964 resultados para life-form


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O objetivo deste trabalho foi avaliar os efeitos de diferentes sistemas de pastejo, com ovinos e bovinos, sobre a quantidade de larvas no estágio L3 de nematódeos de ruminantes. O delineamento experimental foi inteiramente ao acaso, em arranjo fatorial com quatro sistemas de pastejo e quatro períodos de rotação de pastagem. A duração do experimento foi de 91 dias, com sistema rotacionado (7 dias de ocupação e 21 de descanso), em 8 ha de Panicum maximum cv. Tanzânia. Foram avaliados os sistemas de pastejo: alternado, simultâneo e isolado, com ovinos e com bovinos. Foram utilizados 20 bovinos (mestiços), 30 cordeiros e 15 ovelhas adultas (raça Santa Inês). As amostras do capim, para recuperação e identificação dos nematódeos, foram realizadas semanalmente no pré e pós-pastejo dos piquetes. Na média geral de todos os manejos, a ordem decrescente de número de larvas foi: Haemonchus spp., Trichostrongylus spp., Oesophagostomum spp., Strongyloides spp. e Cooperia spp. Correlações médias foram encontradas entre as quantidades de larvas L3 no pré e pós-pastejo. Com o aumento do número de rotações, houve aumento no grau de contaminação da pastagem pelas larvas, independentemente do sistema adotado. O sistema de pastejo simultâneo foi o que apresentou maior controle da carga parasitária de Haemonchus spp. na pastagem de capim-tanzânia.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Embora o conhecimento sobre a florística dos fragmentos de florestas estacionais semideciduais tenha crescido nos últimos anos, ainda sabe-se pouco sobre a comunidade de lianas (lenhosas ou herbáceas) nesses fragmentos. Assim, foi realizado o levantamento florístico de lianas na gleba Maravilha, pertencente ao Parque Estadual de Vassununga (Santa Rita do Passa Quatro, SP), a fim de colaborar com o conhecimento dessa comunidade e subsidiar futuros trabalhos que envolvam essa forma de vida. A área de estudo compreende 127,08 ha, com inverno seco e temperatura média anual de 22 ºC. Para a coleta do material, percorreu-se mensalmente toda a borda do fragmento e três trilhas no interior da mata, de agosto/2002 a setembro/2003. Foram identificadas 120 espécies de lianas, pertencentes a 30 famílias e 71 gêneros, das quais 51% das espécies são volúveis, 42% apresentam gavinhas e apenas 7% são escandentes. As famílias mais representativas em número de espécies foram: Bignoniaceae (26), Malpighiaceae (14), Sapindaceae (12) e Asteraceae (9). Houve baixa similaridade florística entre as espécies de lianas presentes na gleba Maravilha em relação a outras áreas de florestas estacionais semideciduais do interior paulista.

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The reproductive phenology of the entire climber community (96 species of lianas and 40 species of vines) in a semideciduous forest in Southeastern Brazil (22 degrees 49'45''S; 47 degrees 06'33''W and 670 m altitude) was observed from March 1988 to February 1991. Phenological observations were made weekly by walking along a 10.5 km trail in the interior and at the forest edges of the Santa Genebra Reserve (SGR). The most species-rich families of climbers were Bignoniaceae (22), Malpighiaceae (17), Sapindaceae (12) and Asteraceae (12). Flowering patterns for woody lianas and herbaceous vines differed. Lianas had two flowering peaks: a minor peak in March in the transition from wet to dry season, and a major peak in October during the transition from dry to wet season. The flowering peak for herbaceous vines was in April. Fruiting of lianas was highly seasonal, with one peak in the late dry season (July-August). Fruiting for vines was less seasonal with a slight peak in March. These differences were consistent with the predominance of wind-dispersed fruits among lianas (72% of species) versus vines (52%). Low rainfall, high leaf fall, and strong winds during the dry season favor wind dispersal. More species of vines (40%) have animal-dispersed seeds than lianas (19%), and most vines fruited during the wet season. Phenological patterns of climbers and trees and treelets at SGR differed. The life form of lianas and their system of reserve economy may allow them to reproduce during periods unfavorable to trees. Displacement of peak flowering periods of trees and climbers pollinated by bees and small generalist insects may decrease competition for pollen vectors among species of these two groups of plants. Whereas the fruiting patterns of wind-dispersed trees and climbers at SGR were similar (most species fruiting during the dry season), animal-dispersed trees and treelets fruited throughout the year while animal-dispersed climbers exhibited a pronounced peak in late wet season. The distinct phenological patterns of climbers, generally complementary to those presented by trees, resulted in constant availability of Bowers and fruits throughout the year and enhances the importance of this plant group in Neotropical forests.

