282 resultados para BRIC (Brazil, Russia, India and China)


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Solepyris Azevedo is a rarely collected Neotropical genus. It is differentiated from other Sclerodermini genera by having the fore wing venation with a single large closed cell and currently is monotypic containing S. unicus Azevedo. A second species, Solepyris montuosus, sp. nov., from Brazil is described and illustrated. This new species is diagnosed by having radial vein of the fore wing long. An amended diagnosis of Solepyris unicus Azevedo is included. A key for the two species of Solepyris is provided.

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Mosquitoes in the family Culicidae develop their immature forms in different environments depending on various circumstances. This study represents the first contribution to the ecological knowledge of culicids living in the bromeliad G. brasiliensis. The objectives of the study were to compare the Culicidae fauna of bromeliads in two seasonal periods, analyzing their abundance, richness and the influence of pH, conductivity and water volume, on the populations. Sampling was done at Reserva Adolpho Ducke, Manaus, Amazonas, Brazil between 2003 and 2005. Six samplings were done in the rainy season and six in the dry season. On each sampling day, six terrestrial and six epiphytic bromeliads, totaling 144 sampling units, were retrieved. A total of 444 immature mosquitoes were collected, distributed in the following species: Culex (Microculex) stonei Lane & Whitman, Culex (Microculex) chryselatus Dyar & Knab, Culex (Microculex) sp., Wyeomyia (Hystatomyia) autocratica Dyar & Knab and Wyeomyia (Hystatomyia) splendida Bonne-Wepster & Bonne. The relationship between abundance of Culicidae and sampling period was not significant, although abundance was higher in the dry period. There were significant correlations between water volume and the abundance (p = 0.003) and richness (p = 0.001) of culicids. The pH was positively related to the occurrence of the species Wy. autocratica (p= 0.010) and Wy. splendida (p= 0.006), demonstrating the influence of this factor in the structuring of bromeliad-inhabiting communities.

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A new species of Zamischus (Hymenoptera, Cynipoidea, Figitidae) from Brazil. A new species of Zamischus from Brazil is described and diagnosed. The species is closely related to Z. brasiliensis but differs in the morphology of antennae and scutellum. Z. aquilesi sp. nov. was collected via Malaise trapping in a tobacco field in Santa Cruz do Sul, Rio Grande do Sul.

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Diatraea flavipennella (Box) (Lepidoptera, Crambidae) is one of the most destructive pests in sugarcane plantations in the Northeast Region of Brazil. Developmental characteristics and parasitism potential of the egg parasitoids Telenomus alecto Crawford (Hymenoptera, Scelionidae) and Trichogramma galloi Zucchi (Hymenoptera, Trichogrammatidae) were compared with the aim of selecting a suitable species for biological control of D. flavipennella. Both T. alecto and T. galloi developed well and were readily adapted to D. flavipennella eggs as host. Although, T. galloi presented higher viability, with more adults emerging per host egg and higher sex ratio, the developmental period (egg-adult) was shorter in T. alecto and female longevity was extended. In addition, T. alecto exhibited significant higher levels of parasitism during the first three days after emergence than T. galloi. Thus, both parasitoids studied here offer considerable potential for the control of D. flavipennella in sugarcane.

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A new species of Nemopalpus Macquart (Diptera, Psychodidae) from Brazil. Nemopalpus parvus sp. nov. collected in the Atlantic rainforest of the state of Espírito Santo, in southeastern Brazil, is described and illustrated.

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A pictorial key and diagnosis of the Brazilian genera of Micropezidae (Diptera, Nerioidea). This paper provides the first pictorial key and diagnosis for the Brazilian genera of the Micropezidae, based on external morphological characters illustrated with photographs. The key includes 13 genera: Cardiacephala Macquart, Cliobata Enderlein, Grallipeza Rondani, Metasphen Frey, Micropeza Meigen, Parasphen Enderlein, Planipeza Marshall, Plocoscelus Enderlein, Poecilotylus Hennig, Ptilosphen Enderlein, Rainieria Rondani, Scipopus Enderlein and Taeniaptera Macquart. For each genus, the species known to occur in Brazil are listed and their distribution records, including new ones, are provided.

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A new species of Scymnobius Casey (Coleoptera, Coccinellidae, Scymnini) from Pernambuco, Brazil. Scymnobius pernambucensis sp. nov. from Pernambuco, Brazil, is described and illustrated. This is the third species of this genus recorded from Brazil.

