5,554 results for 2013

  • Successful transitions from early intervention to school-age special education services

    Burgon, J; Walker, Joanne (2013)

    Report
    The University of Auckland Library

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  • Duration of cortisol suppression following a single dose of dexamethasone in healthy volunteers: a randomised double-blind placebo-controlled trial

    Elston, MS; Conaglen, HM; Hughes, C; Tamatea, JAU; Meyer-Rochow, GY; Conaglen, JV (2013-09)

    Journal article
    The University of Auckland Library

    The synthetic glucocorticoid dexamethasone is administered to many patients receiving a general anaesthetic to reduce the risk of postoperative nausea and vomiting. Dexamethasone is known to suppress the hypothalamic-pituitary-adrenal axis; however, the duration of this suppression following the standard anti-emetic intravenous dose of 4 to 8 mg used with anaesthesia is unknown. A randomised controlled double-blind crossover trial assessing the effects of 8 mg intravenous dexamethasone versus saline control was performed in ten healthy male volunteers. The adrenal, thyroid and gonadal axes and glucose levels were assessed over a four-day period after dexamethasone administration. All participants had normal baseline hypothalamic-pituitary-adrenal axis function. No difference in cortisol levels was demonstrated at four or eight hours after dexamethasone administration compared with placebo. At 24 hours post dexamethasone, the cortisol had dropped to less than 5% of baseline and returned to normal during the subsequent day. Increased plasma glucose levels were also observed in the dexamethasone group as compared with placebo. A dose of 8 mg of dexamethasone results in significant suppression of the hypothalamic-pituitary-adrenal axis and elevated plasma glucose levels. The cortisol suppression is maximal at approximately 24 hours post dose.

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  • Bronchiectasis exacerbation study on azithromycin and amoxycillin-clavulanate for respiratory exacerbations in children (BEST-2): Study protocol for a randomized controlled trial

    Chang, AB; Grimwood, K; Wilson, AC; van Asperen, PP; Byrnes, Catherine; O'Grady, K-AF; Sloots, TP; Robertson, CF; Torzillo, PJ; McCallum, GB; Masters, IB; Buntain, HM; Mackay, IM; Ungerer, J; Tuppin, J; Morris, PS (2013-02-20)

    Journal article
    The University of Auckland Library

    Background: Bronchiectasis unrelated to cystic fibrosis (CF) is being increasingly recognized in children and adults globally, both in resource-poor and in affluent countries. However, high-quality evidence to inform management is scarce. Oral amoxycillin-clavulanate is often the first antibiotic chosen for non-severe respiratory exacerbations, because of the antibiotic-susceptibility patterns detected in the respiratory pathogens commonly associated with bronchiectasis. Azithromycin has a prolonged half-life, and with its unique anti-bacterial, immunomodulatory, and anti-inflammatory properties, presents an attractive alternative. Our proposed study will test the hypothesis that oral azithromycin is non-inferior (within a 20% margin) to amoxycillin-clavulanate at achieving resolution of non-severe respiratory exacerbations by day 21 of treatment in children with non-CF bronchiectasis.Methods: This will be a multicenter, randomized, double-blind, double-dummy, placebo-controlled, parallel group trial involving six Australian and New Zealand centers. In total, 170 eligible children will be stratified by site and bronchiectasis etiology, and randomized (allocation concealed) to receive: 1) azithromycin (5 mg/kg daily) with placebo amoxycillin-clavulanate or 2) amoxycillin-clavulanate (22.5 mg/kg twice daily) with placebo azithromycin for 21 days as treatment for non-severe respiratory exacerbations. Clinical data and a parent-proxy cough-specific quality of life (PC-QOL) score will be obtained at baseline, at the start and resolution of exacerbations, and on day 21. In most children, blood and deep-nasal swabs will also be collected at the same time points. The primary outcome is the proportion of children whose exacerbations have resolved at day 21. The main secondary outcome is the PC-QOL score. Other outcomes are: time to next exacerbation; requirement for hospitalization; duration of exacerbation, and spirometry data. Descriptive viral and bacteriological data from nasal samples and blood inflammatory markers will be reported where available.Discussion: Currently, there are no published randomized controlled trials (RCT) to underpin effective, evidence-based management of acute respiratory exacerbations in children with non-CF bronchiectasis. To help address this information gap, we are conducting two RCTs. The first (bronchiectasis exacerbation study; BEST-1) evaluates the efficacy of azithromycin and amoxycillin-clavulanate compared with placebo, and the second RCT (BEST-2), described here, is designed to determine if azithromycin is non-inferior to amoxycillin-clavulanate in achieving symptom resolution by day 21 of treatment in children with acute respiratory exacerbations.Trial registration: Australia and New Zealand Clinical Trials Register (ANZCTR) number http://ACTRN12612000010897. http://www.anzctr.org.au/trial_view.aspx?id=347879. ?? 2013 Chang et al; licensee BioMed Central Ltd.

