5,375 results for Lincoln University Research Archive

  • Optical sensors for variable rate nitrogen application in dairy pastures

    Wigley, Kathryn; Owens, Jennifer; Trethewey, Jason A. K.; Ekanayake, Dinanjana; Roten, Rory; Werner, Armin

    Journal article
    Lincoln University

    Reducing the amount of nitrogen (N) fertiliser applied to dairy pastures down to agronomically optimised levels would have positive economic and environmental results. The ability of commercially available optical sensors to estimate biomass yield and foliar-N uptake in pastures was investigated. Vegetative indices (Simple Ratio, SR; Water Index, WI; and Normalised Difference Vegetation Index, NDVI) from two active optical reflectance sensors (N-Sensor, Yara; and Greenseeker, Trimble) were compared with manually measured biomass and N-uptake in above-ground foliage. There were three measurements over time, from pastures that had received different N fertiliser applications rates (0, 10, 20, 40 and 80 kg N/ha). It was found that the sensors were able to detect differences in biomass and foliar N-uptake following defoliation of grazed pastures. The tested optical sensors have the potential to inform a real-time variable rate fertiliser application system.

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  • Variation in the KAP6-1 gene in Chinese Tan sheep and associations with variation in wool traits

    Tao, J.; Zhou, Huitong; Gong, Hua; Yang, Z.; Ma, Q.; Cheng, Paul; Ding, W.; Li, Y.; Hickford, Jonathan G. H.

    Journal article
    Lincoln University

    The keratin-associated protein KAP6-1 gene (KRTAP6-1) was investigated for its effect on wool traits in Chinese Tan sheep. Two previously identified KRTAP6-1 variants (A and B) and two newly identified KRTAP6-1 variants (D and E) were detected with frequencies of 28.9%, 57.1%, 10.3% and 3.7% for A, B, D and E, respectively. The KRTAP6-1 variant C, was not found in the Chinese Tan sheep. Variant D was found to be associated with increased straightened fibre-length at birth, while variant E was found to be associated with increased straightened fibre-length, the number of crimps and the degree of crimping at approximately 35 days post-partum (conventionally called “Er-mao”). Variant E was also associated with increased wool fibre growth rate from birth to Er-mao. These results suggest that variation in ovine KRTAP6-1 may affect wool traits in early life in Chinese Tan sheep.

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  • Managing fire and biodiversity in the wildland-urban interface: A role for green firebreaks

    Curran, Timothy J.; Perry, G. L. W.; Wyse, Sarah . V.; Alam, Md

    Journal article
    Lincoln University

    In the wildland-urban interface, the imperative is often to protect life and property from destructive fires, while also conserving biodiversity. One potential tool for achieving this goal is the use of green firebreaks: strips of low flammability species planted at strategic locations to help reduce fire spread by slowing or stopping the fire front, extinguishing embers or blocking radiant heat. If comprised of native species, green firebreaks also have biodiversity benefits. Green firebreaks have been recommended for use throughout the world, including the Americas, Europe, Asia, Africa and Australasia. However, despite this widespread endorsement, there has been little empirical testing of green firebreaks, particularly with field experiments. This knowledge gap needs addressing. Green firebreaks should be considered as part of the revegetation strategy following recent extensive wildfires in places such as New Zealand and Chile.

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  • A laboratory for design-directed research. Building design scholarship and academic possibility through designing

    Abbott, Michael R.; Bowring, Jacqueline

    Journal article
    Lincoln University

    Designing is an experimental practice. Eschewing traditional concepts of designing as simply solving problems, and ideas of research as a positivist pursuit of truth, Landscope DesignLab embraces an expansive perspective of design-directed research. Using the tools of questioning, collaborating, designing, grounding and communicating, the DesignLab explores the terrains of possibility. Working within an inter-disciplinary milieu fosters strong connections, and seizes the generative possibilities of problems, questions, absences, and data.