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Zethus (Zethusculus) paschoali, a new species from Piraquara, Paraná, Brazil, is described and pictures comparing it to similar species are presented.

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Soils play a fundamental role in the production of human foods. The Oxisols in the state of Paraná are among the richest and most productive soils in Brazil, but degradation and low porosity are frequently documented, due to intensive farming involving various management strategies and the application of high-tech solutions. This study aims to investigate changes in the porosity of two Red Oxisols (Latossolos Vermelhos), denoted LVef (eutroferric) and LVdf (dystroferric) under conventional and no-tillage soil management, with a succession of annual crops of soybean, maize and wheat over a continuous period of more than 20 years. After describing the soil profiles under native forest, no-tillage management and conventional tillage using the crop profile method, deformed and non-deformed soil samples were collected from the volumes most compacted by human intervention and the physical, chemical and mineralogical properties analyzed. The various porosity classes (total pore volume, inter-aggregate porosity between channels and biological cavities) and intra-aggregate porosity (determined in 10 cm³ saturated clods subjected to a pressure of -10 kPa to obtain a pore volume with a radius (r eq), > 15 μm and < 15 μm). The results showed that the effects of no-tillage farming on porosity are more pronounced in both soil types. Porosity of the LVdf was higher than pf the LVef soil, whatever the management type. In the LVdf soil, only pores with a radius of > 15 μm were affected by farming whereas in the LVef soil, pores with a radius of < 15 μm were affected as well.

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In addition to the more reactive forms, metals can occur in the structure of minerals, and the sum of all these forms defines their total contents in different soil fractions. The isomorphic substitution of heavy metals for example alters the dimensions of the unit cell and mineral size. This study proposed a method of chemical fractionation of heavy metals, using more powerful extraction methods, to remove the organic and different mineral phases completely. Soil samples were taken from eight soil profiles (0-10, 10-20 and 20-40 cm) in a Pb mining and metallurgy area in Adrianópolis, Paraná, Brazil. The Pb and Zn concentrations were determined in the following fractions (complete phase removal in each sequential extraction): exchangeable; carbonates; organic matter; amorphous and crystalline Fe oxides; Al oxide, amorphous aluminosilicates and kaolinite; and residual fractions. The complete removal of organic matter and mineral phases in sequential extractions resulted in low participation of residual forms of Pb and Zn in the total concentrations of these metals in the soils: there was lower association of metals with primary and 2:1 minerals and refractory oxides. The powerful methods used here allow an identification of the complete metal-mineral associations, such as the occurrence of Pb and Zn in the structure of the minerals. The higher incidence of Zn than Pb in the structure of Fe oxides, due to isomorphic substitution, was attributed to a smaller difference between the ionic radius of Zn2+ and Fe3+.

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The State of Santa Catarina, Brazil, has agricultural and livestock activities, such as pig farming, that are responsible for adding large amounts of phosphorus (P) to soils. However, a method is required to evaluate the environmental risk of these high soil P levels. One possible method for evaluating the environmental risk of P fertilization, whether organic or mineral, is to establish threshold levels of soil available P, measured by Mehlich-1 extractions, below which there is not a high risk of P transfer from the soil to surface waters. However, the Mehlich-1 extractant is sensitive to soil clay content, and that factor should be considered when establishing such P-thresholds. The objective of this study was to determine P-thresholds using the Mehlich-1 extractant for soils with different clay contents in the State of Santa Catarina, Brazil. Soil from the B-horizon of an Oxisol with 800 g kg-1 clay was mixed with different amounts of sand to prepare artificial soils with 200, 400, 600, and 800 g kg-1 clay. The artificial soils were incubated for 30 days with moisture content at 80 % of field capacity to stabilize their physicochemical properties, followed by additional incubation for 30 days after liming to raise the pH(H2O) to 6.0. Soil P sorption curves were produced, and the maximum sorption (Pmax) was determined using the Langmuir model for each soil texture evaluated. Based on the Pmax values, seven rates of P were added to four replicates of each soil, and incubated for 20 days more. Following incubation, available P contents (P-Mehlich-1) and P dissolved in the soil solution (P-water) were determined. A change-point value (the P-Mehlich-1 value above which P-water starts increasing sharply) was calculated through the use of segmented equations. The maximum level of P that a soil might safely adsorb (P-threshold) was defined as 80 % of the change-point value to maintain a margin for environmental safety. The P-threshold value, in mg dm-3, was dependent on the soil clay content according to the model P-threshold = 40 + Clay, where the soil clay content is expressed as a percentage. The model was tested in 82 diverse soil samples from the State of Santa Catarina and was able to distinguish samples with high and low environmental risk.

