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Assessing the effect of anthocyanins through diet and supplementation on cognitive function in older adults at risk for dementia: protocol for a randomised controlled trial
Introduction: Promising evidence is emerging for the procognitive, anti-inflammatory and neuroprotective properties of dietary flavonoids, particularly anthocyanins that provide red, purple and blue plant pigments.
Methods and analysis: The ‘Food for Thought’ study is a multicentre, 6-month randomised, parallel 3-arm clinical trial. Its primary aim is to investigate whether anthocyanin consumption, either through diet or supplementation, can prevent memory loss progression and improve inflammatory and cardiovascular health in older adults at risk for dementia. Eligible participants will include those aged 60–85 years with a diagnosis of amnestic mild cognitive impairment or with a self-referral of memory concerns and scoring ≤13 on the Memory Index Score within the Telephone Montreal Cognitive Assessment screening test. Participants will be randomised to one of three arms: High anthocyanin (‘purple foods’) diet (aiming for a target of 250 mg anthocyanins/day); freeze-dried product derived from blackcurrants (250 mg anthocyanins/day); or control (coloured maltose powder). The primary outcome is auditory anterograde memory functioning assessed by the Buschke and Grober Free and Cued Selective Reminding Test-Immediate Recall. Secondary outcomes are additional cognitive functions including processing speed, working memory, aspects of executive functioning (attentional shifting and word generativity) and premorbid estimate as well as subjective memory problems and self-reported depression symptoms. Additional secondary outcomes are blood pressure, inflammatory biomarkers, brain-derived neurotrophic factor, fatty acid profile, apolipoprotein E and polyphenol metabolites, gut microbiota composition and function and vascular and microvascular endothelial function tests. Repeated measures analysis of variance and/or mixed linear modelling will evaluate changes over time, with the inclusion of covariates
Image-based mesh generation for constructing a virtual representation of engineered wood product samples
The complex structure of timber has traditionally been difficult to model as it is a highly heterogeneous material. The density and material properties for structural species such as Pinus radiata (radiata pine) can vary greatly across the growth rings. Numerical simulation methods are becoming more prevalent as a method of predicting moisture migration, stress and strain distributions, and fungal/rot intrusion in engineered wood products (EWPs). All these applications require a computational mesh that captures the growth ring structure to facilitate an accurate assessment of the performance of EWPs. In this work, a low-cost image-based algorithm is developed for generating a virtual representation of a small cross laminated timber panel sample. Specifically, the proposed method results in a virtual description of an EWP sample comprised of a triangular prismatic mesh where the nodes are aligned on the growth rings of each individual timber component of the EWP, with specific wood material properties allocated to each mesh element. Each small component is treated individually and we assume there is no longitudinal variation in the density, pith location, and pith angle within the mesh structure. The initial step involves analysing an image of the end grain pattern of a single clear wood sample to identify the growth rings using a spectral clustering algorithm. Next, the centre of the tree (pith) is located through an iterative constrained least-squares algorithm to determine the pith angle. Image analysis of an anatomical image combined with the pith location allows for a constant density value to be assigned to each mesh element. The capability of this framework is then demonstrated by simulating the moisture migration and heat transfer throughout a CLT sample under atmospheric and saturating boundary conditions. Furthermore, the virtual representation provides the basis for simulating additional physical and biological phenomena, such as moisture-induced swelling, decay and fungal growth
Quantifying the resistance of Australian wheat genotypes to Pratylenchus thornei based on a continuous metric from a factor analytic linear mixed model
Genetic resistance to the parasitic root-lesion nematode, Pratylenchus thornei, is one of the main management strategies cereal growers can use to minimise the impact of nematodes on winter cereal cropping. Screening of genotypes in the presence of P. thornei populations must provide reliable resistance measures that are realised under field conditions. Adoption of the latest statistical methodologies can help to better differentiate between resistant and susceptible genotypes. In this study, post-harvest P. thornei population densities were measured from a collection of 17 field experiments, with varying starting P. thornei population densities, conducted between 2011 and 2018 in locations across the northern grain growing region of eastern Australia. The experiments primarily consisted of wheat genotypes. The post-harvest P. thornei population densities were analysed across multiple environments in a linear mixed model framework, with a factor analytic structure used to model genotype by environment (G E) interaction effects exclusively for wheat genotypes. In general, genetic correlations between environments were found to be high, indicating limited G E interaction for resistance to P. thornei. Post-processing of results using the factor analytic selection tools (FAST) method provided a measure of the overall performance for each wheat genotype, as well as a stability measure reflecting the consistency of the resistance status across environments. The FAST method quantified genotype resistance on a continuous scale, better reflecting the nature of genetic resistance based on a quantitative variable such as nematode population density, and provided a statistically robust and informative means of aiding selection decisions for resistance to P. thornei
