Made available in DSpace on 2016-02-26T14:53:12Z (GMT). No. of bitstreams: 1 CarlaCristinaDutra.pdf: 1092589 bytes, checksum: 04438f8333358adca1827a37834f4d61 (MD5) Previous issue date: 2009-03-30 / Genetic engineering has created genetically modified (GM) varieties of many crops that express the toxin from the bacterium Cry Bacillus thuringiensis Berliner (Bt). The Cry toxin has insecticidal properties, is synthesized during growth of the plant, and can be expressed in any part of it. To evaluate the impact of this technology on the environment, this study aimed to find the effect of GM cotton resistant to insects on the fauna of Formicidae and Coleoptera. The field sample was a commercial area located in the municipality of Maracajú, Mato Grosso do Sul, Brazil. There were two treatments: Bt cotton and non-Bt cotton, and 20 samples were taken in each treatment during the reproductive period of cotton in the 2007/2008 crop season. The samplings were done by interception pitfall traps. It was used the paired t test for each day of collection to compare the occurrence of species in both treatments. Seeking to obtain gradients of community structure of Formicidae and Coleoptera based on species composition, it was used the technique of ordering by hybrid multidimensional scaling (HMDS). The studied Bt cotton area negatively affected the fauna of Formicidae, because of the species richness in Bt cotton was lower when compared to non-Bt cotton, and the species of this family occurred in non-Bt crops were different from those presented in Bt. The fauna of Coleoptera was also affected by Bt crop, as the species that make up the community assessed in Bt crops are different from those that make the non-Bt crop. The fact that negative results were observed regarding the impact on entomofauna in an area with little time under cultivation of Bt cotton, strengthens the possibility of further changes in the long term / A engenharia genética tem criado variedades geneticamente modificadas (GM) de muitos cultivos que expressam a toxina Cry da bactéria Bacillus thuringiensis Berliner (Bt). Essa toxina tem propriedades inseticidas e é sintetizada durante o crescimento da planta, podendo ser expressa em qualquer parte da mesma. Visando avaliar os impactos dessa tecnologia no ambiente, neste trabalho avaliamos o efeito do algodão GM resistente a insetos sobre a fauna de Formicidae e Coleoptera de solo. O experimento foi conduzido em uma área comercial situada no município de Maracajú, Mato Grosso do Sul, Brasil. Sendo avaliados dois tratamentos: algodão Bt e algodão não-Bt. Foram realizadas 20 amostras em cada tratamento, durante o período reprodutivo do algodoeiro na safra de 2007/2008. A amostragem foi realizada através de armadilhas de interceptação do tipo pitfall modificada. Para a análise da riqueza de espécies utilizou-se o teste t pareado por dia de coleta para comparar a ocorrência das espécies nos dois tratamentos. Buscando obter gradientes da estrutura da comunidade de Formicidae e Coleoptera baseada na composição de espécies, foi utilizada a técnica de ordenação por escalonamento multidimensional híbrido (HMDS). O algodão Bt da área estudada afetou negativamente a fauna de Formicidae, pois a riqueza de espécies no algodão Bt foi inferior quando comparada ao algodão não-Bt. As espécies de formigas ocorrentes no cultivo não-Bt foram diferentes daquelas presentes no Bt. A fauna de Coleoptera também foi afetada pelo cultivo Bt, já que as espécies que compõe a comunidade avaliada no cultivo Bt foram diferentes daquelas que compõe a cultura não-Bt. O fato de terem sido observados resultados negativos a respeito do impacto sobre a entomofauna em uma área com pouco tempo de cultivo de algodão Bt, indica a possibilidade de efeitos ainda maiores em longo prazo

