Tree growth and stem carbon accumulation in human-modified Amazonian forests following drought and fire

Human-modified forests are an ever-increasing feature across the Amazon Basin, but little is known about how stem growth is influenced by extreme climatic events and the resulting wildfires. Here we assess for the first time the impacts of human-driven disturbance in combination with El Niño–mediated droughts and fires on tree growth and carbon accumulation. We found that after 2.5 years of continuous measurements, there was no difference in stem carbon accumulation between undisturbed and human-modified forests. Furthermore, the extreme drought caused by the El Niño did not affect carbon accumulation rates in surviving trees. In recently burned forests, trees grew significantly more than in unburned ones, regardless of their history of previous human disturbance. Wood density was the only significant factor that helped explain the difference in growth between trees in burned and unburned forests, with low wood–density trees growing significantly more in burned sites. Our results suggest stem carbon accumulation is resistant to human disturbance and one-off extreme drought events, and it is stimulated immediately after wildfires. However, these results should be seen with caution—without accounting for carbon losses, recruitment and longer-term changes in species composition, we cannot fully understand the impacts of drought and fire in the carbon balance of human-modified forests. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Nino on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’

Perfil de pacientes portadores de Diabetes mellitus e seus principais riscos cardiovasculares

No Brasil a diabetes, é causa de importante atenção, por ter se tornado um problema de saúde pública. É uma doença metabólica, que acontece por conta do pâncreas não secretar insulina corretamente ou pela diminuição da sensibilidade dos tecidos em receber a insulina. As principais classificações são a diabete Melittus tipo 1, tipo 2 e gestacional. Doenças Cardiovasculares instituem a primeira causa de morte no mundo e no Brasil, mais de 70% dos pacientes acometidos com DM2 morrem de Doenças Cardiovasculares e não apenas são causas de óbitos, mas também podem causar danos irreversíveis. A Diabetes é reconhecida como fator de risco, independente para doença cardiovascular.  Dentre os riscos cardiovasculares, os mais comuns em pessoas com diabetes são o sedentarismo, obesidade, dislipidemia e hipertensão. Os pacientes com diabetes tipo 2 apresentam um maior volume de ateroma, menor diâmetro do lúmen das artérias coronárias e maior carga aterosclerótica. A resistência a insulina, independente de ser sistêmica ou vascular, está associada a maior incidência dislipidêmica e hipertensão. Um dos fatores que aceleram o processo de calcificação vascular é a hiperglicemia, pacientes com diabetes melittus apresentam índices mais elevados de calcificação arterial. A redução de hiperglicemia caminhar junto ao controle de risco cardiovascular

Genomics and epidemiology for gastric adenocarcinomas (GE4GAC): a Brazilian initiative to study gastric cancer

Abstract Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings

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

A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network

Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off

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

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Variação intraespecífica de características funcionais de espécies arbóreas ao longo de um gradiente de degradação florestal no leste da Amazônia

