91,714 results

  • Research-informed teaching and teaching-informed research: the Contemporary Marketing Practices (CMP) living case study approach to understanding marketing practice

    Little, VJ; Brookes, Richard; Palmer, RA (2008)

    Journal article
    The University of Auckland Library

    Purpose ??? This paper aims to demonstrate how a Contemporary Marketing Practices (CMP)-based living case study approach can be used to enhance student learning, and to develop new theory about marketing practice. Design/methodology/approach ??? The paper compares and contrasts teaching cases and research cases to create context. It then describes two examples of the living case study approach: one project directed at understanding the impact of information technologies (IT) on marketing practice, and the other at examining managerial understandings of customer value. Findings ??? The study finds that a living case approach extends insight into antecedents and consequences of marketing practice, consistent with CMP research objectives. New conceptual frameworks for the IT adoption process and conceptions of customer value are co-created by executive students and the authors. It shows that managers are able contributors to theory development. The paper concludes that the living case approach provides a rich ???zone of mutuality??? between research and teaching. Research limitations/implications ??? Action learning can be used in business schools to enhance theoretical and practical understanding of complex process-based phenomena. Practical implications ??? The living case study is suited to post-experience students rather than undergraduates. In addition to considering the nature of the student body, faculty should also consider fit with their personal competencies and the curriculum prior to taking this approach. However, it should be done so advisedly. Originality/value ??? The study stimulates reflection on alternative approaches to teaching and learning in executive education, and to theory development in marketing practice.

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  • Silicifying Biofilm Exopolymers on a Hot-Spring Microstromatolite: Templating Nanometer-Thick Laminae

    Handley, Kim; Turner, Susan; Campbell, Kathleen; Mountain, BW (2008-08)

    Journal article
    The University of Auckland Library

    Exopolymeric substances (EPS) are an integral component of microbial biofilms; however, few studies have addressed their silicification and preservation in hot-spring deposits. Through comparative analyses with the use of a range of microscopy techniques, we identified abundant EPS significant to the textural development of spicular, microstromatolitic, siliceous sinter at Champagne Pool, Waiotapu, New Zealand. Examination of biofilms coating sinter surfaces by confocal laser scanning microscopy (CLSM), environmental scanning electron microscopy (ESEM), cryo-scanning electron microscopy (cryo-SEM), and transmission electron microscopy (TEM) revealed contraction of the gelatinous EPS matrix into films (approximately 10 nm thick) or fibrillar structures, which is common in conventional SEM analyses and analogous to products of naturally occurring desiccation. Silicification of fibrillar EPS contributed to the formation of filamentous sinter. Matrix surfaces or dehydrated films templated sinter laminae (nanometers to microns thick) that, in places, preserved fenestral voids beneath. Laminae of similar thickness are, in general, common to spicular geyserites. This is the first report to demonstrate EPS templation of siliceous stromatolite laminae. Considering the ubiquity of biofilms on surfaces in hot-spring environments, EPS silicification studies are likely to be important to a better understanding of the origins of laminae in other modern and ancient stromatolitic sinters, and EPS potentially may serve as biosignatures in extraterrestrial rocks.

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  • Jurassic hot spring deposits of the Deseado Massif (Patagonia, Argentina): Characteristics and controls on regional distribution

    Guido, DM; Campbell, Kathleen (2011-06-01)

