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Epidemiological studies generally use particulate matter measurements with diameter less 2.5 μm (PM 2.5 ) from monitoring networks. Satellite aerosol optical depth (AOD) data has considerable potential in predicting PM 2.5 concentrations, and thus provides an alternative method for producing knowledge regarding the level of pollution and its health impact in areas where no ground PM 2.5 measurements are available. This is the case in the Brazilian Amazon rainforest region where forest fires are frequent sources of high pollution. In this study, we applied a non-linear model for predicting PM 2.5 concentration from AOD retrievals using interaction terms between average temperature, relative humidity, sine, cosine of date in a period of 365,25 days and the square of the lagged relative residual. Regression performance statistics were tested comparing the goodness of fit and R 2 based on results from linear regression and non-linear regression for six different models. The regression results for non-linear prediction showed the best performance, explaining on average 82% of the daily PM 2.5 concentrations when considering the whole period studied. In the context of Amazonia, it was the first study predicting PM 2.5 concentrations using the latest high-resolution AOD products also in combination with the testing of a non-linear model performance. Our results permitted a reliable prediction considering the AOD-PM 2.5 relationship and set the basis for further investigations on air pollution impacts in the complex context of Brazilian Amazon Region. [ABSTRACT FROM AUTHOR]

This study presents an environmental assessment of a bi-fuel Thermal Power Plant (TPP) in the Brazilian Amazon Region. The TPP was originally designed to use Heavy Fuel Oil (HFO), but with the Natural Gas (NG) extraction in the Amazon basin, the TPP was modified to use NG and HFO concomitantly. In order to observe the differences, a comparative study of this power plant was performed in two situations: using only heavy fuel oil and using HFO and NG concomitantly. The life cycle assessment methodology was conducted from “cradle-to-gate”. The CML baseline method was used to assess the midpoint impacts. Primary data were collected by personal visits for environmental emissions, wastewater, fuel used, and technical specifications. Eleven impact categories were considered and Monte Carlo (MC) Analysis was used to assess and to obtain robust results. The study shows that upstream processes have more impacts except global warming potential, eutrophication, acidification, human toxicity and photochemical oxidation where TPP showed the main contribution. The bi-fuel conversion resulted in lower power plant participations in the impacts as, for example, a reduction of 61.1% in Eutrophication Potential. In addition, throughout the life cycle the bi-fuel power plant, when the operation is compared with HFO only, has six potential impacts lower. Furthermore, this study showed that bi-fuel operation has lower local and regional impact, and according to the MC analysis, statistically, bi-fuel operation does not contribute to exacerbate global trends in GHG emissions when compared with monofuel operation. It is an interesting observation that global warming results by MC analysis showed that there are no statistical differences between the two modes of operation. [ABSTRACT FROM AUTHOR]

The characterization of behavioral patterns allows a better understanding of the transmission dynamics and the design of more effective malaria vector control strategies. This study analyzed the behavioral patterns of the Anopheles species of the Coração district situated in the northeast of the Brazilian Amazon region. The behavioral patterns of the anopheline species were measured based on the 36 collection sites of this district from December 2010 to November 2011. Collections of four hours for three consecutive nights each month and four 12-h collections, comprising two in the rainy season and two in the dry season, were performed. Furthermore, to infer the anthropophily and zoophily indexes, four additional four-hour collections were performed. The samples were also evaluated for parity rate and natural infectivity for Plasmodium spp. A total of 1689 anophelines were captured, comprising of nine species and two subgenera ( Nyssorhynchus – six species, and Anopheles – three species). Anopheles darlingi was the most abundant and widely distributed species in the area, followed by A. braziliensis and A.marajoara . Anopheles darlingi and A. marajoara were the only species present in the four collections of 12-h, but only A. darlingi showed activity throughout night. Anopheles darlingi was the most anthropophilic species (AI = 0.40), but the zoophily index was higher (ZI = 0.60), revealing an eclectic and opportunistic behavior. Of the six most frequent species, A. nuneztovari s.l. was the most zoophilic species (ZI = 1.00). All captured species showed predominance towards biting in outdoor environments. Anopheles darlingi and A. braziliensis showed multimodal biting peaks, whereas A. marajoara revealed a stable pattern, with the biting peak after sunset. Using the PCR technique, no anopheline was found infected with the malaria parasite. Since A. darlingi and A. marajoara are recognized as important vectors in this region, the district of Coração may be considered as a highly potent area for transmission of malaria, therefore, the prevention and surveillance measures should be taken constantly to prevent the same. The role of A. braziliensis as malaria vector needs to be urgently investigated. [ABSTRACT FROM AUTHOR]

