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Montebello Islands marine sediment retains nuclear weapons-derived radionuclide contamination 70 years after detonations
Get PDFThree nuclear weapons tests were conducted in the 1950s at the Montebello Islands, an Indian Ocean archipelago in NW Australia. Anthropogenic radionuclides were introduced into the surrounding waters, where little quantification of the marine environment has occurred since. Here, we assess the distribution of anthropogenic radionuclides and plutonium (Pu) atom ratios in marine sediment throughout the Montebello Islands and the Western Australian (WA) coastline. Surface sediment was analysed for 90Sr, 137Cs, 238,239,240,241Pu and 241Am, alongside 240Pu/239Pu and 241Pu/239Pu atom ratios. The highest activity concentrations in sediment were from 239,240Pu, at 4- to 4500-fold higher in the Montebello Islands than the WA coastline, with 4-fold higher levels in the northern area of the archipelago compared to the south. Activity concentrations of 239,240Pu (\u3e600 Bq kg−1) were similar to sediment at the Marshall Islands test sites despite 700-fold higher cumulative detonation yields at the latter. Maximum activity concentrations of 90Sr, 137Cs and 241Am across the study were 140, 58 and 20 Bq kg−1 respectively. Our data indicate that the source of anthropogenic radionuclides in marine sediment in the archipelago was dominated by the local detonations, whereas WA coastline samples were additionally influenced by global fallout and Marshall Islands testing. The Pu ratios were very low, and activity concentrations relatively high, compared to world and hemispheric data, representing a distinct and ongoing Pu source that should be considered in regional and hemispheric oceanic studies
Support networks and care needs: Insights from older Vietnam-born Australians living with chronic disease
Get PDFThis study explored the support networks and care needs of older Vietnam-born adults living in Australia, using focused ethnography, and guided by Leininger\u27s Culture Care theory. Data were collected through participant observation and in-depth interviews over 7 months in Perth, Western Australia, and analyzed thematically. Twelve participants were included. Two themes emerged: “The collectivist context of disease management” and “When in Rome, do as the Romans do.” Chronic disease self-management primarily took place within family and community settings, with ethnic communities playing a significant role. Migration-related stigma influenced perceived care needs, creating a gap between perceived and actual support. Findings highlight the essential role of community and family in managing chronic diseases among older Vietnam-born Australians. Health care providers should consider collaborating with ethnic communities using family-based approaches to address these self-management needs. Future studies could explore whether these findings are applicable to other older foreign-born populations from culturally and linguistically diverse backgrounds in Australia
What are safe hemoglobin, neutrophil and platelet counts for people with hematological malignancies to participate in exercise and activities of daily living: A scoping review
Get PDFPurpose: The aim of this scoping review was to summarize the extent of the literature in relation to safe levels of platelet, hemoglobin and neutrophil count for people with hematological cancers to participate in exercise or activities of daily living (ADLs). Methods: A comprehensive search for this scoping review was completed in July 2024 across five databases: the Cochrane Library, Embase, PEDro, PubMed and OTSeeker. Original studies, reviews and expert opinion papers were included if they focused on people with active hematological cancer diagnoses or those undergoing treatment affecting bone marrow, and referenced safe levels of platelet, hemoglobin and neutrophil count for exercise or ADLs participation. Papers were included if they were published in English and after the year 2000. Results: Forty-seven papers were included. Thirty-four were prospective studies, four were retrospective studies, five were reviews and four were expert opinion papers. Forty-four (94%) referenced platelet, 36 (77%) referenced hemoglobin and 17 (36%) referenced neutrophil count. Regarding platelet count, evidence is emerging away from contradicting exercise to adapting exercise and ADLs. Regarding hemoglobin levels, there were much more distinct criteria for cessation or adaptation of exercise/activity. Neutrophil cut-off values focused on minimization of infection risk being the focus when participants were neutropenic. Conclusions: This scoping review emphasizes that, in people with hematological cancers, evidence for safe levels of blood cells cut-off values for exercise and ADL engagement is evolving, and that prescription of safe exercise and functional rehabilitation is multifactorial
Partial shading impact analysis on solar PV system performance: A MATLAB/SIMULINK study on optimal array configurations