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  • Soil inorganic nitrogen in spatially distinct areas within a commercial dairy farm in Canterbury, New Zealand

    Ekanayake, Dinanjana; Owens, Jennifer; Hodge, Simon; Trethewey, Jason A. K.; Roten, Rory; Westerschulte, M.; Belin, S.; Werner, Armin; Cameron, Keith C.

    Journal article
    Lincoln University

    For precision nitrogen (N) fertilisation of grazed dairy paddocks, soil N distribution needs to be quantified. It is expected that farm infrastructure will affect inorganic-N distribution due to its influence on cow grazing behaviour. Surface soil from four spatially distinct areas (main gate, water troughs, non irrigated and the remaining pasture) was analysed for soil ammonium-N (NH₄⁺-N) and nitrate-N (NO₃⁻ -N) from three paddocks (180 soil samples) on an irrigated commercial dairy farm in Canterbury, New Zealand. Variation between paddocks was higher for NO₃⁻ (P<0.001) but not for NO₃⁻(P=0.37), though there was variation in NO₃⁻ with distance from the gates and troughs. This study demonstrates methods for classifying spatially distinct areas of grazed pasture to quantify their influence on inorganic-N distribution. Further research is required to better understand variability.

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  • No saturation in the accumulation of alien species worldwide

    Seebens, H.; Blackburn, T. M.; Dyer, E. E.; Genovesi, P.; Hulme, Philip E.; Jeschke, J. M.; Pagad, S.; Pyšek, P.; Winter, M.; Arianoutsou, M.; Bacher, S.; Blasius, B.; Brundu, G.; Capinha, C.; Celesti-Grapow, L.; Dawson, W.; Dullinger, S.; Fuentes, N.; Jäger, H.; Kartesz, J.; Kenis, M.; Kreft, H.; Kühn, I.; Lenzner, B.; Liebhold, A.; Mosena, A.; Moser, D.; Nishino, M.; Pearman, D.; Pergl, J.; Rabitsch, W.; Rojas-Sandoval, J.; Roques, A.; Rorke, S.; Rossinelli, S.; Roy, H. E.; Scalera, R.; Schindler, S.; Štajerová, K.; Tokarska-Guzik, B.; Van Kleunen, M.; Walker, K.; Weigelt, P.; Yamanaka, T.; Essl, F.

    Journal article
    Lincoln University

    Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of 45,813 first records of 16,926 established alien species, we show that the annual rate of first records worldwide has increased during the last 200 years, with 37% of all first records reported most recently (1970-2014). Inter-continental and inter-taxonomic variation can be largely attributed to the diaspora of European settlers in the nineteenth century and to the acceleration in trade in the twentieth century. For all taxonomic groups, the increase in numbers of alien species does not show any sign of saturation and most taxa even show increases in the rate of first records over time. This highlights that past efforts to mitigate invasions have not been effective enough to keep up with increasing globalization.

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  • Europe's other debt crisis caused by the long legacy of future extinctions

    Dullinger, S.; Essl, F.; Rabitsch, W.; Erb, K. H.; Gingrich, S.; Haberl, H.; Hülber, K.; Jarošík, V.; Krausmann, F.; Kuḧn, I.; Pergl, J.; Pyšek, P.; Hulme, Philip E.

    Journal article
    Lincoln University

    Rapid economic development in the past century has translated into severe pressures on species survival as a result of increasing land-use change, environmental pollution, and the spread of invasive alien species. However, though the impact of these pressures on biodiversity is substantial, it could be seriously underestimated if population declines of plants and animals lag behind contemporary environmental degradation. Here, we test for such a delay in impact by relating numbers of threatened species appearing on national red lists to historical and contemporary levels of socioeconomic pressures. Across 22 European countries, the proportions of vascular plants, bryophytes, mammals, reptiles, dragonflies, and grasshoppers facing medium-to-high extinction risks are more closely matched to indicators of socioeconomic pressures (i.e., human population density, per capita gross domestic product, and a measure of land use intensity) from the early or mid-, rather than the late, 20th century. We conclude that, irrespective of recent conservation actions, large scale risks to biodiversity lag considerably behind contemporary levels of socioeconomic pressures. The negative impact of human activities on current biodiversity will not become fully realized until several decades into the future. Mitigating extinction risks might be an even greater challenge if temporal delays mean many threatened species might already be destined toward extinction.

