250 results for ResearchCommons@Waikato, Modify

  • Assessing drivers of plantation forest productivity on eroded and non-eroded soils in hilly land, eastern North Island, New Zealand

    Heaphy, Marie; Lowe, David J.; Palmer, David John; Jones, Hayden S.; Gielen, Gerty J. H. P.; Oliver, Graeme R.; Pearce, Stephen H. (2014-07-02)

    Journal article
    University of Waikato

    Methods: The impact of soil erosion by mass movement on forest productivity was investigated in a paired plot trial in a planted forest in a mainly hilly to steepland catchment (Pakuratahi) near Napier, eastern North Island, New Zealand. Tree growth and form were measured and soil properties analysed to compare productivity and productivity drivers in adjacent non-eroded and eroded plots. Background: The effect of soil erosion on New Zealand production forestry is not well known and there has been no research prior to our study into the relationship between soil nutrient status and planted forests growing in eroded soils in steeplands. Results: Regression analysis showed that the decreased soil total nitrogen, total carbon, total phosphorus, and soil organic matter content in eroded plots had a negative impact on tree volume, resulting in a 10% decrease in measured tree volume. Based on an assessment of log quality, trees in the eroded plots were forecast to produce 16% less volume from high-quality pruned logs (with associated reduction in revenue of around $4000 per hectare), than trees in non-eroded plots. The total recoverable volume (TRV), estimated (for a 25-year rotation) from the measured Pinus radiata D. Don trees growing on the eroded sites, was valued at $68,500, about 9% less than the estimated TRV from trees measured on non-eroded plots ($76,000). Tree form and mean tree height in eroded and non-eroded plots were not significantly different. Conclusions: Soil erosion impacts production in planted forests. Afforestation of erodible land provides a valuable ecosystem service through land and soil stabilisation but this service is currently not reflected in the market prices for timber in New Zealand. Maintaining the productive capacity of erodible soils through practices such as fertilisation or continuous-cover forestry can add further costs to production forestry. To ensure that sustainable forest practices are carried out to protect the productivity of soils, financial incentives may be justified.

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  • Investigating diet as the source of tetrodotoxin in Pleurobranchaea maculata

    Khor, Serena; Wood, Susanna A.; Salvitti, Lauren R.; Taylor, David I.; Adamson, Janet E.; McNabb, Paul; Cary, S. Craig (2014)

    Journal article
    University of Waikato

    The origin of tetrodotoxin (TTX) is highly debated; researchers have postulated either an endogenous or exogenous source with the host accumulating TTX symbiotically or via food chain transmission. The aim of this study was to determine whether the grey side-gilled sea slug (Pleurobranchaea maculata) could obtain TTX from a dietary source, and to attempt to identify this source through environmental surveys. Eighteen non-toxic P. maculata were maintained in aquariums and twelve were fed a TTX-containing diet. Three P. maculata were harvested after 1 h, 24 h, 17 days and 39 days and TTX concentrations in their stomach, gonad, mantle and remaining tissue/fluids determined using liquid chromatography-mass spectrometry. Tetrodotoxin was detected in all organs/tissue after 1 h with an average uptake of 32%. This decreased throughout the experiment (21%, 15% and 9%, respectively). Benthic surveys at sites with dense populations of toxic P. maculata detected very low or no TTX in other organisms. This study demonstrates that P. maculata can accumulate TTX through their diet. However, based on the absence of an identifiable TTX source in the environment, in concert with the extremely high TTX concentrations and short life spans of P. maculata, it is unlikely to be the sole TTX source for this species.

