Western Amazon Research Articles

Pediatric multisystem inflammatory syndrome (MIS-C) associated with COVID-19 in a child from the Western Amazon

Pediatric multisystem inflammatory syndrome (MIS-C) associated with COVID-19 in a child from the Western Amazon

Fossil Parkia R.Br. (Fabaceae) pollen from the Miocene of western Amazonia

The legume genus Parkia R.Br. has a pantropical distribution and centre of diversity in the Amazon. The molecular phylogeny of the group indicates a Neotropical origin in the Amazon biome during the Miocene, and habitat reconstruction points to terra firme (unflooded) forests. We examined recently described fossil pollen from the Miocene Solimões Formation in western Brazilian Amazonia attributed to this genus. Aiming to establish an infra-generic affinity, comparisons were performed between fossil pollen of Parkiidites marileae Leite and pollen from extant Parkia species using morphological characters and multivariate analyses. Parkiidites marileae is characterised by large and globose polyads, the polyads are composed of 16 monads, and the monads have a verrucate ornamentation. Analyses suggest two well-defined groups, a non-NLR (nearest living relative) group composed of P. decussata, P. gigantocarpa, P. velutina, P. panurensis, P. platycephala, P. pendula, P. multijuga, and P. ulei; and a NLR group composed of P. cachimboensis, P. discolor, P. igneiflora, P. lutea, and P. nitida. All species of the NLR group belong to the same clade, with a molecular age estimated at ∼12.8 million years, which is virtually the same age as interpreted for the first occurrence of P. marileae in the Solimões Formation. The late Middle to Late Miocene in western Amazonia was a time of gradual change from vast wetlands to more river-dominated landscapes that favoured unflooded forests where Parkia diversified and is distributed today.

Economic indicators in the cultivation of passion fruit (passilora edulis) in the central region of Rondônia – Western Amazon

Brazil is the world's largest producer of passion fruit, with an average annual production of 700,000 tons. Although the production of the fruit is concentrated in the northeast region of the country, the states of the Amazon region have a significant production, especially in Amazonas, Pará and Rondônia. Even though there are several studies on passion fruit, there are still few works that address the economic aspects of the activity. Thus, the present study aimed to measure and analyze the main economic indicators of passion fruit cultivation in the Central Region of Rondônia, Western Amazon/Brazil. To reach the objectives, this descriptive and exploratory research, used the bibliographical research and the field study, promoting the collection of data through interviews applied to passion fruit producers established in three municipalities contained in the Western Amazon / Brazil - specifically in the central region of the state of Rondônia, and the information collected was treated qualitatively and quantitatively. Thus, it was especially found that the average monthly Return on Investment (ROI) of the activity was 3.98%, the average profitability was 10.86%, while the average profit was BRL 8,853.28 (US$ 2,425.56) per hectare grown from the fruit. Furthermore, through Pearson's correlation analysis, it was found that most economic indicators were highly dependent on the “production” variables.

Tabanidae (Diptera) captured on horses in Amazon Forest fragments of the state of Rondônia, Brazil

Tabanidae is one of the most diverse families of hematophagous dipterans. Tabanids, in general, are mechanical vectors of some pathogens. Given the vector importance and the lack of knowledge of the tabanid fauna in horses in Amazon Forest fragments of the state of Rondônia, this work aimed to determine the season that the different species of horse flies prefer to carryout hematophagy on horses and verify whether the horse fly community remains the same throughout the year. The sampling areas for tabanid captures were in the municipality of Monte Negro, Western Amazon, Brazil. Four new occurrences were recorded for the state of Rondônia: Stenotabanus albilinearis, Tabanus fuscofasciatus, T. macquarti and T. restrepoensis, which increases the number of species for the state to 109. The horse flies were most frequently collected on the hind leg (43.15%) and front leg (31.11%), followed by the belly (7.41%) and the ear (5.18%). In the other anatomical regions, the collection frequency was 13.15% of the remaining individuals.