    Journal article
    The University of Auckland Library

    The Deseado Massif, Santa Cruz Province, Argentinean Patagonia, hosts numerous Middle to Late Jurassic age geothermal and epithermal features represented by siliceous and calcareous chemical precipitates from hot springs (sinters and travertines, respectively), hydrothermal breccias, quartz veins, and widespread hydrothermal silicification. They indicate pauses in explosive volcanic activity, marking the final stages in the evolution of an extensive Jurassic (ca. 178-151 Ma) volcanic complex set in a diffuse extensional back-arc setting heralding the opening of the Atlantic Ocean. Published paleo-hot spring sites for the Deseado Massif, plus additional sites identified during our recent field studies, reveal a total of 23 locations, five of which were studied in detail to determine their geologic and facies associations. They show structural, lithologic, textural and biotic similarities with Miocene to Recent hot spring systems from the Taupo and Coromandel volcanic zones, New Zealand, as well as with modern examples from Yellowstone National Park, U.S.A. These comparisons aid in the definition of facies assemblages for Deseado Massif deposits - proximal, middle apron and distal siliceous sinter and travertine terraces and mounds, with preservation of many types of stromatolitic fabrics - that likely were controlled by formation temperature, pH, hydrodynamics and fluid compositions. Locally the mapped hot spring deposits largely occur in association with reworked volcaniclastic lacustrine and/or fluvial sediments, silicic to intermediate lava domes, and hydrothermal mineralization, all of which are related to local and regional structural lineaments. Moreover, the numerous geothermal and significant epithermal (those with published minable resources) deposits of the Deseado Massif geological province mostly occur in four regional NNW and WNW hydrothermal-structural belts (Northwestern, Northern, Central, and Southern), defined here by alignment of five or more hot spring deposits and confirmed as structurally controlled by aeromagnetic data. The Northern and Northwestern belts, in particular, concentrate most of the geothermal and epithermal occurrences. Hence, Jurassic hydrothermal fluid flow was strongly influenced by the most dominant and long-active geological boundaries in the region, the outer limits of the Deseado Massif 'horst' itself. (C) 2011 Elsevier B.V. All rights reserved.

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  • Investigation and management of congestive heart failure.

    Arroll, Bruce; Doughty, Robert; Andersen, V (2010)

    Journal article
    The University of Auckland Library

    Congestive heart failure is a common condition that increases in prevalence with increasing age. In 2003, guidance from the National Institute for Health and Clinical Excellence acknowledged that the ???rising epidemic of heart failure??? is partly the result of people living longer and the more effective treatments for coronary heart disease now available. It also acknowledged, however, that average life expectancy is only about three years after diagnosis, which is much worse than for many other serious illnesses such as cancer of the breast or colon.1 The condition is associated with poor quality of life, frequent hospital admissions, and poor survival,2 although this may have changed with the advent of better treatments. Community estimates of prevalence vary from 1.6 to 4.6 cases per 1000 in men aged 45-74 years and from 0.9 to 2.2 cases per 1000 in women. About 1% of men develop heart failure after age 75 and almost 2% after 80 years.3 This review discusses the immediate management of patients who present with the clinical syndrome of heart failure (usually a combination of dyspnoea, fatigue, exercise intolerance, and fluid retention) and the management of chronic congestive heart failure. It is based on evidence from guidelines, randomised controlled trials, and population cohorts followed for many years. We also emphasise the distinction between heart failure with low ejection fraction and heart failure with preserved ejection fraction because although plenty of evidence exists on how to treat the first entity very little exists on how to treat the second.

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  • Time to abandon the bio-bio-bio model of psychosis: Exploring the epigenetic and psychological mechanisms by which adverse life events lead to psychotic symptoms

    Read, John; Bentall, RP; Fosse, R (2009-10)

    Journal article
    The University of Auckland Library

    Mental health services and research have been dominated for several decades by a rather simplistic, reductionistic focus on biological phenomena, with minimal consideration of the social context within which genes and brains inevitably operate. This ???medical model??? ideology, enthusiastically supported by the pharmaceutical industry, has been particularly powerful in the field of psychosis, where it has led to unjustified and damaging pessimism about recovery. The failure to find robust evidence of a genetic predisposition for psychosis in general, or ???schizophrenia??? in particular, can be understood in terms of recently developed knowledge about how epigenetic processes turn gene transcription on and off through mechanisms that are highly influenced by the individual???s socio-environmental experiences. To understand the emerging evidence of the relationship between adverse childhood events and subsequent psychosis, it is necessary to integrate these epigenetic processes, especially those involving the stress regulating functions of the HPA axis, with research about the psychological mechanisms by which specific types of childhood trauma can lead to specific types of psychotic experiences. The implications, for research, mental health services and primary prevention, are profound. Declaration of Interest: None of the authors have any conflicts of interest in relation to this paper.

