Federal regulation and public awareness of agricultural chemical use have fueled precision agriculture research for the last decade. An extensive body of research on potential reduction of herbicide inputs by automated patch-spraying or site-specific management has developed. Two dominant methods have developed for site-specific application of herbicide. Map-based systems use predefined application maps to direct herbicide application and sensor-based systems use real-time weed sensors to identify and treat weeds as the sprayer moves through the field. Weed maps, generated for map-based application of herbicide are beneficial for out-of-field decision-making but are labor intensive to create and sensitive to many types of sampling errors. Real-time sensor-based systems are not as labor-intensive but have historically made no record of what parts of the field received herbicide and are subject to weed discrimination errors. The University of Tennessee Weed Mapping System (UTWMS) is made up of a digital event recorder and a WeedSeeker discrete herbicide application system. The overarching objective of this study was to evaluate the UTWMS under field conditions. Specific objectives included the use of georeferenced manually-sampled plots for evaluation of map accuracy; development of an automated documentation system for quantifying hits, misses, and false triggers of a real-time sensor-based spraying system; updating the logging software of the UTWMS to include a count of spray transitions; and investigate potentials for reducing number of sensors to reflect the existing spatial correlation of weeds. Manually sampled subplots at one-meter resolution did not correlate with weed maps and only weakly correlated when averaged by plot (8x30m). A video documentation system was successfully developed for evaluating discrimination accuracy of sensor-based sprayers. While investigating sensor resolution reduction to reflect spatial correlation of weeds, a sensor was replaced with a conditionally triggered solenoid valve during a simulation. More than 75% of the simulated weeds were accurately sprayed for all four conditional scenarios tested. A software modification to the UTWMS provided enumeration of spray transitions for weed scientist to investigate weed distribution during “percent time on” integration. The update rate of the GPS unit in the UTWMS should be increased if weed maps are to be representative of small research subplots.

Federal regulation and public awareness of agricultural chemical use have fueled precision agriculture research for the last decade. An extensive body of research on potential reduction of herbicide inputs by automated patch-spraying or site-specific management has developed. Two dominant methods have developed for site-specific application of herbicide. Map-based systems use predefined application maps to direct herbicide application and sensor-based systems use real-time weed sensors to identify and treat weeds as the sprayer moves through the field. Weed maps, generated for map-based application of herbicide are beneficial for out-of-field decision-making but are labor intensive to create and sensitive to many types of sampling errors. Real-time sensor-based systems are not as labor-intensive but have historically made no record of what parts of the field received herbicide and are subject to weed discrimination errors. The University of Tennessee Weed Mapping System (UTWMS) is made up of a digital event recorder and a WeedSeeker discrete herbicide application system. The overarching objective of this study was to evaluate the UTWMS under field conditions. Specific objectives included the use of georeferenced manually-sampled plots for evaluation of map accuracy; development of an automated documentation system for quantifying hits, misses, and false triggers of a real-time sensor-based spraying system; updating the logging software of the UTWMS to include a count of spray transitions; and investigate potentials for reducing number of sensors to reflect the existing spatial correlation of weeds. Manually sampled subplots at one-meter resolution did not correlate with weed maps and only weakly correlated when averaged by plot (8x30m). A video documentation system was successfully developed for evaluating discrimination accuracy of sensor-based sprayers. While investigating sensor resolution reduction to reflect spatial correlation of weeds, a sensor was replaced with a conditionally triggered solenoid valve during a simulation. More than 75% of the simulated weeds were accurately sprayed for all four conditional scenarios tested. A software modification to the UTWMS provided enumeration of spray transitions for weed scientist to investigate weed distribution during “percent time on” integration. The update rate of the GPS unit in the UTWMS should be increased if weed maps are to be representative of small research subplots.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains x, 109 p. Vita. Includes abstract. Includes bibliographical references (p. 94-96).

