Identification of vector species (Diptera: Simuliidae) of human onchocerciasis in the Amazonia focus of Brazil and Venezuela

The taxonomic status of three Amazonian simuliid species, Simulium guianese Wise, S. oyapockense Floch & Abonnenc and S. yarzabali Ramirez Perez is reviewed. Simulium cuasisanguineum Ramirez Perez, Yarzabal & Peterson is synonymized with S. oyapockense, and S. yarzabali is revalidated from its synonymy with S. incrustatum Lutz. The role of these three species in the transmission of human onchocerciasis and mansonelliasis in Amazonia is reviewed.

The Amazonia Variant of Vibrio cholerae: Molecular Identification and Study of Virulence Genes

The pathogenic O1 Amazonia variant of Vibrio cholerae has been shown previously to have a cytotoxin acting on cultured Vero and Y-1 cells, and to lack important virulence factors such as the cholera toxin (Coelho et al. 1995a). This study extends the molecular analysis of the Amazonia strains, detecting the presence of the toxR gene, with a very similar sequence to that of the El Tor and classical biotypes. The outer membrane proteins are analyzed, detecting a variation among the group of Amazonia strains, with three different patterns found. As a by-product of this work a polymerase chain reaction fragment was sequenced, reading part of the sequence of the Lon protease of the Amazonia strains. This gene was not previously described in V. cholerae, but its sequence is present in the TIGR database specific for this species.

Outstanding insecurities concerning the use of an Ov16-based ELISA in the Amazonia onchocerciasis focus

In a recent issue of Memórias do Instituto Oswaldo Cruz, published in Rio de Janeiro in February 2014 (109: 87-92), Adami et al. have published a survey reporting Mansonella parasite prevalence in the Amazon Region. This report makes a useful contribution to the existing knowledge of filarial parasite distribution within the Amazon area, parasite prevalence rates in relation to age and occupation and provides observations on the possible clinical impact of Mansonella ozzardi. Their publication also provides an account of what appears to be a novel ELISA that has recently been used in the Simuliidae and Onchocerciasis Laboratory of the Oswaldo Cruz Institute, Rio de Janeiro, Brazil. We are concerned that the publication of this ELISA may have created an excessively positive impression of the effectiveness of the onchocerciasis recrudescence serological surveillance tools that are presently available for use in the Amazonia onchocerciasis focus. In this letter we have, thus, sought to highlight some of the limitations of this ELISA and suggest how continuing insecurities concerning the detection of antibodies to Onchocerca volvulus within the Amazonia onchocerciasis focus might be minimised.

Do the recent severe droughts in the Amazonia have the same period of length?

5 figures Acknowledgments This work was partially supported by the NNSFC (Grant Nos. 11305062, 11135001), the DFG/FAPESP (Grant No. IRTG 1740/TRP 2011/50151-0), and Government of the Russian Federation (Agreement No. 14.Z50.31.0033 with Institute of Applied Physics RAS). All data for this paper is properly cited and referred to in the reference list.

The neuraminidase gene is present in the non-toxigenic Vibrio cholerae Amazonia strain: a different allele in comparison to the pandemic strains

The neuraminidase gene, nanH, is present in the O1, non-toxigenic Vibrio cholerae Amazonia strain. Its location has been assigned to a 150 kb NotI DNA fragment, with the use of pulsed-field gel electrophoresis and DNA hybridization. This NotI fragment is positioned inside 630 kb SfiI and 1900 kb I-CeuI fragments of chromosome 1. Association of the pathogenicity island VPI-2, carrying nanH and other genes, with toxigenic strains has been described by other authors. The presence of nanH in a non-toxigenic strain is an exception to this rule. The Amazonia strain nanH was sequenced (Genbank accession No. AY825932) and compared to available V. cholerae sequences. The sequence is different from those of pandemic strains, with 72 nucleotide substitutions. This is the first description of an O1 strain with a different nanH allele. The most variable domain of the Amazonia NanH is the second lectin wing, comprising 13 out of 17 amino acid substitutions. Based on the presence of nanH in the same region of the genome, and similarity of the adjacent sequences to VPI-2 sequences, it is proposed that the pathogenicity island VPI-2 is present in this strain.

