The purpose of this investigation has been to determine the characteristics of the immune response to 1-fluoro-2,4-dinitrobenzene when this hapten is conjugated with various types of proteins.

The role of Ca++ in olfactory responses was investigated with inorganic and organic calcium channel antagonists. Electrophysiological responses to odorants were recorded from frog olfactory mucosa before and after aerosol application of different agents. Electroolfactogram responses were blocked by certain inorganic ions with the order of effectiveness Zn++ >Ln+++>Cd++>Ca++>Co++>Sr++>Mg++. Ba++ potentiated olfactory responses, and is known to potentiate calcium channel-mediated responses in other tissues. Certain local anesthetics which are thought to act through calcium channel blockade were inhibitory to olfactory responses, with the order of effectiveness being dibucaine>tetracaine>procaine. These data support the idea that Ca++ is involved in olfaction, perhaps acting as a current carrier and/or a second messenger. Preliminary experiments on channel localization were performed using a silicon-labeled amine. Attempts to localize the silicon label were inconclusive, although silicon was detected in the olfactory tissue.

Falling, an epidemic most prevalently seen in the elderly population, accounts for the majority of injury-related cases seen by emergency departments across the United States. Unfortunately, with no large-scale institutionalization of a solution, the problem is only expected to exacerbate as our planet’s population approaches the 7 billion mark. In the wake of the recent surge of falls among the elderly, Japan has implemented a program to include unicycling in the physical education curriculum for elementary schools across the country. The goal for this program is to encourage children to establish strong fundamental balancing skills, which could potentially alleviate the pain—physical, emotional, and financial—incurred from falls in the elderly. This senior thesis study builds off Japan’s unicycling program by investigating ways to improve wobble board balancing, a more practical alternative to unicycling. In previous research, the skill of stick balancing, a motor task that has been shown to behave with the same power laws as wobble board balancing, has been improved with the use of vibrations. Here, we show that learning to wobble board balance is not expedited and wobble board balancing skill is not improved with the employment of vibrations, unlike stick balancing. Nonetheless, those who learned to wobble board balance with background vibrations went on to later outperform those who learned to wobble board balance without vibrations. These results suggest that vibrations (50 Hz, 0.18 mm amplitude) have a beneficial effect on the development of skill for wobble board balancing that is not related to the direct physical effects of the vibration. The observations also suggest that in the presence of vibrations, the nervous system develops more robust strategies for controlling balance.

In these studies we sought to determine the role of Fyn kinase and ADAM10 in B cell biology. A disintegrin and metalloproteinase 10 (ADAM10) is a zinc dependent proteinase related to matrix metalloproteinases. ADAM10 has emerged as a key regulator of cellular processes by cleaving and shedding extracellular domains of multiple transmembrane receptors and ligands. In particular, ADAM10 has been identified as a key regulator of lymphocyte development. Here we report that ADAM10 is dispensable for early B cell development within the bone marrow. However, deletion of ADAM10 from all peripheral B cells or in post-switch cells leads to severe impairments in humoral responses. When ADAM10 was deleted from all peripheral B cells a decrease in antigen specific IgG production was seen both with respect to serum levels and IgG ASCs, indicating that plasma cell (PC) differentiation is influenced. Cells producing high affinity antigen specific antibodies were particularly affected, consistent with defects in germinal center (GC) reactions. Moreover, changes in lymphoid architecture were also observed. Consistent with these findings, follicular dendritic cell (FDC)-reticula was undetectable following immunization. On the other hand, when ADAM10 was deleted in post-switch B cells, GC formation and lymphoid architecture were not impaired. Despite normal architecture, however, antibody production was still affected, likely due to abnormal gene expression in ADAM10-deficient PCs. Consistent with this hypothesis, PCs isolated from ADAM10Δ/ΔIgG1-cre+/- showed decreased expression of genes that facilitate plasma cell differentiation and function and increased expression of Bcl6, an inhibitor of PC differentiation. Fyn kinase is a member of the Src protein tyrosine kinase. Fyn is widely expressed in many cell types, including lymphocytes. Fyn has been shown to interact with both the B cell and T cell receptor (BCR and TCR, respectively). While Fyn-deletion did not impair the development of immature T cells and B cells, TCR signaling was altered in mature T cells. Our results demonstrate that Fyn-KO mice have significantly low basal levels of IgG1 and IgG2a. Additionally, these mice displayed delayed kinetics in the production of NP-specific IgG1 and IgG2b, and significantly low NP-specific IgG2a after a T-dependent immunization protocol. Defects in antibody production correlated with significantly reduced numbers of GC B cells, TFH cells and splenic PCs. Moreover, Fyn-KO B cells showed decreased production antibody following in vitro activation. Our results thus demonstrate that Fyn-mediated signaling and B cell ADAM10 expression are necessary for optimal humoral responses.

