89,525 results

  • Electronic and magnetic properties of two dimensional crystals

    Hatami, Hani (2015)

    Doctoral thesis
    Victoria University of Wellington

    In the last few years, two dimensional crystals have become available for experimental studies. Good examples of such systems are monolayers and bilayers of graphene and monolayers of transition metal dichalcogenides such as MoS₂ and WSe₂. The availability of two dimensional crystals has encouraged physicists to study the electronic and magnetic properties of such systems. This thesis adds to the theoretical knowledge about electronic and magnetic properties of two dimensional crystals with the focus on graphene and MoS₂. As a general theme in this thesis, we calculate how in general these systems interact with electric and magnetic fields and what their response is to such stimuli. In particular, we have studied the response of monolayer graphene to an in-plane electric field. We have also looked at spin-orbit coupling effects that arise from applying perpendicular or in-plane external electric fields, especially their consequences for transport properties of bilayer graphene. We investigated the electronic properties of charge carriers confined in a mesoscopic ring structure using a gate voltage in bilayer graphene. We also showed how spin-orbit coupling can affect the electrical properties of such rings. We found how spin-orbit coupling can affect the transport properties in bilayer graphene. We also investigated the RKKY or indirect exchange coupling between magnetic moments in monolayer MoS₂ through calculating wave vector dependent spin susceptibility. We examined the electronic properties of electrons and holes confined electrostatically into a bilayer graphene ring. We presented an analytical solution for finding energy levels in the ring. We showed that the magnetic field dependence of the lowest energy level with fixed angular momentum in bilayer graphene rings, in contrast to usual semiconductor quantum rings, is not parabolic but displays an asymmetric “Mexican hat“. We found that introducing spin-orbit coupling in the ring can flatten this Mexican hat. We studied the effect of an orbital Rashba type effect, induced by an in-plane electric field in monolayer graphene. Using perturbation theory, we showed that this term can affect the energy levels in a crossed electric and magnetic field such that the electron and hole levels repel each other. We calculated the AC transport of monolayer graphene in the linear-response regime and showed that taking the orbital Rashba term into account casts doubt on the universality of the minimum conductivity of monolayer graphene. We studied the effect of spin-orbit coupling in transport properties of bilayer graphene systems by calculating tunnelling through npn and np junctions. We showed that at sufficiently large spin-orbit strength, normal transmission through a barrier which is forbidden in bilayer graphene becomes finite. We predict that in a weak Rashba spin-orbit regime, outgoing electrons show signals which are spin polarized. We also showed that considering spin-orbit coupling only in the barrier of an npn junction can invert the spin of the incoming electrons. Finally, we obtained analytical expressions for the wave vector-dependent static spin susceptibility of monolayer transition metal dichalcogenides, considering both the electron-doped and hole-doped cases. These results are then applied to the calculations of physical observables of monolayer MoS₂. We claculated that the hole-mediated RKKY exchange interaction for in-plane impurity-spin components decays with a different power law from what is expected for a two-dimensional Fermi liquid. In contrast, we calculated that the out-of-plane spin response shows the conventional long-range behaviour.

    View record details
  • No Longer/Not Yet: lacuna and dissemination in practice

    Meyle, Lucy

    Masters thesis
    Auckland University of Technology

    This drawing project presently considers relationships between traditional elements of comics, and provisional, abstract painting. (Apparently) casual gestures are produced by labour-intensive means as ‘printed materials’, that are then dispersed. The concepts of lacuna and dissemination are key to this project for thinking through ideas of dispersion, production, and supplementation. The gaps between words/images and expectation/reality are used to disrupt normative ways of constructing meaning. The project infiltrates the public and the private: traveling into homes, getting lost, destroyed, pinned up, or thrown out. The categories of ‘original’ and ‘reproduction’ are purposefully blurred as a method to challenge the autonomy and value of images. As the work moves out into the world, how might it interact or disrupt an everyday experience in socio-political spaces?

    View record details
  • Heterosexual couples, gender discourse, and the production of relational subjectivity

    Morris, Brian (2015)

