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Differences in root morphologies of contrasting wheat (Triticum aestivum) genotypes are robust of a drought treatment
No full textWe aimed to assess the effect of water deprivation on root traits and to establish if the wheat cultivars Spica and Maringa would be useful as parental germplasm for a genetic analysis of root traits. Plants were grown in two markedly different soils under well-watered and water-limited treatments in controlled environment growth cabinets. The drought treatment was imposed as a gradual depletion of water over 28 days as seedlings grew from a defined starting moisture content. The root traits analyzed included length, nodal root number, thickness and nodal root angle. The relative differences in traits between genotypes generally proved to be robust in terms of water treatment and soil type. Maringa had a shallower nodal root angle than Spica, which was driven by the nodal roots. By contrast, the seminal roots of Maringa were found to be similar to or even steeper than those of Spica. We conclude that the differences in root traits between Spica and Maringa were robust to the drought treatment and soil types. Phenotyping on well-watered soil is relevant for identifying traits potentially involved in conferring water use efficiency. Furthermore, Spica and Maringa are suitable parental germplasm for developing populations to determine the genetics of key root traits
A comprehensive conceptual and computational dynamics framework for autonomous regeneration of form and function in biological organisms
No full textIn biology, regeneration is a mysterious phenomenon that has inspired self-repairing systems, robots, and biobots. It is a collective computational process whereby cells communicate to achieve an anatomical set point and restore original function in regenerated tissue or the whole organism. Despite decades of research, the mechanisms involved in this process are still poorly understood. Likewise, the current algorithms are insufficient to overcome this knowledge barrier and enable advances in regenerative medicine, synthetic biology, and living machines/biobots. We propose a comprehensive conceptual framework for the engine of regeneration with hypotheses for the mechanisms and algorithms of stem cell-mediated regeneration that enables a system like the planarian flatworm to fully restore anatomical (form) and bioelectric (function) homeostasis from any small- or large-scale damage. The framework extends the available regeneration knowledge with novel hypotheses to propose collective intelligent self-repair machines with multi-level feedback neural control systems, driven by somatic and stem cells. We computationally implemented the framework to demonstrate the robust recovery of both form and function (anatomical and bioelectric homeostasis) in an in silico worm that, in a simple way, resembles the planarian. In the absence of complete regeneration knowledge, the framework contributes to understanding and generating hypotheses for stem cell mediated form and function regeneration which may help advance regenerative medicine and synthetic biology. Further, as our framework is a bio-inspired and bio-computing self-repair machine, it may be useful for building self-repair robots/biobots and artificial self-repair systems
Isolation and genomic sequencing of foliar endophytic communities across a growing season in wild Lycium ferocissimum: A Dissertation submitted in partial fulfilment of the requirements for the Degree of Bachelor of Agricultural Science with Honours at Lincoln University
No full textA total of 15 endophytic genera were genomically identified in this study by culturing methods across three leaf tissue sampling dates, spanning from February to April 2023 in which 96 leaves were sampled. Identification was done using a PCR assay with primers specific to fungi and bacteria, followed by sequencing and identification of the PCR products. Of these 15 genera identified, 12 were not previously known to be associated with any Lycium species. Being novel research, all 15 genera identified were previously unreported as being present in L. ferocissimum. 13 were fungal and 2 were bacterial. Endophyte composition was dynamic, but overall diversity did not change considerably. The dominant genera in this study were Alternaria (50%) and Stemphylium (30%), with Neodidymelliopsis (7%) and Cladosporium (4%) making up the only 4 genera present on all 3 sampling dates. A qPCR assay was used to test each sample leaf used in this study for the presence of CaLso. The presence of CaLso in leaf samples increased from the February sampling group (1.7% positive) to April (33%), despite a considerable decrease in TPP population presence on the plants in that same period. Unexpectedly, the control group of asymptomatic leaves, also sampled in April, had the highest relative frequency of positive leaf samples (44.5%)
Development of a lucerne model in APSIM next generation: 3 Biomass accumulation and partitioning for different fall dormancy ratings
