Aplicação do método COP para avaliação da vulnerabilidade intrínseca à contaminação do aquífero cárstico Salitre, Irecê-BA, Brasil.

A área de estudo localiza-se na microrregião de Irecê, situada na porção centro-norte do estado da Bahia, Brasil. Compreende uma área piloto do aquífero cárstico Salitre, de aproximadamente 250km², delimitada por parte dos municípios de Irecê e Lapão. Constitui-se por rochas carbonáticas da Formação Salitre de idade Neoproterozóica. Para determinação da vulnerabilidade intrínseca à contaminação do aquífero na área foi utilizado o Método COP, e para tanto, alguns produtos foram gerados para aplicação no modelamento, como análise granulométrica dos solos, elaboração do Mapa Hidrogeológico, Mapa de Declividade, Mapa de Dolinas e Fraturas e Mapa de Uso e Ocupação dos Solos, em escala 1:25.000. Esses produtos permitiram a geração do Mapa de Vulnerabilidade Intrínseca à Contaminação da área, que apresentou como resultado um zoneamento de vulnerabilidade que possibilitou a delimitação de 3 classes de vulnerabilidade intrínsecas na área: Moderada (53%), Baixa (40%) e Muito Alta (7%). Os resultados obtidos podem ser utilizados para o planejamento, gestão hídrica e territorial da área

Variability of Settling Particles Fluxes and Isotopic Composition (δ13C and δ15N) from Material Trapped in Coastal Reefs of Abrolhos Bank, Eastern Brazilian Shelf

Elemental and isotopic ratios (C/N, δ13C, δ15N) of sediment samples captured by PVC traps in eight stations along the coastal reefs of the Abrolhos region, Brazil, were analyzed. The study area is characterized by the influence of continental sediments on biogenic sediments. The highest δ13C values were found in the Sebastião Gomes (second shallower station), with average values close to -15‰ in all sampling periods. The isotopic ratio of carbon and nitrogen indicates that the organic matter analyzed has marine origin, with signature features of oceanic regions. The highest C/N ratio average value of 8.29 occurred in Nova Viçosa (the southernmost station and one of the shallowest) during the spring, in other seasons the average value was close to 7 in all periods. Although the values of C/N indicate a significantly marine contribution, δ15N values suggest that N series recycling processes are frequent during the time that the material remained in the environment. The results will provide a baseline for future environmental monitoring and studies on changes in sediment composition in an important set of coastal coral reefs

Hydrogeochemical and Isotopic (δ2H-δ18O) Investigations of Hydrologic Dynamics of the Southern Urucuia Aquifer System, Brazil