An INDEL polymorphism at the X-STR GATA172D05 flanking region

A new polymorphic INDEL was detected at the X-STR GATA172D05 flanking region, which corresponds to an 18-bp deletion, 141 bp upstream the TAGA repeat motif. This INDEL was found to be polymorphic in different population samples from Native Americans, Africans, and Europeans as well as in an admixed population from the Amazonia (Bel,m). Gene diversities varied between 37.5% in Native Americans and 49.9% in Africans. Comparison between human and chimpanzee sequences showed that the ancestral state corresponds to the presence of two copies of 18 bp, detected in both species; and the mutated allele has lost one of these two copies. The simultaneous analysis of the short tandem repeat (STR) and INDEL variation showed an association between the INDEL ancestral allele with the shorter STR alleles. High diversities were found in all population groups when combining the information provided by the INDEL and STR variation. Gene diversities varied between 76.7% in Native Americans and 80.6% in both Portugal and Bel,m.

Litterfall production in intact and selectively logged forests in southern of Amazonia as a function of basal area of vegetation and plant density

Nutrient recycling in the forest is linked to the production and decomposition of litter, which are essential processes for forest maintenance, especially in regions of nutritionally poor soils. Human interventions in forest such as selecttive logging may have strong impacts on these processes. The objectives of this study were to estimate litterfall production and evaluate the influence of environmental factors (basal area of vegetation, plant density, canopy cover, and soil physicochemical properties) and anthropogenic factors (post-management age and exploited basal area) on this production, in areas of intact and exploited forest in southern Amazonia, located in the northern parts of Mato Grosso state. This study was conducted at five locations and the average annual production of litterfall was 10.6 Mg ha-1 year-1, higher than the values for the Amazon rainforest. There were differences in litterfall productions between study locations. Effects of historical logging intensity on litterfall production were not significant. Effects of basal area of vegetation and tree density on litterfall production were observed, highlighting the importance of local vegetation characteristics in litterfall production. This study demonstrated areas of transition between the Amazonia-Cerrado tend to have a higher litterfall production than Cerrado and Amazonia regions, and this information is important for a better understanding of the dynamics of nutrient and carbon cycling in these transition regions.

La Amazonia como elemento geopolítico determinante en la consolidación de Brasil como potencia regional (1988-2011)

La presente monografía busca analizar el papel geopolítico del Amazonas en el proceso de consolidación de Brasil como potencia regional, en el periodo de 1988 al 2011. Desde la democratización de Brasil en 1988, este país empezó a tener un papel destacado en la región debido a su liderazgo en los procesos de integración, estimulado por su intención de ser potencia regional. Ahora bien, esta pretensión no surge exclusivamente como efecto de los nuevos fenómenos de la posguerra fría, de hecho, tiene su origen con los postulados de la escuela geopolítica brasileña de mediados de 1930, donde nace la idea de un Brasil con un destino manifiesto de proyectarse continentalmente, que debe cumplir mediante el desarrollo del Amazonas. Por lo anterior, el Amazonas se consolida como un elemento determinante para Brasil como potencia regional, que por ende, ha definido el direccionamiento de sus políticas nacionales y regionales.

An analysis of the floristic composition and diversity of Amazonian forests including those of the Guiana Shield

A large number of newly published and unpublished hectare plots in Amazonia and the Guiana Shield area allow an analysis of family composition and testing of hypotheses concerning alpha-diversity in the south American rain forest. Using data from 94 plots the family-level floristic patterns in wet tropical South America are described. To test diversity patterns, 268 plots are used in this large area. Contrary to a widely held belief, western Amazonian plots are not necessarily the most diverse. Several central Amazonian plots have equal or even higher tree diversity. Annual rainfall is not a good estimator for tree diversity in the Amazonia area and Guiana shield. Plots in the Guiana Shield area (and eastern Amazonia) usually have lower diversity than those in central or western Amazonia. It is argued that this is not because of low rainfall or low nutrient status of the soil but because of the small area of the relatively isolated rain forest area in eastern Amazonia and the Guiana Shield. The low diversity on nutrient-poor white sand soils in the Amazon basin is not necessarily due to their Low nutrient status but is, at least partly, caused by their small extent and fragmented nature.

