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Bunton, David Rowland. "Linguistic and textual problems in Ph. D and M. Phil theses : an analysis of genre moves and metatext /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21080136.
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Sumell, Albert J. "The role of amenities in the location decisions of Ph. D. recipients in science and engineering." unrestricted, 2005. http://etd.gsu.edu/theses/available/etd-12142005-143519/.
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Thesis (Ph. D.)--Georgia State University, 2005.<br>Title from title screen. Laura O. Taylor, committee chair; Paula E. Stephan, Paul M. Jakus, Erdal Tekin, committee members. Electronic text (170 p.) : digital, PDF file. Description based on contents viewed May 24, 2007. Includes bibliographical references (p. 162-169).
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Stepper, Judith. "The molecular and cellular characterisation of the first glycocin, plantaricin KW30 : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biochemistry at Massey University, Palmerston North, New Zealand [Ph. D] EMBARGOED." Massey University, 2010. http://hdl.handle.net/10179/1184.
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Rai, Debbie S. "A longitudinal study of closed head injury : neuropsychological outcome and structural analysis using region of interest measurements and voxel-based morphometry." Thesis, University of Stirling, 2005. http://hdl.handle.net/1893/92.
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Background: The hippocampus and corpus callosum have been shown to be vulnerable in head injury. Various neuroimaging modalities and quantitative measurement techniques have been employed to investigate pathological changes in these structures. Cognitive and behavioural deficiencies have also been well documented in head injury. Aims: The aim of this research project was to investigate structural changes in the hippocampus and corpus callosum. Two different quantitative methods were used to measure physical changes and neuropsychological assessment was performed to determine cognitive and behavioural deficit. It was also intended to investigate the relationship between structural change and neuropsychology at 1 and 6 months post injury. Method: Forty-seven patients with head injury (ranging from mild to severe) had undergone a battery of neuropsychological tests and an MRI scan at 1 and 6 months post injury. T1-weighted MRI scans were obtained and analysis of hippocampus and corpus callosum was performed using region-of-interest techniques and voxel-based morphometry which also included comparison to 18 healthy volunteers. The patients completed neuropsychological assessment at 1 and 6 months post injury and data obtained was analysed with respect to each assessment and with structural data to determine cognitive decline and correlation with neuroanatomy. Results: Voxel-based morphometry illustrated reduced whole scan signal differences between patients and controls and changes in patients between 1 and 6 months post injury. Reduced grey matter concentration was also found using voxel-based morphometry and segmented images between patients and controls. A number of neuropsychological aspects were related to injury severity and correlations with neuroanatomy were present. Voxel-based morphometry provided a greater number of associations than region-of-interest analysis. No longitudinal changes were found in the hippocampus or corpus callosum using region-of-interest methodology or voxel-based morphometry. Conclusions: Decreased grey matter concentration identified with voxel-based morphometry illustrated that structural deficit was present in the head injured patients and does not change between 1 and 6 months. Voxel-based morphometry appears more sensitive for detecting structural changes after head injury than region- of-interest methods. Although the majority of patients had suffered mild head injury, cognitive and neurobehavioural deficits were evidenced by a substantial number of patients reporting increased anxiety and depression levels. Also, the findings of relationships between reduced grey matter concentration and cognitive test scores are indicative of the effects of diffuse brain damage in the patient group.
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Clark, Alice Rosemary. "The filamin A actin binding domain structure and function: implications for a gain-of-function mechanism for the otopalatodigital syndrome: a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biochemistry at Massey University, Palmerston North, New Zealand [Ph. D] EMBARGOED." Massey University, 2010. http://hdl.handle.net/10179/1185.
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Embargoed until 1 January 2011<br>The filamin family act as scaffolding proteins associating with actin filmanents, acting through a highly conserved actin binding domain (ABD). The ABD of the filamins is homologous to that found in other F-actin binding proteins such as dystrophin. Mutations in the filamin A gene cause a wide range of disease symptoms in humans reflecting the diversity of the roles that filamin A has in cell structure and signalling pathways. The diseases fall into two separate phenotypic groups. Periventricular nodular heterotopia (PVNH) generally results from the complete loss of filamin A protein, and affects the central nervous system. The clinically separate otopalatodigital disorders (OPD) spectrum disorders are skeletal disorders and were hypothesised to be gain of function phenotype diseases. At the beginning of this work, there was very little structural data available for the human filamins, and none for the crucial highly conserved actin binding domain. This lack of structural data limited the interpretation of the biochemical and genetic data and constrained our understanding of the disease associated mutations that cluster in this domain. These studies aimed to provide insights into the structure and mechanism of actin binding domains, and thus provide a better understanding of the diseases caused when this domain is mutated. A secondary structural analysis and crystal structures of the wildtype and OPD2 associated mutant ABDs were obtained. The overall fold of the three proteins was equivalent as determined by circular dichroism spectroscopy and x-ray crystallography. The ABD from filamin A E254K showed 3.7 fold increased F-actin affinity, accompanied by a reduced thermostability (of 5.6 °C). Western blotting of OPD2, frontometaphyseal dysplasia (FMD) and PVNH patient fibroblast lysates showed similar levels of filamin A compared to the control cells. In addition the OPD and PVNH patient fibroblasts were able to adhere to fibronectin and migrate with an equivalent rate to control cells. Together these results have allowed correlations to be developed between structure, protein stability, actin affinity, cellular phenotype and the overall clinical phenotype. Showing that, at least in one example, OPD2 may be due to an increased actin affinity providing further evidence for a gain of function mechanism of OPD2.
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Bocanegra, Cheryl D. "Accent and Grouping Structures in the String Quartets of Béla Bartók." Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc2820/.
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The music of Béla Bartók is defined in part by its unique blend of rhythmic vitality and inventiveness, and his string quartets offer a glimpse into a consistency of technique evident throughout his compositional career. Bartók's rhythmic environments are primarily metrical, but many of his rhythmic configurations are placed in such a way as to potentially override established meter. It is necessary, therefore, to institute an analytical means by which the delineation and comparison of rhythmic structures both within and without the metrical context may be accomplished. An analytical method using Timepoint Accent Structures (TAS) allows for the comparison of rhythms resulting from patterns of accent produced by pitch onset, dynamic stress, articulation or any other accentual factors. Timepoint Grouping Structures (TGS) delineate the number of timepoints present in alternating groups/blocks in a texture, thereby allowing for the recognition of patterning created by these larger groups. By applying TAS and TGS analysis, relationships of rhythmic equivalency, rotation, retrograde, complementation, augmentation, diminution, subset, superset, exchange, compression and expansion are clearly confirmed in the string quartets. In addition, symmetrical structures and arithmetic progressions are discovered. In many ways, Bartók's rhythmic organization mimics his procedures of pitch structuring.
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Breidenbaugh, Joel Randall. "Integrating doctrine and expository preaching: A proposal and an analysis for the twenty-first century." Thesis, 2003. http://hdl.handle.net/10392/262.
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This dissertation proposes and analyzes the integration of doctrine and expository preaching for the twenty-first century. Chapter 1 traces the recent history of doctrinal preaching and expository preaching. Problems related to postmodernism, the New Homiletic, and the changes within contemporary evangelicalism also receive treatment.
Chapter 2 defines and blends the definitions of expository preaching and doctrinal preaching. These definitions form the basis for defining doctrinal expository preaching. Several doctrinal prerequisites of an expositor conclude this section.
