89,483 results

  • Two Novel Superantigens Found in Both Group A and Group C Streptococcus

    Proft, Thomas; Webb, Phillip; Handley, V; Fraser, John (2003)

    Journal article
    The University of Auckland Library

    Two novel streptococcal superantigen genes (speL(Se) and speM(Se)) were identified from the Streptococcus equi genome database at the Sanger Center. Genotyping of 8 S. equi isolates and 40 Streptococcus pyogenes isolates resulted in the detection of

    View record details
  • The streptococcal superantigen SMEZ exhibits wide allelic variation, mosaic structure, and significant antigenic variation

    Proft, Thomas; Moffatt, Sarah; Weller, KD; Paterson, A; Martin, D; Fraser, John (2000)

    Journal article
    The University of Auckland Library

    The frequencies of the newly identified streptococcal superantigen genes smez, spe-g, and spe-h were determined in a panel of 103 clinical isolates collected between 1976 and 1998 at various locations throughout New Zealand. smez and spe-g were found in every group A Streptococcus (GAS) isolate, suggesting a chromosomal location. The spe-h gene was found in only 24% of the GAS isolates and is probably located on a mobile DNA element. The smez gene displays extensive allelic variation and appears to be in linkage equilibrium with the M/emm type. 22 novel smez alleles were identified from 21 different M/emm types in addition to the already reported alleles smez and smez-2 with sequence identities between 94. 5 and 99.9%. Three alleles are nonfunctional due to a single base pair deletion. The remaining 21 alleles encode distinct SMEZ variants. The mosaic structure of the smez gene suggests that this polymorphism has arisen from homologous recombination events rather than random point mutation. The recently resolved SMEZ-2 crystal structure shows that the polymorphic residues are mainly surface exposed and scattered over the entire protein. The allelic variation did not affect either Vbeta specificity or potency, but did result in significant antigenic differences. Neutralizing antibody responses of individual human sera against different SMEZ variants varied significantly. 98% of sera completely neutralized SMEZ-1, but only 85% neutralized SMEZ-2, a very potent variant that has not yet been found in any New Zealand isolate. SMEZ-specific Vbeta8 activity was found in culture supernatants of 66% of the GAS isolates, indicating a potential base for the development of a SMEZ targeting vaccine.

    View record details
  • Transposon mutagenesis reinforces the correlation between Mycoplasma pneumoniae cytoskeletal protein HMW2 and cytadherence

    Krause, DC; Proft, Thomas; Hedreyda, CT; Hilbert, H; Plagens, H; Herrmann, R (1997)

    Journal article
    The University of Auckland Library

    A new genetic locus associated with Mycoplasma pneumoniae cytadherence was previously identified by transposon mutagenesis with Tn4001. This locus maps approximately 160 kbp from the genes encoding cytadherence-associated proteins HMW1 and HMW3, and yet insertions therein result in loss of these proteins and a hemadsorption-negative (HA-) phenotype, prompting the designation cytadherence-regulatory locus (crl). In the current study, passage of transformants in the absence of antibiotic selection resulted in loss of the transposon, a wild-type protein profile, and a HA+ phenotype, underscoring the correlation between crl and M. pneumoniae cytadherence. Nucleotide sequence analysis of crl revealed open reading frames (ORFs) orfp65, orfp216, orfp41, and orfp24, arranged in tandem and flanked by a promoter-like and a terminator-like sequence, suggesting a single transcriptional unit, the P65 operon. The 5' end of orfp65 mRNA was mapped by primer extension, and a likely promoter was identified just upstream. The product of each ORF was identified by using antisera prepared against fusion proteins. The previously characterized surface protein P65 is encoded by orfp65, while the 190,000 Mr cytadherence-associated protein HMW2 is a product of orfp216. Proteins with sizes of 47,000 and 41,000 Mr and unknown function were identified for orfp41 and orfp24, respectively. Structural analyses of HMW2 predict a periodicity highly characteristic of a coiled-coil conformation and five leucine zipper motifs, indicating that HMW2 probably forms dimers in vivo, which is consistent with a structural role in cytadherence. Each transposon insertion mapped to orfp216 but affected the levels of all products of the P65 operon. HMW2 is thought to form a disulfide-linked dimer, formerly designated HMW5, and examination of an hmw2 deletion mutant confirms that HMW5 is a product of the hmw2 gene.

