95,838 results

  • The high reactivity of peroxiredoxin 2 with H2O2 is not reflected in its reaction with other oxidants and thiol reagents

    Peskin, AV; Low, Felicia; Paton, LN; Maghzal, GJ; Hampton, MB; Winterbourn, CC (2007)

    Journal article
    The University of Auckland Library

    Peroxiredoxin 2 is a member of the mammalian peroxiredoxin family of thiol proteins that is important in antioxidant defense and redox signaling. We have examined its reactivity with various biological oxidants, in order to assess its ability to act as a direct physiological target for these species. Human erythrocyte peroxiredoxin 2 was oxidized stoichiometrically to its disulfide-bonded homodimer by hydrogen peroxide, as monitored electrophoretically under nonreducing conditions. The protein was highly susceptible to oxidation by adventitious peroxide, which could be prevented by treating buffers with low concentrations of catalase. However, this did not protect peroxiredoxin 2 against oxidation by added H2O2. Experiments measuring inhibition of dimerization indicated that at pH 7.4 catalase and peroxiredoxin 2 react with hydrogen peroxide at comparable rates. A rate constant of 1.3 ?? 107 M-1 s-1 for the peroxiredoxin reaction was obtained from competition kinetic studies with horseradish peroxidase. This is 100-fold faster than is generally assumed. It is sufficiently high for peroxiredoxin to be a favored cellular target for hydrogen peroxide, even in competition with catalase or glutathione peroxidase. Reactions of t-butyl and cumene hydroperoxides with peroxiredoxin were also fast, but amino acid chloramines reacted much more slowly. This contrasts with other thiol compounds that react many times faster with chloramines than with hydrogen peroxide. The alkylating agent iodoacetamide also reacted extremely slowly with peroxiredoxin 2. These results demonstrate that peroxiredoxin 2 has a tertiary structure that facilitates reaction of the active site thiol with hydrogen peroxide while restricting its reactivity with other thiol reagents.

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  • I. Best practice and patient safety in anaesthesia.

    Weller, Jennifer; Merry, Alan (2013-05)

    Journal article
    The University of Auckland Library

    The pursuit of patient safety involves reducing the gap between best practice and the care actually delivered to patients. Understanding how to reliably deliver best practice care using established anaesthetic techniques may, today, be more important than seeking new ones. Advances in anaesthesia safety involve analysing failures and devising strategies to address these. However, anaesthetists do not work in isolation, and their contribution to the function of the multidisciplinary teams in which they work has far-reaching consequences for patient care.

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  • Patient and family perceptions of hospice services: "I knew they weren???t like hospitals???

    Bray, Yvonne; Goodyear-Smith, Felicity (2013)

    Journal article
    The University of Auckland Library

    Introduction The vision for palliative care service provision in New Zealand is for all people who are dying and their families to have timely access to culturally appropriate quality palliative care services. A south Auckland hospice???s records reveal that patients from non-European ethnicities make up disproportionally less referrals for hospice services. Aim The aim of this research was to gain a patient and their family perspective on the Hospice South Auckland including exploration of components of service care that could be improved for various cultural groups. Methods Patients currently under the care of the hospice and family members were recruited from hospice records. Semi-structured interviews were conducted to explore the emerging issues. The study collected data from a purposive sample of 18 palliative care patients or carer family members ranging in age from 39 to 80 years who reflected the ethnic diversity of the population of the region. Interviewing was carried out by an experienced research assistant and continued till data saturation was reached. Findings Four key themes emerged - hospice personnel???s approach to patients, quality of service, cultural barriers and strategies for future improvement. It was determined that the latter two were the most significant to address. Conclusion The study revealed the need for information-giving and education including public profiling of the hospice to strengthen community involvement. Strategies to reduce ethnic disparities include strengthening the awareness of, and access to, services by connecting with cultural groups through churches, community and specific cultural media.

