Preliminary epidemiological study of latent tuberculosis in Mexican agricultural workers in the Niagara region, Canada

It is well documented that the majority of Tuberculosis (TB) cases diagnosed in Canada are related to foreign-bom persons from TB high-burden countries. The Canadian seasonal agricultural workers program (SAWP) operating with Mexico allows migrant workers to enter the country with a temporary work permit for up to 8 months. Preiimnigration screening of these workers by both clinical examination and chest X-ray (CXR) reduces the risk of introducing cases of active pulmonary TB to Canada, but screening for latent TB (LTBI) is not routinely done. Studies carried out in industrialized nations with high immigration from TBendemic countries provide data of lifetime LTBI reactivation of around 10% but little is known about reactivation rates within TB-endemic countries where new infections (or reinfections) may be impossible to distinguish from reactivation. Migrant populations like the SAWP workers who spend considerable amounts of time in both Canada and TBendemic rural areas in Mexico are a unique population in terms of TB epidemiology. However, to our knowledge no studies have been undertaken to explore either the existence of LTBI among Mexican workers, the probability of reactivation or the workers' exposure to TB cases while back in their communities before returning the following season. Being aware of their LTBI status may help workers to exercise healthy behaviours to avoid TB reactivation and therefore continue to access the SAWP. In order to assess the prevalence of LTBI and associated risk factors among Mexican migrant workers a preliminary cross sectional study was designed to involve a convenience sample of the Niagara Region's Mexican workers in 2007. Research ethics clearance was granted by Brock University. Individual questionnaires were administered to collect socio-demographic and TB-related epidemiological data as well as TB knowledge and awareness levels. Cellular immunity to M tuberculosis was assessed by both an Interferon-y release assay (lGRA), QuantiFERON -TB Gold In-Tube (QFf™) and by the tuberculin skin test (TSn using Mantoux. A total of 82 Mexican workers (out of 125 invited) completed the study. Most participants were male (80%) and their age ranged from 22 to 65 years (mean 38.5). The prevalence of LTBI was 34% using TST and 18% using QFTTM. As previously reported, TST (using ~lOmm cut-off) showed a sensitivity of 93.3% and a specificity of 79.1 %. These findings at the moment cannot predict the probability of progression to active TB; only longitudinal cohort studies of this population can ascertain this outcome. However, based on recent publications, lORA positive individuals may have up to 14% probability of reactivation within the next two years. Although according to the SA WP guidelines, all workers undergo TB screening before entering or re-entering Canada, CXR examination requirements showed to be inconsistent for this population: whereas 100% of the workers coming to Canada for the first time reported having the procedure done, only 31 % of returning participants reported having had a CXR in the past year. None of the participants reported ever having a CXR compatible with TB which was consistent with the fact that none had ever been diagnosed with active pulmonary TB and with only 3.6% reporting close contact with a person with active TB in their lifetime. Although Mexico reports that 99% of popUlation is fully immunized against TB within the first year of age, only 85.3% of participants reported receiving BOC vaccine in childhood. Conversely, even when TST is not part of the routine TB screening in endemic countries, a suqDrisingly high 25.6% reported receiving a TST in the past. In regards to TB knowledge and awareness, 74% of the studied population had previous knowledge about (active) TB, 42% correctly identified active TB symptomatology, 4.8% identified the correct route of transmission, 4.8% knew about the existence of LTBI, 3.6% knew that latent TB could reactivate and 48% recognized TB as treatable and curable. Of all variables explored as potential risk factors for LTBI, age was the only one which showed statistical significance. Significant associations could not be proven for other known variables (such as sex, TB contact, history of TB) probably because of the small sample size and the homogeneity of the sample. Screening for LTBI by TST (high sensitivity) followed by confirmation with QFT''"'^ (high specificity) suggests to be a good strategy especially for immigrants from TB high-burden countries. After educational sessions, workers positive for LTBI gained greater knowledge about the signs and symptoms of TB reactivation as well as the risk factors commonly associated with reactivation. Additionally, they were more likely to attend their annual health check up and request a CXR exam to monitor for TB reactivation.