    View record details
  • Association of environmental tobacco smoke exposure with socioeconomic status in a population of 7725 New Zealanders.

    Whitlock, G; MacMahon, S; Vander Hoorn, S; Davis, Peter; Jackson, Rodney; Norton, R (1998)

    Journal article
    The University of Auckland Library

    Objective - To test the hypothesis that environmental tobacco smoke (ETS) exposure is inversely associated with socioeconomic status. Design - Survey. Setting - General community, New Zealand. Participants - 7725 non-smoking adults (volunteer sample of a multi-industry workforce, n = 5564; and a random sample of urban electoral rolls, n = 2161), including 5408 males; mean age 45 years. Main outcome measures - ETS exposure was assessed as self-reported number of hours per week spent near someone who is smoking, and as prevalence of regular exposure to some ETS. Socioeconomic status was assessed as educational level, occupational status, and median neighbourhood household income. Results - Both measures of ETS exposure were steeply and inversely associated with all three indicators of socioeconomic status (all p<0.0001). Geometric mean ETS exposure ranged from 16 minutes per week among university-educated participants to 59 minutes per week in the second lowest occupational quintile (95% confidence intervals: 14-18 minutes per week and 54-66 minutes per week). The associations with occupational status and educational level were steeper than those with neighbourhood income. The socioeconomic gradients of ETS exposure were steeper among participants aged less than 35 years than among participants aged over 50 years, among men than women, and among Maori than Europeans. Conclusions - In this study population, ETS exposure was inversely associated with socioeconomic status. Greater ETS exposure might therefore contribute to the higher risks of disease and death among low socioeconomic groups. These results provide a further rationale for targeting tobacco control measures to people in low socioeconomic groups.

    View record details
  • Development and Validation of a Food-Frequency Questionnaire to Assess Short-Term Antioxidant Intake in Athletes

    Braakhuis, Andrea; Hopkins, WG; Lowe, T; Rush, E (2011-04)

    Journal article
    The University of Auckland Library

    A quantitative food-frequency questionnaire (FFQ) was developed to determine antioxidant intake in athletes. The questionnaire will be valuable for researchers wishing to standardize antioxidant intake or simply document habitual intake during an intervention trial. One hundred thirteen athletes participated in the validity study, of whom 96 completed the questionnaire and blood test, 81 completed the 7-d food diary and questionnaire, and 63 completed the 7-d food diary and blood test. Validity was investigated by comparing total and food-group antioxidant intakes from the questionnaire with those from a subsequent 7-d food diary. Measures of construct validity were determined by comparing a biomarker of antioxidant capacity (ferric-reducing ability of plasma) in a blood sample with antioxidant intakes from the questionnaire and diary. The correlation between the diary and questionnaire energy-adjusted estimates of total antioxidant intake was modest (.38; 90% confidence limits, ?? .14); the correlation was highest for antioxidants from cereals (.55; ?? .11), which contributed the greatest proportion (31%) of the total antioxidant intake. Correlations were also high for coffee and tea (.51; ?? .15) and moderate for vegetables (.34; ?? .16) and fruit (.31; ?? .16). The correlation of the plasma biomarker with the questionnaire estimate was small (.28; ?? .15), but the correlation with the diary estimate was inconsequential (-.03; ?? .15). One-week test-retest reliability of the questionnaire's estimates of antioxidant intake in 20 participants was high (.83; ?? .16). In conclusion, the FFQ is less labor intensive for participants and researchers than a 7-d diary and appears to be at least as trustworthy for estimating antioxidant intake.

