1,991 results for The University of Auckland Library, 2015

  • Comment on: Cross-border portfolios: assets, liabilities and wealth transfers

    Berka, Martin (2015-10)

    Report
    The University of Auckland Library

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  • Commercial decisions in the Supreme Court of New Zealand: The prominence of agency law in the first ten years

    Watts, Peter (2015)

    Book item
    The University of Auckland Library

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  • Implementación del programa nacional de bilinguismo-Cali Colombia: Perfiles de los docentes de inglés

    Cárdenas Ramos, R; Chaves, O; Hernandez, F (2015)

    Book
    The University of Auckland Library

    El estudio que aquí se presenta es una descripción de las condiciones de implementación del programa nacional de bilingüismo (denominación cambiada más tarde a programa de fortalecimiento al desarrollo de competencias en lenguas extranjeras - PFDCLE y que a partir del 14 de julio de 2014 se denomina programa nacional de inglés - PNI) en instituciones educativas de tradición monolingüe de los sectores público y privado de la ciudad de Santiago de Cali, llevado a cabo en los años 2010-2011. Está obra también pretende ser una fuente de consulta en asuntos teori¬cos relacionados con el ejercicio de la docencia en el área de lenguas, ya que contiene un marco teórico-conceptual amplio y describe en detalle la situación concreta del docente de inglés de Santiago de Cali, situación que se asemeja en muchos aspectos a la realidad nacional. En este sentido, la obra va dirigida a los docentes, directivos docentes, a los formadores de do¬centes, a los docentes en formación y, de manera especial, a las autoridades educativas, quienes toman las decisiones definitivas en lo relacionado con políticas educativas y lingüísticas y la asignación de recursos para el área.

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  • Alberton’s Sheet Music Collection from 1850-1915

    Vickers, Louisa (2015)

    Masters thesis
    The University of Auckland Library

    The Victorian era in colonial New Zealand is lacking extensive research in regards to sheet music collections, particularly in social settings. This research examines the sheet music collection of the Kerr Taylor family of Alberton to recover the attitudes, recreational avenues, and views of the early Auckland elite. The Alberton sheet music collection is set within the socio-historical context, and a history of the Kerr Taylor family is provided for added context. Individual acquisition of various family members (Patty Taylor, Winifred Kerr Taylor, Mildred Kerr Taylor, and Muriel Kerr Taylor) is discussed, condition of the collection is described, and the collection considered in relation to Victorian values. This is presented as a partial case study, with the answers to the research questions woven into the essay narrative. The Alberton sheet collection reflects the norms of Victorian musical values, and music held an important place in the lives of the Kerr Taylors. Patty Taylor and Winifred, Mildred, and Muriel Kerr Taylor are the most prominent names in the collection, with pieces of sheet music existing in varying states of condition. Names and years are the most common annotation, but there are exceptions. This project adds to the body of knowledge surrounding the Kerr Taylor family and Alberton. The sheet music collection exists in the wider context of the bulk of the Alberton collection, and there is scope a more detailed exposition of the music collection, or for the music collection to be considered within the broader Alberton collection.

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  • Real Exchange Rates and Sectoral Productivity in the Eurozone

    Berka, Martin; Devereux, MB; Engel, C (2015-08-06)

    Report
    The University of Auckland Library

    We investigate the link between real exchange rates and sectoral total factor productivity measures for countries in the Eurozone. We show that real exchange rate variation, both in cross-country and time series, closely accords withan amended Balassa-Samuelson interpretation, incorporating shocks both to sectoral productivity and a labor market wedge. We construct a sticky price dynamic general equilibrium model to generate a cross-section and time series of real exchange rates that can be directly compared to the data. Under the assumption of a common currency, estimates from simulated regressions are very similar to the empirical estimates for the Eurozone. Our findings contrast with previous studies that have found little relationship between productivity levels and the real exchange rate among high-income countries, but those studies have included country pairs which have a floating nominal exchange rate.

