231 results for Conference poster

  • Bacterially mediated manganese deposition in novel "anelli" within the biofilms of an impacted urban stream

    Smith, JP; Lewis, Gillian (2007-12-02)

    Conference poster
    The University of Auckland Library

    The purpose of this work is to identify bacteria responsible for the formation of manganese containing anelli within stream biofilms, and study their distribution. Manganese oxidising bacteria are part of a diverse group of organisms found commonly within many disparate environments, which deposit manganese and iron biominerals within biofilms and flocs [1]. The purpose of microbial manganese oxidation is poorly understood, but may be associated with energy production, mobilisation of nutrients, protection and/or detoxification [1, 2]. Manganese has a high sorptive capacity for heavy metals, metalloids, and other ions, as well as a strong oxidizing potential, and therefore frequently induces co-precipitation of cations present within the surrounding environment [1]. Within urban streams contaminants such as heavy metals may therefore potentially be concentrated within steam biofilms in the presence of manganese oxidising bacteria.

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  • A novel implantable blood pressure telemetry device: Comparison between Data Sciences and Telemetry Research systems

    Malpas, Simon; Lim, M; McCormick, John; Kirton, RS; Van Vliet, B; Easteal, Allan; Barrett, Carolyn; Guild, Sarah-Jane; Budgett, David (2008-04-05)

    Conference poster
    The University of Auckland Library

    The pending expiry (May 2008) of a Data Sciences (DSI) patent in the area of blood pressure telemetry permits the development of alternative technologies. A key aspect in providing new telemetry systems is a comparison to existing technology. Important aspects include stability of the calibration over time and the ability to capture the pulsitile blood pressure waveform. In a group of 6 rats and 5 rabbits DSI blood pressure transmitters (C40 or D70 models) were implanted in conjunction with Telemetry Research (TR) transmitters. Both systems incorporate a fluid filled catheter of similar dimensions with a biocompatible gel in the tip. The blood pressure waveform was collected via telemetry for up to 2 months after implantation. The signal was sampled at 500 Hz and digitally transmitted to a receiver up to 5 m away The battery of TR transmitter was recharged within the rat using inductive power transfer technology. The pulsitile waveform associated with each heart beat was reflected similarly in all cases although the frequency response of DSI telemeters was limited to ~40 Hz (–3 dB rolloff point). The calibrated offset level between the two transmitters was not more than 5 mmHg at all times over a 2 month period. We conclude that the Telemetry Research blood pressure transmitters offer comparable performance to existing technology but with extra design advantages (rechargeable, co-housing of animals, greater range).

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  • Metabolomics as a novel approach to study mixed species biofilms of stream bacteria exhibiting mutualistic and antagonistic responses

    Washington, Vidya; Villas-Boas, Silas; Lewis, Gillian (2008-08-17)

    Conference poster
    The University of Auckland Library

    Experimental objective / Purpose 1. To investigate the metabolic interactions of bacterial species using metabolic footprint profiling. 2. As proof of concept, microbes exhibiting mutualistic and antagonistic associations were chosen for this study.

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  • Effects of Storm water metal contaminats on microbial communities in stream biofilm revealed by Automated Ribosomal Intergenic Spacer Analysis (ARISA)

    Ancion, Pierre; Lear, Gavin; Lewis, Gillian (2008-08-17)

    Conference poster
    The University of Auckland Library

    Stormwater metal contaminants are known to be a threat to our freshwater environments but little is known about their effects on stream micro-organisms. This project investigates accumulation and release of the most common stormwater metal contaminants (zinc, copper and lead) in stream biofilms and their effects on bacterial populations.

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  • Visualizing multiscale models of the nephron

    Nickerson, David; Terkildsen, J; Hamilton, K; Hunter, Peter (2010-04)

    Conference poster
    The University of Auckland Library

    We present the development of a tool which provides users with the ability to visualize and interact with multiscale models of the nephron – from the scale of models of membrane bound proteins, to that of an individual nephron. A 1-D finite element model of the nephron has been created and is used for both visualization and modeling of the tubule transport. Mathematical models of nephron segments (for example, Weinstein et al., Am. J. Physiol. 292:F1164-F1181, 2007 for the proximal tubule) are embedded in the finite element model. At the cellular level these segment models utilize models encoded in CellML (www.cellml.org) to describe cellular transport kinetics. A user interface has been developed which allows the visualization and interaction with the multiscale nephron models and simulation results. The zinc extension to Firefox (http://www.cmiss.org/cmgui/zinc/) is used to provide an interactive 3-D view of the model(s). This model viewer is embedded in a web page which dynamically presents content based on user input. For example, when viewing the whole nephron model the user might be presented with information on the various embedded segment models as they select them in the 3-D model view. Similarly, the user might choose to focus the model viewer on a cellular model in a particular segment in order to view the various membrane transport proteins. Selecting a specific protein might present the user with a full reference description of the mathematical model governing the behavior of that protein (Nickerson et al., Bioinformatics 24:1112-1114, 2008).

