95,838 results

  • Targeting GLUT1 and the Warburg Effect in Renal Cell Carcinoma by Chemical Synthetic Lethality

    Chan, DA; Sutphin, PD; Nguyen, P; Turcotte, S; Lai, EW; Banh, A; Reynolds, GE; Chi, JT; Wu, J; Solow-Cordero, DE; Bonnet, Muriel; Flanagan, Jack; Bouley, DM; Graves, EE; Denny, William; Hay, Michael; Giaccia, AJ (2011-08-03)

    Journal article
    The University of Auckland Library

    Identifying new targeted therapies that kill tumor cells while sparing normal tissue is a major challenge of cancer research. Using a high-throughput chemical synthetic lethal screen, we sought to identify compounds that exploit the loss of the von Hippel???Lindau (VHL) tumor suppressor gene, which occurs in about 80% of renal cell carcinomas (RCCs). RCCs, like many other cancers, are dependent on aerobic glycolysis for ATP production, a phenomenon known as the Warburg effect. The dependence of RCCs on glycolysis is in part a result of induction of glucose transporter 1 (GLUT1). Here, we report the identification of a class of compounds, the 3-series, exemplified by STF-31, which selectively kills RCCs by specifically targeting glucose uptake through GLUT1 and exploiting the unique dependence of these cells on GLUT1 for survival. Treatment with these agents inhibits the growth of RCCs by binding GLUT1 directly and impeding glucose uptake in vivo without toxicity to normal tissue. Activity of STF-31 in these experimental renal tumors can be monitored by [18F]fluorodeoxyglucose uptake by micro???positron emission tomography imaging, and therefore, these agents may be readily tested clinically in human tumors. Our results show that the Warburg effect confers distinct characteristics on tumor cells that can be selectively targeted for therapy.

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  • Pelvic floor function in nulliparous women using three-dimensional ultrasound and magnetic resonance imaging

    Kruger, Jennifer; Heap, SW; Murphy, BA; Dietz, HP (2008-03)

    Journal article
    The University of Auckland Library

    OBJECTIVE: To compare biometric measures of pelvic floor function obtained using three-dimensional (3D) ultrasound and magnetic resonance imaging (MRI) in a group of nulliparous asymptomatic young women. METHODS: Twenty-seven asymptomatic nulliparous volunteers were assessed prospectively, using translabial 3D ultrasound and multiplanar 3D MRI. Levator hiatal dimensions were measured in the axial plane in both modalities. All participants were imaged supine, after voiding with data acquired at rest, on maximum Valsalva and maximum pelvic floor contraction. Interobserver variability was determined for both methods. Normally distributed continuous ultrasound data were compared with equivalent MRI parameters, and intraclass correlation coefficients were used to estimate correlation between the two methods. Bland-Altman analysis was also used to estimate agreement between methods. RESULTS: Interobserver repeatability was fair to excellent for all parameters measured with both methods. Moderate-to-substantial agreement between methods was shown for all tested parameters (intraclass correlation coefficients 0.587???0.783). There was a systematic but nonsignificant difference between methods, in that measurements on Valsalva tended to be larger for MRI, and the poorest agreement (intraclass correlation coefficient 0.587) was found for hiatal area on Valsalva. CONCLUSION: Agreement between the two methods was moderate to substantial for all parameters except for hiatal area on Valsalva. Magnetic resonance imaging yielded higher area measurements on Valsalva, which may indicate difficulties in identifying the plane of minimal dimensions due to poorer temporal resolution compared with ultrasound imaging.

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  • Image Correlation Spectroscopy of Multiphoton Images Correlates with Collagen Mechanical Properties

    Raub, CB; Unruh, J; Suresh, Vinod; Krasieva, T; Lindmo, T; Gratton, E; Tromberg, BJ; George, SC (2008)

