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Associação de etnia auto referida e ancestralidade genética com fatores de risco de doença cardiovascular em uma amostra populacional brasileira: ELSA - Brasil / Association of self-reported ethnicity and genetic ancestry with cardiovascular risk factors in a Brazilian population sample: ELSA - BrazilSantos, Hadassa Campos 23 April 2015 (has links)
Doenças cardiovasculares (DCVs) são a principal causa de morbidade e mortalidade no mundo e a etnia do indivíduo tem uma importante influência no diagnóstico e tratamento dessas doenças. No entanto, as bases das disparidades étnicas ainda não estão completamente esclarecidas. O estudo de uma população com alta miscigenação genética, fornece potenciais maneiras de compreender a influência genética na determinação de fenótipos de doenças complexas, como as cardiovasculares, em raízes ancestrais comuns. O presente estudo teve como objetivo principal associar etnia auto referida e ancestralidade genética em indivíduos de uma coorte brasileira com fatores de risco para doenças cardiovasculares. Identificamos associação entre etnia auto referida e hipertensão arterial, acidente vascular cerebral (AVC) e hipercolesterolemia. Analisando a hipercolesterolemia com mais detalhes, encontramos associação de etnia com níveis séricos de triglicerídeos (TG), lipoproteína de alta densidade (HDL-c) e índice TG/HDL-c. Essas associações foram fortemente dependentes de confundidores socioeconômicos, mas variações existem na força e direção de cada padrão. No entanto, observamos que o efeito de etnia persistiu mesmo após todas as correções. Em seguida derivamos um painel de marcadores para inferir ancestralidade genética continental, para os componentes ancestrais africano, europeu e ameríndio, e determinamos as proporções de ancestralidade na nossa população de estudo. Na sequência, conduzimos análises de associação entre ancestralidade genética e níveis séricos de lipídios, a fim de estudarmos uma variável menos influenciada por fatores socioeconômicos. Nessas análises encontramos associação entre a ancestralidade ameríndia e níveis séricos de HDL-c. Entender porque essa heterogeneidade existe pode prover importantes pistas sobre as razões para uma importante parte das disparidades étnicas em doenças cardiovasculares / Cardiovascular diseases (CVDs) are the main cause of morbidity and mortality in the world and ethnicity plays an important influence on diagnosis and treatment of these diseases. However, the basis of these ethnic disparities are not fully understood. Studying a population with a high genetic admixture allows potential ways to understand the genetic influence on determination of complex disease phenotypes, such as cardiovascular, in common ancestral roots. The present study had as main aim associating self-reported ethnicity and genetic ancestry in individuals from a Brazilian cohort which have risk factors for cardiovascular diseases. We identified association between self-reported ethnicity and arterial hypertension, stroke, and hypercholesterolemia. Analyzing hypercholesterolemia more deeply, we found association of ethnicity with serum levels of triglycerides (TG), high density lipoprotein cholesterol (HDL-c), and TG/HDL-c index. These associations were strongly dependent on socioeconomic confounders, but there are variations in the strength and direction of each pattern. However, we observed that the ethnicity effect persisted even after all adjustments. Following, we derived a panel of markers to infer continental genetic ancestry for African, European and Amerindian ancestral components, and we have determined the ancestral proportions of ancestry in our study population. After that, we conducted association analysis between genetic ancestry and lipids serum levels, in order to study a variable which is less influenced by socioeconomic factors. In these analyzes we found association between Amerindian ancestry and serum levels of HDL-c. Understanding why there is this heterogeneity can provide important clues about the reason for an important part of ethnic disparities in cardiovascular diseases
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Modèles multi-états de type Markovien et application à l'asthmeSaint Pierre, Philippe 29 April 2005 (has links) (PDF)
