Epidemiologia da leishmaniose tegumentar americana no Estado do Acre, Amazônia brasileira

Efetuou-se estudo estatístico descritivo em 8.516 casos de leishmaniose tegumentar americana no Estado do Acre, Brasil, no período de 2001 a 2006 (segundo período), comparando-se com os resultados de publicação anterior com dados no mesmo estado entre 1992 e 1997 (primeiro período). A prevalência no estado mais que dobrou entre os dois momentos (55,7/10 mil habitantes de 1992 a 1997 e 128,5/10 mil habitantes entre 2001 e 2006. O sexo masculino foi o mais acometido (68,8%, n = 5.860) no segundo período. A média das idades foi de 26,3 anos, valor discretamente menor do que o do primeiro período. Pacientes com baixa escolaridade foram os mais acometidos pela doença. As demais variáveis avaliadas foram zona de residência, ocupação, critério de diagnóstico, forma clínica, tratamento, recidiva, tempo para procurar tratamento e evolução da doença. Conclui-se que houve piora nos indicadores epidemiológicos da leishmaniose tegumentar americana avaliados no estado entre os períodos estudados.

Epidemiological investigation of an acute case of Chagas disease in an area of active transmission in Peruvian Amazon region

The study objective was to investigate an acute case of Chagas disease in the San Pedro de Shishita community, Pebas District, in the Peruvian Amazon basin, a non-endemic area. Both parents of the index case (acute case) were thoroughly interviewed, a seroepidemiological survey was carried out in the community, parasitological exams were carried out only in relatives of the index case, and triatomine bugs were searched for inside houses, peridomiciliary, and in wild environments. Seroprevalence for IgG anti-T. cruzi antibodies was 1/104 (0.96%), using an ELISA test and an indirect immunofluorescence assay. Panstrongylus geniculatus and Rhodnius pictipes adults were found. The index case is autochthonous from San Pedro de Shishita, but the source of transmission is unknown.

New focus of active transmission of Chagas disease in indigenous populations in the Peruvian Amazon basin

Introduction Several cases of acute Chagas disease (ACD) have been reported in the Peruvian Amazon basin. Methods The objective was to describe and investigate 6 ACD cases in children from indigenous Amazon communities in the province of Datem del Marañón in Loreto department (2006-2010). Results The mean age was 3.6 years. All patients had fever, 4/6 hepatomegaly, 2/6 splenomegaly, and 5/6 had trypomastigotes of Trypanosoma cruzi on thick smears. The fatality rate was 33.3%. Rhodnius pictipes and Rhodnius robustus adults were found inside the homes and in the peri-domiciles. Conclusions All cases reported were isolated cases. We report a new focus of ACD in indigenous populations.

Amazonia boliviana: arqueología de los Llanos de Mojos

A arqueologia da Amazônia boliviana ou das "Terras Baixas" compreende um imenso território que mostra, a luz da informação disponível, significativas descontinuidades espaço-temporais. A identificação nesta área de sociedades constituindo "cacicados da floresta tropical" a partir de critérios baseados em preconceitos, requer a reavaliação da pré-história regional do ponto de vista causal. A arqueologia beniana (de Llanos de Mojos) é conhecida, fundamentalmente, a partir das escavações de Erland Nordenskiöld, que sem dúvida estabeleceu as bases conceituais existentes atualmente. Entre os anos de 1977 e 1981 uma missão do Museu de La Plata (Argentina), sob a direção de B. Dougherty, e em estreita colaboração com o Instituto de Arqueologia de La Paz (Bolívia) e com o Amazonian Ecosystem Research (EUA), conduziu pesquisas sistemáticas considerando variados itens antropológicos e produzindo numerosas datações de radiocarbono. Estas contribuições ajudaram a esclarecer, mas não a simplificar o panorama pré-hispânico regional, tão importante na temática arqueológica sul-americana. Complementa este artigo uma exaustiva lista de bibliografias que facilita o acesso ao conhecimento sobre este grande território.

