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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
820471

Barley and flax hull ingredients as functional foods

Hao, Meili 22 September 2010 (has links)
The purpose of the research was to investigate the potential for converting agricultural by-products, barley hull and flaxseed hull as well as their co-extract, into value-added functional food ingredients. Four varieties of barley hull and 3 types of flaxseed hull were hydrolyzed in calcium hydroxide solution in a water bath at 70°C for 4 hrs with shaking. The major phenolic compounds in barley hull, flaxseed hull and their co-extracts were identified by reversed phase high performance liquid chromatography (HPLC) coupled with photodiode array detection (PAD) and quadrupole - time of flight (Q-TOF) mass spectrometry (LC-MS). Ferulic acid, p-coumaric acid, vanillic acid and vanillin, and four ferulate dehydrodimers were detected in barley hull and their co-extracts. Quantitative analysis was conducted on the phenolic acids using the available standards. However, the phenolic compounds in flaxseed were found to be distinct from that of barley hull. Large amounts of secoisolariciresinol diglucoside (SDG), ferulic acid glucoside (FeAG), p-coumaric acid glucoside (CouAG) were found in flaxseed hull with minor content of caffeic acid glucoside (CAG) and flavonoids herbacitin glucoside (HDG), whereas the phytochemical profile of the co-extract was enriched by combining major phenolic compounds from both barley hull and flaxseed hull.The antioxidant activity of barley hull, flaxseed hull as well as their co-extract was evaluated using DPPH radical scavenging assay while total phenolic content was measured using the Folin-Ciocalteau method. After screening using chemical assays, the representative barley hull extract, flaxseed hull extract as well as their co-extract were tested for their intracellular antioxidant activity and the antiproliferative activity in PC-3 human prostate cancer cells. Both chemical assays and the cell culture assays indicated that barley and flaxseed hull had strong antioxidant activity and antiproliferative activity. Although the co-extract exhibited the strong antioxidant activity in the chemicals assay, it behaved differently in the cell culture assay, which may be attributed to the chemical and biological properties of the major phenolics in the co-extract.Following evaluation of the antioxidant activity and anticancer effect of barley hull extract, flaxseed hull extract as well as their co-extract, each type of extract was incorporated into Chinese steamed bread (CSB). The phytochemical profile of CSB was enriched by incorporating barley hull extract, flaxseed hull extract as well as their co-extract, which resulted in a significant enhancement in the antioxidant activity evaluated by DPPH and ORAC. Therefore, barley hull, flaxseed hull and their co-extract are suggested as promising sources of functional food ingredients.
820472

Utilization of electrolytes to encourage early feed and water consumption in newly weaned piglets

Gigiel, Agnieszka 22 September 2010 (has links)
Four experiments were conducted to determine a management strategy for providing effective electrolyte concentrations in the drinking water of newly weaned piglets to encourage early fluid and feed intake [weaning age=19±1 d, n=360]. In Exp. 1, electrolytes (Vetoquinol, QC, Canada) were provided at the label dose of 60 ml/L of water for 0, 6, 12, 18 or 24 h on d1-d3. In Exp. 2, electrolytes were given ad lib at 100, 75, 50, 25 or 12.5 % of the label dose on d1-d3 (72 h). In Exp. 3, electrolytes, at the label dose, or water (control) were given ad lib on d1, d1 and d2, d1-d3, or d1 and d3. In Exp. 4, based on the results of the previous experiments, the most effective combinations of "hours/concentration/days"(12 h of 25 % or 50 % on d1 or alternate days) were tested. All piglets had water ad lib from d4-d14. In Exp. 1, higher feed disappearance was observed in the 0, 6 and 12 h/d than 18 h/d and 24 h/d electrolyte groups (P<0.05). In Exp. 2, by d14 piglets in the 12.5, 50, 75, and 100 % groups experienced lower weight gain and daily FI than those in the 25 % group (P<0.05). In Exp. 3, piglets that received electrolytes on d1 only had comparable FI to those in the water group (respectively; 64.55 g/pig/day vs. 75.59 g/pig/day; SEM=8.61). Overall, evidence indicated that weanlings tended to benefit from electrolyte administration at 25 % of the label dose and durational period of ≤ 12 h/d. However, in Exp. 4 testing neither 25 % or 50 % concentration for 12 h/d result in improved daily FI despite the increased FLI in groups given electrolytes on alternate days. The results suggest that high electrolyte intake occurred at the expense of feed intake.
820473

