Ce mémoire de thèse décrit la création expérimentale et la caractérisation d'une source de paires d'atomes corrélés. Cette source ajustable repose sur l'utilisation du mélange à quatre ondes dans un réseau optique. Les paires ainsi créées sont similaires aux paires de photons produites par conversion paramétrique et ouvrent la porte à la réalisation d'expériences élaborées d'optique atomique quantique. En plaçant un condensat de Bose-Einstein dans un réseau en mouvement, les conditions d'accord de phase sont vérifiées et des atomes jumeaux sont alors produits spontanément. Grâce à un détecteur d'atomes uniques résolu à trois dimensions nous avons pu caractériser la source de paires obtenue. Nous avons ainsi étudié en profondeur les conditions d'accord de phase, prouvant que les atomes sont diffusés de manière préférentielle dans deux fines classes de vitesses qui conservent l'impulsion et l'énergie. En modifiant la vitesse et la durée du réseau par rapport aux atomes, il est possible de choisir les modes de sorties et leurs populations ce qui rend ce processus ajustable. De plus, nous avons pu mettre en évidence l'importance des interactions et en particulier des effets de champ moyen qui viennent modifier la conservation de l'énergie. La détection d'atome unique permet également d'étudier les propriétés statistiques des atomes jumeaux, nous avons ainsi pu mettre en évidence de fortes corrélations entres les atomes issus d'une même paire. Nous avons également observé une réduction sous le bruit de grenaille du bruit sur la différence du nombre d'atomes dans les modes corrélés. Cette réduction est une indication forte du caractère non classique des paires produites / This thesis describes the experimental realization and characterization of a source of pairs of correlated atoms. This tunable source is based upon four waves mixing in an optical lattice. The created atomic pairs are similar to photon pairs made by parametric down conversion and open the way toward more elaborate quantum atom optic experiments. By placing a Bose-Einstein condensate in a moving optical lattice the phase matching conditions are fulfilled and twins atoms are spontaneously produced. Thanks to a single atom detector with three-dimensional resolution, we were able to characterize our source of pairs. By studying the phase matching conditions, we proved that the atoms are preferentially produced in two narrow velocity classes conserving both momentum and energy. By modifying the duration and the velocity of the lattice with respect to the atoms, one can tune the output modes and their populations providing a fully tunable process. Moreover, we have demonstrated the important effect of interactions -especially of mean field effects- that modifies the energy conservation. The single atom detection provided also a convenient way to look at statistical properties of the twins atoms: we have demonstrated strong correlation between atoms from the same pair and also we have observed a reduction below the shot noise of the noise on the number of atoms in correlated modes. Such a reduction is a strong indication of the non-classical nature of the produced atomic pairs.

Objetivo: Comparar o desempenho de diferentes curvas de referência de crescimento fetal em gestações gemelares com insuficiência placentária grave. Método: Estudo retrospectivo envolvendo gestações gemelares (n=47), com fluxo diastólico zero ou reverso, no estudo dopplervelocimétrico da artéria umbilical de um dos fetos, e ambos os fetos vivos no momento do diagnóstico. Não foram incluídas gestações com anomalia fetal \"major\", síndrome de transfusão feto-fetal, ou de ordem maior. Em ambos os fetos (acometido, FA; e cogemelar, CG), as estimativas de peso fetal foram convertidas em escore zeta de acordo com os critérios de Hadlock, Liao e Araújo. As medidas de circunferência abdominal foram convertidas de acordo com as curvas de Hadlock, Liao, Araújo, Ong e STORK. A análise estatística foi realizada segundo modelos de equações de estimação generalizada. Resultados: A idade materna média foi 27,8 ± 7,4 anos, 24 (51%) pacientes eram primigestas, 12 (25,5%) apresentavam antecedentes clínicos significativos e 61,7% (n=29) eram monocoriônicas. A idade gestacional média no momento do diagnóstico da diástole zero ou reversa foi de 27,4 ± 4,7 semanas. A idade gestacional média do parto foi de 32,9 ± 2,9 semanas e o peso médio ao nascimento dos fetos acometidos foi de 1075 ± 469 g, e dos cogemelares, 1749 ± 544 g. No modelo investigado, foram