    Journal article
    The University of Auckland Library

    Multiphoton microscopy (MPM) holds promise as a noninvasive imaging technique for characterizing collagen structure, and thus mechanical properties, through imaging second harmonic generation (SHG) and two-photon fluorescence in engineered and real connective tissues. Controlling polymerization pH to manipulate collagen gel microstructure, we quantified pore and fiber dimensions using both standard methods and image correlation spectroscopy (ICS) on MPM, scanning electron, and darkfield microscopy images. The latter two techniques are used to confirm microstructural measurements made from MPM images. As polymerization pH increased from 5.5 to 8.5, mean fiber diameter decreased from 3.7 ?? 0.7 ??m to 1.6 ?? 0.3 ??m, the average pore size decreased from 81.7 ?? 3.7 ??m2 to 7.8 ?? 0.4 ??m2, and the pore area fraction decreased from 56.8% ?? 0.8% to 18.0% ?? 1.3% (measured from SHG images), whereas the storage modulus G??? and loss modulus G???, components of the shear modulus, increased ???33-fold and ???16-fold, respectively. A characteristic length scale measured using ICS, WICS, correlates well with the mean fiber diameter from SHG images (R2 = 0.95). Semiflexible network theory predicts a scaling relationship of the collagen gel storage modulus (G???) depending upon mesh size and fiber diameter, which are estimated from SHG images using ICS. We conclude that MPM and ICS are an effective combination to assess bulk mechanical properties of collagen hydrogels in a noninvasive, objective, and systematic fashion and may be useful for specific in vivo applications.

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  • Type I vs type II spiral ganglion neurons exhibit differential survival and neuritogenesis during cochlear development.

    Barclay, Meagan; Ryan, AF; Housley, GD (2011)

    Journal article
    The University of Auckland Library

    Background The mechanisms that consolidate neural circuitry are a major focus of neuroscience. In the mammalian cochlea, the refinement of spiral ganglion neuron (SGN) innervation to the inner hair cells (by type I SGNs) and the outer hair cells (by type II SGNs) is accompanied by a 25% loss of SGNs. Results We investigated the segregation of neuronal loss in the mouse cochlea using ??-tubulin and peripherin antisera to immunolabel all SGNs and selectively type II SGNs, respectively, and discovered that it is the type II SGN population that is predominately lost within the first postnatal week. Developmental neuronal loss has been attributed to the decline in neurotrophin expression by the target hair cells during this period, so we next examined survival of SGN sub-populations using tissue culture of the mid apex-mid turn region of neonatal mouse cochleae. In organotypic culture for 48 hours from postnatal day 1, endogenous trophic support from the organ of Corti proved sufficient to maintain all type II SGNs; however, a large proportion of type I SGNs were lost. Culture of the spiral ganglion as an explant, with removal of the organ of Corti, led to loss of the majority of both SGN sub-types. Brain-derived neurotrophic factor (BDNF) added as a supplement to the media rescued a significant proportion of the SGNs, particularly the type II SGNs, which also showed increased neuritogenesis. The known decline in BDNF production by the rodent sensory epithelium after birth is therefore a likely mediator of type II neuron apoptosis. Conclusion Our study thus indicates that BDNF supply from the organ of Corti supports consolidation of type II innervation in the neonatal mouse cochlea. In contrast, type I SGNs likely rely on additional sources for trophic support.

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  • Identification of large gene rearrangements in KCNQ1 and KCNH2 in patients with long QT syndrome.

    Eddy, CA; McCormick, J; Chung, SK; Crawford, JR; Love, Donald; Rees, Mark; Skinner, Jonathan; Shelling, Andrew (2008)

    Journal article
    The University of Auckland Library

    BACKGROUND Sequencing or denaturing high-performance liquid chromatography (dHPLC) analysis of the known genes associated with the long QT syndrome (LQTS) fails to identify mutations in approximately 25% of subjects with inherited LQTS. Large gene deletions and duplications can be missed with these methodologies. OBJECTIVE The purpose of this study was to determine whether deletions and/or duplications of one or more exons of the main LQTS genes were present in an LQTS mutation-negative cohort. METHODS Multiplex ligation-dependent probe amplification (MLPA), a quantitative fluorescent approach, was used to screen 26 mutation-negative probands with an unequivocal LQTS phenotype (Schwartz score 4). The appropriate MLPA kit contained probes for selected exons in LQTS genes KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2. Real-time polymerase chain reaction was used to validate the MLPA findings. RESULTS Altered exon copy number was detected in 3 (11.5%) patients: (1) an ex13-14del of the KCNQ1 gene in an 11-year-old boy with exercise-induced collapse (QTc 580 ms); (2) an ex6-14del of the KCNH2 gene in a 22-year-old woman misdiagnosed with epilepsy since age 9 years (QTc 560 ms) and a sibling with sudden death at age 13 years; and (3) an ex9-14dup of the KCNH2 gene in a 12 year-old boy (QTc 550 ms) following sudden nocturnal death of his 32-year-old mother. CONCLUSION If replicated, this study demonstrates that more than 10% of patients with LQTS and a negative current generation genetic test have large gene deletions or duplications among the major known LQTS susceptibility genes. As such, these findings suggest that sequencing-based mutation detection strategies should be followed by deletion/duplication screening in all LQTS mutation-negative patients.

