166 research outputs found
Lectins from the Red Marine Algal Species Bryothamnion seaforthii and Bryothamnion triquetrum as Tools to Differentiate Human Colon Carcinoma Cells
The carbohydrate-binding activity of the algal lectins from the closely related red marine algal species Bryothamnion triquetrum (BTL) and Bryothamnion seaforthii (BSL) was used to differentiate human colon carcinoma cell variants with respect to their cell membrane glyco-receptors. These lectins interacted with the cells tested in a dose-dependent manner. Moreover, the fluorescence spectra of both lectins clearly differentiated the cells used as shown by FACS profiles. Furthermore, as observed by confocal microscopy, BTL and BSL bound to cell surface glycoproteins underwent intense internalization, which makes them possible tools in targeting strategies
What is the impact of local control in Ewing sarcoma: analysis of the first Brazilian collaborative study group-EWING1
Background: Relapse in localized Ewing sarcoma patients has been a matter of concern regarding poor prognosis. Therefore, we investigated the impact of local control modality (surgery, surgery plus radiotherapy, and radiotherapy) on clinical outcomes such as survival and recurrence in patients with non-metastatic Ewing sarcoma treated on the first Brazilian Collaborative Group Trial of the Ewing Family of Tumors (EWING1). Methods: Seventy-three patients with localized Ewing sarcoma of bone aged < 30 years were included. The treating physicians defined the modality of local control based on the recommendations of the coordinating center and the patient and tumor characteristics. Possible associations of local control modality with local failure (LF), disease-free survival (DFS), event-free survival (EFS), overall survival (OS), and clinical characteristics were analyzed. Results: Mean patient age was 12.8 years (range, 2 to 25 years) and median follow-up time was 4.5 years (range, 2. 3 to 6.7 years). Forty-seven patients underwent surgery, 13 received radiotherapy, and 13 received both. The 5-year EFS, OS, and DFS for all patients was 62.1%, 63.3%, and 73.1%, respectively. The 5-year cumulative incidence (CI) of LF was 7.6% for surgery, 11.1% for radiotherapy, and 0% for postoperative radiotherapy (PORT) (p = 0.61). The 5-year EFS was 71.7% for surgery, 30.8% for radiotherapy, and 64.1% for PORT (p = 0.009). Conclusions: There was a significant effect of local control modality on EFS and OS in the study. Surgery and PORT modalities yielded very close results. The group treated with radiotherapy alone had considerably worse outcomes. This may be confounded by greater risk factors in these patients. There was no significant effect of local control modality on the CI of LF and DFS.Children's Cancer InstituteRafael Accordi Foundation, Porto Alegre, RS, BrazilHCPA, Serv Orthoped & Traumatol, Rua Ramiro Barcelos 2350, BR-90035903 Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, HCPA, Dept Pediat, Porto Alegre, RS, BrazilPontificia Univ Catolica Rio Grande Sul PUCRS, Dept Pediat, Hosp Sao Lucas, Porto Alegre, RS, BrazilHCPA, Serv Orthoped & Traumatol, Porto Alegre, RS, BrazilUniv Fed Sao Paulo UNIFESP, Support Grp Children & Adolescents Canc GRAACC, Sao Paulo, SP, BrazilHosp Canc Infantojuvenil, Fundacao Pio 12, Barretos, SP, BrazilCtr Hosp Pereira Rossell, Montevideo, UruguayHosp AC Camargo Canc Ctr, Orthoped Serv, Sao Paulo, SP, BrazilSanta Casa Misericordia Porto Alegre, Serv Orthoped & Traumatol, Porto Alegre, RS, BrazilUniv Sao Paulo, Orthoped Trauma Inst, Hosp Clin Sao Paulo, Sch Med, Sao Paulo, SP, BrazilSanta Casa Misericordia Sao Paulo HSCSP, Dept Orthoped & Traumatol, Sao Paulo, SP, BrazilPontificia Univ Catolica Rio Grande Sul PUCRS, Hosp Sao Lucas, Serv Orthoped & Traumatol, Porto Alegre, RS, BrazilUniv Estadual Paulista UNESP, Hosp Clin Botucatu, Sch Med, Botucatu, SP, BrazilInst Canc Infantil, Porto Alegre, RS, BrazilUniv Fed Sao Paulo UNIFESP, Support Grp Children & Adolescents Canc GRAACC, Sao Paulo, SP, BrazilChildren's Cancer InstituteRafael Accordi Foundation, Porto Alegre, RS, BrazilWeb of Scienc
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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
Climate Change and American Bullfrog Invasion: What Could We Expect in South America?
BACKGROUND: Biological invasion and climate change pose challenges to biodiversity conservation in the 21(st) century. Invasive species modify ecosystem structure and functioning and climatic changes are likely to produce invasive species' range shifts pushing some populations into protected areas. The American Bullfrog (Lithobates catesbeianus) is one of the hundred worst invasive species in the world. Native from the southeast of USA, it has colonized more than 75% of South America where it has been reported as a highly effective predator, competitor and vector of amphibian diseases. METHODOLOGY/PRINCIPAL FINDINGS: We modeled the potential distribution of the bullfrog in its native range based on different climate models and green-house gases emission scenarios, and projected the results onto South America for the years of 2050 and 2080. We also overlaid projected models onto the South American network of protected areas. Our results indicate a slight decrease in potential suitable area for bullfrog invasion, although protected areas will become more climatically suitable. Therefore, invasion of these sites is forecasted. CONCLUSION/SIGNIFICANCE: We provide new evidence supporting the vulnerability of the Atlantic Forest Biodiversity Hotspot to bullfrog invasion and call attention to optimal future climatic conditions of the Andean-Patagonian forest, eastern Paraguay, and northwestern Bolivia, where invasive populations have not been found yet. We recommend several management and policy strategies to control bullfrog invasion and argue that these would be possible if based on appropriate articulation among government agencies, NGOs, research institutions and civil society
Inventário de Depressão de Beck (BDI) e Escala de Avaliação de Depressão de Hamilton (HAM-D) em pacientes com epilepsia
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
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
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