Bacillus thuringiensis (Bt) é uma bactéria entomopatogênica encontrada em várias partes do mundo e tem a capacidade de produzir cristais durante a fase estacionária do crescimento. Esses cristais são toxinas compostas por proteínas ativas contra uma ampla variedade de fases imaturas de insetos. As toxinas do Bt têm sido usadas como bioinseticidas por décadas no controle de insetos das ordens Coleoptera, Lepidoptera e Diptera, e algumas toxinas já foram selecionadas como efetivas contra ácaros, nematoides e insetos sugadores de floema da ordem Hemiptera, como os afídeos. Recentemente, foi comprovada a patogenicidade de três isolados de Bt a outro inseto dessa ordem, o psilídeo Diaphorina citri. Esse psilídeo é vetor das bactérias Candidatus Liberibacter spp., agentes causais da principal doença dos citros: o Huanglongbing ou HLB. A descoberta da capacidade endofítica de Bt em plantas de diferentes espécies vegetais abriu perspectivas para novos estudos usando o Bt para controle de insetos sugadores, como a D. citri. O objetivo deste trabalho foi avaliar o efeito patogênico de cada toxina Cry ou Cyt presente nestes três isolados através de isolados de Bt recombinantes expressando as toxinas individualmente. Foram montados bioensaios para confirmar a taxa de mortalidade causada por isolados de Bt contra ninfas de D. citri. Os bioensaios foram feitos usando cinco plantas de laranja doce (Citrus sinensis (L.) Osbeck) e dez ninfas de 3º ínstar de D. citri por planta, além dos controles (sem Bt). A mortalidade das ninfas foi avaliada diariamente durante cinco dias. Durante a avaliação, as ninfas mortas foram coletadas para o isolamento do Bt além da detecção do gene da toxina por PCR. No final do experimento, as folhas jovens onde as ninfas se alimentavam também foram avaliadas quanto à presença do Bt. Nossos resultados confirmaram que os isolados de Bt previamente identificados como patogênicos a D. citri causaram elevada mortalidade (em média 68-93%) em ninfas de 3º ínstar. Dentre os isolados recombinantes testados, um deles apresentou grande destaque, causando a mortalidade de 68-81% das ninfas em 48 horas e 83-93% em 120 horas. Esse isolado possui grande potencial de uso no controle biológico de D. citri através da produção de um bioinseticida ou produção de plantas de citros transgênicas. / Bacillus thuringiensis (Bt) is an entomopathogenic bacterium found in several locations around the world and has the ability to produce crystals during the stationary phase of growth. These crystals are composed of protein toxins that are active against a wide variety of insect larvae. The Bt toxins have been used for decades as biopesticides to control insects of the orders Coleoptera, Lepidoptera, and Diptera. Some toxins have been selected as effective for mites, nematodes and phloem-sucking insects of the order Hemipera, such as aphids. The pathogenicity of strains of Bt to Diaphorina citri, an hemipteran known as Asian citrus psyllid, has been recently demonstrated. This psyllid is the vector of the bacteria Candidatus Liberibacter spp., the causal agents of the main disease of citrus: Huanglongbing or HLB. The discovery of the ability of Bt strains to endophytically colonize plants of different species has opened new perspectives for studies. The aim of this work was to evaluate the pathogenic effect of each Cry or Cyt toxin present in these three isolates through the use of recombinant Bt isolates expressing each toxin individually. A series of bioassays were done in order to confirm the mortality caused by Bt strains against nymphs of D. citri. Bioassays were performed in five seedlings of Citrus sinensis (L.) Osbeck (five replicates/ bioassay) and using ten D. citri 3rd instar nymphs to each assay plant. A suspension containing Bt spores was inoculated via drench in each seedling, and five seedlings were maintained as negative control (without Bt). Mortality was assessed daily for five days. During the bioassays, dead nymphs were collected for further Bt isolation and detection by PCR. At the end of the experiment, young leaves where nymphs feed were also collected to Bt isolation and detection. Our results confirmed that the previously identified Bt isolates pathogenic to D. citri cause high mortality to 3rd instar nymphs. Among the ten recombinant isolates tested, one of them stood out, causing 68-81 % and 83-93% mortality after 48 and 120 hours of inoculation, respectively. The isolation of Bt from dead nymphs and young leaves, and PCR performed with specific primers confirmed the presence of the Bt isolates in psyllids and plants, and their involvement in psyllid mortality. This recombinant Bt with the higher mortality rate found in our results has the potential to be used as a bioinsecticide to control D. citri and the toxin gene can be used to genetic engineering of citrus.

