Background: We examined if it was possible to use routinely available, self-reported data on health behaviours to predict incident cancer cases in the Ontario population. Methods: This retrospective cohort study involved 43 696 female and 36 630 male respondents from Ontario, who were >20 years old and without a prior history of cancer, to the Canadian Community Health Survey (CCHS) cycles 2.1-4.1. The outcome of interest was malignant cancer from any site, termed all-cause cancer, determined from the Ontario Cancer Registry. Predictor variables in the risk algorithm were health behaviours including smoking status, pack-years of smoking, alcohol consumption, fruit and vegetable consumption and physical activity level. A competing-risk Cox proportional hazard model was utilized to determine hazard of incident cancer. The developed risk prediction tool was validated in the CCHS cycle 1.1 on 14 426 female and 11 970 male survey respondents. Results: Incident cancer was predicted with a high degree of calibration (differences between observed and predicted values for females 2.97%, for males 4.23%) and discrimination (C-statistic: females 0.76, males 0.83). Similar results were obtained in the validation cohort. Conclusions: Routinely collected self-reported information on health behaviours can be used to predict incident cancer in the Ontario population. This type of risk prediction tool is valuable for public health purposes of estimating population risk of incident cancer, as well as projection of future risk in the population over time.

Polarization behaviours of copper diffused p-type GaAs was studied in 1. 0M NaCl and 1. 0M NaNO₃ by means of pitting scan and linear sweep potentiodynamic polarization techniques. The thermodynamic potential-pH diagram of the GaAs-H₂O system was constructed. The observed electrode behaviours of GaAs were compared and correlated to the potential-pH diagram. Freely corroding potential, passivation behaviour and pitting potential were examined as a function of a number of factors. These included the effects of different annealing and polishing pretreatments, the bulk solution pH and polarization methods. The corrosion potential (Ecorr) , pitting potential (Epit) and passivation behaviour were affected by the different pretreatments which changed the surface condition of GaAs. For mechanically polished samples, pitting corrosion was found in pH 7.0 solution only. The Ecorr and Eplt were independent of NO₃⁻ and Cl⁻ at pH 7.0. Initial polarization behaviour of p-GaAs at pH 2.0 and 12.0 followed the Tafel Law for semiconductors quite well. There was a reasonable correlation between the experimental observations and the potential-pH diagram of GaAs-H₂O system. SEM images of polarized samples showed that pits formed in NaCl and NaNO₃ had a different shape, being more elongated in NaCl. However, the walls of all pits appeared to be composed of {111} planes. In general, the pit distribution appeared to be similar to the dislocation distribution. A model of pitting corrosion of GaAs was proposed based on strain induced breakdown of the oxide film, localized changes in solution chemistry and the structure of the compound semiconductor. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

Neuroendocrine processes coordinate the behavioural, physiological, and seasonal aspects of reproduction. Some chemicals can disrupt the hypothalamus-pituitary-gonadal axis, impacting reproductive health. Naphthenic acids (NAs), the carboxylic acids in petroleum, are of emerging concern as they contaminate coastlines after oil spills and aquatic ecosystems of the Athabasca oil sands area. They are acutely toxic in fish and tadpoles and possibly endocrine disrupting at sublethal levels. I characterized courtship behaviours and disruption by NAs in the Western clawed frog, Silurana tropicalis. Courtship primarily consists of males producing low trills and achieving amplexus, a mating position where a male clasps a female. Adult frogs were exposed for five days to 20 mg/L NA, a dose low enough to not affect physical activity. In males, absolute calling activity was reduced. Other acoustic parameters such as dominant frequency, click rate, and trill length were not affected. Injecting human chorionic gonadotropin had a slight rescue effect. Vocalization and amplexus were both inhibited after exposure and restored after 2 weeks of recovery. However, calling behaviour did not predict competitive ability or mating success. In females, NA exposure reduced mating success, possibly through decreased attractiveness or receptivity. Receptivity can be indicated by attraction towards the sound of mating calls (phonotaxis), which is cryptic and subjective. I created an apparatus that measures phonotaxis by placing speakers inside traps with infrared lights to detect the time of entry. This novel method is widely applicable for low-visibility observations and studies of choice and preference. This work shows that an aquatic contaminant can reduce mating success in otherwise healthy frogs, and provides a detailed foundation for further investigation.

