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Experimental Evaluation of Heat Transfer on Cold Plates Under Frosting and Condensation Conditions
No full textIn HVAC and refrigeration applications, the performance of heat exchangers gets influenced by what happens on its surface. On the surface, deposits of materials such as condensation of moisture and frost can accumulate that reduce the heat transfer. Further, periodic removal of deposited frost though defrosting is required to restore the normal heat exchanger performance which again adds to energy consumption. In order to improve the heat transfer of such surfaces, strategies to reduce frost or delay frost formation are widely researched. Although a lot has been known about frost formation through nearly five decades of research, the advancements in nano-micro surface fabrication have drawn researchers to revisit these frost experiments in lights of surface properties. This thesis focused on the heat transfer on cold plates under frosting and condensation conditions.
In order to determine heat transfer characteristics, a series of experiments were designed to characterise frost formation on a plain aluminium surface and a coated aluminium surface with different wettability (contact angle, and surface roughness) in a purpose-built psychrometric closed loop wind tunnel facility. Through the collaborative between NZ Product Accelerator and GNS Science, the coated aluminium surfaces were sourced from GNS using their proprietary ion beam implantation technique.
We hypothesised that hydrophobic surfaces can enhance heat transfer under frosting conditions. Boron Nitride (BN) ion implanted, Hydrogen (H) ion implanted hydrophobic aluminium plates and uncoated aluminium plates were tested under frosting conditions. Enhanced heat transfer was detected in the BN frost experiment in comparison with H and uncoated aluminium plates. The thesis explores the heat transfer mechanism causing the enhancement in hydrophobic BN sample. Other effects such as the thermofluidic interaction, surface properties, and phase change heat transfer were systematically reported for all the test samples through a series of experiments.
The engineering and manufacturing of new surfaces that improve performance of heat exchangers have energy saving implication in HVAC and refrigeration sectors of the NZ economy and globally. This thesis contributes towards rapidly testing potential coatings that can improve surface heat transfer through established analysis procedure and measurement systems developed for its use in the purpose-built wind tunnel facility
Variation in clinical presentation, complications and outcomes for Māori and Pacific peoples among hospitalised adults with COVID-19 in 2022, Aotearoa New Zealand
No full textBackgroundPacific region-specific data on the clinical course of COVID-19 are limited. We aimed to describe clinical features and outcomes from Aotearoa New Zealand patients, focusing on Māori and Pacific peoples.MethodsWe conducted a retrospective cohort study among adults (≥16 years) hospitalised due to COVID-19 at 11 hospitals from January to May 2022. We included all Māori and Pacific patients and every second non-Māori, non-Pacific (NMNP) patient using data from chart review and national datasets.ResultsOf 2319 patients, 582 (25%) were Māori, 914 (39%) Pacific peoples and 862 NMNP (median age 52, 57 and 63 years respectively). Vaccination coverage (≥2 doses) was 73.4% (n = 437) for Māori, 76.7% (n = 701) for Pacific peoples (n = 701) and 84.8% (n = 731) for NMNP. Among 832 (35.9%) with complications, Māori had a greater risk than NMNP of acute kidney injury (risk ratio (RR) 1.87, P ConclusionsThe clinical course of patients hospitalised by COVID-19 varied between ethnic groups, likely reflecting differential access to social determinants of health. Healthcare services that respond to this variability are needed to achieve the highest attainable health for all
Only Division of Labor Emerges by Modeling the Evolution of Bacteria in Groups without Inherent and Structured Boundaries
No full textReproductive division of labor plays a crucial role in the evolution of cooperation
and functional specialization in biological systems, especially in multicellular
organisms. In the field of evolutionary biology, reproductive division of labor is
particularly important for understanding how organisms evolve complex behaviors
and division of tasks among individuals. Much research has been devoted to the
High Relatedness Hypothesis, which suggests that high genetic relatedness fosters
the evolution of reproductive division of labor in both boundary and non-boundary
systems. In contrast, the Low Relatedness Hypothesis, which proposes that low
genetic relatedness leads to intensified multi-level selection conflicts and drives the
evolution of reproductive division of labor, has yet to be thoroughly explored in
environments without inherent and structured boundaries. Our model reveals that
the reproductive division of labor does not emerge under any of the tested conditions
in the boundary-free systems. Instead, the bacterial populations evolve
toward a stable division of labor (DOL) state, where one group specializes in public
goods production while maintaining its capacity for differentiation, and the other
focuses on reproduction. This differs from reproductive division of labor, where
individuals specializing in public goods production lose their reproductive capacity.
