13553 research outputs found
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Back to Basics: Rethinking The Way We Design Post-Disaster Homes
No full textNatural disasters are often unpredictable and are happening frequently. Some natural disasters cause damage to communities, resulting in displaced individuals. Due to this there is a need for shelter, however, there are many unknown factors. These include unknown demographics, a strain on time, cost, and resources, and the unknown location. This study begins by identifying a lack of identity and personality in existing post-disaster shelter designs, including the example of Linwood Park from the Christchurch 2011 earthquake. Further research shows the lack of personalisation within shelters, along with addressing key requirements needed for shelters. While providing the basic needs is essential, this thesis also addresses how personalisation can impact a space. Taking bach architecture as a driver for a basic, yet unique approach to temporary accommodation, Lake Clearwater Settlement was used as a case study. Through surveys, interviews, and a reflective design process, the importance of embracing identity emerges as a key element in fostering dignity, livelihood, and a sense of self in displaced individuals.This thesis explores innovative approaches to post-disaster shelter design with a focus on accommodating the unique needs and individuality of displaced individuals. From challenging conventional shelter concepts to embracing self-design and community involvement, the research addresses the question of how interior and exterior features can cater to the diverse requirements of those affected by natural disasters.</p
Rural Renaissance
No full textThis thesis examines the uncertain future of my family's ancestral farm on Banks Peninsula, a legacy deeply ingrained in New Zealand's farming heritage. Focused on speculative architecture, this research will explore architectural opportunities within the adaption of New Zealand's farming industry. An adaption that caters towards a more sustainable future. This research sheds light on the challenges and opportunities in securing the future of sustainable farming in New Zealand.</p
The exact dynamical equations of optimal nonlinear filtering: New approach and results
No full textThis paper develops a novel method for solving nonlinear filtering problems in general continuous-time state-space models. The new method is developed based on an adaptation of the statistical estimation theory for incomplete information which has been primarily developed for maximum likelihood (ML) parameter estimation (Dempster). Distributional identities concerning the score function and information matrix of state are established. Using these identities and the duality principle between ML estimation and optimal control theory, a new set of fully explicit exact recursive filtering equations are derived. They consist of the governing dynamics of the state estimator, the covariance and information matrices. In particular, unless in linear observation, the dynamics of the covariance and information matrices take the form of Riccati equation under the influence of observation process in similar fashion to the dynamics of the state estimator. The results generalize the Kalman-Bucy filter, in particular (Benes,Daum,Kushner,Mortensen,Stratonovich) for nonlinear state-space. A discrete-time representation of the optimal filtering equation is provided for numerical computation. To compare the performance of the optimal filter, a sequential Monte Carlo method (particle filter) is proposed for the time discretization of the state-space. Numerical study confirms the consistency and the accuracy of the exact optimal filter compared to the particle filter's.</p
Molecular Signalling in the Cnidarian-Dinoflagellate Symbiosis
No full textThe cnidarian-dinoflagellate endosymbiosis enables the success of coral reefs, though there are still major knowledge gaps concerning the molecular and cellular biology that underpins this symbiosis, limiting our capacity to understand coral reef function, and its potential responses and adaptability to climate change. One significant knowledge gap concerns the molecular signalling pathways that regulate the onset, persistence and dysfunction of the symbiosis, and determine the success of particular host-symbiont pairings. This thesis therefore aimed to elucidate mechanisms of molecular signalling in the cnidarian-dinoflagellate symbiosis. The specific objectives were: (1) to characterise a potentially key molecular signalling pathway, the phosphatidylinositol (PI) signalling pathway, through the application of bioinformatics, and determine putative functionality of its downstream effects; (2) to characterise how symbiosis and symbiont identity impacts the phosphoproteome of the model cnidarian Exaiptasia diaphana (‘Aiptasia’); (3) to characterise the phosphoproteome of Aiptasia during colonisation with both homologous (native) and heterologous (non-native) symbionts; and (4) to determine whether the symbiotic dinoflagellates release extracellular