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  • Breaking the silence about exiting fieldwork: A relational approach and its implications for theorizing

    Michailova, Snejina; Piekkari, R; Plakoyiannaki, E; Ritvala, T; Mihailova, I; Salmi, A (2014-04-01)

    Journal article
    The University of Auckland Library

    It is surprising that, to date, a discussion of exiting fieldwork is absent from the management and organization literature???an absence we believe is unjustified. We argue that analyzing exit from fieldwork is important for theorizing. We combine two streams of research???ethnography in the broader social sciences and business marketing on dissolving relationships???to propose a relational framework for conceptualizing and analyzing exit. The framework represents a first attempt to examine exiting in a systematic and nuanced manner, with the objective of understanding why and how breaking the silence about exiting fieldwork may advance theorizing. We develop a typology of four exit types leading to four different approaches to theorizing. We suggest that exit may bring about a new beginning in theorizing rather than closure and that it is not only high-quality relationships in the field but also those that are disruptive that may lead to interesting theorizing.

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  • Can we predict which hospitalised patients are in their last year of life? A prospective cross-sectional study of the Gold Standards Framework Prognostic Indicator Guidance as a screening tool in the acute hospital setting.

    O'Callaghan, Anne; Laking, George; Frey, Rosemary; Robinson, Jacqualine; Gott, Caryl (2014-09)

    Journal article
    The University of Auckland Library

    BACKGROUND: Screening to identify hospital inpatients with a short life expectancy may be a way to improve care towards the end of life. The Gold Standards Framework Prognostic Indicator Guidance is a screening tool that has recently been advocated for use in the hospital setting. AIM: To assess the clinical utility of the Gold Standards Framework Prognostic Indicator Guidance as a screening tool in an acute hospital setting. MAIN OUTCOME MEASURES: Mortality at 6 and 12 months and sensitivity, specificity and predictive value of the Gold Standards Framework Prognostic Indicator Guidance at 1 year. DESIGN, SETTING AND PARTICIPANTS: Prospective cross-sectional study of 501 adult inpatients in a tertiary New Zealand teaching hospital screened utilising the Gold Standards Framework Prognostic Indicator Guidance. RESULTS: A total of 99 patients were identified as meeting at least one of the Gold Standards Framework Prognostic Indicator Guidance triggers. In this group, 6-month mortality was 56.6% and 12-month mortality was 67.7% compared with 5.2% and 10%, respectively, for those not identified as meeting the criteria. The sensitivity and specificity of the Gold Standards Framework Prognostic Indicator Guidance at 1 year were 62.6% and 91.9%, respectively, with a positive predictive value of 67.7% and a negative predictive value of 90.0%. CONCLUSION: The sensitivity, specificity and predictive values of the Gold Standards Framework Prognostic Indicator Guidance in this study are comparable to, or better than, results of studies identifying patients with a limited life expectancy in particular disease states (e.g. heart failure and renal failure). Screening utilising the Gold Standards Framework Prognostic Indicator Guidance in the acute setting could be the first step towards implementing a more systematic way of addressing patient need - both current unrecognised and future anticipated - thereby improving outcomes for this population.

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  • Patients prefer pictures to numbers to express cardiovascular benefit from treatment

    Goodyear-Smith, Felicity; Arroll, Bruce; Jackson, Rodney; Wells, Linda; Kenealy, Timothy (2008)

    Journal article
    The University of Auckland Library

    PURPOSE: This study aimed to determine which methods of expressing a preventive medication's benefit encourage patients with known cardiovascular disease to decide to take the medication and which methods patients prefer. METHODS: We identified patients in Auckland, New Zealand, family practices located in areas of differing socioeconomic status who had preexisting heart disease (myocardial infarction, angina, or both) and were taking statins. The patients were interviewed about their preference for methods of expressing the benefit of a hypothetical medication. Benefits were expressed numerically (relative risk, absolute risk, number needed to treat, odds ratio, natural frequency) and graphically. Statistical testing was adjusted for practice. RESULTS: We interviewed 100 eligible patients, representing a 53% response rate. No matter how the risk was expressed, the majority of patients indicated they would be encouraged to take the medication. Two-thirds (68) of the patients preferred 1 method of expressing benefit over others. Of this group, 57% preferred the information presented graphically. This value was significantly greater (P

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  • Past, Present, and Future Controls on Levels of Persistent Organic Pollutants in the Global Environment

    Nizzetto, L; Macleod, M; Borga, K; Cabrerizo, A; Dachs, J; Di Guardo, A; Ghirardello, D; Hansen, KM; Jarvis, A; Lindroth, A; Ludwig, B; Monteith, D; Perlinger, JA; Scheringer, M; Schwendenmann, Luitgard; Semple, KT; Wick, LY; Zhang, G; Jones, KC (2010)

    Journal article
    The University of Auckland Library

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  • Toe-in gait reduces the first peak knee adduction moment in patients with medial compartment knee osteoarthritis.

