Human infection by Salmonella Typhi has been occurring for the last 50,000 years and still accounts for ∼ 22million new cases each year worldwide. Through faeco-oral transmission, this human-restricted infection disproportionately affects the most impoverished sections of endemic communities where adequate sanitation infrastructure and effective vaccination approaches are lacking. Development of new control measures to accurately measure the burden of disease and to prevent infection with new vaccine candidates are hindered by an incomplete understanding of host-pathogen interactions and of what constitutes a protective human response after exposure. In this thesis I describe the practical application of a recently developed human challenge model of typhoid infection in assessing new control measures, including the evaluation of the oral single-dose vaccine candidate, M01ZH09. In performing a large, double-blind, placebo-controlled study, I was able to measure the direct protective efficacy (PE) of vaccination with either M01ZH09 or 3-dose Ty21a by performing human challenge with 104CFU Salmonella Typhi, Quailes strain, 28-days later. Using clinical and microbiological definitions to confirm typhoid diagnosis during a 14-day period after ingestion, I found insignificant levels of protection afforded by a single dose of M01ZH09 (12.9%), and a low PE after Ty21a vaccination (35%), demonstrating the stringency of the model and the endpoints used. Many additional insights into pathogen dynamics and host responses were found highlighting several important characteristics of oral vaccination. M01ZH09 was highly immunogenic, and both active vaccines significantly reduced bacterial burden (bacteraemia and stool shedding) while having no effect on symptomatic severity of infection in those diagnosed. M01ZH09 receipt resulted in a significantly longer incubation period, suggesting underlying protective responses were being generated. Further findings included the first objective demonstration of primary bacteraemia occurring after typhoid exposure, and frequent asymptomatic infection or stool shedding in those exposed but remaining well. Overall, these data also demonstrated significant protective effects against challenge by anti-Vi antibody status and age at baseline. Taking these factors into account, M01ZH09 and Ty21a vaccination did convey an overall protective advantage against developing typhoid infection, each reducing the risk of diagnosis by ~two-fold during the challenge period.

It has been shown that when implanted individually, both cells and biomaterials elicit biological responses. Implanted cells are often destroyed by the host's immune system, while biomaterials activate foreign body reactions which can result in inflammation and fibrotic encapsulation. However, when implanted simultaneously, the inflammatory responses to the biomaterial component can alter the immune responses to the cellular component. The experiments described in this thesis were designed to characterize the effect of different biomaterials on adaptive immune responses towards an allogeneic challenge. Balb/c splenocytes were challenged with irradiated allogeneic L929 cells, and treated with different biomaterials. Alterations in adaptive immune responses were quantified by T cell proliferation and cytokine release (i.e. IL-1(beta), IL-4, IL-12, and IFN-(gamma)). The roles various cell types played in first set responses were investigated. Experimental results indicated that biomaterials had a significant influence on nonspecific proliferation of splenocytes. In particular, analysis of the degree to which biomaterials affected specific proliferation indicated that the soluble alginate treatment significantly increased proliferation differences when compared to the control. However, biomaterials neither significantly affected specific splenocyte proliferation to an allogeneic challenge, nor the profile of secreted cytokines. To elucidate this response, alginate-treated splenocytes were depleted of adherent macrophages, CD4+ cells or CD8+ cells. Within non-challenged mixtures, CD4+ depletion had the most obvious effect. These results were supported by the non-depleted challenges, and indicated the direct influence biomaterials on CD4+ T cell proliferation. / Thesis / Master of Applied Science (MASc)

No description available.

Purpose: The purpose of this thesis is to explore how to manage the potential challenges organizations may face in the consolidation phase, and in order to achieve this, potential challenges need to be identified. Methodology: The research has been performed through an abductive case study method to the subject of change management. The empirical data was gathered from semistructured interviews conducted at an international company, Company X, primarily from the electronic commerce department. The authors used a thematic analysis inspired by Boyatzis (1998) when analyzing the data. Research Limitation: Due to the limited amount of time, the research is limited to only embrace the consolidation phase of an organizational change process. The case study includes 10 interviews from one organization, which will limit the research. The authors apply anonymity due to the company's desire; however, it is also done in order to protect the respondents from any possible harm that might derive from this study (Waldorf,2006). Theoretical Perspective: Literature covering different but highly related areas of change management, and its relation to the consolidation phase constitutes the theoretical foundation of the thesis. Results: The authors identified four potential challenges when consolidating change; communication, prioritize consolidation, policies and employee involvement. Conclusion: In order for organizations to successfully manage the four identified challenges they have to increase the flow of communication, prioritize the consolidation phase, and thereby also allocate resources, which enables the employees to consolidate changes, set up clear policies for the consolidation phase and involve the employees within all levels, in order to increase the employee motivation.

