22,334 results for Journal article

  • Notes on Contributors

    Zeiher, Cindy; Grimshaw, Mike

    Journal article
    University of Canterbury Library

    View record details
  • Book Review - Capitalism and Desire: The Psychic Cost of Free Markets by Todd McGowan

    Zupancic, Alenka

    Journal article
    University of Canterbury Library

    View record details
  • Minimally invasive, patient specific, beat-by-beat estimation of left ventricular time varying elastance

    Davidson S; Pretty C; Pironet A; Kamoi S; Balmer J; Desaive T; Chase JG (2017)

    Journal article
    University of Canterbury Library

    Background: The aim of this paper was to establish a minimally invasive method for deriving the left ventricular time varying elastance (TVE) curve beat-by-beat, the monitoring of which's inter-beat evolution could add significant new data and insight to improve diagnosis and treatment. The method developed uses the clinically available inputs of aortic pressure, heart rate and baseline end-systolic volume (via echocardiography) to determine the outputs of left ventricular pressure, volume and dead space volume, and thus the TVE curve. This approach avoids directly assuming the shape of the TVE curve, allowing more effective capture of intra- and inter-patient variability. Results: The resulting TVE curve was experimentally validated against the TVE curve as derived from experimentally measured left ventricular pressure and volume in animal models, a data set encompassing 46,318 heartbeats across 5 Piétrain pigs. This simulated TVE curve was able to effectively approximate the measured TVE curve, with an overall median absolute error of 11.4% and overall median signed error of -2.5%. Conclusions: The use of clinically available inputs means there is potential for real-time implementation of the method at the patient bedside. Thus the method could be used to provide additional, patient specific information on intra- and inter-beat variation in heart function.

    View record details
  • Engaging Māori in Biobanking and Genetic Research: Legal, Ethical and Policy Challenges

    Beaton, Angela; Smith, Barry; Toki, Valmaine; Southey, Kim; Hudson, Maui (2015)

    Journal article
    University of Waikato

    Publically funded biobanking initiatives and genetic research should contribute towards reducing inequalities in health by reducing the prevalence and burden of disease. It is essential that Maori and other Indigenous populations share in health gains derived from these activities. The Health Research Council of New Zealand has funded a research project (2012-2015) to identify Maori perspectives on biobanking and genetic research, and to develop cultural guidelines for ethical biobanking and genetic research involving biospecimens. This review describes relevant values and ethics embedded in Maori indigenous knowledge, and how they may be applied to culturally safe interactions between biobanks, researchers, individual participants, and communities. Key issues of ownership, privacy, and consent are also considered within the legal and policy context that guides biobanking and genetic research practices within New Zealand. Areas of concern are highlighted and recommendations of international relevance are provided. To develop a productive environment for "next-generation" biobanking and genomic research,"‘next-generation" regulatory solutions will be required.

    View record details
  • A data-driven approach to predict suspended-sediment reference concentration under non-breaking waves

    Oehler, Francois; Coco, Giovanni; Green, Malcolm O.; Bryan, Karin R. (2012)

    Journal article
    University of Waikato

    Using a detailed set of hydrodynamic and suspended-sediment observations, we developed data-driven algorithms based on Boosted Regression Trees and Artificial Neural Networks to predict suspended-sediment reference (near-bed) concentration using water depth, wave-orbital semi-excursion, wave period and bed-sediment grainsize as inputs. With one exception, the response of the data-driven algorithms was physically sound; the exception was the response to water depth. Outside of the range covered by the data, predictor performance could not be assessed and is not necessarily reliable. Boosted Regression Trees provide the best predictor of suspended-sediment reference concentration and have a clear explanatory power. Artificial Neural Networks provide slightly poorer predictions. Although the response of the latter is more difficult to interpret, they can be more easily included in numerical models simulating larger (in space) and longer (in time) morphodynamic behavior. Within the range of variability provided by the measurements, these algorithms outperform conventional process-based predictors.