GPS performance in the quantification of integrated water vapor in Amazonian regions

The Amazonian regions are characterized by large space-time variability in the humidity fields due to the intense convective process in those areas associated with the great humidity potential generated by high temperatures. An experiment denominated RACCI/DRY-TO-WET (RAdiation, Cloud, and Climate Interactions in the Amazonia during the DRY-TO-WET Transition Season) was carried out in the Brazilian Amazonian Region in 2002. The IWV values from GPS and other techniques, such as radiosondes, radiometer and humidity sounding satellites were used in this experiment to supply subsidies to evaluate the aerosols influence in the associated processes modifications to seasonality of atmospheric water vapor. Those regions are one of the most humid of the planet, where IWV (Integrated Water Vapor) average values are in the order of 50 kg/m2. As according the literature the IWV quantification using GPS has not been explored in those circumstances, the objective this paper is to present the preliminary results obtained in the evaluation of the GPS performance in Amazonian Regions when comparing with other techniques. The tendency measurement values indicated that the IWV values from GPS tend to be larger than those from radiosondes and smaller than those from radiometer. On the other hand, IWV values from GPS are very close of the average values supplied by radiosondes and radiometer. Due to the great amount of atmospheric water vapor existent in this region, the results obtained in the experiment in percentile terms are quite better than those found in the literature, which are around of 10%.

Seasonal genetic partitioning in the neotropical malaria vector, Anopheles darlingi

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Soil and biomass mercury emissions during a prescribed fire in the Amazonian rain forest

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sedimentological and provenance response to Cambrian closure of the Clymene ocean: The upper Alto Paraguai Group, Paraguay belt, Brazil

Final Gondwana amalgamation was marked by the closure of the Neoproterozoic Clymene ocean between the Amazonia craton and central Gondwana. The events which occurred in the last stage of this closure were recorded in the upper Alto Paraguai Group in the foreland of the Paraguay orogen. Outcrop-based fades analysis of the siliciclastic rocks of upper Alto Paraguai Group, composed of the Sepotuba and Diamantino Formations, was carried out in the Diamantino region, within the eastern part of the Barra dos Bugres basin, Mato Grosso state, central-western Brazil. The Sepotuba Formation is composed of sandy shales with planar to wave lamination interbedded with fine-grained sandstone with climbing ripple cross-lamination, planar lamination, swaley cross-stratification and tangential to sigmoidal cross-bedding with mud drapes, related to marine offshore deposits. The lower Diamantino Formation is composed of a monotonous, laterally continuous for hundreds of metres, interbedded siltstone and fine-grained sandstone succession with regular parallel lamination, climbing ripple cross-lamination and ripple-bedding interpreted as distal turbidites. The upper part of this formation consists of fine to medium-grained sandstones with sigmoidal cross-bedding, planar lamination, climbing ripple cross-lamination, symmetrical to asymmetrical and linguoid ripple marks arranged in lobate sand bodies. These fades are interbedded with thick siltstone in coarsening upward large-scale cycles related to a delta system. The Sepotuba Formation characterises the last transgressive deposits of the Paraguay basin representing the final stage of a marine incursion of the Clymene ocean. The progression of orogenesis in the hinterland resulted in the confinement of the Sepotuba sea as a foredeep sub-basin against the edge of the Amazon craton. Turbidites were generated during the deepening of the basin. The successive filling of the basin was associated with progradation of deltaic lobes from the southeast, in a wide lake or a restricted sea that formed after 541 +/- 7 Ma. Southeastern to east dominant Neoproterozoic source regions were confirmed by zircon grains that yielded ages around 600 to 540 Ma, that are interpreted to be from granites in the Paraguay orogen. This overall regressive succession recorded in the Alto Paraguai Group represents the filling up of a foredeep basin after the final amalgamation of westem Gondwana in the earliest Phanerozoic. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Política ambiental del gobierno de Lula: el caso de la Amazonía (Tema Central)

El tema del calentamiento global y sus consecuencias pone en el orden del día la discusión sobre la protección y el control de la región amazónica al mismo tiempo que cuestiona la posibilidad del desarrollo sostenible bajo el capitalismo. En Brasil, Lula defiende la Amazonía en palabras, pero en los hechos impulsa una política económica que tiene como prioridad la entrega de los recursos naturales al capital nacional e internacional. ¿A quién interesa la conservación de la Amazonía brasileña?

Are biofuels a feasible option?

Recently a number of objections have been raised against the use of ethanol produced from agricultural products such as maize, sugarcane, wheat or sugar beets as a replacement for gasoline, despite some of their advantages such as being cleaner and to some extent renewable. We address these objections in this paper. Topics discussed include the ""corn connection"" (which was theorized to be a cause of deforestation in the Amazonia), the rise of food prices due to ethanol production and the real possibilities of ethanol in reducing greenhouse gas emissions. It has been shown that such concerns are grossly exaggerated and that ethanol from sugarcane, as produced in Brazil, is the preferred option for the production of fuel not only in terms of cost but also as a favourable energy balance. Finally, the possibility of expanding ethanol production to other sugar-producing countries is also discussed. (C) 2008 Elsevier Ltd. All rights reserved.