Sydney Population Research Articles

Anthropogenic hive movements are changing the genetic structure of a stingless bee (Tetragonula carbonaria) population along the east coast of Australia

Across the world, the keeping of stingless bees is increasingly popular, providing commercial pollination, high-value honey and a rewarding pass time. The popularity of stingless beekeeping has resulted in large-scale anthropogenic movements of nests, sometimes from outside their native range. Colony movement has the potential to impact local populations via transfer of parasites and pathogens and gene flow across unnaturally large geographic scales. Tetragonula carbonaria is the most widespread and commonly kept stingless bee species in Australia. Concerns have been raised that large-scale artificial propagation of T. carbonaria colonies by Sydney beekeepers, from a small number of colonies that originated in south-east Queensland, may have two consequences. First, the managed population may be becoming increasingly inbred. Second, the wild population may be experiencing significant introgression of south-east Queensland genotypes, potentially diluting local adaptations to the Sydney environment and resulting in the loss of local alleles. Here we show, based on microsatellite and mitochondrial markers, that both the managed and wild Sydney populations are significantly different from the south-east Queensland population. Nonetheless there is evidence that introgression of south-east Queensland alleles is impacting the genetic structure of both wild and managed Sydney populations. The two Sydney populations are indistinguishable, suggesting two-way gene flow in Sydney consistent with expectations of gene flow via male dispersal. All populations have low inbreeding coefficients, suggesting that they are genetically healthy.

The Impacts of Household Financial Stress, Resilience, Social Support, and Other Adversities on the Psychological Distress of Western Sydney Parents

This study investigated the prevalence of psychological distress among parents in Western Sydney households and examined its relationship with household financial, family and life stressors, and potential resilience factors. As part of a longer-term study, parents from Western Sydney, New South Wales (NSW), completed computer-assisted telephone interviews (CATI) in May 2011 (N=439). Respondents were primary caregivers of at least one child (aged 4–16). Responses were weighted to reflect the Western Sydney population. Multivariate analyses were conducted to examine the relationship between parent experiences of stressor and resilience factors and reported psychological distress. Overall, 10.7% (95% CI: 7.8, 14.5) reported experiencing high/very high levels of psychological distress. Multivariate analysis indicated that financial hardship factors formed the strongest associations with psychological distress particularly housing and job security factors and, specifically, inability to meet mortgage/rent payments (OR=5.15, 95% CI: 1.74–15.25, p=0.003), poor self-rated health (OR=4.48, 95% CI: 1.88–10.64, p=0.001), adult job loss (OR=3.77, 95% CI: 1.33–10.66, p=0.013), and other family/life events (OR=2.30, 95% CI: 1.05–5.03, p=0.037). High personal resilience was common within this parent population and was a significant protective factor for high psychological distress (OR=0.14, 95% CI: 0.06–0.34, p<0.001). The findings support the development of targeted interventions to promote parent coping strategies in the context of household financial hardship.

Relative Abundance and Strain Diversity in the Bacterial Endosymbiont Community of a Sap-Feeding Insect Across Its Native and Introduced Geographic Range.

Most insects are associated with bacterial symbionts. The bacterial diversity and community composition within hosts may play an important role in shaping insect population biology, ecology and evolution. We focussed on the bacterial microbiome of the Australian fig homotomid Mycopsylla fici (Hemiptera: Psylloidea), which can cause defoliation of its only host tree, Ficus macrophylla. This sap-feeding insect is native to mainland Australia and Lord Howe Island (LHI) but also occurs where its host has been planted, notably in New Zealand. By using a high-throughput 16S rDNA amplicon sequencing approach, we compared the bacterial diversity and community composition in individual adult males of four host populations, Sydney, Brisbane, LHI and Auckland. We also compared males, females and nymphs of the Sydney population. The microbiome of M. fici was simple and consisted mostly of the following three maternally inherited endosymbiont species: the primary endosymbiont Carsonella, a secondary (S-) endosymbiont and Wolbachia. However, the relative abundance of their sequence reads varied between host populations, except for similarities between Sydney and Auckland. In addition, insects from Sydney and Auckland had identical bacterial strains supporting the hypothesis that Sydney is the source population for Auckland. In contrast, mainland and LHI populations harboured the same S-endosymbiont, co-diverged Carsonella but different Wolbachia strains. Besides detecting endosymbiont-specific patterns of either co-evolution or horizontal acquisition, our study highlights that relative abundance of maternally inherited endosymbionts should also be taken into account when studying bacterial communities across host populations, as variations in bacterial density may impact host biology and ecology.