No full textPartial shading of PV systems by clouds, buildings, or trees causes current mismatch among modules and generates more than one peak of power, reducing the power output significantly and complicating MPPT (maximum power point tracking). In this study, the performance of different PV array configurations (SP, BL, HC, and TCT) is compared under 16 partial shading conditions to determine the most suitable possible layout to mitigate the effect of shading losses. In this respect, a 7 × 7 PV array built from SunPower SPRMAX3430 panels was simulated using MATLAB/SIMULINK for 16 different shading conditions: random patterns, central, and diagonal. Results show that the TCT configuration consistently yields higher output power across various shading patterns. For instance, under long-wide shading, it achieves a 23.29% improvement in power output compared to the SP configuration. Additionally, TCT reduces mismatch power loss by up to 47.86% and enhances efficiency without introducing complex circuitry or high costs, thereby making it a practical and cost-effective solution for large-scale PV installations exposed to dynamic shading. These findings offer practical insights into improving solar PV efficiency under diverse shading conditions by optimizing array configurations, without the need for complex or costly MPPT enhancements, and thus supporting the design of more robust and economical renewable energy systems
Artificial Intelligence audio upscaling by the addition of prosody
No full textText-to-speech conversion has been extensively researched and developed since the advent of integrated circuits in computers in 1958. Over sixty years later, most computer-generated voices remained easily identifiable as robotic. The aim of this study was to enhance the realism of computer-generated text-to-speech systems. Increased realism improves artificial voices for individuals reliant on assistive technologies. This research demonstrated that the variable modulated timings of syllables was the most effective way of making robotic sounding voice, become more naturally human. The variable timings reflected the human need to draw breath, with faster speech and longer breaks between words for longer sentences. The research identified classification engines designed for prosody and emotional capture, and examined studies capturing paralinguistic elements capable of conveying more meaning than the literal interpretation of spoken words. Emotive text-to-speech engines were also analysed to leverage prior knowledge of techniques required for modifiable pitch, timbre, and tempo, thereby creating a richer audio experience within the text-to-speech algorithm. Through laboratory experiments, this research created a modular platform for digital speech enhancement. The study filled gaps in academic knowledge, contributing to the development of a flexible and scalable approach to text-to-speech enhancement. Applications of this algorithm include improving high-definition audio codecs for telephony, restoring old recordings, and enhancing human-computer interfaces. Such advancements have the potential to lower barriers to computing and improve accessibility for a wide range of users
The role of IgG N-glycosylation in insulin resistance
No full textBackground. Insulin resistance, a fundamental pathophysiological feature of metabolic disorders, is primarily driven by adipose tissue inflammation. However, reliable biomarkers capturing the underlying immunometabolic processes remain limited. IgG N-glycosylation regulates inflammatory responses and has been implicated in metabolic diseases, yet its specific role in insulin resistance requires further investigation. This PhD aimed to identify the role of IgG N-glycosylation in insulin resistance and its associated inflammatory processes.
Methods. IgG N-glycosylation profiles were analysed in 313 human participants categorized into three groups based on the homeostatic model assessment for insulin resistance (HOMA-IR): insulin-sensitive (HOMA-IR \u3c 2.69 without diabetes, n = 75), mild insulin resistance (HOMA-IR ≥ 2.69 without diabetes, n = 155), and severe insulin resistance (HOMA-IR ≥ 2.69 with type 2 diabetes, n = 83). Canonical correlation analysis was conducted to explore the overall relationship between IgG N-glycosylation and insulin resistance-related inflammatory markers, including tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), and adiponectin. Mediation analysis was performed to evaluate the contribution of IgG N-glycans to insulin resistance via inflammation. Ordinal logistic regression was used to assess the association between IgG N-glycans and insulin resistance severity, with discriminative power evaluated using receiver operating characteristic curves. To validate the dynamic changes in IgG N-glycosylation and its mechanistic role during insulin resistance progression, a longitudinal observational study was conducted in insulin-resistant rat models. Both group-specific and time-specific alterations in IgG N-glycosylation profiles were analysed using a linear mixed-effects model. To further investigate potential mechanisms, adipose tissue inflammation was evaluated through macrophage infiltration and inflammatory markers (TNF-α, IL-6, CRP, and adiponectin), while insulin signalling in adipocytes was assessed via the expression of the insulin receptor, insulin receptor substrate-1 (IRS-1), and glucose transporter-4 (GLUT4).