Additionally, when individual mobility during their lifespan is neither too high nor
too low, and under low mutation rates, DOL is favored due to its higher fitness and
stability compared to non-divided systems. The absence of persistent reproductive
division of labor suggests that inherent and structured boundaries (topological constraints)
may be a necessary condition for the evolution of reproductive division of
labor. These findings provide important insights into the factors that drive division
of labor (DOL), emphasizing that DOL is driven by the dual mechanisms of
resource optimization and competitive defense. The evolution of DOL also reflects
a trade-off between relatedness, cooperation efficiency, and system stability. Our
results suggest that the Low Relatedness Hypothesis can not drive the evolution
of reproductive division of labor through multi-level selection in boundary-free scenarios
under our tested conditions. To determine whether it can be applied to such
scenarios, further testing under a broader range of conditions is necessary
The nature of parental involvement and hearing loss among Pacific children and adolescents within the wider Auckland region
No full textPacific children experience a high prevalence of inequitable ear diseases and access to hearing care services in New Zealand. Parental involvement provides positive contributions in a range of hearing related factors and could provide a new perspective to improve hearing health outcomes for Pacific children in New Zealand. This research aimed to explore Pacific parents’ involvement with caring for children and adolescents with hearing loss and experiences with hearing health services.
This explanatory sequential research employed the Fonua model to underpin implementation. The first phase was a descriptive analysis of Pacific children with a First Specialist Appointment aged 0-10 years old across demographic, audiological and service variables in Manukau SuperClinic in 2023. The second phase comprised 8 one-on-one semi-structured talanoa exploring parental involvement and hearing care among Pacific parents of children with hearing loss. The last phase was 12 talanoa with hearing health and education professionals about parental involvement with Pacific families affected by hearing loss. The Fonua Ola of kumi (search), langa (build), tauhi (evaluation) and tufunga (reconstruct) generated talanoa themes.
In 2023, 32.0% of Pacific children in Manukau SuperClinic aged 0-10 years reported a hearing loss, with most exhibiting a mild loss (20.2%), high Otitis media (35.0%) and situated in high socioeconomically deprived areas (82.3%). Significant associations were found between age and Otitis media (p=0.04), hearing loss (p=0.01) and grommets (p<0.001). Despite high appointment attendance (85.5%), the referral route into the hearing screening pathway was complex. This mirrored calls to action from parents and professionals for family-centred hearing care that is easier to access, navigate and understand. The absence of familial mental and emotional support has made familial experiences burdensome within the hearing care
pathway.
Parental involvement among Pacific families affected by hearing loss, service experiences and the hearing care pathway are bounded by day-to-day challenges and socioeconomic hardships. A family-centred approach can bridge the gap in understanding and foster better referral and parental engagement between Pacific families and professionals along this pathway. Navigators and mechanisms to enhance parental involvement reduces transition and accessibility barriers so Pacific families experience unified and timely hearing care for their hearing-impaired children
Innovating Amid Geopolitical Uncertainty
No full textR&D and supply-chain strategies are undergoing a fundamental transformation. The long-standing emphasis on “just-in-time” efficiency, which prioritized lean inventories and minimized surplus, is evolving toward “just-in-case” models (SAP Citation2025; Spanjol et al. Citation2024). This shift prioritizes safety stock, diversified suppliers, and redundant capacities to mitigate disruptions, even if it involves higher costs. This indicates a broader reprioritization in innovation and R&D management—a move from optimizing solely for cost and speed to building in redundancy, diversification, and robustness.
Moreover, this strategic reorientation directly influences innovation and R&D management decisions. Considerations now extend to material sourcing, manufacturing processes, and product design to enable localized production and reduce reliance on single points of failure (Daymond et al. Citation2023; Spanjol et al. Citation2024). For instance, designing products with modularity and using locally sourced components can enhance resilience and potentially align with sustainability goals.
