Eficiencia del lagunaje profundo como tratamiento para la eliminación de metales pesados en aguas residuales de tipo urbano-industrial

14 páginas, figuras y tablas estadísticas.En 1996 se puso en marcha una laguna experimental para la regeneración de aguas residuales, de 4.75 m de profundidad, alimentada en continuo con agua residual de origen urbano-industrial previamente tratada. Se han realizado diversos estudios a fin de conocer su dinámica interna y de optimizar su rendimiento. El lagunaje profundo, situado en serie con el efluente de una depuradora (tratamiento físico-químico + fangos activos) es una tecnología de tipo terciario que, mediante un procedimiento natural y sin gasto energético adicional, mejora notablemente la calidad química y sanitaria del agua regenerada, tanto para una posible reutilización agrícola, como para su incorporación a un cauce fluvial. La laguna profunda actúa, además, como una trampa de sedimento para los metales pesados. Los procesos de asociación de estos elementos traza con la materia particulada por adsorción, precipitación, coprecipitación o asimilación por la biota, favorecen su eliminación de la columna de agua y su acumulación en el sedimento. La dinámica natural de la laguna posibilita tales procesos. El pH, ligeramente alcalino, las condiciones reductoras, la temperatura, la materia orgánica abundante y la disponibilidad de iones inorgánicos, son las principales variables implicadas. Por otra parte, la profundidad y la amplitud del tiempo de residencia hidráulica favorecen los procesos de sedimentación. Los rendimientos medios del lagunaje profundo en la eliminación de cromo, hierro y zinc se estimaron en torno al 60%.Peer reviewe

A new species of Astyanax (Characiformes, Characidae) from Uruguay river basin in Argentina, with remarks on hook presence in Characidae

In the present paper the new species Astyanax ojiara sp. n. is described, from the headwaters of Yabotí river, an affluent of Uruguay river in the province of Misiones, Argentinean northeast. A combination of characters differentiates the new species from other congeners: one heptacuspid maxillary teeth; teeth of inner premaxillary row gently expanded distally; 7-9 dentary teeth decreasing in size anteroposteriorly; males with hooks in all fins; large males with pelvic axillary scale bearing 1 to 8 hooks; 36-38 perforated scales in lateral line; 20-23 branched anal-fin rays. Number of scales in the lateral line and branched anal-fin rays, humeral spot, and low body of Astyanax ojiara sp. n. resemble those of A. eigenmanniorum, but maxillary, premaxillary and dentary teeth differ in both species. The disposition of the dentary leeth is also similar in A. taeniatus and A. giton but A. ojiara sp. n. has one heptacuspid maxillary tooth.Facultad de Ciencias Naturales y Muse

Applications of micro-fluidic platforms integrating packed stationary phases

To design and fabricate novel centrifugal micro-fluidic platforms integrating packed stationary phases for solid-phase micro-extraction in a wide range of (bio)analytical applications. To design and fabricate novel micro-fluidic platforms integrating packed stationary phases capable of withstanding significant high pressures

Theoretical study of the electronic spectrum of magnesium-porphyrin

Multiconfigurational self-consistent field (SCF) and second order perturbation methods have been used to study the electronic spectrum of magnesium-porphyrin (MgP). An extended ANO-type basis set including polarization functions on all heavy atoms has been used. Four allowed singlet states of E1u symmetry have been computed and in addition a number of forbidden transitions and a few triplet states. The results lead to a consistent interpretation of the electronic spectrum, where the Q band contains one transition, the B band two, and the N band one. The computed transition energies are consistently between 0.1 and 0.5 too low compared to the measured band maxima. The source of the discrepancy is the approximate treatment of dynamic correlation (second order perturbation theory), limitations in the basis set and the fact that all measurements have been made on substituted magnesium [email protected] ; [email protected]

Estructura de deuda corporativa y el mercado de créditos sindicados en México : Serie de documentos de trabajo 2015-02

Este artículo investiga la elección del tipo de deuda que utilizan las empresas mexicanas que cotizan en el mercado de capitales para financiar proyectos de largo plazo. Nuestra metodología permite identificar el efecto promedio y los efectos marginales en la elección del tipo de deuda a lo largo de la distribución de varias características de las empresas. Diferenciamos la elección de créditos sindicados de la de emisión de certificados bursátiles. Nuestros resultados sugieren que la elección entre créditos sindicados y la emisión de bonos corporativos está determinada por el tamaño, la calidad crediticia, y el colateral. Además, los efectos de estas variables sobre la probabilidad de financiamiento en estos instrumentos difieren en tamaño y significancia en el rango de valores asociados a estas variable