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  • Perceptions on the use of Pricing Strategies to stimulate Healthy Eating among Residents of deprived Neighbourhoods: a Focus Group Study

    Waterlander, Willemina; De Mul, A; Schuit, AJ; Seidell, JC; Steenhuis, IHM (2010)

    Journal article
    The University of Auckland Library

    Background: Pricing strategies are mentioned frequently as a potentially effective tool to stimulate healthy eating, mainly for consumers with a low socio-economic status. Still, it is not known how these consumers perceive pricing strategies, which pricing strategies are favoured and what contextual factors are important in achieving the anticipated effects. Methods: We conducted seven focus groups among 59 residents of deprived neighbourhoods in two large Dutch cities. The focus group topics were based on insights from Rogers' Diffusion of Innovations Theory and consisted of four parts: 1) discussion on factors in food selection; 2) attitudes and perceptions towards food prices; 3) thinking up pricing strategies; 4) attitudes and perceptions regarding nine pricing strategies that were nominated by experts in a former Delphi Study. Analyses were conducted with Atlas.ti 5.2 computer software, using the framework approach. Results: Qualitative analyses revealed that this group of consumers consider price to be a core factor in food choice and that they experience financial barriers against buying certain foods. Price was also experienced as a proficient tool to stimulate healthier food choices. Yet, consumers indicated that significant effects could only be achieved by combining price with information and promotion techniques. In general, pricing strategies focusing on encouraging healthy eating were valued to be more helpful than pricing strategies which focused on discouraging unhealthy eating. Suggested high reward strategies were: reducing the price of healthier options of comparable products (e.g., whole meal bread) compared to unhealthier options (e.g., white bread); providing a healthy food discount card for lowincome groups; and combining price discounts on healthier foods with other marketing techniques such as displaying cheap and healthy foods at the cash desk. Conclusion: This focus group study provides important new insights regarding the use of pricing strategies to stimulate healthy eating. The observed perceptions and attitudes of residents of deprived neighbourhoods can be integrated into future experimental studies and be used to reveal if and how pricing strategies are effective in stimulating healthy eating.

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  • Wt1a, Foxc1a, and the Notch mediator Rbpj physically interact and regulate the formation of podocytes in zebrafish

    O'Brien, LL; Grimaldi, M; Kostun, Z; Wingert, RA; Selleck, R; Davidson, Alan (2011-10-15)

    Journal article
    The University of Auckland Library

    Podocytes help form the glomerular blood filtration barrier in the kidney and their injury or loss leads to renal disease. The Wilms' tumor suppressor-1 (Wt1) and the FoxC1/2 transcription factors, as well as Notch signaling, have been implicated as important regulators of podocyte fate. It is not known whether these factors work in parallel or sequentially on different gene targets, or as higher-order transcriptional complexes on common genes. Here, we use the zebrafish to demonstrate that embryos treated with morpholinos against wt1a, foxc1a, or the Notch transcriptional mediator rbpj develop fewer podocytes, as determined by wt1b, hey 1 and nephrin expression, while embryos deficient in any two of these factors completely lack podocytes. From GST-pull-downs and co-immunoprecipitation experiments we show that Wt1a, Foxc1a, and Rbpj can physically interact with each other, whereas only Rbpj binds to the Notch intracellular domain (NICD). In transactivation assays, combinations of Wt1. FoxC1/2, and NICD synergistically induce the Hey1 promoter, and have additive or repressive effects on the Podocalyxin promoter, depending on dosage. Taken together, these data suggest that Wt1, FoxC1/2, and Notch signaling converge on common target genes where they physically interact to regulate a podocyte-specific gene program. These findings further our understanding of the transcriptional circuitry responsible for podocyte formation and differentiation during kidney development. (C) 2011 Elsevier Inc. All rights reserved.