Greenhouse Gas Implications of Peri-Urban Land Use Change in a Developed City under Four Future Climate Scenarios

Present decisions about urbanization of peri-urban (PU) areas may contribute to the capacity of cities to mitigate future climate change. Comprehensive mitigative responses to PU development should require integration of urban form and food production to realise potential trade-offs. Despite this, few studies examine greenhouse gas (GHG) implications of future urban development combined with impacts on PU food production. In this paper, four future scenarios, at 2050 and 2100 time horizons, were developed to evaluate the potential GHG emissions implications of feeding and housing a growing urban population in Sydney, Australia. The scenarios were thematically downscaled from the four relative concentration pathways. Central to the scenarios were differences in population, technology, energy, housing form, transportation, temperature, food production and land use change (LUC). A life cycle assessment approach was used within the scenarios to evaluate differences in GHG impacts. Differences in GHG emissions between scenarios at the 2100 time horizon, per area of PU land transformed, approximated 0.7 Mt CO2-e per year. Per additional resident this equated to 0.7 to 6.1 t CO2-e per year. Indirect LUC has the potential to be significant. Interventions such as carbon capture and storage technology, renewables and urban form markedly reduced emissions. However, incorporating cross-sectoral energy saving measures within urban planning at the regional scale requires a paradigmatic shift.

Prevalence and determinants of cessation of exclusive breastfeeding in the early postnatal period in Sydney, Australia.

BackgroundOptimal breastfeeding has benefits for the mother-infant dyads. This study investigated the prevalence and determinants of cessation of exclusive breastfeeding (EBF) in the early postnatal period in a culturally and linguistically diverse population in Sydney, New South Wales, Australia.MethodsThe study used routinely collected perinatal data on all live births in 2014 (N = 17,564) in public health facilities in two Local Health Districts in Sydney, Australia. The prevalence of mother’s breastfeeding intention, skin-to-skin contact, EBF at birth, discharge and early postnatal period (1–4 weeks postnatal) were estimated. Multivariate logistic regression models that adjusted for confounders were conducted to determine association between cessation of EBF in the early postnatal period and socio-demographic, psychosocial and health service factors.ResultsMost mothers intended to breastfeed (92%), practiced skin-to-skin contact (81%), exclusively breastfed at delivery (90%) and discharge (89%). However, the prevalence of EBF declined (by 27%) at the early postnatal period (62%). Younger mothers (<20 years) and mothers who smoked cigarettes in pregnancy were more likely to cease EBF in the early postnatal period compared to older mothers (20–39 years) and those who reported not smoking cigarettes, respectively [Adjusted Odds Ratio (AOR) =2.7, 95%CI 1.9–3.8, P <0.001 and AOR = 2.5, 95%CI 2.1–3.0, P <0.001, respectively]. Intimate partner violence, assisted delivery, low socio-economic status, pre-existing maternal health problems and a lack of partner support were also associated with early cessation of EBF in the postnatal period.ConclusionsOur findings suggest that while most mothers intend to breastfeed, and commence EBF at delivery and at discharge, the maintenance of EBF in the early postnatal period is sub-optimal. This highlights the need for efforts to promote breastfeeding in the wider community along with targeted actions for disadvantaged groups and those identified to be at risk of early cessation of EBF to maximise impact.

Mixed gonococcal infections in a high-risk population, Sydney, Australia 2015: implications for antimicrobial resistance surveillance?

Previous studies have shown that mixed-strain gonococcal infections can occur. However, it remains unclear whether such infections impact upon the reliability of Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance. In this study, we aimed to resolve this question by intensively sampling isolates from gonorrhoea-positive specimens in a high-risk population in Sydney, Australia. A total of 615 N. gonorrhoeae isolates, originating from 63 clinical samples (31 rectal swabs and 32 throat swabs), were characterized. All isolates were subject to N. gonorrhoeae identification, antimicrobial susceptibility testing and genotyping by SNP-based MLST. Only 2 of the 63 (3.2%) samples provided evidence of mixed-strain infections. These comprised two rectal swabs that harboured isolates of different SNP-based MLST genotypes; however, the AMR susceptibility profiles of the different genotypes from these samples were indistinguishable. Within-sample differences in the AMR susceptibility profiles were observed for a further seven samples; however, the differences were not considered significant; MIC values were typically within a 2-fold difference or were close to test breakpoints. Results of this study provide further evidence that mixed-strain gonococcal infections do occur, although at low prevalence. Our data indicate that at a population level such infections are unlikely to impact significantly upon N. gonorrhoeae AMR surveillance.

