5,048 results for Lincoln University

  • Expanding the conversational terrain: Using a choice experiment to assess community preferences for post-disaster redevelopment options

    Tait, Peter R.; Vallance, Suzanne A.; Rutherford, Paul

    Journal article
    Lincoln University

    The Canterbury region of New Zealand was shaken by major earthquakes on the 4th September 2010 and 22nd February 2011. The quakes caused 185 fatalities and extensive land, infrastructure and building damage, particularly in the Eastern suburbs of Christchurch city. Almost 450 ha of residential and public land was designated as a ‘Red Zone’ unsuitable for residential redevelopment because land damage was so significant, engineering solutions were uncertain, and repairs would be protracted. Subsequent demolition of all housing and infrastructure in the area has left a blank canvas of land stretching along the Avon River corridor from the CBD to the sea. Initially the Government’s official – but enormously controversial – position was that this land would be cleared and lie fallow until engineering solutions could be found that enabled residential redevelopment. This paper presents an application of a choice experiment (CE) that identified and assessed Christchurch residents’ preferences for different land use options of this Red Zone. Results demonstrated strong public support for the development of a recreational reserve comprising a unique natural environment with native fauna and flora, healthy wetlands and rivers, and recreational opportunities that align with this vision. By highlighting the value of a range of alternatives, the CE provided a platform for public participation and expanded the conversational terrain upon which redevelopment policy took place. We conclude the method has value for land use decision-making beyond the disaster recovery context.

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  • Leading different dimensions of organization performance through human resource management practices

    Mansouri, N.; Goher, Khaled

    Journal article
    Lincoln University

    The primary purpose of this research work is to find out how human resource management practices including training, staffing, performance appraisal, participation, and reward system can affect the performance of Malaysian Information and Communication Technology (ICT) companies. Company’s performance is identified in this work in terms of innovation, learning and growth, and internal process. The results of analysis of 223 gathered data showed that human resource management practices have significant and positive impact on innovation, learning and growth, and internal process. In addition, this study showed that performance components can affect each other significantly and positively. In this research work, the data is collected through questionnaire and analyzed by Statistical Package for the Social Sciences (SPSS) software. Moreover, the respondents of this research work are the employees of small and medium size ICT companies located in Cyberjaya, Malaysia.

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  • Walking aids for older adults: review of end-user needs

    Mansouri, N.; Goher, Khaled

    Journal article
    Lincoln University

    Aged population of senior citizens is growing noticeably at different regions in the world. Consequently, there are great numbers of demands for healthcare services. One of the services is assistive walking devices which have important role in mobility, stability, walking, and independency of older adults. Although various type of walking devices are available for older adults, yet fall incidents with severe injuries take place. Therefore, it is critical to analyze fall incidents, find out fall factors, and assess walking devices to minimize fall. This paper mainly focuses on risk factors of fall, considerable role of Information and Communication Technology (ICT) in walking devices, and also analyzes fall incidents with the purpose of understanding how fall incidents take place. This paper assists to have a clear understanding about fall incidents and its associated injuries.

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  • Towards ethical framework for personal care robots: review and reflection

    Mansouri, N.; Goher, Khaled

    Journal article
    Lincoln University

    In recent decades, robots have been used noticeably at various industries. Autonomous robots have been embedded in human lives especially in elderly and disabled lives. Elderly population is growing worldwide significantly; therefore there is an increased need of personal care robots to enhance mobility and to promote independence. A great number of aging and disabled hold appeals for using robots in daily routine tasks as well as for various healthcare matters. It is essential to follow a proper framework in ethics of robot design to fulfill individual needs, whilst considering potential harmful effects of robots. This paper primarily focuses on the existing issues in robot ethics including general ethics theories and ethics frameworks for robots. Consequentialism ethics will be recommended to be applied in robot ethics frameworks.

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  • A systems approach for determining gene expression from experimental observation of compound presence and absence

    Clark, Sangaalofa; Verwoerd, Wynand S.