Dans de nombreux domaines, décrire l'évolution des phénomènes dans le temps est d'un intérêt capital, en particulier pour aborder les problématiques de la prédiction et de la recherche de facteurs causaux. En épidémiologie, on dispose de données de cohorte qui renseignent sur un groupe de patients suivis dans le temps. Les modèles multi-états de type Markovien proposent un outil intéressant qui permet d'étudier l'évolution d'un patient à travers les différents stades d'une maladie. Dans ce manuscrit, nous rappelons tout d'abord la méthodologie relative au modèle de Markov homogène. Ce modèle est le moins complexe, il suppose que les intensités de transition entre les états sont constantes dans le temps. Dans un second temps, nous étudions un modèle semi-Markovien homogène qui suppose que les intensités de transition dépendent du temps écoulé dans un état de santé. La théorie des processus de comptage est ensuite présentée afin d'introduire des méthodes d'estimations non-paramétriques dans le cadre d'un modèle de Markov non-homogène. Dans ce modèle, les intensités de transition dépendent du temps depuis l'inclusion dans l'étude. Les méthodes d'estimation supposent que le mécanisme de censure n'apporte aucune information sur l'évolution de la maladie. Cette hypothèse étant rarement vérifiée en pratique, nous proposons une méthode d'estimation permettant de prendre en compte une censure informative. Nous présentons également une méthode de programmation visant à faciliter la mise en œuvre des estimateurs basés sur les processus de comptage. Toutes ces méthodes sont appliquées afin d'étudier une base de données de patients asthmatiques. L'objectif est d'aider les cliniciens à mieux comprendre l'évolution de la maladie. Les résultats permettent de mettre en évidence l'impact négatif du surpoids sur l'évolution de l'asthme.
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Comparative and Targeted Advertising in Competitive MarketsPousset, Joanna 01 July 2008 (has links) (PDF)
Par sa même nature, publicité est une caractéristique(fonction) pénétrante de vie économique. C'est un outil de plus en plus important dans des interactions stratégiques dans des marchés concurrentiels. Si le rôle de publicité doit améliorer(augmenter) l'image du produit dans les yeux de consommateurs et changer leurs préférences, ou les informer de la sortie d'un nouveau produit au marché, ou plutôt fournir des informations sur des prix ou les qualités de produits existants, une question importante rend perplexe les économistes : Pourquoi les consommateurs répondent-ils à la publicité ? Comme les économistes ont lutté avec cette question, trois vues ont apparu. La première vue est cette publicité est persuasif, c'est-à-dire il change les goût des consommateurs et crée la différenciation de produit fausse et la fidélité à la marque. En conséquence, il n'a aucune valeur "réelle"("vraie") aux consommateurs, mais incite plutôt la différenciation de produit artificielle. La deuxième vue est cette publicité est informatif. Selon cette approche, beaucoup de marchés sont caractérisés par des informations grand public imparfaites, puisque les coûts de recherche peuvent dissuader un consommateur d'apprendre de l'existence de chaque produit, le prix et la qualité. La publicité est la réponse endogène que le marché offre comme une solution : quand une société fait de la publicité, les consommateurs reçoivent des informations. La troisième vue est cette publicité est complémentaire au produit fait de la publicité. Selon cette perspective, publicité ne change pas les préférences des consommateurs, comme dans la vue persuasive; en outre, il, mais n'a pas besoin de pouvoir fournir des informations. Au lieu de cela, il est assumé que les consommateurs possèdent un jeu stable de préférences dans lesquelles la publicité entre directement dans une mode qui est complémentaire avec la consommation du produit fait de la publicité
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Impact of a Teacher Training Program to Increase Informative Praise and Decrease Commands and Negative CommentsBinford, Lauren A 01 July 2015 (has links)
Research has found that many children who come from a low socioeconomic background often begin their schooling careers behind most students. Head Start programs around the nation are utilized to close the gap in achievement, by providing those students with the educational support necessary to prepare them for future schooling. However, when assessed with the Classroom Assessment Scoring System (CLASS), Head Start programs have been found to be weaker in the area of Instructional Support. As a result, teachers are falling short in the way they provide feedback, incorporate higher thinking skills, and foster language development. In order to strengthen the instructional support component, research has supported the utilization of professional development to foster ways of incorporating informative praise which then encourages the desired behaviors and provides a rich language model for children This study was designed to provide professional development to Head Start teachers in order to increase informative praise and decrease commands and negative comments utilized by teachers. An increase in the number of general praise statements and informative praise statements used directly after the training was administered was found. However, as time progressed, the amount of praise decreased back to the levels before the training was given. It was also found that negative comments and commands decreased continuously throughout all observations after the training.
