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Search Results: 1 - 10 of 880614 matches for " Andreia M. S. Fran?a "
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Satellite Images Applied to Assess the Influence of Amazon River Seasonal Dynamic on the Floodplain Lake Morphology  [PDF]
Andreia M. S. Frana, Teresa G. Florenzano, Evlyn M. L. M. Novo
Open Journal of Ecology (OJE) , 2014, DOI: 10.4236/oje.2014.413070
Abstract: The objective of this study is to assess the influence of the Amazon River seasonal dynamic on floodplain lake morphology. The study area includes the Amazon River floodplain reach encompassed by the Madeira and Tapajós River confluences. Products from the Global Rain Forest Mapping (GRFM) and Moderate Resolution Imaging Spectroradiometer (MODIS) were used to derive variables such as lake size, shape and number. The main steps in the research were: data base implementation, legend definition, image processing (merge, segmentation, classification and edition), morphological mapping and quantitative assessment. Four classes of lacustrine morphology were defined in this study: circular/elliptical, elongated, composite, and dendritic. The result showed that 1) the lake class increased 18.38% from the low- to high-water period; 2) there was a reduction in the total number of lakes from low to high water; 3) the most common lake type was the circular/elliptical; and 4) better results were obtained integrating SAR and optical sensors.
Estimates for Carbon Stocks in Soil under Humid Grassland Areas in the Federal District of Brazil  [PDF]
Andreia M. S. Frana, Rodrigo J. O. Paiva, Edson E. Sano, Arminda M. Carvalho
Open Journal of Ecology (OJE) , 2014, DOI: 10.4236/oje.2014.413066
Abstract: The soils that lay below humid ecosystems are characterized as being significant holders of carbon. Because of the great susceptibility of this type of environment to anthropic changes, expressive quantities of carbon stored in the soil can be released into the atmosphere. In the Cerrado biome (Brazil), only a few types of vegetation have had carbon storage levels in their soil estimated. The main purpose of this study was to obtain basic quantitative parameters for carbon storage and to identify the general aspects of soil in regions where there exists Humid Grasslands (Campo Limpo úmido), a kind of humid area phytophysiognomy found in the Cerrado. We selected 6 regions of the Federal District with this kind of vegetation formation, characterized by low anthropic impact and located either in the interior or in the proximity of specially protected areas. In each one of the sampled regions, we marked a transect with 4 equidistant points and collected material at 7 different levels of depth: 0 - 5, 5 - 10, 10 - 20, 20 - 30, 30 - 40, 40 - 50 and 50 - 60 cm. We obtained 168 samples, with 84 related to Humid Grassland areas in gleysols and 84 samples related to areas in plinthosols—types of soil dominant in this environment. We determined the texture, bulk density and concentration of nitrogen and carbon at each depth. The average concentration of carbon for Humid Grassland areas was 55.19 g.kg-1, with an average of 61.65 g.kg-1 for Gleysols and 48.73 g.kg-1 for Plinthosols. The soil samples displayed distinct textural differences between gleysols and plinthosols. There were no significant differences in soil density (0.75 kg.dm-3 for Gleysols and 0.72 kg.dm-3 for Plinthosols). The average concentration of nitrogen was 20.66 g.kg-1, with 23.98 g.kg-1 for Gleysols and 17.34 g.kg-1 for Plinthosols. The average carbon storage for Humid Grassland areas, down to 60 cm deep, was 244.17 mg C ha-1 and the total estimated stock for these areas in the Federal District was 206.71 Gg.C. In general, the samples obtained in gleysols showed a carbon content and nitrogen level superior to those in plinthosols, although a greater sampling effort is needed to confirm the differences observed. The density values of stored carbon in the soil beneath Humid Grassland areas proved to be superior to those values observed for other types of vegetation typical for the Cerrado environment.
Abundance and spatial-temporal distribution of the family Portunidae (Crustacea, Decapoda) in the Curu á estuary on the northern coast of Brazil
Andreia Barbosa das Nevis,J. M. Martinelli,A. S. S. Carvalho,V. J. I. Nahum
Brazilian Journal of Aquatic Science and Technology , 2009,
Abstract: Species composition, abundance and distribution patterns of the family Portunidae in the Curu á estuary in the northeastern portion of the state of Pará (northern Brazil) were studied bimonthly from July 2003 to July 2004. Samples were taken with a wing trawl net during the day at ebb tide during last quarter moon. A total of 427 individuals were collected, comprising three species: Callinectes bocourti, Callinectes danae and Callinectes ornatus. C. danae was the dominant species (56%). C. bocourti demonstrated a preference for the rainy season and C. ornatus preferred the dry season. C. danae was present in both seasons. The results indicate that variation in salinity and pH related to season (dry and rainy) are considered determinant factors for the distribution of C. bocourti and C. ornatus.
