Syftet med denna studie är att granska och undersöka de underliggande orsakerna till ungdomsbrottslighet samt att skaffa en fördjupad förståelse för de faktorer som bidrar till ungdomars deltagande i kriminella nätverk. Genom att genomföra intervjuer med företrädare för KRIS (Kriminellas Revansch i Samhället) och SSPF Grupp (skola, socialtjänst, polis och fritid i samverkan), har specifika faktorer som ligger till grund för ungdomsbrottsligheten kunnat identifieras och granskas. En kvalitativ forskningsansats har antagits för studien genom tillämpningen av två fokusgruppsintervjuer samt fyra individuella semistrukturerade intervjuer med sammanlagt tio respondenter. Denna studie har omfattat tillämpning av teorier såsom sociala bandteorin, social identitet och konformitet. Dessa väletablerade teorier har använts som ramar för att tolka och analysera resultatet. För att skapa en djupare förståelse för fenomenet har vi använt en socialpsykologisk ansats. Resultatet av studien präglas av upplevelser och erfarenheter hos våra intervjupersoner, vilka är yrkesverksamma på samhällsinstanser som arbetar med personer som antingen vill lämna eller har lämnat kriminalitet bakom sig. Slutsatsen i denna studie belyser faktorer som lockar ungdomar till kriminella sammanhang. Dessa inkluderar gemenskap, identitetssökande, grupptillhörighet, familjestruktur, skolgång, effekten av ungdomars vänskap, behovet av status, digitala lockbeten och rekrytering till kriminella nätverk. / The aim of this study is to explore the root causes of youth delinquency and gain deeper insights into the factors contributing to youths' involvement in criminal networks. Through interviews with representatives from KRIS (Criminals' Revenge in Society) and SSPF Group (School, Social Services, Police, and Leisure in Collaboration), specific factors underlying youth delinquency were identified and examined. This qualitative research utilized two focus group interviews and four individual semi-structured interviews with ten respondents in total. The study employed theories such as social bond theory, social identity, and conformity as analytical frameworks to interpret findings. By applying a social psychological approach, we aimed to understand the phenomenon more deeply. The results of our study are characterizedby the experiences and insights of our interviewees, who are professionals in social institutions working with individuals who either want to leave or have left criminality behind. The findings underscore various factors that attract youths to criminal contexts, including community, identity-seeking, group affiliation, family dynamics, schooling, peer influence, the pursuit of status, digital incentives, and recruitment into criminal networks. Through this research, we aim to contribute to a better understanding of youth delinquency and inform strategies for intervention and prevention.

Résumé : INTRODUCTION : L’étude vise à établir un portrait des traumatismes et de la pratique de l’escalade au Québec: 1) en décrivant les caractéristiques des décès associés à l’escalade au Québec; 2) en décrivant les caractéristiques des consultations à l’urgence associées à l’escalade; 3) en estimant la prévalence à vie et l’incidence des traumatismes en escalade, ainsi qu’en explorant les facteurs de risques ou de protection associés. MÉTHODES : 1) Une série de cas des décès en escalade a été analysée à partir d’une extraction des données des rapports d’investigation du coroner, entre 1986 et 2013. 2) Une série de cas des consultations à l’urgence a été analysée à partir des données du Système canadien hospitalier d'information et de recherche en prévention des traumatismes, entre 1992 et 2011. 3) Une étude descriptive transversale par questionnaire en ligne qui a été administré auprès des membres de la Fédération québécoise de la montagne et de l’escalade (FQME), entre le 8 avril 2014 et le 3 juin 2014. RÉSULTATS : 1) et 2) Les 14 décès et 29 cas de consultations à l’urgence retenus pour l’analyse sont survenus en majorité chez des hommes âgés entre 18 et 29 ans. La chute du grimpeur est la principale cause de décès ou de traumatismes aigus. 