Doctoral (PhD) Theses

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https://hdl.handle.net/10182/9

Theses submitted by Lincoln University doctoral students.

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Open Access
The lived experience of adults with Dyspraxia/DCD : A thesis submitted in partial fulfilment of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) McAllum, Leanne Maria
Dyspraxia is an emergent social phenomenon that has generally been associated with childhood and motor coordination difficulties. The experience of Dyspraxia in adulthood is, conversely, not well understood with only a small number of studies examining Dyspraxia across the life course. Dyspraxia is predominantly conceptualised in both the research literature and practice using the biomedical model. Dyspraxia is one of several neurodivergent experiences and possibly the least well known, having only been recognised in the past two decades, in comparison to a longer social awareness of experiences such as Dyslexia and Autism. Known as Developmental Coordination Disorder (DCD) in the medical literature, the phenomenon has been etiologically defined as a physical functional deficit. By contrast, Dyspraxia can also be understood as having cognitive functional aspects, such as in the Aotearoa New Zealand context. The objectives of this research were firstly to examine the lived experiences of participants with Dyspraxia/ DCD in relation to predominant social biomedical conceptualisations. A second objective was to identify the repercussions of contemporary social framings of Dyspraxia/ DCD in Aotearoa New Zealand and how Dyspraxia is understood and addressed, particularly in adulthood. The approach taken to answer the research objectives was that of the thematic analysis of semi-structured interviews undertaken with both people with Dyspraxia and professional participants. In this work, a qualitative approach was employed in the form of semi-structured interviews with twenty-three people with Dyspraxia to better understand the lived experience. Further, twenty-six professionals in medical and education fields were also interviewed to investigate the role of institutions on the Dyspraxia lived experience. Participants were located through two gatekeeper organisations, cold-calling and snowball sampling techniques. This research, undertaken by an insider researcher with Dyspraxia, highlighted that an examination of Dyspraxia is unable to be considered independently of social contexts. Further, it was found that biomedical framings affected the lived experience of participants with Dyspraxia/DCD in Aotearoa New Zealand and the subsequent social response to the phenomenon. The lived experience of Dyspraxia in adulthood was found to have implications for how people with Dyspraxia construct their identity with Dyspraxic participants describing the need to adapt in normative social settings to achieve inclusion. This thesis adds to current conceptualisations by utilising the capabilities approach (CA) to examine the lived experience of Dyspraxia in relation to the medical and social models. Throughout are a range of accounts from Dyspraxic participants, describing their attempts to access the capabilities necessary to ensure the life outcomes they value. The CA can account for the significant changes between childhood and adulthood described by study participants within their social worlds. In contrast to the biomedical perception that DCD is a physical deficit, this thesis shows that the attainment of capabilities is complex and evolves across the lifespan in response to personal heterogeneities but also the social environments that Dyspraxic participants inhabit. The CA was found in the discussion to improve upon, and complement, current conceptualisations of Dyspraxia. Conceptualising Dyspraxia in alternate ways to better explain study findings, such as using the CA, suggests a range of areas for future research and practice.
Embargo
Essays on the role of rural finance, green finance and digital financial inclusion on agricultural carbon emissions reduction : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Hu, Die
Green agricultural development is significant for China against the background of carbon peak and carbon neutrality, and at the same time, it is crucial to secure China's food security. This thesis examines the influence of finance on agricultural carbon emissions, specifically focusing on the significant role of rural finance, green finance and digital financial inclusion. This thesis comprises three essays investigating whether rural finance, green finance and digital financial inclusion help to reduce agricultural carbon emissions in China. The first essay estimates China's agricultural carbon emissions from 2001 to 2020 and analyzes the temporal and spatial characteristics of agricultural carbon emissions, providing a research base for the thesis. Next, the essay examines the impacts of rural finance on agricultural carbon emissions by introducing the rural finance development indicator into the environmental Kuznets Curve Theory. This not only extends the theory but also helps validate the rural environmental Kuznets Curve in China. The findings reveal that the environmental Kuznets Curve hypothesis is invalid in rural China and that rural finance is not conducive to reducing agricultural carbon emissions. The second essay uses a bidirectional-fixed effects regression model, a quantile regression mode, and a difference-in-differences model to investigate the impacts of green finance on agricultural carbon emissions (ACEs). The results reveal that green finance significantly negatively correlates with ACEs in the eastern and central regions but is insignificant for the whole of China. Secondly, there is significant regional heterogeneity in the impact of green finance on ACEs. The impacts of green finance on agricultural carbon emissions also vary across different quantities, showing an asymmetric impact of green finance on ACEs. Thirdly, the Green Finance Reform and Innovation Pilot Zones do not show a direct policy effect on ACEs. The third essay investigates the combined effect of green finance and digital financial inclusion on ACEs using bidirectional fixed-effects regression, moderation mechanism analysis, and Two-Stage Least Squares instrumental methods. The finding reveals that green finance positively impacts ACEs reduction but digital financial inclusion negatively impacts ACEs’ reduction. Moderation mechanism analysis shows that digital financial inclusion has a negative role in moderating the impact of green finance on ACEs, indicating uncoordinated development between green finance and digital financial inclusion in rural China. The results are robust to different methods that address the endogeneity issues. This thesis extends the ACEs theory into the agricultural sector, not only enhancing the scope of the Environmental Kuznets Curve Theory into the agricultural sector but also addressing the omitted variables criticized by scholars by considering financial development's impact on the environment. This thesis also examines the role of green finance in reducing carbon emissions in the agricultural sector, which was overlooked in previous research. Using quantile regression to examine the asymmetric effects of green finance across different quantiles and a difference-in-differences model to examine green policy impacts provides more robust results and critical information for formulating policies. More importantly, this thesis provides a unique perspective to examine the combined effects of green finance and digital financial inclusion, offering pivotal conclusions and policy recommendations.
Embargo
An examination of the quality of sustainability reports in the GCC : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Kashif, Sameerah
The growing global sustainability challenges and rising stakeholder demand for companies to be accountable for their actions have led to an increase in sustainability reporting. Given this increase, it is important to examine the quality of sustainability reports to determine whether they provide incremental information which facilitates informed decision making by stakeholders. However, studies examining the quality of sustainability reports have typically focused on content quality, with few studies investigating textual quality, visual quality and/or balanced reporting. The quality of sustainability reports published by the Gulf Cooperation Council (GCC) listed companies is examined in this research. This research focuses on readability, graphs, and negative information to examine textual quality, visual quality and balanced reporting, respectively. In Phase 1, a quantitative analysis is conducted to investigate textual quality by measuring the level of language difficulty (readability) of sustainability reports. In Phase 2, visual quality is examined by conducting a quantitative analysis of graphs used in sustainability reports. In Phase 3, quantitative and qualitative analyses are used to investigate balanced reporting in sustainability reports. The research findings are examined and interpreted through the lens of impression management and legitimacy theory. This research finds that overall, sustainability reports published by the GCC listed companies include complex language that makes the reports difficult to read. Report readers would require at least a post-graduate level of education to efficiently read and understand the sustainability reports. Considerable evidence of impression management elements is found in the graphs included in the sustainability reports. The findings of the balanced reporting analysis reveal that generally companies are reluctant to report on the challenges and setbacks faced during business operations. When companies report negative information, they mostly adopt legitimation strategies that reinforce corporate commitment towards sustainable business practices. Companies are also found to symbolically portray commitment towards sustainability when reporting negative information. The findings indicate various impression management elements that lower the textual quality, visual quality and impede balanced reporting in sustainability reports. By being the first research that examines textual quality, visual quality and balanced reporting in a single study, this research provides insights into the role of impression management and its potential to affect the quality of sustainability reports and corporate legitimacy. In doing so, this research adds to the limited literature on impression management in sustainability reports and contributes to the debate in academic literature of whether sustainability reports are used to communicate incremental information or as tools for impression management. This research provides guidance to companies on the use of language, graphs and negative information to enable them to communicate information in an accurate, balanced, and clear manner. This research will benefit companies, standard-setters and legislators by highlighting the textual and visual features of best practice and the significance of balanced reporting for publishing good quality sustainability reports.