    View record details
  • Variability in estimation of self-reported dietary intake data from elite athletes resulting from coding by different sports dietitians

    Braakhuis, Andrea; Hopkins, WG; Cox, G; Meredith, K; Burke, LM (2003)

    Journal article
    The University of Auckland Library

    A routine activity for a sports dietitian is to estimate energy and nutrient intake from an athlete's self-reported food intake. Decisions made by the dietitian when coding a food record are a source of variability in the data. The aim of the present study was to determine the variability in estimation of the daily energy and key nutrient intakes of elite athletes, when experienced coders analysed the same food record using the same database and software package. Seven-day food records from a dietary survey of athletes in the 1996 Australian Olympic team were randomly selected to provide 13 sets of records, each set representing the self-reported food intake of an endurance, team, weight restricted, and sprint/power athlete. Each set was coded by 3-5 members of Sports Dietitians Australia, making a total of 52 athletes, 53 dietitians, and 1456 athlete-days of data. We estimated within- and between-athlete and dietitian variances for each dietary nutrient using mixed modelling, and we combined the variances to express variability as a coefficient of variation (typical variation as a percent of the mean). Variability in the mean of 7-day estimates of a nutrient was 2- to 3-fold less than that of a single day. The variability contributed by the coder was less than the true athlete variability for a 1-day record but was of similar magnitude for a 7-day record. The most variable nutrients (e.g., vitamin C, vitamin A, cholesterol) had ~3-fold more variability than least variable nutrients (e.g., energy, carbohydrate, magnesium). These athlete and coder variabilities need to be taken into account in dietary assessment of athletes for counselling and research

    View record details
  • Factors supporting good partnership working between generalist and specialist palliative care services: A systematic review

    Gardiner, Clare; Gott, Caryl; Ingleton, C (2012-05)

    Journal article
    The University of Auckland Library

    Background: The care that most people receive at the end of their lives is provided not by specialist palliative care professionals but by generalists such as GPs, district nurses and others who have not undertaken specialist training in palliative care. A key focus of recent UK policy is improving partnership working across the spectrumof palliative care provision. However there is little evidence to suggest factors which support collaborative working between specialist and generalist palliative care providers Aim: To explore factors that support partnership working between specialist and generalist palliative care providers. Design: Systematic review. Method: A systematic review of studies relating to partnership working between specialist and generalist palliative care providers was undertaken. Six electronic databases were searched for papers published up until January 2011. Results: Of the 159 articles initially identified, 22 papers met the criteria for inclusion. Factors supporting good partnership working included: good communication between providers; clear definition of roles and responsibilities; opportunities for shared learning and education; appropriate and timely access to specialist palliative care services; and coordinated care. Conclusion: Multiple examples exist of good partnership working between specialist and generalist providers; however, there is little consistency regarding how models of collaborative working are developed, and which models aremost effective. Little is known about the direct impact of collaborative working on patient outcomes. Further research is required to gain the direct perspectives of health professionals and patients regarding collaborative working in palliative care, and to develop appropriate and cost-effectivemodels for partnership working.

    View record details
  • Delay in symptom presentation among a sample of older GUM clinic attenders.

    Gott, Caryl; Rogstad, KE; Riley, V; Ahmed-Jushuf, I (1999-01)