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  • Corneal innervation and cellular changes following transplantation: an in vivo confocal microscopy study.

    Niederer, RL; Perumal, D; Sherwin, Trevor; McGhee, Charles (2007)

    Journal article
    The University of Auckland Library

    PURPOSE. Although penetrating keratoplasty is generally considered a successful procedure, transplanted corneal tissue may exhibit abnormal epithelium, decreased sensation, and declining endothelial cell counts after surgery. This study aimed to use in vivo confocal microscopy to correlate corneal microstructure and recovery of the subbasal nerve plexus of the transplanted cornea with indications for, and time from, surgery. METHODS. This was a cross-sectional study comparing corneas from 42 patients after penetrating keratoplasty with those of 30 controls. Subjects were assessed by ophthalmic history and clinical examination, computerized corneal topography, and laser scanning in vivo confocal microscopy. RESULTS. Time from surgery ranged from 1 month to 40 years (mean, 85 105 months). Significant reductions in epithelial (P 0.001), keratocyte (P 0.001), and endothelial (P 0.001) cell densities were noted in comparison with control corneas. Significant reductions in subbasal nerve fiber density (P 0.001) and nerve branching (P 0.001) were also noted. Endothelial cell density decreased with time after surgery (r ???0.472; P 0.003), and nerve fiber density (r .328; P 0.034) increased. Keratoconus as an indication for transplantation was associated with higher subbasal nerve fiber densities (P 0.003) than other indications for corneal transplantation. Neither nerve fiber nor cell density was correlated with bestcorrected visual acuity. CONCLUSIONS. Laser scanning in vivo confocal microscopy highlights profound reductions in cell density at every level of the transplanted cornea and alterations to the subbasal plexus that are still apparent up to 40 years after penetrating keratoplasty.

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  • Geomorphology in action: Linking policy with on-the-ground actions through applications of the River Styles framework

    Brierley, Gary; Fryirs, KA; Cook, N; Outhet, D; Raine, A; Parsons, L; Healey, M (2011)

    Journal article
    The University of Auckland Library

    Integrative approaches to natural resources management build upon scientifically informed policy frameworks. Landscape templates provide a physical platformwith which to develop and enact coherent measures which balance concerns for ecosystem health and economic development. The River Styles framework (Brierley & Fryirs, 2000, 2005, p. 398) is a geomorphic tool that feeds scientific information into river management applications and prioritization, striving to ensure that actions reflect the values of a given place. Three recent developments in the use of the River Styles framework in New South Wales, Australia are reported here. First, the use of this cross-scalar, catchment-framed tool in the development and implementation of proactive and strategic management measures is outlined. Regional-scale conservation planning activities are applied using reference reaches for differing River Styles. Catchmentscale investigations into river character, behaviour and evolutionary trajectory frame site/reach considerations in their catchment context. Second, policy links to on-the-ground activities are explored, highlighting ways in which a physical landscape template provides an integrating platform for catchment action planning, water management planning, vegetation management, water quality assessment, conservation and rehabilitation planning and implementation, and monitoring programs. These applications build upon a fragility index that combines concerns for common values, system condition and risk. Third, extensions to the River Styles framework that support management of urban streams are outlined. The use of Geographic Information Systems as a cross-scalar spatial analysis tool with which to guide coherent management applications is highlighted.

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  • Vitamin D deficiency in early childhood: prevalent in the sunny South Pacific 12(10):, 2009 Oct.

