23 results for Conference poster, 2014

  • Progress Testing: Two Countries Divided by a Common Language

    O'Connor, Barbara; Lillis, Steven; Weston, Kimberley; Freeman, A; Bagg, Warwick (2014)

    Conference poster
    The University of Auckland Library

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  • Coronary artery bifurcation haemodynamics - comparison between phase contrast MRI and computational fluid dynamics

    Beier, Susann; Ormiston, J; Webster, M; Cater, John; Medrano-Garcia, P; Young, Alistair; Cowan, Brett (2014-01-17)

    Conference poster
    The University of Auckland Library

    Coronary atherosclerosis is common at vessel bifurcations. A quantitative approach to measuring blood velocity, vorticity and more complex flow features at bifurcations would enhance the understanding of the mechanisms of atheroma development, and potentially predict vessels at highest risk. The aim of this work was to validate 4D phase contrast (PC) magnetic resonance imaging flow measurements using a simplified arterial model of the left main coronary bifurcation against computational fluid dynamic (CFD) modelling.

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  • The Regional Structure of Technical Innovation

    O'Neale, DR; Hendy, SC (2014-06-04)

    Conference poster
    The University of Auckland Library

    There is strong evidence that the productivity per capita of cities and regions increases with population. One likely factor behind this phenomenon is agglomeration; densely populated regions are able to bring together otherwise unlikely combinations of individuals and organisations with diverse, specialised capabilities. But clearly not all possible combinations of capability are equally valuable, nor are they equally likely. In order to investigate patterns in the typical combinations of capabilities, we have used the REGPAT patent database to construct a bipartite network of geographic regions and the patent classes for which those regions display a revealed comparative advantage. By identifying the pairs of patent classes that are most likely to co-occur within regions, we can infer relationships between the classes, giving a new network that maps out the structure of technical innovation. The resulting network has a core-periphery structure with a central group of highly connected technologies surrounded by branches of more specialised combinations. We investigate measures such as the diversity of regional patent portfolios and the ubiquity of patent classes across regions. We find that diversity is positively correlated with regional population, while the average ubiquity of patents in a region’s patent portfolio is negatively correlated. This suggests that more populous regions are able to expand into more specialised and higher value parts of the patent network.

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  • Refractive errors in the Maldives: a pilot study

    Kandel, H; Kaphle, D; Gyawali, R; Khanal, Safal; Upadhyaya, S (2014-07)

    Conference poster
    The University of Auckland Library

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  • Retrospective host specificity testing of Cotesia urabae to assess the risk posed to the New Zealand nolid moth Celama parvitis

    Avila Olesen, Gonzalo; Withers, TM; Holwell, GI (2014-08-11)

    Conference poster
    The University of Auckland Library

    Additional retrospective testing of the gum leaf skeletoniser (Uraba lugens) biological control agent Cotesia urabae was conducted against the endemic moth Celama parvitis. Although this native was included in host specificity testing before EPA approved the parasitoid's release, this work aimed to increase the sample size to better assess the potential risk posed. The effect that different periods of host deprivation and prior oviposition experience had on the parasitoid's readiness to attack, was examined in a sequence of no-choice tests. No parasitoids emerged from the 52% of larvae that survived to pupation, thus, confirming C. parvitis as a non-host. Dissections of larvae that died during laboratory rearing revealed that 63% had contained a parasitoid, but no C. urabae parasitoid larvae developed beyond the second instar. Significant differences were found in the attack times according to the parasitoid's deprivation levels (age), and it was also observed that the duration until first attack significantly decreased after each non-target presentation.

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  • Neonatal invasive pneumococcal disease in NewZealand in the era of conjugate pneumococcal vaccination 2009 - 2013

    Burton, C; Mount, V; Jackson, C; Heffernan, H; Best, Emma (2014-11-19)

    Conference poster
    The University of Auckland Library

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  • Appropriate Antibiotics for Empyema at Starship Children’s Hospital

    Burton, C; Price, Neil; Best, Emma (2014-11-19)

    Conference poster
    The University of Auckland Library

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  • The Effects of a Vitamin D, Omega 3, Co-enzyme Q10, Zeaxanthin, Lutein and Astaxanthin Supplement (Lester’s Oil) on Healthy People: Preliminary Results.

