Victoria University of Wellington
  • Wellington, New Zealand
Recent publications
It is estimated that more than 500 species of insects have been introduced to the Galápagos Islands via human activities. One of these insect invaders is the yellow paper wasp, Polistes versicolor (Olivier) (Hymenoptera: Vespidae), a social wasp native to continental South America. In Galápagos, these wasps are voracious predators of insect larvae, compete with native species for insect prey or for oral resources and are a human nuisance. Wasp suppression methods currently in use are ine cient and attract non-target species, calling for the development of species-speci c attractants that can be used in baits to lure and kill wasps. To evaluate the potential for using wasp semi- ochemicals in baits, we determined the biochemical composition of the head, thorax, Dufour’s and venom glands of P. versicolor foragers via gas chromatography/mass spectrometry (GC/MS). Male and female wasps were tested for behavioral responses to body segment extracts from both sexes. Female body extracts consistently elicited more behavioral responses in both male and female wasps than male extracts. Females reacted to female head, thorax and abdomen (the Dufour’s and venom glands are located in the abdomen) extracts, whereas males reacted signi cantly to female head and thorax extracts. One male body extract, the head, elicited two signi cant behaviors: female wasps groomed more often, and males touched the lter paper more often compared to the blank control. Head extracts consistently changed the behavior of female and male wasps and, together with female thorax extracts, have potential as species-speci c lures for yellow paper wasps. Heads were mainly composed of hydrocarbon lipids and oleamide, a ligand for odorant-binding proteins. The thorax consisted of fatty aldehydes, long-chain alkanes and fatty amide lipids. Field trials of blends of these compounds in high wasp density areas of Galápagos are the next step to con rm if any of these compounds are attractive to P. versicolor.
Risk stratification of chronic obstructive pulmonary disease (COPD) patients is important to enable targeted management. Existing disease severity classification systems, such as GOLD staging, do not take co-morbidities into account despite their high prevalence in COPD patients. We sought to develop and validate a prognostic model to predict 10-year mortality in patients with diagnosed COPD. We constructed a longitudinal cohort of 37,485 COPD patients (149,196 person-years) from a UK-wide primary care database. The risk factors included in the model pertained to demographic and behavioural characteristics, co-morbidities, and COPD severity. The outcome of interest was all-cause mortality. We fitted an extended Cox-regression model to estimate hazard ratios (HR) with 95% confidence intervals (CI), used machine learning-based data modelling approaches including k-fold cross-validation to validate the prognostic model, and assessed model fitting and discrimination. The inter-quartile ranges of the three metrics on the validation set suggested good performance: 0.90–1.06 for model fit, 0.80–0.83 for Harrel’s c-index, and 0.40–0.46 for Royston and Saurebrei’s $$R_D^2$$ R D 2 with a strong overlap of these metrics on the training dataset. According to the validated prognostic model, the two most important risk factors of mortality were heart failure (HR 1.92; 95% CI 1.87–1.96) and current smoking (HR 1.68; 95% CI 1.66–1.71). We have developed and validated a national, population-based prognostic model to predict 10-year mortality of patients diagnosed with COPD. This model could be used to detect high-risk patients and modify risk factors such as optimising heart failure management and offering effective smoking cessation interventions.
Background Colon cancer is the third most common cancer and second highest cause of cancer deaths worldwide. The aim of the study was to find new biomarkers for diagnosis, prognosis and therapeutic drug targets for this disease. Methods Four low-grade and four high-grade human colon adenocarcinoma tumours with patient-matched normal colon tissues were analysed. Additionally, tissue-derived primary cell lines were established from each tumour tissue. The cell lines were validated using DNA sequencing to confirm that they are a suitable in vitro model for colon adenocarcinoma based on conserved gene mutations. Label-free quantitation proteomics was performed to compare the proteomes of colon adenocarcinoma samples to normal colon samples, and of colon adenocarcinoma tissues to tissue-derived cell lines to find significantly differentially abundant proteins. The functions enriched within the differentially expressed proteins were assessed using STRING. Proteomics data was validated by Western blotting. Results A total of 4767 proteins were identified across all tissues, and 4711 across primary tissue-derived cell lines. Of these, 3302 proteins were detected in both the tissues and the cell lines. On average, primary cell lines shared about 70% of proteins with their parent tissue, and they retained mutations to key colon adenocarcinoma-related genes and did not diverge far genetically from their parent tissues. Colon adenocarcinoma tissues displayed upregulation of RNA processing, steroid biosynthesis and detoxification, and downregulation of cytoskeletal organisation and loss of normal muscle function. Tissue-derived cell lines exhibited increased interferon-gamma signalling and aberrant ferroptosis. Overall, 318 proteins were significantly up-regulated and 362 proteins significantly down-regulated by comparisons of high-grade with low-grade tumours and low-grade tumour with normal colon tissues from both sample types. Conclusions The differences exhibited between tissues and cell lines highlight the additional information that can be obtained from patient-derived primary cell lines. DNA sequencing and proteomics confirmed that these cell lines can be considered suitable in vitro models of the parent tumours. Various potential biomarkers for colon adenocarcinoma initiation and progression and drug targets were identified and discussed, including seven novel markers: ACSL4, ANK2, AMER3, EXOSC1, EXOSC6, GCLM, and TFRC.
