89,483 results

  • Antisaccadic eye movements and attentional asymmetry in schizophrenia in three Pacific populations

    Allen, JS; Lambert, Anthony; Johnson, FYA; Schmidt, K; Nero, KL (1996)

    Journal article
    The University of Auckland Library

    Antisaccadic eye movements were examined in 50 patients with schizophrenia and in 77 controls in three Pacific populations, namely New Zealand, Palau and Papua New Guinea. Despite the great biocultural variation encompassed by these three populations

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  • Extending Supramolecular Fullerene-Porphyrin Chemistry to Pillared Metal-Organic Frameworks

    Sun, D; tham, FS; Reed, CA; Boyd, PDW (2002)

    Journal article
    The University of Auckland Library

    Porphyrins and fullerenes are spontaneously attracted to each other. This supramolecular recognition element can be exploited to produce ordered arrays of interleaved porphyrins and fullerenes. C60???H2TpyP???Pb(NO3)2???1.5TCE (H2TpyP = tetra-4-pyridylporphyrin; TCE = 1,1,2,2-tetrachloroethane) crystallizes in the tetragonal P4/n space group and the structure has been solved to high resolution. The Pb2+ ions connect the pyridylporphyrins in infinite sheets with an interlayer spacing of 12.1 ??. The fullerenes are intercalated between these layers, acting as pillars. The 6:6 ring juncture bonds of C60 are centered over the porphyrins, bringing the layers into strict tetragonal register. This arranagement identifies the fullerene???porphyrin interaction as a structure-defining element. The same motif is seen in a related ribbon structure having C70 intercalated into HgI2-linked H2TpyTP. The supramolecular design principles involved in assembling these chromophores may have applications in materials science.

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  • Synthesis, structure and properties of ferrocene functionalized porphyrins

    Hodgson, MC; Burrell, AK; Boyd, Peter; Brothers, Penelope; Rickard, CEF (2002-01-01)

    Journal article
    The University of Auckland Library

    A series of free-base and metallated mixed ferrocenamido- and pivalamidophenylporphyrins have been prepared from the ??,?????,????????,??????????? isomer of 5,10,15,20-tetra(o-aminophenyl)porphyrin. The X-ray crystal structure of the iron(III) ??,?????,????????,???????????-5,10,15,20-tetrakis(o-ferrocenamidophenyl)- porphyrin bromide has been determined and compared with related structures of cobalt(III) ??,?????,????????,???????????- 5,10,15,20-tetrakis(o-pivalamidophenyl)porphyrin bromide pyridine and the free base ??,?????,????????,???????????- 5,10,15,20-tetrakis(o-pivalamidophenyl)porphyrin. In both metalloporphyrins the coordinated axial bromides are contained in the cavity formed by the appended pickets with all the amide N-H bonds directed toward the anion.

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  • Atom transfer reactions of (TTP)Ti(eta(2)-3-hexyne): Synthesis and molecular structure of trans-(TTP)Ti[OP(Oct)(3)](2)

    Thorman, JL; Young, VG; Boyd, Peter; Guzei, IA; Woo, LK (2001)

    Journal article
    The University of Auckland Library

    Atom and group transfer reactions were found to occur between heterocumulenes and (TTP)Ti(eta (2)-3-hexyne), 1 (TTP = meso-5,10,15,20-tetra-p-(olylporphyrina dianion). The imido derivatives (TTP)Ti=NR (R = Pr-i, 2; Bu-i, 3) were produced upon treatme

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  • Bis(ferrocenyl)porphyrins. Compounds with strong long-range metal-metal coupling

    Burrell, AK; Campbell, WM; Jameson, GB; Officer, DL; Boyd, Peter; Zhao, Z; Cocks, PA; Gordon, KC (1999)

    Journal article
    The University of Auckland Library

    The condensation of a dipyrromethane with ferrocene aldehyde leads to a single atropisomer of ??,??-5,15-bis(ferrocenyl)-2,8,12,18-tetrabutyl-3,7,13,17-tetramethylporphyrin 1; electrochemistry of 1 and Ni-1 reveals two consecutive ferrocene-based one-electron oxidation waves, which are separated by 0.19 and 0.41 V, respectively.

