Caracterización de bacterias alcalófilas sulfoxidantes

En la actualidad, algunas industrias, refinerías y rellenos sanitarios, se han convertido en focos contaminantes ya que sus desechos incluyen al azufre en su composición química. Los compuestos de azufre más importantes emitidos a la atmósfera son el dióxido de azufre (SO2), el ácido sulfhídrico (H2S) y el disulfuro de carbono (CS2), entre otras especies que provocan daños a la salud, lluvia ácida, malos olores y fenómenos de corrosión. Existen bacterias capaces de disminuir los problemas causados por los compuestos azufrados. En particular, las bacterias sulfooxidantes pueden transformar compuestos reducidos de S0 , como el H2S y S2O3, en sustancias menos dañinas, como el azufre elemental, las cuales son menos contaminantes por ser insolubles en agua y, por tanto, fácilmente removibles y/o re-aprovechables por otras industrias o microorganismos sulfatoreductores. En el presente trabajo se investigaron las condiciones ambientales ( [sustrato], pH, temperatura, salinidad) que favorecen el consumo específico de O2 (actividad metabólica) de bacterias alcalófilas previamente aisladas de diferentes zonas del lago de Texcoco. Se encontró que la concentración de tiosulfato (como modelo de H2S) mas favorecedora es de 0.1mM en adelante, el intervalo de pH más favorecedor para el aislado “B” y el consorcio es de 10 a 11, mientras que el aislado “A” mostró ser neutrófilo (pH 8), la temperatura más favorecedora es 30ºC para los tres casos y el intervalo de concentración salina es de 0.5 a 1M. El consumo de O2, la concentración de proteínas, pH y Aw fueron determinadas mediante respirometrías, pruebas de Lowry y potenciómetro. El conocimiento de las condiciones ambientales aquí encontradas, ayudarán a la formación y mantenimiento de consorcios con capacidad sulfooxidante, aplicables a tratamientos ambientales de efluentes industriales.Nowadays some industries, refineries and landfills have become in focus of pollution due to their waste material compounds includes sulfur in their chemical composition. The most important sulfur compounds emitted to the atmosphere are dioxide of sulfur (SO2), the sulfhidric acid (H2S) and the disulphide of carbon (CS2), among others species that cause human diseases, acid rain, bad odors and corrosion phenomena. There are some bacteria that are able to decrease the problems caused by sulfur compounds. In particular, the sulfooxidants bacteria can transform the reduced sulfur compounds, like the H2S and S2O3, into harmless substances like the elemental sulfur, which are eco-friendly because of their water insolubility, therefore, easily removable and/or re-profitable by other industries or sulfate-reductor microorganisms. This thesis searches the environmental conditions ([sustrate], pH, temperature, salinity) that favors the specific O2 consumption (metabolic activity) of alcalophilic bacteria previously isolated from a consortium of different zones of Texcoco lake. It was found that the most favorable thiosulphate concentration (as H2S model) is above 0.1 mM, the most favorable pH range to the isolated “B” and the consortium was from 10 to 11, while the isolated “A” shows to be neutrophile (pH 8), the most favorable temperature is near 30ºC for the tree cases, and the range of saline concentration is between 0.5 to 1M. The results were obtained by respirometers, Lowry’s proof, pH decrease and the activity water (Aw) mesure. The knowledge of environmental conditions found may help the formation and manteniment of consortiums with sulfooxidant capacity, useful for environmental treatments of industrial effluents

Morphological and Physicochemical Characterization of Agglomerates of Titanium Dioxide Nanoparticles in Cell Culture Media

Titanium dioxide nanoparticles (TiO2 NP) are possible carcinogenic materials (2B-IARC) and their toxicity depends on shape, size, and electrical charge of primary NP and on the system formed by NP media. The aim of this work was to characterize agglomerates of three TiO2 NP by evaluating their morphometry, stability, and zeta potential (ζ) in liquid media and their changes with time. Sizes of agglomerates by dynamic light scattering (DLS) resulted to be 10–50 times larger than those obtained by digital image analysis (DIA) given the charged zone around particles. Fractal dimension (FD) was highest for agglomerates of spheres and belts in F12K, and in E171 in FBS media. E171 and belts increased FD with time. At time zero, using water as dispersant FD was larger for agglomerates of spheres than for of E171. Belts suspended in water had the smallest values of circularity (Ci) which was approximately unchanged with time. All dispersions had ζ values around −30 mV at physiological pH (7.4) and dispersions of NP in water and FBS showed maximum stability (Turbiscan Lab analysis). Results help in understanding the complex NP geometry-size-stability relationships when performing in vivo and in vitro environmental-toxicity works and help in supporting decisions on the usage of TiO2 NP

Microsatellite diversity and genetic structure among common bean (Phaseolus vulgaris L.) landraces in Brazil, a secondary center of diversity

