Sample records for forming materials
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1

RESISTENCIA A ANTIBIOTICOS DE BACTERIAS AISLADAS DE BIOPELÍCULAS EN UNA PLANTA DE ALIMENTOS/ ANTIBIOTIC RESISTANCE OF BACTERIA ISOLATED FROM BIOFILMS IN A FOOD PROCESSING PLANT

Vanegas L, María; Correa C, Nancy; Morales M, Ana; Martínez L, Aída; Rúgeles G, Laura; Jiménez I, Francy
2009-08-01

Resumen en español Objetivo. Evaluar la resistencia a antibióticos y la capacidad de formación de biopelículas de bacterias aisladas en una planta de producción de alimentos. Materiales y métodos. Se tomaron muestras de 3 zonas diferentes, en una planta procesadora de alimentos; en la lavadora de canastas, la mesa de producción y en la banda empacadora. Se aislaron e identificaron las bacterias presentes en cada una de las tres zonas y se determinó la capacidad formadora de biopelíc (mas) ulas por medio de cuantificación celular. Asimismo se evaluó la resistencia de cada una de las bacterias aisladas frente a ocho diferentes antibióticos. Resultados. Se recuperaron 29 cepas, correspondientes a 13 géneros diferentes, los cuales fueron todos formadores de biopelículas. Se encontró que cerca del 50% de las bacterias aisladas fueron resistentes a antibióticos como la penicilina G y vancomicina. Adicionalmente se evidenció un alto grado de multirresistencia a los diferentes antibióticos. Conclusiones. La alta multirresistencia encontrada a antibióticos entre las bacterias analizadas podría ser un problema para salud pública ya que pueden ser transmitidas por alimentos. De igual manera es de gran importancia la capacidad de producción de biopelículas de la microbiota analizada así como la alta concentración de bacterias entéricas y ambientales, lo que sugiere deficiencia del programa de limpieza y desinfección de la planta. Resumen en inglés Objective. To assess the antibiotic resistance and the ability to produce biofilms in bacteria isolated from a food processing plant. Materials and methods. Samples from 3 different zones from a food processing plant were analyzed: Baskets washers, production table and baler band. The bacteria were isolated and identified in each of three zones and biofilm forming capacity was measured for all the isolates by quantifying the cells present in the biofilm. Subsequently, a t (mas) est of resistance to eight different antibiotics was assessed. Results. From a total of 29 isolates,13 different genres were identified. All of these genres were biofilm- formers. About 50% of the isolated bacteria were resistant to antibiotics such as penicillin G and vancomycin. Similarly, a high degree of antibiotic multiresistance was demonstrated in the bacteria isolated. Conclusions. Multi-resistance to antibiotics was observed in many of the isolates. Since these bacteria can be transmitted through food, this could be a problem for public health. Aso, it is important the biofilm forming capacity in the analyzed bacteria, as well as the wide number of enteric and environmental bacteria found in this study which suggests inefficiency on food processing plant cleanliness and disinfection program.

Scientific Electronic Library Online (Spanish)

2

LOS CAMINOS DE GANADO EN LAS TIERRAS ALTAS DEL DEPARTAMENTO DE ANTIOQUIA: UNA PRIMERA APROXIMACIÓN/ CATTLE TRAILS IN ANTIOQUIA DEPARTMENT (COLOMBIA) HIGHLANDS: A FIRST APPROACH.

ARISTIZABAL, ANDRÉS FELIPE; HERMELIN, MICHEL
2008-11-01

Resumen en español Los bovinos de las poblaciones pecuarias de América empezaron a llegar hace cinco siglos a las islas del Caribe en las naves españolas y de ahí fueron trasladados al continente. En las regiones de montaña y altiplanos, donde el clima permite la crianza y reproducción de razas para producción de leche, las vacas se desplazan en las vertientes empinadas en forma subhorizontal para alcanzar el pasto. En la zona central del departamento de Antioquia, la vegetación orig (mas) inal de las vertientes y de los altiplanos fue el bosque andino, que fue sustituido en muchas partes por pastos. Ese proceso implicó una gran disminución en el suministro de materia orgánica y la compactación de los horizontes superficiales por los cascos del ganado vacuno. Uno de los resultados es la formación de caminos de ganados; entrecruzados, de unos 60 cm de ancho e inclinación lateral de unos 0º a 20º, que aparecen en pendientes entre 27,5º y 33,4º, que modifican la densidad, la permeabilidad de los suelos y que suprimen prácticamente el recubrimiento vegetal en las áreas de pisoteo. Al evolucionar, provocan erosión superficial que puede llegar a inducir desde pequeños movimientos de masa hasta una destrucción completa del suelo original. Este trabajo se realizó en el centro del departamento de Antioquia en los municipios de Guarne, Rionegro, San Vicente, San Pedro y Medellín, a alturas entre 1500 y 2500 msnm, que corresponden a las formaciones vegetales bh-MB, bmh-MB y bh-PM e incluye suelos derivados de diferentes materiales parentales. Las conclusiones preliminares apuntan hacia la necesidad de limitar el uso del suelo para ganadería a partir de una pendiente crítica. Resumen en inglés Cattle was brought by the Spaniards to the Caribbean Islands about 5 centuries ago, and from there was translated to the American continent. In the Colombian highlands, climate enables rising and reproducing of brands used for milk production, cows . In the central area of the Antioquia department, the natural vegetation before European colonization was humid forest, which was in many places replaced by pastures. This change caused a great loss in organic matter content o (mas) f the soil upper horizons and also an increase in their density due to the effect of cow foots, forming cattle trails. As a result trails appear in slopes between 27.5º and 33.4º, with lateral inclinations of 0º to 20º and a wideness of about 60 cm; they modify soil density and permeability and practically suppress vegetation cover in the stepped areas. Their evolution without control may induce small slope movements and event total soil destruction. This project was carried out in the central area of the Antioquia department, in municipalities of Guarne, Rionegro, San Vicente, San Nicolas and Medellin, at altitudes between 1500 and 2500 m above sea level, which correspond to humid and very humid tropical mountain forest and include soils derived from different parent materials. Preliminary conclusions point toward the necessity to limit cow grazing in slopes to areas located below a critical value.

Scientific Electronic Library Online (Spanish)

