110 resultados para SOUTH-CENTRAL BRAZIL


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We describe and illustrate Paepalanthus sphaeroides (Eriocaulaceae, Paepalanthoideae) from the Mantiqueira Range in South-eastern Brazil and compare it with the morphologically most similar species: Paepalanthus aequalis and Paepalanthus eriophaeus. Paepalanthus sphaeroides has unique membranaceous sheaths tightly adpressed to the scapes, patent involucral bracts slightly surpassing the capitula, and sepals of the staminate flowers fused from the base to the middle as distinctive characteristics. Comments on morphological variation, geographical distribution, ecology, conservation status, as well as a distribution map, line drawings, and photos are provided.

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Leaf and wood plasticity are key elements in the survival of widely distributed plant species. Little is known, however, about variation in stomatal distribution in the leaf epidermis and its correlation with the dimensions of conducting cells in wood. This study aimed at testing the hypothesis that Podocarpus lambertii, a conifer tree, possesses a well-defined pattern of stomatal distribution, and that this pattern can vary together with the dimensions of stem tracheids as a possible strategy to survive in climatically different sites. Leaves and wood were sampled from trees growing in a cold, wet site in south-eastern Brazil and in a warm, dry site in north-eastern Brazil. Stomata were thoroughly mapped in leaves from each study site to determine a spatial sampling strategy. Stomatal density, stomatal index and guard cell length were then sampled in three regions of the leaf: near the midrib, near the leaf margin and in between the two. This sampling strategy was used to test for a pattern and its possible variation between study sites. Wood and stomata data were analysed together via principal component analysis. The following distribution pattern was found in the south-eastern leaves: the stomatal index was up to 25 higher in the central leaf region, between the midrib and the leaf margin, than in the adjacent regions. The inverse pattern was found in the north-eastern leaves, in which the stomatal index was 10 higher near the midrib and the leaf margin. This change in pattern was accompanied by smaller tracheid lumen diameter and length. Podocarpus lambertii individuals in sites with higher temperature and lower water availability jointly regulate stomatal distribution in leaves and tracheid dimensions in wood. The observed stomatal distribution pattern and variation appear to be closely related to the placement of conducting tissue in the mesophyll.

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Albatrosses and petrels (Procellariiformes) are migratory oceanic birds of considerable conservational interest. Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed in the subcutaneous fat, liver and muscle of 100 birds belonging to eight species of Procellariiformes collected during their migration period in southern Brazil, one of the most important feeding areas for these species. Although the profiles of PCBs and OCPs were similar among the individuals, with predominance of penta, hexa and heptachlorobiphenyls and p'p-DDE, organochlorine concentrations exhibited a high degree of intra-species variability. The influence of body condition during the migration period in the distribution of organochlorine contaminants was also evaluated, showing that it is a significant factor in the variation and redistribution of these compounds in the tissues of these birds. The intense use of lipid reserves associated to the contamination from organochlorine compounds could be a troubling factor for seabirds with extended breeding periods and that spend most of their lives at sea migrating long distances, such as most of Procellariiformes. Studies on contamination are necessary to improve the knowledge of the threats to these birds and their populations as well as to contribute with information about persistent organic pollutants in the South Atlantic marine environment.

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Southern Brazil is considered an area of low Hepatitis B endemicity, but some areas of higher endemicity have been described in the Southwest of Parana and Santa Catarina states. The aim of this study was to evaluate viral genotypes circulating throughout Parana state. PCR amplification and partial sequencing of the S gene was carried out in 228 samples from HBsAg positive candidate blood donors. Samples have been collected in seven different counties (Cascavel, Curitiba, Foz do Iguacu, Francisco Beltrao, Matinga Londrina and Paranagua). The most common HBV genotype in Parana state was D (82.9%; 189/228), followed by A (14.1%; 32/228). Genotypes F (1.3%; 3/228), C (1.3%; 3/228) and H (0.4%; 1/228) were also found. Distribution of genotypes was different in the studied counties, but genotype D was the most frequent in all of them. In Francisco Beltrao, all studied samples belonged to genotype D. The high prevalence of HBV genotype Din South of Brazil is explained by the intense migration of settlers from Europeans countries. Subgenotypes A1 and A2 were identified circulating in all cities where HBV/A was found. As observed in other areas of Brazil, HBV/A1 is more frequent than the HBV/A2 in Parana state and its presence was significantly larger in black and mulatto individuals. Genotype C was found only in individuals with Asian ancestry from Londrina and Maringa. Most HBV/F sequences identified in this study were classified as subgenotype F2a that was previously described in Brazil. The sole case of subgenotype F4 was from Foz do Iguacu city, near to Northern Argentina, where F4 is highly prevalent. The single genotype H sample was from Curitiba. This is the first case of this genotype described in Brazil. Further studies should be carried out to determine if more genotype H samples can be found in other populations from Brazil. (C) 2012 Elsevier B.V. All rights reserved.