    View record details
  • Interfacial microstructure and shear strength of Ti-6Al-4V/TiAl laminate composite sheet fabricated by hot packed rolling

    Kong, Fantao; Chen, Yuyong; Zhang, Deliang (2011)

    Journal article
    University of Waikato

    A two layer Ti-6Al-4V(wt%)/Ti-43Al-9V-Y(at%) laminate composite sheet with a uniform interfacial microstructure and no discernible defects at the interfaces has been prepared by hot-pack rolling, and its interfacial microstructure and shear strength were characterized. Characterization of the interfacial microstructure shows that there was an interfacial region of uniform thickness of about 250 μm which consisted of two layers: Layer I on the TiAl side which was 80 μm thick and Layer II on the Ti-6Al-4V side which was 170 μm thick. The microstructure of Layer I consisted of massive γ phases, needlelike γ phases and B2 phase matrix, while the microstructure of Layer II consisted of α₂ phase. The microstructure of the interfacial region is the result of the interdiffusion of Ti element from Ti-6Al-4V alloy layer into the TiAl alloy layer and Al element from the TiAl alloy layer into the Ti-6Al-4V alloy layer. The shear strength measurement demonstrated that the bonding strength between the TiAl alloy and Ti-6Al-4V alloy layers in the laminate composite sheet was very high. This means that the quality of the interfacial bonding between the two layers achieved by the multi-path rolling is high, and the interface between the layers is very effective in transferring loading, causing significantly improved toughness and plasticity of the TiAl/Ti-6Al-4V laminate composite sheet.

    View record details
  • Milk whey protein concentration and mRNA associated with β-lactoglobulin phenotype

    Prosser, Colin G.; Turner, Sally-Anne; McLaren, Robert D.; Langley, Brett; L'Huillier, Phil J.; Molan, Peter C.; Auldist, Martin J. (2000)

    Journal article
    University of Waikato

    Two common genetic variants of β-lactoglobulin (β-lg), A and B, exist as co- dominant alleles in dairy cattle (Aschaffenburg, 1968). Numerous studies have shown that cows homozygous for β-lg A have more β-lg and less α-lactalbumin (α-la) and casein in their milk than cows expressing only the B variant of β-lg (Ng-Kwai-Hang et al. 1987; Graml et al. 1989; Hill, 1993; Hill et al. 1995, 1997). These differences have a significant impact on the processing characteristics of the milk. For instance, the moisture-adjusted yield of Cheddar cheese is up to 10% higher using milk from cows of the β-lg BB phenotype compared with milk from cows expressing only the A variant (Hill et al. 1997). All these studies, however, describe compositional differences associated with β-lg phenotype in established lactation only. No information is available on the first few weeks of lactation, when there are marked changes in the concentrations of β-lg and α-la (Pérez et al. 1990).

    View record details
  • Semigroups with if-then-else and halting programs

    Jackson, Marcel; Stokes, Tim E. (2009)

    Journal article
    University of Waikato

    The "if–then–else" construction is one of the most elementary programming commands, and its abstract laws have been widely studied, starting with McCarthy. Possibly, the most obvious extension of this is to include the operation of composition of programs, which gives a semigroup of functions (total, partial, or possibly general binary relations) that can be recombined using if–then–else. We show that this particular extension admits no finite complete axiomatization and instead focus on the case where composition of functions with predicates is also allowed (and we argue there is good reason to take this approach). In the case of total functions — modeling halting programs — we give a complete axiomatization for the theory in terms of a finite system of equations. We obtain a similar result when an operation of equality test and/or fixed point test is included.