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  • Transfer Pathways Programme (TPP) : New research to determine pathway-specific contaminant transfers from the land to water bodies

    Stenger, Roland; Wilson, Scott; Barkle, Greg; Close, M. E.; Woodward, Simon; Burbery, Lee; Pang, L.; Rekker, Jens; Wöhling, T.; Clague, Juliet; McDowell, Richard; Thomas, Steve; Clothier, B.; Lilburne, L.; Miller, B.

    Conference Contribution - Published
    Lincoln University

    Land use (source) can only be defensibly linked to an effect on a receiving water body (receptor) if the critical transfer pathways and the hydrological and biogeochemical processes that occur along them are understood. Depending on the natural setting of the catchment and the contaminant concerned, surface runoff, interflow, artificial drainage, shallow and deep groundwater may be critical pathways. The Transfer Pathways Programme, which was successful in the MBIE 2015 investment round, has therefore been developed to quantify pathway-specific transfers of nitrogen (N) and phosphorus (P) that take lag times and attenuation potentials of the different pathways into account. The multi-disciplinary research team will be working closely with industry (DairyNZ) and council partners (Waikato Regional Council, Environment Canterbury, Marlborough District Council), as well as iwi on achieving the programme‟s aims.By 2018 we will have established how N and P transfer is partitioned across the pathways relevant in four case study areas (Wairau Aquifer, Ashley-Waimakariri, Hauraki, Upper Waikato). A catchment typology scheme will facilitate the application of transfer pathway understanding in other, less well studied catchments. Concurrently, we will apply an iterative modelling framework to integrate existing data of different types and quality, identify knowledge gaps, characterise and quantify fluxes, analyse uncertainty, and ultimately derive simplified models for management purposes. The quantitative understanding of the contaminant transfers through the various pathways together with the tools developed will enable stakeholders in land and water management to develop fit for purpose policies, management practices and mitigation measures. The research will thus help to maximise economic benefits from land use while achieving the water quality targets mandated by the community.

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  • Comparative virulence of Beauveria bassiana isolates against clover root weevil (Sitona obsoletus)

    Nelson, T. L.; McNeill, M. R.; van Koten, C.; Goldson, Stephen

    Journal article
    Lincoln University

    Clover root weevil (Sitona obsoletus) (CRW) is of Palearctic origin and in New Zealand has become an invasive pest of white clover. A major survey was undertaken in 2000 to identify and collect the most promising CRW biocontrol agents from a wide range of locations in Europe and the UK. Subsequently several Beauveria bassiana strains obtained from the cadavers of weevils originally collected live from England, Wales, France and Romania were isolated in containment at AgResearch, Lincoln. Thereafter bioassays using New Zealand field-collected CRW populations showed that all the European isolates were virulent against the adults, with two being particularly effective. Notably, all of the European B. bassiana isolates exhibited greater virulence against CRW than a New Zealand isolate collected from local CRW populations and a commercial B. bassiana product registered in the USA as Botanigard®.

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  • Potential environmental benefits from blending biosolids with other organic amendments before application to land

    Paramashivam, Dharini; Dickinson, Nicholas; Clough, Timothy J.; Horswell, J.; Robinson, Brett

    Journal article
    Lincoln University

    Biosolids disposal to landfill or through incineration is wasteful of a resource that is rich in organic matter and plant nutrients. Land application can improve soil fertility and enhance crop production but may result in excessive nitrate N (NO₃⁻-N) leaching and residual contamination from pathogens, heavy metals, and xenobiotics. This paper evaluates evidence that these concerns can be reduced significantly by blending biosolids with organic materials to reduce the environmental impact of biosolids application to soils. It appears feasible to combine organic waste streams for use as a resource to build or amend degraded soils. Sawdust and partially pyrolyzed biochars provide an opportunity to reduce the environmental impact of biosolids application, with studies showing reductions of NO₃⁻-N leaching of 40 to 80%. However, other organic amendments including lignite coal waste may result in excessive NO₃⁻-N leaching. Field trials combining biosolids and biochars for rehabilitation of degraded forest and ecological restoration are recommended.