The integration of hydrogeochemical and isotopic data (δ2H-δ18O) allowed the reconstruction of the hydrological dynamics of Southern Urucuia Aquifer System. This system is a combination of aquifers that are responsible for the perennity of the rivers during the rainy recession. In this study, water samples were collected from three sources: rainfall, rivers and pumping wells. The hydrogeochemical data lead to subdivide the aquifers in three main types: regional unconfined, confined, and unconfined with deep water level. The unconfined aquifer with deep water level originates from an groundwater flow deflection in the westernmost portion of the study area. The occurrence of silicified and fractured levels divide the aquifer types and represents a mixing and interfaced zone, allowing a leakage between aquifers and a great variability of hydrogeochemical facies. The hydrogeochemical evolution occurs by local, intermediate and regional flow systems. The buildup of dissolved solids is the major controlling mechanism of the groundwater composition represented by the systematic changes of anion species from HCO3 to SO4 to Cl, and cationic exchange between Ca and Na. The discharge occurs through the baseflow of rivers, which have hybrid composition between regional unconfined and confined aquifer from Na-Ca-Cl to Na-Cl. The analysis of stable isotopes shows that the surface water and groundwater are located in the same range of values, which indicates a connection between the reservoirs. During the rainy season, the regional unconfined isotopic composition becomes similar to the precipitation isotopic composition, with the main recharge occurring mostly by direct infiltration of rainwater. However, there is a modification of this composition in the dry season due to strong isotopic enrichment caused by the evaporation process. The seasonal variation in the isotopic composition represents a continuous cycle. In other words, as the rainy season approaches, the atmospheric air column becomes increasingly saturated with water vapor, what results in a considerably diminishment of evaporation.The integration of hydrogeochemical and isotopic data (δ2H-δ18O) allowed the reconstruction of the hydrological dynamics of Southern Urucuia Aquifer System. This system is a combination of aquifers that are responsible for the perennity of the rivers during the rainy recession. In this study, water samples were collected from three sources: rainfall, rivers and pumping wells. The hydrogeochemical data lead to subdivide the aquifers in three main types: regional unconfined, confined, and unconfined with deep water level. The unconfined aquifer with deep water level originates from an groundwater flow deflection in the westernmost portion of the study area. The occurrence of silicified and fractured levels divide the aquifer types and represents a mixing and interfaced zone, allowing a leakage between aquifers and a great variability of hydrogeochemical facies. The hydrogeochemical evolution occurs by local, intermediate and regional flow systems. The buildup of dissolved solids is the major controlling mechanism of the groundwater composition represented by the systematic changes of anion species from HCO3 to SO4 to Cl, and cationic exchange between Ca and Na. The discharge occurs through the baseflow of rivers, which have hybrid composition between regional unconfined and confined aquifer from Na-Ca-Cl to Na-Cl. The analysis of stable isotopes shows that the surface water and groundwater are located in the same range of values, which indicates a connection between the reservoirs. During the rainy season, the regional unconfined isotopic composition becomes similar to the precipitation isotopic composition, with the main recharge occurring mostly by direct infiltration of rainwater. However, there is a modification of this composition in the dry season due to strong isotopic enrichment caused by the evaporation process. The seasonal variation in the isotopic composition represents a continuous cycle. In other words, as the rainy season approaches, the atmospheric air column becomes increasingly saturated with water vapor, what results in a considerably diminishment of evaporation

Carbon and nitrogen stable isotope compositions of organic matter in marine sediment cores from the Abrolhos region: indicators of sources and preservation

Organic matter is an important source of information on the transport and consolidation processes of sediments. In this study, the isotopes of carbon and nitrogen (δ13C and δ15N), total organic carbon (TOC), total nitrogen, carbon/nitrogen (C/N) ratio, and 13C-NMR were utilized to understand the origin and behavior of organic material in the Abrolhos region. It were analyzed nine sediment cores taken from a mangrove, a channel between the mainland and the coral reefs. The average value of the C/N ratio in the mangrove was 18, which characterizes purely terrigenous areas. For the reefs, the average value of the C/N ratio was 8,which is characteristic of marine and coastal regions. For the sediment cores taken from the channel, the average value of the C/N ratio was 10, a typical value of areas under the influence of mangroves. The mean values of δ13C were -26.9‰ for the mangrove, -20.7‰ for the channel region, and -18.2‰ for the reefs. This variation is associated with the main source of organic matter, which in the mangrove is derived from vascular plants (mainly C3 metabolism) and for the reefs is derived from phytoplankton. The 13C-NMR results corroborate the isotopic and elemental analyses. The analyses of these cores indicate that the anthropogenic influence on the coast did not significantly alter the composition of the material that has been deposited in about the last 80 years in the region of study.A matéria orgânica é uma fonte de informação importante nos processos\ud de transporte e consolidação de sedimentos. Neste estudo, foram utilizados\ud isótopos de carbono e de nitrogênio (δ13C e δ15N), carbono orgânico total\ud (TOC), nitrogênio total, razão carbono/nitrogênio (C/N) e 13C-NMR para\ud entender a origem e o comportamento do material orgânico na região de\ud Abrolhos. Foram analisados nove testemunhos de sedimentos coletados em\ud um manguezal, em um canal e em recifes de corais. O valor médio da razão\ud C/N no manguezal foi de 18, o que caracteriza áreas puramente terrígenas.\ud Nos recifes, esse valor foi de 8, característico de regiões marinhas e costeiras,\ud e, nos testemunhos de sedimentos coletados no canal, foi de 10, um valor\ud típico de áreas sob a influência de manguezais. O valor médio de δ13C foi de\ud -26,9‰ para o manguezal, -20,7‰ para a região do canal e -18,2‰ para os\ud recifes. Essa variação é associada com a principal fonte de matéria orgânicaa qual, no manguezal, é derivada de plantas vasculares (principalmente de\ud metabolismo C3) e, nos recifes, é derivada de fitoplâncton. Os resultados de\ud 13C-NMR corroboram as análises isotópicas e elementais. As análises dos\ud testemunhos indicam que a influência antropogênica da região costeira não\ud altera significantemente a composição do material que tem sido depositado\ud nos últimos 80 anos na região estudad