Background Rangatahi Māori, the Indigenous adolescents of Aotearoa New Zealand (NZ), have poorer health outcomes than Pākehā (NZ European /other European/“White”) adolescents. We explored the influence of policies for Indigenous youth by presenting health trends, inequities and contrasting policy case examples: tobacco control and healthcare access. Methods Cross-sectional representative surveys of NZ secondary school students were undertaken in 2001, 2007, 2012 and 2019. Health indicators are presented for Māori and Pākehā adolescents (relative risks with 95% CI, calculated using modified Poisson regression) between 2001–2019 and 2012–2019. Policy examples were examined utilising Critical Te Tiriti Analysis (CTA). Findings Rangatahi Māori reported significant health gains between 2001 and 2019, but an increase in depressive symptoms (13.8% in 2012 to 27.9% in 2019, RR 2.01 [1.65–2.46]). Compared to Pākehā youth there was a pattern of persistent Māori disadvantage, particularly for racism (RR 2.27 [2.08–2.47]), depressive symptoms (RR 1.42 [1.27–1.59]) and forgone healthcare (RR 1.63 [1.45–1.84]). Tobacco use inequities narrowed (RR 2.53 [2.12–3.02] in 2007 to RR 1.55 [1.25–1.93] in 2019). CTA reveals rangatahi Māori-specific policies, Māori leadership, and political support aligned with improved outcomes and narrowing inequities. Interpretation Age-appropriate Indigenous strategies are required to improve health outcomes and reduce inequities for rangatahi Māori. Characteristics of effective strategies include: (1) evidence-based, sustained, and comprehensive approaches including both universal levers and Indigenous youth-specific policies; (2) Indigenous and rangatahi leadership; (3) the political will to address Indigenous youth rights, preferences, priorities; and (4) a commitment to an anti-racist praxis and healthcare Indigenisation. Funding Two Health Research Council of New Zealand Project Grants: (a) Fleming T, Peiris–John R, Crengle S, Parry D. (2018). Integrating survey and intervention research for youth health gains. (HRC ref: 18/473); and (b) Clark TC, Le Grice J, Groot S, Shepherd M, Lewycka S. (2017) Harnessing the spark of life: Maximising whānau contributors to rangatahi wellbeing (HRC ref: 17/315).
We report both resonant and off-resonant laser excitation of Er³⁺ upconversion fluorescence and colour tunability in Er³⁺/Yb³⁺ co-doped KYF4 and NaYF4 nanoparticles. The nanoparticles were prepared using a hydrothermal method with particle sizes of 74 ± 20 nm and 345 ± 91 nm for β−KYF4 and β−NaYF4, respectively. The Yb3+ 2F7/2 → ²F5/2 absorption spectra exhibit absorption maxima at 10237 cm⁻¹ (977 nm) for β−NaYF4 and 10267 cm⁻¹ (974 nm) for β−KYF4 nanoparticles. The Er³⁺ upconversion fluorescence spectra consist of the ²H11/2, ⁴S3/2, and ⁴F9/2 → ⁴I15/2 transitions for either 974, 977 or 980 nm laser excitation in both materials. We observed an enhancement in the upconversion intensity by a factor of up to 20 for β−KYF4 and 1.5 fold for β−NaYF4 under resonant excitation compared with off-resonant excitation at 980 nm. Tuneable upconversion fluorescence wavelength was achieved in β−KYF4:Yb/Er nanoparticles by adjusting the excitation wavelength. The CIE chromaticity coordinates are (0.6836, 0.3151) with a highest red colour purity of 99.70% for β−KYF4 (4700 K) and (0.3953, 0.5915) with a colour purity of 96.84% for β−NaYF4 (4533 K) nanoparticles. The respective absolute upconversion quantum yields are 1.18% and 2.34% under low power density (1.65 W⋅cm⁻²).