    Doctoral thesis
    University of Waikato

    This study is situated in feminist and poststructural theory. The focus of the study is heterosexual relationships. In particular, the study investigates the shaping effects of patriarchal discourses on the relational subjectivity of a woman partner; how a woman partner responds to and refuses this shaping; and why and how a man might change his positioning in relation to his partner. The data were generated through focus group discussions with women, and individual interviews with men. An initial women’s focus group generated core data for analysis, which was followed by interviews with men, and then a final focus group of women. Documentary practices, derived from narrative therapy, were used to capture and bridge discussions between these three stages of data generation. A poststructural analysis investigated the production of relational subjectivity in the context of heterosexual relationships. Analysis of data included a focus on relational subjectivity as reported by one of the initial focus group women. A deconstructive analysis of material from the initial focus group showed the shaping of women’s relational subjectivities at the intersection of dominant patriarchal and resistant practices. This deconstructive analysis is supported by analyses of material from the men’s interviews, and from the final focus group of women. Further, based in knowledge generated from the initial women’s focus group, an idea for heterosexual relationship as egalitarian is developed in the analysis. The thesis argues that heterosexual relationship is often dominated by patriarchal ideas and practices that privilege the male partner. The thesis offers a philosophical location with the potential to reposition heterosexual relationship to a safe and egalitarian place. An exploration is offered about how men might take up ethical practices so that the repositioning of heterosexual relationship can be maintained, and patriarchally sustained male privilege held accountable. The thesis suggests that the ethical ideas and practices offered for egalitarian heterosexual relationship might be extrapolated to gender relations in general. My accountability as a male researcher is embedded in the process of the study, with feminist supervisors, in the research methodology with the final focus group of women, and in critical reflexivity in the data analysis. In particular, an example is provided which shows the researcher reflexively analysing one moment in the data generation where a research participant was offered a possible non-preferred position. The contribution of this study is to bring Derridean ideas on ethical action to relational subjectivity in heterosexual relationship. Its timeliness is evidenced by the demand from the women participants, and others, for men to engage in respectful and ethical relationship practices. At the same time the study argues that its timeliness is still in the making, produced in the democracy to come that is being brought into existence when the potential for respectful and ethical relationship is enacted in practice. The responsibility for inventing such practices rests with men.

    View record details
  • Planning for Underwater Anthropogenic Noise in New Zealand's Coastal Marine Area

    Daly, Dwayne (2015)

    Masters thesis
    University of Otago

    Human activities in the marine environment, such as shipping, mineral and petroleum exploration, dredging and construction are known to produce underwater noise. Underwater anthropogenic noise can cause behavioural changes, injury and mortality in marine mammals, fish and marine invertebrates and is likely to have long-term impacts on marine animal populations. To reduce environmental effects, spatial planning for underwater noise has been proposed but has only rarely occurred. In New Zealand, regional councils are responsible for planning for underwater noise in the Coastal Marine Area. However, regional coastal plans have been criticised for not considering underwater noise. Therefore, this research aimed to: (1) discern the current approaches of regional councils to underwater anthropogenic noise and to ascertain the reasons for those approaches, and (2) identify areas of both high marine biodiversity and high underwater noise to inform spatial planning for underwater noise. Results revealed that 14 of 17 regional coastal plans do not refer to underwater noise and that general noise provisions in these plans were intended to manage above-water noise, not underwater noise. Only Auckland Council has underwater noise provisions with rules and a permitted underwater noise limit. The main factors for the absence of provisions appear to be the age of regional coastal plans and a lack of awareness of underwater noise as an issue. Results also indicated that without underwater noise provisions councils can still manage the effects of underwater noise through unrelated, high-level provisions or through the Resource Management Act, however only a small number (38%) are doing so. Some councils expressed an interest in developing underwater noise provisions including permitted noise limits but a lack of expertise and resources in councils were considered obstacles to provision development. It is concluded that central government guidance and assistance from external agencies is needed to overcome these obstacles. However, a permitted noise limit of 180 dB re 1 μPa is proposed for inclusion in provisions. To inform spatial planning for underwater noise, regions with high regional biodiversity and with localised biodiversity 'hotspots' for seven marine taxa were identified. Eleven regions were also identified as either high or low underwater noise environments. Areas with both high underwater noise and high biodiversity for the taxa were then identified. Provisions, including rules, for these areas are suggested. It is argued that provisions and spatial zones based on these results could be included in regional coastal plans to manage underwater anthropogenic noise.

    View record details
  • Robustness of Transcranial Random Noise Stimulation Effects on Corticomotor Excitability

    Morris-Cole, Katie-Rose (2015)

    Masters thesis
    University of Otago

    The use of indirect cortical stimulation techniques to affect human corticomotor plasticity is a burgeoning field, not least because of the non-invasive nature of such protocols. Relatively new as a form of transcranial electrical stimulation (tES) is transcranial random noise stimulation (tRNS). While initial studies involving its use have shown promise, there is some concern that the effects of tRNS may share the between- and within-participants variability seen with indirect stimulation procedures (Such as Theta Burst Stimulation (TBS) protocols of Transcranial Magnetic Stimulation (TMS)), and its sibling techniques (Most notably tDCS). A review study consisting of the use of both tRNS and a sham procedure over 46 healthy participants was conducted, in order to test this variability of outcome. A literature review was conducted to examine the history of tES protocols and the ideal parameters for assessing tRNS effect variation. TMS was used to assess changes in motor evoked potential (MEP) amplitude both before and after the application of a standard facilitatory tRNS protocol. Baseline latency measurements with antero-posterior (AP) and latero-medial (LM) coil orientations and MEPs were recorded from the target muscle - the abductor pollis brevis - prior to the application of 10 min of 2 mA tRNS. Twenty MEPs were measured every 5 min for approximately 30 mins after the intervention to assess after-effects on corticospinal excitability. The experiment showed that tRNS at 2 mA was linked to a significant net facilitation of MEPs in the post-stimulation period, compared to sham stimulation. Furthermore, a two-step cluster analysis suggested alongside the presence of an intervention effect (ie. An effect caused by the experimental proceedings, instead of any effect from the tRNS protocol) as a result of both the tRNS and sham protocols, that tRNS had a facilitatory effect which mitigated inhibition or enhanced facilitation occuring as a result of that intervention effect. There was no significant correlation between the AP-LM latency difference of MEPs and the response to tRNS, or with any subject-specific variable beyond time of day. This study indicates that tRNS has a facilitatory effect in general upon corticomotor excitability, albeit rather too variable between subjects to allow tRNS to be considered a robust effector. Ideally, future studies should attempt to define what external or internal factors determine 'ideal' (i.e. significantly facilitatory participant responsiveness to tRNS.)