Existence of different heme iron Fe2+ and Fe3+ spin states cytochrome c ions results the interaction with lipid bilayers.

A associação lipídio/citocromo c é importante e deve ser estudada, pois repercute na atividade peroxidática da proteína abordada e pode contribuir para o processo apoptótico, ou morte programada da célula, e também desempenha um papel significativo na cadeia respiratória. A natureza e a especificidade da interação do citocromo c com bicamadas lipídicas têm sido bastante investigadas ultimamente, mas informações detalhadas e precisas sobre tais assuntos ainda não existem. É aceito que ocorre primeiramente uma interação eletrostática entre a proteína citocromo c e as membranas fosfolipídicas. Em seguida, há uma interação hidrofóbica. Entretanto, ainda não é bem compreendido o papel da cadeia fosfolipídica. A associação do citocromo c com membranas lipídicas induz mudanças no estado de spin do átomo de ferro. A interação entre as vesículas carregadas e o citocromo c induz mudanças estruturais na proteína, as quais são refletidas no seu centro ativo, ou grupo heme. As mudanças do campo cristalino no sítio do ferro hemínico de forte para fraco são acompanhadas por mudanças do estado de spin de baixo para alto, respectivamente. Neste trabalho, estuda-se sistematicamente a natureza da interação entre o citocromo c e a cadeia fosfolipídica. As mudanças estruturais no grupo heme foram correlacionadas com a natureza do lipídio, ou seja, com a carga da cabeça e com o tamanho e o tipo da cadeia fosfolipídica. Foram utilizados treze lipídios diferentes, naturais e sintetizados, com cabeças polares negativas e neutras e com cadeias carbônicas saturadas e insaturadas de diferentes comprimentos. Para tal investigação, utilizamos as técnicas: Ressonância Paramagnética Eletrônica (RPE) Onda Contínua (CW) e Pulsada (PW) e Dicroísmo Circular Magnético (MCD). As técnicas enunciadas avaliam as mudanças de estado de spin e a simetria do citocromo c nos seus estados férrico e ferroso. A interação lipoprotéica lipídio/citocromo c foi avaliada com lipídios diferentes, inclusive com o lipossomo PCPECL, que mimetiza a membrana interna da mitocôndria nos eucariontes. A partir dos resultados experimentais, sugerimos um modelo para esse tipo de associação.This association lipid/cytochrome c is interesting to study in order to understand the peroxidase activity of this protein, that plays an important role in the respiratory chain and in the apoptosis process or the programmed cell death. The nature and specificity of the interaction of cytochrome c with lipid bilayers have been major goals in recent studies, but detailed information on that issue is not yet widely available. In this regard, it is generally accepted that the electrostatic interaction is an important factor in the association of cytochrome c with phospholipid membranes, followed by a hydrophobic interaction. However, the role played by the phospholipid chain is not well understood. The association of cytochrome c with negative membranes induces a change in the heme iron spin state. The interaction between the charged vesicles and cytochrome c leads to structural changes in the active central or heme group. The changing of the crystalline field of the heme iron from strong to weak is accompanied by spin states changes from low to high spin, respectively. These facts concerned us to investigate more systematically the nature of the interaction between cytochrome c and the phospholipid chains. The lipid-induced effects in the heme iron crystalline field are correlated to the nature of the charged head group and to the size and type of the phospholipid chain. Thirteen different lipids, nature and synthetic, were used, with negative and neutra1 polar head group and saturated and unsaturated acyl chains with different length. This work investigates the change of heme iron spin state and symmetry of ferric cytochrome c using Continuous Wave (CW) and pulsed (PW) Electron Paramagnetic Resonance (EPR) and Magnetic Circular Dichroism (MCD) techniques. These techniques analyze the spin state change and the symmetry of the iron cytochrome c in its ferric and ferrous states. The effect of the different lipids were analyzed, including PCPECL membrane that mimetics the inner mitocondrial membrane in eukaryotes