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  • Whole genome sequencing of Mycobacterium tuberculosis reveals slow growth and low mutation rates during latent infections in humans

    Colangeli, Roberto; Arcus, Vickery L.; Cursons, Raymond T.; Ruthe, Ali; Karalus, Noel; Coley, Kathy; Manning, Shannon D.; Kim, Soyeon; Marchiano, Emily; Alland, David (2014)

    Journal article
    University of Waikato

    Very little is known about the growth and mutation rates of Mycobacterium tuberculosis during latent infection in humans. However, studies in rhesus macaques have suggested that latent infections have mutation rates that are higher than that observed during active tuberculosis disease. Elevated mutation rates are presumed risk factors for the development of drug resistance. Therefore, the investigation of mutation rates during human latency is of high importance. We performed whole genome mutation analysis of M. tuberculosis isolates from a multi-decade tuberculosis outbreak of the New Zealand Rangipo strain. We used epidemiological and phylogenetic analysis to identify four cases of tuberculosis acquired from the same index case. Two of the tuberculosis cases occurred within two years of exposure and were classified as recently transmitted tuberculosis. Two other cases occurred more than 20 years after exposure and were classified as reactivation of latent M. tuberculosis infections. Mutation rates were compared between the two recently transmitted pairs versus the two latent pairs. Mean mutation rates assuming 20 hour generation times were 5.5X10⁻¹⁰ mutations/bp/generation for recently transmitted tuberculosis and 7.3X10⁻¹¹ mutations/bp/generation for latent tuberculosis. Generation time versus mutation rate curves were also significantly higher for recently transmitted tuberculosis across all replication rates (p = 0.006). Assuming identical replication and mutation rates among all isolates in the final two years before disease reactivation, the u20hr mutation rate attributable to the remaining latent period was 1.6×10⁻¹¹ mutations/bp/generation, or approximately 30 fold less than that calculated during the two years immediately before disease. Mutations attributable to oxidative stress as might be caused by bacterial exposure to the host immune system were not increased in latent infections. In conclusion, we did not find any evidence to suggest elevated mutation rates during tuberculosis latency in humans, unlike the situation in rhesus macaques.

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  • Technology education in New Zealand

    Jones, Alister; Moreland, Judy (2002)

    Journal article
    University of Waikato

    Technology in New Zealand schools is a new area of learning that is now compulsory for all students (years 1–10). Technology education policy was first developed in 1992 (Jones & Carr, 1993). Since then there has been a sustained research and development focus to inform the structure of the curriculum, its subsequent national implementation, and classroom practice. This article discusses the structure of the technology curriculum, programs that were developed to inform teachers of the curriculum and its content, and strategies to enhance the classroom practice of technology.

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  • Technology education in New Zealand

    Forret, Michael; Jones, Alister; Moreland, Judy (2002)

    Journal article
    University of Waikato

    Technology is one of the seven essential learning areas included to achieve the knowledge and understanding that all New Zealanders need to acquire (Ministry of Education, 1993). Responsibility for the implementation of these curricula rests with schools which have flexibility in making implementation decisions. Within the national curriculum framework, all curriculum statements must reflect the principles of the national curriculum framework, specify clear learning outcomes against which students’ achievements can be assessed, have learning outcomes or objectives defined over eight progressive levels, and be grouped in a number of strands. The national curriculum framework’s principles relate to learning and achievement, development of school programs, and aspects of social justice and equity.

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  • High-resolution coproecology: Using coprolites to reconstruct the habits and habitats of New Zealand’s extinct upland Moa (Megalapteryx didinus)

    Wood, Jamie R.; Wilmshurst, Janet M.; Wagstaff, Steven J.; Worthy, Trevor H.; Rawlence, Nicolas J.; Cooper, Alan (2012)