Embargo
Identification and characterisation of Phytophthora spp. in New Zealand apple orchards : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Toalak, Merriam
Apples, a prominent and widely favoured fruit crop on a global scale, are traded internationally and carry substantial economic importance worldwide. They play a vital role in New Zealand’s agriculture sector, with the World Apple Review consistently ranking the New Zealand apple industry as the most competitive in the world. Apple production encounters various challenges notably the adverse effects of pests and diseases, with Phytophthora crown and root rot being an important soil borne disease in all apple growing regions. Worldwide the disease is primarily caused by Phytophthora cactorum, although other species of Phytophthora have also been associated with crown rot of apple. The aim of this study was to determine the identity of Phytophthora species associated with apple orchards in New Zealand and explore their genetic structure and relative pathogenicity. Furthermore, the impact of two commercial microbial inoculants, arbuscular mycorrhizal fungi and Trichoderma species on the susceptibility of two apple rootstocks to P. cactorum infection in a whole-plant pathogenicity assay was evaluated. In Chapter 2 a survey was conducted to determine the Phytophthora species in the soils of apple orchards. The survey sampled soils from 12 different apple orchards of the five main apple growing regions in New Zealand: Hawke’s Bay (5 orchards), Tasman (4 orchards), Waikato (1 orchard), Otago (1 orchard) and Canterbury (1 orchard). Soil samples were obtained from blocks of the main orchard sites, with apple trees representing different cultivars and ages groups (young, medium and mature). The sampling included 11 orchard blocks from Hawke’s Bay, 13 in Tasman and 2 each from Otago, Waikato and Canterbury, resulting in a total of 30 blocks. The Phytophthora species were recovered by baiting using healthy Himalayan cedar needles (Cedrus deodara), lupin radicles (Lupinus polyphyllus) and apple cotyledons as baits. Lupin was the most effective bait, recovering 147 Phytophthora spp. isolates compared to apple cotyledon and cedar needle recovering 72 and 52 Phytophthora spp. isolates, respectively from the Hawke’s Bay, Tasman, Otago and Waikato samples (Canterbury samples baited with pine and rose). The 280 Phytophthora isolates recovered were identified based on combined results of morphology and DNA sequencing, with a total of seven species identified. These were Phytophthora cactorum, P. cambivora, P. megasperma, P. plurivora, P. rosacearum, P. chlamydospora, P. cryptogea and isolates with unresolved identity (Phytophthora spp.). The most prevalent species was P. cactorum. In Chapter 3, the genetic diversity within the P. cactorum population was determined using random amplified microsatellites (RAMS) and universally primed polymerase chain reaction (UP-PCR) primers and relative aggressiveness of the recovered Phytophthora species assessed using detached tissue assays. The 59 P. cactorum isolates were placed into five major groups of 3, 16, 9, 9 and 20 isolates each with two isolates each placed in groups by themselves, with the P. cactorum population in the orchards dispersed in the different groups. From the genetic diversity analysis isolates of P. cactorum and representative isolates of the different species recovered were selected and their aggressiveness assessed used a developed detached root assay and an existing shoot assay. All Phytophthora species and P. cactorum isolates tested were virulent on the apple rootstocks tested, with rootstock MM106 being more susceptible than M9 and M26. There was no correlation between the genetic diversity and aggressiveness. In Chapter 4 the pathogenicity of four P. cactorum isolates on whole apple plants was determined on MM106, M26 and M9 rootstocks. The rootstocks were inoculated by dipping in 1 × 105zoospores per mL or using 50 g colonized oats grain into the planting hole. All four P. cactorum isolates caused disease on all three apple rootstocks, with there being no difference in the disease score between rootstocks or isolates irrespective of the type of propagule used. In Chapter 5 the effect of inoculation with AMF and/or Trichoderma on susceptibility to P. cactorum infection and overall growth of young rootstock plants was investigated. Rootstocks M9 and MM106 were inoculated with AMF, Trichoderma and combined AMF and Trichoderma, and, after 60 days growth, inoculated with P. cactorum. At harvest, the AMF and/or Trichoderma inocula had no effect on P. cactorum disease level on either rootstock. However, in the absence of P. cactorum, inoculation with both Trichoderma and AMF tended to enhance growth compared to the control. Overall, this study has identified the Phytophthora diversity in New Zealand apple orchards and confirmed the pathogenicity of the recovered species, with particular emphasis on the dominant species, P. cactorum. The findings highlight that further studies are warranted including investigation of management strategies to reduce the potential threats posed by these pathogens.
Embargo
Factors that influence microbial communities in spontaneously fermented wine, beer, and kombucha: insights from a metabarcoding perspective : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Ohwofasa, Aghogho
It is well established that the world contains a vast diversity of microbes, many of which have been unexplored and even as yet uncultivated. Advances in molecular biology techniques such as metabarcoding have helped in improving our insights into this complex microbial world, in every aspect of human civilization, including food and beverage production. The importance of microbial diversity in the processing of wine and other fermented products in general cannot be overemphasized. In wine for example, grape health and the diversity of microorganisms introduced into the winery depends on the number of microbes who are able to form ecological niches in the vine and soil of the vineyard. With extensive knowledge of microbiome diversity and its interactions or shifts within fermentation processes, this could lead to an improved understanding of this activity. With next generation Sequencing (NGS) techniques, it is now feasible to accurately detect and quantify the relative abundance of microbes found in and around these products. Culture based methods previously used in microbial analysis neglects the non-culturable microbial fraction, an advantage NGS methods possesses over culture based techniques. Performing complex multifactorial analyses is now possible by coupling metabarcoding with bioinformatics tools. This is fast becoming the “go to” strategy in monitoring, traceability of products and diagnostic purposes. If properly harnessed, metabarcoding opens up the possibility of adequately monitoring and describing the microbial population during fermentation and how their profile changes with time. The aim of this research was to employ metabarcoding in exploring the microbiomes associated with spontaneously fermented wine and other foods/products such as kombucha and lambic styled beer in New Zealand. These studies included investigating the influences that the environment and/or climate play in shaping the microbiome of these products. Where applicable, the complex relationship between the microorganisms and the organoleptic and chemical properties of the products was also probed. The first experiment in this work explored the impact of differing environmental systems on the microbial communities utilized by an organic winemaker in producing wines. Results indicated that T. delbrueckii and Fructobacillus could be affected by environmental conditions as they were detected in one system but not the other. Together, significant differences were reported between the fungal (RANOSIM = 0.603, p = 0.0001) and bacterial (RANOSIM = 0.5814, p = 0.0001) diversity found in both systems. Assessment of these microbial differences were done to see if they brought about detectable sensory or chemical variations in the resulting wines. Certain volatile compounds were only found in wines from one of the environmental system but not the other, indicating that significantly different bacterial and/or fungal species could have major roles in synthesising these compounds. Specifically, it can be inferred that Gluconobacter may play a role in the taste (bitterness) and ‘mouth feel’ (astringency/tannin) attributes of Pinot noir wines. To gain insights into how the microbial communities associated with kombucha production might differ based on scale (large commercial scale as compared to a small scale production), another experiment was carried out. For the first time in kombucha literature, results uncovered indicated that the fungal and bacterial diversity associated with the commercial fermentation process had a higher diversity as compared to small scale kombucha production. Interestingly, the core fungal microbiome found in the SCOBY and tea phase of both the commercial and small-scale kombucha types were similar. Using linear modelling unravelled how Komagataeibacter might play a key role and shape the pH of kombucha. To understand if the microbial communities detected at the end of spontaneous beer fermentation varies across vintages, a beer experiment was conducted. Results from this experiment revealed how vintage has a huge influence in shaping the detected microbial populations. Climatic factors such as humidity and maximum temperature were identified as variables that may enhance the relative abundance of Penicillium and Hanseniaspora in beer microbiota. When the microbiome of all three fermented food/products were compared, in comparison to the bacterial communities, similarities can be seen with the fungal populations. Spontaneously fermented wine and kombucha fermentation had considerable amounts of Hanseniaspora, Metschnikowia and Saccharomyces. Beer and kombucha fermentation had substantial Brettanomyces and Saccharomyces proportions. Saccharomyces was the only genus present in significant amounts in all three foods/products. For bacteria, spontaneously fermented Pinot noir wine was dominated by Tatumella (2021 vintage) and Lactococcus (2018 vintage). Komagataeibacter and Gluconobacter were abundant in the home and commercial kombucha brew respectively. Lambic styled beer saw Pediococcus as the most dominant bacteria. Summarily, this research unravelled the complex microbiome of spontaneous Pinot noir wine fermentation, kombucha fermentation and lambic beer brewing. Description of how microbial populations can be affected by environmental and/or climatic influences were done. Where applicable, how these microbial differences could result in sensory and/or chemical variations in the resultant product were assessed. This study has described how metabarcoding can be reliable in assessing the microbiome of fermented food/products.