Post-release monitoring of genetically modified canola (Brassica napus L.) in western Canada: escape, persistence and spread of novel traits

Knispel, Alexis L. 22 September 2010 (has links)
Genetically modified (GM) canola (Brassica napus L.) has been widely adopted in Canada since its commercial release in 1995 and now represents over 85% of the canola grown in western Canada. Concurrently, GM canola volunteers have become an increasing management problem in cultivated fields and are ubiquitous in adjacent ruderal (non-cropped disturbed) habitats. However, systematic post-release monitoring is lacking and the ecological and agronomic impacts of escaped GM canola are poorly understood. In this dissertation, I characterize the escape, demography and distribution of GM canola in ruderal habitats in southern Manitoba, at multiple spatial and temporal scales. I characterized GM herbicide tolerance traits in 16 escaped canola populations. The progeny of 129 plants were tested in herbicide trials; 74% of plants produced glyphosate-tolerant progeny, 63% produced glufosinate-tolerant progeny, and 34% produced multiple herbicide-tolerant progeny as a result of gene flow between escaped plants. At the population-scale, four escaped GM canola populations were monitored and periodic matrix models were constructed to describe the dynamics and persistence of flowering plants. Escaped populations were observed to flower in synchrony with adjacent crops and were projected to persist for 2 to 5 years, confirming the potential for gene flow between escaped and cultivated canola populations. At the landscape-scale, the distribution of escaped canola was surveyed in three agricultural regions. Regional factors were important determinants of distribution; escaped canola density was positively correlated with canola cropping intensity and with traffic intensity, and was negatively correlated with distance to grain distribution centres. Local seed dispersal had negligible impact on distribution compared to landscape-scale anthropogenic seed inputs resulting from agricultural transport. These findings suggest that escaped canola persists as a metapopulation, where long-distance dispersal and colonization compensate for frequent extinction of local populations. Escaped populations play an important role in the persistence and spread of GM traits at large spatial scales, with substantial implications for the coexistence of GM and non-GM crops, and especially for organic and reduced-tillage farming operations. Landscape-scale management approaches, designed and implemented collaboratively by multiple stakeholders, are necessary to mitigate the risks of contamination resulting from GM trait escape. Regulation and ongoing monitoring of GM crops must acknowledge and address the dynamic regional nature of seed- and pollen-mediated gene flow.
820474

Risk management behavior of agricultural producers: preferences and perceptions

Hodgson, Karen 22 September 2010 (has links)
The objective of this paper is to examine factors affecting the risk management behavior of Western Canadian grain producers. The first part analyzes factors affecting perceptions of crop insurance. Data for the study is generated from a survey of agricultural producers in Western Canada, and a probit model is used for estimation. Results show that if farmers receive fair crop insurance assessments, quick payments, and have a high knowledge level of crop insurance, they are more likely to have a more positive perception of crop insurance. The second part examines factors that could be influencing the frequency by which agricultural producers hedge their price risk with futures. The same data and estimation method are used. Results show that if farmers use forward contracts and options to hedge price risk, speculate with futures, place a high importance on low brokerage fees, or have larger farms, that are more likely to hedge.
820475

