There is an urgent need to thoroughly review and comprehend the effects of urbanization on wildlife in order to understand both the ecological implications of increasing urbanization and how to ...mitigate its threat to biodiversity globally. We examined patterns in comparative productivity of urban and non-urban passerine birds, using published estimates from paired comparisons, and by reviewing and developing explanations in terms of resources, competitors, predators and other specifically urban environmental factors. The most consistent patterns were for earlier lay dates, lower clutch size, lower nestling weight and lower productivity per nesting attempt in urban landscapes; these were supported by a formal meta-analysis. Nest failure rates did not show consistent patterns across the species considered. We suggest that food availability is a key driver of differences in passerine demography between landscapes. In urban habitats, human-provided food may improve adult condition over winter, leading to earlier lay dates and, in some species, to higher survival and higher breeding densities, but paucity of natural food may lead to lower productivity per nesting attempt. We demonstrate that additional comparative research is needed on a wider range of species, on the effects of natural and human-provided food availability, and on the differences in survival and dispersal between urban and non-urban populations. Importantly, better-targeted research and monitoring is needed in areas that are at greatest threat from urbanization, especially in the developing world.
Some perfluoroalkyl and polyfluoroalkyl substances (PFASs) have become widespread pollutants detected in human and wildlife samples worldwide. The main objective of this study was to assess temporal ...trends of PFAS concentrations in human blood in Australia over the last decade (2002–2011), taking into consideration age and sex trends.
Pooled human sera from 2002/03 (n=26); 2008/09 (n=24) and 2010/11 (n=24) from South East Queensland, Australia were obtained from de-identified surplus pathology samples and compared with samples collected previously from 2006/07 (n=84). A total of 9775 samples in 158 pools were available for an assessment of PFASs. Stratification criteria included sex and age: <16years (2002/03 only); 0–4 (2006/07, 2008/09, 2010/11); 5–15 (2006/07, 2008/09, 2010/11); 16–30; 31–45; 46–60; and >60years (all collection periods). Sera were analyzed using on-line solid-phase extraction coupled to high-performance liquid chromatography–isotope dilution-tandem mass spectrometry.
Perfluorooctane sulfonate (PFOS) was detected in the highest concentrations ranging from 5.3–19.2ng/ml (2008/09) to 4.4–17.4ng/ml (2010/11). Perfluorooctanoate (PFOA) was detected in the next highest concentration ranging from 2.8–7.3ng/ml (2008/09) to 3.1–6.5ng/ml (2010/11). All other measured PFASs were detected at concentrations <1ng/ml with the exception of perfluorohexane sulfonate which ranged from 1.2–5.7ng/ml (08/09) and 1.4–5.4ng/ml (10/11). The mean concentrations of both PFOS and PFOA in the 2010/11 period compared to 2002/03 were lower for all adult age groups by 56%. For 5–15year olds, the decrease was 66% (PFOS) and 63% (PFOA) from 2002/03 to 2010/11. For 0–4year olds the decrease from 2006/07 (when data were first available for this age group) was 50% (PFOS) and 22% (PFOA).
This study provides strong evidence for decreasing serum PFOS and PFOA concentrations in an Australian population from 2002 through 2011. Age trends were variable and concentrations were higher in males than in females. Global use has been in decline since around 2002 and hence primary exposure levels are expected to be decreasing. Further biomonitoring will allow assessment of PFAS exposures to confirm trends in exposure as primary and eventually secondary sources are depleted.
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•Decreasing serum PFOS and PFOA in an Australian population (2002–2011)•PFOS and PFOA both decreased 56% from 2002/03 to 2010/11 in adults.•For 5–15years, PFOS and PFOA decreased 66% and 63% from 2002/03 to 2010/11.•For 0–4years, PFOS and PFOA decreased 50% and 22% from 2006/07 to 2010/11.•Age trends were variable and concentrations were higher in males than in females.
