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The UC Research Repository collects, stores and makes available original research from postgraduate students, researchers and academics based at the University of Canterbury.
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Recent Submissions
A Kaupapa Māori approach to the Storage and Collection of Taonga Seeds
(2024) Shadbolt, Marcus-Rongowhitiao Te Puni
Due to the effects of climate change and widespread ecological destruction, we are seeing global
species loss on an unprecedented scale. In response to this, seed banking has become one method
of storing at-risk species safely, while simultaneously supporting ecological restoration. Seed banking
has therefore become a vital practice globally for ensuring the continual supply of seeds, in both
agricultural and conservation projects. In Aotearoa, knowledge of how to store native seeds is
limited, as the local science system has yet to truly utilise it as a method of conservation. This thesis
therefore aims to look at both the technical aspects of how to store seeds native to Aotearoa, and
what this may look like ethically, legally, and appropriately from an Indigenous Māori perspective.
The technical part of this thesis focused on five species of the Coprosma genus and aimed to find the
optimal germination method for each one, as well as whether these species show signs of
desiccation or freezing sensitivity. Of my study species, C. robusta was identified as orthodox, while
C. propinqua, C. rugosa, C. rhamnoides, and C. autumnalis are all varying degrees of non-orthodox.
Among them, C. propinqua is intermediate with decreasing viability as temperatures decreased, and
C. autumnalis was completely recalcitrant with no germination after drying. Coprosma rugosa and C.
rhamnoides are both intermediate but with a significantly lower number of germinations than in C.
propinqua. More research is needed on these species, specifically into how long in storage these
species can last, in the case of those which can be stored safely.
The cultural aspect of this thesis, however, focused on addressing the past injustices faced by
Indigenous peoples, specifically Māori, in science and conservation, while discussing how to build an
appropriate and ethical seed banking system from the outset in Aotearoa. This chapter aimed to
bring together both international policy and legal precedents from Aotearoa related to seed
ownership. Based on these, I propose a set of best-practice guidelines for working with Māori in
relation to seed banking. These protocols bring together the current literature on appropriate
engagement, and personal experiences of myself and colleagues as Māori people working in the
environmental space. Ultimately, between these two seemingly separate aims, the overall goal of
this thesis is to support the growth of the relatively new seed banking sector in Aotearoa, so that as
the nation progresses, we do it from an ethical and appropriate position.
Exploring the early experiences of assisted dying in Aotearoa New Zealand: a qualitative study protocol
(2024) Reid, Kate; Young, Jessica; Dehkhoda, Aida; Ahuriri-Driscoll, Annabel; Cheung, Gary; Egan, Richard; Karaka-Clarke, Te Hurinui; Moeke-Maxwell, Tess; Robinson, Jackie; Snelling, Jeanne; White, Ben; Winters, Janine Penfield; Diesfeld, Kate
Introduction Increasing numbers of jurisdictions are
legalising assisted dying (AD). Developing research
protocols to study the experiences and outcomes of
legislation is imperative. AD is a topic that, by nature of
its complexity and inherent ethical issues, lends itself to
qualitative research. Using the objectives of the statutory
framework, this qualitative study aims to provide a robust
review of the newly formed AD service in New Zealand
and the extent to which it is safe, people-centred, dignity-enhancing, accessible and available equitably to all eligible
people.
Methods and analysis The research uses an appreciative
inquiry design to focus on what is working well, what
could be improved, what constitutes the ‘ideal’ and how
to enable people to achieve that ideal. We are using online
semi-structured interviews and face-to-face focus groups
to explore the experiences of key stakeholders: eligible/
ineligible service users; eligible/ineligible service users
with impairments; families of service users; AD providers;
non-providers (providers who object to AD and others
who are not directly involved in providing AD but are not
opposed in principle); health service leaders; and Māori
community members. An estimated 110 participants will
be interviewed. We will conduct thematic and regulatory
analyses of data.
Ethics and dissemination The ethical aspects of this
study have been approved by the Northern A Health
and Disability Ethics Committee through the full review
pathway (2023 EXP 18493). To disseminate the findings,
we will draft resources to support interviewee groups, to
be developed with feedback from stakeholder meetings.
We will submit evidence-based recommendations to
inform the government review of the End of Life Choice
Act 2019. Findings will be disseminated in peer-reviewed
publications, conferences, webinars, media, stakeholder
feedback sessions and accessible research briefings.
Reflections on a communication journey into professionalism and organizing
(Oxford University Press (OUP), 2024) McAllum, Kirstie; Barbour , Joshua B.; Fox , Stephanie; Matte , Frédérik
Much research in the field of communication studies has evidenced a 'performative turn' in how it views professionalism, professionals, and the professions. This special issue, Opening up the meanings of 'the professional', professional organizations, and professionalism in communication studies, documents this process and lays out a research agenda in and from communication studies that can inform scholarship on professionalism and organizing. In addition to mapping out and contextualizing the multiple, contested meanings of professionalism, particularly in novel or 'non-standard' contexts, it shows how workers enact, negotiate, reify, and resist the meanings of professionalism in both aspirational and exclusionary ways. When we shift the focus from professional experts (and the institutional apparatus that protects their status, autonomy, and authority) to expertise, as Ashcraft suggests in her contribution to this special issue, scholarly analysis needs to account for an entire network of actors, ideas, instruments, and forms of organizing that allow for successful-or failed-performances of expertise and understand that those performances rest on economies of difference. Economies of difference are distinctions among the sorts of work, workers, and working that wield political power in that they implicate social structures and dictate how specialized expertise is and can be deployed and recognized. Economies of difference create and benefit from inequities. The articles in this special issue offer empirical and conceptual windows into the contested and messy performance of professionalism, how it serves as a resource for some and a constraint for others, and how its contemporary meaning is potentially disrupted.