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  • Afferent axonal pathfinding in developing chicken rhomboencephalon

    Kubke, Maria; Wild, JM (2008)

    Conference poster
    The University of Auckland Library

    The developing hindbrain of vertebrates i organized in a series of rhombomeres, each giving rise to specifi c nuclei. The role of this segmentation has been extensively studied with respect to the origin of motor nuclei. The development of afferent innervation, however, has received little attention. Afferent axons enter the brainstem prior to the migration of their central targets and must therefore navigate in the absence of target derived information. Since the target nuclei for each afferent component originates within discrete rhombomeric boundaries, it is possible that the same positional information that is used by neuronal progenitors to defi ne their fi nal fate, may be available to afferent axons to direct them through their initial growth. This study was aimed at determining the normal sequence that characterises the growth of afferent axons in the hindbrain within the context of the site of origin and of the organisation of second order sensory neurons within specifi c rhombomere boundaries. Afferent axons were labelled at different embryonic ages using fl uorescent lipophilic dyes. Crystals of DiI and/or DiO were placed on specifi c exposed nerves or nerve branches of fi xed embryos. Embryos were incubated at 30 C for 18 hrs, after which the hindbrains were dissected, cleared in glycerol and analysed as whole-mount preparations with confocal microscopy. Afferent axons formed a series of fascicles that extended longitudinally along the alar plate, beyond the rhombomeric boundaries that give rise to their target nuclei. At early stages, the degree of organization and segregation of afferent axons did not appear to refl ect the adult patterns. Thus, it appears that the appropriate pathfi nding and fi nal segregation of the afferent components involves an initial profuse growth into the hindbrain, and that proper afferent patterning involves axon retraction and may require the initiation of migration if the central targets towards their fi nal position.

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  • Molecular investigation of protozoan diversity in stream biofilms

    Dopheide, AJ; Lear, Gavin; Lewis, Gillian (2006-11-21)

    Conference poster
    The University of Auckland Library

    This research aims to test the following hypothesis: that molecular biological methods will allow description of protozoan diversity and ecology in streams.

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  • A Computational Model For Cerebral Circulation And Its Application For Haemodynamic Modelling In Vascular Surgeries

    Ho, Harvey; Mithraratne, K; Hunter, Peter (2009)

    Conference poster
    The University of Auckland Library

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  • A Multiscale, Spatially-Distributed Model of Airway Hyper-Responsiveness

    Donovan, Graham; Politi, Antonio; Sneyd, A; Tawhai, Merryn (2009-05)

    Conference poster
    The University of Auckland Library

    Rationale: Airway hyper−responsiveness (AHR), along with airway hyper−sensitivity, is a defining feature of asthma, and greater understanding of this emergent phenomenon may lead to better insight into and treatment of the condition. We seek a multiscale, spatially−distributed, mathematical model of the lung to help us understand the role of airway smooth muscle and parenchymal material in AHR. Methods: Our model couples together the organ scale with the tissue scale in the lung in a multiscale approach to the problem. At the organ level, parenchymal tissue is modeled as a compressible Blatz−Ko material in three dimensions, with expansion and recoil of lung tissue due to tidal breathing. The governing equations of finite elasticity deformation are solved using a finite element method. An airway tree is embedded in this tissue, with airway smooth muscle behavior described by a modified Hai−Murphy cross−bridge model (Wang et al., Biophys. J. 94:2008). Each airway segment is initially assumed to be radially symmetric and longitudinally stiff, and thus the embedded airway tree is essentially 1D. Results: Our spatially−distributed, multiscale model yields organ−level observations while incorporating tissue−level modeling detail. Preliminary results from the integrated model indicate potential use in the study of many phenomena associated with asthmatic AHR, including spatial distribution of ventilation defects, patchiness, and effects of deep inspirations.

