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Effect of pullulanase treatment on the structural and in vitro digestive properties of starch-ovalbumin complexes
No full textIn this study, corn starch (CS) was debranched using pullulanase (PUL) and complexed with ovalbumin (OVA) under heat-moisture-treatment (HMT) conditions to investigate the physicochemical properties, structural properties and digestibility of corn starch-ovalbumin (CSOVA) complexes with different degrees of debranching. The results showed that PUL hydrolyzed the (1 → 6)-α glycosidic bonds to produce more linear chains as debranching time progressed, and these were able to form complexes between CSOVA complexes effectively. The combination of PUL and OVA treatment significantly changed the physicochemical properties of CS, as evidenced by the reduction in viscosity and swelling of the granules. In addition, the microscopic morphology of the CSOVA complexes gradually changed from small to large aggregates. After the addition of OVA and PUL treatment for 4 h, while X-ray diffraction (XRD) showed a crystallinity shift from A-type to B + V, with relative crystallinity decreasing from 19.45 % to 14.91 %. Fourier-transform infrared (FTIR) spectroscopy confirmed altered starch-protein interactions without new chemical bonds. In vitro digestion demonstrated resistant starch (RS) content increased to 45.6 % after 4 h of debranching. This study provides scientific evidence that the corn starch treated with PUL is a better source to form CSOVA complexes, providing a valuable slow-digesting starch
Impact of firm-level climate change exposure on firm value: The moderating role of carbon transparency
No full textThis study uses a novel measure of climate change exposure at the firm level to investigate the impact of climate change on the value of Asia-Pacific non-financial firms. We examine whether increased carbon disclosure mitigates this impact. The findings reveal that a one-standard-deviation increase in climate change exposure reduces firm value by 4.14%, with this decline primarily driven by climate change-related opportunities and regulatory shock exposure. However, a higher level of carbon transparency significantly mitigates the negative effects of climate change exposure on firm value. Our heterogeneity analysis reveals that the moderating role of carbon transparency is more pronounced among firms operating in environments of lower institutional quality. These findings offer useful practical insights that can help policymakers and governance bodies design effective environmental disclosure regulations and robust institutional frameworks to reduce the adverse effects of climate change exposure on firm value
A risk index tool to minimize the risk of nitrogen loss from land to water
No full textSimple models can help reduce nitrogen (N) loss from land and protect water quality. However, the complexity of primary production systems may impair the accuracy of simple models. A tool was developed that assessed the risk of N loss as the product of N source inputs and relative transport by leaching and runoff. A dynamic process-based model was used to estimate the long-term monthly N loss risk by leaching and runoff in response to the interaction of static biophysical factors like soil type, slope, and long-term climate. Source inputs included dung and urine (from livestock), fertilizer, crop residues, and soil erosion. Estimates of the rank of N loss risk were related (r² = 0.69, p < 0.001) to 96 observations of N loss (kg ha⁻¹ year⁻¹) across nine land uses; all but two of the observations fell within 95% prediction intervals. Across land uses, leaching accounted for 84% of N loss risk. Additional observations are needed to determine if N loss risk is representative of short-rotation vegetables and to account for potential lag times between calculated and measured losses. The good performance of the tool suggests that when displayed spatially, the tool can be used to target high-risk areas with actions to reduce the risk of N loss and the likelihood of water quality impairment
Emergence of downy mildew in cocksfoot (Dactylis glomerata) and its impact on seed production in New Zealand
No full textCocksfoot (Dactylis glomerata) is a pasture species with significant economic and ecological value in temperate regions. It is an important grazing crop in New Zealand to support meat and dairy production. In 2018, cocksfoot downy mildew was identified as an emerging threat to cocksfoot seed production, particularly in the Canterbury region of New Zealand. The disease is characterised by symptoms such as seed head bleaching, chlorosis and reduced yield and quality of seeds. The causal agent has been tentatively identified as Sclerophthora cryophila based on spore morphology. Partial DNA sequencing has confirmed the organism is an oomycete, but phylogenetic analysis will be required to determine its position within the downy mildews. Further research on its biology and epidemiology is currently underway.
