PI3Ks (phosphoinositide 3-kinases), a family of enzymes expressed in immune cells, are activated in response to a wide variety of stimuli by generating second lipid messengers. A subset of singnaling molecules containing lipid-binding pleckstrin homology (PH) domains are downstream molecules of PI3K signaling pathway, essential to mediate the functional outcomes of PI3Ks. Bam32 / DAPP1 is a PH domain-containing adaptor protein, which was discovered from human tonsil germinal centers (GCs); however, its biological function related to GCs, where efficient T-cell-dependent (TD) antibody responses are generated, is unknown. This thesis is focused on the effect of genetic or pharmacological blockade of PI3K p110delta activity on T and B cells, and the role of Bam32 in GC responses. Type 2 cytokine responses are significantly decreased in p110delta-inactivated mice, whereas Type 1 cytokine responses are increased or comparable after primary and secondary immunization. Hallmarks of asthma, airway inflammation and respiratory hyper-responsiveness are dramatically reduced in those mice. Adoptive transfer of OVA-primed splenocytes from normal, but not p110delta-inactivated mice could induce airway eosinophilia in naïve, airway-challenged recipient mice. These data demonstrate a novel functional role for p110delta signaling in induction of Type 2 responses in vivo and may offer a new therapeutic target for Th2-mediated airway disease. Paradoxically, serum IgE levels are markedly increased in OVA-immunized p110delta-inactivated mice despite lower level of swich factor IL-4. In vitro studies showed that p110delta is required to restrain IgE class switch recombination in a B-cell intrinsic manner. Blockade of PI3K activity using broad-spectrum PI3K inhibitors PIK-90 and PI-103 generates similar results. In vivo administration of p110delta-selective inhibitor IC87114 into OVA-immunized mice results in selective elevation of antigen-specific IgE production. Disruption of p110delta signaling leads to increased germline transcription at the epsilon locus (epsilon GLT) and increased induction of activation induced cytidine deaminase (AID) enzyme, suggesting deregulation at the level of the isotype switch process. Moreover, p110delta signaling selectively regulates the expression level of transcription factor Bcl6 and IRF4, which may be responsible for the regulation of AID and epsilon GLT. PI3K signaling regulates multiple steps of GC development, and Bam32 may be involved. GCs dissipate prematurely in Bam32-deficient mice after immunization with OVA/alum. In vitro, Bam32-deficient B cells are functional competent in proliferation, chemotaxis, isotype switching and plasma cell differentiation in response to signals present in GCs. In vivo, Bam32-deficient GC B cells proliferate normally; however, they are more apoptotic. Adoptive transfer studies indicated that intrinsic defect of Bam32-/- B cells leads to premature GC dissolution. Additionally, GCs formed by Bam32-/- B cells contain fewer T cells, implying that Bam32 is required for B cell-dependant T cell accumulation within established GCs. Treatment of Bam32-/- mice with agonistic anti-CD40 fully restored GC persistence and IgG1 isotype switching, demonstrating that Bam32-deficient GC B cells are functionally competent when access to cognate signals is not limiting. Collectively, those data demonstrate that Bam32 is not required for GC initiation, but rather functions in a late checkpoint of GC progression associated with T cell recruitment and GC B cell survival. In general, by focusing on PI3K p110delta and its downstream adaptor protein Bam32, my studies clearly indicate that p110delta is a potential therapeutic target for the treatment of Th2-induced airway inflammation. The unexpected immunomodulatory acitivity on IgE switching associated with multiple PI3K inhibitor compounds is first discovered in this thesis, suggesting that more need to be investigated in this aspect before those inhibitor compounds are widely used in the clinic. Furthermore, the specific regulatory role of Bam32 in GCs represents a unique model for us to study the late GC checkpoint in regarding to in vivo GC B cell and T cell interaction, which is an important issue need to be clarified in order to fully understand GC responses.