An exploration of HIV related stigma within the context of Kerala, India

James, Maria 22 September 2010 (has links)
Purpose: To understand through explorations of the experiences of HIV positive individuals whether these individuals experience stigma in relation to HIV/AIDS and how it has impacted their lives and that of their families. Design: Qualitative study used ethnographic techniques (interviews, questionnaires, informal conversations, observation, field notes) to collect data over a four-month period. Setting: Data was collected from nine districts in the northern, central, and southern regions of the state of Kerala, India. Participants: Shared their perspectives on HIV related stigma (n=49 total). Of the 38 participants interviewed, 12 were HIV positives, 19 were HIV positives who also worked or volunteered with HIV positive networks (known as positive speakers), 2 were caregivers of HIV positives, and 5 were key informants involved with community organizations providing services to HIV positives. Informal conversations with 11 unaffected were also utilized. Findings were organized into four themes. (1) Anti-stigma/prevention strategies such as positive living and positive speaking offered positive speakers unique challenges and opportunities as they were called upon to be the face and voice of HIV (2) Contrary to expectations that formal education which also included awareness about HIV could increase one’s knowledge and subsequently dispel ignorance and stigma, the findings pointed out how knowledge itself is a resource that allowed stigma to unfold along existing social hierarchies. (3) Unconscious prejudices about physical appearances influenced perceptions of HIV risk, and a stigmatized identity waxed and waned with a change in physical appearance as the HIV positive oscillated between illness and health. (4) “Immoral behaviour” as the cause of HIV infection entered into family/caregiver decisions regarding the use of family resources for the treatment and care of the HIV positive member. Gender and social class also impinged on family decisions in numerous ways. Conclusions: This research project has highlighted the need to develop a more nuanced understanding of HIV related stigma that extends beyond the current conceptualization of stigma as “ignorance” or lack of awareness about modes of HIV transmission. Refining current understandings of HIV related stigma could guide research, policy, and practice.
820476

The three-dimensional (3D) organization of telomeres during cellular transformation

Chuang, Tony Chih-Yuan 22 September 2010 (has links)
Statement of Problem Telomere dynamics in the three-dimensional (3D) space of the mammalian nucleus plays an important role in the maintenance of genomic stability. However, the telomere distribution in 3D nuclear space of normal and tumor cells was unknown when the study was initiated. Methods Telomere fluorescence in situ hybridization (FISH) and 3D molecular imaging, deconvolution, and analysis were used to investigate telomere organization in normal, immortalized and tumor cells from mouse and human cell lines, and primary tissues. Results Telomeres are organized in a non-overlapping manner and in a cell-cycle dependant fashion in normal cells. In the late G2 phase of cell cycle, telomeres are assembled into a flattened sphere that is termed the telomeric disk In contrast, the telomeric disk is disrupted in the tumor cells. Moreover, telomeric aggregates (TAs) are found in tumor cells. Conditional c-Myc over-expression induces telomeric aggregation leading to the onset of breakage-bridge-fusion cycles and subsequent chromosomal abnormality. Conclusions Telomeres are distributed in a nonrandom and dynamic fashion in the 3D space of a normal cell. Telomeric aggregates are present in cells with genomic instability such as tumor cells and cells with deregulation of c-Myc. Consequently, TA can be a useful biomarker for research in cancer and other disease processes.
820477

A school-to-adulthood transition follow-up system for youth with disabilities in Manitoba

Park, Youn-Young 22 September 2010 (has links)
In this study, I develop a transition follow-up system (TFS) — a data-collection system that tracks information about persons with disabilities from high school to adulthood — that is socially valid in Manitoba. I investigate the current data-collection practices regarding persons with disabilities in Manitoba and analyze stakeholders’ needs for a transition follow-up system using document review, surveys, focus groups, and individual interviews. There is currently no formal data-collection system documenting the transition from school to adulthood of persons with disabilities in the province. Stakeholders have acknowledged the need for such a data-collection system in order to improve current support systems. The key suggestions that stakeholders have made with regard to implementing a transition follow-up system are (a) ensuring impartial, reliable data management, (b) minimizing any additional work required for schools and adult services programs/agencies, (c) utilizing existing data collection practices, (d) applying various data collection methods, (e) carrying out longitudinal data collection regarding individuals with disabilities, (f) including persons with various disabilities, from mild to severe, (g) involving various government departments in the transition process, (h) protecting privacy and confidentiality, and i) ensuring user-friendly data collection and reporting. The most significant concern that stakeholders express relates to securing the financial and human capacity to develop and maintain a transition follow-up system. Based on these suggestions and the current Manitoba context, I propose a transition follow-up system model, recommending operative aspects such as scope, purpose, administrators, target youth, information to collect, data collectors, data-collection methods, data sources, timeline of data collection, reporting, confidentiality and privacy, and methods of ensuring the reliability and validity of data. Although the model proposed is relevant to the Manitoba context, it also offers a useful set of general guidelines on critical issues that need to be considered in developing and implementing a transition follow-up system.
820478

Balancing act: The relationship between work-family balance, gender, quality of life indicators and self-rated health.

