5,983 results for Scholarly text

  • Playing the Game and Pulling the Fingers: Working for and against the modern University

    Guthrie, O.D. (2015)

    Masters thesis
    Victoria University of Wellington

    Todays’ universities are constantly evolving, and yet they are deeply traditional institutions that bring together often contradictory agendas, with multiple roles and expectations for those working within. I look towards the academics within these universities in order to get a better understanding of what happens when the personal meets the institutional. By reflecting on my time as a student, and talking with thirteen New Zealand academics and post-graduates who in various ways challenge dominant ideas around academia, I aim to broaden and disrupt the academic imagination. Rather than think of this project as an academic study on academia, I like to think of it as me, a student, re-telling the stories of academics; seeking their wisdom, tactics and gaining inspiration from their ability to ‘do’ academia their way, even in today’s tight confines.

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  • "I just find it awkward": Girls' negotiations of sexualised pop music media

    Goddard, Sarah (2016)

    Doctoral thesis
    Victoria University of Wellington

    This thesis examines girls’ relationship with and consumption of female pop stars’ music media. It is contextualised within a period of extensive academic and media debate about girls’ engagement with what has been termed the sexualisation of culture. Much of the alarm concerning girls’ premature sexualisation is underpinned by the presumption of girls as passive media consumers who are uniformly influenced by sexually saturated female pop music, particularly its ubiquitous representation of hyper (hetero) sexually desiring femininity. The notion of girls as precociously sexualised by hypersexual female pop music media has gained homogenous status within mainstream media and popular psychology texts. Girls’ pleasurable consumption and negotiation of a sexually laden media landscape is approached in this research as complicated by their contradictory positioning as savvy consumers within the postfeminist girlhood consumer market and simultaneously as victims within mainstream media and academic literature. Grounded in feminist poststructuralist understandings of girls’ subjectivity, the thesis explores the possibilities of self that representations within female pop music media enable and constrain for girls. Furthermore, the thesis explores ways in which girls make sense of these discourses while carefully managing their positioning as consumers. The research upon which this thesis is based has two parts. Part one of the research involved focus groups within which 30 pre-teen girls, identifying as ‘Kiwis’ or ‘New Zealanders’ discussed their engagement with female popular music media. The second part comprises a thematic discursive and semiotic analysis of girls’ self-recorded group video performances to a favourite pop song by a female artist. Discursive analysis of the professional music videos on which girls’ performances were based accompanied analyses of girls’ videos. The thesis contributes to a growing body of critical feminist research which responds to sexualisation claims that underpin hegemonic understandings of contemporary girlhood. The analyses presented in the research challenge moralistic notions of girls as uniformly influenced by pop music media by highlighting their navigation of this media as a contradictory process of appropriation and rejection. This complex negotiation, while seen in previous feminist literature, is uniquely captured within this thesis through the innovative employment of a performance method that extends feminist theorisations which problematise binary assumptions of girls’ engagement with sexualised media. This research identifies girls’ meaning making as a contradictory and plural process and provides novel insights about girls’ negotiation of postfeminist femininities in their own self-making in relation to self. Crucially, the thesis highlights the way in which girls’ navigation of sexualised media can be understood as occurring through both rejection and reproduction of postfeminist femininity ideals. Contextualised in New Zealand, the research extends knowledge about girls’ navigation of sexualised media beyond a US/UK social context. It also advances the small body of New Zealand literature about girls’ media engagement broadly and about the ways they experience sexualised media in particular.

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  • Exploring the use of ICTs in non-profit sector organisations: supporting the third act

    Priyanga De Silva Senapathy, Nishanie (2016)

    Doctoral thesis
    Victoria University of Wellington

    Life after retirement from full-time work is known as the third act of an individual. In New Zealand the third act has become longer, resulting in an ageing population. An implication of population ageing is the need for increased support and services for older people who live within the community. Non-profit sector organisations primarily cater to those that are either beyond the reach of state services or are unable to afford services offered by the commercial sector. This study is guided by the central research question: how can non-profit sector organisations use ICTs to support service provision for older people living within the community? Using Lamb and Kling’s social actor model, adapted to the context of non-profit sector, the research project explores how ICT use is influenced by factors that are investigated under four key dimensions: affiliations, environment, identities and technology. Employing a case research method, it studies ICT use in four human services non-profit sector organisations. The analysis of the case studies revealed how external influences are enacted within organisations. The study presents a framework which explains post-adoptive use in non-profit sector organisations incorporating external factors, the organisational view and social actor behaviours. The findings suggest that client and funder information requirements influence organisations to select one of four responses to external cues. Organisations adopt either a complementary perspective, a competing perspective, a compatible view or a negotiated view. These organisational information perspectives craft social actor behaviours within non-profit organisations. Further, this study found information challenges associated with maintaining complex client requirements. Mobility of the work force, deficiencies in data capture and limitations of existing client information systems constrain information flow in these organisations. As a result analysis of service utilisation data fails to communicate the actual value created within communities. This study has extended the understanding of ICT use in non-profit human services organisations in New Zealand and contributed to knowledge in the development of the social actor model within specific contexts. The original contribution of this study is the three-tier typology of social actor- information roles. The study presents social actor behaviour associated with a primary entity and an information role. Five main social actor- information roles were identified across three tiers and have been mapped against a spectrum of information behaviours associated with each role. When responding to external cues social actors engage in task related behaviours associated with their information roles. By contributing to ICT use practices, this research presents new perspectives on the components of value in organisational processes. Identifying value adding and value communicating information flows, information loss and informal ICT support roles this study presents a detailed analysis of the factors that enhance and constrain ICT use within human services non-profit sector organisations.