Dendritic cell is one of the professional antigen presenting cells, and it bridges innate immunity and adaptive immunity. To fully activate naïve T cells, it requires DC to provide at least two signals, the interaction between T cell receptor and the MHC class II molecule loaded with antigen processed by DC, and the co-stimulatory signals provided by the co-stimulatory molecules expressed on DC. The identification of more and more co-stimulatory molecules expressed on DC and the studies on their functions highlight the importance of co-stimulatory molecules on the regulation of DC functions. We here hypothesized that different expression levels of co-stimulatory molecules expressed on DC is pivotal of directing DC function towards immunity, tolerance and polarization of Th1/Th2 immune response. Using CD40 as the model molecule to study the effect of its expression levels on DC functions, we found that no/low expression level of CD40 on DC induced antigen-specific immunological tolerance was due to the induction of CD4+CD25+Foxp3+ regulatory T cells, while the polarization of Th2 immune response induced by DC with medium expression level of CD40 was partially due to the impaired IL-12 production by DC during CD40 crosslinking. Our findings that different levels of co-stimulatory molecules have different regulations on DC functions has the significance in DC based immunotherapy for GVHD as well as the Th1 diseases.

The Millennium uranium deposit is located 35 km north of the Key Lake mine, Saskatchewan. Uranium mineralization occurs in a variety of styles including (1) massive replacement, (2) fracture filling veins, (3) fine-grain aggregates associated with “mini” roll fronts, and (4) disseminated grains. The chemical Pb and isotopic 207Pb/206Pb ages of the massive (style 1), vein-type (style 2), and fine-aggregate (style 3) uraninite cluster at 1400-1200 and 1100-900 Ma. The ~1400 Ma ages coincide with the primary mineralization event for many of the uranium deposits (1550-1400 Ma) within the Athabasca Basin. Unlike other uranium deposits from the Athabasca basin, disseminated uraninite (style 4) have 207Pb/206Pb ages from 1770-1650 Ma. These ages are older than the depositional age for the Athabasca sediments (~1710 Ma) and are similar to the ages from the Beaverlodge vein-type uranium deposits.

In this thesis, a series of in vitro diffusion studies were performed to evaluate the transmembrane permeation of picaridin and oxybenzone across human epidermis and poly(dimethylsiloxane) (PDMS) membrane. Transdermal permeation of picaridin and oxybenzone from four commercially available repellent and sunscreen products was also investigated by using different application concentrations and sequences. The results obtained were then compared to those of the repellent DEET and the sunscreen oxybenzone under identical experimental conditions. Permeation of picaridin and oxybenzone across human epidermis was suppressed when both compounds were used concurrently. Increasing concentration of the test compounds further reduced the permeation percentage of picaridin and oxybenzone. While permeation characteristics were correlative between human epidermis and artificial PDMS membrane, permeability of PDMS membrane was significantly larger than that of human epidermis. This finding was different from concurrent use of DEET and oxybenzone in which a synergistic permeation enhancement was observed between the two substances. Transdermal permeation of picaridin across human epidermis from various commercially available spray preparations was significantly lower than that of DEET from similar spray products, both alone and in combination with sunscreen oxybenzone. Concurrent application of the commercial products resulted in either no change or suppression of permeation of picaridin and oxybenzone. This finding was also different from concurrent application of DEET and oxybenzone using commercial preparations. In addition, permeation of picaridin and oxybenzone across human epidermis was dependent on application concentration, use sequence, and preparation type.It was concluded from this thesis that picaridin would be a better candidate for concurrent application with sunscreen preparations in terms of percutaneous permeation.

This paper reports on a qualitative exploratory study focusing on the childbirth experiences of women and their families from a northern isolated community in Manitoba - who had to leave or were about to leave home to give birth. Perspectives from critical medical anthropology, cultural relativism and human ecological theory provided the theoretical foundation for this study. This study utilized ethnographic approaches to explore the perspectives of the women, their families and “significant others” and how they have been affected by policies, practices and structures at all levels of their environment in an attempt to gain a better understanding of the type of support and services that could potentially improve this experience. Presently, women from northern, rural and/or isolated communities leave home from a period of a few days up to 10 weeks to deliver their babies in an urban tertiary centre. They stay in boarding homes with others who have left home to obtain medical care, or with family and friends. During this period of time the women often do not access prenatal support or services within the regional health authority, other than medical care from a primary care provider (whom they may not have seen prior in their pregnancy) or to receive specialized medical intervention and monitoring. The boarding homes where they often stay do not offer any prenatal support or outreach services and are not conducive to housing women so close to delivering a baby. The women spoke of their experiences of giving birth marred by memories of fear, anger, frustration, tears and longing for family. They also spoke of a renewed sense of hope and excitement at the opportunity to share their ideas about possible ways that their experience could be improved. This paper breathed life into their thoughts and brought their ideas together to develop a new vision towards a system of supportive childbirth care for First Nation women in Manitoba, and more specifically, for women who are medically evacuated from the north to deliver their babies in urban Manitoba. For the Faculty of Medicine, it is a Master’s thesis, but for me and the many women and residents of Berens River, it is an opportunity for First Nation women to participate in shaping policy and influencing the direction for care and services that is created for them. It is important to acknowledge that evacuation and temporary relocation for birth is not an issue unique to First Nation women, it impacts hundreds of other northern and rural Métis and non-First Nation women every year. However, their experience is not included in this study. This paper suggests immediate and interim solutions for women who must leave home to give birth, albeit, the ultimate aim is to return birthing services closer to home.

