Research UNE (University of New England)
Not a member yet
39143 research outputs found
Sort by
Saving a Species – Conservation Ecology of the Endangered Western Saw-shelled Turtle (Myuchelys Bellii)
No full textThe Anthropocene era has ushered in unprecedented biodiversity loss and ecological disruption, placing numerous species, including many turtles, at risk. Turtles, ancient reptiles with a fossil record dating back over 220 million years, now face an existential crisis due to anthropogenic pressures. Conservation efforts have struggled to reverse the decline of turtle populations, with over half recognised as threatened. Turtles occupy vital ecosystem niches, and their decline poses threats to biodiversity and ecosystem stability across the globe. In Australia, the introduced European red fox (Vulpes vulpes) pose a significant threat to the persistence of freshwater turtles. Foxes raid high proportions of nests and are likely limiting juvenile recruitment. Traditional lethal fox control methods have shown limited effectiveness at reducing nest predation rates and can pose risks to non-target species. Effective alternative conservation strategies are urgently needed to bolster juvenile numbers in Australian freshwater turtle populations. One species of conservation concern is the western saw-shelled turtle (Myuchelys bellii), an endangered freshwater species with a limited distribution. Populations are characterised by a predominance of mature individuals and sustained low levels of juvenile recruitment. The predation of nests by invasive foxes has been identified as a key threat to M. bellii populations and my PhD research focuses on the implementation and evaluation of strategies to mitigate this threat. I evaluated the effectiveness of customised electric fences, in combination with individual nest protection, for shielding M. bellii nests from fox predation (Chapter 2), I compared the numbers of raided and intact turtle nests found in paired fenced treatment and unfenced control areas. I also individually protected all intact nests found in both area types with wire mesh or steel cages. The total numbers of nests found in treatment and control areas did not significantly differ, but significantly more intact nests were found in treatment areas and significantly more raided nests in control areas. The fences were occasionally damaged by livestock, wildlife, and flooding, rendering them inoperative for varying periods of time. Despite these breaks in functionality, nests inside the fences were raided on only a few occasions. My study demonstrates that electric fences can provide an effective method of protecting entire nesting areas from depredation by foxes. Despite the high efficacy of the in-situ nest protection strategies, logistical challenges in safeguarding sufficient nests, alongside threats from other predators and environmental extremes, can compromise the hatching success of eggs and reduce the number of M. bellii hatchlings that enter the waterways. Artificial incubation of eggs and the release of hatchlings into the wild is a common ex-situ strategy used to try and boost endangered turtle populations. I investigated a range of incubation temperatures to establish an optimal temperature for maximum hatching success of M. bellii eggs (Chapter 3). Eggs were kept at constant temperatures (27°C, 28°C, and 29°C) to assess the impact on incubation period, hatchling dimensions, and residual yolk. Incubation time decreased with higher temperatures. I examined egg and hatchling morphology, finding a correlation with maternal size and mass. A constant 27°C incubation temperature produced the highest hatching success and smallest external residual yolk. In this study I also developed an incubation protocol which resulted in 97% hatching success for M. bellii. This research outcome optimises artificial incubation for M. bellii and serves as a crucial guide for freshwater turtle conservation efforts. Little is known about the movement, behaviour, or survival of hatchling M. bellii in the wild. To address this gap and inform conservation actions, I monitored 39 M. bellii hatchlings using VHF microtransmitters during their first two weeks in the wild (Chapter 4). On release, the hatchlings dispersed in both upstream and downstream directions and daily movements averaged between 47–62 metres. Over the course of the study, the maximum cumulative distance moved by an individual hatchling was 2008 m. The hatchlings used grassy rivulets to traverse between pools and their movements were influenced by water temperature and water level, with higher water levels correlating with increased downstream movements. Hatchlings were predominantly located among vegetation at the water's edge, accounting for 99% of observations. Hatchlings showed a preference for shallow shoals and sections of stream with a mid-stream depth M. bellii. Additionally, my study emphasises the importance of vegetative cover along stream edges in providing shelter for hatchling M. bellii. There are critical gaps in our knowledge of M. bellii growth rates, age at size, and longevity. This information is pivotal for effective design and evaluation of conservation management actions. I analysed data from a long-term M. bellii capture-recapture study spanning more than 19 years and incorporating growth increments from 465 individual turtles with recapture intervals of at least one year (Chapter 5). I boosted the representation of juveniles in our analysis by including growth