Navegando por Assunto "Norte do Brasil"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Mangrove sedimentary characteristics and implications for crab Ucides cordatus (Crustacea, Decapoda, Ucididae) distribution in an estuarine area of the Amazonian region
(2013-12) GOMES, José Diego; ABRUNHOSA, Fernando Araujo; SIMITH, Darlan de Jesus de Brito; ASP NETO, Nils Edvin
At the coastal zone sediments, water and organisms interact intensely. At equatorial tidal-dominated coast mangroves are abundant. These areas are well-known for their ecological importance. Considering the mangroves of Atlantic South America, the mangrove crab, Ucides cordatus has ecological and economic prominence. High densities of this crab are found on the Amazon coast. This study investigates the sediment distribution of the Bragança mangrove area (Amazon coast, Brazil) and its correlations with vegetation and mangrove crab distribution. Sediments of 47 sites, as well as crabs from sites with different sediment and vegetation, were sampled. Results show that surface sediment of the area is mainly composed by silt (59%), with 21% sand and 20% clay. Variations in sorting and skewness are the product of local variations in clay and sand content. The vegetation type was significantly correlated to mangrove crab characteristics, abundance and weight/size. Sediment characteristics are also substantially different according to the vegetation type. Areas where Avicennia germinans prevails have more sand and clay than areas of Rizophora mangle, in which silt is dominant and crabs were significantly heavier. The present results have showed that the distribution of sediments, crabs and vegetation at mangrove areas are strongly correlated. Thus, they should be studied in conjunction.
Acesso aberto (Open Access)
Prevalência e associação da infecção gástrica por Helicobacter pylori e do vírus Epstein-Barr em casos de gastrite na população do Amapá
(Universidade Federal do Pará, 2017-11-03) ALVES, Nélisson Clei Ferreira; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099
The epidemiology of HP and of the Epstein-Barr virus (EBV) is worldwide. The prevalence of both carcinogenic agents, in the world human population is about 45%. A recent study suggests that EBV coinfection with HP cagA positive increases the oncogenic potential of this bacterium. The objective of this study was to identify the prevalence of the bacterium HP and of the virus EBV and the association of those pathogens and of the cagA gene in patients with gastritis in the population of Amapá. A descriptive study was accomplished, of the traversal type, where 292 samples of gastric mucous of the patients were analyzed with gastritis submitted to the endoscopy, age group between 14 and 83 years. For detection of HP, Urease test and Polymerase Chain reaction were used; this methodology was also useful to reveal the positive cagA of the bacterium. Additionally, the technique of in situ hybridization was used for detection of EBV and the microscopic analysis that determined the histopathological characteristics of the gastric mucous. Results: The study showed high prevalence of cases of HP in patients with gastritis with a relative frequency of 87,67% of the 292 analyzed cases, a higher incidence, of HP positive cases, in female, 88,27%. The incidence of the cagA gene in samples of positive patients for HP was 72,66%, higher prevalence in female, 75,32%. In the present study 8,59% of the patients were found with viral infection caused by EBV in positive samples for HP with bigger prevalence in male, 9,18%. According to the age group, the study showed higher prevalence of the gene cagA and of EBV in positive patient for HP in the age group between 44 and 54 years, with 23,12% and 36,37%, respectively. Conclusion: Most of the findings of this study are similar to the reports from the literature, however, it is necessary other studies in order to explain if there is or there is no correlation between the infection for HP and EBV in the north of Brazil.
Acesso aberto (Open Access)
Seasonal effects of wastewater to the water quality of the Caeté river estuary, Brazilian Amazon
(Academia Brasileira de Ciências, 2010-06) PEREIRA, Luci Cajueiro Carneiro; BERNARDI, Marcela Cunha Monteiro; GUIMARÃES, Danielly de Oliveira; QUEIROZ, Jislene Brito Matos; COSTA, Rauquírio André Albuquerque Marinho da
Bragança's socioeconomic situation is highly dependent on estuarine and marine biological resources that are influenced by tidal cycles and climatology. Field measurements (hydrological, hydrodynamic and microbiological variables) were taken in the most urbanized zone from Caeté estuary to characterise the quality of the local environment. During the dry period, the estuary was more eutrophic and presented the highest temperature (30.5 °C in Oct./06), salinity (17 psu in Feb./07), pH (8.24 in Feb./07) and fecal coliform (> 1000 MPN/100 ml in Dec./06 and Feb./07) values. The phytoplankton Cyclotella meneghiniana, Coscinodiscus centralis and other r-strategist species were observed. The lack of basic hydric canalization was responsible for the local contamination, especially during the dry period when more concentrated wastewater from the city was emitted into the estuary, showing the human influence on the reduction of local estuarine water quality. In Bragança, the fishery is considered one of the main economic activities so, this contamination is worrisome because a large part of the local economy depends on biological resources and, thus, the contamination could negatively affect the environmental health of this Amazon ecosystem.