No description available.

Child maltreatment is a significant public health issue. Reducing prevalence of coercive parenting is one means to reducing risk of maltreatment and negative developmental outcomes for children. Parental use of physical punishment has been associated with adverse consequences in childhood and adulthood. Parent education programs, such as the Positive Parenting Program (Triple P), that promote alternatives to using physical punishment with children may reduce coercive parenting. In this study, parental use of physical punishment, non-physical forms of punishment, and non-punitive parenting responses were compared before and after parents attended Level 2 Triple P parent education seminars. International Parenting Survey-Canada (IPS-C) data were used to examine Belsky’s (1984) theoretical proposition that parental factors are the strongest predictor of parenting behaviour followed by contextual and child factors. Independent samples t-tests, Wilcoxon Signed Rank Tests, and a series of regression models were used to examine the study’s hypotheses. A total of 27 parents attended the Triple P sessions. Parental use of physical punishment decreased on only one of the four physical punishment items (shaking) post- intervention. Although there were no significant differences in overall use of non-physical forms of punishment and non-punitive parenting strategies pre and post-intervention, there were significant increases in frequency of use of individual scale items pre- to post-intervention. IPS-C sample of 2,340 Canadian parents was used to examine Belsky’s postulate. Results were mixed and provided partial support for the postulate. Child behaviour problems, participation in parent education programs, parent employment status, and parent age predicted coercive parenting. Findings highlight the need to further examine these hypotheses. / October 2016

Forests play an integral role in regulating the exchange of carbon between the atmosphere and the terrestrial biosphere. These ecosystems only cover for about 30% of the land surface, forests account for almost half of the annual carbon uptake. The amount of carbon sequestered by forest ecosystems is largely dependent upon favorable climate conditions that promote increases in growth. Under the lowest emissions scenario, the United States is projected to undergo an almost 2˚C increase in temperature by the end of the century and it is important that we assess the contemporary climate-growth relationships of multiple forest types to better evaluate the stability and persistence of this vital carbon sink. Tree rings have been used to assess forest response to macroclimate conditions, but often the trees sampled for these analyses are only the most dominant individuals in the forest. This excludes individuals found in the understory of complex forest systems, such as those in the temperate forests of the eastern United States, and climate-growth relationships calculated from only dominant individuals may not be representative of the entire stand. Recent studies have shown that structural complexity of the forest canopy can significantly alter the microclimate conditions at which understory trees grow. Altered growth responses of the understory trees could increase the resilience of complex forest systems to the changes in temperature that are expected by the end of the century. Here, I apply dendrochronology methods to quantify climate-growth relationships of canopy strata in temperate forests of the eastern United States. Many different forest types are found in this region and have been the focus of numerous species-specific studies on climate growth relationships. However, the integrated response of co-occurring species within canopy units is not often investigated, despite measures of productivity being an integration of ecosystem processes. I present research that investigates the differential climate sensitivities of canopy strata, and I present a means to more accurately represent biomass estimates calculated from tree-ring data. The first study quantifies the climate sensitivities of different canopy strata from five temperate forests in the eastern US. We used a generalized additive model (GAM) to assess the influence that growing season mean temperature, growing season precipitation, and tree size have on dominant (uppermost), intermediate, and understory (lowermost) canopy strata. We found that differential climate sensitivities do exist between canopy strata, causing each canopy class to respond to extreme climate conditions in a different manner. For example, during the hottest and wettest years dominant and intermediate trees show slight increases in growth, whereas understory trees show significant decreases in growth. These results suggest that the climate and competitive environments created within stratified canopy layers may provide an added degree of ecosystem stability in the face of changing climate conditions. The second study assesses the spatial coherence of climate-growth relationships between canopy layers from the eastern temperate forest region. We collected increment cores from sites in Missouri, Indiana, Ohio, Michigan, Massachusetts, and Maine and we found that site groupings were relatively consistent between canopy layers. Dominant and intermediate trees showed a strong correlation with temperature that also coincides with the forest types and species distributions that are observed across the region. However, understory trees show stronger relationships with precipitation. Sites from the northeast US and Michigan displayed muted climate relationships, likely due to having both coniferous and hardwood species present. The midwest sites, composed of mostly hardwood species, showed relatively strong, negative temperature relationships in the dominant and intermediate canopy layers, but understory trees displayed strong positive relationships with temperature. These results suggest that although macroclimate conditions influence species distributions and affect the dominant trees, understory trees are likely responding to microclimate conditions. This also suggests that regions with increased functional diversity and complex canopy structure may be better buffered against changing climate conditions. Finally, we identify four main sources of uncertainty in estimating aboveground biomass from tree-ring data. Tree rings are being used more frequently to estimate the annual uptake of biomass by forested ecosystems. However, these calculations require several steps and assumptions that affect the overall accuracy of the biomass estimates. The error range around tree-ring estimates of aboveground biomass is seldom reported. We illustrate how increment upscaling, allometric, stand density, and mortality uncertainties can affect biomass estimates from a well-studied site in the Valles Caldera in northern New Mexico. We found that dominant sources of uncertainty change depending upon whether cumulative or incremental biomass is calculated. At the cumulative level, choice of allometric equation and tree mortality estimates dominate the uncertainty, whereas inter-annual variability in the tree-ring record dominates incremental biomass estimates. Despite the calculations that are required to translate linear ring-width measurements into biomass quantities, the underlying climate-growth relationships recorded within the tree rings are not significantly altered. Tree-rings provide a means for non-destructively quantifying the aboveground biomass in a forest and reporting the accompanying uncertainties will facilitate more accurate comparisons between disparate forest types.