Association between particulate matter from biomass burning and respiratory diseases in the southern region of the Brazilian Amazon

Objective. To investigate the short-term effects of exposure to particulate matter from biomass burning in the Amazon on the daily demand for outpatient care due to respiratory diseases in children and the elderly. Methods. Epidemiologic study with ecologic time series design. Daily consultation records were obtained from the 14 primary health care clinics in the municipality of Alta Floresta, state of Mato Grosso, in the southern region of the Brazilian Amazon, between January 2004 and December 2005. Information on the daily levels of fine particulate matter was made available by the Brazilian National Institute for Spatial Research. To control for confounding factors ( situations in which a non-causal association between exposure and disease is observed due to a third variable), variables related to time trends, seasonality, temperature, relative humidity, rainfall, and calendar effects ( such as occurrence of holidays and weekends) were included in the model. Poisson regression with generalized additive models was used. Results. A 10 mu g/m(3) increase in the level of exposure to particulate matter was associated with increases of 2.9% and 2.6% in outpatient consultations due to respiratory diseases in children on the 6th and 7th days following exposure. Significant associations were not observed for elderly individuals. Conclusions. The results suggest that the levels of particulate matter from biomass burning in the Amazon are associated with adverse effects on the respiratory health of children.

Aerosols in Amazonia: Natural Biogenic Particles and Large Scale Biomass Burning Impacts.

The Large Scale Biosphere Atmosphere Experiment in Amazonia (LBA) is a long term (20 years) research effort aimed at the understanding of the functioning of the Amazonian ecosystem. In particular, the strong biosphere-atmosphere interaction is a key component looking at the exchange processes between vegetation and the atmosphere, focusing on aerosol particles. Two aerosol components are the most visible: The natural biogenic emissions of aerosols and VOCs, and the biomass burning emissions. A large effort was done to characterize natural biogenic aerosols that showed detailed organic characterization and optical properties. The biomass burning component in Amazonia is important in term of aerosol and trace gases emissions, with deforestation rates decreasing, from 27,000 Km2 in 2004 to about 5,000 Km2 in 2011. Biomass burning emissions in Amazonia increases concentrations of aerosol particles, CO, ozone and other species, and also change the surface radiation balance in a significant way. Long term monitoring of aerosols and trace gases were performed in two sites: a background site in Central Amazonia, 55 Km North of Manaus (called ZF2 ecological reservation) and a monitoring station in Porto Velho, Rondonia state, a site heavily impacted by biomass burning smoke. Several instruments were operated to measured aerosol size distribution, optical properties (absorption and scattering at several wavelengths), composition of organic (OC/EC) and inorganic components among other measurements. AERONET and MODIS measurements from 5 long term sites show a large year-to year variability due to climatic and socio-economic issues. Aerosol optical depths of more than 4 at 550nm was observed frequently over biomass burning areas. In the pristine Amazonian atmosphere, aerosol scattering coefficients ranged between 1 and 200 Mm-1 at 450 nm, while absorption ranged between 1 and 20 Mm-1 at 637 nm. A strong seasonal behavior was observed, with greater aerosol loadings during the dry season (Jul-Nov) as compared to the wet season (Dec-Jun). During the wet season in Manaus, aerosol scattering (450 nm) and absorption (637 nm) coefficients averaged, respectively, 14 and 0.9 Mm-1. Angstrom exponents for scattering were lower during the wet season (1.6) in comparison to the dry season (1.9), which is consistent with the shift from biomass burning aerosols, predominant in the fine mode, to biogenic aerosols, predominant in the coarse mode. Single scattering albedo, calculated at 637 nm, did not show a significant seasonal variation, averaging 0.86. In Porto Velho, even in the wet season it was possible to observe an impact from anthropogenic aerosol. Black Carbon was measured at a high 20 ug/m³ in the dry season, showing strong aerosol absorption. This work presents a general description of the aerosol optical properties in Amazonia, both during the Amazonian wet and dry seasons.