preditores significativos do escore-zeta: sexo fetal (p < 0,001) e a interação sub-grupo (feto acometido/cogemelar) e critério (p < 0,001). As estimativas do escore zeta médio (erro padrão) para o peso fetal estimado segundo cada critério examinado foram Hadlock FA: -2.98 (0,18), CG: -1,16 (0,15), Liao FA: -2,89 (0,24), CG: -0,58 (0,19), Araújo FA: -3,05 (0,29), CG: - 0,75 (0,18). Para circunferência abdominal, Hadlock FA: -3,14 (0,26), CG: - 1,13 (0,19), Liao FA: -2,63 (0,27), CG: -0,42 (0,19), Araújo FA: -2,44 (0,22), CG: -0,71 (0,14), Ong FA: -3,36 (0,34), CG: -1,48 (0,23) e STORK FA: -2,36 (0,14), CG: -1,18 (0,10). Conclusão: Em gestações gemelares, com diástole zero ou reversa em um dos fetos, as curvas que melhor diferenciaram os fetos acometidos de seus cogemelares foram as curvas nacionais, publicadas por Liao et al. e Araújo et al / Objectives: To compare the performance of different fetal growth reference curves in twin pregnancies with severe placental insufficiency. Methods: Retrospective analysis of 47 twin pregnancies with absent or reverse end diastolic flow in the umbilical artery in one fetus, and both twins alive at diagnosis. Pregnancies with major fetal abnormality, twin-twin transfusion and higher order were not included. At each ultrasound evaluation, estimated fetal weight zeta-scores were calculated for both fetuses (abnormal Doppler, AD; co-twin, CT) according to the following criteria: Hadlock, Liao and Araújo. Abdominal circumference zeta-scores were calculated according to Hadlock, Liao, Araújo, Ong and STORK. Statistical analysis was performed with generalized estimating equation regression. Results: Mean maternal age was 27.8 ± 7.4 years, 24 (51%) women were primigravida, 12 (25.5%) had a previous clinical history and 29 (61.7%) were monochorionic. Gestational age at abnormal Doppler diagnosis was 27.4 ± 4.7 weeks. Gestational age at delivery was 32.9 ± 2.9 weeks and mean birthweight was 1075 ± 469 g for AD twin, and 1749 ± 544 g in CT group. Zeta-score values were significantly related to fetal sex (p < 0.001) and subgroup (abnormal Doppler/co-twin) versus criteria interaction (p < 0.001). Estimated fetal weight mean zeta-score (standard error) according to each criteria were: Hadlock AD: -2.98 (0.18), CT: -1.16 (0.15), Liao AD: -2.89 (0.24), CT: -0.58 (0.19), Araújo AD: -3.05 (0.29), CT: -0.75 (0.18). Values for abdominal circumference were: Hadlock AD: -3.14 (0.26), CT: -1.13 (0.19), Liao AD: -2.63 (0.27), CT: -0.42 (0.19), Araújo AD: -2.44 (0.22), CT: -0.71 (0.14), Ong AD: -3.36 (0.34), CT: -1.48 (0.23) and STORK AD: -2.36 (0.14), CT: -1.18 (0.10). Conclusion: In twin pregnancies with absent or reversed end diastolic flow in the umbilical artery of one fetus, affected fetuses and their co-twins are best differentiated by Liao et al. and Araújo et al. reference ranges

Este estudo tem como objetivo investigar o desenvolvimento psíquico de gêmeos abrigados no decorrer do primeiro ano de vida. Foram separados ao nascer, tendo como histórico inicial de vida, para um, a ausência do contato materno logo após o nascimento, tendo permanecido hospitalizado até os oito meses de vida e seguido para o abrigamento; e para o outro, a descontinuidade do contato materno e familiar aos dez meses de vida, seguido pelo abrigamento. No desenvolvimento deste estudo, os gêmeos estavam com cinco anos de idade, ainda abrigados, na mesma instituição e próximos da adoção. Trata-se de uma pesquisa qualitativa, do tipo estudo de caso, embasada pelo método psicanalítico, à luz dos pensamentos de D. W. Winnicott. Por meio do diagnóstico psicológico do tipo compreensivo e interventivo, com o emprego das técnicas projetivas hora de jogo e procedimento de desenhos-estórias, buscou-se a compreensão da vida intrapsíquica dos gêmeos. Instrumentos auxiliares como o estudo documental do histórico familiar, como também entrevistas realizadas no abrigo, colaboraram para o alcance de uma visão totalizadora dos casos. A partir da análise dos dados, observaram-se marcantes divergências do funcionamento psíquico dos gêmeos: aquele institucionalizado desde o nascimento apresenta maior interação ambiental e facilita o emprego de intervenções, diante de angústias depressivas emergentes, mostra comportamentos regressivos; o outro separado do lar aos dez meses, diante de angústias despertadas, utiliza-se de mecanismos defensivos de negação e evitação, cujas intervenções, por muitas vezes, são evitadas de modo a afastar a quebra do sistema defensivo operante. Quanto ao sistema