We describe the geographical variation in tree species composition across Amazonian forests and show how environmental conditions are associated with species turnover. Our analyses are based on 2023 forest inventory plots (1 ha) that provide abundance data for a total of 5188 tree species. Within-plot species composition reflected both local environmental conditions (especially soil nutrients and hydrology) and geographical regions.
View Article and Find Full Text PDFNat Ecol Evol
May 2024
Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge.
View Article and Find Full Text PDFCommun Biol
November 2023
Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness.
View Article and Find Full Text PDFIndigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest.
View Article and Find Full Text PDFSci Rep
February 2023
In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies.
View Article and Find Full Text PDFObjective: To investigate the correlation of HRCT findings with pulmonary metabolic activity in the corresponding regions using 18F-FDG PET/CT and inflammatory markers in patients with systemic sclerosis (SSc)-associated interstitial lung disease (ILD).
Methods: This was a cross-sectional study involving 23 adult patients with SSc-associated ILD without other connective tissue diseases. The study also involved 18F-FDG PET/CT, HRCT, determination of serum chemokine levels, clinical data, and pulmonary function testing.
Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity.
View Article and Find Full Text PDFTropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions.
View Article and Find Full Text PDFThe aim of this study was to determine the esophageal transit time in control individuals and in chagasic patients with or without megaesophagus.A total of 148 patients were allocated in 6 groups according to serological diagnostic of Chagas disease and the degree of esophageal dilatation: A, control healthy individuals (n = 34, 22.9%); B, indeterminate form (n = 23, 15.
View Article and Find Full Text PDFEstimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%.
View Article and Find Full Text PDFThe vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.
View Article and Find Full Text PDFObjective: To evaluate the agreement between the criteria used for hospitalization of patients with community-acquired pneumonia (CAP) and those of the Brazilian Thoracic Association guidelines, and to evaluate the association of that agreement with 30-day mortality. Secondarily, to evaluate the agreement between the treatment given and that recommended in the guidelines with length of hospital stay, microbiological profile, 12-month mortality, complications, ICU admission, mechanical ventilation, and 30-day mortality.
Methods: This was a retrospective study involving adult patients hospitalized between 2005 and 2007 at the Federal University of Minas Gerais Hospital das Clínicas, located in Belo Horizonte, Brazil.
Introduction: Despite significant left ventricular (LV) systolic dysfunction and cardiomegaly, pulmonary congestion does not seem to be a major finding in Chagas' cardiomyopathy (CC). This study sought to identify echocardiographic parameters associated with pulmonary congestion in CC and in dilated cardiomyopathy of other etiologies, such as non-CC (NCC), and to compare pulmonary venous hypertension between the two entities.
Methods: A total of 130 consecutive patients with CC and NCC, with similar echocardiographic characteristics, were assessed using Doppler echocardiography and chest radiography.
Introduction: The purpose of this study was to compare respiratory signs and symptoms between patients with and without chest X-ray abnormalities in order to establish the meaning of radiographic findings in pulmonary PCM diagnosis.
Methods: The epidemiological, clinical and radiological lung findings of 44 patients with paracoccidioidomycosis (PCM) were evaluated. Patients were divided into two groups of 23 and 21 individuals according to the presence (group 1) or absence (group 2) of chest X-ray abnormalities, respectively, and their clinical data was analyzed with the aid of statistical tools.
Introduction: Discrepancy between the intensity of pulmonary congestion and the grade of cardiomegaly seems to be a common finding of Chagas cardiomyopathy, in spite of significant systolic dysfunction of the left ventricle. Its mechanism has not been established. The aim of this study was to investigate pulmonary congestion and to analyze if it correlated with Doppler echocardiographic parameters in patients with Chagas dilated cardiomyopathy.
View Article and Find Full Text PDFMedical charts and radiographs from 38 HIV-infected patients with positive cultures for Mycobacterium tuberculosis from sputum or bronchoalveolar lavage were reviewed in order to compare the clinical, radiographic, and sputum bacilloscopy characteristics of HIV-infected patients with pulmonary tuberculosis according to CD4+ lymphocyte count (CD4). The mean age of the patients was 32 years and 76% were male. The median CD4 was 106 cells/mm(3) and 71% had CD4 < 200 cells/mm(3).
View Article and Find Full Text PDFObjective: The objective of this study was to determine the safety and efficacy of renin-angiotensin system (RAS) inhibitors and beta-blockers in chronic Chagas cardiomyopathy.
Background: Chronic Chagas cardiomyopathy causes substantial morbidity and mortality in Latin America. Whether RAS inhibitors and beta-blockers are safe and beneficial has been challenged because of the lack of formal trials.
Objective: To describe data related to the pulmonary function of patients with sequelae of pulmonary tuberculosis, pleural tuberculosis or both.
Methods: In the outpatient clinic of a university hospital, 218 patients were evaluated. Of those 218, 56 had sequelae of tuberculosis (pulmonary, pleural or both), and 162 had other types of tuberculosis.
The fractions of hexane and dichloromethane extraction from marupá (Simaruba amara) and (Bertholletia excelsa) leaves were analyzed by HT-HRGC (high temperature high resolution gas chromatography) and HT-HRGC coupled to mass spectrometry (HT-HRGC-MS). Several compounds can be characterized including unusual high molecular weight compounds.
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