Stephens P.R.,Ministry for the Environment |
Kimberley M.O.,New Zealand Forest Research Institute |
Beets P.N.,New Zealand Forest Research Institute |
Paul T.S.H.,New Zealand Forest Research Institute |
And 4 more authors.
Remote Sensing of Environment | Year: 2012
To meet Kyoto Protocol obligations, New Zealand is required to estimate forest carbon stock change over the first commitment period (2008-2012). New Zealand has three subcategories of forest, namely: Natural forest; Pre-1990 forest; and Post-1989 forest. The Post-1989 forest carbon inventory undertaken in 2008 used discrete return airborne LiDAR and ground-based measurements of 0.06. ha circular plots located on a 4-km × 4-km grid. The national carbon stock estimate was based on a double sampling scheme consisting of 246 plots from which both ground and LiDAR data were obtained, supplemented with 46 additional plots assessed using only LiDAR. This paper describes the relationships established between carbon stocks estimated using ground-based measurements and LiDAR metrics. A regression model explaining 74% of the variation in total carbon was developed using LiDAR 30th percentile height (P30ht) and canopy cover (%Cover). The regression estimator improved the precision of the national carbon stock estimate in 2008 by 6% compared to the ground-based estimate. This inventory indicates that it is possible to reduce the cost of obtaining carbon stock estimates to a specified level of precision using a combination of ground-based and LiDAR measurements in a double sampling approach. The theoretical maximum improvement in precision expected in 2012, when additional LiDAR data are expected to be available, is 50-55%. © 2011.
Morley C.G.,Waiariki Institute of Technology |
Winder L.,Unitec Institute of Technology
PLoS ONE | Year: 2013
This study investigated the effect of the presence of introduced mongoose, environmental quality and habitat on the distribution of native and endemic birds on 16 small islands within Fiji. In total, 9055 birds representing 45 species were observed within four key habitats (forest, villages, crop land and coastal vegetation) on the 16 islands, half of which had mongoose present. Previous studies attribute bird declines and extirpation anecdotally to the mongoose. The presence of mongoose, environmental quality and habitat type had a measurable influence on observed extant native and endemic bird communities. We conclude that three ground birds; Gallirallus phillipensis, Anas supericiliosa and Porphyrio porhyrio were negatively influenced by the presence of mongoose and that Ptilinopus perousii, Phigys solitarius, Chrysoenas victor, Ducula latrans, Clytorhyrchus vitiensis, Pachycephala pectoralis, Prospeia tabunesis, and Foulehaio carunculata were particularly dependent on good quality forest habitat. Conservation priorities in relation to protecting Fiji's endemic birds from the effect of mongoose are discussed and preventative measures suggested. © 2013 Morley, Winder.
Johnstone V.P.A.,Australian National University |
Johnstone V.P.A.,Monash University |
Johnstone V.P.A.,Waiariki Institute of Technology |
Raymond C.R.,Australian National University |
And 2 more authors.
Frontiers in Synaptic Neuroscience | Year: 2013
Long-term potentiation (LTP) in the hippocampus is a fundamental process underlying learning and memory in the brain. At CA3-CA1 synapses, three discrete forms of LTP (LTP1, 2, and 3) have been differentiated on the basis of their persistence, maintenance mechanisms, Ca2+ signaling pathways, expression loci, and electrophysiological requirements. We previously showed that LTP2 and LTP3 involve a presynaptic expression component that is established in a translation-dependent manner. Here we investigate the locus of translation required for presynaptic expression. Neurotransmitter release rate was estimated via FM 1-43 destaining from CA3 terminals in hippocampal slices from male Wistar rats (6-8 weeks). Destaining was measured at sites making putative contact with CA1 dendritic processes in stratum radiatum that had been filled with a membrane impermeable translation inhibitor and a fluorescent indicator. Our results suggest that inhibition of postsynaptic translation eliminates the enhanced release ordinarily observed at 160 min post-LTP induction, and that this effect is limited to sites closely apposed to the filled postsynaptic cell. We conclude that postsynaptic translation is required for the presynaptic component of LTP2 and LTP3 expression. These data considerably strengthen the mechanistic separation of LTP1, 2, and 3 and provide evidence for an expanded repertoire of communication between synaptic elements.
Pasicott P.,Forestal Mininco |
Murphy G.E.,Waiariki Institute of Technology
New Zealand Journal of Forestry Science | Year: 2013
Background: To improve production efficiency and harvesting economics some forest companies are looking at extended hours of use for forest machinery, which may include longer shift lengths, multiple shifts per day, and more harvesting days per week. A review of the literature provides mixed signals on the costs and benefits of extending work hours. Methods: A long-term data base, which contained over 30 000 machine day records and was maintained by a Chilean forest company, was used to evaluate the effects of three types of extended work schedules (beyond a 9 hour work day) on the productivity of two types of harvesting operations; mechanised processing of Pinus radiata D. Don (radiata pine) stems into logs and mechanised harvesting of eucalypt (Eucalyptus globulus Labill and E. nitens H. Deane and Maiden) trees. Results: Production increased as working hours increased. However, average hourly productivity fell by 9 to 30% as the working day length for equipment was extended from 9 to 18 hours. A range of factors, some interacting, were found to affect the level of decrease. These factors included type of work schedule, type of operation, season, tree species, and tree size. Conclusions: Extending working hours beyond 9 hours per day did not result in equivalent increases in production for mechanized harvesting operations in Chile. Further research is needed on the overall economics of working extended hours. © 2013 Pasicott and Murphy; licensee Springer.