Results. Pro-inflammatory IgG N-glycoforms, characterized by reduced sialylation and galactosylation, along with increased bisecting N-acetylglucosamine, were observed as insulin resistance severity increased in humans. Significant correlations between human IgG N-glycans and inflammatory markers were observed across the insulin-sensitive (r = 0.599, p \u3c 0.05), mild insulin resistance (r = 0.461, p \u3c 0.05), and severe insulin resistance (r = 0.666, p \u3c 0.01) groups. Human IgG N-glycosylation significantly influenced insulin resistance (β = 0.406, p \u3c 0.001), partially via modulating inflammatory markers. Increased glycoforms FA2[6]G1 (OR: 0.86, 95% CI: 0.78-0.96) and A2G2S2 (OR: 0.88, 95% CI: 0.82-0.94) were associated with a lower insulin resistance risk in humans, with respective area under the curves (AUCs) of 0.752, 0.683, and 0.764 for the insulin-sensitive, mild insulin resistance, and severe insulin resistance groups. These findings were mirrored in insulin-resistant rat models, where stage-specific changes in IgG N-glycosylation were observed during insulin resistance progression: an initial increase in galactosylated and sialylated glycans (anti-inflammatory) during early glucose impairment, followed by a transition toward reduced galactosylation and sialylation (pro-inflammatory) at later stages. These changes coincided with enhanced adipose tissue inflammation, as evidenced by increased macrophage infiltration, elevated TNF-α, IL-6, and CRP, and reduced adiponectin. Additionally, impaired insulin signalling was observed in adipocytes, characterized by decreased expression of the insulin receptor, IRS-1, and GLUT-4.
Conclusion. IgG N-glycosylation contributes to insulin resistance by modulating inflammatory responses and undergoes dynamic, stage-specific alterations during insulin resistance development, serving as an immunometabolic modulator. Pro-inflammatory IgG N-glycoforms are associated with adipose tissue inflammation and may play a critical role in initiating insulin resistance. Glycoforms FA2[6]G1 and A2G2S2 emerge as protective biomarkers, offering potential for predicting and preventing insulin resistance
Crises in Australian education, the push for educational technology and the medium-oriented perspective of Neil Postman
Get PDFFrom teacher shortages to declining literacy, the Australian education system faces multiple crises. This paper turns to the work of Neil Postman, who started as a high school teacher but later turned towards communication and media studies, to provide an alternative account of parts of this crisis, especially those around the role of technology in education. In his early works, his concern is attached to the concept of education as a ‘subversive concept’ and then a ‘conserving concept’ – first aiming to create young people engaged in civic society, then aiming to preserve written culture against television. After a middle period in which he broadened his critique of technology, Postman made a late return to education, reviving democratic critiques against the technophilic version of education that elevated the economy and individualism over civic society. This paper connects these works together as a comprehensive technology-oriented critique of education, arguing that both the principles and application of technology in Australian education have corrupted the meaning and outcomes of education
Evaluating coal-Jatropha curcas composite briquettes as sustainable fuel alternatives
Get PDFCoal is a major fuel source but raises environmental concerns. This study investigated the feasibility of utilizing a composite briquette sustainable fuel produced from subbituminous coal and Jatropha curcas biomass. Briquettes were prepared with varying weight ratios of coal to J. curcas biomass (90:0–0:90) using corn starch as a binder. The influence of this ratio on the briquettes’ properties was comprehensively evaluated through proximate analysis, ultimate analysis, scanning electron microscopy (SEM), and X-ray fluorescence (XRF) analysis. The results revealed that increasing the J. curcas content in the briquettes gradually decreased the moisture content, ash content, and fixed carbon content while increasing the volatile matter content. The elemental composition analysis showed a decreasing trend in carbon and sulfur content with increasing J. curcas, while nitrogen and oxygen content increased. The gross calorific value (GCV) exhibited a significant positive correlation with the coal content, reaching a maximum value of 28.29 MJ/kg for briquettes specially composed of J. curcas biomass. These findings suggest that coal–J. curcas briquettes offer a promising alternative fuel source with tailorable properties depending on the desired balance between burning characteristics and calorific value. Further research could explore the combustion behavior and emission profiles of these briquettes to assess their environmental impact
Investigating the biological determinants influencing the release of circulating tumour DNA
No full textCirculating tumour DNA (ctDNA) has received enormous attention over the last decade owing to its biomarker potential in cancer detection, monitoring, and genotyping. Despite substantial advancements made in these fronts, little is known of the mechanisms/factors that influence ctDNA released by tumours. The lack of mechanistic framework to relate the biological factors associated with ctDNA release has posed a challenge to interpreting ctDNA results in clinical settings. Here, we ctDNA released from six pairs of BRAF inhibitor- sensitive and matching resistant melanoma cell lines in vitro, and two pairs in vivo, examining factors like apoptosis, necrosis, and proliferation that could potentially affect ctDNA levels. Additionally, we assessed the impact of baseline and cytokine-activated mouse and human-derived macrophages on ctDNA levels produced by melanoma cells in vitro, developing self-optimised co-culture experiments. Finally, xenograft tumour models were evaluated for melanoma cell-intrinsic factors and infiltrating tumour macrophages as modulators of plasma ctDNA.