    Journal article
    University of Waikato

    Knowledge about the diet and ecology of extinct herbivores has important implications for understanding the evolution of plant defence structures, establishing the influences of herbivory on past plant community structure and composition, and identifying pollination and seed dispersal syndromes. The flightless ratite moa (Aves: Dinornithiformes) were New Zealand's largest herbivores prior to their extinction soon after initial human settlement. Here we contribute to the knowledge of moa diet and ecology by reporting the results of a multidisciplinary study of 35 coprolites from a subalpine cave (Euphrates Cave) on the South Island of New Zealand. Ancient DNA analysis and radiocarbon dating revealed the coprolites were deposited by the extinct upland moa (Megalapteryx didinus), and span from at least 6,368±31 until 694±30 ¹⁴C years BP; the approximate time of their extinction. Using pollen, plant macrofossil, and ancient DNA analyses, we identified at least 67 plant taxa from the coprolites, including the first evidence that moa fed on the nectar-rich flowers of New Zealand flax (Phormium) and tree fuchsia (Fuchsia excorticata). The plant assemblage from the coprolites reflects a highly-generalist feeding ecology for upland moa, including browsing and grazing across the full range of locally available habitats (spanning southern beech (Nothofagus) forest to tussock (Chionochloa) grassland). Intact seeds in the coprolites indicate that upland moa may have been important dispersal agents for several plant taxa. Plant taxa with putative anti-browse adaptations were also identified in the coprolites. Clusters of coprolites (based on pollen assemblages, moa haplotypes, and radiocarbon dates), probably reflect specimens deposited at the same time by individual birds, and reveal the necessity of suitably large sample sizes in coprolite studies to overcome potential biases in diet interpretation.

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  • Does Socrates vindicate the coherence theory of truth?

    Deane, Warren (2011)

    Journal article
    University of Waikato

    Within Plato's Socratic Dialogues we routinely observe the character of Socrates employing a formal, yet largely unexplained method of investigation into the beliefs that his interlocutors hold as true. Socrates even goes so far as to claim there will be discord within them their whole life should they not be able refute one of his controversial and counter-intuitive revealed truths. With the beliefs under investigation striking to the core of how one should live a good life, this paper seeks to investigate whether Socrates' formal method justifies him in making the claims he does. After exposing the methodology of his technique, we turn to investigate the theory of truth that the method represents, seeking to ascertain a greater understanding of what truth means to Socrates when he makes the claim that a belief is true.

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  • Growth in densely populated Asia: implications for primary product exporters

    Anderson, Kym; Strutt, Anna (2013)

    Journal article
    University of Waikato

    Economic growth and integration in Asia is rapidly increasing the global economic importance of the region. To the extent that this growth continues and is strongest in natural resource-poor Asian economies, it will add to global demand for imports of primary products, to the benefit of (especially nearby) resource-abundant countries. How will global production, consumption and trade patterns change by 2030 in the course of such economic developments and structural changes? We address this question using the GTAP model and Version 8.1 of the 2007 GTAP database, together with supplementary data from a range of sources, to support projections of the global economy from 2007 to 2030 under various scenarios. Factor endowments and real gross domestic product are assumed to grow at exogenous rates, and trade-related policies are kept unchanged to generate a core baseline, which is compared with an alternative slower growth scenario. We also consider the impact of several policy changes aimed at increasing China's agricultural self-sufficiency relative to the 2030 baseline. Policy implications for countries of the Asia-Pacific region are drawn out in the final section.

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  • Matariki, commodity culture, and multiple identities

    Hardy, Ann (2011)

    Conference item
    University of Waikato

    The event known as Matariki, the rising of the Pleiades in winter, which Māori take as the mark of the beginning of a new year, was not a strong feature of the wider public sphere for most of the 20th century. Since 2001, however, when Te Taura Whiri, the Māori Language Commission, published an explanatory booklet with the aim of reviving interest in Matariki as an aide to the maintenance of te reo, it has been promoted by several quasi-governmental institutions, especially the national museum, Te Papa, as a winter festival for all New Zealanders. Its main public presence to date has been through media products: posters, banners, websites, television programmes, newspaper features, calendars, some theatrical performances and physical commemoration ceremonies. The larger project, of which this paper represents an initial descriptive and positioning phase, is a continuation of the researcher's long-standing interest in the intersections of religiosity, culture, and media as they are active in the environment of Aotearoa New Zealand. It assumes, building on theorists such as Bellah and Lundby that the creation of such festivals is an act of 'civil religiosity' that attempts to create and strengthen national community around a set of numinous symbols. However, the development of an enterprise such as Matariki is pursued in a complex political field, where broad agreement across various factions is needed before the festival can take on an enduring material and symbolic existence. In investigating the factors that will determine the future of Matariki it is relevant to consider the interaction of three factors in particular: the ethno-political history of New Zealand; the characteristics of contemporary reflexive spirituality, which are intertwined with commodificatory tendencies and thirdly, the impacts of increasing globalisation on the parameters of identity-formation for citizens in late-modern societies.