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  • “But I am still a girl after all”: A Discourse Analysis of Femininities in Popular Japanese Manga Comics

    Nishiyama, Yurika (2016)

    Masters thesis
    Victoria University of Wellington

    Where progression towards gender equality is concerned, Japan lags behind most other developed countries with its culture which heavily values tradition. However, its traditional gender roles may be changing as the birth-rate declines and women take up the increasing opportunities opening up for them in the workplace. Within the contexts of these tensions between traditionalism and change, this study investigated the constructions of femininity in popular Japanese manga, one of the most consumed forms of media in Japan which also enjoys global popularity. As such, this study approached manga as a potentially important resource for identifying the available meanings of being a young Japanese woman in contemporary Japanese society. To date, little research has examined manga, and much of the available literature has used content analysis or focused solely on superheroine characters and the romantic interest. As a point of difference, this research implemented discursive analyses and sought to identify a range of femininities made available to readers in manga. It examined four titles within two genres of manga: the shounen genre targeted to male audiences and the shoujo manga, targeted at a female audience. The research employed a feminist, poststructuralist framework to identify the ways in which constructions of femininity in manga drew on dominant Japanese discourses of femininity as well as more globally produced postfeminist discourses associated with popular culture. The study found that manga overall produced femininities within both traditional and contemporary postfeminist discourses. Analyses also highlighted the limited meanings of femininity made available to young female audiences of shoujo manga through dominant postfeminist, empty representations of ‘empowerment’ whilst also underlining the problematic dominance of sexist portrayals of young women in shounen manga. Further, the storylines of shoujo manga were found to be replete with romantic narratives, prioritising romance and marriage as a means to happiness. These findings may identify the implications of such femininities on how young Japanese women view themselves, and are viewed by others globally.

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  • Behavioural and Neurochemical Effects of Acute (±) 3,4 methylenedioxymethamphetamine (MDMA) in the Dopamine D1 Receptor Mutant Rat

    Squire, Hanna (2016)

    Doctoral thesis
    Victoria University of Wellington

    Rationale: (±) 3,4-methylenedioxymethamphetamine (MDMA; ‘ecstasy’) is a recreationally abused psychostimulant that leads to detrimental effects on memory performance. MDMA’s acute effects on memory are often attributed to a working memory impairment resulting from compromised serotonin systems. However, recent evidence from non-human animal experimental studies suggests that acute MDMA may impair memory performance through an MDMA-induced increase in dopamine (DA) release, leading to overstimulation of DA D1 receptors. The overstimulation of D1 receptors during acute MDMA exposure is thought to indirectly impair memory by increasing a subject’s susceptibility to proactive interference, leading to a perseverative pattern of responding during memory tasks. Objective: This project investigates the hypothesis that acute MDMA impairs memory performance via overstimulation of D1 receptors. The acute actions of MDMA will be assessed using DA D1 mutant (DAD1-/-) rats which possess a selective down-regulation in functional DA D1 receptors. On the basis that acute MDMA impairs memory function via overstimulation of D1 receptors it is predicted that, compared to control rats, DAD1-/- rats will be protected from the acute memory deficits caused by MDMA. Due to the novelty of the DAD1-/- rat model, prior to the assessment of the acute effects of MDMA on memory performance in these rats, behavioural and neurochemical characterisations will be conducted. Methods: Firstly, a behavioural characterisation was conducted to explore the tendencies of DAD1-/- rats, compared to controls, in a drug free state. Behaviours relevant for motivation and reward, movement, and memory were the focus of the behavioural investigation due to evidence suggesting a role for D1-like receptors in these functions. Secondly, a neurochemical assessment of DAD1-/- and controls rats in response to MDMA (3 mg/kg) was assayed using c-fos expression, a marker for neuronal activity, in several brain regions with known DA innervation. Thirdly, to assess the acute effects of MDMA on memory performance, DAD1-/- and control rats were trained on a spatial working memory T-maze task, delayed non-matching to position (DNMTP), over 25 sessions. Once trained, rats were administered either MDMA (1.5, 2.25 and 3 mg/kg) or saline fifteen minutes prior to testing on DNMTP, with all subjects experiencing all drug doses three time each. In addition, to further investigate the hypothesis that overstimulation of D1 receptors impairs memory performance, the effects of a D1 receptor agonist, SKF 81297 (0.5, 1, 1.5, 3, 4.5 mg/kg) on DNMTP performance were also assessed. Results: The behavioural characterisation revealed that DAD1-/- rats are capable of performing many behaviours relevant for reward processing, movement and memory function. However, DAD1-/- rats were impaired with regard to some reward-related behaviours, such as the acquitision of lever pressing for sugar pellets. The assessment of c-fos expression demonstrated that DAD1-/- rats express less c-fos in the medial prefrontal cortex, striatum and nucleus accumbens compared to control rats following MDMA administration. Lastly, the effects of acute MDMA administration on memory performance were tested. During the third block of MDMA administration, control rats demonstrated decreased accuracy on the DMNTP task at both the 2.25 and 3 mg/kg doses. The decrease in accuracy during MDMA exposure in control rats was driven by an increase in perseverative errors. On the contrary, DAD1-/- rats were not impaired on the DNMTP task following acute MDMA at any of the doses tested. Administration of SKF 81297 did not lead to any systematic changes in performance, but at the 3 mg/kg dose DAD1-/- rats displayed increased accuracy compared to control rats. Conclusions: DAD1-/- rats were protected from an MDMA-induced decrease in accuracy on the DNMTP task compared to control rats. This finding challenges the assumption that MDMA’s acute effects on memory performance are wholly due to serononergic mechanisms. Specifically, the current study provides evidence for the hypothesis that acute MDMA exposure impairs memory performance in rats.

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  • Blue Cod, Parapercis Colias, Maturity, Fecundity, Sex Change, and Potential Drivers of Sex Ratio in The Marlborough Sounds

    Brandt, Kasper (2016)