Student Number : 0311003J - MA research report - School of Literature and Language Studies - Faculty of Humanities / This dissertation examines the representations of youth identity in print advertisements found in Y Magazine and SL Magazine. The researcher uses Critical Discourse Analysis to analyse the identities that are constructed in four fashion brands. The print advertisements are also interpreted by young people from Grade 11 classes in two Johannesburg high schools. Learners completed survey questionnaires and participated in focus group discussions. My interpretation of the advertisements reveals three over sexualized identities in the Soviet, Guess and Diesel advertisements. Soviet depicts an image of a male penetrative sexual fantasy; Guess depicts feminine self-centred sexual pleasure and Diesel communicates a message of funky, sexy, heterosexual male-female desire. It is proposed that advertisers base their strategies on assumptions that sex sells to the youth. The Levi’s advertisement differs from the rest by constructing a Hip Hop brand identity that appeals to a majority of the respondents. The learners’ responses are varied; some identify with the brands and accept the subject positions that are offered by the advertisements and others critique the sexuality that pervades the majority of the advertisements. Learners’ interpretations also reflect different reading positions, as well as unclear gendered target audiences. I conclude that media representations provide a range of powerful resources, which young people draw on in constructing their identities. I argue that print advertisements can be used productively in the language classroom as part of the body of literature that is studied in the English syllabus, especially because of their contemporary value and role in shaping post-modern subjects.

