University of Canterbury
  • Christchurch, Canterbury, New Zealand
Recent publications
The practice of adding game elements to non-gaming educational environments has gained much popularity. Gamification has been shown in some studies to enhance engagement, motivation and learning outcomes in technology-supported learning environments. Although gamification research has matured, there are some shortcomings such as inconsistency in applying gamification theories and frameworks and evaluating multiple game mechanics simultaneously. Moreover, there is little research on applying gamification to Intelligent Tutoring Systems (ITS). This paper investigates the causal effects of gamification on learning in SQL-Tutor, a mature ITS teaching students how to phrase queries in SQL. Having conducted a study under realistic conditions, we present a quantitative analysis of the performance of 77 undergraduate students enrolled in a database course. There are three main findings of our study: (1) gamification affects student learning by mediating the time-on-task; (2) students’ background knowledge does not influence time-on-task unless students achieve badges; and (3) students’ interest in topic (motivational construct) moderates the relationship between badges and time-on-task, but does not improve learning outcomes directly.
Background The growing worldwide refugee crisis highlights the needs for increased access to mental health services, including in the large urban cities in the Middle East to which refugees are frequently displaced and in which access to such services is limited. The current study offers an initial evaluation of narrative exposure therapy as a treatment for posttraumatic stress disorder among Sudanese refugees in Cairo, delivered by lay counselors. Sudanese refugees with no prior background in counseling were given 27 h of training in narrative exposure therapy. They then delivered this to seven members of the same refugee community with a diagnosis of posttraumatic stress disorder at a local community center, and this was evaluated using a pre-post design and a focus-group with the intervention recipients. Results Despite the small sample size, over the course of the intervention there was significant decrease in trauma and anxiety symptoms, and a close to significant decrease in depression. Moreover, the focus group participants generally spoke positively about their experiences. Conclusions To the best of the authors’ knowledge, this is the first study to examine the viability of lay counselors delivering narrative exposure therapy to refugees with posttraumatic stress disorder in a complex urban setting. The findings suggest that this approach has promise and support the case for a randomized control trial of narrative exposure therapy delivered in this manner in such a setting.
A passive detection method has been proposed in a prior paper to extract key parameters and detect faults using the ambient noise present in water pipeline networks. This paper presents field experiments and data processing results to provide systematic experimental validation of this method. Field experiments were carried out in operational water pipeline networks at the University of Canterbury campus and the Waimakariri District, New Zealand, during which ambient noise was measured by pairs of pressure sensors installed at selected hydrants on pipelines of different materials, network topologies and simulated faults. Auto-correlation and cross-correlation analysis of noise at a single sensor and sensor pairs were carried out to estimate the wave speed and to locate faults in the networks. Data processing results indicate that water usage generating pressure transients are the dominant sources of ambient noise in operational water pipeline networks. This type of ambient noise can also be utilized by the passive detection method to achieve similar wave speed estimation accuracy and fault detection performance as the conventional active pressure wave detection methods.
Objectives A unique dataset of airway flow/pressure from healthy subjects on Continuous Positive Airway Pressure (CPAP) ventilation was collected. This data can be used to develop or validate models of pulmonary mechanics, and/or to develop methods to identify patient-specific parameters which cannot be measured non-invasively, during CPAP therapy. These models and values, particularly if available breath-to-breath in real-time, could assist clinicians in the prescription or optimisation of CPAP therapy, including optimising PEEP settings. Data description Data was obtained from 30 subjects for model-based identification of patient-specific lung mechanics using a specially designed venturi sensor system comprising an array of differential and gauge pressure sensors. Relevant medical information was collected using a questionnaire, including: sex; age; weight; height; smoking history; and history of asthma. Subjects were tasked with breathing at five different rates (including passive), matched to an online pacing sound and video, at two different levels of PEEP (4 and 7 cmH 2 O) for between 50 and 180 s. Each data set comprises ~ 17 breaths of data, including rest periods between breathing rates and CPAP levels.