The evolution of pest resistance to Cry proteins threatens the long-term use of Bt crops. Busseola fusca developed resistance to Bt maize in South Africa but the mechanism of resistance is not well understood. According to the gut microbiota theory, extensive cell lysis caused by Cry proteins provide gut microbes access to the more favourable environment of the hemocoel where they germinate and reproduce, causing septicemia and death of the host. This theory brought on questions about the role of gut microbes in the efficacy of Bt maize against target lepidopteran pests. The aim of this study was to determine whether microbes present in the mid-gut of B. fusca influence the efficacy of Cry 1Ab proteins. Larvae were collected from 30 different geographical locations, dissected to excise the midgut and mid-gut content which was separated according to morphological types. The morphological types were used to test the antibiotic susceptibility of the bacteria and proved that ciprofloxacin, ampicillin and doxycycline were the most effective bacteriostatic and bactericidal antibiotics. These three antibiotics were exposed to the morphological types at different concentrations to visualise the possible deleterious effects of the antibiotics on the bacteria. This visualisation was performed by observing the growth curve of the bacteria in the presence of the combination of antibiotics. The antibiotics concentration of 500 μg/ml showed the highest efficacy compared to the other concentrations tested. An antibiotic concentration of 500 μg/ml of ciprofloxacin, ampicillin and doxycycline was incorporated into an artificial diet for the larvae to feed on for 7 days. This method was used to rid the larvae of gut microbes before allowing them to feed on Bt maize (MON810) plant material expressing Cry proteins. The results suggests that by placing antibiotic reared larvae on a Bt plant, the absence of the mid-gut microbes contributed to larvae survival on Bt maize. This observation will contribute to understanding the role of gut microbes on the efficacy of Cry proteins. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

The evolution of pest resistance to Cry proteins threatens the long-term use of Bt crops. Busseola fusca developed resistance to Bt maize in South Africa but the mechanism of resistance is not well understood. According to the gut microbiota theory, extensive cell lysis caused by Cry proteins provide gut microbes access to the more favourable environment of the hemocoel where they germinate and reproduce, causing septicemia and death of the host. This theory brought on questions about the role of gut microbes in the efficacy of Bt maize against target lepidopteran pests. The aim of this study was to determine whether microbes present in the mid-gut of B. fusca influence the efficacy of Cry 1Ab proteins. Larvae were collected from 30 different geographical locations, dissected to excise the midgut and mid-gut content which was separated according to morphological types. The morphological types were used to test the antibiotic susceptibility of the bacteria and proved that ciprofloxacin, ampicillin and doxycycline were the most effective bacteriostatic and bactericidal antibiotics. These three antibiotics were exposed to the morphological types at different concentrations to visualise the possible deleterious effects of the antibiotics on the bacteria. This visualisation was performed by observing the growth curve of the bacteria in the presence of the combination of antibiotics. The antibiotics concentration of 500 μg/ml showed the highest efficacy compared to the other concentrations tested. An antibiotic concentration of 500 μg/ml of ciprofloxacin, ampicillin and doxycycline was incorporated into an artificial diet for the larvae to feed on for 7 days. This method was used to rid the larvae of gut microbes before allowing them to feed on Bt maize (MON810) plant material expressing Cry proteins. The results suggests that by placing antibiotic reared larvae on a Bt plant, the absence of the mid-gut microbes contributed to larvae survival on Bt maize. This observation will contribute to understanding the role of gut microbes on the efficacy of Cry proteins. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Milton’s use of economic tropes has attracted very little critical attention, and the connections between economics and theology in his thought have not yet been explored. Blair Hoxby’s Mammon’s Music: Literature and Economics in the Age of Milton (2002) focuses on the influence of economic ideas on Milton’s political thought, arguing that the poet persistently associates trade monopolies with autocratic abuses of monarchical power. David Hawkes places Milton’s lifelong professional usury at the centre of his 2009 biography, John Milton: A Hero of Our Time, and his 2011 essay, ‘Milton and Usury,’ fruitfully reads key passages from Paradise Lost in relation to contemporary tracts on usury. Hoxby and Hawkes have astutely highlighted the relationship between economics and Milton’s thought, but neither scholar has pursued these connections into Milton’s theology. Economic ideas lie at the very heart of Milton’s soteriology, and my thesis offers a historicised investigation of Milton’s corpus, demonstrating that the tropes of contemporary economic thought were crucial to his understanding of sin and, more importantly, salvation. Chapter 1 traces the roots of this economic soteriology