Computational bioacoustics for the detection of rare acoustic events
(2024) McEwen, Ben
The field of computational bioacoustics is a rapidly developing area of research. Tradi- tional bioacoustic monitoring has a long history of use particularly for monitoring of avian species. Species that were previously infeasible to monitor due to resource and time constraints are now a possibility. In New Zealand, bioacoustic monitoring has never been applied to the detection and surveillance of invasive terrestrial mammals. This dissertation presents the first research of its kind investigating the use of computational tools for the detection of invasive species. We evaluate the use of computational methods for the detection of common brushtail possums (Trichosurus vulpecula) a species that is invasive to New Zealand we also investigate the potential of acoustic monitoring of other challenging target species such as mustelids and rats.
Low population densities (such as post-eradication efforts) encounter extremely sparse detections where it becomes challenging to reliably differentiate between species absence and non-detection. This issue of non-detection is accentuated by the use of passive acoustic monitoring technology at a landscape-scale. Thousands of hours of raw acoustic data can be collected weekly. Most of this data is empty of events of interest. It is infeasible for a human to manually analyse this data. The post-processing of acoustic data is a common challenge for passive acoustic monitoring applications. Rare feature detection (especially for challenging applications such as incursion detection and probability of absence testing) is currently at the border of feasibility using state- of-the-art computational bioacoustics tools. We present an active few-shot learning methodology that combines semi-supervised prototypical learning methods for efficient analysis of acoustic data with limited existing samples. We evaluate this methodology on an invasive species detection dataset demonstrating high performance at a range of data availability contexts. This methodology achieves a test accuracy of 98.4% (with fine- tuning) as well as 81.2% test accuracy using 2-shot, 2-way prototypical learning without fine-tuning, demonstrating high performance at varying data availability contexts.
The development of improved methodologies capable of detecting rare acoustic features has clear benefits for other bioacoustic monitoring applications. This technology can be applied to other challenging applications such as monitoring of rare and at- risk species. These methods can be applied to scale the efficiency of data analysis of existing bioacoustic monitoring applications to achieve landscape-scale monitoring.
Invasive species detection using bioacoustics represents a challenging but valuable area of research. We present the development of publicly available methodologies, tools and the first invasive species dataset containing 3500 labelled samples and over 1300 samples of brushtail possum vocalisations. The results of this work indicate the potential of computational bioacoustic methods for the detection of invasive species as well as rare and at-risk species that encounter similar monitoring challenges.
In addition to improved bioacoustic detection methods, we also investigate the use of bioacoustic noise reduction methods evaluating both signal processing-based methods and deep audio enhancement methods. We investigate the efficacy of noise reduction for the performance of downstream segmentation and classification tasks identifying the limitations of common perceptual metric-based approaches. We find that noise reduction results in no improvement in segmentation precision and recall with an average AUC performance decrease of 19.2%. We also demonstrate no benefit in classification accuracy when tested using state-of-the-art time-domain and time-frequency-domain audio classification models with a marginal decrease in average validation accuracy of 0.41%. We contrast these findings with common perceptual metrics which demonstrate consistent increases in perceptual quality when noise reduction is applied with SnNR increases ranging from 14.0% to 41.3%.
We also present initial work that investigates the use of visual detection methods. We develop predictive tracking methods used to improve population estimates of low- resolution and low-frame rate thermal cameras. We discuss the use of these tools within the context of predator-free New Zealand and the current pest management paradigm.
Mechanism of Action of Cell Envelope Proteinases on Selected Plant Proteins
(2024) Harper, Aimee
Ethical, environmental and health concerns around dairy products are driving a fast-growing industry for plant-based dairy alternatives, however, undesirable flavours and textures in current products are limiting their uptake into the mainstream. The proteolysis of caseins into peptides and amino acids in dairy products is a well understood process and is fundamental to developing the flavour and texture of fermented dairy products like cheese and yoghurt, yet proteolysis in plant-based alternatives is poorly understood. With this knowledge, bespoke fermentative processes could be engineered for specific food qualities in plant-based foods. This research aimed to lay the foundational groundwork for understanding how proteolysis, specifically that of cell envelope proteinases, works in plant-based dairy alternatives. A cell envelope proteinase from Lactococcus lactis, PrtP, was shown to be able to be expressed and purified in small amounts using Bacillus subtilis as an expression system. In the other component of this work, Lactic acid bacteria cultures were grown using plant proteins as the protein source, demonstrating that plant proteins are a viable substrate for these bacteria. Together, these results set the basis for future work on the detailed mechanisms of action of these proteinases in vitro and in vivo.