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Research Commons is the University of Waikato's open access research repository, housing research publications and theses produced by the University's staff and students.
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Item Healing through culture: Kava-talanoa as a PTSD therapeutic framework(Conference Contribution, Sage, 2025)Introduction: The incidence of post-traumatic stress disorder (PTSD) is increasing, particularly among military personnel, first responders (police, fire, ambulance), and prison officers. PTSD is also a health economic burden, with costs linked to treatment, long-term morbidity, and increased mortality risk. Many cases go undiagnosed due to factors such as trauma-related avoidance behavior, which also negatively impacts PTSD therapy (Watkins et al., 2018, Front. Behav. Neurosci., 12:1-9). There is a significant unmet need for improved and culturally aligned PTSD treatments in the Pacific and beyond. Medical standards of care for acute anxiety/PTSD typically involve psychotropic drugs such as benzodiazepines, tricyclic antidepressants, and antipsychotics. These medications offer short-term relief only, carry addictive risks, are contraindicated for key populations (e.g., the elderly), and have had harmful effects in indigenous communities. Kava (Piper methysticum) is a traditional, culturally significant Pacific Island beverage known for its soporific and relaxant effects, similar to benzodiazepine (Sarris et al., 2012, J. Hum. Psychopharmacol. Clin. Exp., 27:262-9). Unlike benzodiazepines, kava is non-addictive with regular use and extremely safe — regulated as ‘food’ in several countries (Aporosa, 2019, J. Drug Sci. Policy Law, 5:1-13). Kava does not induce marked euphoria or hallucinations (Aporosa et al., 2022, J. Ethnopharm., 291:1-15), and promotes productive discussion known as talanoa—a form of ‘talk therapy’ (Vaka et al., Issues Ment. Health Nurs., 37:537-544). Methods: This ethics approved (21/372) study was guided by the faikava talanoa methodology (Aporosa et al., 2021, Pacific Dynamics, 5:74-92). Self-report experiences of Pacific-based UK and US military veterans and serving combat returnees (n=40) were documented in traditionally influenced kava-use spaces in which attendees engaged in talanoa. While exact kava consumption volumes were not measured, participants typically consumed 3.6 litres (6.33 pints) of kava—approximately 5,000 mg of kavalactones— over six hours. Focused coding was utilised to analyse participant comments. Results: Participants reported that engagement in talanoa within traditionally influenced kava-use spaces increased their relational connectedness, improved meaning making of trauma experiences and promoted better sleep. Conclusions: Aided by kava’s anxiolytic soporific effects, it is suspected that kava use with talanoa reduces the triggering of 'fear structures', minimizes avoidance behavior and aids sleep quality, contributing to symptom reduction. Further, we believe that kava-talanoa offers an innovative, culturally augmented, group-based CBT intervention (Aporosa et al., 2025, Front. Psychol., doi:10.3389/fpsyg.2025.1460731). The findings serve as a foundation for clinical trials (underway) to determine the efficacy of the approach as a much-needed transcultural treatment of trauma that addresses the global PTSD burden.Publication Study on hydrogen storage performance of as-milled Ti-V-Cr-Fe-Mn high entropy alloys(Thesis, The University of Waikato, 2025-07-16)This study aims to fabricate and optimize BCC-based high-entropy hydrogen storage alloys through mechanical alloying. The research systematically investigates the effects of processing parameters (including milling time, ball-to-powder ratio, rotation speed, and process control agent (PCA) addition), alloy composition, and heat treatment on the phase structure, thermodynamic stability, and hydrogen storage performance of the fabricated alloys. Furthermore, the study compares the microstructure and hydrogen storage properties of alloys fabricated by different methods (mechanical alloying and arc melting). Firstly, the study optimizes the mechanical alloying parameters, revealing the critical roles of milling time, ball-to-powder ratio, and rotation speed in forming BCC structures and nanocrystalline grains in Ti-V-Cr-Mn-Fe alloys. The regulatory effects of PCA addition on powder yield and particle size are also analyzed. Subsequently, the impact of composition on hydrogen storage properties, including hydrogen absorption/desorption kinetics, thermodynamic behavior, and cycling stability, are explored by varying the Ti content and Mn/Cr ratios. It is found that increasing Ti content enhances the proportion of C14 Laves phases, while increasing Mn content effectively