Neighbourhood walkability, road density and socio-economic status in Sydney, Australia.

BackgroundPlanning and transport agencies play a vital role in influencing the design of townscapes, travel modes and travel behaviors, which in turn impact on the walkability of neighbourhoods and residents’ physical activity opportunities. Optimising neighbourhood walkability is desirable in built environments, however, the population health benefits of walkability may be offset by increased exposure to traffic related air pollution. This paper describes the spatial distribution of neighbourhood walkability and weighted road density, a marker for traffic related air pollution, in Sydney, Australia. As exposure to air pollution is related to socio-economic status in some cities, this paper also examines the spatial distribution of weighted road density and walkability by socio-economic status (SES).MethodsWe calculated walkability, weighted road density (as a measure of traffic related air pollution) and SES, using predefined and validated measures, for 5858 Sydney neighbourhoods, representing 3.6 million population. We overlaid tertiles of walkability and weighted road density to define “sweet-spots” (high walkability-low weighted road density), and “sour- spots” (low walkability-high weighted road density) neighbourhoods. We also examined the distribution of walkability and weighted road density by SES quintiles.ResultsWalkability and weighted road density showed a clear east-west gradient across the region. Our study found that only 4 % of Sydney’s population lived in sweet-spot” neighbourhoods with high walkability and low weighted road density (desirable), and these tended to be located closer to the city centre. A greater proportion of neighbourhoods had health limiting attributes of high weighted road density or low walkability (about 20 % each), and over 5 % of the population lived in “sour-spot” neighbourhoods with low walkability and high weighted road density (least desirable). These neighbourhoods were more distant from the city centre and scattered more widely. There were no linear trends between walkability/weighted road density and neighbourhood SES.ConclusionsOur walkability and weighted road density maps and associated analyses by SES can help identify neighbourhoods with inequalities in health-promoting or health-limiting environments. Planning agencies should seek out opportunities for increased neighbourhood walkability through improved urban development and transport planning, which simultaneously minimizes exposure to traffic related air pollution.Electronic supplementary materialThe online version of this article (doi:10.1186/s12940-016-0135-y) contains supplementary material, which is available to authorized users.

Adverse reactions in a population of Sydney pet rabbits vaccinated against rabbit calicivirus.

To determine the general clinical presentation and incidence of adverse reactions to Cylap® RCD vaccinations, of a nature serious enough for veterinary attention, in a Sydney population of pet rabbits. A retrospective survey using hospital databases. Nine veterinary hospitals in Sydney participated in a database search for the number of rabbits vaccinated within a 2-year period. The hospitals involved had an identified interest in rabbit medicine and included general, specialist and teaching hospitals. Details of the rabbit, vaccination event and any possible reaction were collected and analysed. Of 933 events recorded in 705 rabbits, 17 (1.8%) adverse reactions were observed. Of the adverse events, local injection site reactions (alopecia, abrasions and scabbing) were most common. Other reactions, including systemic signs of gastrointestinal tract stasis, lethargy and forelimb lameness, were also documented. Overall, rabbits presented for vaccination were mostly male (57.7%) and desexed (71.3%), with an average age of 28.1 months (median 19.0, range 1.4-149.8 months) and an average weight at first vaccination of 2.12 kg (median 2.08 kg, range 0.18-5.6 kg). A significant association between increasing age and decreased incidence of adverse events was demonstrated (P value, 0.038). The benefits of vaccination against RCV outweigh the risks of an adverse reaction occurring. Data from this study show that adverse reactions occur infrequently, are generally mild and self-resolving, and decrease in incidence with increasing age. These results are similar to previous field research on wild rabbit colonies and reports from government and industry.