3) Avec une participation de 19 % (765/4 109), la prévalence à vie de traumatismes a été estimée à 11,1 % pour l’escalade sur structure artificielle, 11,3 % pour l’escalade de rocher et 7,6 % pour l’escalade de glace. Une approximation de l’incidence dans les derniers 12 mois a été estimée à 0,37 événement à l’origine de traumatismes aigus par 1 000 heures de pratique sur structure artificielle d’escalade (SAE), 0,17 pour l’escalade de rocher et 0,10 pour l’escalade de glace. Le jeune âge a été associé à la survenue de traumatismes aigus (p < 0,01) pour tous les types d’escalade et le faible nombre d’années de pratique, à la survenue de traumatisme en escalade de rocher (p = 0,03). Les itinéraires de niveaux de difficulté élevés (p = 0,01) ou une plus grande intensité de la pratique (p < 0,01) ont été associés à la survenue de traumatismes sur SAE. CONCLUSION : L’escalade est une activité physique sécuritaire avec des prévalences et des incidences de traumatismes très faibles. Les résultats permettront d’orienter les interventions pour améliorer la sécurité en escalade. / Abstract : INTRODUCTION: This study aims to produce a portrait of injuries associated with rock climbing in Quebec by: 1) describing the characteristics of deaths associated with climbing in Quebec; 2) describing the characteristics of emergency room visits associated with climbing; 3) estimating the lifetime prevalence and the incidence rate for climbing injuries, and by exploring the associated risk or protective factors. METHODS: 1) A case series of climbing related deaths was analysed by extracting data from coroners’ investigation reports, between 1986 and 2013. 2) A case series of emergency room consultations was analysed from data provided by the Canadian Hospitals Injury Reporting and Prevention Program, between 1992 and 2011. 3) A cross-sectional descriptive study using a self-administered online survey sent to members of the Fédération québécoise de la montagne et de l’escalade (FQME), from April 8th, 2014 to June 3rd, 2014. RESULTS: 1) and 2) Of the 14 deaths and 29 cases of emergency room visits selected and analysed, the majority were men aged between 18 and 29 years. Climber falls were the leading cause of death or acute injury. 3) With a participation rate of 19 % (765/4,109), the lifetime prevalence for trauma was estimated at 11.1% on artificial climbing structures, 11.3% for rock climbing, and 7.6% for ice climbing. An approximation of the incidence in the last 12-months was estimated at 0.37 events causing injuries per 1,000 hours on artificial climbing structures (ACS), 0.17 for rock climbing and 0.10 for ice climbing. Younger age was associated with the occurrence of acute injuries (p < .01) for all types of climbing and the small number of climbing practice years with the occurrence of acute injuries during rock climbing (p = .03). Routes of higher climbing difficulty (p = .01) or a greater intensity of climbing practice (p < .01) and the occurrence of acute injuries on ACS. CONCLUSION: Climbing is a safe physical activity, with very low prevalence and incidence of acute injury. Results will help interventions in order to improve climbing safety.

Background Cardiovascular diseases, including myocardial infarction and stroke, are the main reason of death in Sweden and Western Europe. High iron stores are believed to produce oxygen radicals, which is the presumed putative mechanism behind lipid peroxidation, atherosclerosis and subsequent cardiovascular disease. Iron levels are associated with the hemochromatosis associated HFE single nucleotide polymorphisms C282Y and H63D. Bilirubin is an antioxidant present in relatively high levels in the human body. Several previous studies have found an association between high bilirubin levels and a lower risk for cardiovascular disease. Bilirubin levels are highly influenced by the common promoter polymorphism TA-insertion UGT1A1*28, the main reason for benign hyperbilirubinemia in Caucasians. There is a lack of prospective studies on both the association of iron and bilirubin levels, and the risk for myocardial infarction and ischemic stroke. Material and methods Iron, transferrin iron saturation, TIBC, ferritin and bilirubin were analyzed and HFE C282Y, HFE H63D and UGT1A1*28 were determined in myocardial infarction and stroke cases, and their double matched referents within the Northern Sweden Health and Disease Study Cohort. Results There were no associations between iron levels in the upper normal range and risk for myocardial infarction or stroke. No associations were seen for HFE-genotypes, except for a near fivefold increase in risk for myocardial infarction in HFE H63D homozygous women. Plasma bilirubin was lower in cases vs. referents both in the myocardial infarction and the stroke cohort. Despite a strong gene-dosage effect on bilirubin levels in both cases and referents, the UGT1A1*28 polymorphism did not influence the risk for myocardial infarction or stroke. Conclusion High iron stores are not associated with increased risk for neither myocardial infarction, nor stroke. There was no association between UGT1A1*28 and the risk for myocardial infarction or stroke. Consequently data suggests that other factors, which also may lower bilirubin, are responsible for the elevated risk observed in conjunction with lower bilirubin levels.