This paper investigates the migration and evolution of chlorinated (Cl-) chemicals during the combustion of polyvinyl chloride-calcium carbonate (PVC-CaCO3) composite cable outer sheath under different oxygen (O2) concentrations. Previous studies have mainly focused on the combustion of cables and subsequent generation of gaseous products under ambient air, and there is limited knowledge on the combustion behavior when the O2 concentration of the combustion air varies, especially at elevated, above ambient level. In this paper, the variations of Cl-contents in the remaining solid residues and Cl-gaseous products were studied under different O2 concentrations and external heat fluxes. The results show that when the O2 concentration increases from 12 to 18 %, the increased surface temperature enhances the pyrolysis rate and the hydrogen chloride (HCl) yield which increases from ∼0.15–0.18 g/g. Over 18–24 % O2 concentration, the HCl yield diminishes sharply and continuously, from ∼0.18–0.13 g/g with increasing O2 concentration. By 30 % O2 concentration, HCl yield has reduced by more than 40 %. Under O2-rich combustion, a large amount of chlorine gas (Cl2) is presence in the combustion products following the reduction in HCl yield, where over 75 % converted HCl was oxidized to form Cl2. HCl competes for O2 which is also required for carbon monoxide (CO) oxidation, and the O2 consumed for HCl oxidation is approximately 3 times that of CO oxidation. Under 12–18 % O2 concentration, the presence of high HCl yield inhibits CO oxidation, resulting in an increase in CO yield with intensified pyrolysis.
This research focuses on how city-makers can work to expand the potential of ruins to manifest diverse histories and geographies. We argue that nuanced and ethical approaches to integrating ruins in cities can enhance communities connections, combatting the creeping placelessness of neoliberal urbanism, and promoting overall wellbeing. This study offers a framework to integrate ruins in urban regeneration – what we describe as “prismatic immersion.” Springing from a transdisciplinary literature interrogating urban ruins, and illustrated by a heterogeneous set of international examples, we examine how historical, geographic, design, cultural, and environmental dimensions can shape the experience of communities in, and with urban places. We identify five inherently interrelated threads of “best practices”: a) multi-historical memory that runs through ruins, b) polyvocality – giving voice to diverse groups who occupied and used the ruin, c) holistic urban integration, to make the ruin a living, engaged part of the city, d) capacity for the ruin to evolve, change and continue to engage the city's communities, and e) a recognition of the interplay between human and more-than-human. This aims to ignite critical thinking on the potential contributions that ruins can make to contemporary cities as interactive learning environments for community connection.
Depth cues are crucial to increase user perception and spatial awareness of the remote environment when remotely guiding complex robotic systems. A mixed reality (MR) integrated 3D/2D vision and motion mapping framework for immersive and intuitive telemanipulation of a complex mobile manipulator is presented. The proposed 3D immersive telerobotic schemes provide the users with depth perception through the merging of multiple 3D/2D views of the remote environment via MR subspace. The mobile manipulator platform consists of a 6°-of-freedom (DOF) industrial manipulator, 3D-printed parallel gripper, and mobile base, which can be controlled by non-skilled operators who are physically separated from the robot working space through a velocity-based imitative motion mapping approach. This work evaluates the impact of depth perception and immersion provided by integrated 3D/2D vision and motion mapping schemes on teleoperation efficiency and user experience in an MR environment. In particular, the MR enhanced systems maintain spatial awareness and perceptual salience of the remote scene in 3D, facilitating intuitive mixed reality human-robot interaction (MR-HRI). This study compared two MR-integrated 3D/2D vision and motion mapping schemes against a typical 2D Baseline visual display method through pick-and-place, assembly, and dexterous manufacturing tasks. The MR-integrated 3D/2D vision and motion mapping schemes of teleoperation reduced overall task completion times by 34% and 17%, compared to the MR-2D Baseline, while minimizing training effort and cognitive workload.
Brand love is an often ignored, yet important dimension in consumer-brand relationships. Especially consumer-brand relationships with masstige brands that are hedonic and symbolic in nature. Using an experimental design (n = 465), this study investigated the interplay between brand love and brand loyalty, and its impact on brand equity. Contrary to current literature, the findings indicate that consumers can develop brand love without being loyal to a brand and can exhibit high brand love without purchasing from the brand. Brand love had a greater impact on brand equity than brand loyalty, and both brand love and brand equity diminished when consumers experienced brand betrayal. The brand love-loyalty matrix shows the interplay between these constructs for masstige brand relationships and can be used to increase market share. Finally, a decision tree is provided to guide the growth decisions of luxury brands who want to embark on a masstige strategy.
