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Mineralisation of atmospheric CO2 in hydromagnesite in ultramafic mine tailings – Insights from Mg isotopes
No full textIn this study we present the first Mg isotope data that record the fate of Mg during mineralisation of atmospheric CO2 in ultramafic mine tailings. At the Woodsreef Asbestos Mine, New South Wales, Australia, weathering of ultramafic mine waste sequesters significant amounts of CO2 in hydromagnesite [Mg5(CO3)4(OH)2·4H2O]. Mineralisation of CO2 in above-ground, sub-aerially stored tailings is driven by the infiltration of rainwater dissolving Mg from bedrock minerals present in the tailings. Hydromagnesite, forming on the surface of the tailings, has lower δ26Mg (δ26MgHmgs = −1.48 ± 0.02‰) than the serpentinised harzburgite bedrock (δ26MgSerpentinite = −0.10 ± 0.06‰), the bulk tailings (δ26MgBulk tailings = −0.29 ± 0.03‰) and weathered tailings containing authigenic clay minerals (δ26MgWeathered tailings = +0.28 ± 0.06‰). Dripwater (δ26MgDripwater = −1.79 ± 0.02‰) and co-existing hydromagnesite (δ26MgHmgs = −2.01 ± 0.09‰), forming in a tunnel within the tailings, and nodular bedrock magnesite [MgCO3] (δ26MgMgs = −3.26 ± 0.10‰) have lower δ26Mg than surficial fluid (δ26Mg = −0.36‰) and hydromagnesite.
Complete dissolution of source minerals, or formation of Mg-poor products during weathering, is expected to transfer Mg into solution without significant alteration of the Mg isotopic composition. Aqueous geochemical data and modelling of saturation indices, along with Rayleigh distillation and mixing calculations, indicate that the 26Mg-depletion in the drip water, relative to surficial water, is the result of brucite dissolution and/or precipitation of secondary Mg-bearing silicates and cannot be assigned to bedrock magnesite dissolution. Our results show that the main mineral sources of Mg in the tailings (silicate, oxide/hydroxide and carbonate minerals) are isotopically distinct and that the Mg isotopic composition of fluids and thus of the precipitating hydromagnesite reflects both isotopic composition of source minerals and precipitation of Mg-rich secondary phases. The consistent enrichment and depletion of 26Mg in secondary silicates and carbonates, respectively, underpins the use of the presented hydromagnesite and fluid Mg isotopic compositions as a tracer of Mg sources and pathways during CO2 mineralisation in ultramafic rocks
Adolescent Killers: Using two timeline methods to map life histories of adolescents that Kill
No full textResearch into homicides typically focuses on adults offenders, as they represent the majority of cases. There are, however, a number of cases involving individuals under the age of 18 committing murder. To understand homicides, researchers have been increasingly using temporal methods. The current research investigates the life histories of adolescents who have committed murder, using two leading temporal methods: Behavior Sequence Analysis and Crime Script Analysis. Results show the complexities of behavioral pathways in terms of transitions between behaviors and groups of behaviors into scenes. The application of this research is in helping practitioners and researchers to better understand the life histories of offenders and understanding the strengths and limitations of each method
Early age at menarche is associated with post‐menarche back pain: An analysis of the Raine Study
No full textIntroduction
Back pain (BP) experienced by females during adolescent years appears to predispose them to an increased likelihood of its presence in adulthood. Understanding this phenomenon by identifying risk factors of those at risk potentially fosters preventative strategies and effective treatments.
Objectives
To investigate for associations between post-menarche BP and low back pain (LBP) and age at menarche (AAM) in Australian adolescents using the Western Australian pregnancy cohort (The Raine Study).
Methods
This study used data from a longitudinal cohort study. BP data were collected retrospectively using a questionnaire. Menarche data was split into three established age classifications early (14-years) and late (≥14-years). Logistic regression models examined the effect of AAM on BP.
Results
666 female participants provided valid menarche data with 183 (27.5%) early AAM, 429 (64.4%) normal AAM and 54 (8.1%) with late AAM. The mean AAM was 12.59 years. BP was disclosed by 27.5% in the 14-year follow-up and 31.5% in the 17-year follow-up. Participants who had early AAM had 79% higher odds of experiencing BP compared to participants who had normal AAM, after adjusting for confounders at the 14-year follow-up (adjOR 1.79, 95% CI 1.18–2.64).