    View record details
  • Strategy Now! A review of the literature of ePortfolio use in work integrated learning

    Ayling, Diana (2013)

    Conference item
    Unitec

    Since the arrival of Web 2.0 technologies use of ePortfolios in higher education has dramatically increased in all disciplines. These portfolios are used to encourage students to collate and curate their learning experiences. EPortfolios are sometimes used in assessment processes, and this is challenging as views are mixed as to how a fluid and dynamic portfolio of learning can be effectively assessed. Issues such as access, security, privacy and ownership are further complicating the use of portfolios. There is some use of ePortfolios in work integrated education, and while some practitioners are convinced of the benefits for students, host organisations and academic institutions, other point to significant challenges in implementation and creating positive student learning experiences. This paper is a summary of the writing and emerging issues from implementation of ePortfolios in work integrated learning. EPortfolios offer a range of advantages over traditional methods of collation and curation of learning experiences and development. Within an ePortfolio students have the opportunity to collate artifacts, reflect on their practice and plan their professional development. They can tailor their portfolios for different purposes and audiences.

    View record details
  • Interventions that build resilient relationships: Learning skills for productive conversations.

    Cardno, Carol (2013)

    Conference item
    Unitec

    View record details
  • Luxury for oneself or luxury for others? Exploring the underlying emotions behind inconspicuous luxury consumption

    Makkar, Marian

    Masters thesis
    Auckland University of Technology

    The field of luxury has been widely examined due to the financial advancement the industry has experienced over the last 10 years. Scholars have studied its antecedents by utilising attitude-behavioural models to discover consumers’ motivations to purchase luxury goods. However, research is scarce in understanding the different kinds of luxury brand signals and consumption involved, specifically the inconspicuous and conspicuous kind. This research focuses on inconspicuous luxury consumption with the aim of deepening insights around what related emotions are involved in this consumption preference, why do they experience them and how do they deal with them. Additionally, this study explores non-financial assets such as cultural capital and social capital and how these may emotionally drive inconspicuous consumers to purchase certain levels of luxury brand signals. Utilising an exploratory and qualitative approach, in-depth interviews with 10 luxury consumers in Dubai with inconspicuous preferences were undergone and thematic analysis was used for analysis and interpretation. Themes uncovered revealed that consumers go through a process of planning their luxury journey by pre-evaluating their choices of luxury conspicuousness. They exercise their active roles in the process and experience the choices they make and finally post-evaluate these choices. Emotions were revealed to have an important role in every part of this process, which dictates their behaviours, moving them on to the next stage of their journey. They experience these emotions because of the non-financial resources (social and/or cultural capital) they deem important to them. As they exercise their consumer choice, they experience positive, negative or mixed experiential emotions depending on whether it met their expectations. If it has, they are then able to enjoy their luxuries because it offers them symbolic schemas that complete their internal and external needs and extensions of themselves. After evaluating their experienced emotions throughout the journey, they begin the cycle once again by choosing inconspicuous luxury brands that positively elevates their emotions. It is interesting to note that inconspicuous luxury consumers demonstrate several characteristics based on their social and cultural capital, which have not been identified before in past literature. This research uncovers six groupings yielding a typology of inconspicuous luxury consumers: fashion influencers, trendsetters, fashion followers, fashion indifferent, cultural conservatives and habitual buyers. They not only desire inconspicuous luxury brands for its aesthetic beauty, functionality and quality but because it asserts their different roles in society. The usefulness of the typology is demonstrated through links to emotions and levels of social and/or cultural capital and its applications to consumption levels of inconspicuous luxury goods (i.e. highly inconspicuous versus lower inconspicuous levels). Findings offer theoretical implications in terms of luxury consumption and brand signalling and a deeper understanding into what can only be described as exploratory insights into the lives of inconspicuous luxury consumers. Further research in this line of work is needed to better uncover how emotions have a powerful role in luxury consumers’ decision-making process. Managerial implications for luxury retail management and communications of the brand are also explained to assist in the conception and development process of future luxury brands and designs to better segment and target different desired markets.

    View record details
  • Te Rongoā Kākāriki: Kanohi-ki-te-kanohi, e pai ana?

    Williams, Margaret H.

