159 research outputs found

    Characterisation of microplastics is key for reliable data interpretation.

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    Microplastic research has gained attention due to the increased detection of microplastics (<5 mm size) in the aquatic environment. Most laboratory-based research of microplastics is performed using microparticles from specific suppliers with either superficial or no characterisation performed to confirm the physico-chemical information detailed by the supplier. The current study has selected 21 published adsorption studies to evaluate how the microplastics were characterised by the authors' prior experimentation. Additionally, six microplastic types described as "small" (10–25 μm) and "large" (100 μm) were commercially acquired from a single supplier. A detailed characterisation was performed using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, particle size analysis, and N2-Brunauer, Emmett and Teller adsorption-desorption surface area analysis. The size and the polymer composition of some of the material provided by the supplier was inconsistent with the analytical data obtained. FT-IR spectra of small polypropylene particles indicated either oxidation of the particles or the presence of a grafting agent which was absent in the large particles. A wide range of sizes for the small particles was observed: polyethylene (0.2–549 μm), polyethylene terephthalate (7–91 μm) and polystyrene (1–79 μm). Small polyamide (D50 75 μm) showed a greater median particle size and similar size distribution when compared to large polyamide (D50 65 μm). Moreover, small polyamide was found to be semi-crystalline, while the large polyamide displayed an amorphous form. The type of microplastic and the size of the particles are a key factor in determining the adsorption of pollutants and subsequent ingestion by aquatic organisms. Acquiring uniform particle sizes is challenging, however based on this study, characterisation of any materials used in microplastic-related experiments is critical to ensure reliable interpretation of results, thereby providing a better understanding of the potential environmental consequences of the presence of microplastics in aquatic ecosystems

    Solar-driven semi-conductor photocatalytic water treatment (TiO2, g-C3N4, and TiO2+g-C3N4) of cyanotoxins: proof-of-concept study with microcystin-LR.

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    Cyanobacteria and their toxins are a threat to drinking water safety as increasingly cyanobacterial blooms (mass occurrences) occur in lakes and reservoirs all over the world. Photocatalytic removal of cyanotoxins by solar light active catalysts is a promising way to purify water at relatively low cost compared to modifying existing infrastructure. We have established a facile and low-cost method to obtain TiO2 and g-C3N4 coated floating photocatalysts using recycled glass beads. g-C3N4 coated and TiO2+g-C3N4 co-coated beads were able to completely remove microcystin-LR in artificial fresh water under both natural and simulated solar light irradiation without agitation in less than 2 h. TiO2 coated beads achieved complete removal within 8 h of irradiation. TiO2+g-C3N4 beads were more effective than g-C3N4 beads as demonstrated by the increase reaction rate with reaction constants, 0.0485 min−1 compared to 0.0264 min−1 respectively, with TiO2 alone found to be considerably slower 0.0072 min−1. g-C3N4 based photocatalysts showed a similar degradation pathway to TiO2 based photocatalysts by attacking the C6–C7 double bond on the Adda side chain

    Protocol for a mixed-methods investigation of quality improvement in early childhood education and care in Australia

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    International recognition of the early years as a crucial foundational period has led to the design and implementation of quality rating and improvement systems (QRIS) that define, communicate, and monitor the components of quality in early childhood education and care (ECEC). The aim of these policies is to achieve effective quality assurance and improvement through a system-oriented approach to assessment and evaluation. Informed by ecological systems theory, this paper outlines a three-phase, mixed-methods design for researching a national sample of child care centres that showed overall improvement on the Australian National Quality Standard (NQS) assessment and rating (A&R) criteria. The study samples are drawn from a national dataset of centre-based child care services with two or more A&R rounds and an initial rating of Working Towards NQS (N = 1,935). The results of this study will provide insights into the macro-, exo-, meso- and micro-systems level factors and strategies that support quality in ECEC services

    Aging microplastics enhances the adsorption of pharmaceuticals in freshwater.

