1,069 research outputs found
Food competition in a semi-free-ranging Cebus apella group
The competitive regime faced by individuals is fundamental to modelling the evolution of social organisation. In this paper, we assess the relative importance of contest and scramble food competition on the social dynamics of a provisioned semifree-ranging Cebus apella group (n= 18). Individuals competed directly for provisioned and clumped foods. Effects of indirect competition were apparent with individuals foraging in different areas and with increased group dispersion during periods of low food abundance. We suggest that both forms of competition can act simultaneously and to some extent synergistically in their influence on social dynamics; the combination of social and ecological opportunities for competition and how those opportunities are exploited both influence the nature of the relationships within social groups of primates as well as underlying the evolved social structure
Extração de taninos de Acacia sp. com potencial uso na coagulação: um contributo para a bioeconomia
Coagulation-flocculation is one of the most important steps in water treatment. In Water Treatment Plants, pre-polymerized inorganic coagulants are traditionally used; however, recent studies have shown the potential of condensed tannins for the production of natural coagulants as an alternative to chemical coagulants. In this context, the present work intends to highlight the importance of the development of nature-based solutions that can be alternative to conventional processes, due to the environmental, social and economic benefits they can provide. The study focused on optimizing condensed tannin extraction process from Acacia dealbata barks, as a strategy for valuing forest residues, promoting the territory bioeconomy and sustainability. In the tested extraction conditions, the best yield was obtained at a temperature of 40 oC, using 50% ethanol (v/v) as the solvent, without stirring and an extraction time of 30 min. The highest concentrations of condensed tannins and phenolic compounds were observed in samples of Acacia sp. with higher vegetative development (trunk perimeter of 20 cm), corresponding to 246,2 ± 9,4 miligrams per gram of dry extract (mg ges-1) and 706,2 ± 27,2 mg ges-1, respectively.Este trabalho foi desenvolvido no âmbito do projeto TECH - Tecnologia, Ambiente, Criatividade e Saúde, Norte-01-0145-FEDER-000043, cofinanciado pelo Programa Operacional Regional do Norte (NORTE 2020), através do Portugal 2020 e do Fundo Europeu de Desenvolvimento Regional (FEDER). Leonel Nunes foi apoiado pela
proMetheus - Unidade de Investigação & Desenvolvimento em Materiais, Energia e Ambiente para a Sustentabilidade- UIDP/05975/2020, financiado por fundos nacionais através de FCT — Fundação para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio
A quantitative proteomic approach to highlight Phragmites sp. adaptation mechanisms to chemical stress induced by a textile dyeing pollutant
Phragmites sp. is present worldwide in treatment wetlands though the mechanisms involved in the phytoremediation remain unclear. In this study a quantitative proteomic approach was used to study the prompt response and adaptation of Phragmites to the textile dyeing pollutant, Acid Orange 7 (AO7). Previously, it was demonstrated that AO7 could be successfully removed from wastewater and mineralized in a constructed wetland planted with Phragmites sp. This azo dye is readily taken up by roots and transported to the plant aerial part by the xylem. Phragmites leaf samples were collected from a pilot scale vertical flow constructed wetland after 0.25, 3.25 and 24.25h exposure to AO7 (400mgL-1) immediately after a watering cycle used as control. Leaf soluble protein extraction yielded an average of 1560 proteins in a broad pI range (pH3-10) by two-dimensional gel electrophoresis. A time course comparative analysis of leaf proteome revealed that 40 proteins had a differential abundance compared to control (p<0.05) within a 3.25h period. After 24.25h in contact with AO7, leaf proteome was similar to control. Adaptation to AO7 involved proteins related with cellular signalling (calreticulin, Ras-related protein Rab11D and 20S proteasome), energy production and conversion (adenosine triphosphate synthase beta subunit) carbohydrate transport and metabolism (phosphoglucose isomerase, fructose-bisphosphate aldolase, monodehydroascorbate reductase, frutockinase-1 and Hypothetical protein POPTR_0003s12000g and the Uncharacterized protein LOC100272772) and photosynthesis (sedoheptulose-1,7-bisphosphatase and ferredoxin-NADP+ reductase). Therefore, the quantitative proteomic approach used in this work indicates that mechanisms associated with stress cell signalling, energy production, carbohydrate transport and metabolism as well as proteins related with photosynthesis are key players in the initial chemical stress response in the phytoremediation process of AO7
O Comportamento Cíclico do Capital dos Bancos Brasileiros
No contexto de transição regulamentar para os padrões do acordo de Basiléia II, este artigo analisa o comportamento cíclico do capital bancário brasileiro sob a regulação atual. Utilizamos um painel não-balanceado de dados dos bancos operando no Brasil entre 2003 e 2008 para estimar, através de técnicas de painel dinâmico, uma equação do capital econômico dos bancos. Nossos resultados mostram que esta variável move-se com o ciclo de negócios.Bancos, Basiléia II, Ciclos Econômicos, Capital dos Bancos
Extracellular enolase of Candida albicans is involved in colonization of mammalian intestinal epithelium
