No description available.

5' Nucleotidase (5NU) in <i>Dictyostelium discoideum</i> is an enzyme that shows high substrate specificity to 5'AMP. The enzyme has received considerable attention in the past because of the critical role played by cyclic AMP in cell differentiation in this organism. Degradation of cAMP by cAMP phosphodiesterase (PDE) produces 5'AMP, the substrate of 5NU. Dictyostelium switches its genetic program from growth to cellular differentiation when nutrients become limited. During the time course of development, the activity of 5NU is high and becomes restricted to a narrow band of cells that form the interface between the prestalk/prespore zones. Understanding how this gene is regulated will provide knowledge underlying the process of cell differentiation. In order to understand the functional significance of the 5NU, I first purified of the 5NU protein using an artificial substrate p-nitrophenol phosphate (pNPP). An activity stain on non-denaturing gels with Nitro Blue Tetrazolium (NBT) and 5-Bromo-4-Chloro-3-Indolyl Phosphate (BCIP) as the substrate was also used. A polypeptide of approximately 90 kDa was associated with 5NU enzyme activity after gel filtration chromatography and denaturing gel electrophoreses. Protein sequence of this peptide was obtained from Mass Spectrometry and Edmund Degradation. Various databanks were searched for similar sequences, but no matches with high identity were obtained. However, a search of the sequences of an ongoing cDNA project at the University of Tsukuba in Japan revealed a clone that corresponded to the peptide sequence of 5NU. In addition, a clone was found that corresponded to the classical "alkaline phosphatase" found in several organisms. Analysis of the expression of the 5NU and AP during Dictyostelium development by Northern blotting determined that the 5NU is developmentally regulated while the AP is expressed at all stages of the life cycle. Southern blot analysis showed a single form of the gene for both 5NU and AP. Targeted gene disruption and knockout mutagenesis using the 5NU sequences flanking a blasticidin-resistant cassette was attempted. Analysis of the transformants showed the 5NU gene was not disrupted, and that the blasticidin-resistant cassette was randomly inserted into the genome. / Ph. D.

O objetivo do presente estudo foi avaliar a eficácia de uma solução à base de mamona (Ricinus communis) na remoção do biofilme de próteses totais, comparando-a com dois produtos disponíveis no mercado (hipoclorito de sódio e peróxido alcalino). Cinquenta usuários de próteses totais superiores foram instruídos a escovar suas próteses após as refeições e imergí-las, uma vez ao dia, por um período de 07 dias, nas seguintes soluções: A - Controle: soro fisiológico (20 minutos). B - peróxido alcalino Polident (3 minutos). C - hipoclorito de sódio a 1% (20 minutos). D - solução à base de mamona (20 minutos). Os participantes imergiram suas próteses em cada uma das soluções, de acordo com uma sequência aleatorizada. Para a quantificação do biofilme, antes (Baseline) e após o uso de cada produto, as superfícies internas das próteses totais superiores eram evidenciadas (vermelho neutro 1%), fotografadas (Nikon Coolpix 950, Nikon Corporation,Tokyo, Japan) e o biofilme corado era quantificado com auxílio de um software (Image Tool 3.0). A influência dos tratamentos sobre os resultados foi averiguada pelo teste de Friedman (&alpha;=0,05) e comparações múltiplas foram realizadas por meio do teste de Wilcoxon (com nível de significância corrigido pelo método de Bonferroni: &alpha;=0,005). Os resultados mostraram diferença significante entre os métodos (Fr = 51,67; P < 0,001). A solução à base de mamona (Ricinus communis) e a pastilha à base de peróxido alcalino (Polident) apresentaram resultados intermediários (Mediana:1,0% e 1,5%, respectivamente) e o hipoclorito de sódio a 1% promoveu a mais baixa percentagem de biofilme (Mediana: 0,0%). Pôdese concluir que a solução à base de mamona (Ricinus communis) foi eficaz quanto à propriedade de remoção