No description available.

No description available.

In this study bioluminescence-marker systems were used to investigate the fate of two genetically engineered degradative bacteria in soil under different conditions. These bacteria were chromosomally <I>lux-</I>marked <I>Alcaligenes eutrophus </I>H850 Lr with <I>lux</I>AB genes which was able to degrade polychlorinated biphenyls (PCBs), and <I>Pseudomonas stutzeri </I>P16. <I>P. stutzeri </I>P16 was genetically marked with the <I>lux</I>AB <I>tet</I> cassette by insertional mutagenesis using mini Tn5-transposons and was characterised for <I>lux</I> gene stability, phenanthrene degradability and sensitivity to aldehyde. Insertion of <I>lux</I> gene into genome of <I>P. stutzeri</I> P16 provided a novel strain with lower maximum specific growth rate and less sensitivity to high concentrations of phenanthrene in liquid culture. Survival and activity of <I>P. stutzeri</I> P16 <I>lux</I>AB4 was further investigated in soil amended with low and high concentrations of phenanthrene. Initially high concentrations of phenanthrene had a less toxic effect on viable cell concentrations and luminescence activity of genetically engineered <I>P. stutzeri</I> P16 comparing with its wild type showing that <I>lux</I>-marking the above degradative strain made the marked strain more suitable for environmental application in heavily polluted sites. However, resistant cells to high concentration of phenanthrene were not able to survive longer than those which was inoculated to microcosms with lower concentrations of phenanthrene. This indicates that toxicity of the target compound and its concentration have to be considered before releasing the GEMs. Degradation of phenanthrene was enhanced in both sterile and non-sterile soil inoculated with <I>P. stutzeri </I>P16 <I>lux</I>AB4. This study could be used as model for further investigated of degradation of other PAHs such as fluoranthene, benz[a]anthracene, benzo[a]pyrene, by degradative bacteria and also monitoring the survival and activity of those bacteria in the environment using bioluminescence-marker systems.

No description available.

Flax (Linum usitatissimum L.) is considered as a model plant species for multipurpose uses with whole plant utilization for several purposes including industril, food, animal feed, fiber, nutraceutical, pharmaceutical, and bioproduct markets. Therefore, flax is in the process of genetic engineering to meet the market requirements. Prior to commercial release of genetically engineered (GE) flax, a risk assessment was conducted to determine intra- and inter-specific pollen-mediated gene flow and for quantifing and mitigating the adventitious presence (AP) of volunteer flax in canola (Brassica napus L.). The results of pollen-mediated gene flow study (crop-to-crop) suggest that about 1.85% outcrossing would occur in adjunct area, when two flax cultivars were grown in close proximity of 0.1 m apart. Some rare gene flow events were recorded maximum up to 35 m distance from the pollen source but at a very low frequency. The genus Linum has several wild and weedy species, distributed in many parts of the world. A meta-analysis was conducted to determine the potential for gene introgression from GE flax to wild relatives, the occurrence, the phylogeny of flax wild relatives and reported interspecific hybridization. The results demonstrated that cultivated flax has ability to hybridize and form viable F1 plants with at least nine species of Linum; however, none of these species have been reported to occur in Canada. Hybridization of flax with many other wild relatives has either not been studied or reported. However, based on the evidence of reported work, gene flow from GE flax to wild or weedy relatives may occur elsewhere depending on species distribution, sympatry, concurrent flowering, ploidy level and sexual compatibility. The results of the experiments to mitigate the adventitious presence of flax volunteers in canola suggest that combinations of pre-plant followed by post-emergence herbicides were most effective for reducing volunteer flax density and AP in glufosinate-resistant canola. Post-emergence application of imazamox+imazethapyr, however, was not effective for controlling volunteer flax in imidazolinone-resistant canola. Best management practices were developed to mitigate transgene movement from GE flax to ensure co-existance of GE, conventional and organic flax without market harm. / Plant Science

