76 research outputs found
Prevalence of Dental Fluorosis in a City without Fluoridation in its Water Supply: Effect of Sampling
Objective: To determine the prevalence of dental fluorosis in a population not exposed to fluoridated water and to evaluate the effect of the sampling technique on this measurement. Material and Methods: This observational, cross-sectional and quantitative study was conducted in the city of Mariana, Brazil. The participants were selected based on age, so that they had access to fluoridated dentifrice during the formation of the permanent upper teeth. Based on a nominal survey of schoolchildren aged 14 to 19, a probabilistic sample of 304 such children was clinically examined. Dental fluorosis was measured by the Thylstrup-Fejerskov index. The prevalence of fluorosis identified in a previous study, conducted in 2011 in the same city, using the same methodology but employing convenience sampling, was used as a control to compare the effect of the two sampling techniques. Results: The prevalence of dental fluorosis was 3% based on the probabilistic sampling of the subjects. In the previous study, the prevalence of fluorosis was 7% (p<0.05) based on convenience sampling of the same age group. Both studies detected a Thylstrup-Fejerskov fluorosis index value of 1, corresponding to only a mild degree of dental fluorosis. Conclusion: The convenience sampling technique seems to have affected the prevalence of dental fluorosis identified, with a 4% difference between the two studies. The prevalence of dental fluorosis attributed to the use of fluoridated dentifrice in a population not exposed to fluoridation of the water supply was considered low
Factors associated with edentulism in individuals with chronic kidney disease undergoing hemodialysis: a cross-sectional study
Introdução: A doença renal crônica (DRC) é uma condição caracterizada por anormalidades estruturais ou funcionais do rim. A DRC pode estar associada a diversas alterações bucais, como maior prevalência de cárie dentária, doença periodontal, xerostomia, candidíase e queimação bucal. O objetivo deste estudo foi identificar os fatores de risco associados ao edentulismo em indivíduos com DRC em tratamento com hemodiálise. Materiais e Métodos: Foi realizado um estudo transversal com 650 indivíduos de 18 a 90 anos em hemodiálise no sudeste do Brasil. Foi realizado exame clínico oral e aplicação de questionário abordando características demográficas e histórico odontológico. O estudo foi aprovado pelo Comitê de Ética em Pesquisa em Seres Humanos da UFMG. Resultados: Um total de 183 participantes eram edêntulos (28,2%). Indivíduos com menor escolaridade (OR = 3,99; IC 95%: 2,34-6,79), aqueles que não foram ao dentista nos últimos seis meses (OR = 2,49; IC 95%: 1,52-4,08), aqueles que avaliaram o seu próprio sorriso como excelente ou bom (OR = 2,00; IC95%: 1,35-2,97) e aqueles com alguma alteração de mucosa (OR = 4,17; IC95%: 2,83-6,13) tiveram maior chance de pertencer ao grupo de edêntulos. Discussão: Os presentes achados podem contribuir para o estabelecimento de políticas públicas de saúde voltadas a nortear programas de atenção odontológica à pessoa com doença renal crônica que atendam às necessidades específicas dessa população. Conclusão: O edentulismo esteve associado à baixa escolaridade, falta de atendimento odontológico nos últimos seis meses, sorriso autoavaliado positivo e alterações mucosas.Introduction: Chronic kidney disease (CKD) is a progressive condition characterized by structural or functional abnormalities of the kidney. CKD may be associated with several oral alterations, such as higher prevalence rate of dental caries, periodontal disease, xerostomia, candidiasis and burning mouth. The aim of the study was to identify risk factors associated with edentulism in adults with CKD undergoing hemodialysis. Methods: A cross-sectional study was conducted with 650 individuals aged 18 to 90 years undergoing hemodialysis in southeastern Brazil. Oral clinical examination and administration of a questionnaire addressing demographic characteristics and dental history were performed. The study received approval from the Human Research Ethics Committee of UFMG. Findings: A total of 183 participants were edentulous (28.2%). Individuals with less schooling (OR= 3.99; 95% CI: 2.34-6.79), those who had not been to a dentist in the previous six months (OR = 2.49; 95% CI: 1.52-4.08), those who rated their own smile as excellent or good (OR = 2.00; 95% CI: 1.35-2.97) and those with some mucosal alteration (OR= 4.17; 95% CI: 2.83-6.13) had a greater chance of belonging to the edentulous group. Discussion: The present findings can contribute to the establishment of public health policies aimed at guiding dental care programs for individuals with chronic kidney disease that take into account the specific needs of this population. Conclusion: Edentulism was associated with low schooling, a lack of dental care in the previous six months, a positive self-perception of one’s smile and alterations in the oral mucosa
Comunicação, Saúde e Pluralidade: novos olhares e abordagens em pauta
Propomos um passeio acadêmico por 11 textos de pesquisadores afinados com a temática Health Communication na versão brasileira, mostrando a riqueza de assuntos, metodologias e enfoques que os estudos dessa área permitem na academia. Trata-se de uma visão multidisciplinar, às vezes com a Comunicação no foco principal, por outras a Saúde no estetoscópio dos pesquisadores.O livro Comunicação, Saúde e Pluralidade: novos olhares e abordagens em pauta compõe a Coleção Comunicação & Inovação, que, entre outros volumes, pretende discutir reflexões sobre processos e produtos comunicacionais cujos aspectos de inovação sejam marcantes nas interfaces com diversos conceitos e abordagensUniversidade Municipal de São Caetano do Su
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
Estimating the global conservation status of more than 15,000 Amazonian tree species
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century
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
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
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
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
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