998 resultados para tropical river


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Abstract: We herein report human dermatitis caused by the tropical fowl mite Ornithonyssus bursa (Berlese). The cases occurred in an apartment in a residential district of Porto Alegre City, State of Rio Grande do Sul, Brazil, where three members of the same family presented with pruritic lesions on the arms and legs. On inspecting the bathroom, several mites measuring approximately 1.0mm in length were observed coming from a nest of Rufous Hornero, Furnarius rufus (Gmelin). This is the first report of O. bursa in the urban area of Porto Alegre City, from a nest of F. rufus that bites humans.

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In the State of Amazonas, Brazil, urban expansion together with precarious basic sanitation conditions and human settlement on river banks has contributed to the persistence of waterborne and intestinal parasitic diseases. Time series of the recorded cases of cholera, typhoid fever, hepatitis A and leptospirosis are described, using data from different levels of the surveillance systems. The sources for intestinal parasitosis prevalence data (non-compulsory reporting in Brazil) were Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana (LILACS) and the annals of major scientific meetings. Relevant papers and abstracts in all languages were accessed by two independent reviewers. The references cited by each relevant paper were scrutinized to locate additional papers. Despite its initial dissemination across the entire State of Amazonas, cholera was controlled in 1998. The magnitude of typhoid fever has decreased; however, a pattern characterized by eventual outbreaks still remains. Leptospirosis is an increasing cause of concern in association with the annual floods. The overall prevalence of intestinal parasites is high regardless of the municipality and the characteristics of areas and populations. The incidence of hepatitis A has decreased over the past decade. A comparison of older and recent surveys shows that the prevalence of intestinal parasitic diseases has remained constant. The load of waterborne and intestinal parasitic diseases ranks high among the health problems present in the State of Amazonas. Interventions aiming at basic sanitation and vaccination for hepatitis A were formulated and implemented, but assessment of their effectiveness in the targeted populations is still needed.

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Abstract: INTRODUCTION Mansonella ozzardi is a widely distributed filaria worm in the Amazon region. This study aimed to determine the prevalence of M. ozzardi infection in riverine communities of Lábrea municipality, Amazonas State, Brazil. METHODS A diagnostic blood filtration method in a polycarbonate membrane was used. RESULTS M. ozzardi was found in 50.3% of the sample, with the highest prevalence in farmers/fishermen (69.4%; χ 2 = -19.14, p<0.001). The prevalence was higher in longer-term residents (≥11 years; 60.2%). CONCLUSIONS M. ozzardi infection rates are high near the Purus River, much greater than those previously reported based on diagnosis using thick blood smears.

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Discussed are the taxonomy of the Scleria arundinacea-latifoliacomplex, S. mitis, and S. myricocarpa, all controversial and widespread taxa in tropical America. Scleria cerradicola is described as new in the section Hymenolytrum and a range extension of a rare species, Scleria neogranatensis, is noted.

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Some of the trends and characteristics of the isotopic composition oh precipitation in tropical stations are discussed. Stations in small Pacific islands show a variation with latitude, with lower 8-values between 15°N and 1S°S and higher values at higher. Inland stations are depleted in heavy isotopes with respect to coastal stations but sometimes this continental effect is rather complex, as f,or instance in África. Mean monthly 8-values show a remarkable correlation with the amount of precipitation, but the slope variations do not show a clear dependence on the mean long term 8-value,as should be expected theoretically. In Southern American stations the seasonal variations of the meanmonthly 5-values are correlated and they are greater in inland stations due to con-tinentaly. The possible effects of recycling of water vapour by evapotranspiration are also discussed.

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Calyptothecium planifrons (Ren. & Par.) Argent is reported new to the Western Hemisphere based on two recent collections from Brazilian Amazonia, in Pará and Rondônia; C. planifrons was originally described from Madagascar. Forteen Other species of mosses with apparently disjunct distributions between tropical Africa and tropical America are also discussed. It is likely that mos or all of this species discussed will prove to have wider distributions in the tropics when world-wide revisions are carried out.

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Twenty-eoght algal samples were collected in September-October, 1984, from two distinct habitats in the state of Acre, Brazil. Eleven were from the Moa River, and 17 were from a sulfur water spring which flows into the Moa River. A total of 74 species, representing 48 genera of algae, were identified from these samples. Forty-nine species were found in the Moa River and 67 in the sulfur water spring. Both coolection site had rich assemblages of cyanophycean algae, chlorophycean algae, and diatoms. Chlorophycean species dominated the algae flora at both sites, cut were more numerous at the sulfur water spring. There was also a definite difference in the relatives proportions of desmids to filamentous chlorophycean algae at the two sites.

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A review of the literature on measurements of rain water interception processes by forests is made. Information on Africa, Central and South America, and Asia is given. A general analysis is made and the need to further the measurements under field conditions is stressed.

