Faculty of Health and Environmental Sciences (Te Ara Hauora A Pūtaiao)
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Faculty of Health and Environmental Sciences - Te Ara Hauora A Pūtaiao encompasses theSchool of Clinical Sciences - Te Kura Mātai Haumanu
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Browsing Faculty of Health and Environmental Sciences (Te Ara Hauora A Pūtaiao) by Subject "03 Chemical Sciences"
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- ItemEcosystem Integrity of Active Sand Dunes: A Case Study to Implement and Test the SEEA-EA Global Standard, From Aotearoa New Zealand(Elsevier BV, 2023-05-01) Ryan, C; Case, BS; Bishop, CD; Buckley, HLBiodiversity and ecosystem functions are deteriorating worldwide, and there is an urgent need to reverse these declines and set ecosystems on a path to recovery. Effective monitoring, including a fit for purpose indicator framework, is essential to track progress towards targets but, as yet there is no universal framework that delivers timely data on biodiversity and ecosystem change. Ecosystem integrity is a unifying concept that refers to the capacity of an ecosystem to be resilient to natural or anthropogenic perturbations, and to maintain characteristic species composition, structure, functioning and self-organisation over time within a natural range of variability. Using a case study which can be generalised to international contexts, we implement and test a new global standard for the assessment, monitoring and ranking of ecosystem integrity of active sand dunes in Aotearoa New Zealand.
- ItemInteractive Effects of Elevated Temperature and Photobacterium swingsii Infection on the Survival and Immune Response of Marine Mussels (Perna canaliculus): A Summer Mortality Scenario(Elsevier BV, 2024-02-03) Azizan, Awanis; Venter, Leonie; Zhang, Jingjing; Young, Tim; Ericson, Jessica A; Delorme, Natalí J; Ragg, Norman LC; Alfaro, Andrea CThe New Zealand Greenshell™ mussel (Perna canaliculus) is an economically important aquaculture species. Prolonged increases in seawater temperature above mussel thermotolerance ranges pose a significant threat to mussel survival and health, potentially increasing susceptibility to bacterial infections. Using challenge experiments, this study examined the combined effects of increased seawater temperature and bacterial (Photobacterium swingsii) infection on animal survival, haemocyte and biochemical responses of adult mussels. Mussels maintained at three temperatures (16, 20 and 24 °C) for seven days were either not injected (control), injected with sterile marine broth (injection control) or P. swingsii (challenged with medium and high doses) and monitored daily for five days. Haemolymph and tissue samples were collected at 24, 48, 72, 96, 120 h post-challenge and analysed to quantify bacterial colonies, haemocyte responses and biochemical responses. Mussels infected with P. swingsii exhibited mortalities at 20 and 24 °C, likely due to a compromised immune system, but no mortalities were observed when temperature was the only stressor. Bacterial colony counts in haemolymph decreased over time, suggesting bacterial clearance followed by the activation of immune signalling pathways. Total haemocyte counts and viability data supports haemocyte defence functions being stimulated in the presence of high pathogen loads at 24 °C. In the gill tissue, oxidative stress responses, measured as total antioxidant capacity and malondialdehyde (MDA) levels, were higher in infected mussels (compared to the controls) after 24h and 120h post-challenge at the lowest (16 °C) and highest temperatures (24 °C), indicating the presence of oxidative stress due to temperature and pathogen stressors. Overall, this work confirms that Photobacterium swingsii is pathogenic to P. canaliculus and indicates that mussels may be more vulnerable to bacterial pathogens under conditions of elevated temperature, such as those predicted under future climate change scenarios.
- ItemShort-Term Passive Greenspace Exposures Have Little Effect on Nasal Microbiomes: A Cross-Over Exposure Study of a Māori Cohort(Elsevier, 2024-03-28) Brame, Joel E; Warbrick, Isaac; Heke, Deborah; Liddicoat, Craig; Breed, Martin FIndigenous health interventions have emerged in New Zealand aimed at increasing people's interactions with and exposure to macro and microbial diversity. Urban greenspaces provide opportunities for people to gain such exposures. However, the dynamics and pathways of microbial transfer from natural environments onto a person remain poorly understood. Here, we analysed bacterial 16S rRNA amplicons in air samples (n = 7) and pre- and post-exposure nasal samples (n = 238) from 35 participants who had 30-min exposures in an outdoor park. The participants were organised into two groups: over eight days each group had two outdoor park exposures and two indoor office exposures, with a cross-over study design and washout days between exposure days. We investigated the effects of participant group, location (outdoor park vs. indoor office), and exposures (pre vs. post) on the nasal bacterial community composition and three key suspected health-associated bacterial indicators (alpha diversity, generic diversity of Gammaproteobacteria, and read abundances of butyrate-producing bacteria). The participants had distinct nasal bacterial communities, but these communities did not display notable shifts in composition following exposures. The community composition and key health bacterial indicators were stable throughout the trial period, with no clear or consistent effects of group, location, or exposure. We conclude that 30-min exposure periods to urban greenspaces are unlikely to create notable changes in the nasal microbiome of visitors, which contrasts with previous research. Our results suggest that longer exposures or activities that involves closer interaction with microbial rich ecological components (e.g., soil) are required for greenspace exposures to result in noteworthy changes in the nasal microbiome.
- ItemSynthesis, Mixed-Spin-State Structure and Langmuir-Blodgett Deposition of Amphiphilic Fe(III) Quinolylsalicylaldiminate Complexes(Royal Society of Chemistry (RSC), 2024-09-10) Poungsripong, P; Boonprab, T; Harding, P; Murray, KS; Phonsri, W; Zhang, N; Kitchen, JA; Harding, DJDesigning and integrating Fe(iii)-based spin crossover (SCO) complexes onto substrates remains a challenging goal with only a handful of examples reported. In this work, we successfully synthesized and characterized three [Fe(qsal-OR)2]NO3 (qsal-OR = 5-alkoxy-2-[(8-quinolylimino)methyl]phenolate) complexes, in which R = C12H251, C16H332, and C22H453 to explore the impact of alkyl chain on the modulation of SCO activity and potential for self-assembly on a glass surface. The SCO is found to be gradual and incomplete in all cases, with the LS state more stabilised as the alkyl group shortens. We also demonstrate that all complexes form stable Langmuir films and achieve good transfer ratios to the glass surface, with 2 being the best in terms of stability. This paves the way for the SCO modulation of complexes in this class and the development of SCO devices.