    Journal article
    Lincoln University

    Different genes are expressed in different tissues, depending on functional objectives and selection pressures. Based on complete knowledge of the structure of the metabolic network and all the reactions taking place in the cell, elementary modes (EMs) and minimal cut sets (MCSs) can relate compounds observed in a tissue, to the genes being expressed by respectively providing the full set of non-decomposable routes of reactions and compounds that lead to the synthesis of external products, and the full set of possible target genes for blocking the synthesis of external products. So, for a particular tissue, only the EMs containing the reactions that are related to the genes being expressed in those tissues, are active for the production of the corresponding compounds. This concept is used to develop an algorithm for determining a matrix of reactions (which can be related to corresponding genes) taking place in a tissue, using experimental observations of compounds in a tissue. The program is applied to the Arabidopsis flower and identified 20 core reactions occurring in all the viable EMs. They originate from the trans-cinnamate compound and lead to the formation of kaempferol and quercetin compounds and their derivatives, as well as anthocyanin compounds. Analyses of the patterns in the matrix identify reaction sets related to certain functions such as the formation of derivatives of the two anthocyanin compounds present, as well as the reactions leading from the network’s external substrate erythrose-4P to L-Phenyla- lanine, cinnamyl-alc to trans-cinnamate and so on. The program can be used to successfully determine genes taking place in a tissue, and the patterns in the resulting matrix can be analysed to determine gene sets and the state of the tissue.

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  • Low input weed management in field peas

    Munakamwe, Z.; McKenzie, Bruce A.; Hill, G. D.

    Journal article
    Lincoln University

    Two trials were conducted on a Templeton silt loam soil at Lincoln University, New Zealand (43 ° 38' S, 172 ° 28' E.) in 2007/08. The aim was to compare the competitive ability of different pea canopy architectures as influenced by genotype, population, sowing date and their interaction as a means of low input weed control strategy. The first experiment had three sowing dates, two pea genotypes and two herbicide treatments. Experiment 2 treatments were a factorial combination of four pea populations and three sown artificial weed populations. A significant sowing date x pea genotype interaction showed that in the August sowing genotype had no effect on seed yield. However, in September sown plots Pro 7035 yielded 559 g m⁻², which was 40% more than Midichi, and in the October sowing, the difference was 87% more. Herbicide-sprayed peas produced 19% more seed (508 g m⁻²) than the unsprayed plants. When no weeds were sown, the highest pea total dry matter (TDM) of 1,129 g m⁻² occurred at 200 plants m⁻². This was more than twice (513 g m⁻²) the yield of the lowest population (50 plants m⁻²). There was distinct variation in the weed spectrum over time. Coronopus didymus, Stellaria media and Lolium spp were present in relatively large numbers throughout the season. Some weeds only occurred late in the season meaning they could be successfully controlled by early sowing. It could be concluded that it is possible to obtain high pea yields by using the right sowing date and appropriate seed rate as a means of low input weed management strategy.

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  • Subcutaneous adipose tissue topography in long-term enterally fed children and healthy controls

    Kaimbacher, P. S.; Wallner-Liebmann, S. J.; Dunitz-Scheer, M.; Scheer, P. J. Z.; Cvirn, G.; Schrabmair, W.; Schnedl, W. J.; Hamlin, Michael J.; Tafeit, E.

    Journal article
    Lincoln University

    In the context of enteral feeding in children the influence on growth and the question of fat resorption is of great interest. We, therefore, measured the thickness of subcutaneous body fat in a sample of long-term enterally fed toddlers and healthy controls. In 33 long-term enterally fed toddlers (10 girls, 23 boys) and 275 healthy controls (128 girls, 147 boys) subcutaneous body fat was measured by means of the optical device Lipometer. All participants were divided into three age groups (infants, toddlers and children). The height (p=0.014, –11.7 cm, –12.5%) and weight (p=0.012, –3.0 kg, –21.9%) of long-term enterally fed female toddlers were significantly lower than healthy controls, while male enterally fed toddlers had lower values in all anthropometric measures compared to healthy controls: height (p=0.003, –8.0 cm, –8.4%), weight (p<0.001, –6.2 cm, –12.5%). Tube fed toddlers showed a similar body fat distribution when compared to healthy controls, but demonstrated significantly lower values of anthropometric measurements.The results indicate that long-term enterally fed children have ample fat stores but lack physical development.

