Does Alumina-Refining Waste Increase the Nutrient Level in Tropical Mesotrophic Floodplain Lakes?

Several floodplain lakes of the Orinoco River have been impacted by alkaline alumina-refining waste including red mud, a by-product from the Bayer process. Some of these impacted lakes have undergone algal overgrowth, which has been detected due to the unusual green color of water and the dissolved oxygen oversaturation. Thus, we conducted sampling campaigns in impacted and non-impacted lakes to measure the concentration of nitrogen (N) and phosphorous (P) in water to detect any change in the nutrient levels. Despite the content of N and P in red mud is low, our findings suggest that N is released from red mud accumulated in bed sediments to the water column in the impacted lakes, increasing the content of total N. However, the total P concentrations in impacted lakes were not affected from their background values probably due to the strong adsorptive behavior of P onto red mud minerals.

Temporal and spatial variability of heavy metals in bottom sediments and the aquatic macrophyte Paspalum repens of the Orinoco River floodplain lagoons impacted by industrial activities.

This study investigated the water parameters and the levels of several heavy metals in leaves and roots of the aquatic macrophyte Paspalum repens and in bed sediments of one unpolluted lagoon and two polluted lagoons of the Orinoco River floodplain to know the impact of the alumina refining wastes on these ecosystems. The sampling was performed during four hydrological periods, covering one hydrological year. Chemical parameters in water (pH, conductivity, and total dissolved solids) and the levels of Al, Pb, Cr, and Cu in sediments were the highest in Macanillal (LMaca) lagoon, whereas sediments of Punta Cuchillo (LPC) lagoon also had elevated concentrations of Al and Fe in comparison with Las Aruhacas (LArh) lagoon (unpolluted lagoon). Chemical parameters in waters returned almost to natural values during high water stage because of the huge inundation of the Orinoco River during the high discharge periods. The solid/liquid discharges of industrial effluents over these systems also affected the grain size distribution of sediments in the lagoons. In all the studied lagoons, the distribution of elements in leaves of P. repens was in the order K ≥ Cr > Ca > Mg > Al > Fe > Mn > Cu > Pb, whereas Al was found to be the more abundant element in roots. The high abundance of Cr in P. repens was related with the high Cr accumulation potential shown by aquatic macrophytes. Despite this, the concentration of elements in P. repens did not show differences between the plants collected in the polluted lagoons versus the plants collected in the unpolluted lagoon. This suggests that P. repens is unsuitable for bio-monitoring studies of heavy metals in these aquatic environments impacted by alkaline residues.

Factores de riesgo para desarrollo de Síndrome Hellp. Hospital Regional Hermilio Valdizán Medrano de Huánuco. Años 2010-2014 / Risk factors for developing of the HELLP syndrome. Regional Hospital Hermilio Valdizan Medrano in Huanuco. Years 2010-2014

El objetivo del estudio fue determinar los principales factores de riesgo para desarrollar síndrome HELLP en gestantes preeclámpticas severas en el Hospital Regional Hermilio Valdizán Medrano de Huánuco - Perú, durante los años 2010-2014. Se realizó un estudio retrospectivo transversal, observacional analítico de tipo casos y controles. Se compararon 76 gestantes con preeclampsia severa que desarrollaron síndrome HELLP (casos) con 76 mujeres con preeclampsia severa que no desarrollaron síndrome HELLP (controles). El análisis estadístico se realizó con el programa IBM Statistics SPSS 19. La edad de la población estudiada varió entre los 14 y 44 años, con una media de 26,1 +/- 7,7 años. El análisis de regresión logística no demostró asociación entre las variables desarrollo de síndrome HELLP y antecedente de hipertensión crónica, nivel plaquetario, antecedente de preeclampsia, eclampsia, trombofilia, gestante adolescente, gestante añosa, tabaquismo, sobrepeso/obesidad, desnutrición, paridad y riesgo social. Se concluyó que el antecedente de síndrome HELLP y el antecedente familiar de preeclampsia/HELLP incrementaron significativamente el riesgo para desarrollar síndrome HELLP.