Phlebotomine Fauna (Diptera: Psychodidae) and Infection by Leishmania spp. in Forest Fragments of a University Campus, Western Amazon.

Forest fragments consist of important ecosystems for the maintenance of sand fly populations and Leishmania hosts. This study sought to identify the phlebotomine fauna and its infection by Leishmania spp. in forest fragments on the campus of the Federal University of Acre (UFAC), Western Amazon. Monthly collections with CDC traps were carried out from March 2020 to June 2021, in four forest fragments of UFAC. Male and female insects were processed and identified at species level. A sample of females was subjected to polymerase chain reaction (PCR) analysis to verify the presence Leishmania DNA. In total, 465 specimens were collected, of which 238 were males and 227 were females. The most frequent species were Nyssomyia antunesi (Coutinho, 1939) (47.3%), Trichophoromyia sp. (Mangabeira, 1942) (18.70%), and Ny. whitmani (Antunes & Coutinho, 1939) (8.81%). Molecular analysis detected the presence of Leishmania (Ross, 1903) DNA in a specimen of Ny. antunesi, and another one of Evandromyia walker (Newstead, 1914). The forest fragments of the university campus harbor a diverse sand fly fauna with the presence of Leishmania DNA in these insects, in addition to the presence of other species considered incriminated vectors of Leishmania parasites.

Has the soybean oil supplementation effect on milk production, feed efficiency, and grazing behavior of Girolando cows under moderate heat stress in western Amazonia?

The effect of soybean oil supplementation in the diet of early lactating Girolando cows under moderate heat stress were studied in a grazing trial. Dry matter intake (DMI), milk yield, feed efficiency, and grazing behavior (during daytime and nighttime) were evaluated in two groups of eight crossbred Girolando (Holstein × Gyr) cows grazing palisade grass (Urochloa brizantha syn. Brachiaria brizantha) with initial means of 53±33 days in lactation and 22.6±3 kg of milk day-1. They were arranged in a 2×2 crossover trial with two supplements (with or without soybean oil), two genetic groups and two periods. During the experimental period, the mean of temperature and humidity index (THI) was 75.11, suggesting moderate heat stress. Total DMI was based on fecal production estimated by LIPE® and the diet in vitro DM digestibility (IVDMD). Grazing behavior was assessed for 48 hours by acoustic data collected with MP3 recorders. Soybean oil supplementation had no significant effects on all variables evaluated in this study. Averages of individual milk yield and total DMI were 19.26 kg day-1 and 15.32 kg DM day-1, respectively. Under moderate heat stress, oil supplementation did not change grazing behavior, dry matter intake, or milk yield in early lactating Girolando cows.

Unrecognized species diversity and endemism in the cichlid genus Bujurquina (Teleostei: Cichlidae) together with a molecular phylogeny document large-scale transformation of the western Amazonian river network and reveal complex paleogeography of the Ecuadorian Amazon

Unrecognized species diversity and endemism in the cichlid genus Bujurquina (Teleostei: Cichlidae) together with a molecular phylogeny document large-scale transformation of the western Amazonian river network and reveal complex paleogeography of the Ecuadorian Amazon

Diversification of the Pristimantis conspicillatus group (Anura: Craugastoridae) within distinct neotropical areas throughout the Neogene

Determining the relative importance of dispersal and vicariance events across neotropical regions is a major goal in biogeography. These events are thought to be related to important landscape changes, notably the transition of Amazonia toward its modern hydrological configuration ca. 10 million years ago. We investigated the spatio-temporal context of the diversification of one of the major lineages of Pristimantis, a widespread and large genus of direct-developing Neotropical frogs. We gathered a spatially and taxonomically extensive sampling of mitochondrial DNA sequences from 754 Pristimantis gr. conspicillatus specimens, which led to delimiting 75 Operational Taxonomic Units (OTUs). Complete mitogenomes of 35 of these OTUs were assembled and collated with two nuDNA loci to reconstruct a time-calibrated phylogeny. We identified five major clades that diverged around the Oligocene-Miocene transition and that are largely restricted to distinct Neotropical regions i.e. Western Amazonia (P. conspicillatus clade), the Brazilian Shield (P. fenestratus clade), the Atlantic Forest (P. ramagii clade), the Guiana Shield (P. vilarsi clade) and the northern Andes (P. nicefori clade). The majority of the diversification events within these clades occurred in-situ from the early Miocene onward. Yet, a few ancient dispersal/vicariance events are inferred to have occurred among trans-Andean forests, the Atlantic Forest, the Brazilian and the Guiana Shields, but almost none in the last 10 Ma. The radical landscape transformations during the Miocene caused by the Andean orogeny and hydrological barriers such as the Pebas System and the subsequent transcontinental configuration of the Amazon drainage is a likely explanation for the isolation of the different clades within the P. gr. conspicillatus.

Latitudinal patterns and environmental drivers of taxonomic, functional, and phylogenetic diversity of woody plants in western Amazonian terra firme forests.

Elucidating how environmental factors drive plant species distributions and how they affect latitudinal diversity gradients, remain essential questions in ecology and biogeography. In this study we aimed: 1) to investigate the relationships between all three diversity attributes, i.e., taxonomic diversity (TD), functional diversity (FD), and phylogenetic diversity (PD); 2) to quantify the latitudinal variation in these diversity attributes in western Amazonian terra firme forests; and 3) to understand how climatic and edaphic drivers contribute to explaining diversity patterns. We inventoried ca. 15,000 individuals from ca. 1,250 species, and obtained functional trait records for ca. 5,000 woody plant individuals in 50 plots of 0.1 ha located in five terra firme forest sites spread over a latitudinal gradient of 1200 km covering ca. 10°C in latitude in western Amazonia. We calculated all three diversity attributes using Hill numbers: q = 0 (richness), q = 1 (richness weighted by relative abundance), and q = 2 (richness weighted by dominance). Generalized linear mixed models were constructed for each diversity attribute to test the effects of different uncorrelated environmental predictors comprising the temperature seasonality, annual precipitation, soil pH and soil bulk density, as well as accounting for the effect of spatial autocorrelation, i.e., plots aggregated within sites. We confirmed that TD (q = 0, q = 1, and q = 2), FD (q = 0, q = 1, and q = 2), and PD (q = 0) increased monotonically towards the Equator following the latitudinal diversity gradient. The importance of rare species could explain the lack of a pattern for PD (q = 1 and q = 2). Temperature seasonality, which was highly correlated with latitude, and annual precipitation were the main environmental drivers of variations in TD, FD, and PD. All three diversity attributes increased with lower temperature seasonality, higher annual precipitation, and lower soil pH. We confirmed the existence of latitudinal diversity gradients for TD, FD, and PD in hyperdiverse Amazonian terra firme forests. Our results agree well with the predictions of the environmental filtering principle and the favourability hypothesis, even acting in a 10°C latitudinal range within tropical climates.

Detrital zircon U-Pb provenance analysis of Precambrian and Paleozoic strata from southwestern Brazil: Assessment of potential Grenvillian sediment input and Amazonian-Laurentian tectonic interaction

Southwest Amazonia is proposed to have collided with southeast Laurentia during the Grenville orogeny. In Laurentia, the collision produced a continental-scale late Mesoproterozoic to early Neoproterozoic clastic wedge dominated by detrital zircon (DZ) sourced from Grenvillian magmatic rocks (major Geon 11 and 10, with minor Geon 13, 12, and 9 ages: the “Great Grenvillian Sedimentation Episode”). New DZ ages in clastic units from southwestern Brazil permit testing the hypothesis that Grenvillian sediment from southeast Laurentia spilled onto western Amazonia during Rodinian assembly. Late Mesoproterozoic arenites are dominated by Geons 18, 17, 15, 14, and 13 ages sourced from Amazonia basement provinces. Two samples exhibit major Geon 12 and 11 ages with minor Geon 18–13 ages. Geon 12 and 11 correspond to a conspicuous age gap in Amazonian magmatic events. Latest Neoproterozoic samples exhibit minor Geon 13 to 9 ages interpreted to be sourced from the Rondônia-San Ignacio or Sunsás provinces of western Amazonia. Late Neoproterozoic and Devonian age spectra exhibit multiple Amazonian age modes ∼2500 to 500 Ma but with no dominant modes. The age distributions for all samples indicate a lack of Laurentian Grenville sediment influx to southwest Amazonia during Rodinian assembly and breakup. The enigmatic Geon 12 ages are interpreted to correspond to a buried Andean source or the southwestern Grenville province in Laurentia. In contrast to exposed basement in southwestern Amazonia, Andean basement clastic sequences and Pleistocene to Recent Amazon River sediments exhibit Grenville dominance of DZ ages, strikingly similar to eastern Laurentia clastic systems. The Andean Grenville dominance may be accounted for by extensive Grenvillian crust beneath the Andean clastic wedge containing a major component of Geons 12, 11 and 10 magmatic rocks, and which was not being fully exhumed until the Neoproterozoic, similar to Laurentian Grenville.

Common mental disorders in pregnancy and postnatal depressive symptoms in the MINA-Brazil study: occurrence and associated factors.

ABSTRACTOBJECTIVE To investigate the occurrence and factors associated with common mental disorders in pregnancy and depressive symptoms in postpartum, as well as the association between both in the Brazilian Western Amazon.METHODS This is a prospective cohort in the MINA-Brazil study with women who received primary health care in the town of Cruzeiro do Sul, Acre State. We performed two clinical evaluations during pregnancy (the first: 16–20 weeks; the second: 28 gestational weeks) and three postpartum evaluations (at 3, 6 and 12 months), in which demographic and socioeconomic, gestational, lifestyle and clinical data were collected. We used the Self-Reported Questionnaire (score ≥ 8) to screen the gestational common mental disorder and the Edinburgh Postnatal Depression Scale (score ≥ 10) to identify postpartum depressive symptoms. We used adjusted ordinal logistic regression to investigate the relationship between the covariates and the occurrence of common mental disorders in pregnancy and postpartum depressive symptomatology.RESULTS A total of 461 women completed the two clinical evaluations in pregnancy; of these, 247 completed the three postpartum evaluations. The occurrence of common mental disorder during pregnancy was 36.2% and 24.5% in the first and second evaluations, respectively, and the cumulative incidence was 9.2%. In addition, 50.3% maintained the disorder between evaluations. During postpartum, approximately 20% of the mothers presented depressive symptoms during the first year of their children’s lives. Parity (≥ 2) was associated with common mental disorders, while low maternal education was associated with postpartum depressive symptoms. Women with a common mental disorder in both evaluations during pregnancy were 5.6 times more likely (95%CI: 2.50–12.60) to develop postpartum depressive symptoms.CONCLUSION The occurrence of common mental disorder at any time assessed during pregnancy, but especially its persistence from the second trimester, was strongly associated with depressive symptoms after childbirth. These findings highlight the need for early screening and monitoring of the mental health of pregnant women at the start of prenatal care in order to reduce possible negative impacts on the health of the mother-child binomial caused by such events.

Dry season rainfall as a source of transpired water in a seasonal, evergreen forest in the western Amazon region inferred by water stable isotopes