defensivo, o primeiro apresenta comportamentos regressivos e fragilidade frente ao ambiente, além de dissociações entre movimentos regressivos e evoluídos; o segundo, mostra comportamentos agressivos e oposicionistas frente a limites e regras, como recursos para domínio e controle ambiental e agressões e violência nas relações, desencadeando dificuldades de interação com o ambiente, permanecendo isolado. Além dos aspectos clínicos observados, é possível conjeturar sobre a influência de aspectos psicopatológicos institucionais, especialmente quanto à clivagem dos gêmeos. Esta pesquisa também permitiu vislumbrar que prejuízos ao desenvolvimento também se desencadeiam de lares vitimizadores e não só de contextos institucionais; e que o processo de adoção deve ser mais bem estruturado, a fim de minimizar estados ansiógenos decorrentes, que observamos nos gêmeos, bem como a devolução da criança ao abrigo após sua adoção, como ocorreu com o segundo gêmeo. Dessa forma, concluiu-se que as crianças, mesmo em situação de abrigamento, apresentam aspectos saudáveis propulsores para a saúde e podem aproveitar experiências boas do ambiente, além de apresentarem capacidade para amar e estabelecer relações afetivas; por isso o contexto institucional merece assistência, principalmente psicológica, a fim de favorecer o ambiente e o desenvolvimento das crianças abrigadas. / This essay is aimed at investigating the psychic development of twins institutionalized since before one year of age. Parted at birth, one child is sent to a hospital where it stays for eight months before is sent to an institution. The child undergoes the absence of the early motherly contact. As for the other child, there is the early motherly contact and from the family, however, discontinued. At ten months of age, the child is then sent to the institution. The study is set up when the twins are five years old, and are still inmates at the same institution, and are on the verge of being adopted. This research is qualitative - a case study – grounded on the psychoanalytic method - according to D.W. Winnicott’s lights. By using comprehensive and intervening psychological diagnosis, as well as projective techniques such as Hour Game and the Drawing-stories procedure, it aims at understanding the intra-psychic life of the twins. Additional tools such as the documented study of the family history, along with the interviews carried out at the shelter, contribute to a thorough view of the cases. As data analysis is performed, expressive differences in the functioning psychic of the twins come to light: on the one hand, the child sent to the institution only just after birth shows more interaction with the environment, when confronted with emerging depressive anguish shows regressive behaviour. Also, the child makes it easy for the implementation of interventions. On the other hand, the child parted from its home at ten months of age reacts otherwise. This, when confronted by desperate anguish, utilises defence mechanisms such as negation and avoidance, whose interventions are, in most cases, avoided in order to maintain the ongoing defensive system. When it comes down to the defence system, of the two twins, the first shows regressive behaviour and fragility –as it faces the environment and dissociation in regressive and evolved movements. The second twin shows aggressive behaviour and opposition to limits and regulations as means of controlling the environment followed by aggression and violence in the relationships leading into difficulty in interacting and isolation from the environment. In addition to the clinical aspects, the influence of the psychopathological institutional aspects might also be pondered, such as the split-off the twins. The research, too, permits visualising what damages to the development come from oppressive homes and not only from institutional contexts, and that the adopting process should be thought over, and restructured in order to soothe the state of anxiety, as is observed in the twins during adoption, or the sending back to shelter of the second child, after its adoption. Thus, we conclude that even children under shelter can show healthy aspects, in that the children will benefit from the good experiences of the environment, and be able to love and hold affective relations. For this reason, the institutional context should be given assistance, principally psychological assistance, and then offers the children under shelter an appropriate environment which favours their development.