Developing of in vivo NMR spectroscopy technique and its applications in exercise physiology.

A Espectroscopia por Ressonância Magnética Nuclear (RMN) tem oferecido inúmeras possibilidades de pesquisa nas áreas de Biologia e Medicina. Uma de sus principais aplicações é a Espectroscopia in vivo do 31P no estudo da fisiologia de músculos esqueléticos. A partir desta metodologia pode-se quantificar as concentrações dos diferentes metabólitos fosforados que participam do metabolismo energético dos músculos, bem como suas alterações em função de contrações musculares. Com o objetivo de implantar a técnica de Espectroscopia in vivo no Laboratório de RMN do IFSC/USP, introduzimos várias adaptações ao Espectrômetro de Alta Resolução em Sólidos já existentes, incluindo a confecção de sondas . A partir desta adaptação, estudamos as alterações metabólicas dos compostos fosforados presentes em músculos esqueléticos, bem como o pH intraceleular, de ratos e camundongos em função de estímulos elétricos e exercício físico intenso.The Nuclear Magnetic Resonance (NMR) spectroscopy has been offering many possibilities of research in the areas of Biology and Medicine. One of the most important applications is the 31P in vivo Spectroscopy to study the skeletal muscle physiology. Using this methodology, it is possible to quantify different phosphorus metabolite concentrations that take part of the muscle energetic metabolism, as their variations as a function of muscle contraction. To accomplish the objective of developing the in vivo spectroscopy technique in the NMR laboratory of the IFSC/USP, many modifications to our Solid High Resolution Spectrometer were introduced and probes were constructed. Following these changes, we studied phosphorus compounds metabolic changes in the skeletal muscle and the intracellular pH of rats and mice as a function of electric stimulation and intensive running exercise

Existence of different heme iron Fe2+ and Fe3+ spin states cytochrome c ions results the interaction with lipid bilayers.