Open Access
Monuments and public spaces: Questions of equity, inclusivity and justice: An investigation into three Latin American case studies : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Walker, Yeimy
Responses to inequality, violence, war, genocide, injustice, and trauma take many forms in the built environment. Contemporary conversations around statues and monuments in public spaces have renewed a conversation about the power of the past. This research explores recent responses to monuments that embrace colonial and historical narratives in Latin American public spaces, highlighting their significance for social justice and equity in the field of landscape architecture. Through three case studies, the thesis features diverse responses to historical narratives embedded in monuments, focusing on acts of reclamation, resignification, and recontextualisation. The equestrian Sebastian de Belalcázar monument in Popayán, Colombia, has become a symbol of Spanish oppression of Indigenous people. The Isabela La Católica monument in La Paz, Bolivia, raises concerns about discrimination against native women. Finally, the equestrian monument of General Manuel Jesús Baquedano González in Santiago de Chile symbolises the repression of Indigenous people by the Chilean elite. On-site responses, such as removal, dressing, and graffiti, provide insights into how communities actively engage with and contest dominant narratives. Methodologically, the research employs a case study approach, incorporating online interviews with three key stakeholder groups: public officials, activists/Indigenous leaders, and designers/academics. Social media data, primarily from activists and community participants, further enriches interpretations of each case study by exploring a range of design proposals and on-site responses. This study makes a unique contribution to the academic discourse on the intersection of monuments, public spaces, and landscape architecture. By recognising the contested nature of these sites, landscape architects can actively contribute to the creation of inclusive and reflective environments, prioritising principles of equity and justice. The study emphasises the crucial role that landscape architecture can play in amplifying marginalised voices and fostering dialogue regarding colonial narratives. By doing so, it can create opportunities for diverse interpretations of the past, promote inclusivity, and raise awareness about the implications of colonial histories in the present. Importantly, this research introduces its findings to the English-speaking world, bridging gaps in understanding and enriching global conversations on the subject. In conclusion, this research represents a call for action on reimagining the role of monuments in public spaces. By reassessing their historical significance and embracing diverse perspectives, the field of landscape architecture can pave the way for more equitable and inclusive commemorative designs, acknowledging the complexities inherent in our shared history.
Open Access
Measuring landscape performance: Context, mechanisms, strategies, approaches, and theories : A thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Chen, Guanyu (Hanley)
This research explores various dimensions of Landscape Performance Evaluation (LPE), including its practice context, mechanism, evaluation strategies, approaches, and theories. This study firstly traces the evolution of the evaluation practices in the field of environmental design disciplines from its architectural roots to its integration into landscape architecture, and from its original form of Post-Occupancy Evaluation (POE) to LPE. The challenges arising from ambiguous interpretations and interdisciplinary differences in POE conceptualisation are identified. The study advocates for specificity and clarity in approaching the concept of POE. The research then extends its focus to the New Zealand environmental design and planning context, collecting and analysing a representative range of evaluation cases to unveil barriers and enablers in performance evaluation implementation. This study emphasises the essential role of effective regulating and supporting mechanisms in ensuring balanced resulting benefits relative to costs for all involved parties. Subsequently, the methodological terrain of LPE practices in New Zealand is mapped, proposing a categorising framework for the evaluation models and approaches, and revealing associations between funding sources, evaluator types, and evaluation outcomes. The first New Zealand-based Landscape Performance Evaluation (LPS) Case Study Investigation (CSI) consists of a part of this doctoral research. The CSI evaluation is explored, reflecting from the evaluators' perspectives, challenging the dichotomies in methodological categorisation, and advocating for a universal currency for benefit measurement. This research then introduces the hedonic model approach, quantifying intangible landscape benefits, and demonstrating the potential for using monetary value to measure the value of landscapes and thereby providing evidence for decision-making processes. An economic perspective is applied to conceptualise the current challenges in understanding and communicating landscape benefits, drawing parallels between the market for "lemons" and the landscape architecture industry. LPE emerges as a potent countermeasure to information asymmetry and a lack of information, potentially mitigating negative impacts on the industry. By encapsulating a multidimensional exploration that weaves together context, mechanisms, strategies, approaches, and theories of landscape performance evaluation, this research aims to guide future scholars, practitioners, and decision-makers in navigating LPE explorations, thereby contributing to the enhancement of the built environment and human well-being.
Open Access
Tea (Camellia sinensis (L.) O. Kuntze) plant productivity and protection with microbial stimulants : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Patti Dorage, Prashansani Madhusha Darshani Silva
While there is an increasing consumption of organic tea as a healthy beverage, tea growers are struggling to produce tea without agrochemicals. To help find solutions for this challenge, a study was conducted on bioprospecting microbes to potentially create bioprotectant products against tea pathogens in Sri Lanka and biopromotion products in organic tea cultivation in New Zealand. Blister blight, caused by Exobasidium vexans, is a major tea disease in Sri Lanka. Investigation of this obligate parasite has been limited due to a lack of successful artificial culture media. Potato Dextrose Agar medium was modified with five different tea extracts to investigate the best growth media which can facilitate dual-culture assays among indigenous endophytes and tea pathogens. Brown blight caused by Colletotrichum camelliae was also tested in this study. Potato dextrose agar ammended with either 25% fresh or dried tea leaf infusion incorporated, tea extact agar (TEA) media were successful for in-vitro cultivation of tea pathogens. During the research, Nigespora sp. was arbitrarily identified as a leaf blight pathogen on tea in Sri Lanka for the first time. Twenty indigenous fungi and seven bacterial endophytes were identified from the tea phyllosphere in Sri Lanka. More than 50% of them exhibited biocontrol potential against the economically important tea pathogens in-vitro while Trichoderma harzianum provided the best inhibition. Seven indigenous fungal and four bacterial genera were identified from soil and leaf samples from a tea plantation in New Zealand and used for biopromotion bioassays on young tea plants grown under glasshouse conditions. Indigenous Hypocrea lixii provided the most significant biostimulation, than its exogenous anamorph; T. harzianum, which was tested representing the new taxonomic concept of H. lixii and T. harzianum as two individual species (previously classified as teleomorph and anamorph of the same species). This study isolated H. lixii for the first time in New Zealand under this new taxonomy. T. harzianum was the only fungal species that was able to colonise tea roots in glasshouse experiments, but all tested indigenous and exogenous microbes showed a higher biostimulant efficacy on tea than the controls. Commercially produced, water-soluble Trichoderma atroviride powder with a 2 x 105 cfu mL-1 concentration was in-vivo tested on mature tea plants in Hamilton. A single foliar application of T. atroviride increased tea yield by up to 28% six months post-application. The first-ever microbiome study conducted for tea soil in New Zealand suggested a relationship between yield and Ascomycota presence, indicating that introduced T. atroviride stimulated the growth of the tea plant synergistically favouring its own phylum. Tea soil in New Zealand is reported to be rich with yeasts and less decaying material compared to traditional tea grown under shade trees with high organic matter content, suggesting the soil has higher simple sugars than lignocellulosic compounds which could facilitate the Trichoderma establishment and persistence, thereby artificially introduced T. atroviride might have been overshadowed by the complex resident soil microorganisms. Therefore, the study suggests field application of a multi-strain consortium of the best potential indigenous biostimulants found in the glasshouse experiments (H. lixii, Epicoccum sp., Bacillus sp., Clonostachys candelabrum, Penicillium limosum, and Penicillium arizonense) to form a more stable soil memory and effectively manipulate the resident soil microbiome in-situ, improving the desired biostimulat functions between the biostimulants, soil and plants, which is particularly more important for perennial crops like tea.
