RCAAP Repository

We examined the ecological distribution of macroalgal communities in streams using species groups (taxonomic units = algal phyla, and morphological = morphological types) with similar structures and functions instead of the species themselves. The study was conducted from June to July/2007 in two drainage basins located in mid-southern region of Paraná State , Brazil. Evaluations of macroalgal communities took into consideration the following spatial scales: the drainage basin (the Pedras river and Marrecas river basins), shading regime (open and shaded stream segments), mesohabitats (riffles and pools), and microhabitats (sampling units of 0.05m2). A total of 29 taxa (23 subgeneric, one generic, and five vegetative groups) were identified. On these, 12 taxa belong to Chlorophyta, 11 to Cyanobacteria, four to Heterokontophyta, and two to Rhodophyta. The proportions of morphological types were: 24% free filaments, 17.25% mats, tufts, gelatinous colonies, and gelatinous filaments, 7% crusts. In terms of spatial scales, we observed a predominance of Chlorophyta in open stream segments and Cyanobacteria in shaded stream segments, reflecting the loss of competitive advantage of green algae in sites with low energy availability. In the mesohabitats, the morphological types recorded in pools were predominantly poorly adapted to fast currents (free filaments), while those found in riffles (mats, tufts and gelatinous filaments) were highly resistant to fast water flows. As such, the use of species groupings based on algal taxonomy associated with morphological characteristics proved to be useful to understanding the distributions of these organisms in lotic environments.

We describe the floristic composition of the tree-shrub vegetation in 10 areas of rocky outcrop cerrado in Goiás State, Brazil. Ten 20×50m plots (totaling 1ha) were established and all of the individuals with diameters at 30cm above soil level (DB30) ³5cm were included in the sampling. Comparative analyses of the flora were realized using similarity indices (Sørensen and Czekanowski), classification analysis (TWINSPAN), and the Mantel test. A total of 13,041 tree-shrub individuals were sampled, distributed among 219 species, 129 genera and 55 families. Fabaceae was the most well-represented family, followed by Myrtaceae, Melastomataceae, Vochysiaceae, Malphigiaceae, and Rubiaceae. Fully 42.3% of the comparisons evaluated by the Sørensen index were &gt;0.50, while all the values were <0.50 for the Czekanowski index, with the exception of Jaraguá and Mara Rosa areas. The TWINSPAN classification generated four divisions and, in general, only the differences in the size of the population were responsible for the groupings. The Mantel test indicated that there was no relationship between floristic similarity and the distances between the areas (r=0.32, P=0.05). It therefore appears that the areas of rocky outcrop cerrado in Goiás State are relatively floristically homogeneous and that they are principally distinguished by the differences in the sizes of the populations of their dominant species, and the presence of exclusive species in certain areas.

Wetland vegetation typically includes aquatic macrophytes with high primary production capacities. The present study investigated how hydrological variations affect biomass allocation and primary productivity in the emergent macrophyte Eleocharis acutangula (Roxb.) Schult. Eleocharis acutangula ramets were collected from the Campelo Lagoon flood plain (21°39'S, 41°12'W and 21°37S, 41°11'W) between March/2005 and February/2006. This region experienced an unusually short rainy period between November/2005 and February/2006 that generated atypically high primary production levels (128gDWm-2month-1) and total biomass gains (447gDWm-2) in May and June/2005 respectively. Our data indicated that primary production and biomass allocation were strongly influenced by variations in wetland water levels and that macrophytes quickly invested in biomass accumulation when surface water levels rised.

Leightoniomyces phillipsii (Berk. &amp; Leight.) D. Hawksw. &amp; B. Sutton, an anamorphic fungus, is described and illustrated for the first time for South America. This synnematous fungus with typical coarsely verrucose conidia was previously known to be associated only with lichens, but can be associated with plant roots. This discovery extends its habitat, geographical distribution, and ecosystem roles.