Murphy G.,Waiariki Institute of Technology
New Zealand Journal of Forestry | Year: 2013
Some have claimed that forestry as a profession faces a global crisis and its collapse is imminent. Recent statistics by the Food and Agriculture Organisation of the United Nations (FAO) indicates that this is not likely. Globally, student numbers are rising steadily. However, in some parts of the world forestry programmes are closing and the forestry and wood processing sectors in these areas are facing shortages in their workforce. This article looks at the global and local situation, provides comments from forestry educators at various locations around the world, asks if there is a problem, and reports some of the actual and potential solutions for addressing the problems that have been identified in the literature.
Chepulis L.M.,Waiariki Institute of Technology
Journal of complementary & integrative medicine | Year: 2012
The bioactive properties of Manuka honey are now well recognised, but the nature of honey (a sticky, viscous fluid) can make it hard to use as a health remedy. A new technology using encapsulation of Manuka honey with alpha-cyclodextrin molecules has been developed, creating a free-flowing powder that can easily be added to foods and beverages, or tableted / made into capsules for use in health. In this study, we investigated for antioxidant and anti-inflammatory activity. Antioxidant capacity of raw Manuka honeys and matched complexes was measured using the CUPRAC method. Results showed that the antioxidant activity of honey decreased when complexed, this being directly related to dilution of the final product with alpha-cyclodextrin. Anti-inflammatory activity was assessed by measuring inhibition of neutrophil TNF-alpha secretion. Contradictory results were produced, with both stimulation and inhibition of TNF-alpha being observed. Data from this study indicate that the formation of cyclodextrin-based complexes of Manuka honey may potentiate the anti-inflammatory activity of honey, but this may differ depending on methylglyoxal content and the presence of other factors.
Paradis N.,Laval University |
Murphy G.E.,Waiariki Institute of Technology
New Zealand Journal of Forestry Science | Year: 2013
Background and Methods: Measurements of stress wave velocity were performed with the Fibre-gen Director ST300 on 146 hybrid poplar (Populus sp.) plantation trees from GreenWood Resources Inc. located near the city of Boardman, Oregon USA. A laser scanner (Faro Focus 3D) was used to measure the curvature of the trees. Combinations of two software tools (Treemetrics Autostem and Sweep Extractor) were used to calculate the curvature for two log lengths (3 and 6 m) from a height of 10 cm above the ground. The propagation velocities of the stress waves were measured twice; first at breast height on the convex side of the stem and then at 90 degrees clockwise around the stem from the first measurement. Results and Conclusions: Analysis of the data showed that there was no significant difference (p = 0.24) between propagation velocities when the probes were located on either the convex side or at 90 degrees to the convex side. However, the propagation velocity was significantly greater on trees with higher curvature, suggesting that the velocities measured with the ST300 can take into account the presence of reaction wood (tension wood) in the tree. © 2013 Paradis and Murphy.
Fowler A.,Waiariki Institute of Technology |
Cusack B.,University of Auckland
Proceedings of the 6th International Conference on the Foundations of Digital Games, FDG 2011 | Year: 2011
Integrating games into classroom programs to enrich learning has become easier with the increased range of digital media and the greater access to cost effective computing. In this proposed research a series of exploratory studies is planned to see if student engagement could be enhanced by embedding games and game development into a regular classroom program. An integrated game development environment will be used to provide an exploratory context for creativity and games to engage students in learning programming concepts. Copyright 2011 ACM.
Hulme S.R.,University of Otago |
Jones O.D.,University of Otago |
Raymond C.R.,Waiariki Institute of Technology |
Sah P.,University of Queensland |
Abraham W.C.,University of Otago
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2014
Synaptic plasticity is fundamental to the neural processes underlying learning and memory. Interestingly, synaptic plasticity itself can be dynamically regulated by prior activity, in a process termed 'metaplasticity', which can be expressed both homosynaptically and heterosynaptically. Here, we focus on heterosynaptic metaplasticity, particularly long-range interactions between synapses spread across dendritic compartments, and review evidence for intracellular versus intercellular signalling pathways leading to this effect. Of particular interest is our previously reported finding that priming stimulation in stratum oriens of area CA1 in the hippocampal slice heterosynaptically inhibits subsequent long-term potentiation and facilitates long-term depression in stratum radiatum. As we have excluded the most likely intracellular signalling pathways that might mediate this long-range heterosynaptic effect, we consider the hypothesis that intercellular communication may be critically involved. This hypothesis is supported by the finding that extracellular ATP hydrolysis, and activation of adenosine A2 receptors are required to induce the metaplastic state. Moreover, delivery of the priming stimulation in stratum oriens elicited astrocytic calcium responses in stratum radiatum. Both the astrocytic responses and the metaplasticity were blocked by gap junction inhibitors. Taken together, these findings support a novel intercellular communication system, possibly involving astrocytes, being required for this type of heterosynaptic metaplasticity. © 2013 The Author(s) Published by the Royal Society. All rights reserved.
Fowler A.,Waiariki Institute of Technology
ACM International Conference Proceeding Series | Year: 2013
As a student, educator, and researcher, I have long been interested in the learning opportunity that video games represent a corollary of a pedagogic awareness of the considerable benefit of applied and practical learning experiences. The advent of low cost computing has increased ownership of personal computers in the last twenty years. A result of these decreasing costs has seen significant growth in household ownership of personal computing equipment for entertainment, education and enterprise. The increased ownership of personal computing equipment has also seen a significant increase of ownership and use of video games. The increase interest and use of video games for entertainment has seen a similar increase of interest in the use of video games for education. In this paper, a proposed method is presented for obtaining a better understanding of the education potential of video games for young children.