Life cycle of the eel

Poem

Reproductive health : findings from the Australian Longitudinal Study on Women’s Health. Chapter 3: Use of contraception

Chapter 3: Use of contraception. p15-32 Key findings: This section examines trends in the use of contraception between 1996 and 2006 by women who participated in the surveys for the 1973-1978 cohort of the Australian Longitudinal Study on Women’s Health. 1. The oral contraceptive pill was the most commonly used method of contraception at each survey, but its use decreased over time. 2.Of women who consistently used contraception, 40% used the oral contraceptive pill as their only method of contraception in at least three out of four surveys. 3. The proportion of women using condoms as their only method of contraception remained steady over time (15-18%) but only 3% of all women used condoms only at every survey. 4. The proportion of women using both condoms and the oral contraceptive pill remained steady at 13-14% of all women from Survey 1 to 3, but decreased to 8% of all women at Survey 4. 5. The use of methods other than the oral contraceptive pill and/or condoms increased at Survey 4. 6. The proportion of women using an implant (e.g. Implanon) remained steady between Surveys 3 and 4, with 3% of women using an implant only. Around one third of implant users at Survey 3 continued to use this method at Survey 4. 7. The main reasons for not using contraception at Surveys 3 and 4 were pregnancy, trying to conceive, or no male sexual partners. 8. Women who used contraception were more likely to be in de facto relationships or single, be up to date with Pap tests and have had two or more births. 9. Women who did not use contraception were more likely to be non-drinkers and/or do low levels of exercise, have had one birth and have experienced miscarriage. 10. Contraception changed in expected ways according to reproductive events: women who reported only miscarriages between surveys also stopped using contraception in the same period; most women who did not report reproductive events continued to use the same method of contraception; and women who had a termination tended to switch methods.

The House on stilts

Poem

Poem for my father at Sanssouci

Poem

The Quattrocento as a Waltz

Poem

The Botanist at his Mother's Grave

In this poem about processing human grief, I consciously drew on eco-critical theory – (Wilson 1992, Bate 2000) – and Darwinian literary theory (Carroll 2004) to explore the tension between ideas of the ‘natural’ apprehended through the senses, and poststructuralist ideas of the construction of reality through language.

New insights into magmatism and changing rift styles in the evolution of the Gulf of California

The Gulf of California (GoC) has been an important focus site for understanding the spatial and temporal evolution of rifts, with recent studies concluding: 1) rapid crustal rupturing within 10 Myrs; 2) surprisingly abrupt variations in rifting style and magmatism with apparently wide magma-poor and narrow, magmatic rift segments; and 3) that high sedimentation rates may promote switching from wide to narrow rift modes or thermally blanket the crust to enhance rift magmatism. Critical to these conclusions is the onset of rifting at~12 Ma following the cessation of subduction. New field-based volcanostratigraphic and geochronologic studies along the southeastern GoC margin reveal Early Miocene (~25-18 Ma) bimodal volcanism in wide rifting mode (~400 km width), followed by a mid-Miocene (~18-12 Ma) phase of dominantly intermediate composition magmatism in and around the nascent GoC with lavas/domes often emplaced into actively subsiding basins, but contemporaneous with bimodal volcanism regionally. Flat-lying intraplate basaltic lava fields emplaced ~12-10 Ma along the GoC east coast abut tilted blocks of ~20 Ma ignimbrites onshore, and also occur offshore. The reduction in crustal thickness from ~55 to 20 km along the eastern GoC edge must have been largely achieved by 12 Ma. Extension has demonstrably began earlier than previously thought, downplaying rapid rifting and any thermal effects from <6 Ma sedimentation. New age data from onshore indicate significant structurally controlled corridors of magmatism during 18-12 Ma extension in apparently magma-poor rift segments, and this magmatism temporally coincides with the switch from wide to narrow rifting.