This study investigated the influence of temperature on sporangia formation, zoospore release and spore morphology of the cocksfoot downy mildew pathogen. Symptomatic tissues were floated on water to induce sporulation and incubated under different temperatures (4°C, 9°C, 14°C, 19°C, 24°C). Sporangia which remained attached to the tissue were collected using a cellotape strip and placed onto a microscope slide, whilst zoospores and sporangia which detached into the surrounding water were counted using a haemocytometer. The results showed that the lower temperature (4°C) was beneficial for the formation of sporangia and sustained sporulation, suggesting an adaptation to cold environments. In contrast, slightly higher temperatures (9°C, 14°C) promoted zoospore release, with zoospores tending to encyst more rapidly under these conditions. Investigation of the effect of temperature on sporangia attachment revealed that detachment was more prominent at 19°C and 24°C, whereas sporangia remained predominantly attached at 4°C, suggesting higher temperatures may promote sporangia detachment. These findings provide insights into the biology and epidemiology of cocksfoot downy mildew, supporting further research and the potential for development of effective disease management strategies in cocksfoot seed crop
Central and peripheral nervous system activity and muscle oxygenation in athletes during repeated-sprint exercise in normoxia and normobaric hypoxia
Full text linkAim: To investigate central and peripheral nervous system activity and muscle oxygenation in athletes during repeated-sprint exercise in normoxia and normobaric hypoxia.
Methods: The effects on vastus lateralis muscle strength in a cross-over study were examined in 18 athletes (13 males, 5 females) completing 10 x 6-s cycle sprints. Immediately after and again 5 minutes post-exercise, electromyography (EMG), heart rate variability, maximal voluntary contraction (MVC), muscle oxygenation, peak power output, and arterial oxygen saturation were compared to 2 baseline sets named (“Baseline” and “Pre”).
Results: Post-exercise MVC was significantly lower (6.7 ± 10.0%) than Baseline, but root-mean-square amplitude during hypoxia (all-times) was significantly lower than normoxia (0.38 ± 0.19 vs 0.41 ± 0.17 mV). Comparative frequency analysis of the percentage change in pre- to post-exercise EMG area, at low 1–29 hz (type-1 fibre) and high 75–100 hz (type-2 fibre) areas, revealed a significant reduction in type-1 fibre activity relative to type-2, by 20–30% across time and by 10% in type-1 activity between conditions. Conclusion: Exercise in hypoxia appeared to cause a temporary increase in central sympathetic nervous system activity and greater recruitment of type-2 muscle fibres, with accompanying reduction in type-1. Acute hypoxia may stimulate type-2 fibre conditioning
A 10-year evaluation of management practices and nutrient losses from dairy farms in New Zealand – Trends and drivers
No full textGood management practices (GMPs) on dairy farms have been shown to reduce contaminant losses and improve water quality. Few national long-term datasets exist globally on management practices on dairy farms over time and their effect on nutrient losses. Here, we examine 50 parameters across a 10-year period (from 2013 to 2022) thought to influence estimates of nitrogen (N) and phosphorus (P) losses (kg ha⁻¹ yr⁻¹) to water from dairy-farmed land in New Zealand. The number of farms in our database increased from 137 in 2013 to a total of 378 in 2022. The years from 2013 to 2017 were classed as ‘period 1’ and from 2018 to 2022 as ‘period 2’, which aligned with more intensive extension of GMPs. Nationally, there was a small increase in median N and P loss rates (38 – 40 kg N ha⁻¹ yr⁻¹ and 1.1 – 1.2 P kg ha⁻¹ yr⁻¹), fertiliser applied 140 – 141 kg N ha⁻¹ yr⁻¹ and total milk solids produced by 11 % between periods. However, between 1 – 42 % of farms exhibited decreasing N loss trends regionally, which were related to (in order of decreasing importance): N fertiliser applied, irrigation type, and forage establishment (cultivation) practice. Similarly, 1 – 25 % of farms with decreasing P trends regionally, trends were related to soil order, P fertiliser applied, and effluent storage method. We also found that these farms showed increased adoption of effluent and forage establishment method GMPs between periods, for example, the use of low-rate effluent application, direct drill, and minimum tillage, and increased effluent storage practice. These data suggest good management practices shown to decrease N and P losses from dairy-farmed land to water in New Zealand are being adopted; however, continued uptake on all farms will be required to achieve further improvement
Beyond cultural renaissance: Indigenous events as sites of resistance and resilience