Chapter 3 examines the biblical basis for doctrinal exposition. The semantic domain for preaching and the Bible's practitioners of doctrinal exposition support this basis.
Chapter 4 incorporates the disciplines of biblical and systematic theology for the task of theological interpretation. Moreover, principles for theological exegesis of literary genres prepare the expositor for the homiletical process. The chapter concludes with steps in the doctrinal expository sermon process as well as with two valid approaches for implementing doctrinal exposition.
Chapter 5 covers postmodern issues of truth, entertainment, language, image, and story. Also, the subject of applying doctrine is discussed. Observations of valuable doctrines for contemporary evangelicalism end this section.
Chapter 6 describes many practicalities of doctrinal exposition. A summary concludes the work.
This study argues for the need to integrate doctrine and expository preaching for the twenty-first century. Furthermore, this work proposes doctrinal exposition distinctively, biblically, theologically, and practically. In order for preachers to declare the whole counsel of God, sermons must employ doctrinal exposition.<br>This item is only available to students and faculty of the Southern Baptist Theological Seminary.
If you are not associated with SBTS, this dissertation may be purchased from <a href="http://disexpress.umi.com/dxweb">http://disexpress.umi.com/dxweb</a> or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
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Hamilton, James Merrill Jr. "He is with you and he will be in you: The Spirit, the believer, and the glorification of Jesus." Thesis, 2003. http://hdl.handle.net/10392/261.
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Were OT saints indwelt by the Holy Spirit? This dissertation seeks an answer from John's Gospel. The thesis here is that John 14:17c, "He is with you, and he will be in you," encapsulates the Bible's description of the relationship between the Spirit and the believer in the Old and New Covenants.
In chapter 1 the different positions taken on this question are surveyed. The five actual positions and one alleged position are illustrated with quotations. Not all equate regeneration and indwelling. None think the Spirit had nothing to do with OT saints.
Chapter 2 contends that the OT does not present its faithful as indwelt by the Spirit. Covenant mediators have the Spirit, but the Spirit distinguishes and empowers them. God dwells among his people in the tabernacle/temple, but he does not dwell in each believer. The outpouring of the Spirit passages point to the future, saying nothing about the experience of Old Covenant believers.
Chapter 3 exegetes the Spirit passages in John.
Chapter 4 argues that John 7:39 will not permit the inference that OT saints were indwelt. This chapter lays out the OT expectation of a Spirit-anointed Messiah who inaugurates the age to come. John presents Jesus as the fulfillment of this hope, and Jesus ministers the Spirit to his people.
Chapter 5 shows that regeneration and indwelling are not equivalent in John. John presents Jesus as the replacement of the temple. Jesus is the locus of God's presence and the place where sin is dealt with. Once Jesus fulfills all sacrifice, God can take up residence in a temple where no sacrifices are offered. Jesus confers temple status on those who believe in him. When Jesus ascends, believers become the locus of God's presence with authority to forgive and retain sin, i.e., they are the new temple.
Chapter 6 concludes and summarizes. OT saints were regenerate but not indwelt. The OT does not claim its faithful were indwelt, and the NT says they were not (John 7:39). Under the Old Covenant God's dwelling was the temple. In the New Covenant God dwells in believers.<br>This item is only available to students and faculty of the Southern Baptist Theological Seminary.
If you are not associated with SBTS, this dissertation may be purchased from <a href="http://disexpress.umi.com/dxweb">http://disexpress.umi.com/dxweb</a> or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
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Troxler, Joel Allen Jr. "Doing justice to the Unjust Steward: An exegetical examination of Luke 16:1--13 and its context." Thesis, 2003. http://hdl.handle.net/10392/258.
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This dissertation ascertains the meaning of the Unjust Steward parable (Luke 16:1-13) by examining its language, historical background, and literary context. Chapter 1 introduces the parable's interpretive problems, acknowledges that it is perhaps the most difficult of Jesus' parables to understand, and offers a method for deciphering the meaning.
Chapter 2 offers a detailed history-of-interpretation with special attention given to the work of Dennis J. Ireland ( Stewardship and the Kingdom , 1992) and the interpreters who have come after him, especially those who depart from the traditional interpretation.
Chapter 3 first examines the text-critical concerns for the parable and then analyzes the language of 16:1-13 at the lexical, grammatical, and syntactical levels.
Chapter 4 examines four historical background matters that some scholars have offered as interpretative keys for understanding the parable and determines that most of these background features have been overemphasized and are of limited help.
Chapter 5 examines the literary concerns of the parable. This chapter first examines the nature of the "parable" genre, Luke's use of parables, and the history of parable interpretation in general. The chapter then examines the literary context of the parable, giving special attention to the relationship between the Unjust Steward and all of the major units in Luke 15 and 16. Finally, the chapter examines a few literary conventions that some scholars have proposed as interpretive keys. The conclusion is that some are of more value than others.
Chapter 6 synthesizes the information and conclusions from Chapters 3, 4, and 5 to answer the nine most pressing questions that the parable presents to the reader.
The dissertation concludes that the traditional interpretation, which perceives the parable to be about a dishonest transaction that serves as an exhortation about both the proper use of monetary possession and preparing for the kingdom of God, is still the most plausible.<br>This item is only available to students and faculty of the Southern Baptist Theological Seminary.
If you are not associated with SBTS, this dissertation may be purchased from <a href="http://disexpress.umi.com/dxweb">http://disexpress.umi.com/dxweb</a> or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
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Moore, William Gene. "From biblical fidelity to organizational efficiency: The gospel ministry from English Separatism of the late sixteenth century to the Southern Baptist Convention of the early twentieth century." Thesis, 2003. http://hdl.handle.net/10392/259.
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This dissertation provides a historical and theological examination of Baptist views of the gospel ministry from English Separatists of the late sixteenth century to the Southern Baptist Convention of the mid-1920s. Chapter 1 provides the thesis of the dissertation, background material to its being written, and the methodology by which its conclusions are reached.
Chapters 2 through 4 provide overviews for the ministry among English Separatists, British Baptists of the seventeenth and eighteenth centuries, and American Baptists of the mid-seventeenth through the mid-nineteenth centuries, respectively. Each chapter focuses upon primary writings revealing each group's understanding of such issues as the office of the minister, the divine call to the ministry, ordination, preparation, the call by a congregation to a local church, and mutual responsibilities of ministers and church members.
Chapters 5 through 7 examine the ministry among Southern Baptists from about 1865 to 1925. While the fifth chapter follows the same pattern as the previous three, Chapter 6 examines the beginning of a shift in the focus of the work of the minister from 1865 to 1900 with the introduction of organizational efficiency. Chapter 7 demonstrates that this shift became denominationally accepted during the early twentieth century.
This work maintains that the heritage of Southern Baptists expressed consistent views concerning the office of the minister into the latter decades of the nineteenth century. The minister's call to the ministry, preparation, ordination, call to a congregation, and mutual responsibilities with church members were derived from clear biblical statements and principles. The end of the nineteenth century, however, witnessed a shift in the Southern Baptist view of the work of the ministry regarding the ability to produce quantifiable outcomes-a shift which became firmly established during the first two and a half decades of the twentieth century. This shift fueled a Baptist concern for organizational efficiency, a concern which viewed successful churches as those which were optimally organized to produce quantifiable results. Because pastors were seen as the key to organizational efficiency, they were judged according to the success of their churches' achieving those results.<br>This item is only available to students and faculty of the Southern Baptist Theological Seminary.