Open Access
Effects of extrinsic characteristics, mental simulation and repetitive exposure on the hedonic, emotional and physiological responses of consumers: A study of food choices and purchasing behaviours : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Mehta, Annu
In the globalization era, a multitude of new products enter the market annually. Due to the similarity in sensory properties and prices, innovators need more than traditional sensory methods to ensure product success in the market. Researchers, therefore, must understand the holistic product experience and its influence on consumer preferences. Food choices are a multi-dimensional variable influenced by physiological and psychological factors such as memory, mental simulation, sociocultural aspects, and extrinsic/intrinsic product characteristics. Consequently, food choices and purchase decisions are shaped by the multisensory information derived from products in supermarkets. The intrinsic attributes such as taste, texture, and mouthfeel perception also play a pivotal role in shaping product liking. Moreover, consumer behaviours and familiarity with novel products further influence product liking and acceptance. Therefore, this thesis’s primary aim is to comprehensively evaluate the factors influencing consumer food choices and approach-based behaviours, covering the entire spectrum from the initial encounter with a product to consumption. Additionally, the thesis aims to explore how systematic familiarization with novel products, achieved through increased awareness and repeated tasting, enhances consumer intention to try such products, thereby impacting food preferences. The impact of extrinsic attributes such as product positioning, packaging material, country of origin (COO) logo, nutritional information, and price tags on consumers’ visual attention, emotional responses, and subsequent behaviours within the supermarket setting were investigated. The study was conducted in three stages: an orientation phase for an initial overview of products, an evaluation stage where consumers individually assessed products to decipher extrinsic factors, and a final validation stage where consumers responded to attitudinal questions regarding the importance of packaging attributes. Sensory, emotional, and biometric (eye tracking and facial expressions) measurements were used to capture the consumer perception journey. The heat map results show that consumers focus their attention on products positioned at the top and centre of the supermarket shelves during the orientation stage. Glass and plastic bottles received the highest fixation count compared to other packaging types. While scanning the supermarket shelf, as indicated by Time to First Fixation (TTFF in ms), participants initially glanced at the tetra pack (3.53 ms) before shifting their attention to glass (5.23 ms). Implicit emotions provided a deeper understanding of consumers’ preferences. Principal Component Analysis (PCA) revealed an association between TTFF, engagement, and implicit negative emotions (fear, disgust, anger, and sadness) with tetra pack, tetra pack L (L stands for packaging with country-of-origin label), and pouch L. Conversely, the positive implicit emotion “joy” was associated with glass L. During the individual packaging evaluation stage, nutritional information received the highest fixation count compared to the NZ-made logo, but the NZ-made logo drove purchase intention. The study revealed that the packaging that attracted the maximum attention was not necessarily the one with the highest liking score. The consumers did not allocated significant visual attention to the price attribute despite reporting them as important factors. The study further explores how packaging attributes, such as packaging material and font colour, shape expectations and influence consumers’ approach-based behaviours, including acceptability and purchase intention. The participants evaluated tetra packs, pouches, glass, and plastic bottles using orange and white font colours in blind (tasting juice without information), expectation (evaluating packaging, no tasting), and informed (tasting juice with packaging) sessions. This analysis extends to the subsequent confirmation of these expectations after the product is tasted. The study’s results proved that packaging significantly raises expectations regarding the sensory properties of the juice. The participants perceived juice packaged in glass bottles to be fresher than plastic bottles, pouches, and tetra packs, regardless of packaging font colour. Participants had higher expectations of freshness and overall liking, which were not fulfilled during the informed session, leading to an assimilation effect. Participants penalized juice from the glass-orange bottles and tetra pack-white with declines in the liking scores, citing insufficient sourness. No penalty in liking scores was observed for the tetra pack in the informed session. Negative emotions such as "worried", "bored", and "sad" had negatively impacted approach-based behaviour in the expectation session, while positive emotions such as "happy", "enthusiastic", and "joyful" in the informed sessions positively influenced purchase intention. Therefore, marketers and product designers should prioritize understanding the overall product experience and create packaging that captures visual attention, satisfies consumers’ expectations, and evokes emotional responses, ultimately influencing consumer approach-based behaviours. The research also delves into the influence of initial awareness and repeated exposure on consumer attitudes and behaviour toward novel products, using SCOBY (Symbiotic Culture of Bacteria and Yeast) ice cream as an illustrative example. The study was conducted in three steps: a survey and two tasting sessions. The survey aimed to introduce the health benefits of SCOBY and kombucha while examining consumer attitudes and acceptance towards the novel product (SCOBY ice cream). It utilized the primary constructs (attitude, subjective norms, and perceived behavioural control) of the theory of planned behaviour (TPB) and additional constructs (emotions and food neophobia) to gain comprehensive insights into consumer behaviours. In the survey, participants who confirmed their participation in the tasting sessions were invited for blind tasting (without information) and informed tasting (with information). The study also explored the impact of the SCOBY addition in the ice cream on the texture and mouthfeel perception by measuring the particle size, tribology, and temporal dominance of sensation. In the case of a novel product such as SCOBY ice cream, initial exposure, or awareness significantly impacts consumer's attitudes and intentions to try the product. The study proved that the primary constructs of TPB significantly predicted the intention to consume SCOBY ice cream. Additionally, incorporating emotions into the constructs increased the model’s explanatory power. Attitudes, subjective norms, and emotions were the main predictors of intention, while intention and perceived behavioural control were the main predictors of behaviour. Participants’ beliefs about the safety and taste of SCOBY ice cream were significantly correlated with their intention to try the product, as were the opinions of nutritionists/dietitians, friends, and family. Overall, the model explained 21.7% of the variance in behaviour and 57.4% of the variance in intention, offering valuable insights for shaping marketing strategies for waste-to-value-added products such as SCOBY ice cream. Moreover, repeated tasting of the SCOBY ice cream after the survey significantly impacts the attitude and intention to try the novel product. Compared to the survey, there was a significant improvement in participants’ attitudes toward consuming SCOBY ice cream in tasting sessions 1 and 2. Similarly, the intention to consume SCOBY ice cream significantly increased in tasting session 2 compared to the survey and tasting session 1. Moreover, there was a significant increase in liking scores for flavour, sweetness, texture, and overall liking in tasting session 2 compared to 1. Sensory attributes such as flavour and texture, along with positive emotions such as “happy”, “pleasant”, and “interested” significantly influenced purchase intention. The study’s results suggest that repeated exposure to novel products enhances consumer acceptance and emotional responses, diverging from traditional sensory study approaches. This highlights the potential success of strategies involving repeated tasting exposure. By prioritizing the improvement of familiarity with sensory attributes such as flavour and texture, companies can positively influence purchase intention and the successful integration of innovative products into the market. Additionally, the impact of ice cream texture and mouthfeel perception on consumer preferences were further explored by measuring particle size, texture, tribological properties and temporal dominance of sensation of three samples: SCOBY ice cream and two reference samples (control and guar gum ice cream). SCOBY ice cream contains probiotics content (5.48 cfu/ml), low pH (5.50), and high titratable acidity (3.11%) than reference samples. The addition of SCOBY increased hardness (22.05 N). The frictional factor (µ) at 37˚ C was positively associated with the melting rate, grainy and thin/fluid perception while negatively correlated to firmness, smooth perception and mouthfeel liking. Additionally, the mouthfeel liking was positively related to firmness, mouth/residual coating and smooth perception while negatively associated with grainy and thin/fluid perception. The findings improve our understanding of the textural dynamics of ice cream formulations incorporating SCOBY and its impact on consumer preferences and overall liking, highlighting the importance of product characteristics in novel products. To conclude, the study underscores the significance of extrinsic attributes in shaping consumer attention and forming product expectations, influencing approach-based behaviours. Transparent packaging, such as glass and plastic bottles, elicited more positive expectations and emotions than opaque packaging, affecting consumer liking and purchase decisions. Additionally, nutritional information and country-of-origin logos played crucial roles in influencing visual attention and purchasing behaviours, showcasing the importance of provenance. Implicit and explicit emotions interacted with packaging and elicited distinct responses that affected consumers’ purchase intentions, providing a comprehensive understanding of consumer behaviour. Additionally, repeated tasting positively influenced attitudes and intentions to try novel products, underscoring the importance of consumer education in product acceptance. Sensory attributes such as texture and flavour significantly influenced product liking, highlighting the strategic importance of understanding consumer psychology and fostering positive sensory experiences for the success of innovative food products.