Conclusion
There is evidence of an association, in this cohort, of early AAM with post-menarche BP. This result identifies an area for future exploration, including understanding this mechanism which may lead to the development of effective intervention measures.
Significance
Age at menarche is related to a range of health issues. This study sought to investigate if it was a risk factor for spinal pain. We used an existing Australian data base to explore this possibility and found an association with early age onset and post-menarche back pain. This result identifies an area for future exploration, including understanding this mechanism which may lead to the development of effective intervention measures
Reading the Tulsa V S Naipaul Archive
No full textIn 1993, the University of Tulsa purchased the V S Naipaul papers and installed the V S Naipaul Archive, principally a paper archive, a year later. In this essay, which is also a homage to the late Professor Tom O’Regan, I examine the value of archives, a scholar’s use of them and the ‘Freudian impressions’ or latent texts embedded in in them. Although once established an archive can acquire mystical power, in reading it, one has to be conscious of processes of selection and redaction built into the archive. One ‘Freudian impression’ that requires attending to is the role of Naipaul’s first wife Patricia Naipaul in the growth of the writer’s craft. The archival evidence suggests that his best works were written while she was alive
Voluntary school fees in segregated public schools: How selective public schools turbo-charge inequity and funding gaps
No full textParent-generated revenue in public schools, in the form of fee-giving or fundraising, is fast developing as a robust source of financial revenue for public schools in OECD countries. In this paper we draw on a comprehensive empirical dataset of parent-generated financial revenue for public schools located in New South Wales, Australia. We draw on a census dataset of all public schools over a five-year period, examining how funding gaps are exacerbated by selective processes and school segregation. The analysis compares parent-generated financial revenue within two types of public schools, namely select-entry public schools and local comprehensive public schools. We find that select-entry public schools consistently generate more than three-times more income across different measures, and over a five-year period. Furthermore, the amount of revenue for select-entry schools annually grows, and the gap increases, suggesting that as market logics intensify, cyclical disadvantage and residualisation of comprehensive public schools increase
Conventional tagging of sharks in Western Australia: The main commercial species exhibit contrasting movement patterns
No full textUnderstanding movement patterns underlies effective management and conservation measures. The current study summarises the main findings from a tagging program of Western Australian sharks to provide insights into the movement patterns of the main commercial shark species: dusky (Carcharhinus obscurus), sandbar (C. plumbeus), gummy (Mustelus antarcticus) and whiskery (Furgaleus macki) sharks. Between 1993 and 2020, >12 000 individuals from 52 taxonomic groups were implanted with conventional tags in Western Australia, of which 8.5% were recaptured. Most of the tagged (74.5%) and recaptured (95.8%) individuals belong to the four main commercial shark species. Recaptured individuals of these species, as well as tiger (Galeocerdo cuvier) and bronze whaler (C. brachyurus) sharks showed displacements of >1000 km and rates of movement (ROMs) of >10 km day–1, with the exception of whiskery sharks, which showed much slower ROMs (<3 km day–1). Despite tagged dusky and sandbar sharks being predominately small individuals and gummy and whiskery sharks being large individuals, dusky and sandbar sharks had faster ROMs and a greater proportion of recaptures outside the release zone. Our study provided the information required for estimating movement rates across different fishing zones and therefore defining the spatial scale for managing these shark species
Crop breeding for a changing climate: integrating phenomics and genomics with bioinformatics
No full textClimate change and an additional 3 billion mouths to feed by 2050 raise serious concerns over global food security. Crop breeding and land management strategies will need to evolve to maximize the utilization of finite resources in coming years. High-throughput phenotyping and genomics technologies are providing researchers with the information required to guide and inform the breeding of climate smart crops adapted to the environment. Bioinformatics has a fundamental role to play in integrating and exploiting this fast accumulating wealth of data, through association studies to detect genomic targets underlying key adaptive climate-resilient traits. These data provide tools for breeders to tailor crops to their environment and can be introduced using advanced selection or genome editing methods. To effectively translate research into the field, genomic and phenomic information will need to be integrated into comprehensive clade-specific databases and platforms alongside accessible tools that can be used by breeders to inform the selection of climate adaptive traits. Here we discuss the role of bioinformatics in extracting, analysing, integrating and managing genomic and phenomic data to improve climate resilience in crops, including current, emerging and potential approaches, applications and bottlenecks in the research and breeding pipeline
