967 resultados para Miami Limestone


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Lymphocyte subsets, activation markers and apoptosis were assessed in 20 HIV-exposed noninfected (ENI) children born to HIV-infected women who were or not exposed to antiretroviral (ARV) drugs during pregnancy and early infancy. ENI children and adolescents were aged 6-18 years and they were compared to 25 age-matched healthy non-HIV-exposed children and adolescents (Control). ENI individuals presented lower CD4(+) T cells/mm(3) than Control group (control: 1120.3 vs. ENI: 876.3; t-test, p=0.030). ENI individuals had higher B-cell apoptosis than Control group (Control: 36.6%, ARV exposed: 82.3%, ARV nonexposed: 68.5%; Kruskal-Wallis, p < 0.05), but no statistical difference was noticed between those exposed and not exposed to ARV. Immune activation in CD4(+) T, CD8(+) T and in B cells was comparable in ENI and in Control children and adolescents. Subtle long-term immune alterations might persist among ENI individuals, but the clinical consequences if any are unknown, and these children require continued monitoring.

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On December 9, 2007, a 4.9 m(b) earthquake occurred in the middle of the Sao Francisco Craton, in a region with no known previous activity larger than 4 m(b). This event reached intensity VII MM (Modified Mercalli) causing the first fatal victim in Brazil. The activity had started in May 25, 2007 with a 3.5 magnitude event and continued for several months, motivating the deployment of a local 6-station network. A three week seismic quiescence was observed before the mainshock. Initial absolute hypocenters were calculated with best fitting velocity models and then relative locations were determined with hypoDD. The aftershock distribution indicates a 3 km long rupture for the mainshock. The fault plane solution, based on P-wave polarities and hypocentral trend, indicates a reverse faulting mechanism on a N30 degrees E striking plane dipping about 40 degrees to the SE. The rupture depth extends from about 0.3 to 1.2 km only. Despite the shallow depth of the mainshock, no surface feature could be correlated with the fault plane. Aeromagnetic data in the epicentral area show short-wavelength lineaments trending NNE-SSW to NE-SW which we interpret as faults and fractures in the craton basement beneath the surface limestone layer. We propose that the Caraibas-Itacarambi seismicity is probably associated with reactivation of these basement fractures and faults under the present E-W compressional stress field in this region of the South American Plate. (c) 2009 Elsevier B.V. All rights reserved.

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Gordonia polyisoprenivorans CCT 7137 was isolated from groundwater contaminated with leachate in an old controlled landfill (Sauo Paulo, Brazil), and cultured in GYM medium at different concentrations of sugarcane molasses (2%, 6%, and 10%). The strain growth was analyzed by monitoring the viable cell counts (c.f.u. mL(-1)) and optical density and EPS production was evaluated at the end of the exponential phase and 24 h after it. The analysis of the viable cell counts showed that the medium that most favored bacterial growth was not the one that favored EPS production. The control medium (GYM) was the one that most favored the strain growth, at the maximum specific growth rate of 0.232 h(-1). Differences in bacterial growth when cultured at three different concentrations of molasses were not observed. Production of EPS, in all culture media used, began during the exponential phase and continued during the growth stationary phase. The highest total EPS production, after 24 h of stationary phase, was observed in 6% molasses medium (172.86 g L(-1)) and 10% (139.47 g L(-1)) and the specific total EPS production was higher in 10% molasses medium (39.03 x10(-11)g c.f.u.(-1)). After the exponential phase, in 2%, 6%, and 10% molasses media, a higher percentage of free exopolysaccharides (EPS) was observed, representing 88.4%, 62.4%, and 64.2% of the total, respectively. A different result was observed in pattern medium, which presented EPS made up of higher percentage of capsular EPS (66.4% of the total). This work is the first study on EPS production by G. polyisoprenivorans strain in GYM medium and in medium utilizing sugarcane molasses as the sole nutrient source and suggests its potential use for EPS production by G. polyisoprenivorans CCT 7137 aiming at application in biotechnological processes.

