999 resultados para Northeastern Brazil
Resumo:
The triatomine fauna distribution and the natural infection by Trypanosoma cruzi was evaluated aiming the comprehension of the transmission dynamics of this parasite in the countryside of the State of Rio Grande do Norte. Additionally, the research for Trypanosoma rangeli was also investigated. The captures of triatomines were performed at sylvatic, peridomicile and domicile environments at different municipalities of the central and western mesoregions of this state. The insects were identified and examined by direct method, xenoculture and PCR to detect T. cruzi. The detection of T. rangeli was performed by direct examination of the hemolymph and multiplex PCR of 151 positive specimens for T. cruzi. Of 824 captured insects, the species were distributed in Triatoma brasiliensis (66.4%), Triatoma pseudomaculata (18.2%), Panstrongylus lutzi (12.7%) and Rhodnius nasutus (2.7%), and T. brasiliensis was found in most of the evaluated municipalities. The species were captured at nymph and adult stages, except P. lutzi, exclusively in adult stage. In the sylvatic environment were captured T. brasiliensis (57%), P. lutzi (28%) and T. pseudomaculata (15%) species. At the peridomicile environment were identified T. brasiliensis (74%), T. pseudomaculata (21%) and R. nasutus (5.0%), while in the intradomicile was found only T. brasiliensis. The infection rate of triatomines by T. cruzi was 30.4%, P. lutzi showed highest rate (78%), followed by T. brasiliensis (24.4%), T. pseudomaculata (22.6%) and R. nasutus (4.5%). Infected triatomines indexes at silvatic, peridomicile and domicile environments were of 41.8%, 20.1% and 50.0%, respectively. T. rangeli was only detected by multiplex PCR in 2.6% (4/151) of examined insects, of these 4.4% (3/67) were T. brasiliensis and 1.5% (1/63) P. lutzi species. The data showed that the positivity of P. lutzi allied to its ability to invade domicile attracted by light, suggests a likely participation of this insect between epidemiological transmission cycles of T. cruzi. T. brasiliensis was the only specie present in all environments, what reinforces its importance related to the capacity for adapting to the domestic environment, potential as a vector, and maintenance of sylvatic and domestic transmissions cycles in the semiarid, indicating the necessity of continuous epidemiological surveillance. The presence of T. rangeli in T. brasiliensis and P. lutzi was first recorded in rural zone of this State, broadening the area of occurrence of this protozoan in northeastern Brazil.
Resumo:
The triatomine fauna distribution and the natural infection by Trypanosoma cruzi was evaluated aiming the comprehension of the transmission dynamics of this parasite in the countryside of the State of Rio Grande do Norte. Additionally, the research for Trypanosoma rangeli was also investigated. The captures of triatomines were performed at sylvatic, peridomicile and domicile environments at different municipalities of the central and western mesoregions of this state. The insects were identified and examined by direct method, xenoculture and PCR to detect T. cruzi. The detection of T. rangeli was performed by direct examination of the hemolymph and multiplex PCR of 151 positive specimens for T. cruzi. Of 824 captured insects, the species were distributed in Triatoma brasiliensis (66.4%), Triatoma pseudomaculata (18.2%), Panstrongylus lutzi (12.7%) and Rhodnius nasutus (2.7%), and T. brasiliensis was found in most of the evaluated municipalities. The species were captured at nymph and adult stages, except P. lutzi, exclusively in adult stage. In the sylvatic environment were captured T. brasiliensis (57%), P. lutzi (28%) and T. pseudomaculata (15%) species. At the peridomicile environment were identified T. brasiliensis (74%), T. pseudomaculata (21%) and R. nasutus (5.0%), while in the intradomicile was found only T. brasiliensis. The infection rate of triatomines by T. cruzi was 30.4%, P. lutzi showed highest rate (78%), followed by T. brasiliensis (24.4%), T. pseudomaculata (22.6%) and R. nasutus (4.5%). Infected triatomines indexes at silvatic, peridomicile and domicile environments were of 41.8%, 20.1% and 50.0%, respectively. T. rangeli was only detected by multiplex PCR in 2.6% (4/151) of examined insects, of these 4.4% (3/67) were T. brasiliensis and 1.5% (1/63) P. lutzi species. The data showed that the positivity of P. lutzi allied to its ability to invade domicile attracted by light, suggests a likely participation of this insect between epidemiological transmission cycles of T. cruzi. T. brasiliensis was the only specie present in all environments, what reinforces its importance related to the capacity for adapting to the domestic environment, potential as a vector, and maintenance of sylvatic and domestic transmissions cycles in the semiarid, indicating the necessity of continuous epidemiological surveillance. The presence of T. rangeli in T. brasiliensis and P. lutzi was first recorded in rural zone of this State, broadening the area of occurrence of this protozoan in northeastern Brazil.