increment data retrospectively derived from scute annuli measurements and by including juveniles of unknown sex in models for both females and males. I used the Fabens modification of the von Bertalanffy growth model to refine estimates of age at maturity for M. bellii and show that the species matures at a younger age than previously estimated —approximately 11 years for females and 8 years for males. My study confirms rapid growth in M. bellii juveniles, with growth rate declining post-maturation. The refined growth models from this study will aid in population viability assessments, planning for future conservation actions, and the evaluation of past conservation efforts for M. bellii. In response to the urgent need for effective conservation strategies, my study focuses on evidencebased actions to reinforce juvenile numbers in M. bellii populations. This body of work provides novel insights into M. bellii ecology and practical recommendations for conserving this endangered species
Age-related differences in cerebral blood flow and cortical thickness with an application to age prediction
No full textCerebral cortex thinning and cerebral blood flow (CBF) reduction are typically observed during normal healthy aging. However, imaging-based age prediction models have primarily used morphological features of the brain. Complementary physiological CBF information might result in an improvement in age estimation. In this study, T1-weighted structural magnetic resonance imaging and arterial spin labeling CBF images were acquired in 146 healthy participants across the adult lifespan. Sixty-eight cerebral cortex regions were segmented, and the cortical thickness and mean CBF were computed for each region. Linear regression with age was computed for each region and data type, and laterality and correlation matrices were computed. Sixteen predictive models were trained with the cortical thickness and CBF data alone as well as a combination of both data types. The age explained more variance in the cortical thickness data (average R2 of 0.21) than in the CBF data (average R2 of 0.09). All 16 models performed significantly better when combining both measurement types and using feature selection, and thus, we conclude that the inclusion of CBF data marginally improves age estimation
Exploring Resistance Gene Diversity and Evolution in the Genomes of Diverse Myrtaceae Species
No full textMyrtaceae species are the most significant family of economic and ecological importance in Australia and are considered dominant in many diverse ecosystems. However, many are threatened by co-evolved and exotic diseases, including myrtle rust infection caused by Austropuccinia psidii. Intracellular nucleotide-binding sites and leucine-rich repeat (NBS-LRR) receptors play an essential role in plant response to biotic stresses. To investigate variation in phenotypic responses and identify the diversity and evolution of disease resistance gene family to facilitate future functional resistance gene (R gene) isolation in Myrtaceae, I screened diverse families of Eucalyptus globulus against A. psidii and conducted comprehensive annotation of NBS-encoding gene repertoires from long-read genome assembly of 21 species belonging to the Eucalypteae tribe of Myrtaceae. The genomes were sequenced using Oxford Nanopore Technology (ONT). From the annotated genomes, I identified over 55,536 NBS-encoding genes among 885,078 protein-coding gene models, of which 38,406 belong to the common TNL, CNL and RNL gene classes. Three-quarters of the annotated NBS-encoding genes were found in clusters. All species contained genes present in pairs of head-to-head orientation, suggesting the potential presence of sensor-executer genes that function in immune signalling. In this analysis, I examined 233 unique non-canonical domains (NCDs) integrated into the NBS encoding genes, with varying frequencies of occurrence among the species. Characterisation of the identified NCDs fused to the NBS-encoding genes in terms of diversity within and between species and gene classes shows that the type of NCDs and their integration frequency is highly varied among the species and the gene classes. Only a quarter of the identified NCDs were found in many analysed genomes. In contrast, the remaining three-quarters were rare among the species, indicating continued independent integration and R gene diversification. From the prevalent NCD domains, DNA, Ca2+ and carbohydrate binding domains, including zf-BED family, Jacalin, Calmodulin-binding and Protein kinase domains are most abundant across all species and gene classes. It was examined that Jacalin domain is highly expanded across all species, being integrated in C-terminal to the NBS genes that encode an N-terminal TIR domain (TN) but lacked leucine-rich repeat (LRR) domain, and rarely into the N-domain that lacks both N-and-C- terminal domain (N). Overlaying the NCDs over the phylogenetic tree of NCD containing proteins NB-ARC region reveals Jacalin domain from TN and N were clustered in a large single clade. Hence, I suggest that these domains have evolved with distinct characteristics likely due to duplication from ancestral integration. Jacalin domain integrated into TN genes in a repeated fashion as LRR does in typical NLR genes, suggest that the Jacalin domain might have replaced the LRR domains for pathogen sensing. I describe this potential new class of R genes as TNJ (TIR-NBS-Jacalin) genes. Phylogenetic analysis of TNJ from the broader representative