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A trajectory of financial inclusion: An empirical analysis of Ghana households : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Saka, Abraham Nii Adoteye
The need for a paradigm shift towards inclusive growth has recently received increased attention from governments and policy-makers. Financial inclusion plays a central role in inclusive growth. This is because financial inclusion is an enabler of economic growth, poverty reduction, income inequality reduction and women empowerment, especially in developing countries such as Ghana. Notwithstanding these benefits, the level of financial inclusion in Ghana is low. The World Bank provides a roadmap (the gateway to financial inclusion) on how to move people from being unserved (financial exclusion) to being served (financial inclusion). This roadmap highlights the need for households to have access to formal financial services such as payments, credit, savings, insurance, and remittances. This means that measuring the level of a country’s financial inclusion must include these services for it to be representative. Previous studies focused on banks and neglected other financial intermediaries, such as insurance companies (insurance financial services) in creating a financial inclusion index to measure a country’s level of financial inclusion. This study includes insurance in creating a financial inclusion index for Ghana for our study period (1980 to 2021) to find that there have been improvements in the level of financial inclusion during that time. This suggests that several financial sector reform programmes implemented in Ghana, as well as legal and regulatory reforms in the banking and insurance sectors, have had a positive impact on financial inclusion in Ghana. The financial inclusion score average was 0.25 for Ghana for the study period, which categorizes Ghana as a low financial inclusion country per Sarma’s (2008; 2012) categorization. Overall, however, the upward trend in financial inclusion in Ghana during the study period is an encouraging sign for the push to ensure all Ghanaian households are financially included. The study investigates what factors drive financial inclusion in Ghana and finds financial inclusion has a positive, significant relationship with GNI per capita and MSCPS in Ghana. Conversely, the study finds a negative relationship between financial inclusion and the real effective exchange rate. Government spending, inflation and money supply are negatively but insignificantly related to the level of financial inclusion in Ghana. Finally, I find that insurance and financial service imports (positive), urbanization (positive), mobile money availability (positive), fixed telephone ownership (negative), and remittances (positive) had no influence on the level of financial inclusion in Ghana during the study period. The literature suggests that there is no consensus on the direction of the relationship between financial inclusion, poverty and income inequality. To investigate the direction of the relationship for Ghana, the study runs an ordinary least square multiple regression using household consumption (a proxy for poverty) as the dependent variable, which is regressed against several independent factors including our comprehensive financial inclusion index. I find that level of financial inclusion, which averages 0.25, did not improve household consumption (reduce the prevalence of household poverty) in Ghana during the study period. A possible explanation could be the structure of the financial system of Ghana is not well-developed and financially included (Ghana is classified as low financial inclusion country with an average financial inclusion score of 0.25) to reach majority of the households (especially poorer individuals and households) to effectively reduce the prevalence of poverty in Ghana positively. The ineffectiveness of the financial sector in the allocation of funds causes low labour productivity, which increases the prevalence of poverty amongst households. In addition, an underdeveloped financial system with a low level of competition creates an ineffective financial system and discourages improvements in the level of financial inclusion in an economy. Our finding is supported by a recent study that found household consumption improved countries that had a financial inclusion index score of 0.356 or higher. For the relationship between financial inclusion and Human Development Index (HDI), which is the proxy for income inequality in this study, I find that financial inclusion positively and significantly influences HDI in Ghana. A possible explanation could be that financial inclusion enables households and individuals to afford education to build their skill and capacity, which can help them to secure employment with better and sustainable disposable income to reduce the overall level of income inequality in the country. Access to finance (through borrowing from the financial sector) can support the financial needs of individuals and households as well as help those individuals with entrepreneurial ambition to start small businesses, which can generate further income for them. Further, access to the financial sector helps individuals to save and invest their excess disposable income to generate investment income. Therefore, financial inclusion helps to reduce the level of income inequality amongst households in Ghana. I also find that the GDP per capita growth, ICT literacy and personal inward remittances have positive, significant effects on the HDI level in Ghana, whereas government spending and rural population growth have an inverse effect on HDI. Inflation (negative) and trade openness (negative) both have an insignificant impact on HDI in Ghana over the study period. I also find that FII*GNI per capita is positive and significantly impacts the HDI. An index to measure the level of women’s empowerment in Ghana is missing from the Ghanaian empirical literature. This study uses the PCA approach to create a women empowerment index for Ghana using four dimensions (labour and economics; good-life and health; politics, governance and leadership; and education and skill building) to find that the level of women’s empowerment improved year-on-year during the study period (1990 – 2021). Despite the fact that many studies have suggested that financial inclusion improves women’s empowerment (and vice versa), a study examining the direction of the relationship is missing from the Ghanaian literature. This study investigates the relationship and finds that financial inclusion and women empowerment are positively related during the study period, which means Ghanaian women are increasingly being empowered as time passes. In investigating the relationship between financial inclusion and women’s empowerment, I find that labour and economics, and politics, governance, and leadership exhibit positive, significant relationships with the level of financial inclusion in Ghana whereas good-life and health, and the education and skill building dimensions exhibit a positive but insignificant relationship with financial inclusion in Ghana over the study period.
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Model analysis of electrostatic interactions of ATP-IDE interactions by quantum mechanics/molecular mechanics (QM/MM) calculation and molecular dynamic (MD) simulations : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Somin, Sarawoot
The insulin-degrading enzyme (IDE) plays a significant role in the degradation of the amyloid beta (Aβ), a peptide found in regions of the brain of patients with early Alzheimer’s disease (AD). Adenosine triphosphate (ATP) allosterically regulates the Aβ-degrading activity of IDE. Electrostatic interactions between ATP-IDE including thermostabilities/flexibilities of IDE residues, at the allosteric site of IDE, are essential for drug design. These electrostatic interactions and the thermostabilities/flexibilities of IDE residues at the ATP-binding domain have not yet been systematically understood. The present study elucidates the electrostatic interactions of ATP-IDE interactions and the thermostabilities/flexibilities of the IDE residues. Computational modelling based on (QM/MM) calculation method and molecular dynamic (MD) simulations may offer great opportunities to understand biological interactions. In this study, we apply QM/MM to the proposed computational model for exploring the electrostatic interactions of ATP and IDE. Molecular dynamic (MD) simulations are performed at different heat-shock temperatures for identifying thermostable and flexible residues of IDE at ATP-binding domain. The proposed computational model contains five main procedures, including initial structure preparation, molecular docking, molecular mechanics (MM) equilibration, QM/MM minimisation and MD simulation. Since the allosteric effects resulting from the interactions of Aβ peptide can influence the conformational change at ATP-binding domain, we create two systems for comparing the difference between system with and without the interaction of Aβ peptide. Subsequently, the binding affinity of the electrostatic interactions of ATP-IDE interactions can be identified after performing QM/MM minimisations. Furthermore, we perform the MD simulations to explore the thermostabilities/flexibilities of the IDE residues at the different temperatures (300K, 321.15 K and 315.15 K), which 321.15 K and 315.15 K are the temperatures induce a heat-shock response (a protective mechanism) of IDE. The proposed computational model predicts QM/MM minimised structures. Subsequently, it reveals the IDE residues with high binding affinity (LYS530 and ASP385). Considering root-mean-square-fluctuation (RMSF) values during the MD simulations at the heat-shock temperatures, it indicates that LYS530 and ASP385 are also the thermostable residues of IDE, whereas SER576 and LYS858 have high flexibilities with compromised thermostabilities. The present study sheds light on the phenomenon of biological recognition and interactions at the ATP-binding domain within the IDE which has important implications for pharmacological drug design. The proposed computational model may facilitate the development of allosteric IDE activators/inhibitors which mimic ATP interactions.