Potentially, the restoration of native ecosystems could be combined with the land application of treated municipal wastewater (TMW), reducing TMW discharge into waterbodies. High levels of nutrients, pathogens, and other contaminants from TMW can degrade water quality. The land application of TMW onto native vegetation reduces the nutrient load in water bodies and may create zones of ecological value. However, establishing native plants may be challenging if the species are not adapted to highly fertile environments, such as those resulting from TMW irrigation. There is a critical knowledge gap about the response of native plant species to irrigation with TMW. We aimed to determine the distribution and speciation of nutrients in the soil-plant system following application of TMW onto 11 species of native plants in a long-term field trial on Banks Peninsula, New Zealand (NZ). TMW was irrigated at a rate of 1000 mm per annum, equivalent to N, and P loading rates of 194 and 110 kg ha yr⁻¹, respectively. We determined physicochemical properties from soil profiles (0–65 cm) under selected species as well as the growth and chemical composition of the plants. Despite the site receiving 950 kg ha⁻¹ yr⁻¹ of Na, there was no evidence of impaired soil structure following TMW irrigation. Nitrogen did not accumulate in the soil, and it is likely to have been taken up by plants or lost through denitrification and nitrate leaching. The accumulation rate of P indicated that soil P concentrations will remain within the range found in NZ agricultural soils for at least 50 years. TMW irrigation increased plant height by 10% compared to the control after 3.5 years of growth. Plant species significantly affected the concentrations of total C, total N, nitrate (NO3⁻), and Na in the soil. TMW application had negligible effects on the elemental composition of plant foliage. NZ native vegetation can facilitate the land application of TMW. Future work should elucidate the maximum rates that can be applied as well as the effect of TMW on the soil microbiota.
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).
In this paper, we study the weight distributions of Fq-linear sets in PG(1,q5). Our Main Theorem proves that a linear set S of rank 5, which is not scattered has the following weight distribution for its points with weight larger than 1: (i) one point of weight 4 or 5, (ii) one point of weight 3 and 0, q, or q2 points of weight 2, (iii) s points of weight 2 where s∈[q−2q+1,q+2q+1]∪{2q,2q+1,2q+2,3q,3q+1,q2+1}. In particular, there are no 2-clubs in PG(1,q5).
Carbon-based catalyst was prepared by Ni/Co modification of acid - pickling biochar from peanut shell. The chemical and structural properties of the modified catalyst were analyzed by BET, XRD, FTIR and SEM. At the same time, the catalytic properties of metal loading (4 wt%, 8 wt%, 12 wt%), temperature and S/C on steam reforming of acetic acid were studied. It was found that the acid-pickled biochar had abundant pore structure and oxygen-containing functional groups, and the specific surface area was up to 344.00 m²/g, which was mainly mesoporous structure and provided more active sites for metal particles loading. Under the conditions of 600℃, S/C = 3 and reaction time of 30 min, 8Ni/HPC showed the best catalytic capacity, with hydrogen content of 71.10% and acetic acid conversion of 88.03%. With the increase of temperature, the conversion of acetic acid increased obviously, but the selectivity of hydrogen decreased. Appropriate S/C can improve the selectivity of hydrogen, while excessive S/C will decrease the catalyst activity. Therefore, low-cost carbon supported Ni/Co have higher catalytic activity for the production of H2. The results provide a basis for the design of a new carbon-based catalyst and their application in steam reforming of bio-oil.
How is it that the New Zealand government’s process for re-establishing Indigenous fishing rights has failed to deliver thriving Māori fisheries? This paper examines why, at Te Waihora, a coastal lake, and site of one of the nation’s longest running and best-funded state-Māori co-governance agreements, Māori fishers have been unable to use their rights to support their fishery. As of 2018, the lake’s culturally and ecologically significant eel population was no longer commercially viable, a decline fishers have attributed to rampant dairy industry expansion upstream. Drawing on environmental justice literatures, we deploy a multi-dimensional framework to identify factors shaping possibilities for justice in the wake of rights reconciliation, as experienced by Māori fishers, scientists, and leaders. We engage theories of political economic relations to interpret the implications of these experiences for environmental justice theory and politics. Ethnographic accounts demonstrate that the New Zealand government’s process for re-establishing Māori rights falls short of achieving distributional, procedural, and recognition-based dimensions of environmental justice, and that these effects are interlinked. In particular: (i) downstream fishers are placed to bear disproportionate costs of runoff from upstream land use change; (ii) Māori fishers have little influence over governance decisions that affect land use; and (iii) government claims, including that Māori should, “move beyond grievance mode,” obscure logics for resistance. We suggest that the government’s support for dairy industry expansion represents an attempt to mitigate crises of overaccumulation, characteristic of competitive markets. Unlike those who identify persistent injustice as a logic for turning away from the state, we argue that the recurring nature of these crises, and the role state organizations play in directing responses, indicates a rationale for continued engagement with state governing bodies to advance justice.
