32 results for Conference poster, 2011

  • 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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  • 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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  • 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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  • Household Characteristics of Children Under Two Years Admitted with Lower Respiratory Infection in South Auckland

    Vogel, A; Trenholme, A; Lennon, Diana; McBride, C; Stewart, Joanna; Best, Emma; Mason, H; Siatu'u, Teuila (2011-04-02)

    Conference poster
    The University of Auckland Library

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  • Nonlinear dynamics of an electronic model of one-way coupling in one and two dimensions

    Doud, AB; Breen, Barbara; Grimm, JR; Tanasse, AH; Tanasse, SJ; Lindner, JF; Maxted, K (2011-03-21)

    Conference poster
    The University of Auckland Library

    One-way or unidirectional coupling is a striking example of how topological considerations -- the parity of an array of multistable elements combined with periodic boundary conditions -- can qualitatively influence dynamics. Here we introduce a simple electronic model of one-way coupling in one and two dimensions and experimentally compare it to an improved mechanical model and an ideal mathematical model. In two dimensions, computation and experiment reveal richer one-way coupling phenomenology: in media where two-way coupling would dissipate all excitations, one-way coupling enables soliton-like waves to propagate in different directions with different speeds.

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  • Probing Student Approaches and Engagement in Learning Chemistry at University.

    Salter, David; Simpson, MC; Hamilton, R (2011-06)

    Conference poster
    The University of Auckland Library

    This project aims to identify students’ learning approaches, engagement, attitudes and success in chemistry classes that are service-taught as part of a specified health sciences programme and in chemistry classes that are taught as part of a chemistry major programme. It seeks to determine whether any differences exist in the learning approaches, motivational orientation and engagement, and compare the success of a cohort of students who are required to enrol in a compulsory chemistry course as part of a health sciences degree with that of a cohort of students who choose to enrol in a chemistry course with the possible intention of majoring in chemistry. It is intended that both cognitive and motivational individual difference variables are identified and relationships between students’ goal orientation and university academic success evaluated.

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  • Aged Residential Care Health Utilisation Study (ARCHUS). A randomised controlled trial to reduce acute hospitalisations from residential aged care.

    Broad, J.B; Foster, Susan; Boyd, M.; Kerse, N.; Lumley, T.; Connolly, M.J. (2011)

    Conference poster
    The University of Auckland Library

    Background and Aim Our aim is to reduce avoidable acute hospitalisations of residents of long-term care facilities. Such hospitalisations can cause distress, disruption, and complications for residents. Some conditions have been identified as better managed in the facility providing supports are in place. A randomised controlled trial is underway in Auckland, New Zealand of a targeted, multi-disciplinary team (MDT) to up-skill facility staff. We here outline the study design. Design Clustered randomised controlled trial (~1400 residents) of long-term care facilities, stratified by district health board (DHB). Randomisation and interventions commenced March 2011. Facilities certified for long-term care of older people in greater Auckland are eligible for selection if they have high levels of avoidable hospitalisation. Intervention MDTs supporting facility staff to provide evidence-based care. The supports and services provided comprise an initial stock-take assessment and development of facility plan, direct access to a geriatrician and gerontology nurse specialist (GNS), MDT meetings for individual cases, and provision of targeted education to facility nurses/caregivers, facilitated by a GNS. Education topics are based on modelling of risk factors for avoidable hospitalisation from long-term care in Auckland (2008-2010) and include recognition of illness, wound care, care planning, end-stage dementia care, nutrition/dehydration, family communication, specific clinical coaching with high-risk residents, role modelling of clinical reasoning processes, and provision of benchmarking systems. Control Usual care: the quality assurance, supports, and services routinely provided by the DHB Endpoints Primary endpoints include rate of hospitalisations in which the admission diagnosis code is one of a set pre-identified as being potentially avoidable (“Ambulatory Sensitive Hospitalisations”), emergency admission hospital bed days, and all-cause mortality. Secondary endpoints include number of emergency department presentations and number and type of medications prescribed. Residents’ outcomes will be tracked for 12 months from randomisation using their unique national health identifiers (NHIs).

