136 resultados para Diferenças individuais


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This paper describes a sequential injection chromatography procedure for determination of picloram in waters exploring the low backpressure of a 2.5 cm long monolithic C18 column. Separation of the analyte from the matrix was achieved in less than 60 s using a mobile phase composed by 20:80 (v v-1) acetonitrile:5.0 mmol L-1 H3PO4 and flow rate of 30 μL s-1. Detection was made at 223 nm with a 40 mm optical path length cell. The limits of detection and quantification were 33 and 137 μg L-1, respectively. The proposed method is sensitive enough to monitor the maximum concentration level for picloram in drinking water (500 μg L-1). The sampling frequency is 60 analyses per hour, consuming only 300 μL of acetonitrile per analysis. The proposed methodology was applied to spiked river water samples and no statistically significant differences were observed in comparison to a conventional HPLC-UV method.

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The thermal behavior of two polymorphic forms of rifampicin was studied by DSC and TG/DTG. The thermoanalytical results clearly showed the differences between the two crystalline forms. Polymorph I was the most thermally stable form, the DSC curve showed no fusion for this species and the thermal decomposition process occurred around 245 ºC. The DSC curve of polymorph II showed two consecutive events, an endothermic event (Tpeak = 193.9 ºC) and one exothermic event (Tpeak = 209.4 ºC), due to a melting process followed by recrystallization, which was attributed to the conversion of form II to form I. Isothermal and non-isothermal thermogravimetric methods were used to determine the kinetic parameters of the thermal decomposition process. For non-isothermal experiments, the activation energy (Ea) was derived from the plot of Log β vs 1/T, yielding values for polymorph form I and II of 154 and 123 kJ mol-1, respectively. In the isothermal experiments, the Ea was obtained from the plot of lnt vs 1/T at a constant conversion level. The mean values found for form I and form II were 137 and 144 kJ mol-1, respectively.

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The aim of this study was to analyze the distribution and abundance of the fish fauna of Palmas bay on Anchieta Island in southeastern Brazil. Specimens were caught in the summer and winter of 1992, using an otter trawl at three locations in the bay. The specimens were caught in both the nighttime and daytime. Data on the water temperature and salinity were recorded for the characterization of the predominant water mass in the region, and sediment samples were taken for granulometric analysis. A total of 7 656 specimens (79 species), with a total weight of approximately 300 kg, were recorded. The most abundant species were Eucinostomus argenteus, Ctenosciaena gracilicirrhus, Haemulon steindachneri, Eucinostomus gula and Diapterus rhombeus, which together accounted for more than 73% of the sample. In general, the ecological indices showed no differences in the composition of species for the abiotic variables analyzed. The multivariate analysis showed that the variations in the distribution of the fish fauna were mainly associated with intra-annual differences in temperature and salinity, resulting from the presence of South Atlantic Central Water (SACW) in the area during the summer. The analysis also showed an association with the type of bottom and a lesser association with respect to the night/day periods.

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Concrete modules were deployed on the bottom of the 11, 18 and 30 meters isobaths along a cross-shelf hydrographic gradient off Paraná State, Southern Brazil, with the purpose of studying the colonization of sessile epilithic macroinvertebrates on artificial surfaces. After one year of submersion a total of 63 species of epilithic organisms were identified, dominated by Ostrea puelchana, Chthamalus bisinuatus, Balanus cf spongicola, Astrangia cf rathbuni, Didemnum spp, poryphers and bryozoans. Diversity index and percent cover at reef stations placed at 11, 18 and 30 meters isobaths were respectively 2.28 and 66.7%, 2.79 and 96.6% and 1.66 and 77.4%. Differences of general community structure among the three assemblages were not clearly related to the general environmental conditions at the bottom layers near the reef stations. Turbidity and larval abundance are discussed as important factors affecting colonization processes. Results indicate that depths between 15-20 meters are more suitable for the implementation of large scale artificial reef systems in the inner shelf off Paraná and, possibly, throughout the inner shelves off southern Brazil with similar hydrographic conditions.