3

BIOACTIVIDAD DE VIDRIOS MODIFICADOS DEL SISTEMA Na2O·CaO·SiO2·P2O5

Barrios de Arenas, I; Schattner, C; Vásquez, M
2001-12-01

Resumen en español Desde hace algunos años se han ido desarrollando materiales cerámicos especiales, cuyas propiedades permiten que éstos sean usados como reemplazo de hueso en humanos. Una de las propiedades que se destaca en estos materiales es la biocompatibilidad, que permite que el material sea aceptado por el organismo aún cuando no interactúe con el. Muchos investigadores han estudiado la bioactividad de cerámicas y vidrios, así como su capacidad de unión con tejidos blandos (mas) y duros. Hench y sus colaboradores descubrieron que es posible la unión química entre huesos y vidrios de ciertas composiciones, los cuales denominaron vidrios bioactivos, encontrando numerosas aplicaciones en la reparación y reconstrucción de tejidos enfermos y dañados, especialmente en huesos. El B2O3 y Al2O3 se usan para modificar la superficie de disolución, la durabilidad y las características de fusión y formabilidad de los vidrios bioactivos; sin embargo el alúmina (Al2O3) a diferencia del B2O3 puede inhibir el proceso de unión entre el material bioactivo y el hueso, siendo la cantidad aceptable de alúmina, una función de la composición del vidrio. El propósito de este trabajo fue estudiar la influencia de la adición B2O3 y Al2O3 en proporciones variables sobre la bioactividad de vidrios del sistema Na2O·CaO·SiO2·P2O5, investigando in vitro la formación de la capa de apatita en la superficie de los vidrios, sumergiendo las muestras en un fluido simulado del cuerpo, que es una solución acuosa sin celulas de una concentración iónica similar a la del plasma de sangre humana. La superficie de reacción fue estudiada usando Microscopía Eléctrica de Barrido (MEB) y la capa depositada fue analizada por distribución lineal de barrido usando un detector UTW. Los perfiles composicionales de la capa formada sobre la superficie de los substratos mostraron que esta capa es rica en calcio y fósforo, caracterizada en trabajos anteriores como apatita. Esta fase creció en los vidrios todas las composiciones estudiadas excepto en aquellas con una relación B2O3 / Al2O3 mayor a 0,55. Resumen en inglés Special materials have been developed with properties which allow them to be used where a bone replacement is needed. An important property of these materials is the biocompatibility, this property allows that these materials are accepted by the organism although there is not interaction with it. Research works have been carried out on the bioactivity of ceramics and glasses studying their bond to soft or hard tissues. Hench and co-workers discovered that chemical bonding (mas) between a bone and certain glass compositions is possible, so called bioactive glasses, encountering them numerous applications in the repair and reconstruction of diseased and damaged tissue, especially hard one (bone). B2O3 and Al2O3 have been used in bioactive glasses to modify its surface dissolution and durability, melting and forming characteristics; however, Al2O3 in contrast to B2O3 can inhibit bone bonding, being the acceptable amount of alumina a function of glass composition. The purpose of this work was to study the influence of variable B2O3 / Al2O3 addition on the bioactivity Na2O·CaO·SiO2·P2O5 glasses, being the formation of the apatite layer on the glasses surface investigated in vitro soaked at different time intervals, using simulated body fluid, an acellular aqueous solution which has similar ion concentration to human blood plasma. The reaction surface was studied using Scanning Electron Microscopy (SEM) and the deposited layer was analysed by EDX line scans using UTW detector. The compositional profiles of the deposited surface and substrate showed a layer rich in calcium and phosphorous characterised in previous works as apatite. This phase has grown in all studied compositions except those with B2O3 / Al2O3 contents higher than 0,55.

Scientific Electronic Library Online (Spanish)

4

Estructuras de deformación (¿sismitas?) en la Formación Río Negro, provincia de Río Negro, Argentina

