Widespread reforestation before European influence on Amazonia.

An estimated 90 to 95% of Indigenous people in Amazonia died after European contact. This population collapse is postulated to have caused decreases in atmospheric carbon dioxide concentrations at around 1610 CE, as a result of a wave of land abandonment in the wake of disease, slavery, and warfare, whereby the attendant reversion to forest substantially increased terrestrial carbon sequestration. On the basis of 39 Amazonian fossil pollen records, we show that there was no synchronous reforestation event associated with such an atmospheric carbon dioxide response after European arrival in Amazonia. Instead, we find that, at most sites, land abandonment and forest regrowth began about 300 to 600 years before European arrival. Pre-European pandemics, social strife, or environmental change may have contributed to these early site abandonments and ecological shifts.

Targeting malaria protein kinases.

Malaria is one of the most impacting public health problems in tropical and subtropical areas of the globe, with approximately 200 million cases worldwide annually. In the absence of an effective vaccine, rapid treatment is vital for effective malaria control. However, parasite resistance to currently available drugs underscores the urgent need for identifying new antimalarial therapies with new mechanisms of action. Among potential drug targets for developing new antimalarial candidates, protein kinases are attractive. These enzymes catalyze the phosphorylation of several proteins, thereby regulating a variety of cellular processes and playing crucial roles in the development of all stages of the malaria parasite life cycle. Moreover, the large phylogenetic distance between Plasmodium species and its human host is reflected in marked differences in structure and function of malaria protein kinases between the homologs of both species, indicating that selectivity can be attained. In this review, we describe the functions of the different types of Plasmodium kinases and highlight the main recent advances in the discovery of kinase inhibitors as potential new antimalarial drug candidates.

Caracterização físico-química e análises por espectrofotometria e cromatografia de Peperomia pellucida L. (H. B. K. ) / Physical chemical characterization and spectrophotometric analysis and chromatography (TLC) of the Peperomia pellucida L. (H. B. K. )

O objetivo deste trabalho foi realizar a caracterização físico-química do pó e da tintura, e análise por espectrofotometria e cromatografia do extrato seco de Peperomia pellucida L. (H. B. K.). As metodologias seguiram a Farmacopéia Brasileira IV ed., com exceção da prospecção química, da espectrofotometria, da obtenção do perfil cromatográfico do extrato seco, e determinação do resíduo seco. A prospecção química revelou a presença de saponinas espumídicas; açúcares redutores; proteínas e aminoácidos; fenóis; taninos; flavonóides; esteróides e triterpenóides. Na análise por CCD, o melhor perfil da fração flavonoídica foi obtido com MeOH/CHOOH (90:10). Foi confirmada, através de CLAE, a presença de 3',4',7-tri-O-metoxiflavona no extrato seco deste material vegetal. Os resultados obtidos contribuem para a determinação de especificações de uma futura monografia em Farmacopéias da Peperomia pellucida L. (H.B.K.).

The aim of this study was the physical chemical characterization of the powder and the tincture, and the chromatographic and spectrophotometric analysis of the Peperomiapellucida L. (H. B. K.) dry extract. The methodology followed the Farmacopeia Brasileira IV ed., except for the chemical prospection, the chromatographic profile obtained and the spectrophotometry of the dry extract, and determination of dried residues. The chemical prospection revealed the presence of foaming saponins; reducing sugars; proteins and amino acids; phenols; tannins; flavonoids; steroids and triterpenoids; depsideos and depsidones. The best profile from TLC for flavonoidic fraction was obtained with methanol/formic acid (90:10 v/v). HPLC confirmed the presence of 3 ',4',7-tri-methoxyflavone in the dry extract of the plant material. The results obtained in this work should contribute for the determination of specifications for a future monograph on Peperomia pellucida L. (H.B.K.).

Salmonella spp. em forros de caixa de transporte e órgãos de pintos de um dia / Salmonella spp. in paper pads of chick boxes and organs of one-day-old- chicks

Estudou-se a ocorrência de Salmonella spp. em forros de caixa de transporte e em órgãos de pintos de corte de um dia, por meio de cultura bacteriológica convencional. Foram avaliadas 378 amostras de 18 lotes pertencentes a três empresas integradoras de frangos de corte do Estado de Goiás. Verificou-se a ocorrência de Salmonella spp. em 55,6 por cento (10/18) dos lotes sendo 10 lotes positivos oriundos de caixa de transporte e um lote de órgãos de pinto de um dia. A freqüência de isolamento de Salmonella spp. nos forros de caixas foi de 11,1 por cento, e nos órgãos de pintos de corte de um dia, 3 por cento. Os resultados sugerem a transmissão vertical do agente. Foram isolados os sorovares Salmonella Enteritidis e Salmonella Heidelberg, o primeiro mais freqüente (92,3 por cento)