84 research outputs found
Prevalência de vaginose bacteriana e fatores associados em mulheres que fazem sexo com mulheres
Objetivo: descrever a prevalência de vaginose bacteriana e fatores associados em mulheres que fazem sexo com mulheres. Método: trata-se de estudo transversal, descritivo e analítico com 150 mulheres. O padrão de microbiota vaginal foi analisado por microscopia do conteúdo vaginal corado pelo método de Gram. Amostras de secreção endocervical foram coletadas com cytobrush para a pesquisa de endocervicites por Chlamydia trachomatis e para infecção por Papilomavírus Humano por meio de reação em cadeia da polimerase. Dados sociodemográficos, de comportamento sexual e de história clínica foram obtidos por entrevista. Regressão logística foi realizada para identificar fatores de risco independentemente associados à vaginose bacteriana. Resultados: dentre as 150 participantes, 71 (47,3%) tinham alguma alteração da microbiota vaginal, 54 (36,0%) vaginose bacteriana e 12 (8,0%) Flora II. A variável independentemente associada com vaginose bacteriana foi o uso de acessórios sexuais [2,37(1,13-4,97), p=0,022]. Conclusão: a elevada prevalência de vaginose bacteriana entre mulheres que fazem sexo com mulheres aponta a necessidade de rastreio nessa população. O uso de acessórios sexuais associado a esse agravo sugere a possibilidade de transmissão de fluidos sexuais entre as parceiras durante o ato sexual, o que demonstra necessidade de ações de educação em saúde sexual e reprodutiva.Objective: to describe the prevalence of bacterial vaginosis and factors associated among women who have sex with women. Method: cross-sectional, descriptive and analytical study with 150 women. The vaginal microbiota profile was analyzed by microscopic examination of vaginal swabs according to the Gram method. Endocervical samples were collected with cytobrush for the investigation of endocervicitis by Chlamydia trachomatis. The polymerase chain reaction was used to diagnosis Human Papillomavirus infection. Socio-demographic data, sexual behavior and clinical history were obtained through an interview. Logistic regression was performed to identify risk factors independently associated with bacterial vaginosis. Results: among the 150 participants, 71 (47.3%) presented some alteration in the vaginal microbiota, 54 (36.0%) bacterial vaginosis and 12 (8.0%) Flora II. The variable independently associated with bacterial vaginosis was the use of sexual accessories [2.37(1.13-4.97), p=0.022]. Conclusion: the high prevalence of bacterial vaginosis among women who have sex with women indicates the need for screening this population and association between use of sexual accessories and this disease suggests the possibility of transmission of sexual fluids between the partners during the sexual act, which demonstrates the need for educational actions on sexual and reproductive health.Objetivo: describir la prevalencia de la vaginosis bacteriana y los factores asociados en mujeres que tienen sexo con mujeres. Método: se trata de un estudio transversal, descriptivo y analítico realizado entre 150 mujeres. El patrón de microbiota vaginal se analizó por microscopía del contenido vaginal teñido por el método de Gram. Se recolectaron muestras de secreción endocervical con un citocepillo para investigar la endocervicitis por Chlamydia trachomatis y la infección por el Virus del Papiloma Humano mediante la reacción en cadena de la polimerasa. De la entrevista se obtuvieron datos sociodemográficos, de comportamiento sexual y del historial clínico. Se llevó a cabo una regresión logística para identificar factores de riesgo asociados independientemente a la vaginosis bacteriana. Resultados: entre las 150 participantes, el 71 (47,3%) tenía alteración de la microbiota vaginal, el 54 (36,0%), vaginosis bacteriana y el 12 (8,0%), Flora II. La variable asociada independientemente a la vaginosis bacteriana se debió al uso de accesorios sexuales [2,37(1,13-4,97), p=0,022]. Conclusión: la prevalencia elevada de vaginosis bacteriana entre mujeres que tienen sexo con mujeres señala la necesidad de estudiar dicha población, y el uso de accesorios sexuales asociado a este agravante sugiere la posibilidad de transmisión de fluidos sexuales entre las compañeras durante el acto sexual, razón por la cual deben llevarse a cabo acciones de educación en salud sexual y reproductiva
Prevalencia de vaginosis bacteriana y factores asociados en mujeres que tienen sexo con mujeres