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  • Non-compliance with growth hormone treatment in children is common and impairs linear growth

    Cutfield, Wayne; Behrensdorf Derraik, Jose; Gunn, Alistair; Reid, K; Delany, T; Robinson, Elizabeth; Hofman, Paul (2011)

    Journal article
    The University of Auckland Library

    Background: GH therapy requires daily injections over many years and compliance can be difficult to sustain. As growth hormone (GH) is expensive, non-compliance is likely to lead to suboptimal growth, at considerable cost. Thus, we aimed to assess the compliance rate of children and adolescents with GH treatment in New Zealand. Methods: This was a national survey of GH compliance, in which all children receiving government funded GH for a four-month interval were included. Compliance was defined as ???85% adherence (no more than one missed dose a week on average) to prescribed treatment. Compliance was determined based on two parameters: either the number of GH vials requested by the family or the number of empty GH vials returned. Findings: 177 patients were receiving GH in the study period, aged 12.1 ?? 8.1 years. The rate of returned vials, but not number of vials requested, was positively associated with HVSDS (p<0.05). GHret was therefore used for subsequent analyses. 66% of patients were non-compliant, and this outcome was not affected by sex, age or clinical diagnosis. However, Maori ethnicity was associated with a lower rate of compliance. Interpretation: An objective assessment of compliance such as returned vials is much more reliable than compliance based on parental or patient based information. Non-compliance with GH treatment is common, and associated with reduced linear growth. Non-compliance should be considered in all patients with apparently suboptimal response to GH treatment.

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  • Which population level environmental factors are associated with asthma, rhinoconjunctivitis and eczema? Review of the ecological analyses of ISAAC Phase One

    Asher, Monica Innes; Stewart, Alistair; Mallol, J; Montefort, S; Lai, CKW; and the ISAAC Phase One Study Group; Ait-Khaled, N; Odhiambo, J; Clayton, Tadd; Mitchell, Edwin; Ellwood, Philippa (2010-01-21)

    Journal article
    The University of Auckland Library

    The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13-14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence. The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit.

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  • Signal Transducer and Activator of Transcription (STAT)-5A and STAT5B Differentially Regulate Human Mammary Carcinoma Cell Behavior

    Tang, Jianzhong; Zuo, ZH; Kong, XJ; Steiner, Michael; Yin, ZN; Perry, Johanna; Zhu, T; Liu, Dongxu; Lobie, Peter (2010-01)

    Journal article
    The University of Auckland Library

    Increased activation of signal transducer and activator of transcription (STAT)-5 has been reported in various malignancies including mammary carcinoma. However, it is only recently that potentially distinct roles of STAT5A and STAT5B in neoplasia have begun to emerge. Herein we systematically delineate the functions of STAT5A and STAT5B in human mammary carcinoma cell lines MCF-7 and T47D. Forced expression of constitutively active (CA) STAT5A enhanced both survival and anchor-age-independent growth of human mammary carcinoma cells but concordantly suppressed cell motility as revealed in colony scattering, cell migration, and invasion assays. In contrast, forced expression of CA STAT5B exhibited lower potency than CA STAT5A in enhancing survival and anchorage-independent growth of mammary carcinoma cells and exerted no effects on cell motility. Differential expression of genes that regulate cellular survival and motility was concomitantly observed on forced expression of CA STAT5A or CA STAT5B. Small interfering RNA-mediated depletion of STAT5A significantly impaired anchorage-independent growth of human mammary carcinoma cells, whereas a smaller reduction was observed upon small interfering RNA-mediated depletion of STAT5B. Depletion of endogenous STAT5A also significantly enhanced cell motility, whereas depletion of endogenous STAT5B exhibited no effect. Xenograft studies provided data concordant with the in vitro effects of the two STAT5 isoforms. We therefore demonstrate that STAT5A and STAT5B differentially regulate behavior of human mammary carcinoma cells. (Endocrinology 151: 43-55, 2010)

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  • Lateralization of motor imagery following stroke

    Stinear, Cathy; Fleming, Melanie; Barber, Peter; Byblow, Winston (2007)