to the economic and theological treatises of the 1620s and early 1630s, which argued that money must be not stockpiled but circulated, and that salvation was a transaction between man and God. Chapter 2 considers how Ben Jonson and George Herbert, whose work Milton was familiar with in his youth, used The Staple of Newes (1626) and The Temple (1633) to respond to contemporary developments in economic and theological thought. Chapter 3 reads Milton’s early works as studies of hoarding and consumption, traced through the debate over sexual stockpiling in Comus (1634), the sinfulness of a hoarding nation in the History of Moscovia (early 1640s), and the clergy torn between their compulsions to covet and consume in Of Reformation (1641). Chapter 4 finds in Gerrard Winstanley’s Fire in the Bush (1650) an explicitly economic understanding of the Fall, and demonstrates how Milton’s political and religious writings of the 1650s betray an anxiety that the English cannot govern their economic appetites and, therefore, themselves. Chapter 5 examines how Milton uses tropes of investment, profit, loss, and repayment in the Christian Doctrine and Paradise Lost (1667) to represent redemption as a transaction between Jesus and God on man’s behalf. Chapter 6 reads the History of Britain (1670) as an indictment of isolationist economic policies, with Milton demonstrating that free interactions between peoples facilitate national refinement, and thus strangers become saviours.

This doctoral thesis examines the Arabic translation of Gregory Nazianzen’s Oration on Baptism (Oration 40) by a tenth-eleventh century Melkite translator and writer, Ibrāhīm ibn Yūḥannā al-Anṭākī. In particular, it focuses on the way al-Anṭākī presented Gregory’s theosis theology and investigates the extent to which he engaged with Islamic thought, primarily his borrowing of concepts and structures from Islamic debates such as the unity and the divine attributes of God and the perfection of the soul. This study asks to what extent this theology, which combines both the social and the spiritual aspects of human perfection, or the reception of Gregory helped the Antiochene Melkites develop a strong identity at a time when they were ruled by the Byzantine Empire but attached to the Islamicate culture they shared with their Muslim neighbours. The key conclusion of this thesis is that the Arabic translation of Oration 40 can be said to present a version of Gregory’s theosis theology which is enriched by the concepts and terms used by Christian and Muslim writers of the period. Although it cannot be said to represent a development in this theology but should be viewed as a creative retelling of it, al-Anṭākī’s erudition in the discussions of Christian Arabic theology and Islamic thought, as well as his references to these discussions in the words he used, makes this text particularly interesting. Theosis seems to have captured what he saw as essential for the good of his community: attachment to the Church or tradition, living the life that Christ lived in this world but with an emphasis on the public expression of the faith, perfection of the soul and the union with God here on earth and in the world to come.

This study is intended as a dialogue between literature and theology, utilizing selected works of the playwright and novelist, Henry Fielding (1707-54). While historical studies of Fielding have clearly yielded much of importance, a broader and less deterministic assessment concerning the latent ambivalences of this, one of the earliest novelists, has yet to be explored. Such an assessment has implications for the current relationship between, and the separate study of, literature and theology. The methodology is informed by an awareness of human frailty (what Fielding described as HUMAN NATURE) and centres upon the use of a specific interpretative tool that I call misplacement. By this, I mean the continuous parting with the ineffable – the perpetual recognition that, in writing, there is always a sense of the other, be that an alternative path not taken, the nagging sense of the numinous, or the coming to terms with the ludicrous nature of the human condition. Such fragile, comedic alterity provides a weak metaphysical root which is shared by both literature and theology. To illustrate the effects of such misplacement, this thesis sets the novels of Henry Fielding alongside works of contemporary philosophical theology such as the post onto-theological critique of Gianni Vattimo and John Caputo, as well as alongside postmodern works of fiction, such as those of Vonnegut and Calvino. In so doing, common critical zones such as epistemology, ethics, mimesis, canonicity, and revelation are investigated. The result of this analysis is that, in all these areas, the novel form, in Fielding’s hands, displays a powerful comic resonance with a theology which seeks to move beyond a strictly deterministic approach. Thus, we discover that Fielding’s work, rather than simply being expressive of proto-Enlightenment principles, actually subverts those assumed securities regarding the status of the individual and his place in the world, before God. In its conclusion, this study reveals the challenge of recognising the inescapably theological nature of the novel and that theology itself, is fictive. This assessment points to a greater need for further shared exploration of the relationship between theology and literature - to their mutual benefit.