    Masters thesis
    Victoria University of Wellington

    Blue cod, Parapercis colias (Pinguipedidae), are widely considered to be the most important recreational finfish species in the South Island. However, blue cod have been declining in abundance in the Marlborough Sounds for many years, and currently, sex ratios are highly male- biased. Blue cod are believed to be a socially structured hermaphroditic species whose populations are prone to local depletion. A potting survey in the Marlborough Sounds was carried out by NIWA in 2013, and along with environmental measurements, 3247 blue cod were measured, weighed, sexed, and stage of sexual maturity was classified macroscopically at sea. Gonads from a subsample of these fish were removed and preserved. In Chapter Two, the preserved gonads were processed histologically and a species-specific histological maturity key was developed. Histological and macroscopic maturity classifications and length-at-maturity estimates were compared. Additionally, estimates of spawning frequency and batch fecundity were made using histological and gravimetric methods. In Chapter Three, possible drivers of sex ratio were investigated using the survey data. Density, large male influence, and environmental factors were considered. In Chapter Four, the feasibility of using digital imaging software to age blue cod otoliths was investigated using the OtolithM application in ImagePro Premier. There was poor agreement between macroscopic and histological maturity classifications (20%, overall). Macroscopic methods overestimated the proportion of mature fish at length in the larger sample, which led to biased length-at-50% maturity (L₅₀) estimates. Macroscopic L₅₀ estimates differed markedly from histology estimates. Using histological data, male L₅₀ was 26 cm TL. Histology indicated that there was no length at which 100% of females were mature. Therefore, a three-parameter capped logistic model was used. Histologically, female L₅₀ was 23.6 cm TL, and the Cap was 0.78, indicating the proportion of mature females reached an asymptote at 0.78. Spawning frequency was 4.6 days, and mean relative batch fecundity was 6.5 hydrated oocytes per gram body weight (SD = 3.3). Hermaphroditism was confirmed for blue cod and was macroscopically identifiable. The analyses in Chapter Three indicated that density had some effect on sex ratio, and large males influenced local sex ratios. Finally, the imaging software could not accurately estimate age compared to an expert reader, and it produced highly variable age estimates. This research found that the macroscopic maturity classifications for blue cod were inaccurate, and revision of the macroscopic key is suggested. The biased estimates of L₅₀ from macroscopic data could lead to biased estimates of spawning stock biomass (SSB). Batch fecundity was markedly lower than the previously reported estimates. The finding of a macroscopically identifiable hermaphroditic stage suggested that ‘hermaphrodite’ should be added as a sex class in the macroscopic key. From the GLM in Chapter Three, in more dense populations, the proportion of males increased. This may have been from changes to male mating strategies, or density may influence the occurrence of primary and secondary males. Finally, areas with males > 45 cm TL had a higher proportion of females, suggesting that large males should be protected in order to help balance sex ratios.

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  • Investigating the modulation of methylphenidate’s effects on impulsivity by fluoxetine

    Chittenden, Rosemary (2015)

    Masters thesis
    Victoria University of Wellington

    The co-prescribing of methylphenidate (MPH) and a selective serotonin reuptake inhibitor for patients presenting co-morbidly with both attention deficit/hyperactivity disorder and depression or anxiety is in some cases recommended. Little research has been conducted on the specific cognitive and behavioural outcomes of this. Studies with rats have shown that SSRI’s potentiate MPH-induced dopamine release in the pre-frontal cortex, hippocampus and nucleus accumbens, as well as enhancing MPH-induced hyper-locomotion (Borycz, Zapata, Quiroz, Volkow, & Ferré, 2008; Weikop, Yoshitake, & Kehr, 2007b). Impulsivity is a behavioural construct with dissociable sub-types, of which one, ‘action restraint’, has been consistently shown to be associated with increased dopamine activity in the mesolimbic system, including the nucleus accumbens. It was hypothesised that rats would make more ‘no-go’ errors in a Go/No-Go task, indicative of an increase in ‘action restraint’ type impulsivity, when co-administered fluoxetine (FLX) and MPH compared to either drug administered alone. Although this was not shown in the current study, tentative evidence was found to suggest that the combination of these drugs may negatively impact on attention, based on a decrease in ‘go’ accuracy. A second subtype of impulsivity, “action cancellation”, was tested using a new variant of the Stop-Signal Reaction Time (SSRT) task that we have developed for rats. Studies show that this subtype of impulsivity seems to be unaffected by changes in dopamine activity, but is improved by increases in norepinephrine. In the Weikop study mentioned above, the SSRI citalopram enhanced not only MPH-induced dopamine release, but also norepinephrine release in the nucleus accumbens. Thus it was hypothesised that FLX may potentiate MPH’s impulsivity-reducing effects as measured by stopping latency in the SSRT. We were not able to show this in the current study, however the demonstration that lower doses of MPH reduced stopping latency, consistent with previous versions of the SSRT, validated the new version developed for the current study. A final experiment revealed a rapid, short-term increase in locomotor activity when rats were co-administered FLX and MPH, an effect not present when either drug was administered singly. This synergistic effect replicates previous findings, and indicates a potentiation of dopamine release in the nucleus accumbens, as was found in previous studies. Although FLX was not found to moderate MPH’s effects on impulsivity in the current study, synergistic effects of the two drugs were effects were found on motor activity and potentially on attention also. This is an indication of the value of further research into specific behavioural and cognitive process that may be affected by co-administration of MPH and an SSRI.

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  • The impacts of ocean acidification and warming on the Antarctic bivalve, Laternula elliptica

    Bylenga, Christine Heather (2016)

