22,135 results for Journal article

  • Structure and properties of melt-processed PVDF/PMMA/polyaniline blends.

    Edmonds, Neil; Easteal, AJ; Cooney, Ralph; Ray, Sudip (2009)

    Journal article
    The University of Auckland Library

    Ternary blends composed of the matrix polymer poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA) with different proportions of thermally doped polyaniline (PAni) using an alkylated dopant (dodecylbenzenesulfonic acid) (DBSA) were prepared by melt mixing. The effectiveness of these blends was compared with the corresponding binary blends of PVDF or PMMA with PAni–DBSA complex. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) measurements, thermal analysis by differential scanning calorimetry (DSC) and morphological studies by optical microscopy and scanning electron microscopy (SEM) were carried out to characterize the blends in light of the interactions between their components and on the resulting electrical conductivity. Though a notable dispersion of PAni–DBSA in the PMMA matrix was incurred along with better conductivity with respect to PVDF/PAni–DBSA and PVDF/PMMA/PAni–DBSA blends, the thin films based on PMMA/PAni–DBSA were found to be fragile in nature. However, the presence of PMMA in the ternary blends of PVDF/PMMA/PAni–DBSA provided improved dispersion of PAni–DBSA in the PVDF/PMMA host matrix as compared to PVDF/PAni–DBSA binary blends. An enhancement in the conductivity by about two orders of magnitude at >5 wt% PAni–DBSA was witnessed in the ternary blends than that of PVDF/PAni–DBSA binary blends. Thin films made of ternary blends of PVDF/PMMA/PAni–DBSA also offered superior mechanical properties and flexibility than that of PMMA/PAni–DBSA binary blends due to the contribution of PVDF in the blend.

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  • Orchid sexual deceit provokes ejaculation

    Gaskett, Anne; Winnick, CG; Herberstein, ME (2008-06)

    Journal article
    The University of Auckland Library

    Sexually deceptive orchids lure pollinators by mimicking female insects. Male insects fooled into gripping or copulating with orchids unwittingly transfer the pollinia. The effect of deception on pollinators has been considered negligible, but we show that pollinators may suffer considerable costs. Insects pollinating Australian tongue orchids (Cryptostylis species) frequently ejaculate and waste copious sperm. The costs of sperm wastage could select for pollinator avoidance of orchids, thereby driving and maintaining sexual deception via antagonistic coevolution or an arms race between pollinator learning and escalating orchid mimicry. However, we also show that orchid species provoking such extreme pollinator behavior have the highest pollination success. How can deception persist, given the costs to pollinators? Sexually‐deceptive‐orchid pollinators are almost exclusively solitary and haplodiploid species. Therefore, female insects deprived of matings by orchid deception could still produce male offspring, which may even enhance orchid pollination.

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  • Establishing gender structural invariance of technology acceptance model (TAM)

    Teo, Timothy (2010)

    Journal article
    The University of Auckland Library

    This study examined pre-service teachers' self-reported intention to use technology. Two hundred and seven-four participants completed a survey questionnaire measuring their responses to four constructs from the Technology Acceptance Model (TAM): perceived usefulness, perceived ease of use, attitude towards use, and behavioural intention to use. Structural Equation Modelling (SEM) was used as the main technique for data analysis. The results of this study showed that the four TAM constructs were significant in explaining pre-service teachers' intention to use technology. Overall, this study indicated that the TAM has the predictive ability to explain the intention to use technology among a sample of educational users. In addition, the results of this study showed that the TAM is structurally invariant by gender. Further research is recommended to gain deeper insights into the structural invariance of the TAM by using different subgroups such as culture, age-groups, and technologies.

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  • Profiling pre-service teachers' awareness and regulation of their own thinking: Evidence from an Asian country

    Lee, CB; Teo, Timothy; Chai, CS (2010)

    Journal article
    The University of Auckland Library

    This study aims to examine pre‐service teachers’ knowledge and regulation of cognition. The authors administered Schraw and Dennison’s Metacognitive Awareness Inventory to 254 pre‐service teachers in Singapore. The results showed no significant difference by educational level on all subscales except for evaluation, which is a subscale of regulation of knowledge. The authors also found no significant mean differences by gender. On the other hand, the results indicate that the mean scores for all subscales were significantly different by teaching experience, except for monitoring (which is a subscale of regulation of knowledge) and procedural knowledge (which is a subscale of knowledge of cognition). The implications of these results are discussed and the authors propose that teacher educators should distinguish pre‐service teachers who have substantial teaching experience prior to their enrollment to teacher training college and those without any prior experience. The experienced pre‐service teachers could help promote their counterparts’ metacognition by sharing their teaching experiences.