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  • A facile synthesis of fused aromatic spiroacetals based on the 3,4,3',4'-tetrahydro-2,2'-spirobis(2H-1-benzopyran) skeleton

    Brimble, Margaret; Flowers, Christopher; Trzoss, Michael; Tsang, Kit (2006)

    Journal article
    The University of Auckland Library

    The facile synthesis of a series of aromatic 6,6-spiroacetals based on the parent 3,4,3???,4???-tetrahydro-2,2???-spirobis(2H-1-benzopyran) heterocyclic system is reported. Key steps included the use of a Sonogashira coupling for the synthesis of an aryl acetylene that was coupled to an aryl aldehyde to form a propargyl alcohol intermediate. Hydrogenation of the alkynol followed by oxidation produced a masked dihydroxy ketone that upon treatment with trimethylsilyl bromide underwent deprotection and cyclisation to the fused aromatic spiroacetal.

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  • Total Synthesis of Paecilospirone

    Yuen, TY; Yang, Sung Hyun; Brimble, Margaret (2011)

    Journal article
    The University of Auckland Library

    In 2000, Namikoshi et al. reported the isolation and structural elucidation of a novel [5,6]-bisbenzannulated spiroacetal [1] from the marine fungus Paecilomyces sp. [2] This unique spiro[chroman-2,1???(3???H)-isobenzofuran] derivative was identified as a potential antimitotic agent (20 % inhibition at 50 mm) using an assay screening for microtubule assembly inhibitors and was subsequently named paecilospirone (1).

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  • Maternal influence on philopatry and space use by juvenile brushtail possums (Trichosurus vulpecula).

    Blackie, HM; Russell, James; Clout, Michael (2011)

    Journal article
    The University of Auckland Library

    Summary 1. ???The causes of juvenile sex-biased philopatry and space use in mammals remain poorly understood, and results of previous research have been conflicting. Experimental interventions and manipulations on wild populations are rare, but can play an important role in establishing the factors governing offspring space use. 2. ???We experimentally removed mothers of independent juvenile brushtail possums from the maternal home range and examined changes in offspring space use with global positioning system collars. We examined the influence of mother absence on philopatric behaviour, and determined whether or not maternal presence affected offspring space use. 3. ???We fitted a longitudinal linear mixed effects model to demonstrate a change over time in the home range size of juveniles following experimental treatment by the removal of their mothers. When mothers were removed from the natal range, juveniles occupied significantly larger home range areas, with average increases of 175% in 95% kernel density estimates and 289% in minimum convex polygon estimates. This increase occurred within the first month following mother absence and was independent of juvenile sex. Home ranges of control juveniles did not change during the same time period. 4. ???Changes in the spatial structure of mammalian populations in response to removal of individuals have important implications for pest management. The impacts of management strategies which target particular individuals in a population may counteract conservation benefits through their effect on the space use of survivors. Studies involving experimental removals provide important information on consequences of control and also yield insights into the causes of mammalian space use, philopatric behaviours and ultimately dispersal.

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  • Effect of extraction methods and UHT treatment conditions on the level of isoflavones during soymilk manufacture

    Prabhakaran, MP; Perera, Conrad (2006)

    Journal article
    The University of Auckland Library

    The objective of this study was to compare the effect of hot and cold grinding as well as the effect of direct and indirect ultra high temperature (UHT) treatment conditions on the level of isoflavones during the manufacture of soymilk. Soymilks were manufactured from dehulled soybeans by hot grinding or cold grinding processes. After inactivation of lipoxygenase at 85 ??C, the resulting slurries were decanted and supernatants were held at 120 ??C for 80 s to inactivate the trypsin inhibitor. The decanted soya bases were cooled and subjected to different temperature/time regimes by direct and indirect UHT treatments. Samples were drawn at different points in the processing operation and a reversed phase high performance liquid chromatography method was used to determine the concentration of isoflavones. Results showed that hot grinding caused a higher extraction of isoflavones into the soymilk than the cold-grinding process. However, direct or indirect heating in the UHT process did not significantly influence the concentration of isoflavones.