    Grant, Cameron; Wall, Clare; Crengle, Suzanne; Scragg, Robert (2009)

    Journal article
    The University of Auckland Library

    Objective: To estimate the prevalence of and risk factors for vitamin D deficiency in young urban children in Auckland, New Zealand, where there is no routine vitamin D supplementation. Design: A random sample of urban children. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D ,27?5 nmol/l (,11 ng/ml). Logistic regression analysis was used to calculate odds ratios and, from these, relative risks (RR) and 95% confidence intervals were estimated. Setting: Auckland, New Zealand (368520S), where the daily vitamin D production by solar irradiation varies between summer and winter at least 10-fold. Subjects: Children aged 6 to 23 months enrolled from 1999 to 2002. Results: Vitamin D deficiency was present in forty-six of 353 (10 %; 95% CI 7, 13 %). In a multivariate model there was an increased risk of vitamin D deficiency associated with measurement in winter or spring (RR57?24, 95% CI 1?55, 23?58), Pacific ethnicity (RR57?60, 95% CI 1?80, 20?11), not receiving any infant or follow-on formula (RR55?69, 95% CI 2?66, 10?16), not currently receiving vitamin supplements (RR55?32, 95% CI 2?04, 11?85) and living in a more crowded household (RR52?36, 95% CI 1?04, 4?88). Conclusions: Vitamin D deficiency is prevalent in early childhood in New Zealand. Prevalence varies with season and ethnicity. Dietary factors are important determinants of vitamin D status in this age group. Vitamin D supplementation should be considered as part of New Zealand???s child health policy.

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  • Paternalism in practice: informing patients about expensive unsubsidised drugs

    Dare, Tim; Findlay, Michael; Browett, Peter; Amies, Karen; Anderson, Sarah (2010-05-01)

    Journal article
    The University of Auckland Library

    Recent research conducted in Australia shows that many oncologists withhold information about expensive unfunded drugs in what the authors of the study suggest is unacceptable medical paternalism. Surprised by the Australian results, we ran a version of the study in New Zealand and received very different results. While the percentages of clinicians who would prescribe the drugs described in the scenarios were very similar (73-99% in New Zealand and 72-94% in Australia depending on the scenario) the percentage who would not discuss expensive unfunded drugs was substantially lower in New Zealand (6.4-11.1%) than it was in Australia (28-41%). This seems surprising given the substantial similarities between the two countries, and the extensive interaction between their medical professions. We use the contrast between the two studies to examine the generalisability of the Australian results, to identify influences on clinicians' decisions about what treatment information to give patients, and so the tendency towards medical paternalism and, more pragmatically, about how such decisions might be influenced.

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  • Distributed Power System Automation with IEC 61850, IEC 61499 and Intelligent Control

    Higgins, N; Vyatkin, Valeriy; Nair, NKC; Schwarz, KH (2009)

    Journal article
    The University of Auckland Library

    This paper presents a new approach to power system automation, based on distributed intelligence rather than traditional centralized control. The paper investigates the interplay between two international standards, IEC 61850 and IEC 61499, and proposes a way of combining of the application functions of IEC 61850-compliant devices with IEC 61499-compliant ???glue logic,??? using the communication services of IEC 61850-7-2. The resulting ability to customize control and automation logic will greatly enhance the flexibility and adaptability of automation systems, speeding progress toward the realization of the smart grid concept.

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  • Large non-Gaussianities in single-???eld in???ation

    Chen, X; Easther, Richard; Lim, EA (2006-11-22)

    Journal article
    The University of Auckland Library

    We compute the 3-point correlation function for a general model of inflation driven by a single, minimally coupled scalar field. Our approach is based on the numerical evaluation of both the perturbation equations and the integrals which contribute to the 3-point function. Consequently, we can analyze models where the potential has a "feature", in the vicinity of which the slow roll parameters may take on large, transient values. This introduces both scale and shape dependent non-Gaussianities into the primordial perturbations. As an example of our methodology, we examine the ``step'' potentials which have been invoked to improve the fit to the glitch in the $$ $C_l$ for $l \sim 30$, present in both the one and three year WMAP data sets. We show that for the typical parameter values, the non-Gaussianities associated with the step are far larger than those in standard slow roll inflation, and may even be within reach of a next generation CMB experiment such as Planck. More generally, we use this example to explain that while adding features to potential can improve the fit to the 2-point function, these are generically associated with a greatly enhanced signal at the 3-point level. Moreover, this 3-point signal will have a very nontrivial shape and scale dependence, which is correlated with the form of the 2-point function, and may thus lead to a consistency check on the models of inflation with non-smooth potentials.