Dynamics of productivity in pigeonpea [Cajanus cajan (L.) Millsp.] in subtropical Australia
Pigeonpea productivity can be enhanced by optimally matching the physiology of genotypes to environmental conditions. Information on crop responses to the environment has been lacking for the short-duration pigeonpea genotypes, which are being trialed to develop the Australian pigeonpea industry. The objective of this study was to examine the dynamics of productivity in relation to radiation use efficiency (RUE) and its influence on yield partitioning. Seven field trials, employing three pigeonpea [Cajanus cajan (L.). Millsp.] genotypes, were established at the Gatton Campus, the University of Queensland, Australia, in 2017/2018 and 2018/2019 summer seasons. The study reveals that leaf area development, influenced by growing environment, genotypes, and their interactions, were the key factors for the differences in leaf area duration and RUE. Pigeonpea planted in December had higher seasonal (1.11 g MJ−1) as well as reproductive (0.71 g MJ−1) RUE, resulting in significant differences in total dry matter (TDM) and grain yield (GY). GY was positively associated with seasonal RUE (R2 = 0.62), and the relationship was stronger (R2 = 0.83) for the reproductive phase (RUE(R)). The positive association between GY and RUE(R) suggested that maintaining optimum leaf area during the grain filling period is crucial to achieve higher productivity. Variations in GY were related to amount and rate of TDM accumulation before flowering (R2 = 0.51 and R2 = 0.53, respectively). Hence, achieving greater TDM before flowering was determinant for achieving higher productivity. The present study provided updated information on dynamics of productivity that will enable more comprehensive modelling of pigeonpea adaptation under subtropical conditions
Comprehensive analysis of glulam delamination through finite element modelling considering heat and mass transfer, plasticity and fracture mechanics: a case study using high density hardwood
With the ongoing emphasis on sustainable and eco-friendly construction, there is a rising demand for high-strength and high-stiffness engineered wood products. This trend presents both opportunities and challenges for the Australia’s hardwood industry, particularly concerning native forest-grown spotted gum (Corymbia citriodora). Glue laminated (glulam) spotted gum beams cannot be confidently commercialised due to the difficulty for its high-density to satisfy the bond integrity criteria (referred to as “delamination test”) for external products in accordance with the Australia and New Zealand Standard AS/NZS 1328.1. For in-depth understanding of the delamination process, an accurate numerical model represents a valuable and time-efficient tool. The aim of this study is to develop and detail such a model, considering heat and mass transfer, drying stresses, plasticity and fracture propagation models, using COMSOL Multiphysics 5.5. The model was validated against a series of wetting and drying experiments on spotted gum glulam, considering both moisture content variation and crack propagation along the gluelines. Results from the validated model showed that delamination is principally due to the tensile stress applied to the gluelines
Potential of heartwood extracts as wood preservatives combined with linseed oil in 8-year above-ground and in-ground field trials
The current study assessed the efficacy of heartwood extracts from Tectona grandis, Dalbergia sissoo, Cedrus deodara, and Pinus roxburghii, combined with linseed oil, as protectants for two non-durable wood species against termites and decay fungi. Stakes measuring 45.7 × 1.9 × 1.9 cm and blocks measuring 12.5 × 3.75 × 2.5 cm of the sapwood of southern pine (Pinus sp.) and cottonwood (Populus sp.) were impregnated via vacuum pressure with individual heartwood species extract, linseed oil, or a combination of both. For comparison, solid heartwood stakes and blocks of the wood species used to obtain extracts were also included in the tests. All samples were exposed to decay and termites for eight years at a test site in southern Mississippi using ground contact (AWPA E7) and ground proximity (AWPA E26) tests. Results showed that combining heartwood extract and linseed oil resulted in greater resistance to termites and decay in cottonwood and southern pine compared to using only linseed oil or the individual heartwood species extract in both tests. However, most of the samples that were treated with the combination treatment failed and, in either test, these treatments were not as effective as commercially used wood preservatives, such as copper naphthenate (CuN) or disodium octaborate tetrahydrate (DOT). Additionally, solid heartwood P. roxburghii stakes and blocks decayed completely and failed due to termite attack after eight years in the field in both tests. After eight years in the field, C. deodara and D. sissoo stakes were severely attacked by decay and moderately to severely attacked by termites. Blocks of these two species exposed in a covered ground proximity exposure showed slight attack by termites and decay fungi. Tectona grandis stakes showed moderate decay damage and slight termite attack in the ground contact test. Blocks of T. grandis showed slight damage from fungi and termites in the ground proximity test after eight years in the field
Hymenopteran parasitoids of fall armyworm (Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)) in Australia, with the description of five new species in the families Braconidae and Eulophidae