    Journal article
    The University of Auckland Library

    Objective: Motor imagery may activate the primary motor cortex (M I) and promote functional recovery following stroke. We investigated whether the hemisphere affected by stroke affects performance and M1 activity during motor imagery.Methods: Twelve stroke patients (6 left, 6 right hemisphere) and eight healthy age-matched adults participated. Experiment 1 assessed the speed and ease of actual and imagined motor performance. Experiment 2 measured corticomotor excitability during imagined movement of each hand separately, and both hands together, using transcranial magnetic stimulation.Results: For control participants, imagined movements were performed more slowly than actual movements, and right-hand MEPs were facilitated when they imagined moving their right hand or both hands together. Patients reported being able to imagine movements with either hand, despite no measurable facilitation of MEN in the stroke-affected hand. In left hemisphere patients, MEPs were facilitated in the left hand during imagery of the right hand and both hands together. In right hemisphere patients, motor imagery did not facilitate MEN in either hand.Conclusions: Motor imagery does not appear to facilitate the ipsilesional W following stroke.Significance: Motor imagery may play a role in rehabilitating movement planning, but its role in directly facilitating corticomotor output appears limited. (c) 2007 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

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  • Phenazine-1-carboxamides: Structure-cytotoxicity relationships for 9-substituents and changes in the H-bonding pattern of the cationic side chain

    Gamage, Swarnalatha; Rewcastle, Gordon; Baguley, Bruce; Charlton, PA; Denny, William (2006)

    Journal article
    The University of Auckland Library

    A series of phenazine-1-carboxamides were prepared, including variations in both chromophore substituents and the nature of the cationic side chain. The novel side-chain analogues were prepared from the corresponding phenazine-1-carboxylic acids via Schmidt conversion to the 1-amines and from the corresponding 1-halides. Structure-cytotoxicity relationships for these compounds in a panel of tumor cell lines showed that there is very limited scope for variation of the structure of the 1-carboxamide side chain, consistent with the recent structural model of how tricyclic carboxamides bind to DNA. There was generally little difference in IC(50)s between parent and P-glycoprotein expressing cell lines, suggesting that most of the compounds are not affected by the presence of this efflux pump.

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  • 2-[Bis(2-bromoethyl)amino]-N-(2-hydroxyethyl)-3,5-dinitrobenzamide .

    Atwell, Graham; Boyd, Peter; Denny, William; Yang, S (2006)

    Journal article
    The University of Auckland Library

    The title compound, C13H16Br2N4O6, is a dinitrobenzamide dibromo mustard. The tetrasubstituted benzene ring is significantly distorted from both planarity and ideal hexagonal symmetry. The molecules assemble in the crystal structure via hydrogen-bonding interactions between the amide groups on adjacent molecules, and by O-HO(nitro) and O-HBr contacts. There are short BrBr contacts (3.388 ??) that are significantly less than the sum of the van der Waals radii of two Br atoms.

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  • [7,16-Dibenzyloxycarbonyl-6,18,15,17-tetramethyldibenzo[b,i][1,4,8,11] tetraazacyclotetradecinato-]nickel(II)

    Boyd, Peter; Challis, JB; Rickard, Clifton (2006)

    Journal article
    The University of Auckland Library

    The title compound, [Ni(C38H34N4O4)], is a four-coordinate nickel(II) complex of the 5,15-dihydro-7,16-bis(benzyloxycarbonyl)-6,18,15,17-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecine ligand, which forms a saddle-shaped molecule with divergent concave surfaces. The molecules assemble in the crystal structure via C-HO interactions with the ester carbonyl O atoms and C-H interactions with the propanediiminate portion of the complex.

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  • Phonemic diversity supports a serial founder effect model of language expansion from Africa.

    Atkinson, Quentin (2011-04-15)

    Journal article
    The University of Auckland Library

    Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. Here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder-effect model of expansion from an inferred origin in Africa. This result, which is not explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.

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  • The contribution of gaining an academic qualification to teachers' professional learning

    Williams, Ruth (2011)

    Journal article
    The University of Auckland Library

    Unprecedented numbers of primary teachers in New Zealand are currently involved in professional learning activities, with practice, in essence, the major focal point. In recent years, however, an increasing trend has emerged for primary teachers to undertake a degree qualification. Although study towards formal tertiary qualifications is acknowledged in the literature as a form of teacher professional development, there is limited research available about the role such study has played in teachers??? professional learning. In this research project, both quantitative and qualitative data were collected, the former from 202 questionnaire respondents; the latter from eight teachers who were interviewed. The findings indicated that the teachers were exposed to an array of new knowledge and perspectives that they reported had impacted on their professional learning, both in terms of their classroom practice and their influence on school-wide practices.