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Eliciting Expert Knowledge for Bayesian Logistic Regression in Species Habitat ModellingKynn, Mary January 2005 (has links)
This research aims to develop a process for eliciting expert knowledge and incorporating this knowledge as prior distributions for a Bayesian logistic regression model. This work was motivated by the need for less data reliant methods of modelling species habitat distributions. A comprehensive review of the research from both cognitive psychology and the statistical literature provided specific recommendations for the creation of an elicitation scheme. These were incorporated into the design of a Bayesian logistic regression model and accompanying elicitation scheme. This model and scheme were then implemented as interactive, graphical software called ELICITOR created within the BlackBox Component Pascal environment. This software was specifically written to be compatible with existing Bayesian analysis software, winBUGS as an odd-on component. The model, elicitation scheme and software were evaluated through five case studies of various fauna and flora species. For two of these there were sufficient data for a comparison of expert and data-driven models. The case studies confirmed that expert knowledge can be quantified and formally incorporated into a logistic regression model. Finally, they provide a basis for a thorough discussion of the model, scheme and software extensions and lead to recommendations for elicitation research.
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WEBJORNALISMO COLABORATIVO - A PRESENÇA DOS USUÁRIOS NO CONTEÚDO INFORMATIVO DO PORTAL R7 / Webjonalism collaborative. The present of the users informat content of portal R7VIEGAS, ROBERTA POLIANI 23 September 2015 (has links)
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Previous issue date: 2015-09-23 / The objective of this study is check how works the internet users collaboration in the informative content of “Portal R7” since the web 2.0 was creation in 2004. The term web 2.0 appeared to qualify a second generation of services and communities, in a new interaction and participation environment that includes several languages. With the growth of digital technology accession, some barriers that limited the collaboration in informative contents were overcome and the communication environment becomes an experience exchange local and daily practices.In this scenario, the surfers now have a near relationship in the media processes present in the digital support, in which citizens can express, be more visible and relate from the moment that his produce, post and share any type of content, could be informative or entertainment.The literature review covers the authors such as Ciro Marcondes Filho, José Marques de Melo, Nelson Traquina, Alex Primo, Ana Brambilla, Marcelo Träsel, Raquel Recuero, Polyana Ferrari, Squirra, among others.The research method used is qualitative, through a descriptive exploratory research, like a case study.The instruments for research were the direct observation and the semi-structured interview (or semi-open). The main result is that the collaborate web journalism in the “Portal R7” it is primarily induced by social networks, in specially Facebook and Twitter inspired by call for action like a strategy to call the collaboration.The journalist practices are intrinsically dependent on user’s actions, and the journalist adds to the check practices a new stage related a relationship with the Portal user to assemble and retain the audience, enhancing the cooperation in all production stages / Este estudo procura verificar como ocorre a colaboração dos usuários no conteúdo informativo do Portal R7, a partir da nova configuração da internet, a web 2.0, criada em 2004. O termo web 2.0 surgiu para qualificar uma segunda geração de comunidades e serviços, em um ambiente de interação e participação que engloba diversas linguagens. Com o crescimento da adesão à tecnologia digital, algumas barreiras que limitavam a colaboração nos conteúdos informativos foram superadas e o ambiente comunicacional tornou-se um espaço de intercâmbio para experiências e práticas do cotidiano. Nesse cenário, os internautas passam a ter uma relação mais aproximativa nos processos midiáticos presentes no suporte digital, no qual o cidadão pode se expressar, ter maior visibilidade e se relacionar a partir do momento em que ele produz, publica e compartilha qualquer tipo de conteúdo, seja de caráter informativo ou de entretenimento. A revisão bibliográfica abrangeu autores como Ciro Marcondes Filho, José Marques de Melo, Nelson Traquina, Alex Primo, Ana Brambilla, Marcelo Träsel, Raquel Recuero, Polyana Ferrari, Squirra, entre outros. O método de investigação utilizado é o qualitativo, por meio de uma pesquisa exploratória descritiva, do tipo estudo de caso. Os instrumentos para a investigação foram a observação direta assistemática e a entrevista semiestruturada (ou semiaberta). O principal resultado obtido é que o webjornalismo colaborativo no Portal R7 é prioritariamente induzido pelas redes sociais, especialmente o Facebook e o Twitter, inspirado no “call for action”, como estratégia para chamar à colaboração. As práticas jornalísticas estão intrinsicamente dependentes da ação do usuário, sendo que o jornalista agrega às práticas de checagem uma nova etapa, a de relacionamento com o usuário do Portal, para agregar e fidelizar a audiência, valorizando a colaboração em todas as etapas de produção.
