy as measured by NDS. These findings were also capable of differentiating individuals at higher risk of foot ulceration; however, visual function also proved not to be a maker for early diagnosis of DPN. It was found that neither SAP, nor flicker sensitivity have meaningful associations with DPN when neuropathy status was measured using QST. Importantly diabetic retinopathy did not explain any of the findings in these experiments. The work described here is valuable as no other research to date has investigated the association between diabetic peripheral neuropathy and either retinal structure or visual function.

Bioimpedance in the assessment of unilateral lymphedema of a limb: the optimal frequency

Background: Bioimpedance techniques provide a reliable method of assessing unilateral lymphedema in a clinical setting. Bioimpedance devices are traditionally used to assess body composition at a current frequency of 50 kHz. However, these devices are not transferable to the assessment of lymphedema, as the sensitivity of measuring the impedance of extracellular fluid is frequency dependent. It has previously been shown that the best frequency to detect extracellular fluid is 0 kHz (or DC). However, measurement at this frequency is not possible in practice due to the high skin impedance at DC, and an estimate is usually determined from low frequency measurements. This study investigated the efficacy of various low frequency ranges for the detection of lymphedema. Methods and Results: Limb impedance was measured at 256 frequencies between 3 kHz and 1000 kHz for a sample control population, arm lymphedema population, and leg lymphedema population. Limb impedance was measured using the ImpediMed SFB7 and ImpediMed L-Dex® U400 with equipotential electrode placement on the wrists and ankles. The contralateral limb impedance ratio for arms and legs was used to calculate a lymphedema index (L-Dex) at each measurement frequency. The standard deviation of the limb impedance ratio in a healthy control population has been shown to increase with frequency for both the arm and leg. Box and whisker plots of the spread of the control and lymphedema populations show that there exists good differentiation between the arm and leg L-Dex measured for lymphedema subjects and the arm and leg L-Dex measured for control subjects up to a frequency of about 30 kHz. Conclusions: It can be concluded that impedance measurements above a frequency of 30 kHz decrease sensitivity to extracellular fluid and are not reliable for early detection of lymphedema.

Preparing for Research Assessment: Co-evolution and Gamesmanship

In this paper we adopt a complex systems perspective to examine the perturbations caused by the introduction of the Research Quality Framework (RQF) at a research-intensive Australian university. This case is instructive as it 1) presents a Federal policy initiative that attempted to fundamentally alter the recognition and reward mechanism within a regulated funding environment, 2) analyses the strategies of an institution and its research groups as they sought to not only comply with the implementation of the RQF but to maximise their outcome,and 3) it reveals the ways that some actors used this perturbation to advance their own interests. In short, this case represents an instrumental study into the dynamics of how information systems, organisations, and individuals co-evolve in practice as they seek to navigate a complex problem scenario.

Frock Paper Scissors [annual hard copy fashion magazine editions]

The Frock Paper Scissors magazine (and accompanying web site, www.frockpapersissors.com ) has been the focus of assessment in a Fashion and Style Journalism unit from 2006 to 2011 (current). The research has focused on the ways in which synergies across disciplines can be developed through student engagement on authentic projects (with a public audience). Up to 80 students from the Fashion Design, Journalism, Media Communication, Creative Industries, Business, Creative Writing and Communication Design discipline areas in the Creative Industries Faculty at Queensland University of Technology (QUT) work on the content, production, layout and funding for the Frock Paper Scissors magazine (and web site). Research focusses on how this authentic assessment task has been integrated into the classes; discussing the approaches taken by teaching staff, the challenges faced, and the ways in which student learning outcomes have been improved and their career outcomes enhanced. The final output requires staff to curate a professional hard copy fashion magazine(and website) where 5,000 copies are distributed annually throughout south east Queensland, Sydney, Melbourne, London, New York and Amsterdam.

Assessment of requirements for establishment of a framework to enhance implementation of quality practices in building projects

Quality, in construction projects should be regarded as the fulfillment of expectation of those contributors involved in such projects. Although a significant amount of quality practices have been introduced within the industry, attainment of reasonable levels of quality in construction projects continues to be an ongoing problem. To date, some research into the introduction and improvement of quality practices and stakeholder management has been undertaken, but so far no major studies have been completed that comprehensively examine how greater consideration of stakeholders’ perspectives of quality can be used to contribute to final project quality outcomes. This paper aims to examine the requirements for development of a framework leading to more effective involvement of stakeholders in quality planning and practices thus ultimately contributing to higher quality outcomes for construction projects. Through an extensive literature review it highlights various perceptions of quality, categorizes quality issues with particular focus on benefits and shortcomings and also examines the viewpoints of major stakeholders on project quality. It proposes a set of criteria to be used as a basis for a quality practice improvement framework, which will provide project managers and owners with the required information and strategic direction to achieve their own and their stakeholders’ targets for implementation of quality practices leading to the achievement of improved quality outcomes on future projects.