Resumo:
The present study aims the characterization of thermally affected carbonate rocks from Jandaíra Formation in contact with Paleogene and Neogene basic intrusions in the region of the Pedro Avelino and Jandaíra municipalities (RN), northeastern Brazil. For this study, field, petrographic, x-ray diffraction, electron microprobe, and whole rock litogeochemistry data of carbonates were undertaken. The thermally unaffected limestones are classified like wackstones, grainstones and packstones. They may constitute carbonates grains of benthic foraminifera, echinoderm spines, ostracods, algae, corals, bivalves, gastropods, peloids and intraclasts. The porosities are classified like vug, intraparticle, interparticle, intercrystal and moldic types. The major minerals are calcite, ankerite and dolomite; the detrital are montmorillonite, pyrite, limonite, quartz and microcline. The thermally affected limestones are very coarse to very fine-grained and light to dark gray color. The fossiliferous components totally disappear, and the porosity tends to disappear. With the data obtained, it can be inferred that the carbonate protoliths would be calciferous to dolomitic limestones, both with small amount of clay minerals. Crystalline carbonates from dolomitic protolith have rhombohedral calcite and iron oxides / hydroxides, making the rocks much darker. The carbonates from calciferous protolith have a wide variation of grain size according to the recrystallization degree, increasing toward contact with the basic bodies. In this group, it was identified the minerals lizardite and spinel in weakly to moderately affected samples, and spinel and spurrite in strongly affected rocks, as well as calcite, that occur everywhere. The geological context (shallow level diabase intrusions), the crystallization of the pyrometamorphic minerals spurrite and olivine, and comparison with diagrams from the literature allow estimating temperatures and pressures around 1050-1200 °C and 0.5-1.0 kbar, respectively, for PTOTAL=PCO2. The post-intrusion cooling would have afforded the releasing of metasomatic / hydrothermal fluids, allowing the opening of the metamorphic system, with possible contribution of chemical elements from host units (sandstones, shales) and from basic intrusions. This would induce hydration of previous phases, allowing the formation of serpentine, chlorite and brucite. The results discussed here reveal the strong influence of the heat from basic intrusions within the sedimentary pile. Whereas in the offshore portion of the basin occur sills with up to 1000 m thickness, the understanding of pyrometamorphism might be useful for understanding and measuring the thermally affected rocks.
Resumo:
The present study aims the characterization of thermally affected carbonate rocks from Jandaíra Formation in contact with Paleogene and Neogene basic intrusions in the region of the Pedro Avelino and Jandaíra municipalities (RN), northeastern Brazil. For this study, field, petrographic, x-ray diffraction, electron microprobe, and whole rock litogeochemistry data of carbonates were undertaken. The thermally unaffected limestones are classified like wackstones, grainstones and packstones. They may constitute carbonates grains of benthic foraminifera, echinoderm spines, ostracods, algae, corals, bivalves, gastropods, peloids and intraclasts. The porosities are classified like vug, intraparticle, interparticle, intercrystal and moldic types. The major minerals are calcite, ankerite and dolomite; the detrital are montmorillonite, pyrite, limonite, quartz and microcline. The thermally affected limestones are very coarse to very fine-grained and light to dark gray color. The fossiliferous components totally disappear, and the porosity tends to disappear. With the data obtained, it can be inferred that the carbonate protoliths would be calciferous to dolomitic limestones, both with small amount of clay minerals. Crystalline carbonates from dolomitic protolith have rhombohedral calcite and iron oxides / hydroxides, making the rocks much darker. The carbonates from calciferous protolith have a wide variation of grain size according to the recrystallization degree, increasing toward contact with the basic bodies. In this group, it was identified the minerals lizardite and spinel in weakly to moderately affected samples, and spinel and spurrite in strongly affected rocks, as well as calcite, that occur everywhere. The geological context (shallow level diabase intrusions), the crystallization of the pyrometamorphic minerals spurrite and olivine, and comparison with diagrams from the literature allow estimating temperatures and pressures around 1050-1200 °C and 0.5-1.0 kbar, respectively, for PTOTAL=PCO2. The post-intrusion cooling would have afforded the releasing of metasomatic / hydrothermal fluids, allowing the opening of the metamorphic system, with possible contribution of chemical elements from host units (sandstones, shales) and from basic intrusions. This would induce hydration of previous phases, allowing the formation of serpentine, chlorite and brucite. The results discussed here reveal the strong influence of the heat from basic intrusions within the sedimentary pile. Whereas in the offshore portion of the basin occur sills with up to 1000 m thickness, the understanding of pyrometamorphism might be useful for understanding and measuring the thermally affected rocks.