de biofilme, podendo ser utilizado como higienizador de próteses totais. / The aim of this study was to evaluate the efficacy of a castor bean solution (Ricinus communis) on denture biofilm removal in comparison with two proprietary products (sodium hypochlorite and alkaline peroxide). Fifty maxillary denture wearers were instructed to brush their dentures after meals and to soak them, once a day, for 07 days, in the following solutions: A - Control: saline (20 minutes). B- Polident alkaline peroxide (3 minutes). C - 1% sodium hypochlorite (20 minutes). D - castor oil solution (20 minutes). The participants soaked their dentures in every tested solution according to a randomized sequence. Biofilm was quantified preliminarily (baseline) and after using each product. For that purpose, the inner surfaces of maxillary dentures were disclosed (1% neutral red) and photographed (Nikon Coolpix 950, Nikon Corporation, Tokyo, Japan). Stained biofilm was quantified by Image Tool 3.0 software. Tested solutions were compared by Friedman test (&alpha;=.05) followed by the Wilcoxon test (with Bonferroni correction, &alpha;=.005). The results showed a significant difference between methods (Fr=51.67, P<.001). The castor bean solution (Ricinus communis) and the effervescent tablet showed intermediate results (Median: 1.0% and 1.5%, respectively) and the 1% sodium hypochlorite promoted the lowest biofilm percentage (Median: 0,0%). It was concluded that the castor bean solution (Ricinus communis) was effective on biofilm removal and therefore can be used as a denture cleanser.

Calcite stalactites ranging in length from several inches to a foot long are found forming on the southeastern slag pile at the former Gadsden Steel Mill of the Gulf States Steel Corporation. Analyses of samples collected per EISOPQAM guidelines include the following: petrographic, conductivity, pH, XRD, XRF, TDS, and major cations and anions. Preliminary field pH and conductivity measurements indicate that waters near the slag pile have a pH ranging from 11-12 and a conductivity ranging from 1115-6300 μS/ cm. Titration data indicate that the maximum pH value is 12.5. These calcite stalactites and stream coatings result from the dissolution of the steelmaking slag by rainfall. These alkaline waters precipitate calcite when they are in contact with atmospheric CO2. Improper management of slag products can lead to aesthetically impacted environments and ecosystems. Several studies and this study show that steel slag could be used to sequester atmospheric CO2.

O objetivo do presente estudo foi avaliar a eficácia de uma solução à base de mamona (Ricinus communis) na remoção do biofilme de próteses totais, comparando-a com dois produtos disponíveis no mercado (hipoclorito de sódio e peróxido alcalino). Cinquenta usuários de próteses totais superiores foram instruídos a escovar suas próteses após as refeições e imergí-las, uma vez ao dia, por um período de 07 dias, nas seguintes soluções: A - Controle: soro fisiológico (20 minutos). B - peróxido alcalino Polident (3 minutos). C - hipoclorito de sódio a 1% (20 minutos). D - solução à base de mamona (20 minutos). Os participantes imergiram suas próteses em cada uma das soluções, de acordo com uma sequência aleatorizada. Para a quantificação do biofilme, antes (Baseline) e após o uso de cada produto, as superfícies internas das próteses totais superiores eram evidenciadas (vermelho neutro 1%), fotografadas (Nikon Coolpix 950, Nikon Corporation,Tokyo, Japan) e o biofilme corado era quantificado com auxílio de um software (Image Tool 3.0). A influência dos tratamentos sobre os resultados foi averiguada pelo teste de Friedman (&alpha;=0,05) e comparações múltiplas foram realizadas por meio do teste de Wilcoxon (com nível de significância corrigido pelo método de Bonferroni: &alpha;=0,005). Os resultados mostraram diferença significante entre os métodos (Fr = 51,67; P < 0,001). A solução à base de mamona (Ricinus communis) e a pastilha à base de peróxido alcalino (Polident) apresentaram resultados intermediários (Mediana:1,0% e 1,5%, respectivamente) e o hipoclorito de sódio a 1% promoveu a mais baixa percentagem de biofilme (Mediana: 0,0%). Pôdese concluir que a solução à base de mamona (Ricinus communis) foi eficaz quanto à propriedade de remoção de biofilme, podendo ser utilizado como higienizador de próteses totais. / The aim of this study was to evaluate the efficacy of a castor bean solution (Ricinus communis) on denture biofilm removal in comparison with two proprietary products (sodium hypochlorite and alkaline peroxide). Fifty maxillary denture wearers were instructed to brush their dentures after meals and to soak them, once a day, for 07 days, in the following solutions: A - Control: saline (20 minutes). B- Polident alkaline peroxide (3 minutes). C - 1% sodium hypochlorite (20 minutes). D - castor oil solution (20 minutes). The participants soaked their dentures in every tested solution according to a randomized sequence. Biofilm was quantified preliminarily (baseline) and after using each product. For that purpose, the inner surfaces of maxillary dentures were disclosed (1% neutral red) and photographed (Nikon Coolpix 950, Nikon Corporation, Tokyo, Japan). Stained biofilm was quantified by Image Tool 3.0 software. Tested solutions were compared by Friedman test (&alpha;=.05) followed by the Wilcoxon test (with Bonferroni correction, &alpha;=.005). The results showed a significant difference between methods (Fr=51.67, P<.001). The castor bean solution (Ricinus communis) and the effervescent tablet showed intermediate results (Median: 1.0% and 1.5%, respectively) and the 1% sodium hypochlorite promoted the lowest biofilm percentage (Median: 0,0%). It was concluded that the castor bean solution (Ricinus communis) was effective on biofilm removal and therefore can be used as a denture cleanser.

The work in this thesis relates to the preparation and structural and electrical characterisation of calcium and strontium hydrides, imides and nitride hydrides. Conventional solid state methods in controlled atmospheres were used to synthesise these materials. High temperature neutron diffraction, thermal analysis and conductivity studies performed on calcium and strontium hydride suggest an order – disorder transition in these materials at 350 – 450°C. Disordering is believed to involve rapid exchange of hydride ions across two crystallographic sites. This manifests itself in a lowering of the activation energy for bulk hydride ion conduction. The hydride ion conduction is good in these undoped materials: σ[total]subscript = 0.01 S/cm for CaH₂ at 1000K; for SrH₂, σ[total]subscript = 0.01 S/cm at 830K. Doping of SrH₂ with NaH causes a significant increase in the low temperature conductivity, due to presence of extrinsic defects. The high temperature conductivity is negatively affected by NaH doping. Calcium nitride hydride (Ca₂NH) was obtained as a single phase material by reacting either calcium metal or calcium hydride (CaH₂) in an argon atmosphere containing 5 – 7% H₂ and 1 – 7% N₂. Imide ions substituting for hydride and nitride ions constitute a major chemical defect in this material. Long range ordering of the nitride and hydride ions occurs, giving rise to a double cubic crystal symmetry. This order breaks down at 600 – 650°C. Applying the same reaction conditions to strontium metal results in a mixed phase of strontium nitride hydride and imide. No long range order in the nitride hydride phase could be observed. Doping Ca₂NH with lithium hydride (LiH) causes the appearance of a second calcium imide phase, whereas doping with sodium hydride (NaH) increases the amount of imide ions as a defect in the nitride hydride structure, thereby decreasing the long range ordering of nitride and hydride ions.