    Journal article
    The University of Auckland Library

    Prior research undertaken with predominantly youthful populations has established that delay between symptom recognition and health-care presentation is a common feature of sexually transmitted infection (STI) related illness behaviour. However, it is not known whether similar behaviours are exhibited by older populations with genitourinary symptoms. The present analyses therefore aim to clarify this issue by focusing upon (1) extent of delay behaviour, (2) reasons for delay behaviour and (3) variables predicting delay behaviour among a sample of genitourinary medicine (GUM) clinic attenders aged over 50 years. A self-administered questionnaire study linked to patient note data was undertaken within 3 GUM clinics in the Trent region between January 1997 and March 1998 (Sheffield, Nottingham and Leicester). Of 121 symptomatic older attenders with suspected STI, 43.8% (n=53) waited over 2 weeks between symptom recognition and clinic attendance. Reasons given for delay included wanting to 'wait and see' if symptoms improved and being embarrassed or afraid to attend clinic. A logistic regression analysis identified that delay behaviour was predicted by history of HIV testing. Comparisons with previous research undertaken in this field indicate that levels of delay behaviour reported by this older sample are higher than those exhibited by youthful populations with genitourinary symptoms. This finding has significant implications for health-care professionals working both within a GUM setting, and with older people, especially when viewed in the context of an ageing population.

    View record details
  • A novel bacterial mucinase, glycosulfatase, is associated with bacterial vaginosis

    Roberton, AM; Wiggins, R; Horner, PJ; Greenwood, R; Crowley, T; Fernandes, A; Berry, M; Corfield, Anthony (2005)

    Journal article
    The University of Auckland Library

    The modifications to the vaginal habitat accompanying a change to vaginal flora in bacterial vaginosis (BV) are poorly understood. In this study enzymes involved in mucin degradation were measured, including a novel glycosulfatase assay. Women attending an emergency walk-in sexually transmitted disease clinic were studied. One high vaginal swab (HVS) was used to prepare a gram-stained smear to determine BV status, using Ison and Hay's criteria, and a separate swab was used for the purposes of the assays. The median glycosulfatase activity was 8.5 (range, ???1.2 to 31.9) nmol h???1 1.5 ml???1 of HVS suspension in patients with BV compared to 0.5 (range, ???0.7 to 9.4) nmol h???1 1.5 ml???1 of HVS suspension in patients without BV (P = < 0.001). A rapid spot test for sialidase was positive in 22/24 patients with BV (sensitivity, 91.7%; 95% confidence interval [CI], 73 to 99%) and negative in 32/35 patients without BV (specificity, 91.4%; 95% CI, 76.9 to 98.2%) (P < 0.001). Glycosulfatase activity significantly correlated with both glycoprotein sialidase activity and the sialidase spot test (P = 0.006 and P < 0.001, respectively). The results are consistent with the hypothesis that the consortium of bacteria present in BV requires the ability to break down mucins in order to colonize the vagina and replace the normal lactobacilli.

    View record details
  • Characterization of a Mouse-Adapted Staphylococcus aureus Strain

    Holtfreter, S; Radcliff, Fiona; Grumann, D; Read, Hannah; Johnson, S; Monecke, S; Ritchie, Stephen; Clow, F; Goerke, C; Br??ker, BM; Fraser, John; Wiles, Siouxsie (2013-09-02)

    Journal article
    The University of Auckland Library

    More effective antibiotics and a protective vaccine are desperately needed to combat the 'superbug' Staphylococcus aureus. While in vivo pathogenicity studies routinely involve infection of mice with human S. aureus isolates, recent genetic studies have demonstrated that S. aureus lineages are largely host-specific. The use of such animal-adapted S. aureus strains may therefore be a promising approach for developing more clinically relevant animal infection models. We have isolated a mouse-adapted S. aureus strain (JSNZ) which caused a severe outbreak of preputial gland abscesses among male C57BL/6J mice. We aimed to extensively characterize this strain on a genomic level and determine its virulence potential in murine colonization and infection models. JSNZ belongs to the MLST type ST88, rare among human isolates, and lacks an hlb-converting phage encoding human-specific immune evasion factors. Naive mice were found to be more susceptible to nasal and gastrointestinal colonization with JSNZ than with the human-derived Newman strain. Furthermore, na??ve mice required antibiotic pre-treatment to become colonized with Newman. In contrast, JSNZ was able to colonize mice in the absence of antibiotic treatment suggesting that this strain can compete with the natural flora for space and nutrients. In a renal abscess model, JSNZ caused more severe disease than Newman with greater weight loss and bacterial burden. In contrast to most other clinical isolates, JSNZ can also be readily genetically modified by phage transduction and electroporation. In conclusion, the mouse-adapted strain JSNZ may represent a valuable tool for studying aspects of mucosal colonization and for screening novel vaccines and therapies directed at preventing colonization.