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Réception des publicités des marques allemandes en France et celle des marques françaises en Allemagne : essai sur l'évolution des stéréotypes dans le secteur automobile. / Reception of television advertisements of French automobile brands in Germany, and that of German automobile brands in France : essay on the evolution of stereotypes in the automotive industryMekui, Flora 28 November 2017 (has links)
Cette recherche en Sciences de l’Information et de la Communication a pour objectif d’analyser l’influence de la culture sur la production et la réception des publicités télévisées des marques automobiles françaises en Allemagne et celle des marques automobiles allemandes en France. Pour répondre à cette question de recherche, nous nous sommes inspirées de deux principales études sur les différences culturelles. La première nous vient d’Edward T. Hall qui a distingué les cultures en fonction que celles-ci appartiennent aux pays à contexte riche ou aux pays à contexte pauvre. La deuxième étude concerne l’approche culturelle de Hofstede sur laquelle nous prenons appui sur l’indice de collectivisme et d’individualisme ainsi que l’indice de masculinité et de féminité comme guide de lecture explicatif des différences culturelles entre la France et l’Allemagne. Notre travail a été décliné en deux grandes parties : la production et la réception. A travers l’analyse de contenu des publicités au niveau transnational et local (message, personnages, lieux d’actions, stéréotypes), nous avons mis en évidence deux résultats qui attestent de l’influence de la culture du pays d’origine de la marque et celle du pays de diffusion de la publicité sur la production. Du côté de la réception, trois résultats nous sont apparus au terme d’une enquête qualitative par questionnaire, auprès d’un échantillon d’étudiants français et allemands. Les premiers confirment l’impact de la culture sur la réception, les seconds soutiennent l’homogénéisation du discours publicitaire, c’est-à-dire la conception d’un consommateur unique. Enfin, les derniers ressortent l’influence de la culture du pays d’origine sur l’attitude envers l’annonce et la marque / This research aims to analyze the influence of culture on the production and reception of television advertisements of French automobile brands in Germany, and that of German automobile brands in France. To answer this research question, we were inspired by two main studies on cultural differences: Edward T. Hall’s high and low context cultural factors and two of Hofstede's cultural dimensions, masculinity-femininity and collectivism-individualism. To answer our research question, we divided our research into two main parts: production and reception. For the production, we made a discourse analysis of the advertisements at the transnational and local level (message, characters, places of action, stereotypes). We found two results that attest to the influence of the culture of the brand's country of origin and that of the country where the advertisement will be televised. For the reception analysis, we established a qualitative survey of a sample of French and German students, three results appeared. The first ones confirm the impact of culture on reception. The second supports the homogenization of advertising discourse, that is to say the conception of a single consumer. And the third reflects the influence of the culture of the country of origin on the attitude towards the advertisement and the brand
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Les sites d’informations générales sur Internet : stratégies, conceptions et pratiques des diasporas camerounaises en France, Belgique, États-Unis / Cameroonian's websites of general informations on the Internet : strategies, concepts and practices of Cameroonian's diaspora in France, Belgium, USAHeuchou Nana, Manuella M. 02 March 2017 (has links)