Integration of CENA practice standards for postgraduate emergency nursing assessment

The use of professional competency standards to assess postgraduate nursing student’s clinical performance has been in place since 2004, at the Queensland University of Technology, School of Nursing & Midwifery (SONAM) when the Graduate Certificate in Emergency Nursing degree commenced. Emergency nursing students were assessed in their workplace, using a Clinical Performance Appraisal Tool or CPAT which was based on the Australian College of Critical Care Nurses (ACCCN) Competency Standards. With the subsequent formation of a separate Emergency Nursing Course advisory group in 2007, there was a review of clinical assessment course component. The release of the 2008 CENA revised Practice Standards for the Emergency Nursing Specialist’s, led to the emergency nursing course advisory committee supporting the integration of the CENA practice standards for assessment of emergency nurses in preference to the less relevant ACCCN competency standards. The SONAM emergency nursing study area team commenced the phasing in and progression of the CENA practice standards across the two Graduate Certificate units, and Graduate Diploma and Master of Nursing (emergency) clinical major options in 2009. As some units undertaken in the degree are available to nurses in other disciplines a separate CPAT was devised for the clinical assessments according to speciality context. The team has had to carefully consider how the professional standards are integrated into the teaching and assessment of the unit and not just applied instead of the ACCCN competency standards. Professional standards for the emergency context has also helped tailor course content and learning outcomes to be relevant across a number of emergency nursing contexts in Australia. The assessment of the CPAT is undertaken at the workplace by QUT appointed clinical lecturers. Clinical lecturers need to apply and have suitable postgraduate qualification to undertake the position. The clinical lecturer support role is well established at QUT. The integration of the new CENA practice standards has necessitated a review of the postgraduate assessment of emergency nurses. A clinical lecturer workshop has been organised to review role, scope and how to utilise the new look CENA based CPAT, clinical assessment format.

Quantification of particle emission characteristics and development of an emission model for use in transport microenvironments affected by traffic emissions

