Microbial induced corrosion by ferric–reducing bacteria isolated from an oil separation tank

Se requiere identificar a las poblaciones microbianas que participan en la Corrosión Inducida por Microorganismos, con la finalidad de implementar estrategias de monitoreo eficiente y de control. Las poblaciones de microorganismos anaerobios presentes en la industria petrolera, particularmente en la producción de gas y petróleo, así como en las líneas de transporte y en los tanques de almacenamiento, han sido estudiadas muy pobremente y los estudios presentes se han enfocado principalmente en bacterias sulfatorreductoras de los géneros Desulfovibrio y Desulfobacter. Sin embargo, las bacterias fermentativas también tienen gran relevancia en la corrosión de metales, como se describió en 1997, por el grupo de Magot y colaboradores, quienes caracterizaron una bacteria no sulfidogénica pero con capacidad de producir corrosión. En este estudio se aisló de un tanque de separación, una bacteria anaerobia, fermentativa y reductora de fierro, perteneciente al género Sedimentibacter, con capacidad de producir corrosión en el acero al carbón SAE1018.It has required the characterization and identification of the microbial populations responsible for Microbial Induced Corrosion (MIC), and their interactions with distinctive microorganisms allocated on metallic surfaces, in order to implement efficient monitoring and control strategies. Microbial anaerobic communities present at oil and gas producing, transporting and storage facilities have been poorly characterized and studies had mainly focused on Desulfovibrio and Desulfobacter genus. However, fermentative bacteria have important participation on corrosion metals as described by Magot et al. (1997), which characterization of non-SRB sulfidogenic bacteria was able to produce corrosion. In this study, it was isolated of an oil-water tank separation, an anaerobic bacterium, fermentative and ferric-reducing, belong to Sedimentibacter genus with corrosion capability on Carbon Steel SAE1018

Robust Timing Synchronization for Multicarrier Systems Based on RST Invariance

In this paper, a blind robust timing synchronization method, based on invariance properties and cyclostationarity, for multicarrier systems such as Orthogonal Frequency Division Multiplexing (OFDM) is proposed and evaluated. Its results outperform the state-of-the-art for blind methods, specially in hard wireless channels where our proposal is highly superior. It even surpasses the performance of most of non-blind (pilot-aided) methods, while at the same time, it gets the advantages of energy and bandwidth saving of blind proposals. Moreover, since this technique does not require the use of pilots, it can be easily applied to either packet-based or broadcasting systems.This work has been partly funded by the Spanish national projects GRE3N-SYST (TEC2011-29006-C03-03) and COMONSENS (CSD2008-00010).Publicad

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A vision of uses and gratifications applied to the study of Internet use by adolescents

Based on uses and gratifications theory, the aim of this paper is to identify the reasons for using Internet among teenagers and to check different variables in order to predict types of uses. After conducting a representative survey applied to 397 high school students in Community of Madrid (Spain), Internet users’ gratifications and their relationships with variables related to adolescent characteristics, family context and time of online exposure are analyzed. The article concludes that daily use of Internet predicts higher consumption of communication and social relationship

Adaptation of the “Assessment of Adherence to Antiretroviral Therapy Questionnaire” (“Cuestionario de Evaluación de la Adhesión al Tratamiento antirretroviral” - CEAT-VIH) for its use in Peru