    Doctoral thesis
    Victoria University of Wellington

    Laternula elliptica are large bivalves found in high densities in soft sediments in coastal regions of the Southern Ocean. L. elliptica form an important part of the ecosystem, due to significant sediment stabilisation and deposition. Despite the important role L. elliptica play in their environment, little is known about how projected ocean change will impact future populations of this species. Invertebrate larvae are considerably more sensitive to environmental stressors than juveniles and adults, and increases in mortality and minor reductions in dispersal could significantly reduce future population sizes. In a rapidly changing climate, some of the greatest changes are expected at high latitudes. The greatest rates of warming of surface waters are occurring in the Southern Ocean. Additionally, undersaturation of aragonite due to ocean acidification is expected to affect these waters within decades. Calcifying organisms such as molluscs may be particularly sensitive to reduced pH and saturation states associated with ocean acidification. However, information on larval responses to these stressors in Antarctic species is limited. The larvae of L. elliptica are large and lecithotrophic. Maternally provided energy reserves sustain development until the completion of metamorphosis. While large reserves may support long development times and extended encapsulation, they are finite and cannot be replenished. Any stress during larval development could increase metabolic costs and deplete reserves, preventing metamorphosis. These stressors may also impact the calcification process and shell structures, resulting in weaker larvae at settlement that are more vulnerable to injury. Small reductions in larval survival could limit recruitment and population growth may decline. Various responses to ocean acidification (OA) and warming were studied in the larvae of L. elliptica. Larvae were raised under control pH and temperatures (~8.00 and - 1.7°C, respectively) and conditions representing projections for the Antarctic by the end of the century and 2300 (pH 7.80, 7.65 and -0.5, +0.5 and +1.5°C), both individually and in combination. The effect of these stressors on fertilisation rates, development timing and rates of abnormalities at various life stages were examined. Furthermore, SEM analysis determined the impacts of OA and warming on larval shell growth and morphology. Respiration rates and lipid reserves in developing larvae were also determined. Information on OA and temperature responses in Antarctic larvae is limited, and this is the first study on the effects of these stressors in Antarctic bivalves. Elevated temperatures largely improved development, increased early fertilisation rates, and accelerated development through all larval stages and larvae reached competency 5 d ahead of larvae at the control temperature. This would allow for faster settlement, significantly reducing time spent in more vulnerable development stages. Elevated temperatures also improved calcification in later D-stage larvae increasing shell lengths and reducing pitting and cracking, suggesting these larvae will be in a better condition at settlement. Reduced pH improved fertilisation at control temperatures, but impaired it at elevated temperatures, although overall fertilisation was greater at pH 7.65/0.4°C compared to the control temperatures (60% and 50%, respectively). Developmental delays were observed at reduced pH; however the effect varied between experiments. In the first, developmental delays due to reduced pH were observed at all experimental temperatures and were greatest at 0.4°C, while in the second experiment, delays only occurred at ambient temperature. The delay at ambient temperature was 2 d in both experiments. The delaying effect in the first experiment was mitigated by the overall faster development with elevated temperature. Larvae at pH 7.65/0.4°C reached competency at 22 d compared to 24 d at pH 7.98/-1.6°C. Larvae from the most extreme treatment (pH 7.65 and 0.4°C) still reached the D-larvae stage two days ahead of those at control conditions (pH 7.98 and -1.6°C). This also was the first study to perform a detailed analysis of the effect of pH and temperature on shell size and ultra-structure in Antarctic bivalve larvae. D-larvae from reduced pH treatments had significantly larger shells at elevated temperatures. While light microscopy suggested no significant effect of pH on development, SEM analysis revealed that reduced pH severely impaired the quality of the larval shell at all temperatures. They were more likely to have abnormal larval shapes, as well as malformed hinges and edges. These malformations will carry over into juvenile stages, impairing swimming and feeding capacity, which would reduce settlement success and condition. Additionally, these larvae had lower shell integrity, with high frequencies of pitting and shell damage, including cracking under reduced pH, although elevated temperatures partially ameliorated this effect. Larval shells at reduced pH were weaker, indicating they will be more susceptible to injury and predation. This would flow on to later life-history stages, impairing success in settlement when juveniles must bury in the sediments. This is the second study, and the first for molluscs and Antarctic species, to perform a detailed biochemical analysis of the use of energetic reserves in larvae in response to OA. The larvae of L. elliptica are lecithotrophic, depending on maternally provided energy for development to competency. However, the composition and size of the reserves were unknown. The lipid reserves in the larvae were large, dominated by triacylglycerols and phospholipids. Despite significant depletion of both these lipid classes during development, more than 65% of the original lipid pool remained at the D-larval stage, suggesting significant reserves exist for later metamorphosis. Higher metabolic rates are expected in response to pH and temperature stress and supporting these rates may be energetically demanding. However, larvae did not alter use of any of the lipid classes at elevated temperatures. Increases in oxygen consumption in the larvae at elevated temperature indicated low temperature tolerances in L. elliptica larvae, possibly around -0.5°C. These may place increased energetic demands on later life stages that cannot depend on maternally provided resources. Under OA, the energetic demands of calcification are expected to increase due to the costs of active maintenance of the pH of cellular fluids. However, respiration rates were unaffected by reduced pH and a greater lipid reserve remained in larvae at pH 7.65/-1.7°C compared to all other treatments, suggesting larvae may respond to OA by reducing calcification. Additionally, the impact of reduced pH on biodeposition was assessed in adult L. elliptica. Short term (48 h) exposure to reduced pH (to pH 7.54) did not influence biodeposition rates or the organic composition of faeces and pseudofaeces, although compositional changes may have occurred in the latter due to increased mucous production or altered particle selection. Overall, some resilience to projected climate change conditions was observed in the larvae of L. elliptica. Under future elevated temperatures, larger populations could occur due to improved fertilisation as well as larvae reaching competency sooner with no added energetic costs. However, changes in respiration rates indicate that temperature tolerance thresholds are low. The increased metabolic demands with temperatures above -0.5°C could impair growth beyond the D-larval stage, when they are no longer dependent on maternally provided energetic reserves. Additionally, larvae may be compromised by reduced pH, as shell quality and integrity were significantly impaired. This could significantly influence recruitment and mortality rates in settlement, exposing larvae to crushing fractures in burial or reducing burial capacity. Even with slightly greater larval numbers and faster development, an overall population decline would occur if larvae fail in settlement. This study has shown that the larvae of L. elliptica are highly sensitive to future ocean change conditions, but future studies of later life history stages are needed to confirm the impacts of these changes on the greater population.

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  • Seismic investigations of the lithosphere in an amagmatic back-arc region: North Island, New Zealand

    Dimech, Jesse-Lee (2016)

    Doctoral thesis
    Victoria University of Wellington

    New seismic constraints on crustal and upper mantle structures, kinematics, and lithospheric rheology are reported from an amagmatic back-arc region: the southwest North Island of New Zealand. Robust earthquake locations reveal a hypocentre 'downwarp' beneath the east-west trending Taranaki–Ruapehu Line. These earthquakes occur in the uppermost mantle, at depths of 30–50 km, and are distinct from shallower 8–25 km-deep earthquakes near Mt. Ruapehu in terms of focal mechanisms and principal stress directions. A receiver function CCP stack shows that the mantle earthquakes occur beneath a large change in crustal thickness, where the Moho 'steps' from 28 to 35 km-deep and the steepest part of that step has a 20–50° dip. The mantle earthquakes are dominated by strike-slip fault movement and have a maximum compressive stress direction of NE–SW. The existence of mantle earthquakes beneath a steeply-dipping Moho step implies some sort of dynamic modication is occurring in the mantle lithosphere. One possibility to explain these features is the convective removal of the mantle lithosphere due to a Rayleigh–Taylor-type instability. South of the Taranaki–Ruapehu Line, the Moho conversion weakens on both the receiver function CCP stack, and marine seismic reflection data under most of the Wanganui Basin (SAHKE02 and GD100 seismic lines). However, localised bright reflections at Moho depths can be seen in both near-vertical and wide-angle seismic data. Attribute analysis of near-vertical seismic reflections suggests that the rocks beneath the reflectivity are strongly-attenuating (Q ~20) with a negative velocity contrast relative to the lower crust. These observations are interpreted to be related to the presence of serpentinite (antigorite) and/or high pore fluid pressures in the mantle wedge. The links between hydration of amagmatic back-arcs, serpentinisation and/or high pore fluid pressures, rock viscosity, and mantle instabilities are documented here for the southwest North Island of New Zealand. These associations may be applicable to other amagmatic back-arcs around the world.

