Brazilian migration to Guyana as livelihood strategy: a case study approach

Este estudo de caso de metodologia mista foi conduzido com foco na migração brasileira para a Guiana como uma estratégia de sobrevivência. O estudo examinou, descreveu e analisou o processo da migração e da adaptação, e os impactos socioeconômicos e ambientais físicos e as preocupações associadas com as atividades de sobrevivência destes migrantes na Guiana. Foram utilizados questionários, entrevistas, documentários, arquivos e observações (direta e participante) com o objetivo de obter um entendimento profundo do fenômeno em questão. O estudo confirma que através de um forte sistema de rede, os brasileiros de classes socioeconômicas e culturais mais baixas são capazes de adotar a migração como estratégia de sobrevivência, à medida que eles migram através de uma rota por passos (step-wise) prédefinida para a Guiana. Este sistema de rede permite aos migrantes responderem prontamente às novas atividades de sobrevivência tanto interna como internacionalmente. Na Guiana, a mineração e a prostituição são identificadas como as principais atividades de sobrevivência que tem gerado conseqüências socioeconômicas tanto positivas quanto negativas e impactos ambientais negativos.

Genetic variability and efficiency of DNA microsatellite markers for paternity testing in horse breeds from the Brazilian Marajó archipelago

In this study, 15 microsatellite DNA loci used in comparative tests by the International Society for Animal Genetics were applied to the evaluation of genetic diversity and management, and the efficiency of paternity testing in Marajoara horses and Puruca ponies from the Marajó Archipelago. Based on the genotyping of 93 animals, mean allelic diversity was estimated as 9.14 and 7.00 for the Marajoara and Puruca breeds, respectively. While these values are similar to those recorded in most European breeds, mean levels of heterozygosity were much lower (Marajoara 49%, Puruca 40%), probably as a result of high levels of inbreeding in the Marajó populations. The mean informative polymorphic content of this 15-marker system was over 50% in both breeds, and was slightly higher in the Marajoara horses. The discriminative power and exclusion probabilities derived from this system were over 99% for both populations, emphasizing the efficacy of these markers for paternity testing and genetic management in the two breeds.

O sistema político e a Amazônia brasileira: considerações político-institucionais

O artigo trata do contexto em que se inserem os estados subnacionais que formam a Amazônia brasileira, discutindo as peculiaridades político-institucionais do sistema político da Região e sua relação com os dispositivos constitucionais recentes (CF de 1988) e os reflexos na configuração das instituições políticas representativas. Discute-se como o sistema representativo nacional, construído historicamente com as constituições nacionais, fez da Amazônia uma região privilegiada no que diz respeito à representatividade, quando comparada com as demais regiões, porém semelhante à federação quanto aos problemas político-partidários e aos desenhos institucionais. Conclui-se que a ausência de solidariedade regional dificulta a participação dos estados amazônicos no sistema nacional.

Pharmacogenetic polymorphisms in Brazilian-born, first-generation japanese descendants

Brazil hosts the largest Japanese community outside Japan, estimated at 1.5 million individuals, one third of whom are first-generation, Brazilian-born with native Japanese parents. This large community provides a unique opportunity for comparative studies of the distribution of pharmacogenetic polymorphisms in native Japanese versus their Brazilian-born descendants. Functional polymorphisms in genes that modulate drug disposition (CYP2C9, CYP2C19 and GSTM3) or response (VKORC1) and that differ significantly in frequency in native Japanese versus Brazilians with no Japanese ancestry were selected for the present study. Healthy subjects (200 native Japanese and 126 first-generation Japanese descendants) living in agricultural colonies were enrolled. Individual DNA was genotyped using RFLP (GSTM3*A/B) or TaqMan Detection System assays (CYP2C9*2 and *3; CYP2C19*2 and *3; VKORC1 3673G>A, 5808T>G, 6853G>C, and 9041G>A). No difference was detected in the frequency of these pharmacogenetic polymorphisms between native Japanese and first-generation Japanese descendants. In contrast, significant differences in the frequency of each polymorphism were observed between native or first-generation Japanese and Brazilians with no Japanese ancestry. The VKORC1 3673G>A, 6853G>C and 9041G>A single nucleotide polymorphisms were in linkage disequilibrium in both native and first-generation Japanese living in Brazil. The striking similarity in the frequency of clinically relevant pharmacogenetic polymorphisms between Brazilian-born Japanese descendants and native Japanese suggests that the former may be recruited for clinical trials designed to generate bridging data for the Japanese population in the context of the International Conference on Harmonization.