Comparing properties of natural biogenic with biomass burning particles in Amazonia.

The Large Scale Biosphere Atmosphere Experiment in Amazonia (LBA) is a long-term (20 years) research effort aimed at the understanding of the functioning of the Amazonian ecosystem. The strong biosphere-atmosphere interaction is a key component of the ecosystem functioning. Two aerosol components are the most visible: The natural biogenic emissions of particles and VOCs, and the biomass burning emissions. Two aerosol and trace gases monitoring stations were operated for 4 years in Manaus and Porto Velho, two very distinct sites, with different land use change. Manaus is a very clean and pristine site and Porto Velho is representative of heavy land use change in Amazonia. Aerosol composition, optical properties, size distribution, vertical profiling and optical depth were measured from 2008 to 2012. Aerosol radiative forcing was calculated over large areas. It was observed that the natural biogenic aerosol has significant absorption properties. Organic aerosol dominates the aerosol mass with 80 to 95%. Light scattering and light absorption shows an increase by factor of 10 from Manaus to Porto Velho. Very few new particle formation events were observed. Strong links between aerosols and VOC emissions were observed. Aerosol radiative forcing in Rondonia shows a high -15 watts/m² during the dry season of 2010, showing the large impacts of aerosol loading in the Amazonian ecosystem. The increase in diffuse radiation changes the forest carbon uptake by 20 to 35%, a large increase in this important ecosystem.

Solar energy budgets in central Amazonian ecosystems: a comparison between natural forest and bare soil areas

In order to estimate the deforestation consequences on the actual solar energy budget of the Central Amazon Region, two ecosystems of different characteristics were compared. The present conditions of the region were represented by a typical 'terra firme' forest cover located at INPA's Ducke Forest Reserve, where the measurements necessary to evaluate its solar energy balance were carried out. The second ecosystem, simulating a deforested area, was represented by an area about 1.0 ha without natural vegetation and situated in the same Reserve. In this area lysimeters were placed, two of them filled with yellow latosol and two others with quartzose sand soil. Both soils are representative soils in the region. Their water balances were taken into account as well as the other parameters necessary to compute the solar energy balances. The results showed that water loss by evaporation was about 41.8% of the total precipitation in the yellow latosol lysimeters and about 26.4% for the quartzose sand ones. For the forest cover it was estimated an evapotranspiration of 67.9% of the rainfall amount. In relation to solar energy balance calculated for the forest cover, it was found that 83.1% of the total energy incoming to this ecosystem was used by the evapotranspiration process, while the remaining of 16.9% can be taken as sensible heat. For bare soils, 55.1% and 31.8% of the total energy were used as latent heat by yellow latosol and quartzose sand soils, respectively. So, the remaining amounts of 44.9% and 68.2% were related to sensible heat and available to atmospheric air heating of these ecosystems. Such results suggest that a large deforestation of the Amazon Region would have direct consequences on their water and solar radiation balances, with an expected change on the actual climatic conditions of the region. © 1993.

Mechanical tillage of degraded mining areas at Jamari national forest (Amazonian forest, Rondônia - BR)

According to the environmental legislation enforced in Brazil and the process of marketing globalization, the commitment of the nations to the preservation of the environment is intensified. By reason of nature's negative responses to its intensive use, awareness then appears from enterprises and agencies about how the anthropic action over the environment needs to be minimized, becoming a challenge: development and sustainability. In this context, the present work made use of the Mechanical tillage of the soil, as a technique to apply, in a large scale, the strategies and methods to recover mined areas that were researched and developed experimentally by researchers on a theme project about the recovering of degraded areas. This work was conducted in the Amazon ecosystem, inside the Jamari National Forest - Rondônia (FLONA do Jamari), in deactivated cassiterite mines. The objectives of this work were to: Develop a computational program capable of managing a database and assist in the selection of machines and preparation methods to execute the operations of topographical reconstitution and tillage of surfaces in areas degraded by the mineral exploitation of cassiterite. Use the program that was developed in the planning of costs and operational development, for the operations required in the strategies for recovering the areas. Analyze the vegetable productivity in the mobilized areas and the quality of the superficial mobilization, making use of indicators and tillage methods. Evaluate, through biological indicators, the efficiency of the recovery strategies and techniques that were mechanized and applied on the location. The results showed that the developed computational program (SGMAD) served the methodological purposes (the analysis of costs and operational capacity) established for the planning and the selection of the tillage machines and methods in the areas of mineral exploitation of cassiterite. The applied methods and quality of the superficial mobilization were significant to the development of leguminous plants in the areas. The use of biological indicators (microbial biomass and enzymatic activity) in the evaluation of the adopted techniques and strategies revealed that the planting of leguminous plants and their posterior incorporation have been promoting gradually positive alterations in some of the analyzed soil/substract parameters. © 2010 WIT Press.