Objetivos: El objetivo de este estudio fue adaptar y validar el “Cuestionario para evaluar la adhesión al tratamiento antirretroviral” (CEAT-VIH) para su uso en el Perú, en pacientes VIH y SIDA en tratamiento antirretroviral de gran actividad (TARGA). Métodos: Se evaluó la comprensión del cuestionario así como sus propiedades psicométricas en una muestra de 41 pacientes con VIH y SIDA en tratamiento antirretroviral de gran actividad (TARGA) por más de tres meses. El periodo de estudio estuvo comprendido entre diciembre 2005 y enero 2006, el proceso de validación incluyó la aplicación del cuestionario el mismo día de la toma de muestra para el análisis de la carga viral y de los linfocitos TCD4. Se analizó la fi abilidad, la correlación de la puntuación con el recuento de linfocitos TCD4 y la carga viral. Resultados: Los resultados mostraron una adecuada fi abilidad (α = 0,706) y validez de criterio externa: respecto al recuento de linfocitos TCD4 (r = 0,439, p < 0,005), y respecto a la carga viral (r = - 0,548, p < 0, 005). Conclusiones: El CEAT-VIH ha demostrado ser una adecuada herramienta para evaluar el nivel de adherencia e identifi car los factores que infl uyen en la adherencia al tratamiento antirretroviral en una muestra de pacientes VIH y SIDA en Perú.Objective: To adapt and validate the “Assessment of Adherence to Antiretroviral Therapy Questionnary” “Cuestionario para evaluar la adhesión al tratamiento antirretroviral” (CEAT-VIH) for use in Peru, in HIV-infected patients in highly active antiretroviral therapy (HAART). Method: Understanding of the questionnaire was evaluated as well as its psychometric properties in 41 HIV-infected patients; antiretroviral therapy for at least 3 months was required. Data was obtained between December 2005 and January 2006. CEAT-VIH was carried out the day when sample for HIV viral load and CD4 cell count were taken. Reliability and validity related to two external criterions were evaluated. Results: CEAT-VIH showed appropriate reliability (α = 0,706) and adequate external criterion-related validity for CD4 cell count (r = 0,439, p < 0.005), and for HIV viral load (r = - 0,548, p < 0, 005). Conclusions: CEAT-VIH has proved to be useful to assess the level of adherence and to identify the factors affecting patient adherence to highly active antiretroviral therapy in Peru

Estudio de puriscal II. Crecimiento fetal y su influencia sobre el crecimiento fisico posnatal