Background Indigenous peoples with traditional lifestyles worldwide are considered particularly vulnerable to climate change effects. Large climate change impacts on the spread of infectious vector-borne diseases are expected as a health outcome. The most rapid climate changes are occurring in the Arctic regions, and as a part of this region northernmost Sweden might experience early effects. In this thesis, climate change effects on the lives of Sami reindeer herders are described and 30 years of weather changes are quantified. Epidemiology of the climate sensitive human infection tularemia is assessed, baseline serologic prevalence of tularemia is investigated and the disease burden is quantified across inhabitants in the region. Methods Perceptions and experiences of climate change effects among the indigenous Sami reindeer herders of northern Sweden were investigated through qualitative analyses of fourteen interviews. The results were then combined with instrumental weather data from ten meteorological stations in a mixed-methods design to further illustrate climate change effects in this region. In two following studies, tularemia ecology and epidemiology were investigated. A total of 4,792 reported cases of tularemia between 1984 and 2012 were analysed and correlated to ecological regions and presence of inland water using geographical mapping. The status of tularemia in the Swedish Arctic region was further investigated through risk factor analyses of a 2012 regional outbreak and a cross-sectional serological survey to estimate the burden of disease including unreported cases. Results The reindeer herders described how the winters of northern Sweden have changed since the 1970s – warmer winters with shorter snow season and cold periods, and earlier spring. The adverse effects on the reindeer herders through the obstruction of their work, the stress induced and the threat to their lifestyle was demonstrated, forcing the reindeer herders towards the limit of resilience. Weather data supported the observations of winter changes; some stations displayed a more than two full months shorter snow cover season and winter temperatures increased significantly, most pronounced in the lowest temperatures. During the same time period a near tenfold increase in national incidence of tularemia was observed in Sweden (from 0.26 to 2.47/100,000 p&lt;0.001) with a clear overrepresentation of cases in the north versus the south (4.52 vs. 0.56/100,000 p&lt;0.001). The incidence was positively correlated with the presence of inland water (p&lt;0.001) and higher than expected in the alpine and boreal ecologic regions (p&lt;0.001). In the outbreak investigation a dose-response relationship to water was identified; distance from residence to water – less than 100 m, mOR 2.86 (95% CI 1.79–4.57) and 100 to 500 m, mOR 1.63 (95% CI 1.08–2.46). The prevalence of tularemia antibodies in the two northernmost counties was 2.9% corresponding to a 16 times higher number of cases than reported indicating that the reported numbers represent only a minute fraction of the true tularemia. Conclusions The extensive winter changes pose a threat to reindeer herding in this region. Tularemia is increasing in Sweden, it has a strong correlation to water and northern ecoregions, and unreported tularemia cases are quite common.