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  • Optimizing the ratio of captures to trapping effort in a black rat Rattus rattus control programme in New Zealand

    King, Carolyn M.; Scurr, Don (2013)

    Journal article
    University of Waikato

    The ratio of captures to unit effort is an important cost/benefit measure for volunteer pest control programmes. We describe an experiment designed to investigate the use of pre-feeding and trap pulsing as possible means of increasing this ratio. In 20 traps locked-open and pre-fed with non-toxic pellets for five days, the same number of black rats was caught over the next 5 days as in 20 non pre-fed traps set for the whole 10 days (32 rats each). Allowing for successful traps being unavailable for an average of half a night each, the capture rate in the pre-fed traps was 47% over five days, more than double that in the non pre-fed traps set for twice as long (total 19% in 10 days).

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  • Structure Theory for Extended Kepler-Coulomb 3D Classical Superintegrable Systems

    Kalnins, Ernie G.; Miller, W., Jr. (2012)

    Journal article
    University of Waikato

    The classical Kepler-Coulomb system in 3 dimensions is well known to be 2nd order superintegrable, with a symmetry algebra that closes polynomially under Poisson brackets. This polynomial closure is typical for 2nd order superintegrable systems in 2D and for 2nd order systems in 3D with nondegenerate (4-parameter) potentials. However the degenerate 3-parameter potential for the 3D extended Kepler-Coulomb system (also 2nd order superintegrable) is an exception, as its quadratic symmetry algebra doesn't close polynomially. The 3D 4-parameter potential for the extended Kepler-Coulomb system is not even 2nd order superintegrable. However, Verrier and Evans (2008) showed it was 4th order superintegrable, and Tanoudis and Daskaloyannis (2011) showed that in the quantum case, if a second 4th order symmetry is added to the generators, the double commutators in the symmetry algebra close polynomially. Here, based on the Tremblay, Turbiner and Winternitz construction, we consider an infinite class of classical extended Kepler-Coulomb 3- and 4-parameter systems indexed by a pair of rational numbers (k1,k2) and reducing to the usual systems when k1=k2=1. We show these systems to be superintegrable of arbitrarily high order and work out explicitly the structure of the symmetry algebras determined by the 5 basis generators we have constructed. We demonstrate that the symmetry algebras close rationally; only for systems admitting extra discrete symmetries is polynomial closure achieved. Underlying the structure theory is the existence of raising and lowering constants of the motion, not themselves polynomials in the momenta, that can be employed to construct the polynomial symmetries and their structure relations.

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  • Is it time to turn our attention toward central mechanisms for post-exertional recovery strategies and performance?

    Rattray, Ben; Argus, Christos K.; Martin, Kristy,; Northey, Joseph; Driller, Matthew W. (2015-03-17)

    Journal article
    University of Waikato

    • Central fatigue is accepted as a contributor to overall athletic performance, yet little research directly investigates post-exercise recovery strategies targeting the brain • Current post-exercise recovery strategies likely impact on the brain through a range of mechanisms, but improvements to these strategies is needed • Research is required to optimize post-exercise recovery with a focus on the brain Post-exercise recovery has largely focused on peripheral mechanisms of fatigue, but there is growing acceptance that fatigue is also contributed to through central mechanisms which demands that attention should be paid to optimizing recovery of the brain. In this narrative review we assemble evidence for the role that many currently utilized recovery strategies may have on the brain, as well as potential mechanisms for their action. The review provides discussion of how common nutritional strategies as well as physical modalities and methods to reduce mental fatigue are likely to interact with the brain, and offer an opportunity for subsequent improved performance. We aim to highlight the fact that many recovery strategies have been designed with the periphery in mind, and that refinement of current methods are likely to provide improvements in minimizing brain fatigue. Whilst we offer a number of recommendations, it is evident that there are many opportunities for improving the research, and practical guidelines in this area.