If you are not associated with SBTS, this dissertation may be purchased from <a href="http://disexpress.umi.com/dxweb">http://disexpress.umi.com/dxweb</a> or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
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Scroggins, James H. IV. "A proposal for the training of indigenous youth workers for the International Mission Board of the Southern Baptist Convention." Thesis, 2003. http://hdl.handle.net/10392/255.
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This dissertation examines the current state of global youth ministry leadership, with a focus on the training of indigenous youth workers. The goal of this work is to encourage the International Mission Board and other missions organizations to consider the need for a global strategy to train youth workers for every people group. Chapter 1 introduces and defines the subjects of youth ministry and youth missions. Attention is given to the emergence of the North American Youth Culture in the twentieth century, as well as the church and parachurch organizations that developed concurrently with the American Youth Culture.
Chapter 2 examines the strategies for global youth ministry that are currently being implemented by ReachOut, Youth Ministry International, Youth Builders, and SonLife. In addition to presenting a brief history along with the guiding vision of each organization, this chapter sets forth the similarities and differences among the various organizations, and identifies indigenous youth worker training as a key component of each strategy.
Chapter 3 analyzes and evaluates the effectiveness of the strategies of each of the aforementioned missions organizations. Strengths and weaknesses of each organization are presented, with special attention to their respective strategies for training indigenous youth workers.
Chapter 4 describes the current state of Southern Baptist mission work among the youth of the world. The results of surveys from IMB missionaries from every region, as well as feedback from interviews with IMB missionaries, are set forth. Data from the surveys and interviews is used to assess the current situation and priority of global youth ministry among Southern Baptists. In Chapter 5, IMB youth work is evaluated and critiqued.
Chapter 6 offers a proposal for the IMB of the SBC to train indigenous youth workers for the people groups of the world. A brief concluding chapter offers suggestions for further study in the area of global youth ministry.
This study suggests that youth ministry ought to be playing a key role in the world of missions in the twenty-first century. The fact that the majority of the world's population is under age 25, accompanied by evidence that youth are the most receptive age group for the Christian gospel, serves as an indictment against missiologists and missions organizations that fail to incorporate youth into their world missions strategies. In spite of the evidence, it appears that only a handful of missions "experts" and organizations are strategizing to reach the young people of the world.
This dissertation seeks to perform an assessment of youth work done by IMB personnel. The research revealed that many IMB missionaries are focusing on young people. This study concludes that although the IMB is involved in youth work around the world, its involvement is generally not strategic, completely uncoordinated, and not sufficiently prioritized and encouraged. I argued that youth ministry and indigenous youth worker training warrant a higher level of emphasis and priority from the IMB, and I have made a series of recommendations for the IMB to address its shortcomings in the area of global youth ministry. The work of ReachOut, Youth Ministry International, Youth Builders, and SonLife were analyzed and principles from the work of these organizations informed the evaluation of, and recommendations for, IMB youth work.<br>This item is only available to students and faculty of the Southern Baptist Theological Seminary.
If you are not associated with SBTS, this dissertation may be purchased from <a href="http://disexpress.umi.com/dxweb">http://disexpress.umi.com/dxweb</a> or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
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Anderson, Robert William Gerard. "A study on the biomechanics of axonal injury, Ph D Thesis." Thesis, 2000. http://hdl.handle.net/2440/32245.
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Ryoo, David Eung-Yul. "Paul's preaching in the Epistle to the Ephesians and its homiletical implications." Thesis, 2003. http://hdl.handle.net/10392/268.
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The purpose of this dissertation was to explore Paul's preaching of the significant theological themes in Ephesians in an attempt to establish a model of expository preaching for modern preachers. The study comprised five chapters. The introduction justified the investigation, explained and evaluated the New Homiletic, and summarized the history of the studies of Paul's preaching and Paul's use of the Old Testament in Ephesians.
Chapter 2 examined Paul's preaching on the triune God against the Old Testament backdrop. God has provided the spiritual blessings of unity and reconciliation to humanity by the work of Christ's death and resurrection through the Holy Spirit. The investigation demonstrated that Paul's preaching of God the Father, Jesus Christ, and the Holy Spirit reflects his eschatological perspective that believers have already experienced the salvation but they still anticipate its consummation.
Chapter 3 surveyed Paul's preaching on the Christian life as a new creation primarily dealing with the latter three chapters. Paul's imperative messages, emphasizing on how newly created believers should live a Christian life in conformity of their calling, are grounded on his indicative messages, focusing on what God has done for humans through the sacrificial death and resurrection of Christ. In Paul's preaching there is no dichotomy between the internal work of the Holy Spirit for the believer's redemption and His external ethical exhortation for the believer's life. Paul's preaching of the believer's life also reflected an eschatological dimension. The believer has experienced an ultimate triumph over the evil powers in Christ, but the fruits of that victory have not yet been fully realized.
Chapter 4 studied homiletical implications of Paul's preaching in Ephesians and proposed a model of expository preaching. First, expository preaching should be the indicative-grounded and the imperative-oriented. Second, expository preaching should be Christ-centered preaching, focusing on the redemptive work of the triune God in the canonical context. The conclusion summarized the main results of the investigation and suggested Paul's preaching in Ephesians and proposed a future direction for expository preaching.<br>This item is only available to students and faculty of the Southern Baptist Theological Seminary.
If you are not associated with SBTS, this dissertation may be purchased from <a href="http://disexpress.umi.com/dxweb">http://disexpress.umi.com/dxweb</a> or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
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Chon, Joseph Joon-Hong. "Albert B. Simpson's theology and practice of evangelism." Thesis, 2003. http://hdl.handle.net/10392/242.
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This dissertation examines the evangelistic theology of Albert B. Simpson and demonstrates how his theology affected his practice of evangelism. A corollary purpose of this work is to provide a framework by which a pastor or an evangelist could evaluate a theology of evangelism in a contemporary setting. Simpson's theology and practice of evangelism are examined mainly along the specific theme of union with Christ.
Chapter 1 states the thesis and presents background information, including the research methodology and limitations. A theology of evangelism is defined. Chapter 2 delineates a biographical sketch of Simpson. It includes his birth, childhood, education, conversion, and early Presbyterian ministries. Simpson's responses to the cultural and social context of the years 1881 through 1912 are examined.
Chapter 3 examines Simpson's theology of evangelism. Using the theological theme of union with Christ, key concepts that relate to evangelism are examined. These concepts include the interpretation of Scriptures, the Fourfold Gospel, the nature of sin, the atonement and the cross of Christ, the death and resurrection of Christ, salvation, regeneration, faith and repentance, justification, God's sovereignty versus man's free will, the exclusiveness of salvation in Christ, sanctification, and the church.
Chapter 4 focuses on evangelistic practices that Simpson used to reach unchurched people in New York City and unreached people around the world. Simpson's evangelistic ministries were carried out through the Gospel Tabernacle and the Christian and Missionary Alliance. His evangelistic practices included preaching, music ministries, prayer ministries, healing ministries, social ministries, publications, the Missionary Training Institute, and cooperative ministries.