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  • Case Study as Antidote to the Literal

    Kushner, Saville (2015)

    Book item
    The University of Auckland Library

    Much programme and policy evaluation yields to the pressure to report on the productivity of programmes and is perforce compliant with the conditions of contract. Too often the view of these evaluations is limited to a literal reading of the analytical challenge. If we are evaluating X we look critically at X1, X2 and X3. There might be cause for embracing adjoining data sources such as W1 and Y1. This ignores frequent realities that an evaluation specification is only an approximate starting point for an unpredictable journey into comprehensive understanding; that the specification represents only that which is wanted by the sponsor, and not all that may be needed; and that the contractual specification too often insists on privileging the questions and concerns of a few. Case study evaluation proves an alternative that allows for the less-than-literal in the form of analysis of contingencies how people, phenomena and events may be related in dynamic ways, how context and action have only a blurred dividing line and how what defines the case as a case may only emerge late in the study.

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  • Using assessment to enhance learning for the Net Generation

    Ovens, AP; Garbett, D; Heap, R (2015)

    Book item
    The University of Auckland Library

    Assessment has traditionally been seen as a way of finding out what students have learned. There has been a relatively recent shift to embedding assessment as an integral aspect of the learning culture of Net Generation learners. In such a shift, pedagogical encounters are characterised by learners engaging with and connecting to other key agentive elements in ways that combine to create a personalised learning network that extends outwards from each student. In this chapter, we focus on four case studies that enhance learning by viewing assessment as part of the ongoing activity emerging from such pedagogical encounters. Each case study acknowledges that an essential part of working with the Net Generation of learners is having a greater sensitivity to how they make sense of learning activities and enacting forms of assessment that are more student centred, reflective and proactive in enabling students to self-manage their learning activity. This has required numerous changes in our roles as teachers, changes in the role of students, changes in the nature of student–teacher interaction and changes in the relationship between the teacher, the student and the course content. One important insight is that if teachers are to be leading learning in their classrooms, it behoves them to become Net Generation learners themselves. We conclude by suggesting that assessment must be deeply embedded as a part of student learning culture and be evoked in ways that work for the Net Generation of learners.

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  • Beyond shush: Talking to your librarian about teaching for tomorrow today

    Moselen, Christine (2015)

    Book item
    The University of Auckland Library

    Teaching for tomorrow today in academic libraries is primarily a conversation around information literacy (IL) and lifelong learning; IL is “a prerequisite and essential enabler for lifelong learning” (Bundy, 2004, p.4). But it is not just libraries who are interested in lifelong learning. The New Zealand education system also has a strong interest in lifelong learning as seen in the New Zealand Curriculum whose vision for the future is “young people who will be confident, connected, actively involved, lifelong learners." (Ministry of Education, 2007, p.7). This paper discusses the broadening concepts of literacy (and information literacy) in schools and universities and the need to develop a culture of continuous learning to meet the perceived needs of the 21st century workplace. It argues that academic libraries, with their focus on learning and teaching, have a critical role to play in the development of such a culture. The paper outlines, in the context of international and local literature, why it is important that teachers of today (and tomorrow) acquire the skills necessary to make them future-proof; it describes what those skills are, and provides examples of the collaboration between academic staff, librarians and learning advisers which have resulted in the integration of academic and information literacy skills into the curriculum.

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  • Sobre a guerra

    Silva, Pedro (2015)

    Book item
    The University of Auckland Library

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  • Lawrence Stenhouse and the Refutation of Progressivism in Curriculum

    Kushner, Saville (2015)

    Book item
    The University of Auckland Library

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  • Electron Accumulation in InN Thin Films and Nanowires

    Colakerol Arslan, L; Smith, Kevin (2015-12-14)

    Book item
    The University of Auckland Library

    An overview on the electron accumulation layer on InN thin film and nanowire surfaces is provided. The interactions between the valence and conduction bands due to the narrow band gap and high electron density at the surface of these materials have a big influence on the electronic structure and the device performance of these materials. We first review the current understanding on the electron accumulation on InN thin films, pointing out the role of defects and dislocations on the unintentional n-type conductivity. Then we carry out detailed investigation on tuning the surface charge properties of InN nanowires depending on the growth process.