Despite numerous calls for tourism research on the LGBTQ + community beyond western developed nations, this gap remains unaddressed in a way that empowers LGBTQ + people – particularly those in places where such identities are still criminalised. Travel can play an essential role in the lives of LGBTQ + people by providing a space for identity exploration, affirmation and reinvention. Yet, the risks inherent to participants and researchers alike have impeded such research from being conducted. This paper identifies these risks and discusses theoretical and methodological approaches to elucidate and provide solutions. Finally, a research agenda is provided to guide exploration.
Exotic plants have the potential to increase pathogen inoculum that can affect native plants. New Zealand’s iconic kauri tree (Agathis australis) is threatened by disease caused by Phytophthora agathidicida, which is most prevalent in fragmented forests that have been invaded by or are adjacent to populations of exotic species. Exotic plants have been introduced intentionally (i.e., plantations and pastures) and unintentionally along the margins of kauri forests, yet it is unclear if invasive species play a role in pathogen spread. To determine the extent to which native and exotic plant litter supports P. agathidicida inoculum, we performed a phylogenetically controlled detached leaf assay. We inoculated 60 native and 44 invasive species’ leaves with three isolates of P. agathidicida collected from two different geographical regions of New Zealand, measured disease symptoms and re-isolated the pathogen from infected leaves. Lesions grew larger and faster on exotic leaves across all three isolates tested. However, pathogen recovery was not necessarily more likely from exotic leaves. In contrast, one of the three isolates grew faster when recovered from native compared with exotic leaves. Phylogeny did not predict disease expression. This data suggests that native and exotic plant litter may be reservoirs for P. agathidicida, but reservoir potential varies among isolates. These results also support key management tools used in New Zealand aimed at reducing pathogen spread by foot traffic in fragmented kauri forests, such as hygiene stations for shoe cleaning at trailheads and boardwalks in sensitive forest areas. Further, these tools may benefit forest management worldwide, as pathogens and exotic, invasive species increase at a global scale.
Geochemical heterogeneities observed in the mantle are usually attributed to recycling of oceanic lithosphere through subduction. However, it remains hotly debated where recycled material stagnates, and how quickly it can be liberated back to surface. This knowledge gap hinders our understanding of mantle circulation and the chemical evolution of the Earth. Here we address these questions using a combination of geochronology and geochemistry from South China Sea (SCS) seamounts. The Shixingbei seamount lavas formed during active seafloor spreading at c. 19.1 Ma show limited geochemical variability, whereas the Zhenbei-Huangyan seamount chain formed during the post-spreading stage at c. 7.8 Ma and displays a wide range of compositions. However, melt inclusions in olivine and plagioclase from the Zhenbei-Huangyan basalts show considerably greater isotopic variability than seen in the whole rock compositions of both the SCS syn- and post-spreading lavas. A previously unidentified third mantle source component (FOZO) revealed by olivine-hosted melt inclusions along with both depleted (DMM) and enriched (EMII) mantle components is required in the source region to explain the observed isotopic and chemical variability. On the basis of our results, the age of the recycled ocean crust and sediments in this region are estimated to be c. 120 – 350 Ma. We infer that these enriched components in the SCS lavas come from the mantle transition zone. Variations in mantle source heterogeneity coupled with melting process control spatial–temporal (spreading vs. post-spreading stage) geochemical variations of lavas from the SCS and surrounding areas. Together with the results from published studies, we propose that marginal basins are one of the major locations on Earth where oceanic and/or continental lithosphere is transferred into the upper mantle and transition zone, representing an important source of upper mantle heterogeneity. We provide a simple conceptual model linking plate subduction and upper mantle heterogeneity and the volcanism in the SCS and surrounding areas.
Teachers’ understandings of social-emotional wellbeing contribute to developing ways that teachers can engage with students to develop social-emotional skills. This collaborative research project adopted a critical participatory action research methodology, informed by Kaupapa Māori research principles. The perceptions of teachers were explored through wānanga (ethical spaces for research) to inform the development of a co-constructed culturally and linguistically sustaining framework for social-emotional wellbeing. Findings suggested that creating a framework requires being informed by indigenous models of wellbeing. Results suggest that developing such a framework requires teachers to develop understandings of their own social-emotional competencies, as well as their students.