suppresses Laves phase formation, thereby increasing the BCC phase fraction and improving hydrogen storage kinetics. Additionally, the role of heat treatment is examined. Microstructural evolution analysis reveals the phase transformation behavior among BCC, FCC, and Laves phases under different heat treatment conditions and their effects on hydrogen storage capacity. Specifically, as the temperature increases, the BCC structure first decomposes into a BCC + FCC dual-phase structure, followed by the precipitation of the Laves-2 phase within the FCC phase. After high-temperature treatment, the lattice constant of the BCC phase decreases, and the synergistic effect of the Laves and FCC phases results in a slight reduction in the hydrogen absorption and desorption capacity of the alloy. Finally, by comparing different fabricating process, the differences in microstructure and hydrogen storage performance of Ti25V35(CrMnFe)40 alloys prepared by these methods are investigated. The results suggested that Mechanical alloying significantly enhances initial the activation performance and hydrogen absorption kinetics of the as-milled alloys are improved compared to the counterparts of as-cast alloys.Item Māori-focused course content in undergraduate psychology programmes in Aotearoa New Zealand(Journal Article, Christchurch New Zealand Psychological Society, 2025)Item 15 yr of interstellar neutral hydrogen observed with the interstellar boundary explorer(Journal Article, IOP, 2025-05-01)The interactions of our heliosphere with the surrounding local interstellar medium (LISM) lead to a range of observable phenomena such as energetic neutral atoms (ENAs) from the boundary regions of the heliosphere and the influx of interstellar neutrals (ISNs) into the inner solar system. Hydrogen is the dominant neutral species in the LISM, but due to ionization and radiation pressure, only a fraction of the ISN H atoms reach the inner solar system close to Earth. Monitoring this signal therefore provides observational constraints on our assumptions of the LISM and the solar-activity-dependent loss processes inside the heliosphere. The IBEX-Lo instrument on board the Interstellar Boundary Explorer has been the only instrument so far to measure ISN H atoms directly, together with ISN D, He, Ne, O, and ENAs in the energy range from tens of eV to 2 keV. This study covers 15 yr of IBEX-Lo ISN H observations, i.e., more than one solar cycle and includes two solar minima when the ISN H signal in IBEX-Lo is strongest. Despite the very intense ISN He signal, the ISN H signal can be retrieved with appropriate knowledge of the instrument, choice of optimum observation season, and supporting modeling. The retrieved ISN H signal shows a clear anticorrelation with solar activity. The resulting ISN H maps are available in orbit format and in ecliptic coordinates and will be the basis for future more detailed comparison with heliosphere models.Item Social media and the evolution of vaccine preferences during the COVID-19 pandemic: Discrete choice experiment(Journal Article, JMIR Publications Inc., 2025)Vaccine information and misinformation are spread through social media in ways that may vary by platform. Understanding the role social media plays in shaping vaccine preferences is crucial for policymakers and researchers. Objective This study aims to test whether social media use is associated with changes in vaccine preferences during the COVID-19 pandemic in New Zealand, and whether trust in sources of information has a moderating role. Methods Our data consist of a balanced panel of 257 web-based respondents in New Zealand in August 2020, October-November 2020, and March-April 2021. We use a novel approach with stated choice panel data to study transitions between different vaccine preference groups. We analyze the associations between these transitions and social media use. We classify respondents as resistant (never chose a vaccine), hesitant (chose a vaccine between 1 and 5 times), and provaccine (chose a vaccine 6 out of 6 times) in each wave of data. Results We found a positive or neutral association between social media use and vaccine uptake. Facebook, Twitter (pre-2022), and TikTok users who are provaccine are less likely to become hesitant or resistant. Facebook and Instagram users who are hesitant are more likely to become pro. Some social media platforms may have a more positive association with vaccine uptake preferences for those who do not trust the government. Conclusions The paper contributes to the wider literature, which shows social media can be associated with reinforcing both pro and antivaccination sentiment, and these results depend on where individuals get their information from and their trust in such sources.
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