Lignin, after cellulose, is the second most abundant biopolymer on Earth, accounting for 30% of the organic carbon in the biosphere. It is considered an important evolutionary adaptation of plants during their transition from the aquatic environment to land, since it bestowed the early tracheophytes with physical support to stand upright and enabled long-distance transport of water and solutes by waterproofing the vascular tissue. Although essential for plant growth and development, lignin is the major plant cell wall component responsible for biomass recalcitrance to industrial processing. The fact that lignin is a non-linear aromatic polymer built with chemically diverse and poorly reactive linkages and a variety of monomer units precludes the ability of any single enzyme to properly recognize and degrade it. Consequently, the use of lignocellulosic feedstock as a renewable and sustainable resource for the production of biofuels and bio-based materials will depend on the identification and characterization of the factors that determine plant biomass recalcitrance, especially the highly complex phenolic polymer lignin. Here, we summarize the current knowledge regarding lignin metabolism in plants, its effect on biomass recalcitrance and the emergent strategies to modify biomass recalcitrance through metabolic engineering of the lignin pathway. In addition, the potential use of sugarcane as a second-generation biofuel crop and the advances in lignin-related studies in sugarcane are discussed.

We surveyed the aquatic macrophytes in reservoirs in Camocim de São Félix in the Agreste zone of Pernambuco State, Brazil. Plants were collected on a bimonthly schedule from November/2008 to May/2009 in four reservoirs, and 33 taxa distributed among 23 families were encountered. The family Cyperaceae had the greatest number of species, followed by Lemnaceae. The predominant biologic form was emergent (33.3%) reflecting the extensive shorelines around the reservoirs analyzed.

The Brazilian Atlantic Rainforest is a highly heterogeneous ecosystem comprising large numbers of tropical and subtropical habitats favorable to the development of cyanobacteria. Studies on cyanobacteria in this ecosystem are still rare, however, especially those involving unicellular and colonial types. The high biodiversity and endemism of this biome has been extremely impacted and fragmented, and less than 10% of its original vegetation cover remains today. We describe here a new species of a colonial cyanobacteria, Lemmermanniella terrestris, found on dry soils in a subtropical region of the Atlantic Rainforest in the municipality of Cananéia in southern São Paulo State, Brazil. This new taxon demonstrated all of the diacritical features of the genus Lemmermanniella but, unlike the other species of the genus, it was growing on the soil surface and not in an aquatic environment. A set of morphological features, including colonies composed of subcolonies, and cell dimensions, shapes and contents distinguish it from other species of the genus. Considering that species of Lemmermanniella are found in very distinct habitats (such as thermal and brackish waters) and that they maintain the same life cycle described for the genus in all of those environments, the morphological structures of the colonies can be used as reliable markers for identifying the genus, and its species differ primarily in relation to the habitats they occupy.

This study describes and illustrates non-heterocytous filamentous cyanobacteria found in lagoon systems on the coastal plains of Rio Grande do Sul State. Collections were carried out in different freshwater bodies along the eastern (Casamento Lake area) and western (Tapes City area) margins of the Patos Lagoon (UTM 461948-6595095 and 542910-6645535) using a plankton net (25 µm mesh) in pelagic and littoral zones as well as by squeezing submerged parts of aquatic macrophytes, during both the rainy and dry seasons, from May to December/2003. Twenty two species belonging to the families Phormidiaceae (eight taxa), Pseudanabaenaceae (seven taxa), Oscillatoriaceae (six taxa), and Spirulinaceae (one taxon) were identified. Among these species, five are reported for the first time from Rio Grande do Sul State: Leptolyngbya cebennensis, Microcoleus subtorulosus, Oscillatoria cf. anguina, O. curviceps and Phormidium formosum.

Structural differences between cerrado species with different leaf phenologies are linked to crown architecture, leaf production, and biomass allocation to shoots and leaves. The present study characterized crown structures and the patterns of biomass allocation to leaves and shoots in two woody cerrado species with contrasting leaf phenologies and quantified the irradiance reaching their leaves to determine the best period during the day for photosynthetic activity. The shoots and leaves of five individuals of both Annona coriacea (deciduous) and Hymenaea stigonocarpa (evergreen) were collected along a 50 m transect in a cerrado fragment within the urban perimeter of Catalão - GO, to determine their patterns of biomass allocation in their crowns. The evergreen H. stigonocarpa had significantly higher mean values of shoot inclination (SI), petiole length (PL), leaf area (LA), leaf display index (LDI), and individual leaf area per shoot (ILA), while the deciduous species A. coriacea had significantly higher leaf numbers (LN). The more complex crown of H. stigonocarpa had shoots in more erect positions (orthotropic), with intense self-shading within shoots; A. coriacea, on the other hand, had slanting (plagiotropic) shoots in the crown, allowing similar irradiance levels to all leaf surfaces. The production of plagiotropic shoots by the deciduous species (A. coriacea) is a strategy that enables its use of incident sunlight early in the morning and preventing excessive water loss or excessive irradiance. Hymenaea stigonocarpa (an evergreen), by contrast, had orthotropic shoots and uses intense self-shading as a strategy to avoid excessive irradiance, especially at midday. Differences in crown architectures between evergreen and deciduous species of cerrado sensu stricto can therefore be viewed as adaptations to the environmental light regime.