Cyberbullying is one of the major problems of social networking sites, which has been known to have prolonged adverse psychological effects on social network users. Cyberbullying has been discussed a lot in the literature, but little research has been done on cyberbullying and its related factors. This study seeks to examine the factors influencing cyberbullying on Instagram among young adults. Instagram was chosen as a case study for the thesis because research shows that Instagram is the most preferred social networking site among the age cohort (18–30), who are popularly referred to as young adults. An extensive review of the literature was carried out, and six constructs (Instagram Usage, Vulnerability, Peer Pressure, Anonymity, and Instagram Features) were used to examine the influence of cyberbullying among young adults on Instagram. This study draws from the theory of routine activity theory (RAT), which is grounded on the postulation that criminal acts can be easily committed by any individual who has the opportunity. The researcher reviewed the process and deployed a methodological and concept-centric approach to create a comprehensive conceptual model that included key factors. This dissertation is different from most cyberbullying research in the sense that it reviews cyberbullying behaviours from the context in which they occur rather than the intent or motivation of the perpetrator. The model allowed a holistic examination of factors that influenced cyberbullying behaviours on Instagram. Using a survey methodology, over 201 Instagram users who are also students at the University of Cape Town completed an instrument measuring factor influencing cyberbullying. The researcher deployed Smart PLS, a statistical package for the social sciences, to test for reliability, validity and to analyse the entire dataset. The study critically examined the factors that influence cyberbullying among young adults. The results of this dissertation indicated that peer pressure and online vulnerability have a strong significance in cyberbullying behaviours. Surprisingly, Instagram usage had a weak correlation with cyberbullying behaviours. This study contributes significantly to the exciting research on cyberbullying as it helps identify the factors that contribute to cyberbullying behaviours. From this research, cyberbullying interventions or solutions can be accurately developed.