    View record details
  • Fiction and theory of mind

    Boyd, Brian (2006-10)

    Journal article
    The University of Auckland Library

    View record details
  • The impact of leadership on student outcomes: An analysis of the differential effects of leadership types

    Robinson, Viviane; Lloyd, CA; Rowe, KJ (2008)

    Journal article
    The University of Auckland Library

    Purpose: The purpose of this study was to examine the relative impact of different types of leadership on students??? academic and nonacademic outcomes. Research Design: The methodology involved an analysis of findings from 27 published studies of the relationship between leadership and student outcomes. The first metaanalysis, including 22 of the 27 studies, involved a comparison of the effects of transformational and instructional leadership on student outcomes. The second meta-analysis involved a comparison of the effects of five inductively derived sets of leadership practices on student outcomes. Twelve of the studies contributed to this second analysis. Findings: The first meta-analysis indicated that the average effect of instructional leadership on student outcomes was three to four times that of transformational leadership. Inspection of the survey items used to measure school leadership revealed five sets of leadership practices or dimensions: establishing goals and expectations; resourcing strategically; planning, coordinating, and evaluating teaching and the curriculum; promoting and participating in teacher learning and development, and ensuring an orderly and supportive environment. The second meta-analysis revealed strong average effects for the leadership dimension involving promoting and participating in teacher learning and development and moderate effects for the dimensions concerned with goal setting and planning, coordinating, and evaluating teaching and the curriculum.

    View record details
  • DOA Estimation of Speech Signal Using Microphones Located at Vertices of Equilateral Triangle

    Hioka, Yusuke; Hamada, N (2004-03)

    Journal article
    The University of Auckland Library

    In this paper, we propose a DOA (Direction Of Arrival) estimation method of speech signal using three microphones. The angular resolution of the method is almost uniform with respect to DOA. Our previous DOA estimation method using the frequency-domain array data for a pair of microphones achieves high precision estimation. However, its resolution degrades as the propagating direction being apart from the array broadside. In the method presented here, we utilize three microphones located at vertices of equilateral triangle and integrate the frequency-domain array data for three pairs of microphones. For the estimation scheme, the subspace analysis for the integrated frequency array data is proposed. Through both computer simulations and experiments in a real acoustical environment, we show the efficiency of the proposed method.

    View record details
  • Needle-free jet injection using real-time controlled linear Lorentz-force actuators

    Taberner, Andrew; Hogan, NC; Hunter, Ian (2012-11)

    Journal article
    The University of Auckland Library

    Needle-free drug delivery by jet injection is achieved by ejecting a liquid drug through a narrow orifice at high pressure, thereby creating a fine high-speed fluid jet that can readily penetrate skin and tissue. Until very recently, all jet injectors utilized force- and pressure-generating principles that progress injection in an uncontrolled manner with limited ability to regulate delivery volume and injection depth. In order to address these shortcomings, we have developed a controllable jet injection device, based on a custom high-stroke linear Lorentz-force motor that is feed-back controlled during the time-course of an injection. Using this device, we are able to monitor and modulate continuously the speed of the drug jet, and regulate precisely the volume of drug delivered during the injection process. We demonstrate our ability to control injection depth (up to 16 mm) and repeatably and precisely inject volumes of up to 250 ??L into transparent gels and post-mortem animal tissue.