Penner, Leslie 22 September 2010 (has links)
Substantial numbers of Canadians work shifts. The reasons individuals work shifts are varied and complex. Prior research regarding the relationship between work-family balance, gender, quality of life indicators and health has yielded mixed results. The goal of this research was to examine the association between work-family balance, quality of life indicators and Canadians' overall health status while controlling for socio-economic status, education, family structure and life satisfaction. The two objectives of this study were: 1) to explore how the relationship between work-related characteristics, quality of life and overall health status is different among Canadian male and Canadian female workers, controlling for age, education, socio-economic status, family structure, and life satisfaction and, 2) to examine the relationship between shift configuration and employees' overall health status, controlling for socio-economic status, gender, education, family structure and life satisfaction. This study involved analyses of cross-secional national data from the General Social Survey (GSS) 2006, Cycle 20. The sample for the study included employed men and women who were married or living in common-law relationships, ages 18 through 69. Bivariate and logistic regression analyses were conducted to address the stated research objectives. Appropriate survey weights were applied to estimate population characteristeics. To fully account for the survey's complex sample design, mean bootstrap weights were used for variance estimation and calculation of confidence intervals. Findings indicated that for women and shift workers, both work-to-family spillover and family-to-work spillover were predictve of poor self-rated health. Spillover was not a predictor of poor health for men or day workers. Shift configuration was not found to be significantly correlated with poor self-rated health. Analyses should be repeated to test for interaction between shift work and sleep quality as sleep quality was controlled for in this study.
820479

The nutritional intake of persons with type 2 diabetes mellitus who have peripheral neuropathy, compared to those who do not have peripheral neuropathy

Ross, Courtney 22 September 2010 (has links)
Objectives: The incidence of type 2 diabetes mellitus (DM2) is on the rise worldwide. The primary objective was to determine the prevalence of nutrient inadequacy and excessiveness in persons with DM2 with and without diabetic peripheral neuropathy (DPN). Study Design: A validated semi-quantitative food frequency questionnaire was used to determine the prevalence of inadequacy of nutrients with an estimated average requirement; the mean intake of nutrients with an adequate intake; and the proportion of persons not meeting the recommendations for the acceptable macronutrient distribution range (AMDR). Results: Differences were observed in the prevalence of inadequacy of vitamin A and the proportion of persons not meeting the AMDR for total fat, linoleic acid and carbohydrate. Conclusion: The aforementioned nutrients may have a significant role in the progression/development of DPN and should be studied in further detail. We recommend a balanced diet and use of a multi-vitamin for persons with DM2.
820480

Aggression in siblings exposed to domestic violence

Tachie, Rose-Marie 22 September 2010 (has links)
Exposure to domestic violence in childhood has serious consequences for children’s health and well-being and is an important predictor of domestic abuse. However, as compared to other forms of domestic abuse, the effects of exposure to domestic violence on the quality of sibling interactions have been relatively underexplored. The major objective of the current study was to examine the impact of exposure to domestic violence on the quality of the sibling relationship, and to better understand the influence of age and gender on sibling aggression. Social learning theory and family systems theory were the guiding frameworks for this study. Participants consisted of 47 school-aged sibling dyads with a history of exposure to domestic violence recruited from the community. Aggressive behaviour was measured by standardized questionnaires completed by mothers and children and by observations of naturalistic sibling interactions. As predicted, analyses of observed aggression which controlled for exposure to domestic violence revealed brothers were significantly more aggressive than sisters or mixed gender dyads. Unexpectedly, analyses of observed aggression found that boys were significantly more aggressive with their siblings than their female counterparts when exposure to maternal violence was taken into account. Findings indicate that children exposed to domestic violence, especially boys, may be at greater risk for aggressive behaviour. Results are expected to be useful for practice and future research.

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