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Diet of an Assemblage of Four Species of Turtles (Podocnemis) in the Rio Uatumã, Amazonas, Brazil
No full textThe structure and functioning of freshwater turtle communities remain understudied topics, especially in tropical regions where biodiversity is higher. The objective of our study was to compare the diets of Podocnemis erythrocephala ,P. expansa, P. sextuberculata, and P. unifilis living in syntopy in Amazonas, Brazil. We tested for qualitative and quantitative variations in the way different species used the same available food resources. We collected fresh stomach flushings from all turtles captured in trammel nets in three lakes in 2012. Sampling was conducted in the four distinct tropical seasons: Beginning of rainy season (rising water), peak of rainy season (rapidly rising water), end of rainy season (highest flooded forest water level), and dry season (when water levels were receding). We tested the hypothesis that different food items are available in different quantities at different times of the year due to the seasonality of fruiting trees and other plants in response to the wet and dry conditions. We examined whether food items consumed were related to turtle body size and if there was feeding niche overlap among species. Podocnemis sextuberculata consumed the least amount of food by volume, while P. expansa consumed the highest diversity of food items. All four species are primarily herbivorous, and their diets were composed mainly of fruits and seeds (85.4% mean proportion by volume). Genipa americana (Rubiaceae) was most important in the diet of all species, except in P. sextuberculata. We found some evidence of seasonal differences in the consumption of some plant species. Body size did not influence qualitative (diversity of food items eaten) or quantitative variation of food items (volume), except in P. erythrocephala for which we detected a significant linear relationship between carapace length and the volume of stomach contents. The highest food niche overlap was between P. expansa and P. unifilis, and the lowest niche overlap was between P. erythrocephala and P. sextuberculata. Turtles tended to partition food resources more in areas that had more species feeding in syntopy than in areas with fewer syntopic species. © 2020 by the American Society of Ichthyologists and Herpetologists
Interspecific cytogenetic relationships in three Acestrohynchus species (Acestrohynchinae, Characiformes) reveal the existence of possible cryptic species
Full text linkThe karyotypes and chromosomal characteristics of three Acestrorhynchus Eigenmann et Kennedy, 1903 species were examined using conventional and molecular protocols. These species had invariably a diploid chromosome number 2n = 50. Acestrorhynchus falcatus (Block, 1794) and Acestrorhynchus falcirostris (Cuvier, 1819) had the karyotype composed of 16 metacentric (m) + 28 submetacentric (sm) + 6 subtelocentric (st) chromosomes while Acestrorhynchus microlepis (Schomburgk, 1841) had the karyotype composed of 14m+30sm+6st elements. In this species, differences of the conventional and molecular markers between the populations of Catalao Lake (AM) and of Apeu Stream (PA) were found. Thus the individuals of Para (Apeu) were named Acestrorhynchus prope microlepis. The distribution of the constitutive heterochromatin blocks was species-specific, with C-positive bands in the centromeric and telomeric regions of a number of different chromosomes, as well as in interstitial sites and completely heterochromatic arms. The phenotypes of nucleolus organizer region (NOR) were simple, i. e. in a terminal position on the p arm of pair No. 23 except in A. microlepis, in which it was located on the q arm. Fluorescence in situ hybridization (FISH) revealed 18S rDNA sites on one chromosome pair in karyotype of A. falcirostris and A. prope microlepis (pair No. 23) and three pairs (Nos. 12, 23, 24) in A. falcatus and (Nos. 8, 23, 24) in A. microlepis; 5S rDNA sites were detected in one chromosome pair in all three species. The mapping of the telomeric sequences revealed terminal sequences in all the chromosomes, as well as the presence of interstitial telomeric sequences (ITSs) in a number of chromosome pairs. The cytogenetic data recorded in the present study indicate that A. prope microlepis may be an unnamed species. © 2020, Alber Sousa Campos et al
Thermal Diagnosis of Heat Conduction and Combustion Time of Fruits of the Brazil Nut Tree (<i>Bertholletia excelsa</i> Bonpl.)