articulo -- Universidad de Costa Rica. Instituto de investigaciones en Salud, 1982. Segundo artículo de una serie de investigaciones llevadas a cabo en Puriscal.El Estudio de Puriscal gira alrededor del estudio longitudinal del crecimiento y desarrollo del niño desde su vida intrauterino. Para tal propósito es preciso establecer un contacto periódico con las familiares de los niños de las falanges, y medir con precisión el crecimiento del Mike, expresado por el peso y talla a diversos intervalos, desde el nacimiento y a través de su primera infancia. Dicho objetivo se ha logrado con bastante exit° gracias a la creaciOn de una infraestructura que se contra en Ia Estacion de Campo de Puriscal dotada do personal calificado, equipos y recursos necesarios pare lograr el objetivo propuesto. El estudio, iniciado en septiembre de 1979, no ha tenido tropiezos y continua haste el presente., y ha permitido integrar otros proyectos de investigacion, asi como realizar una intervencion en salud fructifera pare Ia comunidad. Con el fin de analizar el crecimiento intrauterine y su relecion con el crecimiento postnatal, se hizo un corte a septiembre de 1981 que incluyo todos los niños que tengan por lo menos once años de edad a esa fecha, hacienda un total de 247 varones y 256 hembras. Mediante un programa de computadora que separo a los niños en subfalanges man el sexo, peso al nacer, edad gestacional y madurez fetal. Para cada subfalange so calculo la curva promedio de crecimiento de el nacimiento hasta los nueve años de edad.Los resultados mostraron qua los varones tienen, en general, major peso qua las hembras desde su necimiento y durante la lactancia. Tanto los varones como les hembras crecieron en canales influenciados por caracteristicas antropometricas definibles al nacer. Los ninos con mayor peso al nacer crecieron major durante los priirieros nueve metes qua los ninos que nacieron con menos peso. La edad gestacional tarnbien se correlacion6 con el crecimiento postnatal. Las subfalanges definidas por madurez fetal (edad gestacional y peso al nacer combinados) crecieron en canales de crecimiento influenciados por el crecirniento antenatal. Asi los ninos nacidos a termini) con peso adecuado para su edad gestacional, crecieron en forma analoga al 50 percentilo de las curves del National Center for Health Statistics (NCHS); los nacidos a termino con peso mayor pars is edad gestacional crecieron por arriba del 50 percentilo de Ia curve NCHS. Los ninos a termini) pero pequerios para edad gestational crecieron por debajo de la curve de referencia. Contrario a to observado en paises donde is infeccion y desnutricion son prevalentes, los nilios de Puriscal crecieron paralelo a las curves del NCHS lo qua denote que la variable mas importante en esta poblacion as el crecimiento intrauterino. Tal observacion denote que los factores ambientales qua afectan el consumo y utilizaciOn de los nutrientes esten actuando con poca a igual intensidad sobre las diversas subfalanges. Asimismo, las observaciones indican que no puede establecarte claramente el estado nutricional sin conocerse el peso al nacer por lo que se hace necesario insistir de nuevo sabre los criterios pare evaluar el estado nutricional. Finalmente, este estudio ha permitido, mediante el "Carrie de Salud", robustecer la conciencia comunitaria sobre la importancia de le vigilancia del estado nutricional directamente por la madre.An analysis of physical growth of cohorts of infants was made with regard to antenatal characteristics (birth weight, gestational age and fetal growth. All Puriscal neonates belonging to the first yearly cohort were classed by computer into subcohorts definied by these variables. Mean grwoth curves of the subcohorts so arranged were then calculated for visual and statistical study. In general, infants grew in tracks definied by antenatal characteristics. Differences in growth velocity observed at birth were maintained throughout the study period (birth to nine months). Birth weight and fetal matueity were the best predictors of postnatal physical growth. Most Puriscal infants grew at a velocity comparable to that of infants from the United States. Infants born at term with adequate weight for gestational age grew according to the 50th percentile of the reference curves.Universidad de Costa Rica, Instituto de investigaciones en Salud.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Autophagic Proteome in Two Saccharomyces cerevisiae Strains During Second Fermentation for Sparkling Wine Elaboration

A correlation between autophagy and autolysis has been proposed in order to accelerate the acquisition of wine organoleptic properties during sparkling wine elaboration. In this context, a proteomic analysis was carried out in two industrial Saccharomyces cerevisiae strains (P29, conventional sparkling wine strain and G1, implicated in sherry wine elaboration) with the aim of studying the autophagy-related proteome and comparing the effect of CO2 overpressure during sparkling wine elaboration. In general, a detrimental effect of pressure and second fermentation development on autophagy-related proteome was observed in both strains, although it was more pronounced in flor yeast strain G1. Proteins mainly involved in autophagy regulation and autophagosome formation in flor yeast G1, and those required for vesicle nucleation and expansion in P29 strain, highlighted in sealed bottle. Proteins Sec2 and Sec18 were detected 3-fold under pressure conditions in P29 and G1 strains, respectively. Moreover, ‘fingerprinting’ obtained from multivariate data analysis established differences in autophagy-related proteome between strains and conditions. Further research is needed to achieve more solid conclusions and design strategies to promote autophagy for an accelerated autolysis, thus reducing cost and time production, as well as acquisition of good organoleptic properties

Biological Processes Highlighted in Saccharomyces cerevisiae during the Sparkling Wines Elaboration