    View record details
  • New Zealand teachers' experiences in implementing the technology curriculum

    Jones, Alister; Harlow, Ann; Cowie, Bronwen (2004)

    Journal article
    University of Waikato

    This paper describes the results of a national study to investigate teachers' experiences in the implementation of the technology curriculum in New Zealand schools from years 1–13. This investigation of the implementation of the technology curriculum is part of a larger study being undertaken nationally in all curriculum areas (National Schools Sampling Study) to explore how effective the curriculum is in practice and how the results can inform future developments. National focus groups, questionnaires and case studies are used to explore how the curriculum is being implemented. The questionnaires were distributed to over 10% of New Zealand schools. The key findings indicate that most primary school teachers are aiming for curriculum coverage, have moderate levels of confidence but are concerned about curriculum overcrowding. Years 7 and 8 teachers are mainly concerned about assessment, whereas secondary school teachers are constrained by existing structures in schools.

    View record details
  • Groups with fix-set quasi-order

    Stokes, Tim E.; Hawthorn, Ian; Manoharan, Siva (2015)

    Journal article
    University of Waikato

    If X is a set, the fix-set quasiorder on a group of permutations of X is the quasiorder induced by containment of the fix-sets of elements of SX. Axioms for such quasiorders on groups have previously been given. We generalise these to allow non-faithful group actions, the resulting abstract quasiorders being called fix-orders. We characterise the possible fix-orders on a given group G in terms of certain families of subgroups of G. The special case in which the members of the defining family of subgroups are all normal is considered. Software is used to construct and analyse the lattices of fix-orders of many small finite groups.

    View record details
  • Joins of subalgebras and normals in 0-regular varieties

    Stokes, Tim E.; McConnell, N. R. (2015)

    Journal article
    University of Waikato

    In any 0-normal variety (0-regular variety in which {0} is a subalgebra), every congruence class containing 0 is a subalgebra. These “normal subalgebras” of a fixed algebra constitute a lattice, isomorphic to its congruence lattice. We are interested in those 0-normal varieties for which the join of two normal subalgebras in the lattice of normal subalgebras of an algebra equals their join in the lattice of subalgebras, as happens with groups and rings. We characterise this property in terms of a Mal’cev condition, and use examples to show it is strictly stronger than being ideal determined but strictly weaker than being 0-coherent (classically ideal determined) and does not imply congruence permutability.

    View record details
  • The Chthonomonas calidirosea genome is highly conserved across geographic locations and distinct chemical and microbial environments in New Zealand's Taupo Volcanic Zone

    Lee, Kevin C.; Stott, Matthew B.; Dunfield, Peter F.; Huttenhower, Curtis; McDonald, Ian R.; Morgan, Xochitl C. (2016)

    Journal article
    University of Waikato

    Chthonomonas calidirosea T49T is a low-abundance, carbohydrate-scavenging, and thermophilic soil bacterium with a seemingly disorganized genome. We hypothesized that the C. calidirosea genome would be highly responsive to local selection pressure, resulting in the divergence of its genomic content, genome organization, and carbohydrate utilization phenotype across environments. We tested this hypothesis by sequencing the genomes of four C. calidirosea isolates obtained from four separate geothermal fields in the Taupō Volcanic Zone, New Zealand. For each isolation site, we measured physicochemical attributes and defined the associated microbial community by 16S rRNA gene sequencing. Despite their ecological and geographical isolation, the genome sequences showed low divergence (maximum, 1.17%). Isolate-specific variations included single-nucleotide polymorphisms (SNPs), restriction-modification systems, and mobile elements but few major deletions and no major rearrangements. The 50-fold variation in C. calidirosea relative abundance among the four sites correlated with site environmental characteristics but not with differences in genomic content. Conversely, the carbohydrate utilization profiles of the C. calidirosea isolates corresponded to the inferred isolate phylogenies, which only partially paralleled the geographical relationships among the sample sites. Genomic sequence conservation does not entirely parallel geographic distance, suggesting that stochastic dispersal and localized extinction, which allow for rapid population homogenization with little restriction by geographical barriers, are possible mechanisms of C. calidirosea distribution. This dispersal and extinction mechanism is likely not limited to C. calidirosea but may shape the populations and genomes of many other low-abundance free-living taxa.