Schillizzi, Roberto; Luna, Liliana; Falco, Juan Ignacio
2010-07-01

Resumen en español A Las estructuras de deformación (ED) en sedimentos blandos comprenden las alteraciones que se producen casi simultáneamente con la sedimentación. Estos procesos se hallan en relación directa con las características internas de los materiales sedimentarios y de los factores externos que actúan sobre ellos. Sus resultados incluyen deformaciones como inyecciones, fracturas, volcanes y laminaciones convolutas que afectan total o parcialmente la estratificación. Los se (mas) dimentos blandos deformados por sismos se incluyen bajo la denominación general de sismitas (seismites). Como objetivo de esta investigación se plantea reconocer, por primera vez, estructuras de deformación ubicadas en la Formación Río Negro presentes en el sector norte del Golfo San Matías, en inmediaciones del Faro Río Negro. La metodología empleada consistió en el reconocimiento y descripción de las estructuras, para lo cual se extrajeron muestras para determinar granulometría, mineralogía y contenido de materia orgánica. Se fotografiaron los distintos sectores con deformaciones con el fin de establecer modelos comparativos. El sector estudiado, de 4 km de extensión, se ubica entre el faro de Río Negro y el inicio del Banco Verde y morfológicamente corresponde a un frente acantilado con orientación ENE-OSO. En él se determinaron las siguientes ED: a- de carga simple, pseudonódulos contiguos y aislados, y estructuras complejas; b- de escape de fluidos y c- estructuras de deslizamiento basal y por presión dirigida. El origen de las deformaciones se debe a las características de las sedimentitas y a los procesos que las afectan tales como los efectos por carga, escapes de fluidos y las presiones dirigidas. Como origen de estos procesos se señalan: la presión de la columna litológica, las olas de tormentas y los terremotos. Por los rasgos hallados las deformaciones del litoral rionegrino tendrían un origen sísmico, proceso ocurrido en un único evento durante el ciclo Andino cuyos inicios se fijan hace aproximadamente 45 Ma. Por otra parte sus techos y bases no se hallan asociados a otros procesos de deformación y sus espesores no exceden el metro de potencia. Además se hallan acotadas a la zona de transición entre los miembros medio y superior de la Formación Río Negro descansando en algunos casos sobre arcilitas y en otros sobre limolitas, originadas en un paleorelieve de interdunas. Resumen en inglés Soft-sediment deformation structures (SSD) are alterations produced almost simultaneously with sedimentation. They are directly related to internal characteristics of sedimentary materials as well as to external factors acting on them. Results derived from such alterations are evidenced as injections, fractures, volcanoes and convolute laminations, among other forms, affecting stratification either totally or partially. Soft-sediment deformation structures resulting from (mas) seisms are known as seismites. The present study aims at determining for the first time the presence of SSD structures in the Río Negro Formation, located in the northern area of San Matías Gulf, near Río Negro Lighthouse, Argentina (Fig. 1). To this end, structures were firstly identified and further described. Samples were subsequently collected for the determination of grain-size, mineralogy and organic matter content. Photographs of the different sectors evidencing deformations were taken in order to determine further comparative models. Morphology in the study area is associated to cliffs with vertical, fractured fronts and with an average height of 70 m in whose base torn-down blocks are accumulated. The geological structure of the study area is related to the Cuenca del Colorado and the Comarca Nordpatagónica, whose basement is mainly composed of Paleozoic and Mesozoic crystalline rocks. The sedimentary tertiary cover from the Miocene-Pliocene is represented by light-blue sandstones of the Río Negro Formation (Andreis, 1965). This unit was formed in an aeolian environment with intercalations of clay-silt shallow lagoons and a marine episode located in the mid area of the Río Negro Formation. At the top of the Río Negro Formation there are Pleistocene-Holocene sedimentites having a thickness of up to 5 m. Within the local structural framework of our study area there are fractures with a NE-SW and a NW-SE direction, which are related with fractures N55º, N90º and N350º azimuth located in the abrasion platform. According to Dzulinsky and Walton (1965), Lowe (1975), Brencley and Newall (1977), Clauss (1993), van Loon (2002), Owen (2003), Neuwerth et al. (2006), Alfaro et al. (2006), Montenat et al. (2007), among others (Table 1), and, taking into account the geometry of deformations, laboratory reconstructions and field observations from our study area, it can be concluded that the classifications of SSD structures tend to establish morphologic and genetic systematizations. The following characteristics were identified in our study area: limited deformations among stratigraphic horizons; a lateral continuity of SSD structures at considerable distances; and a confinement between non-deformed strata and its lithological association with psamitic-pelitic sediments. The study area, which is 4 km long and is located between Río Negro Lighthouse and the beginning of Banco Verde, is from the morphological point of view, a cliffed front with an ENE-WSW orientation. Different types of SSD structures were identified in this area. For example, from the morphological point of view and according to the loading mechanisms observed, simple-load structures (Fig. 2), attached and detached pseudonodules (Figs. 3, 4 and 5) and complex structures (Fig. 6) were identified. Furthermore, from the genetic point of view and according to the intrusion processes observed in soft sediments, water-scape structures (Fig. 7) and plate- or fountain-like deformations (Fig. 8) were found. From the genetic point of view, and based on the collapse and pressure mechanisms observed, basal slumping (Fig. 9) and directed-pressure structures (Fig. 11) were also found. The above-mentioned SSD structures were analyzed and interpreted following Strachan´s model (2002) (Fig. 10) and Laird´s model (1968) (Fig. 12). The origin of SSD structures depends on the characteristics of sedimentites and on the mechanisms that produce them. In the study area, the materials susceptible to deformation come from an interdune environment that is characterized by granulometric variations derived from the fluctuating and restrictive climatic conditions (Cojan and Thiry, 1992) that typify the Río Negro Formation. Fine-grained materials having low cohesion and poor sorting such as the sediments of deformed strata (Fig. 13) produced SSD structures as a result of high pore pressure and liquefaction effects (Tsuchida and Hayashi, 1971; Obermeier, 1996). Grain packing with a porous value as that allows intercommunication among grains and saturated material, is also crucial to the formation of SSD structures. The mineralogic content of deformed levels is composed of i) quartz, chalcedony, orthose, plagioclase, pyroxenes and biotite, opaques (magnetite and ilmenite, autigenic pyrite) in crystalline aggregates; ii) undetermined Fe oxides; and iii) colorless and light-brown unaltered volcanic glass shards, clays identified as smectite-illite interstratified and scarce kaolinite. Grains are mainly subangular and, to a lesser extent, sub-round and round. The surface of the majority of grains in the study area was found clean and with some marks. The percentage of CaCO3 was found to vary from 0.5 to 3% and that of total organic carbon (TOC) was found to reach 1.5%. Deformations may be produced as a result of load deformation mechanisms, fluid escape, basal slumping or pressure-directed displacements. Due to load deformation mechanisms, structures are linked to gravity-related movements occurring during the initial stages of deposition. For these deformations to occur, grain-size at the overlaying levels should be thicker than at the underlying levels, for example, sandstones rather than silstones or claystones. These deformations are related to water saturation at the deformed level (fluidization-liquefaction). Therefore, deformation mechanisms, which involve both expulsion and rotation of fragments as well as fluid escape, are characterized by the action of lithostatic pressure which produces movement (deformation) and by the action of the underlying sedimentary levels. Deformations may also result from a fluid escape mechanism, i.e., from a mechanism associated to i) the spatial arrangement of grains (packing), ii) their shape, iii) their tendency to inequigranularity, and iv) the communication among macro- and micro- pores as well as the high or low sinuosity connection among themselves (Net and Limarino, 2000). Further requirements for deformations to occur include particular thixotrophic conditions, especially the presence of colloids among grains. The rupture of unions of particles either by hitting or by shearing is, among others, a cause which produces an unbalance between hydrostatic pressure and lithostatic pressure. If the latter is altered, the energetic unbalance makes fine sediments flow among the weakly lithified sandstones whose extrusion will occur via both vertical and horizontal pore ducts (Lopez Gamundi, 1986; Clauss, 1993). Basal slumping produces deformations that are associated not only to soft sediments deposited in natural slopes but also to interbedded sand- and mud-levels. Layers tend to have a prismatic-shaped geometry whose materials are under ductile-to-fragile conditions, in which antique layers support younger ones. Once horizontality is affected, movement, which is marked by a rupture of the original slope, begins. The lower levels are expected to transport the upper ones without affecting the original succession of layers. At the delay of movement derived from the compressive effect of the displacement front, fluids extrude forming cones or cut dikes (Fig. 10). Several deformations of this type initiate movement as result of differences in the hydrostatic gradient (Strachan, 2002). Deformations may be also produced as a result of pressure-directed displacements which are conditioned by the compaction level, thickness and ability of materials to deform. Thus, deformations occur because the original level is saturated in water as a result of the ductile behavior of materials (Bracco et al., 2005). Laird (1968) claims that SSD structures should meet some of the following requirements to be considered of seismic origin: slightly curved strata walls and floors to follow the original stratification and interruption of continuity of the stratum that is marked by a scar in which the sedimentary fillings keep their characteristics both above and below stratification. There could be rotated sediment clasts below the discontinuity as a result of a thrust-induced drag of the upper sedimentary packing. These processes could be, in turn, triggered either by the charge or pressure of the lithologic column, storm waves and seismicity. Storm-wave impact may also produce deformation in soft sediments. Nonetheless, no high energy structures such as cross-beddings or tsunami-type chaotic sedimentation were observed in our study area. Noteworthingly, for stormwave-derived liquefaction to occur, waves should reach magnitudes higher than 6 m (Alfaro et al., 2002), this being a phenomenon that was not recorded in our study area. Taken together, findings from the present study indicate that SSD structures in our study area are seismic alterations that occurred in an event during the Andean cycle whose beginnings are traced approximately 45 My ago. The fact that i) both the roofs and bottoms of these structures are not associated to other processes of deformation, ii) their thickness does not exceed one meter, and iii) they are confined to a transitional area between the middle and top members of the Río Negro Formation, lying in some cases on claystones and in some other cases, on siltstones, originated in an interdune paleorelief, confirms their seismic origin.

Scientific Electronic Library Online (Spanish)

5

Zeolites in Tertiary coal from the Çayirhan mine, Beypazari, Turkey

Whateley, M. K. G; Querol, Xavier; Fernandez-Turiel, J. L.; Tuncali, E.
1996-01-01

Digital.CSIC (Spain)

7

Universal features of water dynamics in solutions of hydrophilic polymers, biopolymers, and small glass-forming materials

Cerveny, Silvina; Alegría Loinaz, Ángel; Colmenero de León, Juan

5 pp.-- PACS nrs.: 82.35.Pq, 61.25.Em, 77.22.Gm.-- PMID: 18517410. | A systematic investigation by dielectric spectroscopy of 18 different water-rich mixtures with very different hydrophilic substances shows universal features for the water dynamics. The temperature dependence of the relaxation time...

DRIVER (Spanish)

8

Ultrasound device for improving the solid-liquid separation process in suspensions.

Gallego Juárez, Juan Antonio; Rodríguez, Corral; Elvira Segura, Luis
2006-12-16

Digital.CSIC (Spain)

10

Tin–carbon composites as anodic material in Li-ion batteries obtained by copyrolysis of petroleum vacuum residue and SnO2

Tirado, J. L.; Santamaría Ramírez, Ricardo; Ortiz, G. F.; Menéndez López, Rosa M.ª; Lavela, P.; Jiménez-Mateos, J. M.; Gómez García, F. J.; Concheso Álvarez, Alejandro; Alcántara, R.
2007-04-02

Digital.CSIC (Spain)

11

The role played by the reactive alumina content in the alkaline activation of fly ashes

Fernández-Jiménez, Ana; Palomo Sánchez, Ángel; Sobrados, Isabel; Sanz, J.
2006-04-01

Digital.CSIC (Spain)

12

Templated synthesis of nanosized mesoporous carbons

Álvarez García, Sonia; Valdés-Solís Iglesias, Teresa; Fuertes Arias, Antonio Benito
2008-07-01

Digital.CSIC (Spain)

13

Synthesis of granular zeolitic materials with high cation exchange capacity from agglomerated coal fly ash

Juan Mainar, Roberto; Hernández, S.; Andrés Gimeno, José Manuel; Ruiz, Carmen
2007-02-07

Digital.CSIC (Spain)

14

Support for enzymes and proteins comprising an inorganic solid combined material comprising the support.

