68 research outputs found

    Intergeracionalidades em análise: (re)composições ético-estético-políticas em pesquisas-inter(in)venções com crianças e adultos

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    Neste artigo, pretende-se analisar movimentos de produção de um território de pesquisa e exercícios de políticas cognitivas inventivas na transversalização da Psicologia social e política e do campo dos estudos das infâncias. Transposição de limites geográficos da zona urbana de uma cidade nordestina pela criação correlata de territórios existenciais no encontro com crianças. Põe-se em análise o plano de composição de pesquisas, projetos de extensão, propostas para editais com ONGS, nos últimos 5 anos, visualizando deslocamentos ético estéticos e políticos. A questão da intergeracionalidade vai se diferenciando em meio a cenas e problemas já constituídos, inspirando planos de análise e preservando sua condição como problema (faz pensar). As recomposições vão delineando modos de operar na pesquisa sob inspiração da cartografia, pelas pistas do plano comum, do território existencial e dos processos, abrindo a intergeracionalidade às forças do virtual a ser atualizado nas cenas partilhadas por crianças e seus outros

    Ant Community Evolution According to Aging in Brazilian Cocoa Tree Plantations

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    Agriculture is frequently held accountable for the depletion of biotic diversity, although a few agroforestry systems support the conservation of a number of organisms. Cocoa farming is noteworthy as an example of an agricultural activity that benefits or maintains species richness. However, the mechanism by which the biodiversity persists throughout the entire process of plant development remains obscure. In Southeastern Bahia, Brazil, cacao tree plantations support the conservation of a large amount of organisms native to the Atlantic Forest, between them the ants. This study aims at recording the relationship between cocoa tree development and ant community structure. The experiment was carried out in a series of six cocoa tree plantations aged one, three, four, eight, fifteen and 33 years, distributed across the experimental grounds of the Cocoa Research Center at Ilhéus. 1,500 ant samples were collected using the sampling techniques: hand collection, honey and sardine baits, entomological blanket and “pitfall”. Highest values for diversity and richness were reported in the 15-years-old cocoa plantation. No significant correlations between diversity, richness or plant age were reported. Considering the faunistic composition, a statistical similarity was observed between the plantations close in age to one another. Plant aging did not exert any influence on the diversity gradient and richness in the succession process of the ant community. In young plantations, there are low differences between the ants found on the ground and the ones found on the young cocoa trees. In older plantations, the ant community divides in two distinct assemblages on the ground and on the trees. The variations observed in the ant community along the plant development were likely caused by the structural organization of the dominant species mosaic

    Toxicity and antioxidant activity of flavonoids from Lonchocarpus filipes root bark

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    The phytochemical investigation of dichloromethane extract from root bark of Lonchocarpus filipes Benth (Leguminosae) afforded four flavonoids including three dibenzoylmethane derivatives rarely found in nature. The structures were established based on their spectral data (¹H and 13C NMR, 2D-NMR) as being: lanceolatin B (1), pongamol (2), (E)-7-O-methylpongamol (3) and (E)-9-O-methylpongamol (4). Compound (4) is described herein for the first time as a natural product. The extracts and the isolated compounds (1), (2) and (3) displayed high toxicity in the brine shrimp lethality assay. Only compound (2) showed antioxidant activity using a DPPH radical scavenging assay. This is the first report on the phytochemical study of Lonchocarpus filipes.22552258Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Toxicidade e atividade antioxidante de flavonoides das cascas das raízes de Lonchocarpus filipes

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    The phytochemical investigation of dichloromethane extract from root bark of Lonchocarpus filipes Benth (Leguminosae) afforded four flavonoids including three dibenzoylmethane derivatives rarely found in nature. The structures were established based on their spectral data (¹H and 13C NMR, 2D-NMR) as being: lanceolatin B (1), pongamol (2), (E)-7-O-methylpongamol (3) and (E)-9-O-methylpongamol (4). Compound (4) is described herein for the first time as a natural product. The extracts and the isolated compounds (1), (2) and (3) displayed high toxicity in the brine shrimp lethality assay. Only compound (2) showed antioxidant activity using a DPPH radical scavenging assay. This is the first report on the phytochemical study of Lonchocarpus filipes

    A SARS-CoV-2 Negative Antigen Rapid Diagnostic in RT-qPCR Positive Samples Correlates With a Low Likelihood of Infectious Viruses in the Nasopharynx

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    Severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) transmission occurs even among fully vaccinated individuals; thus, prompt identification of infected patients is central to control viral circulation. Antigen rapid diagnostic tests (Ag-RDTs) are highly specific, but sensitivity is variable. Discordant RT-qPCR vs. Ag-RDT results are reported, raising the question of whether negative Ag-RDT in positive RT-qPCR samples could imply the absence of infectious viruses. To study the relationship between negative Ag-RDT results with virological, molecular, and serological parameters, we selected a cross-sectional and a follow-up dataset and analyzed virus culture, subgenomic RNA quantification, and sequencing to determine infectious viruses and mutations. We demonstrated that RT-qPCR positive while SARS-CoV-2 Ag-RDT negative discordant results correlate with the absence of infectious virus in nasopharyngeal samples. A decrease in sgRNA detection together with an expected increase in detectable anti-S and anti-N IgGs was also verified in these samples. The data clearly demonstrate that a negative Ag-RDT sample is less likely to harbor infectious SARS-CoV-2 and, consequently, has a lower transmissible potential

    Single origin of sex chromosomes and multiple origins of B chromosomes in fish genus Characidium

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    Chromosome painting with DNA probes obtained from supernumerary (B) and sex chromosomes in three species of fish genus Characidium (C. gomesi, C. pterostictum and C. oiticicai) showed a close resemblance in repetitive DNA content between B and sex chromosomes in C. gomesi and C. pterostictum. This suggests an intraspecific origin for B chromosomes in these two species, probably deriving from sex chromosomes. In C. oiticicai, however, a DNA probe obtained from its B chromosome hybridized with the B but not with the A chromosomes, suggesting that the B chromosome in this species could have arisen interspecifically, although this hypothesis needs further investigation. A molecular phylogenetic analysis performed on nine Characidium species, with two mtDNA genes, showed that the presence of heteromorphic sex chromosomes in these species is a derived condition, and that their origin could have been unique, a conclusion also supported by interspecific chromosome painting with a CgW probe derived from the W chromosome in C. gomesi. Summing up, our results indicate that whereas heteromorphic sex chromosomes in the genus Characidium appear to have had a common and unique origin, B chromosomes may have had independent origins in different species. Our results also show that molecular phylogenetic analysis is an excellent complement for cytogenetic studies by unveiling the direction of evolutionary chromosome changes.This research was funded by grants from the State of Sao Paulo Research Foundation (FAPESP) to EAS (2013/02143-3), grants from National Council for Research and Development (CNPq) to FF (480449/2012-0), and by Coordenacao de Aperfeicoamento de Pessoal de Nıvel Superior (CAPES)
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