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  • The assessment and management of insomnia in primary care.

    Falloon, K; Arroll, Bruce; Elley, Carolyn; Fernando, Antonio (2011)

    Journal article
    The University of Auckland Library

    Insomnia affects a third of people and is a common cause of consultation in primary care History is the main diagnostic tool There are many causes of secondary insomnia, which should be ruled out and treated first Excessive daytime sleepiness should raise questions about obstructive sleep apnoea Primary insomnia is diagnosed after excluding other causes of insomnia. It can be treated effectively by sleep hygiene techniques, by restricting time in bed, or with behavioural interventions Sedatives should be used as a last resort when other approaches have failed because of risks of tolerance and adverse effects

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  • Martin Greschat. Martin Bucer: Ein Reformator und seine Zeit (1491-1551). 2nd edition (Münster: Aschendorff, 2009). 339 pp. ISBN 978-3-402-12780-3.

    Thompson, Nicholas (2011)

    Journal article
    The University of Auckland Library

    Martin Bucer: Ein Reformator und seine Zeit (1491-1551) is a revised and modestly expanded edition of the biography that Martin Greschat published in time to mark the 500th anniversary of Bucer’s birth in 1991. Since 2004 English-speaking readers have benefitted from Stephen Buckwalter’s eminently readable translation. ...

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  • Nature and Impact of Alcohol Messages in a Youth-Oriented Television Series

    Russell, Cristel; Russell, D (2009)

    Journal article
    The University of Auckland Library

    This research contributes to the extant literature on television influence by pairing a stimulus-side approach documenting how information is presented within a television series with a response-side assessment of whether connectedness and exposure to a series influence the processing of that information differently depending on its format. The inquiry focuses on the nature and impact of messages about alcohol contained within a youth-oriented television program. The findings indicate that the recall and perception of the more overt negative messages increase with exposure and that receptiveness to the subtle and less remembered positive messages increases with levels of program connectedness. Highly connected viewers are both more receptive to and in greater agreement with the underlying positive alcohol message communicated in the series. [PUBLICATION ABSTRACT]

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  • Evolution of steel surface composition with heating in vacuum and in air

    Doyle, Colin; Seal, Christopher; James, Bryony (2011-06-15)

    Journal article
    The University of Auckland Library

    X-ray photoelectron spectroscopy (XPS) has been used to investigate the changes in surface composition of three steels as they have undergone heating. The steels were mild steel, and two austenitic stainless steels, commonly designated 304 and 316 stainless steels. XPS measurements were made on the untreated samples, and then following heating for 30 min in vacuo and in a 1 × 10−6 Torr partial pressure of air, at temperatures between 100 °C and 600 °C. Mild steel behaves differently to the two stainless steels under the heating conditions. In mild steel the iron content of the surface increased, with oxygen and carbon decreasing, as a function of increasing temperature. The chemical state of the iron also changed from oxide at low temperatures, to metallic at temperatures above 450 °C. In both stainless steels the amount of iron present in the surface decreased with increasing temperature. The decrease in iron at the surface was accompanied by an increase in the amount of chromium at the steel surface. At temperatures above 450 °C the iron in both 304 and 316 stainless steels showed significant contributions from metallic iron, whilst the chromium present was in an oxide state. In 316 stainless steel heated to 600 °C there was some metallic chromium present in the surface layer. The surfaces heated in air showed the least variation in composition, with the major change being the loss of carbon from the surfaces following heating above 300 °C. There was also a minor increase in the concentration of chromium present on both the stainless steels heated under these conditions. There was also little change in the oxidation state of the iron and chromium present on the surface of these steels. There was some evidence of the thickening of the surface oxides as seen by the loss of the lower binding energy signal in the iron or chromium core level scans. The surfaces heated in vacuum showed a similar trend in the concentration of carbon on the surfaces, however the overall concentration of oxygen decreased throughout the heating of these steels. There were also significant changes in the oxidation state of the iron and chromium on these surfaces with significant amounts or iron and chromium present in the metallic form following heating up to 600 °C. It appears that the carbon contamination on the surfaces plays an important role in the fate of the surface oxide layer for all of the steels heated in a vacuum environment.