The health benefits of reducing air pollution in Sydney, Australia

Among industrialised countries, fine particle (PM2.5) and ozone levels in the Sydney metropolitan area of Australia are relatively low. Annual mean PM2.5 levels have historically remained below 8μg/m3 while warm season (November–March) ozone levels occasionally exceed the Australian guideline value of 0.10ppm (daily 1h max). Yet, these levels are still below those seen in the United States and Europe. This analysis focuses on two related questions: (1) what is the public health burden associated with air pollution in Sydney; and (2) to what extent would reducing air pollution reduce the number of hospital admissions, premature deaths and number of years of life lost (YLL)? We addressed these questions by applying a damage function approach to Sydney population, health, PM2.5 and ozone data for 2007 within the BenMAP-CE software tool to estimate health impacts and economic benefits. We found that 430 premature deaths (90% CI: 310–540) and 5800 YLL (95% CI: 3900–7600) are attributable to 2007 levels of PM2.5 (about 2% of total deaths and 1.8% of YLL in 2007). We also estimate about 630 (95% CI: 410–840) respiratory and cardiovascular hospital admissions attributable to 2007 PM2.5 and ozone exposures. Reducing air pollution levels by even a small amount will yield a range of health benefits. Reducing 2007 PM2.5 exposure in Sydney by 10% would, over 10 years, result in about 650 (95% CI: 430–850) fewer premature deaths, a gain of 3500 (95% CI: 2300–4600) life-years and about 700 (95% CI: 450–930) fewer respiratory and cardiovascular hospital visits. These results suggest that substantial health benefits are attainable in Sydney with even modest reductions in air pollution.

Smoking among Aboriginal adults in Sydney, Australia.

Issue addressed Tobacco consumption contributes to health disparities among Aboriginal Australians who experience a greater burden of smoking-related death and diseases. This paper reports findings from a baseline survey on factors associated with smoking, cessation behaviours and attitudes towards smoke-free homes among the Aboriginal population in inner and south-western Sydney. Methods A baseline survey was conducted in inner and south-western Sydney from October 2010 to July 2011. The survey applied both interviewer-administered and self-administered data collection methods. Multiple logistic regression was performed to determine the factors associated with smoking. Results Six hundred and sixty-three participants completed the survey. The majority were female (67.5%), below the age of 50 (66.6%) and more than half were employed (54.7%). Almost half were current smokers (48.4%) with the majority intending to quit in the next 6 months (79.0%) and living in a smoke-free home (70.4%). Those aged 30-39 years (AOR 3.28; 95% CI: 2.06-5.23) and the unemployed (AOR 1.67; 95% CI: 1.11-2.51) had higher odds for current smoking. Participants who had a more positive attitude towards smoke-free homes were less likely to smoke (AOR 0.79; 95% CI: 0.74-.85). Conclusions A high proportion of participants were current smokers among whom intention to quit was high. Age, work status and attitudes towards smoke-free home were factors associated with smoking. So what? The findings address the scarcity of local evidence crucial for promoting cessation among Aboriginal tobacco smokers. Targeted promotions for socio-demographic subgroups and of attitudes towards smoke-free homes could be meaningful strategies for future smoking-cessation initiatives.

Use of a syndromic surveillance system to describe the trend in cycling-related presentations to emergency departments in Sydney.

To describe population-based trends in cycling-related presentations to EDs over the past decade. A retrospective cohort of road trauma patients (motor vehicle, motor cyclist, cyclist and pedestrian) presenting to EDs in the Sydney Greater Metropolitan Area between 2004 and 2013 was obtained using the Public Health Real-time Emergency Department Surveillance System. The outcomes of interest were the cycling-related ED presentation rate per 1000 population, as well as the proportion of cycling-related presentations that died in ED or were admitted to a critical care ward. Trends in ED presentation rates based on presentation counts and Sydney population data were plotted and described. There were 68,438 cycling-related presentations identified, representing 30% of all road trauma patients presenting to EDs in Sydney. There was a 91% increase in cycling-related presentations for the 35 to 64-year-old age group and a 123% increase in cycling-related presentations in the 65-year-old and over age group. All other age groups were associated with a stable or decrease in cycling-related ED presentation rates. The proportion of presentations requiring critical care ward admission or death in ED has decreased by 20%. Using an ED syndromic surveillance system, cycling-related ED presentation rates in Sydney Australia have increased in those aged 35 years and over the past 10 years, with a relative decrease in the proportion of deaths in ED or those requiring critical care admission.