Testosterone levels change in response to a variety of social situations including, sexual and challenge situations. Yet, little is known about the role of testosterone dynamics in in young adults in romantic relationships. Furthermore, the effect of compatibility of the relationship dyad on testosterone reactivity in response to social-challenge is unknown. Prior studies suggest that attachment levels may predict testosterone responsivity during stressors such as social challenge. What is missing from the literature is whether testosterone response to social-challenge is specifically modified within the confines of an attachment relationship, such as within romantic couples. I measured salivary testosterone in healthy romantically involved young adult couples in response to a examined romantic couples during a standardized laboratory stressor in the SPIT lab. Testosterone was measured repeatedly from saliva in both members of each dyad and assayed using an enzymeimmunoassay. Participants completed questionnaires measuring perceived relationship commitment, support, satisfaction, and passion. This was collectively described as relationship compatibility. I revealed that participants in romantic relationships showed significant testosterone response to the Trier Social Stress Test (TSST). Testosterone levels of the participant were moderated by testosterone levels of the supporter during the socialchallenge, such that the supporter’s response was coupled with their partner’s testosterone response to stress. When the couples reported high-compatibility, their testosterone profiles were more coupled than for couples reporting low-compatibility. Findings fit within the challenge hypothesis and extend it in interesting ways. Testosterone may help an individual confront a challenge, and, more interestingly, testosterone may help a couple confront a challenge together.

Christianity is the dominant religion in the Fiji islands today. However, this was not the case in the early eighteen hundreds. Back then, the Fijians had lived a life and culture of their own that was not known to the world. This all changed when different groups of Europeans started to arrive in the early eighteen hundreds. Of these, the group that had the most influence on the Fijians was the English Wesleyan missionaries. The result of their evangelism was the establishment of the Methodist church in 1835. This church is the dominant denomination in Christian Fiji and has been closely meshed with concepts of Fijian identity. However, the church's dominance is being challenged, partly because of the entwining of concepts of church and the vanua (land, people). Additionally the arrival of other, new denominations with their different ideologies has also affected the standing and influence of the Methodists. In this thesis the way in which the missionaries had introduced themselves to the Fijians and how they influenced and converted them to Christianity are outlined. This was not a one-way affair, where only the missionaries' ways of living and ideologies were involved. They first had to accept the structure and some of the customs of the vanua before their mission could proceed. It was found that the influence and ideologies brought by the missionaries was incorporated into the vanua ideologies and has formed the basis of what became the Fijian way of life. When Fiji became a colony of Britain in 1874, the incorporation of the vanua and Methodist Christian ideologies and structure was well established. However, all these views, and the previously accepted local views of Fijian culture, have changed in response to the challenges from the new denominations. The effect of these new approaches and ideologies on the vanua and the Methodists in Fiji is discussed. The outcome of this on-going situation is not yet clear.

<p>To date five classes of resistance proteins have been identified in plants and these include the intracellular protein kinases, receptor-like protein kinases with extracellular leucinerich repeat (LRR) domain, LRR proteins that encode membrane bound extracellular proteins, toxin reductase and intracellular LRR proteins with a nucleotide-binding site (NBS). These proteins recognise &ldquo / invading pathogen&rdquo / and in turn trigger defence response systems that act to protect plants from invading pathogens. The NBS-LRR genes which constitutes the major class encode a family of resistance proteins that are made up of a centrally located nucleotide binding site domain and a C-terminal leucine rich repeat receptor. This class of genes constitute the largest family of resistance genes identified in plants to date. They make up the majority of proteins involved in the plant basal and inducible defence systems against pathogen infection.</p>

