O leitor nas trilhas do texto: um diálogo entre a teoria de Umberto Eco e a poética da leitura de Jorge Luis Borges

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

IMPORTÂNCIA DE ESTUDOS FISIOGRÁFICOS NO PLANEJAMENTO MUNICIPAL: EXEMPLO DO JARDIM BOTÂNICO DE POÇOS DE CALDAS, MG.

Pela conjugação dos aspectos geológicos, geomorfológicos e pedológicos da área de implantação do Jardim Botânico de Poços de Caldas, definiu-se a dinâmica fisiográfica da paisagem, com o objetivo de contribuir para o conhecimento dos aspectos físicos da região e, desta forma, ocupá-la de forma ordenada e sustentável. Verificou-se que o Jardim Botânico insere-se em uma paisagem aluvial associada a paisagens lacustres menores, em que as coberturas de alteração intempérica são mais ou menos espessas e possuem composição mista e características de transporte gravitacional. A ocorrência de organossolos restringe-se à paisagem lacustre atual/subatual, podendo estar aflorantes ou soterrados por material de transporte gravitacional. As unidades fisiográficas das cotas mais elevadas do terreno decorreram de esforços neotectônicos, que levaram ao soerguimento de blocos e mudança do nível de base. A estas unidades associam-se os neossolos e cambissolos, em sua maioria regolíticos e concrecionários. O estudo permitiu a delimitação de cinco classes de uso e ocupação do solo na área do Jardim Botânico.

Extratos padronizados para o tratamento de doenças crônicas: Serjania marginata Casar. (Sapindaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tecnologias para produção de mudas de espinheira-santa: propagação vegetativa por estacas caulinares

Pós-graduação em Agronomia (Horticultura) - FCA

Structural characterization of a new acylpolyaminetoxin from the venom of Brazilian garden spider Nephilengys cruentata

Mario Sergio Palma, Yasuhiro Itagaki, Tsuyoshi Fujita, Hideo Naoki and Terumi Nakajima. Structural characterization of a new acylpolpaminetoxin from the venom of Brazilian garden spider Nephilengys: cruentata. Toxicon 36, 455-493, 1998.-The use of mass spectrometry, in which high-energy CID and charge remote fragmentation both of protonated and sodium-attached molecular ions was applied, afforded the structural elucidation of a new acylgolyaminetoxin with M-W= 801 da from the venom of the Brazilian garden spider Nephilengys cruentata. In spite of having the same M-W of the NPTX-2, previously described in the venom of the Joro spider Nephila clavata, neither toxins are isomers. In order to differentiate them by using the most usual nomenclature, the new toxin was named NPTX-801C and the NPTX-2 was renamed to NPTX-801E. Both toxins have as common structure the 4-hydroxyindole-3-acetyl-asparaginyl-cadaveryl moiety in their molecules and their structure may be represented in a simplified way: NPTX-801E is HO-indole-Asn-Cad-Pta-Orn-Arg and NPTX-801C is HO-indole-Asn-Cad-Gly-Put-Pta-Pta. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants

We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix.

The effect of plant diversity on fungus garden development and foraging behavior of leaf-cutting ants (Hymenoptera: Formicidae)

The leaf-cutting ants forage a wide variety of plant species, used for symbiotic fungus cultivation. To better understand this tripartite complex interaction, 24 colonies of Acromyrmex subterraneus brunneus were conditioned for 4 months to 6 different plants (Citrus spp., Ligustrum spp., Acalypha spp., Eucalyptus spp., Alchornea triplinervia, Melia spp.), to verify the influence of conditioning on foraging behavior of workers. The effect of plants on symbiotic fungus development was studied separately, through macerated plants in Agar and culture medium A as the control. During foraging, workers presented polyphagic foraging behavior, refusing the plants to which they were conditioned. The selection of plants is not correlated with the plant substrate that promotes good development of symbiotic fungus. Such results demonstrate the importance of plant diversity for fungus garden maintenance.

Fungal communities in the garden chamber soils of leaf-cutting ants

Leaf-cutting ants modify the properties of the soil adjacent to their nests. Here, we examined whether such an ant-altered environment impacts the belowground fungal communities. Fungal diversity and community structure of soil from the fungus garden chambers of Atta sexdens rubropilosa and Atta bisphaerica, two widespread leaf-cutting ants in Brazil, were determined and compared with non-nest soils. Culture-dependent methods revealed similar species richness but different community compositions between both types of soils. Penicillium janthinellum and Trichoderma spirale were the prevalent isolates in fungus chamber soils and non-nest soils, respectively. In contrast to cultivation methods, analyses of clone libraries based on the internal transcribed spacer (ITS) region indicated that richness of operational taxonomic units significantly differed between soils of the fungus chamber and non-nest soils. FastUnifrac analyses based on ITS sequences further revealed a clear distinction in the community structure between both types of soils. Plectania milleri and an uncultured Clavariaceae fungus were prevalent in fungus chamber soils and non-nest soils, respectively. FastUnifrac analyses also revealed that fungal community structures of soil from the garden chambers markedly differed among ant species. Our findings suggest that leaf-cutting ants affect fungal communities in the soil from the fungus chamber in comparison to non-nest soils. © 2013 WILEY-VCH Verlag GmbH & Co.

Absence of the Parasite Escovopsis in Fungus Garden Pellets Carried by Gynes of Atta sexdens

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)