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  • Processing Alignments: Semantic, Thematic and Structural Prominence in Samoan SLA

    Charters, Areta; Muagututi’a, G (2015)

    Book item
    The University of Auckland Library

    PT proposes two key hypotheses to account for sentence-like structures in early SLA: (i) the Unmarked Alignment Hypothesis says that learners map the most prominent semantic role onto the subject function and the most prominent structural position; (ii) the Topic Hypothesis says that learners do not differentiate subject and topic (Pienemann, DiBiase & Kawaguchi, 2005). This chapter identifies theory-internal problems for these claims, and presents empirical data which shows that they do not hold for Samoan SLA. For theoretical reasons, no NPs produced by early learners can be considered ‘subjects’ and, while initial NPs in early L2 Samoan tend overwhelmingly to be semantically prominent, the converse is not true, initial NPs are not always topical, and semantically prominent NPs may be focal, or background. An account of the observed facts is provided within the framework of LFG without exceeding the procedural capacities accorded to early learners by PT.

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  • Non-Thermal and Thermal Processing of Fruit Products to Control Enzymatic Browning

    Sulaiman, Alifdalino (2015)

    Doctoral thesis
    The University of Auckland Library

    Browning, an on-going problem of high economy impact to the fruit industry, is caused by polyphenoloxidase (PPO), fruits’ endogenous enzyme. With the increasing demand for high nutrients and ‘fresh-like’ fruit products, there is an interest to study non-thermal preservation technologies such as High Pressure Processing (HPP), ultrasound and pulsed electric fields (PEF). This research investigated the PPO inactivation in fruits by HPP, ultrasound, PEF and thermal processing. PPO inactivation kinetics was modeled for HPP, ultrasound and thermally treated pear, apple and strawberry purees. Additionally, quality assessments after processing and during storage were carried out for strawberry puree and apple juice. Room temperature HPP strawberry puree at 600 MPa for 5 min resulted in 35% PPO inactivation. When combining the same process with mild heat (40-60ºC), a residual activity (RA) of 9-65% as opposed to 44-100% with exclusively thermal processing was obtained. Pear, apple and strawberry purees were HPP combined with mild heat up to 60 min. The pear PPO was found to be resistant even after 60 min at 600 MPa-71°C. HPP-thermal inactivation of apple and strawberry PPOs followed a biphasic first order kinetics exhibiting stable and labile fractions. Ultrasound processing (1.3 W/g, 32°C) for 10 min of pear, apple and strawberry purees significantly reduced PPO activity (25-58% RA). The PPO thermosonication (ultrasound combined with thermal) and thermal inactivation were successfully modeled with a simple first order kinetics. For processed strawberry puree and apple juice yielding ≤18% PPO residual activity, lower processing energy was observed for thermal treatment followed by HPP, ultrasound and PEF. Ultrasound and HPP resulted in better antioxidant activity (70-74%) than thermally treated (60%) strawberry purees. Regarding apple juice, antioxidant activity was improved from 86 to 103% with thermosonication. Ultrasound, HPP and thermal processing produced a 30 days’ shelf-stable strawberry puree and apple juice. However, apple juice processed by PEF required refrigerated storage.

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  • A Brushless DC Motor Drive Without a DC Link Capacitor

    Hewa Kokawalage, Samitha Ransara (2015)