Le présent travail questionne la place des acteurs diasporiques dans les processus de production et des usages de l’information sur Internet via les sites web d’informations générales. Des supports électroniques qui émergeraient dans un contexte au sein duquel l’espace médiatique serait « reconfiguré » par les TIC. À cet effet, les sites web camerounais d’information générales nous ont servi d’étude de cas. En effet, notre travail s’est axé autour d’une question centrale : qu’est-ce qui explique la multiplication des sites d’informations camerounais alors qu’existe déjà la presse en ligne ? Une presse en ligne qui peine déjà à s’affirmer et/ou, à développer des modèles économiques viables et indépendants. Comment et selon quelles logiques ces acteurs réagissent-ils ? Répondre à ces deux questionnements nous a conduit à montrer ou démontrer que des jeux et des stratégies d’acteurs se construisent sur et autour de ces sites web, afin de « légitimer » (Charaudeau, 2005, p. 123) leurs choix et orientations/opinions dans les contenus médiatiques.La grille théorique mobilisée pour rendre compte de cela a tourné autour des paradigmes d’agenda building et/ou construction de l’actualité (Esquenazi, (2002), Charaudeau (1997, 2011), de constructivisme social (Bernard Delforce, p. 208, Sismondo, Mucchieilli) et d’identité éditoriale avec Roselyne Ringoot (2014). Nous avons opté pour une étude quali-quantitative. Ainsi, nous nous sommes inscrit dans une logique de recherche empirico-inductive. Les outils méthodologiques usités sont l’observation indirecte, la recherche documentaire, l’entretien semi-dirigé adressé aux promoteurs des sites web camerounais d’informations générales, questionnaire adressé aux internautes et l’analyse de contenu des titrailles des dits sites, du 15 janvier 2014 au 15 janvier 2015.Les résultats de cette étude montrent aussi bien que les diasporas camerounaises ont pris conscience de l’inéluctabilité des medias électroniques et du « webjournalisme », en attestent leurs pratiques communicationnelles et interactions autour de ces sites web. Cependant les promoteurs des sites web camerounais d’informations générales rencontrent des difficultés de financement et font rarement appel à des professionnels de la communication. Cet engouement pour Internet et le développement des TIC augurerait donc la mise en place d’un espace sociétal en formation (si l’on prend acte de la fragmentation de l’espace public, traité par Miège) au sein duquel les citoyens seraient « libres » de s’exprimer sur des questions sociétales. / The present work questions the place of diasporic actors in the production process and uses of information on the Internet through general information websites. Electronic media that would emerge in a context in which the media space would be "reconfigured" by ICT. To this end, the Cameroonian websites general information we have served as a case study. Indeed, our work is focused around a central question: what explains the proliferation of Cameroonian news sites while already exists online news? An online press that is already struggling to assert themselves and / or to develop viable and independent business models. How and by what logic these actors react? Answering these two questions led us to show or demonstrate that games and player strategies are built on and around these sites in order to "legitimize" (Charaudeau, 2005, p. 123) their choices and orientations / opinions in media contents.The theoretical grid mobilized to realize this has turned around the building agenda paradigms and / or the news’ construction (Esquenazi, (2002), Charaudeau (1997, 2011), social constructivism (Bernard Delforce, p. 208 , Sismondo, Mucchieilli) and editorial identity Roselyne Ringoot (2014).We opted for a quali-quantitative study. Thus, we registered in empirical-inductive search logic. Our methodological tools are indirect observation, documentary research, semi-structured intervieuws assigned to promoters of general information Cameroonian websites , surveys to users and content analysis of such websites titrailles of 15 January 2014 to January 15, 2015The results of this study show that as well as the Cameroonian diaspora have realized the inevitability of electronic media and the "webjournalisme" as attest their communication practices and interactions around these websites. However promoters of Cameroonian general informations websites have difficulty financing and rarely make use of communication professionals. This craze for Internet and ICT development thus would cause the establishment of a societal space training (if one notes the fragmentation of the public space, treated by Miege) in which citizens would be "free "to speak on societal issues.
