The aim of this work was to extend the theory of Everett and Cruickshank, for the determination of activity coefficients at infinite dilution, Y 13 (where 1 refers to the solute and 3 to the solvent), to accommodate solvents of moderate volatility, using the gas liquid chromatography (GLC) method. A novel data treatment procedure is introduced to account for the loss of solvent off the column, during the experiment. The method also allows us to determine the vapour pressure of the solvent. No auxiliary equipment is required, and the method does not employ the use of a presaturator. Further, the effect of a polar involatile solute is examined using various types of solutes. The activity coefficient was found to be independent of column packing and flowrate. Considering the volatile solvent, the systems investigated by the GLC method were straight chain hydrocarbons, (n-pentane, n-hexane and n-heptane), cyclic hydrocarbons (cyclopentane, and cyclohexane) and an aromatic compound, benzene. The systems were investigated at 2 temperatures, 280.15 K and 298.15 K. The results indicate a clear dependence of the activity coefficient on temperature. For the polar nonvolatile solvent, sulfolane (tetrahydrothiophene, 1,1 dioxane) was used. The systems studied were sulfolane + n-pentane, n-hexane, n-heptane, cyclopentane, cyclohexane, benzene, tetrahydrofuran, and tetrahydropyran. The systems were studied at one temperature, 303.15 K, due to the low melting point of sulfolane i.e. 301.60 K. Part of this study into the thermodynamics of solutions'\vas conducted at the Technical University of Warsaw, where the equilibria of sulfolane was studied using· two techniques, a dynamic solid-liquid equilibrium method (SLE), and an ebulliometriGI vapor-liquid method (VLE) . The main purpose of this was to apply solution theories to this data in order to predict the.activity coefficient at infinite dilution for the sulfolane mixtures. The systems measured using solid liquid equilibrium are sulfolane + tetrahydrofuran, or, 1,4-dioxane, or, I-heptyne, or, 1, 1, l,-trichloroethane, or, benzene, and cyclohexane. The results of these measurements were then described using various solution theories, and· new interaction parameters obtained. The vapour liquid equilibrium systems measured were sulfolane + I-heptyne, or, tetrahyrdofuran, or, 1,1, I-trichloroethane, and tetrachloromethane. Here as in SLE the results were described using solution theories. The results of both the VLE and SLE measurements were used in a multiple optimization procedure to produce new parameters for the interaction of sulfolane with various groups, using two group contribution method, DISQUAC and modified UNIFAC. The predicted activity coefficients compare well with the measured values using GLC. / Thesis (Ph.D.)-University of Natal, 1995.

The present study examined the multilayered social contexts that foster or hinder adolescent girls’ participation in physical activity. The current study consisted of two phases, prospective interviews followed by focus group discussions. The interviews utilized a guided, life history format with 7 girls of diverse backgrounds, ages 9-15 years old over a 4-year period. Key themes that emerged in the interviews were used to inform the focus group discussions. In total, 4 focus groups discussions were conducted with 13 girls of diverse backgrounds, ages 12-13 years old. Both the interviews and focus group discussions were transcribed and analyzed for themes using a constructivist grounded theory methodology. Data analysis was informed by the feminist theoretical approach, with an emphasis on social and contextual factors. The domains of school, family, peers, and embodied experiences of physicality emerged as facilitative contexts to engagement with physical activity during childhood. During adolescence, however, these contexts became barriers to physical activity. This study suggests that physical activity promotion programs for adolescent girls require multifaceted strategies, with a particular emphasis on the intersection of gender, socioeconomic status, and ethnocultural/racial heritage.