Sparkling wines elaboration has been studied by several research groups, but this is the first report on analysis of biological processes according to the Gene Ontology terms (GO terms) and related to proteins expressed by yeast cells during the second fermentation of sparkling wines. This work provides a comprehensive study of the most relevant biological processes in Saccharomyces cerevisiae P29, a sparkling wine strain, during the second fermentation under two conditions (without and with endogenous CO2 overpressure) in the middle and the end of second fermentation. Consequently, a proteomic analysis with the OFFGEL fractionator and protein identification with LTQ Orbitrap XL coupled to HPLC were performed. The classification of biological processes was carried out using the tools provided by the Saccharomyces Genome Database. Results indicate that a greater number of biological processes were identified under condition without CO2 overpressure and in the middle of the fermentation versus the end of the second fermentation. The biological processes highlighted under condition without CO2 overpressure in the middle of the fermentation were involved in the carbohydrate and lipid metabolic processes and catabolic and biosynthetic processes. However, under CO2 overpressure, specific protein expression in response to stress, transport, translation, and chromosome organization and specific processes were not found. At the end of fermentation, there were higher specific processes under condition without CO2 overpressure; most were related to cell division, growth, biosynthetic process, and gene transcription resulting in increased cell viability in this condition. Under CO2 overpressure condition, the most representative processes were related to translation as tRNA metabolic process, chromosome organization, mRNA processing, ribosome biogenesis, and ribonucleoprotein complex assembly, probably in response to the stress caused by the hard fermentation conditions. Therefore, a broader knowledge of the adaptation of the yeast, and its behavior under typical conditions to produce sparkling wine, might improve and favor the wine industry and the selection of yeast for obtaining a high-quality wine

Comparative Study of the Proteins Involved in the Fermentation-Derived Compounds in Two Strains of Saccharomyces cerevisiae during Sparkling Wine Second Fermentation

Sparkling wine is a distinctive wine. Saccharomyces cerevisiae flor yeasts is innovative and ideal for the sparkling wine industry due to the yeasts’ resistance to high ethanol concentrations, surface adhesion properties that ease wine clarification, and the ability to provide a characteristic volatilome and odorant profile. The objective of this work is to study the proteins in a flor yeast and a conventional yeast that are responsible for the production of the volatile compounds released during sparkling wine elaboration. The proteins were identified using the OFFGEL fractionator and LTQ Orbitrap. We identified 50 and 43 proteins in the flor yeast and the conventional yeast, respectively. Proteomic profiles did not show remarkable differences between strains except for Adh1p, Fba1p, Tdh1p, Tdh2p, Tdh3p, and Pgk1p, which showed higher concentrations in the flor yeast versus the conventional yeast. The higher concentration of these proteins could explain the fuller body in less alcoholic wines obtained when using flor yeasts. The data presented here can be thought of as a proteomic map for either flor or conventional yeasts which can be useful to understand how these strains metabolize the sugars and release pleasant volatiles under sparkling wine elaboration conditions

Differential Analysis of Proteins Involved in Ester Metabolism in two Saccharomyces cerevisiae Strains during the Second Fermentation in Sparkling Wine Elaboration

The aromatic metabolites derived from yeast metabolism determine the characteristics of aroma and taste in wines, so they are considered of great industrial interest. Volatile esters represent the most important group and therefore, their presence is extremely important for the flavor profile of the wine. In this work, we use and compare two Saccharomyces cerevisiae yeast strains: P29, typical of sparkling wines resulting of second fermentation in a closed bottle; G1, a flor yeast responsible for the biological aging of Sherry wines. We aimed to analyze and compare the effect of endogenous CO2 overpressure on esters metabolism with the proteins related in these yeast strains, to understand the yeast fermentation process in sparkling wines. For this purpose, protein identification was carried out using the OFFGEL fractionator and the LTQ Orbitrap, following the detection and quantification of esters with gas chromatograph coupled to flame ionization detector (GC-FID) and stir-bar sorptive extraction, followed by thermal desorption and gas chromatography-mass spectrometry (SBSE-TD-GC-MS). Six acetate esters, fourteen ethyl esters, and five proteins involved in esters metabolism were identified. Moreover, significant correlations were established between esters and proteins. Both strains showed similar behavior. According to these results, the use of this flor yeast may be proposed for the sparkling wine production and enhance the diversity and the typicity of sparkling wine yeasts