The cotyledons of Hymenaea courbaril store large amounts of xyloglucan, a cell wall polysaccharide that is believed to serve as storage for the period of seedling establishment. During storage mobilisation, xyloglucan seems to be degraded by a continuous process that starts right after radicle protrusion and follows up to the establishment of photosynthesis. Here we show evidence that events related to the hydrolases activities and production (α-xylosidase, β-galactosidase, β-glucosidase and xyloglucan endo-β-transglucosilase) as well as auxin, showed changes that follow the diurnal cycle. The period of higher hydrolases activities was between 6pm and 6am, which is out of phase with photosynthesis. Among the enzymes, α-xilosidase seems to be more important than β-glucosidase and β-galactosidase in the xyloglucan disassembling mechanism. Likewise, the sugars related with sucrose metabolism followed the rhythm of the hydrolases, but starch levels were shown to be practically constant. A high level of auxin was observed during the night, what is compatible with the hypothesis that this hormone would be one of the regulators of the whole process. The probable biological meaning of the existence of such a complex control mechanism during storage mobilisation is likely to be related to a remarkably high level of efficiency of carbon usage by the growing seedling of Hymenaea courbaril, allowing the establishment of very vigorous seedlings in the tropical forest.

Fruits were collected from trees of Coffea arabica cv. Obatã grown at Mococa and Adamantina in São Paulo State, Brazil, which are regions with marked differences in air temperature that produce coffee with distinct qualities. Mococa is a cooler location that produces high-quality coffee, whereas coffee from Adamantina is of lower quality. The amino acid and protein contents, amino acid profile, and proteinase activity and type in endosperm protein extracts were analysed. Proteinase genes were identified, and their expression was assayed. All results indicate that temperature plays a role in controlling proteinase activity in coffee endosperm. Proteinase activity was higher in the endosperm of immature fruits from Adamantina, which was correlated with higher amino acid content, changes in the amino acid profile, and increased gene expression. Cysteine proteinases were the main class of proteinases in the protein extracts. These data suggest that temperature plays an important role in coffee quality by altering nitrogen compound composition.

The diversity of algal banks composed of species out the genera Gracilaria Greville and Hypnea J.V. Lamouroux have been impacted by commercial exploitation and coastal eutrophication. The present study sought to construct dynamic models based on algal physiology to simulate seasonal variations in the biomasses of Gracilaria and Hypnea an intertidal reef at Piedade Beach in Jaboatão dos Guararapes, Pernambuco State, Brazil. Five 20 × 20 cm plots in a reef pool on a midlittoral reef platform were randomly sampled during April, June, August, October, and December/2009 and in January and March/2010. Water temperature, pH, irradiance, oxygen and salinity levels as well as the concentrations of ammonia, nitrate and phosphate were measured at the sampling site. Forcing functions were employed in the model to represent abiotic factors, and algal decay was simulated with a dispersal function. Algal growth was modeled using a logistic function and was found to be sensitive to temperature and salinity. Maximum absorption rates of ammonia and phosphate were higher in Hypnea than in Gracilaria, indicating that the former takes up nutrients more efficiently at higher concentrations. Gracilaria biomass peaked at approximately 120 g (dry weight m-2) in March/2010 and was significantly lower in August/2009; Hypnea biomasses, on the other hand, did not show any significant variations among the different months, indicating that resource competition may influence the productivity of these algae.

Abstract The goal of the present study was to analyze the factor structure of the Inventory of Dimensions of Emerging Adulthood (IDEA) in Brazil, in order to use the measure in subsequent studies in the country, and to provide data for comparison of the measure factor structure in different countries. The sample included 547 individuals; residents in Porto Alegre (RS), from low and high SESs, ranging in age from 18 to 29 years old. Results pointed out that the inventory presented a different structure when compared with the original measure. For instance, the item "separating from parents" migrated from the dimension Identity Exploration to Self-focused , influenced by Brazilian cultural specificities. The inventory examined IDEA presented a new factor structure, associated with Brazilian context and the structure of the items on the original measure. In conclusion, the measure is a satisfactory tool of investigation of the emerging adulthood phenomenon in Brazil and Latin America.