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The occurrence of two alien alpheid shrimps of the genus Athanas Leach, 1814 [in Leach 1813-1814], the Indo-West Pacific A. dimorphus Ortmann, 1894 and the Eastern Atlantic A. nitescens (Leach, 1813 [in Leach 1813-1814]), on the coast of the state of So Paulo, Brazil, is reported. The presence of A. dimorphus extends the range of this species in the western Atlantic farther to the south in Brazil, whereas A. nitescens is reported for the first time in the western Atlantic, representing the second alien alpheid species on this side of the Atlantic and the twenty-first decapod crustacean introduced in Brazil. We provide morphological accounts of the material examined and illustrate the most important diagnostic characters of both species. An overview of the possible mechanisms of their introduction on the coast of So Paulo is also provided.

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Despite the general belief that the interaction between extrafloral nectaries (EFNs) and ants is mutualistic, the defensive function of EFNs has been poorly documented in South American savannas. In this article, we evaluate the potential impact of EFNs (benefits and costs) on two species of plants from the dry areas of Central Brazil, Anemopaegma album and Anemopaegma scabriusculum (Bignoniaceae). In particular, we characterize the composition of substances secreted by the EFNs, test whether EFNs attract ants, and whether ants actually present a defensive role, leading to reduced herbivory and increased plant fitness. Histochemical analyses indicated that EFNs from both species of Anemopaegma secrete an exudate that is composed of sugars, and potentially lipids and proteins. Furthermore, EFNs from both species were shown to present a significant role in ant attraction. However, contrary to common expectations, ants were not found to protect plants against herbivore attack. No effect was found between ant visitation and flower or fruit production in A. album, while the presence of ants led to a significant decrease in flower production in A. scabriusculum. These results suggest that EFNs might present a similar cost and benefit in A. album, and a higher cost than benefit in A. scabriusculum. Since the ancestor of Anemopaegma occupied humid forests and already presented EFNs that were maintained in subsequent lineages that occupied savannas, we suggest that phylogenetic inertia might explain the presence of EFNs in the species of Anemopaegma in which EFNs lack a defensive function.

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Since the beginning of the HIV epidemic, there has been a significant increase in the number of histoplasmosis cases in Ceara, a state in north-east Brazil. The lack of epidemiological data on the genotypes circulating in the north-east region shows the importance of more detailed studies on the molecular epidemiology of Histoplasma capsulatum var. capsulatum in this region. Different molecular techniques have been used to better characterize the genetic profile of H. capsulatum var. capsulatum strains. The aim of this study was to analyse the genetic diversity of H. capsulatum var. capsulatum isolates in Fortaleza, the capital of Ceara, through the sequencing of the internal transcribed spacer (ITS)1-5.8S-ITS2 region, and establish the molecular profile of these isolates, along with strains from south-east Brazil, by RAPD analysis, featuring the different clusters in those regions. The isolates were grouped into two clusters. Cluster 1 included strains from the south-east and north-east regions with separation of isolates into three distinct subgroups (subgroups 1a, 1 b and 1 c). Cluster 2 included only samples from north-east Brazil. Sequencing of the ITS1 -5.8S-ITS2 region allowed the detection of two major clades, which showed geographical correlation between them and their subgroups. Therefore, it can be concluded that the H. capsulatum var. capsulatum isolates from Ceara have a high degree of genetic polymorphism. The molecular data also confirm that populations of this fungus are composed of different genotypes in Brazil and worldwide.

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Glacigenic diamictite successions of the Macaubas Group are widespread in the western domain of the Aracuai orogen, east of the Sao Francisco craton (Brazil). Diamictites also occur on this craton and in the African counterpart of the Aracuai orogen, the West Congo belt. Detrital zircon grains from the matrix of diamictites and sandstones from the Macaubas Group were dated by the U-Pb SHRIMP technique. The geochronological study sets the maximum depositional age of the glacial diamictites at 900 Ma, and indicates multiple sources for the Macaubas basin with ages ranging from 900 to 2800 Ma. Sm-Nd T-DM model ages, determined on whole rock samples, range from 1.8 Ga to 2.5 Ga and get older up-section. Comparison of our data with those from the cratonic area suggest that these glacial deposits can be correlated to the Jequitai and Carrancas diamictites in the Sao Francisco craton, and to the Lower Mixtite Formation of the West Congolian Group, exposed in Africa. The 900-1000 Ma source is most probably represented by the Zadinian-Mayumbian volcanic rocks and related granites from the West Congo belt. However, one of the most voluminous sources, with ages in the 1.1-1.3 Ga interval, has not been detected in the Sao Francisco-Congo craton. Possible sources for these grains could occur elsewhere in Africa, or possibly from within the Brasilia Belt in western central Brazil. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