    View record details
  • Burial duration and frequency influences resilience of differing propagule types in a subtidal seagrass, Posidonia australis

    Campbell, Marnie L. (2016)

    Journal article
    University of Waikato

    Sedimentation that leads to periodic, and often prolonged, burial events is becoming more common on the world’s coastlines as human populations expand and create urbanised marine environments. Different seagrass species react differently to sediment burial but many species in the southern hemisphere are yet to be examined. How seagrasses react to burial has restoration implications. There is a need to critically assess seagrass transplant propagule responses to periodic (pulse) and prolonged (press) burial events before selecting the most appropriate species, transplant propagule, and transplant site. In my study, mesocosm experiments, coupled with field measurements were used to assess how sexual (seedlings) and vegetative (sprigs) propagules of Posidonia australis responded to pulse and press burial events. Seedlings were highly susceptible to burial (both pulse and press), with no survival at the end of the experimental period. In contrast, rhizome growth in vegetative propagules was stimulated by pulse burial, although press burial events resulted in mortality. The implication for Posidonia australis restoration efforts in areas where burial is periodic, was that vegetative propagules are optimal transplant units, in comparison to seedlings. Press burial however, renders a transplant site sub-optimal for both seedling and sprig transplants.

    View record details
  • Mineral analysis of pine nuts (Pinus spp.) grown in New Zealand

    Vanhanen, Leo P.; Savage, Geoffrey P.

    Journal article
    Lincoln University

    Mineral analysis of seven Pinus species grown in different regions of New Zealand; Armand pine (Pinus armandii Franch), Swiss stone pine (Pinus cembra L.), Mexican pinyon (Pinus cembroides Zucc. var. bicolor Little), Coulter pine (Pinus coulteri D. Don), Johann’s pine (Pinus johannis M.F. Robert), Italian stone pine (Pinus pinea L.) and Torrey pine (Pinus torreyana Parry ex Carrière), was carried out using an inductively coupled plasma optical emission spectrophotometer (ICP-OES) analysis. Fourteen different minerals (Al, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S and Zn) were identified in all seven varieties, except that no Al or Na was found in Pinus coulteri D. Don. New Zealand grown pine nuts are a good source of Cu, Mg, Mn, P and Zn, meeting or exceeding the recommended RDI for these minerals (based on an intake of 50 g nuts/day) while they supplied between 39%–89% of the New Zealand RDI for Fe. Compared to other commonly eaten tree-nuts New Zealand grown pine nuts are an excellent source of essential minerals.

    View record details
  • Effect of cooking on the oxalate content of selected Thai vegetables

    Juajun, O.; Vanhanen, Leo P.; Sangketkit, C.; Savage, Geoffrey P.

    Journal article
    Lincoln University

    View record details
  • Calcium and oxalate contents of curly leaf (Petroselinum crispum) and flat leaf (P. crispum var. neapolitanum) parsley cultivars

    Savage, Geoffrey P.; Vanhanen, Leo P.

    Journal article
    Lincoln University

    The total, soluble and insoluble oxalate contents of the leaves and stems of curly leaf (Petroselinum crispum) and flat leaf (P. crispum var. neapolitanum) parsley cultivarswere extracted from fresh tissue and measured using HPLC chromatography. There were no significant differences between the total and insoluble oxalate contents of the leaves between the flat leaf and curly leaf cultivars. There was a small difference (P < 0.05) between the soluble oxalate contents of the leaves of the two cultivars. The mean total, soluble and insoluble oxalates of the leaves of the two cultivars were 1137.0, 177.9 and 959.3 mg/100 g dry matter (DM), respectively. The mean total, soluble and insoluble oxalate contents of the stems were 1680.7, 386.2 and 1294.5 mg/100 g DM, respectively, and these were significantly higher than the mean values for the leaves of the two cultivars. Insoluble oxalate made up a mean of 77.0% of the curly leaf stems and leaves compared to a mean of 84.4% found in the flat-leaved cultivar. Unavailable calcium, that is, calcium bound to oxalate as insoluble oxalate, made up a mean of 26.9% of the total calcium in the leaves of both cultivars while the unavailable calcium made up 45.0% of the total calcium in the stems of the two cultivars. Overall, the oxalate contents of both parsley cultivars are relatively high, on a dry matter basis, but their overall contribution to dietary intake is likely to be quite small as parsley is an herb that is only used in small amounts to garnish foods.