A survey of attitudes of agricultural society leaders toward leadership development education

It was the purpose of this study to investigate attitudes toward leadership development education of one client group served by the ontario Ministry of Agriculture and Food. The survey, answered by 175 participants, attempted to answer the following questions: (a) What is a common definition of leadership?, (b) What leadership concepts are important to leadership development education? and, (c) What are client attitudes toward leadership development education? A descriptive research approach was used and the data were analyzed according to a model developed by Colaizzi. Concept maps were developed under the broad areas of: (a) Developing leader qualities; (b) Past experiences that developed leadership skills that worked on the jOb; (c) Leadership skills developed from present day positions; and (d) How leadership skills may be developed in future situations. A description of the dynamics of leadership development was written and the essential dynamics of leadership skill development in one volunteer organization was described. This study supports the linkages perspective of leadership within voluntary organizations developed by Vandenberg, Thullen and Fear (1987). The linkages perspective consists of three major components: perception, property and process. As a perception, leadership is the set of beliefs each group member holds regarding the behaviours and qualities characteristic of effective leaders. As a property, leadership represents the qualities attributed by group members to persons perceived as effectively (or potentially) influencing the goal achievement process. As a process, leadership involves the use of non-coercive influence to facilitate group accomplishment of valued goals. Leadership concepts important for development in a leadership development education program related to personal, organizational and societal development. The top five concepts in terms of rank order are communicating effectively, forming and working with groups, working creatively (tie), developing followers, managing meetings, directing projects or activities, understanding financial matters, managing negotiations (tie), developing resources and understanding and developing oneself (tie). Several recommendations are relevant for extension personnel as educators. Theoretical concepts on leadership need to be shared to extension practitioners involved in leadership development. currently used teaching materials for leadership development should be evaluated to see if they include concepts from preferrred theoretical leadership perceptions.

Leisure-time physical activity in individuals with osteoporosis : associations with psychological well-being

With approximately 16% of the Canadian population living with osteoporosis, and rates expected to increase (Osteoporosis Canada, 2009), cost-effective treatment modalities that improve bone health and psychological well-being reflect an important public health agenda. Physical activity has been implicated as one non-pharmaceutical mechanism to help improve psychological well-being in the general population (Fox, Stathi, McKenna, & Davis, 2007) and in people diagnosed with osteoporosis (Osteoporosis Canada, 2007). The purpose of this investigation was to determine the association between leisure-time physical activity (LTP A) and well-being in people diagnosed with osteoporosis. A secondary purpose, using Basic Needs Theory (BNT; Deci & Ryan, 2002) was to determine if the fulfillment of three psychological needs (i.e., competence, autonomy and relatedness) mediated the relationship between LTP A and well-being. People diagnosed with osteoporosis (N= 190; Mage = 68.14; SDage = 11.54) were asked to complete a battery of questionnaires assessing L TP A, hedonic and eudaimonic well-being and perceived psychological need satisfaction in physical activity contexts. Bivariate correlations revealed a pattern of negligible (r's -0.02 to 0.35) to small correlations between LTP A and well-being with contextual positive affect (r = 0.24) and subjective vitality (r = 0.22) demonstrating statistical significance (p < .01). Results of the multiple mediation analysis indicated that perceived satisfaction of the three psychological needs mediated the relationship between LTPA and well-being with perceived competence emerging as a unique mediator. As such, LTP A was positively associated with well-being in people who are diagnosed with osteoporosis, and the fulfillment of the three psychological needs may be the mechanism through which this 111 effect is carried. Health promotion specialists and practitioners should encourage patients with osteoporosis to engage in LTP A, and support their needs for competence, autonomy and relatedness. Practical implications for researchers and health promotion specialists are discussed in terms ofthe results of this investigation.

Vitamin D status and latent tuberculosis infection : a preliminary study in a group of healthy Mexican agricultural workers