Genetically engineered cells have the potential to solve the cell availability problem in developing a pancreatic tissue substitute for the treatment of insulin-dependent diabetes (IDD). These cells can be beta-cells genetically engineered so that they can be grown in culture, such as the betaTC3 and betaTC tet mouse insulinomas developed by Efrat et al; or, they can be non-beta cells genetically engineered to secrete insulin constitutively or under transcriptional regulation. The aim of this work was to thoroughly characterize and improve the secretion dynamics of pancreatic substitutes based on genetically engineered cells. One issue involved with the continuous beta-cell lines is the remodeling of the cells inside an encapsulated cell system, which may affect the insulin secretion dynamics exhibited by the construct. To evaluate the effect of remodeling on the secretion properties of the construct, we used a single-pass perfusion system to characterize the insulin secretion dynamics of different alginate beads in response to step-ups and downs in glucose concentration. Results indicated that the secretion dynamics of beads indeed changed after long-term culture. On the other hand, data with a growth-regulated cell line, betaTC tet cells, showed that the secretion profile of beads can be retained if the cell growth is suppressed. A major concern associated with genetically engineered cells of non-beta origin is that they generally exhibit sub-optimal insulin secretion characteristics relative to normal pancreatic islets. Instead of relying on molecular tools such as manipulating gene elements, our approach was to introduce a glucose-responsive material acting as a control barrier for insulin release from a device containing constitutively secreting cells. Proof-of-concept experiments were performed with a disk-shaped prototype based on recombinant HepG2 hepatomas or C2C12 myoblasts, which constitutively secreted insulin, and concanavalin A (con A)-based glucose-responsive material as the control barrier. Results demonstrated that the a hybrid pancreatic substitute consisting of constitutively secreting cells and glucose-responsive material has the potential to provide a more physiologic regulation of insulin release than the cells by themselves or in an inert material.

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The 18 September 2000 disclosure that StarLink corn, a genetically engineered variety not approved for human consumption, had been detected in food was a seminal event in agricultural biotechnology. This thesis presents a comprehensive case study of the StarLink incident (part one), reviews the StarLink situation in terms of crisis management theory (part two) and develops crisis management theory using the StarLink incident as an example of a crisis (part three). Part one provides background information, then a meticulous day-by-day account of StarLink-related events. Part two presents a detailed overview of crisis management theory, then examines the StarLink situation in terms of pre-crisis (warning signals, preconditions for a crisis, crisis trigger), crisis (how Aventis, the biotechnology provider, managed the crisis and opinions concerning crisis handling) and post-crisis (lessons learned). Part three develops crisis management theory using the StarLink situation as an example of a crisis. It evaluates whether the StarLink incident possessed characteristics predicted for modern crises and suggests other factors which may become more prevalent and significant in future crises. The StarLink incident delivers certain practical lessons for managers, regulators and others and demonstrates a number of characteristics of modern crises.

This dissertation traces the historical transformation of the Canada-UK commodity chain for wheat-bread as a lens on processes of local and global change in agrofood relations. During the 1990s, the Canadian Wheat Board (Canada’s monopoly wheat seller) and Warburtons, a British bakery, pioneered an innovative identity-preserved sourcing relationship that ties contracted prairie farmers to consumers of premium bread in the UK. Emblematic of the increasing importance of quality claims, traceability, and private standards in the reorganization of agrifood supply chains, I argue that the changes of the 1990s cannot be understood outside of historical legacies giving shape to unique institutions for regulating agrofood relations on the Canadian prairies and in the UK food sector. I trace the rise, fall, and re-invention of the Canada-UK commodity chain across successive food regimes, examining the changing significance of wheat- bread, inter-state relations between Canada, the UK, and the US, and public and private forms of agrofood regulation over time. In particular, I focus on the way in which changing food regime relations transformed the CWB, understood as the nexus of institutions tying prairie farmers into global circuits of accumulation. When in the 1990s, the CWB and Warburtons responded to structural crises in their respective industries by re-inventing the Canada-UK wheat trade, the result was significant organizational and industry change. On the prairies, the CWB has shown how – contrary to expectations -- centralized marketing and quality control may help prairie farmers adapt to the demands of end-users in the emerging ‘economy of qualities’. In the UK, Warburtons has led the ‘premiumisation’ of the bread sector, traditionally defined by consumer taste for cheap bread, over the last 15 years. The significance of the shift towards quality chains in the wheat-bread sector is analyzed in light of conflicts over the proposed introduction of genetically engineered (GE) wheat to the Canadian prairies.

This research project examines the degree of transparency of the Canadian Federal Government’s decision-making processes and institutions with respect to the human consumption of animals produced through modern biotechnology (biotechnology-produced animals). It provides a timely study of the Federal Government’s decision-making process; as of January 2013 the government has yet to determine whether, and how, biotechnology-produced animals are to be approved for human consumption. Foods that contain genetically modified organisms (GMOs) are already commercially widely available in Canada. Research is well underway to see if biotechnology-produced animals may also be developed and introduced into the food system. Government decisions regarding the human consumption of biotechnology-produced animals have the potential to revolutionize food systems globally and nationally. This thesis offers an analysis of primary and secondary data focusing on the degree of federal transparency with respect to regulating GMO foods generally and, more specifically, the emerging policy issues around biotechnology-produced animals. This exploration sets the stage for the following investigation of barriers as well as opportunities to fostering federal transparency with respect to policy and regulatory decisions regarding GMO foods. Findings are directed towards members of the communities of interest who are interested in questions relating to the degree of federal transparency and government approaches to foods that contain material produced through modern biotechnology.