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We report 6 K-Ar ages and paleomagnetic data from 28 sites collected in Jurassic, Lower Cretaceous and Paleocene rocks of the Santa Marta massif, to test previous hypothesis of rotations and translations of this massif, whose rock assemblage differs from other basement-cored ranges adjacent to the Guyana margin. Three magnetic components were identified in this study. A first component has a direction parallel to the present magnetic field and was uncovered in all units (D 352, I = 25.6, k = 57.35, a95 = 5.3, N = 12). A second component was isolated in Cretaceous limestone and Jurassic volcaniclastic rocks (D = 8.8, I = 8.3, k = 24.71, a95 = 13.7, N = 6), and it was interpreted as of Early Cretaceous age. In Jurassic sites with this component, Early Cretaceous K-Ar ages obtained from this and previous studies are interpreted as reset ages. The third component was uncovered in eight sites of Jurassic volcaniclastic rocks, and its direction indicates negative shallow to moderate inclinations and northeastward declinations. K-Ar ages in these sites are of Early (196.5 +/- 4.9 Ma) to early Late Jurassic age (156.6 +/- 8.9 Ma). Due to local structural complexity and too few Cretaceous outcrops to perform a reliable unconformity test, we only used two sites with (1) K-Ar ages, (2) less structural complexity, and (3) reliable structural data for Jurassic and Cretaceous rocks. The mean direction of the Jurassic component is (D = 20.4, I = -18.2, k = 46.9, a95 = 5.1, n = 18 specimens from two sites). These paleomagnetic data support previous models of northward along-margin translations of Grenvillian-cored massifs. Additionally, clockwise vertical-axis rotation of this massif, with respect to the stable craton, is also documented; the sense of rotation is similar to that proposed for the Perija Range and other ranges of the southern Caribbean margin. More data is needed to confirm the magnitudes of rotations and translations. (C) 2009 Elsevier Ltd. All rights reserved.

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In Sweden, there are about 0.5 million single-family houses that are heated by electricity alone, and rising electricity costs force the conversion to other heating sources such as heat pumps and wood pellet heating systems. Pellet heating systems for single-family houses are currently a strongly growing market. Future lack of wood fuels is possible even in Sweden, and combining wood pellet heating with solar heating will help to save the bio-fuel resources. The objectives of this thesis are to investigate how the electrically heated single-family houses can be converted to pellet and solar heating systems, and how the annual efficiency and solar gains can be increased in such systems. The possible reduction of CO-emissions by combining pellet heating with solar heating has also been investigated. Systems with pellet stoves (both with and without a water jacket), pellet boilers and solar heating have been simulated. Different system concepts have been compared in order to investigate the most promising solutions. Modifications in system design and control strategies have been carried out in order to increase the system efficiency and the solar gains. Possibilities for increasing the solar gains have been limited to investigation of DHW-units for hot water production and the use of hot water for heating of dishwashers and washing machines via a heat exchanger instead of electricity (heat-fed appliances). Computer models of pellet stoves, boilers, DHW-units and heat-fed appliances have been developed and the parameters for the models have been identified from measurements on real components. The conformity between the models and the measurements has been checked. The systems with wood pellet stoves have been simulated in three different multi-zone buildings, simulated in detail with heat distribution through door openings between the zones. For the other simulations, either a single-zone house model or a load file has been used. Simulations were carried out for Stockholm, Sweden, but for the simulations with heat-fed machines also for Miami, USA. The foremost result of this thesis is the increased understanding of the dynamic operation of combined pellet and solar heating systems for single-family houses. The results show that electricity savings and annual system efficiency is strongly affected by the system design and the control strategy. Large reductions in pellet consumption are possible by combining pellet boilers with solar heating (a reduction larger than the solar gains if the system is properly designed). In addition, large reductions in carbon monoxide emissions are possible. To achieve these reductions it is required that the hot water production and the connection of the radiator circuit is moved to a well insulated, solar heated buffer store so that the boiler can be turned off during the periods when the solar collectors cover the heating demand. The amount of electricity replaced using systems with pellet stoves is very dependant on the house plan, the system design, if internal doors are open or closed and the comfort requirements. Proper system design and control strategies are crucial to obtain high electricity savings and high comfort with pellet stove systems. The investigated technologies for increasing the solar gains (DHW-units and heat-fed appliances) significantly increase the solar gains, but for the heat-fed appliances the market introduction is difficult due to the limited financial savings and the need for a new heat distribution system. The applications closest to market introduction could be for communal laundries and for use in sunny climates where the dominating part of the heat can be covered by solar heating. The DHW-unit is economical but competes with the internal finned-tube heat exchanger which is the totally dominating technology for hot water preparation in solar combisystems for single-family houses.

