Brasilacarus cocaris (Acari: Opilioacaridae), a new genus and species from Amazonia, Brazil

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

Measurement of the natural variation of 13C:12C ratio in leaves at Reserva Ducke Forest, central Amazonia

Investigation of carbon isotope fractionation by plants was carried out at two sub-areas located in Reserva Ducke, central Amazonia: open reserve (virgin forest with low density of plant species); and closed reserve (virgin forest with high density of plant species). Preliminary results (δ‰ 13C: 12C values, PDB) of leaf analysis at different plant heights indicate the following: Eschweilera matamata Hub. (Lecythidaceae), common name 'matamata', -31.55±0.61; Protium heptaplyllum March. (Burseraceae), common name 'breu branco', -32.34±1.39; Calophyllum brasiliense Camb. (Guttiferae), common name 'jacareúba', -30.72±0.23; Scleronema micrantthum Ducke. (Bombacaceae), common name 'cardeiro'. -28.81±0.68; and Carapa guianensis Aubl. (Meliaceae), common name 'andiroba', -31.07±0.51. It is possible that the plant species analysed belong to the C3 photosynthetic cycle. In general, the species in the open reserve show differences of the order of 1.66±0.34‰ (greater in 13C) as compared with the same species in the closed reserve. The old leaves show differences in the relative isotopic enrichment (δ) of the order of 1‰, being smaller in new leaves in both reserves. The probable occurrence of an isotopic gradient from the lower (2-5 m) to the upper part (15-20 m) of the plant, of the order of 1.3‰, smaller in 13C, in species from the dense forest was noted. However, only two plants from each species were analysed during a two-year period, data obtained to far are still preliminary, and results should, therefore, be revised. Moreover, according to the literature, the natural carbon isotope fractionation by plants shows metabolic, physiological and environmental dependence. © 1991.

Morphometric relationships and indirect determination of the length frequency structure of the pirarucu, Arapaima gigas (Cuvier), in Brazilian Amazonia

The pirarucu (giant red fish), Arapaima gigas (Cuvier), (Arapaimidae) is among the diverse fish resources of Amazonia which are threatened by over-exploitation. Little is known about the biology of this species despite its commercial importance. The present paper provides indirect information about the length-frequency structure of the stock which was estimated by sampling its tongue bone in craft shops and weighing fresh manias (processed fish product) in fish markets since these were the only remaining recognizable features of the fish. The length-frequency reconstruction was carried out using a regression analysis calculated by utilizing individuals caught in experimental fishing.

Morphometric relationships and indirect determination of the length frequency structure of the pirarucu, Arapaima gigas (Cuvier), in Brazilian Amazonia

The pirarucu (giant red fish), Arapaima gigas (Cuvier), (Arapaimidae) is among the diverse fish resources of Amazonia which are threatened by over-exploitation. Little is known about the biology of this species despite its commercial importance. The present paper provides indirect information about the length-frequency structure of the stock which was estimated by sampling its tongue bone in craft shops and weighing fresh manias (processed fish product) in fish markets since these were the only remaining recognizable features of the fish. The length-frequency reconstruction was carried out using a regression analysis calculated by utilizing individuals caught in experimental fishing.

Influence of wood moisture content on modulus of elasticity on tension paralllel to the grain of brasilian species

Periodically, when necessary, standard documents are revised in order to analyze inconsistencies and to include considerations according new realities verified. In this sense, aiming to quantify the wood moisture content influence on modulus of elasticity, it was applied tension tests parallel to the grain for six specimens of different strength classes of wood, considering nominal moisture of 12, 20, 25, and 30% in Brazil. The present paper examine the adequacy of the current Brazilian standard ABNT NBR7190:1997, in review, about the adoption of a first degree equation to describe the influence of wood moisture content for timber structures design. It was obtained a new first degree equation which leads to statically equivalent estimations when compared with results by ABNT NBR7190:1997 equation. However, as recommendations it could be maintain the current expression for the next text of the referred document review, without prejudice to statistical significance of the estimates.