The dead are bored

Poem in international anthology

The Flowers on his bedside speak of eternity

Poem

The hazards

Poem

A class B switch-mode assisted linear amplifier

A switch-mode assisted linear amplifier (SMALA) combining a linear (Class B) and a switch-mode (Class D) amplifier is presented. The usual single hysteretic controlled half-bridge current dumping stage is replaced by two parallel buck converter stages, in a parallel voltage controlled topology. These operate independently: one buck converter sources current to assist the upper Class B output device, and a complementary converter sinks current to assist the lower device. This topology lends itself to a novel control approach of a dead-band at low power levels where neither class D amplifier assists, allowing the class B amplifier to supply the load without interference, ensuring high fidelity. A 20 W implementation demonstrates 85% efficiency, with distortion below 0.08% measured across the full audio bandwidth at 15 W. The class D amplifier begins assisting at 2 W, and below this value, the distortion was below 0.03%. Complete circuitry is given, showing the simplicity of the additional class D amplifier and its corresponding control circuitry.

Hysteretic multilevel NPC converter control for a Switch Mode Assisted Linear Amplifier

A Switch-Mode Assisted Linear Amplifier (SMALA) combines the high quality of a linear amplifier required for audio applications with the high efficiency of a switch-mode amplifier. The careful choice of current sense point and switch placement allows a simple non-isolated hysteresis current controller for the switch-mode section. This paper explains the extension of the hysteresis current controller for the control of a three level Neutral Point Clamped (NPC) converter, with simulations as proof of concept. The NPC topology allows the use of lower voltage switches and lower switching frequencies to implement high power audio amplifiers using the SMALA topology.

A method of switch selection for an electric vehicle drive

The key to reducing cost of electric vehicles is integration. All too often systems such as the motor, motor controller, batteries and vehicle chassis/body are considered as separate problems. The truth is that a lot of trade-offs can be made between these systems, causing an overall improvement in many areas including total cost. Motor controller and battery cost have a relatively simple relationship; the less energy lost in the motor controller the less energy that has to be carried in the batteries, hence the lower the battery cost. A motor controller’s cost is primarily influenced by the cost of the switches. This paper will therefore present a method of assessing the optimal switch selection on the premise that the optimal switch is the one that produces the lowest system cost, where system cost is the cost of batteries + switches.

A cross-discipline and collaborative approach to identifying the predictors of environmentally friendly and health protective behaviour

