Performance de Azolla caroliniana Willd. e Salvinia auriculata Aubl. em efluente de piscicultura

The increasing release of untreated fish farming effluents into water courses that flow to the Pantanal wetlands in Mato Grosso (Brazil) may drive this ecosystem to eutrophication. Therefore, the growth of Azolla caroliniana Willd. and Salvinia auriculata Aubl. in fish farming effluent and their effect on its quality were evaluated for 48 days in a greenhouse. The results were compared to those obtained in a nutrient rich solution (Hoagland 1/2 medium). Azolla caroliniana showed lower relative growth rate in fish farming effluent (0.020 d-1) than in Hoagland 1/2 medium (0.029 d-1). However, S. auriculata grew slightly better in fish farming effluent (0.030 d-1) than in Hoagland 1/2 medium (0.025 d-1). The species apparently contributed to reduce nitrate and phosphate concentration in Hoagland 1/2 medium. However, in fish farming effluent, only electrical conductivity and pH were reduced by plants compared to the control without plants. Thus, A. caroliniana and S. auriculata show low potential for improving effluent quality

Protecting forests at the expense of native grasslands: Land-use policy encourages open-habitat loss in the Brazilian cerrado biome

The agricultural conversion of natural habitats is one of the main drivers of biodiversity loss worldwide. In the ∼2 million km2 Brazilian cerrado biome, a global biodiversity hotspot, vast areas have been converted into croplands and cattle pastures. Because the cerrado biome is overwhelmingly contained within private lands, Brazil's environmental legislation should serve as a decisive instrument in protecting these natural ecosystems. We assessed the role of Legal Reserves (LRs), legally defined as the minimum proportion of private landholdings set aside to protect natural vegetation, in the conservation of the cerrado biome. We assume that the property-scale allocation of LRs is primarily based on economic decision-making, creating a bias against cerrado protection. We therefore assessed the area ratio between forest vegetation (FV) and grassland vegetation (GV) areas across LRs within 48,762 landholdings, 9 formal protected areas (PAs) and 34 Indigenous Lands (ILs) within the cerrado (sensu lato) of the 903,357-km2 state of Mato Grosso, Brazil. We show that there are 7.26 ha of forest lands for each hectare of native grasslands within private RLs of the cerrado biome within Mato Grosso, a ratio almost three-fold larger than that found in formal PAs and ILs. ILs protect in absolute values (hectares) six-fold more native grassland vegetation than PAs. We discuss the policy relevance of this severe land-use bias in maintaining the heterogeneity of cerrado habitats for biodiversity conservation within private properties, which account for 90% of the entire cerrado biome

Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension

Estrutura e estado de explotação dos estoques do Jurupoca, Hemisorubim platyrhynchos, e do Jurupensém, Sorubim cf. lima, na Bacia do Rio Cuiabá, Pantanla Mato-Grossense.