Entre as urnas e as togas: Justiça Eleitoral e competição política no Pará (1982/1986)

Neste trabalho, analisamos a governança eleitoral exercida pelo TRE/PA, especialmente o seu nível de isenção no contencioso eleitoral (rule adjudication) concernente aos pleitos majoritários (governador e senador) de 1982 e 1986, com retrospecto no período de 1945 a 1965 - o primeiro momento de atuação contínua e prolongada da Justiça Eleitoral num contexto democrático, isto é, antes do Golpe Militar de 1964. Partimos do pressuposto segundo o qual, dada a peculiar composição da Justiça Eleitoral, que funciona tomando de empréstimo magistrados da justiça comum - sendo os TRE‟s compostos, em sua maioria, por membros dos tribunais de justiça estaduais -, somado ao padrão de relacionamento executivo-judiciário estadual, em que, historicamente, constatamos uma hipertrofia do primeiro em relação ao segundo poder, estimamos existir uma grande probabilidade de favorecimento do TRE aos candidatos majoritários do partido governamental. Esta circunstância seria agravada no período histórico em tela, em vista da enorme ingerência do executivo estadual sobre o respectivo poder judiciário, verificada anteriormente à promulgação da Constituição Federal de 1988. Com efeito, encontramos fortes indícios a corroborar esta hipótese no período 1945-65, mas não encontramos evidências suficientes para sustentá-la por ocasião dos pleitos de 1982 e 1986. No pleito de 1982, o TRE manifestou razoável grau de isenção e coerência em seus acórdãos, exceto em dois processos semelhantes: um deles provocado pelo PDS e o outro pelo PMDB, ambos envolvendo um número expressivo de votos. O PMDB, partido então patrocinado pelo governador, venceu a lide, enquanto o PDS, o partido oposicionista, foi derrotado. No tocante, ao pleito de 1986, observamos uma disposição da Corte para denegar os pedidos propostos pelas legendas oposicionistas, sobretudo o PT e o extinto PMB, ainda que não tenha sido possível demonstrar um claro favorecimento ao partido governamental.

Length-weight relationship and reproduction of the guppy Poecilia reticulata (Cyprinodontiformes: Poeciliidae) in urban drainage channels in the Brazilian city of Belém

O presente trabalho tem por objetivo descrever aspectos populacionais relacionados ao estabelecimento da relação peso/comprimento, estimativa de tamanho de primeira maturação (L) e período reprodutivo de Poecilia reticulata encontrados em sistemas de coleta residual no campus da Universidade Federal do Pará, região metropolitana de Belém – PA (Brasil). Foram realizadas coletas mensais no período de junho de 2006 a março de 2007, utilizando um puçá, que resultou na captura de 1.936 exemplares, sendo 942 machos e 994 fêmeas. As fêmeas apresentaram-se maiores e mais pesadas que os machos. A relação peso/comprimento para machos foi estabelecida pela equação Pt = 5 × 10^-5× Ct^2,397 e para fêmeas esta foi dada pela fórmula Pt = 3 × 10^-6 × Ct3,419. Os valores estimados para L foi 17,5 mm para machos 20,4 mm para fêmeas, sugerindo que os machos iniciam atividades reprodutivas em tamanhos menores que as fêmeas. A frequência mensal de fêmeas maduras não variou significativamente. Além disso, também não foram encontradas diferenças na proporção sexual durante os períodos investigados, sendo no geral, a proporção de fêmeas iguais as de machos. Desta forma, verificamos que, apesar das condições presentes nos sistemas de coleta residual da UFPA, a espécie P. reticulata parece ter adaptado seus processos biológicos.

Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon

The mercury rejected in the water system, from mining operations and lixiviation of soils after deforestation, is considered to be the main contributors to the contamination of the ecosystem in the Amazon Basin. The objectives of the present study were to examine cytogenetic functions in peripheral lymphocytes within a population living on the banks of the Tapajós River with respect to methylmercury (MeHg) contamination, using hair mercury as a biological indicator of exposure. Our investigation shows a clear relation between methylmercury contamination and cytogenetic damage in lymphocytes at levels well below 50 micrograms/gram, the level at which initial clinical signs and symptoms of mercury poisoning occur. The first apparent biological effect with increasing MeHg hair level was the impairment of lymphocyte proliferation measured as mitotic index (MI). The relation between mercury concentration in hair and MI suggests that this parameter, an indicator of changes in lymphocytes and their ability to respond to culture conditions, may be an early marker of cytotoxicity and genotoxicity in humans and should be taken into account in the preliminary evaluation of the risks to populations exposed in vivo. This is the first report showing clear cytotoxic effects of long-term exposure to MeHg. Although the results strongly suggest that, under the conditions examined here, MeHg is both a spindle poison and a clastogen, the biological significance of these observations are as yet unknown. A long-term follow-up of these subjects should be undertaken.

Epigenetic alterations in human brain tumors in a Brazilian population

Aberrant methylation of CpG islands located in promoter regions represents one of the major mechanisms for silencing cancer-related genes in tumor cells. We determined the frequency of aberrant CpG island methylation for several tumor-associated genes: DAPK, MGMT, p14^ARF, p16^INK4a, TP73, RB1 and TIMP-3 in 55 brain tumors, consisting of 26 neuroepithelial tumors, 6 peripheral nerve tumors, 13 meningeal tumors and 10 metastatic brain tumors. Aberrant methylation of at least one of the seven genes studied was detected in 83.6% of the cases. The frequencies of aberrant methylation were: 40% for p14^ARF, 38.2% for MGMT, 30.9% for, p16^INK4a, 14.6% for TP73 and for TIMP-3, 12.7% for DAPK and 1.8% for RB1. These data suggest that the hypermethylation observed in the genes p14^ARF, MGMT and p16^INK4a is a very important event in the formation or progression of brain tumors, since the inactivation of these genes directly interferes with the cell cycle or DNA repair. The altered methylation rate of the other genes has already been reported to be related to tumorigenesis, but the low methylation rate of RB1 found in tumors in our sample is different from that so far reported in the literature, suggesting that perhaps hypermethylation of the promoter is not the main event in the inactivation of this gene. Our results suggest that hypermethylation of the promoter region is a very common event in nervous system tumors.

Molecular analysis of three FUT3 gene single nucleotide polymorphisms and their relationship with the lewis erythrocytary phenotype in a human population of japanese-ancestry living in Tomé Açu, a town in the Brazilian Amazon

The Lewis blood group system involves two major antigens, Le^ª and Le^b. Their antigenic determinants are not primary gene products but are synthesized by the transfer of sugar subunits to a precursory chain by a specific enzyme which is the product of the FUT3 gene (Lewis gene). The presence of three FUT3 gene single nucleotide polymorphisms (SNPs) (59T > G; 508G > A and 1067T > A) was related to the Lewis phenotype of erythrocytes from 185 individuals of Japanese ancestry living in the town of Tomé-Açu in the Brazilian Amazon region. This relationship was detected using a serological hemagglutination test and the Dot-ELISA assay along with the molecular technique PCR-RFLP. We found that the three SNPs investigated in this study only accounted for a proportion of the Lewis-negative phenotype of the erythrocytes.

Molecular analysis of three FUT3 gene single nucleotide polymorphisms and their relationship with the lewis erythrocytary phenotype in a human population of japanese-ancestry living in Tomé Açu, a town in the Brazilian Amazon

The Lewis blood group system involves two major antigens, Le^a and Le^b. Their antigenic determinants are not primary gene products but are synthesized by the transfer of sugar subunits to a precursory chain by a specific enzyme which is the product of the FUT3 gene (Lewis gene). The presence of three FUT3 gene single nucleotide polymorphisms (SNPs) (59T > G; 508G > A and 1067T > A) was related to the Lewis phenotype of erythrocytes from 185 individuals of Japanese ancestry living in the town of Tomé-Açu in the Brazilian Amazon region. This relationship was detected using a serological hemagglutination test and the Dot-ELISA assay along with the molecular technique PCR-RFLP. We found that the three SNPs investigated in this study only accounted for a proportion of the Lewis-negative phenotype of the erythrocytes.