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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.
541

Matériaux pour une histoire : les tentatives d'organisation politique nationale et autonome de l'immigration et des quartiers populaires : (France 1982/1992) / Materials for a story : the attempts of national and autonomous political organization of the immigration and the popular districts : (France 1982/1992)

Taharount, Karim 20 June 2014 (has links)
Cette thèse porte sur les tentatives de constitution d'une organisation nationale et autonome de l'immigration et des quartiers populaires entre 1982 et 1992, et ce à travers l'histoire de Résistance des banlieues et de ses fondateurs. / This thesis concerns the attempts of constitution of a national and autonomous organization of the immigration and the popular districts between 1982 and 1992, and it through the history of the Résistance des banlieues and his founders.
542

Identificação de marcadores moleculares associados com a susceptibilidade ao desenvolvimento do carcinoma de próstata em pacientes brasileiros. / IDENTIFICATION OF MOLECULAR MARKERS ASSOCIATED WITH THE SUSCEPTIBILITY TO THE DEVELOPMENT OF PROSTATE CARCINOMA IN BRAZILIAN PATIENTS

Iughetti, Paula 27 August 2001 (has links)
No mundo inteiro, o carcinoma de próstata ocupa o quinto lugar entre as neoplasias malignas de maior mortalidade. No Brasil, estima-se para o ano de 2001 que, entre os tumores malignos no sexo masculino, o carcinoma de próstata terá a segunda maior taxa de mortalidade e a primeira taxa de incidência (Estimativa da incidência e mortalidade por câncer no Brasil – 2001 – INCA). Uma vez que a taxa de mortalidade por carcinoma de próstata na população brasileira tem aumentado significativamente nos últimos anos, a presente tese se propôs a investigar regiões polimórficas em genes conhecidos que poderiam estar associadas a um aumento na predisposição a esta forma de câncer. Assim sendo, estudamos as regiões polimórficas CAG e GGC do gene do receptor de andrógeno; o polimorfismo C1171T do gene do receptor de vitamina D; o polimorfismo D104N do gene da endostatina; o polimorfismo Pro72Arg do gene p53 e a região polimórfica AAAAC localizada na região 3’ não traduzida do gene MXI1. / In the world’s population prostate carcinoma is the fifth most commom male cancer-related death malignancy. In Brazil, among all male invasive cancers it is expected that prostate carcinoma will have the second highest death rate and the highest incidence rate (Estimativa da incidência e mortalidade por câncer no Brasil, 2001). As the prostate carcinoma death rate in brazilian population has been increasing over the last several years we proposed to investigate polymorphic regions of known genes that might be associated with prostate carcinoma predisposition. We studied the androgen receptor CAG and GGC polymorphic regions, the vitamin D receptor C1171T polymorphism, the endostatin D104N polymorphism, the p53 Pro72Arg polymorphism and the MXI1 AAAAC polymorphic region.
543

Choix d'un associateur 2-D pour le balayage multiple et optimisation de l'estimation des pistes

Moreau, Francis January 2009 (has links)
No description available.
544

Using Association Rules to Guide a Search for Best Fitting Transfer Models of Student Learning

Freyberger, Jonathan E 30 April 2004 (has links)
Transfer models provide a viable means of determining which skills a student needs in order to solve a given problem. However, constructing a good fitting transfer model requires a lot of trial and error. The main goal of this thesis was to develop a procedure for developing better fit transfer models for intelligent tutoring systems. The procedure implements a search method using association rules as a means of guiding the search. The association rules are mined from the instances in the dataset that the transfer model predicts incorrectly. The association rules found in the mining process determines what operation to perform on the current transfer model. Our search algorithm using association rules was compared to a blind search method that finds all possible transfer models for a given set of factors. Our search process was able to find statistically similar models to the ones the blind search method finds in a considerably shorter amount of time. The difference in times between our search process and the blind search method is days to minutes. Being able to find good transfer models quicker will help intelligent tutor system builders as well as cognitive science researchers better assess what makes certain problems hard and other problems easy for students.
545

A comparative analysis of the views of leaders, former members, and the agency of family life education discussion groups