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The occurrence, distribution and abundance of ichthyoplankton in Todos os Santos and Camamu Bays were analyzed based on four samplings (winter 2003, summer 2003, winter 2004 and summer 2005). Samples were obtained by surface horizontal hauls, using a 200-µm mesh conical-cylinder plankton net. The distribution and abundance of eggs indicate a remarkable seasonal and annual variation of spawning activity in the region, especially when the two summer campaigns are compared. In summer 2003 the highest quantitative values were recorded, especially for Camamu, where the maximum reached 106.56 eggs.m-3, with an overall average of 43.46 eggs.m-3 for the two areas. In summer 2005 values were relatively low, the overall average being 3.49 eggs.m-3. The larval taxonomic composition is characterized by the predominance of gobiids, with small variation from summer to winter. Considering all the campaigns and samplings undertaken in both areas, larvae of 11 families were identified: Engraulidae, Clupeidae, Mugilidae, Atherinopsidae, Hemiramphidae, Syngnathidae, Blenniidae, Carangidae, Gobiidae, Achiridae and Tetraodontidae.

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Extending from latitude 34ºS to 22ºS the Southern Brazilian shelf constitutes the only part of the Brazilian shelf with a subtropical to temperate environment. The studies on the different geological aspects of the area began in the 1960's and have recently been reassessed after studies related to the determination of the Economic Exclusive Zone. In terms of morphology, the Southern Brazilian shelf may be divided into three sectors, the São Paulo Bight, the Florianópolis-Mostardas Sector and the Rio Grande Cone, characterized by conspicuous differences in terms of geological determining factors, bathymetry, declivities and the presence of canyons and channels. Despite the existence of hundreds of radiocarbon datings the sea level changes curve of southern Brazil during the Last Glacial Cycle is still a matter of debate. A recent controversy on the Middle and late Holocene sea level changes curve raised the question of the amplitude of the oscillations which occurred in the period. Also, a few but relatively consistent radiocarbon datings suggest the occurrence of a high sea level during Isotope Stage 3. In terms of sedimentary cover the Southern Brazilian shelf exhibits a very strong hydrodynamic control, both latitudinal and bathymetrical. The sector southward from 25ºS is characterized by the influence of the plume of water carrying sediments originating from the Río de La Plata. Actually its presence is conspicuous up to 28ºS, with the area between this latitude and 25ºS constituting a transitional zone. In terms of bathymetry the outer shelf is marked by the "floor-polisher" effect of the Brazil Current, which is responsible for the maintenance of a relict facies in areas deeper than 100 meters.

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This study investigated the effect of environmental factors on the annual average zonation pattern of benthic macrofauna of sub-aerial profile of three exposed sandy beaches of Santa Catarina with different morphodynamic characteristics. Sampling was carried out between March 2000 and March 2001, with monthly frequency on reflective and dissipative morphodynamic extremes and bimonthly frequency on the intermediate state. Results showed that macrobenthic zonation presented marked differences across the morphodynamic spectrum. The main differences observed from reflective to dissipative conditions were: a) increase in the number of species in lower zones of the beach; b) expansion of zones characterized by high water content of sediment and c) increase in the overlapping of zones, mainly on lower levels of the beach. Canonical Correspondence Analysis related these differences to distinctive cross-shore gradients in sediment moisture levels, sediment reworking and mean grain size that exist across the morphodynamic spectrum, showing that it is important to analyze these environmental factors in studies conducted to investigate zonation on microtidal exposed sandy beaches.