    Doctoral thesis
    Auckland University of Technology

    In Aotearoa New Zealand the prevalence of Type 2 diabetes mellitus (T2DM) is three times higher for Māori than New Zealand European and is increasing. Participation of Māori newly diagnosed with T2DM with the Te Rongoā Kākāriki (Green Prescription, GRx) health service is lower than for New Zealand European. This thesis has four linked aims: i) to examine differences in the engagement and active participation (adherence) (Chapter 4), ii) to compare changes in physical and metabolic measures (Chapter 5) using a kanohi-ki-te-kanohi (face-to-face) mode of delivery or waea (telephone) for Māori and New Zealand European, iii) to better understand the perceptions, knowledge and activities of the participants that enabled them to participate (Chapter 6) and iv) to understand better how participants make and maintain lifestyle changes through the GRx health service. This GRx research study was a randomised trial (ACTRN012605000622606) using a kaupapa Māori framework and research principles, with a mixed methods approach, in which Māori and New Zealand European women and men newly diagnosed with T2DM were randomised to either kanohi-ki-te-kanohi (face-to-face) mode of delivery or waea (telephone) for six months. Physical and metabolic measurements were made, questionnaires completed and interviews undertaken at baseline, six and 12 months. After 12 months medical records were accessed for glycated haemoglobin (HbA1c) and lipid measures associated with metabolic risk. Analysis of variance (ANOVA) was used to examine for differences among the categorical variables of ethnicity, mode of delivery and gender. A total of 152 (96 women, 56 men) participants aged 30-86 years consented to participate and completed baseline measurements. Recruitment was less than the target (240), but equal numbers of Māori and New Zealand European were recruited, from GRx referrals that were predominantly non-Māori. The participants included 68 Māori, 70 New Zealand European and 14 ‘Other’ (neither Māori nor New Zealand European). The main findings excluded the ‘Other’ group. More New Zealand European than Māori remained in the randomised trial at six (74% vs. 51%) and 12-months (56% vs. 30%), respectively. There was a trend for more participants to remain in the kanohi-ki-te-kanohi (face-to-face) (68%) compared with the waea (telephone) (58%) mode of delivery at six months. The physical and metabolic data revealed that at the end of the 6-month GRx intervention, for 88 participants, body weight was reduced by 1.6 kg (95% CI, 0.3 to 2.8) and waist circumference by 3.6 cm (95% CI, 2.4 to 4.9). At six months, of the 63 who had HbA1c measured there was a reduction of 1.3% (95% CI, 0.3 to 2.4). No differences by GRx mode of delivery, ethnicity or gender were observed in these analyses. At the 12-month follow-up, for the 59 participants measured (20 Māori and 39 New Zealand European), the body weight and waist circumference measures were reduced from baseline by 2.3 kg (95% CI, 0.5 to 4.0) and 5.5 cm (95% CI, 3.4 to 7.6), respectively. In 36 participants (12 Māori and 24 New Zealand European) the HbA1c was reduced by 0.6% (95% CI, 0.0 to 1.3). No differences for GRx mode of delivery, ethnicity or gender were observed. In general, improvements in physical characteristics were associated with improvements in HbA1c concentrations. The greatest improvement was in those who had higher HbA1c (worse glycaemic control) at baseline. Data from the questionnaires showed that most participants were inactive at baseline (≤ 30 min/day) and 25% reportedly increased their participation in walking activities at six and 12 months with no differences noted between mode of delivery, ethnic groups or gender. Overall, no changes in intensity and time spent in physical activity were found between six and 12 months. Optimism and positive self-belief in ability to manage their diabetes did not change. However, a small association was found between the changes in the perceived need for special training and changes in body weight, waist circumference and the diabetes empowerment score. Five key themes from the interviews, in relation to improved self-management of T2DM, were found. The themes involved: whānaungātanga: strengthening relationships; pātaka mātauranga: sharing knowledge; whakamana: empowerment; manaakitanga: giving and receiving support and assistance from others and pikitia ngā maunga: overcoming barriers. A shared responsibility of the participants, the researcher and Māori GRx kaiwhakahaere, including the general practitioner and/or practice nurse to communicate better and overcome barriers, was identified. Kanohi-ki-te-kanohi (face-to-face) was the preferred approach to GRx even though there were no differences in metabolic/physical outcomes with mode of delivery. Overall, participants endorsed that the initial kanohi-ki-te-kanohi (face-to-face) contact was instrumental to their understanding and participation. To conclude, the GRx health service delivered by Sport Waikato Regional Sports Trust was associated with comparable improvements in HbA1c and weight among Māori and New Zealand European with no difference between the two modes of delivery. Kanohi-ki-te-kanohi (face-to-face) contact was the preferred approach to GRx. Participation by Māori once referred was relatively high and probably higher than New Zealand European, but with high drop-out. Understanding of GRx was poor prior to entering the service. The major hurdle to GRx uptake among Māori appears to be in primary care. Primary care needs to improve their explanation of GRx and their linkage with the GRx programme. New strategies are required to maintain participation.