Le présent mémoire s’intéresse aux interventions policières en contexte de crise. Il s’attarde plus particulièrement à l’usage de la force par les structures d’intervention spécialisée. L’intérêt de cette étude découle principalement du manque de connaissances empiriques sur le sujet. L’objectif général de cette étude est de comprendre les éléments qui peuvent expliquer le recours à la force par les structures d’intervention spécialisées et de vérifier si ces facteurs varient selon le type de menace auquel font face les policiers. Nous nous sommes intéressés à 438 événements de crise suicidaire, de barricade et de prise d’otage qui se sont déroulés au Québec, de 1990 à 2011, et durant lesquels est intervenu le groupe tactique d’intervention (GTI) de la Sûreté du Québec (SQ). Pour une meilleure compréhension de cette problématique, il sera en premier lieu question de comparer, selon leur niveau de risque, les personnes présentant une menace uniquement pour elles-mêmes avec celles présentant une menace pour autrui et les personnes qui présentent une menace tant pour elles-mêmes que pour autrui. En second lieu, malgré le fait que près de 90 % des situations de crise se terminent par une reddition pacifique, il est pertinent de connaître les facteurs qui expliquent l’usage de la force de la part des policiers et de voir si ces facteurs varient selon le niveau de risque de l’individu. Des analyses descriptives ont permis d’établir que les situations où l’individu en crise présente uniquement une menace pour lui-même diffèrent des autres groupes sur la base de certaines variables. Cet individu est davantage jugé comme suicidaire et il possède plus souvent des antécédents psychiatriques. L’élément déclencheur est souvent associé aux problèmes conjugaux, ce qui coïncide avec le fait que c’est souvent la conjointe ou l’ex-conjointe qui appelle les autorités. Des analyses bivariées n’ont pas illustré de profils distincts selon la problématique de la crise. Or, certains facteurs se démarquent des autres de manière générale pour l’ensemble de l’échantillon et les différents groupes. La possession d’une arme par l’individu, le degré d’intoxication, la présence d’antécédents psychiatriques, la durée du premier contact avec les policiers et la qualité de la négociation sont effectivement des facteurs qui semblent influencer à un certain point les opérations. Les analyses de régression logistique indiquent que les policiers interviennent davantage lorsqu’il n’y aucun contact n’est établi avec l’individu. Nous observons également que ces derniers restent davantage en retrait lorsque l’individu, présentant une menace pour lui-même, est en possession d’une arme à feu. D’autre part, il semble que les policiers réagissent plus souvent auprès des individus présentant une menace pour autrui lorsque la négociation est jugée non satisfaisante. Nous pouvons en conclure qu’ils semblent davantage s’attarder à des facteurs précis qu’au type de menace, ce qui rejoint un certain segment de la littérature à ce sujet. / This thesis argues that police intervention in a crisis context focuses specifically on the use of force by specialized intervention teams. The interest in this study pinpoints mainly the lack of empirical data on the subject. Therefore, the main objective is to understand how to explain the use of force by specialized intervention teams and to verify if these factors vary according to the type of threat police encounter in a particular situation. We studied 438 suicidal crises, barricade and hostage-taking situations that occurred in Quebec from 1990 to 2011, supervised by the Sûreté du Québec’s tactical intervention group (GTI). To begin with, for a better understanding of this issue, we will compare individuals according to the level of risk each one represents, i.e. those presenting a threat only to themselves, those presenting a danger to others and those who pose a threat to themselves and others. Secondly, despite the fact that almost 90 % of critical incidents end in a non-violent conclusion, it is interesting to understand the risk factors involved that explain the use of force by the police and to realize that these factors vary according to the level of risk exhibited by the individual in crisis. Descriptive analyses were used to demonstrate that the situation where the individual in crisis was a threat only to himself differed from other instances based on different variables. Overall, the general level of risk for this type of intervention is less significant since the danger appears to be directed specifically to the individual in crisis, taking into consideration that negotiation has been successful, also, considering the subject has limited or no access to firearms, and considering weapons are not frequently used. Bivariate analysis relating the different characteristics of the individual, the situation and negotiation with the use of force by the police, suggest that certain variables can have different effects depending on the type of threat facing authorities. For example, a history of psychiatric issues would increase the risk of police intervention among those who pose a non-aggressive threat to himself, but would decrease the probability of police intervention for those individuals who present a double threat, i.e. to themselves and others. Consequently, bivariate analyses suggest that certain variables, such as the possession of a weapon by an individual, the degree of intoxication, the presence of known psychiatric issues, the duration of the first contact with the police and the quality of the negotiation, could influence the use of force by police officers. Logistic regression analyses indicate that few of these variables resist multivariate analyses. These findings suggest that police intervene more so when there is no contact established with the individual, and this, regardless of the type of threat manifested. On the contrary, a non-satisfactory negotiation would encourage police to use force in cases where the individual presents no threat to himself. In sum, these multivariate analyses show that the police are less influenced by the type of threat, rather preferring negotiation as long as possible.