The 2005 Dietary Guidelines for Americans for the first time emphasized an increase in daily whole grain consumption in children, adolescents, and adults, and identified a recommended intake of 3 one-ounce servings per day. Despite national dietary policy recommendations and current scientific evidence encouraging an increase in whole grain intake, most Americans are consuming less than one whole grain serving per day. Therefore, a need to determine methods to increase whole grain intake in Americans does exist. One identified method would be to increase whole grain intake in children through the incorporation of whole grain foods into school meals. This study was designed to determine, through the creation of an online survey, methods utilized by school food service professionals overseeing HealthierUS School Challenge Gold rated elementary schools to successfully incorporate whole grain food products into school meals. Data collected from the online survey indicated school food service professionals that incorporated whole grains into their school meals by slowly modifying recipes and gradually incorporating new whole grain foods onto their existing menu were the most successful. Survey results also indicated that students preferred partial blend whole grain products compared to those made from 100% whole wheat. Additionally, survey participants reported barriers to whole grain food incorporation which included: product acceptability, whole grain product identification, whole grain product availability, and cost. There is a need to further understand measures that can be taken to successfully introduce more whole grain food products into elementary school lunches without causing a decrease in consumption of the school meals by students. Data gathered from this survey will be shared with the United States Department of Agriculture's Food and Nutrition Service (USDA-FNS) to provide technical assistance to schools participating in the National School Lunch Program and School Breakfast Program on how to successfully menu whole grain food products in their schools and maintain alignment with current national dietary recommendations.

<p>To date five classes of resistance proteins have been identified in plants and these include the intracellular protein kinases, receptor-like protein kinases with extracellular leucinerich repeat (LRR) domain, LRR proteins that encode membrane bound extracellular proteins, toxin reductase and intracellular LRR proteins with a nucleotide-binding site (NBS). These proteins recognise &ldquo / invading pathogen&rdquo / and in turn trigger defence response systems that act to protect plants from invading pathogens. The NBS-LRR genes which constitutes the major class encode a family of resistance proteins that are made up of a centrally located nucleotide binding site domain and a C-terminal leucine rich repeat receptor. This class of genes constitute the largest family of resistance genes identified in plants to date. They make up the majority of proteins involved in the plant basal and inducible defence systems against pathogen infection.</p>

Amino acids (AA) are required for protein accretion and the need for a specific AA depends on the physiological status, breed, and the health of the pig. Inasmuch as the AA requirements for growing pigs are given in an ideal AA ratio for protein accretion, the utilization of all AA is beyond growth and at least 30% of the total dietary AA will be used by the splanchnic tissue. A ban in the use of antimicrobial growth promoters (AGP) in piglets’ diets is likely to increase incidences of disease occurrence and exert additional AA requirements. Immune challenge models were used to determine standardized ileal digestible (SID) Lys and sulfur amino acids (SAA):Lys requirements for piglets under an antibiotic-free feeding regime. The first objective was to establish the dietary Lys requirement for piglets raised under both clean and unclean sanitary conditions. The Lys requirement could not be determined in the first experiment. However, from the second and third experiments the dietary SID Lys content for optimal growth of 7 to 16 kg weaned piglets was estimated to be 1.32%. The objective of fourth experiment was to determine the optimum SID SAA:Lys ratio in piglets when reared under clean or unclean conditions. Based on performance parameters, the optimum SAA:Lys ratios were 58 and 61 for piglets raised under clean and unclean conditions, respectively. However, VH estimates were 60 and 66 SAA:Lys under clean and unclean sanitary conditions, respectively. The objective for the fifth experiment was to determine SID SAA:Lys ratio of piglets under an enterotoxigenic Escherichia coli challenge using genes for expression of key products in the Met metabolic pathway. Gene expressions of methionine adenosyltransferase 1 and 2-α, 5-methyltetrahydrofolate-homocysteine methyltransferase, and cystathionine γ-lyase was done for liver and ileal tissue. The gene expressions indicates that the dietary SAA:Lys ratio of 60 was enough to support piglet’s immune response and performance during an immune challenge. Therefore, under an antibiotic-free feeding regime, the Lys requirement recommended by NRC (2012) is sufficient, however, the SAA:Lys should be raised to 60 in diets of both healthy and immune challenged piglets.