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Novel drivers of voluntary intake of low dry matter forages in sheep : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2023) Jayasinghe, Nadeesha Kumari
Fresh forages account for a significant part of the ruminant’s diet in pasture-based systems. Previous studies have suggested dry matter content below 16% reduce dry matter intake, but contemporary NZ temperate grazing systems using a range of low DM% forages are reported to have strongly positive production features, so, an experimental series (1, 2 and 3) was designed to assess DMI using fodder beet (FB), plantain, chicory and ryegrass cultivars using young sheep. In experiment one, DMI, water intake, urine volumes and mineral (Na, K, Ca, Mg, P) balance were measured with young sheep using metabolism crates and fresh harvested FB to represent a total diet DM% below 14%, with grass silage (GS) as a control. Eight (49±1.75 kg) Coopworth hogget rams were fed one of the three treatments, sequentially in runs 1 to 3; treatment 1 (ad libitum GS) - FB 0%: GS 100%; treatment 2 (restricted FB) - FB 30%: GS 70%; treatment 3 (ad libitum FB) - FB 90%: GS 10%. Total diet DM% were 43.21, 30.44, and 13.56%; total diet CP% were 13.38, 13.97, and 12.18%; and total diet NDF was 57.19, 43.13, and 22.29%, respectively for runs 1, 2 and 3. In run 3 the mean daily DMI was greater at 2.74% of LWT compared to run 2 (2.21%) and run 1 (2.49%) (p<0.05). Mean daily water intake in run 3 was 239 ml/kg of LWT, fourfold higher (p<0.05) than observed in run 1 (61 ml/kg of LWT). Mean daily urine production in run 3 was 160 ml/kg LWT, significantly greater (p<0.05) than observed in run 1 or run 2. The mean daily Na intake in run 3 was 21.27 (g/d), significantly greater than runs 1 and 2 (p<0.05), with greater (p<0.05) urinary Na concentration and mean daily urinary Na output in run 3, increasing from 105 to 2090 (mg/L) and 0.14 to 17.89 (g/d) runs 1 to 3. Mean daily N intake was not different between runs, while mean daily urinary N output (g/d) was significantly lower in run 3 (6.19g/d) compared to run 1 (7.88 g/d). Urinary N% was greater in run 1 than run 2, and run 3 (0.6, 0.28 and 0.08% respectively). The N utilization (N retained/total diet N) was greater in run 3 (67%) compared with run 1 (35%) and run 2 (33%). The DMI observed in run 3 was high by comparison with other pen fed harvested forage studies, but lower than the intake observed in grazed forages of similar DM%, and neither the NDF intake nor the CP content of the diet likely limited intake. There was no evidence of rumen dysfunction, and it was concluded that, when FB was fed ad libitum, despite being a low DM% forage, high DMI could be achieved, and the very high urine volumes observed suggested a role for Na in excreting the considerable water load consumed with these DMI. However, it was not clear whether all these effects could be related to an effect of increased Na intake in ad libitum FB diet. Plantain and chicory are low DM% forages that have higher Na content compared to ryegrass, and comparatively high N content compared to FB. Therefore, the second experiment was conducted to investigate the role of Na in DMI in low DM% forages, using eight different plantain varieties, chicory, and ryegrass, in four different sequential runs. In each run, 32 young sheep (41±7kg) were used in four groups of eight animals, with the first two runs using the same sheep and forages on a 14d delay and were conducted as sequential runs. In runs 1 and 2 the treatments were tonic, agritonic, ecotain (plantain varieties) and ryegrass, and in run 3 the treatments were tonic, captain, SF and oracle (plantain varieties), and in run 4 the treatments were tonic, tuatara, boston (plantain varieties) and chicory. In all four runs, ad libitum feed was given (refusals > 20%). Despite low DM% (8.47 to 16.56%), plantain and chicory treatments recorded significantly higher (p<0.05) DMI compared to the grass treatments where DM% varied from 13.06 to 16.17%. The DMI/fasted LWT varied from 3.1 to 5.0, 3.5 and 2.6 to 3.2% respectively for plantain, chicory and grass, and the mean daily NDF intake for plantain and chicory varied from 0.74 to 1.64% (NDF/LWT), and for grass 1.17 to 1.22%. The mean daily urine production was highest in the chicory treatment (11654 ml/d), and expressed against fasted LWT, 177 to 294 ml/kg for the plantain and 98 to 118 ml/kg for the grass treatment. Mean daily Na intake in plantain varied (0.3 to 10.57 g/d) across runs, but all except boston and tuatara treatments were >3g/d, while the chicory treatment was 3.5g/d, and both mean plantain and chicory values were significantly greater (p<0.05) than the mean of the grass treatments (0.43 g/d). The plantain treatments in runs 1 and 2 had greater (p<0.05) mean daily urinary Na concentration and mean daily urinary Na outputs (g/d) compared to the grass treatments. The mean daily Na intake (3.51 g/d) was lower in the chicory treatment, and the mean daily urinary Na output for chicory treatment (3.51 g/d) was equal to the intake. Despite the plantain DM% doubling from run 1 to run 2, the mean daily total water intakes were closely similar between runs within plantain treatments (range 378-398 vs 366-376 ml/fasted LWT, respectively for run 1 and run 2). When the mean daily DMI was expressed against LWT, run 2 plantain treatments were observed to have the highest for any treatment (4.62 to 5.08% of LWT) in all four runs, and it was concluded this water intake was an effective upper physiological limit, thereby limiting DMI. The results from this experiment do not support the hypothesis that forage DM% below 16% restrict DMI, and it was concluded that a total water intake of approximately 370-400ml/ kg LWT represents a physiological upper water intake limit, and that a daily urinary Na concentration of approximately 300mg/L, and a daily urinary Na output of approximately 3.5g was required to enable corresponding urine outputs to achieve the DMI observed. It was also concluded that diet Na content and daily intakes facilitated water excretion, and that only sufficient Na intakes would therefore enable high DMI with low DM% forages. The third experiment was conducted to investigate the effect of Na on DMI and urine production when the animals were externally dosed with Na while feeding on low DM% pasture that was originally low in Na. Twenty-four young sheep (39±5 kg) were divided into three groups of eight and three dietary treatments were used in two sequential runs in a cross-over design (grass and grass + salt treatments). The ad libitum FB treatment was maintained as the control treatment in both runs, while the other dietary treatments were grass and grass + salt (12 g of Na was added via oral drenching to achieve a daily intake similar to that of ad libitum FB feeding treatment). The mean daily DMI and the mean daily DMI/fasted LWT were significantly lower (p<0.05) in the FB treatment in both runs 1 and 2, and no significant differences (p<0.05) were observed between the grass treatment or grass + salt treatments in DMI or DMI expressed against LWT. The mean daily NDF intake expressed against the LWT was significantly higher (p<0.05) in the grass treatment and grass + salt treatments compared to the FB treatment and varied from 1.14 to 1.22% from run 1 to run 2. The mean daily urine production (ml/d) was not significantly different (p<0.05) between treatments in run 2, but in run 1 the grass + salt treatment was greater than the FB treatment. The mean daily total water intake expressed against fasted LWT were significantly higher (p<0.05) in grass and grass + salt treatments than the FB treatment, while in run 2, none of the treatments were found to be significantly different. The mean daily feed Na intake (g/d) was significantly higher (p<0.05) in the grass + salt treatment than in grass treatment in both runs. Despite the five to tenfold greater mean daily Na intake in the grass + salt compared to the grass treatment, there were no significant differences in mean daily urine production among the grass and grass + salt treatments in run 1 or 2. The urinary Na concentration was significantly increased (p<0.05) in the grass + salt treatment compared with the grass treatment (1316 vs 223 mg/L). The mean daily urinary Na mass output (g/d) was significantly higher (p<0.05) in the grass + salt treatment in both runs compared to the grass treatment. In both run 1 and run 2, grass + salt treatment had significantly higher (p<0.05) urine production (ml) and urinary Na output (g) in the early part of the diurnal period compared to that with the latter part. However, both grass and the FB treatments did not significantly differ in urine production (ml) and urinary Na output (g/d) during the diurnal period. It was concluded that supplemented Na does not necessarily increase the DMI or the urine volume in the grass + salt treatment despite the grass treatment being low in DM% (<16%), when the DMI was likely to be initially restricted by the NDF intake (1.14 to 1.22% NDF/LWT), and the excess of Na intake could have led to increase the urinary Na concentration once the minimum Na intake has been reached without necessarily increasing the urine production. It was concluded the lower DMI observed in the FB treatment was most likely a result of the CP content of the FB diet (8.06-8.38%) limiting the RDP of the diet. From the results of this series of experiments it was concluded that when FB was fed ad libitum, despite being a low DM% forage (<16%), high DMI could be achieved, and therefore high urine volumes were associated with this intake. It was also concluded that low DM% in forages did not restrict DMI if the animals consumed sufficient daily Na intake to enable high urine outputs of a minimum Na concentration (c.300mg/L) required for diuresis, and if the animals remained below a physiological upper water intake limit of approximately 370-400ml/ kg LWT, which was observed with the DMI observed in very low DM% forages such as some plantain and chicory treatments in this study. This process required a daily Na output of approximately 3.5g to enable corresponding urine outputs allowing the DMI to be increased in low DM%. However, supplementary Na does not necessarily increase the DMI or the urine volume despite the forage being low in DM% (<16%) if the DMI is restricted by the NDF intake, suggesting Na supplementation on most NZ ryegrass pastures will not be effective. In such cases, the excess of Na intake leads to an increase in urinary Na concentration once the minimum Na intake has been reached without necessarily increasing the urine production or the DMI.
Open Access
Nutrifermentics: Microbial epigenetics for innovation in fermentation : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2023) Kong, Yanzhuo
Microbial epigenetics presents a novel and efficient approach for manipulating microorganisms without altering their genetic information. This present study focuses on harnessing the potential of microbial epigenetics to transform and revolutionise fermented product development, a concept termed "nutrifermentics." The dynamic interplay between microbial epigenetics and dietary factors were investigated in both eukaryotic (Saccharomyces cerevisiae) and prokaryotic (Lactobacillus acidophilus) strains, with a specific focus on the capacity of nutrifermentics to drive innovations in fermentation, particularly within the food industry. In this study, benzoic acid, a common food additive and a recognised histone deacetylase inhibitor (HDACi), was shown to alter the formation of epigenetic histone marks (H3K4Me2, H3K27Me2, H3K18ac, and H3Ser10p) in S. cerevisiae yeast. Consequently, the phenotypic behaviour of the yeast was altered, with increased production of phenylethyl alcohol and ester compounds during alcoholic fermentation observed. Subsequently, the relationship between short-term and long-term stress induced by benzoic acid in yeast and their effects on aging was explored. Through comprehensive transcriptomic and metabolomic analyses, it was established that short-term stress fosters longevity, while long-term stress diminishes lifespan. Interestingly, cells under long-term stress (LT) demonstrate the activation of genes associated with epigenetic regulatory enzymes and secondary stress response genes, including heat shock proteins (HSPs). Paradoxically, despite this heightened cellular stress response activity, these cells exhibit shorter lifespans when compared to their short-term stressed counterparts (ST). These findings indicate there is a potential evolutionary advantage, specifically an enhanced short-term survival, associated with aging markers like HSPs. Additionally, these results imply potential applications for aging interventions through the use of inhibitors targeting heat shock proteins. To determine the impact of a diverse range of epigenetically active compounds, such as genistein, in bacteria, the epigenetic responses of L. acidophilus, a well-known probiotic bacterium widely used in yoghurt production, were evaluated. Epigenetics, transcriptomics, and metabolomics were used to demonstrate the potential to alter individual gene or loci expression without genetic modification. The production of both primary and secondary metabolites, such as melibiose, were altered in response to different epigentically active compounds, which provides insight into the role these dietary compounds can play in enhancing bacterial fermentative capability in a sustainable and genetic modification-free way. In conclusion, this present study unveils the potential of microbial epigenetics and dietary compounds to enhance fermentation processes. It offers valuable insights and practical applications for researchers and industries in the field of fermented product development and biotechnology applications.