Coxiella burnetii est une bactérie zoonotique affectant un grand nombre d’espèces animales. Chez les ruminants domestiques, l’infection est généralement asymptomatique, mais parfois associée à des problèmes reproducteurs. Néanmoins, le cycle de transmission de l’infection chez ceux-ci demeure peu connu. Dans ce contexte, nous avons réalisé une étude auprès de fermes bovines, ovines et caprines dans deux régions administratives du Québec afin d’estimer les prévalences de cette infection et d’identifier les facteurs de risque, aux niveaux individuel et troupeau, associés à la positivité. Nous avons estimé une prévalence de positivité au niveau troupeau de 44.6 % (IC95%=33.0-56.6) chez les bovins, de 70.8 % (IC95% =48.9-87.4) chez les ovins et de 66.7 % (IC95% =22.3-95.7) chez les caprins. Une association a été observée chez les troupeaux bovins entre leur positivité et la densité de petits ruminants par kilomètre carré dans un rayon de cinq kilomètres entourant la ferme. Chez les petits ruminants, une association avec la positivité des troupeaux a été observée avec la taille des troupeaux et la présence d’un chien sur la ferme. Au niveau individuel, le nombre de jours en lait ainsi que l’âge des petits ruminants étaient associés à la positivité, et ce dernier facteur était modulé par l’accès des animaux au pâturage. Aucun agrégat spatial de fermes positives n’a été détecté chez aucune des trois espèces. L’infection par Coxiella burnetii est donc fréquente dans les troupeaux de ruminants domestiques québécois et semble associée à certaines pratiques de régie et à la présence, ou proximité, d’autres animaux domestiques. / Coxiella burnetii is a zoonotic bacteria affecting a vast range of animal species. In domestic ruminants, the infection is usually asymptomatic, but sometimes linked with reproductive disorders. However, the transmission cycle of infection among them remains unclear. In that context, we conducted a study among dairy cattle, sheep and goats farms in two administrative regions of Québec to estimate the infection prevalence and identify the risk factors associated with farms and animals positivity. We estimated a herd prevalence of 44.6 % (95%CI=33.0 to 56.6) in dairy cattle, 70.8 % (95%CI=48.9 to 87.4) in sheep and 66.7 % (95%CI=22.3-95.7) in goats. On dairy cattle farms, we observed an association between their positivity and the density of small ruminants per square kilometer within a five kilometers radius around the farm. In small ruminants, at herd level, we observed an association with positivity and herd’s size and the presence of a dog on the farm. At the individual level, an association with positivity was found with the number of days in milk for small ruminants and their age, but the latter was also modulated by the individual’s previous access to pasture. No spatial cluster of positive farms was detected significant among dairy cattle nor small ruminants. The infection by Coxiella burnetii is therefore common on dodmestic ruminants’ farms in Québec and associated with some farm management practices and the presence, or proximity, of other domestic animals.

Ce travail de thèse a permis, dans un premier temps, de mettre en évidence de nouveaux grandsréarrangements dans trois pathologies étudiées au laboratoire : la mucoviscidose, la pancréatitechronique et l’hémochromatose. En particulier, ces travaux ont permis de trouver de nouveaux CNVs(Copy Number Variations) pathologiques dans le gène CFTR (Cystic Fibrosis Transmembraneconductance Regulator), de mieux comprendre les mécanismes d’un remaniement complexe dansPRSS1 (Protease Serine 1) et d’aider à caractériser finement un réarrangement dans HFE(Hemochromatosis). Ces études ont donc servi de preuve de concept pour l’utilisation de puces à ADN àl’échelle d’un gène et dans des zones difficiles car riches en séquences répétées.Dans un second temps, la recherche de facteurs de susceptibilité génétiques aux infarctus cérébraux(AICs) du sujet