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Avaliação da precisão da amostragem sistemática em relação a amostragem aleatória, ambas utilizadas em inventários florestais, com base no erro padrão estimado e tendo como parâmetro de comparação, a área basal. Os dois tipos de amostragem foram aplicados em uma população florestal, 100% inventariada (DAP maior ou igual a 25 cm), constituída de 4 blocos experimentais de 24 hectares cada e distribuídos aleatoriamente sobre uma bacia hidrográfica de aproximadamente 600 hectares. Essa área experimental faz parte do projeto de Manejo Ecológico (Bacia 3). O menor erro padrão estimado foi obtido através da amostragem sistemática, mesmo considerando que na amostragem aleatória foram feitos 5 sorteios diferentes para a tomada das unidades amostrais do inventário simulado.

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Apresenta um modelo matemático para expressar a taxa de regeneração natural em florestas tropicais, através dos valores de abundância. 0 modelo proposto e. o seguinte-.tr = { (A1/A0)- 1 }. 100, onde:tr = taxa de regeneração natural em percentagem;A = abundância absoluta = número de indivíduos por unidade de área;A1 = A0 + ne - ns = abundância absoluta final;ne = número de indivíduos que ingressaram no estudo, por germinação ou mudança de categoria de tamanho (in-put)) ;ns = número de indivíduos que saíram do estudo, por morte ou mudança de categoria de tamanho (out-put).-1 = constante que indica a mortalidade.Os resultados demonstram que a floresta está em equilíbrio dinâmico, uma vez que, apresentou um valor de + 0,10% para a taxa de regeneração natural, a qual pode ser utilizada para espécies, grupos de espécies ou para o total da floresta.

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Analisam a estrutura da floresta equatorial úmida próxima a Manaus, introduzindo a qualidade de fuste na. análise. Utilizam 8 amostras de 20m x 500m para indivíduos com DAP > 20cm, 24 subamostras de 10m x 100m para. indivíduos com DAP entre 5cm e 20cm e 120 subamostras de 2m x 10m para indivíduos com DAP < 5cm. Determinam valores mínimos de 2,6 e 22 amostras para composição florística é de 6,18 e 80 para a abundância em cada fração da floresta. Concluem que a floresta é muito heterogênea, com 324 espécies, 173 gêneros e 57 fiamílias e com grande diferença entre a regeneração e o povoamento adulto. Eschweilera odora, Corythophora alta., Protium apiculatum e Radlkoferella sp. são as espécies mais importantes. A floresta em geral apresenta a estrutura diamétrica regular esperada para florestas nativas devido às espécies do estrato inferior e sub-bosque.

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Qualitative and quantitative collections of ants made in the region of Manaus, Brazil (evergreen tropical humid forest), and in western North Carolina, USA (deciduous temperate/wet forest), were undertaken to investigate. latitudinal patterns of ant diversity and community organization on regional and local scales. We have found to date 307 ant species in the Municipality of Manaus. Totals ranging from 134 to 270+ species have been reported in the literature for other tropical regions of less than 10,000km2. In contrast, temperate ant surveys generally report only SO to 150 species in similar or larger areas. Sampling at sardine baits set 10m apart on square grids, we found forest ecosystems near Manaus to be much richer and more diverse in ants than those sampled in North Carolina: 28 species vs. 5-10 species in 50 collections and 16 vs. 3 previously unrecorded species discovered with each doubling of sample size. Room's (1975a) results from climatically simllar Papua New Guinea forest agree closely with those from Manaus. We suggest that one important factor contributing to the increased diversity of tropical, omnivorous ants may be greater variety of nest sites available for specialization.

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RESUMOO presente trabalho teve como finalidade determinar a composição florística e os índices de agregação das espécies da regeneração natural de uma floresta tropical úmida da região de Manaus, sob quatro níveis de exploração. Pelos resultados observou-se a influência dos tratamentos no número total de indivíduos e no número de indivíduos por classe de tamanho. A floresta estudada compreendeu 291 espécies, 169 gêneros e 56 famílias botânicas. A testemunha aprensetou o menor número de espécies. Os valores do grau de homogeinidade e Quociente de mistura de Jentsch também evidenciaram uma alta heterogeneidade, sendo a testemunha mais heterogênea. As famílias predominantes foram: Burserapeae, Annonaceae, Violaceae, Melastomataceae e Rubiaceae. As famílias mais ricas em espécies foram: Caesalpiniaceae, Sapotaceae, Lauraceae e Mimosaceae. O ìndice de Fracher & Brischle apresentou maior número de espeécies agrupadas nos 4 tratametnos, já o índice de Payandeh apresentou maior número de espécies não agrupadas.