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The results obtained in the August and December 2003, August 2004 and January 2005 oceanographic campaigns in the northern region of the Todos os Santos Bay (lat. 12º44.5'S; long. 038º35.00'W) between the Madre de Deus and Maré islands are analyzed. Instruments of continuous and discrete samplings were used to measure hydrographic properties currents and tides. The water mass of the northern region of the bay is forced by semidiurnal and mesotides of form number 0.08 and the lunar component M2 height was estimated at 91cm. The time series of the surface currents indicated movements in the N/S direction, forced by the tide with maximum magnitudes of 0.73 m.s-1 on the December 2003 campaign. However, in August 2004 the currents were dominated by the wind stress forcing, with a maximum speed of 1.85 m.s-1 and SE direction. Near the bottom, the influence of the tide is not as evident, with a decrease in intensity due to internal and bottom friction, with a maximum velocity of 0.17 m.s-1. The thermal and haline structures were weakly horizontally, as well as vertically stratified, with extreme values varying in the intervals 23ºC (August, 2004) to 28ºC (December, 2003) and 31.0 psu (August, 2003) to 36.0 psu (December, 2003), respectively. Some conclusions may be drawn from these results: i) The signs of the dilution of the fresh water discharges of the Caípe, Mataripe and São Paulo rivers in the region under the influence of the RLAM were observed only during the winter periods, but in the summer the region was flooded by waters of oceanic origin and the salinities above 36.0 indicated TW mass intrusion; ii) The N-S circulation near the RLAM is strongly dominated by the tide, and the importance of the M2 component was unequivocal, however, the E-W component presented some tidal modulation away from abrupt bottom topographical changes, and iii) The residual series, calculated as the difference between the original and modeled, is about ¼ of the original and confirmed its semidiurnal character.

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This study compared the arm regeneration frequencies in two different populations of Ophionereis reticulata (Say, 1825) in São Sebastião, Southeast Brazil and observed arm regeneration between age classes (juvenile and adults) and sexes (male and female). From the 1,170 individuals sampled, 1,089 (92.2%) showed signs of arm regeneration. The relative frequencies of regenerating arms in the two areas were not different (Baleeiro Isthmus: 91.3% and Grande Beach: 99.5%). Both areas also presented similar values for the number of arms regenerating/individual and in the frequency of regenerating individuals. The major part of the regenerating scars was concentrated in the distal portion of the arm. Sub-lethal predation is most likely the cause to the high rates of arm regeneration in O. reticulata. There was no significant differences in the regeneration rates between females (3.57 ± 1.36 arms regenerating/individual) and males (3.47 ± 1.42).

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Os síntipos de Corydoras meridionalis Rodolpho von Ihering, 1911, tidos como desaparecidos da coleção de peixes do Museu de Zoologia da USP, foram encontrados; os exemplares tinham sido identificados como C. ehrhardti Steindachner, 1910, espécie atualmente considerada sinônimo sênior da primeira. O exame desses sintipos permite confirmar a sinonímia proposta. Dados sobre os síntipos são apresentados e comparados com os dados das descrições originais de C. ehrhardti e C. meridionalis, sendo comentadas as poucas diferenças encontradas entre eles. É designado o lectótipo de C. meridionalis e uma fotografia deste é apresentada.

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The Dark-winged Trumpeter, Psophia viridis (Gruiformes, Psophiidae) is a Brazilian endemic species and includes three subspecies: Psophia viridis viridis Spix, 1825; Psophia v. dextralis Conover, 1934, and Psophia v. obscura Pelzeln, 1857, as well as P. v. interjecta Griscom & Greenway, 1937, whose validity has been questioned by several authors. These taxa are allopatric in distribution along the south of the Amazon River, although the precise limits of their distribution still remain unknown. This complex has never been taxonomically reviewed and this work aims to test the validity of its taxa based on the Phylogenetic Species Concept. Morphometrical characters and plumage colour patterns were analyzed, and the distribution of the taxa was also revised. In this study, 108 specimens from 41 localities were examined (all types included), with each reliable literature-based locality being included in order to delimit the geographical distribution of the complex. Morphometrical data did not point out significant differences between the taxa, also showing no sexual dimorphism among them. Meanwhile, plumage characters showed consistent and distinct patterns for each of the taxa, except for P. v. interjecta, whose features indicated by authors as diagnosable are the result of individual variation. No clinal variation or intergradation were observed, even at regions close to the rivers headwaters, where supposedly populations could be in contact. It is suggested that the currently accepted subspecies be elevated to the species level, such as: Psophia viridis Spix, 1825, distributed in the Madeira-Tapajós interfluvium, P. dextralis, found in the Tapajós-Tocantins interfluvium, and P. obscura, which occurs from the right bank of the Tocantins River to the west of the State of Maranhão.

