The effect of genetically modified crop plants on the microbiology of the rhizosphere was investigated using the single-gene Bt cotton as a case study. The project compared the rhizosphere microbiota of four Ingard® 1cotton plant varieties that were closely matched with their non-GM parental strains. The plants were grown in three different Australian soils, ie, a vertisol from a cotton-growing region, and two soils, a fine sandy loam and a red sand from South Australia that had not been exposed to cotton. At the time of the commencement of the project, the only commercially available genetically modified plants were cotton and carnations. The cotton industry in Australia is worth $1.5b annually, and care of the soil and the dynamics of its living microbial consortia needs to be understood for optimum management to enable agricultural sustainability. The general outline of the thesis incorporated four main sections: 1. Experimental setup and analysis of the soils and plants to be used, quantification of the Cry1A(c) plant-produced Bt protein, and its persistence in the soil environment. 2. Measurement of the selected microbial populations of bacteria, fungi, AMfungi, protozoans and nematodes, by counting and estimation by dilution and most-probable number methods. 3. Assessment of selected metabolic pathways to determine the effects on the soil microbial community by chemical and other biochemical methods 4. An overall analysis between different group ratios of expression of each of the variables tested, and the summary of the risk analysis and conclusion. The outcome of this work was the acquisition of scientific data to produce an environmental impact report. The findings of this study showed that generally the microbial populations and the products of major metabolic pathways correlated more closely within the non-GM and GM plant rhizospheres of the paired trials than those of separate trials, indicating that soil and plant cultivar had a stronger environmental effect. The results obtained from the paired trials did not show that there were consistent effects on the rhizosphere soil microbiota that could be attributed to the presence of the Cry1A(c) Bt plant protein on the selected strains of cotton plants. The results from the tests of the paired trials correlate highly with previously published work that the risk factors of genetically modified cotton plants on the microbiology of the rhizosphere soil were found be negligible and not consistent across trials. 1 ® Monsanto Co. St Louis, MO.

This thesis examines consumer behavior towards food risks in three different papers, focusing on two food concerns: genetically modified (GM) food and bovine spongiform encephalopathy (BSE). The first paper investigates the roles of different measures of trust on consumers stated choices for functional GM/nonGM canola oil products. These analyses show that consumers choices for GM/nonGM canola oil are influenced by both generalized trust and trust in food institutions. In general, trusting people are less likely to be in the group of respondents that can be characterized as being anti-GM; trusting people also tend to place a lower discount on the presence of a GM attribute. The second paper focuses on the modeling of consumers choices of foods with potential health and risk attributes. The analysis extends the linear compensatory utility model by allowing for use of attribute cutoffs in decision making. We find evidence that attribute cutoffs are commonly used by decision makers. Further, incorporating attribute cutoffs into the modeling of consumers choices significantly improved the model fit. This paper also examines a potential problem of endogeneity that may be associated with respondents self-reported cutoffs. Model estimates based on self-reported cutoffs differ substantially from those based on predicted cutoffs (where these are based on respondents demographic characteristics); potential reasons include the possibility that self-reported cutoffs may be endogenous. The third paper reports the impacts of habit and trust on consumers responses to a series of three BSE incidents in Canada. We observe that households reactions to the first two BSE events followed a similar pattern: households reduced their beef expenditure shares following the BSE announcements, but these subsequently recovered. We find that habit persistence reduced some households initial negative reactions to the first BSE incident, but that these households modified their beef consumption habits following recurring BSE incidents. Assessing the impacts of trust on households reactions to these BSE incidents, we find that trust tended to offset the negative effects of recurring BSE cases. / Agricultural and Resource Economics

Genetic modification presents the potential to advance not only agricultural production but to increase quality of life as well. The potential this innovation presents will be irrelevant if the public is unwilling to accept and adopt it. The following study examines public perceptions of biotechnology, specifically the consumer approval of genetically modified food products. This study was based on data collected from a national survey conducted in both the United States and South Korea. The United States survey was designed to be nationally representative and consisted of 1201 respondents. The South Korean survey was also designed to be nationally representative and consisted of 1054 respondents Analysis was conducted using two questions from the survey questionnaire as dependent variables: (1) approval of the use of genetic modification in the creation of plant-based food products, and (2) approval of the use of genetic modification in the creation of animal-based food products. This study utilized probit models for binary choice and ordered probit models to analyze the likelihood of consumer approval of the use of genetic modification for the creation of food products. Findings indicated that consumers in the U.S. and South Korea who possessed an accurate knowledge of the applications and outcomes of GM technology were more likely to approve of its use for the creation of foods than those who had inaccurate or no knowledge of the technology. Additionally, the majority of consumers in the U.S. and South Korea believe that GM foods should be labeled as such. Those consumers who felt GM labeling to be necessary were less likely to approve of the GM of foods than those who did not feel GM labeling to be necessary. It was also found that consumers in both countries are less approving of the GM of animals than the GM of plants. Consumer approval of the use of genetic modification in the creation of food products can be increased with proper education that provides accurate knowledge of the applications of GM. Labeling of GM products is likely to result in a decrease in demand, which may be offset by public educational campaigns.

No description available.