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The Apiai gabbro-norite is a massive fine-grained Neoproterozoic intrusion emplaced in a core of synformal structure that deforms low-grade marine metasedimentary rocks of the Ribeira Belt of south-eastern Brazil. The lack of visible magmatic layering or any internal fabric has been a major limitation in deciding whether the emplacement occurred before or after the regional folding. To assist in the tectonic interpretations, we combine low-field anisotropy of magnetic susceptibility (AMS) and silicate shape preferred orientation (SPO) to reveal the internal structure of the mafic intrusion. Magnetic data indicate a mean susceptibility of about 10(-2) SI and a mean anisotropy degree (P) of about 1.08, essentially yielded by titanomagnetite. The magnetic and silicate foliations for P >= 1.10 are parallel to each other, while the lineations tend to scatter on the foliation plane, in agreement with the dominant oblate symmetry of the AMS and SPO ellipsoids. For lower P values, the magnetic and silicate fabrics vary from coaxial to oblique, and for P <= 1.05, their shapes and orientations can be quite distinct. The crystal size distribution (CSD) of plagioclase for P > 1.05 is log linear, in agreement with a bulk simple crystallisation history. These results combined show that for a strong SPO, corresponding to a magnetic anisotropy above 1.10, AMS is a reliable indicator of the magmatic fabric. They indicate that the Apiai gabbro-norite consists of sill-like body that was inclined gently to the north by the regional folding.

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The paleoclimatic record of Jureia Paleolagoon, coastal southeastem Brazil, includes cyclic and gradual changes with different intensities and frequencies through geological time, and it is controlled by astronomical, geophysical, and geological phenomena. These variations are not due to one single cause, but they result from the interaction of several factors, which act at different temporal and spatial scales. Here, we describe paleoenvironmental evidence regarding climatic and sea level changes from the last 9400 cal yr BP at the Jureia Paleolagoon - one of the main groups of protected South Atlantic ecosystems. Geochemical evidences were used to identify anomalies from multi-proxy analyses of a paleolagoon sediment core. The anomalies of centennial scale were correlated to climate and transgression-regression cycles from the Holocene period. Decadal scale anomalous oscillations in the Quaternary paleolagoon sediments occur between 9400 and 7500 cal yr BP, correlated with long- and short-term natural events, which generated high sedimentation rates, mainly between 8385 and 8375 cal yr BP (10 cm/yr). Our results suggest that a modem-day short-duration North Atlantic climatic event, such as the 82 ka event, could affect the environmental equilibrium in South America and intensify the South American Summer Monsoon. (C) 2011 University of Washington. Published by Elsevier Inc. All rights reserved.

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The Neotropical genus Carrerapyrgota Aczel is restricted to the South America (Brazil and Argentina). The genus is composed of two previously described species, which are revised herein: C. miliaria Aczel and C. personata (Lutz & Lima). Two new Brazilian species are described: C. aczeli from Sao Paulo and C. bernardii from Bahia. Illustrations of the external morphology of adults and male and female terminalia are also included. An identification key to the species is presented, as well as a brief discussion of the biology and distribution of the genus.

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In tropical forests, the environmental heterogeneity can provide niche partitioning at local scales and determine the diversity and plant species distribution. Thus, this study aimed to investigate the variations of tree species structure and distribution in response to relief and soil profile features in a portion of the largest remnant of Brazilian Atlantic rain forest. All trees >= 5 cm diameter at breast height were recorded in two 0.99 ha plots. Topographic survey and a soil characterization were accomplished in both plots. Topsoil samples (0-20 cm) were taken from 88 quadrats and analyzed for chemical and particle size properties. Differences for both diversity and tree density were identified among three kinds of soils. A canonical correspondence analysis (CCA) indicated that the specific abundance varied among the three kinds of soils mapped: a shallow Udept - Orthent / Aquent gradient, probably due to differences in soil drainage. Nutrient content was less likely to affect tree species composition and distribution than relief, pH, Al3+, and soil texture. Some species were randomly distributed and did not show restriction to relief and soil properties. However, preferences in niche occupation detected in this study, derived from the catenary environments found, rise up as an important explanation for the high tree species diversity in tropical forests.