vesicles to their surrounding culture medium, and if so characterise their proteome, to elucidate their potential role in inter-partner communication. In Chapter 2, bioinformatic evidence is provided for a functionally complete PI pathway in both anthozoans and symbiotic dinoflagellates, through the identification of PI-kinases and PI-phosphatases using publicly available transcriptomes and genomes. The pathways identified in anthozoans were conserved relative to other multicellular model organisms, while the pathway identified in Symbiodiniaceae shared a high level of conservation with the parasitic Apicomplexa. The downstream function of phosphoinositide (PIP)-binding proteins was further elucidated, revealing a diverse array of roles associated to the likes of vesicle formation, MAPK-, Notch-, Wnt- and NF-κB signalling, and the JAK-STAT pathway. The diverse range of potential cellular impacts revealed in Chapter 2 led to the decision to analyse cellular signalling events more widely in the host, via the application of phosphoproteomics (Chapter 3). Indeed, the activation and activity of the PI pathway and many aspects of the downstream effects of PIP-binding proteins are controlled by phosphorylation, a powerful post-translational modification. Aiptasia in long-term symbiosis (> 1 year) with the homologous Breviolum minutum and heterologous Durusdinium trenchii was analysed alongside aposymbiotic (i.e., symbiont-free) Aiptasia. Many of the same signalling pathways identified in Chapter 2 were again identified here, such as MAPK signalling, NF-κB signalling, and the JAK-STAT pathway, while interactions with Ca2+ and cytokines were also apparent. Symbiont identity impacted the phosphoproteomic response, however, with the homologous symbionts dampening host immunity, as well as evidence of the regulation of cell adhesion and cell signalling pathways. Conversely, the heterologous symbiont induces an abundance of phosphoproteins associated with nutritional and oxidative stresses, and an increased host inflammatory response. Phosphoproteomics analysis was then applied (Chapter 4) to examine the signalling events that occur during the establishment of the symbiosis, from onset to the fully symbiotic state. Once again, two symbiont species were compared: the homologous B. minutum vs. the heterologous Symbiodinium microadriaticum. This heterologous species was used to provide a marked contrast with the homologous symbiont as it is known to struggle to form a symbiosis with this culture of Aiptasia (‘NZ1’), thereby aiding differentiation of phosphorylation events underpinning the establishment of a successful symbiosis. Pathways such as MAPK-, Wnt- and NF-κB signalling were again identified in the symbiotic state, plus modifications in cytokine and Ca2+ activity. Symbiosis onset was characterised by an abundance of phosphoproteins associated with inflammation, mRNA decay, cell proliferation/apoptosis, and oxidative and nutritional stress, irrespective of symbiont species. However, as colonisation progressed, these latter stress related-phosphopeptides declined in abundance and presence as the homologous symbiont successfully proliferated, but remained at elevated levels in the presence of the heterologous symbiont, which persisted at much lower densities. The late stages of symbiosis establishment were characterised by an abundance of phosphopeptides related to cellular homeostasis, with putative roles such as cell cycle and mRNA/DNA regulation, Ca2+ signalling, and vesicle trafficking, though interestingly, many of these phosphoproteins exhibited elevated abundances irrespective of symbiont identity or density. Finally, Chapter 5 provided evidence for the release of extracellular vesicles (EVs) by B. minutum and the free-living Symbiodiniaceae species Effrenium voratum, and successfully characterised their proteome. Putative functions for proteins that were significantly enriched in the EVs relative to the dinoflagellate cell, or indeed were EV-specific, were explored to elucidate possible roles that EVs might play in communication and molecular exchange between cnidarians and dinoflagellates. Consistent with the results of Chapters 2, 3 and 4, proteins were identified with putative functionality in MAPK signalling, cytokine interactions, Ca2+ activity, and more broadly in immunity, cell adhesion and host cell modulation. The proteome of EVs from B. minutum was characterised by a higher proportion of proteins with putative roles in cell adhesion, whereas E. voratum EVs were characterised by a higher proportion of immune suppressing and anti-inflammatory-related proteins. In both EV proteomes there were proteins identified with putative roles in host cell invasion and symbiosis maintenance. In summary, this study employed a range of powerful bioinformatic and omics methods to provide insight into the molecular signalling events that underlie the successful establishment and persistent of the cnidarian-dinoflagellate symbiosis. As discussed further in Chapter 6, it has identified candidate molecules and pathways for future study. It has thereby provided valuable targets for the engineering of more thermally-resistant, novel host-symbiont partnerships for helping to conserve, or at lease slow the decline of the world’s critically endangered coral reefs.</p