The present study examined the multilayered social contexts that foster or hinder adolescent girls’ participation in physical activity. The current study consisted of two phases, prospective interviews followed by focus group discussions. The interviews utilized a guided, life history format with 7 girls of diverse backgrounds, ages 9-15 years old over a 4-year period. Key themes that emerged in the interviews were used to inform the focus group discussions. In total, 4 focus groups discussions were conducted with 13 girls of diverse backgrounds, ages 12-13 years old. Both the interviews and focus group discussions were transcribed and analyzed for themes using a constructivist grounded theory methodology. Data analysis was informed by the feminist theoretical approach, with an emphasis on social and contextual factors. The domains of school, family, peers, and embodied experiences of physicality emerged as facilitative contexts to engagement with physical activity during childhood. During adolescence, however, these contexts became barriers to physical activity. This study suggests that physical activity promotion programs for adolescent girls require multifaceted strategies, with a particular emphasis on the intersection of gender, socioeconomic status, and ethnocultural/racial heritage.

Wheat bran contains a diverse collection of macronutrients, micronutrients and bioactive components, including those thought to have an important role in reducing the risk of many chronic diseases. The complication of wheat bran as a functional food relates to its high insoluble fibre content, which renders bran and its constituent bioactives largely indigestible, and hence with limited bioavailability. The main objective of this thesis research was to evaluate the effects of heat treatments of branon the antioxidant activity and chemical composition of the bran. Presumably, if the solubility of wheat bran can be enhanced by pre-treatment, its biological impact associated with its fibre and resident phytochemicals would also be enhanced. Compared to untreated bran, freeze dried water soluble extracts of thermally treated bran had substantially enhanced levels of antioxidant activity and signficantly increased concentration of a very broad spectrum of bran bioactive constituents including phenolics, minerals, phytate, B vitamins, and non-starch polysaccharide fibre compounds. Results taken together point to the development of novel wheat bran and extracts with considerable commercial potential for whole grain food use and a variety of nutraceutical applications far beyond what may be possible with whole grain wheat or normal bran. Outcomes of the research highlight the conclusion that the nutritional and functional food benefits of normal wheat bran probably represent a fraction of its potential due to the limited digestibility of wheat bran, which in turn, limits the bioavailability of its fiber and constituent bioactive compounds.

The investigation conducted for this thesis endeavoured to determine to what extent a relationship exists between pre-service elementary school teacher enjoyment of participating in science laboratory activities in a university-level background science course and their understanding of the science involved in those activities. A student enjoyment score for two science laboratory activities was generated from survey data. A student understanding score was generated from responses to relevant questions on the final exam of the course. A step-wise logistic regression was then conducted on the student enjoyment and understanding scores. Within the scope of the investigation described in this thesis, the findings lead to the conclusion that enjoyment appears to be unrelated to understanding.