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  • Evolution of specialization of Cassida rubiginosa on Cirsium arvense (Compositae, Cardueae)

    Cripps, M. G.; Jackman, S. D.; Roquet, C.; van Koten, C.; Rostas, Michael; Bourdôt, G. W.; Susanna, A.

    Journal article
    Lincoln University

    The majority of herbivorous insects are specialized feeders restricted to a plant family, genus, or species. The evolution of specialized insect–plant interactions is generally considered to be a result of trade-offs in fitness between possible hosts. Through the course of natural selection, host plants that maximize insect fitness should result in optimal, specialized, insect–plant associations. However, the extent to which insects are tracking plant phylogeny or key plant traits that act as herbivore resistance or acceptance characters is uncertain. Thus, with regard to the evolution of host plant specialization, we tested if insect performance is explained by phylogenetic relatedness of potential host plants, or key plant traits that are not phylogenetically related. We tested the survival (naive first instar to adult) of the oligophagous leaf-feeding beetle, Cassida rubiginosa, on 16 selected representatives of the Cardueae tribe (thistles and knapweeds), including some of the worst weeds in temperate grasslands of the world in terms of the economic impacts caused by lost productivity. Leaf traits (specific leaf area, leaf pubescence, flavonoid concentration, carbon and nitrogen content) were measured as explanatory variables and tested in relation to survival of the beetle, and the phylogenetic signal of the traits were examined. The survival of C. rubiginosa decreased with increasing phylogenetic distance from the known primary host plant, C. arvense, suggesting that specialization is a conserved character, and that insect host range, to a large degree is constrained by evolutionary history. The only trait measured that clearly offered some explanatory value for the survival of C. rubiginosa was specific leaf area. This trait was not phylogenetically dependant, and when combined with phylogenetic distance from C. arvense gave the best model explaining C. rubiginosa survival. We conclude that the specialization of the beetle is explained by a combination of adaptation to an optimal host plant over evolutionary time, and key plant traits such as specific leaf area that can restrict or broaden host utilization within the Cardueae lineage. The phylogenetic pattern of C. rubiginosa fitness will aid in predicting the ability of this biocontrol agent to control multiple Cardueae weeds.

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  • A city in a water crisis: the responses of the people of Gaborone

    Kadibadiba, Arabang Tshepiso

    Thesis
    Lincoln University

    Worldwide, countries are challenged by the increasing pressure on potable water resources. In Botswana these pressures are particularly severe. Gaborone, the capital city of Botswana, is faced with a water crisis. There are no nearby permanent water sources to supply the city and successive years of drought led to extreme water shortages in Gaborone in 2015. This study investigates how the government has responded to the developing water shortage over the last decades and how the water use and management practices of the people changed in response to this water crisis. Social practice theory is applied as an analytical theoretical framework with a focus on the elements of practices and the norms of consumption (three Cs of cleanliness, comfort and convenience) reveal how and why consumption takes place. It is shown that the co-evolution of water supply infrastructure and customer demand creates imperatives and expectations that water is always available and ready to be used. It is also concluded that practices of water use are shaped around the concepts of cleanliness, comfort and convenience and that when water was very scarce, practices evolved so that acceptable social standards could still be maintained. The study shows that although people’s practices changed, there were limits to their adaptability in the context of the supply and demand paradigm that dominates water infrastructure across the world. This study illustrates that social practice theory’s conventions of comfort, cleanliness and convenience (the 3Cs) needs to be extended to survival to adequately capture how people respond in a resource constrained situation, which is a contribution this thesis makes to the social practice theory literature. While the importance of technical supply solutions to water situations cannot be overlooked, this study shows that addressing water demand and supply cannot be entirely dependent on them. Understanding people’s social practices and the ways in which they adjust to changes in water provision can be valuable to inform policy aimed at building resilience and adaptive strategies to crisis situations such as water paucity.

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  • A comparison of the lactation performaces between Romney, Corriedale and Merino ewes under high country conditions

    Scales, G. H.