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  • The impact of New Zealand CVD risk chart adjustments for family history and ethnicity on eligibility for treatment (PREDICT CVD-5).

    Wells, Linda; Kerr, Andrew; Broad, Joanna; Riddell, Tania; Kenealy, Timothy; Jackson, Rodney (2007)

    Journal article
    The University of Auckland Library

    Aims Current New Zealand cardiovascular (CVD) risk management guidelines advocate targeting treatment to patients with a high 5-year CVD risk assessed using a calculator derived from the Framingham Heart Study. For some high-risk population subgroups, a 5% upward adjustment to their calculated 5-year CVD risk is recommended. We estimated the impact of these adjustments on eligibility for treatment in a primary care setting. Methods Between 2002 and 2006, 23,709 patients visting their primary care provider in Auckland, New Zealand had CVD risk assessments as part of an opportunistic screening programme using PREDICT, a web-based clinical decision support system. We calculated their baseline CVD risk with and without the 5% upward adjustment for family history of premature ischaemic CVD or for being of Māori, Pacific or Indian subcontinent ethnicity. Results A baseline CVD risk could be calculated for 23,693 (99.9%) patients of whom 90% were between ages 35 and 74 years. Unadjusted risk scores classified the majority (70%) below the 10% 5-year risk threshold for specific individualised treatment. A further 11% were between 10 to 15% risk (recommended to receive individualised lifestyle counselling in general practice) and 19% had a greater than 15% risk ( recommended for drug treatment and referral to a dietician in addition to individualised lifestyle counselling). Over a quarter of patients were recorded as having a premature family history of CVD; 21% were Māori, Pacific, or Indian subcontinent and thus met the criteria for a single 5% upward adjustment. This increased the number of people eligible for drug treatment, intensive lifestyle management, and dietician referral by approximately 20% and individualised lifestyle assessment and counselling by 50%. Conclusions The upward adjustments to the calculated CVD risk recommended by the New Zealand CVD risk management guidelines has the potential to substantially increase resource requirements for CVD preventive services in primary care. Moreover the true impact is likely to be underestimated given other adjustment factors related to diabetes risk that were not available in this dataset. Given the impact of these relatively small changes to the CVD risk calculator, locally developed and validated risk equations are urgently needed.

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  • Register in Haydn's String Quartets: Four Case Studies

    November, Nancy (2007)

    Journal article
    The University of Auckland Library

    This study argues that register – a neglected subject of music analysis – assumes the status of a primary parameter in Haydn's string quartets. The claim is substantiated with four case studies. The first movement of Op. 9 No. 4 exemplifies registral techniques that Haydn deployed and developed throughout his career as a quartet composer. Op. 20 No. 2 uses register as a main topic of compositional discourse, and as a means of establishing large-scale connections both within and between movements. The first movement of Op. 76 No. 5 employs register to create stability as well as instability, while the finale of Op. 74 No. 2 epitomises the paradox that registral destabilisation may help to create large-scale coherence.

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  • The impact of inadequate customer collaboration on self-organizing Agile teams

    Hoda, Rashina; Noble, J; Marshall, S (2011)

    Journal article
    The University of Auckland Library

    Context Customer collaboration is a vital feature of Agile software development. Objective This article addresses the importance of adequate customer involvement on Agile projects, and the impact of different levels of customer involvement on real-life Agile projects. Method We conducted a Grounded Theory study involving 30 Agile practitioners from 16 software development organizations in New Zealand and India, over a period of 3 years. Results We discovered that Lack of Customer Involvement was one of the biggest challenges faced by Agile teams. Customers were not as involved on these Agile projects as Agile methods demand. We describe the causes of inadequate customer collaboration, its adverse consequences on self-organizing Agile teams, and Agile Undercover — a set of strategies used by the teams to practice Agile despite insufficient or ineffective customer involvement. Conclusion Customer involvement is important on Agile projects. Inadequate customer involvement causes adverse problems for Agile teams. The Agile Undercover strategies we’ve identified can assist Agile teams facing similar lack of customer involvement.