Enolase is secreted by C. albicans and is present in its biofilms although its extracellular function is unknown. Here we show that extracellular enolase mediates the colonization of small intestine mucosa by C. albicans. Assays using intestinal mucosa disks show that C. albicans adhesion is inhibited, in a dose dependent mode, either by pretreatment of intestinal epithelium mucosa disks with recombinant C. albicans enolase (70% at 0.5 mg/ml enolase) or by pretreatment of C. albicans yeasts with anti-enolase antibodies (48% with 20 µg antiserum). Also using flow cytometry, immunoblots of conditioned media and confocal microscopy we demonstrate that enolase is present in biofilms and that the extracellular enolase is not an artifact due to cell lysis, but must represent functional secretion of a stable form. This is the first direct evidence that C. albicans extracellular enolase mediates colonization on its primary translocation site. Also, because enolase is encoded by a single locus in C. albicans, its dual role peptide, as glycolytic enzyme and extracellular peptide, is a remarkable example of gene sharing in fungi
Analysis of risk factors for maxillary denture-related oral mucosal lesions : a cross-sectional study
To evaluate the frequency of maxillary dentures-related lesions and the possible associated risk factors. Ninety-seven participants were selected, and a complete anamnesis, physical examination and tests of occlusion vertical dimension (OVD), retention and stability of the denture, biofilm quantification, cytopathology, sialometry, pH analysis and buffer capacity of the saliva were performed. Statistical analyses were performed with the Pearson?s chi-square, Mann-Whitney tests, and Pearson?s coefficient (p<0.05). In 78% of the participants at least one denture-related lesion was found. Denture-associated stomatitis (63%), inflammatory fibrous hyperplasia (19%) and traumatic ulceration (11%) were the 3 most frequent lesions. The habit of night use of the denture was considered an independent risk factor for the development of oral lesions [OR=3.0 (95% CI 1.09-8.56); p<0.05]. Furthermore, the longest period of use of the same denture and biofilm also had statistically significant relation to oral lesions. The biofilm seems to be more related to the prevalence of oral lesions according to the multiple logistic regression [OR=1.3 (95% CI: 1.01-1.83) p<0.05]. The lack of a dentures? cleaning solution and detrition of the prothesis were independent risk factors for denture-associated stomatitis. Male gender, loss of OVD and bad buffer capacity were risk factors for angular cheilitis. Fractures of the base and repair of broken dentures were risk factors for traumatic ulcers. These results show a high frequency of denture-related lesions. Besides, participants hygiene habits and poor quality of the dentures were the main factors for the development of these lesions
Proteomics-based identification of differentially abundant proteins reveals adaptation mechanisms of Xanthomonas citri subsp citri during Citrus sinensis infection
Background: Xanthomonas citri subsp. citri (Xac) is the causal agent of citrus canker. A proteomic analysis under in planta infectious and non-infectious conditions was conducted in order to increase our knowledge about the adaptive process of Xac during infection. Results: For that, a 2D-based proteomic analysis of Xac at 1, 3 and 5 days after inoculation, in comparison to Xac growth in NB media was carried out and followed by MALDI-TOF-TOF identification of 124 unique differentially abundant proteins. Among them, 79 correspond to up-regulated proteins in at least one of the three stages of infection. Our results indicate an important role of proteins related to biofilm synthesis, lipopolysaccharides biosynthesis, and iron uptake and metabolism as possible modulators of plant innate immunity, and revealed an intricate network of proteins involved in reactive oxygen species adaptation during Plants'Oxidative Burst response. We also identified proteins previously unknown to be involved in Xac-Citrus interaction, including the hypothetical protein XAC3981. A mutant strain for this gene has proved to be non-pathogenic in respect to classical symptoms of citrus canker induced in compatible plants. Conclusions: This is the first time that a protein repertoire is shown to be active and working in an integrated manner during the infection process in a compatible host, pointing to an elaborate mechanism for adaptation of Xac once inside the plant.Fundacao de Amparo a Pesquisa do Estado de Sao PauloFundacao de Amparo a Pesquisa do Estado de Minas GeraisBIGA grant-CAPESUniv Fed Ouro Preto, Inst Ciencias Exatas & Biol, Dept Ciencias Biol DECBI, Ouro Preto, MG, BrazilUniv Fed Ouro Preto, Nucleo Pesquisas Ciencias Biol NUPEB, Ouro Preto, MG, BrazilUniv Fed Rio de Janeiro, Inst Quim, Dept Bioquim DBq, Rio De Janeiro, RJ, BrazilUniv Estadual Paulista, UNESP, Dept Tecnol, Fac Ciencias Agr & Vet Jaboticabal, Jaboticabal, SP, BrazilUniv Estadual Campinas, UNICAMP, Inst Quim, Campinas, SP, BrazilUniv Sao Paulo, Inst Quim, Dept Bioquim, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Ciencias Biol, Diadema, SP, BrazilVirginia Tech, Biocomplex Inst, Blacksburg, VA USAUniv Sao Paulo, Inst Quim, Dept Bioquim, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Ciencias Biol, Diadema, SP, BrazilCAPESFAPESP: 04/02006-7Fundacao de Amparo a Pesquisa do Estado de Minas Gerais: CBB-APQ-04425-10BIGA grant-CAPES: 3385/2013Web of Scienc
Isolation and enzyme bioprospection of endopytic bacteria associated with plants of Brazilian mangrove ecosystem
The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems
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