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The fungus-farming ant genus Mycetagroicus Brandão & Mayhé-Nunes was proposed based on three species from the Brazilian "Cerrado": M. cerradensis, M. triangularis and M. urbanus. Here we describe a new species of Attini ant of the genus Mycetagroicus, M. inflatus n. sp., based on two workers collected in eastern Pará State, Brazil. A new key for species identification, comments on differences among species and new geographical distribution data are furnished.

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Population structure of the lancelet Branchiostoma caribaeum Sandevall, 1853 was studied in four surveys, corresponding to austral seasons, in a tropical bay, southeast of Brazil. Abundance was higher in the spring and was positively correlated to coarse sediments, limiting its occurrence to some sectors of the sampling area. Body length and biomass differed seasonally but not between sexes. Sexually mature individuals occurred in all seasons, suggesting continuous breeding that is typical of tropical species. Variation in the frequency of small specimens indicates temporal differences in the intensity of breeding. The body length of recruits differed from other population of lancelets and the small length which B. caribaeum attained sexual maturity in Guanabara Bay may be related to local environmental stress or the great availability of food.

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As diferenças socioeconômicas têm reflexos no perfil epidemiológico de câncer, no que diz respeito a incidência, mortalidade, sobrevida e qualidade de vida após o diagnóstico. Neste artigo examinam-se as disparidades da ocorrência de câncer na população brasileira e sintetizam-se evidências das investigações sobre determinantes sociais em câncer. Foram considerados os principais fatores que modulam a influência das condições socioeconômicas na ocorrência do câncer, como tabagismo, consumo de álcool, hábitos alimentares e obesidade, ocupação e acesso aos serviços de saúde. Modificações nas condições sociais dependem de mudanças estruturais na sociedade, a exemplo de melhorias do nível educacional; no entanto, investigações epidemiológicas bem conduzidas podem contribuir para o planejamento de intervenções visando a reduzir o impacto dos determinantes sociais em câncer. Esses estudos devem prover estratégias para promoção da qualidade das informações de incidência e mortalidade; realização periódica de inquéritos populacionais sobre prevalência de fatores de risco para câncer; desenvolver desenhos epidemiológicos mais eficientes para avaliar o efeito de fatores etiológicos em câncer e suas relações com o status social; análise de programas de rastreamento para tumores passíveis de detecção precoce; e avaliações do acesso da população ao diagnóstico e tratamento. Essas pesquisas devem contemplar populações em distintas regiões do mundo, em particular aquelas vivendo em regiões marginalizadas da dinâmica do atual sistema econômico global.

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Os objetivos do estudo foram: estimar as prevalências de doenças crônicas na população brasileira em 2008, comparando-as com as de 2003; avaliar o impacto da doença crônica no uso de serviços e nas restrições das atividades; e, analisar os diferenciais nas prevalências de doenças crônicas específicas, segundo nível de escolaridade e filiação a plano privado de saúde. Os dados foram obtidos do suplemento saúde das PNAD-2008 e 2003. As análises (prevalências e razões de prevalências brutas e ajustadas) foram feitas com o aplicativo Stata 11. A prevalência de ter ao menos uma doença crônica foi mais elevada em: idosos, mulheres, cor/raça preta ou indígena, menor escolaridade, migrantes, moradores em áreas urbanas e na região Sul do país. As condições crônicas mais prevalentes foram: hipertensão, doença de coluna, artrite e depressão. Houve, entre 2003 e 2008, aumento da prevalência de diabetes, hipertensão, câncer e cirrose, e redução de insuficiência renal crônica e tuberculose. A maioria das doenças estudadas foram mais prevalentes nos segmentos de menor escolaridade e sem plano de saúde. As maiores diferenças entre os segmentos sociais foram observadas nas prevalências de cirrose, insuficiência renal crônica, tuberculose e artrite/reumatismo.