    View record details
  • Battle of the hemichannels -- Connexins and Pannexins in ischemic brain injury

    Davidson, Joanne; Green, Colin; Bennet, Laura; Gunn, Alistair (2015-10)

    Journal article
    The University of Auckland Library

    Perinatal ischemic brain injury can occur as a result of a global ischemic insult or focal ischemic stroke in the preterm or full-term neonate. One of the most striking features of HI injury is that, after initial recovery of cellular oxidative metabolism, there is a delayed, 'secondary' mitochondrial failure that spreads over time from the most severely damaged areas outwards, into previously undamaged regions. This secondary failure is accompanied by transient seizure activity and cytotoxic edema. The specific mechanisms of this spread are poorly understood, but it is at least partly associated with spreading waves of depression that can trigger cell death in neighboring uninjured tissues. Both Connexin and Pannexin hemichannels may mediate release of paracrine molecules that in turn propagate cell death messages by releasing intracellular mediators, such as ATP, NAD(+), or glutamate or by abnormally prolonged opening to allow cell edema. This review will discuss the controversy around the relative contribution of both Connexin and Pannexin hemichannels and mechanisms by which they may contribute to the spread of ischemic brain injury.

    View record details
  • Effects of splenectomy for hereditary spherocytosis on glycated haemoglobin in a woman with type 2 diabetes

    McCready, F; Cundy, Timothy (2009)

    Journal article
    The University of Auckland Library

    View record details
  • Is active recruitment of health workers really not guilty of enabling harm or facilitating wrongdoing?

    Brock, Gillian (2013)

    Journal article
    The University of Auckland Library

    View record details
  • Exploring the environmental modeling of road construction operations using discrete-event simulation

    Gonzalez, Vicente; Echaveguren, T (2012)

    Journal article
    The University of Auckland Library

    The practical implementation of sustainability is a challenge for the construction industry, for which there have been several research efforts to model sustainability. However, the current approaches for modeling sustainability have several limitations: they are mainly deterministic and do not properly describe the dynamic nature of the productive environment in construction. To overcome this, a dynamic modeling framework based on discrete-event simulation, which integrates environmental and traffic models, is explored in this paper. This modeling framework explicitly incorporates environmental goals (a sustainable goal) in the design of road construction operations, in terms of the fugitive and exhaust emissions generated by the production and traffic conditions. A hypothetical project is studied to illustrate the use of this framework. The main results show that an optimum number of trucks and front loaders can minimize the emission levels. Further research should consider multi-objective analyses involving cost, time and emission levels.

    View record details
  • Running with a load increases leg stiffness

    Silder, A; Besier, Thor; Delp, SL (2015-04)

    Journal article
    The University of Auckland Library

    Spring-mass models have been used to characterize running mechanics and leg stiffness in a variety of conditions, yet it remains unknown how running while carrying a load affects running mechanics and leg stiffness. The purpose of this study was to test the hypothesis that running with a load increases leg stiffness. Twenty-seven subjects ran at a constant speed on a force-measuring treadmill while carrying no load, and while wearing weight vests loaded with 10%, 20%, and 30% of body weight. We measured lower extremity motion and created a scaled musculoskeletal model of each subject, which we used to estimate lower extremity joint angles and leg length. We estimated dimensionless leg stiffness as the ratio of the peak vertical ground reaction force (normalized to body weight) and the change in stance phase leg length (normalized to leg length at initial foot contact). Leg length was calculated as the distance from the center of the pelvis to the center-of-pressure under the foot. We found that dimensionless leg stiffness increased when running with load (p=0.001); this resulted from an increase in the peak vertical ground reaction force (p<0.05). Our results reveal that subjects run in a more crouched posture and with higher leg stiffness to accommodate an added load.

    View record details
  • The CellML Metadata Framework 2.0 Specification

    Cooling, Michael; Hunter, Peter (2015)

    Journal article
    The University of Auckland Library

    The CellML Metadata Framework 2.0 is a modular framework that describes how semantic annotations should be made about mathematical models encoded in the CellML (www.cellml.org) format, and their elements. In addition to the Core specification, there are several satellite specifications, each designed to cater for model annotation in a different context. Basic Model Information, Citation, License and Biological Annotation specifications are presented.

    View record details