The present dissertation, which can be framed in the fields of behavioural and psychiatric genetics, was aimed to study how early environmental factors such as parental negativity and childhood adversity, directly or in interaction with genetic factors account for psychopathological variation (subclinical and clinical psychiatric symptoms) in general populatiol including childhood behavioural problems, adult psychotic, depressive and anxious symptoms and their neuroimaging correlates. Furthermore, from the different studies included in this dissertation, additional research questions were also explored. The studies included in the thesis were based in singletons and twins samples. We found evidence indicating that child behaviour problems, anxious and depressive symptoms and psychotic experiences (PEs) were present in our samples drawn from the general population which is in agreement with a dimensional approach to psychopathology. Furthermore, using neuroimaging techniques, we were able to find structural brain correlates of vulnerability for anxiety and depression in a MZ twin sample from the general population. Also, psychotic experiences were associated with brain activation to facial emotion in this MZ twin sample. In regard to the specific environmental factors studied (parental negativity and childhood maltreatment), experiences occurring early in life showed to be associated to adolescent behaviour problems and adult psychotic experiences highlighting the enduring effects of exposure to childhood adversity. These results highlight the relevance of early adversity in the understanding of psychopathological features. Finally, our findings provide evidence of different ways through genes, environment and their interplay can modulate the final expression of the phenotype. Thus, while there is no doubt regarding that genes and environmental factors can have a direct influence in the phenotype, there is a gene-environment interdependence that must be considered when studying the etiology of complex characters. / Esta tesis doctoral, que se puede enmarcar en las áreas de la genética de la conducta y psiquiatría genética, se centró en el estudio del papel que desarrollan los factores ambientales, tales como la negatividad parental y la adversidad infantil, de manera directa o en interacción con factores genéticos, en la expresión de características psicopatológicas subclínicas en población general. La variación psicopatológica subclínica estudiada incluyó problemas de conducta en la infancia y el desarrollo de experiencias psicóticas y síntomas ansiosos y depresivos en la etapa adulta. Además se exploraron posibles correlatos de neuroimagen de estos fenotipos subclínicos. En cuanto a los resultados, se hallaron evidencias que indicaban que los problemas de conducta infantil, los síntomas ansiosos y depresivos y las experiencias psicóticas se distribuyen de forma continua en la población general. Estos hallazgos están de acuerdo con el enfoque dimensional a la psicopatología. Por otra parte, mediante el uso de técnicas de neuroimagen, se encontraron correlatos cerebrales estructurales para la vulnerabilidad para el desarrollo de síntomas ansiosos y depresivos en una muestra de gemelos monozigóticos (MZ) de la población general. Además, las experiencias psicóticas se asociaron con la activación del cerebro en respuesta a la emoción facial en esta muestra de gemelos MZ. En referencia a los factores ambientales específicos estudiados (negatividad parental y maltrato en la infancia), las experiencias que acontecen durante los primeros años de vida se asociaron con el desarrollo de problemas de conducta adolescentes y el riesgo a desarrollar experiencias psicóticas en la etapa adulta. Estos hallazgos ponen de relevancia los efectos a largo de la exposición a la adversidad durante la infancia. Por último, nuestros resultados ponen de manifiesto la compleja interacción y diferentes tipos de efectos mediantes los cuales los factores genéticos y ambientales ejercen sus influencias en la variabilidad fenotípica. En este sentido, variación en algunas variantes genéticas como el gen del BDNF o el gen de la COMT proporcionaban mayor vulnerabilidad neurobiológica a algunos individuos que habían estado expuestos a maltrato infantil y/o consumo de cannabis, factores de riesgo ampliamente reconocidos en psicosis.