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  • Gravitational wave production at the end of inflation

    Easther, Richard; Jr, JTG; Lim, EA (2006-12-12)

    Journal article
    The University of Auckland Library

    We consider gravitational wave production due to parametric resonance at the end of inflation, or ``preheating''. This leads to large inhomogeneities which source a stochastic background of gravitational waves at scales inside the comoving Hubble horizon at the end of inflation. We confirm that the present amplitude of these gravitational waves need not depend on the inflationary energy scale. We analyze an explicit model where the inflationary energy scale is ~10^9 GeV, yielding a signal close to the sensitivity of Advanced LIGO and BBO. This signal highlights the possibility of a new observational ``window'' into inflationary physics, and provides significant motivation for searches for stochastic backgrounds of gravitational waves in the Hz to GHz range, with an amplitude on the order of \Omega_{gw}(k)h^2 ~ 10^-11. Finally, the strategy used in our numerical computations is applicable to the gravitational waves generated by many inhomogeneous processes in the early universe.

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  • Rogue-wave-like characteristics in femtosecond supercontinuum generation

    Erkintalo, Miro; Genty, G; Dudley, JM (2009-08-15)

    Journal article
    The University of Auckland Library

    We experimentally study the characteristics of optical rogue waves in supercontinuum generation in the femtosecond regime. Specifically, the intensity histograms obtained from spectrally filtering the supercontinuum exhibit the L-shaped characteristics typical of extreme-value phenomena on both the long-wavelength and short-wavelength edges of the spectrum owing to cross-phase modulation and soliton-dispersive wave coupling. Furthermore, the form of the histogram on the long-wavelength edge varies from L-shaped to quasi-Gaussian as wavelengths closer to the pump are included in the filtered measurements. Our observations are in agreement with numerical simulations. (C) 2009 Optical Society of America

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  • A randomised feasibility study of EPA and Cox-2 inhibitor (Celebrex) versus EPA, Cox-2 inhibitor (Celebrex), resistance training followed by ingestion of essential amino acids high in leucine in NSCLC cachectic patients--ACCeRT study.

    Rogers, Elaine; MacLeod, Roderick; Stewart, Joanna; Bird, SP; Keogh, JW (2011)

    Journal article
    The University of Auckland Library

    Cancer cachexia is a syndrome of progressive weight loss. Non-small cell lung cancer patients experience a high incidence of cachexia of 61%. Research into methods to combat cancer cachexia in various tumour sites has recently progressed to the combination of agents.The combination of the anti-cachectic agent Eicosapentaenoic acid (EPA) and the cyclo-oxygenase-2 (COX-2) inhibitor celecoxib has been tested in a small study with some benefit. The use of progressive resistance training (PRT) followed by the oral ingestion of essential amino acids (EAA), have shown to be anabolic on skeletal muscle and acceptable in older adults and other cancer groups.The aim of this feasibility study is to evaluate whether a multi-targeted approach encompassing a resistance training and nutritional supplementation element is acceptable for lung cancer patients experiencing cancer cachexia.

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  • A Low-Mass Planet with a Possible Sub-Stellar-Mass Host in Microlensing Event MOA-2007-BLG-192

    Bennett, Diane; Bond, IA; Udalski, A; Sumi, T; Abe, F; Fukui, A; Furusawa, K; Hearnshaw, JB; Holderness, Sharon; Itow, Y; Kamiya, K; Korpela, A; Kilmartin, PM; Lin, Wei-Ting; Ling, Chai; Masuda, K; Matsubara, Y; Miyake, N; Muraki, Y; Nagaya, M; Okumura, T; Ohnishi, K; Perrott, YC; Rattenbury, Nicholas; Sako, T; Saito, T; Sato, T; Skuljan, J; Sullivan, DJ; Sweatman, Winston; Tristram, PJ; Yock, Philip; Kubiak, M; Szymanski, MK; Pietrzynski, G; Soszynski, I; Szewczyk, O; Wyrzykowski, L; Ulaczyk, K; Batista, V; Beaulieu, JP; Brilliant, S; Cassan, A; Fouque, P; Kervella, P; Kubas, D; Marquette, JB (2008)