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  • Respiratory health outcomes 1 year after admission with severe lower respiratory tract infection

    Trenholme, Adrian; Byrnes, Catherine; McBride, C; Lennon, Diana; Chan-Mow, F; Vogel, AM; Stewart, Joanna; Siatu'u, Teuila (2013-08)

    Journal article
    The University of Auckland Library

    Severe lower respiratory infection (LRI) is believed to be one precursor of protracted bacterial bronchitis, chronic moist cough (CMC), and chronic suppurative lung disease. The aim of this study was to determine and to describe the presence of respiratory morbidity in young children 1 year after being hospitalized with a severe LRI. Children aged less than 2 years admitted from August 1, 2007 to December 23, 2007 already enrolled in a prospective epidemiology study (n???=???394) were included in this second study only if they had a diagnosis of severe bronchiolitis or of pneumonia with no co-morbidities (n???=???237). Funding allowed 164 to be identified chronologically, 131 were able to be contacted, and 94 agreed to be assessed by a paediatrician 1 year post index admission. Demographic information, medical history and a respiratory questionnaire was recorded, examination, pulse oximetry, and chest X-ray (CXR) were performed. The predetermined primary endpoints were; (i) history of CMC for at least 3 months, (ii) the presence of moist cough and/or crackles on examination in clinic, and (iii) an abnormal CXR when seen at a time of stability. Each CXR was read by two pediatric radiologists blind to the individuals' current health. Results showed 30% had a history of CMC, 32% had a moist cough and/or crackles on examination in clinic, and in 62% of those with a CXR it was abnormal. Of the 81 children with a readable follow-up X-ray, 11% had all three abnormal outcomes, and 74% had one or more abnormal outcomes. Three children had developed bronchiectasis on HRCT. The majority of children with a hospital admission at <2 years of age for severe bronchiolitis or pneumonia continued to have respiratory morbidity 1 year later when seen at a time of stability, with a small number already having sustained significant lung disease.

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  • Molecular identification of the prey range of the invasive Asian paper wasp

    Ward, Darren; Ram??n-Laca, A (2013-11)

    Journal article
    The University of Auckland Library

    The prey range of the invasive Asian paper wasp, Polistes chinensis antennalis, was studied using molecular diagnostics. Nests of paper wasps were collected from urban residential and salt marsh habitats, larvae were removed and dissected, and DNA in the gut of the paper wasp larvae was amplified and sequenced with cytochrome c oxidase subunit I (COI). Seventy percent of samples (211/299) yielded medium-to high-quality sequences, and prey identification was achieved using BLAST searches in BOLD. A total of 42 taxa were identified from 211 samples. Lepidoptera were the majority of prey, with 39 taxa from 91% of samples. Diptera was a relatively small component of prey (three taxa, 19 samples). Conclusive species-level identification of prey was possible for 67% of samples, and genus-level identification, for another 12% of samples. The composition of prey taken was different between the two habitats, with 2.5?? more native prey species being taken in salt marsh compared with urban habitats. The results greatly extend the prey range of this invasive species. The technique is a more effective and efficient approach than relying on the collection of "prey balls", or morphological identification of prey, for the study of paper wasps.

