Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Antioxidant activity of rosemary and oregano ethanol extracts in soybean oil under thermal oxidation Ação antioxidante de extratos etanólicos de alecrim (Rosmarinus officinalis L.) e orégano (Origanum vulgare L.) em óleo de soja submetido à termoxidação

Four experiments were conducted to measure the antioxidant activity of ethanol extracts of rosemary and oregano compared with synthetic antioxidants such as TBHQ and BHA/BHT. The antioxidant activity was determined and results differed from those of the Oven test at 63&ordm; C. Peroxide values and absorptivities at 232 nm of soybean oil under Oven test were lower in treatments with 25, 50, 75, 100 and 200 mg.Kg-1 TBHQ than in treatments with 1000 mg.Kg-1 oregano extract (O), 500 mg.Kg-1 rosemary extract (R) and their mixture R+O. All the treatments were effective in controlling the thermal oxidation of oils; the natural extracts were as effective as BHA+BHT and less effective than TBHQ. The natural extracts were mixed with 25, 50, 75 and 100 mg.Kg-1 TBHQ and then added to the oil. No improvement in antioxidative properties was observed. The best antioxidant concentration could be determined from polynomial regression and quadratic equation from the experimental data.<br>Foram realizados quatro ensaios para verificação da atividade antioxidante de extratos etanólicos de alecrim (A) e orégano (O) comparados com os antioxidantes sintéticos TBHQ e BHA+BHT. Os resultados de atividade antioxidante do teste usando sistema modelo diferiram das respostas do teste acelerado em estufa. Nos ensaios em estufa os valores de peróxido e absortividade em 232nm dos óleos de soja, adicionados de 25, 50, 75, 100 e 200mg TBHQ. Kg-1, foram menores do que os dos óleos adicionados dos extratos de orégano (O) (1000mg.Kg-1), de alecrim (A) (500mg.Kg-1) ou da mistura deles (A + O). Todos os tratamentos retardaram a oxidação do óleo, entretanto os extratos naturais não atingiram a eficiência do TBHQ, mas foram tão efetivos quanto a mistura BHA+BHT. A adição dos extratos naturais a doses reduzidas de TBHQ não melhorou a eficiência em retardar a oxidação