The purpose of this thesis was to develop an approach that could evaluate the burden of unhealthy behaviours over a lifetime through linked population-based health surveys. The Canadian Community Health Survey (CCHS) is one such cross-sectional survey that is routinely administered to the household population and has been linked to a multitude of administrative healthcare databases. Utilizing the linked CCHS to evaluate the burden of unhealthy behaviours over a lifetime is challenging. Health behaviours naturally change over a lifetime due to many factors, and the burden of unhealthy behaviours has many different dimensions (e.g., mortality, disability, and healthcare costs) that are interconnected with each other. The degree to which lifetime disability and healthcare costs vary in relation to differences in life expectancy remains an area of debate. It is unclear whether individuals with healthy behaviours actually experience less lifetime disability and healthcare costs than individuals with unhealthy behaviours since they typically live much longer. Through several studies, this thesis developed various components that can be potentially combined into a lifetime approach which incorporates multivariable transitions. The first two studies assessed the burden of unhealthy behaviours on period life expectancy and period lifetime healthcare costs. In the first study, CCHS-based multivariable risk algorithms were constructed to provide estimates of the causal associations between each unhealthy behavior (smoking history, leisure physical inactivity, non-active transport, leisure sedentary activity, and poor diet) and mortality. The burden of unhealthy behaviours on period life expectancy was estimated to be 7.5 (6.5-8.3) life years in 2000-2004 and 6.7 (5.8-7.4) life years in 2010-2014. The largest burdens were attributed to non-active transport and smoking. In the second study, CCHS-based multivariable risk algorithms were constructed to provide estimates of the causal associations between each unhealthy behavior and healthcare costs within different phases of life (i.e., defined by proximity to death). Unhealthy behaviours were attributed with 10.2% (2.5%-17.7%) of the period lifetime healthcare costs in 2000-2004, and 12.9% (5.6%-19.8%) in 2010-2014. Leisure sedentary activity and non-active transport were responsible for almost this entire burden, while the other unhealthy behaviours appeared to actually reduce period lifetime healthcare costs. The degree to which these estimates are accurate is unclear given the limitations of period life tables and the potential for unhealthy behaviours relating to physical activity to be a product of aging and prior illness. The third study focused on developing methods by which to derive CCHS-based multivariable transition risk algorithms, which would allow for the creation of cohort life tables rather than period life tables. Novel methods involving multiple imputation models were utilized to create quasi-longitudinal CCHS cohorts from multiple cycles of the CCHS. These quasi-longitudinal cohorts were leveraged to develop multivariable risk algorithms for transitions towards different levels of immobility, an exposure that had been included in the prior algorithms for mortality and healthcare costs. Transitions towards moderate immobility were predicted by all unhealthy behaviours except poor diet, and transitions towards severe immobility were predicted by all unhealthy behaviours except sedentary activity. This approach can also be utilized to develop multivariable transitions for the unhealthy behaviours, which were simultaneously allowed to transition in the quasi-longitudinal CCHS cohorts. Such multivariable transition algorithms could potentially be combined with the previously derived algorithms for mortality and healthcare costs to generate more realistic estimates of life expectancy and lifetime healthcare costs. Large variability in the imputed quasi-longitudinal CCHS cohorts requires further examination, and may be reduced by including comorbidities, healthcare costs, and other information from linked administrative healthcare databases. The last two studies evaluated the representativeness of linked CCHS respondents for population-based studies. Response and consent (to linkage) rates in the CCHS have been declining since its introduction raising concerns surrounding the comparability of CCHS samples over time. Similar to other population-based surveys, survey weights are provided that are designed address biases that may arise from non-response and non-consent to linkage. Unfortunately, these survey weights are not necessarily appropriate for many linked health outcomes that are rare. As a result, CCHS-based multivariable health risk algorithms are frequently derived from pooled unweighted CCHS samples. Fortunately, relative to wider sampling frames, unweighted linked CCHS samples were observed to be comparable over time. Nevertheless, linked CCHS respondents were observed to be healthier than comparable individuals in the community-dwelling and general populations at older ages, where they demonstrated lower risks of mortality, long-term care admission, and healthcare costs. This was not unexpected given that important segments of the population (e.g., residents of retirement homes and long-term care care) are excluded from the CCHS sampling frame. These studies highlighted the difficulties of estimating life expectancy and corresponding lifetime healthcare costs from the household population, and the necessity to ensure that such estimates realistically incorporate the time individuals may live outside of the household population over a lifetime. These series of studies therefore resulted in mortality, healthcare cost, and transition risk algorithms that could potentially be combined to generate lifetime estimates of life expectancy, disability, and healthcare costs for a CCHS respondent. The development of transition risk algorithms requires further research. Once these methods are optimized and transition risk algorithms for all exposures of interest are generated, all the components required for this framework will be complete. At that point, explicit methods by which to combine the algorithms and validate projections will be required. This framework will enable a cause-deleted approach to be applied that simultaneously considers the impact of unhealthy behaviours on mortality, disability, transitions, and healthcare costs. This thesis represents an initial first step towards creating a framework that has the potential to generate lifetime estimates, as well as counterfactual estimates, which better reflect the complex nature of lifetime trajectories.

Yes / OBJECTIVE: Develop and validate a child and adolescent version of the Three Factor Eating Questionnaire (CTFEQr17), and to assess its psychometric properties and factor structure. We also examined associations between the CTFEQr17 and body mass index (BMI) and food preferences. DESIGN: A two-phase approach was utilised, employing both qualitative and quantitative methodologies. SETTING: Primary and secondary schools, UK. SUBJECTS: In phase 1, 76 children (39 boys; mean age: 12.3±1.4 years) were interviewed to ascertain their understanding of the original TFEQr21 and to develop accessible and understandable items to create the CTFEQr17. In phase 2, 433 children (230 boys; mean age: 12.0±1.7 years) completed the CTFEQr17 and a food preference questionnaire, a subsample (n = 253; 131 boys) had their height and weight measured and 45 children (23 boys) were interviewed to determine their understanding of the CTFEQr17. RESULTS: The CTFEQr17 showed good internal consistency (Cronbach’s α=0.85) and the three factor structure was retained: cognitive restraint (CR), uncontrolled eating (UE) and emotional eating (EE). Qualitative data demonstrated a high level of understanding of the questionnaire (95%). A high CR was found to be significantly associated with a higher body weight, BMI and BMI percentile. High UE and EE scores were related to a preference for high fat savoury and high fat sweet foods. The relationships between CTFEQr17, anthropometry and food preference were stronger in girls compared to boys. CONCLUSIONS: The CTFEQr17 is a psychometrically sound questionnaire for use in children and adolescents, and is associated with anthropometric and food preference measures.