Corma Canós, Avelino; Fornés, Vicente; Jordá Moret, José Luis; Rey García, Fernando; Fernández Lafuente, Roberto; Guisán Seijas, José Manuel; Mateo, Cesar
2001-08-24

Digital.CSIC (Spain)

15

Spectroscopic characterization and Langmuir-Blodgett films of a novel azopolymer material.

Haro, Marta; Ross, Daniel J.; Oriol, Luis; Gascón, Ignacio; Cea, Pilar; López, Maria Carmen; Aroca, Ricardo F.
2007-01-04

Digital.CSIC (Spain)

17

Signature of nitrogen compounds responsive for changes in C and N forms in peat subjected to progressive thermal stress

Piedra Buena, A.; González-Vila, Francisco J.; González-Pérez, J. A.; Almendros, G.
2009-01-01

Digital.CSIC (Spain)

18

Seroprevalencia de infección por Leptospira spp. en auxiliares y veterinarios de consultorios de pequeños animales de Villavicencio (Colombia)/ Leptospira spp. infection seroprevalence in assistants and veterinarians working in small animal consulting rooms in Villavicencio (Colombia)

Quitián, Helena; Parra, Julieth; Góngora Orjuela, Agustín; Parra Arango, Jorge L; Gallego, Juan F; Aponte Garzón, Luz H
2009-06-01

Resumen en español Objetivo: Determinar seroprevalencia por la prueba de MAT a seis serovares de Leptospira spp. en el grupo de riesgo: auxiliares y veterinarios de consultorios de pequeños animales de Villavicencio, Meta, Colombia, que previamente había sido serorreactor por Elisa-Pambio. Materiales y métodos: Se tomaron 72 muestras de sueros de individuos pertenecientes al subgrupo de auxiliares y veterinarios, de una población mayor que incluía otros 7 grupos humanos a riesgo a Lept (mas) ospira spp. y que había presentado reactividad serológica considerada como "positiva" (17 %) a la prueba de Elisa para Leptospira spp. con un kit de Pambio. Los sueros, que se habían conservado a -70°C en el Laboratorio de Reproducción y Genética Animal de la Universidad de los Llanos, fueron evaluados para reactividad serológica a la prueba de microaglutinación-lisis (MAT) con los serovares L. hardjoprajitno, L. copenhageni, L. canícola, L. icterohaemorrhagiae, L. autumnalis, L. bratislava, L. australis y L. pomona. Se utilizó el protocolo de laboratorio del Programa Nacional de Investigación en Salud Animal de CORPOICA-CEISA. Resultados: La seropositidad a MAT fue 26.4%. En los auxiliares 21% y los veterinarios 29%. La seropositidad por serovar fue L. bratislava 24%, L. australis 8%, L. copenhageni 6%, L. canícola 3%, L. autumnalis y L. hardjoprajitno 1%. No se encontraron reactores a icterohaemorrhagiae y pomona. Los títulos serológicos estuvieron en un rango entre 1:25 y 1:400. La copositividad entre MAT y ELISA IgM fue 42% y la conegatividad 77%. Conclusiones: La seropositidad en el grupo estudiado es alta y preocupante, por lo tanto, exige extremar las medidas de bioseguridad durante la práctica médico veterinaria. Resumen en inglés Objective: Determining to six serovares Leptospira spp. seroprevalence in assistants and veterinarians working in small animal consulting rooms in Villavicencio, Meta Colombia that previously had been seroreactor for Elisa-Pambio. Materials and Methods: 72 sera samples were taken from a subgroup of individuals consisting of assistants and veterinarians, in turn forming part of a larger population which included another 7 human groups at risk of becoming infected by Leptos (mas) pira spp.; a cross-sectional epidemiological model was used and subjects were chosen by convenience. The sera had remained frozen (-70°C) in the Universidad de los Llanos Animal Reproduction and Genetics laboratory since being obtained. A commercial indirect ELISA kit (Pambio) was used for determining IgM antibodies. hardjoprajitno, copenhageni, canícola, icterohaemorrhagiae, autumnalis, bratislava, australis and pomona serovars were used in the microscopic agglutination test (MAT). The protocol of laboratory of the national program of investigation in animal health of CORPOICA-CEISA was used. Results: MAT seropositivity was 26.4% (21% in assistants and 29% in veterinarians) Seropositivity by serovar was: 24% bratislava, 8% australis, 6% copenhageni, 3% canícola, 1% autumnalis and hardjoprajitno. No reactors to icterohaemorrhagiae and pomona were found. Serological titres ranged from 1:25 to 1:400. Conclusions: It was thus concluded that seropositivity in the group being studied was high and worrying, meaning that biosafety measures must be maximized for all people working in veterinary practice.

Scientific Electronic Library Online (Spanish)

19

Recuento bacteriano en bilis de pacientes con colangitis aguda: Reporte preliminar/ Assessment of bacterial load in bile among patients with acute cholangitis

LOSADA M, HÉCTOR; MANTEROLA D, CARLOS; PINEDA N, VIVIANA; VIALG, MANUEL
2006-02-01

Resumen en español Introducción: No se encuentra bien establecido el rol que desempeña la carga bacteriana de la bilis en la fisiopatología o evolución de los pacientes con colangitis. El objetivo del presente trabajo fue describir la carga bacteriana y los gérmenes más frecuentes en la bilis coledociana de pacientes con colangitis aguda litiásica intervenidos quirúrgicamente en el Hospital Hernán Henríquez de Temuco entre diciembre del año 2004 y marzo del 2005. Material y Méto (mas) do: Estudio de serie de casos prospectiva. Se incluyeron pacientes mayores de 18 años con colangitis aguda litiásica. Los cultivos de la bilis coledociana se sembraron en agar sangre y agar Mac Conkey. Resultados: Se estudió un total de 30 cultivos de bilis. Los gérmenes aislados presentaron cargas bacterianas sobre 105 UFC/ml en 25 cultivos (83,3%), 4 (12,3%) presentaron carga bacteriana inferior a 105 UFC/ml y en 1 cultivo (3,4%) no se registró presencia de gérmenes. El germen más frecuentemente aislado fue Escherichia coli (53%), seguido por Klebsiella pneumoniae (20%). Las bacterias gram negativas no mostraron resistencia a los aminoglucósidos ni cefalosporinas de tercera generación. Los gérmenes gram positivos no mostraron resistencia a la ampicilina y vancomicina. Conclusiones: La carga bacteriana en los pacientes con colangitis aguda litiásica es >105 UFC/ml en la mayoría de los casos. El germen más frecuentemente aislado fue Escherichia coli, seguido por Klebsiella pneumoniae. Llama la atención el aislamiento de Morganella morganii y Citrobacter freundii en 1 cultivo Resumen en inglés Background: The role that bile bacterial load plays in the physiopathology or the evolution of patients with cholangitis has not been well established. Aim: To assess the bacterial load and the most common bacteria infecting the bile of patients with acute gallstone cholangitis. Materials and Methods: A prospective series of patients over 18 years of age with acute gallstone cholangitis operated at Temuco Regional Hospital between December, 2004 and March, 2005. The bile (mas) cultures from the choledochus were placed in blood and MacConkey agar plates. Results: A total of 30 bile cultures were studied. In 25 cultures (83%) the bacterial load was over 105 colony forming units (CFU)/ml, four cultures (12.3%) had a bacterial load of less than 105 CFU/ml and one culture (3.4%) was negative. The most commonly isolated bacteria was Escherichia coli (53%), followed by Klebsiella pneumoniae (20%). All gram-negative bacteria were susceptible to either aminoglucosides or third-generation cephalosporins. All gram-positive bacteria were susceptible ampicillin or vancomycin. Conclusions: The bacterial load in patients with acute gallstone cholangitis is >105 CFU/ml in most cases. The most frequently isolated germ was Escherichia coli, followed by Klebsiella pneumoniae

Scientific Electronic Library Online (Spanish)

20

Pyridine Gold Complexes. An Emering Class of Luminescent Materials.

