990 resultados para Melozzo, da Forlì, 1438-1494.


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Environmental factors strongly affect mangrove crabs, and some factors modulate population structure and habitat partitioning during the crabs' life cycle. However, the effect of these environmental factors on habitat selection by mangrove crabs is still unknown. We evaluated habitat selection by the mangrove crab Ucides cordatus in mangrove forests with different degrees of predominance of Rhizophora mangle, Laguncularia racemosa or Avicennia schaueriana, two tidal flooding levels (less- and more-flooded), and two biological periods (breeding and non-breeding seasons). Sampling was conducted in four mangrove forests with different influences of these biotic and abiotic parameters. We used the data for sex ratio to explain environmental partitioning by this species. Females predominated in R. mangle mangroves, independently of the biological period (breeding or non-breeding seasons), and males predominated only in the less-flooded L. racemosa mangroves. The flooding level affected the sex ratio of U. cordatus, with a predominance of males in less-flooded mangroves, independently of the biological period; and a gender balance in the more-flooded mangroves only during the breeding season. Outside the breeding season, the largest specimens were recorded in the R. mangle mangroves, but in the breeding season, the largest crabs were recorded in the L. racemosa mangroves with a higher level of flooding. These results suggest that tree-species composition and tidal flooding level can have a significant effect on the habitat partitioning of sexes and sizes of the mangrove crab U. cordatus both during and outside the breeding season. © 2012 Springer-Verlag and AWI.

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Self-compatibility in apomictic pseudogamic species is considered fundamental to assure reproduction by seeds in extreme situations, making apomictic species more advantageous than sexual ones in these scenarios. Anemopaegma acutifolium is a polyploidy, apomictic sporophytic species with no endosperm development in ovules of unpollinated pistils, which indicates obligate pseudogamy. Thus, the aim of the present work is to study the breeding system and post-pollination events to test if there is similar pseudogamous development irrespective of pollination treatment. We analysed fruit and seed set obtained in controlled experimental pollinations, as well as embryo number per seed, and the progress of ovule penetration, fertilisation and early endosperm development between self- and cross-pollinated pistils. We found that the species is self-fertile and that spontaneous selfing fruit set is also possible, although emasculated flowers never form fruits. Selfed pistils were as efficient as crossed ones for all parameters analysed, except for a delay in endosperm development observed in the former that may be an effect of the late-acting self-incompatibility. Therefore, the avoidance of selfed pistil abortion seems to be promoted by the presence of adventitious embryos and a normal endosperm. We conclude that A. acutifolium shows apomixis-related pseudo-self-compatibility, as in other self-fertile apomictic species of Bignoniaceae, which confer reproductive assurance and increases fruit-set and persistence ability in fast-changing tropical habitats. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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O presente estudo aborda o papel dos sítios e terreiros enquanto interface entre agricultura e extrativismo na Reserva Extrativista Arióca Pruanã, em Oeiras do Pará. A agricultura depende da floresta e a reconfigura em capoeiras e sítios, assim como a floresta se insinua nos terreiros à medida que espécies vegetais silvestres são aí introduzidas por mãos humanas. O resultado deste manejo é o agroflorestamento da paisagem, face visível do amálgama entre agricultura e floresta, base da reprodução da vida ribeirinha.

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This paper shows that the distribution of basic illocutions (defined as grammatical structures that can be related to a default communicative intentions) within and across the indigenous languages of Brazil can be described systematically in terms of a set of implicational hierarchies by means of which the existence of certain basic illocutions can be predicted from the existence of others. In doing so, a case is made for a major distinction between propositional and behavioural basic illocutions, the former having to do with the exchange of information, the latter with influencing behaviour.

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)