Thesis (Ph.D.)--OGI School of Science & Engineering at OHSU, July 2006. / Includes bibliographical references (leaves 97-114).

Please read the abstract in the section 00front of this document / Dissertation (M Inst Agrar (Sustainable Plant-Genetic Resource Management))--University of Pretoria, 2006. / Genetics / unrestricted

M.Tech. / The tobacco species Nicotiana tabacum has been cultivated in South Africa since 1657, South Africa is considered to be a major producer and exporter of tobacco worldwide. The chlorine percentage of the leaf is very important to cigarette manufacturers when purchasing tobacco from farmers, as a high chlorine percentage value affects the burning quality of the cigarette. The chlorine percentage of the leaves depends on many factors such as rainfall, fertilizer, soil content of chlorine and irrigation. If tobacco with a high chlorine content is not phased out, South African tobacco will lose its export value and the value of the farmers crop may decrease by up to 35%. The research study was undertaken to establish the effect of an isopathically prepared treatment, Chlorine 9CH, on the chlorine percentage levels of (growing) Nicotiana tabacum plants. The research was conducted on the farm J151 in Marble Hall, Mpumalanga from 15 November 2004 to 4 March 2005. Two groups each containing fifty plants were randomly chosen to serve as the Control and Experimental group. There was an initial control period of four weeks during which two Pre-tests were performed on ten plants in each group at two week intervals. The experimental component of the study took place over two months during which the Experimental group was treated with Chlorine 9CH via a knapsack and the Control group was treated with filtered water only via a knapsack sprayer. Both groups were treated twice daily. During the experimental component, two Post-tests were performed on ten plants from each group (at week 8 and week 12) and the third Post-test was performed on the cured leaves the final row of each group (at week 12 and week 14).

Thesis (M.S.)--University of Tennessee, Knoxville, 2008. / Title from title page screen (viewed on Sept. 23, 2009). Thesis advisor: Carrie Ann Stephens. Vita. Includes bibliographical references.

Plain packaging first appeared on the UK policy agenda in the Department of Health’s 2008 ‘Consultation on the Future of Tobacco Control’. Since then, plain (or standardised) packaging has been framed through the potential benefit to young people. Within the period of this thesis, plain packaging has been actively debated and draft plain packaging regulations were published in June 2014. An extended literature review of academic and practitioner marketing literature, internal tobacco company documents and public health packaging research, establishes that the research informing the policy debate, while consistent in its approach and findings, fails to recognise the strategic nature of pack design, the full extent of the influence that branded design can have on consumer responses, and the importance of product design as a marketing tool. This thesis attempts to address these gaps in the plain packaging evidence base. It explores if, and how, adolescents engage with different styles of packaging and product design, whether or not an association between tobacco packaging and adolescent smoking exists, and whether it is possible to observe cognitive, affective and behavioural responses to packaging. The study uses a sequential exploratory mixed methodology design with two stages of research. First, focus groups were conducted with 15 year olds (n=48) to explore adolescent responses to tobacco packaging and product design. The findings show that adolescents are most appreciative of ‘novelty’ pack designs. These ‘novelty’ packs, for instance with innovative structures or distinctive designs and colours, generated positive user imagery and influenced affective feelings among participants. Cigarettes with slim diameters, white tips and decorative designs increased appeal and communicated a weaker tasting and less harmful product. Conversely, a plain pack eliminated positive perceptions and feelings, and exposed tobacco as harmful, dirty and not for young people. The qualitative findings were used to develop measures and hypotheses which were tested in a quantitative survey. The second stage of research utilised a cross-sectional in-home survey (n=1373) with 11 to 16 year olds. Respondents were asked to rate three different pack styles - ‘novelty’, ‘regular’ and ‘plain’ - on 11 pack ratings items and four pack feelings items. The findings show adolescents hold ‘novelty’ packaging in higher regard than ‘regular’ packaging across pack ratings items. There were fewer differences between ‘novelty’ and ‘regular’ packaging for the pack feelings items. Plain packaging was consistently rated most negatively across all survey items. Logistic regressions, controlling for factors known to influence youth smoking, showed that susceptibility to smoke was associated with positive appraisal and also receptivity for ‘novelty’ packaging. There was no association with pack appraisal or receptivity for the plain pack. While susceptibility is not a direct behavioural response it is a reasonable predictor of future tobacco use. Collectively the findings show that ‘novelty’ packaging and product design holds greatest appeal for adolescents. Plain packaging limits the opportunity for tobacco companies to communicate with, mislead and influence consumers. Based upon the role of packaging for consumer goods in general, and tobacco in particular, plain packaging would effectively reduce the promotional role of packaging.