L’amusie congénitale est un trouble neuro-développemental se définissant par des difficultés à percevoir la musique, et ce malgré une ouïe et une intelligence normales. Un déficit de discrimination fine des hauteurs serait à l’origine de ce trouble, qui se traduit notamment par une incapacité à détecter les fausses notes. afin de mieux comprendre les facteurs génétiques contribuant à la manifestation de l’amusie congénitale, la présente étude avait pour objectif: (a) de déterminer si la performance sur diverses tâches musicales et auditives était plus similaire chez les jumeaux identiques (monozygotes ; MZ) que chez les jumeaux non-identiques (dizygotes ; DZ) et (b) d’explorer les variables relatives à l’environnement musical des jumeaux, afin de mieux comprendre les contributions de l’environnement et de la génétique dans les différences sous-tendant les habiletés musicales. De plus, le profil des sujets amusiques a été analysé afin de vérifier s’il correspondait à celui décrit dans la littérature, faisant état de difficultés tonales, mais non rythmiques. Huit paires de jumeaux MZ et six paires de jumeaux DZ, parmi lesquelles au moins un des co-jumeaux était potentiellement amusique, ont pris part à cette étude. Les tâches consistaient en un test en ligne de perception mélodique et rythmique, un test de détection des différences de hauteurs, ainsi qu’un test de chant. L’analyse de la performance et de l’environnement musical des jumeaux MZ et DZ ne révèle aucune distinction comportementale entre ces deux groupes en ce qui concerne les habiletés musicales. Cela suggère que celles-ci puissent être davantage influencées par l’environnement partagé que par les facteurs génétiques. Enfin, les jumeaux amusiques ont le profil habituel d’habiletés musicales. En effet, ils commettent des erreurs de perception et de production musicale au niveau mélodique, mais ont une perception rythmique préservée. D’autres études, notamment avec de plus grands échantillons de jumeaux, seront nécessaires afin d’élucider la possible étiologie génétique sous-tendant l’amusie congénitale. / Music is an important part of every known culture, and its universality raises the question of a possible biological basis. Musical disorders, such as congenital amusia, offer compelling insight into these roots. In order to examine the genetic basis of this phenotype, we used a classical twin study paradigm. Our study had two main goals: (a) investigate if identical (monozygotic; MZ) co-twins perform more similarly on auditory and musical tasks than non-identical (dizygotic; DZ) co-twins and (b) explore the twins’ musical environments in order to better understand the contribution of environmental versus genetic factors in the differences underlying musical abilities. In addition, we sought to replicate previous investigations that demonstrated impaired pitch processing but intact rhythm perception in amusic participants. To do so, we tested eight pairs of MZ and six pairs of DZ twins in which at least one of the co-twins was potentially amusic. Participants completed an online amusia test, a pitch detection task and a singing task. We observed no performance or musical environment differences between MZ and DZ twins, suggesting that musical abilities might be more influenced by the twins’ shared environment than by genetic factors. In addition, and as reported in previous studies, amusics made pitch processing errors in both perception and production, but rhythmic perception was preserved. Future studies, particularly those with access to larger twin samples, will be able to further elucidate the roles of environmental and genetic factors in the amusic phenotype.

[Truncated abstract] Background: Genetic epidemiology draws on the mechanisms of heredity and the reproductive characteristics of populations to formulate methods to investigate the role of genetic factors and their interaction with the environment in disease aetiology. Asthma and atopy are complex genetic disorders and are among the most common diseases to affect the developed world. Twin studies provide an elegant means of disentangling genetic and environmental contributions to the aetiology of conditions that have a significant impact on the health of the general population in ways that cannot be achieved by any other study design, by comparing disease frequency in monozygotic (MZ) or identical twins, who share 100% of their genes with that in dizygotic (DZ) or non-identical twins who share, on average, 50% of their genes. Twin-family studies allow the complete partitioning of phenotypic variation into components representing additive genetic, dominance, shared environment and non-shared environment. ... For twin family data, the best fitting model was the one which included additive genetic effects and either genetic dominance or shared sibling environment, and that shared family environment was not important. With respect to asthma in WA twin families, there are no reasons to conclude that the EEA is not valid. Conclusions: The WA Twin Register is the first population-based register of childhood multiples to be established in Australia, and the WATCH study is one of only a few population-based twin-family studies in the world. Families who participated in the WATCH study were no different from non-participants with respect to social class and there was no difference in the prevalence of DDA in WATCH study twins and either their singleton siblings or the general population of WA children. Results from the GEE models replicate those found in numerous studies from many different countries. The BUGS models developed have been shown to produce consistent results with both simulated and real data sets and offer alternative methods of analyzing twin and twin-family data. By including an extra term in the partitioning of the variance to account for the environment effect of being a MZ twin, a numerical value is calculated for the difference in MZ and DZ correlation with respect to the phenotype examined, which allows the validity of the EEA to be directly assessed.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.

