This study aimed to examine farmers’ descriptions of their experiences of cultivating Bt cotton and to see whether or not the farmers’ descriptions of their experiences are in coherence with the purposes with Bt cotton. This was carried out through qualitative semi-structured interviews with Bt cotton farmers in Vidarbha, Maharashtra, and a qualitative content analysis of the farmers’ descriptions. Our conclusions are among other, that the experiences of the farmers are various. Some farmers have experienced what Bt cotton was aimed to lead to; higher yields and reduced use of pesticides while other farmers have experienced the opposite.

Resistance to Bacillus thuringiensis (Bt) cotton, Gossypium hirsutum, is associated with fitness costs in pink bollworm, Pectinophora gossypiella. Previous work has demonstrated that costs of resistance are induced by environmental factors including insecticidal cotton phytochemicals such as gossypol. This study (1) tested the hypothesis that the presence of toxic phytochemicals would increase the dominance and magnitude of fitness costs associated with genes conferring resistance to the Bacillus thuringiensis (Bt) toxin, (2) coupled a selection experiment and simulation modeling to evaluate the fitness cost of resistance to Bt in pink bollworm and (3) used laboratory strains containing susceptible and resistant genotypes to test the hypothesis that gossypol accumulates more readily in pink bollworm with Bt resistance alleles, and that this gossypol accumulation reduces fitness. To test hypothesis (1), larval survival and weight were measured in two independent strains of pink bollworm, Pectinophora gossypiella, reared on diet containing the cotton phytochemicals gossypol and cyclopropenoid fatty acid, alone, or in combination. Cotton phytochemicals increased the dominance and magnitude of fitness costs associated with cadherin-based resistance to Bacillus thuringiensis (Bt) toxin. Gossypol and cyclopropenoid fatty acid combined had a more detrimental effect on fitness of pink bollworm than either compound alone. To test hypothesis (2), two pink bollworm strains fed synthetic diet were monitored over 30 generations to test the hypothesis that costs associated with Bt resistance would result in a decline in the frequency of resistance. A decrease in resistance allele frequency did occur in both strains and costs affecting each resistant genotypes were estimated. To test hypothesis (3), two strains of pink bollworm were fed on diet containing gossypol and on diet without gossypol, and gossypol accumulation in tissues of genotypes was measured. In both strains, significantly more gossypol accumulated in genotypes containing at least one resistance allele and gossypol accumulation was additive to dominant. In both strains, an increase in the dominance or magnitude of costs affecting larval weight was observed on gossypol diet, and the change in the magnitude of costs was positively associated with gossypol absorption. In one strain, the presence of gossypol increased survival costs but only in the genotype with the highest gossypol absorption. The mutation conferring resistance to the Bt toxin Cry1Ac is found in the cadherin-encoding region in three lepidopeteran pests (Helicoverpa armigera, Heliothis virescens and Pectinophora gossypiella) including the pink bollworm. Cadherin proteins had been hypothesized to play a role in maintaining the integrity of the insect midgut epithelial tissue. Taken together, these results support the hypothesis that cadherin proteins do contribute to gut integrity, toxic plant phytochemicals accumulate more readily in pink bollworm with resistance alleles, and that such accumulation increases the dominance and magnitude of fitness costs.

At the beginning of the twentieth century we find novelists using their medium to express doubt in both the Judeo-Christian narrative as archetype and the possibility of purposive narrative in their own work. Often these writers took well-recognized paradigms of purposive narratives, such as 'the quest', or 'historical narrative' and adapted them to show them failing to reach their purposed denouement. The work of these novelists was paralleled by that of contemporary poets. Although the poets' concerns were less immediately affected by the specific challenges to Judeo-Christian narratives, their concern for the efficacy of language was motivated by a similar sense that language no longer possessed the edenic quality of reaching the thing it aimed at. Furthermore the frameworks of art themselves (perspective, rhyme, formal representation, and so on) were found to be unstable. Literary responses to the failure of language and narrative were varied. In a radically simplified form they may be located on a continuum between two points: at one end a desire to fill the void left by an absent God; at the other a fascination with the possibilities of the void. My thesis situates the work of Conrad in particular, as well as Forster, Eliot, Woolf, Imagism and Dada, on this continuum, during the period of, roughly, 1899-1925. The works of these individuals and groups are considered individually and comparatively through detailed readings of texts and images. Through such consideration it becomes apparent that the fascination of the void, which attracted all these writers to varying extents, also brought them to realize new aesthetic possibilities that seemed to fill the void. In particular, the modernist texts under consideration developed an aesthetic of aperture, that is to say an aesthetic of the momentary, more specifically, the moment prior to comprehension, the moment of experience. In fiction this aesthetic grew out of a deconstruction of purposive narrative in favour of imagistic presentation; in poetry and the visual arts the poem or picture abstracted its object from reality and yet equivalenced reality by presenting an inherent internal logic. That logic apparent in the poem or picture was often placed beyond the grasp of the reader or viewers' understanding, representing the sense that the logical operations of the world or the divine machinations of God, were either beyond comprehension,if not non-existent altogether. This aesthetic of aperture is once again illustrated through detailed examination of particular texts and images. In the works considered this reinstatement of the possibility of purposive narrative and language through an aesthetic of aperture is figured mystically, presented in negative-theological terms of absence, silence and the unknowable. The mysticism identified appears at odds with the predominantly practical theological debates in Europe at the time and yet finds philosophical parallels in Wittgenstein's Tractatus. The thesis concludes that the return, in modernist works, of attempts to fill the void is the result not only of aesthetic, but also of social and personal (in particular the repercussions of world war), desires for at least the possibility of purposive narrative and language.