Distinct profiles of mental health need and high need overall among New Zealand adolescents – Cluster analysis of population survey data
No full textObjective: The objective was to identify clinically meaningful groups of adolescents based on self-reported mental health and wellbeing data in a population sample of New Zealand secondary school students. Methods: We conducted a cluster analysis of six variables from the Youth19 Rangatahi Smart Survey ( n = 7721, ages 13–18 years, 2019): wellbeing (World Health Organization Well-Being Index), possible anxiety symptoms (Generalized Anxiety Disorder 2-item, adapted), depression symptoms (short form of the Reynolds Adolescent Depression Scale) and past-year self-harm, suicide ideation and suicide attempt. Demographic, contextual and behavioural predictors of cluster membership were determined through multiple discriminant function analysis. We performed cross-validation analyses using holdout samples. Results: We identified five clusters ( n = 7083). The healthy cluster ( n = 2855, 40.31%) reported positive mental health across indicators; the anxious cluster ( n = 1994, 28.15%) reported high possible anxiety symptoms and otherwise generally positive results; the stressed and hurting cluster ( n = 667, 9.42%) reported sub-clinical depression and possible anxiety symptoms and some self-harm; the distressed and ideating cluster ( n = 1116, 15.76%) reported above-cutoff depression and possible anxiety symptoms and high suicide ideation; and the severe cluster ( n = 451; 6.37%) reported the least positive mental health across indicators. Female, rainbow, Māori and Pacific students and those in higher deprivation areas were overrepresented in higher severity clusters. Factors including exposure to sexual harm and discrimination were associated with increasing cluster severity. Conclusion: We identified high prevalence of mental health challenges among adolescents, with distinct clusters of need. Youth mental health is not ‘one size fits all’. Future research should explore youth behaviour and preferences in accessing support and consider how to best support the mental health of each cluster.</p
An Experimental Approach: Investigating the Directive Function of Autobiographical Memory
No full textHow is autobiographical memory useful? Researchers have proposed a directive function—memory for experiences helps to guide and direct behaviour during open-ended problems. The experimental research on the directive function is limited and mixed but suggests that enhancing self-efficacy—the belief or the confidence one holds that they can perform a specific behaviour and achieve certain goals (Bandura, 1997)—can help with open-ended problem solving. Our research programme therefore had two aims: 1) experimentally test whether autobiographical memory recall enhances open-ended problem solving; and 2) experimentally test whether increasing self-efficacy, via autobiographical memory recall, enhances open-ended problem solving.Across three, high-powered, preregistered experiments (Experiments 1, 2 and 4, Chapters 2 and 4), we found no significant main effects of recalling success autobiographical memories—specific memories of feeling successful and competent, either related or unrelated to the problems—on open-ended problem solving (measured by the Means End Problem Solving Task; Platt & Spivack, 1975). We therefore investigated why that might be, particularly given that other studies have found significant experimental effects. For instance, Experiment 3 (n = 209; Chapter 3) found no significant evidence that differences in instructions lead to different results between our own and other studies.Instead, we found that across all conditions in Experiments 1 (n = 169) and 2 (n = 341; Chapter 2), during the problem-solving task some participants recalled additional autobiographical memories related to the problems (i.e., memories we did not request), and they did significantly better at open-ended problem solving than those that did not. We therefore hypothesised that different effects between our own and other studies could be due to some participants in our undergraduate student samples already using their autobiographical memory in a directive and helpful way. Therefore, the experimental manipulation provides no extra benefit for some. Experimental effects could also be dampened if participants in the control condition are already using their autobiographical memory in a directive way. Indeed, in Experiment 4 (n = 237; Chapter 4), we found a significant effect of related, success autobiographical memories on open-ended problem solving, but only for those who self-report not using their autobiographical memory in a directive way (i.e., for those who scored lower on the directive-function subscale of the Thinking About Life Experiences-Revised Questionnaire; Bluck & Alea, 2011).In Experiment 4, we also found