This study focuses on investigating the effect of post-harvest handling conditions and storage time on the dehulling efficiency and cooking quality of two varieties of red lentils, as well as optimizing the dehulling conditions. The effects of storage time, storage moisture content and storage temperature, as well as the effect of different storage pre-treatments aiming to simulate post-harvest handling, were studied. Dehulling efficiency was mostly affected by the pre-milling moisture content, regardless of the storage conditions. Pre-treatments involving moisture content changes lowered the dehulling efficiency of both varieties of red lentils, whereas freezing and thawing cycles had less of a negative effect on the dehulling characteristics. Textural parameters were mostly affected by storage time; samples became harder after storage. The final recommendation arising from this study is to monitor the moisture content of lentils during storage as it has a detrimental effect on both the dehulling and cooking quality.

Transition metal and related compounds have been extensively studied over the past several decades. These investigations revealed a wide range of behavior, encompassing colossal magnetoresistance (CMR), high-TC superconductivity, and magnetic semiconductivity, all of which continue to present fundamental challenges to the understanding of such phenomena. There is, however, a close correlation between such characteristics and the appearance of magnetic order. This correlation underlies the present study, which focuses on the magnetic and transport behavior of various Manganese (Mn), Iron (Fe) and Cobalt (Co) containing materials, with particular emphasis on the nature of the magnetic order they display and the critical exponents that characterize the accompanying phase transition. The magnetic and transport properties of two specific systems will be covered: first various doped manganites from the series (La,Pr)1-x(Ca,Ba)xMnO3, and second the magnetic semiconductors Fe0.8Co0.2Si and Ga0.98Mn0.02As. In the manganites, the influence of doping on; (i) the evolution of the metal-insulator transition (MIT) with composition; (ii) the universality class of the magnetic critical behavior associated with the paramagnetic to ferromagnetic transition, which occurs in the vicinity of a MIT with which CMR is associated; (iii) the mechanisms underlying ferromagnetism across the MIT; (iv) the correlation between the appearance of a Griffiths-like phase and CMR, and (v) the origin of Griffiths-like phase have been investigated. Four different systems have been studied: La1-xCaxMnO3 (0.18 ≤ x ≤ 0.27), La1-xBaxMnO3 (x ≤ 0.33), (La1-yPry)0.7Ca0.3Mn16/18O3 (y ≤ 0.85), and Pr1-xCaxMnO3 (x = 0.27, 0.29). In Fe0.8Co0.2Si and Ga0.98Mn0.02As, the scaling between magnetization and conductivity has been the subject of ongoing debate. In bulk Fe0.8Co0.2Si, a novel scaling between the anomalous Hall effect (AHE) and the magnetization enables the anomalous Hall coefficient to be accurately determined. In turn, this enables the universality class for the transition to ferromagnetism to be established independently from the anomalous Hall conductivity. In an epitaxial (metallic) Ga0.98Mn0.02As microstructure, the magnetization has been indirectly determined from the AHE. Subsequent analysis yields magnetic critical exponents consistent with the Mean-Field model, direct support for which had previously been lacking.

