Forest structure of artificial islands in the Tucuruí dam reservoir in northern Brazil: a test core-area model

Construction of hydroelectric dams in tropical regions has been contributing significantly to forest fragmentation. Alterations at edges of forest fragments impact plant communities that suffer increases in tree damage and dead, and decreases in seedling recruitment. This study aimed to test the core-area model in a fragmented landscape caused by construction of a hydroelectric power plant in the Brazilian Amazon. We studied variations in forest structure between the margin and interiors of 17 islands of 8-100 hectares in the Tucuruí dam reservoir, in two plots (30 and >100m from the margin) per island. Mean tree density, basal area, seedling density and forest cover did not significantly differ between marginal and interior island plots. Also, no significant differences were found in liana density, dead tree or damage for margin and interior plots. The peculiar topographic conditions associated with the matrix habitat and shapes of the island seem to extend edge effects to the islands' centers independently of the island size, giving the interior similar physical microclimatic conditions as at the edges. We propose a protocol for assessing the ecological impacts of edge effects in fragments of natural habitat surrounded by induced (artificial) edges. The protocol involves three steps: (1) identification of focal taxa of particular conservation or management interest, (2) measurement of an "edge function" that describes the response of these taxa to induced edges, and (3) use of a "Core-Area Model" to extrapolate edge function parameters to existing or novel situations.

Visceral leishmaniasis in Brazil: rationale and concerns related to reservoir control

The control of zoonotic visceral leishmaniasis is a challenge, particularly in Brazil, where the disease has been gradually spreading across the country over the past 30 years. Strategies employed for decreasing the transmission risk are based on the control of vector populations and reservoirs; since humans are considered unnecessary for the maintenance of transmission. Among the adopted strategies in Brazil, the sacrifice of infected dogs is commonly performed and has been the most controversial measure. In the present study, we provide the rationale for the implementation of different control strategies targeted at reservoir populations and highlight the limitations and concerns associated with each of these strategies.

Paracoccidioides brasiliensis: a mycologic and immunochemical study of a sample isolated from an armadillo (Dasipus novencinctus)

A sample of P. brasiliensis isolated from the spleen and the liver of an armadillo (Dasipus novencinctus) has been analysed under a mycological and immunochemical viewpoint. The armadillo was captured in an area of Tucuruí (State of Pará, Brazil), the animal being already established as an enzootic reservoir of P. brasiliensis at that region of the country. This sample maintained in the fungal collection of the Tropical Medicine Institute of São Paulo (Brazil) numbered 135, has got all the characteristics of P. brasiliensis, with a strong antigenic power and low virulence for guinea-pigs and Wistar rats. The specific exoantigen of P. brasiliensis - the glycoprotein with a molecular weight of 43 kDa - was easily demonstrated with double immunodiffusion, immunoelectrophoresis, SDS-PAGE and immunobloting techniques.

dogs may be a reservoir host for Angiostrongylus costaricensis

Angiostrongylus costaricensis is a parasitic nematode of wild rodents. Several other vertebrate species including man may become infected by ingestion of the third stage larvae produced by the intermediate hosts, usually slugs from the family Veronicellidae. There is a report of the diagnosis of abdominal angiostrongyliasis in Canis familiaris with lesions resembling those found in human disease. As a preliminar evaluation of the adequacy of a canine model for pathogenetic studies, a dog was inoculated with 75 L3 of A. costaricensis. Infection was established and fist stage larvae were found in feces up to 88 days post infection, sometimes in very large numbers (9.5 x 10(4) L1/g). No clinical manifestations or significant lesions were detected. These are indications that dog may play a role as a reservoir host for A. costaricensis.

Retrospective study of malaria prevalence and Anopheles genus in the area of influence of the binational Itaipu reservoir

The importance of hydroelectric dams beside the human interchange in the maintenance of malarious foci and the occurrence of the Anopheles genus on the Binational Itaipu Reservoir were the main points of this retrospective study. Data were collected from existing registrations at National, State and Municipal Health Departments and literature systematic overview, from January 1984 to December 2003. The occurrence of some outbreak of malaria, mainly by Plasmodium vivax, and the prevalence of species of the Anopheles genus different from Anopheles darlingi in the region are discussed. The malaria in the left bank of Paraná River is a focal problem, which must be approached locally through health, educational and social actions to prevent the continuity of outbreaks in the area. Concomitantly, it is necessary to plan and apply effective surveillance measures in the influence area of the Itaipu Reservoir.