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  • Epigenetic changes in the hypothalamic proopiomelanocortin and glucocorticoid receptor genes in the ovine fetus after periconceptional undernutrition.

    Stevens, A; Begum, G; Cook, A; Connor, Kristin; Rumball, C; Oliver, Mark; Challis, J; Bloomfield, Francis; White, A (2010-08)

    Journal article
    The University of Auckland Library

    Maternal food restriction is associated with the development of obesity in offspring. This study examined how maternal undernutrition in sheep affects the fetal hypothalamic glucocorticoid receptor (GR) and the appetite-regulating neuropeptides, proopiomelanocortin (POMC) and neuropeptide Y, which it regulates. In fetuses from ewes undernourished from -60 to +30 d around conception, there was increased histone H3K9 acetylation (1.63-fold) and marked hypomethylation (62% decrease) of the POMC gene promoter but no change in POMC expression. In the same group, acetylation of histone H3K9 associated with the hypothalamic GR gene was increased 1.60-fold and the GR promoter region was hypomethylated (53% decrease). In addition, there was a 4.7-fold increase in hypothalamic GR expression but no change in methylation of GR gene expression in the anterior pituitary or hippocampus. Interestingly, hypomethylation of both POMC and GR promoter markers in fetal hypothalami was also identified after maternal undernutrition from -60 to 0 d and -2 to +30 d. In comparison, the Oct4 gene, was hypermethylated in both control and underfed groups. Periconceptional undernutrition is therefore associated with marked epigenetic changes in hypothalamic genes. Increase in GR expression in the undernourished group may contribute to fetal programming of a predisposition to obesity, via altered GR regulation of POMC and neuropeptide Y. These epigenetic changes in GR and POMC in the hypothalamus may also predispose the offspring to altered regulation of food intake, energy expenditure, and glucose homeostasis later in life.

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  • Contralesional hemisphere control of the proximal paretic upper limb following stroke

    Bradnam, LV; Stinear, Cathy; Barber, Peter; Byblow, Winston (2012)

    Journal article
    The University of Auckland Library

    Cathodal transcranial direct current stimulation (c-tDCS) can reduce excitability of neurons in primary motor cortex (M1) and may facilitate motor recovery after stroke. However, little is known about the neurophysiological effects of tDCS on proximal upper limb function. We hypothesized that suppression of contralesional M1 (cM1) excitability would produce neurophysiological effects that depended on the severity of upper limb impairment. Twelve patients with varying upper limb impairment after subcortical stroke were assessed on clinical scales of upper limb spasticity, impairment, and function. Magnetic resonance imaging was used to determine lesion size and fractional anisotropy (FA) within the posterior limbs of the internal capsules indicative of corticospinal tract integrity. Excitability within paretic M1 biceps brachii representation was determined from motor-evoked potentials during selective isometric tasks, after cM1 sham stimulation and after c-tDCS. These neurophysiological data indicate that c-tDCS improved selective proximal upper limb control for mildly impaired patients and worsened it for moderate to severely impaired patients. The direction of the neurophysiological after effects of c-tDCS was strongly related to upper limb spasticity, impairment, function, and FA asymmetry between the posterior limbs of the internal capsules. These results indicate systematic variation of cM1 for proximal upper limb control after stroke and that suppression of cM1 excitability is not a “one size fits all” approach.

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  • Free, Accurate, Unbiased, Up-to Date Information

    Jordan, VMB (2005)

    Journal article
    The University of Auckland Library

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  • Modulation of trophoblast angiogenic factor secretion by antiphospholipid antibodies is not reversed by heparin.

    Carroll, TY; Mulla, MJ; Han, CS; Brosens, JJ; Chamley, Lawrence; Giles, I; Pericleous, C; Rahman, A; Sfakianaki, AK; Paidas, MJ; Abrahams, VM (2011-10)