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  • The role of 5-HT1A and 5-HT1B receptors in MDMA self-administration

    Aronsen, Dane (2016)

    Doctoral thesis
    Victoria University of Wellington

    Rationale: 3,4-methylenedioxymethamphetamine (MDMA) is a less efficacious reinforcer than other drugs of abuse. However, following repeated self-administration, responding increases for some animals and efficacy becomes comparable to other drugs of abuse. MDMA-stimulated serotonin (5-HT) release was negatively associated with acquisition of MDMA self-administration, and a neurotoxic 5-HT lesion reduced the latency to acquire self-administration. These findings suggest that MDMA-produced 5-HT release is an important component of self-administration. The receptor mechanisms are not, however, well understood, although it has often been suggested that the mechanism involves 5-HT-mediated inhibition of dopamine. Both 5-HT1A and 5-HT1B receptors are well localised to regulate dopamine release, and both have been implicated in modulating the reinforcing effects of many drugs of abuse. Objectives: The first objective was to establish specific behavioural assays to reflect 5-HT1A and 5-HT1B receptor activation. Then, using the established behavioural assays, the aim was to determine the role of 5-HT1A and 5-HT1B receptors in the acquisition of MDMA self-administration. The impact of substantial MDMA self-administration on 5-HT1A and 5-HT1B receptors was also assessed. Methods: Firstly, dose-effect relationships for the hyperactive response to the 5-HT1A receptor agonist, 8-OH-DPAT (0 – 3.0 mg/kg) and the hyperactive and adipsic response to the 5-HT1B/1A receptor agonist, RU 24969 (0 – 3.0 mg/kg) were determined. Selectivity of these responses was determined by co-administration of the 5-HT1A receptor antagonist, WAY 100635, or the 5-HT1B/1D receptor antagonist, GR 127935. Secondly, a pretreatment regimen of the RU 24969 (2 × 3.0 mg/kg/day, 3 days), which had been suggested to down-regulate 5-HT1B/1A receptors, was administered prior to self-administration testing. The effect of this manipulation on both the acquisition of MDMA self-administration, and the behavioural responses to 5-HT1A and 5-HT1B receptor activation, was measured. A further study measured behavioural responses to 5-HT1A or 5-HT1B receptor agonists prior to self-administration, to determine whether the variability in these responses would predict the variability in the latency to acquisition of MDMA self-administration. Lastly, the effect of substantial MDMA self-administration (350 mg/kg) on dose-response curves for the behavioural effects of 5-HT1A or 5-HT1B receptor activation was assessed. Results: The hyperactive response to the 5-HT1B/1A receptor agonist, RU 24969, was blocked by the 5-HT1A receptor antagonist, WAY 100635, but not the 5-HT1B receptor antagonist, GR127935. Similarly, the hyperactive response to the 5-HT1A receptor agonist, 8-OH-DPAT, was dose-dependently blocked by WAY 100635. GR 127935, but not WAY 100635, blocked the adipsic response to RU 24969. Repeated administration of RU 24969 produced rightward shifts in the dose-response curves for 8-OH-DPAT-produced hyperactivity and RU 24969-produced adipsia, and also greatly facilitated the acquisition of MDMA self-administration. However, there was no correlation between latency to acquire MDMA self-administration and the hyperactive response to 8-OH-DPAT or the adipsic response to RU 24969, and MDMA self-administration failed to alter these behavioural response to activation of 5-HT1A or 5-HT1B receptors. Conclusions: The hyperactive response to 8-OH-DPAT and the adipsic response to RU 24969 reflect activation of 5-HT1A and 5-HT1B receptors, respectively. The variability in acquisition of MDMA self-administration was reduced by a treatment that also down-regulated 5-HT1A and 5-HT1B receptors, however there was no further indication that these receptors play a critical role in the self-administration of MDMA. Instead, it seems likely that other 5-HT receptors have a greater impact on MDMA self-administration.

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  • The effect of MDMA self-administration on MDMA-produced hyperactivity and c-fos expression

    Bukholt, Natasha (2016)

    Masters thesis
    Victoria University of Wellington

    Background: MDMA preferentially releases serotonin (5HT) but following repeated exposure there is a decrease in this MDMA-produced effect. At the same time, some studies suggest an increase in MDMA-produced dopamine (DA) release following repeated exposure. The sensitised DA response is often accompanied by sensitisation of MDMA-produced locomotor activity. Because DAergic mechanisms have been implicated in the positively reinforcing properties of MDMA, these neuroadaptations might be relevant to MDMA self-administration. Objectives: The main objective of this study was to determine whether MDMA self-administration and non-contingent MDMA exposure differentially affected the development of sensitisation to MDMA-produced hyperactivity. Additionally, the relationship between MDMA-produced hyperactivity and changes in c-fos expression in DA terminal regions was determined. Methods: Triads of rats were designated ‘master’, ‘yoked MDMA’, or ‘yoked saline’. Lever press responding by the master rat resulted in an intravenous infusion of MDMA for both the master rat and the yoked MDMA rat, as well as an equal infusion of vehicle for the yoked control rat. Daily tests continued until a total of 350 mg/kg MDMA had been self-administered. Three days following the last self-administration session, forward and vertical locomotion produced by MDMA (5.0 mg/kg, i.p) were measured during a 2 hr test. Rats were sacrificed immediately following the behavioural test, and c-fos immunohistochemistry was measured. Results: Repeated MDMA exposure resulted in sensitised forward and vertical locomotor activity. Sensitisation of the increase in forward locomotion was produced only in rats that self-administered MDMA; non-contingent MDMA administration failed to sensitise this behavioural response. In contrast, sensitisation to MDMA-produced vertical activity was produced following both contingent and non-contingent MDMA exposure. C-fos expression was reduced in ventrolateral, and ventromedial areas of the dorsal striatum, as well as the infralimbic cortex, after MDMA exposure, regardless of whether the exposure was via self-administration or yoked administration. A selective decrease in c-fos expression in the nucleus accumbens (NAc) core and the cingulate cortex was produced by MDMA self-administration. There was a negative correlation between MDMA-produced forward locomotor activity and MDMA-produced c-fos expression in the NAc core, cingulate cortex and infralimbic cortex. A negative correlation between rearing activity and MDMA-produced c-fos expression in the NAc core, NAc shell, cingulate cortex, and infralimbic cortex was also found. Conclusions: These data provide evidence of behavioural sensitisation as a result of repeated MDMA exposure. Furthermore, MDMA-produced behavioural sensitisation was associated with a decrease in c-fos expression that was evident in the NAc and prefrontal cortex. Finally, region-specific changes in c-fos expression suggest an important role of neuroadaptations in the NAc core and the infralimbic cortex as a consequence of MDMA self-administration.