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Nesta dissertação foram estudas rochas máficas dos complexos alcalinos de Morro de São João, Rio Bonito, Tanguá, Gericinó-Mendanha, Morro Redondo, Itatiaia e Passa Quatro. Essas rochas ocorrem na forma de diques e/ou sills. As amostras coletadas foram classificadas como lamprófiros, fonolitos, gabros e diabásios alcalinos. A análise geoquímica permitiu identificar um trend fortemente insaturado e um trend moderadamente alcalino para os complexos estudados. O primeiro é caracterizado por foiditos e fonolitos como membros parentais e mais evoluídos, respectivamente, enquanto o segundo tem basaltos alcalinos como membros parentais e traquitos como os mais evoluídos. Todas as amostras plotam no campo da série alcalina, sendo majoritariamente miaskíticas, sódicas ou potássicas. Adicionalmente, o estudo geoquímico indicou que os complexos alcalinos representam câmaras magmáticas distintas, onde diferentes processos evolutivos tiveram lugar. As modelagens apontaram dois processos de diferenciação distintos nos complexos estudados. Os complexos alcalinos de Morro de São João, Morro Redondo, Gericinó-Mendanha e Itatiaia estariam relacionados a processos de cristalização fracionada. Por outro lado, o Complexo Alcalino de Passa Quatro teria sido diferenciado por processos de cristalização fracionada com esvaziamento e posterior reabastecimento da câmara magmática (RTF). De um modo geral, esses modelos indicaram a presença de mais do que uma série magmática nos complexos estudados e a não cogeneticidade entre as séries agpaíticas e miaskíticas. A discriminação de fontes foi feita com base na análise dos elementos terras raras das amostras parentais de cada um dos complexos (gabro em Morro de São João e lamprófiro nos demais). No entanto, este procedimento não foi aplicado para o Complexo Alcalino de Morro Redondo, uma vez que todas as suas amostras apresentaram valores de MgO muito abaixo do típico para líquidos parentais. O líquido parental do Complexo Alcalino do Gericinó-Mendanha apresentou razões de La/Yb e La/Nb, maior e menor que a unidade, respectivamente, típicas de derivação a partir fontes férteis. Os líquidos parentais dos outros complexos alcalinos tiveram suas razões La/Yb e La/Nb maiores que a unidade, típicas de derivação a partir de fontes enriquecidas. Os modelos desenvolvidos revelaram que os líquidos parentais de cada um dos complexos estudados estariam relacionados a fontes lherzolíticas com granada residual. Além disso, a fusão parcial destas fontes teria ocorrido num intervalo de 1 a 7% dentro da zona da granada. Finalmente, as modelagens petrogenéticas elaboradas permitiram a proposição de um cenário geodinâmico, envolvendo a descompressão adiabática do manto litosférico e sublitosférico anomalamente aquecidos. As características geoquímicas dos líquidos parentais parecem ter sido controladas essencialmente pela mistura desses dois tipos de fontes. / Mafic rocks from the Morro de São João, Rio Bonito, Tanguá, Gericinó-Mendanha, Morro Redondo, Itatiaia and Passa Quatro alkaline complexes were studied based on field, petrographic and lithogeochemical data. The mafic rocks are mostly alkaline lamprophyres and alkaline gabbro (in Morro de São João). The complexes show both strongly undersaturated and mildly alkaline evolutionary trends, having foidites and alkaline basalts as parental compositions. Trachytes and phonolites are the most common evolved rocks. Geochemical modelling has show that miaskitic and agpaitic series are unlikely to be related by fractional crystallization. Enriched mantle sources predominate although a fertile mantle source seems to be related with the Gericinó-Mendanha complex. Parental compositions are related to small amounts of partial melting (1-7%) of garnet lherzolite within the garnet stability field in the mantle. Simple geodynamic models indicate that the alkaline complexes are related to the adiabatic decompression of anomalously hot (~1570C) mantle although unrelated to lithospheric translation over a fixed hotspot or mantle plume. Parental compositions are likely to be strongly controled by mixing of distinctive lithospheric mantle sources and a more homogeneous sublithospheric mantle. The lithospheric components seem to be related with the accreted terranes during the Gondwana amalgamation in Early Proterozoic times.