The Pampulha reservoir remains a potential urban focus of schistosomiasis mansoni in Brazil: changes in the occurrence patterns of Biomphalaria species and a new record of the parasite

Introduction The Pampulha reservoir has long been a focus of schistosomiasis transmission in Belo Horizonte, State of Minas Gerais, Brazil. The last malacological study conducted in this urban reservoir was more than two decades ago, and thus, an update on the distribution of the species of Biomphalaria as well as new data on the presence of Schistosoma mansoni in this water body are required. Methods The current distribution of Biomphalaria spp. in the Pampulha reservoir and their infection with S. mansoni was evaluated during 55 malacological surveys conducted between 2009 and 2012. Results Biomphalaria straminea displayed a high population density and distribution, and 13.7% (2,233/16,235) of the specimens collected were infected with larval trematodes other than Schistosoma mansoni. Biomphalaria tenagophila and Biomphalaria glabrata, species currently presenting a restricted distribution and small populations, displayed trematode infection rates of 15.2% (98/644) and 13% (83/640), respectively. Thirteen (2%) specimens of B. glabrata were found to be infected with S. mansoni. In addition, a historical review based on previous and new data on the occurrence patterns of Biomphalaria species in this reservoir is presented. Conclusions The results indicate that the Pampulha reservoir remains a potential focus of urban schistosomiasis in Brazil, and significant changes in the occurrence patterns of Biomphalaria species were verified.

The existence of only one haplotype of Leishmania major in the main and potential reservoir hosts of zoonotic cutaneous leishmaniasis using different molecular markers in a focal area in Iran

IntroductionLeishmania major is the causative agent of zoonotic cutaneous leishmaniasis (ZCL), and great gerbils are the main reservoir hosts in Iran. Abarkouh in central Iran is an emerging focal point for which the reservoir hosts of ZCL are unclear. This research project was designed to detect any Leishmania parasites in different wild rodent species.MethodsAll rodents captured in 2011 and 2012 from Abarkouh district were identified based on morphological characteristics and by amplification of the rodent cytochrome b (Cyt b) gene. To detect Leishmania infection in rodents, deoxyribonucleic acid (DNA) of each ear was extracted. Internal transcribed spacer-ribosomal deoxyribonucleic acid (ITS-rDNA), microsatellites, kinetoplast deoxyribonucleic acid (kDNA) and cytochrome b genes of Leishmania parasites were amplified by polymerase chain reaction (PCR). Restriction fragment length polymorphism (RFLP) and sequencing were employed to confirm the Leishmania identification.ResultsOf 68 captured rodents in the region, 55 Rhombomys opimus were identified and nine Leishmaniainfections (9/55) were found. In addition, eight Meriones libycus and two Tatera indicawere sampled, and one of each was confirmed to be infected. Two Meriones persicus and one Mus musculuswere sampled with no infection.ConclusionsThe results showed that all 11 unambiguously positive Leishmania infections were Leishmania major. Only one haplotype of L. major(GenBank access No. EF413075) was found and at least three rodents R. opimus, M. libycus and T. indica—appear to be the main and potential reservoir hosts in this ZCL focus. The reservoir hosts are variable and versatile in small ZCL focal locations.

The influence of the area of the Serra da Mesa Hydroelectric Plant, State of Goiás, on the frequency and diversity of anophelines (Diptera: Culicidae): a study on the effect of a reservoir

INTRODUCTION: Bioecological aspects of anophelines (Diptera: Culicidae) near areas under the direct influence of the hydroelectric plant reservoir of Serra da Mesa in Goiás, Brazil, were analyzed. METHODS: Samples were collected at the surrounding dam area during the phases before and after reservoir impoundment. The influence of climatic and environmental factors on the occurrence of Anopheles darlingi, Anopheles albitarsis, Anopheles triannulatus, Anopheles oswaldoi and Anopheles evansae was assessed using Pearson's correlations with indicators for richness and diversity as well as the index of species abundance (ISA) and the standardized index of species abundance (SISA). RESULTS: The highest anopheline density occurred during the phase after filling the tank; however, no direct correlation with the climatic factors was observed during this stage. The reservoir formation determined the incidence of the anopheline species. An. darlingi was the predominant species (SISA = 1.00). CONCLUSIONS: The significant difference (p < 0.05) observed between the species incidence during the different reservoir phases demonstrates the environmental effect of the reservoir on anophelines.

The nares as a CA-MRSA reservoir in the healthy elderly

Abstract:INTRODUCTION:The frequency of methicillin-resistant Staphylococcus aureus (MRSA) has increased in the community. This study evaluated the prevalence of MRSA and community-acquired (CA)-MRSA in 120 healthy elderly.METHODS:The MRSA were evaluated for the presence of the IS256, mecA, agr, icaA, icaD, fnbB , and pvl genes with PCR. Results: Frequency of S. aureus and MRSA colonization was 17.8% and 19%, respectively. CA-MRSA isolate showed SCC mec IV, fnbB+ , and icaD+ .CONCLUSIONS:CA-MRSA was detected, with genotype determined as SCC mec type IV/IS256/ fnbB+ / icaA / icaD+ / bbp-/agr2 / bap / pvl, characterizing this population as a possible reservoir of this organism in the community.

Triatomíneos da Amazônia: Ocorrência de triatomíneos na área do reservatório da hidrelé trica de Tucuruí (Pará) e observações sobre o ciclo evolutivo de Rhodnius robustos Larrousse, 1927 (HEMIPTERA, REDUVIIDAE, TRIATOMINAE).