Objetivo: descrever a prevalência de vaginose bacteriana e fatores associados em mulheres que fazem sexo com mulheres. Método: trata-se de estudo transversal, descritivo e analítico com 150 mulheres. O padrão de microbiota vaginal foi analisado por microscopia do conteúdo vaginal corado pelo método de Gram. Amostras de secreção endocervical foram coletadas com cytobrush para a pesquisa de endocervicites por Chlamydia trachomatis e para infecção por Papilomavírus Humano por meio de reação em cadeia da polimerase. Dados sociodemográficos, de comportamento sexual e de história clínica foram obtidos por entrevista. Regressão logística foi realizada para identificar fatores de risco independentemente associados à vaginose bacteriana. Resultados: dentre as 150 participantes, 71 (47,3%) tinham alguma alteração da microbiota vaginal, 54 (36,0%) vaginose bacteriana e 12 (8,0%) Flora II. A variável independentemente associada com vaginose bacteriana foi o uso de acessórios sexuais [2,37(1,13-4,97), p=0,022]. Conclusão: a elevada prevalência de vaginose bacteriana entre mulheres que fazem sexo com mulheres aponta a necessidade de rastreio nessa população. O uso de acessórios sexuais associado a esse agravo sugere a possibilidade de transmissão de fluidos sexuais entre as parceiras durante o ato sexual, o que demonstra necessidade de ações de educação em saúde sexual e reprodutiva.Objective: to describe the prevalence of bacterial vaginosis and factors associated among women who have sex with women. Method: cross-sectional, descriptive and analytical study with 150 women. The vaginal microbiota profile was analyzed by microscopic examination of vaginal swabs according to the Gram method. Endocervical samples were collected with cytobrush for the investigation of endocervicitis by Chlamydia trachomatis. The polymerase chain reaction was used to diagnosis Human Papillomavirus infection. Socio-demographic data, sexual behavior and clinical history were obtained through an interview. Logistic regression was performed to identify risk factors independently associated with bacterial vaginosis. Results: among the 150 participants, 71 (47.3%) presented some alteration in the vaginal microbiota, 54 (36.0%) bacterial vaginosis and 12 (8.0%) Flora II. The variable independently associated with bacterial vaginosis was the use of sexual accessories [2.37(1.13-4.97), p=0.022]. Conclusion: the high prevalence of bacterial vaginosis among women who have sex with women indicates the need for screening this population and association between use of sexual accessories and this disease suggests the possibility of transmission of sexual fluids between the partners during the sexual act, which demonstrates the need for educational actions on sexual and reproductive health.Objetivo: describir la prevalencia de la vaginosis bacteriana y los factores asociados en mujeres que tienen sexo con mujeres. Método: se trata de un estudio transversal, descriptivo y analítico realizado entre 150 mujeres. El patrón de microbiota vaginal se analizó por microscopía del contenido vaginal teñido por el método de Gram. Se recolectaron muestras de secreción endocervical con un citocepillo para investigar la endocervicitis por Chlamydia trachomatis y la infección por el Virus del Papiloma Humano mediante la reacción en cadena de la polimerasa. De la entrevista se obtuvieron datos sociodemográficos, de comportamiento sexual y del historial clínico. Se llevó a cabo una regresión logística para identificar factores de riesgo asociados independientemente a la vaginosis bacteriana. Resultados: entre las 150 participantes, el 71 (47,3%) tenía alteración de la microbiota vaginal, el 54 (36,0%), vaginosis bacteriana y el 12 (8,0%), Flora II. La variable asociada independientemente a la vaginosis bacteriana se debió al uso de accesorios sexuales [2,37(1,13-4,97), p=0,022]. Conclusión: la prevalencia elevada de vaginosis bacteriana entre mujeres que tienen sexo con mujeres señala la necesidad de estudiar dicha población, y el uso de accesorios sexuales asociado a este agravante sugiere la posibilidad de transmisión de fluidos sexuales entre las compañeras durante el acto sexual, razón por la cual deben llevarse a cabo acciones de educación en salud sexual y reproductiva
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
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 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R = 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
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
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
Consistent patterns of common species across tropical tree communities
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. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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'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 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 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
Rarity of monodominance in hyperdiverse Amazonian forests.
Tropical 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. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors
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