Root niche separation can explain avoidance of seasonal drought stress and vulnerability of overstory trees to extended drought in a mature Amazonian forest

Large areas of Amazonian evergreen forest experience seasonal droughts extending for three or more months, yet show maximum rates of photosynthesis and evapotranspiration during dry intervals. This apparent resilience is belied by disproportionate mortality of the large trees in manipulations that reduce wet season rainfall, occurring after 2-3 years of treatment. The goal of this study is to characterize the mechanisms that produce these contrasting ecosystem responses. A mechanistic model is developed based on the ecohydrological framework of TIN (Triangulated Irregular Network)-based Real Time Integrated Basin Simulator + Vegetation Generator for Interactive Evolution (tRIBS+VEGGIE). The model is used to test the roles of deep roots and soil capillary flux to provide water to the forest during the dry season. Also examined is the importance of "root niche separation," in which roots of overstory trees extend to depth, where during the dry season they use water stored from wet season precipitation, while roots of understory trees are concentrated in shallow layers that access dry season precipitation directly. Observational data from the Tapajo's National Forest, Brazil, were used as meteorological forcing and provided comprehensive observational constraints on the model. Results strongly suggest that deep roots with root niche separation adaptations explain both the observed resilience during seasonal drought and the vulnerability of canopy-dominant trees to extended deficits of wet season rainfall. These mechanisms appear to provide an adaptive strategy that enhances productivity of the largest trees in the face of their disproportionate heat loads and water demand in the dry season. A sensitivity analysis exploring how wet season rainfall affects the stability of the rainforest system is presented. Citation: Ivanov, V. Y., L. R. Hutyra, S. C. Wofsy, J. W. Munger, S. R. Saleska, R. C. de Oliveira Jr., and P. B. de Camargo (2012), Root niche separation can explain avoidance of seasonal drought stress and vulnerability of overstory trees to extended drought in a mature Amazonian forest, Water Resour. Res., 48, W12507, doi:10.1029/2012WR011972.

Disproportionate single-species contribution to canopy-soil nutrient flux in an Amazonian rainforest

Rainfall, throughfall and stemflow were monitored on an event basis in an undisturbed open tropical rainforest with a large number of palm trees located in the southwestern Amazon basin of Brazil. Stemflow samples were collected from 24 trees with a diameter at breast height (DBH) > 5 cm, as well as eight young and four full-grown babassu palms (Attalea speciosa Mart.) for 5 weeks during the peak of the wet season. We calculated rainfall, throughfall and stemflow concentrations and fluxes of Na+, K+, Ca2+, Mg2+,, Cl-, SO42-, NO3- and H+ and stemflow volume-weighted mean concentrations and fluxes for three size classes of broadleaf trees and three size classes of palms. The concentrations of most solutes were higher in stemflow than in rainfall and increased with increasing tree and palm size. Concentration enrichments from rainfall to stemflow and throughfall were particularly high (81-fold) for NO3-. Stemflow fluxes of NO3- and H+ exceeded throughfall fluxes but stemflow fluxes of other solutes were less than throughfall fluxes. Stemflow solute fluxes to the forest soil were dominated by fluxes on babassu palms, which represented only 4% of total stem number and 10% of total basal area. For NO3-, stemflow contributed 51% of the total mass of nitrogen delivered to the forest floor (stemflow + throughfall) and represented more than a 2000-fold increase in NO3- flux compared what would have been delivered by rainfall alone on the equivalent area. Because these highly localized fluxes of both water and NO3- persist in time and space, they have the potential to affect patterns of soil moisture, microbial populations and other features of soil biogeochemistry conducive to the creation of hotspots for nitrogen leaching and denitrification, which could amount to an important fraction of total ecosystem fluxes. Because these hotspots occur over very small areas, they have likely gone undetected in previous studies and need to be considered as an important feature of the biogeochemistry of palm-rich tropical forest. (C) 2011 Elsevier B.V. All rights reserved.