Vitamin D metabolites are important in the regulation of bone and calcium homeostasis, but also have a more ubiquitous role in the regulation of cell differentiation and immune function. Severely low circulating 25-dihydroxyvitamin D [25(OH)D] concentrations have been associated with the onset of active tuberculosis (TB) in immigrant populations, although the association with latent TB infection (LTBI) has not received much attention. A previous study identified the prevalence of LTBI among a sample of Mexican migrant workers enrolled in Canada's Seasonal Agricultural Workers Program (SA WP) in the Niagara Region of Ontario. The aim of the present study was to determine the vitamin D status of the same sample, and identify if a relationship existed with LTBI. Studies of vitamin D deficiency and active TB are most commonly carried out among immigrant populations to non-endemic regions, in which reactivation of LTBI has occurred. Currently, there is limited knowledge of the association between vitamin D deficiency and LTBI. Entry into Canada ensured that these individuals did not have active TB, and L TBI status was established previously by an interferon-gamma release assay (IGRA) (QuantiFERON-TB Gold In-Tube®, Cellestis Ltd., Australia). Awareness of vitamin D status may enable individuals at risk of deficiency to improve their nutritional health, and those with LTBI to be aware of this risk factor for disease. Prevalence of vitamin D insufficiency among the Mexican migrant workers was determined from serum samples collected in the summer of 2007 as part of the cross sectional LTBI study. Samples were measured for concentrations of the main circulating vitamin D metabolite, 25(OH)D, with a widely used 1251 250HD RIA (DiaSorin Inc.®, Stillwater, MN), and were categorized as deficient «37.5 nmoI/L), insufficient (>37.5 nmollL, < 80 nmol/L) or sufficient (2::80 nmoI/L). Fisher's exact tests and t tests were used to determine if vitamin D status (sufficiency or insufficiency) or 25(OH)D concentrations significantly differed by sex or age categories. Predictors of vitamin D insufficiency and 25(OH)D concentrations were taken from questionnaires carried out during the previous study, and analyzed in the present study using multiple regression prediction models. Fisher's exact test and t test was used to determine if vitamin D status or 25(OH)D concentration differed by LTBI status. Strength of the relationship between interferongamma (IFN-y) concentration (released by peripheral T cells in response to TB antigens) and 25(OH)D concentration was analyzed using a Spearman correlation. Out of 87 participants included in the study (78% male; mean age 38 years), 14 were identified as LTBI positive but none had any signs or symptoms of TB reactivation. Only 30% of the participants were vitamin D sufficient, whereas 68% were insufficient and 2% were deficient. Significant independent predictors of lower 25(OH)D concentrations were sex, number of years enrolled in the SA WP and length of stay in Canada. No significant differences were found between 25(OH)D concentrations and LTBI status. There was a significant moderate correlation between IFN-y and 25(OH)D concentrations ofLTBI-positive individuals. The majority of participants presented with Vitamin D insufficiency but none were severely deficient, indicating that 25(OH)D concentrations do not decrease dramatically in populations who temporarily reside in Canada but go back to their countries of origin during the Canadian winter. This study did not find a statistical relationship between low levels of vitamin D and LTBI which suggests that in the presence of overall good health, lower than ideal levels of 2S(OH)D, may still be exerting a protective immunological effect against LTBI reactivation. The challenge remains to determine a critical 2S(OH)D concentration at which reactivation is more likely to occur.

The Informational Value of Corporate Credit Ratings

This thesis examines the quality of credit ratings issued by the three major credit rating agencies - Moody’s, Standard and Poor’s and Fitch. If credit ratings are informative, then prices of underlying credit instruments such as fixed-income securities and credit default insurance should change to reflect the new credit risk information. Using data on 246 different major fixed income securities issuers and spanning January 2000 to December 2011, we find that credit default swaps (CDS) spreads do not react to changes in credit ratings. Hence credit ratings for all three agencies are not price informative. CDS prices are mostly determined by historical CDS prices while ratings are mostly determined by historical ratings. We find that credit ratings are marginally more sensitive to CDS than CDS are sensitive to ratings.

Competing and Conflicting Land Uses at the Rural-Urban Interface: Understanding the Impacts of Residential Development on Agricultural Landscapes

Rural communities are currently undergoing rapid restructuring as globalization impacts the future viability of many small towns. Agricultural regions throughout Canada, in particular, Niagara-on-the-Lake, are forced to adapt to changes within the industry. In addition to these challenges, sprawling residential developments from nearby urban centres are changing the dynamic of this town, resulting in conflicts between the residential and agricultural land uses. This thesis explores these conflicts from the perspective of the residents and the farmers. It was found that the initial sources of conflict related to noise-generating farm activities are no longer a concern, while the use of pesticide have become a source of contention among the residents. The farmers, alternately, were found to be proactive and strived to limit the potential for conflict with adjacent residents. Lastly, it was determined that planning legislation aggravates land use conflicts within Niagara-on-the-Lake and need to better address these land use conflicts.

Longitudinal associations between passions and adjustment in adolescence: Positive mood and unstructured leisure activities as mediators

Passions are activities that people find important, like or enjoy, and on which they spend large amounts of time. Research examining passions in adolescence has been limited, despite a tendency for adolescents to explore their identity by trying new activities (Dworkin et aI., 2003). The purpose of the present study was to examine the association between adolescent passions and positive adjustment (psychological well-being, optimism, purpose in life, and low risktaking), as well as investigate possible underlying mechanisms for the link between passions and adjustment. High school students (N=2270, 48.7% female) from Southern Ontario completed questionnaires in grades 10, 11, and 12. Path analyses were conducted to examine cross-lag paths among all study variables. Passions predicted higher optimism and purpose, as well as lower negative risk-taking, over time, but these adjustment indicators in tum did not predict higher passions over time. Additionally, positive mood and unstructured leisure activities partially mediated these associations. Passions appears to be important for adolescent adjustment, and may serve as a protective factor or help to foster thriving.