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  • Blood flow redistribution following pulmonary micro-embolism

    Clark, Alys; Burrowes, KS; Tawhai, Merryn (2010)

    Conference poster
    The University of Auckland Library

    Occlusion of pulmonary arteries by autologous clot and bead emboli affect pulmonary function by elevating arterial pressures and reducing the number of functional gas exchange units in the lung. The occlusion of multiple arterioles at the acinar level can have a significant impact on pulmonary function. However, the contribution of acinar structure to perfusion distribution and the significance of arteriole occlusion is not well characterized.

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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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  • A synthetic study towards aryl 6,6-spiroacetal analogues of rubromycin

    Choi, Peter; Rathwell, DC; Brimble, Margaret (2008)

    Conference poster
    The University of Auckland Library

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  • Test- retest reliability of an instrumented elastometer for measuring passive stiffness of the levator ani muscle

    Kruger, Jennifer; Nielsen, Poul; Dietz, HP; Taberner, Andrew (2011-08-31)

    Conference poster
    The University of Auckland Library

    Hypothesis / aims of study Clinical evidence demonstrates strong associations between vaginal birth, the incidence of levator ani (LA) muscle injury, and a decrease in muscle function (1). Imaging modalities such as ultrasound and magnetic resonance imaging have provided insight into the nature of LA injury, confirming that it is significantly implicated in the development of pelvic organ prolapse (2). Strain of the LA muscles during delivery of the fetal head is considerable, and childbirth related trauma to the muscle has been shown to occur in 10-30% of women delivering vaginally (1,2). Thus, developing measures to identify a-priori, those who are most likely to suffer from injury during vaginal birth should be a high research priority. The inherent elasticity of the muscle clearly plays a role in the ability of the muscle to accommodate the fetal head. However, measuring passive stiffness of the muscle in vivo remains challenging. The aim of this study was to further develop and test a novel elastometer (3), designed to estimate in vivo passive stiffness produced by the puborectalis component of the LA muscle, where it passes in close contact with the lateral walls of the vagina, from its origin on the pubic ramus. Study design, materials and methods The elastometer used in this study is a more sophisticated version of a previously developed first-generation device (3). The current version of this instrument (Figure 1) boasts enhanced aesthetics and patient friendliness compared to our previous device. Notably, our elastometer can now implement user-defined measurement protocols under automatic computer control in order to measure the force-displacement characteristics of the LA muscle. The device consists of a hand-piece comprising two aluminium arms, with detachable acetyl plastic speculum ends, actuated by a DC servo mechanism via a load cell. A load cell amplifier and displacement transducer are integrated into the hand-piece, providing force and speculum separation measurements. The hand-piece is connected to a control box that communicates with a laptop computer via a USB connection. The control box contains a data-acquisition device (USB-6009, National Instruments), motor drive circuit, and battery-based power supply. A custom MSWindows application implements a closed-loop motor control algorithm on the laptop, records measurements of speculum displacement and force, and provides feedback to the user. The laptop user-interface displays speculum separation and force on a strip chart, together with a force-displacement graph. The design of the speculum end of the elastometer is such that the tip is wider than the neck, (26mm compared to 18mm) to reduce the likelihood of perineal muscles confounding measurement of passive stiffness. Magnetic clips attach the speculum ends to the device which allows for easy cleaning, and provides the facility of attaching speculums of various sizes. Reliability and repeatability of the elastometer was assessed in 12 volunteers. None of the participants had had vaginal surgery, or any contraindications for vaginal examination. All participants were tested twice, 3 to 5 days apart using the same protocol. The speculum was inserted to the level of the puborectalis muscle (2-4 cm from the introitus) orientated in the coronal plane. After initial familiarisation with the device in situ, recording of the data commenced. All participants were encouraged to remain relaxed during the experiment. Data acquisition was automated with the device opening in 20 stepwise increments, to the desired separation, over 60 seconds. Data were collected at a frequency of 100 Hz. Averaged data over a three second period gave 21 data points per test. The procedure was repeated three times, with the initial run being considered as a preconditioning step and not used for data analysis. Statistical analysis was carried out using “R” version 2.12.2 (Copyright (C) 2011 The R Foundation for Statistical Computing). Results from Day 1 were compared with the re-test results using Bland/Altman repeated measures to determine any bias and limits of agreement and Intraclass correlation co-efficient (ICC) to determine reliability across tests and Days. Results The mean age of the 12 participants was 44.3 years (range 26 to 58 years), BMI 26 kg/m2 (range 20.4 to 33.7 kg/m2). Two of these were nulliparous, with the median number of vaginal delivery being 2. Data was visualised in graphic form for each subject across all tests for both days. A representative plot from one subject is shown in Figure 2. ICC’s for the second and third tests respectively were 0.92 (CI 0.89- 0.93), and 0.86 (CI 0.82-0.89). Limits of agreement (from repeated measures Bland Altman) were -2.79 N to +2.31 N, with a mean difference of -0.21 N. Interpretation of results Repeated Bland Altman demonstrates minimal bias with the mean difference close to zero at -0.12 N. The 95% limits of agreement range was slightly over 4 N, and likely to be due to biological variability. The high Intraclass correlation co-efficient for both tests between Days indicate minimal variability of the measurements. Concluding message This second generation elastometer has proved reliable and consistent in the measurement of passive stiffness of the puborectalis muscle in this group of volunteers. These results confirm satisfactory performance of the instrument in preparation for future studies validating this method in clinical and research settings. References 1. DeLancey JO. The hidden epidemic of pelvic floor dysfunction: achievable goals for improved prevention and treatment. Am J Obstet Gynecol. 2005 May;192(5):1488-95. 2. Dietz HP, Simpson JM. Levator trauma is associated with pelvic organ prolapse. BJOG. 2008 Jul;115(8):979-84. 3. Kruger J, et al.. Pelvic floor muscle compliance in Elite nulliparous Athletes. 38th Annual meeting of the International Continence Society. Cario 2008