Chapter 5 concludes with an evaluation of a pastor-evangelist, sets forth specific conclusions from each chapter, and provides implications for a contemporary model for pastoral evangelism.<br>This item is only available to students and faculty of the Southern Baptist Theological Seminary.
If you are not associated with SBTS, this dissertation may be purchased from <a href="http://disexpress.umi.com/dxweb">http://disexpress.umi.com/dxweb</a> or downloaded through ProQuest's Dissertation and Theses database if your institution subscribes to that service.
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Collie, Stewart Roger. "Development of durable textile-conductive polymer composites : a thesis presented in partial fulfilment of the requirements for the degree of Ph. D. in Chemistry at Massey University, Palmerston North, New Zealand." 2007. http://hdl.handle.net/10179/1430.
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The research described in this thesis investigated a range of techniques for the in situ polymerisation of thiophene-based intrinsically conductive polymers (ICPs) on textile substrates. Following a review of the literature, three potentially useful techniques were identified; a simple aqueous technique; a vapour phase technique; and a two-stage impregnation technique. The literature also indicated that thiophene-based ICPs were likely to be more durable than those prepared from other precursors. The aqueous technique proved unsuccessful, but both the vapour and two-stage impregnation techniques were used to prepare textile-ICP composites using 2,2'-bithiophene and 3,4-ethylenedioxythiophene (EDOT). Polymerisation was effected by chemical oxidation of the precursor, with iron (III) salts being the best oxidants. The main drawbacks of the vapour system were the long vapour exposure times (e.g. several days) and/or elevated temperatures required to polymerise these relatively unreactive precursors. Two-stage impregnation was somewhat messy and inefficient, so a novel refinement of the technique (referred to as 'single dip') was developed. With this system, the specimen was impregnated with both precursor and oxidant from a single solution, then removed from the solution and the solvent allowed to evaporate. It was only at this stage that polymerisation occurred, and when more reactive ICP precursors (such as pyrrole) were used, polymerisation tended to occur in solution, and was less effective. The influence of various treatment parameters was established, while tests confirmed that the deposited ICP layer had no detrimental effect on the desirable fabric properties of flexibility and strength. Composites with surface resistance as low as 65 Ω/square were prepared with less than 6% ICP load on the textile (perchlorate-doped poly(EDOT)). The durability of poly(EDOT) composites was far better than polypyrrole under ageing in ambient conditions, accelerated ageing at elevated temperatures, and when given a treatment that simulated laundering. Finally, a scheme for continuously depositing ICPs onto textiles by this approach was designed, as a way of demonstrating the potential for scale-up of the system.
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Yang, Jingyu. "Improving effectiveness of dialogue in learning communities : a thesis presented in partial fulfilment of the requirements for the degree of Ph. D. in Information Systems at Massey University, Palmerston North, New Zealand." 2009. http://hdl.handle.net/10179/1410.
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In a learning community, conventional discussion forums are integral to webbased interventions in traditional classrooms as well as on-line learning environments. Despite popular belief that they are a great success in fostering deep and meaningful discussions and support active learning; research has found that there are millions of messages posted by users to express such an opinion, but it is hard to be directly delivered to all users. Finally there are millions of postings in databases across the country stored away and never reused. This thesis introduces a PhD student’s current research work. It proposes a distributed intelligent discussion forum system dedicated to supporting both students and teachers. The system is developed with the primary goal of reducing the number of problems associated with conventional discussion forum systems in web-based environments and improving the effectiveness of dialogue between students with each other and with teachers so that it can enhance each individual student’s ability to share and learn knowledge.
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Kshatri, Bhoj Bahadur. "Evaluation of multipurpose fodder trees in Nepal : a thesis submitted in partial fulfilment of the requirement for the degree of Doctor of Philosophy (Ph. D.) in Forestry, Institute of Natural Resources, Massey University, Palmerston North, New Zealand." 2007. http://hdl.handle.net/10179/1438.
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This PhD thesis consists of nine chapters describing aspects of the subsistence farms of western Nepal in general, and a need-based evaluation of multipurpose fodder trees (MFT) as a source of dry-season forage for ruminants in particular, as a basis for mitigating the current high rate of land degradation and loss of productivity in livestock production systems in the region. Understanding the complex farming systems that provide a living for 65% of the 27.1 million people in Nepal is the key to designing effective programmes of research and development. Evaluation methods include review of past work, farmers group workshops to identify current practice in the use of MFT in Nepal, studies on biomass production of Artocarpus lakoocha and Ficus glaberrima trees older than 50 years in Nepal and the propagation of F. benjamina, comparison of the feeding preferences of sheep for alternative browse species, and study of the nutritive value of alternative forage diets for lactating buffalo. Reviews showed 2.2 million cattle and 1 million buffalo are an extra burden to steep land where productivity is declining at the rate of 1.25% per year. Indigenous knowledge identified Ficus glaberrima with its three varieties (Maghe, Chaite and Jethe), A. lakoocha, F. benjamina and Bassia butyracea as the best four MFT for renovating degraded lands. A survey study showed significantly higher dry matter (DM) production by F. glaberrima than A. lakoocha (154 vs 91 kg DM /tree/year) during dry periods at low altitude (800 - 1000m). There was no significant difference in production of fat - corrected milk (FCM ) between buffalos eating A. lakoocha, F.glaberrima or a diet of 53% straw and 47% F. glaberrima (DM basis). Metabolisable energy balance (MJME/day) was greater in Artocarpus than Ficus, with the mixed diet intermediate (+1.60, -0.34 and -12.94 MJ ME/buffalo/day respectively, relative to requirements, P=0.0318). When fed together in an indoor trial, poplar (48% = 106 g DM/sheep/day) and willow (43% = 95 g DM/sheep/day) were preferred to Ficus benjamina (8% = 18 g DM/sheep/day) by sheep, reflecting the greater maturity and structural strength of leaves of Ficus. These results are used to develop recommendations for choice of MFT species and management strategies to improve the sustainability and productivity of livestock systems incorporating fodder trees
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Nahid, Amsha. "Modeling heat transfer in butter products : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Bioprocess Engineering, Institute of Technology and Engineering, Massey University, Palmerston North, New Zealand." 2007. http://hdl.handle.net/10179/1442.