Prediction of lane changes (LCs) provides critical information to enhance traffic safety and efficiency in a connected and automated driving environment. It is essential to precisely detect LCs from driving data to lay the groundwork for LC prediction. This study aims to develop LC detection and prediction models using large-scale real-world data collected by connected vehicles (CVs). At first, an autoencoder was used to detect LCs, and proved to be more precise and robust than conventional methods. Next, a transformer-based LC prediction model was developed, which concentrated computation power on key information via an attention mechanism. It outperformed the baseline models in terms of accuracy and computational efficiency. The prediction horizon was also analyzed and LC could be accurately predicted up to two seconds in advance. At last, the transformer model was implemented for real-time prediction and demonstrated a great potential for practical applications.
Purpose Individualised predictive models of cognitive decline require disease-monitoring markers that are repeatable. For wide-spread adoption, such markers also need to be reproducible at different locations. This study assessed the repeatability and reproducibility of MRI markers derived from a dementia protocol. Methods Six participants were scanned at three different sites with a 3T MRI scanner. The protocol employed: T1-weighted (T1w) imaging, resting state functional MRI (rsfMRI), arterial spin labelling (ASL), diffusion-weighted imaging (DWI), T2-weighted fluid attenuation inversion recovery (FLAIR), T2-weighted (T2w) imaging, and susceptibility weighted imaging (SWI). Participants were scanned repeatedly, up to six times over a maximum period of five years. One participant was also scanned a further three times on sequential days on one scanner. Fifteen derived metrics were computed from the seven different modalities. Results Reproducibility (coefficient of variation; CoV, across sites) was best for T1w derived grey matter, white matter and hippocampal volume (CoV < 1.5%), compared to rsfMRI and SWI derived metrics (CoV, 19% and 21%). For a given metric, long-term repeatability (CoV across time) was comparable to reproducibility, with short-term repeatability considerably better. Conclusions Reproducibility and repeatability were assessed for a suite of markers calculated from a dementia MRI protocol. In general, structural markers were less variable than functional MRI markers. Variability over time on the same scanner was comparable to variability measured across different scanners. Overall, the results support the viability of multi-site longitudinal studies for monitoring cognitive decline.
The toxic effects of diesel fuel on whole plants have been reported before, but little is known about the toxic effect of diesel fuel on callus cultures. This knowledge is a pre-requisite for exploring the possibility of using a sub-lethal diesel concentration as an agent for in vitro cell line selection to obtain novel somaclonal variants resistant to diesel toxicity. These novel variants could be useful for the phytoremediation of diesel-contaminated soil. Here, a callus induction medium [Murashige and Skoog medium supplemented with 1.8 µM of naphthlene-1-acetic acid (NAA) and 6.6 µM of 6-benzyladenine (BA)] was found to induce 85% of Petunia grandiflora leaf explants to form light green calli. Since it was not possible to include diesel in aseptic culture, the P. grandiflora calli were exposed to diesel under non-aseptic conditions. It was found that the calli did not exhibit any sign of necrosis immediately after up to 9 min of diesel exposure. The diesel-treated calli were subsequently subcultured successfully on the callus induction medium using the proliferating, non-necrotic cells. Transverse sections of the control and diesel-treated calli after 2 weeks of culture revealed that the control calli exhibited more small meristematic cells while diesel-treated calli exhibited larger, empty-looking parenchyma cells. Moreover, it was possible to induce, though at a low frequency (< 15%), shoot formation in the control calli and those derived from the diesel treatment on the Murashige and Skoog medium supplemented with 1.1 µM of indole-3-acetic acid (IAA) and 13.3 µM of BA. Under glasshouse conditions, the shoots regenerated from the calli derived from the diesel treatment exhibited higher biomass than those from the control calli and P. grandiflora seedlings when grown in a potting mix spiked with 0%, 2% and 7% diesel. Taken together, these results suggest that up to 9 min of diesel exposure of P. grandiflora calli was sub-lethal.
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6,999 members
Arindam Basu
  • School of Health Sciences
David L. Wiltshire
  • Department of Physics and Astronomy
Daniel Joseph Holland
  • Department of Chemical and Process Engineering
Ewald Neumann
  • Department of Psychology
Christoph Bartneck
  • Human Interface Technology (HIT) Lab
Kirkwood, 8140, Christchurch, Canterbury, New Zealand
Head of institution
Dr Rod Carr
+64 3 366 7001