Having a river basin as the study site, it is of fundamental importance to comprehend the sediment dynamics of river systems, in order to diagnose and understand them, aiming to carry out predictions. The observance of the sediment supply carried by the river systems is related to the erosion, transport and deposition, through rainfall and dynamic land use and cover in hillside environments. The Purus River basin is part of this context, the study area of this paper and it is located in the Amazon biome. This study aims to start the first steps to understand the suspended sediment dynamics of that basin, because of its expressive environmental variations. For this purpose was considered the sediment present in the river systems as an indicator which can be understood and used in order to support soil and water conservation measures in the Purus River basin, distinguishing the natural dynamics and anthropogenic dynamics. Thus, this study has the objective of evaluating the suspended sediments discharge in the Purus River basin, in order to collaborate with action planning and watershed management, with the objective of generating knowledge about the suspended sediment dynamics of that spring. [ABSTRACT FROM PUBLISHER]

Abstract: The aim of this study was to assess the prevalence pattern of mixed-Plasmodium falciparum malaria infections in Brazil by molecular diagnosis and to address its clinically important features. DNA was extracted from 115 thick blood film P. falciparum human blood positive samples using the phenol–chloroform method, followed by a semi-nested PCR protocol with species-specific primers. Seventy-three percent of P. falciparum single infections and 26.95% of mixed infections were found. Amongst mixed infections, the majority was double infection (96.77%). Our results suggest that the prevalence of one species over the other can be important on weakening P. falciparum malaria clinical symptoms. We confirm that P. falciparum co-infections frequently occur in Brazilian malaria endemic areas, with underestimated diagnosis. The results point to the need of improving microscopy or changing for another accurate diagnosis technique to differentiate among human malaria species, as this is essential to choose the best treatment and control measure for malaria. More investigations are necessary in order to clarify the role of mixed-infections in the severity of P. falciparum disease. [Copyright &y& Elsevier]

We compared the serological phenotypic frequencies of ABO, MNSs, and Duffy in 417 blood donors and 309 malaria patients from four Brazilian Amazon areas. Our results suggest no correlation between ABO phenotype and malaria infection in all areas studied. We observed significant correlation between the S+s+, S+s -, and S-s+ phenotypes and malaria infection in three areas. Some of the Duffy phenotypes showed significant correlation between donors and malaria patients in different areas. These data are an additional contribution to the establishment of differential host susceptibility to malaria. [ABSTRACT FROM AUTHOR]

Carbon isotope data on soil organic matter (SOM) were collected along an ecosystem transect 90 m in length that includes a tropical forest on the plateau, a transitional forest-savanna and savanna in a depression. Total organic carbon data show a significant increase in carbon content from sites representing forest ecosystem to sites representing savanna ecosystem. It was hypothesized that carbon accumulation in the depression is controlled by flooding conditions that slow down carbon decomposition and in part by carbon transport from the upper part of the transect (the savanna and the transition forest-savanna areas) into the depressions by water during the rainy season. The origin of the carbon was confirmed by using soil 13 C analysis. The savanna sites located in the depression showed d 13 C values between –19.5‰ and –22.5‰ indicating a mixture of C3 and C4 plants. The vegetation cover in the depression is predominantly C3 grasses with d 13 C values of about –27‰ and –26‰. In the site under savanna located at an elevation slightly higher, the d 13 C value was more enriched (–16‰) showing the predominance of C4 plants ( d 13 C of –13.6‰). At the forest-savanna transition and in the forest ecosystem the d 13 C values were characteristic of C3 plants (–25‰ and –28.1‰). 14 C and 13 C data indicate that the organic matter of mixed origin has been deposited for at least the last 7000 years in the savanna depressions. The 13 C pattern observed in the soil organic matter profiles indicate a predominance of C3 plants in the early part of the Holocene. About 7000 to 4000 years ago, the data show the influence of C4 plants, indicating forest regression associated with a drier climate than at present. The more recent 13 C records suggest forest expansion, and the return to a climate similar to the present. [ABSTRACT FROM AUTHOR]