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    Plastic pollution is an increasing environmental concern. Pollutants such as microplastics (< 5 mm) and pharmaceuticals often co-exist in the aquatic environment. The current study aimed to elucidate the interaction of pharmaceuticals with microplastics and ascertain how the process of photo-oxidation of microplastics affected the adsorption of the pharmaceuticals. To this end, a mixture containing ibuprofen, carbamazepine, fluoxetine, venlafaxine and ofloxacin (16 μmol L−1 each) was placed in contact with one of six either virgin or aged microplastic types. The virgin microplastics were acquired commercially and artificially aged in the laboratory. Polypropylene, polyethylene, polyethylene terephthalate, polyamide, polystyrene and polyvinyl chloride microparticles were evaluated at two sizes, described as small (D50 < 35 μm) and large (D50 95–157 μm). Results demonstrated that the study of virgin particles may underestimate the adsorption of micropollutants onto microplastics. For virgin particles, only small microparticles of polypropylene, polyethylene, polyvinyl chloride and both sizes of polyamide adsorbed pharmaceuticals. Aging the microplastics significantly increased the adsorption of pharmaceuticals by microplastics. Fluoxetine adsorbed onto all aged microplastics, from 18% (large polyethylene terephthalate) to 99% (small polypropylene). The current investigation highlights the potential of microplastics to act as a vector for pharmaceuticals in freshwater, especially after aging

    Adsorption of cyanotoxins on polypropylene and polyethylene terephthalate: microplastics as vector of eight microcystin analogues.

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    Plastics are utilised globally but are of environmental concern due to their persistence. The global presence of microplastics (particles <5 mm in all dimensions) in freshwater environments is increasingly reported, as has the presence of cyanobacterial toxins, including the microcystins. We elucidated the potential role of microplastics as a vector for eight microcystin analogues. Two sizes of polypropylene (PP) and polyethylene terephthalate (PET) microparticles were evaluated. The median particle size distribution (D50) was 8–28 μm for small particles, and 81–124 μm for large particles. Additionally, microcystin-LR and -LF were evaluated individually using small PP and PET to elucidate the adsorption behaviour in the absence of competition. Microcystin hydrophobicity, polymer material, and particle size were key factors influencing adsorption to the plastic microparticles. The small size PP microparticles demonstrated a high affinity for the 8 microcystin analogues. The proportion of microcystin adsorbed onto the small particles of PP after 48 h contact was between 83 and 100%, depending on the analogue. Of all analogues investigated, only microcystin-LW and -LF adsorbed onto the larger sized PP and PET microparticles. Individually, greater amounts of MC-LF adsorbed onto the small PET (19%) compared to when it was present in the mixture of microcystins (11%). While MC-LR did not adsorb onto small PET microparticles in the mixture, 5% adsorption was observed when individually in contact with small PET microparticles. The results demonstrated that microplastics can adsorb eight different microcystin analogues and that more hydrophobic analogues are more likely to adsorb than less hydrophobic analogues

    Mapping the leap: Differences in quality improvement in relation to assessment rating outcomes

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    Introduction: Australia’s National Quality Standard (NQS) outlines the criteria to assess the quality of early childhood services. A four-point rating scale: (i) Exceeding NQS; (ii) Meeting NQS; (iii) Working Toward NQS; and (iv) Significant Improvement Required is applied to services following a regular assessment and rating process. Settings rated as Working Toward are reassessed within 12 months. Most settings achieved a one-step improvement in this Time 2 reassessment, moving to a Meeting rating but some settings made a two-step improvement, moving to an Exceeding rating. The QIP is a key document used by authorities to assess the quality of a service. Methods: A grounded theory, data driven approach was taken to deepen understanding of quality rating improvements in long day care services in Australia of quality rating improvements by early childhood education and care [ECEC] services in Australia. This study, part of the second phase of a three phase study involved a document analysis of the Time 2 Quality Improvement Plans (QIPs) of a representative sample of Long Day Care (LDC) services (n = 60) from all Australian states and territories to determine what factors may have contributed to these different levels of improvement, with a focus on Quality Area 1 (QA1) (Educational programs and practices) and Quality Area 7 (QA7) (Governance and leadership). The study utilized the semantic analysis tool Leximancer 4.5. Leximancer 4.5 statistically analyses the semantic relationships between concepts in documents by measuring word proximity and correlation. The software creates visual maps of concepts and their connections to each other in texts. Concepts located near one another on the map are more likely to be contextually related. This tool is particularly useful when there are multiple, complex documents to analyze, reducing the potential biases that can arise from documents that use language with which these researchers are very familiar with. Results: The analysis found clear differences between the Time 2 QIPs of services who had made a two-step rating improvement and those who made a one-step improvement. Two-step (Exceeding NQS) category improvers for QA1 placed attention in their QIPs on improvement to the program and overall practice, with an orientation to the role of the educational leader. Two-step (Exceeding NQS) category improvers for QA7 seemed to be more oriented to a systemic view of the processes encompassed by QA7; how the management of the service and information supports the work of educators, with stronger links made between leadership roles (the manager and nominated supervisor) and the work of educators. Discussion: The QIPs demonstrated how the intentional and systemic processes in these quality areas related to practice, management, and leadership