Background. As a society, our interaction with the environment is having a negative impact on human health. For example, an increase in car use for short trips, over walking or cycling, has contributed to an increase in obesity, diabetes and poor heart health and also contributes to pollution, which is associated with asthma and other respiratory diseases. In order to change the nature of that interaction, to be more positive and healthy, it is recommended that individuals adopt a range of environmentally friendly behaviours (such as walking for transport and reducing the use of plastics). Effective interventions aimed at increasing such behaviours will need to be evidence based and there is a need for the rapid communication of information from the point of research, into policy and practice. Further, a number of health disciplines, including psychology and public health, share a common mission to promote health and well-being. Therefore, the objective of this project is to take a cross-discipline and collaborative approach to reveal psychological mechanisms driving environmentally friendly behaviour. This objective is further divided into three broad aims, the first of which is to take a cross-discipline and collaborative approach to research. The second aim is to explore and identify the salient beliefs which most strongly predict environmentally friendly behaviour. The third aim is to build an augmented model to explain environmentally friendly behaviour. The thesis builds on the understanding that an interdisciplinary collaborative approach will facilitate the rapid transfer of knowledge to inform behaviour change interventions. Methods. The application of this approach involved two surveys which explored the psycho-social predictors of environmentally friendly behaviour. Following a qualitative pilot study, and in collaboration with an expert panel comprising academics, industry professionals and government representatives, a self-administered, Theory of Planned Behaviour (TPB) based, mail survey was distributed to a random sample of 3000 residents of Brisbane and Moreton Bay Region (Queensland, Australia). This survey explored specific beliefs including attitudes, norms, perceived control, intention and behaviour, as well as environmental altruism and green identity, in relation to walking for transport and switching off lights when not in use. Following analysis of the mail survey data and based on feedback from participants and key stakeholders, an internet survey was employed (N=451) to explore two additional behaviours, switching off appliances at the wall when not in use, and shopping with reusable bags. This work is presented as a series of interrelated publications which address each of the research aims. Presentation of Findings. Chapter five of this thesis consists of a published paper which addresses the first aim of the research and outlines the collaborative and multidisciplinary approach employed in the mail survey. The paper argued that forging alliances with those who are in a position to immediately utilise the findings of research has the potential to improve the quality and timely communication of research. Illustrating this timely communication, Chapter six comprises a report presented to Moreton Bay Regional Council (MBRC). This report addresses aim's one and two. The report contains a summary of participation in a range of environmentally friendly behaviours and identifies the beliefs which most strongly predicted walking for transport and switching off lights (from the mail survey). These salient beliefs were then recommended as targets for interventions and included: participants believing that they might save money; that their neighbours also switch off lights; that it would be inconvenient to walk for transport and that their closest friend also walks for transport. Chapter seven also addresses the second aim and presents a published conference paper in which the salient beliefs predicting the four specified behaviours (from both surveys) are identified and potential applications for intervention are discussed. Again, a range of TPB based beliefs, including descriptive normative beliefs, were predictive of environmentally friendly behaviour. This paper was also provided to MBRC, along with recommendations for applying the findings. For example, as descriptive normative beliefs were consistently correlated with environmentally friendly behaviour, local councils could engage in marketing and interventions (workshops, letter box drops, internet promotions) which encourage parents and friends to model, rather than simply encourage, environmentally friendly behaviour. The final two papers, presented in Chapters eight and nine, addresses the third aim of the project. These papers each present two behaviours together to inform a TPB based theoretical model with which to predict environmentally friendly behaviour. A generalised model is presented, which is found to predict the four specific behaviours under investigation. The role of demographics was explored across each of the behaviour specific models. It was found that some behaviour's differ by age, gender, income or education. In particular, adjusted models predicted more of the variance in walking for transport amongst younger participants and females. Adjusted models predicted more variance in switching off lights amongst those with a bachelor degree or higher and predicted more variance in switching off appliances amongst those on a higher income. Adjusted models predicted more variance in shopping with reusable bags for males, people 40 years or older, those on a higher income and those with a bachelor degree or higher. However, model structure and general predictability was relatively consistent overall. The models provide a general theoretical framework from which to better understand the motives and predictors of environmentally friendly behaviour. Conclusion. This research has provided an example of the benefits of a collaborative interdisciplinary approach. It has identified a number of salient beliefs which can be targeted for social marketing campaigns and educational initiatives; and these findings, along with recommendations, have been passed on to a local council to be used as part of their ongoing community engagement programs. Finally, the research has informed a practical model, as well as behaviour specific models, for predicting sustainable living behaviours. Such models can highlight important core constructs from which targeted interventions can be designed. Therefore, this research represents an important step in undertaking collaborative approaches to improving population health through human-environment interactions.

The changing performance of multifocal contact lenses compared to monovision.

Purpose:Multifocal contact lenses (MCLs) have been available for decades. A review of the literature suggests that while, historically, these lenses have been partially successful, they have struggled to compete with monovision (MV). More recent publications suggest that there has been an improvement in the performance of these lenses. This study set out to investigate whether the apparent improved lens performance reported in the literature is reflected in clinical practice. Methods:Data collected over the last 5yrs via the International Contact Lens Prescribing Survey Consortium was reviewed for patients over the age of 45yrs. The published reports of clinical trials were reviewed to assess lens performance over the time period. Results:Data review was of 16,680 presbyopic lens fits in 38 countries. The results are that 29% were fit with MCLs, 8% MV and 63% single vision (SV). A previous survey conducted in Australia during 1988-89 reported that 9% of presbyopes were fit with MCLs, 29% MV and 63% SV. The results from our survey for Australia alone were 28% (MV 13%) vs 9% (MV 29%) suggesting an increase in usage of MCLs from 1988-89 to 2010. A review of the literature indicates the reported level of visual acuities with MCLs in comparison to MV has remained equivalent over this time period, yet preference has switch from MV to MCLs. Conclusions:There is evidence that currently more MCLs than MV are being fit to presbyopes, compared to 1988-89. This increased use is likely due to the improved visual performance of these lenses, which is not demonstrated with acuity measures but reported by wearers, suggesting that patient-based subjective ratings are currently the best way to measure visual performance.