Characterisation of microsatellite markers for fig-pollinating wasps in the Pleistodontes imperialis species complex

We characterised a set of nine polymorphic microsatellite loci for Pleistodontes imperialis sp. 1, the pollinator wasp of Port Jackson fig (Ficus rubiginosa) in south-eastern Australia. Characterisation was performed on 30 female individuals collected from a population in Sydney, Australia. The average number of alleles per locus was 7.33, and eight loci were not in Hardy–Weinberg equilibrium. This was expected as fig wasps are known to be highly inbred. A test of genetic differentiation between two natural populations of P. imperialis sp. 1 (Sydney and Newcastle, Australia – some 120 km apart) yielded a very low FST value of 0.012, suggesting considerable gene flow. Bayesian clustering analysis using TESS 2.3.1, which does not assume Hardy–Weinberg equilibrium, however, indicated potential spatial substructuring between the Sydney and Newcastle populations, as well as within the Sydney population. The described loci were also characterised for two other species in the P. imperialis complex: P. imperialis sp. 2 (Townsville, Australia) and P. imperialis sp. 4 (Brisbane, Australia). Seven and six of the nine loci were polymorphic for P. imperialis sp. 2 and P. imperialis sp. 4, respectively.

Low-Intensity Pulsed Ultrasound in Lower Limb Bone Stress Injuries

To evaluate the effectiveness of low-intensity pulsed ultrasound (LIPUS) for the improvement of lower limb bone stress injuries in a civilian population. A prospective, randomized, double-blinded, placebo-controlled trial to compare LIPUS with placebo. Civilian private practice population in Sydney, Australia. Subjects were recruited if a grade II-IV bone stress injury was diagnosed on magnetic resonance imaging (MRI) of either the postero-medial tibia, fibula or second, third, or fourth metatarsal. Subjects of all levels of sporting activity were included. Thirty subjects were initially recruited, and 23 subjects were included in the final analysis. Subjects were randomized into either the treatment or placebo arm and matched to the site of injury (tibia, fibula, or metatarsal). Subjects in both arms used either treatment or placebo devices for 20 minutes daily for 4 weeks. Six clinical parameters (night pain, pain at rest, pain on walking, pain with running, tenderness, and pain with single leg hop) were compared before and after intervention. The changes in MRI grade and bone marrow edema size were also compared. There were no significant differences between the treatment and placebo conditions for changes in MRI grading (2.2 vs 2.4, P = 0.776) or bone marrow edema size (3 vs 4.1, P = 0.271). There were no significant differences between the treatment and placebo conditions for the 6 clinical parameters. Low-intensity pulsed ultrasound was found not to be an effective treatment for the healing of lower limb bone stress injuries in this study. However, this was measured over a relatively short duration of 4 weeks in a small, mostly female population. This double-blinded, randomized, placebo-controlled trial has shown that LIPUS is not an effective treatment for lower limb bone stress injuries.

Reproduction of the Diadematidae sea urchin Centrostephanus rodgersii in a recently colonized area of northern New Zealand

Reproduction of the sea urchin Centrostephanus rodgersii at the Mokohinau Islands (northeast New Zealand) was studied in terms of the gametogenetic cycle and sex ratio, and larval range of thermal tolerance was determined. A comparison with the reproductive patterns in populations located in New South Wales (NSW), the historical range of the species, and Tasmania, where the species has only recently arrived (≈ 50–60 years ago), was made. Results indicate that C. rodgersii in New Zealand is capable of growing gonads, completing a gametogenetic cycle and producing viable gametes. The timing of this process is similar to the population in Sydney (central NSW), where spawning is probably triggered by the winter solstice and lasts from July to September. The sex ratio was skewed towards females (1.6 females for each male), which may be indicative of the recent arrival of the species in New Zealand. Larvae obtained from this population were able to develop at a measurable rate after 72 h only between 16°C and 25°C. Ambient temperatures during spawning at the Mokohinau Islands (15.7–16.8°C) appear to be at the lower end of the range of temperatures suitable for early larval development.

