Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 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 or ganism 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 ne glected 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 lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 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,18,19 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

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Indirect measurement of photosynthetic pigments in the leaves of Jatropha curcas

The aim of this work was to generate mathematical models capable of identifying photosynthetic pigments and soluble proteins from the leaves of Jatropha curcas using the relationship between classical readings performed by spectrophotometry and the chlorophyll meter, ClorofiLOG ® 1030. The work was conducted at Embrapa Cotton, in the city of Campina Grande, state of Paraíba, Brazil. For indirect analysis, portable equipment was used to read leaf discs at different stages of development. The chlorophyll in these discs was then determined using a classical method, while the Bradford method was used to determine soluble proteins. The data were subjected to analysis of variance and regression analyses, in which the readings obtained using the portable chlorophyll meter were the dependent variables and the photosynthetic pigments and soluble protein determined by the classical method the independents variables. The results indicated that with the exception of chlorophyll b and soluble protein, the mathematical models obtained with the portable chlorophyll ClorofiLOG ® 1030 can be used to estimate the concentration of photosynthetic pigments with high precision, thus saving time and the chemical reagents required for conventional procedures

GROWTH AND YIELD OF CASTOR BEAN (Ricinus communis L.) CV. ‘BRS ENERGIA’ UNDER DIFFERENT SPACINGS

The use of appropriate spacing when planting large crops is a technology that can be very easily applied, and that can result in a significant increase in yield. The aim of this work was to estimate the best spacing between rows in the Castor Bean cv. ‘BRS Energia’ (Ricinus communis L.), with a view to optimising maximum yield. The experiment was carried out on the Juá farm, in Itatuba, in the State of Paraíba, Brazil, in the 2015 agricultural year. The experimental design was of randomised blocks, with four replications and six treatments of different spacing between rows (0.5, 0.75, 1.0, 1.25, 1.50 and 1.75 m). Values for plant height, stem diameter, number of racemes and yield were determined at the end of the crop cycle. Reducing the spacing promoted an increase in plant height. At the smallest spacing, plants reached heights of more than 2.0 m. At the larger spacings, the plants achieved greater stem diameter and number of racemes. The highest yield was obtained at the two smallest spacings, where yields of more than 2000 kg ha-1were achieved

Crescimento inicial de mamoneira em função do cloreto de mepiquat e adubação nitrogenada em cobertura

This work aimed at evaluating the initial biometry of the castor bean crop by using a growth regulator, the mepiquat chloride, by means of a seed treatment with and without nitrogen feltilization. The experiment was conducted in a greenhouse at the headquarters of Embrapa Cotton, with an experimental desing of 4 x 2 (levels of regulator x nitrogen), with four repetitions. Tests of germination and index of germination speed were carried out prior to sowing. Morphogenesis was evaluated five times through the variables: plant height, stem diameter, leaf number and leaf area, besides the characters of chlorophyll content, dry above-ground biomass and root dry biomass of the castor bean at the last evaluation period. The results showed that there was a consistent reduction in the biometrics at the initial phase of the castor bean, as increasing doses of the regulator were applied, and it was more intensified with the absence of nitrogen.Objetivou-se com esse trabalho avaliar a biometria inicial na cultura da mamona, utilizando-se um regulador de crescimento, o cloreto de mepiquat, via tratamento de sementes com e sem adubação nitrogenada. O experimento foi conduzido em casa de vegetação na sede da Embrapa Algodão, em delineamento experimental 4 x 2 (doses de regulador x nitrogênio), com quatro repetições. Foram realizados os testes de germinação e de índice de velocidade de emergência antes da semeadura. A morfogênese foi avaliada em cinco épocas, por meio das variáveis: altura de planta, diâmetro caulinar, número de folhas e área foliar, além dos caracteres índice de clorofila e fitomassa seca da parte aérea e radicular da mamona, no último período de avaliação. Os resultados evidenciaram que houve uma consistente redução na biometria na fase inicial da mamona, conforme foram aplicadas doses crescentes do regulador, tendo sido mais intensificado com a ausência do nitrogênio

Effect of calcium and magnesium silicate on the growth of the castor oil plant subjected to salinity levels<br> Efeito de silicato de cálcio e magnésio sobre o crescimento de plantas de mamoneira submetidas a níveis de salinidade

Salt stress decreases the osmotic potential of soil solution causing water stress, causing toxic effects in the plants resulting in injuries on the metabolism and nutritional disorders, thus compromising the plant growth, resulting in lower production. The calcium silicate and magnesium can perform the same function as limestone, besides providing silicon to plants, may also contribute to the resistance of plants to salt stress. Thus, the objective of this study was to evaluate the effect of calcium and magnesium silicate on the growth of the castor oil plant BRS Energia cultivated under saline conditions. This study evaluated plant height, stem diameter, number of leaves, leaf area, dry weight of shoot and root, and soil chemical characteristics. There was no interaction between factors of salinity level and of silicate level regarding the evaluated variables. There was a direct relationship between salinity levels and plant growth in height and stem diameter. The K concentration in soil were affected by salinity levels. <p><p>O estresse salino diminui o potencial osmótico da solução do solo causando estresse hídrico, provocando efeitos tóxicos nas plantas que resultam em injúrias no metabolismo e desordens nutricionais, comprometendo assim o crescimento das plantas, resultando em menor produção. O silicato de cálcio e magnésio pode desempenhar a mesma função do calcário, além de fornecer silício para as plantas, podendo ainda, contribuir para a resistência de plantas ao estresse salino. Nesse sentido, objetivou-se com esse trabalho avaliar o efeito do silicato de cálcio e magnésio no crescimento da mamoneira BRS Energia cultivada sob condições salinas. Avaliou-se a altura da planta, diâmetro do caule, número de folhas, área foliar, massa seca da parte aérea e da raiz e as características químicas do solo. Não houve interação entre os fatores níveis de salinidade e silicato sobre as variáveis analisadas. Houve relação direta entre os níveis de salinidade e o crescimento da planta em altura e diâmetro do caule. Os teores de K no solo foram influenciados pelos níveis de salinidade