A presente dissertação trata-se de um estudo de caso exploratório que discorre sobre fatores neuro-estruturais, hormonais, neuropsicológicos e suas possíveis associações, em um par de gêmeos monozigóticos adulto, do sexo masculino, discordantes para o transexualismo. Ambos os gêmeos foram submetidos a entrevistas semi-estruturadas por meio de equipe especializada pertencente ao Programa de Transtorno de Identidade de Gênero do Hospital de Clínicas de Porto Alegre (HCPA). Aplicou-se o intrumento Wechsler Adult Intelligence Scale (WAIS), com o objetivo de avaliar diversas funções cognitivas verbais e não-verbais que contribuem para a inteligência geral e realizou-se Ressonância Magnética do encéfalo, com a finalidade de medir o volume de uma série de estruturas cerebrais. Ainda, a mãe dos sujeitos (o pai alegou não ter disponibilidade em participar) forneceu informações sobre a gestação, parto, condições de nascimento, infância, meio ambiente, alterações clínicas presentes e passadas e eventos incomuns na história de vida dos gêmeos. Em cinco regiões cerebrais foram detectadas diferenças nos volumes de determinadas estruturas, e nas habilidades de linguagem e raciocínio viso-espacial houve divergência entre os gêmeos. Sugere-se que fatores epigenéticos possam estar envolvidos tanto na discordância fenotípica como nos achados deste estudo. / The present work is an exploratory study case that discusses about neuroanatomical, hormonal and neuropsychological factors and their possible associations in one monozygotic male twin pair discordant for transsexualism. Both twins answered semi-structural interviews applied by specialized team from Gender Identity Disorder Program of Hospital de Clínicas de Porto Alegre, Brazil; In addition, they were tested with the Wechsler Adult Intelligence Scale (WAIS) battery that evaluate verbal and non verbal cognitive functions that contribute to general intelligence; and underwent magnetic resonance imaging (MRI) to measure the volumes of specific cerebral structures. The mother of the twins gave information (father did not want to participate) about the pregnancy, delivery, conditions of birth, childhood, raising environment, unusual medical or life history events. Both neuroimaging and cognitive function testing detected different outcome between the twins. In six different cerebral regions differences have been found in the volume of specific structures, as well as in language, visuo-spatial abilities. It is suggested that epigenetic factors could be related to the phenotypic discordance and the findings of this study

L’alliage de magnésium AZ31 présente une très faible densité. Cette caractéristique en fait un matériau apprécié pour la conception de structures légères. La limitation principale de son utilisation industrielle est sa mauvaise formabilité et ce en raison de la texture cristallographique des tôles qui s’avère être peu adaptée aux procédés de mise en forme tel que l’emboutissage. Cette texture résultant du laminage initial, l’ambition de ce travail est de la modifier en utilisant la technique de laminage asymétrique et de mesurer l’impact de cette voie sur la formabilité de l’alliage. Il a été montré que l’asymétrie, produite par un différentiel de vitesses de rotation des cylindres du laminoir, induit systématiquement de fortes instabilités plastiques sous forme de bandes de cisaillement. Des techniques de cartographie sur microscope électronique en transmission (ACOM) et à balayage (EBSD) ainsi que des analyses de texture par DRX ont été utilisées pour analyser les mécanismes physiques concourant à l’émergence de cette instabilité. Il résulte de cette analyse que l’asymétrie du laminage provoque une forte activité du système de glissement basal que ne compense ni les autres systèmes ni le maclage. Ceci conduit à une localisation marquée de la déformation plastique et à la ruine du matériau. / The low density of the magnesium alloy AZ31 makes it valuable for low weight components. The main limitation for industrial applications is the poor formability of sheets during deep drawing type processing. This is linked to the fibre crystallographic texture resulting from rolling. The objective of the present work is to modify the sheet texture through asymmetrical rolling. It has appeared that the asymmetry promoted by monitoring the roll speeds separately induces plastic instabilities through shear banding. The physical mechanisms involved in the instability were analysed with the help of orientation imaging techniques on transmission electron (ACOM/TEM) and scanning electron (EBSD/SEM) microscopes as well as with X-ray measurements. It is concluded that the shear resulting from the asymmetry in roll speeds promotes a dramatic increase of basal slip that neither twinning nor the activities of other slip systems are able to compensate. Such activity induces strain localisation and premature failure of the material.