The present work aimed to investigate the potential sources of water for plants in an area of evergreen forest located in western Amazonia (Rebio Jaru). We used a natural abundance of water isotopes—δ2H and δ18O—to trace the main source of water to plants at the beginning of the dry period (May 2016) and at the end of the dry period/transition to the wet period (October 2016) following a severe El Niño drought (ENSO 2015/16). Soil samples were collected in a soil profile up to 4 m depth. Plant samples from 18 trees (14 species) were collected in May and in October 2016. Rainwater and river water samples were collected between September 2015 and February 2017. We found that, at the end of the dry period/transition to the wet period (i.e., October 2016), the average plant xylem signal was more enriched (δ2H: −20.0 ± 8.1‰; δ18O: −1.13 ± 1.88‰) than in May 2016 (δ2H: −36.7 ± 5.6‰; δ18O: −3.50 ± 1.30‰), the onset of the dry period. The averaged isotopic soil signal in May 2016 (δ2H: −35.4 ± 5.90‰; δ18O: −5.19 ± 0.70‰) is slightly more depleted than in October (δ2H: −27.6 ± 13.8‰; δ18O: −4.35 ± 1.73‰) and, in general, more depleted than the xylem signal. In the dual isotope space, the xylem signal at the beginning of the dry period follows the rainfall signal of the wet period, while the xylem signal at the end of the dry period/transition to the wet period follows the signal of the dry season rainfall, suggesting that plants mostly transpire recent rainwater. Contrary to what was expected, we did not find evidence in the xylem signal of the water stored in the soil pores, which suggests that to meet to the water demands of the dry period, plants do not use the water from past periods stored in the soil layers.

Genomic Variability of Hepatitis B Virus Circulating in Brazilian Western Amazon.

The emergence of clinically relevant mutations in the hepatitis B virus (HBV) genome has been a matter of great debate because of the possibility of escape from the host’s immune system, the potential to cause more severe progression of liver diseases and the emergence of treatment-resistant variants. Here we characterized the circulating variants of HBV in Rondônia State, in the north of Brazil. Serum samples of 62 chronic HBV carriers were subjected to PCR assays and clinical data were collected. Mutations and genotypes were characterized through direct sequencing. The findings show the presence of subgenotypes A1 (54.83%, 34/62), D3 (16.13%, 10/62), F2 (16.13%, 10/62), A2 (4.84%, 3/62), D2 (3.23%, 2/62), D1 (1.61%, 1/62), D4 (1.61%, 1/62) and F4 (1.61%, 1/62). Deletions in the pre-S2 region were found in 13.79% (8/58) of the samples, mutations in the S gene in 59.68% (37/62) and RT mutations in 48.39% (30/62). We found a variable genotypic distribution in different locations and important mutations related to immune escape and drug resistance in Western Amazonia, which contributed to genetic surveillance and provided important information to help control the disease.

Soil type determines the magnitude of soil fertility changes by forest-to-pasture conversion in Western Amazonia

The deforestation of tropical forests raises environmental concerns worldwide. Removing the pristine forest impacts the soil, consequently affecting the environmental services it provides. Within this context, the main goal of this study was to determine how the conversion of the tropical rainforest to pasture affects soil fertility across an extended range of soil heterogeneity, including different soil types. We sampled 13 sites, among forests, recent pastures (≤7-year-old), and old pastures (≥10-year-old), on Acrisols, Ferralsols, Plinthosols, and Luvisols, across a ± 800 km geographical range in the Western Brazilian Amazon. Soils were classified taxonomically, and their superficial layer's chemical and physical properties (0–10 cm) were analyzed. Furthermore, we tested the sensibility of Actinobacteria and Proteobacteria to detect changes in these soil properties based on their ecological habitat. An inter-regional gradient of soil fertility was observed, and the sampling sites were clustered mostly by soil type and associated land use than by spatial distance. The Sum of bases, Ca + Mg, base saturation, Al saturation, and pH were consistently affected by land use, increasing after conversion to pasture, at different degrees and with a more pronounced effect on oxidic soils. The Sum of bases was the only property that increased significantly among the study sites (Radj = 0.860, p < 0.001), being able to detect the effect of anthropic land use on a larger coverage of soil types. Finally, the Actinobacteria:Proteobacteria ratio was also sensitive to the impact of forest-to-pasture conversion, with a higher ratio observed in pasture systems, and it was positively correlated with soil pH (rho = 0.469, p < 0.001). Our results consistently show that the forest-to-pasture conversion leads to strong alterations in the soil environment, with varying intensities depending on soil type.