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  • Evolution of ZnO nanostructures in sol-gel synthesis.

    Lee, Jim; Easteal, Allan; Pal, U; Bhattacharyya, Debes (2009)

    Journal article
    The University of Auckland Library

    Evolution of the microstructure and optical properties of ZnO nanoparticles in a mild sol???gel synthesis process is studied. The ZnO nanostructures were prepared by reacting zinc acetate dihydrate with NaOH in water at 50???60 ??C. Evolution of ZnO nanostructures with reaction time is studied using UV???Vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy techniques. During the process of Zn2+ hydroxylation, well defined rod-like crystals were formed within 15 min. Further hydroxylation leads to the formation of a gel-like structure within about 45 min. However, XRD, FT-IR and energy dispersive spectroscopy (EDS) confirmed that these initial products were zinc hydroxyl double salts (Zn-HDS), not ZnO. On ageing the reaction mixture, ZnO nanoparticles with wurtzite structure evolved.

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  • Effect of Metal ion Doping on the Optical Properties of Nanocrystalline ZnO Thin Films.

    Mendoza-Galvan, A; Trejo-Cruz, C; Lee, Jim; Bhattacharyya, Debes; Metson, James; Evans, PJ; Pal, U (2006)

    Journal article
    The University of Auckland Library

    Optical properties of metal (Al, Ag, Sb, and Sn)-ion-implanted ZnO films have been studied by ultraviolet-visible spectroscopy and spectroscopic ellipsometric techniques. The effects of metal-ion doping on the optical band gap (Eg), refractive index (n), and extinction coefficient (k) of nanocrystalline ZnO films have been studied for the similar implantation dose of all the metal ions. The ellipsometric spectra of the ion-implanted samples could be well described by considering an air/roughness/ZnO???M (layer 1)/ZnO (layer 2)/glass model. The band gap of ZnO films increases with Al ion doping and decreases with doping of Ag, Sb, and Sn ions. The refractive index of ZnO films in the visible spectral region increases substantially on Sb and Sn ion doping, while it decreases to some extent with Al ion doping.

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  • Bayesian Inference of Species Trees from Multilocus Data

    Heled, Yosef; Drummond, Alexei (2010)

    Journal article
    The University of Auckland Library

    Until recently, it has been common practice for a phylogenetic analysis to use a single gene sequence from a single individual organism as a proxy for an entire species. With technological advances, it is now becoming more common to collect data sets containing multiple gene loci and multiple individuals per species. These data sets often reveal the need to directly model intraspecies polymorphism and incomplete lineage sorting in phylogenetic estimation procedures. For a single species, coalescent theory is widely used in contemporary population genetics to model intraspecific gene trees. Here, we present a Bayesian Markov chain Monte Carlo method for the multispecies coalescent. Our method coestimates multiple gene trees embedded in a shared species tree along with the effective population size of both extant and ancestral species. The inference is made possible by multilocus data from multiple individuals per species. Using a multiindividual data set and a series of simulations of rapid species radiations, we demonstrate the efficacy of our new method. These simulations give some insight into the behavior of the method as a function of sampled individuals, sampled loci, and sequence length. Finally, we compare our new method to both an existing method (BEST 2.2) with similar goals and the supermatrix (concatenation) method. We demonstrate that both BEST and our method have much better estimation accuracy for species tree topology than concatenation, and our method outperforms BEST in divergence time and population size estimation.

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  • Proper analytic free maps

    Helton, JW; Klep, Igor; McCullough, S (2011)

    Journal article
    The University of Auckland Library

    This paper concerns analytic free maps. These maps are free analogs of classical analytic functions in several complex variables, and are defined in terms of non-commuting variables amongst which there are no relations ??? they are free variables. Analytic free maps include vector-valued polynomials in free (non-commuting) variables and form a canonical class of mappings from one non-commutative domain ....

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