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  • DNA barcoding and the taxonomy of Microgastrinae wasps (Hymenoptera, Braconidae): Impacts after 8 years and nearly 20000 sequences

    Smith, MA; Fernandez-Triana, JL; Eveleigh, E; Gomez, J; Guclu, C; Hallwachs, W; Hebert, PDN; Hrcek, J; Huber, JT; Janzen, D; Mason, PG; Miller, S; Quicke, DLJ; Rodriguez, JJ; Rougerie, R; Shaw, MR; Varkonyi, G; Ward, Darren; Whitfield, JB; Zaldivar-Riveron, A (2013-03)

    Journal article
    The University of Auckland Library

    Microgastrine wasps are among the most species-rich and numerous parasitoids of caterpillars (Lepidoptera). They are often host-specific and thus are extensively used in biological control efforts and figure prominently in trophic webs. However, their extraordinary diversity coupled with the occurrence of many cryptic species produces a significant taxonomic impediment. We present and release the results of 8 years (2004???2011) of DNA barcoding microgastrine wasps. Currently they are the best represented group of parasitoid Hymenoptera in the Barcode of Life Data System (BOLD), a massive barcode storage and analysis data management site for the International Barcoding of Life (iBOL) program. There are records from more than 20 000 specimens from 75 countries, including 50 genera (90% of the known total) and more than 1700 species (as indicated by Barcode Index Numbers and 2% MOTU). We briefly discuss the importance of this DNA data set and its collateral information for future research in: (1) discovery of cryptic species and description of new taxa; (2) estimating species numbers in biodiversity inventories; (3) clarification of generic boundaries; (4) biological control programmes; (5) molecular studies of host-parasitoid biology and ecology; (6) evaluation of shifts in species distribution and phenology; and (7) fostering collaboration at national, regional and world levels. The integration of DNA barcoding with traditional morphology-based taxonomy, host records, and other data has substantially improved the accuracy of microgastrine wasp identifications and will significantly accelerate further studies on this group of parasitoids.

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  • Model-based identification of motion sensor placement for tracking retraction and elongation of the tongue

    Wang, YK; Nash, Martyn; Pullan, AJ; Kieser, JA; R??hrle, O (2013-04)

    Journal article
    The University of Auckland Library

    Electromagnetic articulography (EMA) is designed to track facial and tongue movements. In practice, the EMA sensors for tracking the movement of the tongue's surface are placed heuristically. No recommendation exists. Within this paper, a model-based approach providing a mathematical analysis and a computational-based recommendation for the placement of sensors, which is based on the tongue's envelope of movement, is proposed. For this purpose, an anatomically detailed Finite Element (FE) model of the tongue has been employed to determine the envelope of motion for retraction and elongation using a forward simulation. Two optimality criteria have been proposed to identify a set of optimal sensor locations based on the pre-computed envelope of motion. The first one is based on the assumption that locations exhibiting large displacements contain the most information regarding the tongue's movement and are less susceptible to measurement errors. The second one selects sensors exhibiting each the largest displacements in the anterior-posterior, superior-inferior, medial-lateral and overall direction. The quality of the two optimality criteria is analysed based on their ability to deduce from the respective sensor locations the corresponding muscle activation parameters of the relevant muscle fibre groups during retraction and elongation by solving the corresponding inverse problem. For this purpose, a statistical analysis has been carried out, in which sensor locations for two different modes of deformation have been subjected to typical measurement errors. Then, for tongue retraction and elongation, the expectation value, the standard deviation, the averaged bias and the averaged coefficient of variation have been computed based on 41 different error-afflicted sensor locations. The results show that the first optimality criteria is superior to the second one and that the averaged bias and averaged coefficient of variation decrease when the number of sensors is increased from 2, 4 to 6 deployable sensors.