Resumo Da obra de B. F. Skinner fazem parte preocupações de ordem epistemológica, encerrando discussões sobre metodologia e critérios de verdade, e outras de ordem política e social, concernentes à relação entre ciência e sociedade. De um discurso, em alguns aspectos, coincidentes com uma forma de positivismo, Skinner passou a crítico de tendências puramente formalistas sobre o método científico, e de uma defesa do gerenciamento da sociedade por especialistas, passou a uma crítica à centralização do poder e à proposta de uma forma de organização baseada no controle face-a-face. Tratando de temas semelhantes, Paul Feyerabend desconstruiu a ideia de um método científico universal, denunciou um caráter potencialmente opressor da ciência, reclamando que o conhecimento científico não deveria ter inerente predileção sobre outras formas de conhecimento para o acesso às instituições de poder. Considerando a relevância da obra de ambos os autores para debates suscitados no âmbito da história e da filosofia das ciências, este trabalho objetiva apresentar e discutir aspectos do comportamentalismo radical, de Skinner, e do anarquismo epistemológico, de Feyerabend, que tratam de temas comuns. Conclui-se que, apesar de diferenças salientes, as duas perspectivas contêm algumas proposições convergentes e virtualmente complementares, cuja interlocução poderia ser útil a seus objetivos de busca por uma sociedade livre.

Resumo Um corpo amplo de evidências científicas já existente documenta a importância da relação pai-filho. O objetivo deste estudo foi desenvolver um modelo teórico de envolvimento paterno, organizado de acordo com princípios de Análise de Equações Estruturais, que requerem especificar as variáveis associadas ao construto central, com base em dados empíricos. Em 2015, foi realizada uma busca sistemática nas bases de dados eletrônicas APA PsycNET, Bireme, PEPSIC, Web of Science e IndexPsi Periódicos, usando os descritores "envolvimento" e "paterno", cruzados com "avaliação" ou "instrumento", nos idiomas inglês e português. Não foram impostas restrições em relação ao ano de publicação. foram encontrados 39 textos completos que incluíam dados empíricos sobre o envolvimento paterno. As informações encontradas foram agrupadas em três categorias: (a) dimensões do envolvimento paterno, (b) fatores que afetam o envolvimento paterno e (c) impactos deste envolvimento sobre outras variáveis. O modelo apresentado sintetiza os resultados dos estudos e representa um avanço no desenvolvimento teórico na área. Este modelo aumenta a visibilidade de questões conceituais sobre o envolvimento paterno e seus correlatos, e, depois da sua testagem empírica, poderá contribuir para o aprimoramento de programas de intervenção para pais.

Resumo Este artigo apresenta o recorte de uma experiência de pesquisa-intervenção com um grupo de discussão composto por adolescentes de uma escola particular de Fortaleza. Tomando como referência a articulação entre discurso e modos de subjetivação em Foucault, a pesquisa teve como objetivo analisar e problematizar como estes estudantes são subjetivados pelos discursos que circunscrevem a adolescência na contemporaneidade. Na presente análise, cujo foco foram os discursos em que se evidencia a distinção entre uma adolescência mais favorecida socialmente e outra menos favorecida, esta comumente associada aos riscos e demais problemas sociais, foi possível perceber que as versões que os adolescentes constroem sobre si e sobre o outro adolescente são atravessadas pelos campos discursivos sociológico e midiático. No primeiro campo, destaca-se a relativização no que diz respeito à liberdade, responsabilidade e ao medo. No interior do discurso midiático os adolescentes se posicionaram agregando concepções excludentes sobre a gravidez na adolescência. A abertura para as mudanças e negociações em seus posicionamentos, engendrada no grupo de discussão, pôde promover deslocamentos discursivos, ampliando as possibilidades de constituição subjetiva para estes adolescentes.