    Doctoral thesis
    The University of Auckland Library

    In recent years, economic and environmental considerations have led the industry towards energy efficient technologies. As a result, in the context of industrial motor drives, Brushless DC (BLDC) and Permanent Magnet Synchronous (PMS) motors have become popular as energy efficient and reliable alternatives for induction motors. Both BLDC and permanent magnet synchronous motors are electronically commutated based on the position of the rotor by using voltage source inverters that consist of a rectifier, a DC link capacitor and an inverter. In comparison to the other electronic components in the circuit, the DC link capacitor has a limited lifetime, which is severely dependent on the ambient operating temperature. However, with advancements in technology, direct power converters such as matrix converters that do not employ DC link capacitors are becoming popular in industry. At present, matrix converters and similar style direct converters are economically feasible in high power applications and are expected to be economically feasible for low power ratings in the future. A technique to eliminate the DC link capacitor from conventional BLDC motor drives is proposed in this thesis. Without the DC link capacitor, the BLDC motor directly operates from the rectified mains supply. A single switch control technique that allows speed and torque control of the BLDC motor is adopted. The proposed technique is simulated and experimentally validated. Also, a comprehensive performance comparison is carried out between the proposed technique and the conventional techniques. Although the proposed technique produces periodic torque ripples, the effectiveness of the proposed technique is validated for low cost BLDC motor drives. A new comprehensive buck converter based mathematical model for the BLDC motor drive is presented to analyse the torque ripple. Using the model, uncontrollable torque regions that occur due to the variable input voltage of the DC link capacitor free BLDC motor drive are identified. The reduction in torque due to the absence of the DC link capacitor is obtained by iteratively solving the mathematical model. The proposed buck converter based model is verified by comparing the analytical results, simulated results, and the experimental results. To compensate for the torque ripple, a compensation technique based on an actively controlled small DC link capacitor is proposed. A further simplified buck converter based model for the DC link capacitor free BLDC motor drive is proposed for practical purposes. The simplified model is compared with the comprehensive buck converter based model to show the accuracy of the model. Although the proposed compensation technique increases the hardware complexity of the motor drive, the overall cost is expected to be lower. A price comparison between the conventional BLDC motor drive and a DC link capacitor free BLDC motor drive with the proposed compensation technique is presented using volumetric pricings obtained through retailers. The effectiveness of the proposed compensation technique is verified by simulations and experimental results. As a solution for complex controls associated with matrix converters, a simple switching algorithm that facilitates the driving of a BLDC motor by a 1 3 matrix converter is presented. Safe commutation techniques are described in detail and the proposed technique is verified by using simulation and experimental results. In principle, the techniques proposed in this thesis are expected to be useful in manufacturing low cost BLDC motor drives with comparable performance.

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  • Quantification of climate change impacts on catchment water balance

    Pham, Hoa (2015)

    Doctoral thesis
    The University of Auckland Library

    Water balance modelling at the catchment scale is valuable for regional planning, design and management of water resources systems as well as for risk assessment and disaster management. This is due to the fact that water-related disasters such as floods and droughts have become more frequent and destructive as a result of climate change which has been observed worldwide over past decades. As part of climate change, changes in precipitation and evapotranspiration are likely to have dramatic impacts on catchment water resources. This results in altering the catchment streamflow and runoff volume. Literature indicates that in practice current water balance models consider the effect of precipitation change rather than evapotranspiration, which is usually assumed to be time-invariant. On the one hand, precipitation estimation in a changing climate is considerably driven by extreme events, particularly by their magnitude and occurrence. The frequency analysis of extreme occurrence based on partial duration series (PDS) may outperform that based on annual maximum series (AMS), however this has not yet been examined with future data. On the other hand, the impacts of climate change on evapotranspiration at the catchment scale have not yet been finalized in terms of methods and data sources used to estimate evapotranspiration. This research thesis develops guidelines on future precipitation projections based on extreme events using frequency analysis of partial duration series. This is tested for cases of point precipitation at individual stations and areal precipitation over the North Island of New Zealand. The testing period ranges between 1945 and 2010. Statistically downscaled daily precipitation from CGCM3.1/T47 and GCM HadCM3 models with spatial resolution of 3.750 x 3.750 and 2.50 x 2.50 respectively, were compared to that directly obtained from RCM HadCM3 at 0.050 x 0.050 spatial resolution for the 1961-2090 period. Moreover, the variation of evapotranspiration across the Waikato catchment and its three forest and grass sub-catchments is accordingly examined for the first time using the integration of the FAO- 56 method coupled with very high spatial resolution RCM HadCM3 data. As a result, the combined effects of changing precipitation and evapotranspiration on the future runoff and volume of the three selected sub-catchment are projected. The results of this research indicate that, in general, precipitation and evapotranspiration have been changing from present to the predicted future and this change has a dramatic impact on catchment runoff. Thus the prediction is that daily precipitation will increase by 1.17% and 2.095% for the 2011-40 and 2041-70 periods, respectively, and the predicted annual precipitation will increase by about 0.89% until the end of 21st century. Likewise, the increase in daily and annual evapotranspiration is about 0.4% to 1.2% per 30-years. Water losses due to evapotranspiration are higher from grassed surface than that from forested surface. As a consequence, mean annual runoff is projected to decrease by 27.8% or to increase by 7.3% per 30-years from 2001 to 2090 depending on the sub-catchment, at the highest rate. In addition to above findings, this research also provides a guideline on the projection of future precipitation based on extreme events using frequency analysis of partial duration series. This could be useful for studying the variability of precipitation with details on how to cope with its complexity. This PhD research attempts to develop a deeper understanding of hydrological response subject to changing climate, as well as adding some case studies of a quantitative nature unlike most of the previous studies.