This thesis is an inquiry into the nature and structure of face-to-face conversation, with a special focus on group meetings in the workplace. I argue that conversations are composed of episodes, each of which corresponds to an identifiable communicative activity such as giving instructions or telling a story. These activities are important because they are part of participants’ commonsense understanding of what happens in a conversation. They appear in natural summaries of conversations such as meeting minutes, and participants talk about them within the conversation itself. Episodic communicative activities therefore represent an essential component of practical, commonsense descriptions of conversations. The thesis objective is to provide a deeper understanding of how such activities may be recognized and differentiated from one another, and to develop a computational method for doing so automatically. The experiments are thus intended as initial steps toward future applications that will require analysis of such activities, such as an automatic minute-taker for workplace meetings, a browser for broadcast news archives, or an automatic decision mapper for planning interactions. My main theoretical contribution is to propose a novel analytical framework called participant relational analysis. The proposal argues that communicative activities are principally indicated through participant-relational features, i.e., expressions of relationships between participants and the dialogue. Participant-relational features, such as subjective language, verbal reference to the participants, and the distribution of speech activity amongst the participants, are therefore argued to be a principal means for analyzing the nature and structure of communicative activities. I then apply the proposed framework to two computational problems: automatic discourse segmentation and automatic discourse segment labeling. The first set of experiments test whether participant-relational features can serve as a basis for automatically segmenting conversations into discourse segments, e.g., activity episodes. Results show that they are effective across different levels of segmentation and different corpora, and indeed sometimes more effective than the commonly-used method of using semantic links between content words, i.e., lexical cohesion. They also show that feature performance is highly dependent on segment type, suggesting that human-annotated “topic segments” are in fact a multi-dimensional, heterogeneous collection of topic and activity-oriented units. Analysis of commonly used evaluation measures, performed in conjunction with the segmentation experiments, reveals that they fail to penalize substantially defective results due to inherent biases in the measures. I therefore preface the experiments with a comprehensive analysis of these biases and a proposal for a novel evaluation measure. A reevaluation of state-of-the-art segmentation algorithms using the novel measure produces substantially different results from previous studies. This raises serious questions about the effectiveness of some state-of-the-art algorithms and helps to identify the most appropriate ones to employ in the subsequent experiments. I also preface the experiments with an investigation of participant reference, an important type of participant-relational feature. I propose an annotation scheme with novel distinctions for vagueness, discourse function, and addressing-based referent inclusion, each of which are assessed for inter-coder reliability. The produced dataset includes annotations of 11,000 occasions of person-referring. The second set of experiments concern the use of participant-relational features to automatically identify labels for discourse segments. In contrast to assigning semantic topic labels, such as topical headlines, the proposed algorithm automatically labels segments according to activity type, e.g., presentation, discussion, and evaluation. The method is unsupervised and does not learn from annotated ground truth labels. Rather, it induces the labels through correlations between discourse segment boundaries and the occurrence of bracketing meta-discourse, i.e., occasions when the participants talk explicitly about what has just occurred or what is about to occur. Results show that bracketing meta-discourse is an effective basis for identifying some labels automatically, but that its use is limited if global correlations to segment features are not employed. This thesis addresses important pre-requisites to the automatic summarization of conversation. What I provide is a novel activity-oriented perspective on how summarization should be approached, and a novel participant-relational approach to conversational analysis. The experimental results show that analysis of participant-relational features is a.

This thesis examined the contextual factors involved in teaching six students on the autistic spectrum (AS) in a regular primary school in Aotearoa/New Zealand. The research looked at the work of five teachers, including myself as a participant researcher. Through classroom observations and in depth conversations this research aimed to uncover how the teachers tried to meet the needs of their students on the AS and what affordances and/or constraints they encountered in their journeys. A social constructionist approach framed the research approach, together with a constructivist understanding of teaching and learning and these were used in conjunction with a philosophical activity theory base to explore mediators within the complex teaching and learning contexts. The contrast between teachers viewing the AS as a disability or a difference was found to be important to the way the teachers constructed their student’s value in the class or their willingness to try and meet the student’s needs. This is in line with findings that teachers’ attitudes towards disability are a key factor in the inclusiveness of teaching (Macartney & Morton, 2011; Tait & Purdie, 2000). The role of support professionals in developing inclusive teaching was found to be complex, being both affording and/or constraining for the classroom teacher. The complexity of teaching and the myriad of mediators (Lampert, 1985) involved in teaching students on the AS was analysed to uncover a number of key mediators. One of the key mediators was found to be teacher construction of the student on the AS as competent which was linked to the construction of teacher as competent (Morton, 2011). Key affordances to viewing the student on the AS as competent were the teacher having a belief in the value and worth of the student as a person and a learner and having an understanding of what it means to be a student on the AS. Teacher willingness to be student focused was found to be an important affording mediator, where there was a perceived conflict between student need and school or national policies.