In in vitro models, five out of the six cell pairs (83.3%) demonstrated a statistically significant increase in ctDNA shedding in BRAF inhibitor-resistant melanoma cells compared to their sensitive counterparts. The main difference in ctDNA levels between these cell pairs was in the amount of high molecular weight ctDNA released, followed by mononucleosomal and polynucleosomal ctDNA. The elevation in ctDNA was consistently associated with the elevation of apoptosis and necrosis, varying in a cell-specific manner. Notably, there was a strong positive correlation between changes in ctDNA over time and cell proliferation.
Protocols for in vitro co-culture experiments of mouse and human-derived baseline and cytokine-activated macrophages with melanomas were developed to investigate the role of macrophages on ctDNA levels. Results consistently showed reduced ctDNA levels in cultures with macrophages, which was associated with their phagocytic capacity.
Xenograft models showed differences in ctDNA release between the two sensitive-resistant melanoma pairs tested. BRAF-inhibitor resistant M249 R4 melanoma cells demonstrated significantly lower release of ctDNA compared to sensitive M249, consistent with their release pattern in vitro. The other pair, SKMel28 and its resistant counterpart SKMel28 BR9, showed no difference in ctDNA shedding. Notably, the resistant cell SKMel28 BR9 xenografts exhibited significantly higher number of macrophages than SKMel28 tumours, suggesting these macrophages might consume ctDNA, resulting in lower levels in circulation, in contrast to in vitro settings- where the TME was absent. Indeed, a strong negative correlation between the macrophage infiltrate and ctDNA levels was observed for SKMel28 BR9 tumours, further supporting the role of macrophages in modulating ctDNA shedding into the circulation.
These findings underscore the notion that cellular and TME features may influence ctDNA release into circulation, and therefore impacting diagnostic tests based on ctDNA analysis. In particular, macrophages were found as a key biological factor that affect ctDNA levels in circulation. Overall, studying ctDNA biology is essential to solidify its role as a powerful liquid biopsy tool
Clostridioides (Clostridium) difficile in children and adolescents in the community in Cambodia
Get PDFBackground: Clostridioides (Clostridium) difficile transmission between community and healthcare settings has been increasingly reported. We aimed to identify the prevalence and molecular epidemiology of C. difficile colonising adolescents and non-hospitalised children in Cambodia. Methods: Stool samples were collected from 266 students at the University of Health Sciences (UHS) in Phnom Penh, between July and August 2022, and 246 children ≥1 year old visiting the outpatient department (OPD) at Angkor Hospital for Children in Siem Reap, between January and August 2022. C. difficile culture, toxin gene detection and PCR ribotyping were performed. Results: Overall, C. difficile was recovered from 07/266 specimens (2.6 %) from UHS students and 59/246 specimens (23.9 %) from OPD children. The overall prevalence of C. difficile in children peaked in April, and of toxigenic strains peaked in August. Children with loose stools were less likely to be colonised by C. difficile (COR = 0.05, 95 %CI: 0.008–0.32) than children with normal stools. UHS students were colonised only by toxigenic C. difficile. Of the 66 isolates, 36 % (24/66) were toxigenic: C. difficile ribotype (RT) 017 was the most predominant, followed by RTs 012, 046, 056, QX709, 001, 014/020 and QX710. Non-toxigenic strains accounted for 35 RTs including 32 novel RTs that had not been isolated previously. Conclusions: The findings of only toxigenic strains in adolescents and the high prevalence of C. difficile in OPD children suggest exposure to C. difficile within the community; thus, appropriate interventions may be needed. Genotypic identification of diverse C. difficile is important for molecular epidemiological purposes