no significant, positive correlation between the directive-function subscale scores and problem-solving scores. Thus, while we found that autobiographical memory recall may be functional for open-ended problem solving, it is perhaps not a uniquely advantageous approach to solving open-ended problems. Therefore, experimentally investigating the directive function is complex due to individual differences in how people approach open-ended problems and how they recall and use their autobiographical memories during such times.We also found no evidence that enhancing self-efficacy, via autobiographical memory recall, significantly enhances open-ended problem solving. We did find, however, significant small-to-medium effect sized correlations between self-efficacy scores (i.e., the extent to which the success autobiographical memory made the participant feel confident after recall) and problem-solving scores across all our experiments. The correlations were positive when participants recalled a success experience unrelated to the problem and negative when the memory was related. Thus, our research challenges an assumption in the literature that the relationship between self-efficacy and problem solving is always linear and positive.To end, we suggest some options that may help to mitigate the complexity of experimentally investigating autobiographical memory function. We also propose to reconceptualise the directive function as a process, whereby autobiographical memory recall can help people attain many needs. By doing so, existing, and future experimental findings can be integrated and help to refine the directive function theory—highlighting what, when, how, and for who, autobiographical memory recall is functional, and perhaps even the most advantageous approach, to achieving one’s needs.</p
Heart Health Through Play
No full textThis thesis proposal addresses the global heart health crisis and focuses on improving heart health in New Zealand, particularly within the built environment. The research findings demonstrate that designers can enhance heart health by creating urban and architectural public spaces with playful atmospheres, a community focus, and physical activity and stress reduction opportunities. Through a comprehensive approach, including exploration of theory and case studies, the study site and design led the research at different scales. The thesis ensures a contextual solution to improved heart health in urban and architectural realms. Playful design tools, such as sensory and community-oriented approaches, successfully promote physical activity and reduce stress. The findings are validated through various testing methods, including theoretical research, case studies, and participatory research. The importance of urban interventions, sensory design, and inclusive community design is highlighted. The research emphasizes mixed land use, accessibility, and the transformation of underutilized public spaces into human-centred environments. In conclusion, this thesis proposal provides significant urban and architectural findings applicable to Nelson and other small cities, offering practical strategies for improving heart health, urban vitality, and community well-being through playful design strategies.</p
Machine Learning Assisted Signal Enhancement
No full textIn an era of abundant signals, the ability to obtain desired signals while rejecting undesired ones has become increasingly crucial. Often, the desired signals are mixed with interference or contaminated by noise. Signal enhancement techniques play a vital role in performing tasks such as signal separation, extraction, and suppression. This thesis addresses critical challenges in signal enhancement tasks by harnessing the power of machine learning techniques.Firstly, we propose a novel independence criterion called the Finite Basis Independence Criterion (FBIC). This criterion estimates the Hirschfeld-Gebelein-Rényi maximum correlation coefficient between tested variables and is based on mapping functions from a subspace of finite basis. FBIC detects dependence between variables in linear time and outperforms more computationally expensive kernel-based counterparts. Extensive testing in Independent Component Analysis benchmarks demonstrates its potential for various signal separation applications.Secondly, we conduct a comprehensive robustness analysis of a popular signal enhancement approach: fixed beamforming based on first-order linear Differential Microphone Arrays (DMAs). We demonstrate that both bounded and unbounded phase errors of microphones can affect the mainlobe orientation of the beamformer. Analytically derived white noise gain thresholds indicate when mainlobe misorientation occurs. Through rigorous mathematical derivations, we prove that a higher number of microphones and increased spacing between microphones contribute to the robustness of the beamformer. This work provides practical guidelines for designing robust first-order linear DMAs.Thirdly, we propose a neural network model to optimize both the geometry and spatial filter of linear DMAs. The model