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  • Effect of panretinal photocoagulation on corneal sensation and the corneal subbasal nerve plexus in diabetes mellitus

    Misra, Stuti; Ahn, HN; Craig, Jennifer; Pradhan, M; Patel, Dipika; McGhee, Charles (2013-07-02)

    Journal article
    The University of Auckland Library

    PURPOSE: To assess the effects of panretinal photocoagulation (PRP) for diabetic retinopathy (DR) on the human corneal subbasal nerve plexus (SBNP) and to investigate correlations between corneal subbasal nerve (SBN) density, corneal sensitivity, and diabetic peripheral neuropathy. METHODS: Thirty-eight subjects with at least a 10-year history of diabetes mellitus (DM) or DR were included. Subjects were assigned to a PRP group (n = 19), having undergone a treatment of retinopathy in at least one eye or a non-PRP group (n = 19), with no history of PRP. The Michigan Neuropathy Screening Instrument (MNSI) was administered to enable quantification of neuropathic symptoms. Laser scanning in vivo confocal microscopy was performed to capture images of the corneal SBNP to allow determination of SBNP density. Central corneal sensitivity (CST) was evaluated by noncontact aesthesiometry and peripheral vibration perception threshold was measured with a biothesiometer. RESULTS: Mean SBNP densities were 12.27 ?? 4.28 mm/mm??) in the PRP group and 12.75 ?? 3.59 mm/mm?? in the non-PRP group. There were no significant differences in SBNP density (P = 0.71), CST (P = 0.84), MNSI score (P = 0.19), and biothesiometry (P = 0.77) between the PRP and non-PRP groups. When data from both groups (n = 38) were combined, corneal sensitivity was modestly correlated with SBNP density (r = 0.30, P = 0.06), and peripheral biothesiometry (r = 0.26, P = 0.11). CONCLUSIONS: In DM correlation of corneal sensitivity, SBNP density, and peripheral biothesiometry may have a potential role in estimating the severity of peripheral neuropathy. Corneal SBNP density and sensitivity appear to be unaffected by PRP laser treatment compared with non-PRP diabetic eyes.

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  • The influence of loading conditions on equine hoof capsule deflections and stored energy assessed by finite element analysis

    Ramsey, Glenn; Hunter, Peter; Nash, Martyn (2013-07)

    Journal article
    The University of Auckland Library

    The biomechanical effects on the hoof capsule of the location of the centre of pressure of the ground reaction force may be important to understand the functioning of the hoof capsule. This study investigated the effect of changes in loading and contact friction on hoof deflections and elastic energy storage by varying the boundary conditions applied to finite element models. For all cases a load of 10 N kg???1, typical of the peak load in the trot gait, was used. In one scenario the coefficient of contact friction was varied from 0 (frictionless) to 1, at a constant non-zero joint moment, to simulate the effects of restriction of the hoof at the ground surface. In the other scenario a varying joint moment, with contact friction set at 0, was used to move the centre of pressure (COP) forward. Both increasing the ground surface friction and moving the COP forward caused the hoof capsule deflections and stored elastic energy to decrease. Peak strain energy in the capsule occurred when the frictional coefficient was 0 and when the COP was below the centre of rotation of the distal interphalangeal joint. Minimum strain energy occurred when the frictional coefficient was 1.0 and when the COP location was 30 mm forward of the joint centre. Hoof expansion and elastic energy storage are considerably influenced by ground surface friction and centre of pressure location. Therefore model validation studies should account for these parameters. Maximising the energy absorption may explain why heel first landing is preferred.

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  • Changes in In Vivo myocardial tissue properties due to heart failure

    Wang, Yang; Young, Alistair; Cowan, Brett; Nash, Martyn (2013)

    Conference item
    The University of Auckland Library

    A clinical image data driven mechanics analysis was used to quantify changes in tissue-specific passive and contractile material properties for groups of normal and HF patients. We have developed an automated mechanics modelling framework to firstly construct left ventricular (LV) mechanics models based on shape information derived from non-invasive dynamic magnetic resonance images, then to characterise passive tissue stiffness and maximum contractile stress by matching the simulated LV mechanics with data from the dynamic cardiac images. Preliminary statistical analysis revealed that patients with hypertrophy or non-ischemic heart failure exhibited increased passive myocardial stiffness compared to the normals. Elevated maximum contractile stress was also observed for hypertrophic patients. Tissue-specific parameter estimation analysis of this kind can potentially be applied in the clinical setting to provide a more specific disease measure to assist with stratification of HF patients. ?? 2013 Springer-Verlag.