    Laing, Bobbi; Ellett, S; Marlow, G; Han, Dug; Jesuthasan, A; Ferguson, Lynnette (2014-08-25)

    Conference poster
    The University of Auckland Library

    Background: Diet is a key component in the disease susceptibility of individuals. Reducing inflammation especially in people with inflammatory disorders is thought to decrease disease susceptibility. The aim of this trial was to investigate the effects of a dietary supplement which contains Vitamin D, Omega 3, Co-enzyme Q10, Zeaxanthin, Lutein and Astaxanthion inflammatory markers in healthy people. Methods: The cross over trial was double blinded, randomised and placebo controlled. The study population (n = 30) was recruited from Auckland, New Zealand. The intervention or placebo was for 28 days, followed by a washout of 28 days followed by the placebo or intervention for 28 days. In this preliminary analysis blood samples were measured for C-Reactive protein (CRP), HDL, LDL, Triglycerides and cholesterol levels. A quality of life questionnaire, height and weight were also assessed. Results: Analysis of these measures found significant differences between the intervention and placebo groups for CRP (p < 0.0288) HDL (p < 0.0019) and triglycerides (p < 0.0091). Conclusion: In this preliminary analysis the supplement was shown to be effective in reducing key inflammatory markers in healthy people.

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  • Measuring the electrical impedance of mouse brain cortex

    Wilson, MT; Elbohouty, M; Lin, Oliver; Voss, LJ; Jones, K; Steyn-Ross, DA (2014)

    Conference poster
    The University of Auckland Library

    We report on an experimental method to measure conductivity of cortical tissue. We use a pair of 5mm diameter Ag/AgCl electrodes in a Perspex sandwich device that can be brought to a distance of 400 microns apart. The apparatus is brought to uniform temperature before use. Electrical impedance of a sample is measured across the frequency range 20 Hz-2.0 MHz with an Agilent 4980A four-point impedance monitor in a shielded room. The equipment has been used to measure the conductivity of mature mouse brain cortex in vitro. Slices 400 microns in thickness are prepared on a vibratome. Slices are bathed in artificial cerebrospinal fluid (ACSF) to keep them alive. Slices are removed from the ACSF and sections of cortical tissue approximately 2 mm times 2 mm are cut with a razor blade. The sections are photographed through a calibrated microscope to allow identification of their cross-sectional areas. Excess ACSF is removed from the sample and the sections places between the electrodes. The impedance is measured across the frequency range and electrical conductivity calculated. Results show two regions of dispersion. A low frequency region is evident below approximately 10 kHz, and a high frequency dispersion above this. Results at the higher frequencies show a good fit to the Cole-Cole model of impedance of biological tissue; this model consists of resistive and non-linear capacitive elements. Physically, these elements are likely to arise due to membrane polarization and migration of ions both intra- and extra-cellularly.

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  • Diphthong trajectories in Māori

    King, J; Watson, Catherine; Maclagan, M; Keegan, Peter; Harlow, R (2014-12-03)

    Conference poster
    The University of Auckland Library

    Sound change over time has been identified in monophthongs in Māori, the language of the indigenous people of NZ [1], with /u u:/ fronting, the mid vowels rising, so that /i~i:~e~e:/ can appear identical, and the quantitative distinctions between long and short monophthongs being reduced apart from /a~a:/ [1], [2]. The five most frequent diphthongs in Māori are /ai ae au ou ao/. Analysis has shown mergers between two pairs of these diphthongs, /ai~ae/ and /au~ou/ [3]. This study argued that only one of these mergers is due to the monophthong movements: we have shown that /e e:/ have risen [3], but the second target of /ae/ is falling. It was suggested that this merger is due to glide weakening of /ai/. The merger of /au/ and /ou/ is probably influenced by the fronting of /u u:/. The major distinction for /au ou/ is in the first target, but the fronting of T1 for both /au/ and /ou/ is highly correlated both to the fronting of T2, and the fronting of /u u:/ [3]. Diphthong analysis to date has only offered schematic formant trajectories with arrows from T1 to T2 indicating the movement [2], [3]. Here we present for the first time an analysis of the vowel mergers looking at the entire diphthong trajectories, for T1 and T2 for the male speakers. These plots reveal the course and timing of the diphthong movements.