Fall armyworm, Spodoptera frugiperda (J.E. Smith) is an invasive pest of agriculturalcrops including sweet corn and maize. The moth was first recorded in Australia inJanuary 2020 and is now considered established in most states and territories, andresearch is underway to develop management strategies. Extensive rearing ofS. frugiperda larvae and eggs occurred from March 2020 to April 2023 to under-stand the parasitoid complex present in Australia and identify potential biologicalcontrol agents. We report here on the hymenopteran parasitoids reared duringthis period, which were identified using a combination of morphology and COIDNA barcoding, and provide images, a key to species, and contextual informationto facilitate future research. Twelve species of parasitoids from five families ofHymenoptera are formally reported as parasitising S. frugiperda in Australia. Fivespecies are here described as new: Chelonus patbat Fagan-Jeffries, sp. nov.(Braconidae), Chelonus trojanus Fagan-Jeffries, sp. nov. (Braconidae), Coccygidiummellosiheroine Atkin-Zaldivar & Fagan-Jeffries, sp. nov. (Braconidae), Coccygidiumnecatrix Atkin-Zaldivar & Fagan-Jeffries, sp. nov. (Braconidae), and Euplectrus frugi-perdata Fagan-Jeffries, sp. nov. (Eulophidae)
Understanding the Adhesion Performance of Glued Laminated Timber Manufactured with Australian Softwood and High-Density Hardwood Species
To be commercialised, glued laminated timber must typically conform to a strict bond integrity assessment. While the associated testing protocols vary slightly from country to country, the general method consists of a series of swelling (water immersion) and shrinkage (drying) cycles. The approach is independent of the species and adhesive type. Those cycles strain the gluelines to a level depending on the species’ moisture uptake, timber dimensional movement and modulus of elasticity, as well as adhesive layer elasticity. High density and high modulus of elasticity materials frequently fail within the glueline regions rather than within the timber and therefore fail the bond integrity assessment. To better understand the mechanisms that lead to glueline failure, glulam samples were manufactured using three prominent Australian commercial timbers of various densities (Radiata pine – Pinus radiata, Southern pine – Pinus caribaea/Pinus elliottii, and Spotted gum – Corymbia citriodora) and two structural adhesive types (resorcinol formaldehyde and polyurethane). Using advanced measurement techniques (digital image correlation and strain gauges), the response of the different species and adhesive types to moisture swelling and shrinkage, as well as times at which glueline separation occurs, were captured. A relationship was observed between moisture uptake and delamination percentages with spotted gum producing significantly higher levels of delamination and significantly lower moisture uptake values, compared to both radiata pine and southern. While the polyurethane glued samples on average produced higher levels of delamination, the digital image correlation data indicates that the time at which this delamination occurs is later than the samples glued with resorcinol formaldehyde. No relationship exists between the block shear strength, wood fibre amounts, and delamination percentages
Modelling unseen flow pathways of water and contaminants in the Wet Tropics: the role of alluvial palaeochannels
Nutrients from agriculture in catchments draining to the Great Barrier Reef (GBR) are a stressor of this important ecosystem. Current GBR catchment models do not mechanistically link movement of nutrients from paddocks to rivers. An understanding of these water and nutrient flow pathways is crucial in any attempt to model and manage the GBR catchments. Conduits of water transport include surface drains and subsurface features such as palaeochannels. Palaeochannels are a common feature in alluvial landscapes, representing old river or stream beds that are often filled with coarse in-fill material which make them ideal water storage zones and conduits of water movement, either by recharging surrounding ground water (GW) or exchanging water with surface drainage networks (e.g., Keen et al., 2007, Owen & Dahlin, 2010, McLachlan et al., 2017). Their presence results in heterogeneity of soil and aquifer properties, which need to be accounted for in any attempt to assess water and nutrient transport in these flat agricultural landscapes
Mycorrhizal fungi increase plant nutrient uptake, aggregate stability and microbial biomass in the clay soil
Arbuscular mycorrhizal fungi (AMF) are beneficial soil organisms that can form symbiotic associations with the host plant roots. Mycorrhizal symbiosis between plant root and fungi can influence plant diversity and ecosystem productivity. However, the impacts of AMF frequently documented in the loamy to sandy soil, whereas it has no precise mechanism of influencing plant productivity, macronutrient uptake, and aggregation in a clay soil. A pot experiment was carried out to investigate the impact of AMF on plant growth, nutrient uptake and soil aggregation in a clay soil of Bangladesh. Okra (Abelmoschus esculentus L.) was cultivated over 105 days with AMF and without AMF (NAMF) with 5 replications. Plant productivity, nutrient uptake, soil organic carbon (SOC), microbial biomass carbon (MBC), aggregate stability (MWD), and glomalin-related soil protein (GRSP) were measured after 105 days. Results showed that the plant productivity and nutrient availability in soil and their subsequent uptake in AMF were significantly higher compared to the NAMF treatment (p < 0.01). We observed 17% increase in aggregate stability (measured as mean weight diameter) and 28% increase in organic carbon in AMF inoculated soil compared to NAMF. The microbial biomass carbon and GRSP were significantly higher in the AMF than NAMF treatment (p < 0.01). The findings highlight that AMF introduction can be a promising tool for improving plant production and soil condition in the clay soil instead of conventional farming system