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  • Molecular basis for binding and subtype selectivity of 1,4-benzodiazepine antagonist ligands of the cholecystokinin receptor

    Cawston, Erin; Sexton, PM; Miller, LJ (2011-01)

    Conference poster
    The University of Auckland Library

    Allosteric intramembranous binding pockets in peptide-binding GPCRs create opportunities to develop novel small molecule drugs with substantial benefit over orthosteric-acting drugs. To gain insights into the molecular determinants of the allosteric binding pocket within cholecystokinin (CCK) receptors, we prepared and characterized a series of receptor constructs in which residues proposed to line this pocket that are distinct in each receptor were reversed (chimeric constructs). Two novel ligands were studied, representing 1,4-benzodiazepine antagonists that differ only in the stereochemistry (S or R) of the 3-position side chain, while exhibiting binding selectivity for either CCK1R or CCK2R, respectively. Radioiodinated 1,4-benzodiazepine ligands were used as tracers in the binding assays. Six mutations within four transmembrane segments of CCK1R and CCK2R were studied. When all six residues were mutated in CCK1R to the corresponding residues in CCK2R, the selectivity of this receptor was completely reversed, yet its peptide-binding selectivity was unaffected. To further investigate which regions may be responsible for this change in selectivity, mutagenesis of the residues within individual transmembrane segments within CCK1R and CCK2R was performed and resulted in minimal impact in binding to the iodinated 1,4-benzodiazepines. Therefore, combining the residue changes within two or three segments were also prepared and studied. This detailed mutational analysis provides important information on the benzodiazepine allosteric binding site present within the CCK receptors and provides insight into ligand-receptor interactions that may be important in selectivity of this allosteric binding pocket within CCK receptors.

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  • High throughput methods for the investigation of the human microbiome

    Lau, Kelvin; Berg, A; Ketley, J; Barer, M (2011-03-09)

    Conference poster
    The University of Auckland Library

    Microorganisms can colonise many sites within the human host, including the skin, gastrointestinal tracts, oronasopharyngeal cavity and urogenital tract. Comprehensive studies of the human microbiome often need to encompass a large number of samples as a consequence of the variety of distinct sites that are colonised, and the significant variation in microbiota that can exist between individuals. For large sample sets, the cost of sequencing and the bioinformatics resources required to process sequence data can be prohibitive, and become limiting factors for the depth of the investigation. ....

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  • A Structure-Based Model Analysis Of Ventilation And Contrast Gas Distribution In The Ovine Lung

    Mitchell, JH; Hoffman, EA; Mitchell, Jennine (2011-05-23)

    Conference poster
    The University of Auckland Library

    Rationale: Sheep are increasingly used as a model for human ventilation, however there are substantive anatomical differences between human and ovine lungs that may affect the gravitational distribution of tissue at rest and during ventilation. Understanding ventilation and gas transport in the ovine lung is important for interpreting measurements acquired via in vivo gas contrast imaging, such as xenon enhanced computed tomography (Xe-CT). In this study a computational model that integrates finite elastic deformation of the soft tissue with distribution of inspired air was applied to the ovine lung to determine whether a model that is consistent with human ventilation and gas distribution in also suitable for the simulation of ventilation in experimental animals. Methods: Xe-CT imaging was acquired in three sheep at the University of Iowa Division of Physiologic Imaging. Image based finite element meshes were constructed for each lung and the airway tree at a positive end expiratory pressure (PEEP) of 25 cmH 20 in prone and supine postures. Ventilation and gas transport were simulated for each animal using a computational model that includes finite deformation elasticity to define the pressure volume relationship of the lung, and time-dependent advective and diffusive transport of inhaled Xe gas. Gravitational deformation was simulated prone and supine, and ventilation was simulated for the prone lung. The specific volume change predicted from the advective flow simulation was compared to specific ventilation calculated using the time constant method that is used in Xe-CT analysis. Results: The finite deformation model accurately predicts the regional tissue density in prone but underestimates the supine gradient. Ventilation simulated in the prone posture for each of the three animals indicates that the ventilation distribution predicted by an advective flow model typically differs from that predicted from the time constant method of analysis. The R 2 correlations between the simulations and time constant calculations were 0.7824, 0.3423 and 0.42881 for each of the three animals. Conclusions: The human-consistent model is inadequate for predicting ventilation in supine sheep, because the model does not include movement of the heart or fluid shifts that were evident in the imaging. However the model is sufficiently predictive for the prone ovine lung. That advective ventilation differs from inert gas transport is consistent with experimental findings that show a correlation of R 2 of 0.66 between specific volume and ventilation calculated from tracer gas mixing (1). Fuld et al (2008) J. Appl. Physiol 104:1174-1184 This abstract is funded by: NIH Grant ROI-HL-064368-06A1

