ABSTRACT
Benthic communities are highly relevant in the study of aquatic ecosystems, both for their role in the functioning of the ecosystem and also as markers or indicators of paleo-conditions. Their distribution, as in other communities, is conditioned by abiotic and biotic factors and to their interactions, which determine the structure of the community that is established. The aim of this study was to determine the taxonomic composition, abundance and spatial distribution of the benthic community, by collecting at 20 sampling sites in Caçó Lake (State of Maranhão, Brazil). Seasonal variation in these community parameters was analysed and related to the seasonal displacement of the Intertropical Convergence Zone. The results indicated that changes occur in the taxa richness, diversity and density of the benthic species of this lake that are mainly related to seasonality. All those parameters were higher in the dry than in the rainy period. The family Chironomidae (Diptera, Insecta) was the most important component of the community, representing approximately 50 percent of the total benthic fauna of the lake. The identification of the Chironomidae currently occurring in Lake Caçó is relevant, even at the genus level, considering the fact that this group produces fossilizing remains and could perhaps be good paleolimnological and paleoclimatic tracers that could be used to make inferences on past lake and climate conditions.
As comunidades bentônicas são relevantes nos ecossistemas aquáticos devido ao seu papel no seu funcionamento e também como marcadores ou indicadores de paleocondições. Sua distribuição, similarmente à de outras comunidades, é condicionada por fatores abióticos e bióticos e pela interação entre eles, determinando a estrutura da comunidade que se estabelecerá. O objetivo do presente trabalho foi determinar a composição taxonômica, a abundância e a distribuição espacial da comunidade bentônica, amostrando-se em 20 pontos na lagoa do Caçó (Estado do Maranhão, Brasil). As variações sazonais nas características desta comunidade foram analisadas e relacionadas ao deslocamento sazonal da Zona de Convergência Intertropical. Os resultados indicaram que ocorrem mudanças na riqueza de taxons, diversidade e densidade da comunidade bentônica deste lago que são principalmente relacionadas à sazonalidade. Todas as variáveis analisadas foram maiores no período seco do que no chuvoso. Os organismos pertencentes à família Chironomidae (Diptera, Insecta) foram os mais importantes componentes da comunidade, representando aproximadamente 50 por cento do total da fauna. A identificação dos Chironomidae atualmente presentes no Lago Caçó, mesmo em nível de gênero, é relevante, considerando-se o fato de que as larvas deste grupo produzem remanescentes fósseis que podem ser bons traçadores paleolimnológicos e paleoclimáticos, podendo ser utilizados para fazer inferências sobre as condições passadas neste lago e no clima regional.
Subject(s)
Animals , Ecosystem , Invertebrates/classification , Biodiversity , Brazil , Fresh Water , Population Density , SeasonsABSTRACT
ßS-Globin haplotypes were studied in 80 (160 ßS chromosomes) sickle cell disease patients from Salvador, Brazil, a city with a large population of African origin resulting from the slave trade from Western Africa, mainly from the Bay of Benin. Hematological and hemoglobin analyses were carried out by standard methods. The ßS-haplotypes were determined by PCR and dot-blot techniques. A total of 77 (48.1 percent) chromosomes were characterized as Central African Republic (CAR) haplotype, 73 (45.6 percent) as Benin (BEN), 1 (0.63 percent) as Senegal (SEN), and 9 (5.63 percent) as atypical (Atp). Genotype was CAR/CAR in 17 (21.3 percent) patients, BEN/BEN in 17 (21.3 percent), CAR/BEN in 37 (46.3 percent), BEN/SEN in 1 (1.25 percent), BEN/Atp in 1 (1.25 percent), CAR/Atp in 6 (7.5 percent), and Atp/Atp in 1 (1.25 percent). Hemoglobin concentrations and hematocrit values did not differ among genotype groups but were significantly higher in 25 patients presenting percent fetal hemoglobin ( percentHbF) > or = 10 percent (P = 0.002 and 0.003, respectively). The median HbF concentration was 7.54 ± 4.342 percent for the CAR/CAR genotype, 9.88 ± 3.558 percent for the BEN/BEN genotype, 8.146 ± 4.631 percent for the CAR/BEN genotype, and 4.180 ± 2.250 percent for the CAR/Atp genotype (P = 0.02), although 1 CAR/CAR individual presented an HbF concentration as high as 15 percent. In view of the ethnic and geographical origin of this population, we did not expect a Hardy-Weinberg equilibrium for CAR/CAR and BEN/BEN homozygous haplotypes and a high proportion of heterozygous CAR/BEN haplotypes since the State of Bahia historically received more slaves from Western Africa than from Central Africa
Subject(s)
Humans , Male , Female , Anemia, Sickle Cell , Fetal Hemoglobin , Globins , Haplotypes , Anemia, Sickle Cell , Benin , Brazil , Central African Republic , Fetal Hemoglobin , Genotype , Immunoblotting , Polymerase Chain Reaction , SenegalABSTRACT
Os autores apresentaram um caso de neurofibroma com lesao ossea. Devido a ausencia de complicacoes, nao houve indicacao cirurgica para o caso. Um aspecto importante foi a ausencia de sardas e manchas cafe com leite, presentes em quase todos os pacientes
Subject(s)
Adult , Humans , Male , Neurofibromatoses , Sacrococcygeal RegionABSTRACT
O presente trabalho consiste na apresentacao de um caso de raquitismo D resistente em um menor de 12 anos de idade, do sexo masculino, com historia de mais ou menos 1 ano de lombalgia e dores articulares. Nao apresentava queixas sistemicas, antecedentes patologicos e familiares valorizados.Ao exame fisico observa-se discreto defeito pondo-estatural, diminuicao da cifose dorsal, retificacao da coluna lombar, geno valgum bilateral, pes cavo e atrofia muscular generalizada. O diagnostico foi realizado atraves de exames laboratoriais radiologicos