Furthermore, the volatile geopolitical climate necessitates a heightened focus on foresight and scenario planning within companies of all sizes (Crews and Farrington Citation2017; Sarpong et al. Citation2023; Spanjol et al. Citation2024; Townsend et al. Citation2025). Practitioners must anticipate and mitigate risks arising from trade disputes, sanctions, and data localization requirements. This proactive approach helps companies prepare for unexpected challenges and business volatility, transitioning from reactive responses to strategic foresight
Targeting Connexin Hemichannels to Regulate the NLRP3 Inflammasome Pathway in Alzheimer's Disease
No full textBackground: Alzheimer’s Disease (AD) is a devastating neurodegenerative disease that demands novel treatments and earlier diagnostic strategies to enable timely intervention. Overactive inflammasome pathways initiated by the pathogenic amyloid beta 1-42 peptide (Aβ1-42) may contribute to AD pathology. Connexin hemichannels are ‘pathological pores’, which open in response to Aβ1-42 and release signals that sustain inflammasome activation, making them potential therapeutic targets. Despite promising therapies, late diagnosis is an obstacle to AD treatment, requiring more accessible early biomarkers to identify at-risk individuals earlier. AD patients usually manifest ocular pathology before dyscognitive symptoms, presenting the eye as a potential biomarker source. Aims: This thesis investigated 1) the effect of the AD-associated peptide Aβ1-42 on glia and neurons in the hippocampus and the effect on Nucleotide-binding oligomerization domain, Leucine-rich repeat and Pyrin domain-containing receptor 3 (NLRP3) inflammasome activation; 2) anatomical changes to the retina, and changes to glia or NLRP3-associated inflammasome markers in the optic nerve head and retina following injection of Aβ1-42 into the hippocampus; and 3) the impact of the connexin hemichannel blocker, tonabersat, on Aβ1-42-induced changes identified in the hippocampus and the eye. Methods: Daily oral administration of tonabersat began one day after bilateral intrahippocampal injection (I.H.I) of Aβ1-42 in C57BL6 mice. Live ocular imaging, followed by fluorescent immunohistochemistry on brain and eye tissue, was undertaken 17 days after I.H.I. Results: Aβ1-42 increased ionised calcium-binding adapter 1 (Iba1) labelling, non-NLRP3 inflammasome activation, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC) particle size, Iba1 and ASC colocalisation, and neuron loss in the hippocampus. In the mouse retina, Iba1 density, ASC size, and Iba1 and ASC colocalisation were also increased following I.H.I of Aβ1-42. Tonabersat significantly prevented increased Iba1 labelling, ASC size, and Iba1 and ASC colocalisation in both brain and retina tissues and neuron loss in the hippocampus without affecting NLRP3 inflammasome activation. Conclusion: Our findings indicate that localised induction of Aβ1-42 brain pathology readily affects the retina, reinforcing its use as an early AD biomarker source. Connexin hemichannel blockade can prevent significant Aβ1-42-induced changes in the hippocampus and retina, highlighting its potential as a therapeutic for AD
Investigating the usage and impacts of satellite data in New Zealand
No full textGlobal commercialisation of space data has created an intimate relationship between people and satellite systems for the benefit of day-to-day activities. Satellites support services ranging from Earth observation, research, navigation, communication, and national security, and many of these are accessible to an average New Zealander. However, this relationship and its impact are poorly understood. A satellite data chain has been developed from a mixed-method approach using quantitative databases and qualitative frameworks to establish the present state of satellite data in New Zealand and assess the impact of it on everyday New Zealanders. The satellite data chain pieces together the relationship from end-user to satellite operator and demonstrates how data transitions from the satellite system to the providers of satellite-enabled services (or the Satellite-Service Provider, referred to as SSP) and finally to the activities used by individuals that rely on the satellite data. At the time of research, there are over 20 satellite services available in New Zealand supplied by 43 SSPs with data sourced from up to 36 satellite systems and operated by one of 33 entities. Satellite broadband is the most frequently offered satellite service in New Zealand with roughly 20% of SSPs providing it across the country. The satellite systems and operators are almost exclusively internationally owned, amounting to 8000+ satellites with more than 18,000 future satellites planned by these operators alone. There are seven satellite-enabled services that are more than 50% likely to be used by average New Zealanders, provided by seven different SSPs, 15 satellite systems and 15 operators. This satellite data chain reveals economic, environmental, and geopolitical consequences—many of which hold the potential to impact individuals in New Zealand. Awareness of this relationship sparks discussion around data regulation and security as satellite services and data persist further into daily activity
Mitochondria-derived peptide MOTS-c restores mitochondrial respiration in type 2 diabetic heart