species of Myrtaceae showed that TNJ formed a monophyletic clade between the TNL clades and evolved with the conservation of necessary motifs in its NBS domain and essential amino-acid residues including the catalytic glutamic acid (E) in its TIR domains. Shannon entropy and positive selection analyses show that most hyper-variable sites and residues that underwent diversifying selection have been clustered in the Jacalin region of TNJ, suggesting that surfaces of the Jacalin domain would potentially harbour a cluster of pathogen recognition specificity determining residues. These findings suggest that TNJ would potentially be a new class of R gene family in Myrtaceae with Jacalin as a replacement for LRR. The large number of NBS-encoding gene repertoire identified in this finding suggests the pathogen recognition potential possessed in Myrtaceae and the importance of such documentation in a future comparative and evolutionary study in flowering plants. The phenotypic screening shows high genetic variability among individuals with resistance responses manifested as a non-symptom or hypersensitive response (HR) to A. psidii. Individuals within families exhibited highly resistant and highly susceptible responses are a potential for targeted resistance sequencing to narrow down the identification of presence-absence markers variation influencing disease resistance for candidate NLR genes associated to the major resistance loci
Influence of regular exercise on body fat and eating patterns of patients with intermittent claudication
Get PDFThis study examined the impact of regular supervised exercise on body fat, assessed via anthropometry, and eating patterns of peripheral arterial disease patients with intermittent claudication (IC). Body fat, eating patterns and walking ability were assessed in 11 healthy adults (Control) and age- and mass-matched IC patients undertaking usual care (n = 10; IC-Con) or supervised exercise (12-months; n = 10; IC-Ex). At entry, all groups exhibited similar body fat and eating patterns. Maximal walking ability was greatest for Control participants and similar for IC-Ex and IC-Con patients. Supervised exercise resulted in significantly greater improvements in maximal walking ability (IC-Ex 148%–170% vs. IC-Con 29%–52%) and smaller increases in body fat (IC-Ex −2.1%–1.4% vs. IC-Con 8.4%–10%). IC-Con patients exhibited significantly greater increases in body fat compared with Control at follow-up (8.4%–10% vs. −0.6%–1.4%). Eating patterns were similar for all groups at follow-up. The current study demonstrated that regular, supervised exercise significantly improved maximal walking ability and minimised increase in body fat amongst IC patients without changes in eating patterns. The study supports the use of supervised exercise to minimize cardiovascular risk amongst IC patients. Further studies are needed to examine the additional value of other lifestyle interventions such as diet modification
Supporting Maternal Autonomy in Medical Abortion Pathways
No full textFrom the woman's perspective, the clinical safety of medical abortion using a recommended regimen is well-established. There is, however, considerable debate about options for women who change their mind wishing to discontinue a medical abortion and continue their pregnancy instead. Mifepristone antagonization with progesterone, known colloquially as "abortion reversal", has been proposed by some and opposed by others in political, clinical, and scientific arenas. Current literature and clinical guidelines recommend against providing active measures for women who change their mind after commencing medical abortion, citing pharmacological implausibility of the progesterone-after-mifepristone approach, and lack of quality evidence from well-designed clinical trials in this area. For women in such a situation who choose to then try and keep their pregnancy, adherence to the four pillars of medicine, namely autonomy, justice, beneficence and non-maleficence, favours treatment of these women with progesterone. This chapter critically analyses key areas relevant to the intervention of mifepristone antagonism by progesterone, including demand, pharmacological basis, clinical evidence, safety for the woman, patient autonomy, and clinician duty of care. Other important issues requiring consideration include: evidence for untreated pregnancy continuation rates after mifepristone, success rates relating to gestational age, and the actual number of women discontinuing medication abortion and seeking to keep their pregnancy
Meat chicken breeder stress: causes, effects, and mitigation strategies
No full textMeat chicken (broiler) breeders are exposed to many stressors, and arguably the most severe are feed restrictions during rearing and aggression during production. Chronic stress is a significant animal welfare concern and reduces productive performance in meat chicken breeders, including reduced egg production and hatchability. As such, minimising stress through effective management strategies is essential for the economic viability and sustainability of the chicken meat industry. This review evaluates approaches to reduce stress associated with hunger and aggression, including qualitative feeding programmes, appetite suppressants, and shed design. We highlight knowledge gaps that must be addressed before strategies can be implemented to reduce stress in breeders on commercial farms. Relaxing commercial feed restrictions could reduce hunger, improve welfare