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

Sorghum (Sorghum bicolor L., Moench) is the fifth most important cereal crop in the world and represents an important source of food, feed and energy in several countries. Recently, there has been an increasing interest in sorghum cultivation worldwide, since it is relatively more drought- and heat-tolerant than other cereal crops, and it is better suited for the predicted consequences of global warming. In Africa and Asia, sorghum is primarily used as food for more than 500 million people, while in the Americas and Australia, it is used mainly as a maize-substitute in livestock feed. In the United States, sorghum is also being used in the production of ethanol. In view of its diverse utility, sorghum offers a large number of target traits that could be modified to meet the required applications. In this work, we have used different genetic engineering approaches to address two important issues in sorghum: seed quality and nitrogen use efficiency. First, we examined the temporal and spatial activity of a rice glutelin gene (GluA-2) promoter, in transgenic sorghum. Results from quantitative and histochemical GUS assays, as well as from transcript analyses, showed that this promoter is highly active during the middle stages of sorghum seed development and that it controls transgene expression specifically in the seed endosperm. This means that the GluA-2 promoter can serve as a useful tool in introducing novel traits into sorghum seed in order to improve the quality of this important cereal. Furthermore, we investigated the effects of cytosolic glutamine synthetase (GS1) and alanine aminotransferase (AlaAT) gene overexpression on nitrogen metabolism and plant growth in sorghum. T_(2) generation plants transformed with a sorghum GS1 gene (Gln1) driven by the maize ubiquitin promoter exhibited enhanced grain yield and biomass accumulation under optimal nitrogen levels.

This study investigates the relationship between national institutional context andnational advantage in the biotechnology sector. It is argued that differences in nationaltechnological advantage may be traced to differences in deep-rooted, country-specificinstitutional systems which support the accumulation and diffusion of knowledge betweenthe scientific and industrial communities. The study contributes to a better understandingof the relationship between societal context and national innovative performance. Itfurther enriches theory through considering how national patterns are imprinted upon theR&D strategies which firms pursue.[...] / Cette these etudie la relation au niveau national entre le contexte institutiormel etI'avantage technologique dans I'industrie de la biotechnologie. U est suggere que lesdifferences dans les avantages technologiques peuvent etre reliees aux differences dessystemes institutionnels propres aux pays respectifs qui soutiennent la production et ladiffusion de cormaissance entre les communautes scientifique et industrielle. Cette etudepermet une meilleure comprehension de la relation entre le contexte social et laperformance d'innovation d'un pays. De plus, cette these etudie comment les tendancesnationales sont impregnees des strategies de R & D prises par les entreprises.[...]

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On title page "B" is superscript. / Bibliography: leaves 159-171. / iii, 171 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--Adelaide University, Dept. of Plant Science, 2001

Glioblastoma multiforme (GBM) is an incurable brain tumor, with patients only expecting to live 15 to 16 months post-diagnosis with the most current treatments options including surgery, chemotherapy, and radiation. How GBM resist treatment is still not very well known. However, cancer stem cells (CSCs), a subset of cells in GBM tissue considered responsible for therapeutic resistance and the poor patient prognosis. NANOG, a homeobox gene, is responsible for maintaining pluripotency of embryonic stem cells and is observed in CSCs. NANOGP8, a retrogene in the NANOG family is expressed in CSCs and provides cells with stem-like characteristics previously observed in stem cells. Thus, we hypothesize that NANOGP8 is not only useful as diagnostic and/or prognostic marker, but a target to improve the efficacy of current GBM treatments since it regulates signaling pathways responsible for cell proliferation. I will investigate the mechanisms in which NANOGP8 expression starts in CSCs and increase TMZ efficacy by silencing embryonic stem cell genes in Glioblastoma. As a retrogene, NANOGP8 derive from reverse transcription of the parent gene NANOG and lacks the promoters for expression in cells. We expect to detect some modifications to the upstream sequence of NANOGP8 that may serve as initiators of expression, such as an insertion of a promotor. Although NANOGP8 has similar function to original NANOG parent gene, NANOGP8 may also have additional oncogenic functions making CSCs more resistant to therapy.

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 1998. / Includes bibliographical references.