Full text linkThe rising of the Matariki constellation (also known as Pleiades) is a special time for Māori in Aotearoa New Zealand for remembering the dead, celebrating the present, and preparing the ground for the coming year. Its observation had all but ceased by 1940, but it has experienced a resurgence since the 1990s. Previous longitudinal research into media narratives about Matariki events concluded that they acted as an expression of empowerment for Māori. In a time marked by heightened hostility towards ‘things Māori’, we ask how media narratives frame Matariki as a site of resistance, renaissance and resilience. We analyse media narratives from 2020 to 2024 using a qualitative kaupapa Māori framework. We find they have begun to connect the issues facing contemporary Māori with colonization, and make them more visible. Through the lens of Matariki, the Aotearoa NZ media are moving towards portraying a more accurate ‘reality’ of the contemporary Māori lifeworld
One bad rainstorm away from disaster: Why proposed changes to forestry rules won't solve the 'slash' problem
Full text linkThe biggest environmental problems for commercial plantation forestry in New Zealand's steep hill country are discharges of slash (woody debris left behind after logging) and sediment from clear-fell harvests.
During the past 15 years, there have been 15 convictions of forestry companies for slash and sediment discharges into rivers, on land and along the coastline.
Such discharges are meant to be controlled by the National Environmental Standards for Commercial Forestry, which set environmental rules for forestry activities such as logging roads and clear-fell harvesting. The standards are part of the Resource Management Act (RMA), which the government is reforming.
The government revised the standards' slash-management rules in 2023 after Cyclone Gabrielle. But it is now consulting on a proposal to further amend the standards because of cost, uncertainty and compliance issues.
We believe the proposed changes fail to address the core reasons for slash and sediment discharges
Why is single-use plastic still in the conservation sector toolbox?
Full text linkMicroplastic residue left in the environment from plastic chewcards in three pest mammal monitoring operations was estimated at an average of 15% of the starting weight. This finding highlight the issue of single-use plastics within New Zealand’s (NZ) conservation sector. A review of other research operations across NZ shows a significant number of plastic chewcards are deployed, potentially contributing to microplastic pollution in environmentally sensitive areas. Our research shows the need for sustainable alternatives to plastic chewcards in order to mitigate the environmental impact. Alongside an estimation of microplastic being left in the environment, we evaluated wood-pulp chewcards as a potential alternative to corflute chewcards, with results indicating wood-pulp cards maintain comparable interaction rates across key pest species. By identifying the environmental issues of microplastics in the environment and offering a potential alternative, we aim to open a dialogue about adopting more sustainable tools and practices in the NZ conservation sector
Examining the value realization of ecological agricultural products in China: A tripartite evolutionary game analysis
No full textAgricultural products are essential for nutrition and food security, particularly in China where agricultural production capacity is growing steadily. Despite the benefits of Ecological Agricultural (EA) products, including environmental protection and enhanced consumer utility, their widespread adoption and maximization of value are impeded by various factors. This study explores the intricate tripartite relationship – government, agribusiness, and consumer, in the value realization of EA products in China by establishing an evolutionary game model. The purpose is to illuminate the evolution of system equilibrium strategies across various scenarios and examine how significant external factors influence these strategies, thereby summarizing the evolutionary process of EA products' value realization and providing guidance for stakeholders' decision-making processes. The results indicate that with increased government regulatory efforts, technological advancements, and scale expansion in agribusiness, as well as the refinement of market mechanisms, the production cost of EA products decreases, leading to a steady rise in EA product prices and economic benefits for consumers purchasing them. Ultimately, the value of EA products was primarily realized through market forces. Simulation analysis using Matlab further validated the model's effectiveness and precision, highlighting the influence of government regulatory measures, consumer green sensitivity and preferences, and product base value on system equilibrium strategies. These conclusions provide insights for policymakers to facilitate the realization of EA product value and promote green and low-carbon agricultural development