Immune cytokines tumor necrosis factor alpha and type I interferons provide front-line defense against viral infection and are regulated in part by ubiquitin (Ub) and Ub-like molecules. Ubiquitin and Ub-like molecule ISG15 share a conserved C-terminal motif where a terminal glycine residue becomes attached to cellular target proteins. Nairoviruses and arteriviruses contain an ovarian tumor domain-containing protease (OTU protease) that was found to corrupt pathways by removing Ub or ISG15 from target proteins. This broad substrate specificity is unlike mammalian deubiquitinating enzymes, which cannot recognize both substrates. To understand how viral OTU domain-containing proteases remove Ub and ISG15, the crystal structure of the Crimean-Congo Heamorhaggic Fever nairovirus (CCHFV) was determined with Ub to 2.5 Å resolution. A computational model was built of the CCHFV Otu protease bound to ISG15 as well. The CCHFV Otu protease has several structural differences from known OTU proteases, manifesting in its broad substrate recognition capability.

This thesis is an attempt to present and to preserve, in an accessible form,certain pertinent data concerning the formation and major changes which took place in the organization of the rural school districts of Manitoba between 1871 and 1971. During that century, the original districts were established, dissolved or reorganized into one or more of a variety of administrative units before becoming indistinguishable parts of school divisions. A brief survey of the history of education in the Red River settlement and Manitoba is first presented, providing the background necessary for an account of the development of rural educational facilities within the province. The author was granted access to the formation files of the school distrícts of Manitoba. She also had several informal discussions with officials of the Administration Branch of the Manitoba Department of Education. Although there are some empty formation files and several which contain a minimal amount of information, the author, taking into consideration the frontier and pioneer conditions which existed in various sections of the province for many years following 1871 and realizing the difficulties and human frailties involved in setting up the original system of collecting data, was surprised to note, not how litt1e, but rather how much information has been recorded and preserved. The data presented consist of the names and numbers of the districts, sites of their school buildings and their formation, reorganization and dissolution dates along with indications of the administrative means used to effect those changes. These devices, created by the government and authorized for use through the Statutes of Manitoba, have been identified and illustrated...

As a result of transcriptional editing, Ebola virus (EBOV) produces multiple soluble products from its glycoprotein gene, the primary product of which is the secreted glycoprotein (sGP), in addition to the membrane-bound viral spike protein GP1,2. A lack of leukocyte infiltration is observed during EBOV infection, which is thought to allow virus replication to proceed unchecked and thus represents a significant role in the immunopathology of the disease. Currently the only know function of sGP is that it has an anti-inflammatory effect on endothelial cells treated with TNF-α, an effect that has been hypothesized to interfere with recruitment or extravasation of leukocytes. To better characterize this anti-inflammatory function, a link between sGP structure and function was sought. Mass spectrometry (MS) analysis of recombinant sGP demonstrated that it is a parallel-orientated disulphide-linked homodimer that contains Cys53-C53’ and Cys306-C306’ intermolecular disulphide bonds. In addition to being glycosylated with complex N-glycans, sGP also contained a novel post-translation modification, termed C-mannosylation. C-mannosylation was not required for the anti-inflammatory function of sGP; however, glycine mutations at amino acids 53 and 306 resulted in the complete loss of the anti-inflammatory effect on TNF-α treated endothelial cells. Thus, a specific structure mediated by intermolecular disulphide bonds is required for the proposed anti-inflammatory function of sGP, suggesting that this effect is the result of a specific interaction. The spike protein GP1,2, also contains C-mannosylation motifs. MS analysis of GP1,2 indicated that GP1 was C-mannosylated, while two adjacent motifs in the membrane proximal region (MPER) of GP2 were not. The infectious virus-like particle (iVLP) assay, a system for investigating virus particle assembly and entry, was utilized to determine the functional importance of these conserved tryptophans. Elimination of the C-mannosylation motif, which resides in an external loop region of GP1, increased reporter activity, suggesting that particle entry is enhanced and this region may interact with the cell surface despite being outside of the receptor binding site. Decreased reporter activity was observed for all MPER mutants, with multiple MPER tryptophan mutations resulting in decreased GP1,2 incorporation. These data place the MPER tryptophan residues in an important role for glycoprotein incorporation and particle entry. Given the tryptophan content and location is similar to the MPER of HIV gp41, where these residues are required for glycoprotein incorporation and fusion, the MPER of EBOV GP2 may function similarly.