Fernández, Eduardo J.; Laguna, Antonio; López-de-Luzuriaga, José M.; Monge, Miguel; Montiel, Manuel; Olmos, M. Elena; Pérez, Javier; Rodríguez-Castillo, María
2008-01-01

Digital.CSIC (Spain)

21

Process for the synthesis of zeolite ITQ-13 in a basic medium and in the absence of fluoride ions

Corma Canós, Avelino; Rey García, Fernando; Fornés, Vicente; Castañeda Sánchez, Rafael
2005-05-06

Digital.CSIC (Spain)

22

Process for preparing multilayers with and ordered mesoporous structure, material obtained in this manner, and use

Míguez García, Hernán Ruy; Soler Illia Galo, Juan de Avila; Fuertes, María Cecilia; López Alcaráz, Javier
2008-03-27

Digital.CSIC (Spain)

25

Porous crystalline material (zeolite ITQ-24), preparation method thereof and use of same in the catalytic conversion of organic compounds

Corma Canós, Avelino; Castañeda Sánchez, Rafael; Fornés, Vicente; Rey García, Fernando
2005-12-28

Digital.CSIC (Spain)

26

Plant parasitic nematodes associated with olive in countries bordering the mediterranean sea.

Vovlas, Nicola; Castillo, Pablo; Rapoport, Hava F.; Jiménez-Díaz, Rafael M.
2002-01-01

Digital.CSIC (Spain)

27

Photonic bandgap materials based on germanium.

Miguez García, Hernan Ruy; John, Sajeev; Chomski Emmanuel, Benjamin; López Fernández, Ceferino; Meseguer Rico, Francisco; Ozin Geoffrey, Alan
2001-11-15

Digital.CSIC (Spain)

28

Patterns of spatial regularity in late prehistoric material culture styles of the NW Iberian Peninsula

Prieto-Martínez, M. Pilar; Cobas Fernández, Isabel; Criado-Boado, Felipe
2003-01-01

Digital.CSIC (Spain)

29

Organic-inorganic hybrid material for storage and release of active principles

Corma Canos, Avelino; Arrica, María Antonia; Díaz Morales, Urbano Manuel
2010-04-21

Digital.CSIC (Spain)

30

Organic sensor device and its applications

Laukhina, Elena; Mas Torrent, Marta; Rovira Angulo, Concepción; Veciana Miró, Jaume; Laukhin, Vladimir
2008-05-22

Digital.CSIC (Spain)

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33

Niveles de infección de Streptococcus mutans en niños menores de dos años y sus madres en el Instituto Nacional de Perinatología/ Levels of infectivity of Mutans Streptococcus in lower two years old children an her mothers at Instituto Nacional de Peritanología

Revuelta Pérez, Regina; Díaz-Romero, Rosa María
2006-09-01

Resumen en español Introducción: La ventana de infectividad, descrita por Caufield en niños norteamericanos, comprende el periodo durante el cual el ser humano es más susceptible de adquirir Streptococcus mutans (SM), tiempo durante el cual se incrementa la susceptibilidad a padecer caries. Hasta el momento no existen estudios que determinen el nivel de infectividad de SM en niños mexicanos. Objetivos: Determinar los niveles de infección en un grupo de niños mexicanos y conocer la aso (mas) ciación entre la presencia SM en saliva de la madre y su hijo. Un segundo objetivo fue determinar la relación que existe entre las unidades formadoras de colonias (UFC) de SM, con diferentes factores, tales como: edad, número de dientes erupcionados y capacidad amortiguadora de la saliva en niños. Materiales y métodos: Se realizó un estudio transversal, prospectivo, observacional y analítico, que incluyó 71 mujeres sin patología asociada, que hubiesen llevado su control prenatal en Instituto Nacional de Perinatología "Isidro Espinosa de los Reyes" (INPerIER) y cuyos hijos, al momento de la invitación, estuviesen sanos y se encontraran entre los cuatro a 24 meses de edad. Se formaron dos grupos: Grupo 1, constituido por 35 niños menores de 12 meses de edad. Grupo 2, constituido por 36 niños > 12 meses de edad. Se realizaron cultivos bacteriológicos de saliva total utilizando el Test de Riesgo de Caries de Ivoclar Vivadent. Resultados: Se encontró una asociación estadística directa con las UFC de SM de la madre (r = .356, p 10(5)con el numero de dientes erupcionados. Los programas preventivos de higiene bucal deben comenzar durante el periodo de gestación, a fin de prevenir la transmisión temprana de SM de las madres a sus infantes. Resumen en inglés Introduction: The window of infectivity described by Caufield in North-American children is a period during which children are more susceptible to the acquisition of Mutans streptococci (MS). As a consequence their dental caries susceptibility is increased. To date, this level of infectivity of MS has not been described in mexican children. Objectives: To determine the level of infectivity of MS in a group of Mexican children and to identify the association between MS in (mas) saliva from mothers and their children. A second objective was to determine the relationship between the colony-forming units (CFU) of MS with the number of teeth in the children's mouth and their saliva's buffering capacity. Materials and methods: A transversal, prospective and observational study was carried out on 71 healthy women who had their prenatal care at the INPer. At the time of the study their children were healthy and between 4-24 months of age. The children were grouped according to age: G1 comprised 35 children 12 months of age. Bacteriological studies of their saliva (mother and children) were performed using the Caries Risk Test (CRT) kit [Ivoclar, Vivadent]. Results: Exists direct relationship with the CFU of the mother (r = .356), as well as the number of decayed teeth of the mother (r = .350). The level of infectivity of MS in this group of children was on average 14.9 months. Conclusions: There is a direct relationship between the CFU > 10(5) and with the number of erupted teeth in the children. The preventive programs should be initiated during pregnancy as an attempt to prevent the premature tranSMission of MS from mothers to their infants.