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What to do with should : A Translation Study of the Modal Verb ShouldLarsson, Caroline January 2018 (has links)
Due to vague boundaries, a diversity of meanings and variations of modal strength, the translation of modals might be challenging. This paper investigates the translation of the modal should in a text with recommendations on horse feeding. The translations of deontic and epistemic meanings of should expressing an obligation or necessity are analysed using a framework based on grammatical definitions and linguistic theory. The translation strategies are based on Reiss’ text typology and strategies recommended for informative and operative texts (2000), and Newmark’s communicative translation (1988). Also, procedures of Vinay & Darbelnet (1995) are used to describe some of the translations. The study reveals that majority of the examples are used in the deontic sense and that should is mostly translated as bör and ska. The high frequency of ska might be related to its flexibility and multifunctional properties. Possible translation problems involve differences in the interpretation, where a modal might come across as too strong or too weak to target readers. Another translation problem may arise if the chosen modal can be perceived as less moralising than intended. There are also ambiguous cases that could be said to have both deontic and epistemic meanings. The analysis shows how deontic and epistemic meanings can be determined by context. However, even though a deeper understanding of the topic and an evaluation of the context might support the translation choices, some ambiguity can still be said to remain. The paper concludes that the translation of modals requires thoughtful consideration. A thorough interpretation of meaning related to context and profound knowledge on the topic are equally important in the translation of should.
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Análise de ancestralidade genômica e de polimorfismos associados à pigmentação da pele em amerídios e em descendentes de africanos, de europeus e de japoneses / Análise de ancestralidade genômica e de polimorfismos associados à pigmentação da pele em amerídios e em descendentes de africanos, de europeus e de japonesesBomfim, Thais Ferreira January 2012 (has links)
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Previous issue date: 2012 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / A população brasileira apresenta extensa variabilidade genética, resultado da
miscigenação entre ameríndios, europeus e africanos. Contudo, a proporção de
africanos, ameríndios e europeus difere significativamente a depender da região
geográfica. Atualmente são utilizados marcadores moleculares conhecidos como
Marcadores Informativos de Ancestralidade (AIM) para avaliar mistura genética nas
populações. A cor da pele é um dos fenótipos que mais variam entre e em
populações humanas de diferentes etnias e regiões geográficas, devido à grande
heterogeneidade gênica e ação da seleção natural. Muitos genes já foram descritos
como associados à pigmentação, e alguns deles apresentam frequências alélicas
distintas entre diferentes grupos étnicos, porém os mecanismos que respondem pela
variação da pigmentação normal da pele ainda não estão completamente
estabelecidos. O objetivo deste estudo foi estimar a ancestralidade genética,
analisar polimorfismos em genes que modulam a variação normal da pigmentação
da pele e verificar associação entre ancestralidade e pigmentação, utilizando nove
AIM (AT3-I/D, APO, SB19.3, PV92, FYnull, LPL, CKMM, GC-F, GC-S e CYP3A4),
seis polimorfismos em genes envolvidos na pigmentação da pele (SCL45A2,
SCL24A5, MC1R, OCA2, TYR, ASIP) em duas tribos indígenas do Norte do Brasil –
Tiriyó e Waiampi; em indivíduos caracterizados fenotipicamente como negros de
Salvador, numa amostra de miscigenados da Bahia e em descendentes de
japoneses e de europeus de Ribeirão Preto-SP. As frequências alélicas de todos os
marcadores encontradas nos afro e eurodescendentes foram similares às
encontradas nos ancestrais africanos e europeus e a estimativa de mistura mostrou
respectivamente maior contribuição africana - 71% e 66%; e europeia - 86% e 99%
com AIM e com os marcadores de pigmentação respectivamente. Os japoneses