La transfusion sanguine est un traitement essentiel à la survie de millions de patients. Son principal risque immunologique est l’allo-immunisation post-transfusionnelle. Elle se traduit par la production d’allo-anticorps contre des antigènes de globules rouges (GR) conduisant à des hémolyses post-transfusionnelles. Les mécanismes à l’origine de la tolérance des GR ou de son inhibition lors de l’allo-immunisation sont mal connus. Ainsi, mes travaux de thèse, portant sur la compréhension de ces effets, se sont articulés en trois parties avec 1/ l’étude des conditions optimales aux réponses allo-immunes, 2/ l’étude des effets d’une stratégie thérapeutique utilisant un anticorps monoclonal et 3/ l’étude des effets immunomodulateurs, incluant la tolérance, médiée par des composants présents dans les concentrés de globules rouges (CGR).Afin d’étudier l’allo-immunisation, nous avons utilisé le modèle murin. Nous montrons qu’une variation du délai entre la transfusion et la stimulation du TLR3 impacte la réponse immune dans la rate. Une activation importante des lymphocytes T CD4+ (LT CD4+) allo-réactifs accompagnée d’une production accrue d’allo-anticorps ont été montrées à 7 jours de délai. Afin de limiter l’allo-immunisation, l’utilisation d’un anticorps anti-CD20 déplétant les lymphocytes B (LB) montre une altération des LB mais surtout des LT CD4+ impliqués dans le processus d’induction de l’allo-immunisation. Enfin, la modification du phénotype des cellules dendritiques CD11c+ de la rate des souris transfusées, observée hors contexte inflammatoire, suggère une maturation incomplète à l’origine d’une tolérance antigénique. Pour finir, l’analyse de différents composants présents dans les CGR confirme l’existence de microparticules (MPs) lymphocytaires. Ces MPs présentent des molécules inhibitrices et pourraient donc être impliquées dans la tolérance des antigènes transfusés.En conclusion, mes travaux montrent la coopération des DCs avec les LT CD4+ permettant celle des LT CD4+ avec les LB pour induire une réponse immune. Comme toute réponse humorale, nous confirmons que l’allo-immunisation fait intervenir des DCs, des LT CD4+ et des LB. Ces résultats ouvrent de nouvelles voies de recherche pour mieux caractériser l’allo-immunisation en particulier chez les patients drépanocytaires qui sont les plus touchés. / Red blood cell (RBC) transfusion is a life-saving treatment for millions of patients. However, its main immunological risk is RBC alloimmunization resulting in antibody production against RBC antigen. Alloimmunization can lead to severe complications threatening the life of the patient. The mechanisms explaining RBC alloimmunization are poorly understood. Therefore, my doctoral work aiming at understanding transfusion effects, was subdivided into three parts with 1/ the study of optimal conditions for alloimmune responses, 2/ the impact of a therapeutic strategy using a monoclonal antibody to inhibit alloimmunization and 3/ the study of immunomodulatory effects of transfusion, including tolerance, through components present in the RBC concentrates.We also used HOD murine model for the study of alloimmunization to show an impact of the delay between the TLR3 agonist injection and the transfusion on immune responses against RBCs. At 7 days of delay, we have demonstrated an important alloreactive CD4+ T-cell activation and a wider alloantibody production. Furthermore, B-cell depletion, using a monoclonal anti-CD20 antibody, revealed potential changes on LB implicated in alloimmunization induction and mostly on alloreactive CD4+ T cells. We finally observed a modification of splenic CD11c+ DC phenotype from transfused mice out of a TLR context. This suggest an incomplete maturation that could explain antigen-specific tolerance. The investigation of several components in RBC concentrates confirmed the presence of microparticules (MPs) issued from T lymphocytes. These MPs carry inhibitory markers and could thus inhibit DC activation to induce antigen-specific tolerance.Therefore, my doctoral work highlights the implication and the cooperation of DCs with CD4+ T cells to allow cellular cooperation between CD4+ T cells and B cells for immune response induction. As in any humoral response, we confirmed that RBC alloimmunization involves DCs, CD4+ T cells and B cells. In addition, these results are opening up new areas of investigation for a better characterization of alloimmunization in particular in the most affected patients, the SCD patients.