    View record details
  • He Marae Ora, He Marae Manawaroa: exploring the resilience in a Marae which has survived without gaming machine proceeds funding

    Thompson-Evans, Te Pora

    Masters thesis
    Auckland University of Technology

    Quality funding that is clear of repercussion and ethical questioning is fundamental to marae development and whaanau wellbeing. With more and more communities becoming reliant on Gaming machine funding with little regard to the communities from which the funds were first generated. Gaming machines situated outside of casino are predominately located within low socio-economic, deprived and vulnerable neighbourhoods. Although the people within these neighbourhoods are least economically resourced, they are more than likely to be the greatest financial contributors to the gaming machine pool of funds. Problem gambling is a growing concern for such neighbourhoods and communities. Furthermore and quite often it is Maaori who make up a large portion of these communities and are again likely to suffer great harm from problem gambling, alongside their whaanau. To date studies have not yet considered in great depth the implications of receiving gambling funds from gaming machines. This eclectic kaupapa Maaori research study explored the resilience in marae who survived without the need for gambling funds from gaming machines. In-depth semi-structured interviewed were conducted with eight marae committee members of Te Iti o Hauaa marae in the Waikato region. The findings indicated that traditions of tikanga, tapu and mauri were the greatest factors that enabled and maintained a decision-making process by which gambling and the taking of gambling funds especially those from pokie machines has been disallowed on the marae for over one hundred years. The marae funding model in the form of four pou draws on whanaungatanga and relationship linkages the marae has established within the marae itself, the wider iwi and its kinship ties and also the relationship linkages to the community and government. Ethical issues relating to harms to whaanau also arose as a significant theme to not accepting gaming machine funding. Participants discussed their use of succession planning through building the capacity of their generations towards self-determinations has enabled the marae to sustain their operations and development with no funding sought outside their model. This study concludes that utilising such a model of funding based on tikanga values and ensuring succession planning to build social capital, community cohesion and participation may very well enable more marae to reduce and eliminate their reliance on gaming machine funding

    View record details
  • Effects of FUX on gemcitabine sensitivity in lung cancer cells

    Lu, Wei

    Masters thesis
    Auckland University of Technology

    Lung cancer has accounted for the most deaths from cancer (19.2% of all cancer deaths) in registered cancer cases in New Zealand. At present lung cancer treatment is inadequate, as patients treated with the front-line drugs, such as gemcitabine, rapidly develop drug resistance by decreasing cellular accumulation and/or avoiding apoptosis. Fucoxanthin (FUX), extracted from edible seaweed such as Undaria pinnatifida, has recently been reported to inhibit membrane drug efflux transporters (ABC transporters) and induce apoptosis in various cancer cell lines. Previous studies in AUT have defined FUX extracted from New Zealand Undaria pinnitifida with anti-cancer properties by using in vitro cell models. FUX has been reported to have few adverse effects in some animal models. We hypothesize that FUX may be a safe sensitizer to reverse gemcitabine resistance in lung cancer cells by increasing cellular accumulation of gemcitabine. The primary objective of this study was to assess the potential effects of FUX to reverse gemcitabine resistance in human lung cancer cell lines. The secondary objective of current study is to investigate the mechanisms of FUX actions if FUX may potentiate gemcitabine sensitivity. The third objective of this study is to evaluate the effects of FUX on modifying gemcitabine toxicity in two typical normal human cell lines. Several types of human cell lines were used in this study including a lung carcinoma cell line A549, and two typical normal human cell lines embryonic kidney cell HEK293 and adult dermal fibroblasts (HDFa). Anti-proliferative effects were determined by 48-hr and 72-hr MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays. As a single agent, either gemcitabine or FUX showed concentration-dependant inhibition of lung cancer proliferation in 72-hr MTT assays, with IC50 values of 9nM and 13μM, respectively. FUX increases gemcitabine sensitivity in an NSCLC cell line, A549 cell in a time and concentration dependant manner. Indeed, the 72-hr IC50 value for gemcitabine was only 3.9nM in the presence of 8μM FUX, which was decreased by 59% when comparing with control (P< 0.05). More importantly, FUX has no apparent effects on gemcitabine toxicity in two typical cell lines representing normal human tissues. It would be expected that FUX may represent a unique sensitizer, which may turn a less effective anti-cancer drug into an exceptional one. To elucidate the mechanisms of action of FUX, it is necessary to carry out a mechanistic study to investigate if FUX changes the intracellular gemcitabine accumulation in A549 cells. To determine gemcitabine in A549 cellular homogenates, an HPLC method has been developed and validated. In this study, while gemcitabine cannot be separated sufficiently from the cellular interferences using a conventional C18 column, aphenyl-hexyl column was found to be efficient to achieve better separation for quantitation of gemcitabine. This is because that separation using the phenyl column is conducted via the π electron, which in this case utilizes the π-π interaction between the phenyl group π electron and the analyte's π electron. Validation data indicates that the method is sensitive and reliable, with acceptable accuracy (85-115% of true values) and precision (CV < 15%). The assay specificity was indicated by the absence of interfering chromatographic peaks in cellular homogenates, and the LOQ of the assay was 0.5 μM. Calibration curves for gemcitabine were linear with the mean correlation coefficients > 0.987. This method has the advantage of being relatively rapid and efficient, with the retention time of gemcitabine separated from the substances in cellular homogenates. Therefore, this HPLC method is suitable for gemcitabine measurement in A549 cellular homogenates studies. Cellular accumulation studies suggest uptake of gemcitabine may reach equilibrium after 4-hr in the presence or absence of FUX. FUX (10 μM) shows the potentials to increase the steady-state accumulation of gemcitabine in A549 cells. However, it does not affect the initial cellular uptake of gemcitabine in A549 cells. While this mechanistic research provides some clues to elucidate the effects of FUX on gemcitabine accumulation, more details about the exact mechanisms of its action, are warranted for further studies in the future. However, a major limitation of this HPLC method is a lack of detection of gemcitabine metabolites. The cytotoxic action of gemcitabine has been attributed to inhibition of DNA synthesis by dFdCDP and dFdCTP. The HPLC method described in this study may not be suitable to simultaneously measure these active metabolites. Thus it is worthwhile to determine the cellular pharmacokinetics of gemcitabine and its metabolites in A549 cells and other NSCLC cells simultaneously by using an LC-MS/MS system. In conclusion, fucoxanthin increases gemcitabine sensitivity to A549 cancer cell lines, and more importantly, it has no apparent effects on gemcitabine toxicity in two typical cell lines representing normal human tissues. It would be expected that FUX may represent a unique sensitizer, which may turn a less effective anti-cancer drug into an exceptional one.