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Butter keeping quality and pallet physical stability during transport and storage are dependent on the temperature distribution through the product. Understanding these temperature changes are of vital importance for the dairy industry with regard to butter manufacture, storage and shipping. Three dimensional mathematical models of heat transfer were developed to predict thawing and freezing in butter products. These models require accurate thermophysical data as an input. Specific heat capacity and enthalpy of butter with different composition was measured using Differential Scanning Calorimetry. The specific heat capacity of butter differs for cooling and heating operations due to significant supercooling and delayed crystallization of the fat fraction of butter at temperatures well below the equilibrium phase change temperature during cooling. This reduces the heat capacity for cooling relative to that for heating. Thawing of individual blocks of butter was accurately predicted by the conduction only model (no mass transfer limitations) with equilibrium thermal properties giving accurate predictions when the butter was completely frozen before thawing. For partially frozen butter the conduction model with the measured temperature dependent specific heat capacity data for unfrozen butter including melting of some of the fat fraction gave accurate predictions. For freezing it was observed that water in the butter supercools many degrees below its initial freezing point before freezing due to its water in oil structure. Experiments suggested that during freezing release of latent heat observed as a temperature rebound is controlled as much by the rate of crystallisation of water in each of the water droplets as by the rate of heat transfer. A conduction only model including water crystallization kinetics based on the Avrami Model predicted freezing in butter successfully. Simple models with equilibrium thermal properties and nucleation only kinetics (based on homogenous nucleation theory) or the sensible heat only model (no release of latent heat) gave poor predictions. The models for individual blocks were extended to predict heat transfer in butter pallets. A butter pallet contains product, packaging material and the air entrapped between the packaging and butter cartons. Measurements were made for freezing and thawing of full and half pallets at a commercial storage facility and in the University laboratory. Thawing and freezing in wrapped tightly stacked pallets was predicted accurately by the conduction only model with effective thermal properties (incorporating butter, packaging and air) estimated by the parallel model. For unwrapped tightly stacked or loosely stacked pallets there is potential for air flow between the adjacent cartons of butter. An alternative approach was developed which consisted of modeling the pallet on block by block basis using effective heat transfer coefficients for each surface. Different heat transfer coefficients were used on different faces of the blocks depending on the location of the block in the pallet. This approach gave good predictions for both unwrapped tightly stacked and loosely stacked pallets using the estimated effective heat transfer coefficients from the measured data. Further experimental and/or modelling work is required in order to develop guidelines for estimating effective heat transfer coefficient values for internal block face for industrial scenarios.
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Sulaiman, Zulkefly. "Establishment and silvopastoral aspects of willow and poplar : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Plant Science, Institute of Natural Resources, Massey University, Palmerston North, New Zealand." 2006. http://hdl.handle.net/10179/1488.
Full textAbstract:
Willow and poplar are the main trees used for soil erosion control in New Zealand (NZ) with successful establishment critical to greater use of this technology. Five experiments were conducted at the Pasture and Crop Research Unit, Massey University Palmerston North, NZ to examine the ability of willow and poplar to establish as a willow/poplar pasture system in NZ over a period of 3 years from December 2002 to April 2005. With an objective to select the best size for low cost planting, stem diameters (10 mm, 25 mm and 35 mm) were planted vertically and stem lengths (50 mm, 200 mm and 600 mm) were planted horizontally to determine their growth, establishment, biomass production and regrowth after browsing. From December 2002 to March 2003, three management treatments, mowing, herbicide and control (no weed control) treatments, were designed and applied to determine their effects on growth and shoot biomass production. From September 2004 to April 2005, mowing was replaced by sheep browsing and the effect of browsing, herbicide and control treatments on soil and tree water status (soil water content, soil water loss and deficit, and stem water potential) were examined. Longer (600 mm) and thicker stem diameters (35 mm) produced the greatest shoot biomass (edible biomass, total biomass and root biomass) compared to the thin stem cuttings (50 mm length and 10 mm diameter). Higher tree survival was also found for longer (600 mm) and thicker stems diameter (35 mm). The mown treatment produced significantly more edible and total shoot dry matter (DM) than the herbicide and control treatments, with willow clone 'Kinuyanagi' producing higher total shoot DM than 'Tangoio'. Pasture management had no significant effect on soil water content during spring 2004 and late summer/autumn 2005, however, it was significant during early and mid summer. Strong relationships between (i) soil water content and stem water potential (SWP), and (ii) SWP and soil water deficit were found and could help growers to predict the amount of water required during the growing season. The results clearly demonstrated that sheep grazing had negligible damaging effect on willow and poplar (main stem, branch breakage and tree leaning) and tree mortality, and that young trees can be browsed during pasture shortages in summer drought. Cutting size and understorey control for establishing willow and poplar into pasture have been better defined by this research. It is recommended that farmers establishing willow and poplar for fodder plant thick (vertical planting) and long stems (horizontal planting) for higher growth and biomass production.
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Hussain, Zaker. "Environmental effects of densely planted willow and poplar in a silvopastoral system : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Agroforestry, Institute of Natural Resources, Massey University, Palmerston North, New Zealand." 2007. http://hdl.handle.net/10179/1405.
Full textAbstract:
New Zealand, having large areas of hilly landscapes, is subject to the risk of soil erosion, and summer and autumn droughts that limit pasture growth, which in turn affects the livestock-based economy. The nitrogen and phosphorus input in fertilisers coupled with livestock excreta and soil disturbance impose a serious threat to downstream water quality. The planting of trees is one option used to decrease soil erosion, increase the quantity of forage and manage runoff. To date, research has mainly focused on wide spaced poplar trees for feed quality and their effects on understorey pasture growth. However, there is increasing interest in the use of densely planted willow and poplar for fodder purpose. The effects of young (< 5 yrs old) willow and poplar planted at close spacing on runoff, soil erosion, growth of understory pasture and nutrient losses have never been studied in New Zealand. Three field trials (two at Crop and Research Unit, Moginie, Manawatu and one at Riverside Farm, Masterton) were conducted between October 2004 and November 2006 that incorporated comparative establishment and growth of densely planted willow and poplar and their effects on soil moisture, runoff, sediment load and nutrient losses from grazed and fertilised farmland. It was concluded that densely planted willow and poplar (3-4 yrs) reduced total nitrogen (TN) and dissolved reactive phosphorus (DRP) by 47 % each and sediment load by 52 %. Young trees reduced surface runoff and soil moisture more as they aged. However, due to their deciduous nature willow and poplar were not effective in reducing surface runoff in winter and early spring. Sheep preferred camping under trees, especially in late spring and summer, and this led to greater deposition of dung and urine under trees than open pasture. Sheep grazing, especially in winter, significantly increased sediment and nutrient loads in runoff water. The N and P fertiliser application increased nutrient load in runoff water well above the threshold level required to initiate algal growth to create eutrophication. Densely planted willow and poplar significantly reduced understorey pasture growth by 23 % and 9 %, respectively, in their second year at Moginie, mainly due to shade, but coupled with soil moisture deficit in summer. The pasture growth in a willow browse block was 52 % of that in open pasture as a result of shade and differences in pasture species composition. Sheep browsing reduced willow leaf area significantly. Willow and poplar survival rates were similar (P > 0.05) after two years of establishment (100 % vs 90.5 %, respectively). However, willow grew faster than poplar in height (1.90 vs 1.35 m), stem diameter (43.5 vs 32.6 mm), canopy diameter (69 vs 34 cm) and number of shoots (8.7 vs 2.3) at the age of two years, respectively. The research clearly demonstrated that densely planted young willow and poplar trees can reduce runoff, sediment load and nutrient losses from farmland to freshwater, but shade and soil moisture can limit pasture growth under trees. It is recommended that willow and poplar should be planted at wide spacing on the whole farm to minimise loss of pasture. Where blocks of trees are necessary, such as willow browse blocks, sheep browsing can be used as a tool to reduce shade to improve pasture growth. Livestock access to riparian strips should be minimal to avoid livestock camping that can have deleterious effects on water quality.
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Cahn, Miranda. "Sustainable rural livelihoods, micro-enterprise and culture in the Pacific Islands : case studies from Samoa : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Development Studies, Massey University, Palmerston North, New Zealand." 2006. http://hdl.handle.net/10179/1532.