Les neutrophiles sont d'une grande importance dans la première ligne de défense de l'organisme contre les pathogènes. Ils participent activement par leurs actions antimicrobiennes, comme la phagocytose et la relâche de granules, mais influencent également la réponse immunitaire par les différentes cytokines et chimiokines qu'ils produisent. L'étude des différentes fonctions du neutrophile a permis d'établir les étapes clés de la signalisation intracellulaire qui mène à ces différentes fonctions. De plus, les études dé signalisation, dans différents organismes, ont placé TAK1, une MAP3K, à l'avant-plan dans l'activation des sentiers MAP kinase et des facteurs de transcription NF-kB. Nos efforts pour élucider les sentiers métaboliques du neutrophile nous ont fait nous pencher sur le rôle que TAK1 pouvait y jouer. Nous avons donc découvert que TAK1 était la kinase d'importance dans le contrôle des fonctions du neutrophile avec le LPS et le TNF[alpha], deux stimuli activateurs de NF-kB. Dans cette étude, nous nous sommes penchés sur le rôle de TAK1 chez le neutrophile avec des stimuli dont les réponses cellulaires ne passent pas par l'activation de NF-kB. C'est dans cette perspective que nous avons utilisé un chimioattractant, le fMLP, et un facteur de croissance, le GM-CSF. Ce sont deux stimuli physiologiques fréquemment retrouvés aux sites inflammatoires. Le fMLP et le GM-CSF activent rapidement TAK1 et celle-ci se retrouve en amont de la voie MEK/ERK, mais pas des voies p38 MAPK et PI3K/AKT. L'inhibition de TAK1 diminue l'expression et la sécrétion d'IL-8 et d'IL-1RA. L'inhibition de MEK/ERK et de PI3K/AKT a le même effet. De plus, l'inhibition de TAK1 empêche l'effet antiapoptotique du GM-CSF ainsi que diminue la production de leucotriènes par le fMLP. En conclusion, les travaux présentés montrent que TAK1 est une MAP3K essentielle dans les réponses fonctionnelles du neutrophile au fMLP et au GM-CSF. Cette découverte ouvre la porte à de nouvelles cibles thérapeutiques, particulièrement dans le cas de maladies chroniques impliquant le GM-CSF.

In this paper, the need to develop a control strategy and test apparatus for next generation hybrid vehicles was realized. The complexity of today’s and future hybrid vehicles necessitates the need for an equally advanced method of control that can extract the optimal fuel economy from the system as a whole. A review of existing hybrid vehicle control strategies was performed. Overall, much research has been done on the optimization of series and parallel type vehicles, but virtually no information was found on the optimal use of advanced powersplit drivetrains. However, the control strategy concepts explored in the literature are useful, and can be extended to complex architectures like the General Motors Two-Mode design. The equivalent consumption minimization strategy (ECMS) method developed by Rizzoni et al at the Ohio State University has proven to be a well developed control strategy that has seen much progress over the last decade. Although it has been only demonstrated on parallel-type vehicles, it was chosen as the basis for the control strategy methodology. An in-depth analysis on the Two-Mode transmission operation was performed. The fundamental equations for each of its range states were derived for future use in developing a plant model, and for use in control strategy development. The torque and speed capabilities of each of its modes and gears were analysed. A detailed plant model was created to form a virtual test bed for control strategy development purposes. The models use empirical data provided by manufactures, which ensures a reasonable level of accuracy in portraying component constraints and efficiencies. Building on the ECMS, a similar hybrid vehicle control strategy was developed for Two-Mode transmission based vehicles. It was modified to handle two degrees of freedom as required by the system. Its objective is to constantly minimize the total equivalent power use in the system which is defined as the sum of the chemical power in the fuel and the power used by the battery multiplied by an equivalency factor. Overall, the control strategy provides a strong basis for the optimal control of nextgeneration hybrid vehicles incorporating powersplit transmissions. It is suggested that further research be explored in combining rule-based control methods with the developed optimization based method since rule-based methods can add the stability required for enhanced drivability. / Graduate / 10000-01-01

University, Diss., 2006--Giessen.

Zugl.: Giessen, Univ., Diss., 2006

Freiburg, Univ., Diss., 1999.

Young people face escalating unemployment rates and insufficient or unsatisfactory job opportunities. Despite this, most of them prefer a career in a formal organisation to a career in entrepreneurship. To more effectively prompt young people to choose entrepreneurship as a career, it is critically important to understand the personal and environmental factors relating to entrepreneurial career choice: the antecedents of entrepreneurial career choice. The core research question underlying this study is: What are the factors relating to entrepreneurial career choice in young people? This study first constructs a conceptual framework of antecedents starting from the extant literature in this field. It then attempts to validate the framework empirically in a sample of South African secondary-school students, laying the foundation for building a theory of antecedents of entrepreneurial career choice. The data collection instrument is a questionnaire compiled mainly on the basis of validated questions available in the literature. The sample is made up of Grade-10, -11 and -12 secondary school learners, aged sixteen, seventeen and eighteen, respectively, selected using a convenience sampling technique. Different statistical tests are employed to examine the relationship between each antecedent factor of the conceptual framework and entrepreneurial career choice. The majority of respondents expressed entrepreneurial-career-choice intentions. The results confirmed a relationship between entrepreneurial career choice and the following antecedents: family support, community support, early childhood experiences, work experience, prior start-up experiences and education. An intricate network of relationships was also found among the antecedents investigated, including some biographical variables. The findings suggest that the current Economic and Management Science (EMS) curriculum implemented in South African secondary schools is achieving its objective of raising students’ entrepreneurial-career-choice intentions. At the same time, however, a number of extra-curricular activities and experiences seem to be related to students’ entrepreneurial-career-choice intentions. This signifies that efforts to foster the choice of an entrepreneurial career among the youth should not be focused entirely on adjusting the school curriculum. Lastly, the number of inter-relationships observed among the antecedents of entrepreneurial career choice signifies that entrepreneurial career choice is a complex phenomenon and that building a theory of antecedents is an arduous undertaking. / Thesis (PhD)--University of Pretoria, 2013. / Business Management / unrestricted