Time filter

Source Type

de Almeida L.B.,University of the State of Amazonas | Barbosa M.G.V.,University of the State of Amazonas | Martinez-Espinosa F.E.,Gerencia de Entomologia e Malaria | Martinez-Espinosa F.E.,Centro Universitario Nilton Lins
Revista da Sociedade Brasileira de Medicina Tropical | Year: 2010

Introduction: The SIVEP-Malaria Epidemiological Surveillance Information System has been in use for notification of malaria cases diagnosed in Brazil since 2003. This study analyzed malaria cases notified among women aged 10 to 49 years between 2003 and 2006, according to the presence or absence of pregnancy. Methods: Authorization to evaluate the data was requested from the Health Surveillance Foundation (FVS). Results: Over this period, 13,308 malaria cases were notified, of which 815 (6.1%) were among pregnant women. There was a gradual decrease in the absolute numbers of cases among pregnant and non-pregnant women. Regarding species, 14.3% of the notified cases were caused by Plasmodium falciparum; 85% by Plasmodium vivax and 0.6% by both of them. The frequency of Plasmodium falciparum infection was greater among pregnant women than among non-pregnant women (p > 0.05). Although most of the cases lived in the eastern zone of the city, the western zone appeared to be the likely location of infection in 39% of the cases. Endemic peaks of malaria in July and August were observed among the non-pregnant women in all four years analyzed. Conclusions: The data showed that SIVEP-Malaria was an important tool for determining the distribution of malaria cases and that it should be used for controlling the endemic disease. However, the data from its first four years of operation showed that the quality was compromised by data entry failures, using the field of notification of pregnancy as an example.

Duarte R.M.,National Institute for Research in the Amazon | Honda R.T.,Centro Universitario Nilton Lins | Val A.L.,National Institute for Research in the Amazon
Aquatic Toxicology | Year: 2010

The main goal of this study was to investigate the toxicological effects of the chemical dispersant Corexit 9500, crude oil and the combination of the two components in the form of chemically dispersed crude oil (CO + DIS) on the ion regulation of the tropical fish tambaqui (Colossoma macropomum). Gill ion regulation was evaluated on the basis of unidirectional flux measurements (influx-Jin, efflux-Jout and net flux-Jnet) of Na+, Cl- and K+. Plasma ion composition, haematocrit, haemoglobin and glucose concentrations in the blood of tambaqui were determined by classical methods. The exposure of fish to chemically dispersed crude oil promoted a significant increase in Jout Na+ across the gills, which, together with the inability of fish to stimulate Na+ uptake to compensate for these losses resulted in significantly higher Jnet Na+ outward, particularly within the first 3 h of exposure. Increased outward Jnet Cl- was also seen in fish that were exposed to dispersed crude oil, whereas outward Jnet K+ was only increased at crude oil dispersed in higher concentration of Corexit 9500. Plasma Na+ and Cl- concentrations decreased between 6 and 12 h of exposure, whereas Ca2+ concentrations remained significantly lower than those of the control group over the entire experimental period. There were significant increases in plasma K+ concentrations and in the haematocrit after 6 and 24 h of exposure to dispersed crude oil, suggesting significant changes in the permeability of the erythrocytic membrane. Collectively, our results suggest that chemically dispersed crude oil promotes a more extensive impairment of gill ion regulation, in addition to changes in plasma ion levels and blood parameters, in tambaqui compared with exposure to Urucu crude oil or Corexit 9500 alone. Thus, in the event of an oil spill in Amazonian waters, the chemical dispersion of Urucu crude oil could represent a great risk to tambaqui, challenging their ability to maintain ionic and osmotic gradients in native ion-poor waters. © 2010 Elsevier B.V. All rights reserved.

Couceiro S.R.M.,Centro Universitario Nilton Lins | Hamada N.,National Institute of Amazonian Research | Forsberg B.R.,National Institute of Amazonian Research | Padovesi-Fonseca C.,University of Brasilia
Austral Ecology | Year: 2011

This study assessed the results of anthropogenic sediment input on macroinvertebrate trophic structure in streams located in an area of oil and natural gas exploitation in Brazil's Amazon forest. The results indicate that macroinvertebrate communities both in streams impacted by anthropogenic sediments and in non-impacted streams are composed mainly of taxa in the following functional feeding groups: predators, gathering-collectors, scrapers, shredders and filtering-collectors. The highest densities were observed for collector-gatherers, followed by scrapers, predators, shredders and filtering-collectors. However, both the richness and the density of all groups were reduced in impacted streams. The reductions were significantly related to suspended inorganic sediment load and to the colour of suspended sediments. The relative proportion of shredders in streams impacted by anthropogenic sediments was significantly reduced as compared with the proportion observed in non-impacted streams. This resulted from lower availability of coarse particulate organic matter in these streams owing to burial of leaves and other plant material. These results indicate changes in the functioning and productivity of streams owing to anthropogenic siltation. This is because the benthic macroinvertebrate communities, sampled during this study, were dependent on the degradation of leaves, which are the primary energy source sustaining the benthic foodweb. © 2010 The Authors. Journal compilation © 2010 Ecological Society of Australia.

Siqueira T.,University of Guelph | Siqueira T.,Federal University of Sao Carlos | Bini L.M.,Federal University of Goais | Roque F.O.,Federal University of Grande Dourados | And 4 more authors.
Ecography | Year: 2012

Ecologists have long investigated why communities are composed of a few common species and many rare species. Most studies relate rarity to either niche differentiation among species or spatial processes. There is a parallel between these processes and the processes proposed to explain the structure of metacommunities. Based on a metacommunity perspective and on data on stream macroinvertebrates from different regions of Brazil, we answer two questions. 1) Are sets of common and rare species affected by similar niche and spatial processes? 2) How does the community composition of common and of rare species differ? The main hypothesis we test is that common species are mainly affected by environmental factors, whereas rare species are mostly influenced by dispersal limitation. We used variation partitioning to determine the proportion of variation explained by the environment and space in common and rare species matrices. Contrary to our expectations, evidence supported the idea that both common and rare species are affected mainly by environmental factors, even after controlling for the differing information content between common and rare species matrices. Moreover, the abundance of some common species is also a good predictor of variation in rare species matrices. Niche differences are unlikely to be the sole cause of patterns of rarity in these metacommunities. We suggest that sets of common and rare species react to similar major environmental gradients and that rare species also respond to processes that operate at a more fine-grained spatial scale, particularly biotic interactions. We extend the view that species sorting is the dominant process structuring metacommunities and argue that future studies focusing on rarity would benefit from a metacommunity perspective. © 2011 The Authors. Ecography © 2012 Nordic Society Oikos.

Inoue L.A.K.A.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuaria | Boijink C.L.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuaria | Ribeiro P.T.,Centro Universitario Nilton Lins | da Silva A.M.D.,INPA | Affonso E.G.,INPA
Acta Amazonica | Year: 2011

Tambaqui is the main farmed fish in the Western Amazon. However, in handling this fish has to be anesthetized for safety purposes, usually when evaluating growth and health conditions. Eugenol, the main component of clove oil, has been reported as an alternative fish anesthetic, because it is an inexpensive natural product. However, continued studies are necessary about the metabolic responses of tropical fish to anesthetics. The present work evaluated metabolic responses of tambaqui to eugenol in simulated anesthetic baths, measuring blood and plasma parameters. Typical metabolic stress responses to handling were detected, but they were not totally reduced by eugenol. On the other hand, the anesthetic dissolved in water did not provoke any extra charge of stress during short-term exposures in concentrations of about 20mg L-1 for 15 min.

Discover hidden collaborations