jeune a été réalisée chez 168 cas et 200 témoins âgés de moins de 40 ans. Dans notrepopulation, l’hypertension, les migraines, le tabac, et la prise de stupéfiants sont des facteurs de risqueimportants, multipliant respectivement par 35, 3,8, 4 et 2,8 le risque d’AIC. Notre étude pangénomiquepar CGH-array (Comparative Genomic Hybridization-array) a mis en évidence 98 régionspolymorphiques dans le génome humain. Parmi elles, la délétion d’une partie du gène NOTCH2, pourraitjouer un rôle protecteur dans la survenue des AICs (OR=0,11 [0,01-0,87] ; p=0,013) mais qui ne dépassepas le seuil fixé par la correction de Bonferroni). Ce travail a également mis en évidence environ 400CNVs rares, dont deux récurrents chez les cas, l'un portant les gènes CRELD2 (cysteine-rich with EGFlikedomains 2) et AGL12 (asparagine-linked glycosylation 12, alpha-1, 6-mannosyltransferase) (p=0,02)et le deuxième situé en 5’ du gène VBP1 (von Hippel-Lindau binding protein 1) (p=0,04). Enfin, uneapproche gènes candidats a été effectuée sur les gènes NOTCH2 et ALOX5AP (5-lipoxygenaseactivating protein) sans donner de résultats significatifs. Ceci a également été réalisé sur les mutationsprincipales de trois gènes de la coagulation (Facteur II, Facteur V Leiden et MTHFR). Une associationsignificative a été mise en évidence entre la C677T du gène MTHFR (5,10-methyltetrahydrofolate) et lesinfarctus cérébraux du sujet jeune (OR=2,39, p=0,02 pour le génotype TT). Ce travail de thèse a permisde confirmer l’existence de facteurs de risque environnementaux et génétiques déjà connus mais surtoutd’émettre de nouvelles hypothèses génétiques dans la survenue des AICs du sujet jeune. / The use of locus-specific array-CGH (Comparative Genomic Hybridization) has allowed us to detect largerearrangements in three pathologies of our laboratory: cystic fibrosis, chronic pancreatitis andhemochromatosis. We successfully observed new pathological CNV (Copy Number Variations) in theCFTR (Cystic Fibrosis Transmembrane conductance Regulator) gene and characterized complex eventsin PRSS1 (Protease Serine 1) and HFE (Hemochromatosis) genes, showing that the use of thistechnique is possible even in regions with high sequence homologies.We also confirmed that hypertension, migraine, tobacco and drugs are high significant risk factors forischemic strokes (IS) in young population (under 40 years) (OR=35, 3.8, 4 and 2.8, respectively). Then,we tried to identify new genetic susceptibility loci using a pangenomic approach. Among the 98 copynumber polymorphisms (CNP) observed, an interstitial NOTCH2 deletion is candidate for a protective rolein IS (OR=0.11 [0.01-0.87] ; p=0.013 before Bonferonni correction). We also observed approximately 400uncommon CNV, two of them being particularly reccurent in patients: a 22q13.31 duplication containingCRELD2 (cysteine-rich with EGF-like domains 2) and AGL12 (asparagine-linked glycosylation 12, alpha-1, 6-mannosyltransferase) genes (p=0.02) and a Xq28 deletion localised in the 5’ region of the VBP1 (vonHippel-Lindau binding protein 1) gene (p=0.04). We also applied a candidate-gene approach onNOTCH2, ALOX5AP (5-lipoxygenase activating protein) and coagulation genes (Factor II, Factor VLeiden and MTHFR). A significant association was found for the C677T in the MTHFR gene (5,10-methyltetrahydrofolate) and young ischemic strokes (OR=2.39, p=0.02 for TT genotype). In conclusion,this study confirmed the implication of environmental and genetic factors in ischemic strokes before 40years and suggests new genetic risk factors for IS.

This diploma thesis "Methods of risk aggregation on financial markets" introduces all kinds of risk that are present on the financial markets. In the first part there are explained the ways and methods of measurement of these risks. Next there are shown the methods of aggregation of credit, market and operational risks. One of these methods are copula functions which are constructed in practical part of this thesis.