Trichogramma limit pest damage to Ord River Irrigation Area (ORIA) cotton crops by killing the developing embryo of their insect host at the egg stage, effectively reducing the number of emergent pests ingesting transgenic tissue. Their impact on the potentially resistant species, Helicoverpa armigera (Hübner), is considered integral to the Insect Resistance Management (IRM) strategy for transgenic cotton production in the ORIA. This thesis examines aspects of Trichogramma ecology pertinent to this strategy. The dominant species of egg parasitoid in ORIA cotton crops is the introduced Trichogramma pretiosum Riley. Other species make up less than one percent of collected specimens. Surveys revealed T. pretiosum has been introduced or adventitiously dispersed to all developed agricultural regions of northern Australia. Several new species were discovered during surveys in more pristine habitats. Based on field collected eggs, T. pretiosum appears to prefer H. armigera over H. punctigera Wallengren as a host in ORIA cotton. Measured as percent parasitism, Trichogramma activity appears highly variable and does not necessarily coincide with periods of peak insect pest density. Host abundance alone does not define conditions suitable for Trichogramma activity. Environmental constraints on wasp survival, such as the impact of temperature, humidity and insecticide applications, limit their effectiveness in biological control. Despite consistently high rates of percentage egg parasitism (60-99%), acceptable pest control is not readily achieved in ORIA cotton without the aid of insecticides as Helicoverpa numbers exceed damage thresholds. Insecticides inhibit Trichogramma considerably, hence the conundrum regarding initiation of insecticidal control. Trichogramma activity is relatively high early season (May to July), significantly limiting the buildup of pests. Trichogramma effectively stifle Helicoverpa population increase following initial pest egg lay at least during high density years. The impact of farming practices, especially insecticide applications, should be avoided early season to ensure pest mortality attributed to Trichogramma egg parasitisation is maximised. Pre-season habitat manipulation to establish large populations of Trichogramma in alternative hosts is advised. Despite being rare in surrounding habitats and suffering near 50% immature mortality in the field, Trichogramma effectively disperse into young crops attractive to ovipositing hosts and display a high intrinsic rate of increase. Spatial patterns of parasitism tend toward heterogeneity and do not necessarily coincide with host spatio-temporal dynamics. Both host abundance patterns and mean rates of parasitism are not good indicators of parasitoid patchiness. Parasitism rates are highest within the middle strata of the plant canopy prior to complete canopy closure despite a similar number of host eggs being available elsewhere in the plant. Pest density declines as the season progresses. However, insecticide applications become necessary if Bt expression in cotton plants wanes and larval damage increases. Measuring parasitism during periods of declining and low host density is prone to inaccuracy due to small sample size, but can be overcome with the use of egg cards. A better indication of parasitoid activity is achieved using egg cards during periods when insecticide applications are possibly required. As Trichogramma are most active in ORIA cotton from morning to early afternoon, insecticide applications if needed should occur outside of these periods. Trichogramma survival is constrained by environmental influences. Adult female T. pretiosum were exposed to ambient conditions in dialysis tubing sleeve cages to test survival and fecundity in cotton fields. Peak survival and fecundity occurs mid season with both life history variants displaying an inverse relationship to temperature. Adult female T. pretiosum survive longest in the field when provided with sustenance however mortality attributed to handling was considerable. Sleeve cages are not effective for survival measurement of small parasitoids if the cages are frequently moved. Trichogramma effectively reduce pest abundance but are clearly hindered by insecticides and hot dry conditions in ORIA cotton crops. The decision to initiate insecticide applications is best delayed unless absolutely necessary to avoid disruption of Trichogramma impact on pests. Parasitoid activity must be carefully monitored if chemical control becomes imminent. The impact of Trichogramma on pest species can then be optimally exploited.