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  • Application of the precautionary principle during consenting processes in New Zealand: Addressing past errors, obtaining a normative fix and developing a structured and operationalised approach

    Scott, Dale (2016)

    Masters thesis
    Victoria University of Wellington

    The precautionary principle is increasingly being adopted as a legal risk management tool in international environmental law and regulation, especially in the marine context. In fact, over the last 35 years it has been included, often as a central feature, in the vast majority of international law instruments relating to protection and management of the environment. This rise to prominence is largely driven by widespread recognition that the ability of environmental law to successfully avert long term and significant harm is very much contingent on the successful implementation and application of the precautionary principle (specifically, the decision-making and planning measures it advocates). Owing to the above, it is unsurprising that like many other countries New Zealand has incorporated the precautionary principle expressly and implicitly into domestic law and policy over the last 25 years. The most recent and arguably most notable instance of the incorporation of the precautionary principle in New Zealand law is in the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act 2012 (“EEZ Act”). Indeed, for reasons explained in this paper, the success of the EEZ Act will in large part depend on the successful application of the precautionary principle contained in the Act. Unfortunately, New Zealand’s incorporation and application of the precautionary principle to date has been problematic, with confusion and a variety of approaches taken to its core concepts, and arguably outright misapplication of it. For this reason, this paper seeks to take comprehensive stock of the precautionary principle, first to identify what is the likely cause of such confusion and misapplication, and second, to provide a foundational understanding to assist policy makers and the courts with the task of operationalising and applying it during legislative consenting processes. In doing so, this paper focuses on its operation in the marine setting, with a view to assisting with its interpretation and application under the EEZ Act. It argues that in order to secure consistent and proper application of the precautionary principle, significant work needs to be done to clarify definitional ambiguities embedded within the principle. It then argues that further work needs to be done to properly operationalise the New Zealand formulations of the precautionary principle (i.e. unpack the substantive content of the principle and pin down what such content requires of decision-makers in practice) so they can be consistently and correctly applied under New Zealand’s environmental risk management regimes.

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  • The Two Faces of Ascorbate: Prooxidant Activity and Radio-Sensitisation

    Carson, Georgia (2016)

    Masters thesis
    Victoria University of Wellington

    Although not recommended by mainstream oncologists, intravenous injections of pharmacological ascorbate are currently an alternative therapy option for cancer patients. Research has not yet determined whether high-dose ascorbate interacts favourably with radiation therapy to increase DNA damage, and therefore cell death in cancer. Some studies suggest that ascorbate can act as a prooxidant and increase the cytotoxic effect of irradiation in vitro. Glioblastoma multiforme (GBM) is a primary brain astrocytoma that is highly therapy resistant, so patients would be advantaged if ascorbate radiosensitised their cancer. In this investigation, flow cytometry and single cell gel electrophoresis (comet tail assay) were used to measure three indicators of DNA damage in GBM cells in response to ascorbate and irradiation, and were contrasted with immunofluorescence-revealed DNA damage from an intracranial mouse model of GBM. The pro-oxidant, radiosensitisation role of ascorbate was confirmed, as measured by H2AX, 8OHdG, and DSBs in vitro. With all three of these markers of DNA damage, combinations of irradiation and ascorbate had increased damage compared with individual treatments. However preliminary in vivo evidence indicates that increased DNA damage did not occur in an animal model of GBM, and in fact ascorbate may protect from DNA damage in an in vivo context. These findings complement previous results from our lab, and serve to fill in gaps in knowledge specifically around the DNA damaging effects of ascorbate. The unique nature of the brain environment, as enclosed by the blood brain barrier, prevents translation of data from other non-brain cancer studies, as such, this investigation also contributes to the exploration of a much needed avenue of research. Considering the context of ascorbate treatment as a potentially harmful currently used adjuvant, it is imperative to confirm or disprove its efficacy in a clinically relevant environment.

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  • Who knows what and who has the rights to know it?: Knowledge and reality construction in interaction

    Edmonds, David (2016)

    Masters thesis
    Victoria University of Wellington

    Knowledge has been at the centre of philosophical and scientific enquiry for centuries. It remains a topic of central importance in psychology. The current thesis examined how knowledge was managed and treated as relevant by speakers in social interaction in situ. Complaint calls to a dispute resolution telephone helpline service were studied using discursive psychology and conversation analysis as theoretical and methodological frameworks. The thesis focused on how knowledge was implicated in the accomplishment of the institutional task of jointly establishing the facts of the complaint. In particular, the research examined how the issues of ‘who knows what’ and ‘who has the rights to know it’ were demonstrably relevant for speakers in these interactions. The empirical work focused on two types of question-answer sequences. In cases where some requested information was not forthcoming or not immediately provided, callers’ conduct displayed their orientations to a normative expectation that they knew what was asked for and that they had an obligation to provide it. A second set of cases was a collection of declarative requests for confirmation. The different types of responses to such questions were described. It was proposed that the responses could be placed along a continuum, by the extent to which they asserted a caller’s epistemic rights to knowledge about the relevant information. The thesis contributed to existing research by drawing together recent conversation analytic work on epistemics as a domain of organization in social interaction, and more established discursive psychological work on reality construction. The thesis highlighted the practical nature of knowledge, as it was relevant for accomplishing a key institutional task, and other actions, in telephone-mediated dispute resolution.