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  • Is the invasive species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine stem weevil) a threat to New Zealand natural grassland ecosystems?

    Barratt, B. I. P.; Barton, D. M.; Philip, B. A.; Ferguson, C. M.; Goldson, Stephen

    Journal article
    Lincoln University

    Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants.

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  • Effect of Epichloë endophyte strains in Lolium spp. cultivars on Argentine stem weevil parasitism by Microctonus hyperodae

    Goldson, Stephen; Tomasetto, Federico; Popay, A. J.

    Journal article
    Lincoln University

    This paper reports on an extensive field investigation conducted at Lincoln during the 2014-2015 summer/early autumn. This aimed to assess the effects of a range of novel Epichloë endophytes when present in different cultivars of Lolium spp. on parasitism rates by the biological control agent, Microctonus hyperodae, in Listronotus bonariensis (i.e. The Argentine stem weevil). Results for the entire summer, and including all treatment combinations, did not find any significant differences in parasitism in L. bonariensis populations. However, in the early autumn, independent of the endophytes present, significantly higher levels of parasitism were found in a tetraploid Lolium multiflorum cultivar and a tetraploid L. perenne selection compared to the L. perenne cultivars. Whether this finding has any bearing on a possible mechanism of weevil resistance is discussed.

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  • Farmland, food, and bioenergy crops need not compete for land

    Littlejohn, C. P.; Curran, Timothy J.; Hofmann, Rainer; Wratten, Stephen D.

    Journal article
    Lincoln University

    The need to mitigate the effects of climate change has resulted in some governments setting mandates to attain targets for bioenergy production. Recently, there has been concern that the large-scale use of first-generation biofuel feedstocks may result in ‘food displacement.’ New second-generation bioenergy crops can be produced on poor soil and provide a potential solution to this problem if grown on marginal land that was previously uneconomic for agricultural production. However, consequences of this production method are biodiversity loss and carbon release if previously fallow land is cultivated. Marginal land is also less agriculturally productive, and if profits from biomass plantations exceed those from food production, farmers will grow bioenergy crops on prime agricultural land in order to maximize profit. Alternative approaches include utilizing mixtures of native grassland perennials grown on agriculturally degraded lands for bioenergy production and producing biodiesel from microalgae. In New Zealand, research is being conducted on the benefits of integrating bioenergy crops within the present farming system. In this research, the ecosystem services (ES) value of re-instated shelter on irrigated dairy farms is assessed using the novel approach of adopting a bioenergy crop for shelterbelt creation. Together with on-farm ES as well as those external to the farm, ES delivery from shelterbelts—rows of trees or shrubs planted to provide wind protection—potentially improves the profitability of the farming enterprise. By planting a shelterbelt of Miscanthus x giganteus (Mxg), a sterile hybrid bioenergy grass that grows four meters tall, in the northerly corners of fields, we were able to measure the multiple ES advantages generated including shelter for livestock, the growing of a harvestable crop for fodder or renewable fuels, and benefits from creating a new on-farm habitat such as a refuge for beneficial predatory insects and pollinators. Findings show that pastures benefiting from the shelter of the grass have reduced evapotranspiration rates, the process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces and by transpiration from plants, resulting in increased yields. In the sheltered field areas, there was a positive influence on soil mineralization rates and beneficial insects. By having bioenergy crops as a valuable co-product of the existing farming system, in this case dairy production, the problem of replacing land used for food production with bioenergy cropping is overcome. The loss of food-productive land is potentially more than compensated for by the value of ES benefits gained if long term sustainability of the farming system and global threats associated with fossil-carbon use are considered.