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  • Non-graduate and graduate entry medical students attitudes to psychiatry

    Pillay, SM; Sundram, Frederick; Mullins, D; Rizvi, N; Grant, T; Boohan, M; Murphy, KC (2013-12)

    Journal article
    The University of Auckland Library

    Graduate entry medical students??? views of psychiatry may differ from those of school leavers. This study hypothesised that (i) exposure to a psychiatry attachment is associated with a positive change in attitudes towards psychiatry in both graduate entry and non-graduate entry students, (ii) graduate entry students exhibit a more positive attitude to psychiatry compared to non-graduate entry students and (iii) graduate entry students are more interested in a career in psychiatry than non-graduate entry students. In this study 247 medical students (118 females and 129 males) completing their psychiatry rotation were invited to complete questionnaires examining career choice, attitudes to psychiatry and career attractiveness for a range of specialties including surgery, medicine, general practice and psychiatry before and after their psychiatry attachment. Questionnaires were distributed prior to commencement of their attachment and redistributed on the final day of the attachment. Of the 165 participants in the study, 75 students entered medicine via the traditional route (without a primary degree), 49 entered via the graduate entry programme and 41 had a primary degree. Overall, medical students displayed positive attitudes towards psychiatry. However, while there was an improvement in attitudes towards psychiatry and the career attractiveness of psychiatry on completion of the rotation, no differences were found between graduate and non-graduate entry students. Psychiatry and general practice had lower ratings for career attractiveness than other specialities. No significant changes were found in the first and second choice of specialty. Our results show that improvements in attitude and career attractiveness do not necessarily correlate with increased choice of psychiatry as a specialty. Graduate entry has been considered a possible opportunity for increasing recruitment in psychiatry but our results suggest that this may not be the case. Follow-up studies are required to determine whether career attractiveness correlates with future career choice.

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  • An exploration into diffusion tensor imaging in the bovine ocular lens

    Vaghefi Rezaei, Seyed; Donaldson, Paul (2013)

    Journal article
    The University of Auckland Library

    We describe our development of the diffusion tensor imaging modality for the bovine ocular lens. Diffusion gradients were added to a spin-echo pulse sequence and the relevant parameters of the sequence were refined to achieve good diffusion weighting in the lens tissue, which demonstrated heterogeneous regions of diffusive signal attenuation. Decay curves for b-value (loosely summarizes the strength of diffusion weighting) and TE (determines the amount of magnetic resonance imaging-obtained signal) were used to estimate apparent diffusion coefficients (ADC) and T2 in different lens regions. The ADCs varied by over an order of magnitude and revealed diffusive anisotropy in the lens. Up to 30 diffusion gradient directions, and 8 signal acquisition averages, were applied to lenses in culture in order to improve maps of diffusion tensor eigenvalues, equivalent to ADC, across the lens. From these maps, fractional anisotropy maps were calculated and compared to known spatial distributions of anisotropic molecular fluxes in the lens. This comparison suggested new hypotheses and experiments to quantitatively assess models of circulation in the avascular lens.

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  • Long-term azithromycin for Indigenous children with non-cystic-fibrosis bronchiectasis or chronic suppurative lung disease (Bronchiectasis Intervention Study): a multicentre, double-blind, randomised controlled trial

    Valery, PC; Morris, PS; Byrnes, Catherine; Grimwood, K; Torzillo, PJ; Bauert, PA; Masters, IB; Diaz, A; McCallum, GB; Mobberley, C; Tjhung, I; Hare, KM; Ware, RS; Chang, AB (2013-10)