    Thesis
    Lincoln University

    Factors which affect the growth of the lamb are of considerable economic importance in animal production. Most workers in this field have shown that growth rates are influenced to a large extent by milk production, especially in the early stages, hence the study of the yields, composition and persistency of lactation is of the utmost importance. Information was sought in this trial on the lactation performances of the Merino, Corriedale and Romney ewes grazing under high country conditions. This trial was designed to measure the relative milk yields and milk composition between the three breeds run in this environment. In general it is hoped that this trial will increase the knowledge on some of the factors influencing growth rates both quantitatively and qualitatively in this somewhat different environment.

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  • Determination of maximal oxygen uptake using the Bruce or a novel athlete-led protocol in a mixed population

    Hamlin, Michael J.; Draper, N.; Blackwell, G.; Shearman, J. P.; Kimber, Nicholas E.

    Journal article
    Lincoln University

    Treadmill tests for maximal oxygen uptake (V O2max) have traditionally used set speed and incline increments regardless of participants training or exercise background. The aim of this study was to determine the validity of a novel athlete-led protocol for determining maximal aerobic fitness in adults. Twenty-nine participants (21 male, 8 female, age 29.8 ± 9.5 y, BMI 24.4 ± 3.1, mean ± SD) from a variety of exercise backgrounds were asked to complete two maximal treadmill running tests (using the standard Bruce or a novel athlete-led protocol [ALP]) to volitional failure in a counter-balanced randomised cross-over trial one week apart. We found no substantial difference in maximal oxygen uptake (47.0 ± 9.1 and 46.8 ± 10.7 ml.kg-1.min-1, mean ± SD for the ALP and Bruce protocols respectively), evidenced by the Spearman correlation coefficient of 0.93 (90% confidence limits, 0.88-0.96). However, compared to the Bruce protocol, participants completing the ALP protocol attained a substantially higher maximal heart rate (ALP = 182.8 ±10.5, Bruce = 179.7 ± 8.7 beats.min-1). Additionally, using the Bruce protocol took a longer period of time (23.2 ± 17.0s) compared to the ALP protocol. It seems that using either treadmill protocol will give you similar maximal oxygen uptake results. We suggest the ALP protocol which is simpler, quicker and probably better at achieving maximal heart rates is a useful alternative to the traditional Bruce protocol.

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  • Integrated signaling pathway and gene expression regulatory model to dissect dynamics of Escherichia coli challenged mammary epithelial cells

    den Breems, N. Y.; Nguyen, L. K.; Kulasiri, Gamalathge D.

    Journal article
    Lincoln University

    Cells transform external stimuli, through the activation of signaling pathways, which in turn activate gene regulatory networks, in gene expression. As more omics data are generated from experiments, eliciting the integrated relationship between the external stimuli, the signaling process in the cell and the subsequent gene expression is a major challenge in systems biology. The complex system of non-linear dynamic protein interactions in signaling pathways and gene networks regulates gene expression. The complexity and non-linear aspects have resulted in the study of the signaling pathway or the gene network regulation in isolation. However, this limits the analysis of the interaction between the two components and the identification of the source of the mechanism differentiating the gene expression profiles. Here, we present a study of a model of the combined signaling pathway and gene network to highlight the importance of integrated modeling. Based on the experimental findings we developed a compartmental model and conducted several simulation experiments. The model simulates the mRNA expression of three different cytokines (RANTES, IL8 and TNFα) regulated by the transcription factor NFkB in mammary epithelial cells challenged with E. coli. The analysis of the gene network regulation identifies a lack of robustness and therefore sensitivity for the transcription factor regulation. However, analysis of the integrated signaling and gene network regulation model reveals distinctly different underlying mechanisms in the signaling pathway responsible for the variation between the three cytokine's mRNA expression levels. Our key findings reveal the importance of integrating the signaling pathway and gene expression dynamics in modeling. Modeling infers valid research questions which need to be verified experimentally and can assist in the design of future biological experiments.