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Researches have shown that the introduction of rubber in concrete improves the features of its deformability, as well as contributes to environmental disposal of waste generated in the tire retreading process. Furthermore, there is a high availability of limestone within RN and CE country. Ignorance about this stone, does not allow its wide use as aggregate, leaving, this abundant supply idle. A composite of limestone gravel, with proportions of tire rubber waste which could be used as concrete would be an alternative to concrete for low applications. Therefore, this research aims to evaluate the characteristics of concrete containing limestone gravel and proportions of little aggregate replacement (sand) by tire rubber waste. To this goal, the material components of the concrete were characterized, concrete specimens with limestone gravel were made, from the dash 1.0: 2.5: 3.5, varying the water/cement ratio, and inserting a commercial plasticizer, without a proportion of residue, known as reference. From this, concrete with and without the presence of the additive in the same proportions were chosen, as well as these with the use of granite gravel, for being the most used. Selected the references, to these, replacements of little aggregate (sand) were added replaced by rubber waste from the tire retreading process, treated with 1M NaOH in proportions from 5.0 to 20.0 % by mass, cured and exposed to the semiarid environment. The results indicate the possibility of using limestone gravel in the concrete composition with workability correction using plasticizer. There was a decrease in the mechanical properties of the concrete with increments of waste rubber, but there is an improvement in toughness and deformability of the composite, which makes it interesting for the construction of non-structural concrete floors, as well as, the rubber waste delayed the hardening process, continuing to gain resistance after 28 days

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It is estimated that the Brazilian karst areas sum about 200.000 km2. The caves, one of the main components of karst, are important windows into the biological studies on hypogean environments. In Rio Grande do Norte are known 563 caves, and 476 of them are in the municipalities of Baraúna, Felipe Guerra, Governador Dix-Sept Rosado, Apodi and Mossoró, the Western region of the State. However, like in the rest of the country, the cave fauna of the State is still poorly understood. This study used data from invertebrates harvested in 47 caves and aimed to analyze the effect of environmental change between the dry and rainy seasons in the communities of cave invertebrates, characterize these communities and evaluate the relationships between morphological and biotic variables of the caves and surroundings, and to define priority areas for conservation of cave environments of the study area from biotic parameters. Strong effects were found in the community structure of cave invertebrates due environmental changes between seasons, with values of total richness, abundance, diversity and ecological complexity significantly higher in the rainy season. It was possible to assess how the morphology of the cave and the external environment variables affect the biotic system, so that the variety of resources, forest cover in the vicinity, the area of the cave and its entrance were the variables that best explained the structure communities of cave invertebrates in the region. High values of total richness of invertebrates (36,62 ± 14,04 spp / cave) and troglomorphic species (61 species, mean 1,77 ± 2,34 spp / cave) were found and, given the biological relevance in the context of the area national and the imminent anthropogenic pressures existing, we defined four priority areas for actions aiming cave biodiversity conservation in the region.

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Foram avaliadas as características morfológicas da carcaça, musculosidade e composição tecidual da perna de cordeiros criados em regime de pasto, provenientes de ovelhas Romney, acasaladas com três raças paternas (Romney, East Friesian x (Finn x Texel) e Finn x Poll Dorset). Aos 150 e 300 dias de idade, os cordeiros foram abatidos em dois lotes, cada um com 15 animais de cada raça paterna, num total de 90 animais. O grupo oriundo de animais East Friesian x (Finn x Texel) apresentou maior quantidade de músculo na perna (1.975 g) e, em comparação ao grupo Romney, semelhante musculosidade da perna (0,45) e maior relação músculo:osso (7x6,69). A musculosidade da perna nos animais descendentes de Finn x Poll Dorset foi menor (0,44), quando comparada à dos demais grupos. Cordeiros abatidos mais tardiamente apresentaram carcaças mais longas e magras, provavelmente pelas condições adversas do verão e do outono, em que são típicas a menor taxa de crescimento e a qualidade inferior de forragem. O genótipo e a idade de abate influem nas características morfológicas da carcaça, no índice de musculosidade e de composição tecidual da perna dos cordeiros.

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Este estudo objetivou avaliar a correção do solo no estabelecimento do sistema plantio direto em Latossolo Vermelho localizado em região típica de Cerrado, Selvíria - MS. Os tratamentos consistiram em cinco formas de aplicação de calagem, em dose única ou parcelada, e duas culturas de cobertura. A calagem sem incorporação, independentemente do modo de aplicação, corrigiu a acidez do solo e aumentou os teores de Ca e Mg na camada de 0-0,05 m; nas demais profundidades, não houve alterações significativas desses atributos. A incorporação do calcário na camada de 0-0,2m modificou, uniformemente, os valores de pH, Ca, Mg e soma de bases do solo até à profundidade de 0,2 m. O sorgo como cultura de cobertura possibilitou maiores teores de Ca e Mg quando a dose de calcário foi subdividida em três aplicações.

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O conhecimento da dinâmica populacional e da distribuição vertical de insetos pragas em plantas hospedeiras é fundamental para o desenvolvimento de programas de manejo integrado de pragas. No presente trabalho efetuou-se um levantamento populacional de formas ápteras do pulgão Brevicoryne brassicae (L.), visando determinar a época de maior densidade populacional e a distribuição vertical em plantas de couve, (Brassica oleracea L. var. acephala DC.), cultivadas em Jaboticabal, SP. O estudo foi realizado durante as safras de brássicas de 1998 e 1999, efetuando-se correção da acidez do solo por meio de aplicação de calcário apenas no campo utilizado em 1998. A amostragem dos pulgões foi feita visualmente em folhas classificadas em três categorias: apical, mediana e basal. Nas duas safras estudadas, a infestação de B. brassicae na couve atingiu a maior densidade populacional em setembro, diminuindo rapidamente a seguir. Nos dois campos não se observou a mesma distribuição de B. brassicae em folhas apicais, medianas e basais. Os fatores que podem ter contribuído para as diferenças observadas no padrão de distribuição do pulgão devem estar relacionados com a precipitação pluvial e o calcário magnesiano.

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A modelagem matemática associada ao conhecimento da variabilidade dos atributos do solo e mapeamento das formas do relevo pode auxiliar no manejo da fertilidade do solo em usinas sucroalcooleiras. O presente trabalho teve como objetivo avaliar o uso da geoestatística e da modelagem matemática na estimativa de custos de fertilização, em diferentes formas do relevo. em uma área de 200 ha, foram identificadas duas formas de relevo, uma côncava e outra convexa, sendo os solos coletados nos pontos de cruzamento de uma malha, com intervalos regulares de 50 m, perfazendo um total de 623 pontos. As amostras foram submetidas a análises químicas, e, posteriormente, os dados foram avaliados por meio da estatística descritiva, geoestatística e modelagem matemática. Os resultados mostraram que, quando as formas do relevo são incorporadas às análises geoestatística e de modelagem matemática, ocorre aumento na eficiência de aplicação do calcário, fósforo e potássio no solo.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Soil acidity in no tillage system, if not in high situations, can be neutralized by lime surface application, improving mineral nutrition and crop yield. Aiming to evaluate the agronomic performance of common bean cultivars, to surface lime application, in no tillage system, an experiment was conducted in Oxisol, Botucatu Municipal District, São Paulo State, Brazil. The experimental design was a complete randomized block in split plot with four replications, where the plots were formed by common bean cultivars (Carioca, IAC Carioca Ete, Perola, IAPAR 81 e Campeao 2) and subplots consisted of surface application of dolomitic limestone (zero, 1.8 t ha(-1), 3.6 t ha(-1) and 5.4 t ha(-1)). The surface lime application on the soil occurred in October 2002 and subsequently the sequence millet (spring) - beans (summer) - oat (autumn-winter) were planted under rainfed conditions. Bean cultivars sowing were done on December 17, 2003. It can be concluded that there is influence of cultivars and limestone surface application under no tillage, where IAPAR 81 showed better grain yield with the increase of lime rates, obtaining values of 2,025 kg ha(-1) without the lime application to 2,655 kg ha(-1) with 5.4 t ha(-1) lime rate, obtaining 31% yield increase.