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Ornithochorous fruits make up an important part of the diet of birds and many studies have related the different morphological types of fruits with the choice by birds. We analyzed the intrinsic characteristics of plants and how human impact can affect this choice. Through analyses of covariance we related the degree of human pressure in each study site (high or low) and the morphological characteristics of 57 ornithochorous species with visiting rates and consumption of fruits by birds. We did not find any intrinsic plant characteristic (life form, size and type of diaspore) that explains the rates of consumption and visit by birds. On the other hand, the degree of human impact affected directly the mutualism between plants and birds. Plant species located in areas that suffer high human pressure had number of visits and consumption rates 3,3 and 3,5 lower than plants located in pristine areas, respectively. The negative consequences of the reduction of consumption of fruits in areas with high human pressures may directly affects the interactions between birds and plants and the regeneration of the ornithochorous species.

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The Marsh Antwren (Stymphalornis acutirostris) is restricted to the lowlands between Antonina Bay, in the coastal plain of the state of Paraná, and Itapocu river, in the northern coastal plain of the state of Santa Catarina (from 0 to c. 5 m a.s.l.). It doesn't occur continuously in this region, being found in eight populations that span over an total area of about 6,060 ha (= area of occupancy; 4,856.67 in Paraná and c. 1,200 in Santa Catarina). Nine habitat types used by the Marsh Antwren were defined, based on vegetation physiognomy, localization, dominancy of botanical species, dominant life-form and history of the region. Five of these are herbaceous (marshes), while four have an upper arboreal stratum and an herbaceous lower stratum with marsh plants. According to the classification criteria of the Brazilian vegetation proposed by the Radambrasil Project, they were classified as Pioneering Formation of Fluvial Influence, Pioneering Formation of Fluvial-marine Influence, and/or Pioneering Formation of Lacustrine Influence. They occur as patches or narrow strips ranging from 0.001 to 203.0 ha in the state of Paraná. They are found mainly in the interior of bays, in the lower courses of rivers that drain into bays, in alluvial plains, and between sand dunes in the coastal plain. Characteristic herbaceous species are cattail (Typha domingensis), bulrush (Scirpus californicus), Crinum salsum, Panicum sp. cf. P. mertensii, saw grass (Cladium mariscus) and Fuirena spp. Hibiscus pernambucensis is the characteristic bush species, and Calophyllum brasiliense, Tabebuia cassinoides, Annona glabra and Laguncularia racemosa are the characteristic arboreal species. The Marsh Antwren lives in herbaceous vegetation, but also uses bushes and branches of small tress. It has low flight capacity and a single flight of more than 25 m was never recorded. Territories of 0.25 ha were estimated in one kind of habitat (tidal marsh) (= 8 individuals per hectare) and of 3.2 ha in another one (saw grass marsh) (= 0.62 individual per hectare). The global population estimate is of about 17,700 mature individuals (13,700 in Paraná and 4,000 in Santa Catarina). The species is really under threat of extinction, mainly because of it's restricted geographical distribution and habitat loss by human activities and biological contamination caused by invasion of exotic grasses (Urochloa arrecta and Brachiaria mutica).

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The marine environment offers both economic and scientific potential which are relatively untapped from a biotechnological point of view. These environments whilst harsh are ironically fragile and dependent on a harmonious life form balance. Exploitation of natural resources by exhaustive wild harvesting has obvious negative environmental consequences. From a European industry perspective marine organisms are a largely underutilised resource. This is not due to lack of interest but due to a lack of choice the industry faces for cost competitive, sustainable and environmentally conscientious product alternatives. Knowledge of the biotechnological potential of marine organisms together with the development of sustainable systems for their cultivation, processing and utilisation are essential. In 2010, the European Commission recognised this need and funded a collaborative RTD/SME project under the Framework 7-Knowledge Based Bio-Economy (KBBE) Theme 2 Programme 'Sustainable culture of marine microorganisms, algae and/or invertebrates for high value added products'. The scope of that project entitled 'Sustainable Production of Biologically Active Molecules of Marine Based Origin' (BAMMBO) is outlined. Although the Union is a global leader in many technologies, it faces increasing competition from traditional rivals and emerging economies alike and must therefore improve its innovation performance. For this reason innovation is placed at the heart of a European Horizon 2020 Strategy wherein the challenge is to connect economic performance to eco performance. This article provides a synopsis of the research activities of the BAMMBO project as they fit within the wider scope of sustainable environmentally conscientious marine resource exploitation for high-value biomolecules. © 2013 Elsevier B.V.