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  • The Structure of the Oligomerization Domain of Lsr2 from Mycobacterium tuberculosis Reveals a Mechanism for Chromosome Organization and Protection

    Summers, Emma Louise; Meindl, Kathrin; Usón, Isabel; Mitra, Alok K.; Radjainia, Mazdak; Colangeli, Roberto; Alland, David; Arcus, Vickery L. (2012)

    Journal article
    University of Waikato

    Lsr2 is a small DNA-binding protein present in mycobacteria and related actinobacteria that regulates gene expression and influences the organization of bacterial chromatin. Lsr2 is a dimer that binds to AT-rich regions of chromosomal DNA and physically protects DNA from damage by reactive oxygen intermediates (ROI). A recent structure of the C-terminal DNA-binding domain of Lsr2 provides a rationale for its interaction with the minor groove of DNA, its preference for AT-rich tracts, and its similarity to other bacterial nucleoid-associated DNA-binding domains. In contrast, the details of Lsr2 dimerization (and oligomerization) via its N-terminal domain, and the mechanism of Lsr2-mediated chromosomal cross-linking and protection is unknown. We have solved the structure of the N-terminal domain of Lsr2 (N-Lsr2) at 1.73 Å resolution using crystallographic ab initio approaches. The structure shows an intimate dimer of two ß-ß-a motifs with no close homologues in the structural databases. The organization of individual N-Lsr2 dimers in the crystal also reveals a mechanism for oligomerization. Proteolytic removal of three N-terminal residues from Lsr2 results in the formation of an anti-parallel β-sheet between neighboring molecules and the formation of linear chains of N-Lsr2. Oligomerization can be artificially induced using low concentrations of trypsin and the arrangement of N-Lsr2 into long chains is observed in both monoclinic and hexagonal crystallographic space groups. In solution, oligomerization of N-Lsr2 is also observed following treatment with trypsin. A change in chromosomal topology after the addition of trypsin to full-length Lsr2-DNA complexes and protection of DNA towards DNAse digestion can be observed using electron microscopy and electrophoresis. These results suggest a mechanism for oligomerization of Lsr2 via protease-activation leading to chromosome compaction and protection, and concomitant down-regulation of large numbers of genes. This mechanism is likely to be relevant under conditions of stress where cellular proteases are known to be upregulated.

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  • Technical note: A significance test for data-sparse zones in scatter plots

    Vetrova, V. V.; Bardsley, W. Earl (2012)

    Journal article
    University of Waikato

    Data-sparse zones in scatter plots of hydrological variables can be of interest in various contexts. For example, a well-defined data-sparse zone may indicate inhibition of one variable by another. It is of interest therefore to determine whether data-sparse regions in scatter plots are of sufficient extent to be beyond random chance. We consider the specific situation of data-sparse regions defined by a linear internal boundary within a scatter plot defined over a rectangular region. An Excel VBA macro is provided for carrying out a randomisation-based significance test of the data-sparse region, taking into account both the within-region number of data points and the extent of the region. Example applications are given with respect to a rainfall time series from Israel and also to validation scatter plots from a seasonal forecasting model for lake inflows in New Zealand.

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  • Development Impacts of Seasonal and Temporary Migration: A Review of Evidence from the Pacific and Southeast Asia

    Gibson, John; McKenzie, David; Rohorua, Halahingano Tu'akolo Siufanga (2013)

    Journal article
    University of Waikato

    Seasonal and temporary migration programs are widely used around the world, yet there is scant evidence as to their development impacts. Absent such evidence, it is difficult to evaluate whether the proliferation of temporary worker programs in recent years is a useful development. This article reviews studies that attempt to measure impacts of seasonal and temporary migration with a particular focus on evidence from the Pacific and Southeast Asia.