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  • Directing: A Mirror to Solo Performance Provocation, Collaboration and Proxy Audience

    Richards, Sally (2016)

    Doctoral thesis
    Victoria University of Wellington

    Solo performance is a challenging, immediate and exhilarating form of theatre. Its popularity in the field of westernised contemporary theatre is evidenced in the increasing programming of solo performances at international festivals and in commercial theatres. However, whilst there is considerable analysis of the genre of solo performance there is little examination of the relationship between director and solo performer in the rehearsal room. Prior research has focused on the theoretical or on the practical, but rarely have the two approaches actively engaged with each other. This thesis contributes a much-needed analysis of directing practice in this area, and an integration of theory and practice that offers tangible approaches in the rehearsal room. In what ways can the director best serve the solo performer to create a theatrical experience that can hold the audience's attention, imagination and memory? Solo performance is characterised by a heightened presence in both performer and audience, incited by a minimalism that abandons the theatrical premise of artifice and turns to primary storytelling. The rehearsal room relationship between director and solo performer also shares these qualities, heightened and focused by the one-one engagements. Directing in this context contrasts from that of a multi-cast, with distinctly different dynamics arising from an artistic collaboration between two people, rather than with many. This thesis considers how the director is placed as a flexible paradigm as proxy audience and as a bidirectional-mirroring device in the rehearsal process – situating the director as an articulated reflection to the transforming solo performer. I analyse this unique partnership and focus primarily on strategies that directors use to create effective solo performance. This thesis is comprised of 80% critical writing and 20% for the creative/practice-based research project. I examine the particular qualities of solo performance as a genre; its theatrical origins, function and purpose, the scope of styles and forms and its potential for political and social meaning. However, my focus is on the rehearsal room processes, working predominantly with a director, rather than an analysis of the end product - the performance. I interview practitioners in the field about their rehearsal room experiences, across the spectrum of styles and forms of solo performance. My theoretical framework is centred on Practice as Research (PaR). In order to scrutinise the relationship between director and solo performer I have gained access to the rehearsal room as both director/practitioner and researcher. The PaR component of this thesis includes the analysis of the experimental rehearsal process and performance of PocaHAUNTus - a new autobiographical solo play. In addition I draw on a body of retrospective work – re-examining my direction of five solo performances that occurred prior to this thesis. Production journals, rehearsal and performance footage, interviews, communications and photographs evidence all components. My research question is not simply “Does a solo performer need a director?” Instead, my research pursues how the relationship between the two might be negotiated, asking: “In what ways can the director best serve the solo performer?” The research examines the fundamental challenges of the genre, namely: the delineation of multiple characters by a single performer, immediacy of the audience relationship to the lone performer, stage geography and scenographic choices. The research also identifies and refines practical strategies to accommodate the intensity of working one-on-one. At its best, the director-solo performer relationship is a vibrant and supportive partnership but because of its intimacy, it is often also a complex and challenging engagement. The contribution of this thesis and its originality is in a PaR model that utilises my past experience of directing solo performance, expands on this foundation through the collection of extensive interview material from a diverse range of significant directors and performers of solo work, and then pursues a new creative laboratory where I test key approaches to directing solo performance.

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  • Matroids, Cyclic Flats, and Polyhedra

    Prideaux, Kadin (2016)

    Masters thesis
    Victoria University of Wellington

    Matroids have a wide variety of distinct, cryptomorphic axiom systems that are capable of defining them. A common feature of these is that they are able to be efficiently tested, certifying whether a given input complies with such an axiom system in polynomial time. Joseph Bonin and Anna de Mier, rediscovering a theorem first proved by Julie Sims, developed an axiom system for matroids in terms of their cyclic flats and the ranks of those cyclic flats. As with other matroid axiom systems, this is able to be tested in polynomial time. Distinct, non-isomorphic matroids may each have the same lattice of cyclic flats, and so matroids cannot be defined solely in terms of their cyclic flats. We do not have a clean characterisation of families of sets that are cyclic flats of matroids. However, it may be possible to tell in polynomial time whether there is any matroid that has a given lattice of subsets as its cyclic flats. We use Bonin and de Mier’s cyclic flat axioms to reduce the problem to a linear program, and show that determining whether a given lattice is the lattice of cyclic flats of any matroid corresponds to finding integral points in the solution space of this program, these points representing the possible ranks that may be assigned to the cyclic flats. We distinguish several classes of lattice for which solutions may be efficiently found, based upon the nature of the matrix of coefficients of the linear program, and of the polyhedron it defines, and then identify families of lattice that belong to those classes. We define operations and transformations on lattices of sets by examining matroid operations, and examine how these operations affect membership in the aforementioned classes. We conjecture that it is always possible to determine, in polynomial time, whether a given collection of subsets makes up the lattice of cyclic flats of any matroid.

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  • Characterization of Groundwater with Complementary Age Tracers

    Beyer, Monique (2015)

    Doctoral thesis
    Victoria University of Wellington

    Groundwater age or residence time is the time water has resided in the subsurface since recharge. Depending on the application, this definition may or may not include travel through the unsaturated zone. The determination of groundwater age can aid understanding and characterization of groundwater resources, because it can provide information on e.g. groundwater mixing and flow, and volumes of groundwater and recharge. Groundwater age can be inferred from environmental tracers, such as SF₆ and tritium, that have a known input to groundwater and/or undergo known alteration processes in groundwater. The currently used age tracers face limitations regarding their application range and reliability. For example, some age tracers have local sources that can lead to contamination of groundwater. This contamination can result in misleading estimates of age. Other tracers have ambiguous inputs to groundwater, which can result in ambiguous age estimations. To reduce these limitations, it is now recognized that multiple tracers should be applied complementarily. There is also a need for new groundwater age tracers and/or new groundwater dating techniques to supplement the existing ones. Cost-effective and easily applicable tracers/techniques are preferred, since most established groundwater dating techniques are very costly and/or complex. Commonly measured hydrochemistry parameters , such as the concentrations of major ions and pH, have been suggested as cost-effective and easily determinable potential age tracers. To date, the use of commonly measured hydrochemistry parameters as independent age tracer has only been demonstrated for water recharged weeks to months ago relying on seasonal changes. Other studies applied commonly measured hydrochemistry complementarily to established age tracers to better constrain groundwater age and/or better understand and predict anthropogenic effects on groundwater quality. Further study is needed to assess the extent to which commonly measured hydrochemistry can be used to reduce uncertainty in tracer-inferred age as well as the extent to which commonly measured hydrochemistry can be used to extrapolate tracer-inferred age. In addition to tracer specific limitations, quantification of uncertainty and ambiguity is not standard in age modelling. Although a few studies have attempted to quantify uncertainty in age modelling with the aid of probabilistic approaches, their methods are often relatively complex and not transferrable to the many cases with little available data. Uncertainties in the tracer’s recharge estimate and identification of appropriate model components, such as the objective function, have not been considered. Studies in other areas of hydrological modelling, where probabilistic approaches are more commonly used, have highlighted the need for careful identification of model components.