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  • Tutoring the new tutors: training that works

    Brailsford, Ian; Trafford, Julie; Bates, M; Mead, Andrea (2008)

    Journal article
    The University of Auckland Library

    This article draws together the thoughts of an academic advisor and a student learning advisor (Ian and Julie), who together organise tutor training from within the university???s Centre for Academic Development (CAD), and two senior tutors (Meg and Andrea) who run departmental training for new tutors in their respective disciplines (Politics and Psychology) with Ian and Julie. ...

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  • Attention in musicians is more bilateral than in non-musicians

    Patston, Lucy; Hogg, SL; Tippett, Lynette (2007)

    Journal article
    The University of Auckland Library

    Attention in neurologically intact adults normally errs towards the left side of space, as documented in studies involving tasks of visual attention (i.e., line bisection). The aim of this study was to further investigate lateralisation of attention in musicians and non-musicians. Reaction times and accuracy were recorded to stimuli presented to the left and right of a vertical line in 20 right-handed musicians and 20 matched non-musician controls. While both groups performed more accurately to left-sided stimuli, performance by the musician group was significantly more accurate than the non-musician group for the right-sided stimuli. Musicians also had faster reaction times overall. Consistent with previous research, the results indicate a more balanced attentional capacity in musicians, as well as enhanced visuomotor ability, and are interpreted with reference to extended musical training.

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  • Adsorption and enzymatic cleavage of osteopontin at interfaces with different surface chemistries

    Malmstrom Pendred, Jenny; Shipovskov, S; Christensen, B; Sorensen, ES; Kingshott, P; Sutherland, DS (2009)

    Journal article
    The University of Auckland Library

    Osteopontin is a highly charged glycoprotein present in the extra cellular matrix of a wide range of tissues. It is, in particular, relevant for biomaterials through its role in mineralized tissue remodeling. The adsorption and enzymatic cleavage of osteopontin at four different surface chemistries (methyl-, carboxylic-, and amine-terminated alkanethiol self-assembled monolayers and bare gold) have been studied utilizing a combination of the quartz crystal microbalance with dissipation and surface plasmon resonance. Full length bovine milk osteopontin was used which is well characterized with respect to post-translational modifications. Osteopontin adsorbed at all the surfaces formed thin (similar to 2-5 nm) hydrated layers with the highest amount of protein and the highest density layers observed at the hydrophobic surface. Less protein and a higher level of hydration was observed at the polar surfaces with the highest level of hydration being observed at the gold surface. The energy dissipation of these thin films (as measured by the Delta D/Delta F value) was altered at the different surface chemistries and interestingly a higher dissipation correlated with a higher density. Thrombin was able to bind and cleave the surface bound osteopontin at the hydrophobic surface. The altered levels of osteopontin binding, hydration of the layer, and susceptibility to thrombin cleavage suggest that osteopontin adopts different conformations and/or orientations at the different material surfaces. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3187529]

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  • Surfactant Protein SP-B Strongly Modifies Surface Collapse of Phospholipid Vesicles: Insights from a Quartz Crystal Microbalance with Dissipation

    Cabre, EJ; Malmstrom Pendred, Jenny; Sutherland, D; Perez-Gil, J; Otzen, DE (2009)

    Journal article
    The University of Auckland Library

    Pulmonary surfactant protein B (SP-B) facilitates the rapid transfer of phospholipids from bilayer stores into air-liquid interfacial films along the breathing cycle, and contributes to the formation of a surface-associated multilayer reservoir of surfactant to optimize the stability of the respiratory interface. To obtain more insights into the mechanisms underlying this transfer and multilayer formation, we established a simple model system that captures different features of SP-B action. We monitored the formation of supported planar bilayers from the collapse of intact phospholipid vesicles on a silica surface using a technique called quartz crystal microbalance with dissipation, which provides information on changes in membrane thickness and viscosity. At physiologically relevant concentrations, SP-B dramatically alters vesicle collapse. This manifests itself as a reduced buildup of intact vesicles on the surface before collapse, and allows the stepwise buildup of multilayered deposits. Accumulation of lipids in these multilayer deposits requires the presence of SP-B in both the receptor and the arriving membranes, surrounded by a comparable phospholipid charge. Thus, the quartz crystal microbalance with dissipation system provides a useful, simplified way to mimic the effect of surfactant protein on vesicle dynamics and permits a detailed characterization of the parameters governing reorganization of surfactant layers.