Resumen El objetivo del presente trabajo es obtener información del patrón evolutivo de desempeño en tareas de fluidez verbal para una muestra de niños argentinos de nivel primario de 3°, 5° y 7° grado. Se evaluó a los participantes con una tarea de fluidez semántica, en la que se evaluaron las categorías de animales, frutas y verduras, y partes del cuerpo para el dominio de seres vivos, y medios de transporte, instrumentos musicales y ropa para el de objetos inanimados. Asimismo fueron evaluados con una tarea de fluidez fonológica en la que se testearon los fonemas /f/, /a/ y /s/. Los datos obtenidos dan cuenta de diferencias de rendimiento entre las tareas de fluidez con un mejor desempeño en las tareas de fluidez semántica. Asimismo, en las tareas de fluidez semántica se observa un mejor rendimiento en el dominio de seres vivos. Las diferencias obtenidas en ambas tareas se identifican al comparar los grupos según escolaridad, siendo únicamente los niños de 3° grado los que, con menor cantidad de ejemplares recuperados, se disocian significativamente de los de 5° y 7° grado. Estos hallazgos son discutidos a la luz de posibles diferencias en función del desarrollo cognitivo, de las funciones ejecutivas y del sistema semántico.

Resumo Este estudo analisa a constituição de comunidades de prática no contexto do sexo tarifado exercido por homens, com foco nos exercícios de sexualidade e identificações de gênero. Utilizou-se de uma abordagem inspirada na Teoria Fundamentada, por meio da qual se realizaram diários de campo das incursões em ambientes de sexo tarifado, entrevistas narrativas com seis homens que se dedicam a atividade e dois gerentes de duas casas especializadas no mercado de sexo porto-alegrense, durante o ano de 2015. O corpus foi analisado discursivamente e identificaram-se dinâmicas associadas à formação de comunidades de prática pela via de estratégias de vigilância e correção, de modo que aspectos como o investimento corporal e outras dimensões performativas atualizavam relações de consumo circunscritas em algumas esferas de controle. Exercício de poder se mostram pela via da "dessexualização" do cliente, ou da feminilização do garoto de programa, indicando que a noção de comunidade não se dissociava de aspectos discursivos heteronormativos.

Resumo O esquecimento é uma condição vivenciada diariamente pelos indivíduos e um conceito de extrema importância para a ciência da memória, apesar de sua experimentação ser complexa. Algumas teorias que tentam definir a ciência do esquecimento são apresentadas neste estudo, todavia, aqui focamos na Teoria da Interferência, principalmente na Interferência Retroativa (IR). A IR é a interferência que ocorre quando uma informação ou tarefa é inserida entre a apresentação de uma informação-alvo e sua posterior recordação. A IR pode ser explicada como uma competição de itens, mas atualmente surge a proposta que ela seja fruto da interrupção de um outro processo, chamado de Consolidação da Memória. A consolidação da memória é o processo através do qual as informações tornam-se estáveis, a partir de processos neurais posteriores ao registro inicial de uma informação que contribuem para o registro definitivo – ou, ao menos, mais duradouro – desta informação. A IR perturbaria estes processos posteriores à aprendizagem, resultando na perda destes materiais. O presente estudo visa propor a possibilidade da investigação mais aprofundada deste tópico para a melhor compreensão desse relevante conceito, visando aprofundar o conhecimento desta hipótese e outras possíveis causas do esquecimento.

Resumo A Prova de Compreensão de Texto da Bateria PROLEC (PROLEC-T), amplamente utilizada no Brasil, apresenta amostra limitada e apenas análises descritivas dos escores. Objetivos: conhecer a estrutura interna (adequação dos itens via Teoria de Resposta ao Item) e os índices de validade externa (concorrente) da referida prova. Método: estudo das respostas de 457 alunos (49,7% meninos) do 2º ao 5º ano, aleatoriamente selecionados em 77 salas de aula de oito escolas estaduais, ao PROLEC-T e a três testes de leitura. Resultados: a prova apresenta baixo nível de dificuldade e pouca variabilidade de escores, evidenciando validade interna não satisfatória. Mostra também limitações em relação à validade concorrente, uma vez que as correlações entre os seus escores e o ano escolar, a idade da criança e as notas finais na disciplina Língua Portuguesa foram fracas, embora tenham sido medianas com as medidas de leitura. Conclusão: Em sua forma atual, o PROLEC-T parece ser adequada apenas para uma avaliação informal de crianças com dificuldade de leitura. No entanto, caso seja reformulada, sugere-se a substituição de seus textos por histórias inéditas, em ordem crescente de dificuldade, com apenas perguntas inferenciais.