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  • Learning Feature Selection and Combination Strategies for Generic Salient Object Detection

    Naqvi, Syed (2016)

    Doctoral thesis
    Victoria University of Wellington

    For a diverse range of applications in machine vision from social media searches to robotic home care providers, it is important to replicate the mechanism by which the human brain selects the most important visual information, while suppressing the remaining non-usable information. Many computational methods attempt to model this process by following the traditional model of visual attention. The traditional model of attention involves feature extraction, conditioning and combination to capture this behaviour of human visual attention. Consequently, the model has inherent design choices at its various stages. These choices include selection of parameters related to the feature computation process, setting a conditioning approach, feature importance and setting a combination approach. Despite rapid research and substantial improvements in benchmark performance, the performance of many models depends upon tuning these design choices in an ad hoc fashion. Additionally, these design choices are heuristic in nature, thus resulting in good performance only in certain settings. Consequentially, many such models exhibit low robustness to difficult stimuli and the complexities of real-world imagery. Machine learning and optimisation technique have long been used to increase the generalisability of a system to unseen data. Surprisingly, artificial learning techniques have not been investigated to their full potential to improve generalisation of visual attention methods. The proposed thesis is that artificial learning can increase the generalisability of the traditional model of visual attention by effective selection and optimal combination of features. The following new techniques have been introduced at various stages of the traditional model of visual attention to improve its generalisation performance, specifically on challenging cases of saliency detection: 1. Joint optimisation of feature related parameters and feature importance weights is introduced for the first time to improve the generalisation of the traditional model of visual attention. To evaluate the joint learning hypothesis, a new method namely GAOVSM is introduced for the tasks of eye fixation prediction. By finding the relationships between feature related parameters and feature importance, the developed method improves the generalisation performance of baseline method (that employ human encoded parameters). 2. Spectral matting based figure-ground segregation is introduced to overcome the artifacts encountered by region-based salient object detection approaches. By suppressing the unwanted background information and assigning saliency to object parts in a uniform manner, the developed FGS approach overcomes the limitations of region based approaches. 3. Joint optimisation of feature computation parameters and feature importance weights is introduced for optimal combination of FGS with complementary features for the first time for salient object detection. By learning feature related parameters and their respective importance at multiple segmentation thresholds and by considering the performance gaps amongst features, the developed FGSopt method improves the object detection performance of the FGS technique also improving upon several state-of-the-art salient object detection models. 4. The introduction of multiple combination schemes/rules further extends the generalisability of the traditional attention model beyond that of joint optimisation based single rules. The introduction of feature composition based grouping of images, enables the developed IGA method to autonomously identify an appropriate combination strategy for an unseen image. The results of a pair-wise ranksum test confirm that the IGA method is significantly better than the deterministic and classification based benchmark methods on the 99% confidence interval level. Extending this line of research, a novel relative encoding approach enables the adapted XCSCA method to group images having similar saliency prediction ability. By keeping track of previous inputs, the introduced action part of the XCSCA approach enables learning of generalised feature importance rules. By more accurate grouping of images as compared with IGA, generalised learnt rules and appropriate application of feature importance rules, the XCSCA approach improves upon the generalisation performance of the IGA method. 5. The introduced uniform saliency assignment and segmentation quality cues enable label free evaluation of a feature/saliency map. By accurate ranking and effective clustering, the developed DFS method successfully solves the complex problem of finding appropriate features for combination (on an-image-by-image basis) for the first time in saliency detection. The DFS method enables ground truth free evaluation of saliency methods and advances the state-of-the-art in data driven saliency aggregation by detection and deselection of redundant information. The final contribution is that the developed methods are formed into a complete system where analysis shows the effects of their interactions on the system. Based on the saliency prediction accuracy versus computational time trade-off, specialised variants of the proposed methods are presented along with the recommendations for further use by other saliency detection systems. This research work has shown that artificial learning can increase the generalisation of the traditional model of attention by effective selection and optimal combination of features. Overall, this thesis has shown that it is the ability to autonomously segregate images based on their types and subsequent learning of appropriate combinations that aid generalisation on difficult unseen stimuli.

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  • Project Management Internship in Post-Earthquake Christchurch: A review of experiences gained and lessons learned

    Helm, Benjamin (2013)

    Masters thesis
    University of Canterbury Library

    This report discusses the experiences gained and lessons learned during a project management internship in post-earthquake Christchurch as part of the construction industry and rebuild effort.

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  • Curvature dependence of propagating velocity for a simplified calcium model

    Zhang, W (2014-02-20)

    Scholarly text
    Auckland University of Technology

    It is known that curvature relation plays a key role in the propagation of two-dimensional waves in an excitable model. Such a relation is believed to obey the eikonal equation for typical excitable models (e.g., the FitzHugh-Nagumo (FHN) model), which states that the relation between the normal velocity and the local curvature is approximately linear. In this paper, we show that for a simplified model of intracellular calcium dynamics, although its temporal dynamics can be investigated by analogy with the FHN model, the curvature relation does not obey the eikonal equation. Further, the inconsistency with the eikonal equation for the calcium model is because of the dispersion relation between wave speed s and volume-ratio parameter γ in the closed-cell version of the model, not because of the separation of the fast and the slow variables as in the FHN model. Hence this simplified calcium model may be an unexpected excitable system, whose wave propagation properties cannot be always understood by analogy with the FHN model.

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