    View record details
  • Teenage girls' daily engagement with mass media: implications for identity construction and well-being

    Gooch, Andrea

    Masters thesis
    Auckland University of Technology

    A process of identity formation often defines teenage years where young people transition into adulthood. Multiple factors such as family environment and sociocultural context contribute to shaping teen girls’ identities, what they believe in and how they see themselves as fitting into the world around them. Mass media plays a big part in constructing social realities, often depicting narrow and limited depictions of masculinity, femininity and ideal girlhood. Young people, who may have less experience and critical awareness when it comes to media messages, may take on stereotypical or problematic images as representing reality. This research project explores from a social constructionist perspective, teenage girls daily engagement with the mass media and the implications of this for their identity construction, health, and well-being. Six face-to-face interviews were conducted with teen girls aged between 14 and 17 years old. These girls were asked to collect media images over one week and their responses to these images were discussed. An inductive thematic analysis was conducted and four dominant themes were identified within the talk: ‘It’s all about appearance’; ‘Attracting the boys’; “Inspirational content”; and ‘The pressure to be “trendy”. These themes are discussed demonstrating the difficult terrain teen girls face in navigating the vast and pervasive nature of mass media in constructing their personal identity. Further research is necessary into the nature of teen girls’ engagement with mass media with comparative data required from a teen boy population to expand and support initial insights gained from this project.

    View record details
  • Capturing recurring concepts in high speed data streams

    Sakthithasan, Sripirakas

    Doctoral thesis
    Auckland University of Technology

    This research addresses two key issues in high speed data stream mining that are related to each other. One fundamental issue is the detection of concept change that is an inherent feature of data streams in general in order to make timely and accurate structural changes to classification or prediction models. The shortcomings in the past research were addressed in two versions of a change detector that were produced during this research. The second major issue is the detection of recurring patterns in a supervised learning context to gain significant efficiency and accuracy advantages over systems that have severe time constraints on response time to change due to safety and time critical requirements. Capturing recurrent patterns requires the detection of concept change with minimal false positives. This research addresses this latter problem as a pre-requisite to formulating a novel mechanism for recognizing recurrences in a dynamic data stream environment. The first approach to change detection, termed SeqDrift1 that relies on a detection threshold derived using the Bernstein bound and sequential hypothesis strategy ensured much lower false positive rates and processing time than the most widely used change detector, ADWIN. The second version of the change detector, SeqDrift2, achieved significant improvement on detection sensitivity over SeqDrift1. This was achieved through two separate strategies. The first was the use of reservoir sampling to retain a larger proportion of older instances thus providing for better contrast with newer arriving instances belonging to a changed concept. The second strategy was to trade off false positive rate for detection delay in an optimization procedure. The net result was that SeqDrift2 achieved much lower detection delay than SeqDrift1 but sacrificed some of its false positive rate when compared to SeqDrift1, while still retaining its superiority with respect to this measure vis-à-vis ADWIN and other change detectors. Having proposed a robust and efficient mechanism for change detection two different meta-learning schemes for recurrent concept capture were proposed. A novel framework using the two schemes consists of concept change detectors to locate concept boundaries, a Hoeffding tree compressor to exploit the application of Discrete Fourier Transform on Decision Trees to produce compact Fourier Spectra, a forest of Hoeffding Trees to actively learn and a pool of Fourier spectra to be reused on similar recurring concepts. In the first scheme, termed Fourier Concept Trees (FCT), each Fourier spectrum is separately stored and reused on similar concepts. Accuracy and memory advantages have been empirically shown over an existing method called, MetaCT. In the second scheme, instead of storing each spectrum on its own, an ensemble approach, Ensemble Pool (EP), was adopted whereby several spectra were aggregated into single composite spectrum. The major advantage of this strategy over the first was the reduction in storage overhead as redundancies in separate spectra are eliminated by merging into one single entity. In addition, Fourier spectrum generation is optimized with theoretical guarantees to suit high speed environments. Extensive experimentation that demonstrated the benefits including accuracy stabilization, memory gain, reusability of existing models etc., has been done with a number of synthetic and real world datasets. This includes a case study on a Flight simulator system which is one of the target applications of this research.