No full textModelling lucerne growth requires response functions that represent seasonal partitioning of biomass into above-ground and below-ground organs. An additional challenge is to parameterize perennial organ responses across contrasting fall dormancy (FD) genotypes. Current models use empirical approaches to simulate biomass accumulation and partitioning. This research integrated knowledge of lucerne biomass accumulation and partitioning into the Agricultural Production Systems sIMulator (APSIM) next generation (APSIM NextGen) model framework. Biomass supply was calculated from light interception and total radiation use efficiency (RUEtotal), and then allocated based on the relative demand of each organ. Leaf biomass demand was parameterized as a function of specific leaf area (SLA). Stem biomass demand was parameterized as a positive power function of shoot biomass. Root biomass (taproots and crowns) showed a strong seasonal pattern. The observed decrease of root biomass in periods of an increasing photoperiod (mid-winter to mid-summer) was assumed as remobilization to shoots and carbon loss from maintenance respiration. Periods of decreasing photoperiod showed increased biomass of root caused by greater carbon partitioning to this organ. To capture this, a model optimization approach was used to fit required parameters. Fitted parameters included a remobilization coefficient (percentage of storage biomass per day) of 0.01common to all FD cultivars tested (FD5, FD2 and FD10). The regrowth coefficient (remobilization duration) remained constant at 0.01 post-defoliation until 250 °Cd for FD5, 200 °Cd for FD2 and 300 °Cd FD 10, and then declined to 0 after another 50 °Cd. The model was parameterized to have maximal root demand in a decreasing photoperiod to capture carbon partitioning. The model had good prediction of shoot biomass (NSE=0.70) and fair prediction (NSE=0.60) of root biomass for 42 day defoliation treatments. It was less accurate for predictions of shoot biomass under a frequent (28 day) defoliation regime. This highlights the importance to include the response to limitations caused by depleted root N reserves in future model versions. The APSIM NextGen lucerne model provided a mechanistic framework to model perennial organ biomass dynamics with structural and storage components, root maintenance respiration, remobilization in spring, partitioning in autumn and the regrowth effect. This framework accounted for differences in fall dormancy of genotypes and provided a methodology that can be integrated into models of other perennial crops
Application of a decision-making framework for multi-objective optimisation of urban heat mitigation strategies
No full textThe significant number of urban heat mitigation strategies (UHMSs) and varying mitigation performances across different urban settings are challenging for governments to make decisions. In response to this challenge, we have previously developed an artificial intelligence-based decision-making framework that can provide governments with optimal UHMS in their urban contexts. To support and demonstrate the use of the framework, this study developed a prototype implementation and applied the framework in Leppington and Green Square, Sydney, Australia. The results showed that optimised UHMS combinations and key planning and design variables were automatically identified to achieve optimal multi-objective performances in reducing air temperature (0.7–0.9 °C), land surface temperature (7.5–11.3 °C), heat-related mortality rate (5.5–6.4%), thermal discomfort (0–0.5 °C), economic productivity loss (1.8–3.5%), electricity energy bills (5.2–6.1%), and implementation cost (22.2–42.2%). The successful application of the decision-making framework in two urban development cases demonstrates a novel approach for governments to obtain the optimal solution for urban heat mitigation in their cities
Effects of Zelp, an NZ Kelp product, on pasture germination and production compared to a processed nutrient solution : A dissertation submitted in partial fulfilment of the requirements for the Degree of Bachelor of Agricultural Science at Lincoln University
No full textRegenerative agriculture (RA) has be every more popular due to the consumers change towards more sustainable products. One of RA agriculture practice is to turn away from processed nutrient fertiliser and use organic fertiliser. One organic fertiliser that has been use is seaweed extract based. Seaweed extracts are suggested to improve soil health, plant health & disease resistance and to increase germination. This is said to be through, natural plant growth hormones, micronutrients, complex polysaccharides (sugars), antibacterial/antiviral properties, chelating agents and alginates. However, due to the very limited research conducted especially using common pastures in New Zealand pastoral systems it is difficult to understand if the seaweed extracts do what they suggest.
Four common pasture species were experimented using Zelp an seaweed extract plant promotor from NZ Kelp and a nutrient solution which contains equivalent amounts of nutrients. There were 2 different experiments conducted, germination test and a pot trial where Zelp and the nutrient solution were compared to each other. There were two separate germination test, one using Zelp and the other using the nutrient solution. Both tests were conducted over 15 days in an incubator set to 20C. The pot trial was completed for 3.5 months under glasshouse conditions. At the competition of the pot trial shoot and root yields measurements were completed.