Resumo:
Recent endogenous processes provide dynamic movements in the lithosphere and generate the varied forms of relief, even in areas of passive continental margins, such as the research area of this work located in northeastern Brazil. The reactivation of Precambrian basement structures, after the breakup between South America and Africa in the Cretaceous played an important role in the evolution of basins, which provided generated forms of relief. These morphodynamic characteristics can be easily observed in marginal basins that exhibit strong evidence fault reactivations. The purpose of this study is to investigate the influence of morphotectonic processes in the landscape structuring of Paraíba Basin. Therefore, we used aeromagnetic, high–resolution images of the Shuttle Radar Topographic Mission–SRTM, structural geological data, deep well data and geological field data. Based on the results of the data was observed that some preexisting structures in the crystalline basement coincide with magnetic and topographic lineaments interpreted as fault reactivation of the Post–Miocene units in the Paraíba Basin. Faults that offset lithostratigraphic units provided evidence that tectonic activity associated with the deposition and erosion in the Paraíba Basin occurred from Cretaceous to the Quaternary. The neotectonic activity that occurred in Paraíba Basin was able to influence the deposition of sedimentary units and landforms. It indicates that the deposition of post–Cretaceous units was influenced by reactivation of Precambrian basement structures in this part of the Brazilian continental margin.
Resumo:
We compare a compilation of 220 sediment core d13C data from the glacial Atlantic Ocean with three-dimensional ocean circulation simulations including a marine carbon cycle model. The carbon cycle model employs circulation fields which were derived from previous climate simulations. All sediment data have been thoroughly quality controlled, focusing on epibenthic foraminiferal species (such as Cibicidoides wuellerstorfi or Planulina ariminensis) to improve the comparability of model and sediment core carbon isotopes. The model captures the general d13C pattern indicated by present-day water column data and Late Holocene sediment cores but underestimates intermediate and deep water values in the South Atlantic. The best agreement with glacial reconstructions is obtained for a model scenario with an altered freshwater balance in the Southern Ocean that mimics enhanced northward sea ice export and melting away from the zone of sea ice production. This results in a shoaled and weakened North Atlantic Deep Water flow and intensified Antarctic Bottom Water export, hence confirming previous reconstructions from paleoproxy records. Moreover, the modeled abyssal ocean is very cold and very saline, which is in line with other proxy data evidence.
Resumo:
The MAREDAT atlas covers 11 types of plankton, ranging in size from bacteria to jellyfish. Together, these plankton groups determine the health and productivity of the global ocean and play a vital role in the global carbon cycle. Working within a uniform and consistent spatial and depth grid (map) of the global ocean, the researchers compiled thousands and tens of thousands of data points to identify regions of plankton abundance and scarcity as well as areas of data abundance and scarcity. At many of the grid points, the MAREDAT team accomplished the difficult conversion from abundance (numbers of organisms) to biomass (carbon mass of organisms). The MAREDAT atlas provides an unprecedented global data set for ecological and biochemical analysis and modeling as well as a clear mandate for compiling additional existing data and for focusing future data gathering efforts on key groups in key areas of the ocean. The present data set presents depth integrated values of diazotrophs abundance and biomass, computed from a collection of source data sets.