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  • Large area protein nanopatterning for biological applications

    Agheli, H; Malmstrom Pendred, Jenny; Larsson, EM; Textor, M; Sutherland, DS (2006)

    Journal article
    The University of Auckland Library

    Large area nanopatterns of functional proteins are demonstrated. A new approach to analyze atomic force microscopy height histograms is used to quantify protein and antibody binding to nanoscale patches. Arrays of nanopatches, each containing less than 40 laminin molecules, are shown to be highly functional binding close to 1 monoclonal anti-laminin IgG (site by IKVAV sequence) or 3-4 polyclonal anti-laminin IgG's per surface bound laminin. Complementary quartz crystal microbalance measurements indicate higher functionality at nanopatches than on homogeneous surfaces.

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  • The disciplinary constraints of SLA and TESOL: Additive bilingualism and second language acquisition, teaching and learning

    May, Stephen (2011)

    Journal article
    The University of Auckland Library

    Published in a tier 1 sociolinguistics journal, this article explores why the ???monolingual bias??? inherent in SLA and TESOL research has persisted to the present, despite direct criticism of this bias by socio-critical scholars since the early 1990s. The article explores why SLA and TESOL have remained impervious to this critique by drawing on Bourdieu's notion of field, and Bernstein's concepts of classification and framing, arguing innovatively that the construction of SLA and TESOL as academic disciplines actively delimits the possibilities of developing an additive bilingual approach, although it does not foreclose it. By way of example, the article concludes by discussing LEAP, a major web-based professional development resource for teachers, developed by a research team led by the author, which integrates research in bilingualism and bilingual education with second language teaching and learning.

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  • Synthesis of a functionalized 7,6-bicyclic spiroimine ring fragment of the spirolides.

    Gu??ret, SM; Furkert, Daniel; Brimble, Margaret (2010)

    Journal article
    The University of Auckland Library

    The asymmetric synthesis of a functionalized 7,6-spiroimine related to the spirolides is described. Intermolecular Diels-Alder cycloaddition of a chiral trisubstituted dienophile and Danishefsky's diene enabled simultaneous installation of the C7 and C29 stereocenters. Further transformations and late-stage aza-Wittig cyclization afforded the spiroimine in good yield. During this study, an unprecedented 14-membered dialdimine was also obtained.

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  • Synthesis of the FG ring fragment of pectenotoxins 1-9

    Heapy, Amanda; Brimble, Margaret (2010)

    Journal article
    The University of Auckland Library

    The synthesis of the FG ring fragment common to pectenotoxins 1-9 is reported. The successful, convergent synthesis relied on high yielding routes to access two key intermediates; aldehyde 1 and phosphonium salt 2. A Z-selective Wittig reaction gave access to advanced linear precursor 3, which was converted to FG ring fragment 4 using two sequential cyclization reactions. (C) 2010 Elsevier Ltd. All rights reserved.

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  • anti-Helicobacter Pylori Activity of Derivatives of the Phthalide-Containing Antibacterial Agents Spirolaxane Methyl Ether, CJ-12,954, CJ-13,013, CJ-13,102, CJ-13,104, CJ-13,108 and CJ-13,015

    Radcliff, Fiona; Fraser, John; Wilson, Zoe; Heapy, Amanda; Robinson, James; Bryant, Christina; Flowers, Christopher; Brimble, Margaret (2008)