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  • Understanding pasture performance: the interaction between perennial ryegrass and viruses

    Farquhar, Maxine

    Thesis
    Lincoln University

    In New Zealand livestock-based agriculture is an essential component of the economy, and at the very core of the majority of livestock-based farming systems in New Zealand is a pasture comprised of perennial ryegrass (Lolium perenne L.). Therefore, the productivity and profitability of livestock industries is inextricably linked to, and influenced by, the quality and performance of the underlying perennial ryegrass pasture. However, previous research indicates that ryegrass pastures in New Zealand could be infected with multiple viruses, and that the incidence or “load” of viruses within ryegrass pastures could potentially increase over time. Considering the significance of ryegrass to agricultural productivity, and current targets to increase the output of ryegrass pastures, these findings are concerning, as 1) multiple virus infections could have synergistic effects, in which the impact of one pathogen could potentially be exacerbated by the concurrent presence of other pathogens within a single host, and 2) increasing viral load or incidence within a pasture could potentially undermine the productivity and persistence of a ryegrass pasture over time. However, the extent to which multiple virus infections and/or increasing viral load undermines the persistence and productivity of perennial ryegrass is yet to be ascertained. Therefore, the purpose of this research is to elucidate the potential impact of multiple virus infections and increasing viral load upon the yield and persistence of ryegrass. To determine the impact of viral load and/or multiple viruses upon ryegrass, tillers obtained from 10-year-old and 1-year-old ryegrass were screened for multiple viruses, viral load was quantified, and the yield of old and new ryegrass was compared over time, to ascertain if there was or is potentially a link between viral load and ryegrass performance. The results of this project indicate 1) that multiple viruses are present within the ryegrass material examined, 2) that viral load is higher in 10-year-old ryegrass, and 3) 10-year-old old ryegrass produced less biomass (4-29%) than young ryegrass. Overall, the results of this research demonstrate that there is a potential correlation or link between increasing and/or high viral load and yield deficit in old ryegrass.

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  • Rhizosphere and endophytic colonisation of ryegrass and sweet corn roots by the isolate Trichoderma atroviride LU132 at different soil pHs

    Cripps-Guazzone, Natalia; Jones, Elizabeth E.; Condron, Leo M.; McLean, Kirstin L.; Stewart, Alison; Ridgway, Hayley J.

    Journal article
    Lincoln University

    The colonisation of plant roots by biological control agents is dependent on abiotic factors, one of the most important being soil pH. The rhizosphere and endophytic colonisation of ryegrass and sweet corn roots by the biological control agent Trichoderma atroviride LU132 were assessed in a pot experiment with non-sterile soil at three different pHs (5.5, 6.5 and 7.5). T. atroviride LU132 colonised the roots of both plants regardless of the soil pH with 1.13-1.47 × 10⁶ CFU/g of dry rhizosphere soil (DRS) for ryegrass and 1.36-3.50×10⁵ CFU/g DRS for sweet corn. T. atroviride LU132 was able to colonise both plants endophytically, regardless of soil pH. However, the isolate was recovered from entire ryegrass roots but only from the upper parts of sweet corn roots. These experiments demonstrated that T. atroviride LU132 colonised the rhizosphere and roots within a soil pH range common to most NZ soils, which is a desirable trait for biological control agents.

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  • Cost recovery - at what cost?

    Daniel, D. J.

    Thesis
    Lincoln University

    The world trend is to recover costs for services and products provided by government. No longer is it a matter of what might be desirable in presenting and implementing agricultural policy – rather it is, what are the economic realities. The New Zealand Ministry of Agriculture and Fisheries (NZ MAF) was confronted by the economic reality. No longer was the farmer to be treated as if he was special. To remain a relevant organization the NZ MAF had to come out from behind the farm gate and actively identify where it could successfully compete in the market place. The facts were: • Restructure to operate as an economic unit • Reduce staff numbers • Develop a new culture • Produce to survive Three years after the introductory charges and eight months after major restricting the important lessons are: A) Develop a functional focus with clear objectives, a clear idea of where the organisation is going and how to get there B) Identify clients and tailor products/services to their needs C) Find out what is important to staff to obtain job satisfaction and develop the new culture around it That is the economic reality and now it can be argued that the tax payer won’t be expected to provide services for the benefit of a limited few. However, in the zeal for profit, there is a danger of undermining the proper role of the state as the guardian of the interests of the whole society. Will the public service that emerges from the profit making state be appropriate – is it the best way to serve the public and be a good employer?