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Este estudo tem por objetivo avaliar os modelos de educação gerados nos processos de ocupação da terra nos municípios Juazeiro, Uauá e Valente no Estado da Bahia, tanto nas áreas irrigadas quanto nas de sequeiro, tendo como hipótese norteadora a educação rural como mecanismo disseminador de informações à população e grande mobilizadora das transformações social, econômica, política e cultural das comunidades, na promoção do seu desenvolvimento sustentável. A metodologia da pesquisa tomou por base a análise das redes de relações sociais engendradas no processo, elegendo-se como categorias preferências para a compreensão do fenômeno estudado o capital social, o desenvolvimento local, pedagogias alternativas, currículo escolar e as parcerias intersetoriais, através da ruptura com o antagonismo dos conceitos de indivíduo e de sociedade. Trata-se de pesquisa quanti-qualitativa fundamentada numa abordagem de caráter interativo, onde o discurso emerge como espaço de negociação do sentido e da construção dos sujeitos aprendizes, cujos subsídios somados às evidências quantitativas permitiram o aprofundamento da complexidade dos fenômenos, suas contradições e seu relacionamento com o contexto. A análise dos dados permitiu compreender que a Educação Rural nas áreas pesquisadas vive duas situações: uma, veiculada pelo sistema público de ensino que, salvo algumas experiências pontuais, não atende aos interesses dos povos que habitam e trabalham no campo. Outra, exercitada por Organizações Não Governamentais que valorizando o rural como espaço de vida, forma indivíduos com um repertório de saberes, habilidades e valores capaz de mobilizá-los para uma ação transformadora.

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Pós-graduação em Ciências Biológicas (Biologia Vegetal) - IBRC

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Questions What are the main features of the seed rain in a fragmented Atlantic forest landscape? Can seed rain species attributes (life form, dispersal mode, successional status) relate to the spatial arrangement (size and number of fragments, edge density and presence of corridor) of forest fragments in the landscape? How does the rain forest landscape structure affect the seed rain? Location Atlantic rainforest, Sao Paulo State, Southeastern Brazil. Methods Seed rain samples were collected monthly throughout 1yr, counted, identified and classified according to species dispersal mode, successional status and life form. Seed rain composition was compared with woody species near the seed traps. Relationships between seed rain composition and landscape spatial arrangement (fragment area, presence of corridor, number of fragments in the surroundings, proximity of fragments, and edge density) were tested using canonical correspondence analysis (CCA). Results We collected 20142 seeds belonging to 115 taxa, most of them early successional and anemochorous trees. In general, the seed rain had a species composition distinct from that of the nearby forest tree community. Small isolated fragments contained more seeds, mainly of anemochorous, epiphytic and early-successional species; large fragments showed higher association with zoochorous and late-successional species compared to small fragments. The CCA significantly distinguished the species dispersal mode according to fragment size and isolation, anemochorous species being associated to small and isolated fragments, and zoochorous species to larger areas and fragment aggregation. Nevertheless, a gradient driven by proximity (PROX) and edge density (ED) segregated lianas (in the positive extremity), early successional and epiphyte species (in the negative end); large fragments were positively associated to PROX and ED. Conclusions The results highlight the importance of the size and spatial arrangement of forest patches to promote habitat connectivity and improve the flux of animal-dispersed seeds. Landscape structure controls seed fluxes and affects plant dispersal capacity, potentially influencing the composition and structure of forest fragments. The seed rain composition may be used to assess the effects of landscape spatial structure on plant assemblages, and provide relevant information for biodiversity conservation.