Through a philosophical analysis of realist interpretations of Madhyamaka Buddhism, I will argue that the Madhyamaka is not well represented when it is represented as nihilism, absolutism or as some non-metaphysical alternative. Indeed, I will argue that the Madhyamaka is misrepresented when it is represented as anything; its radical context sensitivity entails that it cannot be autonomously volunteered. The Madhyamaka analysis disrupts the ontic and epistemic presuppositions that consider inherent existence and absolute truth to be possible and necessary, and so the ultimate truth, śūnyatā, is not an absolute truth or ultimate reality. However, I will argue that śūnyatā does qualify as a universal truth and should be understood as a context-insensitive, non-propositional truth in a non-dual dependent relationship with the multitudinous context-sensitive, propositional truths. This analysis will prove helpful in an investigation of those tensions, discernible within Buddhist modernism and the discourse of scientific Buddhism, that arise when Buddhist apologists claim a timeless modernity and a non-hostility with respect to contemporary worldviews. I will argue that apologists can resolve these tensions and satisfy their intuitions of timelessness, but only if they are willing to foreground the crucial distinction between their Buddhist worldview (their context-sensitive propositional truths) and their Madhyamaka attitude towards that worldview (the context-insensitive truth of śūnyatā). I will go on to generalise this result, showing that this Madhyamaka analysis opens up the possibility for frictionless co-operation between any and all worldviews, and that we therefore have a philosophical basis for a workable and sensitive theory of worldview pluralism. I will find it necessary to defend this position by demonstrating that, despite its context-insensitivity, the ultimate truth’s non-dual relationship with conventional truth mitigates against moral and epistemic relativism. I will further substantiate my claim as to the universal truth of śūnyatā by showing that, in Karan Barad’s ‘agential realism’, we find a revealing example of śūnyatā being articulated from within a non-Buddhist context. Thus, I hope to demonstrate some of the good effects of the Madhyamaka message, and show that this message can only be communicated clearly when it is distinguished from the discourses of Buddhism. In this manner, not by giving it a voice but through finding its voiceless authority, I hope to enable the Madhyamaka speak to the West.

it is the aim of this thesis to demonstrate that the concept of the covenant, as a traditional theological idea, has practical utility in public discourse in the UK. This is done with reference to the secular humanist outlook of John Rawls. It is concluded that such an outlook that sees no role for Christianity in the public realm of political and social policy, does not of itself contain sufficient conceptual resources to furnish the world as fully as an approach that is inclusive of a religious dimension. That such a non-sectarian approach is possible is indicated by the use of New Natural Law, associated with Germain Grisez. The Military Covenant is used as the vehicle to enable this project. The end of the Cold war led to a re-examination of the relationship between the people of the United Kingdom and the British army. After a lengthy and difficult process the connection was summarised by the Military Covenant. This bound together the nation, the state and the army in a solemn manner. However what is a covenant? In an increasingly secular society such concepts that have a theological root are little understood. This is to the impoverishment of national life. The rise of secular liberalism is examined through John Rawls’ Theory of Justice. This is presented as a significant text in understanding this change. Rawls’ misplaced reliance on the rationality of human nature means that secular liberalism is inadequate as a comprehensive model for public policy. In the light of the emergence of the covenant-idea as a robust example of Christian theology, a means of its accommodation is found in New Natural Law. Grisez and his colleagues propose a scheme of thought is based upon the general aspiration people have to live purposeful lives. The Military Covenant is found to find its home in this approach. The legitimate place of Christianity in British society is affirmed as a means to promoting the common good.

No description available.

The successful realization of highly efficient bulk heterojunction OPV devices requires the development of organic donor and acceptor materials with tailored properties. Recently, non-fullerene acceptors (NFAs) have emerged as an alternative to the ubiquitously used fullerene derivatives. NFAs showed a rapid increase in efficiencies, now exceeding a PCE of 13%. In my thesis research, I used two small molecule IDT-based acceptors, namely O-IDTBR and O-IDTBCN, in combination with a wide bandgap donor polymer, GeNIDT-BT, as active material in BHJ solar cells and investigated their photophysical characteristics. The polymer combined with O-IDTBR as acceptor achieved a power conversion efficiency of only 2%, which is significantly lower than that obtained for the system of GeNIDT-BT: O-IDTBCN (5.3%). Using nano- to microsecond transient absorption spectroscopy, I investigated both systems and demonstrated that GeNIDT-BT:O-IDTBR exhibits more geminate recombination of interfacial charge-transfer states, leading to lower short circuit currents. Using time-delayed collection field experiments, I studied the field dependence of charge generation and its impact on the device fill factor. Overall, my results provide a qualitative understanding of the efficiency-limiting processes in both systems and their impact on device performance.