    View record details
  • What's your game? Heterogeneity amongst New Zealand hunters

    Kerr, G. N.; Abell, W.

    Conference Contribution - Published
    Lincoln University

    The introduction of the New Zealand Game Animal Council in 2014 heralds a new era for New Zealand big game management. Now that management of game animals to enhance benefits from susutained use is possible, it is important to understand who values game resources and the attributies than enhance benefits from their use. Choice experiements uisng a pivot design around actual travel distance identified salience of hunt-related attributes for recreational hunters of Himalayan tahr (Jemlahicus Hemitragus) and Sika deer (Cervus Nippon). The choice experiments successfully used travel distance as the numeraire of value to overcome resistance to the commodification of hunting. Results show the high value of recretional hunting, and identifiy disparate preferences both within and between species. Understanding heterogeneity offers important insights into managing hunting experiences to enhance their value for recreational hunters.

    View record details
  • Current status of biological control of Cirsium arvense in New Zealand

    Cripps, M.; Bourdot, G.; Fowler, S.; Edwards, G.

    Conference Contribution - Unpublished
    Lincoln University

    Cirsium arvense (L.) Scop. (Californian, Canada or creeping thistle) is an exotic perennial herb that successfully established in New Zealand (NZ) approximately 130 years ago, and is now considered one of the worst invasive weeds in NZ arable and pastoral systems. Two insects, Cassida rubiginosa and Ceratapion onopordi, were recently released for classical biological control. Studies carried out from 2006 to 2009 in both the native (Europe) and introduced (NZ) ranges of the plant aimed to quantify C. arvense growth characteristics and assess incidence of the specialised rust pathogen, Puccinia punctiformis, in regions with and without the supposed pathogen vector, C. onopordi. In permanent field plots natural enemies were excluded with insecticides and fungicides, and compared with controls. The impact of C. rubiginosa was also assessed under different pasture competition scenarios. The survey data indicate that C. arvense expresses similar growth characteristics in both ranges, and that incidence of the rust pathogen is similar in both ranges, regardless of the presence of C. onopordi. The data suggest that the overall suite of natural enemies is capable of exerting some regulating influence on the plant in its native range, but that the released biocontrol agents will not likely have a significant impact on this weed in NZ.

    View record details
  • Economic Valuation of Water Quality Improvements in New Zealand

    Mkwara, Lena Asimenye (2015)

    Doctoral thesis
    University of Waikato

    Efficient decision making in environmental management requires good data on the costs and benefits of changes in environmental quality. However, full assessment of the benefits of better water quality has been a challenge because some of the component values cannot be directly measured. The advent of non-market valuation techniques has made it possible to estimate these values. In this thesis, the travel cost random utility model and fishing choice data from the National Angling Survey are used to assess the benefits of better water quality for trout anglers in the Rotorua Lakes and a choice experiment is used to assess the benefits of cleaner streams for Karapiro catchment residents. We also explore three methodological aspects which may affect non market value estimates, namely within season variability, scale heterogeneity across individuals and respondent perceptions of the status quo. Accounting for within-season variability in site attributes that are variable across the season may reduce multicollinearity. We find that differences in welfare estimates between models accounting for within-season variability and those that do not may result from differences in attribute and collinearity levels or the combined effect of both. We assess whether benefit estimates remain stable over time using models that account for scale heterogeneity across individuals and demonstrate that ignoring scale heterogeneity across the sampled population may result in researchers erroneously concluding that estimates of marginal willingness to pay are stable over time. A choice experiment on preferences for stream water quality is used to assess the effects of respondent’s perception of status quo conditions on welfare estimates. The results build on earlier findings which suggest that failure to take account of respondents’ beliefs leads to biased welfare estimates. Overall we find that lakes with better water clarity, that are larger in size, with bigger fish, more facilities and more forest cover are preferred. Similarly, streams with water quality that is suitable for swimming and where trout are found, are preferred. We estimate the aggregate annual benefit for anglers of a one metre increase in water clarity in all the Rotorua Lakes which currently have poor or average water water quality to be NZ$2.3 million. The travel cost RUM is also used to assess the overall benefit that trout anglers obtain from each lake. The annual level of these benefits totals NZ$21.7 million.