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Der Ausheilung von Infektionen mit Leishmania major liegt die Sekretion von IFN- von sowohl CD4+ als auch CD8+ T Zellen zugrunde.rnAktuell konnte in der Literatur nur ein Epitop aus dem parasitären LACK Protein für eine effektive CD4+ T Zell-vermittelte Immunantwort beschrieben werden. Das Ziel der vorliegenden Arbeit bestand daher darin, mögliche MHC I abhängige CD8+ T Zell Antworten zu untersuchen. rnFür diesen Ansatz wurde als erstes der Effekt einer Vakzinierung mit LACK Protein fusioniert an die Protein-Transduktionsdomäne des HIV-1 (TAT) analysiert. Die Effektivität von TAT-LACK gegenüber CD8+ T Zellen wurde mittels in vivo Protein-Vakzinierung von resistenten C57BL/6 Mäusen in Depletions-Experimenten gezeigt.rnDie Prozessierung von Proteinen vor der Präsentation immunogener Peptide gegenüber T Zellen ist unbedingt erforderlich. Daher wurde in dieser Arbeit die Rolle des IFN--induzierbaren Immunoproteasoms bei der Prozessierung von parasitären Proteinen und Präsentation von Peptiden gebunden an MHC I Moleküle durch in vivo und in vitro Experimente untersucht. Es konnte in dieser Arbeit eine Immunoproteasom-unabhängige Prozessierung aufgezeigt werden.rnWeiterhin wurde Parasitenlysat (SLA) von sowohl Promastigoten als auch Amastigoten fraktioniert. In weiterführenden Experimenten können diese Fraktionen auf immunodominante Proteine/Peptide hin untersucht werden. rnLetztlich wurden Epitop-Vorhersagen für CD8+ T Zellen mittels computergestützer Software von beiden parasitären Lebensformen durchgeführt. 300 dieser Epitope wurden synthetisiert und werden in weiterführenden Experimenten zur Charakterisierung immunogener Eigenschaften weiter verwendet. rnIn ihrer Gesamtheit trägt die vorliegende Arbeit wesentlich zum Verständnis über die komplexen Mechanismen der Prozessierung und letztendlich zur Identifikation von möglichen CD8+ T Zell Epitopen bei. Ein detailiertes Verständnis der Prozessierung von CD8+ T Zell Epitopen von Leishmania major über den MHC Klasse I Weg ist von höchster Bedeutung. Die Charakterisierung sowie die Identifikation dieser Peptide wird einen maßgeblichen Einfluss auf die weiteren Entwicklungen von Vakzinen gegen diesen bedeutenden human-pathogenen Parasiten mit sich bringen. rn

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Despite its appeal to explain plant invasions, the enemy release hypothesis (ERH) remains largely unexplored for tropical forest trees. Even scarcer are ERH studies conducted on the same host species at both the community and biogeographical scale, irrespective of the system or plant life form. In Cabrits National Park, Dominica, we observed patterns consistent with enemy release of two introduced, congeneric mahogany species, Swietenia macrophylla and S. mahagoni, planted almost 50 years ago. Swietenia populations at Cabrits have reproduced, with S. macrophylla juveniles established in and out of plantation areas at densities much higher than observed in its native range. Swietenia macrophylla juveniles also experienced significantly lower leaf-level herbivory (~3.0%) than nine co-occurring species native to Dominica (8.4–21.8%), and far lower than conspecific herbivory observed in its native range (11%–43%, on average). These complimentary findings at multiple scales support ERH, and confirm that Swietenia has naturalized at Cabrits. However, Swietenia abundance was positively correlated with native plant diversity at the seedling stage, and only marginally negatively correlated with native plant abundance for stems ≥1-cm dbh. Taken together, these descriptive patterns point to relaxed enemy pressure from specialized enemies, specifically the defoliator Steniscadia poliophaea and the shoot-borer Hypsipyla grandella, as a leading explanation for the enhanced recruitment of Swietenia trees documented at Cabrits.

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The technical definition of ‘wood’ is well accepted, but its botanical understanding remains vague. Different degrees and amounts of lignification in plants and their imprecise description, together with a conceptually doubtful life form catalog including trees, shrubs and herbs further complicate our understanding of ‘wood’. Here, we use permanent micro sections to demonstrate that the xylem and bark of terrestrial plants can vary from one tissue with a few lignified cells to an almost fully lignified tissue. This universal principle of plant growth and stabilization, accounting for all taxonomic units within vascular plants, suggests that the classical life form separation into herbs, shrubs and trees is not valid. An anatomical-based differentiation between ‘wood’, ‘woody’ and ‘woodiness’ is also only meaningful if supplemented by insight on the particular plant section and its lignified proportion. We therefore recommend utilizing the botanically more neutral term ‘stem anatomy’ instead of ‘wood anatomy’, which further implies integration of the xylem and bark of all terrestrial plants. Since dendrochronology considers shrubs, dwarf shrubs and perennial herbs in addition to trees, its semantic expansion toward ‘xylemchronology’ might be worthwhile considering.