Murdoch University

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    The long-term uncertainty of biodegradable mulch film residues and associated microplastics pollution on plant-soil health

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    Biodegradable mulch film potentially offers an encouraging alternative to conventional (petroleum-based) plastic films. Since biodegradable films are more susceptible to rapid degradation, more microplastics (MPs) are likely to be generated than conventional films within the same time frame, probably leading to more severe MPs pollution and associated effects. However, the effect of biodegradable mulch film residues and associated MPs pollution on plant-soil health remains uncertainty. Here, we evaluated the potential effect of bio-MPs pollution on soil carbon (C) and nutrient (i.e., N and P) cycling, soil biology (microorganisms and mesofauna), and plant health, as these are crucial to agroecosystem functioning and the delivery of key ecosystem services. Unlike the inert (and therefore recalcitrant) C contained within petroleum-based MPs, at least 80% of the C from bio-MPs is converted to CO2, with up to 20% immobilized in living microbial biomass (i.e., < 0.05 t C ha−1). Although biodegradable films are unlikely to be important in promoting soil C storage, they may accelerate microbial biomass turnover in the short term, as well as CO2 production. Compared to conventional MPs, bio-MPs degradation is more pronounced, thereby inducing greater alterations in microbial diversity and community composition. This may further alter N2O and CH4 emissions, and ultimately resulting in unpredictable consequences for global climate warming. The extent to which this may occur, however, has yet to be shown in either laboratory or field studies. In addition, bio-MPs have a large chance of forming nanoplastics, potentially causing a stronger toxic effect on plants relative to conventional MPs. Consequently, this would influence plant health, crop productivity, and food safety, leading to potential health risks. It is unclear, however, if these are direct effects on key plant processes (e.g. signaling, cell expansion) or indirect effects (e.g. nutrient deficiency or acidification). Overall, the question as to whether biodegradable mulch films offer a promising alternative to solve the conventional plastic legacy in soil over the long term remains unclear

    The physicochemical properties of a starch–sodium stearoyl lactylate complex formed via annealing treatment in ethanol solutions

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    This work examined the physicochemical properties of potato starch–sodium stearoyl lactylate (SSL) complexes formed by annealing potato starch with 0.6% SSL in different ethanol solutions (65–100%). The complexes exhibited a higher iodine binding capacity compared to annealed potato starch without SSL. The iodine binding capacity values of the complexes increased from 46.65% to 96.87% as the ethanol solution concentration decreased from 100% to 65%. Rapid viscosity analysis showed peak viscosities of the complexes ranging from 11 cP to 2012 cP and breakdown values of zero, indicating that the complex pastes showed both thermal and shear stability. Differential scanning calorimetry results showed an increase in the gelatinization temperature of starch treated in SSL–ethanol solutions (65–85%) and a decrease in enthalpy. The formation of complexes markedly decreased the swelling power and solubility of the starch granules. Overall, the starch–SSL complexes formed by annealing in ethanol solution had the performance characteristics of chemically crosslinked starch and have potential applications in high-temperature processed foods

    The interaction between physical activity and sleep on cognitive function and brain beta-amyloid in older adults

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    Background Lifestyle factors such as physical activity and optimal sleep are associated with better cognition and lower levels of Alzheimer’s disease (AD) biomarkers, including brain beta-amyloid (Aβ) burden. Objective We utilised cross-sectional data from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study to determine whether self-reported physical activity (measured via the International Physical Activity Questionnaire) moderates the relationship between self-reported sleep (measured via the Pittsburgh Sleep Quality Index), cognition, and brain Aβ. Methods Participants were 349 community-dwelling cognitively normal older adults (75.3 ± 5.7 years), all of whom underwent comprehensive cognitive assessment. Data from a subset of participants (n = 201) were used for analyses with brain Aβ burden (measured by positron emission tomography) as the outcome. Result Physical activity moderated the relationship between sleep duration and episodic memory (β = −0.10, SE =0.03, p = .005), and sleep efficiency and episodic memory (β = −0.09, SE =0.04, p = .011), such that greater amounts of physical activity mitigated the impact of suboptimal sleep duration and efficiency on episodic memory. Physical activity also moderated the relationship between sleep duration and brain Aβ (β = −0.13, SE =0.06, p = .031), and overall sleep quality and brain Aβ (β = 0.13, SE =0.06, p = .027). Conclusion Our findings suggest that physical activity may play an important role in the relationship between sleep and cognitive function, and brain Aβ