Children Safety Devices in Brazil—Why Do People Don’t Use Them after the Law?  [PDF]
S. C. V. Abib, A. M. Fran?óia, F. Ricci, M. V. B. Cezillo, B. R. Müller
Journal of Transportation Technologies (JTTs) , 2014, DOI: 10.4236/jtts.2014.43021
Abstract:

Introduction: Children safety car devices decrease injuries and death in children. A survey conducted in Brazil in 2009 revealed that only 36.1% of children safely transported. In 2010, a Brazilian law was implemented, obligating the use of safety devices. The aim of this study is to evaluate the use of such devices after the law and the eventual reasons for non-use. Methods: A significant sample of Brazilian population aged 18 years or more, which normally carry children until 10 years old answered a survey between August 16 and 25, 2012. The study was conducted in two phases. The first one aimed to raise the proportion and profile of the target population, while the second investigated the children car safety device use (or not). Results: 622 interviews. Children’s transporters are young males (57%), living in a metropolitan area in the South region, concerned about safety and law supervision, with greater education level and income than non-transporters (31%) who are male with lack of information, living in a non-metropolitan area of the Northeast region that would be motivated to use the device by effective law fiscalization or threat of an accident. Conclusion: Two years after the law it is observed that education, income, age, gender and region of origin influence the use/non-use of the safety seats in Brazil. The accident threat and fiscalization are the main reasons for using the device, showing that the lack of information impairs the democratization of its use and the prevention culture has to be enhanced in the country.

Catalytic Performance of Ceria Nanorods in Liquid-Phase Oxidations of Hydrocarbons with tert-Butyl Hydroperoxide
Andreia G. Macedo,Sílvia E. M. Fernandes,Anabela A. Valente,Rute. A. S. Ferreira,Luís D. Carlos,Jo?o Rocha
Molecules , 2010, DOI: 10.3390/molecules15020747
Abstract: The CeO2 nanorods (CeNR) promote the oxidation of ethylbenzene (PhEt) and cyclohexene with t-BuOOH, at temperatures as low as 55 oC. For both substrates the saturated C-H bonds are preferentially activated over the unsaturated ones. The catalyst seems fairly stable towards leaching phenomena. The liquid-phase oxidation catalysis may be associated with the Ce3+/Ce4+ inter-conversion in the one-electron redox processes mediating the formation of tert-butyl-(per)oxy radicals. CeNR is very effective in H2O2 disproportionation. Pre-treatment of CeNR with H2O2 or t-BuOOH prior to the catalytic reaction enhances the reaction rate of PhEt with t-BuOOH in comparison to CeNR. Textural characterization and spectroscopic studies suggest that catalytic activation is associated to defect sites.
Effects of flow reduction and spillways on the composition and structure of benthic macroinvertebrate communities in a Brazilian river reach
Maroneze, DM.;Tupinambás, TH.;Frana, JS.;Callisto, M.;
Brazilian Journal of Biology , 2011, DOI: 10.1590/S1519-69842011000400008
Abstract: dams are a major threat to aquatic biological diversity. by altering the natural flow of rivers, dams modify fluvial habitats, making them unsuitable for the growth and reproduction of many aquatic species. the aim of this study was to evaluate the effects of a reduced flow reach (rfr) on benthic macroinvertebrate communities. benthic macroinvertebrates were collected at six sites downstream of the amador aguiar power plant i before (lotic phase) and after (semi-lentic phase) araguari river mean flow was reduced from 346 to 7 m3.s-1. changes in macroinvertebrates richness, diversity and total biomass were not observed. ablabesmyia, tanytarsus (chironomidae, diptera), leptoceridae and polycentropodidae (trichoptera) densities significantly increased the first year after flow reduction and the construction of spillways (t-test; p < 0.05). an analysis of similarity (anosim) showed statistical differences in taxonomical composition despite considerable overlap in communities between the lotic and semi-lentic phases (r = 0.3; p < 0.01). in both phases, the macroinvertebrates were characterised by the dominance of groups tolerant to human disturbance (e.g., chironomidae, ceratopogonidae and oligochaeta) and by the presence of the alien bivalve species corbicula fluminea (veneroidae), suggesting that the river was already degraded before the hydraulic modifications. since the 1980s, the araguari river has been continuously subjected to human pressures (e.g., cascade dams, urbanization and replacement of native vegetation by pasture and crops). these activities have led to impoverishment of biological communities and have consequently altered the ecosystem.
Transport functions for hypercubic and Bethe lattices
Louis-Fran?ois Arsenault,A. -M. S. Tremblay
Physics , 2013, DOI: 10.1103/PhysRevB.88.205109
Abstract: In calculations of transport quantities, such as the electrical conductivity, thermal conductivity, Seebeck, Peltier, Nernst, Ettingshausen, Righi-Leduc, or Hall coefficients, sums over the Brillouin zone of wave-vector derivatives of the dispersion relation commonly appear. When the self-energy depends only on frequency, as in single-site dynamical mean-field theory, it is advantageous to perform these sums once and for all. We show here that in the case of a hypercubic lattice in d dimensions, the sums needed for any of the transport coefficients can be expressed as integrals over powers of the energy weighted by the energy-dependent non-interacting density of states. It is also shown that our exact expressions for the transport functions can be obtained from differential equations that follow from sum rules. By substituting the Bethe lattice density of states, one can obtain the previously unknown transport function for the electrical or thermal Hall coefficients and for the Nernst coefficient of the Bethe lattice.