Populations in developed and developing countries are becoming increasingly sedentary and the adverse health effects of relatively sedentary lifestyles, the so called lifestyle diseases, are now obvious. However, moderately vigorous physical activity is positively linked via a cause-and-effect relationship with a range of improved health outcomes. Broadly, current physical activity recommendations suggest that adults should achieve a total of at least 30 minutes a day of at least moderate intensity physical activity on five or more days of the week; however, estimates suggest that the majority of adults in the Western World do not meet these recommendations. Many of the factors involved in the initiation and long-term maintenance of physical activity are not fully understood. Considering the rapid pace of technological development and the general move away from labour-based economies, it does appear that the required level of physical activity necessary for optimal health needs to come from leisure-time activity– specifically, planned, regular, moderately vigorous exercise and/or sport. Unfortunately, many people experience great difficulty in engaging with and maintaining a physically active lifestyle and typically there is a rather large gap between what people know to be healthy and what they actually do. The general aim of this project was to design, implement and evaluate the clinical, social and behavioural effectiveness of a buddy-Motivational Interviewing intervention (buddy-MI) in assisting relatively sedentary adults to adopt and maintain regular physical activity for the purpose of improving their cardio-respiratory fitness, health, and quality of life. Specific aims of the intervention included formally involving social support (via the self-selected motivational-buddy) and strengthening individuals’ motivation for and movement toward their physical activity goals. The experimental intervention specifically aimed to extend the MI treatment effect by enhancing participants’ commitment to physical activity over time via intra-treatment social support (support provided within treatment sessions) as well as extra-treatment social support (day-to-day support) provided by the motivational-buddy. A fundamental was to deliver the intervention in a format that could realistically be implemented within typical primary care settings, workplaces, schools or other similar setting: to work towards healthier more active communities and to potentially reduce health system resource utilisation. Using a repeated-measures pragmatic parallel group randomised controlled trial (RCT) design, relatively sedentary adolescents and adults, in stable health, recruited from a university campus population were allocated to one of two interventions. In the experimental intervention, participants were supported by a self-selected motivational-buddy and they received 2-4 sessions of buddy-MI over a period of 12-months (participant determined schedule) as well as pro-active follow-up emails. The control intervention was standard care MI, and the same email follow-up as in the experimental group but without the additional support of a motivational-buddy. The main outcomes were self-reported physical activity, cardio-respiratory fitness and health related quality of life. These primary outcomes were measured at four time-points over the 12-months intervention and follow-up period and quantitative methods were used to analyse the data. Qualitative data were also analysed and presented in relation to the motivational-buddy component of the intervention. The study evaluated the feasibility and incremental effectiveness of motivational-buddy support compared to one-on-one MI in people who had expressed an interest in becoming more physically active. It used a novel intervention design incorporating self-selected motivational-buddies in an effort to mitigate the twin problems of poor adherence and behavioural regression that are commonly associated with physical activity promotion programmes. The intervention was found to have merit and the potential implications for the health-care system, and the wider community, are discussed.

Objectives: Evidence suggests that physical activity reduces symptoms of clinical anxiety and depression, however, very little research has been published about service user’s experiences with physical activity interventions. The ABE Programme is a client-centred, individualised physical activity intervention for people with mental illness delivered by non-government organisation Richmond Services Limited. The objectives of this study were to investigate service users’ outcomes, experiences, barriers to physical activity and contributing factors for physical activity adherence, to make recommendations for health policy, community development, service improvements and further research. Methods: An explanatory concurrent mixed methods design was applied: for the quantitative component a simple quasi-experimental reversal study to analyse participants’ physical (blood pressure, body weight), mental (self-esteem, mental well-being) measures, physical activity level and smoking status; for the qualitative component a descriptive study conducting semi-structured interviews with participants of the programme. Results: Thirty assessment results were available for the quantitative data analysis. Self-esteem, mental well-being and physical activity levels showed significant improvements, whereas physical measurements and smoking status showed no changes. Thirteen interviews were conducted. Qualitative findings reinforced and enhanced quantitative results. Participants’ experiences were physical, psychological and social. Support was important to overcome barriers. Multiple factors contributed to maintaining physical activity. Clients made suggestions related to the support, structure and contents of the programme. Conclusions: The ABE Programme contributes to the improvements of participants’ mental and physical well-being. Professional support is crucial. Improvements are recommended regarding follow-up support, group activities and evidence-based physical activity adherence methods. Emphasis for policy should be on early intervention, collaboration between services and physical activity promotion approaches on multiple levels. Further research is recommended, for example, to develop efficient and cost-effective physical activity adherence approaches. Future research could include single subject studies, surveys and focus groups studies within Richmond and across the wider mental health sector.

No description available.