Scientific Electronic Library Online (Spanish)

35

Nanocomposite hybrid molecular materials for application in solid-state electrochemical supercapacitors

Cuentas Gallegos, A. K.; Lira-Cantú, Monica; Casañ Pastor, Nieves; Gómez-Romero, P.
2005-01-01

Digital.CSIC (Spain)

36

Monitoring by analytical pyrolysis the post-mining soil rehabilitation with urban compost in Southern Spain (Almería)

Castelló, Ricardo; Castillejo, J. M.; González-Pérez, J. A.; Hernández, Z.; Piedra Buena, A.
2008-01-01

Digital.CSIC (Spain)

37

Microstructural changes induced in Portland cement-based materials due to natural and supercritical carbonation

Hidalgo, Ana; Domingo, Concepción; Garcia, Carlos; Sabine Petit, Sabine; Andrade, Carmen; Alonso, C.
2008-02-28

Digital.CSIC (Spain)

38

Microporous materials (TIQ-6 and METIQ-6) of high surface area active in oxidation reactions

Corma Canós, Avelino; Fornés, Vicente; Díaz Morales, Urbano; Dómine, Marcelo Eduardo
2005-07-16

Digital.CSIC (Spain)

39

Method of obtaining ferrite-zirconia composite materials

Moya Corral, José Serafín; Bartolomé Gómez, José Florindo; Pecharromán García, Carlos; Requena, J.; López Esteban, Sonia; París Torres, Miguel Angel; ArcasS Guijarro, Juan Manuel
2005-05-12

Digital.CSIC (Spain)

41

Iron oxide and oxide-hydroxide nanoparticles in organic-inorganic matrices

Silva, Nuno Joâo O.; Millán, Ángel; Amaral, Vitor S.; Palacio, Fernando; Fu, Lianshe; Carlos, Luis D.; Zea Bermúdez, V. de
2006-05-01

Digital.CSIC (Spain)

45

Influencia de la microestructura de partida en la ecuación constitutiva para la fluencia de un acero.

Castellanos, J.; Gutiérrez, V.; Rieiro, I.; Ruano, Oscar Antonio; Carsí, M.
2009-02-28

Digital.CSIC (Spain)

46

Infecciones de vías urinarias en el Hospital Universidad del Norte/ Urinary tract infections in the Hospital Universidad del Norte

Álvarez Barranco, Luis Carlos
2007-07-01

Resumen en español Objetivo: Determinar el comportamiento epidemiológico de las Infecciones de Vías Urinarias y cambios en sensibilidad y resistencia antibiótica de la Escherichia coli en el Hospital Universidad del Norte, Soledad (Atlántico, Colombia), desde enero de 2005 a diciembre de 2006. Materiales y métodos: Estudio descriptivo de tipo retrospectivo, con muestra de 537 urocultivos de pacientes que consultan al Hospital Universidad del Norte. Se evaluaron a través del recuento d (mas) e unidades formadores de colonias (UFC) y se analizaron los reportes de antibiogramas anotando la resistencia, sensibilidad antibiótica y evaluando el comportamiento epidemiológico de los principales antibióticos utilizados en la práctica clínica en la institución. Resultados: Distribución porcentual de infección del tracto urinario (ITU) para el 2005 en mujeres: 72.9%, en hombres: 27.1%; para 2006, en mujeres 73.8% y en hombres 26.2%. Los microorganismos más frecuentemente aislados en el 2005 fueron: Escherichia coli (66.24%) y Klebsiella (10.63%), y para el 2006: Escherichia coli (85 %) y Proteus (5.29%). Las mayores tasas de resistencia antibiótica de Escherichia coli en el 2005 fue: ampicilina, trimetoprim sulfa y ciprofloxacina. En el 2006, el comportamiento fue similar, y hubo además disminución en la resistencia a fluoroquinolonas. Las mayores tasas de sensibilidad en el 2005 incluyen nitrofurantoína, ampicilina/sulbactam y aminoglucósidos en relación con el 2006, en el cual hubo disminución en la sensibilidad a los dos primeros. Conclusión: La ITU se presenta con más frecuencia en mujeres. La mayoría de las ITU son causada por Escherichia coli. En el 2006 disminuyó la resistencia a la ampicilina, trimetoprim sulfametaxol, cefalosporinas de primera generación y ciprofloxacina con relación al 2005. También redujeron las tasas de sensibilidad a nitrofurantoína, ampicilina/sulbactam y gentamicina. Resumen en inglés Objective: Determine the epidemiological behavior of the Urinary Tract Infections and the changes in sensibility and antibiotic resistance of Escherichia coli in the Hospital Universidad del Norte, Soledad, Atlántico. January 2005 to december 2006. Materials and methods: There was realized a descriptive study of retrospective type, with a sample of 537 cultures of the patients who consult at Hospital Universidad del Norte. The cultures were evaluated across the colonies (mas) forming units (CFU) and then the antibiograms’ reports were analyzed, annotating the information for resistance, antibiotic sensibility and evaluating the epidemiological behavior of the principal antibiotics used in the clinical practice at this institution. Results: The percentage distribution of Urinary Tract Infection f (UTI) found in 2005 in women: 72.9 %, men: 27.1 %, and in 2006, women: 73.8 %, men: 26.2 %. The most frecuent microorganisms in 2005 were Escherichia coli (66.24 %), Klebsiella (10.63 %) and for 2006: Escherichia coli (85 %), Proteus (5.29 %). The major rates of antibiotic resistance of the Escherichia coli in 2005 was: ampicilina, trimetoprim sulfa and ciprofloxacina. In 2006 the behavior was similar, but decrease is observed in the resistance to fluoroquinolonas; the major rates of sensibility in 2005 include nitrofurantoína, ampicilina/sulbactam and aminoglucosidos in relation to 2006, in which decrease is observed in the sensibility to the first and the second one. Conclusion: The percentage distribution shows that UTI is more frequent in women. The causal microorganism of most of UTI’s cases is Escherichia coli. Decrease was demonstrated in the rates of resistance to ampicilina, trimetoprim sulfametaxol, first generation cefalosporines and ciprofloxacina in 2006 with relation to 2005.

Scientific Electronic Library Online (Spanish)

47

In-Situ Synthesis of Polypyrrole-MnO2−x Nanocomposite Hybrids

Cuentas Gallegos, A. K.; Gómez-Romero, P.
2005-06-23

Digital.CSIC (Spain)

48

In Situ Bone-Like Apatite Formation From a Bioeutectic SBF Dynamic Flow

Aza Moya, Antonio H. de; Velásques, P.; Alemany, M.I.; Pena Castro, María del Pilar; Aza, Piedad N. de
2007-01-01

Digital.CSIC (Spain)

49

Hydration water dynamics in solutions of hydrophilic polymers, biopolymers and other glass forming materials by dielectric spectroscopy

Cerveny, Silvina; Alegría Loinaz, Ángel; Colmenero de León, Juan

6 pages.-- PACS nrs.: 77.22.Gm, 61.41.+e, 64.70.P-.-- Communication presented at the 5th International Workshop on Complex Systems (September 25-28, 2007, Sendai, Japan). | Broadband dielectric spectroscopy (10^−2 Hz–10^6 Hz) and differential scanning calorimetry measurements have been performed to ...