Evolution of Helicoverpa armigera resistance to Bacillus thuringiensis (Bt) cotton producing Cry1Ac is progressing in northern China, and replacement of Cry1Ac cotton by pyramided Bt cotton has been considered to counter such resistance. Here, we investigated four of the eight conditions underlying success of the refuge strategy for delaying resistance to Cry1Ac+Cry2Ab cotton, a pyramid that has been used extensively against H.armigera outside China. Laboratory bioassays of a Cry2Ab-selected strain (An2Ab) and a related unselected strain (An) reveal that resistance to Cry2Ab (130-fold) was nearly dominant, autosomally inherited, and controlled by more than one locus. Strong cross-resistance occurred between Cry2Ab and Cry2Aa (81-fold). Weaker cross-resistance (18- to 22-fold) between Cry2Ab and Cry1A toxins was also present and significantly increased survival of An2Ab relative to An on cotton cultivars producing the fusion protein Cry1Ac/Cry1Ab or Cry1Ac. Survival on Cry1Ac+Cry2Ab cotton was also significantly higher in An2Ab than in An, showing that redundant killing on this pyramid was incomplete. Survival on non-Bt cotton did not differ significantly between An2Ab and An, indicating an absence of fitness costs affecting this trait. These results indicate that a switch to three-toxin pyramided cotton could be valuable for increasing durability of Bt cotton in China.

The author of the Book of James names four exemplars in the course of his work. These serve specific functions within their individual contexts in the composition; Abraham and Rahab as exemplars of a vital active faith, Job as an exemplar of steadfast endurance, and Elijah as an exemplar of effective prayer. This thesis explores the wider stories of the exemplars in the Hebrew Bible, traces their development in elements of early Jewish tradition, and compares the author’s use of the exemplars with that of other New Testament writers. It argues that, the author of the Book of James uses the exemplars collectively as a means to encourage his messianic audience to remain faithful to God in the trials of everyday life until the imminent Parousia of the Lord. The four exemplars share three characteristics that will aid the audience in their daily struggles: they were all tested to the limit, yet demonstrated their whole-hearted commitment to God by remaining faithful to him; they were all outsiders who rejected the wisdom (values) of the world and they all faced their life-defining trials reliant on God rather than on other human beings.

This work seeks to examine traditional Christian doctrines regarding life after death, from a pastoral perspective. The study explores new ways of interpreting the meaning in human identity, dis-innocence and forgiven-ness specifically as relating to the continuing evolution of Humankind, and offers a description of humankind as Homo sanctus. The thesis is built around three individual selected case examples of death and dying together with a constructed narrative of ‘problem dying’, and a group of five persons in a Fellowship of the Dying; it describes the development and praxis of new approaches to ministry in these areas. A number of new terms are introduced to better convey the substance of meanings. The study itself may be considered as offering significant new insight in two respects: 1. It engages with the idea that bio-death has teleological meaning within the evolution of Personhood in resurrection. 2. It offers the experiences of Christian pastoral ministry pro-actively engaging with dying as a pilgrimage into and through bio-death, in which every member of the immediate community of faith is pro-active in pilgrimage with the dying Person. The study draws on extensive cross-cultural and multi-faith experience in Britain and Africa.