A associação lipídio/citocromo c é importante e deve ser estudada, pois repercute na atividade peroxidática da proteína abordada e pode contribuir para o processo apoptótico, ou morte programada da célula, e também desempenha um papel significativo na cadeia respiratória. A natureza e a especificidade da interação do citocromo c com bicamadas lipídicas têm sido bastante investigadas ultimamente, mas informações detalhadas e precisas sobre tais assuntos ainda não existem. É aceito que ocorre primeiramente uma interação eletrostática entre a proteína citocromo c e as membranas fosfolipídicas. Em seguida, há uma interação hidrofóbica. Entretanto, ainda não é bem compreendido o papel da cadeia fosfolipídica. A associação do citocromo c com membranas lipídicas induz mudanças no estado de spin do átomo de ferro. A interação entre as vesículas carregadas e o citocromo c induz mudanças estruturais na proteína, as quais são refletidas no seu centro ativo, ou grupo heme. As mudanças do campo cristalino no sítio do ferro hemínico de forte para fraco são acompanhadas por mudanças do estado de spin de baixo para alto, respectivamente. Neste trabalho, estuda-se sistematicamente a natureza da interação entre o citocromo c e a cadeia fosfolipídica. As mudanças estruturais no grupo heme foram correlacionadas com a natureza do lipídio, ou seja, com a carga da cabeça e com o tamanho e o tipo da cadeia fosfolipídica. Foram utilizados treze lipídios diferentes, naturais e sintetizados, com cabeças polares negativas e neutras e com cadeias carbônicas saturadas e insaturadas de diferentes comprimentos. Para tal investigação, utilizamos as técnicas: Ressonância Paramagnética Eletrônica (RPE) Onda Contínua (CW) e Pulsada (PW) e Dicroísmo Circular Magnético (MCD). As técnicas enunciadas avaliam as mudanças de estado de spin e a simetria do citocromo c nos seus estados férrico e ferroso. A interação lipoprotéica lipídio/citocromo c foi avaliada com lipídios diferentes, inclusive com o lipossomo PCPECL, que mimetiza a membrana interna da mitocôndria nos eucariontes. A partir dos resultados experimentais, sugerimos um modelo para esse tipo de associação.This association lipid/cytochrome c is interesting to study in order to understand the peroxidase activity of this protein, that plays an important role in the respiratory chain and in the apoptosis process or the programmed cell death. The nature and specificity of the interaction of cytochrome c with lipid bilayers have been major goals in recent studies, but detailed information on that issue is not yet widely available. In this regard, it is generally accepted that the electrostatic interaction is an important factor in the association of cytochrome c with phospholipid membranes, followed by a hydrophobic interaction. However, the role played by the phospholipid chain is not well understood. The association of cytochrome c with negative membranes induces a change in the heme iron spin state. The interaction between the charged vesicles and cytochrome c leads to structural changes in the active central or heme group. The changing of the crystalline field of the heme iron from strong to weak is accompanied by spin states changes from low to high spin, respectively. These facts concerned us to investigate more systematically the nature of the interaction between cytochrome c and the phospholipid chains. The lipid-induced effects in the heme iron crystalline field are correlated to the nature of the charged head group and to the size and type of the phospholipid chain. Thirteen different lipids, nature and synthetic, were used, with negative and neutra1 polar head group and saturated and unsaturated acyl chains with different length. This work investigates the change of heme iron spin state and symmetry of ferric cytochrome c using Continuous Wave (CW) and pulsed (PW) Electron Paramagnetic Resonance (EPR) and Magnetic Circular Dichroism (MCD) techniques. These techniques analyze the spin state change and the symmetry of the iron cytochrome c in its ferric and ferrous states. The effect of the different lipids were analyzed, including PCPECL membrane that mimetics the inner mitocondrial membrane in eukaryotes

Developing of in vivo NMR spectroscopy technique and its applications in exercise physiology.

A Espectroscopia por Ressonância Magnética Nuclear (RMN) tem oferecido inúmeras possibilidades de pesquisa nas áreas de Biologia e Medicina. Uma de sus principais aplicações é a Espectroscopia in vivo do 31P no estudo da fisiologia de músculos esqueléticos. A partir desta metodologia pode-se quantificar as concentrações dos diferentes metabólitos fosforados que participam do metabolismo energético dos músculos, bem como suas alterações em função de contrações musculares. Com o objetivo de implantar a técnica de Espectroscopia in vivo no Laboratório de RMN do IFSC/USP, introduzimos várias adaptações ao Espectrômetro de Alta Resolução em Sólidos já existentes, incluindo a confecção de sondas . A partir desta adaptação, estudamos as alterações metabólicas dos compostos fosforados presentes em músculos esqueléticos, bem como o pH intraceleular, de ratos e camundongos em função de estímulos elétricos e exercício físico intenso.The Nuclear Magnetic Resonance (NMR) spectroscopy has been offering many possibilities of research in the areas of Biology and Medicine. One of the most important applications is the 31P in vivo Spectroscopy to study the skeletal muscle physiology. Using this methodology, it is possible to quantify different phosphorus metabolite concentrations that take part of the muscle energetic metabolism, as their variations as a function of muscle contraction. To accomplish the objective of developing the in vivo spectroscopy technique in the NMR laboratory of the IFSC/USP, many modifications to our Solid High Resolution Spectrometer were introduced and probes were constructed. Following these changes, we studied phosphorus compounds metabolic changes in the skeletal muscle and the intracellular pH of rats and mice as a function of electric stimulation and intensive running exercise