White, Lewis A. January 1957 (has links)
Thesis (M.S.)--Boston University / This study was undertaken to compare the views of leaders, former members of discussion groups and the agency's view of what is involved in discussion groups carried on by the Family Life Education Department of the Greater Boston Family Service Association. It is felt that by gaining additional insight into how the practitioner, in the case of the leaders, and the consumer, in the case of the former members, see the discussion groups, it is hoped that some of these views obtained may eventually be applied in improving future groups. It is also felt that if the agency's stated purpose of the discussion groups is considered in the comparison of the leaders' views and the former members' views of the groups, this will serve to suggest ways of improving the future groups. Another purpose of this study is that it is believed that it will yield indications as to the value of discussion groups of this type.
546

Genetic studies of cardiometabolic traits

Riveros Mckay Aguilera, Fernando January 2019 (has links)
Diet and lifestyle have changed dramatically in the last few decades, leading to an increase in prevalence of obesity, defined as a body mass index >30Kg/m2, dyslipidaemias (defined as abnormal lipid profiles) and type 2 diabetes (T2D). Together, these cardiometabolic traits and diseases, have contributed to the increased burden of cardiovascular disease, the leading cause of death in Western societies. Complex traits and diseases, such as cardiometabolic traits, arise as a result of the interaction between an individual's predisposing genetic makeup and a permissive environment. Since 2007, genome-wide association studies (GWAS) have been successfully applied to complex traits leading to the discovery of thousands of trait-associated variants. Nonetheless, much is still to be understood regarding the genetic architecture of these traits, as well as their underlying biology. This thesis aims to further explore the genetic architecture of cardiometabolic traits by using complementary approaches with greater genetic and phenotype resolution, ranging from studying clinically ascertained extreme phenotypes, deep molecular profiling, or sequence level data. In chapter 2, I investigated the genetic architecture of healthy human thinness (N=1,471) and contrasted it to that of severe early onset childhood obesity (N=1,456). I demonstrated that healthy human thinness, like severe obesity, is a heritable trait, with a polygenic component. I identified a novel BMI-associated locus at PKHD1, and found evidence of association at several loci that had only been discovered using large cohorts with >40,000 individuals demonstrating the power gains in studying clinical extreme phenotypes. In chapter 3, I coupled high-resolution nuclear magnetic resonance (NMR) measurements in healthy blood donors, with next-generation sequencing to establish the role of rare coding variation in circulating metabolic biomarker biology. In gene-based analysis, I identified ACSL1, MYCN, FBXO36 and B4GALNT3 as novel gene-trait associations (P < 2.5x10-6). I also found a novel link between loss-of-function mutations in the "regulation of the pyruvate dehydrogenase (PDH) complex" pathway and intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL) and circulating cholesterol measurements. In addition, I demonstrated that rare "protective" variation in lipoprotein metabolism genes was present in the lower tails of four measurements which are CVD risk factors in this healthy population, demonstrating a role for rare coding variation and the extremes of healthy phenotypes. In chapter 4, I performed a genome-wide association study of fructosamine, a measurement of total serum protein glycation which is useful to monitor rapid changes in glycaemic levels after treatment, as it reflects average glycaemia over 2-3 weeks. In contrast to HbA1c, which reflects average glucose concentration over the life-span of the erythrocyte (~3 months), fructosamine levels are not predicted to be influenced by factors affecting the erythrocyte. Surprisingly, I found that in this dataset fructosamine had low heritability (2% vs 20% for HbA1c), and was poorly correlated with HbA1c and other glycaemic traits. Despite this, I found two loci previously associated with glycaemic or albumin traits, G6PC2 and FCGRT respectively (P < 5x10-8), associated with fructosamine suggesting shared genetic influence. Altogether my results demonstrate the utility of higher resolution genotype and phenotype data in further elucidating the genetic architecture of a range of cardiometabolic traits, and the power advantages of study designs that focus on individuals at the extremes of phenotype distribution. As large cohorts and national biobanks with sequencing and deep multi-dimensional phenotyping become more prevalent, we will be moving closer to understanding the multiple aetiological mechanisms leading to CVD, and subsequently improve diagnosis and treatment of these conditions.
547

The nonfarm income of Kansas Farm Management Association farmers for years 1973-1975

Lobmeyer, Harold L January 2011 (has links)
Typescript. / Digitized by Kansas Correctional Industries
548

Imposing structure on odor representations during learning in the prefrontal cortex