The objective of the study was to determine the major risk factors for developing HELLP syndrome in severe preeclamptic pregnant women in the Hospital Regional Hermilio Valdizán Medrano of Huánuco - Peru between the years 2010-2014. An observational, retrospective, cross-sectional case-control study was performed. It was compared 76 pregnant women with severe preeclampsia who developed HELLP syndrome (cases) with 76 women with severe preeclampsia who did not develop HELLP syndrome (controls). Statistical analysis was performed using IBM SPSS Statistics 19. The age of the population studied ranged between 14 and 44 years, with a mean of 26.1 +/- 7.7 years. The logistic regression analysis showed no association between the variables HELLP syndrome development and a history of chronic hypertension, platelet level, history of preeclampsia, eclampsia, thrombophilia, pregnant adolescent, aged pregnant, smoking, overweight/obesity, malnutrition parity and social risk. It was concluded that a history of HELLP syndrome and a familiar history of preeclampsia / HELLP increased significantly the risk to develop HELLP syndrome.

Differences in crop bacterial community structure between hoatzins from different geographical locations.

The hoatzin is the only known folivorous bird with foregut fermentation, and is distributed in Venezuela in rivers of the central savannas to the eastern Orinoco River. Differences in diet are expected to affect the digestive microbiota and we hypothesized that hoatzins from different habitats might have a different crop microbiota. We thus characterized the microbiota of six birds from the Cojedes and Orinoco Rivers using the G2 PhyloChip and, in parallel, we compared plant availability and foraging behavior of the hoatzins from the two locations. Plant composition differed between the 2 locations, which shared 5 out of 18 plant families and 1 plant genus--Coccoloba--that was highly consumed in both locations. The PhyloChip detected ∼1600 phylotypes from 42 phyla. There was a core microbiota with ~50% of the OTUs shared by at least 4 of the 6 individuals, but there were also differences in the crop microbiota of animals from the two regions. There existed a higher relative abundance of Alphaproteobacteria and Actinobacteria in the crops of birds from the Cojedes River and of Clostridia and Deltaproteobacteria in the crops of birds from the Orinoco River. The results showed both a core crop microbiota and also the bacterial taxa responsible for geographical differences among individuals from the two locations with different vegetation, suggesting an effect of both diet and geography in shaping the crop bacterial community of the hoatzin.

Stability and spatio-temporal structure in fish assemblages of two floodplain lagoons of the lower Orinoco River

Fish assemblage structure and variability were analyzed in two floodplain lagoons (Las Arhuacas and Los Cardonales) along the lower Orinoco over a hydrological cycle. Every three months during continuous three-day sampling, experimental gill nets (5 to 12.5 cm of mesh opening) and 1 mm-mesh seine nets were utilized according to the types of habitats presents. A total of 133 fish species were found in Las Arhuacas and 95 species in Cardonales. Fifty five and 17 species were exclusive to Las Arhuacas and Los Cardonales respectively, and 77 were common to both lagoons. In Las Arhuacas, the most speciesrich orders were Characiformes, Siluriformes, Perciformes and Gymnotiformes and in Los Cardonales, the most species-rich orders were Characiformes, Siluriformes, Clupeiformes and Perciformes. The richness, abundance and biomass were significantly higher (p < 0.001) in Arhuacas than in Cardonales. In general, the fishes assemblage was highly variable during the high water phase and moderately stable during low water phase in both lagoons, with more stability or less variability in Cardonales than Arhuacas. Also, there were significant differences in the fish assemblages between the two lagoons, mainly during low waters (ANOSIM; p < 0.001). The species that contributed most to the mean dissimilarity between the lagoons were Hypostomus argus, Aphanotorulus ammophilus, Potamorhina altamazonica, Prochilodus mariae, Loricaria gr. cataphracta, Oxydoras sifontesi, Hydrolycus armatus, Hyphopthalmus edentatus and Pterodoras rivasi. The last four species were more commonly collected in Los Cardonales. Also, the species of small size (mainly SL < 5 cm) such as Rhinosardinia amazonica, Moenkhausia sp. 1 "lepidura", Moenkhausia sp. 2, Aphyocharax alburnus, Characidium sp. 1, Moenkhausia sp. 3, Exodon paradoxus and Roeboides dientonito contributed to the mean dissimilarity among the beach and aquatic vegetation habitats. The patterns of the species assemblage ...(AU)