Effect of Urucu oil (Brazilian Amazon) on the biomass of the aquatic macrophyte Eichhornia crassipes (Mart.) Solms (Pontederiaceae)

Os rios e lagos de várzea da província petrolífera de Urucu, na Amazônia Central, são amplamente colonizados por macrófitas aquáticas, que podem ser afetadas por acidentes durante a exploração e o transporte de petróleo. Entre as macrófitas, a espécie flutuante Eichhornia crassipes (aguapé) ocorre abundantemente na região; OBJETIVO: O objetivo desse estudo foi verificar o efeito de diferentes dosagens do petróleo de Urucu (0; 0,5; 1,5 e 3,0 L.m-2) na biomassa viva e morta de E. crassipes e em algumas características físicas e químicas da água; MÉTODOS: O experimento teve oitenta e quatro dias de duração. A cada sete dias foi determinada a biomassa (viva e morta) de E. crassipes e os valores de temperatura, pH, condutividade elétrica e oxigênio dissolvido da água; RESULTADOS: A dosagem de 0,5 L.m-2 foi suficiente para causar mortalidade parcial (48%) em E. crassipes após trinta e cinco dias de exposição ao petróleo. A dosagem de 3,0 L.m-2 causou mortalidade total (100%) em E. crassipes em oitenta e quatro dias de exposição. A decomposição do petróleo e da biomassa morta de E. crassipes provocam a redução do oxigênio dissolvido e do pH, e aumento da condutividade elétrica e de fósforo total na água; CONCLUSÕES: Nós concluímos que um derramamento de petróleo pode provocar mortalidade total em uma população de uma espécie de macrófita, mas não em uma outra. Isto pode alterar a diversidade de espécies de macrófitas na região impactada. No caso de Eichhornia crassipes e Pistia stratiotes, um derramamento de petróleo de Urucu pode favorecer E. crassipes, a espécie menos sensível ao petróleo.

The history of the introduction of the giant river prawn, Macrobrachium cf. rosenbergii (Decapoda, Palaemonidae), in Brazil: new insights from molecular data

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

Phylogeography and Pleistocene demographic history of the endangered marsh deer (Blastocerus dichotomus) from the Rio de la Plata Basin

The marsh deer is the largest neotropical cervid with morphological and ecological adaptations to wetlands and riparian habitats. Historically, this now endangered species occupied habitats along the major river basins in South America, ranging from southern Amazonia into northern Argentina to the Parana river delta. This particularly close association with wetlands makes marsh deer an excellent species for studying the effects of Pleistocene climatic changes on their demographic and phylogeographic patterns. We examined mitochondrial DNA variation in 127 marsh deer from 4 areas distributed throughout the Rio de]a Plata basin. We found 17 haplotypes in marsh deer from Brazil, Bolivia and Argentina that differed by 1-8 substitutions in a 601 bp fragment of mitochondrial control region sequence, and 486 bp of cytochrome b revealed only 3 variable sites that defined 4 haplotypes. Phylogeny and distribution of control region haplotypes suggest that populations close to the Pantanal area in central Brazil underwent a rapid population expansion and that this occurred approximately 28,000-25,000 years BP. Paleoclimatic data from this period suggests that there was a dramatic increase for precipitation in the medium latitudes in South America and these conditions may have fostered marsh deer's population growth.

Nutrient recycling and physical indicators of an alley cropping system in a sandy loam soil in the pre-Amazon region of Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The relationship between pasture degradation and soil properties in the Brazilian amazon: a case study

Pasture degradation is one of the greatest problems related to land use in the Amazon region, forcing farmers to open new forest areas. Many studies have identified the causes and the factors involved in this degradation process, in an attempt to reverse the situation. The purpose of this study was to examine the relationship between pasture degradation and some soil properties, to try to identify the most significant soil features in the degradation process. A cattle raising farm in the eastern Amazon region, with pastures of different ages and degrees of degradation, was used as the site for this study: a primary forest area, PN; three Guinea grass (Panicum maximum Jacq.) pastures in an increasingly degraded sequence-P1, P2 and P3; one Gamba grass (Andropogon gayanus Kunth) pasture following an extremely degraded Guinea grass pasture, P4. Aboveground phytomass data showed differences between the pastures, reflecting initially observed degradation levels. Grass biomass decreased sharply from P1 to P2 and disappeared at P3. Pasture recovery with Gamba grass at P4 was very successful, with grass biomass higher than P1 and weed biomass smaller than P2 and P3. Root biomass also decreased with pasture degradation. Soil bulk density increased with pasture decrease at the topsoil layer. Results from the soil chemical analysis showed that there were no signs of decrease in organic carbon and total nitrogen after the forest was transformed into pasture. In all pastures, degraded or not, the soil pH, the sum of bases and the saturation degree were higher than in the forest soil. The extractable phosphorus content, lower in forest soil, remained quite stable in pasture soils, but it could become a limiting factor for the maintenance of Guinea grass. Results indicated that pasture degradation does not seem to be directly related to the modification of the chemical features of soils. (C) 2004 Elsevier B.V. All rights reserved.