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  • Image-assisted dietary assessment Evaluating the potential of wearable cameras to enhance self - report in the 24-hour dietary recall method

    Gemming, Luke (2015)

    Doctoral thesis
    The University of Auckland Library

    Background Traditional methods of dietary assessment are prone to self-report bias. Images captured by wearable cameras may reduce self-report bias for foods and dietary energy intake (EI). Aims To investigate the use of wearable cameras to (1) reduce the reporting bias associated with traditional self-reported dietary assessment, and (2) passively record and assess contexts of dietary behaviours. Methods Five modules of research were undertaken: (1) a secondary analysis of the 2008/09 New Zealand Adult Nutrition Survey (ANS 08/9) estimated the prevalence of low energy reporters (LERs), (2) a systematic review examined evidence for image-assisted methods of dietary assessment, (3) a feasibility study explored the use of wearable cameras to enhance self-report in the 24-hour dietary recall, (4) a doubly labelled water (DLW) study validated a wearable camera imageassisted 24-hour dietary recall, and (5) secondary analysis of images collected during the validation study explored the utility of wearable cameras to objectively record, and reliably assess, environmental and social contexts of eating episodes in free-living settings. Results The primary findings were: (1) 21% of New Zealand men and 25% of women were classified as LERs in the ANS08/9, and a systematic bias was observed with LERs more prevalent amongst women, people aged >65 years, and Maori and Pacific peoples, (2) literature published up to 2013 suggests images can provide objective information to independently verify and assess selfreported dietary intake but the limited existing evidence highlighted the need for further research, (3) a small study (n=10) using wearable cameras revealed unreported or misreported errors in the 24-hour dietary recall, which increased self-reported dietary EI, (4) a DLW study (n=40) showed that wearable cameras reduce reporting bias for dietary EI in 24-hour dietary recalls by 9% in men (from 17% to 9%) and 6% in women (from 13% to 7%), and (5) wearable cameras images can be analysed to objectively and reliably assess important contexts of dietary behaviours such as eating location, physical position, social interaction, and media screens. Conclusion Wearable cameras significantly reduce the reporting bias for dietary EI in the 24-hour dietary recall. Used in nutrition research, wearable cameras provide a new tool to verify and enhance self-reported dietary intake, and compared to self-report alone, allow additional information on dietary behaviours to be objectively assessed.

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  • Understanding Reciprocity in Chinese Social Media: Examining the Influence of Social Capital and Emotion on Reciprocal Behaviour

    Zhu, Andrew Qiang (2015)