    Journal article
    The University of Auckland Library

    The naturally occurring phthalide-containing antibiotics spirolaxine methyl ether, CJ-12,954, CJ-13,013, CJ-13,015, CJ-13,102, CJ-13,103, CJ-13,104 and CJ-13,108, have been reported to exhibit anti-H. pylori activity. However, the exact stereochemistry of spirolaxine methyl ether, CJ-12,954 or CJ-13,013, contributing to this observed activity has not been confirmed. The anti-H. pylori activity of several analogues of spirolaxine methyl ether, CJ-12,954 and CJ-13,013 of defined stereochemistry together with the anti-H. pylori activity of several indole analogues of the simpler phthalide-containing antibiotics CJ-13,102, CJ-13,104, CJ-13,108 and CJ-13,015 is reported herein. A 1:1 mixture of spiroacetals 5b and 6b in which the phthalide substituent exhibited (3R)-stereochemistry was sixty times more active than the corresponding 1:1 mixture of spiroacetals with (3S)-stereochemistry. Notably, the unnatural (2???S)-diastereomer of spirolaxine methyl ether exhibited more potent anti-H. pylori activity than the natural product spirolaxine methyl ether. The 4,6-dimethoxyindoles 9, 10, 11 and 13 were all found to be less active than their parent compounds 1, 2, 3 and 4, respectively. Chain-shortened 4,6-dimethoxyindole analogue 12 of CJ-13,108 3 and 4,6-dimethoxyindole-spiroacetal 13 exhibited weak anti-H. pylori activity thus providing future opportunity for drug discovery programs.

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  • Pyranonaphthoquinone Derivatives of Eleutherin, Ventiloquinone L, Thysanone and Nanaomycin A Possessing a Diverse Topoisomerase II Inhibition and Cytotoxicity Spectrum

    Sperry, Jonathan; Loreno-Castrillejo, I; Brimble, Margaret; Machin, F (2009)

    Journal article
    The University of Auckland Library

    A series of pyranonaphthoquinone derivatives related to the known topoisomerase II inhibitor eleutherin 1 have been shown to act as specific topoisomerase II catalytic inhibitors, with several analogues displaying greater potency than the natural product itself. Amongst the compounds tested were the natural products ventiloquinone L 4 and thysanone 8 with a diverse range of topoisomerase II inhibition properties being observed. Interestingly, the natural products are generally weaker inhibitors than their synthetic counterparts, emphasising that subtle changes in the basic molecular structure of a natural product led to significant changes in the inhibition profile. It has also been demonstrated for the first time that analogues related to nanaomycin A and cardinalin-type dimeric pyranonaphthoquinones exhibit potent topoisomerase II inhibitory properties. With respect to structural features, it appears that the nature of the substituents at C1 on the pyran ring and oxygenated substituents on the aryl ring are critical for anti-topoII activity. Importantly, the topoisomerase II inhibition strength does not correlate well with the measured cytotoxicity against yeast, indicating that other molecular features in the pyranonaphthoquinone family must be considered for the design and use of this structural class as highly specific topoisomerase II inhibitors.

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  • Suzuki-Miyaura homocoupling of naphthyl triflates using bis(pinacolato)diboron: approaches to the biaryl skeleton of crisamicin A

    Brimble, MA; Lai, MYH (2003)

    Journal article
    The University of Auckland Library

    Homocoupling of naphthyl triflates 27, 16, 17 to the respective binaphthyls 28, 31 and 35 has been achieved in a one-pot procedure using bis(pinacolato)diboron and PdCl2(dppf). Use of potassium acetate as the base provides access to the initial naphthylboronate intermediates whereas the stronger base potassium phosphate is required in order to promote subsequent coupling of the naphthylboronate with a second equivalent of the naphthyl triflate. Attempts to convert binaphthyl 35 into bis-acetylnaphthalene 14, a key intermediate for the synthesis of the dimeric pyranonaphthoquinone antibiotic crisamicin A 2, via double Fries rearrangement of bis-acetate 37 derived from binaphthyl 35, were unsuccessful. Attempts to introduce the acetyl groups at C-7 and C-7??? on bis-acetylnaphthalene 14via Fries rearrangement of the monomeric precursors 21 and 15, before effecting homocoupling to a biaryl were unsuccessful. Introduction of an acetyl group via initial bromination ortho to the hydroxyl group in naphthol 18, which bears an electron rich benzyl ether at C-7, was plagued by the formation of phenolic coupling product 42 and naphthoquinone 43. Bromination of naphthol 45, bearing a less electron rich triflate group at C-7, also afforded binaphthol 47 resulting from phenolic coupling as well as naphthoquinone 48 when using N-bromosuccinimide at low temperature.

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