    Journal article
    The University of Auckland Library

    Background: Indigenous children in high-income countries have a heavy burden of bronchiectasis unrelated to cystic fibrosis. We aimed to establish whether long-term azithromycin reduced pulmonary exacerbations in Indigenous children with non-cystic-fibrosis bronchiectasis or chronic suppurative lung disease. Methods: Between Nov 12, 2008, and Dec 23, 2010, we enrolled Indigenous Australian, Maori, and Pacific Island children aged 1-8 years with either bronchiectasis or chronic suppurative lung disease into a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial. Eligible children had had at least one pulmonary exacerbation in the previous 12 months. Children were randomised (1:1 ratio, by computer-generated sequence with permuted block design, stratified by study site and exacerbation frequency [1-2 vs ???3 episodes in the preceding 12 months]) to receive either azithromycin (30 mg/kg) or placebo once a week for up to 24 months. Allocation concealment was achieved by double-sealed, opaque envelopes; participants, caregivers, and study personnel were masked to assignment until after data analysis. The primary outcome was exacerbation (respiratory episodes treated with antibiotics) rate. Analysis of the primary endpoint was by intention to treat. At enrolment and at their final clinic visits, children had deep nasal swabs collected, which we analysed for antibiotic-resistant bacteria. This study is registered with the Australian New Zealand Clinical Trials Registry; ACTRN12610000383066. Findings: 45 children were assigned to azithromycin and 44 to placebo. The study was stopped early for feasibility reasons on Dec 31, 2011, thus children received the intervention for 12-24 months. The mean treatment duration was 20??7 months (SD 5??7), with a total of 902 child-months in the azithromycin group and 875 child-months in the placebo group. Compared with the placebo group, children receiving azithromycin had significantly lower exacerbation rates (incidence rate ratio 0??50; 95% CI 0??35-0??71; p<0??0001). However, children in the azithromycin group developed significantly higher carriage of azithromycin-resistant bacteria (19 of 41, 46%) than those receiving placebo (four of 37, 11%; p=0??002). The most common adverse events were non-pulmonary infections (71 of 112 events in the azithromycin group vs 132 of 209 events in the placebo group) and bronchiectasis-related events (episodes or investigations; 22 of 112 events in the azithromycin group vs 48 of 209 events in the placebo group); however, study drugs were well tolerated with no serious adverse events being attributed to the intervention. Interpretation: Once-weekly azithromycin for up to 24 months decreased pulmonary exacerbations in Indigenous children with non-cystic-fibrosis bronchiectasis or chronic suppurative lung disease. However, this strategy was also accompanied by increased carriage of azithromycin-resistant bacteria, the clinical consequences of which are uncertain, and will need careful monitoring and further study. Funding: National Health and Medical Research Council (Australia) and Health Research Council (New Zealand).

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  • Dielectrophoretic manipulation and solubility of protein nanofibrils formed from crude crystallins

    Domigan, Laura; Andersen, KB; Sasso, L; Dimaki, M; Svendsen, WE; Gerrard, Juliet; Castillo-Le??n, J (2013-04)

    Journal article
    The University of Auckland Library

    Protein nanofibrils and nanotubes are now widely accepted as having potential for use in the field of bionanotechnology. For this to be a feasible alternative to existing technologies, there is a need for a commercially viable source. Previous work has identified amyloid fibrils formed from crude crystallin proteins as such a source, since these fibrils can be produced in large quantities at a low cost. Applications include use of fibrils as templates for the formation of nanowires or as biosensing scaffolds. There remains a number of practical considerations, such as stability and the ability to control their arrangement. In this study, crude crystallin amyloid fibrils are shown to be stable in a range of biological and clean room solvents, with the fibril presence confirmed by transmission electron microscopy and the thioflavin T fluorescent assay. The fibrils were also immobilised between microelectrodes using dielectrophoresis, which enabled the recording of I-V curves for small numbers of fibrils. This investigation showed the fibrils to have low conductivity, with current values in the range of 10(-10) A recorded. This low conductivity could be increased through modification, or alternately, the fibrils could be used unmodified for applications where they can act as templates or high surface area nanoscaffolds.