    Shull, PB; Shultz, R; Silder, A; Dragoo, JL; Besier, Thor; Cutkosky, MR; Delp, SL (2013-01)

    Journal article
    The University of Auckland Library

    The first peak of the knee adduction moment has been linked to the presence, severity, and progression of medial compartment knee osteoarthritis. The objective of this study was to evaluate toe-in gait (decreased foot progression angle from baseline through internal foot rotation) as a means to reduce the first peak of the knee adduction moment in subjects with medial compartment knee osteoarthritis. Additionally, we examined whether the first peak in the knee adduction moment would cause a concomitant increase in the peak external knee flexion moment, which can eliminate reductions in the medial compartment force that result from lowering the knee adduction moment. We tested the following hypotheses: (a) toe-in gait reduces the first peak of the knee adduction moment, and (b) toe-in gait does not increase the peak external knee flexion moment. Twelve patients with medial compartment knee osteoarthritis first performed baseline walking trials and then toe-in gait trials at their self-selected speed on an instrumented treadmill in a motion capture laboratory. Subjects altered their foot progression angle from baseline to toe-in gait by an average of 5?? (p<0.01). Toe-in gait did not increase the peak external knee flexion moment (p=0.85). The reduced knee adduction moment was accompanied by a medially-shifted knee joint center and a laterally-shifted center of pressure during early stance. These results suggest that toe-in gait may be a promising non-surgical treatment for patients with medial compartment knee osteoarthritis.

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  • Predicting the metabolic cost of incline walking from muscle activity and walking mechanics.

    Silder, A; Besier, Thor; Delp, SL (2012-06)

    Journal article
    The University of Auckland Library

    The goal of this study was to identify which muscle activation patterns and gait features best predict the metabolic cost of inclined walking. We measured muscle activation patterns, joint kinematics and kinetics, and metabolic cost in sixteen subjects during treadmill walking at inclines of 0%, 5%, and 10%. Multivariate regression models were developed to predict the net metabolic cost from selected groups of the measured variables. A linear regression model including incline and the squared integrated electromyographic signals of the soleus and vastus lateralis explained 96% of the variance in metabolic cost, suggesting that the activation patterns of these large muscles have a high predictive value for metabolic cost. A regression model including only the peak knee flexion angle during stance phase, peak knee extension moment, peak ankle plantarflexion moment, and peak hip flexion moment explained 89% of the variance in metabolic cost; this finding indicates that kinematics and kinetics alone can predict metabolic cost during incline walking. The ability of these models to predict metabolic cost from muscle activation patterns and gait features points the way toward future work aimed at predicting metabolic cost when gait is altered by changes in neuromuscular control or the use of an assistive technology.

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  • Homologous recombination repair-dependent cytotoxicity of the benzotriazine di-N-oxide CEN-209: Comparison with other hypoxia-activated prodrugs

    Hunter, Francis; Wang, Jingli; Patel, R; Hsu, H-L; Hickey, Anthony; Hay, Michael; Wilson, William (2012)