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The dynamics of socially responsible investment funds’ performance persistence : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Shanthirathna, Neleesha
Socially Responsible Investment (SRI) is an investment strategy that considers social, ethical and environmental elements in investment. SRIs have grown into a widely followed investment practice offering a variety of products to investors. This fund industry is more focused on embracing sustainability practices in its operations. Performance persistence is a good indication for investors, analysts, portfolio managers and institutions. However, there is a paucity of research on the persistence of SRI funds. This study analyses the performance persistence of SRI funds in the United States (US) from 2001 to 2021, including the 2008 global financial crisis and the COVID-19 pandemic crisis. First, we examine the performance persistence of SRI funds before, during and after the 2008 global financial crisis. Second, we investigate the performance persistence of SRI funds before and during the COVID-19 pandemic crisis. Third, we focus on the relationships between fund-specific factors and the performance persistence of SRI funds. Finally, we explore the impact of macroeconomic indicators on the performance persistence of SRI funds. We use Carhart (1997) and Fama French (2015) models to measure the performance of SRI funds. We then follow Hendricks, Patel and Zeckhauser (1993) and Carhart (1997) recursive methods to analyse the performance persistence of SRI funds. We use multinomial logit regression to identify the relationships between fund-specific factors (fund size, age, flow and asset class), macroeconomic variables (interest rate, inflation, money supply and economic activity) and the performance persistence of SRI funds. Our results reveal a positive, significant performance persistence in SRI funds before and during the 2008 global financial crisis. However, the results show no evidence of performance persistence before the COVID-19 period crisis; only the nonparametric tests reveal positive performance persistence of SRI funds during the COVID-19 pandemic crisis. Fund characteristics and macroeconomic variables significantly affect the performance persistence of SRI funds. We divide the study period following the 2008 global financial crisis and the COVID-19 pandemic crisis. Our results show most fund characteristics and macroeconomic variables are significant after the 2008 global financial crisis and before the COVID-19 pandemic crisis. This is the first empirical study to evaluate these aspects of the performance persistence of SRI funds. Identifying SRI fund performance persistence in different market conditions is important for investors to make better investment decisions, manage risk and build a diversified portfolio. Fund analysts can identify potential problems early and adjust their recommendations. They can enhance their reputation as trusted advisors by providing informed recommendations.
Open Access
Conflicted property rights – balancing the need for seismic safety with heritage conservation : A thesis submitted in partial fulﬁlment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2023) Nahkies, Peter Brent
Traditionally described as a “bundle of rights” the creation and protection of private property rights is seen as a cornerstone of western democratic societies. However, property rights are not fixed but are a constantly evolving mix of private rights and community rights that ebb and flow with changing community expectations. As a result of the Christchurch earthquakes increased community expectations of seismic safety led to the passing of new legislation imposing mandatory seismic mitigation for buildings considered an unacceptable risk to society. These buildings are defined legally as “earthquake-prone”. The costs of seismic mitigation must be met by the property owner potentially causing significant financial hardship to the individual, but also with the potential to have significant negative impacts on communities. One form of mitigation promoted by the legislation is to demolish the building which puts the owner of an earthquake-prone building with heritage value in conflict with community expectations of heritage conservation. This conflict often leads to litigation with an owner demanding the right to demolish while the community pursues the retention of the heritage building. The results of the litigation are uncertain and often costly. This thesis looks at altering property rights in New Zealand in order to avoid litigation and achieve a more equitable balance between private and public rights and thus achieve a better balance between safety, heritage and property rights. This rebalancing is necessary to protect individuals from financial hardship. It is also necessary to achieve better outcomes for communities by protecting them from the unexpected outcomes of the new legislation and by promoting sustainability by reducing building demolition and instead facilitating heritage-led urban regeneration.
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Assessing the prevalence, diversity, and damage potential of plant-parasitic nematodes on maize (Zea mays L.) : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Nagarathnam, Thiruchchelvan
Maize cultivation faces challenges from plant-parasitic nematodes (PPNs), which can significantly reduce yields. Despite their importance, PPNs are often underestimated in agricultural ecosystems. Research in New Zealand and Sri Lanka reported the presence of PPNs in maize fields. However, comprehensive data is still lacking. Environmental factors such as soil pH, moisture content, nutrient levels, and rainfall could influence PPN population densities and pathogenicity. Hence, understanding PPN dynamics and environmental interactions is crucial for sustainable production. This study aimed to; i) examine the prevalence, abundance, and distribution of PPNs associated with maize cultivation in Sri Lanka and New Zealand, ii) identify the most abundant PPN species and their distribution in New Zealand maize fields, iii) investigate the relationship between soil edaphic and climatic characteristics with PPN abundance in New Zealand maize fields, and iv) screen the susceptibility of commercially available maize hybrids in New Zealand against the most abundant PPN genus under glasshouse conditions. A survey conducted in Sri Lanka's semi-arid regions with major maize cultivation areas found that over 92% of maize fields tested positive for PPNs. The dominant species was Pratylenchus spp., with a mean population density of 2020 kg-1 of soil. Sampling at different maize growth stages revealed that Pratylenchus spp. populations were below 1000 kg-1 of soil at the seedling stage but increased by 2 to 10-fold at harvest. In New Zealand, a total of 384 soil samples were collected from 25 sites from both the North (NI) and South Island (SI) of New Zealand from maize growing regions. The major PPNs identified by morphology were Pratylenchus (91%), Helicotylenchus (38%), Meloidogyne (14%), Tylenchus (14%), Heterodera (8%), Paratylenchus (3%), and Criconemella (1%). Pratylenchus spp. were widespread across all surveyed regions. In most sampled sites from both islands, Pratylenchus spp. exceeded 1000 kg-1 of soil, which is recognised as the economic threshold set by nematologists worldwide. Five Pratylenchus spp. in New Zealand maize fields: P. crenatus, P. neglectus, P. thornei, P. penetrans, and P. pratensis, were identified based on morphology and the sequencing of DNA-PCR products extracted from single nematode using Sanger sequencing. Among these, P. crenatus and P. neglectus were predominant across maize-growing regions in New Zealand. The soil analysis revealed that tested soil properties varied between the sampled regions, while PPN abundance and diversity exhibited a regional dissimilarity. The relationship between PPN composition and soil physicochemical properties of New Zealand maize fields analysed using the canonical correspondence analysis (CCA). Results showed that soil moisture, pH, soil P, and percentages of sand, clay, N, and C significantly influenced PPN abundance and distribution. However, the influence of soil parameters on the PPN population varied within the regions, where soil moisture content was the main driver for the PPN population abundance within all three regions. A year-round sampling conducted at one of the sites in the Canterbury region of SI revealed the influence of seasonal and cropping factors on PPN abundance. This indicated a 5-fold population increase of Pratylenchus spp. from crop establishment to maturity during a season. Also, CCA on seasonal variations on soil physicochemical, climatic factors, and PPN population abundance in a field revealed that the soil moisture, volumetric water content, bulk density, sand%, N and C with the climatic factors; rainfall, relative humidity, and sunshine hours had a significant relationship with PPN population dynamics. Three nematode extraction methods for maize roots were tested. Centrifugal sugar flotation yielded the highest nematode count but with low clarity for microscopic observation. The Baermann funnel had 35.9% extraction efficiency with high clarity. The Whitehead tray had 60.8% efficiency with moderate clarity compared to centrifugal sugar flotation. The Whitehead tray is a good compromise for clarity and count, while sugar flotation is efficient and faster processing of samples for Pratylenchus nematodes, adding another layer of information for future studies. The outcomes from the glasshouse experiments using 15 commercial maize hybrids and a mixed field population of Pratylenchus spp. showed that most tested maize hybrids were susceptible to Pratylenchus spp. and demonstrated varying degrees of susceptibility. Another glasshouse experiment was conducted to determine the pathogenicity and reproduction of Pratylenchus on three selected maize hybrids based on the results from the previous trials. The results demonstrated significant reductions in root dry weight across hybrids, with losses ranging from 33% to 42%, and shoot weight losses varied among hybrids 10 to 22% compared to the controls 60 days after planting. This is the first comprehensive study on the PPN community association with maize in Sri Lanka and New Zealand. These findings emphasised the potential impact of PPNs, particularly Pratylenchus spp., on maize yield in both countries, highlighting the urgent need for further research to develop effective PPN management tactics adapted to local conditions.