Wolfram syndrome (WS) is an ultra-rare progressive neurodegenerative disorder defined by early-onset diabetes mellitus and optic atrophy. The majority of patients harbour recessive mutations in the ...WFS1 gene, which encodes for Wolframin, a transmembrane endoplasmic reticulum protein. There is limited availability of human ocular and brain tissues, and there are few animal models for WS that replicate the neuropathology and clinical phenotype seen in this disorder. We, therefore, characterised two wfs1 zebrafish knockout models harbouring nonsense wfs1a and wfs1b mutations. Both homozygous mutant wfs1a
and wfs1b
embryos showed significant morphological abnormalities in early development. The wfs1b
zebrafish exhibited a more pronounced neurodegenerative phenotype with delayed neuronal development, progressive loss of retinal ganglion cells and clear evidence of visual dysfunction on functional testing. At 12 months of age, wfs1b
zebrafish had a significantly lower RGC density per 100 μm
(mean ± standard deviation; 19 ± 1.7) compared with wild-type (WT) zebrafish (25 ± 2.3, p < 0.001). The optokinetic response for wfs1b
zebrafish was significantly reduced at 8 and 16 rpm testing speeds at both 4 and 12 months of age compared with WT zebrafish. An upregulation of the unfolded protein response was observed in mutant zebrafish indicative of increased endoplasmic reticulum stress. Mutant wfs1b
zebrafish exhibit some of the key features seen in patients with WS, providing a versatile and cost-effective in vivo model that can be used to further investigate the underlying pathophysiology of WS and potential therapeutic interventions.
Incomplete fusion of the optic fissure leads to ocular coloboma, a congenital eye defect that affects up to 7.5 per 10,000 births and accounts for up to 10 percent of childhood blindness. The ...molecular and cellular mechanisms that facilitate optic fissure fusion remain elusive. We have profiled global gene expression during optic fissure morphogenesis by transcriptome analysis of tissue dissected from the margins of the zebrafish optic fissure and the opposing dorsal retina before (32 hours post fertilisation, hpf), during (48 hpf) and after (56 hpf) optic fissure fusion. Differential expression analysis between optic fissure and dorsal retinal tissue resulted in the detection of several known and novel developmental genes. The expression of selected genes was validated by qRT-PCR analysis and localisation investigated using in situ hybridisation. We discuss significantly overrepresented functional ontology categories in the context of optic fissure morphogenesis and highlight interesting transcripts from hierarchical clustering for subsequent analysis. We have identified netrin1a (ntn1a) as highly differentially expressed across optic fissure fusion, with a resultant ocular coloboma phenotype following morpholino antisense translation-blocking knockdown and downstream disruption of atoh7 expression. To support the identification of candidate genes in human studies, we have generated an online open-access resource for fast and simple quantitative querying of the gene expression data. Our study represents the first comprehensive analysis of the zebrafish optic fissure transcriptome and provides a valuable resource to facilitate our understanding of the complex aetiology of ocular coloboma.
Perfluorinated alkyl acids (PFAAs) have been detected in serum at low concentrations in background populations. Higher concentrations haven been observed in adult males compared to females, with a ...possible explanation that menstruation offers females an additional elimination route. In this study, we examined the significance of blood loss as an elimination route of PFAAs. Pooled serum samples were collected from individuals undergoing a medical procedure involving ongoing blood withdrawal called venesection. Concentrations from male venesection patients were approximately 40% lower than males in the general population for perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). A simple pharmacokinetic model was used to test the hypothesis that blood loss could explain why adult males have higher concentrations of PFAAs than females, and why males undergoing venesections had lower concentrations compared to males in the general population. The model application generally supported these hypotheses showing that venesection might reduce blood serum concentrations by 37% (PFOA) and 53% (PFOS) compared to the observed difference of 44% and 37%. Menstruation was modeled to show a 22% reduction in PFOA serum concentrations compared to a 24% difference in concentrations between males and females in the background population. Uncertainties in the modeling and the data are identified and discussed.
Used frequently in food contact materials, bisphenol A (BPA) has been studied extensively in recent years, and ubiquitous exposure in the general population has been demonstrated worldwide. ...Characterizing within- and between-individual variability of BPA concentrations is important for characterizing exposure in biomonitoring studies, and this has been investigated previously in adults, but not in children. The aim of this study was to characterize the short-term variability of BPA in spot urine samples in young children. Children aged ≥2–<4years (n=25) were recruited from an existing cohort in Queensland, Australia, and donated four spot urine samples each over a two day period. Samples were analysed for total BPA using isotope dilution online solid phase extraction–liquid chromatography–tandem mass spectrometry, and concentrations ranged from 0.53 to 74.5ng/ml, with geometric mean and standard deviation of 2.70ng/ml and 2.94ng/ml, respectively. Sex and time of sample collection were not significant predictors of BPA concentration. The between-individual variability was approximately equal to the within-individual variability (ICC=0.51), and this ICC is somewhat higher than previously reported literature values. This may be the result of physiological or behavioural differences between children and adults or of the relatively short exposure window assessed. Using a bootstrapping methodology, a single sample resulted in correct tertile classification approximately 70% of the time. This study suggests that single spot samples obtained from young children provide a reliable characterization of absolute and relative exposure over the short time window studied, but this may not hold true over longer timeframes.