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  • Consumer socialisation of over-the-counter medicines: does culture matter?

    Abdul Hamid, Suriani B.; Cohen, David A.; Manna, Valerie A.

    Journal article
    Lincoln University

    Self-medication with over-the-counter medicines (OTCs) is common practice not only for adults, but also among adolescents. Tapping into this potentially lucrative segment of adolescents as consumers will require marketers and academic researchers to understand this market well. The long-term benefits are worthy of focus as the buying patterns developed during teenage years are likely to continue throughout adult lives. Furthermore, as this population begins to age, they become a stronger customer base for pharmaceutical products. The majority of studies about OTCs have been conducted from the perspective of pharmacists or healthcare professionals in medical sociology, pharmacy practice and public policy. Very limited research has examined these products from the consumer behaviour perspectives.Using a consumer socialisation perspective, this study seeks to understand how adolescents learn to use OTCs. The study aimed to understand similarities and differences between adolescents living in Malaysia and New Zealand with respect to this product class. Data was collected at high schools in Christchurch, New Zealand and Johor Bahru, Malaysia. A total of 509 (New Zealand n=276 and Malaysia n=233) usable responses were obtained. Overall, the results of this study showed that self-medication with OTCs was widespread among respondents with a high percentage of them having purchased the medicines themselves. The results of this study also suggested that there were some differences and similarities among adolescents in New Zealand and Malaysia when it came to OTC-related consumer socialisation.

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  • Predation by Ostenia robusta on Costelytra zealandica pupae

    Chynoweth, Richard J.; Marris, John W. M.; Armstrong, Karen F.; Chomic, Anastasija; Linton, J.; Chapman, R. B.

    Journal article
    Lincoln University

    Soil sampling in a cereal crop near Southbridge, Canterbury, revealed dipteran larvae attacking Costelytra zealandica (White) pupae. Approximately 50% of the pupae had larvae associated with them. DNA sequencing analysis of larval specimens indicated they most likely belonged to the family Dolichopodidae. Larval specimens were reared through to adults and were identified as Ostenia robusta (Hutton) (Diptera: Dolichopodidae). This is the first record of the association of O. robusta larvae with C. zealandica pupae. A general description of the adult and larva of this species is provided, along with DNA sequencing data and observations on its association with C. zealandica pupae. The potential role of O. robusta in regulating populations of C. zealandica is briefly considered.

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  • Beetling: A method for capturing trapdoor spiders (Idiopidae) using tethered beetles

    Smith, V. R.; Vink, C. J.; Cruickshank, Robert H.; Paterson, Adrian M.

    Journal article
    Lincoln University

    © 2015, British Arachnological Society. All Rights Reserved.Collecting trapdoor spiders (Idiopidae) for research is diffcult due to their deep, convoluted burrows and almost entirely fossorial life history. Digging idiopids out of their burrows is laborious, disturbs the environment, and can only be undertaken in open areas with soft soil. Here we describe “beetling”: a quicker, easier method of capturing idiopids, using tethered beetles to lure the spiders from their burrows. Beetling was used to capture 123 individual Cantuaria spp. (Idiopidae) out of a total of 130 successfully throughout New Zealand during March–June, September, November, and December. We conclude that beetling is an effective method for the live capture of idiopids, despite some limitations such as the need to work at night, and to culture live beetles, but they are outweighed by the advantages of having a reliable, effcient method of capturing live spiders. Beetling could also be used to catch other fossorial invertebrates, such as lycosids and carabid larvae.