Smouldering combustion of sewage sludge: Volumetric scale-up, product characterization, and economic analysis
No full textThis contribution reports volumetric scale-up, full product characterization, and the economic performance of sewage sludge (SS) treatment via self-sustaining smouldering combustion. Here, we firstly conducted laboratory-scale smouldering experiments, using a local SS supported by sawdust as an auxiliary fuel, to identify optimized operating conditions. Under a Darcy air flux of 3.5 cm/s, the highest wet SS destruction rate of 44.00 kg/(h·m2) is achieved when the mass ratio of sand/SS/sawdust is 18/5/1. These optimized conditions were then employed in a pilot-scale experiment, the result of which suggests a successful scale-up. Systematic characterization of the smouldering products from the laboratory-scale experiment under optimized conditions was then carried out. The results suggest that the content of total organic carbon in the ash residue is very low (3.81 wt%, dry basis), indicating effective destruction of the SS via smouldering. The condensed liquid is dominated by water (96.11 wt%), with organic carbon content of 0.33 wt%. These organic compounds are rich in N-/O-containing monocyclic aromatic and heterocyclic compounds. The non-condensable flue gas mainly consists of O2 (16.08 vol%), CO2 (3.72 vol%), CO (8964.69 mg/Nm3), CH4 (93.38 mg/Nm3), and non-methane hydrocarbon (298.26 mg/Nm3) rich in volatile organic compounds such as benzenes, aldehydes, furans, ketones, and alkanes/alkenes, necessitating a dedicated flue gas treatment facility. The economic analysis demonstrates that for the treatment of SS, the minimum charging price for running a typical smouldering project is 325.5 CNY/ton (wet basis), which is considerably competitive compared with conventional technologies
Numerical analysis of velocity magnitude on wave energy converter system in perforated breakwater
Get PDFWaves are an alternative energy source that can be used for electricity generation. Wave Energy Converter (WEC) system in perforated breakwater is potentially applicable WEC system for coastal area. The magnitude of wave energy generated is determined by the volume of sea water inside the perforated breakwater. This volumetric flow rate is calculated using the flow velocity at perforated holes on the structure slope. Therefore, this research aims to study the velocity magnitude by analyzing the interrelation among wave steepness, wave run-up and relative velocity. The method used consists of applying numeric 3D flow model in the perforated structure of the breakwater with the variation of wave height, wave period and structure slope. The result shows that, the steeper the structure, the bigger is the relative run up (Ru/H). The higher the relative run up, the higher are the relative run-up velocities (V/Vru). As the velocity increase, the volumetric flow rate inside perforated breakwater will be higher, which leads to higher wave energy. Hence, it can be concluded that the higher the velocities (V/Vru), the higher is the wave energy generated
Effects of dietary vitamin E on growth performance, body composition, antioxidant capacity, and some immune responses in Caspian trout (Salmo caspius)
Get PDFThis study was conducted to evaluate the effect of dietary vitamin E on growth performance, feed utilization, biochemical properties and some immune responses in Caspian trout, Salmo caspius. Six experimental diets were formulated with semi-purified ingredients supplemented with vitamin E in the form of DL-α-tocopherol acetate to provide the actual vitamin E concentrations of 4.9 (the basal diet), 8.6, 17.4, 35.4, 78.8 and 137.0 mg kg−1 diet, respectively. Each diet was assigned to three replicate groups of Caspian trout (initial average weight of 9.73 ± 0.34 g) for eight weeks. Weight gain ratio (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) were found to be significantly enhanced by increasing dietary vitamin E level and reached to the highest values in fish fed with 78.8 mg kg−1 vitamin E supplemented diet (P < 0.05). A significantly linear increasing trend was recorded in crude protein, fat content, superoxide dismutase (SOD) activity, liver vitamin E concentration, immunoglobulin M (IgM), and alternative complement activity (ACH50), while glutathione peroxidase (GPX) activity was linearly and quadratically enhanced in response to increasing dietary vitamin E supplementations (P < 0.05). There were also linearly and quadratically decreasing trend in alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) activities as well as serum glucose (GLC) and malondialdehyde (MDA) levels by supplementing dietary vitamin E (P < 0.05). Analysis by the polynomial regression of SGR, GLC, and SOD activity against varying levels of dietary vitamin E revealed that the optimum dietary vitamin E requirements in Caspian trout were 79.44, 78.73, and 82.16 mg kg−1, respectively