The envelopes of amphibian oocytes: physiological modifications in Bufo arenarum

A characterization of the Amphibian Bufo arenarum oocyte envelope is presented. It was made in different functional conditions of the oocyte: 1) when it has been released into the coelomic cavity during ovulation (surrounded by the coelomic envelope, (CE), 2) after it has passed through the oviduct and is deposed (surrounded by the viteline envelope, (VE), and 3) after oocyte activation (surrounded by the fertilization envelope, (FE). The characterization was made by SDS-PAGE followed by staining for protein and glycoproteins. Labeled lectins were used to identify glycosidic residues both in separated components on nitrocellulose membranes or in intact oocytes and embryos. Proteolytic properties of the content of the cortical granules were also analyzed. After SDS-PAGE of CE and VE, a different protein pattern was observed. This is probably due to the activity of a protease present in the pars recta of the oviduct. Comparison of the SDS-PAGE pattern of VE and FE showed a different mobility for one of the glycoproteins, gp75. VE and FE proved to have different sugar residues in their oligosaccharide chains. Mannose residues are only present in gp120 of the three envelopes. N-acetyl-galactosamine residues are present in all of the components, except for gp69 in the FE. Galactose residues are present mainly in gp120 of FE. Lectin-binding assays indicate the presence of glucosamine, galactose and N-acetyl galactosamine residues and the absence (or non-availability) of N-acetyl-glucosamine or fucose residues on the envelopes surface. The cortical granule product (CGP) shows proteolytic activity on gp75 of the VE

Social Exclusion Modifies Climate and Deforestation Impacts on a Vector-Borne Disease

American Cutaneous Leishmaniasis emergence has been associated with changes in the interaction between people and forests. The association between outbreaks and forest clearance, higher risk for populations living close to forests, and the absence of this disease from urban settings has led to the proposal that it will disappear with the destruction of primary forests. This view ignores the complex nature of deforestation as a product of socioeconomic inequities. Our study shows that such inequities, as measured by a marginalization index, may ultimately determine risk within the country, with socially excluded populations most affected by the disease. Contrary to the established view, living close to the forest edge can diminish the risk provided other factors are taken into account. Additionally, differences in vulnerability to climatic variability appear to interact with forest cover to influence risk across counties where the disease has its largest burden. Incidence exacerbation associated with El Niño Southern Oscillation is observed in counties with larger proportions of deforestation. Our study calls for control efforts targeted to socially excluded populations and for more localized ecological studies of transmission in vectors and reservoirs in order to understand the role of biodiversity changes in driving the emergence of this disease

A theoretical study of the electronic spectrum of bithiophene

The electronic spectrum of bithiophene in the energy range up to 6.0 eV has been studied using multiconfigurational second order perturbation theory (CASPT2) and a basis set of ANO type, with split valence quality and including polarization functions on all heavy atoms. Calculations were performed at a planar (trans) and twisted geometry. The calculated ordering of the excited singlet states is 1Bu, 1Bu, 1Ag, 1Ag, and 1Bu with 0–0 transition energies: 3.88, 4.15, 4.40, 4.71, and 5.53 eV, respectively. The first Rydberg transition (3s) has been found at 5.27 eV. The results have been used in aiding the interpretation of the experimental spectra, and in cases where a direct comparison is possible there is agreement between theory and [email protected] ; [email protected] ; [email protected]

Manejo clínico de la infección viral del herpes simple y Candidiasis oral: Reporte de un caso clínico

La infección por herpes simple tipo I es una de las enfermedades más frecuentes que afecta a la cavidad bucal, se manifiesta en forma de vesículas que tienden a remitir después de 10 a 12 días y es altamente recidivante. El siguiente trabajo tiene como finalidad presentar el caso clínico de un paciente con herpes simple recidivante intrabucal, acompañado de dolor intenso, con síntomas y signos clínicos persistentes por un largo periodo de tiempo, que no remitía con el tratamiento. Se detectó infección de Cándida Albicans acompañando al cuadro. Se realizaron análisis de laboratorio, incluyendo el test de Elisa para confirmar presencia de HIV resultando negativo, PCR para detección de VHS tipo 1 y cultivo de Cándida Albicans. Se trató la virosis con Aciclovir en altas dosis, la infección sobreagregada con nistatina y se indicó polivitamínicos para reforzar el huésped. El paciente fue tratado multidisciplinariamente y derivado al psicólogo por presentar un cuadro de estrés, lo que permitió disminuir la ansiedad del mismo ejerciendo un rol importante en el tratamiento.Fil: Gonzalez, Maria Mercedes. Universidad Nacional del Nordeste. Facultad de Odontologia; ArgentinaFil: Rosende, Roque O.. Universidad Nacional del Nordeste. Facultad de Odontologia; ArgentinaFil: Krupp, Sebastian. Universidad Nacional del Nordeste. Facultad de Odontologia; ArgentinaFil: Rosales, Carlos A.. Universidad Nacional del Nordeste. Facultad de Odontologia; ArgentinaFil: Fernandez, Estefania Raquel. Universidad Nacional del Nordeste. Facultad de Odontologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentin