| 1. |
- Householder, John Ethan, et al.
(författare)
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One sixth of Amazonian tree diversity is dependent on river floodplains
- 2024
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Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X.
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Tidskriftsartikel (refereegranskat)abstract
- Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
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| 2. |
- Peripato, Vinicius, et al.
(författare)
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More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia
- 2023
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Ingår i: Science (New York, N.Y.). - 1095-9203. ; 382:6666, s. 103-109
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Tidskriftsartikel (refereegranskat)abstract
- Indigenous 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. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.
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| 3. |
- ter Steege, Hans, et al.
(författare)
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Mapping density, diversity and species-richness of the Amazon tree flora
- 2023
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Ingår i: COMMUNICATIONS BIOLOGY. - 2399-3642. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- 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. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution. A study mapping the tree species richness in Amazonian forests shows that soil type exerts a strong effect on species richness, probably caused by the areas of these forest types. Cumulative water deficit, tree density and temperature seasonality affect species richness at a regional scale.
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| 4. |
- Cantelli, Carina Pacheco, et al.
(författare)
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Rotavirus A shedding and HBGA host genetic susceptibility in a birth community-cohort, Rio de Janeiro, Brazil, 2014-2018
- 2020
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have investigated whether the human histo-blood group antigen (HBGAs) could affect the effectiveness of the oral rotavirus vaccines, suggesting secretor positive individuals develop a more robust response. We investigated the Rotavirus A (RVA) shedding in association with the host susceptibility profile in children from a birth community-cohort in Rio de Janeiro, Brazil, from 2014 to 2018. A total of 132 children were followed-up between 0 to 11-month-old, stool samples were collected before/after the 1(st)/2(nd) RV1 vaccination doses and saliva samples were collected during the study. RVA shedding was screened by RT-qPCR and G/P genotypes determined by multiplex RT-PCR and/or Sanger nucleotide sequencing. The sequencing indicated an F167L amino acid change in the RV1 VP8* P[8] in 20.5% of shedding follow-ups and these mutant subpopulations were quantified by pyrosequencing. The HBGA/secretor status was determined and 80.3% of the children were secretors. Twenty-one FUT2 gene SNPs were identified and two new mutations were observed. The mutant F167L RV1 VP8* P[8] was detected significantly more in Le (a+b+) secretors (90.5%) compared to non-secretors and even to secretors Le (a-b+) (9.5%). The study highlights the probable association between RV1 shedding and HBGAs as a marker for evaluating vaccine strain host susceptibility.
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| 5. |
- de Castro Moreno, Claudia Roberta, et al.
(författare)
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COVID-19 pandemic is associated with increased sleep disturbances and mental health symptoms but not help-seeking : a cross-sectional nation-wide study
- 2022
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Ingår i: Sleep Science. - : Georg Thieme Verlag KG. - 1984-0659 .- 1984-0063. ; 15:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study aimed firstly to describe sleep-related and mental health symptoms before and during the COVID-19 pandemic in a national-wide sample and, secondly, to verify attitudes towards help-seeking to treat these symptoms. Material and Methods: Data were collected through an online questionnaire sent through the Brazilian Sleep Association's social media. The questionnaire included sociodemographic and sleep aspects questions currently and before the pandemic period. In addition, the survey addressed current and previous anxiety, depression, and burnout symptoms. The outcome help-seeking was addressed in the questionnaire as well by a single question asked when the participant reported mental or sleep problems. Results: The study covered 6,360 participants, mean age 43.5 years (SD=14.3), 76.7% female and 63.7% with undergraduate or higher degree filled out the survey. Seventy percent of participants reported sleep disturbances and 80% reported symptoms of anxiety during the pandemic. Help-seeking behavior was found only in one third of them. Hours of sleep reduced from 7.12 to 6.2h, which can be related with the increase in 28.2% of dissatisfaction with sleep duration during the pandemic. The highest frequency of complaints related to sleep was difficulty to fall asleep three or more times a week (going from 27.6% before the pandemic to 58.9% during the pandemic; p<0.001). Moreover, it was observed that help-seeking was more prevalent in men than women, and more in younger participants than in older ones. Conclusion: There was an increase of sleep and mental self-reported problems during the pandemic, which was not followed by help-seeking.
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| 6. |
- de Moraes, Marcia Terezinha Baroni, et al.
(författare)
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G6P[8] Rotavirus a Possessing a Wa-like VP3 Gene from a Child with Acute Gastroenteritis Living in the Northwest Amazon Region
- 2023
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Ingår i: Pathogens. - : MDPI. - 2076-0817. ; 12:7
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Tidskriftsartikel (refereegranskat)abstract
- The introduction of rotavirus A (RVA) vaccines has considerably reduced the RVA-associated mortality among children under 5 years of age worldwide. The ability of RVA to reassort gives rise to different combinations of surface proteins G (glycoprotein, VP7) and P (protease sensitive, VP4) RVA types infecting children. During the epidemiological surveillance of RVA in the Northwest Amazon region, an unusual rotavirus genotype G6P[8] was detected in feces of a 2-year-old child with acute gastroenteritis (AGE) that had been vaccinated with one dose of Rotarix(& REG;) (RV1). The G6P[8] sample had a DS-1-like constellation with a Wa-like VP3 gene mono-reassortment similar to equine-like G3P[8] that has been frequently detected in Brazil previously. The results presented here reinforce the evolutionary dynamics of RVA and the importance of constant molecular surveillance.
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| 7. |
- Drager, Luciano F., et al.
(författare)
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Insomnia episodes, new-onset pharmacological treatments, and other sleep disturbances during the COVID-19 pandemic : a nationwide cross-sectional study in Brazilian health care professionals
- 2022
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Ingår i: Journal of Clinical Sleep Medicine (JCSM). - : American Academy of Sleep Medicine (AASM). - 1550-9389 .- 1550-9397. ; 18:2, s. 373-382
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Tidskriftsartikel (refereegranskat)abstract
- Study Objectives: To evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on insomnia and other sleep disturbances in health care professionals.Methods: A survey was distributed using social media and organizational emails to Brazilian active health care professionals during the COVID-19 outbreak. We explored potential associated factors including age, sex, occupation, workplace, work hours, income, previous infection with COVID-19, recent/current contact with COVID-19 patients, regional number of incident deaths, anxiety, and burnout. We evaluated new-onset/previous insomnia worsening episodes (primary outcome), new pharmacological treatments, sleep quality, duration, nightmares, and snoring (secondary outcomes).Results: A total of 4,384 health professionals from all regions of the country were included in the analysis (44 ± 12 years, 76% females, 53.8% physicians). Overall, 55.7% were assisting patients with COVID-19, and 9.2% had a previous COVID-19 infection. The primary outcome occurred in 32.9% of respondents inparallel to 13% new pharmacological treatments for insomnia. The sleep quality worsened for 61.4%, while 43.5% and 22.8% reported≥1-hour sleep duration reduction and worsening or new-onset nightmares, respectively. Multivariate analyses showed that age (odds ratio [OR]: 1.008; 95% confidence interval [CI] 1.001–1.015), females (OR: 1.590; 95% CI 1.335–1.900), weight change (decrease: OR: 1.772; 95% CI 1.453–2.161; increase: OR: 1.468; 95% CI 1.249–1.728), prevalent anxiety (OR: 3.414; 95% CI 2.954–3.948), new-onset burnout (OR: 1.761; 95% CI 1.489–2.083), family income reduction > 30% (OR: 1.288; 95% CI 1.069–1.553), and assisting patients with COVID-19 (OR: 1.275; 95% CI 1.081–1.506) were independently associated with new-onset or worsening of previous insomnia episodes.Conclusions: We observed a huge burden of insomnia episodes and other sleep disturbances in health care professionals during the COVID-19 pandemic.
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| 8. |
- Luize, Bruno Garcia, et al.
(författare)
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Geography and ecology shape the phylogenetic composition of Amazonian tree communities
- 2024
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Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699.
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.
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