    View record details
  • Effect of temperature on the drying characteristics, colour and ascorbic acid content of green and gold kiwifruits

    Diamante, Lemuel; Durand, M.; Savage, Geoffrey P.; Vanhanen, Leo P.

    Journal article
    Lincoln University

    The drying characteristics of green and gold kiwifruit were determined using an air velocity of 0.20 m/s at ambient humidity and different temperatures (60, 80 and 100°C). The colour values (L*, a* and b*) and ascorbic acid content were also measured for the different fresh and dried kiwifruits. The drying of green and gold kiwifruit slices consists of a constant rate period (CRP) and two parts of falling rate period (FRP). The CRP drying rate, first and second FRP drying coefficients increase with drying temperature for both the green and gold kiwifruit slices. The first critical moisture content (CMC) and the dynamic equilibrium MC decrease with drying temperature for both the green and gold kiwifruit slices. The second CMC for both green and gold kiwifruit slices were not affected by drying temperature. The values for chroma of the dried green kiwifruit increased while the dried gold kiwifruit decreased with higher temperature as compared with the fresh samples. The values for hue angle of dried green and gold kiwifruits decreased at higher temperature. Lastly, the values for browning index of dried green and gold kiwifruits increased at higher temperature. There was not much change on the ascorbic acid contents of fresh and dried green and gold kiwifruits when drying at 60 and 80°C. But there was about 19% decrease in the ascorbic acid content of dried green and gold kiwifruits after drying at 100°C.

    View record details
  • Effects of calcium chloride, zinc chloride and water infusion on metmyoglobbin reducing activity and fresh lamb colour

    Bekhit, Alaa E. A.; Alayan, Mohammadatta; Morton, James D.; Vanhanen, Leo P.; Sedcole, John R.; Bickerstaffe, Roy

    Journal article
    Lincoln University

    Calcium chloride (CaCl 2), zinc chloride (ZnCl 2), or water infusions were used to investigate the biochemical factors that affect fresh lamb color, and to examine the role of metmyoglobin-reducing activity in regulating this important quality attribute. Immediately after exsanguination, lamb carcasses (n = 6 per treatment) were infused (10% of BW) with 0.3 M CaCl 2, 0.05 M ZnCl 2, or water via a catheter inserted into the left carotid artery. The right LM was excised at 24-h postmortem and divided into two halves. The caudal portion was cut into 2.5-cm-thick chops and displayed for 6 d under 1,076 1x of white fluorescent lighting at 2°C, whereas the cranial half was vacuum-packaged and stored at 2°C for 3 wk before retail display. Objective color measurements and samples for biochemical analysis were taken at 0, 1, 3, and 6 d of display. In infused carcasses, pH decline was more rapid (P < 0.05) than in untreated controls, and it was greatest for CaCl 2-infused carcasses. Calcium chloride-infused carcasses had lower (P < 0.01) NAD and higher (P < 0.001) NADPH concentrations than water- and ZnCl 2-infused or untreated control carcasses. The negative effects of calcium infusion on fresh lamb color, higher (P < 0.01) metmyoglobin accumulation rate, and lower (P < 0.01) L*, a*, and b* color measurements could be explained by the lower amounts of unbound water (P < 0.01), shorter sarcomere length (P < 0.01), lower NAD concentration (P < 0.01), and higher lipid peroxidation (P < 0.01). Zinc and water-infusions produced less (P < 0.01) lipid oxidation and improved the color and color stability of fresh lamb (P < 0.001). Rate of lipid oxidation in LM chops was greater (P < 0.01) after 3 wk of vacuum-packaged storage than 24-h postmortem. Metmyoglobin-reducing activities (sarcoplasmic and myofibrillar) were decreased in response to infusion treatments (P < 0.001), and ZnCl 2 infusion resulted in the lowest metmyoglobin-reducing activities (P < 0.001). A significant association between the myofibrillar metmyoglobin-reducing activity and lipid peroxidation was observed, but metmyoglobin-reducing activities were not associated with any improvement in lamb color. Strategies to increase the antioxidant levels in lamb are very important to improve lamb quality, especially during vacuum-packaging storage. ©2005 American Society of Animal Science. All rights reserved.