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Factors influencing GlobalGAP adoption and its impact on income and production costs of small-scale pineapple farmers in Ghana : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2023) Annor, Prince Baah
The adoption of Global Good Agricultural Practices (GlobalGAP) improves food quality and safety along fresh produce value chains, but adoption rates have been low among small-scale pineapple farmers in Ghana. Low adoption rates have contributed to a fall in smallholder participation in export-oriented production and declining export performance. While policymakers and other industry stakeholders have tried to find ways to improve GlobalGAP adoption in Ghana, little is known about the determinants and impacts. Consequently, stakeholders do not know which smallholders are most likely to respond positively to interventions aimed at promoting adoption. Moreover, previous studies have identified significant increases in smallholder production costs associated with GlobalGAP compliance. However, there is limited information on how specific inputs used by GlobalGAP certified farmers increase production costs. Such information would help policymakers to target interventions at the most important drivers of quality-enhancing compliance costs. Furthermore, it would make adoption more affordable to farmers and less expensive for taxpayers who fund these interventions. In the first instance, this study set out to measure the impact of GlobalGAP adoption on the net incomes of smaller and larger small-scale pineapple farmers, recognising that compliance incurs significant fixed costs, and that fixed costs pose a greater obstacle to adoption on smaller farms. Small-scale farmers were defined as those operating farms no larger than five hectares. The study used probit and two-stage regression models to estimate the impact of GlobalGAP adoption on net income. These techniques were applied to a representative sample of 546 small-scale pineapple farmers located in Ghana’s two leading export production districts. Of these 546 farmers, 236 were GlobalGAP adopters; the remaining 310 were non-adopters. The probit model showed that the probability of adoption was higher for households that had larger land endowments, were members of an agricultural cooperative, engaged with extension services, and had female heads. The regression models showed that GlobalGAP adoption reduced net income on farms producing less than one hectare of pineapples, but increased net income on farms growing more than one hectare of pineapples. The study thus recommends that extension and other interventions intended to promote GlobalGAP adoption amongst pineapple farmers in Ghana should be targeted at those able and willing to grow more than one hectare of pineapples. Second, this study used a quality-adjusted transcendental logarithmic (translog) cost function to identify the main contributors to production costs in the sub-sample of 236 GlobalGAP adopters. The results showed that production cost is most sensitive to changes in the plantlet price, followed by wages, agrochemical prices, and expenditure on capital items. Smaller small-scale farmers are much more sensitive to increases in capital expenditure than are larger small-scale farmers. Post-estimation analysis showed that improvements in product quality increased production costs at an increasing rate. Key policy recommendations include joint ventures to increase nursery capacity and competition in the market for plantlets, scrutiny of mandatory fees impacting the cost of imported labour-saving inputs, facilitating sharing arrangements between smallholders to lower the cost of on-farm infrastructure, and research to identify constraints preventing certified farmers from exploiting size economies.
Open Access
Spatial agroecology: modelling multiple ecosystem services in periurban landscapes : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2024) Morris, Richard Minton
Urban growth and agricultural intensification share a common trait of reducing landscapes' capacity of producing the critical ecosystem services (ES) on which they depend. The objective of the work described in this thesis was to develop a spatially explicit ES-based design method for the configuration of landscapes to generate regulating ES. Literature review, which is described in Chapter 2, identified a nexus of four research fields - Ecological Urbanism, Landscape Ecology, ES science and agroecology - as an unexplored framework for this ES-based design approach. The method used in this work is described in Chapter 3, where a key flaw in current ES modelling tools forms the basis for a Geographic Information Systems (GIS)-based conceptual model, ESMAX. Present models are characterised by 'the biophysical gap', an oversight of spatial interactions between ES-supplying landscape components. This inhibits their application to spatial design i.e., the configuration of those components to enhance ES performance. ESMAX is structured around the fundamental natural phenomena of distance-decay as exhibited by all regulating ES, enabling an original method of quantifying and visualising regulating ES produced by different configurations of landscape components. The results of Chapter 3 conceptually validated the model and provided the data for Chapter 4, which proposed a model for assessing landscape multifunctionality (or simultaneous supply of multiple ES) from different landscape configurations. Importantly, the results for different configuration options generate a solution space with which to negotiate specific ES demands and specific contextual spatial constraints. Chapter 5 applied ESMAX and the solution space in an agricultural context. This spatial agroecological approach determined that different configurations of the same total area of trees in a 1 ha paddock produce markedly different levels of ES performance, and that this approach may be useful in supporting an adaptive transition from conventional agriculture to agroecologically based farming systems. Chapter 6 applied spatial agroecology to a 190 ha periurban development site, demonstrating how the same apportioned area of agroecological systems, when subdivided and distributed differently across the site, has a significant bearing on multiple ES production. This suggests that urgent consideration should be given not only to placing trees on farm, but how trees should be placed on farm. Similarly, it supports not only the integration of agriculture with urban systems, but the specific spatial design of agroecological systems to address the regulating ES demands of the urban system. The spatial agricultural approach outlined in this thesis highlights the potential for agroecology in the Anthropocene as a spatially effective source of multiple regulating ES to surrounding communities at various scales.
Embargo
Integrative dynamics of action potential in Axon Initial Segment (AIS) of neurons: A novel computational model : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2023) Pashang, Abolghasem
The Axon Initial Segment (AIS) plays a critical role in neuronal excitability and action potential initiation. Computational modelling of the AIS can provide valuable insights into the biophysical mechanisms underlying these processes and their relevance to various AIS-related disorders. The Hodgkin-Huxley model laid the foundation for understanding action potential initiation, utilising empirical differential equations to describe sodium and potassium ion conductance and their gating functions. However, the specific role of the scaffold protein Ankrin-G (AnkG) in regulating ion channel function and ion currents in the AIS remains poorly understood. This thesis investigates the impact of AnkG concentration on sodium (Nav) and potassium (Kv) channel gating and ion current properties using electrophysiology, molecular biology, and computational modelling approaches. AnkG acts as a molecular bridge between the Nav and Kv channels and the cytoskeleton, ensuring proper channel localisation and density in the AIS. Disruptions to AnkG expression can lead to alterations in channel localisation and function, affecting neuronal excitability and firing properties. This thesis endeavors to unravel the mechanisms underlying AnkG's influence on Nav and Kv channel function and its subsequent impact on ion currents in the AIS. Understanding these interactions is crucial for comprehending the pathogenesis of AIS-related disorders and shed light on the complexities of action potential initiation and propagation in neurons.
Embargo
Can the presence of a fungal volatile organic compound improve plant resilience to abiotic stress? : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2023) Echaide Aquino, Jesus Francisco
Climate change is a matter of increasing concern, as the severity, duration, and area affected by drought have steadily risen since the 1970s. These changes have severely affected the agricultural industry, as drought stress is a major contributor to crop loss. Therefore, it is crucial to develop new strategies to address this problem. Seed coating shows the potential to mitigate the challenges faced by the agricultural industry, as it provides physical and physiological properties to seeds, helping alleviate both biotic and abiotic stress. This research aims to evaluate the protective effect of the fungal volatile (FVOC) organic compound when applied via polymer seed coating. The FVOC seed coating treatment's effects were assessed regarding plant emergence, resilience to drought stress, and transgenerational stress adaptations. By conducting a comprehensive transcriptomic analysis, it was possible to identify the transcriptional changes induced by the presence of the FVOC molecule. The application of the FVOC led to significant changes in gene expression in plants under drought-stress conditions, enabling them to cope more effectively with stress. Moreover, when plants grown from FVOC-treated seeds were exposed to a second round of drought stress, they exhibited a more specific and refined response to this stress. Moreover, when the second-generation plants derived from FVOC-treated seeds were exposed to drought, they exhibited improved resilience to environmental stress. This observation strongly suggests the occurrence of transgenerational changes. The drought stress initially triggered these changes in the first-generation plants and was further enhanced by the presence of the FVOC molecule. Subsequently, these changes were transmitted to the second generation, resulting in enhanced resilience plants.

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