193 results for Conference poster, 2010

  • Effects of complex milk lipid components on neurodevelopment in vitro

    Lim, JH; Hodgkinson, S; Dragunow, M; Norris, C; Vickers, M (2010-11)

    Conference poster
    The University of Auckland Library

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  • Bronchoconstriction and the MBNW: Insights from anatomical lung modelling.

    Mitchell, Jennine; Tawahi MH (2010-11-30)

    Conference poster
    The University of Auckland Library

    Bronchoconstriction and the MBNW: Insights from anatomical lung modelling. Jennine Mitchell and Dr Merryn Tawhai Auckland Bioengineering institute The multiple breath nitrogen washout (MBNW) is a global test of lung function that produces two indices Sacin and Scond that are reflective of ventilation heterogeneity arising at the level of acinus and between more spatially disparate regions of the lung respectively. An important application of the MBNW is in the study of asthma. Ventilation defects have been noted to occur in imaging studies of asthma. These regional ventilation defects have not previously been considered in relation to the MBNW indices. Scond is purported to be related to the state of conducting airways however no modelling studies exist which directly link the airway state to Scond. In this work regional ventilation defects have been simulated in an anatomically based human lung model and theoretically linked to the MBNW indices Sacin and Scond. Ventilation is simualted to the level of the acinus in a model in which acinar ventilation is considered independent of ventialtion in other acini. As previously indicated in modelling studies a high degree of constriction is required to produce a ventilation defect. The relationship between the degree of constriction in airways leading to the defect and the Scond index is however highly non-linear and shows a sharp decrease at very high levels of constriction. Ventilation defects potentially cause non-communication of gas trapped in the ventilation defects with the mouth. This may alter the calculation of FRC if nitrogen dilution is used to calculate FRC. As the indices are dependent on the phase III slope for each breath being normalised by FRC this alters MBNW results. The index Scond is not be able to be explained simply in terms of increased time constants due to increased resistance in the main conducting airway tree. The model indicates that the Scond index is more complex than current MBNW theory indicates and cannot be simply explained in terms of a longer time constant due to constriction in the conducting airway tree resulting in increased late emptying of poorly ventilated regions.

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  • Using stream biofilm microbial communities as indicators of freshwater ecosystem health

    Lewis, Gillian; Ancion, PY; Lear, G; Roberts, K; Washington, V (2010-08-23)

    Conference poster
    The University of Auckland Library

    Stream biofilms are a complex aggregation of microorganisms embedded in a polymer matrix and cover almost every surface in freshwater environments. Because of their sedentary way of life, microorganisms associated with biofilms are affected by past and present environmental conditions and therefore constitute a potential integrative indicator of stream health. A wide range of experiments was conducted in both flow chamber microcosms and natural stream environments to investigate the main drivers of microbial community structure and composition and evaluate the potential use of biofilms as a bio-indicator of freshwater ecosystem health. Using community fingerprinting techniques such as terminal-Restriction Fragment Length Polymorphism and Automated Ribosomal Intergenic Spacer Analysis as well as 16S rRNA gene clone libraries we investigated variations occurring in biofilm bacterial and ciliate protozoan communities. Initial experiments conducted in flow chamber microcosms showed that significant differences in microbial community structure could be detected within only a few days of exposure to common water contaminants and remained detectable weeks after transfer to uncontaminated water. Further research investigating biofilm of more than 60 stream sites variously impacted by urbanization revealed a strong separation between rural and urban streams and confirmed the potential use of stream biofilm as a bio-indicator of stream health. Environmental monitoring techniques developed in this project were then successfully tested to investigate the efficacy of an enclosed stormwater treatment system, where traditional biological indicators such as macro-benthic invertebrates were not available. We are now extending our research to 300 different streams in order to define a general Bacterial Community Index characterising stream ecosystem health based on the structure of biofilm bacterial communities.