Subtype distribution of Blastocystis isolates identified in a Sydney population and pathogenic potential of Blastocystis

Blastocystis is one of the most common enteric parasites present in humans. There is still much uncertainty about the pathogenic potential of this parasite, and it was suggested that its pathogenicity could be subtype-related. This report aimed to study 98 Blastocystis isolates found in human stool specimens to identify the subtypes present and carry out phylogenetic analysis on these isolates. This study also aimed to show the relationship between subtype and symptoms. Five-hundred and thirteen stool samples were submitted to five different diagnostic techniques for the detection of Blastocystis. Polymerase chain reaction (PCR)-positive samples were then sequenced and the small subunit (SSU) rDNA sequences were aligned and submitted to phylogenetic analysis. Ninety-eight samples were positive by any of the diagnostic methods for Blastocystis and 96 were positive by PCR. There were seven different subtypes (1, 2, 3, 4, 6, 7 and 8) identified by PCR and sequencing. This is the first large-scale study to examine the occurrence of Blastocystis in Australia. This study reports the high incidence of subtype 3 (44%) in this population and discusses the emerging idea of subtype-dependent pathogenicity.

Areca nut chewing in an expatriate population in Sydney: report of two cases

Areca nut (betel nut) consumption occurs in a variety of forms, either on its own or with the addition of a number of products. This habit is prevalent in the Indian Subcontinent and South-East Asia. Recent immigration statistics indicate that 30% of new arrivals in Australia are from these geographical regions and are known to perpetuate this custom long after migration. The objective of this paper is to highlight the variety of oral presentations that may occur as a result of areca nut consumption in these particular demographic subgroups. Dental practitioners must be familiar with the wide spectrum of oral lesions that may present in this setting. More significantly, they must be aware that some of these lesions possess the potential for malignant transformation and hence require more specific management. Best practice mandates that dental practitioners in a multicultural society must: (1) be capable of recognizing the expatriate populations in which this custom is widely practised; (2) incorporate this particular line of questioning into the routine risk factor analysis that is undertaken for every patient from these particular sub-populations; and (3) institute appropriate referral and follow-up of these lesions if required.

Risk factors for feline infectious peritonitis in Australian cats.

The objective of this study was to determine whether patient signalment (age, breed, sex and neuter status) is associated with naturally-occurring feline infectious peritonitis (FIP) in cats in Australia. A retrospective comparison of the signalment between cats with confirmed FIP and the general cat population was designed. The patient signalment of 382 FIP confirmed cases were compared with the Companion Animal Register of NSW and the general cat population of Sydney. Younger cats were significantly over-represented among FIP cases. Domestic crossbred, Persian and Himalayan cats were significantly under-represented in the FIP cohort, while several breeds were over-represented, including British Shorthair, Devon Rex and Abyssinian. A significantly higher proportion of male cats had FIP compared with female cats. This study provides further evidence that FIP is a disease primarily of young cats and that significant breed and sex predilections exist in Australia. This opens further avenues to investigate the role of genetic factors in FIP.

Genetic structure and diversity of introduced eastern mosquitofish (Gambusia holbrooki) in south-eastern Australia

The closely related eastern mosquitofish (Gambusia holbrooki) and western mosquitofish (Gambusia affinis) have been introduced into many countries and collectively represent the most widely distributed freshwater fish in the world. We investigated genetic patterns associated with the spread of G. holbrooki in its introduced range in south-eastern Australia, by sampling 60 G. holbrooki populations (n = 1771) from major regions where G. holbrooki was initially introduced into Australia, and characterising the genetic diversity and population structure of G. holbrooki, using five polymorphic nuclear microsatellite loci and sequences from two mitochondrial genetic markers. Results were compared with published data on American and European Gambusia samples and historical records. Low microsatellite diversity and strong population genetic structuring were found within G. holbrooki in south-eastern Australia. Observed heterozygosity and allelic richness declined regionally in the order Sydney, Brisbane, Canberra, Melbourne and Adelaide. Microsatellite variation in Australia was reduced compared with native populations. Two mitochondrial DNA haplotypes of G. holbrooki were found; one was common, whereas the other was detected in one Sydney population and one Melbourne population. Cytochrome b sequence diversity was reduced compared with native and European ranges, and sequences were identical to two haplotypes previously identified. Microsatellite diversity of G. holbrooki in south-eastern Australia validates historical records of its spread, beginning north and moving south. Mitochondrial sequencing confirms that G. holbrooki is present in Australia, but the origins of Australian G. holbrooki populations remain unclear.

