Global warming assessment suggests the endemic Brazilian kelp beds to be an endangered ecosystem.

Kelps are canopy-forming brown seaweed sustaining critical ecosystem services in coastal habitats, including shelter, nursery grounds, and providing food resources to a myriad of associated species. This study modeled the fundamental niche of Laminaria abyssalis along the Brazilian continental margin, an endemic species of the South Atlantic, to anticipate potential distributional range shifts under two contrasting scenarios of future environmental changes (RCP2.6 and RCP8.5). The model for fundamental niche predictions considering the "present scenario" has shown a wider potential area than the realized niche (i.e., the area where the species actually occurs) along the Brazilian coast. In both future scenarios, the models have shown niche erosion on the northern portion of the Brazilian coast and niche gains towards the south. In both scenarios, L. abyssalis populations tend to shift to deeper regions of the reef. The restricted range of occurrence (33,000 km2), intense anthropic activities along these beds (e.g., trawling fisheries, oil/gas mining, or removal for agricultural purposes) acting synergically with global warming, may drive this ecosystem to collapse faster than kelp species' ability to adapt. We propose to classify L. abyssalis as Endangered - (EN) under IUCN criteria, and highlight that long-term monitoring of kelp beds is an urgent need to develop effective conservation initiatives to protect such rare and invaluable ecosystem.

Can severe drought periods increase metal concentrations in mangrove sediments? A case study in eastern Brazil.

Mangrove ecosystems are essential to society, providing ecological and economic services, and play a crucial role in the geochemical land-ocean interface as a sink for potentially toxic metals. This study assessed metals (Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn) and arsenic in sediments from three mangrove zones (Tidal Flat, Rhizophora mangle L. and Avicennia schaueriana Stapf & Leechman ex Moldenke forests) during two seasons: spring of 2015 and autumn of 2016, with the latter being a severe drought year. Overall results suggest that Fe/Mn oxyhydroxides and clay minerals control the distribution of metal and arsenic in the Tidal Flat zone. In the mangrove forest however, sulfur and organic matter dominate complexation, with Fe mainly present as insoluble sulfide, and As, Cd, Cu and Zn as metal sulfides or organometallic complexes. In the autumn of 2016, all elements except Cd and Pb had lower concentrations compared to the spring of 2015. Cd and Pb were probably transferred from sources other than mangrove sediments, due to increased saline water intrusion, a consequence of reduced riverine flow, and precipitated in the Rhizophora mangle and Avicennia schaueriana mangrove forests. This increase of Cd and Pb in the mangrove forest suggests potential storage of metal contaminants in the organic rich areas, a change in availability and potential toxicity to fauna and flora and a need for regulatory responses to sediment quality. These results indicate a change in sediment metal contaminant dynamics with the increasing occurrence of extreme weather events - an increased risk to the ecosystem.

Análise da resistência externa e da atividade eletromiográfica do movimento de extensão de quadril realizado segundo o método Pilates / Analysis of the external resistance and electromyographic activity of hip extension performed according to the Pilates method

OBJETIVOS: Comparar a ativação elétrica do reto femoral (RF), do bíceps femoral cabeça longa (BF) e semitendíneo (ST) e o torque de resistência (T R) do movimento de extensão de quadril (EQ) realizado com a mola fixada em duas posições distintas no Cadillac. MÉTODOS: 12 sujeitos realizaram 5 repetições de EQ com a mola fixada em duas posições (alta e baixa). Dados de eletromiografia (EMG) e eletrogoniometria foram coletados simultaneamente. O root mean square foi calculado e normalizado com base na contração voluntária máxima. Para o cálculo do T R, foram usados diagramas de corpo livre (DCL) e equações de movimento. ANOVA one-way foi usada para verificar as diferenças para EMG entre as posições de mola (p<0,05). RESULTADOS: Com a mola fixa na posição alta, o T R foi classificado como decrescente e ocorreu no "sentido" de flexão na maior parte da amplitude de movimento (ADM). Para posição baixa, o T R foi descrescente até 60º de flexão de quadril no sentido de flexão e, a partir daí, assumiu um comportamento crescente no sentido da extensão. CONCLUSÕES: A análise EMG pareceu acompanhar o T R, apresentando valores maiores para o RF na posição baixa e maiores valores de ativação para o BF e ST na posição alta, onde a demanda externa foi maior. Dados de EMG e T R fornecem informações complementares para prescrição de exercícios no Pilates.

OBJECTIVES: To compare the electrical activation of the rectus femoris (RF), long head of the biceps femoris (BF) and semitendinosus (ST) and the resistance torque (T R) of the hip extension (HE) movement performed on the Pilates Cadillac with the attachable spring in two different positions. METHODS: Twelve subjects performed five hip extensions with the attachable spring in two positions (high and low). Electromyography (EMG) and electrogoniometry data were colleted simultaneously. The root mean square (RMS) was calculated and normalized based on the maximal voluntary contraction. A free-body diagram (FBD) and movement equations were used to calculate T R. One-way ANOVA was used to investigate EMG differences between spring positions (p<0.05). RESULTS: When the spring was in the high position, T R was classified as descending and occurred in the "direction" of flexion over most of the range of motion (ROM). In the low position, T R descended until 60º of hip flexion, in the direction of flexion, and from there it took on an ascending pattern in the direction of extension. CONCLUSIONS: The EMG analysis seemed to follow the T R, with higher values for the RF in the low position and higher activation values for the BF and ST in the high position, where the external demand was greater. EMG and T R data supply complementary information for prescribing Pilates exercises.