Vehicle emitted particles are of significant concern based on their potential to influence local air quality and human health. Transport microenvironments usually contain higher vehicle emission concentrations compared to other environments, and people spend a substantial amount of time in these microenvironments when commuting. Currently there is limited scientific knowledge on particle concentration, passenger exposure and the distribution of vehicle emissions in transport microenvironments, partially due to the fact that the instrumentation required to conduct such measurements is not available in many research centres. Information on passenger waiting time and location in such microenvironments has also not been investigated, which makes it difficult to evaluate a passenger’s spatial-temporal exposure to vehicle emissions. Furthermore, current emission models are incapable of rapidly predicting emission distribution, given the complexity of variations in emission rates that result from changes in driving conditions, as well as the time spent in driving condition within the transport microenvironment. In order to address these scientific gaps in knowledge, this work conducted, for the first time, a comprehensive statistical analysis of experimental data, along with multi-parameter assessment, exposure evaluation and comparison, and emission model development and application, in relation to traffic interrupted transport microenvironments. The work aimed to quantify and characterise particle emissions and human exposure in the transport microenvironments, with bus stations and a pedestrian crossing identified as suitable research locations representing a typical transport microenvironment. Firstly, two bus stations in Brisbane, Australia, with different designs, were selected to conduct measurements of particle number size distributions, particle number and PM2.5 concentrations during two different seasons. Simultaneous traffic and meteorological parameters were also monitored, aiming to quantify particle characteristics and investigate the impact of bus flow rate, station design and meteorological conditions on particle characteristics at stations. The results showed higher concentrations of PN20-30 at the station situated in an open area (open station), which is likely to be attributed to the lower average daily temperature compared to the station with a canyon structure (canyon station). During precipitation events, it was found that particle number concentration in the size range 25-250 nm decreased greatly, and that the average daily reduction in PM2.5 concentration on rainy days compared to fine days was 44.2 % and 22.6 % at the open and canyon station, respectively. The effect of ambient wind speeds on particle number concentrations was also examined, and no relationship was found between particle number concentration and wind speed for the entire measurement period. In addition, 33 pairs of average half-hourly PN7-3000 concentrations were calculated and identified at the two stations, during the same time of a day, and with the same ambient wind speeds and precipitation conditions. The results of a paired t-test showed that the average half-hourly PN7-3000 concentrations at the two stations were not significantly different at the 5% confidence level (t = 0.06, p = 0.96), which indicates that the different station designs were not a crucial factor for influencing PN7-3000 concentrations. A further assessment of passenger exposure to bus emissions on a platform was evaluated at another bus station in Brisbane, Australia. The sampling was conducted over seven weekdays to investigate spatial-temporal variations in size-fractionated particle number and PM2.5 concentrations, as well as human exposure on the platform. For the whole day, the average PN13-800 concentration was 1.3 x 104 and 1.0 x 104 particle/cm3 at the centre and end of the platform, respectively, of which PN50-100 accounted for the largest proportion to the total count. Furthermore, the contribution of exposure at the bus station to the overall daily exposure was assessed using two assumed scenarios of a school student and an office worker. It was found that, although the daily time fraction (the percentage of time spend at a location in a whole day) at the station was only 0.8 %, the daily exposure fractions (the percentage of exposures at a location accounting for the daily exposure) at the station were 2.7% and 2.8 % for exposure to PN13-800 and 2.7% and 3.5% for exposure to PM2.5 for the school student and the office worker, respectively. A new parameter, “exposure intensity” (the ratio of daily exposure fraction and the daily time fraction) was also defined and calculated at the station, with values of 3.3 and 3.4 for exposure to PN13-880, and 3.3 and 4.2 for exposure to PM2.5, for the school student and the office worker, respectively. In order to quantify the enhanced emissions at critical locations and define the emission distribution in further dispersion models for traffic interrupted transport microenvironments, a composite line source emission (CLSE) model was developed to specifically quantify exposure levels and describe the spatial variability of vehicle emissions in traffic interrupted microenvironments. This model took into account the complexity of vehicle movements in the queue, as well as different emission rates relevant to various driving conditions (cruise, decelerate, idle and accelerate), and it utilised multi-representative segments to capture the accurate emission distribution for real vehicle flow. This model does not only helped to quantify the enhanced emissions at critical locations, but it also helped to define the emission source distribution of the disrupted steady flow for further dispersion modelling. The model then was applied to estimate particle number emissions at a bidirectional bus station used by diesel and compressed natural gas fuelled buses. It was found that the acceleration distance was of critical importance when estimating particle number emission, since the highest emissions occurred in sections where most of the buses were accelerating and no significant increases were observed at locations where they idled. It was also shown that emissions at the front end of the platform were 43 times greater than at the rear of the platform. The CLSE model was also applied at a signalled pedestrian crossing, in order to assess increased particle number emissions from motor vehicles when forced to stop and accelerate from rest. The CLSE model was used to calculate the total emissions produced by a specific number and mix of light petrol cars and diesel passenger buses including 1 car travelling in 1 direction (/1 direction), 14 cars / 1 direction, 1 bus / 1 direction, 28 cars / 2 directions, 24 cars and 2 buses / 2 directions, and 20 cars and 4 buses / 2 directions. It was found that the total emissions produced during stopping on a red signal were significantly higher than when the traffic moved at a steady speed. Overall, total emissions due to the interruption of the traffic increased by a factor of 13, 11, 45, 11, 41, and 43 for the above 6 cases, respectively. In summary, this PhD thesis presents the results of a comprehensive study on particle number and mass concentration, together with particle size distribution, in a bus station transport microenvironment, influenced by bus flow rates, meteorological conditions and station design. Passenger spatial-temporal exposure to bus emitted particles was also assessed according to waiting time and location along the platform, as well as the contribution of exposure at the bus station to overall daily exposure. Due to the complexity of the interrupted traffic flow within the transport microenvironments, a unique CLSE model was also developed, which is capable of quantifying emission levels at critical locations within the transport microenvironment, for the purpose of evaluating passenger exposure and conducting simulations of vehicle emission dispersion. The application of the CLSE model at a pedestrian crossing also proved its applicability and simplicity for use in a real-world transport microenvironment.

Assessment of preterm infants' readiness to commence breastfeeding

Preterm infants commence breastfeeding when health-care professionals deem them to be ready. However, the optimal timing for commencement of breastfeeding is unclear. Currently, there is little guidance for neonatal care providers to decide when to initiate breastfeeding among preterm infants. A mixed-methods study was conducted to develop and test the Preterm Sucking Readiness (PTSR) scale in four phases. The first phase involved a chart audit to explore the use of age as a criterion by investigating when preterm infants meet feeding milestones as well as other factors that may affect an infant’s readiness to engage in nutritive sucking behaviour. The second phase utilised focus groups to explore and define how neonatal care providers decide when to commence breastfeeding. To gain consensus on the criteria mentioned by the focus groups, a Delphi survey was conducted in phase 3, involving neonatal providers across Australia and New Zealand. Phase 4 of the study involved an observational study that was used to test the six-item PTSR. The age at which specific feeding milestones were reached was consistent with what has been previously described in the literature. The chart audit showed that the time taken to the first feeding attempt in the preterm infant population was affected by gestational age at birth, birth weight, and specific interventions. Staff also considered age along with other criteria when deciding when to initiate feeding. Consensus on nine criteria for inclusion into the six-item PTSR was achieved using the Delphi technique. Three items of PTSR showed significant differences between the preterm and fullterm infant groups. Only two items, feeding-readiness behaviour and low pulse oximetry during handling, explained the variance in breastfeeding behaviour. The inter-rater variability ranged between moderate and very good for the PTSR items. The results of this study indicate the importance of assessing behavioural cues as an indication of breastfeeding readiness in the preterm infant population, once an infant is deemed physiologically stable. Age continues to be a factor in some clinicians' decisions to commence breastfeeding. However, age alone cannot be used to decide if an infant is ready to engage in breastfeeding. Further research is needed to confirm these findings.