    View record details
  • Vacuum fried gold Kiwifruit: Effects of frying process and pre-treatment on the physico-chemical and nutritional qualities

    Diamante, Lemuel; Presswood, Hannah; Savage, Geoffrey P.; Vanhanen, Leo P.

    Journal article
    Lincoln University

    A study was conducted to determine the effects of frying process and pre-treatment on the physico-chemical and nutritional qualities of vacuum fried gold kiwifruit. The kiwifruit samples were peeled and cut into slices 5 mm thick. Half of the kiwifruit samples were soaked for one hour in a 33% maltodextrin solution, then placed into plastic bags and frozen and the other half (unsoaked) were simply frozen. The two set of samples were subjected to three frying processes and all at 2.3 kPa vacuum, after which the kiwifruit was removed from the fryer and centrifuged in cheese cloth for four minutes to remove excess surface oil. Generally, the vacuum fried gold kiwifruit samples from the 80°C for 50 minutes process gave higher moisture content and lower oil content followed by the samples from the 90°C for 35 minutes process and then the 100°C for 25 minutes process. The vacuum fried samples from the 100°C for 25 minutes process gave consistently higher total colour change and browning index, followed by the 90°C for 35 minutes process and then the 80°C for 50 minutes process. The unsoaked sample from the 80°C for 50 minutes process gave significantly lower breaking force than the sample from the 100°C for 25 minutes process. There was no significant difference in the breaking force of all vacuum fried soaked samples. Generally the samples from the 80°C for 50 minutes process gave higher ascorbic acid contents followed by the samples from the 90°C for 35 minutes process and then the 100°C for 25 minutes process. © 2011.

    View record details
  • Comparison of oxalate contents and recovery from two green juices prepared using a masticating juicer or a high speed blender

    Vanhanen, Leo P.; Savage, Geoffrey P.

    Journal article
    Lincoln University

    © 2015 The Authors. Background: Juicing is a popular health trend where green juice is prepared from a range of common vegetables. If spinach is included in the mix then the juice may contain significant quantities of oxalates and these are not safe to consume regularly in large amounts as they predispose some people to kidney stone formation. Methods: Green juice, prepared from spinach and other common vegetables using a high speed blender that produced a juice containing all the original fiber of the processed raw vegetables, was compared with a juice produced using a masticating juicer, where the pulp containing most of the fiber was discarded in the process. The oxalate contents of both juices were measured using HPLC chromatography. Results: Two juices were prepared using each processing method, one juice contained a high level of spinach, which resulted in a juice containing high levels of total, soluble and insoluble oxalates; the other was a juice mixture made from the same combination of vegetables but containing half the level of spinach, which resulted in a juice containing considerably (P < 0.001) lower levels of oxalates. Removal of the pulp fraction from the green vegetable juice had resulted in significantly (P < 0.01) higher levels of oxalates in the remaining juices made from both levels of spinach. Conclusion: Green juices prepared using common vegetables can contain high levels of soluble oxalates, which will vary with the type and proportion of vegetables used and whether or not the pulp fraction was retained during processing.

    View record details