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A full checklist of the species of Telebasis Selys, 1865, housed in the Brazilian collections Colecao Entomologica Prof. Jose Alfredo Pinheiro Dutra, Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio do Janeiro (DZRJ), and Museu de Zoologia, Universidade de Sao Paulo (MZSP) is presented. A total of 325 specimens representing 19 species were studied. Ten new records for Brazilian States were found for T. carmesina Calvert, 1909 (Rio de Janeiro and Rio Grande do Sul), T. corallina (Selys, 1876) (Pernambuco), T. demarara (Williamson, 1917) (Maranhao), T. filiola (Perty, 1834) (Paraiba and Santa Catarina), T. gigantea Daigle, 2002 (Sao Paulo), T. inalata (Calvert, 1961) (Mato Grosso do Sul), T. pallida Machado, 2010 (Goias) and T. obsoleta (Selys, 1876) (Mato Grosso do Sul), as well as a new record of T. carminita Calvert, 1909 for Suriname. Telebasis pallida Machado, 2010 is redescribed and diagnosed based on 14 males collected near the type locality, and its genital ligula is described and illustrated for the first time. Furthermore, the status of the three species of the Telebasis racenisi Bick & Bick, 1995 complex is evaluated. Of these, Telebasis pareci Machado, 2010 syn. n. is proposed as junior subjective synonym of Telebasis lenkoi Machado, 2010, and a possible synonymy among the three species is discussed under T. racenisi. ((c) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

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As one of the few areas apt for horticulture in Northern Chile's arid landscape, the prehistory of the Atacama oases is deeply enmeshed with that of the inter-regional networks that promoted societal development in the south central Andes. During the Middle Horizon (AD 5001000), local populations experienced a cultural apex associated with a substantial increase in inter-regional interaction, population density, and quantity and quality of mortuary assemblages. Here, we test if this cultural peak affected dietary practices equally among the distinct local groups of this period. We examine caries prevalence and the degree of occlusal wear in four series recovered from three cemeteries. Our results show a reduction in the prevalence of caries for males among an elite subsample from Solcor 3 and the later Coyo 3 cemeteries. Dental wear tends to increase over time with the Late Middle Horizon/Late Intermediate Period cemetery of Quitor 6 showing a higher average degree of wear. When considered in concert with archaeological information, we concluded that the Middle Horizon was marked by dietary variability wherein some populations were able to obtain better access to protein sources (e.g., camelid meat). Not all members of Atacameno society benefited from this, as we note that this dietary change only affected men. Our results suggest that the benefits brought to the San Pedro oases during the Middle Horizon were not equally distributed among local groups and that social status, relationship to the Tiwanaku polity, and interment in particular cemeteries affected dietary composition. Am J Phys Anthropol, 2012. (C) 2012 Wiley Periodicals, Inc.

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Background: Sugarcane cultivation plays an important role in Brazilian economy, and it is expanding fast, mainly due to the increasing demand for ethanol production. In order to understand the impact of sugarcane cultivation and management, we studied sugarcane under different management regimes (pre-harvest burn and mechanical, unburnt harvest, or green cane), next to a control treatment with native vegetation. The soil bacterial community structure (including an evaluation of the diversity of the ammonia oxidizing (amoA) and denitrifying (nirK) genes), greenhouse gas flow and several soil physicochemical properties were evaluated. Results: Our results indicate that sugarcane cultivation in this region resulted in changes in several soil properties. Moreover, such changes are reflected in the soil microbiota. No significant influence of soil management on greenhouse gas fluxes was found. However, we did find a relationship between the biological changes and the dynamics of soil nutrients. In particular, the burnt cane and green cane treatments had distinct modifications. There were significant differences in the structure of the total bacterial, the ammonia oxidizing and the denitrifying bacterial communities, being that these groups responded differently to the changes in the soil. A combination of physical and chemical factors was correlated to the changes in the structures of the total bacterial communities of the soil. The changes in the structures of the functional groups follow a different pattern than the physicochemical variables. The latter might indicate a strong influence of interactions among different bacterial groups in the N cycle, emphasizing the importance of biological factors in the structuring of these communities. Conclusion: Sugarcane land use significantly impacted the structure of total selected soil bacterial communities and ammonia oxidizing and denitrifier gene diversities in a Cerrado field site in Central Brazil. A high impact of land use was observed in soil under the common burnt cane management. The green cane soil also presented different profiles compared to the control soil, but to at a lesser degree.