Higher number of Helicobacter pylori CagA EPIYA C phosphorylation sites increases the risk of gastric cancer, but not duodenal ulcer
Sérgio A Batista, Gifone A Rocha, Andreia MC Rocha, Ivan EB Saraiva, M?nica MDA Cabral, Rodrigo C Oliveira, Dulciene MM Queiroz
BMC Microbiology , 2011, DOI: 10.1186/1471-2180-11-61
Abstract: The number of EPIYA C segments was significantly associated with the increased risk of gastric carcinoma (OR = 3.08, 95% CI = 1.74 to 5.45, p < 10-3) even after adjustment for age and gender. Higher number of EPIYA C segments was also associated with gastric atrophy (p = 0.04) and intestinal metaplasia (p = 0.007). Furthermore, patients infected by cagA strains possessing more than one EPIYA C segment showed decreased serum levels of pepsinogen I in comparison with those infected by strains containing one or less EPIYA C repeat. Otherwise, the number of EPIYA C segments did not associate with duodenal ulcer.Our results demonstrate that infection with H. pylori strains harbouring more than one CagA EPIYA C motif was clearly associated with gastric cancer, but not with duodenal ulcer.Higher number of EPIYA C segments was also associated with gastric precancerous lesions as demonstrated by histological gastric atrophic and metaplastic changes and decreased serum levels of pepsinogen I.Helicobacter pylori colonizes the stomach of more than half of the world's population and is associated with development of complications such as peptic ulcer disease, gastric cancer, and gastric mucosa-associated lymphoid tissue lymphoma [1-4]. The factors that lead few individuals to develop the associated diseases, while the majority of infected people remain asymptomatic, are unknown, but they have been subject of intense research. Among the host factors, cytokine gene polymorphisms were shown to increase the risk of gastric cancer, specifically IL1B-31, IL1RN, and TNFA-307 single nucleotide polymorphisms in European populations, and IL1RN in a Brazilian population [5-9]. Pathogen strain-specific factors have been strongly investigated. Among them, the CagA protein is accepted as a risk factor for both peptic ulcer disease and gastric cancer [5,10-12]. In a study of our group, infection by H. pylori cagA-positive strains had an odds ratio (OR) of 11.9 for gastric cancer, after adjusti
Partial sequence and toxic effects of granulitoxin, a neurotoxic peptide from the sea anemone Bunodosoma granulifera
Santana A.N.C.,Leite A.B.,Frana M.S.F.,Frana L.
Brazilian Journal of Medical and Biological Research , 1998,
Abstract: A neurotoxic peptide, granulitoxin (GRX), was isolated from the sea anemone Bunodosoma granulifera. The N-terminal amino acid sequence of GRX is AKTGILDSDGPTVAGNSLSGT and its molecular mass is 4958 Da by electrospray mass spectrometry. This sequence presents a partial degree of homology with other toxins from sea anemones such as Bunodosoma caissarum, Anthopleura fuscoviridis and Anemonia sulcata. However, important differences were found: the first six amino acids of the sequence are different, Arg-14 was replaced by Ala and no cysteine residues were present in the partial sequence, while two cysteine residues were present in the first 21 amino acids of other toxins described above. Purified GRX injected ip (800 μg/kg) into mice produced severe neurotoxic effects such as circular movements, aggressive behavior, dyspnea, tonic-clonic convulsion and death. The 2-h LD50 of GRX was 400 ± 83 μg/kg.
Phenolic Compounds Influence Seed Dormancy of Palicourea rigida H.B.K. (Rubiaceae), a Medicinal Plant of the Brazilian Savannah  [PDF]
Marielle C. Inácio, Rita Maria Moraes, Patrícia C. Mendon?a, Lucas J. F. Morel, Suzelei C. Frana, Bianca W. Bertoni, Ana M. S. Pereira
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.41017
Abstract: Palicourea rigida H.B.K. (Rubiaceae), a medicinal species commonly known as douradinha, has wide distribution across ecosystems in Central and South America. This species exhibits seed dormancy delaying germination until optimal conditions for seedling growth and development are in place. While dormancy ensures species survival, it also presents a technical problem for developing P. rigidas plant production program. Thus, the objective of this study was to investigate if secondary metabolites present in seeds influence the seed dormancy of P. rigida. Mature fruits were harvested from the native habitat, in the savanna region of the State of Minas Gerais during February 2009, 2010 and 2011. The content of phenolic compounds in the seed of P. rigida was measured, and the allelopathic effects were assessed using the germination of lettuces as model to detect phytotoxicity. The P. rigida seeds geminated at rates varying between 7% and 31% with a Seed Germination Index (SGI) of 0.09. Data suggest that the phenolic compounds present in the seeds may be
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