No full textType 2 diabetes (T2D) is a global epidemic, and heart failure is the primary cause of premature death among T2D patients. Mitochondrial dysfunction has been linked to decreased contractile performance in diabetic heart, partly due to a disturbance in the mitochondrial capacity to supply adequate metabolic energy to contractile proteins. MOTS-c, a newly discovered mitochondrial-derived peptide, has shown promise as a therapeutic for restoring energy homeostasis and muscle function in metabolic diseases. However, whether MOTS-c therapy improves T2D heart function by increasing mitochondrial bioenergetic function remains unknown. Here we studied the mitochondrial bioenergetic function of heart tissues isolated from a rat model mimicking type 2 diabetes induced by a high-fat diet and low-dose streptozotocin. Treated diabetic group received MOTS-c (15 mg/kg) daily injection for 3 weeks. We employed high-resolution respirometric and fluorometric techniques to simultaneously assess mitochondrial ATP production and hydrolysis capacity, reactive oxygen species (ROS) production, and oxygen flux in cardiac tissue homogenates. We found that untreated T2D rats had hyperglycemia, poor glucose control, and left ventricular hypertrophy relative to controls. T2D mitochondria showed decreased oxygen flux at the oxidative phosphorylation (OXP) while ROS production, ATP production and hydrolysis rates remained unchanged. Diabetic rats treated with MOTS-c showed decreased fasting glucose levels, improved glucose homeostasis, and decreased degree of cardiac hypertrophy. At the subcellular level, MOTS-c treated mitochondria showed increased OXPHOS respiration and ROS levels and decreased ATP hydrolysis rate during anoxic conditions. These findings demonstrate beneficial effects of MOTS-c treatment on glucose homeostasis and suggest a useful therapeutic option for diabetic-related cardiomyopathy and mitochondrial dysfunction
Expansion of the killing spectrum and functional study of tailocins constructs as potential antibiotic alternatives
No full textBacteria use diverse strategies to combat rivals, including tailocins – large multi-protein bacteriocins encoded within the bacterial genome. These extracellular agents can eliminate competing strains. Tailocins likely evolved from prophages, resembling the contractile tail. They employ tail fibers to anchor, and puncture recipient cell membranes, leading to cell lysis and death. However, natural tailocins usually have a narrow specificity, so our study hopes to insert a broad-spectrum lipopolysaccharide (LPS) binding domain CD14 or a peptidoglycan (PG) binding domain PGBP at the end of tail fiber protein through protein engineering, hoping to obtain tailocins with a broader killing spectrum through functional studies. Research in the Hay lab has established a platform for recombinant production and isolation of Pseudomonas syringae tailocins and identified tail fibers that provide specificity. The LPS-binding domain CD14, derived from a pattern recognition receptor in the human immune system, recognizes LPS in the outer membrane of Gram-negative bacteria and mediates the transmembrane transport of LPS, playing a key role in the innate immune response. The PG-binding domain is derived from human peptidoglycan recognition protein 3, which was previously used to bind to the surface of several Gram-positive cells. We anticipate that research may yield tailocins constructs with a broader killing spectrum for Gram-negative or Gram-positive bacteria. Overall, in the current scenario of increasing antibiotic resistance, the specific and efficient killing function of tailocins may provide a new solution for finding and developing potential antibiotic alternatives or supplements
Understanding the impact of religion on consumption: Is religiosity or religiocentrism more appropriate?
No full textPurpose
While the existing literature has extensively studied how available religiosity scales measure the impact of religion on consumption, a conceptual gap still exists about its actual utility and recent literature has indicated the need for a more useful construct. Furthermore, there are limited studies on how this impact can be adequately studied, specifically by using religiocentrism as a construct in marketing. The purpose of this study is to conceptually establish the appropriateness of religiocentrism scale through comprehensive and systematic literature review (SLR).
Design/methodology/approach
A systematic and comprehensive literature review was conducted by searching studies, as per inclusion and exclusion criteria, which were conducted by using religiosity and religiocentrism constructs. The scale items were studied in the given marketing context. The paper presents findings comparing scale items from both religiosity and religiocentrism constructs, highlighting the items specifically related to consumption only. Based on these findings, a conceptual model is proposed to differentiate and indicate the actual utility of both these constructs for studying the impact of religion on consumption.
Findings
The findings indicate that religiosity primarily assesses individual personal characteristics, such as beliefs and practices, rather than consumption behaviours rooted in religious influences. In contrast, religiocentrism focuses more on measuring consumption behaviours explicitly shaped by religious factors. This limitation underscores the inadequacy of using religiosity scales to measure religion-based consumption. Finally, the study recommends that future researchers adopt religiocentrism scales to measure the impact of religion on consumption, as they provide a more precise and relevant framework.
Originality/value
This study presents a systematic literature review and conceptual model which give future directions to researchers.
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