Made available in DSpace on 2014-12-17T14:44:18Z (GMT). No. of bitstreams: 1 MicheleVO_DISSERT.pdf: 9305862 bytes, checksum: 2d47288223836ac6ba52c9de6822c77f (MD5) Previous issue date: 2013-12-11 / genetic and environmental factors contribute to the development of cardiovascular risk and that influence can be differentiated by factors characteristic of each population, age and sex. Aim: To investigate the heritability of anthropometric and biochemical markers as predictors of cardiovascular risk in men and women of different age groups, using the method of twins. Methods: A sample of 88 subjects and of these 52 children and adolescents (08-17 years old) 32 monozygotic (20 female and 12 male) and 20 dizygotic (12 female and 08 male) and 36 adults (18-28 years age) 24 monozygotic (08 female and 16 male) and 12 dizygotic (06 female and 06 male), living in the metropolitan region of Natal / RN, Brazil. Anthropometric measures were taken as the height, body mass, waist circumference (WC), sum of skinfolds (&#931;DC), fat percentage CUN-BAE, BMI and conicity. Biochemical markers analyzed were: fasting glucose (GLU), total cholesterol (COL), HDL-C, LDL-C and triglycerides (TG). After processing the data the index of heritability (h2) = (S ? MZ) / S ? DZ (DZ S ?) X100 was applied disaggregated by sex and age. Results: The variables showed differential heritability of behavior for men and women, depending on age. The variables with the highest heritability values were &#931;DC, GLU, HDL, TG, in men and BMI, WC, &#931;DC, GLU, HDL-C and TG in women. And more influenced by the environment variables were: body mass, BMI, Chol, LDL-C in men; body mass and LDL-C in women. Conclusion: Differences index of heritability by gender for cardiovascular risk predictors may assist in planning specific intervention strategies according to gender and stage of life of that individual. It is from the level of environmental influence that can run interventions for changes of components related to cardiovascular risk / Os fatores gen?ticos e ambientais contribuem para o desenvolvimento do risco cardiovascular e essa influ?ncia pode ser diferenciada por fatores caracter?sticos de cada popula??o, idade e sexo. Objetivo: investigar a herdabilidade de vari?veis antropom?tricas e marcadores bioqu?micos como preditores do risco cardiovascular em homens e mulheres de diferentes faixas et?rias, utilizando o m?todo de g?meos. M?todos: Amostra composta por 130 g?meos, sendo do sexo feminino 42 monozigotos e 32 dizigotos e do sexo masculino 28 monozigotos e 28 dizigotos, residentes na regi?o metropolitana de Natal/RN, Brasil. Como medidas antropom?tricas foram aferidas a estatura, massa corporal, circunfer?ncia da cintura (CC), somat?rio de dobras cut?neas (&#8721;DC), percentual de gordura CUN-BAE, IMC e ?ndice de conicidade. Os marcadores bioqu?micos analisados foram: glicemia de jejum (GLI), colesterol total (COL), HDL-C, LDL-C e triglicer?deos (TG). Ap?s o tratamento dos dados foi aplicado o ?ndice de herdabilidade (h2) = ((S? DZ S? MZ) / S? DZ) x 100; separado por sexo e idade. Resultados: As vari?veis apresentaram comportamento de hereditariedade diferenciado para homens e mulheres, dependendo da idade. As vari?veis com maior herdabilidade foram: &#8721;DC, GLI, HDL, TG, nos homens; e IMC, CC, &#8721;DC, GLI, HDL-C e TG nas mulheres. E as vari?veis mais influenciadas pelo ambiente foram: Massa, IMC, COL, LDL-C, nos homens; massa e LDL-C nas mulheres. Conclus?o: As diferen?as por sexo do ?ndice de herdabilidade para os preditores do risco cardiovascular podem auxiliar no planejamento de estrat?gias de interven??o espec?ficas de acordo com o sexo e est?gio da vida desse indiv?duo. ? a partir do n?vel de influ?ncia ambiental que poder? correr as interven??es para modifica??es dos componentes relacionados ao risco cardiovascular