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  • CO2 Fluxes and Concentrations in a Residential Area in the Southern Hemisphere

    Weissert, Lena; Salmond, Jennifer; Turnbull, JC; Schwendenmann, Luitgard (2014-12-15)

    Conference poster
    The University of Auckland Library

    While cities are generally major sources of anthropogenic carbon dioxide (CO2) emissions, recent research has shown that parts of urban areas may also act as CO2 sinks due to CO2 uptake by vegetation. However, currently available results are related to a large degree of uncertainty due to the limitations of the applied methods and the limited number of studies available from urban areas, particularly from the southern hemisphere. In this study, we explore the potential of eddy covariance and tracer measurements (13C and 14C isotopes of CO2) to quantify and partition CO2 fluxes and concentrations in a residential urban area in Auckland, New Zealand. Based on preliminary results from autumn and winter (March to July 2014) the residential area is a small source of CO2 (0.11 mol CO2 m-2 day-1). CO2 fluxes and concentrations follow a distinct diurnal cycle with a morning peak between 7:00 and 9:00 (max: 0.25 mol CO2 m-2 day-1/412 ppm) and midday low with negative CO2 fluxes (min: -0.17 mol CO2 m-2 day-1/392 ppm) between 10:00 and 15:00 local time, likely due to photosynthetic CO2 uptake by local vegetation. Soil CO2 efflux may explain that CO2 concentrations increase and remain high (401 ppm) throughout the night. Mean diurnal winter delta13C values are in anti-phase with CO2 concentrations and vary between -9.0 - -9.70/00. The depletion of delta13C compared to clean atmospheric air (-8.20/00) is likely a result of local CO2 sources dominated by gasoline combustion (appr. 60%) during daytime. A sector analysis (based on prevailing wind) of CO2 fluxes and concentrations indicates lower CO2 fluxes and concentrations from the vegetation-dominated sector, further demonstrating the influence of vegetation on local CO2 concentrations. These results provide an insight into the temporal and spatial variability CO2 fluxes/concentrations and potential CO2 sinks and sources from a city in the southern hemisphere and add valuable information to the global database of urban CO2 fluxes.

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  • The role of conspicuity in bicycle crashes involving a motor vehicle

    Tin Tin, Sandar; Woodward, Alistair; Ameratunga, Shanthi (2014-10-30)

    Conference poster
    The University of Auckland Library

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  • Clinical ICT Tools: Are we able to measure their effectiveness? A Case Study

    Ewens, Andrew; Orr, M; Starr Jr, RG (2014-09-10)

    Conference poster
    The University of Auckland Library

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  • The STn-SNc hyperdirect pathway modulates dopaminergic neuron activity by inhibiting GABAergic inputs from the SNr via endocannabinoids

    Freestone, Peter; Wu, XH; de Guzman, G; Lipski, Janusz (2014-07-05)

    Conference poster
    The University of Auckland Library

    The hyperdirect pathway of the basal ganglia circuitry terminates with a glutamatergic projection from the Subthalamic Nucleus (STN) to the Substantia Nigra pars compacta (SNc). We recently showed that glutamate released in the SNc drives endocannabinoid production in dopaminergic neurons, which in turn inhibits GABAergic transmission in that region. The present study investigated the potential role of STN glutamatergic projections of the hyperdirect pathway in this novel endocannabinoid modulatory mechanism. Whole-cell patch-clamp recordings were made from SNc dopaminergic neurons in horizontal brain slices (rat) containing STN, SNc and Substantia Nigra pars reticulata (SNr) regions. Either electrical (bi-polar electrode) or pharmacological (local carbachol application) stimulation of the STN was performed to evoke selective glutamate release from terminals in the SNc. GABAergic inputs to the SNc from the SNr were electrically stimulated to evoke inhibitory post-synaptic currents (eIPSCs). Single-pulse electrical stimulation of the STN caused transient (< 1 sec) attenuation of GABAergic eIPSCs amplitudes recorded from dopaminergic neurons (to 73% of control). The eIPSC attenuation was prevented by block of either cannabinoid CB1 receptors with rimonabant (3 µM) or metabotropic glutamate mGluR1 receptors with CPCCOEt (100 µM). Pharmacological activation of STN neurons by rapid local perfusion of muscarinic agonist carbachol (100 µM, 10 s) caused a similar attenuation of eIPSC amplitude. These findings show that glutamate release from STN terminals in the SNc modulates GABAergic transmission through endocannabinoid signalling – a previously undescribed function of the hyperdirect pathway.