•First characterization of short-term variability of urinary BPA in young children•Four urinary samples collected from children ages 2 to 4 over 48h•Between- and within-individual variability are approximately equal.•Use of one sample produces correct tertile classification 70% of the time.
Parabens, benzophenone-3 and triclosan are common ingredients used as preservatives, ultraviolet radiation filters and antimicrobial agents, respectively. Human exposure occurs through consumption of ...processed food and use of cosmetics and consumer products. The aim of this study was to provide a preliminary characterisation of exposure to selected personal care product chemicals in the general Australian population. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n=24 pools of 100). Concentrations of free and total (sum of free plus conjugated) species of methyl, ethyl, propyl and butyl paraben, benzophenone-3 and triclosan were quantified using isotope dilution tandem mass spectrometry; with geometric means 232, 33.5, 60.6, 4.32, 61.5 and 87.7ng/mL, respectively. Age was inversely associated with paraben concentration, and females had concentrations approximately two times higher than males. Total paraben and benzophenone-3 concentrations are significantly higher than reported worldwide, and the average triclosan concentration was more than one order of magnitude higher than in many other populations. This study provides the first data on exposure of the general Australian population to a range of common personal care product chemical ingredients, which appears to be prevalent and warrants further investigation.
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•First characterisation of urinary parabens, TCS and BP-3 in an Australian population.•24 urine pools consisting of 100 individual specimens each, pooled by age and sex.•Paraben concentrations significantly higher in children.•Australian population concentrations significantly higher than many others globally.
Habitat associations of 40 bird species were analysed using data from a survey of 12892 garden sites throughout the United Kingdom between 1995 and 2002. Gradients in 20 garden habitat variables and ...25 variables describing the surrounding local habitat were derived from Detrended Correspondence Analysis. The main garden axis explained 13.3% of variation in the data and described a gradient from sites containing and bounded by high levels of vegetation cover to open sites bounded by walls and fences. The main local axis explained 29.9% of variation in the data and described a gradient from rural to urban habitats. Higher probability of occurrence was detected in larger sites in 25 species and in smaller sites in four (urban-associated) species. Many species (22 out of 40) were significantly associated with the local gradient: seven species showed the highest probability of occurrence in sites within more urbanised habitats. Other species were most likely to occur in sites within rural or suburban habitats. Only five species showed a significant association with garden habitat gradient, four of these being most likely to occur in sites with highest vegetation cover. These associations were similar when controlling for garden size and for food provision in gardens. The results imply that the likelihood of many species occurring in gardens is dependent on the surrounding local habitat rather than the garden habitat. However, survey participants were likely to have "bird-friendly" gardens which may have reduced the variation in garden habitat across the sample. An assessment of the representativeness of survey sites is needed to further understand habitat associations of garden birds.
Increased public awareness of PFAS contamination in Australia has resulted in serum biomonitoring efforts in individuals in potentially affected communities. However, population-based reference ...values for assessing whether individual results exceed the typical range in the Australian general population are not currently available.
Estimate population upper bound reference values based on updated serum PFAS concentrations in pooled samples from southeast Queensland, Australia and population variation observed in the US National Health and Nutrition Examination Survey (NHANES) datasets.
We calculated ratios of 95th percentile to arithmetic mean (P95:AM ratios) using data from the NHANES 2013–14 and 2015–16 cycle samples for frequently detected PFASs: PFOA, linear and branched PFOS, perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluorohexanesulfonate (PFHxS). We estimated Australian age-specific means for PFAS using pooled serum samples collected in 2014–15 and 2016–17. We used the P95:AM ratios to estimate 95th percentile concentrations in the Australian population based on the results of the 2016–17 pooled samples.
P95:AM ratios for each PFAS were similar across NHANES cycle and age group, so overall compound-specific ratios were estimated for PFOA (2.1), PFNA (2.4), PFDA (2.7), PFHxS (2.7), and linear (2.4) and summed PFOS (2.3). Australian mean PFAS concentrations continued previously reported declining trends. The estimated P95 values can be used as preliminary substitutes for more rigorous population reference values to identify samples with clearly elevated serum PFAS concentrations in Australian biomonitoring efforts. Given uncertainties and variability inherent in this evaluation, the estimated P95 values should be interpreted with caution. Mean and estimated P95 serum PFAS concentrations in Australia should continue to be monitored to document declining trends in population serum concentrations.
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