Foram analisadas a estrutura e a variabilidade da comunidade de peixes ao longo de um ciclo hidrológico em dois lagos (Arhuacas e Cardonales) da planície de inundação do baixo rio Orinoco. Amostragens trimestrais foram realizadas por meio de coletas contínuas durante três dias, utilizando-se redes de espera experimentais (5 a 12,5 cm de malha) e redes de arrasto (1 mm de malha), de acordo com os tipos de habitats presentes. Foi encontrado um total de 133 espécies de peixes em Arhuacas e 95 espécies em Cardonales. Cinquenta e cinco espécies foram exclusivas do lago Arhuacas, 17 do lago Cardonales, e 77 foram comuns a ambos os lagos. Em Arhuacas, as ordens mais ricas em espécies foram Characiformes, Siluriformes, Perciformes e Gymnotiformes; em Cardonales, foram Characiformes, Siluriformes, Clupeiformes e Perciformes. A riqueza, abundância e biomassa foram significativamente mais altas (p < 0.001) em Arhuacas que em Cardonales. A comunidade de peixes teve alta variação durante a fase de cheia e permanceu moderadamente estável durante fase de seca em ambos os lagos, com mais estabilidade ou menos variabilidade durante todas as fases do ciclo hidrológico em Cardonales que Arhuacas. Ademais, houve diferenças significativas nas comunidades ícticas entre os dois lagos, em especial durante o período da seca (ANOSIM; p < 0.001). As espécies que mais contribuíram para a dissimilaridade média entre os lagos foram Hypostomus argus, Aphanotorulus ammophilus, Potamorhina altamazonica, Prochilodus mariae, Loricaria gr. cataphracta, Oxydoras sifontesi, Hydrolycus armatus, Hyphopthalmus edentatus e Pterodoras rivasi. As últimas quatro espécies foram geralmente mais coletadas em Cardonales. As espécies pequenas (principalmente SL < 5 cm), como Rhinosardinia amazonica, Moenkhausia sp. 1 "lepidura", Moenkhausia sp. 2, Aphyocharax alburnus, Characidium sp. 1, Moenkhausia sp. 3, Exodon paradoxus e Roeboides dientonito, foram as que mais contribuiram para a ...(AU)

Vegetación pionera sobre rocas un potencial biológico para la revegetación de áreas degradadas por la minería de hierro / Pionner vegetation on rocks a biological potential for regevetation of degraded areas by iron-ore mining

Se realizó un inventario de la vegetación colonizadora dominada por comunidades arbustivas y herbáceas en áreas degradadas por la minería de hierro a cielo abierto, con el fin de seleccionar especies nativas para la revegetación de áreas de minería de hierro. El estudio se realizó en la mina Los Barrancos, ubicada en la Región Guayana, Estado Bolívar, Venezuela. Se inventariaron las especies colonizadoras y los suelos asociados en comunidades arbustivas y herbáceas desarrolladas en la vertiente sur de la mina que drena hacia el Río Arasiama, un tributario del Embalse Guri en el Río Caroní. El inventario resultó en un total de 51 especies en 30 familias presentes en 7 parcelas con suelos pedregosos, ácidos (pH <4,5) con altas concentraciones de Fe y Mn. Las especies más importantes por su abundancia en las comunidades arbustivas fueron Pterandra sericea, Myrcia citrifolia, Banara nitida, Mimosa microcephala, Jacaranda obtusifolia, Clusia rosea y Lippia origanoides. En las comunidades herbáceas fueron Borreria verticillata, Paspalum millegrana, Ouratea roraimae, Cyperus odoratus, Trachypogon plumosus y Xyris fallax. La mayoría de las especies colonizadoras son típicas de comunidades asociadas a afloramientos rocosos, por lo que se discute la importancia de dichas comunidades como una alternativa para la revegetación de áreas afectadas por la minería de hierro en la Guayana Venezolana