No full textSeroprevalence of cytomegalovirus and its coinfection with epstein-barr virus in adult residents from manaus: A population-based study
Full text linkIntroduction: This study assessed the seroprevalence of cytomegalovirus, associated factors, and Epstein-Barr virus coinfection among adult residents of Manaus. Methods: Using a cross-sectional study design, we collected blood samples from 136 individuals in a household survey in 2016. Prevalence ratios were calculated using Poisson regression. Results: Cytomegalovirus and Epstein-Barr virus seroprevalences were 67.6% (95% CI: 9.7-75.6%) and 97.8% (95% CI: 95.3-100.0%), respectively. Coinfection was observed in 66.2% (95% CI: 58.1-74.2%) of participants. Bivariate analysis showed no statistical association. Conclusions: Seroprevalences were high among participants and approximately 7 out of 10 individuals had cytomegalovirus and Epstein-Barr virus coinfection. © 2020, Sociedade Brasileira de Medicina Tropical. All rights reserved
Palm distribution patterns in the southwestern Brazilian Amazon: Impact of a large hydroelectric dam
No full textMega hydroelectric dams cause loss of habitat for many species and lead to local or regional extinction. Despite these dire facts, little is known about the impact of these mega-dams on Amazonia. Using palms as a model, we investigated this question by sampling 26 1-ha plots distributed in the influence areas of the Jirau mega-dam in southwestern Brazilian Amazonia. We examined palm community patterns and species distributions as a function of environmental variables, as well as the effect of this large dam on plant survival. Palm communities on the banks of the Madeira River differ among three main habitats sampled (campinarana, terra-firme and várzea forests), and these differences are associated with the gradient of C, pH, N, P, soil texture, slope, and depth to the water-table. The level of the Madeira River raised after the construction of the Jirau mega-dam, directly affecting the populations of 61.3% of the palm species, particularly those species associated to areas with silty soils, low slope, and low depth to the water-table. Várzea and terra-firme forests near the river, as well as low-lying plots, even those distant from the river, were affected by the filling of the reservoir. Várzea forests and campinaranas had a greater proportion of palm species flooded by the reservoir and the reduction of water-table depth. Várzea forests and campinaranas harbor distinct palm communities from the terra-firme forests and require priority in conservation policies and management to mitigate harmful environmental impacts in the Amazon. © 2020 Elsevier B.V
Multi-scale integration of satellite remote sensing improves characterization of dry-season green-up in an Amazon tropical evergreen forest
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Diversity trapped in cages: Revision of Blumenavia Möller (Clathraceae, Basidiomycota) reveals three hidden species
No full textBasidiomata of Phallales have a diversified morphology with adhesive gleba that exudes an odor, usually unpleasant that attracts mainly insects, which disperse the basidiospores. The genus Blumenavia belongs to the family Clathraceae and, based on morphological features, only two species are currently recognized: B. rhacodes and B. angolensis. However, the morphological characters adopted in species delimitations within this genus are inconsistent, and molecular data are scarce. The present study aimed to review and identify informative characters that contribute to the delimitation of Blumenavia species. Exsiccates from America and Africa were analyzed morphologically, and molecularly, using ITS, LSU, ATP6, RPB2 and TEF-1α markers for Maximum Parsimony, Bayesian and Maximum likelihood analyses, and also for coalescent based species delimitations (BP&P), as well as for bPTP, PhyloMap, Topo-phylogenetic and Geophylogenetic reconstructions. According to our studies, seven species can be considered in the genus: B. rhacodes and B. angolensis are maintained, B. usambarensis and B. toribiotalpaensis are reassessed, and three new species are proposed, B. baturitensis Melanda, M.P. Martín & Baseia, sp. nov., B. crucis-hellenicae G. Coelho, Sulzbacher, Grebenc & Cortez, sp. nov., and B. heroica Melanda, Baseia & M.P. Martín, sp. nov. Blumenavia rhacodes is typified by selecting a lectotype and an epitype. Macromorphological characters considered informative to segregate and delimit the species through integrative taxonomy include length of the basidiomata, color, width and presence of grooves on each arm as well as the glebifer position and shape. These must be clearly observed while the basidiomata are still fresh. Since most materials are usually analyzed after dehydration and deposit in collections, field techniques and protocols to describe fugacious characters from fresh specimen are demanded, as well as the use of molecular analysis, in order to better assess recognition and delimitation of species in Blumenavia. © 2020 Melanda et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
In vitro antibiotic and modulatory activity of Mesosphaerum suaveolens (L.) kuntze against candida strains
Full text linkThe emergence of fungal resistance to commercial drugs has been a major problem for the WHO. In this context, research with natural products is promising in the discovery of new active substances. Thus, this work evaluated the antifungal effect of a medicinal plant (i.e., Mesosphaerum suaveolens) against strains of the genus Candida, tested the combined effect with the drug fluconazole, and, finally, determined the phenolic constituents present in the species. Initially, aqueous extracts of leaves (AELMs) and aerial parts (AEAPMs) of the species were prepared. For microbiological assays, the minimum fungicidal concentration was determined by broth microdilution, and the combined effect of fluconazole extracts were verified by sub‐inhibitory microdilution concentrations (CFM/8) followed by spectrophotometric readings which were used to determine the IC50. HPLC detected the presence of flavonoids and phenolic acids, detecting eight compounds present in the samples of which caffeic acid and quercetin were major components. The AELMs modulated fluconazole activity since it decreased fluconazole’s IC50 from 7.8 μg/mL to an IC50 of 4.7 μg/mL (CA LM 77) and from 28.8 μg/mL to 18.26 μg/mL (CA INCQS 40006) for the C. albicans strains. The AEAPMs were able to potentiate the effect of fluconazole more effectively than the AELMs. Such an effect was significant for the 16 μg/mL concentration for CA LM 77 and 32 μg/mL for CA INCQS 40006. The AEAPMs as well as the AELMs presented clinically relevant activities for C. tropicalis strains. For the C. tropicalis LM 23 strain, the AEPMs obtained an IC50 of 25 μg/mL and the AELMs an IC50 of 359.9 μg/mL. © 2020 by the authors. Licensee MDPI, Basel, Switzerland