Wang, Yiliu January 2019 (has links)
Animals have evolved sensory systems that afford innate and adaptive responses to stimuli in the environment. Innate behaviors are likely to be mediated by hardwired circuits that respond to invariant predictive cues over long periods of evolutionary time. However, most stimuli do not have innate value. Over the lifetime of an animal, learning provides a mechanism for animals to update the predictive value of cues through experience. Sensory systems must therefore generate neuronal representations that are able to acquire value through learning. A fundamental challenge in neuroscience is to understand how and where value is imposed in brain during learning. The olfactory system is an attractive sensory modality to study learning because the anatomical organization is concise in that there are relatively few synapses separating the sense organ from brain areas implicated in learning. Thus, the circuits for learned olfactory behaviors appear to be relatively shallow and therefore more experimentally accessible than other sensory systems. The goal of this thesis is to characterize the representation and function of neural circuits involved in olfactory associative learning. Odor perception is initiated by the binding of odors onto olfactory receptors expressed in the sensory epithelium. Each olfactory receptor neuron (ORN) expresses one of 1500 different receptor genes, the expression of which pushes the ORN to project with spatial specificity onto a defined loci within the olfactory bulb, the olfactory glomeruli. Therefore, each and every odor evokes a stereotyped map of glomerular activity in the bulb. The projection neurons of the olfactory bulb, mitral and tufted (M/T) cells, send axons to higher brain areas, including a significant input to the primary olfactory cortex, the piriform cortex. Axons from M/T cells project diffusely to the piriform without apparent spatial preference; as a consequence, the spatial order of the bulb is discarded in the piriform. In agreement with anatomical data, electrophysiological and optical imaging studies also demonstrate that individual odorants activate sparse subsets of neurons across the piriform without any spatial order. Moreover, individual piriform neurons exhibit discontinuous receptive fields that defy chemical or perceptual categorization. These observations suggests that piriform neurons receive random subsets of glomerular input. Therefore, odor representations in piriform are unlikely to be hardwired to drive specific behaviors. Rather, this model suggests that value must be imposed upon the piriform through learning. Indeed, the piriform has been shown to be both sufficient and necessary for aversive olfactory learning without affecting innate odor responses. However, how value is imposed on odor representations in the piriform and downstream associational areas remain largely unknown. We first developed a strategy to track neural activity in a population of neurons across multiple days in deep brain areas using 2-photon endoscopic imaging. This allowed us to assay changes in neural responses to odors during learning in piriform and in downstream associative areas. Using this technique, we first observe that piriform odor responses are unaffected by learning, so learning must therefore impose discernable changes in neural activity downstream of piriform. Piriform projects to multiple downstream areas that are implicated in appetitive associative learning, such as the orbitofrontal cortex (OFC). Imaging of neural activity in the OFC reveal that OFC neurons acquire strong responses to conditioned odors (CS+) during learning. Moreover, multiple and distinct CS+ odors activatethe same population of OFC neurons, and these responses are gated by context and internal state. Together, our imaging data shows that an external and sensory representation in the piriform is transformed into an internal and cognitive representation of value in the OFC. Moreover, we found that optogenetic silencing of the OFC impaired the ability of mice to acquire learned associations. Therefore, the robust representation of expected value of the odor cues is necessary for the formation of appetitive associations. We made an important observation: once the task has been learned with a set of odors, the OFC representation decays after learning has plateaued and remains silent even when mice encounter novel odors they haven’t previously experienced. Moreover, silencing the OFC when it was not actively engaged during the subsequent learning of new odors had no effect on learning. These sets of imaging and silencing experiments reveal that the OFC is only important during initial learning; once task structure has been acquired, it is no longer needed. Task performance after initial task acquisition must therefore be accommodated by other brain regions that can store the learned association for long durations. We therefore searched for other brain regions that held learned associations long-term. In the medial prefrontal cortex (mPFC), we observe that the learned representation persists throughout the entire course of training. Unlike the OFC, not only does this representation encode the positive expected value of CS+ odors, it also encodes the negative expected value of CS- odors in a non-overlapping ensemble of neurons. We further show through optogenetic silencing that this representation is necessary for task performance after the task structure has already been acquired. Therefore, while the OFC representation is required for initial task acquisition, the mPFC representation is required for subsequent appetitive learning and performance. Why would a learned representation vanish in the OFC and betransfered elsewhere? We hypothesize that the brain may allocate a portion of its real estate to be a cognitive playground where experimentation and hypothesis testing takes place. Once this area solves a task, it may unload what it has learned to storage units located elsewhere to free up space to learn new tasks. We further imaged another associative area, the basolateral amygdala (BLA), and found a representation of positive value that appears to be generated from a Hebbian learning mechanism. However, the silencing of this representation during learning had no effect. This suggests that while multiple and distributed brain areas encode cues that predict the reward, not all may be necessary for the learning process or for task performance. In summary, we have described a series of experiments that map the representation and function of different associational areas that underlie learning. The data and the techniques employed have the potential to significantly advance the understanding of learned behavior.
549

What are the relationships among high school academic outcomes and attendance?