    Journal article
    The University of Auckland Library

    CEN-209 (SN30000) is a second-generation benzotriazine di-N-oxide currently in advanced preclinical development as a hypoxia-activated prodrug (HAP). Herein we describe the DNA repair-, hypoxia- and one-electron reductase-dependence of CEN-209 cytotoxicity. We deployed mutant CHO cell lines to generate DNA repair profiles for CEN-209, and compared the profiles with those for other HAPs. Hypoxic selectivity of CEN-209 was significantly greater than PR-104A and the nitro-chloromethylbenzindoline (nCBI/SN29428) and comparable to tirapazamine and TH-302. CEN-209 was selective for homologous recombination (HR) repair-deficient cells (Rad51d???/???), but less so than nitrogen mustard prodrugs TH-302 and PR-104A. Further, DNA repair profiles for CEN-209 differed under oxic and hypoxic conditions, with oxic cytotoxicity more dependent on HR. This feature was conserved across all three members of the benzotriazine di-N-oxide class examined (tirapazamine, CEN-209 and CEN-309/SN29751). Enhancing one-electron reduction of CEN-209 by forced expression of a soluble form of NADPH:cytochrome P450 oxidoreductase (sPOR) increased CEN-209 cytotoxicity more markedly under oxic than hypoxic conditions. Comparison of oxygen consumption, H2O2 production and metabolism of CEN-209 to the corresponding 1-oxide and nor-oxide reduced metabolites suggested that enhanced oxic cytotoxicity in cells with high one-electron reductase activity is due to futile redox cycling. This study supports the hypothesis that both oxic and hypoxic cell killing by CEN-209 is mechanistically analogous to tirapazamine and is dependent on oxidative DNA damage repaired via multiple pathways. However, HAPs that generate DNA interstrand cross-links, such as TH-302 and PR-104, may be more suitable than benzotriazine di-N-oxides for exploiting reported HR repair defects in hypoxic tumour cells.

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  • New distributional record for Pyropia koreana: confirmed to occur on the South Island, New Zealand

    Nelson, Wendy; Sutherland, Judith; Hwang, MS; Choi, HG (2014-09)

    Journal article
    The University of Auckland Library

    An epiphytic bladed member of the Bangiales was found growing in Christchurch (South Island, New Zealand). Mo- lecular sequence data and morphological comparisons revealed that the New Zealand specimens belong to the species Pyropia koreana (M. S. Hwang & I. K. Lee) M. S. Hwang, H. G. Choi, Y. S. Oh & I. K. Lee. This is the first record of Py. kore- ana in the southern hemisphere and a new record of an introduced species in New Zealand.

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  • Throughfall reduction in a cacao agroforest: tree water use and soil water budgeting

    K??hler, M; Schwendenmann, Luitgard; H??lscher, D (2010-07-15)

    Journal article
    The University of Auckland Library

    In a cacao agroforest with Gliricidia shade trees we studied the effects of experimentally reduced throughfall on tree sap flux densities and soil water budget. The objectives of our study were: (1) to identify the response of cacao and Gliricidia sap flux densities to reduced soil water availability, and (2) to analyze the changes in stand level soil water partitioning, measured as changes in transpiration, drainage and soil moisture storage under reduced throughfall. The study was conducted in Sulawesi, Indonesia at a site where ambient precipitation was 2841 mm yr(-1). The research site was subdivided into three control plots and three plastic roof plots in which net precipitation was reduced by 71% through the use of a sub-canopy roof for 13 months, to create rainfall conditions similar to an extended El Nino event. The two species differed in their sap flux response to declining soil water content. Daily Gliricidia sap flux declined at higher soil water contents than cacao, while Gliricidia sap flux declined in response to all levels of vapor pressure deficit (VPD) and cacao only responded to high levels of VPD. Average monthly sap flux densities of cacao and Gliricidia in the roof plots decreased linearly with decreasing soil water content reaching a maximum reduction of 21% (cacao) and 29% (Gliricidia) as compared to control plots. Cacao withdrew water mainly from the topsoil where small amounts of throughfall entering gaps in the roof frequently rewetted the soil. Therefore the competition between the two species for water resources during long periods with only little precipitation was low or in favor of cacao. Average daily stand transpiration was 1.3 mm in roof plots and 1.5 mm in control plots. Measured soil water contents were simulated satisfactorily by the application of a one-dimensional soil water model based on Richards unsaturated flow equation. The model suggested that drainage amounted to 1554 mm yr(-1) in control plots. Drainage in roof plots was greatly reduced, totaling 299 mm yr(-1). Soil moisture storage in the control underwent minor variations while it was heavily reduced in roof plots. Drainage in roof plots was a large driver of changes in soil moisture storage especially in deeper soil layers while precipitation and root water uptake were the main influencing factors for the topsoil. Deep root water uptake seemed to play a minor role in this experiment. Despite the strong reduction in net precipitation, declines in stand transpiration were moderate, suggesting that the stand did not react sensitively to the reduced throughfall scenario. (C) 2010 Elsevier B.V. All rights reserved.