Introdução: A captação e o estudo de respostas cerebrais evocadas por um estímulo sonoro vem permitindo a investigação objetiva do processamento da informação auditiva e uma melhor compreensão da via auditiva central. A utilidade deste método diagnóstico tem sido cada vez mais valorizada pelos audiologistas, no entanto sua aplicação clínica corrente requer a realização de uma quantidade mais expressiva de estudos, especialmente na literatura nacional, para um conhecimento mais profundo deste método, sobretudo quanto a normatizações, critérios de identificação das ondas e interferências de variáveis como idade, sexo e parâmetros utilizados na aquisição. Os Potenciais Evocados Auditivos de Média Latência são compostos por uma seqüência de ondas com latências em torno de 10 a 80ms, com origem neurogênica múltipla (projeções tálamo-corticais e córtex auditivo, colículo inferior e formação reticular em menor escala). O presente estudo tem como objetivo pesquisar os componentes dos PEAMLs, numa população de crianças saudáveis, estudando a latência e amplitude das ondas, a fim de conhecer as características dos PEAMLs para esta faixa etária. Metodologia: Participaram do estudo 32 crianças de ambos os sexos com idade entre 10 e 13 anos, otologicamente normais e sem histórias neurológicas. A análise estatística incluiu a realização da estatística descritiva (média e desvio-padrão) e análise da variância pelo teste F. Os PEAMLs foram pesquisados utilizando como estímulo tone-burst, nas intensidades de 50, 60 e 70 dBNA. Resultados e conclusão: Os valores médios de latência dos componentes foram Na=20,79ms, Pa=35,34ms, Nb=43,27ms e Pb=53,36ms. Para a amplitude Na-Pa os valores médios obtidos no estudo variaram entre 0,2 e 1,9mV (M=1,0mV). As formas de onda Na-Pa constituíram os componentes mais consistentes e mais facilmente identificáveis. Pode-se concluir que a amplitude aumenta e a latência diminui com o aumento da intensidade sonora. Na intensidade de 50dBNA as latências obtidas são significativamente maiores que as intensidades de 60 e 70 dBNA para a onda Na. A partir de 60dBNA os valores se estabilizam e não há mudanças significativas na latência ou morfologia da onda. Nas comparações inter e intra-individual foram observadas latências mais longas e amplitudes menores para o lado E (A1/Cz). Numa análise posterior dos dados segundo queixa de dificuldade escolar não foram observadas diferenças ao nível de significância para os componentes Na, Pa, Nb e Pb para os grupos de crianças com e sem queixa de dificuldades escolares. Nestas crianças foram observadas anormalidades na morfologia das ondas, as quais não foram atribuídas exclusivamente à queixa de dificuldade escolar, já que poderia haver também interferência da idade do sujeito avaliado e do neuro-desenvolvimento do Sistema Nervoso Auditivo Central. O presente estudo possibilitou um melhor conhecimento das características dos PEAMLs, o que contribuirá para a aplicação mais segura da técnica. Porém, outros estudos ainda se fazem necessários, principalmente na literatura nacional, a fim de estabelecer padrões normativos para o uso na rotina clínica. / Introduction: The record and study of corticals responses evoked by auditory stimulus has allowed the objective investigation from process of auditory information and a better understanding of central auditory path. The utility of the procedure has been valued by audiologists, nevertheless her clinical aplication current demand the a execution a sum more significative of the study, especially in nationals researchs, to knowledge profoundest this procedure, over all as for normative studys, waves?s identification criterion and interference of the variables with age, gender and parameters used in records. The PEAMLs are composed of a waves?s sequence with latency are around 10 a 80ms, with multiple neurogenic origen (thalamus corticais projections and auditory cortex, coliculus inferior and reticular formation in small scale). The present study objetive examined the components dos PEAMLs, in healthy childrens, researching the waves?s latency and amplitude, to know the PEAML in this band of age. Methods: make part of study 32 childrens in both genders between the ages of 10 e 13, normal hearing without neurological desorders. The statistical analises involved the descrition statistical (mean and standard deviation) and variance analises by test F. The PEAMLs are investigated with tone-burst stimuli in 50, 60 e 70 dBNA. Results and conclusions: the means values of the components are Na=20,79ms, Pa=35,34ms, Nb=43,27ms e Pb=53,36ms. To the amplitude Na-Pa the means values obtained in the study varies between 0,2 and 1,9mV (M=1,0mV). The waveforms are more consistents e more easyly identifiable. We are able to conclude that the amplitude increase and latency decrease with growth of intensity of sound. In 50dBNA the latency are significative higher that 60 and 70 dBNA to wave Na. From 60dBNA the values are stabilize and there is no significatives changes in the latency ou morphology of wave. In the comparisions inter e inta-hemisferical were observed latencys lengthest and amplitudes higher to side left (A1/Cz). In a posterior analises in conformity to complaint of hardness scholar were observeds diferrences no significants to the components Na, Pa, Nb e Pb in the childrens groups with and without complaint of hardness scholar. Anormalities in the morphology of waves were viewed in this childrens wich weren´t atribute to complaint of hardness scholar exclusively once there was interference of the patient?s age and the neural development of Central Auditory System Nervous. The present study made possible a better knowledge of PEAMLs and will contribute to securest aplication this procedure. But, another studys still are requisite, essentialy in the researchs national to established normatives standard to utily in the clinical practice.