Os autores apresentam dados sobre a ocorrênncia de triatomíneas silvestres encon-tiados em vários ecótopos (palmeiras, tocas de roedores e epífitas aéreas), assim como, capturas através de atração luminosa, no reservatório da Usina Hidrelétrica Tucu ruí, num trecho compreendido entre Santo Antonio e Ipixuna, rio Tocantins; enfocando as pectos do ciclo de vida de Rhodnius robustus realizado no laboratôrio do INPA, Manaus.

Variação espacial e temporal da irradiância solar e da razão entre vermelho e vermelho - extremo que chegam ao solo em diferentes microhabitats na região de Tucuruí - PA

RESUMOEste trabalho visa preliminarmente estudar a irradiância total entre 300 e 1100 nm, assim como a razão vermelho-vermelho extremo que chegam ao solo de um trecho de floresta primária e de uma clareira. As áreas selecionadas estão localizadas numa região próxima a cidade de Tucurui, Estado do Pará, Brasil.

Impacto ecológico em Tucuruí (PA): Climatologia

Neste trabalho, mostra-se o comportamento climático da região da UHE de Tucuruí, durante o período de Dezembro de 1982 a Dezembro de 1986. São apresentados os padrões sazonais de temperatura e umidade relativa do ar, regime de velocidade de vento (a 2 metros), distribuição da precipitação local, fluxo de radiação solar e razão de insolação. Aplica-se a formulação de Penman-Monteith para a evapotranspiração potencial (EP) na região. Como resultados, encontra-se uma evapotranspiração média diária maior à encontrada na literatura, pois assumiu-se condições de saturação da superfície para todos meses antecedentes da formação do lago.

VARIAÇÃO NA QUALIDADE ÓPTICA DA ÁGUA DO SISTEMA RIO-RESERVATÓRIO DA USINA HIDRELÉTRICA DE TUCURUÍ/PA

Entre os anos de 1983 e 1986 foram coletadas informações sobre o comportamento áa penetração na água da radiação solar noe períodos anterior e posterior a formação do reservatório da usina hidrelétrica de Tucuruí, no Pará. Tais medidas foram obtidas em locais pré-fixados à montante da barragem, abrangendo as épocas chuvosa e seca. Para cada série de dados foram calculadas a irradiância, o coeficiente de atenuação Κ e a profundidade da zona eufótica. Erros associados aos cálculos também foram analisados. Através das análises efetuadas verificou-se que a atenuação da radiação solar pela água foi maior no período chuvoso, ocorrendo a situação inversa durante a estiagem. Constatado o comportamento sazonal de K, este foi relacionado com a enorme quantidade de sedimentos em suspensão transportado anualmente pelo sistema Araguaia-Tocantins. Notou-se que no período pós-enchimento do reservatório, houve uma nítida alteração nos valores de K, com diminuição dos valores máximos. Evidenciou-se que, com a diminuição da velocidade do curso d'água, o apote no lago de material suspenso começou a se depositar, iniciando o fenômeno da segmentação.

RADIAÇÃO SOLAR TOTAL DENTRO E FORA DE FLORESTA TROPICAL ÚMIDA DE TERRA FIRME (TUCURUÍ, PARÁ)

Medidas de radiação solar global foram executadas dentro e fora de mata tropical úmida de terra firme durante o dia 07 de novembro de 1986, em Tucuruí, Pará. As intensidades de radiação solar incidentes em 3 sensores instalados aleatoriamente no chão da floresta e um sensor localizado em área aberta (sensor padrão) são avaliadas e intercomparadas. A radiação média que atinge o chão da floreeta foi 4.7% da radiação incidente em área aberta adjacente à floresta. As diferenças entre as medidas dos sensores da mata e o padrão pode ser atribuída à distribuição espacial heterogênea da radiação solar que alcança o chão da floresta.

Observations on aquatic Macrophyte Dynamics In the Reservoir Of The Balbina Hydroelectric Powerplant, Amazonas State, Brazil

Between 1991 and 1995 aquatic macrophyte composition was observed in the lower part of the reservoir of the hydroelectric power plant of Balbina (Amazonas, Brazil). After closure of the dam in 1987, vegetation cover - mostly Eichhornia crassipes - was high, but was not quantified. After 1990 it declined rapidly with a characteristic succession pattern: Eichhornia ® Vincularia + Cyperaceae ® Salvinia. The Cyperaceae, and many other less dominant species, were mostly associated with drift wood, produced by the decomposing, emergent forest. Comparison of the chemical data of the Uatumã river before the construction of the dam (1983) with those of later years (1989 - 1995) suggests that the succession was the result of a relatively mild and short period of eutrophication, followed by declining nutrient levels. Annual variation of water levels, followed by aquatic and terrestrial decomposition of the marginal vegetation, may allow for the maintenance of relatively productive vegetation belts along the shore lines of islands and inundated stream valleys.