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  • Impact of PCV7 on antibiotic susceptibiity of nasophayngeal Streptococcus pneumoniae in South Auckland children

    Sekikawa, E; Trenholme, A; Taylor, S; Lennon, Diana; McBride, C; Best, Emma (2011-03-17)

    Conference poster
    The University of Auckland Library

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  • Cardiac response to weak electrical shocks challenges the functional syncytium paradigm

    Caldwell, Bryan; Trew, Mark; Pertsov, AM (2015-04-11)

    Conference poster
    The University of Auckland Library

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  • Mechanisms Of Differences In Ventilation Distribution In The Upright, Supine, And Prone Postures

    Tawhai, Merryn; Hedges, Kerry (2011-05-13)

    Conference poster
    The University of Auckland Library

    Rationale: Measurements of ventilation distribution using various imaging modalities have suggested that the distribution of ventilation in the supine and prone postures is less evidently gravitational than when the lung is upright, and with some studies showing little difference between ventilation distributions in the prone and supine lung. This is despite the concurrent observations of a significant gradient in tissue density when supine, and a typically smaller - or absent - tissue density gradient prone. In this study we use a computational model of lung tissue elasticity coupled to air-flow to study the relationship between posture, density distribution, and ventilation. Methods: An imaging-based geometric model of the lung and airway tree that was developed in a separate study was used here. Flow in the airways was simulated using a one-dimensional fluid dynamics model that includes flow-dependent airway resistance and coupling to tissue elasticity at the airway walls and at the acini. A finite deformation elasticity model was used to predict the effect of gravity on tissue deformation, and the non-linear elasticity of each acinar tissue unit during simulated breathing. The upright lung volume was defined from pulmonary function testing; the supine and prone volumes were assumed to be the same, and equal to the supine air volume as calculated from the subject's computed tomography imaging acquired at FRC. Tissue density and ventilation at each of the ~32,000 distributed acini in the model were averaged within iso-gravitational slices of 10 mm thickness. Results: The gradient of tissue density predicted by the model was markedly larger in supine than in upright or prone. Ratios of the maximum to minimum slice density were 1.95, 1.51, and 1.39 for supine, prone, and upright, respectively. Ventilation in the upright model increased on average towards the dependent tissue, whereas ventilation in supine and prone was decreased in the most dependent and non-dependent regions. The ratios of maximum to minimum slice ventilation were 1.09, 1.03, and 1.31 for supine, prone, and upright, respectively. Conclusions: A lack of gravitational distribution of ventilation in the supine and prone postures compared with upright is predicted on the basis of the smaller size of the horizontal lung and a shift of the dependent tissue to a less-compliant region of the sigmoidal pressure-volume curve at its lower asymptote. This is the same mechanism that results in early filling of the non-dependent tissue when inhaling from residual volume.

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  • Delayed Cerebral Post-arteriole Dilation is Consistent with Observations at Multiple Spatial and Temporal Scales: Evidence from Mathematical Modelling

    Barrett, MJP; Tawhai, MH; Suresh, Vinod (2011-05-25)

    Conference poster
    The University of Auckland Library

    Background and aims: Observations from different neurovascular imaging modalities provide conflicting evidence about the presence and/or extent of volume changes in post-arteriole blood vessels. At the level of individual vessels, two-photon imaging during functional activation shows a rapid increase in arteriolar diameter, but little or no increase in capillaries or venules 1 . In contrast, 'bulk' measurements of flow-volume relationships show large increases in arterial volume 2 , and smaller - but still significant - increases in venous volume 3 . Here, we reconcile these competing observations using a dynamic, biophysically based mathematical model of the hemodynamic response. Methods: We use the widely known Windkessel model that represents blood flow as analogous to electrical current, and networks of blood vessels as analogous to electrical resistances and capacitances. The model also includes a novel description of vascular compliance, viscoelastic effects, and stimulus-driven vasodilation. Experimental observations at progressively more detailed scales are used to constrain and validate the model, following a 'top down' approach. In addition, we test the assumption that post-arteriole vessels do not dilate, and use the model to predict observations at progressively more aggregated scales, following a 'bottom up' approach. Results: Model predictions of the total, arterial, and venous steady state flow-volume relationships agree well with experimental observations, as do predictions of transient changes in flow and volume during functional activation. The model also predicts rapid arteriole dilation during activation. Interestingly, this is accompanied by slow increases in capillary and venule diameter that - for brief stimulation - are near indistinguishable from baseline noise. When assuming no dilation of capillaries or venules, there are only minor differences between the model predictions at the single vessel scale. However, predictions at more aggregated scales are qualitatively and quantitatively different from experimental observations. Conclusions: The model presented here is able to reproduce the main features of experimental observations over a range of spatial and temporal scales. These results suggest that arterial dilation represents the majority of regional cerebral blood volume increases during functional activation, especially during brief stimulation. However, passive dilation in capillaries and venules may be increasingly significant during extended stimulation. This is an important consideration when interpreting or comparing results from neurovascular imaging modalities, such as optical methods and magnetic resonance imaging.