    Journal article
    The University of Auckland Library

    We report the detection of an extrasolar planet of mass ratio q 2 ; 10 4 in microlensing eventMOA-2007-BLG-192. The best-fit microlensing model shows both themicrolensing parallax and finite source effects, and these can be combined to obtain the lens masses of M ?? 0:060??0:028 0:021 M for the primary and m ?? 3:3??4:9 1:6 M for the planet. However, the observational coverage of the planetary deviation is sparse and incomplete, and the radius of the source was estimated without the benefit of a source star color measurement. As a result, the 2 limits on the mass ratio and finite source measurements are weak. Nevertheless, the microlensing parallax signal clearly favors a substellar mass planetary host, and the measurement of finite source effects in the light curve supports this conclusion. Adaptive optics images taken with the Very Large Telescope (VLT) NACO instrument are consistent with a lens star that is either a brown dwarf or a star at the bottomof the main sequence. Follow-up VLTand/or Hubble Space Telescope (HST ) observationswill either confirm that the primary is a brown dwarf or detect the low-mass lens star and enable a precise determination of its mass. In either case, the lens star, MOA-2007-BLG-192L, is the lowest mass primary known to have a companion with a planetary mass ratio, and the planet,MOA-2007-BLG-192Lb, is probably the lowest mass exoplanet found to date, aside from the lowest mass pulsar planet.

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  • The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR): three-dimensional structure and localization of a channel gate.

    Rosenberg, MF; O'Ryan, Liam; Hughes, G; Zhao, Z; Aleksandrov, LA; Riordan, JR; Ford, RC (2011)

    Journal article
    The University of Auckland Library

    Cystic fibrosis affects about 1 in 2500 live births and involves loss of transmembrane chloride flux due to a lack of a membrane protein channel termed the cystic fibrosis transmembrane conductance regulator (CFTR). We have studied CFTR structure by electron crystallography. The data were compared with existing structures of other ATP-binding cassette transporters. The protein was crystallized in the outward facing state and resembled the well characterized Sav1866 transporter. We identified regions in the CFTR map, not accounted for by Sav1866, which were potential locations for the regulatory region as well as the channel gate. In this analysis, we were aided by the fact that the unit cell was composed of two molecules not related by crystallographic symmetry. We also identified regions in the fitted Sav1866 model that were missing from the map, hence regions that were either disordered in CFTR or differently organized compared with Sav1866. Apart from the N and C termini, this indicated that in CFTR, the cytoplasmic end of transmembrane helix 5/11 and its associated loop could be partly disordered (or alternatively located).

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  • Population dynamics and responses to management of plateau pikas Ochotona curzoniae

    Pech, Roger; Jiebu; Arthur, AD; Zhang, Y; Hui, L (2007-06-01)

    Journal article
    The University of Auckland Library

    1. Plateau pikas Ochotona curzoniae are considered a pest species on the Tibetan Plateau because they compete with livestock for forage and their burrowing could contribute to soil erosion. The effectiveness of pest control programmes in Tibet has not been measured, and it is not known whether changes in livestock management have exacerbated problems with plateau pikas or compromised their control. This study measured the impact of control programmes and livestock management for forage conservation on populations of plateau pikas in alpine meadow in Naqu District, central Tibet, during 2004 and 2005.2. Current techniques for controlling plateau pikas in spring cause large reductions in abundance, but high density-dependent rates of increase result in no differences between treated and untreated populations by the following autumn. Rates of increase from spring to autumn are not influenced by standing plant biomass or concurrent grazing by yaks Bos grunniens and Tibetan sheep Ovis aries.3. In autumn there was significantly lower biomass outside fenced areas with year-round livestock grazing compared with inside fenced areas with equivalent or higher numbers of plateau pikas but predominantly winter grazing by livestock. Inside fenced areas, control of plateau pikas in spring produced no detectable effect on standing plant biomass at the end of the following summer compared with uncontrolled populations of plateau pikas.4. Regardless of their initial density, populations of plateau pikas declined rapidly over winter outside fenced areas where there was very low standing plant biomass in autumn. However, inside fenced areas with higher plant biomass in autumn, low-density populations of plateau pikas declined more slowly than high-density populations.5. Synthesis and applications. Current control programmes have limited effect because populations of plateau pikas can recover in one breeding season. There was no apparent increase in forage production in areas where plateau pikas were controlled. However, plateau pikas appear to benefit from changes in grazing management, with low-density populations declining less over winter inside fenced areas than elsewhere. It was not evident that control programmes are warranted or that they will improve the livelihoods of Tibetan herders.