“Because I saw my mother cooking”: the sociocultural process of learning and teaching domestic culinary skills of the Western Brazilian Amazonian women

This article describes and discusses the sociocultural process of learning and teaching women’s domestic culinary skills. Drawing on descriptive qualitative research, we conducted an in-depth analysis of semi-structured interviews with 16 cisgender women who cooked at home at least once a day and lived in Cruzeiro do Sul, Acre state, Brazilian Western Amazon. Our results suggest that women develop their domestic cooking skills at different moments. In childhood, the women interviewed were taught by their maternal figures and learned the required culinary skills to prepare “Rainforest Foods,” traditional foods in their original places. In adulthood, female employers taught them the culinary skills needed to prepare “City food,” meals made with ingredients, tools, and cooking methods available in the urban area. Notably, the women interviewed also reported being taught by their husbands to cook foods that met their tastes and eating patterns. In contrast, women teach their sons and daughters culinary skills to develop their food autonomy and promote the egalitarian division of domestic culinary work. These findings are essential to understand the sociocultural process of learning and teaching domestic culinary skills among communities or membership groups who lived in forest or rural areas and migrated to urban centers.

Local hydrological conditions influence tree diversity and composition across the Amazon basin

Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well‐drained and potentially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of 443 1‐ha non‐flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1) tree alpha diversity, 2) the community‐weighted wood density mean (CWM‐wd) – a proxy for hydraulic resistance and 3) tree species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more evident in wetter forests, where diversity increases towards locations with well‐drained soils. CWM‐wd increased towards better drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients in Central‐Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood density of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures.

The Acre Basin basement (NW Brazil) and the transition from the intracratonic to retroarc foreland basin system

AbstractThe understanding of the crustal transition between orogenic zones and cratonic portions in distal regions of foreland basins has received increasing attention, but the analysis is often hampered by the sedimentary cover. Despite the peculiar location of the Acre Basin, specifically between the Amazonian Craton and the sub‐Andean zone, local basement studies are still scarce due to lacking seismic data and exploratory wells. Therefore, this work aims to map basement depths, estimate crustal compositions and identify the main depocenters, structures and limits of Acre Basin using an integrated analysis to understand better the region lithospheric evolution, its relationship with the Amazonian Craton and its positioning within the Andean orogeny. For that, we used well, 2D seismic reflection, airborne and ground gravity and magnetic data as well as the EMG2008. Tilt Depth estimates indicate basement depths between 500 and 7800 m and larger sedimentary thicknesses in the northern portion. Additionally, we modelled groups of potential sources between 0.1 and 22 km and Moho depths between 26 and 37 km. Compositionally, the upper crust consists dominantly of meta‐sedimentary and low‐grade metamorphic rocks and granites, indicating that the sub‐Andean and Acre Basins share a similar basement. Thus, there are indications that the basement of the Acre Basin is essentially formed by the Sunsás province in the Amazonian Craton. However, local differences in basement depth, magnetic susceptibility and exploratory potential led to the subdivision into Divisor and Xapuri sub‐basins, north and south of the Fitzcarrald Arch, respectively. Finally, it was possible to establish the limits of the Andean orogeny influence in the Acre Basin and delimit the area of the Western Amazon Foredeep installed during the Neogene.

Epidemiological characterization and sensitivity to traditional antimalarials of Plasmodium spp. isolates from Porto Velho, western Amazon, Brazil