    Doctoral thesis
    The University of Auckland Library

    The functioning of social networking sites (SNSs) depends on reciprocal behaviours. This research begins from the premise that in SNSs reciprocity is a key element facilitating the establishment and development of interpersonal relationships between strangers. Specifically, the proposed Social Capital – Emotion – Reciprocity conceptual model and hypotheses concerning the effects of social capital and emotion on reciprocity were derived from the literature and from exploratory research. The conceptual model particularly utilised the Cognition – Emotion school of thought, which conceptualises the act of reciprocity as an outcome of an iterative process of cognitive evaluation of social capital and emotion. The cognitive evaluation of social capital was tested in two experiments. In the experiments, the concepts of bridging social capital and bonding social capital were operationalised and manipulated, and consistent effects were found. In both experiments, discrepancies in relative levels of combined capital, bridging capital and bonding capital affected the likelihood of reciprocity (i.e., more social capital generates more reciprocation). Specifically, discrepancies in bridging capital strongly affected reciprocal behaviour. Discrepancies in bonding capital are significant, but less important. There was no interaction effect between bridging social capital and (indirect) bonding social capital, however an interaction effect did exist when bridging social capital and (direct) bonding social capital were tested. Findings from hypothesis tests provided strong evidence to support the conceptual model, with emotion acting as a mediator between social capital and reciprocal action. Specifically, bridging social capital had a larger impact on reciprocity through the mediation of emotion, and in practical terms, this finding is consistent with the significance of the concept of “who you know” in Chinese business practice. Overall, reciprocity in Chinese social media can be considered as a process of mutual recognition between user-benefactors and user-recipients, each of these actors cognitively evaluates the embedded value of the other’s social capital, which is mediated through emotions triggered in social networking practice. The research findings contribute to the theoretical understanding of reciprocity and practice relevance in virtual environments. The mixed methods design focused on the practical relevance to the research context and provided consistent findings through a sequential development of experiments and modelling, which enhanced the validity of the research outcome. Finally, limitations and directions for future research are described with respect to the broader conceptualisation of reciprocity and the specific operationalisation of potential constructs.

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  • Clinical Compatibility of an Implantable Pressure Sensing Device With Consideration of the Intracranial Pressure Application

    Stehlin, Ellyce (2015)

    Doctoral thesis
    The University of Auckland Library

    Implantable pressure sensing devices have the potential to improve patient management and treatment outcomes in a wide variety of conditions, including monitoring intracranial pressure (ICP) in hydrocephalus patients. The intracranial pressure application requires a long-term implantable device with high accuracy, resolute stability, a rechargeable power supply and must not exclude hydrocephalus patients from existing diagnostic medical procedures – namely medical imaging. ICP is the gold-standard indicator for patient health in the hydrocephalus condition, where the accumulation of cerebrospinal fluid in the ventricles of the brain leads to an increase of ICP. Current treatment involves implanting a shunt to redirect the excess fluid, however shunt failure rates are high (up to 40% in the first year of implantation) and difficult to diagnose. Standard diagnostic procedures require costly medical imaging of ventricle size followed by burr-hole surgery to insert an acute transcutaneous lead ICP sensor into the brain parenchyma. In this thesis the feasibility of a lifetime fully implantable ICP measuring device is investigated. Such a device will comprise of a pressure sensing catheter (where the sensor is implanted in the parenchyma), connected to an electrical unit outside the skull, under the skin. The unit contains signal conditioning circuitry, wireless communication antenna, and an inductive power pickup coil allowing the implant to sit dormant until interrogated by an external reader wand. This thesis reports on the clinical compatibility of a pressure monitoring system. Pressure measurement stability over time has been a major cause of failure for previous attempts at a long term ICP device, and this research has shown some (but not all) pressure sensors do have adequate stability over one year of operation within a model of the challenging environment of full implantation. An implantable device was tested in animal in-vivo experimentation including using the high fidelity sensor to make accurate recordings of rat LVP, and validating the device’s ability to measure ICP in acute large animal experiments. MRI compatibility was investigated for the device, including the development and validation of numerical models for RF heating analysis to guide prototype design. It is concluded that the implantable pressure sensing device has the potential to perform in the clinical environment, by screening for pressure sensor performance and avoiding critical lengths of the sensor catheter to limit patient risk in the MRI.

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  • Interactions of the cannabinoid CB1 and dopamine D2 receptors

    Hunter, Morag (2015)