Naphthalene sulfonates and disulfonates have been widely used in the geothermal industry as tracer chemicals and knowledge of their rates of thermal breakdown is essential to ensure their successful use. In this study the stabilities of six polyaromatic sulfonates: 1-naphthalene sulfonate (1-NS); 2-naphthalene sulfonate (2-NS); 2,6-naphthalene disulfonate (2,6-NDS); 2,7-naphthalene disulfonate (2,7-NDS); 1,5-naphthalene disulfonate (1,5-NDS); and 1,6-naphtahlene disulfonate (1,6-NDS) in 0.050 mol kg − 1 NaCl solution was investigated. The NDS/NS thermal stabilities were studied as a function of temperature and pH in oxygen-free solutions. Three sets of experiments were conducted using quartz glass ampoules. The first set of experiments studied the breakdown rates of both 1,5-NDS and 2-NS at a range of pH values at 200 and 300 • C. The second set studied 1,6-NDS thermal decay to determine the breakdown products at 200, 250, and 300 • C. The third set involved a mixture of 1,5-NDS, 1,6-NDS, 2,6-NDS, 2,7-NDS, and 2-NS in 0.050 mol kg − 1 NaCl, with and without the presence of greywacke, at temperatures up to 300 • C. The results show that 1,5-NDS and 2-NS breakdown is temperature and pH-dependent. The breakdown of 1,6-NDS forms mainly 2-naphthalene sulfonate (2-NS), whereas above 300 • C, 1,6-NDS generated significant amounts of naphthalene (NAP). The results show that the stabilities of all tested NDS/NS compounds are temperature-dependent with their relative stabilities increasing in the order 1,5-NDS < 1,6-NDS < 2,6-NDS ≈ 2,7-NDS < 2-NS. In the presence of greywacke, fluid-rock interactions served to buffer pH thereby stabilizing the NDS over experiments where no rock was present. The finding presented in this study support need for reevaluation of historic NDS tracer tests, and consideration of reservoir temperature and pH when planning future tests.
Papua New Guinea (PNG) is the most linguistically diverse nation on the planet, but also one of the world’s least developed countries. What accounts for that heterogeneity? Can this explain weak development outcomes, or do other factors – such as geographical constraints or historical legacies – play the more significant role? For this paper, we assembled a unique database showing the extent of linguistic diversity in PNG’s 85 rural districts in order to investigate its impact on human development (measured using child mortality and school attendance). We find some evidence of a relationship between linguistic diversity and development, but a careful reading of PNG’s history suggests that it would be mistaken to interpret this as evidence of heterogeneity impeding development. Whereas some economists see linguistic diversity as having a linear relationship with the time-distance since human settlement, we argue that shifting crop cultivation technologies, warfare, disease and environmental convulsions – in tandem with time-depth – offer the better explanation. We also test and reject the fashionable hypothesis that ‘pre-colonial hierarchy’ has a strong and enduring influence over contemporary development outcomes.