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  • A case study on frontline perspectives of organizational change: A practitioner-academic partnership to analyse the creation of a Youth Justice entity in Child, Youth and Family

    Webster, Michael; Herrmann, Klaus (2009-11-11)

    Conference poster
    The University of Auckland Library

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  • A frontline perspective of organizational change: Analyzing the creation of a Youth Justice entity in Child, Youth and Family using Lewin, Kotter & Schein's change management and organizational culture models

    Webster, Michael; Herrmann, K (2009-03-19)

    Conference poster
    The University of Auckland Library

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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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  • Managing inpatient hypoglycaemia: A clinical audit

    Coats, A; Marshall, Dianne (2010-09-10)

    Conference poster
    The University of Auckland Library

    Aim To examine nursing management of hypoglycaemic episodes in the hospitalised adult patient with Type 1 or Type 2 Diabetes Mellitus in the general medical/surgical wards at a secondary level hospital. Objective To describe hypoglycaemia treatment patterns in the adult inpatient by examining nursing adherence to the Northland District Health Board hospital hypoglycaemia protocol. Method A retrospective audit of 32 sets of treatment and progress notes identified nurses’ adherence to the protocol for management of inpatient hypoglycaemia . Results Adherence to the individual steps of the protocol was low. Nurses administered the recommended initial treatment in 40.4% of cases. Within 30 minutes of detection, 36.7% episodes were corrected. Medical staff were informed of hypoglycaemia in 11.4% of cases. This step achieved the lowest adherence. Nurses documented 87.7% of episodes. There was a high degree of recurrent hypoglycaemia (71.9%). Discussion It is critical to patient outcomes that the steps of the protocol are undertaken correctly. Failure to provide the recommended treatment resulted in some patients experiencing prolonged episodes. Whilst frequency of nursing documentation of episodes was high, critical assessment of causes and or a management plan were not routinely documented. Nurses did not routinely advise medical staff of episodes, consequently medical review of causes of hypoglycaemia and the management plan occurred infrequently. Failure to review management contributed to the high number of recurrent episodes.

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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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  • 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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  • What Does My Grade Mean?: Differing Assessment Models in Chemistry.

    Salter, David (2009-06)

    Conference poster
    The University of Auckland Library

    Determining whether students have learnt what was intended is a crucial aspect of every course. How this is done and what the outcome shows can however vary greatly. Traditionally in New Zealand, tertiary students’ academic ability is assessed using methods that allow for discrimination between students through norm-referencing, typically producing a single cumulative percentage value which is translated into a letter grade. In contrast, the Government-mandated system for assessing secondary school students in New Zealand is based on a model of criterion-referenced assessment that aims to describe students’ current level of performance with reference to specific performance criteria which are derived from national curriculum statements. Consequently, in progressing from secondary to tertiary education in New Zealand, students experience a major change in the assessment of their performance from being independent of others to being relative to others. A comparison of these two assessment systems used in New Zealand will be presented as well as a description of how standards-based assessment is being introduced into several first-year tertiary chemistry courses as a way to better indicate students’ current capabilities and assist students in the transition between secondary and tertiary education.

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