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  • Doped Diamond-Like Carbon (DLC) coated surfaces to reduce fouling from milk

    Patel, Jaiminkumar; Bansal, B; Jones, MI; Hyland, M (2010-11-09)

    Conference poster
    The University of Auckland Library

    In the dairy industry, fouling of processing surfaces is a common and unresolved problem. Surface modification, for example through the application of a surface coating, can alter the surface properties of a material, and may be a potential way to reduce fouling. Typical dairy plant stainless steel surfaces were modified by the deposition of doped Diamond-Like Carbon (DLC) films with varying concentration of doped elements. These modified surfaces were studied for their fouling behavior with milk at both laboratory and pilot scale. None of the doped DLC modified surfaces investigated in the study presented benefits in fouling reduction as compared to unmodified surface.

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  • The development of online learning environments (OLEs) at The University of Auckland Library: collaboration, integration and usability testing

    Zdravkovic, Neda (2013-04-09)

    Conference poster
    The University of Auckland Library

    In order to meet the learning needs of a large number of in-house, flexible learning and distance-learning students from a variety of disciplines, The University of Auckland Library has enhanced the provision of information and academic literacy instruction through the design of online learning environments. Learning Services Librarians, learning designers and subject librarians from The University of Auckland Library have collaborated with faculty, Centre for Academic Development staff, graphic design professionals and web developers to design online courses and tutorials, such as: • Academic Integrity - stand-alone online academic integrity course, compulsory for all new students at the University of Auckland from Semester I 2013; • COMLAW 101: New Zealand’s Legal Framework - curriculum- integrated information literacy online tutorial designed for COMLAW 101: Law in a Business Environment academic course with 2000 students each year; • POPLHLTH 701: Research Methods in Health - curriculum- integrated online information literacy learning environment for postgraduate students completing the POPLHLTH 701: Research Methods in Health course and compulsory assessment activity bearing 15% course mark; • FTVMS 100: Assignment Research Path – curriculum-integrated information literacy online tutorial and compulsory assessment activity (10% course mark) designed for FTVMS 100: Media studies first year undergraduate course with 1000 students each year; • Understanding Your Reading List - generic information literacy online tutorial designed for all first year undergraduate students. The focus of the paper will be on the development framework of online courses, curriculum-integrated and generic tutorials and the analysis of different stages of each project, their collaborative nature and usability testing practices applied (user observation, focus group interviews, surveys) and outcomes. It will introduce CourseBuilder as a web-based tool for the design of online learning environments and activities, its features, functionalities and published outputs. CourseBuilder, developed by the University of Auckland’s Centre for Academic Development, is an authoring tool that provides customisable templates to develop online interactive activities (eg, case studies, reflections and quizzes), import text, insert media, monitor student responses and more. Finally the paper will describe issues and challenges during each development stage, as well as benefits and limitations of using an online learning environment development system.

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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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  • 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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  • Sequence Coverage Abnormalities and Sex-Specific Autosomal Regions in Cattle

    Lopdell, Thomas; Harland, C; Johnson, T; Keehan, M (2012-08-21)

    Conference poster
    The University of Auckland Library

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  • Detection of tissue- and sex-specific gene expression in Bos taurus using high depth RNA sequencing

    Lopdell, Thomas; Littlejohn, M (2013-08-13)

    Conference poster
    The University of Auckland Library

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  • Fostering the exchange of geoscience resources for knowledge exploration and discovery

    Whitehead, Brandon; Gahegan, Mark; Everett, M; Hills, S; Brodaric, B (2010-11-11)

    Conference poster
    The University of Auckland Library

    Geoscience data capture is expensive. In order to extract maximum value, the data need to be consistently described, easily found, and then shared among those who need it. There has been recent momentum in the geoscience community to develop a common descriptive framework which facilitates data sharing. While storage and transfer standards are vital, they lack a descriptive element which standarizes the meaning of their contents. Metadata capture is appropriate for data stores, but often the terminology carries different meanings as domains become more specialised. For example, the term “migration” to a petroleum geochemist refers to the movement of hydrocarbons in geologic time, yet to a seismologist describes an imaging process. Furthermore, concepts associated with a term may change through time or as contextual factors in a discussion are modified. How, therefore, can the concepts evoked from geoscience resource terminology be defined and aligned to represent this multi-scaled orthogonal variability? Here we show how a community knowledge acquisition exercise was orchestrated to discuss fundamental concepts and their meanings as interpreted by leaders in basin characterization. The result of this exercise is a formal description of many of the features and processes associated with sedimentary basins, i.e. a basin ontology. This ontology allows the use of semantic connections between concepts as a backbone for search and discovery of research artifacts in large data stores.