DRIVER (Spanish)

52

Heat-insulating material based on cullet subjected to mechanochemical activation

Gorokhovskii, A. V.; Meshcheryakov, D. V.; Burmistrov, I. N.; Spiricheva, D. S.; Escalante-Garcia, J. I.; Puertas, F.
2010-01-01

Digital.CSIC (Spain)

53

Fate of the main carbon forms in soil organic matter from post-mining soils amended with urban compost in southern Spain (Almería)

Castelló, Ricardo; Castillejo, J. M.; Piedra Buena, A.; Hernández, Z.; Almendros, G.
2008-01-01

Digital.CSIC (Spain)

54

Evaluación del Endurecimiento de Barras de Acero y de Latón en Ensayos de Tracción y de Torsión Cíclica/ Evaluation of the Hardening of Steel and Brass Bars in Tension and Cyclic Torsion Tests

Corrêa, E.C.S.; Aguilar, M.T.P.; Cetlin, P.R.
2005-01-01

Resumen en español Se ha estudiado el comportamiento mecánico de muestras de acero de bajo carbono y de latón sometidas a pruebas sucesivas de tracción y de torsión cíclica. Se han empleado los siguientes experimentos: tracción axial, torsión cíclica pura, tracción-torsión cíclica, torsión cíclica-tracción y tracción-torsión cíclica-tracción. Los efectos de las alteraciones en la dirección de la deformación han sido observados en las curvas tensión efectiva-deformación (mas) efectiva, a través del análisis del límite elástico y de la velocidad de endurecimiento de los metales. Los resultados han evidenciado la influencia de la secuencia de deformación, de las características estructurales de los materiales y de la naturaleza de los esfuerzos en el endurecimiento durante la conformación de metales Resumen en inglés A study was made of the mechanical behavior of low carbon steel and brass samples submitted to sequential tensile and cyclic torsion straining. The following experiments were conducted: pure tension, pure cyclic torsion, tension-cyclic torsion, cyclic torsion-tension and tension-cyclic torsion-tension. The effects of strain path changes on the work-hardening of these metals were verified on the effective stress-effective strain curves, through the analysis of the flow str (mas) ess and the strain hardening rate. The results showed the influence of the deformation sequence, of the material characteristics and of the straining nature of the materials, on the hardening behavior of metals during forming

Scientific Electronic Library Online (Spanish)

55

Estudio químico-microbiológico comparativo de dos soluciones propuestas para la desinfección de endoscopios

Hidalgo Rodríguez, Roxana; Castellanos Fernández, Vivian; Chiroles Despaigne, Sonia; Villavicencio Betancourt, Odalys
2000-12-01

Resumen en español Se evaluó desde el punto de vista químico-microbiológico la actividad germicida de una solución propuesta para la desinfección del instrumental de endoscopia, (peróxido de hidrógeno al 7 %. Se tomó como solución de referencia el glutaraldehído al 2 %. Las soluciones fueron ensayadas a las concentraciones propuestas por los fabricantes y se expusieron frente al instrumental durante 20 min, tiempo indicado por los mismos. Se obtuvo como resultado de la valoración (mas) microbiológica que la solución de peróxido de hidrógeno al 7 % brinda un 100 % de inhibición de unidades formadoras de colonias microbianas comparadas con la solución de glutaraldehído al 2 % la cual ofrece un 100 % de inhibición. Como resultado de los ensayos químicos de compatibilidad de materiales en los cuales se desarrollaron pruebas de corrosión, enfrentamiento de las soluciones a diferentes polímeros y a 2 clases de cristales resultaron satisfactorios para las soluciones propuestas. Resumen en inglés From the chemical-microbiological point of view the germicide activity of a solution proposed for the desinfection of endoscopy instruments (7 % hydrogen peroxide) was evaluated. 2 % glutaraldehyde was taken as a reference solution. The solutions were assayed at the concentrations proposed by the manufacturers for 20 minutes, period of time indicated by them. As a result of the microbiological assessment it was observed that 7 % hydrogen peroxide solution gives 100 % inhi (mas) bition of microbial colonies forming units compared with 2 % glutaraldehyde solution which offers 100 % inhibition. The chemical assays of materials compatibility in which corrosion tests and confrontantion of the solutions to different polymers and to 2 classes of crystal developed were satisfactory for the solutions proposed.

Scientific Electronic Library Online (Spanish)

56

Estimación del esfuerzo de fluencia para Materiales Laminados en frío

Torres, Mary; Di Graci, Verónica; González, Gustavo; Zurita, Omar
2004-01-01

Resumen en español Las ecuaciones de Hollomon en tensión simple de un acero AISI 1040 y un cobre puro recocidos se emplean para estimar sus resistencias a la fluencia después de trabajárseles en frío mediante laminación. Los valores así calculados para ambos materiales, resultan siempre mayores que los valores experimentales obtenidos mediante ensayos de tensión simple, para los correspondientes valores de deformación aplicada. Con la finalidad de corregir esta discrepancia entre lo (mas) s valores calculados y los experimentales, se formulan ecuaciones de Hollomon modificadas con un factor que debe ser característico del proceso de endurecimiento durante el conformado del metal en particular. Resumen en inglés Hollomon´s equation from a tension test for AISI 1040 steel and pure copper both in an annealed condition has been used to predict the yield strength of both materials after being cold-worked by rolling. The yield strength of the cold-worked materials was experimentally determinated by means of tension tests and compared to those values estimated through Hollomon´s equation. The experimental yield strength values were always lower than those calculated by means of Hollo (mas) mon´s equation. A Modified Hollomon´s equation with a deformation factor is presented in order to obtain the right values. It is expected that the factor will be characteristic of the forming process for each metal.

Scientific Electronic Library Online (Spanish)

59

Efficient methods for radiation, scattering and propagation

Álvarez Melcón, Alejandro; Coves Soler, A.; Andrés Bou, M.V.; Bonia Esbert, V.E.

This document describes the research activities performed in the areas of antennas, scattering and wave propagation by several research groups belonging to different Universities located in Eastern Spain. These groups are working in the practical applications of efficient numerical electromagnetic m...

DRIVER (Spanish)

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Efecto de las puzolanas naturales en la porosidad y conectividad de poros del hormigón con el tiempo/ Effect of natural pozzolans on porosity and pore connectivity of concrete with time

López, Mauricio; Castro, José Tomás
2010-01-01

Resumen en español Los materiales puzolánicos adicionados a las mezclas de hormigón con cemento portland reaccionan con la portlandita formando nuevos silicatos de calcio hidratados los pueden mejorar la durabilidad de estructuras de hormigón. Con el objetivo de mejorar el entendimiento del rol de las puzolanas naturales en el desempeño del hormigón, este estudio caracterizó la porosidad e interconectividad de los poros de hormigones en función del contenido de puzolanas naturales. E (mas) l programa experimental caracterizó la resistencia y permeabilidad de hormigones con diferentes contenidos de puzolanas y con edades entre 28 y 84 días para así evaluar el efecto de las puzolanas en función del tiempo. Los resultados muestran que la ganancia en impermeabilidad debido al uso de puzolanas naturales es muy superior al efecto observado en resistencia. Por ejemplo, hormigones con 33% de puzolanas en reemplazo del cemento presentaron una resistencia a compresión 27% inferior a la del hormigón sin puzolanas; sin embargo, su impermeabilidad fue aproximadamente 200% superior a las de los hormigones sin puzolanas. Los ensayos de permeabilidad a iones cloruro y absorción capilar, presentaron baja variabilidad y buena correlación con las reacciones puzolánicas. Se concluye que se debe controlar independientemente la permeabilidad y la resistencia del hormigón ya que son afectadas de manera diferente por las reacciones puzolánicas; además, se concluye que para considerar el efecto de las puzolanas se debe ensayar permeabilidad a edades tardías Resumen en inglés Pozzolanic materials in portland cement concrete mixtures hydrate forming new calcium silicate hydrates which improve durability of concrete structures. The aim of this research was to enhance the understanding of the role of natural pozzolans in concrete performance. This study characterized porosity and pore connectivity of concrete mixtures as function of the content of natural pozzolans. The experimental program measured compressive strength and permeability of concre (mas) te mixtures with different levels of cement replacement by natural pozzolans between 28 and 84 days of age, so the effect of pozzolans could be assessed as a function of time. Results clearly show that the gain in impermeability of concrete due to the use of natural pozzolans is much more pronounced that the effect in compressive strength. For instance, concrete with 33% of cement replaced by natural pozzolans had a compressive strength 27% lower that those with no pozzolans replacement; nevertheless, their impermeability was approximately 200% superior to those with no pozzolans replacement. Chloride ion permeability and rate of water absorption showed low variability and good correlation with pozzolanic reactions. It can be concluded that it is important to control compressive strength and permeability independently because they are affected very differently by pozzolanic reactions; also, for taking advantage of natural pozzolans in concrete, it is important to specify and measure permeability at late ages