    Journal article
    The University of Auckland Library

    PROBLEM  Women with antiphospholipid antibodies (aPL) are at risk of miscarriage and pre-eclampsia, obstetrical disorders associated with reduced trophoblast invasion and spiral artery transformation. aPL target the placenta by binding beta(2) -glycoprotein I (β(2) GPI) on the trophoblast. In this study, we determined whether aPL alter the trophoblast secretion of angiogenic factors and evaluated the effect of low molecular weight heparin (LMWH) on this response. METHOD OF STUDY  First-trimester trophoblast was treated with anti-β(2) GPI antibodies with or without LMWH. Angiogenic factor secretion was measured by enzyme-linked immunosorbent assay. RESULTS  Trophoblast cells produced more vascular endothelial growth factor (VEGF), placenta growth factor (PlGF), and soluble endoglin following exposure to anti-β(2) GPI Abs, and this occurred in both a MyD88-dependent and MyD88-independent manner. LMWH was unable to reverse the effects of the anti-β(2) GPI Abs on trophoblast VEGF secretion, but enhanced PlGF. Strikingly, LMWH upregulated soluble fms-like tyrosine kinase receptor-1 (sFlt-1) secretion independently of aPL. CONCLUSION  This study demonstrates that aPL perturb the secretion of trophoblast angiogenic factors. LMWH does not reverse this effect but exacerbates sFlt-1 secretion, a potent anti-angiogenic factor. These findings may help to explain why women with antiphospholipid syndrome, who are treated with heparin to prevent early pregnancy loss, remain at increased risk of developing late obstetrical complications, such as pre-eclampsia.

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  • Thyroxine: Anatomy of a health scare

    Faasse, KE; Cundy, Timothy; Petrie, Keith (2010-01-02)

    Journal article
    The University of Auckland Library

    Hypothyroidism is a common medical disorder that is easily managed by replacement treatment with synthetic thyroxine. About 70 000 New Zealanders have hypothyroidism and take thyroxine replacement treatment. Since 1973 the only thyroid hormone replacement drug approved and funded by the government for use in New Zealand was the Eltroxin brand, made by GlaxoSmithKline. In 2007 the company moved the manufacture of Eltroxin from Canada to Germany. This resulted in a change in the tablets’ inert ingredients: the new formulation differed in markings, size, and colour and—according to some reports—also in taste and rate of dissolution on the tongue. The active ingredient (thyroxine) remained unchanged and continued to be made in Austria.

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  • The Politics of Erasure: Implications for Latino/a Education

    Jaramillo, Nathalia; McLaren, Peter (2007)

    Journal article
    The University of Auckland Library

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  • The health of children in sole-parent families in New Zealand: Results of a population-based cross-sectional survey

    Tobias, M; Kokaua, J; Gerritsen, Sarah; Templeton, R (2010)

    Journal article
    The University of Auckland Library

    Objective: To investigate whether children in sole-parent families in New Zealand bear excess risks of poor mental and physical health relative to children in two parent families. Data sources and statistical methods: The data source was the 2006/07 New Zealand Health Survey, a nationally representative household survey that sampled 502 children (5-14 years) of sole mothers and 1,281 children of partnered mothers. Results: Children of sole mothers were 1.26 (0.94 - 2.69) times as likely as children of partnered mothers to return a low PhS score. Adjusting for maternal health and family socio-economic disadvantage eliminated this weak association (which in any case was of borderline statistical significance). Children of sole mothers were more than twice as likely as children of partnered mothers to return a low PsS score, adjusting for demographic variables only. Conclusions: There is only a weak negative association (if any) between sole-parenting and child physical health, but a stronger association with child mental health - consistent with most of the New Zealand and international literature. The association with child mental health is largely (but possibly not completely) 'explained' by the poorer mental health of sole-parents and the poorer socio-economic circumstances of single-parent families (on average). Implications: These findings support policies aiming to improve access of sole-parents and their children to community mental health services, and (more especially) policies aiming to ameliorate the disadvantaged economic circumstances of single parent families.

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  • Should we prescribe diuretics for patients with prediabetes and hypertension

    Arroll, Bruce; Kenealy, Timothy; Elley, Carolyn (2008-12-13)

    Journal article
    The University of Auckland Library

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  • 8'-Methoxy-3H-spiro[1-naphthofuran-2,2'-chroman]

    Clark, George; Tsang, Kit; Brimble, Margaret (2006)

    Journal article
    The University of Auckland Library

    The crystal structure of the title compound, C21H18O3, has been determined to establish the relative stereochemistry at the spiro ring junction. Each O atom adjacent to the junction lies axial to the neighbouring ring; this is presumably due to anomeric effects.

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