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  • Context and relationship: defining resilience in health social workers

    Adamson, Carole; Beddoe, Elizabeth; Huggard, Peter (2011-11-05)

    Conference poster
    The University of Auckland Library

    A qualitative study of social workers in physical and mental health asked experienced social workers who self-defined as resilient to define the concept and to explore the elements of resiliency within their practice. Initial definition of resilience as a personal characteristic was developed into a strongly contextual and relational construct, the binding feature of which was self-awareness and the capacity to reflect. A strong feature of the social workers’ understanding of resilience was their focus on relationship with colleagues and the quality of professional social work practice with service users. Further reflexive and structural elements in their professional lives were identified, highlighting that resilience within health social workers is in dynamic relationship with the organisational context. A resilience framework derived from current literature and from the research is presented.

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  • Targeting synthetic glycopeptides to MGL on Dermal Dendritic cells

    McIntosh, Julie; Angel, CE; Chen, CJJ; Manning, K; Mansell, Claudia; Agrawai, S; Harris, Paul; Williams, Geoffrey; Squire, Christopher; Brimble, Margaret; Dunbar, Peter (2011-02-14)

    Conference poster
    The University of Auckland Library

    The ability of a peptide vaccine to stimulate T cells in vivo might be improved by specifically targeting the peptide to dendritic cells (DC). The C-type lectin Macrophage Galactose-type lectin, MGL (CD301), has been shown to bind to N-acetyl-galactosamine (GalNAc) and small peptides bearing O-linked GalNAc. Synthetic GalNAc can be produced using relatively simple organic chemistry when compared with the complicated branched sugars that are recognised by other C-type lectins. MGL therefore represents a promising target for the design of synthetic peptide vaccines. We have identified that antigen-presenting cells in human skin express MGL and have confirmed that CD14+ dermal DCs might be targeted via MGL. The intracellular fate of MGL following internalisation was tracked by confocal microscopy. MGL traffics through early endosomes to late endosomes/lysosomes, and colocalises with MHC class I and class II. Synthetic glycopeptides were produced incorporating either native O-linked GalNAc or GalNAc residues linked to the peptide chain via non-native ???Click??? chemistry. Biophysical analysis of the ability of both ???Click??? and native glycopeptides peptides with recombinant MGL confirmed the ability of both these peptides to bind MGL. Ongoing work aims to determine whether targeting to MGL using these synthetic peptides results in efficient presentation of antigen to T cells.

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  • The skeletal effects of the tyrosine kinase inhibitor nilotinib

    O'Sullivan, Susannah; Lin, Jian; Watson, M; Callon, K; Tong, PC; Naot, Dorit; Horne, Anne; Aati, O; Porteous, F; Gamble, G; Cornish, Jillian; Browett, Peter; Grey, Andrew (2011-09)

    Conference poster
    The University of Auckland Library

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  • Diabetes Management by Primary Health Care Nurses in Auckland, New Zealand

    Daly, Barbara; Arroll, B; Sheridan, N; Kenealy, T; Scragg, R (2011-11-04)

    Conference poster
    The University of Auckland Library

    Methods PHC nurses in Auckland (a 26% random sample) were asked to complete postal and telephone questionnaires (86% response rate), on education, experience, knowledge and diabetes management practice, and to log their care given to diabetes patients on a randomly selected day (n=265). Results Responses were received from 287 PHC nurses (86% response rate) comprising 210 practice nurses (PN), 49 district nurses (DN) and 28 specialist nurses (SNs). Most nurses (96%) were able to identify excess body weight as a major risk factor for type 2 diabetes and elevated blood glucose levels (BGLs) or glycosylated haemoglobin (HbA1c) (86%) for diabetes-related complications. In contrast, CV risk factors were less well identified, particularly smoking, although more by SNs (43%) than PNs (14%) and DNs (12%, p=0.0005). CV complications, especially stroke, were less well known than microvascular complications, and by significantly fewer PNs (13%) and DNs (8%) than SNs (36%, p=0.002). Stronger associations were found between nurse???s knowledge of elevated HbA1c as a risk factor for diabetes-related complications and management activities related to BGLs and medication, compared with knowledge of CV risk factors, which was not associated with assessment of blood pressure or knowledge of patient???s total cholesterol or smoking status. The median number of patients consulted on the randomly selected day was one by 38% of PNs, two by 47% of DNs and 4-5 by 57% of SNs. Overall, PNs consulted almost 60% of the patients sampled, while patients consulted by DNs were older and more likely to be European New Zealanders, tobacco uses and have diabetes-related complications and co-morbidities, while SNs consulted by Maori and Pacific patients. Conclusion: There is a need for PHC nurses to increase their knowledge of CV risk factors with more effective management required and particularly of smoking.