Le cancer du sein est un problème majeur de santé publique en Amérique Latine (AL). Il a été montré que le surpoids, l'obésité, et les traitements hormonaux sont des facteurs de risque majeurs pour le développement du cancer du sein. Toutefois ces associations restent incertaines dans les populations d'AL. Le but de cette Thèse est donc de contribuer à combler ces lacunes en développant des études sur l'impact du surpoids et de l'obésité, ainsi que des traitements hormonaux, dans des populations latino-américaines. Nous avons donc utilisé les données originales d'une étude cas-témoins basée sur la population Mexicaine. Préalablement à cette étude, nous avons conduit une méta-analyse sur l'obésité et le cancer du sein chez la femme pré-ménopausée à travers le monde. Cette méta-analyse montre qu'à l'exception des Asiatiques, les personnes qui ont un indice de masse corporelle (IMC) élevé ont un risque diminué de cancer du sein pré-ménopausique tandis que celles qui ont un rapport tour de taille/hanches (RTH) élevé ont un risque du cancer du sein accru. L'étude cas-témoins montre une association inverse entre l'IMC élevé et le risque de cancer du sein en pré-ménopause tandis qu'en post ménopause aucune association n'a été observée. Cependant, le tour de taille, de hanche, et le RTH s'avèrent également inversement associés au risque de cancer du sein en pré et post-ménopause. D'autre part, l'augmentation de la silhouette tout au long de la vie est associée à un risque accru de cancer du sein. L'utilisation des traitements hormonaux substitutifs à la ménopause est également associée à un risque accru de cancer du sein. Cette étude apporte de nouvelles informations sur l'impact de ces facteurs sur le risque de cancer du sein / Breast cancer is a major public health problem in Latin America (LA). It has been shown that, overweight, obesity, and hormonal treatments are major risk factors for breast cancer development. However, these associations remain uncertain among Latin American populations. The aim of this thesis is to contribute to fill these gaps by developing studies on the impact of overweight and obesity, and hormonal treatments in Latin American populations. We used the original data from a multi-center population-based case–control study conducted in Mexico. Prior to this study, we conducted a dose-response meta-analysis on obesity and premenopausal breast cancer. This meta-analysis shows that, in the exception of Asians, increase in body mass index was inversely associated with the risk of premenopausal breast cancer; whereas, increase in waist-to-hip ratio are associated with an increase of this risk. The results of the case-control study show an inverse association between high BMI and the risk of breast cancer in pre-menopausal women, whereas no association was observed among post-menopausal. However, other anthropometric measures (waist and hip circumference, and waist hip ratio) are also inversely associated with risk of breast cancer in pre and post-menopausal women. Further analysis of body shape evolution throughout life showed significant increase in risk of breast cancer among women with increasing silhouettes size over time. With regards to menopausal hormone replacement therapy, users have a significant increased risk of breast cancer. This study provides new information about the effects of these factors on breast cancer risk, which may be of relevance for the population of LA as a whole

Introdução - A prematuridade, definida como nascimento antes de 37 semanas completas de gestação, ainda tem suas vias causais pouco explicadas. Objetivo - Analisar a prevalência de prematuridade e dos fatores do período pré-natal a ela relacionados, por meio de análise secundária dos dados da Região Sudeste, da pesquisa Nascer no Brasil. Métodos - A regressão binária de Poisson foi empregada na seleção das variáveis e as que apresentaram valor de p<0,20 foram incluídas a seguir no modelo de regressão logística hierarquizado, divididas em blocos de acordo com a proximidade temporal em relação ao desfecho, utilizando critérios clínicos e as interações atualmente já mais bem estabelecidas entre as variáveis. A análise estatística do modelo foi feita com regressão linear múltipla de Poisson, com ajuste robusto da variância. As variáveis com valor de p<0,20 foram incluídas no nível seguinte, como fator de ajuste. A medida de efeito foi o Risco Relativo (RR), calculadas com intervalos de confiança (IC) de 95 por cento e, ao final da análise, as variáveis que apresentaram valores de p<0,05 dentro de cada nível foram consideradas fatores de risco para a prematuridade. Resultados - As variáveis estatisticamente significativas foram: no nível intermediário I (bloco 2.1), a