There are often two different types of index used to determine how effected gastropods are from imposex, Vas Deferens Sequence Index (VDSI) and Relative Penis Length Index (RPLI). Data samples of Tritia nitida have been downloaded from IVL’s database and were collected around the Swedish west coast. Regression analysis and T-test were performed on all the data collected and at three different locations (Gothenburg, Lysekil and Strömstad) to analyse how the VDSI, RPLI plus the index Percent Female Displaying Imposex (IMPF) were correlated with the concentration of organic tin compounds in their tissue. Results show that the Index VDSI has the strongest correlation in all the studied areas which makes it the preferable index to analyse organic tin compounds in Tritia nitida with. Result also show a stronger correlation with ∑BT (TBT+DBT+MBT) than for TBT alone at all the studied areas, which can be an indication that TBT effected the organism and then transforms to its degradation components. Significant p-values from t-tests when comparing the areas with each other also suggest that there are local variations in how Tritia nitida is affected by organic tin compounds. There is also a trend where higher concentration of ∑BT in the tissue leads to a higher correlation with VDSI (except for “3.1 Alla kommuner kombinerade).

Bluetongue (BT) is a non-contagious disease of mainly sheep but other ruminants like cattle, goats, and wild ruminants like alpacas, African antelopes and deer can also be affected. It is transmitted by Culicoides midges and its occurrence is seasonal, especially after good rains. The disease is subsiding when temperatures drop. The virus is distributed throughout the world in the tropical, subtropical and temperate areas where there are culicoides vectors which can transmit it (Tabachnick et al., 2011). This includes most countries in Africa, the Middle East, India, China, Australia, the United States of America, Canada and Mexico. Until 2008 24 BTV serotypes were known, but from 2008, data on the 25th serotype was published and recently, the 26th serotype has been identified (Hofmann et al., 2008; Maan et al., 2012a). In Africa 21 serotypes have been identified and BT is controlled mainly by annual vaccinations using a freeze–dried live attenuated polyvalent BTV vaccine. Currently the vaccine used in the Southern African Development Community (SADC) region is produced by Onderstepoort Biological Products (OBP). The vaccine is constituted of fifteen serotypes of the bluetongue virus (BTV) divided into three separate bottles. Each bottle contains five serotypes. The inoculation procedures are that bottle B is given three weeks after bottle A and bottle C three weeks after bottle B. The full immunity is established three weeks after the last bottle. The vaccine is effective and it induces both humoral and cellular immune response (Dungu et al., 2004). However, the challenge with the vaccine is that during outbreaks, sheep might not have nine full weeks to develop protection against the disease; and the farmer loses money on treatment and death of animals. Hence the purpose of the study is to determine whether the number of serotypes in the vaccine can be reduced without affecting efficacy; thus shorten the time taken for the full development of immunity after vaccination of animals. This study is based on previously reported cross-neutralization of specific BTV serotypes in in vitro studies by Howell et al. (1970) and Dungu et al. (2004). Bluetongue virus serotype 4 was selected for this trial and was tested for cross-protection against serotype 4 (control), 1, 8 (unrelated serotypes) 9, 10 and 11 in sheep using the serum neutralization test (SNT). The unvaccinated animals in all groups reacted to the challenge material. The animals vaccinated with and challenged with BTV-4, showed good immune response. Those animals that were vaccinated with BTV-4 and challenged with BTV-1 which is not directly related to BTV-4 (Howell et al., 1970), only 20% of the group was completely protected and did not show clinical signs other than a temperature reaction. The rest showed clinical signs, however the reaction was not as severe as the unvaccinated animal. The animals challenged with BTV-9 and 11 had good protection while those challenged with BTV-10, some showed good protection, some got very sick while others had mild clinical signs. The results showed that BTV serotype 4 do not only develop a specific immune response but can also protect against other serotypes. Future studies should be done looking at more serotypes but also look at the specific titres used per serotype in the vaccine. The development of cellular immunity should also be taken in consideration. With further studies it should be possible to develop a vaccine with fewer serotypes without compromising the immunity against the disease. / Dissertation (MSc)--University of Pretoria, 2012. / Veterinary Tropical Diseases / unrestricted