    View record details
  • The Potential for Augmented Reality to Bring Balance betweenthe Ease of Pedestrian Navigation and the Acquisition of Spatial Knowledge

    Wen, James (2014)

    Doctoral thesis
    University of Canterbury Library

    Being completely lost in an unfamiliar environment can be inconvenient, stressful and, at times, even dangerous. Maps are the traditional tools used for guidance but many people find maps difficult to use. In recent years, new tools like outdoor Augmented Reality (AR) have become available which allow virtual navigation cues to be directly overlaid on the real world, potentially overcoming the limitations of maps. However, it has been hypothesized that lower effort invested in processing navigation guidance may lead to diminished spatial knowledge (SK) thereby making users of such navigation tools far more vulnerable to getting lost should the tools fail for any reason. This thesis explores the research question of how AR and maps compare as tools for pedestrian navigation guidance as well as for SK acquisition and if there is a potential for AR tools be developed that would balance the two. We present a series of studies to better understand the consequences of using AR in a pedestrian navigation tool. The first two studies compared time-on-task performance and user preferences for AR and Map navigation interfaces on an outdoor navigation task. The results were not aligned with expectations, which led us to build a controlled testing environment for comparing AR and map navigation. Using this simulated setting, our third study verified the assumption that AR can indeed result in more efficient navigation performance and it supported the hypothesis that this would come at the cost of weaker SK. In our fourth study, we used a dual task design to compare the relative cognitive resources required by map and AR interfaces. The quantitative data collected indicated that users could potentially accept additional workload designed to improve SK without incurring significantly more effort. Our fifth and final study explored an interface with additional AR cues that could potentially balance navigation guidance with SK acquisition. The contributions of this thesis include insights into performance issues relating to AR, a classification of user types based on navigation tool usage behavior, a testbed for simulating perfect AR tracking in a virtual setting, objective measures for determining route knowledge, the capacity that pedestrian navigation tool users may have for performing additional tasks, and guidelines that would be helpful in the design of pedestrian navigation tools.

    View record details
  • Revealing the cryptic

    Bish, A.; Davies, Renee; Haines, L. (2013)

    Conference paper
    Unitec

    Invertebrate numbers worldwide are declining, predominantly due a lack of knowledge and detrimental activities on habitat such as urban expansion. "Invertebrates ore essential to our natural environment and to humans,"(Department of Conservation, 2006), due to the numerous ecosystem services they provide. Without invertebrates, human life as we currently know it would be very different This research explores how urban landscapes can be designed to provide for invertebrates and uses the highly urbanised Auckland City Centre as a case study. CBD spatial characteristics were identified using GIS,Auckland Council documents and on site observation. The CBD is a fragmented landscape of patches, which together form an ecological network. At the landscape scale this network is reinforced by designed interventions, and consists of a series of nodes that ore used by invertebrates. Invertebrate information was collected, analysed and categorised into functional groups, which enabled a set of criteria to be established for local design interventions, for both species specific and general habitat types.These interventions are based at each node within the network.Although some interventions will be species specific, it is expected that a range of invertebrate species will take advantage of these interventions, thus increasing biodiversity.An adaptive management strategy will be used to monitor and adjust habitat requirements accordingly. Invertebrates are cryptic and these small to medium interventions throughout the city are aimed at revealing the presence of invertebrates. Interpretive devices such as QR Codes and projector screens allow the public to better perceive invertebrates as part of their daily environment and to follow mapped habitat routes. A set of guidelines allows habitat interventions to be retrofitted within most urban sites.Throughout the city these interventions facilitate positive interactions between people and invertebrates through education, increased invertebrate visibility and biodiversity.

    View record details
  • A longitudinal comparison of aspects of diversity in two common wealth countries.

    Nel, Pieter; Fourie, Leon; Du Plessis, Andries (2013)

    Conference paper
    Unitec

    Commonwealth countries have a common colonial background with accompanying problems and opportunities. Recognising and addressing diversity and equal employment opportunity are common issues in these countries. The focus is on four empirical research projects over 10 years in New Zealand and South Africa between 2000 and 2010 with forecasts up to 2020 enabling comparative analyses in a longitudinal manner. The overall results show a heightened awareness of particularly diversity and equal employment opportunity which highlights an increased rolefor HR practitioners in both countries. Opportunities are created for business leaders to take note of the commonality between New Zealand and South Africa which could lead to enhanced inter-country business activities and improved returns

    View record details
  • The use of the balanced scorecard to enhance performance culture in a New Zealand information technology organisation.

    Du Plessis, Andries; Tachiwona, G.; Sukumaran, Sukesh; Marriott, Jeff (2014)

    Conference paper
    Unitec

    This paper shed light on how managers can use the balanced scorecard to transform low performing information technology service teams into highly productive and profitable units that meet customer service expectations. Two research questions are answered: what were the major drivers of low business performance, and how were they addressed? How did managers get the necessary buy-in from employees for the balanced scorecard to be successful? An exploratory research was executed covering three years of the balanced scorecard implementation in a New Zealand Information Technology Service Organisation interviewing managers, employees and a customer director. Some findings are: a lack of process and management leadership; communication was poor; relationships between engineers, managers, Medicare and NZIS were also tensed and distrustful. Some recommendations are made and the conclusions form the last part of the paper.

    View record details