    Doctoral thesis
    The University of Auckland Library

    The effects of cannabinoids in the nervous system are predominantly mediated by cannabinoid receptor 1 (CB1), a G protein-coupled receptor (GPCR). GPCRs are known to form homodimeric and heterodimeric structures, which affect the signalling and regulation of each constituent receptor. CB1 has been shown to have functional interactions with the dopamine D2 receptor (D2). This thesis explores the structure, regulation and function of the CB1-D2 heterodimer. A bioluminescence resonance energy transfer (BRET) assay was utilised to detect constitutive CB1-D2 heterodimer, which was not detectibly altered by receptor agonists. BRET was also utilised to test a proposed heterodimer interface containing four key residues on transmembrane helix 1 of each receptor, however mutation of these residues did not significantly disrupt detection of heterodimer. Previous studies on GPCR heterodimers have suggested that interactions may occur throughout the protein synthesis and ligand-mediated trafficking pathways. Immunocytochemistry-based receptor trafficking and expression assays were used to determine whether CB1 and D2 interact in their regulation. Subtle differences were found in CB1 agonist-driven internalisation in the presence of a D2 agonist. Co-expression of CB1 and a flag-tagged D2 resulted in changes to flag-D2 processing, perhaps by the addition of a post-translational modification, although it is not clear if this is solely a modification of the flag-tag. When activated concurrently, CB1 and D2 have been shown to “switch” signalling phenotype from Gαi-like to Gαs-like activity, resulting in accumulation of cAMP. When this signalling interaction was first observed by Glass et al. (1997), it was hypothesised that this may be a result of the receptors competing for a limited pool of Gαi proteins. If this were the case, this mechanism would also be in effect when CB1 was expressed alone. In order to test this, a mixed population of cells was created and sorted by flow cytometry on the basis of CB1 surface expression. cAMP assays performed on these cells showed that cells with low to moderate expression of CB1 inhibit cAMP production, while cells with high CB1 expression increase cAMP accumulation. In conclusion, while it is likely that CB1 and D2 form a constitutive heterodimer, this does not affect ligand-mediated receptor trafficking. CB1 expression does, however, change the synthesis and processing of flag-tagged D2 in a manner that has yet to be determined. Since CB1 expression alone is sufficient to change the predominant cAMP phenotype to Gαs, presumably by competition of G proteins, this work suggests that CB1-D2 heterodimerisation may function simply to increase the local competition for G proteins, rather than the dimer itself mediating the functional signalling switch.

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  • Neuropsychological, Psychological and Functional Outcomes 12-Months Post-Subarachnoid Haemorrhage: Population-Based Sample Compared to Matched Controls

    Nicholson, Rebecca (2015)

    Doctoral thesis
    The University of Auckland Library

    Stroke is a common neurological disorder that is a leading cause of disability worldwide and may result in deterioration of functioning in neuropsychological, psychological and functional abilities. While accounting for a small proportion of all strokes, subarachnoid haemorrhage (SAH) affects a comparatively young age group who live with its burden for longer. A thorough understanding of SAH survivors’ short-term (≤12-months) outcomes and trajectory is imperative as most change and rehabilitation occurs during this time. However, previous research has been limited by use of hospital- and clinic-based samples, comparison to normative data, limited outcomes focus, and use of brief measures. The current population-based study examined SAH survivors’ (n=30) outcomes throughout the first 12-months compared to control participants (n=29) matched on age, gender and ethnicity. Both groups were assessed using a neuropsychological test battery (e.g., verbal and visual memory, cognitive flexibility, processing speed, cognitive screening measure) and on psychological (anxiety, depression, overall) and functional (stroke symptoms, disability, health related quality of life [HRQoL]) outcomes; the SAH group at 28-days, 6- and 12-months post-SAH. As compared to controls, the SAH group performed significantly worse with greater proportions falling in the impaired range on some neuropsychological outcomes (e.g., cognitive screening measure) and most psychological and HRQoL outcomes throughout the 12-months, despite good outcomes regarding stroke symptoms and disability. Some early improvement in outcomes was found but this plateaued during the 6- to 12-month period and SAH survivors’ outcomes remained poor compared to controls. Psychological and HRQoL outcomes in particular were interrelated, with previous stroke and surgical clipping related to worse HRQoL outcomes. The current findings demonstrate the importance of psychological and HRQoL outcomes in particular throughout the first 12-months post-SAH as compared to the more frequent emphasis of stroke symptoms and disability, suggesting a different direction for assessment and intervention focus. Neuropsychological outcomes are also impaired, though more research using a larger population-based sample and test battery are required to better understand domain specific impairment, trajectory and relation to other outcomes.

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