    The role of digital technologies in supporting quality improvement in Australian early childhood education and care settings

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    This national study explored the role of digital technologies in early childhood education and care settings and whether they could contribute to quality improvement as reported by educators and assessors of quality in Australia. In this paper, data from Stage 2 of the Quality Improvement Research Project were used, which comprised 60 Quality Improvement Plans from educators linked with 60 Assessment and Rating reports from the assessors who visited early childhood centres as part of the administration of the National Quality Standards by each of Australia’s State and Territory jurisdictions. Bronfenbrenner’s ecological systems theory (Bronfenbrenner, U. (1995).Developmental ecology through space and time: A future perspective. In P. Moen, G.H. Elder, Jr., & K. Lüscher (Eds.), Examining lives in context: Perspectives on the ecologyof human development (pp. 619 – 647). American Psychological Association. https://doi.org/10.1037/10176-018; Bronfenbrenner & Ceci, Bronfenbrenner and Ceci, Psychological Review 101:568 – 586, 1994) was adopted to facilitate a systemic and dynamic view on the use of digital technologies in these 60 ECEC settings. References (e.g. comments/ suggestions/ examples) made by the educators about the implementation of digital technologies were counted and thematically analysed. Results revealed the strong role new technologies (e.g. documentation and management platforms, tablets, apps, etc.) play in the majority of ECEC settings and especially in relation to three of the seven Quality Areas: Educational programme and practice (Quality Area 1); Collaborative partnerships with families and communities (Quality Area 6) and Governance and leadership (Quality Area 7). Future directions for research are suggested and implications for embracing a more holistic, integrated and broad view on the use of digital technologies are discussed

    Intragenic copy number variation within filaggrin contributes to the risk of atopic dermatitis with a dose-dependent effect

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    Loss-of-function variants within the filaggrin gene (FLG) increase the risk of atopic dermatitis. FLG also demonstrates intragenic copy number variation (CNV), with alleles encoding 10, 11, or 12 filaggrin monomers; hence, CNV may affect the amount of filaggrin expressed in the epidermis. A total of 876 Irish pediatric atopic dermatitis cases were compared with 928 population controls to test the hypothesis that CNV within FLG affects the risk of atopic dermatitis independently of FLG-null mutations. Cases and controls were screened for CNV and common FLG-null mutations. In this population the 11-repeat allele was most prevalent (allele frequency 51.5%); the 10-repeat allele frequency was 33.9% and the 12-repeat allele frequency was 14.6%. Having excluded FLG mutation carriers, the control group had a significantly higher number of repeats than cases (χ2P=0.043), and the odds ratio of disease was reduced by a factor of 0.88 (95% confidence interval 0.78–0.98, P=0.025) for each additional unit of copy number. Breakdown products of filaggrin were quantified in tape-stripped stratum corneum from 31 atopic dermatitis patients and urocanic acid showed a positive correlation with total copy number. CNV within FLG makes a significant, dose-dependent contribution to atopic dermatitis risk, and therefore treatments to increase filaggrin expression may have therapeutic utility

    Photocatalytic removal of the cyanobacterium Microcystis aeruginosa PCC7813 and four microcystins by TiO2 coated porous glass beads with UV-LED irradiation.

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    Cyanobacteria and their toxic secondary metabolites are a challenge in water treatment due to increased biomass and dissolved metabolites in the raw water. Retrofitting existing water treatment infrastructure is prohibitively expensive or unfeasible, hence 'in-reservoir' treatment options are being explored. In the current study, a treatment system was able to photocatalytically inhibit the growth of Microcystis aeruginosa and remove released microcystins by photocatalysis using titanium dioxide coated, porous foamed glass beads and UV-LEDs (365 nm). A 35% reduction of M. aeruginosa PCC7813 cell density compared to control samples was achieved in seven days. As a function of cell removal, intracellular microcystins (microcystin-LR, -LY, -LW and -LF) were removed by 49% from 0.69 to 0.35 μg mL−1 in seven days. Microcystins that leaked into the surrounding water from compromised cells were completely removed by photocatalysis. The findings of the current study demonstrate the feasibility of an in-reservoir treatment unit applying low cost UV-LEDs and porous foamed beads made from recycled glass coated with titanium dioxide as a means to control cyanobacteria and their toxins before they can reach the water treatment plant
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