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  • The genomes of three uneven siblings: footprints of the lifestyles of three trichoderma species

    Schmoll, M.; Dattenböck, C.; Carreras-Villaseñor, N.; Mendoza-Mendoza, A.; Tisch, D.; Alemán, M. I.; Baker, S. E.; Brown, C.; Cervantes-Badillo, M. G.; Cetz-Chel, J.; Cristobal-Mondragon, G. R.; Delaye, L.; Esquivel-Naranjo, E. U.; Frischmann, A.; Gallardo-Negrete, J.; García-Esquivel, M.; Gomez-Rodriguez, E. Y.; Greenwood, D. R.; Hernández-Oñate, M.; Kruszewska, J. S.; Lawry, R.; Mora-Montes, H. M.; Muñoz-Centeno, T.; Nieto-Jacobo, M. F.; Nogueira Lopez, Guillermo; Olmedo-Monfil, V.; Osorio-Concepcion, M.; Piłsyk, S.; Pomraning, K. R.; Rodriguez-Iglesias, A.; Rosales-Saavedra, M. T.; Sánchez-Arreguín, J. A.; Seidl-Seiboth, V.; Stewart, A.; Uresti-Rivera, E. E.; Wang, C.-L.; Wang, T.-F.; Zeilinger, S.; Casas-Flores, S.; Herrera-Estrella, A.

    Journal article
    Lincoln University

    Copyright © 2016, American Society for Microbiology. All Rights Reserved. The genus Trichoderma contains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for "hot topic" research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism in T. reesei, T. atroviride, and T. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of each Trichoderma species discussed, which is > 20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved in N-linked glycosylation was detected, as were indications for the ability of Trichoderma spp. to generate hybrid galactose-containing N-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique to Trichoderma, and these warrant further investigation. We found interesting expansions in the Trichoderma genus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique to T. atroviride is the duplication of the alternative sulfur amino acid synthesis pathway.

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  • Plant-mediated interactions between the entomopathogenic fungus Beauveria bassiana, insect herbivores and a plant pathogen

    Raad, Maya

    Thesis
    Lincoln University

    The entomopathogenic fungus Beauveria bassiana can adopt an endophytic lifestyle by colonising a wide array of plant species. Several studies have reported enhanced resistance against insects and plant pathogens from colonised plants. However, little is known about the molecular and physiological mechanisms that govern such interactions. Elucidating the responses of the plant is therefore needed and will help to better understand this recently discovered aspect in the ecology of entomopathogens. The B. bassiana strains FRh2 and BG11 were used in this study. Their antagonistic effects, as endophytes, on the necrotic fungus Sclerotinia sclerotiorum and the two herbivore species Myzus persicae and Plutella xylostella were assessed. Treatment of Arabidopsis thaliana roots with B. bassiana FRh2 and BG11 significantly decreased leaf lesion size caused by S. sclerotiorum but did not affect M. persicae population growth and P. xylostella body mass. Genome expression analysis of A. thaliana leaves 15 days post infestation provided evidence for transcriptional reprogramming and induction of plant defence pathways following colonisation by both B. bassiana strains. The transcriptional responses aligned with reports on A. thaliana interaction with other plant growth promoting fungi such as the known root endophytes Trichoderma spp. and Piriformospora indica. The results also showed that B. bassiana strains FRh2 and BG11 colonisation evoked microbe-associated molecular pattern triggered immunity and the induction of several jasmonic (JA) and salicylic acid (SA) signalling pathway genes. Furthermore, systemic colonisation of plant tissue by FRh2 and BG11 resulted in the induction of genes involved in the biosynthesis of the antimicrobial phytoalexin camalexin and genes encoding multiple reactive oxygen species scavengers such as peroxidases and glutathione transferases. However, JA levels measured in FRh2 and BG11 colonised plants were only induced by P. xylostella caterpillar feeding but were not influenced by the presence of the fungus. Neither caterpillar feeding nor B. bassiana presence had an effect on endogenous SA levels. Also, B. bassiana colonisation by either strain did not result in major changes in leaf glucosinolate profiles, although a lower content of total aliphatic glucosinolates was recorded in FRh2 colonised Arabidopsis only. Based on this, it can be speculated that camalexin-induction by B. bassiana, and possibly priming of SA or JA mediated defences, could have resulted in enhanced resistance against S. sclerotiorum. However, since B. bassiana colonised both roots and shoots, direct effects on the pathogenic fungus cannot be ruled out entirely. Further investigations are required to determine the mechanisms underlying the protective effects of B. bassiana against S. sclerotiorum infection. This is one of the first studies to assess the metabolic and transcriptomic responses of a plant colonised by the entomopathogen B. bassiana and showed induction in the expression of host defence-related genes.

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