Relative to more mature fault zones, immature fault zones that have accumulated smaller total displacement are characterized by less efficient strain localization and more complicated earthquake ruptures. How differences in maturation are reflected in regional-scale upper-crustal fracturing is not well known. Recently, complicated earthquake ruptures associated with immature fault zones, such as the 2016 Kaikōura earthquake in New Zealand, have occurred in areas that are in regional proximity (<100 km away) to more mature faults. Here we examine whether inefficient strain localization in less mature fault zones is associated with a broader distribution and anomalously elevated concentration of fractures over distances of tens of kilometers. We use regional seismic arrival-time tomography in a broad area around the Kaikōura earthquake to investigate lateral variations in Vp and Vp/Vs. Focusing on the extensively faulted but compositionally uniform Torlesse-Pahau terrane in the Marlborough region where the earthquake occurred, we attribute lateral variations in Vp and Vp/Vs to differences in concentration of fluid-filled fractures. Using numerical models relating seismic velocities and fracturing, we solve for the lateral variation in concentration of ∼0.01 aspect ratio fluid-filled fractures. We find that areas near the Kaikōura rupture have >3% elevated fracture porosity compared to the adjacent area to the north. The elevated regional fracturing in the Kaikōura area is interpreted to result from more distributed deformation, and broader distribution of earthquakes, due to inefficient localization of strain from a regionally uniform strain rate field, highlighting the relationship between relative maturity of upper-crustal fault zones and lateral variability of regional upper-crustal properties. Plain language summary: When earthquakes occur in immature fault zones (areas that have accumulated small total displacement), they tend to rupture multiple poorly developed faults of diverse orientations. In contrast, more mature fault zones are associated with more developed, smoother faults and more localized earthquake activity. How these differences in maturation are reflected in the regional distribution of fractures is not well known. Here we use the arrival times of P and S waves from earthquakes to constrain seismic velocities (Vp and Vp/Vs) and use numerical models to relate seismic velocities to fracture concentration. We focus on the Marlborough region of the South Island, New Zealand, where immature fault zones recently ruptured during the 2016 Kaikōura earthquake but which also has more mature fault zones <100 km away. We find elevated fracture concentrations (3% higher fracture porosity), indicative of more distributed deformation along immature fault zones relative to more mature fault zones. In immature settings, fracturing is not as effectively localized along individual fault traces, leading to a broadly distributed fracture network.
Background Māori, the indigenous people of New Zealand, have traditionally used the kānuka tree as part of their healing system, Rongoā Māori, and the oil from the kānuka tree has demonstratable anti-inflammatory and anti-bacterial properties. This trial investigated the efficacy and safety of a 3% kānuka oil (KO) cream compared to vehicle control (VC) for the topical treatment of eczema. The trial was conducted through a nationwide community pharmacy research network. Methods This single-blind, parallel-group, randomised, vehicle-controlled trial was undertaken in 11 research trained community pharmacies across New Zealand. Eighty adult participants with self-reported moderate-to-severe eczema, assessed by Patient Orientated Eczema Measure (POEM) were randomised by blinded investigators to apply 3% KO cream or VC topically, twice daily, for six weeks. Randomisation was stratified by site and eczema severity, moderate versus severe. Primary outcome was difference in POEM scores at week six between groups by intention to treat. The study is registered on the Australian New Zealand Clinical Trial Registry (ANZCTR) reference number, ACTRN12618001754235. Findings Eighty participants were recruited between 17 May 2019 and 10 May 2021 (41 KO group, 39 VC group). Mean POEM score (standard deviation) improved between baseline and week six for KO group, 18·4 (4·4) to 6·8 (5·5), and VC group, 18·7 (4·5) to 9·8 (6·5); mean difference between groups (95% confidence interval) was -3·1 (-6·0 to -0·2), p = 0·036. There were three adverse events reported in the KO group related to the intervention and two in the control group. Interpretation The KO group had a significant improvement in POEM score compared to VC. Rates of adverse events and withdrawals were similar between groups with no serious adverse events reported. Treatment acceptability was high for both groups across all domains. Our results suggest that in adults with moderate-to-severe eczema, the addition of KO to a daily emollient regimen led to a reduction in POEM score compared to VC. KO may represent an effective, safe, and well tolerated treatment for moderate-to-severe eczema in adults. Funding Hikurangi Bioactives (Ruatoria, New Zealand) and HoneyLab (Tauranga, New Zealand), supported by a grant from Callaghan Innovation.