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  • An early sophisticated East Polynesian voyaging canoe discovered on New Zealand???s coast

    Johns, Dilys; Irwin, Geoffrey; Sung, Yun (2014)

    Journal article
    The University of Auckland Library

    The colonization of the islands of East Polynesia was a remarkable episode in the history of human migration and seafaring. We report on an ocean-sailing canoe dating from close to that time. A large section of a complex composite canoe was discovered recently at Anaweka on the New Zealand coast. It dates to ca. A.D. 1400 and was contemporary with continuing inter-island voyaging. It was built in New Zealand as an early adaptation to a new environment, and a sea turtle carved on its hull makes symbolic connections with wider Polynesian culture and art. We describe the find, identify and radiocarbon date the construction materials. We present a reconstruction of the whole canoe and compare it to another early canoe previously discovered in the Society Islands.

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  • Transcriptomics to study the effect of a Mediterranean-inspired diet on inflammation in Crohn's disease patients

    Ferguson, Lynnette; Ellett, S; Ferguson, IR; Zhu, Shuotun; Karunasinghe, N; Jesuthasan, AC; Han, Dug; Fraser, Alan; Ferguson, LR (2013)

    Journal article
    The University of Auckland Library

    BACKGROUND: Inflammation is an essential immune response; however, chronic inflammation results in disease including Crohn's disease. Therefore, reducing the inflammation can yield a significant health benefit, and one way to achieve this is through diet. We developed a Mediterranean-inspired anti-inflammatory diet and used this diet in a 6-week intervention in a Crohn's disease population. We examined changes in inflammation and also in the gut microbiota. We compared the results of established biomarkers, C-reactive protein and the micronuclei assay, of inflammation with results from a transcriptomic approach. RESULTS: Data showed that being on our diet for 6 weeks was able to reduce the established biomarkers of inflammation. However, using transcriptomics, we observed significant changes in gene expression. Although no single gene stood out, the cumulative effect of small changes in many genes combined to have a beneficial effect. Data also showed that our diet resulted in a trend of normalising the microbiota. CONCLUSIONS: This study showed that our Mediterranean-inspired diet appeared to benefit the health of people with Crohn's disease. Our participants showed a trend for reduced markers of inflammation and normalising of the microbiota. The significant changes in gene expression after 6 weeks highlighted the increased sensitivity of using transcriptomics when compared to the established biomarkers and open up a new era of dietary intervention studies.

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  • Teachers' conceptions of assessment in Chinese contexts: A tripartite model of accountability, improvement, and irrelevance

    Brown, Gavin; Hui, SKF; Yu, FWM; Kennedy, KJ (2011)

    Journal article
    The University of Auckland Library

    The beliefs teachers have about assessment influence classroom practices and reflect cultural and societal differences. This paper reports the development of a new self-report inventory to examine beliefs teachers in Hong Kong and southern China contexts have about the nature and purpose of assessment. A statistically equivalent model for Hong Kong and southern China teachers had three factors (i.e., improvement, accountability, and irrelevance). The Chinese teachers very strongly associated accountability with improvement (r = .80). This is consistent with the Chinese tradition and policy of using examinations to drive teaching quality and student learning and as a force for merit based decisions. Small differences between the two groups of teachers are consistent with assessment policy differences in the two jurisdictions.

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  • Anaesthetists' management of oxygen pipeline failure: room for improvement

    Weller, Jennifer; Merry, Alan; Warman, Guy; Robinson, B (2007)

    Journal article
    The University of Auckland Library

    Oxygen pipeline failure is a rare but potentially catastrophic event which can affect the care of patients throughout an entire hospital. Anaesthetists play a critical role in maintaining patient safety, and should be prepared to support an institution-wide emergency response if oxygen failure occurs. We tested the preparedness for this through observation of 20 specialist anaesthetists to a standardised simulator scenario of central oxygen supply failure. Responses were documented using multiple approaches to ensure accuracy. All anaesthetists demonstrated safe immediate patient care, but we observed a number of deviations from optimal management, including failure to conserve oxygen supplies and, following restoration of gas supplies, failure to test the composition of the gas supplied from the repaired pipelines. This has implications for patient care at both individual and hospital level. Our results indicate a gap in anaesthesia training which should be addressed, in conjunction with planning for effective hospital-wide responses to the event of critical resource failure.