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  • The TFOS International Workshop on Contact Lens Discomfort: Executive summary

    Nichols, JJ; Willcox, MDP; Bron, AJ; Belmonte, C; Ciolino, JB; Craig, Jennifer; Dogru, M; Foulks, GN; Jones, L; Nelson, JD; Nichols, KK; Purslow, C; Schaumberg, DA; Stapleton, F; Sullivan, DA (2013-10)

    Journal article
    The University of Auckland Library

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  • The role of the internet in international competitive strategy: The case of Qantas

    Crawford, H; Northey, Gavin (2013)

    Book item
    The University of Auckland Library

    Picture this: Geoff Dixon, the newly appointed Qantas CEO, sat in his office looking at the 2001 annual report. Group revenue was up 12% and Net Passenger Revenue had increased 13% year-on-year. However, despite solid numbers, he must have known that tough times lay ahead for the airline. Online travel agents and buying sites had been taking an increasingly large share in the travel industry, to the point that airlines were losing touch with their customer base. Qantas management had seen the introduction of the internet within the airline sector and realised that online channels were the key to future growth. To them, technology and communication channels were constantly evolving, but the customer???s desire to do business with a brand that provided value was constant. The stakes were high, but Qantas had a plan that would engage customers and deliver benefits to both the consumers and the company.

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  • The Waitangi Tribunal Te Paparahi O Te Raki Inquiry District Wai 1040 Wai 1837

    Hoskins, Te Kawehau (2013-10-14)

    Report
    The University of Auckland Library

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  • A multivariate approach to seasonal adjustment

    Greenaway-McGrevy, Ryan (2013-04)

    Report
    The University of Auckland Library

    This paper suggests a new semi-parametric multivariate approach to seasonal adjustment. The primary innovation is to use a large dimensional factor model of cross section dependence to estimate the trend component in the seasonal decomposition of each time series. Because the trend component is speci??ed to capture covariation between the time series, common changes in the level of the time series are accommodated in the trend, and not in the seasonal component, of the decomposition. The seasonal components are thus less prone to distortion resulting from severe business cycle ??uctuations than univariate ??lter-based seasonal adjustment methods. We illustrate these points this using a dataset that spans the 2007-2009 recession in the US.

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  • What colour do you feel? Cross-modal interactions between colour and texture of food

    Northey, Gavin; Chylinski, M; Ngo, LV (2013)

    Conference item
    The University of Auckland Library

    This research explores the cross-modal interaction between colour and perceived texture, and links its influence with standard marketing metrics. In line with our expectation, we find that colour interacts with actual texture to affect an individual???s overall perception of texture. Specifically, we show that changing hue from red to blue dampens the perception of particular types of texture. Further analysis of the effects of colour on marketing metrics shows that the effect on pleasure and intention to purchase is mediated by the cross-modal perceptions of texture. These results contribute to emerging marketing literature on cross-modal sensory interactions and consumer behaviour.

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  • A team-oriented approach to particle swarms

    Hafiz, Faizal; Abdennour, A (2013-09)

    Journal article
    The University of Auckland Library

    The Particle Swarm Optimization (PSO) is a simple, yet very effective, population-based search algorithm. However, degradation of the population diversity in the late stages of the search, or stagnation, is the PSO's major drawback. Most of the related recent research efforts are concentrated on alleviating this drawback. The direct solution to this problem is to introduce modifications which increase exploration; however it is difficult to maintain the balance of exploration and exploitation of the search process with this approach. In this paper we propose the decoupling of exploration and exploitation using a team-oriented search. In the proposed algorithm, the swarm is divided into two independent teams or sub swarms; each dedicated to a particular aspect of search. A simple but effective local search method is proposed for exploitation and an improvised PSO structure is used for exploration. The validation is conducted using a wide variety of benchmark functions which include shifted and rotated versions of popular test functions along with recently proposed composite functions and up to 1000 dimensions. The results show that the proposed algorithm provides higher quality solution with faster convergence and increased robustness compared to most of the recently modified or hybrid algorithms based on PSO. In terms of algorithm complexity, TOSO is slightly more complex than PSO but much less complex than CLPSO. For very high dimensions (D > 400), however, TOSO is the least complex compared to both PSO and CLPSO.

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