The analysis of Metarhizium robertsii potential as endophytic plant root coloniser, plant growth enhancer and antagonist to bean root pathogen Fusarium solani f. sp. phaseolis.

The soil-inhabiting insect-pathogenic fungus Metarhizium robertsii also colonizes plant roots endophytically, thus showing potential as a plant symbiont. M robertsii is not randomly distributed in soils but preferentially associates with the plant rhizosphere when applied in agricultural settings. Root surface and endophytic colonization of switchgrass (Panicum virgatum) and haricot beans (Phaseolus vulgaris) by M robertsii were examined after inoculation with fungal conidia. Light and confocal microscopies were used to ascertain this rhizosphere association. Root lengths, root hair density and emergence of lateral roots were also measured. Initially, M robertsii conidia adhered to, germinated on, and colonized, roots. Furthermore, plant roots treated with Metarhizium grew faster and the density of plant root hairs increased when compared with control plants. The onset of plant root hair proliferation was initiated before germination of M robertsii on the root (within 1-2 days). Plants inoculated with M robertsii AMAD2 (plant adhesin gene) took significantly longer to show root hair proliferation than the wild type. Cell free extracts of M robertsii did not stimulate root hair proliferation. Longer term (60 days) associations showed that M robertsii endophytically colonized individual cortical cells within bean roots. Metarhizium appeared as an amorphous mycelial aggregate within root cortical cells as well as between the intercellular spaces with no apparent damage to the plant. These results suggested that not only is M robertsii rhizosphere competent but displays a beneficial endophytic association with plant roots that results in the proliferation of root hairs. The biocontrol of bean (Phaseolis vulgaris) root rot fungus Fusarium solani f. sp. phaseolis by Metarhizium robertsii was investigated in vitro and in vivo. Dual cultures on Petri dishes showed antagonism of M robertsii against F. solani. A relative inhibition of ca. 60% of F. solani growth was observed in these assays. Cell free culture filtrates of M robertsii inhibited the germination of F. solani conidia by 83% and the inhibitory metabolite was heat stable. Beans plants colonized by M robertsii then exposed to F. solani showed healthier plant profiles and lower disease indices compared to plants not colonized by M robertsii. These results suggested that the insect pathogenic/endophytic fungus M robertsii could also be utilized as a biocontrol agent against certain plant pathogens occurring in the rhizosphere.

Letter from the Chairman of the Committee of Ways and Means to the Secretary of the Treasurer on the subject of a system of revenue to revive and maintain unimpaired the public credit, with the answer of the Secretary thereto. (1814)

October 18, 1814. Read, and committed to the Committee of the whole House on the report of the Committee of Ways and Means on so much of the President's message as relates to the finances of the United States.

Is Pride a Vice or a Virtue? Associations to Well-Being and Physical Activity

The first objective of the present study was to determine patterns of association between authentic and hubristic fitness-related pride to outcomes of well-being and leisure-time physical activity (LTPA). A second objective was to examine motivation as a potential mediator of these relationships. Participants (N = 119) were young adults who completed self-report questionnaires at two time points separated by 4-weeks. Authentic and hubristic pride were associated with well-being and LTPA at Time 1 and Time 2. Changes in pride were associated with changes in well-being but not LTPA. Results of the mediation analyses highlight the role of more autonomous motives, specifically intrinsic motivation, as important mediators between pride and well-being. Motivation did not mediate the relationship between pride and LTPA. Overall, both authentic and hubristic pride seem to be important in the promotion of well-being More research is needed to elucidate the relationship between pride and LTPA.

Larval habitat associations with human land uses, roads, rivers, and land cover for Anopheles albimanus, A. pseudopunctipennis, and A. punctimacula (Diptera: Culicidae) in coastal and highland Ecuador