Degradation of tropical forests has been intensified by anthropogenic activities such as fires and predatory logging, which are associated with a number of land use changes. As a result, in the tropical region, some 156 million hectares of forest degradation were detected during the period. There are only 10.3 million hectares of degraded forests in the Amazon alone. Given the magnitude and expansion of forest degradation in the region, it is very important to understand the resilience of vegetation to changes caused by environmental changes. Studies of functional diversity allow us to investigate the mechanisms used for plant survival and persistence that determine the resilience of ecosystems. In this work, we hypothesized that the species of arboreal plants of the Amazon are responding to the pressures of forest degradation through the variability of their functional traits. Therefore, it is expected that in more disturbed environments, the plants present greater variability of their functional traits, as a strategy of adaptation and survival, in face of the changes generated by the forest degradation. In this way, the objective of this study is to investigate if species of arboreal plants present intraspecific variability of their functional traits along a gradient of degradation in response to the alterations caused by the disturbances in the forest. The study was carried out in Santarém, Eastern Amazonia, in a landscape that varies between the classes of undisturbed forest (n = 5), logging forest (n = 5), logging and burned forest (n = 5) and secondary forest (n = 5). The tree species that contributed 80% of the basal area of each of the twenty plots of study, n = 268, were selected. Among the most abundant species, those that presented at least 4 individuals in two or more forest classes were evaluated. In total, three hundred and four individuals and twenty-one tree species were evaluated. Six functional traits were measured: leaf and petiole thickness, specific leaf area, leaf area, leaf dry-matter content and bark thickness were performed based on protocols established in the literature. The secondary density of the wood collected from the global wood density database (DRYAD) was used as secondary data. In this work, sixteen of the twenty - one species studied showed no significant variation of their functional traits between forest class pairs and 5 presented significant differences for leaf thickness, petiole thickness, leaf area and specific leaf area. The functional traits dry leaf matter and bark thickness did not show variations between forest classes. In forest classes with greater species abundance, the coefficient of variation of the functional traits did not differ along the forest degradation gradient. Here we also tested the relationship between the mean density of wood and the coefficient of variation of the functional traits of tree plants, it was observed that with the increase of the average density of the wood the variability of the functional traits reduced. These results demonstrate that plants have low plasticity and may not survive if forest degradation intensifies, leading to a change in floristic composition and loss of species with unique functions for the functioning of ecosystems.FADESP - Fundação de Amparo e Desenvolvimento da PesquisaA degradação de florestas tropicais tem sido intensificada por atividades antrópicas como queimadas e extração predatória de madeira, as quais são associadas a diversas mudanças de uso da terra. Em consequência, na região tropical, cerca de 156 milhões de hectares de degradação florestal foram detectados no período 2000-2012. Somente na Amazônia existem cerca de 10,3 milhões de hectares de florestas degradadas. Diante da magnitude e expansão da degradação florestal na região, é muito importante compreender a capacidade de resiliência da vegetação às alterações ocasionadas pelas mudanças ambientais. Os estudos da diversidade funcional permitem investigar os mecanismos utilizados para sobrevivência e persistência das plantas que determinam a resiliência dos ecossistemas. Neste trabalho foi testada a hipótese de que as espécies de plantas arbóreas da Amazônia estão respondendo às pressões da degradação florestal através da variabilidade de suas características funcionais. Portanto, espera-se que em ambientes mais perturbados, as plantas apresentem maior variabilidade de suas características funcionais, como estratégia de adaptação e sobrevivência, frente às mudanças geradas pela degradação florestal. Desta forma, o objetivo deste estudo é investigar se espécies de plantas arbóreas apresentam variabilidade intraespecífica de suas características funcionais ao longo de um gradiente de degradação em resposta às alterações ocasionadas pelos distúrbios na floresta. O estudo foi desenvolvido em Santarém, Leste da Amazônia em uma paisagem que varia entre as classes de florestas primárias conservadas (N= 5), florestas primárias com extração madeireira (N= 5), florestas primárias queimadas e exploradas para madeira (N= 5) e florestas secundárias (N= 5). Foram selecionadas as espécies arbóreas que contribuíram com 80% da área basal de cada uma das vinte parcelas de estudo, N= 268. Dentre as espécies mais abundantes, foram avaliadas aquelas que apresentaram no mínimo 4 indivíduos em duas ou mais classes de floresta. No total foram avaliados trezentos e quatro indivíduos e vinte e uma espécies arbóreas. Foram medidas seis características funcionais: espessura foliar e do pecíolo, área foliar específica, área foliar, matéria seca foliar e espessura da casca foram realizadas com base em protocolos estabelecidos na literatura. Foram utilizados como dados secundários a densidade média da madeira coletada da base de dados global de densidade de madeira (DRYAD). Neste trabalho, dentre as vinte e uma espécies estudadas, dezesseis não apresentaram variação significativa de suas características funcionais entre pares de classes de floresta e 5 apresentaram diferenças significativas para as características espessura foliar, espessura do pecíolo, área foliar e área foliar específica. As características funcionais matéria seca foliar e espessura da casca não apresentaram variações entre as classes de floresta. Nas classes de floresta com maior abundância de espécies, o coeficiente de variação das características funcionais não diferiu ao longo do gradiente de degradação florestal. Aqui também foi testada a relação entre a densidade média da madeira e o coeficiente de variação das características funcionais de plantas arbóreas, foi observado que com o aumento da densidade média da madeira a variabilidade das características funcionais reduziu. Estes resultados demonstram que as plantas possuem baixa plasticidade e que podem não sobreviver caso a degradação florestal se intensifique, levando à mudança de composição florística e perda de espécies com funções únicas para o funcionamento dos ecossistemas