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  • Collaborative Problem Solving for Do-ers and Teachers of Mathematics

    Sheryn, Sarah; Frankcom, G; Ledger, G (2014-11-27)

    Conference poster
    The University of Auckland Library

    This study sought to explore and analyse the phenomenon of maths anxiety within a real-life context, and to identify if levels of maths anxiety can be reduced through participation in a reciprocal teaching process. This poster presents a small element of the larger study, which investigated how to reduce maths anxiety in teacher candidates. Maths anxiety is a well-researched phenomenon that is known to impede the successful mathematics teaching and learning experiences of some teacher candidates. The maths anxiety these students bring to their mathematics education courses results in poor quality mathematics teaching (Biddulph 1999; Frankcom 2006; Sloan 2010). Mathematics education lecturers have become increasingly aware of how some students become visibly anxious when they walk into the mathematics classroom, and/or are asked to collaborate to solve mathematical problems. These observations are supported by the level of maths anxiety reported by these students. The model developed for this study was informed by the work of Palinscar and Brown (1984) and complemented by problem-solving models from Mullis, et al. (2008), Reilly, Parsons and Bortolot (2009), and Polya (1945). The Revised Reciprocal Teaching Model (RRTM) was designed is to facilitate teacher candidates’ access to mathematical practices used in schools, and simultaneously develop their personal mathematical knowledge and understanding. Cognisant of the problem solving and peer mentoring literature, researchers provided opportunities for graduates to develop adaptive expertise. While peer mentoring is thoroughly established in literacy education it is under-researched within mathematics education. Reciprocal teaching falls within this area of research and provides a framework for individuals to mutually support each other while learning. The RRTM was developed to promote discourse within mathematical communities in an attempt to reduce maths anxiety. The implementation of the RRTM was through a two-phased structured framework, designed to take place over a university calendar year. The framework began with specific training of peer mentors who in turn worked with assigned mentees. The second phase promoted less reliance on the peer mentors and resulted in the students forming their own peer mentoring groups outside of class time. Results suggest that the model has a positive effect on students’ ability to confidently talk about and solve mathematical problems. This is evidenced by the decrease in maths anxiety levels self-reported by teacher candidates. This research indicates the RRTM has the potential to reduce maths anxiety levels of teacher candidates and produce confident do-ers and teachers of mathematics.

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  • Gelation of oxidised cereal beta-glucan extracts

    Mohan, Anand (2014-02-21)

    Conference poster
    The University of Auckland Library

    Cereal β-glucan, which occurs in plant cell walls, is the major component of soluble dietary fiber in oat and barley. Soluble fibers with a high solution viscosity, which is positively correlated to molecular weight (MW), lower the serum glucose and cholesterol levels. The relevant health claims on β-glucan as a functional food have been allowed by regulatory authorities, including the EFSA and the US FDA. In most processed-food systems, the native hydrolytic enzymes are inactivated, but oxidative degradation of this non-starch polysaccharide can, however, adversely affect the claimed health benefits. (Kivelä 2011). Although the physiological benefits are positively correlated with the viscosity of β-glucan, the relationship with its gelling capacity is not fully understood. The scope of the Master’s thesis included (1) the study of gelation characteristics of oxidised solutions of oat and barley β-glucan, and (2) correlating the results obtained by dynamic light scattering (DLS) microrheology with conventional rheology.