Christensen, Morgan 06 September 2017 (has links)
Research for the past decade has examined academic performance gaps among students from the perspective of sex, race and ethnicity groups, and low socio-economic status. Across those studies school attendance has been identified as a primary correlate with academic success. I used a descriptive non-experimental design to investigate the relationship of student academic outcomes (i.e., GPA, credits earned toward graduation) among student groups (i.e., sex, race, and special education status) on attendance type of unexcused or excused absences. This study included two cohorts of 9th grade high school students (n = 2,262) from the Eugene 4J School District during the 2013 to 2016 school year. I calculated Chi-square tests, Independent t-tests, and Pearson’s correlation coefficient to examine the relationship of attendance with student academic outcomes for GPA and credits earned toward graduation and to further compare attendance type (i.e., unexcused or excused absences) among student groups. Findings indicated statistically significant differences for unexcused and excused absences and for GPA and credits earned by specific demographic subgroups – males v. females, white v. minority, special education v. not special education. There were also statistically significant correlations for GPA and credits earned based on unexcused and excused absences among demographic subgroups. In addition, there were statistically significant differences by academic and attendance variables for students who remained in comparison to students who left Eugene 4J.
550

Genetic analysis of IgG N-glycosylation in health and disease

Klarić, Lucija January 2018 (has links)
Glycosylation is among the most common post-translational protein modifications. Glycans are complex carbohydrates attached to the surface of many proteins, but are rarely extensively studied in a high-throughput manner. However, there is an increasing evidence of their involvement in various physiological processes and diseases. Glycosylation of Immunglobulin G was shown to be important in adaptive immunity, where it can act as a "safety switch" for different types of the immune response. Although the main enzymes of the glycosylation pathway are known, little is understood about how this template-independent process is regulated to result in a faithful synthesis of a specific glycoform. This question was previously addressed using genome-wide association studies (GWAS) and 9 loci were identified as being significantly associated with IgG N-glycosylation. Only 4 of these loci were the known glycosylation enzymes. An additional five loci were discovered by applying a newly developed multivariate GWAS method on the same dataset. Here, by performing a GWAS on 77 IgG N-glycan traits measured by ultra-performance liquid chromatography in more than 8000 samples from four European cohorts the number of genome-wide significant (p? ≤ 2.4 x 10−9) loci increased to 27, 15 of which are novel, with 6 additional loci being suggestively associated (p? ≤ 2.4 x 10−8). To assess which of the genes from the associated loci are more likely to be regulating IgG glycosylation, different gene prioritising strategies were employed. For 7 loci evidence of a non-synonymous amino acid change was found, two of which were predicted to be deleterious. Evidence of regulation through changes in gene expression levels in B-cells, the cell lineage responsible for production of IgG, was found for 4 genes, with an additional 11 genes exhibiting the same evidence with expression in peripheral blood or other immune cells. For the remaining loci the most likely candidate gene was proposed based on co-expression with genes from the enriched gene-sets or based on a physical proximity to the variant with the strongest association. To narrow down the most important loci for a functional follow-up, the omics nature of this data was used to compare glycome-wide SNP effects and suggest how newly discovered loci form a functional network that regulates the established members of the glycosylation pathway. The potential role of IgG glycosylation in various complex traits and diseases was explored by assessing the pleiotropy of the associated SNPs. The inflation of SNPs related to autoimmune, digestive and neurological diseases was observed in glycosylation SNPs. To assess whether IgG N-glycosylation is likely to share the same causal variant as the identified pleiotropic traits and diseases, regional association patterns were compared using summary data based Mendelian Randomisation analyses. This work demonstrates that an increased sample size empowered the identification of novel loci, enabling further insights into the molecular mechanisms underlying protein glycosylation and its relationship with complex human diseases. It also shows that such analyses of omic traits can assist in creating a functional network of the identified loci, prioritising the most important genes and allowing a more focused approach to future experimental functional follow-up.

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