Full textAbstract:
This thesis is about the relationships between sustainable livelihoods, micro-enterprise and culture in Samoa. The 'sustainable livelihoods approach' provides a basis for analysis. The research focuses on one livelihood strategy, micro-enterprise, in order to illustrate and explain issues that are important in supporting sustainable livelihoods in Samoa. Micro-enterprise is regarded as a livelihood strategy that, if successful and sustainable, can support livelihood outcomes for rural Samoan people, and reduce poverty. The sustainable livelihoods approach is reviewed and the thesis argues that culture is integral to sustainable livelihoods, but existing theory and frameworks do not incorporate cultural aspects in a way that provides a sound theoretical basis for this research, or any sustainable livelihoods analysis. The thesis argues that culture is interwoven into each of the components of the sustainable livelihoods framework, and in fact culture is a context in which livelihoods exist. Each of the components provides an entry point for analysis of the relationships between culture and livelihoods. This concept was used as a basis for an analysis of rural livelihoods in Samoa, where fa'aSamoa was found to be interwoven with almost every aspect of rural livelihoods in a complex and influential way. A revised definition of a sustainable livelihood, and a revised framework were then developed which were more appropriate for this research. A strength of sustainable livelihoods theory, and the related frameworks, is that the theory embraces flexibility, and could thus be adapted to incorporate cultural aspects in this way. The thesis reviewed business enterprise in Samoa, and described the relationships between fa'aSamoa and business enterprise. The research revealed both harmonies and tensions between fa'aSamoa and business which influenced the success and sustainability of business enterprise. Two 'types' of small and micro-enterprise were identified in Samoa (with a continuum between): private sector enterprises and traditional 'sphere ' enterprises. 'Traditional sphere' enterprises, in order to be sustainable, normally operate within the cultural context of fa'aSamoa, ensuring that relationships, trust and harmony within the family and community are maintained and social and cultural assets, which provide a sense of identity and security, are sustained. The field research described in the thesis focused on two separate groups of micro-entrepreneurs in Samoa, fine mat weavers and village-based coconut oil producers. The case studies described the outcomes the micro-entrepreneurs aspire to, the risk, adversity, and challenges they face, and the work of the non-government organisations (NGOs) that support them. The case studies illustrated and further developed concepts developed in previous chapters, and also demonstrated just how the relationships between fa'aSamoa and sustainable livelihoods were expressed in practice. In the fine mat weaving case study there was considerable harmony between fa'aSamoa and the livelihood strategy. However, in the village-based coconut oil case study there were some tensions between fa'aSamoa and the venture that were causing vulnerability. The thesis concluded that understanding the relationships between culture, and sustainable livelihoods is critical for ensuring that good judgements are made about development intervention and policy. The revised sustainable livelihoods framework, and the concept of using the components of the frameworks as multiple entry points for analysis, provided an appropriate and useful theoretical framework for understanding the relationships between fa'aSamoa, sustainable livelihoods and micro-enterprise in Samoa.
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Okorley, Ernest. "An operational framework for improving decentralised agricultural extension : a Ghanaian case study : a thesis submitted in partial fulfilment of the requirement for the degree of Doctor of Philosophy (Ph. D.) in Agricultural Extension, Massey University, Institute of Natural Resources, Agricultural/Horticultural Systems & Management." 2007. http://hdl.handle.net/10179/1404.
Full textAbstract:
The pressure on the public agricultural extension organisation in Ghana to improve its responsiveness to meet the needs of farmers has increased since the globalisation of trade in the early 1990s. To improve agricultural productivity and the livelihood security of farm households, the Ministry of Food and Agriculture in Ghana decentralised its extension service in 1997. Although this was a critical change in agricultural policy, the extension service has struggled to implement this policy effectively. Further improvement in the situation is hampered because there has been little research published in this area. To provide this understanding, a single-case study of a successful decentralised district level extension organisation in Ghana was used to identify the factors, processes and outcomes that contribute to its performance. The case organisation is an example of a district agricultural extension organisation that operates under a decentralisation system at the level of deconcentration, with a high farmer-to-extension agent ratio and limited and uncertain levels of Government funding. The results of the study emphasised the importance of the effects of both external and internal (or organisational) factors on the performance of the case organisation. The external factors included: (1) the political will to decentralise, (2) the level of decentralisation of other government departments, (3) the provision of a clear legal framework for decentralisation and (4) the existence of established institutions that are willing to support the decentralisation process. New external factors that were identified in this study were (1) the type and drivers of decentralisation, (2) stakeholders' willingness and commitment to support the decentralisation process and (3) the community characteristics in terms of land tenure arrangements and gender roles. The results confirmed the importance of the organisational factors prescribed in the literature: (1) stakeholder participation, (2) managerial and technical capacity, (3) operational funding and (4) accountability. However, the study also identified five other interrelated organisational factors that influenced the success of the case organisation that had not been previously reported in the literature. These included the needs to: (1) develop a needs-based extension programme, (2) expand the extension service focus and roles, (3) foster a cross-sector pluralistic extension approach (4) use needs-based groups for service delivery, and (5) extension staff attitudinal change. Multistakeholder (farmer and other organisations) participation was critical for the development of a needs-based extension programme. The case organisation had modified the traditional extension programme planning process to involve stakeholders at different levels of participation. Similarly, the case organisation involved stakeholders in its multilevel monitoring and evaluation processes. Stakeholder participation in planning and evaluation, although aimed ultimately at efficient and effective programme implementation and improvement, did enhance accountability. Because the case organisation had taken on a broader livelihood security focus to extension, the definition of farmer needs was extended to encompass on-farm and off-farm needs that have impact on the contribution agriculture makes to the livelihood security of farm households in the district. This broader livelihood security focus to extension required the case organisation to take on additional roles from those it traditionally held. In the study, a typology of such roles was developed and a role selection process used by the case organisation during its programme planning process was described. Similarly, because of this broader focus, the case organisation had to work both across sectors and with other extension providers from within the sector to meet the needs of farmers. Again, the multistakeholder programme planning process was central to fostering coordination and collaboration amongst the various extension providers in the district. Decentralisation has placed greater managerial responsibility on management staff of the case organisation. In addition, the livelihood security focus has required technical staff and attitudinal changes to develop and seek for a much broader range of skills and knowledge - meaning that the development of both managerial and technical capacity was important for the case organisation. Needs-based training, the development of a learning environment and the enhancement of staff motivation were critical for the development of staff capacity. As with other extension organisations in developing countries, the funding for the case organisation was limited and uncertain. To overcome these constraints, the case organisation had in place mechanisms to ensure its resources were used efficiently and that it could mobilise additional resources from outside the organisation. Resource efficiency was improved through an intensive monitoring system and the use of stable needs-based groups. Additional resources were mobilised by lobbying government and international donors for funds for projects that would meet the needs of farmers. Further resources were obtained through collaboration with other stakeholder organisations. Again, the multistakeholder planning process provided a platform for collaboration. Networking and special issue forums also provided mechanisms for enhancing collaboration within the district. Decentralisation was introduced into Ghana in 1997 with the aim of eventually developing a demand-driven extension system. Although viewed as successful, the case organisation has yet to achieve the level of farmer participation (i.e. self-mobilisation) that is required for a demand-driven extension system. Currently, after six years of decentralisation, the level of farmer participation can be classified as somewhere between consultation and collaboration. Therefore, the results of this study suggest that the transition from a top-down to a demand-driven extension system will take considerable time and resources.