idade materna entre 12 e 19 anos (RR: 1,23; IC: 1,05 - 1,46); no nível intermediário II (bloco 2.2), a decisão pelo parto cesáreo (RR: 1,47; IC: 1,20 - 1,80); no nível proximal (bloco 3), a idade materna maior que 35 anos (RR: 1,28; IC: 1,06 - 1,54), a não decisão da via de parto (RR: 1,34; IC: 1,11 - 1,61), realizar menos de 5 consultas de PN (RR: 2,57; IC: 2,20 - 3,01), realizar 12 ou mais consultas de PN (RR: 0,74; IC: 0,55 - 0,99), cor da pele preta ou parda (RR: 0,83; IC: 0,73 - 0,95), nenhuma gestação anterior (RR: 1,43; IC: 1,17 - 1,74), baixo peso ao nascer anterior (RR: 1,35; IC: 1,01 - 1,82), prematuro anterior (RR: 2,01; IC: 1,51 - 2,68), condições clínicas prévias maternas (RR: 1,31; IC: 1,05 - 1,63), condições obstétricas na gestação atual (RR: 1,58; IC: 1,18 - 2,12), condições clínicas diagnosticadas na admissão para o parto (RR: 1,81; IC: 1,50 - 2,18) e internação durante a gestação atual (RR: 2,07; IC: 1,78 - 2,41) Conclusões - Identificados como fator de proteção contra a prematuridade: a mãe apresentar cor da pele preta ou parda e realizar mais de 12 consultas de pré-natal. Condições de maior risco para prematuridade: mãe primípara, extremos de idade materna, decisão da via de parto cesáreo ou a não participação materna na mesma, realizar menos de cinco consultas no PN, antecedentes de baixo peso ao nascer e prematuridade, ter alguma complicação clínica diagnosticada na gestação atual ou na admissão para o parto, alguma complicação obstétrica diagnosticada, hipertensão arterial ou alguma internação durante a gestação. O nascimento prematuro ainda é a maior causa de mortes em RNs no mundo, com aumento progressivo da incidência nos últimos anos, por isso a pesquisa básica visando inovar sobre o tema é tão importante / Introduction: Prematurity is defined as a birth occurring before 37 complete weeks of gestation and its causal pathways are not entirely understood. Objectives: To analyse the prevalence of prematurity and risk factors related to it in a secondary analysis of data from the Brazils Southeast region in Birth in Brazil survey. Method: Binary Poisson regression was used to select the variables and those with p<0,20 were included in the hierarchical model. The blocks of variables in the model were then structured according to variables temporal relation to the outcome, clinical plausibility and current known interactions with each other. Statistical analysis was conducted with general linear model and Poisson regression, with robust adjustment of variance. Variables with p<0,20 were included in the next level as an adjustment factor. The outcome measure was Relative Risk (RR), calculated with confidence intervals of 95 per cent . In the final model, variables with p<0,05 were considered independent risk factors for preterm birth. Results: Variables with statistical significance were: in the intermediary level I (block 2.1): age between 12 and 19 years-old (RR: 1,23; IC: 1,05 - 1,46); in the intermediary level II (block 2.2): decision for caesarean delivery (RR: 1,47; IC: 1,20 - 1,80), in the proximal level (block 3): maternal age > 35 years-old (RR: 1,28; IC: 1,06 - 1,54); not having a decision for the mode of birth (RR: 1,34; IC: 1,11 - 1,61), >5 antenatal appointments (RR: 2,57; IC: 2,20 - 3,01), >12 prenatal appointments (RR: 0,74; IC: 0,55 - 0,99), maternal black/ brown skin colour (RR: 0,83; IC: 0,73 - 0,95), no previous pregnancies (RR: 1,43; IC: 1,17 - 1,74), previous low birthweight new-born (RR: 1,35; IC: 1,01 - 1,82), previous preterm birth (RR: 2,01; IC: 1,51 - 2,68), previous clinical complications (RR: 1,31; IC: 1,05 - 1,63), obstetric complications in the current pregnancy ((RR: 1,58; IC: 1,18 - 2,12), clinical complications diagnosed at the hospital admission (RR: 1,81; IC: 1,50 - 2,18) and admission at the hospital in the current pregnancy (RR: 2,07; IC: 1,78 - 2,41). Conclusions: Variables identified as protection factors against prematurity were: maternal black or brown skin colour and >12 antenatal appointments. Variables identified as risk factors were: primiparity, maternal age 35, decision for caesarean as the mode of birth, non-participation of the mother in the decision of the mode of birth, <5 prenatal appointments, previous low birth weight new-born, previous preterm birth, having one or more clinical complication in the current pregnancy or at the admission for delivery, having one or more obstetric complications diagnosed during pregnancy, hypertension or a hospital admission at the hospital during the current pregnancy. Preterm birth is still the main cause of child death in the world, with increasing rate in the past years, which justificates the importance of basic and innovative research in this area of knowledge