An impact evaluation of the Ontario ban on smoking in schools and on school property : does the ban on smoking influence high school students' intentions to smoke cigarettes?

The Ontario Tobacco Control Act of 1994 imposed a total ban on smoking in schools, and on school property for every school in the province. The imposition of this policy created problems for school administrators. For instance, students who were smoking on walkways and properties adjacent to school boundaries, clashed with neighbouring property owners who were angry about the resulting damage and disruption. The enforcement of this policy consumes valuable resources at each school; therefore, knowledge about the impact of the policy is important. If effective, this policy has the potential to improve the health of students over their lifetime, by preventing or delaying smoking behaviour. Alternatively, an ineffective policy will continue to create administrative problems for the school and serve no legitimate purpose. Therefore, knowledge about the impact of the smoking ban policy on students' smoking intentions assists policy makers and school administrators in their understanding of the policy's impact within the schools. This research provided an impact evaluation of the ban on smoking in schools and on school property in Ontario. A total of 2069 students, from five high schools, in the Niagara Region, provided complete responses to a survey, designed to test whether smoking intentions were affected by the imposition of the policy. The study used Ajzen's theory of planned behaviour (Ajzen, 1991), specifically, the perceived behavioural control measure, to gain some understanding of students' perceptions of control over smoking imposed by the ban. The findings indicate the policy has the potential to influence students' overall smoking intentions. The ban on smoking policy was found to be a significant predictor of the smoking intentions of high school students. As well, attitude, social norms, and perceptions of control were significant predictors of smoking intentions. Exploratory findings also indicated differences between the control beliefs of students from different high schools, indicating potential differences in the enforcement of the smoking ban between schools. The findings also support the utility of the theory of planned behaviour as a methodology for evaluating the influence of punitive policies. This research study should be continued by utilizing the full theory of planned behaviour, including two phases of data collection and the measurement of actual smoking behaviour.

Radiation-induced changes in the export of photoassimilated carbon /|nBarry Jess Shelp. -- 260 0 St. Catharines, [Ont. : s. n.],

Low levels of ionizing radiation induce two translocation responses in soybean: a reduction in photoassimilate export from leaves and a change in the distribution pattern of exported photoassimilate within the plant. In this investigation these responses have been further studied specifically to ascertain the site of radiation damage and to better understand the physiological responses observed. Experimentally the primary data was obtained from studies in which a mature trifoliate leaf of a young soybean plant (Glycine ~ L. cultivar Harosoy '63) is isolated in a closed transparent chamber and allowed to photoassimilate 14C02 for 15 minutes. This is followed by an additional 45 ~_il'1;ute period before the plant is sectl.o ne d an d 14 C-ra dl' oactl.v.l ty d eterml. ne d'l n a 11 parts. Such 14c data provides one with the magnitude and distribution pattern of translocation. Further analyses were conducted to determine the relative levels of the major photosynthetic products using the techniques of paper chromatography and autoradiography. Since differences between control and irradiated P 1 ants were not 0 b serve d l' n t h e par tl't"lo nlng 0 f 14 C between the 80% ethanol-soluble and -insoluble fractions 14 or in the relative amounts of C-products of photosynthesis, the reduction in export in irradiated plants is not likely due to reduced availability of translocatable materials. Data presented in this thesis shows that photoassimilate export was not affected by gamma radiation until a threshold dose between 2.0 and 3.0 krads was reached. It was also observed that radiation-induced damage to the export process was capable of recovery in a period of 1 to 2 hours provided high light intensity was supplied. In contrast, the distribution pattern was shown to be extremely radiosensitive with a low threshold dose between .25 and .49 krads. Although this process was also capable of recovery,lt" occurred much earlier and was followed by a secondary effect which lasted at least for the duration of the experiments. The data presented in this thesis is interpreted to suggest that the sites of radiation action for the two translocation responses are different. In regards to photoassimilate export, the site of action of ionizing radiation is the leaf, quite possibly the process of photophosphorylation which may provide energy directly for phloem loading and for membrane integrity of the phloem tissue* In regards to the pattern of distribution of exported photoassimilate, the site is likely the apical sink, possibly the result of changes of levels of endogenous hormones. By the selection of radiation exposure dose and time post-irradiation, it is possible to affect independently these two processes suggesting that each may be regulated independent of the other and involves a distinct site.