Human alkaline phosphatase (ALP) comprises four isozymes, viz liver/bone/ kidney or tissue unspecific (AP), intestinal (LAP), placental (PLAP) and germ cell or PLAP-like alkaline phosphatase, with their main expression in specific tissues as indicated by their names. The isozymes are coded by different genes, but they are closely related, with more than 50% amino acid sequence homologies. Their biological function is unclear. In certain malignant and benign diseases, serum elevations of one or more of the isozymes occur, which is of diagnostic importance. In this study, the special expression of the intestinal isozyme in human tissues and sera, in normal as well as in pathological conditions, has been investigated by use of isozyme specific monoclonal antibodies. Monoclonal antibodies against the AP, IAP and PLAP isozymes were prepared, and specific assays developed, based on these monoclonal antibodies and the catalytic activity of the isozymes. By use of these assays the basal levels of all three isozymes were examined in selected normal organs. The isozymes were found to be expressed in measurable amounts in all the examined organs. IAP was immunohistochemically localized to the epithelial cells of membranes lining the ducts and tubules of the kidney, liver, pancreas and small intestine. Normal human serum contained all three isozymes. The AP isozyme constituted about 90% of the total ALP activity, the IAP isozyme less than 10% and the PLAP isozyme about 1%. Considerable interindividual variations of the serum IAP activity were observed. The serum activities of the IAP isozyme were related to the individual ABO blood group and secretor status. Non-secretors had low levels of IAP activity amounting to about one tenth of the activity in sera from blood group B or 0 secretors, while blood group A secretors had serum IAP activities in the same order as non-secretors. High individual day to day variations were observed. Fat absorption caused serum IAP to increase significantly for all persons, but it was rapidly cleared from the blood. We found that the release of IAP into the blood was linked to lipid absorption, but removal from the blood was not linked to lipoprotein clearance. Certain tumors of the testis expressed elevated levels of all three ALP isozymes. The highest activitiy of LAP was observed in one yolk sac tumor, in agreement with the endodermal origin of this tumor. In seminoma tissue the AP and PLAP isozymes were significantly, and IAP moderately elevated. Cirrhosis of the liver caused significantly increased serum levels of IAP besides the AP isozyme. In inflammatory diseases of the small intestine, normal serum IAP activities were observed. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1992, härtill 7 uppsatser.</p> / digitalisering@umu

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A intrusão alcalina do Marapicu é uma intrusão localizada no maciço Marapicu-Gericinó-Mendanha situado na região metropolitana do Rio de Janeiro. Este maciço é formado por dois corpos alcalinos: Marapicu e Mendanha que fazem parte do lineamento magmático Poços de Caldas-Cabo Frio. Este lineamento inclui dezenas de corpos ígneos alcalinos de idade Cretácea com uma direção preferencial WNW-ESE. Os litotipos mais abundantes do Maciço Marapicu são representados por nefelina sienitos e sienitos de caráter plutônico, além de, fonolitos caracterizados por intrusões rasas geralmente em forma de diques. Além desses litotipos foram amostradas duas rochas com características químicas de magma parental (lamprófiro e fonolito tefrítico), porém, essas duas amostras não apresentam relação genética com as demais. Também foi amostrado um nefelina sienito que possui sodalita azul como feldspatóide, sendo assim, chamado de nefelina sodalita sienito. Entre os fonolitos coletados para esse trabalho, uma amostra apresenta granada melanita em sua assembleia mineralógica, e esta foi então denominada melanita fonolito. Quimicamente as rochas do Marapicu formam uma série alcalina predominantemente insaturada em sílica, miaskítica e metaluminosa. Dentro desta série se observam duas suítes sendo uma potássica (predominante) e outra sódica. A evolução química do corpo se deu por processo de cristalização fracionada com ou sem assimilação de crosta continental provavelmente dentro de uma fonte mantélica enriquecida. Duas idades de cristalização foram obtidas para o