    Risk-averse Volt-VAr management scheme to coordinate distributed energy resources with demand response program

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    Distributed energy resources (DERs), such as renewable energy sources (RESs) and energy storage systems (ESSs), are inevitable parts of future power grids. However, the high penetration of RESs may cause voltage violation issues in distribution levels. To this end, the application of the Volt-VAr management (VVM) scheme is highlighted. This paper aims to maintain voltage levels within standard ranges with optimal coordination of different resources at minimum operational costs and voltage deviation. In more detail, this article develops a new VVM in distribution networks to effectively coordinate novel smart grid technologies such as PV inverters, time of use demand response program (TOU-DRP), energy storage systems (ESSs) with traditional devices, including on-line tap changer transformer (OLTC) and switchable capacitor banks (SCBs). Because the coordinated VVM is a bi-objective model that minimizes both operating cost and voltage deviation, it is proposed to use the ε-constraint technique to identify optimal Pareto solutions. To handle the uncertainty related to RESs and load demands, a robust technique based on information gap decision theory (IGDT) is also utilized. The formulation is configured as a mixed-integer linear program (MILP) and solved by CPLEX. It was implemented on the 118-bus distribution network under various conditions. The simulation results clearly show that the coordination of DERs and traditional devices has a significant impact on maintaining voltage levels within permissible ranges while minimizing operational costs. A higher degree of uncertainty radius can also be obtained if DRP participates in the VVM scheme

    Leaching of phthalate acid esters from plastic mulch films and their degradation in response to UV irradiation and contrasting soil conditions

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    Phthalate acid esters (PAEs) are commonly used plastic additives, not chemically bound to the plastic that migrate into surrounding environments, posing a threat to environmental and human health. Dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) are two common PAEs found in agricultural soils, where degradation is attributed to microbial decomposition. Yet the impact of the plastic matrix on PAE degradation rates is poorly understood. Using 14C-labelled DBP and DEHP we show that migration from the plastic matrix into soil represents a key rate limiting step in their bioavailability and subsequent degradation. Incorporating PAEs into plastic film decreased their degradation in soil, DBP (DEHP) from 79% to 21% (9% to <1%), over four months when compared to direct application of PAEs. Mimicking surface soil conditions, we demonstrated that exposure to ultraviolet radiation accelerated PAE mineralisation twofold. Turnover of PAE was promoted by the addition of biosolids, while the presence of plants and other organic residues failed to promote degradation. We conclude that PAEs persist in soil for longer than previously thought due to physical trapping within the plastic matrix, suggesting PAEs released from plastics over very long time periods lead to increasing levels of contamination

    LGBTQI+ Allies in Education, Advocacy, Activism, and Participatory Collaborative Research

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    This topical book explores the ally perspective in advocating for Lesbian, Gay, Bi-sexual, Transgender, Queer and Inter-sex (LGBTQI+) human rights across American, Canadian, and Australian educational contexts. This book aims to clarify the terms and dynamics of mobilizing heterosexual and cisgender privilege in the interests of promoting safe, welcoming and inclusive educational communities for all stake holders, particularly those students who self- identify as LGBTQI+. By highlighting concrete examples of allies engaged in participatory collaborative research, and by investigating the historical and theoretical dimensions of ally work more generally, this volume presents a comprehensive research account of allies’ role in education, advocacy and activism. This book will benefit researchers, academics, and educators in higher education with an interest in gender and sexuality, the sociology of education and schools and schooling more broadly. Those specifically interested in gender studies, as well as the politics of higher education, will also benefit from this book