Objective: Maternal infections are a well-known risk factor for neurodevelopmental defects. Such defects are associated with a range of symptoms, and environmental enrichment (EE) could be a promising approach to rehabilitate these. We used the well-established prenatal poly I:C (polyinosinic-polycytidylic acid) model in rats to examine the effects of preweaning EE on rat pups' ultrasonic vocalisations (USVs) when separated from their mothers. USVs are one of the earliest indicators of a pup's functional level and, thus, well-suited as a marker of neurodevelopmental abnormalities. Methods: We used a two-by-two factorial design in which pregnant Sprague-Dawley rats received either saline or the viral mimic poly I:C, and one group of pups was exposed to preweaning enrichment. We measured maternal separation-induced USVs both before postnatal day (PND) 7 and after preweaning enrichment on PND 14. Results: Poly I:C significantly reduced the number of USVs on PND 7. EE interacted with the poly I:C treatment in that poly I:C pups in the enrichment group called more, whereas saline pups in the enriched environment called less on PND 14 than the respective controls. Conclusion: We showed that the effects of maternal poly I:C on the offspring's USVs could be reduced by early EE. If replicated, it could open novel and safe avenues for treating children of mothers who were exposed to infections during pregnancy.
Based on fieldwork in Bangladesh Rural Advancement Committee (BRAC), the world’s largest Non-Governmental Organization in Bangladesh, focusing on a Gramscian perspective of hege mony and Gramsci’s military metaphors, this paper examines whether and how BRAC’s cultural and moral leadership helped build a counter-hegemony through a ‘war of position’ and extended its functional accountability into social accountability. We found that BRAC endeavored to disseminate an ‘alternative’ hegemony and develop a ‘historic bloc’ for waging a ‘war of position’. Our approach informs the difficulty large hybrid NGOs such as BRAC face in effectively combining functional and social accountability and pursuing their financial and social goals simultaneously given the political, cultural, and ethical factors paradoxically confronting them. While functional accountability survives through changing regulations and directions of state apparatuses demanding to see NGO’s accounts for legitimacy purposes and appearing to enact regulation within the dominant hegemony, BRAC has become large conglomerates, and their more effective delivery of social and economic welfare programs give them an appearance of an ‘alterative state’ and reinforces their advocacy. To this end, they involve beneficiaries through continuous social accountability practices, but due to their desire to be financially independent, they maintain a commercial orientation based on neoliberal ideals being propagated in LDCs.
The decline of participation in traditional civic political processes, like voting in elections and writing to elected representatives, continues to deepen in contemporary liberal democracies. However, civics comprise only one avenue for political participation. Social movements also play a key role in influencing political affairs by exerting pressure on established institutions from outside rather than within. ‘Political activation’ is key to understanding and addressing non‐participation in both movement and civic settings alike, yet activation in movement settings, like non‐participation more generally, remains under‐researched. This article seeks to address this imbalance by exploring ways of using political activation theory to synthesise research on the fields of political participation and non‐participation, in both civic and social movement contexts. After reviewing the literature on activation, which favours political participation in civic settings, I then juxtapose this existing scholarship with a case study focused more on non‐participation and social movements as they are understood by movement organisers in Aotearoa New Zealand. In so doing, I demonstrate how civics, social movements, participation and non‐participation can be better understood together to advance scholarship on why people do or do not engage with politics.
Ash emission in explosive silicic eruptions can have widespread impacts for human health, agriculture, infrastructure, and aviation. Estimates of the total grainsize distribution (TGSD) generated during explosive magma fragmentation underpins eruption models and ash dispersal forecasts. Conventionally, the TGSD constrained via erupted deposits is assumed to match the TGSD produced at explosive fragmentation. Here we present observations from within the vent of a recent rhyolitic eruption (Cordón Caulle, Chile, 2011–2012), demonstrating that fine (<63 μm diameter) and ultra-fine (<2.5 μm diameter) ash particles are captured and sintered to fracture surfaces, and thus sequestered in the shallow subsurface, rather than emitted. We establish a conceptual model—uniquely contextualised through a combination of syn-eruptive observations and detailed post-eruption field investigation—in which turbophoresis (particle migration towards zones of lower turbulence) and rapid sintering create an inverse relationship between particle size and the probability of its subsurface capture. Such size-dependent capture efficiency preferentially removes submicron-diameter ash from the erupted componentry, decoupling the erupted size distribution from magmatic source conditions and potentially playing an important role in modulating eruption dynamics.
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7,273 members
Markus Luczak-Roesch
  • School of Information Management
Alejandro C. Frery
  • School of Mathematics, Statistics and Operations Research
Joanna Kidman
  • Te Kura Māori
Hedwig Eisenbarth
  • School of Psychology
23 Lambton Quay, 6140, Wellington, New Zealand
Head of institution
Professor Grant Guilford, Vice-Chancellor
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