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  • At your service: An interactive, flexible web-service for translating classification systems and taxonomies

    Whitehead, Brandon; Banchuen, Tawan; Gahegan, Mark; Smart, William; Masoud-Ansari, S (2010-11-11)

    Conference poster
    The University of Auckland Library

    Geoscientists have developed and applied classification systems and taxonomies in an effort to enhance and share their understanding of complex geoscience information. However, the classification systems and taxonomies used throughout the geosciences for land cover and land use, soils, geology are neither static nor universal; the classes that we use to represent the Earth vary considerably with time and from place to place. As a general example, think of a geologic map. There are instances when mapped data contains desirable categories, but the granularity of those categories is not suitable. There are also instances where two or more maps (or data sets) lack the desired categories, or the categories across maps are semantically incompatible. This is to be expected, given that: (i) new science, social and economic agendas change what we may wish to differentiate when we look at a map and (ii) new technologies make differentiation of previously inseperable classes more reliable, thus viable. This paper describes ongoing work to create a web-based semantic translation service that allows users to: (i) experiment with mappings between classification systems and taxonomies; (ii) visualize translation maps using a given mapping; and (iii) persist their translation maps, and share them with others. Semantic equivalence and similarity are supported via underlying ontologies, which also facilitate the merging and re-grouping of classes.

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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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  • Impact of conjugate pneumococcal vaccine on nasopharyngeal S.pneumoniae serotypes and antibiotic susceptibility over 7 years

    Best, Emma; Taylor, S; Tse, F; McBride, C; Stewart, Joanna; Lennon, Diana; Trenholme, A (2015-03-19)

    Conference poster
    The University of Auckland Library

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  • Over-expression of Human Amylin Leads to Oligomerization and beta-cell Dysfunction Associated with Mitochondrial Uncoupling, Activation of c-Jun and Decrease Expression of JNK Interacting Protein-1

    Zhang, Shaoping; Liu, H; Chuang, CL; Li, XL; Au, M; Zhang, L; Cooper, GJS (2012-06-10)

    Conference poster
    The University of Auckland Library

    Over-expression of human amylin (hA) in pancreatic β-cells has been shown to contribute to cytotoxic hA aggregation and islet amyloid formation that can lead to β-cell dysfunction in type-2 diabetes mellitus. We aimed to investigate the functional and molecular changes associated with hA oligomer formation and their relation to β-cell dysfunction and diabetes development using transgenic mouse model that over-expresses hA in their islet β-cells.We showed that both homozygous and hemizygous hA transgenic mice developed spontaneous diabetes with different elevated levels of hA and with different time frame of disease onset and death. Homozygous mice displayed hyperinsulinemia and self-limiting insulin resistance during the pre-diabetic state, whereas by contrast, hemizygous mice had a longer prediabetic phase without insulin resistance. Intracellular and extracellular oligomers were clearly detectable before onset of diabetes with strong correlation with the time of β-cell apoptosis occurred in homozygous but not in hemizygous mice, indicating a difference in the extent of cytotoxic oligomerization between these animals. In addition, RT-qPCR analysis demonstrated progressive decrease in β-cell expression of functional and key regulatory molecules such as insulin, amylin, Pdx1, MafA, Glut2 and GCK. We also detected changes in expression of the mitochondrial membrane protein UCP-2 which contributes to decreased mitochondrial function. Further molecular analysis demonstrated activation of c-Jun/JNK and decrease expression of JNK-interacting protein 1, suggesting their role in mediating beta-cell death/apoptosis. Our studies should lead to a better understanding of the role and regulation of hA-evoked β-cell dysfunction and β-cell death in diabetes

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  • Monitoring the health of New Zealand’s young people: A decade of surveillance research

    Clark, TC; Fleming, T; Bullen, P; Crengle, S; Denny, S; Dyson, B; Peiris John, R; Robinson, E; Rossen, F; Sheridan, J; Teevale, T; Utter, J; Fortune, S; Lewycka, S (2013)

    Conference poster
    The University of Auckland Library

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  • High Pressure and Thermal Processing of kiwifruit puree: the effect on antioxidants and vitamin C

    Soloman, N; Oliveira, Maria (2011-11-30)

    Conference poster
    The University of Auckland Library

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