Brazil is the largest producer and consumer of common bean (Phaseolus vulgaris L.), which is the most important source of human dietary protein in that country. This study assessed the genetic diversity and the structure of a sample of 279 geo-referenced common bean landraces from Brazil, using molecular markers. Sixty-seven microsatellite markers spread over the 11 linkage groups of the common bean genome, as well as Phaseolin, PvTFL1y, APA and four SCAR markers were used. As expected, the sample showed lower genetic diversity compared to the diversity in the primary center of diversification. Andean and Mesoamerican gene pools were both present but the latter gene pool was four times more frequent than the former. The two gene pools could be clearly distinguished; limited admixture was observed between these groups. The Mesoamerican group consisted of two sub-populations, with a high level of admixture between them leading to a large proportion of stabilized hybrids not observed in the centers of domestication. Thus, Brazil can be considered a secondary center of diversification of common bean. A high degree of genome-wide multilocus associations even among unlinked loci was observed, confirming the high level of structure in the sample and suggesting that association mapping should be conducted in separate Andean and Mesoamerican Brazilian samples

Política Nacional de Saúde Integral da População Negra: implementação, conhecimento e aspectos socioeconômicos sob a perspectiva desse segmento populacional

A Política Nacional de Saúde Integral da População Negra tem o objetivo de garantir a equidade na atenção à saúde para esse segmento populacional. Tal medida possui um caráter compensatório em virtude das discriminações raciais existentes ao longo da história do Brasil. A população negra apresenta maior vulnerabilidade social e econômica, o que reflete uma menor expectativa de vida e maior susceptibilidade a agravos. O objetivo do estudo é investigar o conhecimento da população negra acerca da política, seus potenciais benefícios e as dificuldades de acesso à saúde. Trata-se de uma pesquisa transversal, descritiva e quantitativa. Foram realizadas entrevistas estruturadas com 391 indivíduos negros, usuários do SUS, da cidade de Juiz de Fora. A amostra foi estratificada de acordo com raça (preto e pardo), renda e escolaridade. Cerca de 90% dos entrevistados relataram desconhecer a existência de uma política de saúde para a população negra e 53% declararam uma possível discriminação racial. Observou-se também associação positiva entre discriminação e menor escolaridade e renda. Apesar de desconhecerem a existência da PNSIPN, a maioria dos entrevistados aprovou seus objetivos, mesmo relatando a possibilidade de discriminação dela advinda

COMPLEXIDADE RACIAL: mitos e realidades em duas freguesias de Salvador em 1775

A partir da análise minuciosa dos dados do Censo de 1775 sobre duas freguesias de Salvador (São Pedro e Penha), são colocados em questão cinco mitos dominantes sobre a escravidão no imaginário nacional: (1) o domínio total do trabalho escravo na sociedade; (2) uma sociedade formada apenas por senhores e escravos; (3) uma sociedade constituída, por um lado, por um segmento de dominantes e exploradores e, por outro, por dominados e explorados; (4) uma sociedade urbana segregada; (5) uma sociedade patriarcal, em que as mulheres eram submissas e economicamente subordinadas. Os resultados do censo, portanto, levantam novas questões para o entendimento da complexidade do nosso passado, o que ajuda a entender a manutenção das extremas desigualdades atuais, além de evidenciar a existência de diferenciações espaciais na cidade. PALAVRAS-CHAVE: escravos, libertos, agregados, freguesias, Salvador.RACIAL COMPLEXITY: myth and reality in two Salvador freguesias in 1775 Pedro de Almeida Vasconcelos The meticulous analysis of data from the Census of 1775 on two freguesias of Salvador (São Pedro and Penha), bring doubt to five dominant myths on slavery in the national imaginary: (1) the exclusivity of slave work in the society; (2) a society just formed by slave owners and slaves; (3) a society where, on one side, live a segment of dominant exploiters and, on the other, dominated explored people; (4) a segregated urban society; (5) a patriarchal society, in which women were submissive and economically subordinates. The results of the census, therefore, bring new subjects to understanding the complexity of our past, what helps to understand the maintenance of the extreme current inequalities, besides showing the existence of space differentiations in the city. KEYWORDS: slaves, freed men, agregados, freguesias, Salvador.COMPLEXITÉ RACIALE: mythes et réalités dans deux paroisses de Salvador en 1775 Pedro de Almeida Vasconcelos A partir de l’analyse minutieuse des données du recensement de 1775 concernant deux paroisses de Salvador (São Pedro et Penha) sont remis en question cinq mythes dominants à propos de l’esclavage dans l’imaginaire national: (1) l’exclusivité du travail esclave dans la société; (2) une société formée uniquement de seigneurs et d’esclaves; (3) une société constituée d’une part par un segment de dominants et d’exploiteurs et d’autre part de dominés et d’exploités; (4) une société urbaine ségréguée; (5) une société patriarcale où les femmes étaient soumises et subordonnées économiquement. Les résultats de ce recensement soulèvent donc de nouvelles questions pour la compréhension de la complexité de notre passé, ceci permet de comprendre le maintien d’extrêmes inégalités actuelles et de mettre aussi en évidence l’existence de différenciations spatiales dans la ville. MOTS-CLÉS: esclaves, personnes libres, domestiques, paroisses, Salvador. Publicação Online do Caderno CRH: http://www.cadernocrh.ufba.b