Objective: To describe the epidemiological profile of patients infected with malaria in Porto Velho and the susceptibility of Plasmodium spp. to different classes of drugs used in current treatment methods. Methods: 708 patients infected with malaria were treated at the Center of Tropical Medicine in Porto Velho, where they answered standard epidemiological questionnaires. Maps were built using place of residence information of 199 infected patients. In chemosensitivity assay, dihydroartemisinin, chloroquine, mefloquine and lumefantrine half maximal inhibitory concentration (IC50) was assessed by schizont maturation assay. Results: A higher prevalence of Plasmodium spp. infection among men, young people, with recurrent events of malaria and residents of urban area can be observed. The most prevalent malaria species was P. vivax followed by P. falciparum. Regarding treatment, it was observed that P. falciparum demonstrated resistance only to chloroquine (CQ) with a median of IC50 (MD of IC50) = 119.8 nM, whereas P. vivax demonstrated sensitivity to all drugs (MD IC50 &lt; 10; 100; 30; and 150 nM for dihydroartemisinin, CQ, mefloquine and lumefantrine, respectively). Conclusion: This study contributes to the understanding of the disease by the city’s public health organs, to Plasmodium chemosensitivity literature and vigilance, and to decision making processes of city officials.

Population dynamics of Amazonian floodplain forest species support spatial variation on genetic diversity but not range expansions through time

AbstractAimThe distribution and connectivity of floodplain environments along major Amazonian rivers changed considerably over time following physiographic and climatic events. However, how historical alteration in floodplain habitats affected endemic species' demography and diversification is not fully understood. We tested if historical demographic changes of populations occurring on the floodplains of a major Amazon Basin tributary could be associated with range expansions from upper and middle sections of the river, following the establishment of widespread river‐created environments during the Late Pleistocene and Holocene.LocationSolimões River, Western Amazon, South America.TaxonMyrmoborus lugubris, Thamnophilus cryptoleucus and Myrmotherula assimilis.MethodsWe explored spatial patterns of genetic diversity and connectivity among 13 sampled localities using thousands of UltraConserved Elements. We used a total of 73 individuals of three species with populations restricted to the Solimões River. Range expansions were tested with spatial explicit methods designed to capture variations in allele frequency over space. To test whether the occupation of dynamic habitats could predict spatial patterns of genetic diversity, we quantified habitat preference for the three analysed species by creating a metric of habitat dynamicity over time.ResultsWe found considerable variation in the spatial distribution of the genetic diversity between studied taxa rejecting shared population range expansions related to historical regionalized changes in habitat availability. Species with higher levels of specialization to dynamic environments have a more heterogeneous distribution of genetic diversity and reduced levels of gene flow across space.Main conclusionsThe demographic expansions along the Solimões River might be linked to spatially homogeneous oscillation in the distribution of floodplain environments, promoting effective population size changes but not range expansion. Habitat specificity might be a good predictor of population connectivity along the Amazonian floodplains.

Level of Physical Activity and Health Conditions of Military Policemen in The State of Rondônia, Western Amazon

Objective: To analyze the sociodemographic characteristics, levels of physical activity and health conditions of active military police officers in the State of Rondônia, in the Western Amazon, Brazil in times of the Covid-19 pandemic. Methodology: This is a descriptive, cross-sectional field study, with a convenience sample, non-probabilistic and with a quantitative approach, with 358 PMs working in the PMRO. A self-report questionnaire was used to collect sociodemographic data and health conditions. The IPAQ-short version was used to assess the level of physical activity (NAF). Results: The age variable obtained (39.21 ± 6.41) years and (61.17%) of the PMs were less than 40 years old. The variable length of service was (15.44 ± 7.64) and (78.21%) of the police officers had less than 20 years of experience in the police service. The working hours obtained (6.87 ± 2.04) and (29.10 ± 80.79) days away from work due to NCDs or Covid-19. According to the NAF, 29.61% were classified as very active, 23.74% active, 14.24% irregularly active A, 8.38% irregularly active B and 24.86% sedentary. Of the CNCDs, musculoskeletal diseases (16.49%), psychosomatic diseases (14.80%), SAH (8.10%), dyslipidemias (5.58%), CVDs (2.51%), cancer (0, 56%) and DM2 (0.28%). Of the total number of infectious diseases, 34.08% contracted Covid-19. Conclusion: The physical activity levels (47.48%) of the military police were in the classification (irregularly active + sedentary) according to the IPAQ-short version, confirming the low PAL of these individuals. Low NAF, NCDs and Covid-19 contributed to momentarily worsening the quality of life of PMs.