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  • Purple Peaks Curry Reserve pest animal management plan

    McFarlane, Lynette; Ross, James G.

    Report
    Lincoln University

    The purpose of this report is to create a pest animal management plan for Purple Peaks Curry Reserve. The work was commissioned by NZ Native Forest Restoration Trust in June 2017, and the plan was written by Lyne McFarlane and Dr James Ross of Lincoln University.

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  • The manipulation of gene expression and the biosynthesis of Vitamin C, E and folate in light-and dark-germination of sweet corn seeds

    Liu, Fengyuan; Xiang, N.; Hu, J. G.; Shijuan, Y.; Xie, L.; Brennan, Charles S.; Huang, W.; Guo, X.

    Journal article
    Lincoln University

    This study investigates the potential interrelationship between gene expression and biosynthesis of vitamin C, E and folate in sweet corn sprouts. Germination of sweet corn kernels was conducted in light and dark environments to determine if this relationship was regulated by photo-illumination. Results indicated that light and dark environments affected the DHAR, TMT and GTPCH expression and that these genes were the predominant genes of vitamin C, E and folate biosynthesis pathways respectively during the germination. Levels of vitamin C and folate increased during the germination of sweet corn seeds while vitamin E had a declining manner. Sweet corn sprouts had higher vitamin C and E levels as well as relevant gene expression levels in light environment while illumination had little influence on the folate contents and the gene expression levels during the germination. These results indicate that there might be a collaborative relationship between vitamin C and folate regulation during sweet corn seed germination, while an inhibitive regulation might exist between vitamin C and E.

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  • The potential of treated municipal wastewater irrigation to cause aggregate instability and pore sealing on Banks Peninsula soils.

    McIntyre, Cameron

    Thesis
    Lincoln University

    The discharge of Treated Municipal Wastewater (TMW) into surface waters can degrade water quality and represents a waste of potentially valuable irrigation water and plant nutrients. While the application of TMW to soil can enhance plant growth, TMW containing high sodium (Na) concentrations can degrade soil structure resulting in decreased permeability and increased runoff. TMW from Banks Peninsula, New Zealand is currently discharged into Akaroa Harbour, however, a legal injunction requires that discharge into water be discontinued and therefore land application is being investigated. This thesis aimed to determine whether TMW application to Banks Peninsula soils would result in significant degradation to soil structure. The TMW contained 40 mg/L Na. Soil columns (0.1m x 0.19m) containing the Pawson Silt Loam and intact lysimeters (0.5m x 0.7m) containing both Pawson Silt Loam and Barry’s soil (a silt loam) were irrigated with a total volume of TMW of up to 1500 mm. The TMW irrigated onto the soil columns was spiked with Na up to 325 mg/L. Infiltration occurred unimpeded on all the soils, indicating that irrigating TMW would not degrade soil structure in the short term. Irrigation with TMW resulted in a significant increase in Na in the soil profile (from 330 mg/kg to 1760 mg/kg), however, there was sufficient native Ca and Mg in these soils (6540 mg/kg and 4130 mg/kg) to offset this increased Na. It is likely that in the long term, lime or gypsum will need to be added to maintain soil structure.

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  • A spatial decision support system for flood hazard in Quang Nam province, Vietnam

    Ong Dinh Bao, Tri

    Thesis
    Lincoln University

    The general aim of this study is to provide decision makers and planners with a spatial decision support system (SDSS), for quantifying flood hazards in order to cope with deluge situations within the Quang Nam basin of Vietnam. This flood management SDSS provides a comprehensive set of tools for rainfall and runoff modelling, hydraulic modelling and frequency analysis for the examination of the flood nature in the Quang Nam basin. This system is implemented in the context of complex aspects of hydrological features present in the province, such as relationships between the river systems, rainfall patterns and topographical features of the basin. The concrete result of the study is an IT system that is developed on the information derived from the aforementioned context using Visual Basic programming language running on top of a GIS platform. This exploration is ‘state of the art’ in its usage of modern science and technology in quantifying the aspects of flood hazards, including the mapping of flood areas and ranking of different levels of probability in multi-scale and temporal resolution. This analytical approach is also a reflection of a ‘best practice’ methodology which is a combination of enhanced local knowledge and modern technology: that is a GIS-based flood simulation and analysis, to assist decision makers to gain quick feedback through interactive spatial IT tools.