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  • Pregnancy Associated Changes in Insulin Signalling in Daughters of Adolescent Ewes

    Oliver, Mark; Hancock, SN; Kenyon, PR; Blair, HT; Pain, S; Morris, S; Phua, Hui; Bloomfield, Francis (2011-09)

    Conference poster
    The University of Auckland Library

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  • Characterisation of a transgenic ovine model of Huntington???s disease

    Reid, Susanne; Handley, R; Patassini, S; Rudiger, S; Keynes, P; McLaughlan, C; Waldvogel, H; Jacobsen, J; MacDonald, M; Gusella, J; Morton, J; Bawden, S; Faull, R; Snell, R (2011-09-11)

    Conference poster
    The University of Auckland Library

    A transgenic ovine model of Huntington???s disease has been developed to enable the examination of the earliest disease changes in a large mammal. Ovis aries were selected because their basal ganglia and cortex is similar to analogous regions of the human brain. Importantly, they live for more than a decade, allowing for the study of the chronic effects of a fulllength HTT expressing transgene. Microinjection of a fulllength human HD cDNA containing 73 polyglutamine repeats under the control of the human promoter, resulted in six transgenic founders varying in copy-number of the transgene.

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  • Talking Allowed!

    Davies, Maree; Sinclair, A (2011)

    Conference poster
    The University of Auckland Library

    Research on the Paideia Method (a method for discussing a topic) was conducted in 20 classrooms across five schools, of varying socioeconomic environments (ages 11-13) in Auckland, New Zealand, in 2010. The researchers sought to further examine the results from their pilot study of the Paideia Seminar, entitled 'Talking Allowed: I like it when the teacher lets us talk without telling us what to say', trialed in 2008 (Sinclair & Davies, 2011). In addition, in order to provide the optimum conditions to prepare the students for the face-to-face seminars, an online component (open source software) was added as an alternative medium to assist students in their preparation. The research questions were: What happens to the Nature of Interaction, and the Complexity of the Discussion when students participate in a Paideia Seminar, and an on-line discussion in preparation for the face-to-face seminar? What is the optimal role of the teacher when participating in a Paideia Seminar and an on-line discussion to increase complexity of discussion?

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  • Examination of miRNAs involved in programming human T cells

    Sheppard, Hilary; Feisst, Vaughan; Brooks, Anna; Dunbar, R (2011-09)

    Conference poster
    The University of Auckland Library

    The differentiation state of CD8+ T cells is an important determinant of their ability to eradicate tumours and infection; progressive differentiation appears to lead to a decreased effectiveness. Therefore the development of effective immunotherapies depends on a better understanding of the molecular mechanisms that underlie T cell differentiation. Several key cell surface markers are down regulated as differentiation progresses so we can define CD8+ T cells into 4 main subsets (see Fig. 1). Each subset is generated by a specific transcriptional programme. Our hypothesis is that miRNAs are important in this process of T cell differentation. If you take a cancer patient???s cells, expand in vitro, and re-infuse to the patient, the phenotype of the T cell will determine its efficacy in vivo. We have found that we can pre-condition T cells using the cytokine IL21 to have a more favourable phenotype than using the traditionally used cytokine IL2 (data not shown). We aim to explore this cytokine driven differentiation process by examining the miRNAs involved.

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  • Potential Uses of Adipose Derived Stem Cells in Reconstructed Human Skin

    Feisst, Vaughan; Dunbar, PR (2011-01-30)

    Conference poster
    The University of Auckland Library

    Adipose derived stem cells (ASC) are multipotent adult mesenchymal stem cells with great potential for use in regenerative medicine. ASC are obtained from lipoaspirate, making them a relatively abundant and accessible source of adult stem cells. The aim of this investigation was to evaluate whether ASC can substitute dermal fibroblasts, and provide benefits for neovascularisation, in reconstructed human skin.

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