Parent involvement in treatment programmes for child anxiety disorders aims to change the parental behaviours and cognitions implicated in the development and maintenance of childhood anxiety disorders. However, very few studies have included parental behaviours and cognitions as outcomes, and the methodological shortcomings of those that have, preclude clear conclusions. This study aimed to provide the first comprehensive examination of change in parental behaviours and cognitions after a guided parent-delivered cognitive-behavioural therapy (CBT) programme compared to a waitlist control. The association between change in parental behaviours and cognitions with child treatment outcome was also considered. Eighty-eight children aged 7 to 12 years old with a diagnosed anxiety disorder were randomised to either an 8-week guided parent-delivered CBT programme (n=41) or waitlist control group (n=47). None of the parents met diagnostic criteria for an anxiety disorder. Observational measures of parental behaviours whilst their child completed an anxiety-provoking task were taken before and after the intervention. Parent expectations were also measured of their child's and own response in the laboratory task, as well as for hypothetical situations that were ambiguous for whether or not they presented a threat. The treatment programme was not associated with greater change in parental behaviours compared to the waitlist control. After the treatment programme there was a change in specific parental cognitions, in that parents perceived themselves and their child to have more control in hypothetical threat ambiguous situations. Change in parental behaviour and cognition was not significantly associated with child treatment outcomes. The results suggest that guided parent-delivered CBT can increase parental self-efficacy in the management of child anxiety. However, the absence of any association of treatment with other parental cognitions or behaviours questions the salience of parental change in the treatment of childhood anxiety disorders.

The degradation of the environment and climate change represent some of the most important environmental issues affecting our society today, and we need to better understand what can be done in order to mitigate the negative effects of human activity on the environment. The present program of research proposes to examine, through three studies, how the frequency of pro-environmental behaviours (PEB) and harmful-environmental behaviours (HEB) are related to self-determined (SDM) and non-self-determined motivation (NSDM), stages of change (SOC), the satisfaction versus the frustration of basic psychological needs as defined by Self-Determination Theory, and nature relatedness. In Study 1 (N = 377), a scale was created to measure two distinct types of environmental behaviours, PEB and HEB, and the relationships between these types of environmental behaviours and SDM and NSDM were examined. Results demonstrated that both types of behaviours loaded on two distinct factors when conducting an exploratory factor analysis, that they were associated differently with environmental motivation, and that levels of motivation were different according to the reported frequency of adoption of PEB and HEB. In Study 2a (N = 266) and 2b (N = 529), the role of stages of change (SOC) was introduced to determine whether environmental motivation and behaviours were different across SOC and to examine whether SOC played a mediating or moderating role in the relationship between environmental motivation and behaviours. Results indicated that people in the later SOC displayed higher levels of SDM and PEB while people in the earlier stages reported higher levels of NSDM and HEB. It was also observed that SOC partially mediated the relationship between environmental motivation and behaviours. In Study 3 (N = 507) nature relatedness was compared to the satisfaction and frustration of basic psychological needs proposed by SDT to examine their respective roles in the association of motivation, SOC, PEB and HEB. Results revealed that nature relatedness was incremental to need satisfaction and frustration with regard to levels of SDM. Also, nature relatedness was an important determinant of SOC and both types of environmental behaviours. As for the proposed model, it was demonstrated that high levels of nature relatedness were associated with higher PEB and lower HEB through partial mediation by SDM and SOC, while need frustration was linked to a higher reported frequency of HEB through mediation by NSDM. Overall this thesis expands on SDT research by highlighting the importance of including HEB in conjunction with PEB and by demonstrating the prominent roles that SOC and nature relatedness could play in the motivational process associated with environmental action.