The key findings from the two-germination tests completed was that lucerne seed had a greater germination % for Zelp than the nutrient solution, with a 10% increase in total mean germination. Subterranean clover and Italian ryegrass had a significant greater germination % to the control and commercially recommend rate of Zelp (2 kg/ha) than the two higher rates of Zelp (4, and 8 Kg/ha). For the pot trial there were four key findings; both Italian ryegrass and cocksfoot had an increase in shoot fresh weight when using the nutrient solution compared to Zelp. Italian ryegrass also had a greater response in the shoots dry weight using nutrient solution. The final key finding for the pot trial was that Italian ryegrass shoots: roots ratio was significantly greater when using Zelp.
Only lucerne had a greater response to Zelp compared to the nutrient solution. This is an interesting result, as it was expected that if Zelp had positive effects on one species that it would have positive effects on all of the species tested. This therefore, indicates that the effect of Zelp on seed germination % is species specific, or that the mechanism involved causing this result is species specific. Nutrient solution had greater yields in the grasses. This could be because of grasses requiring nitrogen to increase growth unlike the legumes which fix atmospheric nitrogen. Another possibility is that the nitrogen and nutrients in the nutrient solution was more readily available compared to the organic nitrogen in Kelp which is the nutrients found in Zelp. Based on these findings further research is required to fully understand Zelp’s contribution to New Zealand’s pastoral systems and if seaweed based fertiliser can be compared to the processed nutrients
Review of Development Economics
No full textThis special issue contributes to the development economics literature by highlighting the role of information communication and technologies (ICTs) in supporting rural and agricultural development. It is comprised of nine papers. Key findings from this special issue include: (1) internet use increases rural consumption diversity and agricultural productivity; (2) smartphone use empowers rural women in household decision-making and off-farm work participation; (3) smartphone-based agricultural extension services boost rural income growth; (4) a lack of ICT infrastructure and inadequate skills to use digital technologies are two key factors that lead to digital poverty traps for smallholder rural farmers; (5) ICT adoption increases the probability of rural households' access to credit and empowers rural women and farm households in relatively less developed regions to access credit; (6) digital financial inclusion reduces farmers' vulnerability to poverty; and (7) e-commerce adoption increases both sales prices and marketing costs, but the magnitude of increasing the former is higher than the magnitude of increasing the latter, which finally contributes to a higher gross return. This special issue also proposes practical instruments and implications for advancing the application of ICTs in rural areas to accelerate rural and agricultural development in the digital age
Indigenous peoples and accounting: A systematic literature review
Get PDFThe purpose of this systematic literature review on ‘indigenous peoples and accounting’ is to identify major themes and derive insights to guide future research and policy agendas. We also investigate whether accounting has been used by the indigenous peoples for emancipation. Seventy-one peer-reviewed journal articles are categorised into three clusters (imperialism, accounting profession and need for emancipation) and analysed. This review positions accounting not as a mere neutral, benign, technical practice but as a racist and ethnocentric tool through the context in which it has been practised. Accounting was an integral part of imperial rule, inheriting colonial structures and separating and reducing indigenous peoples from their own cultures and structures. Indigenous accountants remain severely under-represented; indigenous autonomy, voice and participation are vital for transforming the ethnocentric systems that have led to the devaluation of indigenous peoples. For effecting change we identify a need to focus on forward-looking solutions and how indigenous cultural values can contribute to a more enabling accounting
Activity patterns of captive red panda (Ailurus fulgens)
Get PDFWe studied the activity budgets of seven Ailurus fulgens, at three zoos within Australasia, using video cameras, and in-person observations. Red panda in this study followed a crepuscular activity pattern, with another short peak of activity around midnight. Ambient temperature greatly affected panda activity patterns; red panda allocated more time to resting and sleeping when temperatures increased. This preliminary study suggests how environmental factors affect captive red panda, which will help better inform captive facilities, and how this might impact their wild conspecifics
Orthogonal bases for biomedical inverse scattering
No full textWe present an orthonormal parameterization of the complex dielectric susceptibility for a collection of tissues relevant to diagnostic microwave imaging. We have considered frequencies in the range 1.0 GHz to 4.0 GHz, which is common for medical applications of microwave imaging. We provide an analysis of the commonly used monopole Debye model, showing poor conditioning between two of its basis functions. Analysis on multi-frequency sensitivity matrices show that our parameterization generally yields lower condition numbers than equivalent scenarios using the Debye basis. Finally, we present examples of image reconstruction comparing the use of these different bases