Queensland Government

The northern hairy-nosed wombat (Lasiorhinus krefftii, NHNW) is critically endangered following major range and population declines during the 20th century, resulting in a population bottleneck of ~30 individuals in the 1980s. Understanding the population history, impact of extirpations, range contraction and the bottleneck in this species is critical to contextualising ongoing efforts to understand and manage surviving genetic diversity. We generated mtDNA genomes from contemporary and historical samples of the NHNW from the extant and two extirpated populations and compared mtDNA diversity and phylogeography to the closely related southern hairy-nosed wombat (L. latifrons, SHNW) from southern Australia. The NHNW had very low mtDNA diversity, with shallow phylogeographic structure across its former range. A single mtDNA haplotype has been present in the extant population since at least 1937, suggesting a small long-term female effective population size and a possible pre-1937 bottleneck. In contrast SHNWs show four to five times higher mtDNA diversity and evidence of phylogeographic divergence across the Pleistocene Eyrean Barrier. Our results highlighted the need for further genomic analyses of the extant NHNW population, to estimate the extent of inbreeding and inbreeding depression and to help minimise loss of functional genetic diversity in this species.

Abstract Offspring survival is a central component in understanding the life-history of species. With sea turtles, estimates of hatchling survival to adulthood can be traced back to theoretical considerations made over 50 years ago and before key parameters needed in the hatchling survival calculation had been quantified. Here, using up-to-date figures for adult survival rates and hence adult longevity and lifetime reproductive output, we show that the survival rate of hatchlings to adulthood will generally lie between 1 in 400 and 1 in 2000. We show that this survival rate probably varies across populations and species in line with variations in adult survival rates, remigration intervals and clutch frequency and will likely be impacted by factors such as local management, resource availability and bycatch pressures. Popular articles that tend to quote this survival rate as 1 in 1000 are broadly comparable with our estimates, although the survival rate likely varies appreciably across populations. We identify the key parameters that need to be measured for this value to be determined accurately for individual populations around the world. This approach of using values for adult reproductive output to estimate offspring survival rates to adulthood likely has broad utility across reptiles and other taxa.

We present a case study on the effects of a commercial urea spill on a stand of Avicennia marina subsp. australasica mangroves (grey mangrove) in South East Queensland, Australia, from data collected during an investigation into environmental harm. We describe the localised impact of the spill and analyse nitrogen stable isotopes and ammonium concentrations from the spill source, soil and the surrounding vegetation. The spill source (ultrapure urea) had δ15N values of -2.93‰, and δ15N values in grey mangrove leaves increased significantly with distance from the spill, indicating the decreasing uptake of spill-derived nitrogen with distance, with mean leaf δ15N -4.28‰ near the spill source compared to 4.57‰ in control samples. Mean δ15N of mangrove roots at the impacted area was 2.97‰, rising to 7.96‰ at the control area. We found lower δ15N in leaves compared to roots and spilled urea δ15N values which support previously described nitrogen pathways that have shown that ammonium assimilation occurs mainly in roots, while nitrate assimilation happens in both roots and shoots. Lower δ15N in foliage compared to roots was consistent with other studies on grey mangroves showing leaf δ15N values significantly lower than root material. Linear regression revealed a significant correlation between sediment pH and ammonium concentration, with pH reaching 9.00 in the most contaminated samples, which had ammonium concentrations in sediment of 2490 mg kg-1. Our findings highlight the localised yet significant impact of urea spills on mangrove ecosystems and support a theoretical framework for using stable isotope analysis in conjunction with sediment ammonium concentrations when assessing these impacts.

Background Achieving quality of life (QoL) outcomes for people living with HIV (PLHIV) is reliant on a mix of clinical and community service initiatives. A brief, agreed‐upon set of Patient‐Reported Outcome Measures (PROMs) may enhance shared care, strengthen service partnerships, and improve QoL monitoring and other relevant outcomes. Currently, there is no consensus on PROMs across HIV clinical, community and research settings. This study aimed to identify a small set of PROMs with Australian HIV peer, community, clinical, research and policy collaborators. Methods We conducted a review of PROM literature and Australian policy documents to assemble an initial list of social and health PROMs. A 3‐round online adapted Delphi consensus process asked participants in PLHIV peer, community, clinical, research and policy settings how important, appropriate and feasible each PROM would be in their work. A final consensus meeting confirmed the proposed structure of the PROM set. Results The review produced an initial list of 47 PROMs. The Delphi process resulted in 23 PROMs reaching consensus after Round 1 ( n = 40), which were then refined to 17 PROMs after Round 2 ( n = 34). In Round 3, participants preferred six PROMs to form a primary outcome set. Following the final consensus meeting, the PROM set included a building block structure, with a “Group A” set of six preferred PROMs (20 questions). A set of 10 “Group B” PROMs could be used optionally, depending on the specific context of community and clinical organisations, with one alternative PROM that applies across all outcomes. Conclusion This study identified 17 PROMs using an adapted Delphi consensus process that can be used to standardise measurement tools for QoL monitoring for PLHIV across community, clinical, and research settings in Australia. The future adoption of consensus‐based tools may enhance holistic, person‐centred care and improve the evaluation of shared care models.