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  • Making sense of suburbia: A spatial history of a small rural town in New Zealand

    Montgomery, Roy L.; Page, Shannon; Borrie, Nancy C.

    Journal article
    Lincoln University

    Theories of urban planning are often associated with particular movements such as Modernism and New Urbanism, or with key thinkers such as Jane Jacobs, or urban designers such as Kevin Lynch and Jan Gehl. However, much planning activity proceeds privately and at a small scale, or “street-by-street,” so to speak. Only upon later reflection do patterns or trends seem to emerge. This discussion tracks changes in urban planning thought and practice by close scrutiny of the largely unremarkable unit of urban planning practice: the suburban residential subdivision. Analysis and interpretation centres on the establishment in the mid-nineteenth century of a very small rural village in the South Island of New Zealand, and the growth that has occurred subsequently. Changes in town layout in plan or overhead view over time is a principal tool for analysis in this discussion accompanied by contextual or explanatory argumentation. It is concluded that both incrementalism and major shocks, or seismic shifts, serve to perpetuate rather than disrupt or significantly alter the standard urban planning typology of privately-owned single homes on land parcels of between 500-1000m², or the stereotypical ‘quarter acre’ dream as it often referred to in New Zealand.

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  • Corporate governance disclosures in the New Zealand agricultural companies

    Roudaki, Jamal; Shahwan, Y.

    Journal article
    Lincoln University

    Livestock, agriculture, and horticulture products are essential in the New Zealand economic sustainable development. Consequently performance and governance of active companies in these areas of business are constantly monitored by the public through legislators, stock market, government agencies, and media. Practically corporate governance disclosures are providing essential information for such monitoring and analysis. This paper intention includes critically evaluate corporate governance disclosures of agriculture companies. Implementation of the content analysis methodology enables this research project to present analysis of the level of compliance with the 2004 Corporate Governance Principles and Guidelines that put forwarded by the New Zealand Stock Exchange (governance related disclosure and their non-listed counterpart as expected providing even less disclosure in this area. The financial and governance reports of these companies are suffering from deficient transparency in the area of corporate governance.

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  • Spectral CT data acquisition with Medipix3.1

    Walsh, M. F.; Nik, S. J.; Procz, S.; Pichotka, M.; Bell, S. T.; Bateman, Christopher J.; Doesburg, R. M. N.; Ruiter, N. D.; Chernoglazov, A. I.; Panta, R. K.; Butler, A. P. H.; Butler, P. H.

    Journal article
    Lincoln University

    This paper describes the acquisition of spectral CT images using the Medipix3.1 in spectroscopic mode, in which the chip combines 2 ×2 pixel clusters to increase the number of energy thresholds and counters from 2 to 8. During preliminary measurements, it was observed that the temperature, DAC and equalisation stability of the Medipix3.1 outperformed the Medipix3.0, while maintaining similar imaging quality. In this paper, the Medipix3.1 chips were assembled in a quad (2×2) layout, with the four ASICs bump-bonded to a silicon semiconductor doped as an np-junction diode. To demonstrate the biological imaging quality that is possible with the Medipix3.1,an image of a mouse injected with gold nano-particle contrast agent was obtained. CT acquisition in spectroscopic mode was enabled and examined by imaging a customised phantom containing multiple contrast agents and biological materials. These acquisitions showed a limitation of imaging performance depending on the counter used. Despite this, identification of multiple materials in the phantom was demonstrated using an in-house material decomposition algorithm. Furthermore,gold nano-particles were separated from biological tissues and bones within the mouse by means of image rendering.

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