Maciço do Marapicu sendo uma idade 40Ar/39Ar de 80,46 0,58 Ma em hornblenda, e uma idade U-Pb em zircão bastante concordante de 78,0 2,1 Ma. Os dados apresentados aqui em conjunto com dados da literatura apontam para dois modelos geodinâmicos de geração dos corpos alcalinos do sudeste brasileiro, um considera a existência de uma pluma mantélica gerada na astenosfera, o outro tem por base a hipótese de flexura crustal e considera que a carga de sedimentos depositados na plataforma continental exerceria esforços que provocariam fraturas profundas permitindo a ascenção desses magmas. O presente trabalho vem para contribuir no entendimento do alojamento dos corpos alcalinos do sudeste brasileiro através do estudo especifico do Maciço Marapicu em conjunto com dados da literatura / The Marapicu Alkaline intrusion is an intrusion into the Marapicu-Gericinó-Mendanha massif. This massif is formed by two alkaline bodies: Marapicu and Mendanha both making part of the Cretaceous Poços de Caldas-Cabo Frio magmatic lineament located in the Southeastern region of Brazil. This lineament includes tens of Cretaceous alkaline bodies and has a WNW-ESE trend. The most abundant rocks in the massif are plutonic nepheline syenites and syenites and also phonolitic rocks characterized for shallow intrusions as a dike. Besides these rocks were sampling two rocks with chemistry characteristcs of parental magma (basanite tefrite and phonolitic tefrite), nevertheless, this samples have not relationship with the others. There is also a nepheline syenite having blue sodalite as a feldspatoid called nepheline sodalite syenite. Between sampled fonolites to this work there is only sample including melanita garnet in his mineralogy assemblage and them called melanita fonolite. Chemically the Marapicu massif rocks forming an alkaline series SiO2-undersatured predominantly miaskitic and metaluminous. This series presents both potassic and sodic suites being the first one in greater content. Geochemistry data shows that evolution process involved fractional crystallization with or without continental crust assimilation and also indicates that this alkaline magma was generating into the enriched mantle source. Two crystallization age were obtained for Marapicu: 40Ar/39Ar age in hornblende of 80.46 0.58 Ma and U-Pb age in zircon of 78.0 2.1 Ma. The presented data together with literature data pointing for two geodynamic models responsible by the generation of Brazilian alkaline bodies. The first one consider there is a mantellic plume from asthenosphere, the second is based on the hypotheses of crustal flexure and consider that sedimentary charge on the continental platform would make deep fails which the magma ascending. The present work came to contribute on understanding of Brazilian alkaline bodies emplacement through the specific study of Marapicu in conjunct with literature data

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Lamprófiros e diabásios alcalinos afloram no litoral dos estados de São Paulo e Rio de Janeiro e integram o Enxame de Diques da Serra do Mar (EDSM). Essas rochas ocorrem sob a forma de diques e intrudem o Orógeno Ribeira, de idade Neoproterozóica/Cambro-Ordoviciana, inserindo-se no contexto geodinâmico de abertura do Oceano Atlântico Sul durante o Cretáceo Superior. Essas intrusões são subverticais e orientam-se preferencialmente a NE-SW, seguindo a estruturação das rochas encaixantes. Os lamprófiros são classificados como monchiquitos e camptonitos e exibem, respectivamente, textura hipocristalina e holocristalina. Apresentam também textura panidiomórfica, fenocristais de clinopiroxênio e olivina, imersos em matriz formada essencialmente por esses mesmos minerais, além de biotita, kaersutita e minerais opacos. O camptonito apresenta ainda plagioclásio na matriz. Os diabásios alcalinos são hipocristalinos a holocristalinos, equigranulares a inequigranulares, com fenocristais de olivina e/ou clinopiroxênio e/ou plagioclásio, em uma matriz composta essencialmente por esses minerais. As rochas estudadas caracterizam séries alcalinas miaskíticas, com os lamprófiros sendo tanto sódicos, potássicos e ultrapotássicos e os diabásios alcalinos como predominantemente sódicos. Modelagens petrogenéticas envolvendo possíveis processos evolutivos mostram que é improvável que os lamprófiros sejam cogenéticos por processos evolutivos envolvendo tanto cristalização