Efficacy of chitosan supported organic acaricide extract from Melia azedarach leaves on Rhipicephalus (Boophilus) microplus ticks

The Rhipicephalus (Boophilus) microplustick control is mainly performed by chemicals products, but organic acaricides use has higher advantages compared to conventional products. Brazilian cerrado native plants are known for their bioactive potential. Due to this fact, the objective of this study is to evaluate the acaricide action of native cerrado specie, Meliaazedarach, known as Santa Barbara in the tick control. Also, the chitosan nanosphere was evaluated on the extract adsorption and release, as a proposal to raise the acaricide phytotherapic profile. The ethanol extract was obtained by cool extraction from dried leaves of the plant. Chitosan nanospheres were obtained by the phase inversion method. Conductometric titration, ultraviolet-visible ("UV-Vis") and Fourier transform infrared spectroscopy (FTIR) analysis were conducted with materials to evaluate the chitosan anchoring ability. In vitro test was used in engorged females for each treatment, which consisted of control, raw extract and three treatments with increasing concentrations of 0.2; 0.4 and 1%. The organic product effectiveness of 0.2% concentration was found by observing reduction in the eggs mass compared to control group. The nanomaterial proved capable to anchor and release the acaricide gradually in pH between 6 and 7, which makes it feasible for use in cattle, prolonging the exposure time between the tick and acaricide.Keywords: Cerrado specie, Rhipicephalus (Boophilus) microplustick, ectoparasites, tick control, acaricide, chitosan nanoparticl

Efficacy of antiparasitic drugs in control of gastrointestinal helminthiasis in naturally colored and white lambs from southern Brazil

Parasitic infections and the efficiency of different drugs were evaluated considering efficacy percentages, reduction in count of eggs per gram of feces (EPG) and larval culture in 60, 30 white and 30 naturally colored Corriedale lambs. Each phenotypic group was subdivided into six groups of five animals, each of which was administered one of the active ingredients: albendazole, levamisole hydrochloride, dysophenol, nitroxynil and moxidectin, in addition to a control group, unmedicated. Helminths were considered susceptible to nitroxinil and resistant to albendazole, levamisole, moxidectin (moderately effective) and to dysophenol (insufficiently active). In the culture of larvae, levamisole, nitroxinil and moxidectin were totally efficient (100%) against Oesophagostomum spp., moxidectin was totally efficient against Trichostrongylus spp. and nitroxinil was efficient (97%) against Haemonchus spp. Evaluating the EPG means of the phenotypic groups, it was observed higher parasitic infections in white ewes (p<0.05), in pre- and post-treatment. Therefore, it was concluded that the drug nitroxinil was the only effective for the reduction of the total parasite load of both phenotypic groups, being indicated for use in the herd in question. The genus Haemonchus spp. was the most prevalent and resistant to the drug action. Naturally colored Corriedale lambs, from the herd, showed increased resistance to gastrointestinal nematode infections

Abscesso hepático por Tuberculose em paciente com HIV: um relato de caso / Liver abscess by Tuberculosis IN HIV patient: a case report

A tuberculose é uma doença infectocontagiosa causada pelo Mycobacterium tuberculosis, comum em países em desenvolvimento. Os acomentimentos pulmonares são as principais manifestações da doença, embora existam, também, manifestações extrapulmonares, as quais são mais comuns em pacientes imunocomprometidos, a exemplo dos pacientes coinfectados com o HIV. O abscesso hepático é a forma menos comum de lesão. Entretanto, quando analisadas as taxas de mortalidade e os resultados dos tratamentos, é uma das manifestações extrapulmonares com pior prognóstico. O caso relatado segue com o diagnóstico através dos sinais e sintomas clínicos, além da realização dos exames laboratoriais e de imagem, a fim de diagnosticar e indicar os tratamentos cirúrgico e medicamentoso para tratar a infecção e sua consequente manifestação

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

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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\u27s 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 várzea forest types, the phylogenetic composition varies by geographic region, but the igapó 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

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AimAmazonia 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.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData 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.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó 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 (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous 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

Mapping density, diversity and species-richness of the Amazon tree flora

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