Anthocyanins, a flavonoid subclass present in certain blue, purple and red fruits and vegetables, have potential neuroprotective properties due to their anti-inflammatory, antioxidant, and signalling effects. Clinical and epidemiological studies of anthocyanins provide promising evidence for attenuation of memory loss and improved cognitive function. We investigated the effects of anthocyanins, provided through diet or supplementation, on cognitive function and related parameters. A multi-centre, 24-week randomised, parallel 3-arm clinical trial was conducted in participants aged 60-85 years with self-reported memory complaints and scoring ≤13 on the Memory Index Score within the Telephone Montreal Cognitive Assessment (T-MoCA). Participants were randomised to high anthocyanin diet, freeze-dried product derived from blackcurrants (250 mg anthocyanins per day), or control (placebo). The primary outcome was auditory episodic memory functioning. Secondary outcomes were additional cognitive functions, subjective memory complaints and self-reported depression symptoms, blood pressure, inflammatory biomarkers, lipid profile, vascular and microvascular endothelial function tests. Mixed linear modelling evaluated changes over time using both intention-to-treat and completer analyses. Of 110 participants enrolled (mean age 69.2 years SD 6.7; 36 males, 74 females), 94 completed the study. There was no treatment × time effect on any primary or secondary outcomes. We postulate that the potential anti-inflammatory, antioxidant, and signalling effects of anthocyanins were insufficient to significantly modulate any outcomes due to participants' overall good health and lack of relevant cognitive decline. We recommend future interventional studies focus on subjects with diagnosed cognitive impairment, such as MCI and dementia, and those with more severe comorbidities, particularly chronic inflammatory conditions. Trial Sponsor: National Health and Medical Research Centre (NHMRC) Dementia Collaborative Research Centre.

Root decomposition is a key coastal wetland ecological process. Despite this, there are limited empirical studies on root decomposition. In this study, we investigated the effect of species, root size and burial habitat on root decomposition of supratidal tree species ( Casuarina glauca , Melaleuca quinquenervia ), and intertidal mangrove ( Avicennia marina ) and saltmarsh species ( Sarcocornia quinqueflora , Sporobolus virginicus ) in Southeast Queensland, Australia. Decomposition curves for all tested factors indicated a plateau in remaining root mass by the end of the experiment, and the plateau is therefore inferred as the “expected liable fraction”. Root decomposition rates and fractions of expected labile root biomass of supratidal and intertidal species were not significantly different. The percentage mass remaining of fine roots (<2 mm) of woody species varied by species, but that of coarse roots (2–20 mm) did not vary among species. Decomposition rates and expected labile fractions of roots of intertidal species were not significantly different between burial in the same habitat (“at home”) versus in habitats dominated by other species (“away”). Overall, we found lowest variation in percentage mass remaining, followed by expected labile fractions and root decomposition rates across species and habitats after 18 months. The mean root decomposition rate using two-pool asymptotic models was 0.0169 ± 0.0019 day -1 ; the mean expected labile fraction was 28.3 ± 1.0%. These experimental root decomposition results across the intertidal to supratidal zone provide insights to the drivers of decomposition rates in coastal wetlands that can be used in ecological models. • Species, root size and burial habitat had limited effects on root decomposition. • Mean asymptotic decomposition rate was 0.0169 ± 0.0019 day -1 . • Among decomposition parameters, lowest variance was found in %remaining mass.

ABSTRACT In bacteria, plasmids can confer the ability to cause disease. Although they can potentially vary in copy number, little has been reported on the dynamics of plasmids in plant‐pathogenic bacteria. Pathogenicity of the bacterium Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), which causes foliar disease in leguminous crops, including mung bean ( Vigna radiata ), has previously been linked to a plasmid. This study explored the variation in plasmid copy number among a genetically diverse collection of 25 Cff isolates using purposely designed quantitative PCR assays for chromosomal and plasmid DNA targets. Pathogenicity and virulence of six Cff isolates, including one plasmid‐free isolate, were assessed on the susceptible mung bean cultivar Opal‐AU using visual symptoms, trifoliate leaf dry weights and Cff DNA quantities following stem inoculation. Plasmid copy numbers varied significantly ( p &lt; 0.001) among plasmid‐carrying isolates, ranging from 1.37 to 2.74. For subsequent quantification in planta, the single‐copy chromosomal PCR target gene, gyrase b , was selected. Mung beans inoculated with plasmid‐carrying isolates exhibited significant variation in visual symptoms ( p &lt; 0.001), while trifoliate leaf dry weights and Cff DNA quantities did not significantly differ. The treatment using a plasmid‐free isolate was not significantly different from the negative control for each of the disease traits. Knowledge of plasmid dynamics in Cff populations lays a foundation for improved understanding of the inheritance and impact of plasmid‐related traits. The quantification assays will be useful for monitoring Cff populations, and the demonstrated variation in pathogenicity and virulence can assist efforts to breed host plant germplasm with reduced susceptibility to Cff.