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  • Moral Considerations in Embodied Curriculum: A Review Essay

    Barbour, Karen (2016)

    Journal article
    University of Waikato

    This book is a treasure – a collection of significant and insightful works by an outstanding scholar in our international community of practitioner-researchers in dance and arts education. Recognized with both the American National Dance Education Organization’s (NDEO) Lifetime Achievement Award and the Congress On Research in Dance’s (CORD) Award for Outstanding Scholarly Contribution to Dance Research, Sue Stinson is known to many of us through her articles, her work in these organizations and Dance and the Child International (DaCi), and as a leader in the University of North Carolina Greensboro Department of Dance. I recommend this book as essential reading for critical dance researchers engaged in ‘western’ higher education and as an appropriate textbook for graduate students in dance pedagogy and curriculum.

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  • Concluding commentary: Response to Eugene and Kiyo

    White, Elizabeth Jayne (2014)

    Journal article
    University of Waikato

    At the risk of speaking on his behalf I could almost swear I heard Bakhtin laughing gleefully over my shoulder as I read this fascinating dialogue between Eugene and Kiyo. His reason for this might be partly inspired by the glaring misunderstandings both men reveal through their associated interplay with key pedagogical concepts. While polemic in nature, it occurs to me, somewhat ironically, that each man makes the same careful, empirically located, argument from different cultural and philosophical standpoints. At the centre of their debate is the concept of pedagogy and its capacity to promote ‘authentic’ learning. Despite this shared agenda their interpretations of key terms are often at variance and, as a result, they passionately bang their heads against each other in vehement misunderstanding that makes for what Bakhtin (2004) would describe as “lively and expressive” debate (p. 24) on this topic.

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  • Secondary school technology education in New Zealand: Does it do what it says on the box?

    Reinsfield, Elizabeth (2014)

    Journal article
    University of Waikato

    Technology education, as mandated in the New Zealand Curriculum (Ministry of Education, 2007) provides an opportunity for schools and teachers to offer contextually relevant and innovative curriculum responses. Recent governmental initiatives appear to offer additional transitional pathways for ‘at risk’ students but signpost new challenges for technology teachers who are already experiencing tensions between political agenda, school compliance and community expectations. The research upon which this article is based highlights that even when technology teachers feel motivated and empowered to enact curriculum change in their schools, local constraints require ongoing, negotiated responses to ensure that all of their students’ diverse learning needs are being addressed. This article asserts that the continued political shift towards vocational education through initiatives such as the introduction of the Youth Guarantee Scheme, have the potential to further undermine the position of technology teachers and technology education within the New Zealand secondary schooling system.

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  • Separation of variables and contractions on two-dimensional hyperboloid

    Kalnins, Ernie G.; Pogosyan, G.S.; Yakhno, Alexander (2012)

    Journal article
    University of Waikato

    In this paper analytic contractions have been established in the R → ∞ con- traction limit for exactly solvable basis functions of the Helmholtz equation on the two- dimensional two-sheeted hyperboloid. As a consequence we present some new asymptotic formulae.

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  • Central oxytocin and food intake: focus on macronutrient-driven reward

    Klockars, Anica; Levine, Allen Stuart; Olszewski, Pawel K. (2015)

    Journal article
    University of Waikato

    Centrally acting oxytocin (OT) is known to terminate food consumption in response to excessive stomach distension, increase in salt loading, and presence of toxins. Hypothalamic-hindbrain OT pathways facilitate these aspects of OT-induced hypophagia. However, recent discoveries have implicated OT in modifications of feeding via reward circuits: OT has been found to differentially affect consumption of individual macronutrients in choice and no-choice paradigms. In this mini-review, we focus on presenting and interpreting evidence that defines OT as a key component of mechanisms that reduce eating for pleasure and shape macronutrient preferences. We also provide remarks on challenges in integrating the knowledge on physiological and pathophysiological states in which both OT activity and macronutrient preferences are affected.

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