mostraram frequências alélicas diferentes quando comparadas com os Nativos
Americanos, e a contribuição Ameríndia/Asiática observada foi 81% com AIM e 86%
com marcadores de pigmentação. Entre os índios Tiriyó e Waiampi foi observada
baixa contribuição de povos não indígenas nas estimativas de mistura com AIM (<
10%) e nenhuma mistura quando avaliados apenas os marcadores de pigmentação,
sugerindo que essas tribos conservam muitas características ancestrais. As
estimativas de mistura nos indivíduos miscigenados da Bahia mostrou predomínio
de contribuição europeia utilizando os marcadores de pigmentação da pele e maior
contribuição africana utilizando os AIM. A distribuição genotípica dos marcadores de
pigmentação da pele foi concordante com a classificação fenotípica realizada nos
miscigenados (Bahia) em brancos, mulatos e negros, corroborando dados da
literatura que mostram o envolvimento desses marcadores na variação normal da
pigmentação da pele em diferentes grupos étnicos. / The Brazilian population presents extensive genetic variability, resulting from
admixture among Amerindian, Europeans and Africans. However, the proportion of
Africans Amerindians and Europeans differ depending on the geographic region. To
evaluate the admixture and understand how it occurred, nowadays has been used
molecular markers known as Ancestry Informative Markers (AIMs). Skin color is one
of the phenotypes that vary most among human populations and different ethnic
groups and geographic regions, due to genetic heterogeneity and natural selection.
Many genes that are involved in the synthesis of melanin, and proteins involved in
cellular metabolism have been described as associated with pigmentation (eye color,
hair and skin), and some of them have different allele frequencies between different
ethnic groups, but the mechanisms that involved with the variation of the normal skin
pigmentation are not yet fully established. The aims of this study was to estimate the
genomic ancestry and analyze polymorphisms in genes that modulate normal
variation in pigmentation and verify the association between ancestry and skin
pigmentation, using nine AIMs (AT3-I/D, APO, SB19.3, PV92, FYnull, LPL, CKMM,
GC-F and GC-S) and six genes relate to pigmentation (SCL45A2, SCL24A5, MC1R,
OCA2, TYR, ASIP) in two Amerindian tribes from North of Brazil,Tiriyó and Waiampi;
urban samples of African descents from Salvador and European and Japanese
descents from Ribeirão Preto,SP. The results show that allele frequencies of all
markers found in blacks and whites were similar to those in European and African
populations and the estimation of admixture with AIMs presents greater African
contribution (71%) and European (86%), respectively; which was also observed with
the pigmentation markers (99% of European contribution in whites and 66% of
African contribution in blacks). The analysis in the Japanese showed allelic
frequencies different from the Amerindians and the Amerindian/ Asian contribution
observed were 81% with the AIMs and 86% with the pigmentation markers. Among
the Amerindians from Tiriyó and Waiampi was observed low contribution of non-
Amerindian populations in the admixture estimation with AIMs and even no admixture
when used markers of pigmentation, suggesting that, despite the intense process of
admixture occurred in Brazil, some tribes still present a homogeneous genetic profile
and, preserve the ancestors’ characteristics. The ancestry estimation with markers
of skin pigmentation in admixed individuals from Bahia showed high levels of
European and Amerindian ancestry contribution compared with the African
contribution, which had been the most significant in studies with AIMs, but when
analyzed the genotypic distribution of pigmentation markers’ between admixed
individuals phenotypically classified as white, mulatto and black, it can be observed
that the most frequent allele in Europeans and Africans were in homozygosity among
blacks and whites, confirming published data that show the involvement of these
markers in mechanisms that determinate the skin pigmentation in different ethnic
groups, but also suggest that these markers are not useful tools to define ancestry in
admixed populations.
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