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Phyllophaga cuyabana is a univoltine species and its development occurs completely underground. Its control by conventional methods, such as chemical and biological insecticides, is difficult, so it is important to understand its dispersion, reproduction, and population behavior in order to determine best pest management strategies. The objective of this work was to study the behavior of adults of P. cuyabana. This study was carried out in the laboratory, greenhouse and field sites in Paraná State, Brazil (24º25' S and 52º48' W), during four seasons. The results obtained demonstrate that: a) P. cuyabana adults have a synchronized short-flight period when mating and reproduction occurs; b) adults tend to aggregate in specific sites for mating; c) the majority of adults left the soil on alternate nights; d) the choice of mating and oviposition sites was made by females before copulation, since after copulation adults did not fly from or bury themselves at nearby locations; e) females that fed on leaves after mating, oviposited more eggs than females that had not fed;f) plant species such as sunflower (Helianthus annuus) and the Crotalaria juncea are important food sources for adults.

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BACKGROUND: In recent decades, early diagnosis of childhood cancer has taken an important place on the international agenda. The authors of this study evaluated a group of medical students in Recife, Brazil, regarding knowledge and practices related to early diagnosis of common childhood cancers. METHODS: Cross-sectional study with a sample of 82 medical students, from a total of 86 eligible subjects. Data were collected using self-completed questionnaires. Subgroups were defined according to knowledge of the theme and students' perceptions of their own skills and interest in learning. RESULTS: 74.4% of the sample demonstrated a minimum level of knowledge. The group without minimum knowledge or self-perceived competence to identify suspected cases (23.3%) was in the worst position to perform early diagnosis. All subjects expressed interest in learning more about this topic. CONCLUSIONS: Despite acceptable levels of knowledge among these medical students, the definition of central aspects of the teaching and learning processes would be useful for training physicians with the skills for diagnosing and treating pediatric cancers

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Approximately 7.2% of the Atlantic rainforest remains in Brazil, with only 16% of this forest remaining in the State of Rio de Janeiro, all of it distributed in fragments. This forest fragmentation can produce biotic and abiotic differences between edges and the fragment interior. In this study, we compared the structure and richness of tree communities in three habitats - an anthropogenic edge (AE), a natural edge (NE) and the fragment interior (FI) - of a fragment of Atlantic forest in the State of Rio de Janeiro, Brazil (22°50'S and 42°28'W). One thousand and seventy-six trees with a diameter at breast height > 4.8 cm, belonging to 132 morphospecies and 39 families, were sampled in a total study area of 0.75 ha. NE had the greatest basal area and the trees in this habitat had the greatest diameter:height allometric coefficient, whereas AE had a lower richness and greater variation in the height of the first tree branch. Tree density, diameter, height and the proportion of standing dead trees did not differ among the habitats. There was marked heterogeneity among replicates within each habitat. These results indicate that the forest interior and the fragment edges (natural or anthropogenic) do not differ markedly considering the studied parameters. Other factors, such as the age from the edge, type of matrix and proximity of gaps, may play a more important role in plant community structure than the proximity from edges.

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With the intense debate, in Brazil, between landowners and public agencies about the amount of area with forest cover needed in different regions, there is an increase of the need for provision of technical data used as a basis for decision making. One of the criteria to evaluate the effect of forest cover in protecting water resources is the soil loss, which leads to several consequences on the environment, including the silting of the rivers. Therefore, this study aimed to evaluate the reduction in the soil loss in micro watersheds with different reliefs, size and location of forest cover, in the Corumbataí River watershed, in the state of São Paulo, using the Revised Universal Soil Loss Equation (RUSLE) in a GIS environment. For this study, 18 watersheds in three degrees of slope were selected, and 20 scenarios for land-use were established, by analyzing the influence of the PPA size, and the size and the location of the Legal Reserve. The results showed that: a) the effect of forest cover in reducing annual soil loss varies depending on the average slope of the watershed; b) the PPA width must be determined taking into account the slope of the watershed; c) the Legal Reserve must be located along the PPA. These provide better results in reducing annual soil loss.