The fishery is an important economic activity at Pantanal. This study describe and analyse the age, the individual growth, the structure, the exploitation and the management alternatives for the two pimelodidae catfish stocks fished in region. The Porthole Shovelnose Catfish, Ilemisorubim platyrhynchos , and the Duckbill Catfish, Sorubim lima, are, respectively, the sixth and the seventh bigger Pantanal pimelodidae catfish. The fishes were caught by comercial and experimental fisheries with hook and line in Cuiabá river, Pantanal. The age and the individual growth were studied from the (a partir dos) pectoral fin-spines. The estimates fo growth parameters were used to obtain estimate of instantaneous mortality rates for the stocks. The consequences of different managemtn actions for the fishes and the fisheries were assessed with (através) the Beverton and Holt relative yield per recruit model. The results indicate that Il. platyrhynchos and S. lima show slow growth and intermediate natural mortality coeficient. The longevity of Il. platyrhynchos is of 11,4 years, and of S. lima is of 9,6 years. The fisheries catches several fishes cohorts and, in general, individuals abovemean lenght of first maturation. Because historical data are not available it is hard to assess the effects of arising (crescente) fisheries pressure on the stocks. Nevertheless, the results of relative yield per recruit model simulations indicate that presente fisheries effort is below of a conservative biological reference point - the P 0,1. So, the two species stocks are underexploited . However, an arising of presente fisheries effort must be seen with caution because (uma vez que) the raltion between stocks size and recruitment for the two species is not knewFinanciadora de Estudos e ProjetosA pesca é uma importante atividade econômica no Pantanal Mato-grossense. Este estudo descreve e analisa a idade, o crecimento dos indivíduos, a estrutura, o estado de explotação e as opções de manejo para os estoques de duas espécies de bagres pescados na região. O Jurupoca Ilemisorubim platyrhynchos e o Jurupensén Sorubim Lima são, respectivamente, o sexto e o sétimo maiores bagres do Pantanal. Os exemplares provieram da pesca comercial e experimental realizadas com linha e anzol no rio Cuiabá, Pantanal Mato-grossense. A idade e o crescimento dos indivíduos das espécies foram estudados a partir dos espinhos de nadadeiras peitorais. As estimativas dos parâmetros de crescimento foram posteriormente utilizadas na obtenção de estimativas dos coeficientes instântaneos de mortalidade para os estoques. As consequências da adoção de diferentes medidas de manejo para os estoques e a pesca foram avaliadas através do modelo de rendimento relativo por recruta. Os resultados indicam que Il. platyrhynchos e S. lima apresentam crescimento lento e coeficiente de mortalidade natural intermediário. A longevidade do Il. platyrhynchos é de 11,4 anos e a do S. lima de 9,6 anos. A pesca se concentra na captura de várias coortes de peixes, em geral, sobre indivíduos acima do comprimento médio de primeira maturação. A inexistência de dados históricos dificulta qualquer avaliação dos efeitos da crescente pressão de pesca sobre os estoques. Porém, os resultados das simulações do modelo de rendimento relativo por recruta indicam que o esforço de pesca atual está abaixo de um ponto de referência biológico conservador - o P 0,1. Assim pode-se concluir que o estado atual de explotação dos estoques das duas espécies está aquém do que o estoque teoricamente suportaria, portanto subexplotados. Contudo, um aumento no esforço de pesca atual deve ser visto com cautela uma vez que não se conhece a relação entre o tamanho do estoque e o recrutamento para as espécie

High beta diversity of fishes in vegetated littoral zones of floodplain lakes in the Cuiabá River Basin, northern Pantanal, Brazil

This study evaluated whether the alpha and beta diversity of fishes in vegetated littoral zones of floodplain lakes in the Pantanal are randomly distributed on three different spatial scales: within the lake, among lakes, and between regions. Three alternative hypotheses were contrasted: (1) that regional diversity is generated at local scale, depending on the internal environmental heterogeneity of lakes, (2) that the diversity of fishes in floodplain lakes is produced at intermediate spatial scales, depending on structural differences and on the landscape matrix between lakes, and (3) that the diversity of fishes in the littoral zone is generated at regional scale, due to regional differences in land-use pattern and the presence of a geographical barrier represented by the river. Our results indicate that the regional diversity of fishes in the vegetated littoral zone of lakes in the northern Pantanal is a consequence of high diversity at the local level (α) and the wide differences in species composition among lakes and between regions. This suggests that we need to maintain environmental heterogeneity, represented by the structural differences among the lakes and their landscape matrix as well as regional differences in the flood pattern, if we hope to preserve the diversity of fishes in the region. Besides, it is necessary to establish new conservation units at the different Pantanal subregions, which should incorporate a set of lakes with different landscape features such as size, shape, and distance from and degree of connection to rivers. © 2011 Springer Science+Business Media B.V

Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources

The influence of habitat, biomass of herbaceous vegetation, depth and distance from permanent water bodies on the structure of fish assemblages of a seasonal floodplain was evaluated using data collected along 22 transects in an area of 25 km² in the floodplain of Cuiabá River, Pantanal, Brazil. Each transect was sampled for fish using throw traps and gillnets during the flood period of 2006. Multivariate multiple regression analysis and multivariate analysis of covariance indicated that depth was the only variable that affected the structure of the fish assemblage, both for quantitative data (abundance) and qualitative data (presence-absence). Species such as Neofundulus parvipinnis and Laetacara dorsigera were more abundant in shallower sites (below 25 cm), while Serrasalmus maculatus and Metynnis mola were found mostly in the deepest areas (over 55 cm). However, species such as Hoplias malabaricus and Hoplerythrinus unitaeniatus occurred at all sampled depths. Although the distribution of most species was restricted to a few sites, there was a positive relationship between species richness and depth of the water body. Surprisingly, the replacement of native vegetation by exotic pasture did not affect the fish assemblage in the area, at the probability level considered