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  • Racializing the "Social Development" State: Investing in Children in Aotearoa/New Zealand

    Elizabeth, Vivienne; Larner, W (2009)

    Journal article
    The University of Auckland Library

    This paper focuses on the claim that the child is emerging as a key figure of social governance. International studies suggest that as liberal welfare states increasingly draw on social investment discourse, the child -particularly the child-as-worker-in-becoming - has emerged as an iconic figure. This has resulted in the child becoming the central subject of social policies and programs and the focus of new spending priorities. In Aotearoa/New Zealand, however, the figure of the child is much less prominent than elsewhere. Moreover, in the policies and programs of the New Zealand "social development" state, the child is often racialized by virtue of its location within specific family groupings and geographical communities. In turn, this has implications for the positioning of women. As we show, the child/mother who stands to benefit from the "investments" of social development in Aotearoa/New Zealand is actually more likely to be a Pakeha child/mother, whereas the child/mother requiring continued programmatic intervention is more likely to be Maori or Pacific. This finding points to the need for feminist scholars to examine further the complex interpenetration of gender and race/ethnicity in the shaping of contemporary socio-political landscapes.

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  • Experimental continuation of periodic orbits through a fold

    Sieber, J; Gonzalez-Buelga, A; Neild, SA; Wagg, DJ; Krauskopf, Bernd (2008)

    Journal article
    The University of Auckland Library

    We present a continuation method that enables one to track or continue branches of periodic orbits directly in an experiment when a parameter is changed. A control-based setup in combination with Newton iterations ensures that the periodic orbit can be continued even when it is unstable. This is demonstrated with the continuation of initially stable rotations of a vertically forced pendulum experiment through a fold bifurcation to find the unstable part of the branch.

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  • Hydramacin-1, structure and antibacterial activity of a protein from the basal metazoan Hydra.

    Jung, S; Dingley, Andrew; Augustin, R; Anton-Erxleben, F; Stanisak, M; Gelhaus, C; Gutsmann, T; Hammer, MU; Podschun, R; Bonvin, AM; Leippe, M; Bosch, TC; Gr??tzinger, J (2009)

    Journal article
    The University of Auckland Library

    Hydramacin-1 is a novel antimicrobial protein recently discovered during investigations of the epithelial defense of the ancient metazoan Hydra. The amino acid sequence of hydramacin-1 shows no sequence homology to any known antimicrobial proteins. Determination of the solution structure revealed that hydramacin-1 possesses a disulfide bridge-stabilized motif. This motif is the common scaffold of the knottin protein fold. The structurally closest relatives are the scorpion oxin-like superfamily. Within this superfamily hydramacin-1 establishes a new family of proteins that all share antimicrobial activity. Hydramacin-1 is potently active against Gram-positive and Gram-negative bacteria including multi-resistant human pathogenic strains. It leads to aggregation of bacteria as an initial step of its bactericidal mechanism. Aggregated cells are connected via electron-dense contacts and adopt a thorn apple-like morphology. Analysis of the hydramacin-1 structure revealed an unusual distribution of amino acid side chains on the surface. A belt of positively charged residues is sandwiched by two hydrophobic areas. Based on this characteristic surface feature and on biophysical analysis of protein-membrane interactions, we propose a model that describes the aggregation effect exhibited by hydramacin-1.

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