The sharpnose pufferfish Canthigaster valentini is widespread over the Indo-Pacific tropical coral-reef region. The social system contains territorial male, non-territorial male, and territorial female. Territorial male always occupy a fixed territory and own several territorial females forming a harem in its territory. Previous researches were concerned about field observations or laboratory tests for agonistic respondences towards self-mirror stimuli. Research on dyad interaction is rarely seen in literature. The first objective of this study focuses on the agonistic interactions between two individuals from different combinations of the abovementioned (i.e., male-male and female-female) social categories under a more spacious laboratory condition. Characteristics for intra-individual behavioral sequences were described and compared. Besides, attentions were also paid to the possible factors (e.g., sex, social status) controlling the major aggressive display (i.e., Circling). The second objective is to conduct research on the water spitting behavior of this species that I had discovered. Factors including body size, presence of food and depth of water were tested to see if any of them is the releasing factor for this behavior. The amount of information transmitted in an intra-individual behavior sequence for a male winner was highest, whereas that for a female winner was lowest. Except for Circling, FRD, FLD, and HD were the other major aggressive behaviors. The average number of aggressive behavior in an intra-individual behavior sequence and display time for male were higher than that for female. More attacks were launched in female pairs than in male pairs. For female pairs, attacks were performed by both contestants , whereas only the winners attacked its opponent in male pairs. Male tended to launch the first attack after the longest Circling but that situation did not hold for female. Circling , a agonistic behavior nor quantitatively described in other studies, can be classified into S-type and C-type. The probability of occurrences for these two types of circling were not significant different. Cycle number was higher in the early phase of an aggressive interaction in male pairs. And male spent more time in circling during an aggressive interaction. Under the experimental setting of this study, body length did not affect the outcomes of a aggressive contest. For male pairs, ratio of body high/body length played a role in determining the outcomes. Presence of food , water depth, and movement of objects above the holding aquarium were all releasing factors for the water spitting behavior and presence of food might be the most important one.

Asthma affects over 2.2 million people in Australia. Asthma morbidity is increasing while mortality is decreasing. People with asthma experience shortness of breath as their airways narrow and become inflamed. After an episode of acute asthma many patients experience a relapse requiring further emergency department care. Numerous studies have been undertaken to identify the determinants of asthma morbidity and these studies have primarily used asthma oriented and co-morbidity scales such as anxiety and depression indices. Other studies in this area have indicated psychosocial factors such as coping, asthma attitudes and beliefs that may be linked to people with asthma who are non-compliant or adherent to treatment. Currently, there is no research available that has examined the link between general health promoting behaviours, an individual’s risk behaviour assessment and a brief asthma education encounter that is patient-centred. This study provides a description of the health promoting and risk taking behaviours of people who attend the emergency department with acute asthma. Secondly, it examines the effectiveness of patient-centred education compared with standard education. One hundred and forty-six people with acute asthma who attended the emergency departments of the Princess Alexandra and Mater Adult Public Hospitals were enrolled in this study. Participants self-reported health promoting and risk taking behaviours by completing the questionnaire that contained the Health Promoting Lifestyle Profile (HPLPII) and the Health Risk Appraisal (HRA) instruments. The Hospital Anxiety and Depression Scale (HADS) was also incorporated into the questionnaire to ascertain levels of anxiety and depression in this acute asthma group of people. The asthma education curriculum had the same topics for both the standard education and the patient-centred groups. However, the patient-centred group were able to prioritise the order of the topics according to their identified need. Secondly, the patient-centred group were asked two questions to ascertain the most important issue and asthma issue for them at that point in time. Both groups of participants were educated using the Asthma Foundation Leaflet “Asthma - Basic Facts” during the individual education session. There were 56% females and 44% males with a mean age (+SD) of 34 (13.8) years with 70.3% reported year 12 or above education and 49% of participants earned less that $20,000. Nearly half of the participants were admitted to a hospital ward following emergency department assessment and care. A large proportion of the participants had either moderate or severe asthma. The health behaviour findings from this study suggest people with acute asthma follow preventive health recommendations and safety guidelines more so than the wider community. However, they did not self-initiate home based health actions such as breast self-examination. At the time of attendance to the emergency department with acute asthma there were no statistical difference between the patient-centred education and standard format education groups for age, gender, education, income, asthma control and previous emergency department attendances. The patient-centred education group had fewer re-attendances in the four months after the education intervention when compared with prior emergency department attendances than the control group (p=0.057; p=0.486). In conclusion, people with acute asthma report undertaking a number of preventive health behaviours and actions according to national guidelines and safety recommendations. They report a lack of self-initiated home based health behaviours. Further research is required to investigate the impact on the National Asthma Council’s recommendations of the importance of asthma action plans on people who follow preventive health guidelines and who lack self-initiative abilities. In terms of asthma education, patient-centred education when compared to standard format education may be useful in reducing further emergency department attendances for acute asthma. More research is required to identify other key education issues for people with acute asthma.