Ecosystem Engineering Effects On Species Diversity Across Ecosystems: A Meta-analysis.

Ecosystem engineering is increasingly recognized as a relevant ecological driver of diversity and community composition. Although engineering impacts on the biota can vary from negative to positive, and from trivial to enormous, patterns and causes of variation in the magnitude of engineering effects across ecosystems and engineer types remain largely unknown. To elucidate the above patterns, we conducted a meta-analysis of 122 studies which explored effects of animal ecosystem engineers on species richness of other organisms in the community. The analysis revealed that the overall effect of ecosystem engineers on diversity is positive and corresponds to a 25% increase in species richness, indicating that ecosystem engineering is a facilitative process globally. Engineering effects were stronger in the tropics than at higher latitudes, likely because new or modified habitats provided by engineers in the tropics may help minimize competition and predation pressures on resident species. Within aquatic environments, engineering impacts were stronger in marine ecosystems (rocky shores) than in streams. In terrestrial ecosystems, engineers displayed stronger positive effects in arid environments (e.g. deserts). Ecosystem engineers that create new habitats or microhabitats had stronger effects than those that modify habitats or cause bioturbation. Invertebrate engineers and those with lower engineering persistence (<1 year) affected species richness more than vertebrate engineers which persisted for >1 year. Invertebrate species richness was particularly responsive to engineering impacts. This study is the first attempt to build an integrative framework of engineering effects on species diversity; it highlights the importance of considering latitude, habitat, engineering functional group, taxon and persistence of their effects in future theoretical and empirical studies.

Dental caries profile in Monte Negro, Amazonian state of Rondônia, Brazil, in 2008

OBJECTIVE: This epidemiological survey assessed the dental caries profile in Monte Negro, a small town in the Amazonian state of Rondônia, Brazil, and its relationship with the northern region, national and global goals for oral health in the years 2000 and 2020. MATERIAL AND METHODS: The groups randomly examined were composed of individuals aged 5, 12, 15 to 19, 35 to 44, 65 to 74 years, living in both rural and urban areas. RESULTS: The means dft (standard deviation) and DMFT (standard deviation) for the groups were, respectively, 3.15 (3.12), 3.41 (2.69), 5.96 (4.19), 16.00 (7.30) and 25.96 (9.82). Caries-free individuals were 34.42%, 14.81% and 8.16% in the preschoolchildren, schoolchildren and adolescent groups, respectively. The Significant Caries Index percentages applied to the two younger groups were 6.65 and 6.70, and they increased to 32.00 in the individuals aged 65 to 74 years. Care Index percentages for adolescents, adults and elderly groups were, respectively, 29.40, 25.00 and 1.41. The dental caries profile in Monte Negro in 2008 shows that, 8 years after the year 2000, no FDI/WHO goal for any age settled in 1982 has been achieved. Dental caries increased with age and the main dental problem of adult and elderly groups was tooth loss. CONCLUSION: Oral health promotion and prevention of oral disease policies are urgent needs. Setting of oral health goals and targets to people living in Monte Negro or Amazonia to be pursuit and achieved in a near future is an important action to do because of the culture, sanitary conditions and socioeconomic aspects of this particular population.