consists of two feed forward neural networks and is trained end-to-end. The signals enhanced by this model exhibit superior quality compared to those obtained from conventional DMA approaches. Furthermore, the model offers flexibility in controlling the tradeoff between different performance metrics, allowing for customized optimization.Lastly, we extend the neural network model to a general framework that allows optimization of microphone arrays of any geometry, along with their spatial filters. This model employs ResNets and augmented Lagrangian techniques to achieve state-of-the-art frequency-invariant fixed beamforming performance. We showcase our performance in linear, circular, and concentric circular microphone arrays. Moreover, our findings challenge the conventional belief that concentric circular arrays require multiple rings, as we demonstrate that good performance can be achieved with only one ring.Overall, this thesis contributes novel techniques and insights to the field of signal enhancement, leveraging machine learning approaches to address key challenges. The proposed criteria, guidelines and models have the potential to advance various signal separation applications and enhance the overall quality of processed signals.</p
Investigating the Effects of Psychopathic and Empathic Traits on Interpersonal Resonance Over Time
No full textEmpathy is the cornerstone of many forms of human relationships and is a core skill for building meaningful connection between one another. A growing interest in empathy from psychology researchers over the last few decades has seen vast pool of literature surrounding empathy come to be. The same could also be said for psychopathic personality traits. Very little research has enquired about the role of psychopathy on how people resonate with each other at an interpersonal level, with consideration of empathy, interpersonal closeness, and synchronous physiological responding. This study aims to investigate how psychopathic personality traits and cognitive empathy influence interpersonal resonance between two people over a period of time. 106 participants (53 dyads) had their physiological responding recorded, as well as their interpersonal closeness with their partner reported during the study. Participants had their psychopathic personality traits and cognitive empathy levels rated also. Physiological synchrony values were obtained, as well as values representing self-reported interpersonal closeness, as measures of interpersonal resonance. These were then analysed using linear mixed models to determine the effect of psychopathic and empathic traits on these measures of interpersonal resonance. Results showed no significant relationship between any of the three measures of interpersonal resonance used in this study. Though the core results as well as some exploratory visualisations did provide many paths for future research in this area.</p
Investigating the Effects of the Kappa Opioid Receptor Agonist Nalfurafine, in a Mouse Model of Optic Nerve Demyelination
No full textOptic neuritis is an inflammatory demyelinating disease of the optic nerve (ON) which is often associated with autoimmune diseases such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorder. Its relationship with MS is closely interwoven, as optic neuritis is commonly the first clinical sign of MS and is experienced by 60-70% of MS patients in the course of their disease. Disease occurs when white matter lesions appear on the ON, leading to axonal loss and atrophy of the retinal nerve fibre layer, potentially leading to permanent vision loss despite the individual recovering from the acute immune attack. There is no cure for MS-associated optic neuritis, and current immunomodulatory treatments for MS and optic neuritis focus only on preventing attacks and slowing disease progression, not repairing the damage that has already been done.Treatments targeting the oligodendrocyte lineage - responsible for myelination of the central nervous system - are promising due to their potential to drive remyelination. Recent preclinical studies using models of demyelination have presented the kappa opioid receptor (KOPr) as a target for remyelination, with KOPr receptor agonists having been shown to promote oligodendrocyte precursor cell differentiation into oligodendrocytes and increase myelination. The current research investigated the ON features in the experimental autoimmune encephalomyelitis (EAE) model of demyelination and the effect of the clinically available KOPr agonist, nalfurafine, on myelination, immune infiltration, oligodendrocyte lineage cells, microglia, and astrocytes in the model. Techniques used were Black-Gold II and haematoxylin and eosin staining, and immunolabelling with anti-SOX10, -GST-pi, -IBA1, and -GFAP antibodies. It was shown that demyelination and immune infiltration occur, mature oligodendrocytes are fewer, while microglia and astrocyte numbers increase in ONs of EAE mice. Additionally, nalfurafine suppressed astrocyte GFAP expression in the EAE model.</p
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