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  • Searching for anomalous light curves in massive data sets

    Rattenbury, Nicholas (2014-01-19)

    Conference poster
    The University of Auckland Library

    The photometric surveys currently under way by the MOA and OGLE collaborations have produced and are extending databases of millions of stellar light curves. These databases have allowed investigations into diverse astrophysical fields including variable stars, proper motion studies and Galactic structure. Odd, or otherwise curious events have been discovered in the databases. We consider here one such event and propose methods for discovering more like it in the microlensing databases. A further aim of this initial work is to set out the prospects of the classification scheme for identifying time series that are maximally discordant - i.e. those that do not look like any other time series in the data set, and which therefore, may be of particular interest.

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  • Comparison and refinement of hip joint centre prediction methods on a large contemporary population

    Zhang, Ju; Hislop-Jambrich, J; Besier, T (2014)

    Conference poster
    The University of Auckland Library

    The location of the hip joint centre (HJC) is critical for accurate lower limb kinematics. A number of methods allow the HJC to be predicted from the locations of bony pelvic landmarks. However, widely used predictions methods are often developed on small populations, or have inappropriate parameters when considering different populations. We compare the accuracy of prediction methods by Tylkowski[1], Bell[2], and Seidel[3], and update their parameters using a large urban population. 3-D models of the pelvis were automatically segmented from 159 (86 male, 73 female) post-mortem CT scans collected at the Victorian Insitute of Forensic Medicine. The dataset reflects a contemporary western urban adult population from the state of Victoria, Australia. Bony landmarks (ASIS, PSIS, symphysis pubis) were defined on an atlas model and propagated to correspondent positions on each subject-specific model. The three published methods above were used to predict HJC locations first using their published parameters, then using parameters fitted to the current dataset. Ground truth HJC locations were calculated as the centre of a sphere fitted to the acetabular regions of each model. Using published parameters, mean errors in millimetres for the Tylkowski, Bell, and Seidel methods were, respectively, 23 (4.9), 26 (4.1), and 18 (3.9). After fitting parameters to the current dataset, corresponding mean errors were 13 (5.5), 7.3(4.0), and 5.7 (3.3). Published parameter errors were similar to published errors for the Tylkowski and Bell methods, and more than twice that published for the Seidel method. After fitting parameters, errors for all methods were significantly lower than those previously published. These results highlight the need to validate and recalibrate joint centre prediction methods on large and population-specific datasets.

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  • Effect of contact lens induced retinal defocus on the thickness of the human choroid

    Chiang, Samuel; Backhouse, S; Phillips, John (2014-04-22)

    Conference poster
    The University of Auckland Library

    PURPOSE The aim of this study was to describe the amplitude and time-course of choroidal thickness changes induced by imposed hyperopic and myopic retinal defocus and to compare the responses in emmetropic and myopic subjects. METHODS Twelve Asian subjects (6 emmetropes and 6 myopes) aged between 18 and 34 years had OCT images of the choroid taken in both eyes at 5 min intervals while exposed to monocular defocus (random right or left eye) for 60 min; the fellow eye was kept optimally corrected (no defocus). Two different monocular defocus conditions (2 D hyperopic or 2 D myopic defocus) were tested on separate occasions. Thickness changes were measured as absolute changes in microns. RESULTS Prior to applying defocus, mean choroidal thickness in myopic eyes (mean ± SD, 256.30µm ± 41.24µm) was significantly less than in emmetropic eyes (mean ± SD, 423.09µm ± 60.69µm) (p<0.05) in 60 minutes. No significant difference was found between emmetropes and myopes in changes of choroidal thickness with the two types of defocus. CONCLUSIONS Small but significant choroidal thickness changes occurred when human eyes were exposed to both myopic and hyperopic monocular defocus. In each case these changes acted to move the retina towards the altered image plane, so as to reduce the degree of defocus. In this small sample we could detect no difference in responses of myopic eyes compared to emmetropic eyes.

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  • What influences the association between previous and future crashes among cyclists.

    Tin Tin, Sandar; Woodward, Alistair; Ameratunga, Shanthi (2014-10-09)

    Conference poster
    The University of Auckland Library

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