Short-term response of the long-nosed bandicoot, Perameles nasuta, and the southern brown bandicoot, Isoodon obesulus obesulus, to low-intensity prescribed fire in heathland vegetation

Context Prescribed burning is routinely performed within the Sydney Basin as a method of fire-hazard mitigation. Despite the widespread use of prescribed fire, knowledge of the impact of prescribed fire on most fauna species remains unclear. This is particularly the case for bandicoot species. Aims To determine the impact of a low-intensity prescribed fire on the survival of the long-nosed bandicoot, Perameles nasuta, and the southern brown bandicoot, Isoodon obesulus obesulus (hereafter abbreviated to I. obesulus), immediately after the fire and at 5 weeks, 5 months and 13 months following the fire. To document the spatial ecology and nesting requirements of I. obesulus and P. nasuta before and after fire. Methods One I. obesulus and seven P. nasuta (five female and two male) individuals were radio-tracked. Animals were tracked before, during and following a hazard-reduction burn to assess the impact of fire on home range, survival and nesting behaviour. Key results Post-fire survival of P. nasuta and I. obesulus was high and the population remained stable up to 5 months following the fire. All animals tracked within the burn area (three female P. nasuta) survived the passage of fire. The home range for one male I. obesulus was found to be 2.35 ha 50% kernel-density estimate (KDE) and 12.35 ha 95% KDE. Female P. nasuta (n = 5) had a home range of 1.3 ha ± 0.2 s.e. 50% KDE and 7.5 ha ± 1.7 s.e. 95% KDE. Male P. nasuta (n = 1) had a home range of 1.1 ha 50% KDE and 6.5ha 95% KDE. Nesting for both species tended to occur in dense vegetation, with a slight shift to non-combustible refuge sites post-fire. Animals tended to maintain exclusive and relatively stable core home ranges, although overlap of non-core home ranges was common. Conclusions The survival of bandicoots following a low-intensity hazard-reduction fire was high in the short term; however, further research is required to determine how the components of a fire regime affect native species, in particular peramelids. Implications Hazard-reduction fires should be used with caution to manage the isolated and endangered northern Sydney population of I. obesulus, so as to ensure the persistence of this species.

The Health Impacts of Ethanol Blend Petrol

A measurement program designed to evaluate health impacts or benefits of using ethanol blend petrol examined exhaust and evaporative emissions from 21 vehicles representative of the current Australian light duty petrol (gasoline) vehicle fleet using a composite urban emissions drive cycle. The fuels used were unleaded petrol (ULP), ULP blended with either 5% ethanol (E5) or 10% ethanol (E10). The resulting data were combined with inventory data for Sydney to determine the expected fleet emissions for different uptakes of ethanol blended fuel. Fleet ethanol compatibility was estimated to be 60% for 2006, and for the air quality modelling it was assumed that in 2011 over 95% of the fleet would be ethanol compatible. Secondary organic aerosol (SOA) formation from ULP, E5 and E10 emissions was studied under controlled conditions by the use of a smog chamber. This was combined with meteorological data from Sydney for February 2004 and the emission data (both measured and inventory data) to model pollutant concentrations in Sydney’s airshed for 2006 and 2011. These concentrations were combined with the population distribution to evaluate population exposure to the pollutant. There is a health benefit to the Sydney population arising from a move from ULP to ethanol blends in spark-ignition vehicles. Potential health cost savings for Urban Australia (Sydney, Melbourne, Brisbane and Perth) are estimated to be A$39 million (in 2007 dollars) for a 50% uptake (by ethanol compatible vehicles) of E10 in 2006 and $42 million per annum for a 100% take up of E10 in 2011. Over 97% of the estimated health savings are due to reduced emissions of PM2.5 and consequent reduced impacts on mortality and morbidity (e.g., asthma, cardiovascular disease). Despite more petrol-driven vehicles predicted for 2011, the quantified health impact differential between ULP and ethanol fuelled vehicles drops from 2006 to 2011. This is because modern petrol vehicles, with lower emissions than their older counterparts, will make up a higher proportion of the fleet in the future. Hence the beneficial effects of reductions in particulate matter become less significant as the fleet as a whole produces lower emissions.