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  • The effects of deductive and inductive instruction on the acquisition of direct object pronouns in French as a second language

    Erlam, Rosemary (2003)

    Journal article
    The University of Auckland Library

    This article presents results from a recent study that isolated grammar instruction that is deductive (i.e., involving rule presentation and metalinguistic information) as a variable and contrasted it with an instructional treatment that is inductive (i.e., focusing on form with no explicit grammar instruction). The effectiveness of these two types of instruction was compared on measures of both comprehension and production. The study also investigated the interaction between type of instruction and the morphological and syntactical features involved in the acquisition of direct object pronouns in French as a second language. The results revealed a significant advantage for the deductive instruction group. The study highlighted the difficulty of designing language measures that access implicit language knowledge. It also underlined the strong relationship that exists between the observed effectiveness of a particular type of instruction and tests/measures used.

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  • Synthesis of a novel polyaniline glycopolymer and its lectin binding studies

    Wilcox, Christopher; Jin, J; Charville, H; Swift, Simon; To, Teresa; Kilmartin, Paul; Evans, Clive; Cooney, Ralph; Brimble, Margaret (2013)

    Journal article
    The University of Auckland Library

    We report the multistep synthesis and polymerisation of a novel aniline derivative with a pendant ??-d-mannose substituent. The ??-D-mannose functionality was successfully introduced before polymerisation via copper-catalysed azide alkyne click chemistry and the resulting monomer was polymerised using general oxidative polymerisation conditions, producing a water soluble mannosylated polyaniline. The polymer was characterised by several techniques and compared with standard polyaniline. The selective binding of the polymer to Concanavalin A (ConA) was successfully demonstrated by the precipitation of polymer???ConA aggregates. Potential applications of these novel polyaniline glycopolymers could include the development of electroactive biomaterials with the ability to bind mannose receptors, or as sensors for proteins or microbes

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  • Late Quaternary terrestrial vertebrate coprolites from New Zealand

    Wood, JR; Wilmshurst, Janet (2014-08)

    Journal article
    The University of Auckland Library

    Over the past decade, concerted efforts to find and study Late Quaternary terrestrial vertebrate coprolites in New Zealand have revealed new insights into the diets and ecologies of New Zealand's prehistoric birds. Here, we provide a broader review of the coprolites found in natural (non-archaeological) Late Quaternary deposits from New Zealand. We summarise the morphological diversity of the coprolites, and discuss the taphonomy of the sites in which they are found. Since the 1870s more than 2000 coprolites have been discovered from 30 localities, all restricted to the South Island. The distribution of coprolite localities appears to reflect the presence of geological and climatic factors that enhance the potential for coprolite preservation; coprolites require dry conditions for preservation, and have been found on the ground surface within drafting cave entrances and at shallow (<300 mm) depths beneath rock overhangs with a northerly aspect. We classify the coprolites into eleven morphotypes, each of which may represent a range of different bird and/or reptile species. A review of genetically identified specimens shows that coprolites of different bird species overlap in size and morphology, reinforcing the need for identifications to be based on ancient DNA analysis.

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  • Surfing injuries requiring first aid in New Zealand, 2007-2012

    Moran, Kevin; Webber, Jonathon (2013-08)

    Journal article
    The University of Auckland Library

    In an island nation such as New Zealand with easy access to surf beaches, surfing activities are very popular and, while generally perceived as a healthy form of outdoor recreation, they do have attendant risks. This study reports on nondrowning, surfing-related incidents that required medical first aid on beaches during five summer seasons from 2007-2012. Retrospective descriptive analysis of data from lifeguard first-aid reports found that 16% (n = 1,327) of injuries were the consequence of surfing activity. More males than females were treated for surfing injuries (68% male, 31% female). Lacerations (59%) and bruising (15%) accounted for most of the injuries. The head was the most common site of injury (32%), and most injuries were caused by contact with the victim's own board (50%). Ways of promoting surf safety via equipment modification, the use of protective head gear, the management of surfing activity by lifeguards, and public education are discussed. ?? 2013 Human Kinetics, Inc.

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