Resumo:
The mid-Holocene (6000 calibrated years before present) is a key period in palaeoclimatology because incoming summer insolation was lower than during the late Holocene in the Southern Hemisphere, whereas the opposite happened in the Northern Hemisphere. However, the effects of the decreased austral summer insolation over South American climate have been poorly discussed by palaeodata syntheses. In addition, only a few of the regional studies have characterised the mid-Holocene climate in South America through a multiproxy approach. Here, we present a multiproxy compilation of mid-Holocene palaeoclimate data for eastern South America. We compiled 120 palaeoclimatological datasets, which were published in 84 different papers. The palaeodata analysed here suggest a water deficit scenario in the majority of eastern South America during the mid-Holocene if compared to the late Holocene, with the exception of northeastern Brazil. Low mid-Holocene austral summer insolation caused a reduced land-sea temperature contrast and hence a weakened South American monsoon system circulation. This scenario is represented by a decrease in precipitation over the South Atlantic Convergence Zone area, saltier conditions along the South American continental margin, and lower lake levels.
Resumo:
Abundant hydroclimatic evidence from western Amazonia and the adjacent Andes documents wet conditions during Heinrich Stadial 1 (HS1, 18-15 ka), a cold period in the high latitudes of the North Atlantic. This precipitation anomaly was attributed to a strengthening of the South American summer monsoon due to a change in the Atlantic interhemispheric sea surface temperature (SST) gradient. However, the physical viability of this mechanism has never been rigorously tested. We address this issue by combining a thorough compilation of tropical South American paleorecords and a set of atmosphere model sensitivity experiments. Our results show that the Atlantic SST variations alone, although leading to dry conditions in northern South America and wet conditions in northeastern Brazil, cannot produce increased precipitation over western Amazonia and the adjacent Andes during HS1. Instead, an eastern equatorial Pacific SST increase (i.e., 0.5-1.5 °C), in response to the slowdown of the Atlantic Meridional Overturning Circulation during HS1, is crucial to generate the wet conditions in these regions. The mechanism works via anomalous low sea level pressure over the eastern equatorial Pacific, which promotes a regional easterly low-level wind anomaly and moisture recycling from central Amazonia towards the Andes.
Resumo:
SOUSA,M.B.C. et al. Reproductive Patterns and Birth Seasonality in a South-American Breeding Colony of Common Marmosets, Callithrix jacchus. Primates, v.40, n.2, p. 327-336, Apr. 1999.
Resumo:
GAUDENCIO, Sale Mario; BORBA, Maria do Socorro de Azevedo. O cordel como fonte de informaçao: a vivacidade dos folhetos de cordeis no Rio Grande do Norte. Biblioonline, Joao Pessoa, v.6, n. 1, p.82-92, 2010.
Resumo:
XIMENES, Maria de Fátima Freire de Melo; MACIEL, Janaína Cunha; JERONIMO, Selma Maria Bezerra. Characteristics of the Biological Cycle of Lutzomyia evandroi Costa Lima & Antunes, 1936 (diptera: psychodidae) under experimental conditions. Memorias do Instituto Oswaldo Cruz, Rio de Janeiro, v.96, n.6, p.883-886, ago. 2001. Disponivel em:
Resumo:
Traçar o perfil socioeconômico dos pacientes com úlcera venosa. Método: estudo quantitativo, transversal e descritivo, realizado com 50 pessoas no ambulatório de clínica cirúrgica do Hospital Universitário Onofre Lopes/HUOL, localizado no município de Natal/RN/Nordeste do Brasil, utilizando-se um roteiro de entrevista. Os dados coletados foram tabulados e armazenados numa planilha do software Excel e analisadas pela estatística descritiva. O estudo foi aprovado pelo Comitê de Ética em Pesquisa, CAAE 0038.0.294.000-11. Resultados: idade média de 59,72 anos, 66% pertenciam ao sexo feminino, 60% possuíam companheiro, a média de estudos foi de 4,98 (±3,36) anos e a renda familiar 2,3 salários mínimos. Encontrou-se, portanto, o perfil de pessoas com úlcera venosa semelhante ao evidenciado na literatura. Conclusão: é imprescindível conhecer as características dessa clientela para desenvolver estratégias visando à melhoria de suas condições de saúde
Resumo:
SOUSA,M.B.C. et al. Reproductive Patterns and Birth Seasonality in a South-American Breeding Colony of Common Marmosets, Callithrix jacchus. Primates, v.40, n.2, p. 327-336, Apr. 1999.