Call number: LD2668 .T4 1965 R662 / Master of Science

A key mechanism utilized by plants to make iron (Fe) available for uptake is the reduction of Fe(III) to Fe(II) via an inducible, plasma membrane-bound Fe(III) reductase. Genes encoding such enzymes have not yet been isolated from plants; however, two Fe(III) reductases have been cloned from yeast. FRE1 and FRE2 account for the total membrane-associated Fe(III) reductase activity in Saccharomyces cerevisiae. If yeast reductase genes could be expressed in a plant system, root Fe(III) reduction may be enhanced, leading to a decrease in Fe chlorosis in transgenic plants. FRE1 and FRE2 were introduced into tobacco via Agrobacterium-mediated transformation. Fe(III) reductase activity was measured in homozygous transformants containing FRE1, FRE2, or both. The highest Fe(III) reduction levels were found in lines containing both FRE1 and FRE2. Liquid reductase assays showed three to four times more Fe(III) reduction in these transformants as compared to controls, and visual plate assays showed reduction along the entire length of the roots. One FRE1 containing line initially exhibited chlorosis on medium with low Fe at pH 7.5, but later recovered. Other transformants and the control remained chlorotic. Agrobacterium-mediated transformation often produces mutant phenotypes. A temperature-dependent morphological mutant was found among the progeny of tobacco transformed by Agrobacterium. The mutation is recessive and is expressed at low temperature (21��C). Mutant characteristics include formation of thick, narrow leaves with abnormal mesophyll cells and near absence of apical dominance. Also in the greenhouse (21-23��C), most plants remain vegetative, and the few flowers that are formed have petaloid stamens. High temperature (30��C) reverses the mutant phenotype, with formation of normal leaves and restoration of apical dominance. However, many flowers still have petaloid stamens. This mutant shares several phenotypic characteristics with transgenic tobacco plants overexpressing maize and Arabidopsis homeodomain proteins. / Graduation date: 1997

Youth represent a substantial portion of smokeless tobacco (ST) users in Canada compared to the general population. Highest prevalence of use is typically seen in males, in current smokers, and in the Western provinces. ST use has also been associated with youth who participate in sports teams. Furthermore, ST has been marketed to youth through the use of flavours and sweeteners to make ST more attractive and appealing. The goal of this study was to determine the prevalence of ST use among Canadian youth and examine factors associated with its use. The study used self-report data from 29,007 grade 9-12 youth who participated in the 2010-2011 Canadian Youth Smoking Survey (YSS). Logistic regression analyses were used to determine factors associated with ST ever and current use among Canadian youth as well as among the sub-population of youth smokers. A mediation analysis was also used to understand if (a) sports team participation or (b) physical activity mediate an association between attempting to quit smoking and ST use among youth smokers. In 2010-2011, 5.3% of Canadian youth had ever used ST and 1.9% were current ST users. Odds of ST use were highest among males, grade 12 students, youth with more than $100 of weekly spending money and current smoking youth. This study was the first to identify associations between both physical activity and sports team participation and ST use among grade 9-12 Canadian youth. Continued monitoring of ST use among youth is recommended. Additionally, further research is needed to explore beyond individual-level factors and understand broader influences of ST use among youth.

Includes bibliographical references (p. 90-100).

In flowering plants, pollen grains are surrounded by extremely strong outer walls providing solid and firm structure for protecting pollen and species-specific interactions with female stigma. The outer wall of pollen, referred to as exine, is composed of sporopollenin polymer, but the composition and synthesis of sporopollenin remains poorly understood. Previous studies have indicated that several genes such as Fatty Acyl-CoA Synthetase (ACOS5), Polyketide Synthases (PKSA and PKSB), and Tetraketide α-Pyrone Reductase (TKPR1) take part in the biosynthesis of sporopollenin in Arabidopsis thaliana. The existence of ancient biochemical pathways for sporopollenin biosynthesis has been widely proposed but experimental evidence from plant species other than Arabidopsis is not extensively available. In this study, two homologous PKS genes, NtPKS1 and NtPKS2, were found in tobacco (Nicotiana tabacum). Results of RT-PCR and in situ hybridization revealed that NtPKS1 and NtPKS2 are specifically and transiently expressed in tapetal cells during microspore development in tobacco anthers. RNAi plants of NtACOS1 and NtPKS1 were investigated. Comparing with wild-type tobacco (SR1), abnormal pollens, defect exine structure, and male sterility were found in the RNAi lines. Enzymatic assays show that NtPKS1 and NtPKS2 encode anther-specific enzymes using fatty acyl-coenzyme A and p-coumaroyl coenzyme A as substrates to yield tri- and tetra- ketide α-pyrone and bisnoryangonin respectively. In this study, the metabolic steps catalyzed by the anther-specific acyl- CoA synthetase (ACOS), polyketide synthase (PKS), and tetraketide α-pyrone reductase (TKPR) were investigated. Using fatty acids as starting substrates, sequential activities of heterologously-expressed tobacco enzymes NtACOS1, NtPKS1, and NtTKPR1 resulted in the production of reduced tetraketide α- pyrones which propose to contribute to the biosynthesis of sporopollenin precursors in tobacco. / published_or_final_version / Biological Sciences / Master / Master of Philosophy