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Singh, Jagrati. "The role of inhibitors in mitigating nitrogen losses from cattle urine and nitrogen fertiliser inputs in pastures : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Soil Science at Massey University, Palmerston North, New Zealand." 2006. http://hdl.handle.net/10179/1483.
Full textAbstract:
The major land use in New Zealand is pastoral farming of sheep and cattle. In intensively grazed dairy-pasture systems, animals graze on nitrogen (N)-rich legume-based pastures, but do not efficiently utilize the N they ingest. On average only 10.5% of the N in forage-based animal feed is converted into milk and the remainder is excreted in dung and urine. In the pastures, a cow urine patch can typically contain up to 1000 kg N ha-1. Nitrogen input, either in the form of cow urine or fertilizer, often exceeds immediate plant requirements and hence is susceptible to losses as ammonia (NH3) volatilisation and nitrous oxide (N2O) emissions and removal in drainage water through nitrate (NO3-) leaching. This loss of N from grazed pastures causes detrimental environmental impacts in the form of acidification and eutrophication of the soil and water bodies, global warming, destruction of stratospheric ozone, and NO3- toxicity. Various approaches have been attempted to mitigate the economic and environmental impacts of N losses. One such approach is the use of Urease (UIs) and Nitrification (NIs) inhibitors. There have been extensive studies on the value of UIs in arable farming and NIs in grazed pastures. However, only limited work on the impact of UI and NI alone and in combination in influencing the N dynamics, and thus mitigating N gaseous losses from pastures, has been conducted. This thesis examines the impact of UI (Agrotain; N-(n-butyl) thiophosphoric triamide) and NI (Dicyandiamide, commonly known as DCD), when applied alone or in combination to cow urine and urea fertiliser, on N losses through NH3 and N2O emissions and NO3- leaching, and on herbage production under glasshouse conditions and a field-plot study. The degradation rate of DCD, and its effect on nitrification and on N2O emissions from four soils varying in their physical and chemical properties was also examined under laboratory incubations. The results from the field-plot study were then used to predict the effect of DCD on N2O emissions reductions from urine by adapting the process-based NZ-DNDC model. Both NH3 and N2O emissions have common sources in agriculture. Therefore, chambers were adapted to measure their emissions simultaneously using active and passive gas sampling. Active sampling involved continuous air flow and the use of acid (0.05 M H2SO4 and 2% H3BO3) traps for NH3 measurements and passive sampling involved collecting three gas samples over a one-hour period from a static chamber used for N2O emissions. The first glasshouse experiment used UI with urine or urea to assess its effect on NH3 and N2O emissions, changes in soil mineral-N and N uptake by pasture plants. The UI treatments also involved two commercial products, Sustain Yellow (urea coated with Agrotain and elemental S) and Sustain Green (urea coated with Agrotain). The use of UI effectively decreased total NH3 emissions, as well as delaying the time of maximum NH3 emissions from both urea (600 kg N ha-1) and urine (476 kg N ha-1) by 27% and 22%, respectively. The UI-induced decrease in NH3 volatilization ranged from 42-48% when urea was applied @ 100 kg N ha-1. Urease inhibitor was also effective in decreasing N2O emissions significantly from urine and urea applied @ 100 kg N ha-1. The addition of UI increased dry matter yield by 13-19% as compared to the urea-alone treatment. In the second glasshouse study, NI (DCD) was added @ 25 kg ha-1 to urea (@ 25, 50 and 75 kg N ha-1) and urine (@ 144, 290 and 570 kg N ha-1) applied at different rates. Addition of DCD reduced N2O emissions from both urea and urine and NO3- leaching from urine. Dicyandiamide reduced N2O emissions by 34-93% from the added urea and 33-80% from the added urine. However, its use increased the amount of ammonium (NH4+) present in the soil by 3 to 13% both in the urea and urine treatments, and this NH4+ was susceptible to leaching and volatilisation losses. The addition of DCD, however, resulted in a 60-65% reduction in NO3- leaching from urine applied to pasture soil cores. It also caused a significant reduction in NO3- -induced cation leaching. Leaching of K+, Mg+2 and Ca+2 ions was reduced by 36-42%, 33-50% and 72%, respectively, with DCD applied to cattle urine (290 and 570 kg N ha-1). The combined use of UI and NI was more effective in controlling N gaseous losses than using them individually. The combination of UI and NI retarded NH3 emissions by 70% in the urea treatment and by 4% in the urine treatment (field-plot study). It also considerably reduced N2O emissions (50-51%) following the application of urea and urine (field-plot study) to pasture soil. With the combined inhibitors, there was a 14 and 38% increase in herbage yield from added urea and urine (field-plot study), respectively. A laboratory incubation experiment was undertaken to study the effect of soil types and the rate of DCD application on the degradation kinetics of DCD. The rate of degradation of DCD varied among the four soils studied. The degradation was slowest (half-life period of 6 to 11 days) in an allophanic soil with a high concentration of organic matter. The effectiveness of DCD in inhibiting nitrification also varied depending on the nature and amount of soil organic matter and clay content. The maximum inhibition was observed in a soil with low organic matter and high clay content. Finally, 'NZ-DNDC', a process-based model, was adapted and used to simulate the effect of DCD on emissions reduction using DCD inhibition values that vary according to different soil types. This model effectively simulated the effect of DCD on N2O emissions reductions in Tokomaru silt loam following urine application. However, more field data are required from a range of pasture soils with contrasting amount of soil organic matter and clay content under differing climatic conditions to further test this model modification to predict emission-reductions with DCD application in different soil types.
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Aslam, Tehseen. "Investigations on growth and P uptake characteristics of maize and sweet corn as influenced by soil P status : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) (Plant & soil science), Institute of Natural Resources, Massey University, Palmerston North, New Zealand." 2005. http://hdl.handle.net/10179/1587.