Larval habitat for three highland Anopheles species: Anopheles albimanus Wiedemann, Anopheles pseudopunctipennis Theobald, and Anopheles punctimacula Dyar and Knab was related to human land uses, rivers, roads, and remotely sensed land cover classifications in the western Ecuadorian Andes. Of the five commonly observed human land uses, cattle pasture (n = 30) provided potentially suitable habitat for A. punctimacula and A. albimanus in less than 14% of sites, and was related in a principal components analysis (PCA) to the presence of macrophyte vegetation, greater surface area, clarity, and algae cover. Empty lots (n = 30) were related in the PCA to incident sunlight and provided potential habitat for A. pseudopunctipennis and A. albimanus in less than 14% of sites. The other land uses surveyed (banana, sugarcane, and mixed tree plantations; n = 28, 21, 25, respectively) provided very little standing water that could potentially be used for larval habitat. River edges and eddies (n = 41) were associated with greater clarity, depth, temperature, and algae cover, which provide potentially suitable habitat for A. albimanus in 58% of sites and A. pseudopunctipennis in 29% of sites. Road-associated water bodies (n = 38) provided potential habitat for A. punctimacula in 44% of sites and A. albimanus in 26% of sites surveyed. Species collection localities were compared to land cover classifications using Geographic Information Systems software. All three mosquito species were associated more often with the category “closed/open broadleaved evergreen and/or semi-deciduous forests” than expected (P ≤ 0.01 in all cases), given such a habitat’s abundance. This study provides evidence that specific human land uses create habitat for potential malaria vectors in highland regions of the Andes.

A Longitudinal Examination of Bidirectional Associations between Subjective Sleep Characteristics and Psychosocial Functioning among University Students

A number of studies have found a significant link between sleep and psychosocial functioning among university students. A critical examination of this literature, however, indicates that one important gap within the literature is the need for longitudinal studies that specifically test for bidirectional associations between these two constructs. The main purpose of my dissertation was to address this gap by conducting three studies that examined bidirectional associations between sleep and psychosocial functioning among a sample of university students. Participants were 942 (71.5% female) undergraduate students enrolled at a Canadian university, who completed survey assessments annually for three consecutive years, beginning in their first year of university. In the first study, I assessed bidirectional associations between two sleep characteristics (sleep quality and sleep duration) and three psychosocial functioning variables (academics, friendship quality, and intrapersonal adjustment). Results based on cross-lagged models indicated a significant bidirectional association between sleep quality and intrapersonal adjustment, such that more sleep problems predicted more negative intrapersonal adjustment over time, and vice versa. Unidirectional associations indicated that both higher academic achievement and more positive friendship quality were significant predictors of less sleep problems over time. In the second study, in which I examined bidirectional associations between sleep and media use, results provided support only for unidirectional associations; such that more sleep problems predicted increases in both time spent watching television and time spent engaged in online social networking. In the third study of my dissertation, in which I examined social ties at university and sleep quality, results indicated a significant bidirectional association, such that more positive social ties predicted less sleep problems over time, and vice versa. Importantly, emotion regulation was a significant mediator of this association. Findings across the three studies, highlight the importance of determining the direction of effects between different sleep characteristics and various aspects of university students’ psychosocial functioning, as such findings have important implications for both methodology and practice. A better understanding of the nature of the associations between sleep and psychosocial functioning will equip students, parents and university administrators with the tools necessary to facilitate successful adjustment across the university years.

Sport Values of Bantam, Midget and Intermediate Female Hockey Players and Their Minor Hockey Associations

The sport values of female hockey players and their minor hockey associations were explored to better inform a values-based approach for adult-managed minor hockey. Data were collected from 294 participatory HL and competitive Rep players (12-22 years of age) using the Youth Sport Values Questionnaire-2 and from 30 hockey association board members using a modified YSVQ-2. Results indicated player importance (VI) ratings for Moral (M = 4.08) and Competence (M = 4.15) values were not significantly different but were significantly higher than Status (M = 2.11) value. Significant weak relationships between age and competition level versus VI ratings were found. There were medium/ high Moral, medium/ low Competence and high/ high Status value congruence between Rep and HL Player-Board Members, respectively. Based upon the findings, girls’ minor hockey associations need to recognize the values female youth players prioritize, and ensure each is considered within a values-based decision-making approach to governance.

Associations Between Personal Cancer History and Lung Cancer Risk

The study aim was to investigate the relationship between factors related to personal cancer history and lung cancer risk as well as assess their predictive utility. Characteristics of interest included the number, anatomical site(s), and age of onset of previous cancer(s). Data from the Prostate, Lung, Colorectal and Ovarian Screening (PLCO) Cancer Screening Trial (N = 154,901) and National Lung Screening Trial (N = 53,452) were analysed. Logistic regression models were used to assess the relationships between each variable of interest and 6-year lung cancer risk. Predictive utility was assessed through changes in area-under-the-curve (AUC) after substitution into the PLCOall2014 lung cancer risk prediction model. Previous lung, uterine and oral cancers were strongly and significantly associated with elevated 6-year lung cancer risk after controlling for confounders. None of these refined measures of personal cancer history offered more predictive utility than the simple (yes/no) measure already included in the PLCOall2014 model.