    Effects of product recovery methods on the yields and properties of hydrochars from hydrothermal carbonization of algal biomass

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    This contribution reports the effects of product recovery methods on the yields and properties of hydrochars produced from hydrothermal carbonization (HTC) of algal biomass. A slurry of Chlorella vulgaris with 10 wt% of solid loading was hydrothermally carbonized at 180 – 220 °C with holding time of 15 and 60 min. The resulting hydrochars were recovered by two prevailing methods, namely direct filtration and dichloromethane (DCM)-aided filtration. The results indicate that, under identical HTC conditions, compared with DCM-aided filtration, direct filtration always results in higher hydrochar yield because of the biocrude retained on its surface. The presence of residue biocrude in the hydrochars from direct filtration further leads to considerable differences in their properties, as compared with their counterparts from DCM-aided filtration. Specifically, under identical HTC temperature and holding time, DCM-aided filtration yields hydrochars of lower volatile matter contents but higher fixed carbon and ash contents, as compared with the hydrochars from direct filtration. Direct filtration generally recovers hydrochars of greater higher heating values and energy-based yields as compared to DCM-aided filtration. The product recovery methods show considerable impacts on the concentrations of Na, K, Mg, and Ca and their retentions in the hydrochars at 220 °C for 60 min, with higher concentrations and retentions of these elements being observed in the hydrochars from DCM-aided filtration. The hydrochars at 220 °C for 15 and 60 min from DCM-aided filtration show higher specific reactivity of 0.040 – 0.058 min−1 and 0.066 – 0.096 min−1 at hydrochar conversions of ≤ 82 % and ≤ 78 %, respectively, as compared with their direct-filtration counterparts, due to their higher concentrations of catalytic alkali and alkaline earth metals. These findings highlight the importance of considering product recovery methods when comparing the yields and properties of hydrochars from HTC of algae reported in the literature

    Field application of biodegradable microplastics has no significant effect on plant and soil health in the short term

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    Bioplastics (biodegradable plastics) potentially offer an encouraging alternative to conventional (petroleum-based) plastics. In practice, bioplastics inevitably generate a large number of bio-microplastics (bio-MPs, diameter <5 mm) during the degradation progress. However, the impact of bio-MPs on plant and soil health within agroecosystems remains incomplete. Here, a field study was conducted to investigate the effect of two shapes (fiber and powder) of pure polylactic acid (PLA) bio-MPs on oat (Avena sativa L.) and soybean (Glycine max (L.) Merr.) growth and soil health. Our results showed that PLA application at a representative soil loading rate of 0.2% (w/w) had no significant effect on soil enzyme activities, soil physicochemical properties (soil water content, pH, etc.), root characteristics, plant biomass, and crop yield. Thus, we conclude that soil quality, plant health, and ecosystem multifunctionality were not affected by PLA over one growing season (5 months) in the presence of either bio-MP shape (fiber and powder) for either crop species (oat and soybean). Overall, PLA based bio-MPs may not pose a significant threat to agroecosystem functions in the short term (days to months) in the field, thus may provide a viable environmentally benign solution to replace traditional non-biodegradable plastics in agroecosystems

    Food neophobia and disgust, but not hunger, predict willingness to eat insect protein

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    Due to the environmental benefits of entomophagy, a growing field of research is now investigating the factors that predict people's willingness to eat insects. In the current studies, we examined how willingness to eat insects may vary as a function of individual differences in disgust sensitivity, food neophobia, and hunger. We conducted two studies, one using a self-report measure and one using a behavioral measure of willingness to eat insects. In both studies, higher food neophobia predicted reduced willingness to eat insects. Disgust predicted lower self-reported, but not behavioral, willingness to eat insects. By contrast, hunger did not predict willingness to eat insects in either study. Our findings suggest that reducing food neophobia toward insects may be important for acceptance of entomophagy and may inform future marketing strategies that aim to encourage people to view insect protein as a viable source of nutrition


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