Intercomparison of integrated water vapor estimates from multisensors in the amazonian region

Water vapor is an atmospheric component of major interest in atmospheric science because it affects the energy budget and plays a key role in several atmospheric processes. The Amazonian region is one of the most humid on the planet, and land use change is able to affect the hydrologic cycle in several areas and consequently to generate severe modifications in the global climate. Within this context, accessing the error associated with atmospheric humidity measurement and the validation of the integrated water vapor (IWV) quantification from different techniques is very important in this region. Using data collected during the Radiation, Cloud, and Climate Interactions in Amazonia during the Dry-to-Wet Transition Season (RACCI/DRY-TO-WET), an experiment carried out in southwestern Amazonia in 2002, this paper presents quality analysis of IWV measurements from RS80 radiosondes, a suite of GPS receivers, an Aerosol Robotic Network (AERONET) solar radiometer, and humidity sounding from the Humidity Sounder for Brazil (HSB) aboard the Aqua satellite. When compared to RS80 IWV values, the root-mean-square (RMS) from the AERONET and GPS results are of the order of 2.7 and 3.8 kg m(-2), respectively. The difference generated between IWV from the GPS receiver and RS80 during the daytime was larger than that of the nighttime period because of the combination of the influence of high ionospheric activity during the RACCI experiment and a daytime drier bias from the RS80.

Espaço inventado: o teatro pós-dramático na escola

Com a publicação da lei n. 9394/96, a arte integra-se ao currículo do ensino básico como área de conhecimento. Neste ensaio, problematiza-se essa nova condição da arte na escola, refletindo a particularidade da experiência artística em relação às outras disciplinas, de modo a não se descaracterizar o que é próprio dela. A partir do entendimento de que a presença da arte é provocadora de mudanças, busca-se observar aquilo que, na escola, é necessário ser tocado por ela. Esse olhar investigativo flagra uma cena de destruição, com problemáticas muito próximas daquelas expressas pelo teatro contemporâneo. Com isso, sugere-se aproximar a realidade escolar de formas do teatro pós-dramático, com o intuito de inventar espaços que possam vir a ser coletivos e que acolham o que se chamou de trocas de intimidades. Dessa aproximação, reitera-se o conceito de conhecimento como invenção, defendido por Michel Foucault, e detecta-se a necessidade de elaborar uma atitude docente que seja provocativa e crie ações educativas de tipo estratégico.

Gene flow networks among American Aedes aegypti populations

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A new species of Leucoagaricus (Agaricaceae) from Colombia

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

Alterations following a fire in a forest community of Alto Rio Xingu

This study records the consequences of fire upon the soil and structure of the Amazonian Forest of Gaucha do Norte, Mato Grosso state, Brazil (13degrees12'S and 53degrees20'W). For this, the number of individuals sampled in 1 ha of the forest, during a phytosociological survey completed 2 days before the accidental fire, was compared with the survivors recorded afterwards in the reinventory of the area taken 2 days and 10 months after the fire. For the surveys, the area of 1 ha was subdivided into 50 plots of 10 m x 20 m, and all the individuals with circumference at breast height (CBH) greater than or equal to 15 cm were sampled. Chemical analysis of the 30 soil samples collected 2 days before the fire were compared with those obtained 15 days and 1 year after the fire. It was seen that, soon after the fire, there was a significant increase in the nutrient levels in the soil, an increase in the pH and a decrease in the aluminum toxicity. However, after 1 year, losses by lixiviation resulted in a nutrient reserve in the soil of less than that before the fire. The tree mortality was extremely high (23.98%), particularly amongst the younger individuals of the population (93.68% of the total of deaths in the period). There was no significant reduction in the forest richness analyzed: 60% of the species had reduced populations after the fire, but just four species were locally extinct. Results, however, demonstrated a role for fire in the selection of resistant species or those adapted to fires, since some species demonstrated a greater tolerance to the fire than others. (C) 2003 Elsevier B.V. B.V. All rights reserved.