Full textAbstract:
Despite being different cultivars of the same plant species (Zea mays L.), maize and sweet corn have contrasting P fertiliser recommendations in New Zealand, that are reflected in different target Olsen P values of 10-15 mg P/kg soil for optimum maize growth and 26-35 mg P/kg soil for optimum sweet corn growth. Three key hypotheses were developed in this study to explain why these differences may exist: i) maize and sweet corn differ in their responsiveness to P fertiliser i.e. maize is more internally P efficient and requires less P than sweet corn to grow, ii) both cultivars differ in external P efficiency i.e. their ability to take P up from soil iii) both cultivars differ in external P efficiency because they have different root system structure. Two field experiments evaluated the growth and yield responses of maize and sweet to different rates of P fertiliser application. The first experiment was conducted in Hawke's Bay (2001-02) and second in the Manawatu (2002-03) with P application rates of 0, 100 and 200 kg P/ha in the Hawke's Bay and 0, 15 and 70 kg P/ha in the Manawatu. Both experiments were conducted on soils of low available P status. The Olsen P test values of 13 mg P/kg soil in the Hawke's Bay and 11 mg P/kg soil in the Manawatu were far below the recommended values for sweet corn (25-35 mg P/kg soil). In both experiments and across all P treatments maize produced significantly higher dry matter yields than sweet corn during all sampling stages. In the Hawke's Bay experiment at 100 days after sowing (DAS), the maize (87719 plants/ha, 20.9 t/ha) produced 43% more dry matter than sweet corn (71124 plants/ha, 14.6 t/ha), whereas, in the Manawatu experiment (140 DAS), maize (71124 plants/ha, 15.2 t/ha) had a 39% higher dry matter yield than sweet corn (71124 plants/ha, 10.9 t/ha). In both the field experiments, the sweet corn fresh cob yield of 27 and 28 t/ha in the Hawke's Bay and the Manawatu regions and maize grain yields of 16 and 10 t/ha, respectively, were within the range of the reported commercial yields for each region. In both experiments, the P fertiliser application raised the soil P status (Olsen P test values) but caused no significant increases in either maize or sweet corn yields (total dry matter, sweet corn fresh cob or maize grain). Commercially viable yields of both cultivars were able to be achieved without P fertiliser application with Olsen P soil test in the range of 10-15 mg P/kg soil. Sweet corn reached harvestable maturity at 115 DAS in the Hawke's Bay and 140 DAS in the Manawatu experiments. By this time maize had produced 4-6 t/ha more total dry matter yield than sweet corn, yet maize and sweet corn had achieved similar total P uptake (32-37 kg P/ha at 100 DAS in the Hawke's Bay and 18-19 kg P/ha at 140 DAS in the Manawatu). At silking (after 75 DAS in the Hawke's Bay and approximately 110 DAS in the Manawatu), both cultivar's total leaf P concentrations (0.21-0.25%) were within the sufficiency range values for maize crops in New Zealand (0.18-0.33 %). Maize, however was more internally P efficient growing more dry matter per unit P taken up, which was more noticeable in the drier season. Fertiliser P application increased P uptake with both cultivars under moist conditions in the Hawke's Bay experiment (2001-02). However, the dry conditions in the Manawatu (2002-03) limited P uptake as well as restricted dry matter yields with both cultivars. Further, there were no significant differences between maize and sweet corn P uptake efficiency (kg P/kg root) despite significant differences in the root system structure (biomass) for both cultivars at all stages, which lead to different temporal patterns of P uptake. The lack of maize yield response to fertiliser P in both field experiments is consistent with the New Zealand recommendations for growing a maize grain crop (because soil Olsen P was in the range of 10-15 mg P/kg). However, the lack of sweet corn yield response in both field experiments does not support the New Zealand recommendations for growing sweet corn (which assume optimal Olsen P values are 26-35 mg P/kg).
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Young, Carolyn Anne. "The indole-diterpene gene cluster from the ryegrass endophyte, Neotyphodium lolii, is required for the biosynthesis of lolitrem B, a bioprotective alkaloid : this thesis is presented as a partial fulfillment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Molecular Biology at Massey University, Palmerston North, New Zealand." 2005. http://hdl.handle.net/10179/1670.
Full textAbstract:
Content removed due to copyright: Young, C. A., Bryant, M. K., Christensen, M. J., Tapper, B. A., Bryan, G. T., & Scott, B. (2005). Molecular cloning and genetic analysis of a symbiosis-expressed gene cluster for lolitrem biosynthesis from a mutualistic endophyte of perennial ryegrass. Molecular Genetics and Genomics, 274(1), 13-29.<br>Lolitrems are indole-diterpene alkaloids produced by Epichloë and Neotyphodium endophytes in association with their host grass Lolium perenne. Some indole-diterpene (ID) alkaloids are proposed to have insecticidal properties, but lolitrem B is known as the causative agent of the animal syndrome ryegrass staggers. Lolitrems are preferentially synthesised in planta. which suggests that the genes required for lolitrem biosynthesis are symbiotically expressed. The lolitrem biosynthesis pathway has been proposed as a metabolic grid based on the identification of likely intermediates from endophyte-infected ryegrass. Closely related ID compounds are expected to serve as substrates for the same enzyme, but until recently these steps had not been validated. The identification and characterisation of a Petticillium paxilli gene cluster required for the synthesis of the ID paxilline has identified key enzymes required for the production of the ID backbone. Based on the similarity of lolitrem B to paxilline it was proposed that these two biosynthesis pathways would share orthologous early steps but later steps to convert paxilline to the more complex lolitrem B would require additional enzymes. The lolitrem biosynthesis genes (ltm) were isolated using degenerate PCR and from candidate genes identified as ESTs in cDNA libraries. Ten ltm genes were identified that had functions consistent with those required for lolitrem B biosynthesis. The 10 ltm genes were contained on three gene clusters that are separated by repetitive AT-rich sequences that contain remnants of retrotransposons. The ltm clusters 1 and 2 contain eight genes, seven of which are orthologues of the characterised P. paxilli paxilline biosynthesis gene cluster (pax). Functional characterisation of ltmM an FAD-dependent monooxygenase and ltmC a prenyl transferase confirmed these two genes were required for ID biosynthesis and were orthologues of paxM and paxC, respectively. All 10 ltm genes have similar expression profiles and were highly expressed in planta where the production of lolitrem B is most prevalent. The taxonomic distribution of the ltm genes has established which endophyte strains are likely to produce ID compounds. This work provides the basis for elucidation of the lolitrem biochemical pathway and opens the way for determining how the plant regulates the synthesis of this important group of bioprotective molecules.
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Sartie, Alieu Mortuwah. "Phenotypic assessment and quantitative trait locus (QTL) analysis of herbage and seed production traits in perennial ryegrass (Lolium perenne L.) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph. D.) in Plant Science, Institute of Natural Resources, College of Sciences, Massey University, Palmerston North, New Zealand." 2006. http://hdl.handle.net/10179/1474.
Full textAbstract:
The aims of this study were to develop a genetic linkage map of perennial ryegrass, identify quantitative trait loci (QTL) for herbage and seed production traits, and to identify DNA markers associated with QTL for use in marker-assisted selection (MAS). Major traits identified for herbage production were leaf elongation rate (LER), leaf lamina length (LL), tiller number (TN) and tiller weight (TW), and for increased seed production were seed yield per head (SdYH), reproductive tiller number (RT), reproductive tillers with matured heads (TMH), florets per head (FH), spikelets per head (SH), florets per spikelet (FS), floret site utilization (FSU) and seed weight (TSW). A genetic linkage map spanning 582 centimorgans (cM) was constructed with EST-SSR (simple sequence repeat markers derived from expressed sequence tags) and used to identify QTL for herbage dry weight (DW) and seed yield per plant (SdYP), and their key component traits. Significant genotype by environment effects were encountered for herbage yield, with fewer QTL identified in spring than in autumn. For some traits, ranking of genotypes differed greatly between seasons and different QTL were identified. QTL for DW were identified on linkage groups (Lg) 1 and 6. The QTL on Lg 6 co-located with QTL for TN, while that on Lg 1 co-located with LER and LL. Markers at Lg 1 QTL (qDW-03-1.1) may be more useful for increasing herbage production by MAS because selection for high LER and long LL has been suggested to increase herbage production in perennial ryegrass. QTL for SdYP were identified on Lg 2 and Lg 6. The QTL on Lg 6 co-located with QTL for SdYH, FSU and TSW, while that on Lg 2 co-located with FH, SH and FS. For seed production, markers at Lg 6 QTL (qSdYP-03-6) may be very useful because this QTL co-located with QTL for SdYH, FSU and TSW, and SdYH has been identified previously as a key selection criterion for increasing seed yield. Marker-trait validation confirmed markers pps0495 and pps0698 identified by QTL analysis to be potentially useful for selecting for fast leaf appearance and long LL, respectively, in perennial ryegrass.