and boost productivity, and current feeding practices should be reassessed for modern breeder strains, focusing on behaviour and stress. Although slower-growing strains and certain feed additives can reduce hunger, they remain impractical due to the economic costs and potential welfare concerns, respectively. Qualitative feed restrictions, involving non-nutritive ingredients such as fibre, show promise in alleviating hunger-related stress. However, research is required to determine the optimal concentrations and composition to balance satiety, gut health, and water retention without causing other welfare problems like wet litter and dermatitis. Managing aggression-related stress currently relies on physical mutations, which are also problematic for welfare. Alternative strategies – such as adjusting sex ratios, synchronising sexual maturity and optimising lighting and shed design – offer potential solutions. Insights from rodent research suggest that building stress resilience through environmental complexity could also be effective. However, it is crucial to determine what environmental changes are both beneficial for the birds and feasible to implement in commercial conditions. We recommend a multidisciplinary approach to reducing stress in meat chickens, combining dietary fibre with strategies to enhance stress resilience, enabling birds to better cope with challenging situations
Influence of Ni on carbon nanotube production with Fe-based catalysts
No full textThis study investigates the role of Ni in CNT production using Fe-based catalysts. Among the various catalysts used, such as 40Fe–0Ni, 40Fe–1Ni, 40Fe–3Ni, 40Fe–5Ni, 40Fe–7Ni, and 40Fe– 10Ni, the 40Fe–5Ni catalyst achieved a notable yield of 5.80 gC per g metal, which is higher than the 1.03 gC per g metal obtained with the pure Fe catalyst. DFT study reveals that Fe3Ni exhibits stronger carbon binding, enabling more efficient CNT production and supporting our experimental results
What does the seawater desalination industry need from polymer scientists?
No full textThe seawater desalination industry does not need exotic two-dimensional materials. However, it faces challenges in terms of membrane resilience to stressors such as temperature and oxidation and especially in the area of (bio)fouling. Membrane replacement is a large part of the operating expenditure of modern desalination plants and anything that increases the effective lifespan of a membrane will have economic impact. There are also emerging requirements for membrane selectivity, especially in desalination-adjacent brine-valorisation activities. These challenges provide abundant scope for the exercise of creativity by polymer scientists
Contextualised, Not Neoliberalised, Approaches to Families in Five Countries: Quality and Practice
No full textPartnerships with parents in early childhood education and care services are a hallmark of quality education. Educators in Western countries work within a highly regulated environment, where government documents, such as frameworks, standards, and curricula, direct most of their work, time, and energy. Despite this, data from our mixed methods online survey from Australia, Canada, Denmark, Georgia, and Italy revealed a strong resistance to the homogeneity these documents prescribe. For the quantitative data, we used cross-tabulation and descriptive statistics. For the qualitative data, we used deductive thematic analysis using a parent–educator partnership framework. Educators described parents in their service as partners in their child's education. This included efforts to share information, consult, negotiate, and build partnerships; problem solve; and monitor, report and manage the partnership. The educators talked about the uniqueness of their approaches to parents and families within their contextualised services. They then revealed how these unique features impacted their notions of quality and practice in these services. This will be of interest to policymakers, educators, and teacher educators
News that Moves the Market: DSEX-News Dataset for Forecasting DSE Using BERT
No full texttock market is a complex and dynamic industry that has always presented challenges for stakeholders and investors due to its unpredictable nature. This unpredictability motivates the need for more accurate prediction models. Traditional prediction models have limitations in handling the dynamic nature of the stock market. Additionally, previous methods have used less relevant data, leading to suboptimal performance. This study proposes the use of Bidirectional Encoder Representations from Transformers (BERT), a pre-trained Large Language Model (LLM), to predict Dhaka Stock Exchange (DSE) market movements. We also introduce a new dataset designed specifically for this problem, capturing important characteristics and patterns that were missing in other datasets. We test our new dataset of headlines and stock market indexes on various machine learning techniques, including Decision Tree (DT), Logistic Regression (LR), K-Nearest Neighbors (KNN), Random Forest (RF), Linear Support Vector Machine (LSVM), Long Short-Term Memory (LSTM), Gated Recurrent Units (GRUs), Bidirectional Long Short-Term Memory (Bi-LSTM), BERT, Financial Bidirectional Encoder Representations from Transformers (FinBERT), and RoBERTa, which are compared to assess their predictive capabilities. Our proposed model achieves 99.83% accuracy on the training set and 99.78% accuracy on the test set, outperforming previous methods