fracionada, com ou sem assimilação concomitante, quanto hibridização. O mesmo ocorre para os diabásios alcalinos. A discriminação de fontes mantélicas foi feita com base nos teores de elementos traços de amostras representativas de líquidos parentais e indica que esse magmatismo alcalino está relacionado a fontes lherzolíticas com fusão parcial na zona de estabilidade do espinélio, isto é, a poucas profundidades. Os dados litogeoquímicos e isotópicos do sistema Sr-Nd das rochas estudadas sugerem tanto o envolvimento de fontes férteis, associadas ao manto sublitosférico, quanto de fontes enriquecidas, relacionadas ao manto litosférico subcontinental. Modelagens de mistura binária revelam que a petrogênese dos lamprófiros e diabásios alcalinos envolveu uma grande participação de um componente fértil misturado com contribuições menores de um componente enriquecido. Idades TDM (760-557 Ma) obtidas sugerem remobilização do manto litosférico no Neoproterozóico, talvez relacionadas à subducção da Placa São Francisco preteritamente à colisão do Orógeno Ribeira. Altas razões CaO/Al2O3 para os líquidos lamprofíricos menos evoluídos, altos teores de Zr, correlações negativas Zr/Hf e Ti/Eu e associação com carbonatitos indicam condições metassomáticas de alto CO2/H2O. Em escala local, modelos geodinâmicos baseados na astenosfera não isotérmica parecem mais aplicáveis. No entanto, modelos geodinâmicos baseados na astenosfera isotérmica (com o envolvimento de plumas) parecem mais indicados num contexto regional, considerando-se outras províncias alcalinas contemporâneas e correlatas. / Alkaline lamprophyres and alkaline diabases of the Serra do Mar Dyke Swarm (SMDS) outcrop along the Southeastern Brazil. These dykes intrude rocks of the so-called Rio Negro Magmatic Arc within the Late Proterozoic-Ordovician Ribeira Orogen and are associated with the opening of South Atlantic Ocean during the Late Cretaceous. Typically, the intrusions are subvertical bearing a NE-SW preferential trend which follows the main lineaments in the area. The lamprophyres are classified as monchiquites and camptonites and show holocrystalline and hypocrystalline textures, respectively. They also have panidiomorphic texture and olivine and clinopyroxene phenocrysts within a matrix composed essentially by these same minerals, kaersutite and biotite. Camptonites still have plagioclase in the matrix. The alkaline diabases are holo- to hypocrystalline, equi- to inequigranular rocks with olivine and/or clinopyroxene and/or plagioclase phenocrysts in a matrix composed essentially by these minerals. These alkaline rocks have miaskitic compositions. Lamprophyres are sodic, potassic and ultrapotassic and alkaline diabases are predominantly sodic. Petrogenetic modeling indicates that lamprophyres are unlikely to be cogenetic by evolutionary processes involving either fractional crystallization, with or without concomitant assimilation, or hybridization. The same applies to the alkaline diabases. Modal-batch partial melting models using samples representing parental liquids indicate that these alkalines mafic rocks are related to lherzolitic sources and that partial melting occurred in the spinel stability field, pointing to a thin continental lithosphere in the region. Lithogeochemical and Sr-Nd isotopic data show that the petrogenesis of these alkaline rocks can be assigned to mixing of mantle sources. Binary mixing models and assimilation tests reveal that the petrogenesis of the lamprophyres and alkaline diabases involve a large amount of participation of a fertile component with small contribution of an enriched component. TDM model ages for the studied rocks suggest remobilization ages of the of the lithospheric mantle during the Neoproterozoic, possibly related to the subduction of the San Francisco plate prior to the collision of the Ribeira Orogen. The high CaO/Al2O3 ratios of less evolved lamprophyric melts, high Zr contents, Zr/Hf and Ti/Eu negative correlations and association with carbonatites point to high CO2/H2O conditions during metassomatism of the subcontinental lithospheric mantle. Geodynamic models based on the non-isothermal asthenospheric mantle seem to apply to the studied mafic alkaline magmatism on a local scale although the isothermal asthenospheric mantle model appears to conceal the petrogenesis of other coeval alkaline provinces in central and southeastern Brazil.