Scientific Electronic Library Online (Spanish)

61

Efecto de la relación área-volumen en la sinterización de varistores cerámicos basados en ZnO-Bi2O3

Rubia, Miguel Ángel de la; Peiteado, Marco; Fernández Lozano, José Francisco; Caballero Cuesta, Amador
2002-01-01

Digital.CSIC (Spain)

62

Efectividad del proceso de preesterilización mediante el empleo de una nueva técnica

Concepción Rojas, Miriam; Delgado García, Josefina
1997-04-01

Resumen en español Se ensayó una nueva técnica para el control de la calidad del proceso de preesterilización en diferentes tipos de materiales que iban a ser sometidos a procesos de esterilización por calor húmedo y óxido de etileno en la central de esterilización de un hospital clinicoquirúrgico de Ciudad de La Habana. Mediante el ensayo de la técnica se pudo evaluar la efectividad de los procesos de esterilización y conocer la carga microbiana con que el material entra en el eq (mas) uipo. Permitió, además, tomar las medidas para disminuir las UFC (unidades formadoras de colonias) y lograr la calidad requerida en dichos procesos a fin de disminuir el riesgo de infección. Resumen en inglés A new technique was assayed for the control of the quality of presterilization process of different types of materials which were to be subjected to sterilization process by wet heat and ethylene oxide in the sterilization department of a Clinical and Surgical hospital from Havana City. By the assay of this technique, the effectiveness of sterilization process could be evaluated and it was possible to know the microbial load contained in the material to be sterilized. It (mas) also allowed to take measurements in order to reduce the unit-forming colonies and to attain the quality required in such process with the aim of decreasing the risk of infection.

Scientific Electronic Library Online (Spanish)

63

Diagnóstico de proliferación bacteriana intestinal en niños: evidencia experimental para sustentar el empleo de lactulosa en la prueba de hidrógeno y su validación como prueba tamiz/ Diagnosis of small intestinal bacterial overgrowth in children: the use of lactulose in the breath hydrogen test as a screening test

Mendoza, Evelyn; Crismatt, Carlos; Matos, Ramón; Sabagh, Olga; Campo, Mercedes; Cepeda, Johana; Villanueva, Daniel
2007-09-01

Resumen en español Introducción. Un recuento superior a 10(5) unidades formadoras de colonias por ml de aspirado duodenal se considera la "prueba de referencia" para el diagnóstico de proliferación bacteriana intestinal, a pesar de su caracter invasivo. La prueba de hidrógeno en el aliento, con lactulosa, se aplica como alternativa diagnóstica no invasiva, pero el fundamento para el empleo de lactulosa carece de solidez. Objetivos. Aportar evidencia experimental para sustentar el uso d (mas) e lactulosa en la prueba de hidrógeno y validarla frente al cultivo de aspirado duodenal. Materiales y métodos. Para fundamentar el uso de lactulosa se comparó la cinética de la lactasa intestinal frente a lactulosa con su cinética frente a la lactosa. Con el fin de validar la prueba de hidrógeno, ésta se aplicó a 47 niños afectados por trastornos gastrointestinales y los resultados se compararon con los de la prueba de referencia. Mediante una tabla de contingencia se estimó la validez y con el índice kappa, la concordancia. Resultados. La cinética mostró que la lactasa es 240 veces menos eficiente que la lactulosa. La sensibilidad de la prueba de hidrógeno fue de 85,7% (82,0%-89,4%), la especificidad de 90,9% (89,3%-92,5%), el valor diagnóstico positivo de 80% (76,5%-83,5%) y el valor diagnóstico negativo de 93,8% (92,1%-95,4%). El índice kappa de 0,785 (0,54-0,95) indicó una importante concordancia entre las pruebas diagnósticas. Conclusiones. Se aporta evidencia experimental para sustentar el uso de la lactulosa en la prueba de hidrógeno y se valida ésta frente al patrón de referencia como prueba tamiz para diagnosticar la proliferación bacteriana intestinal. Resumen en inglés Introduction.The standard method for diagnosis of small intestinal bacterial overgrowth is a duodenal aspirate that produces a coliform count greater than 105 colonic forming units/ml. Because this is an invasive procedure, the lactulose breath hydrogen test is considered as a non-invasive alternative. Better experimental support is required, however, for the routine use of lactulose in diagnosis. Objective. Experimental evidence is provided to support the use of lactulos (mas) e in the breath hydrogen test. Validation of the test is accomplished by comparison to the duodenal aspirate culture. Materials and methods. A rational basis for the use of lactulose was established by a comparison of the kinetics of lactulose and lactose on intestinal lactase. For validation, the hydrogen test was applied to 47 children suffering from gastrointestinal disorders, and the results compared with aspirate culture counts. The validity of the hydrogen test was assessed by a contingency table and the degree of agreement established by the kappa index. Results. The kinetics data showed that lactase is 240 times less efficient in presence of lactulose than it is in presence of lactose. The sensitivity of the breath hydrogen test was 85.7% (82.0-89.4%), its specificity 90.9% (89.3-92.5%), the predictive positive value 80.0% (76.5-83.5%) and the predictive negative value 93.8% (92.1-95.4%); the kappa index=0.785 (0.54-0.95) showed excellent agreement between the two diagnostic tests. Conclusion. The results provided experimental support for the use of lactulose in the breath hydrogen test, and it was validated as screening test in the diagnosis of small intestinal bacterial overgrowth.

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Development of microelectrode arrays modified with inorganic–organic composite materials for dopamine electroanalysis

Lupu, Stelian; Campo García, Francisco Javier del; Muñoz Pascual, Francisco Javier
2010-01-01

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Control of the structural properties of mesoporous polymers synthesized using porous silica materials as templates

Fuertes Arias, Antonio Benito; Sevilla Solís, Marta; Álvarez García, Sonia; Valdés-Solís Iglesias, Teresa
2008-07-01

Digital.CSIC (Spain)

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Cemented matrices use in the storage of low and medium radioactive waste: Spanish experience

Goñi Elizalde, Sara; Hernández Crespo, M.ª Soledad; Guerrero Bustos, Ana María
2009-11-01

Digital.CSIC (Spain)

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Carbon molecular sieves as model active electrode materials in supercapacitors

Ruiz Ruiz, Vanesa; Blanco Rodríguez, Clara; Santamaría Ramírez, Ricardo; Juárez-Galán, J. M.; Sepúlveda-Escribano, A.; Rodríguez-Reinoso, F.
2008-04-15

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Caracterización fisicoquímica de almidones doblemente modificados de plátano/ Physicochemical characterization of dually-modified banana starch

Zamudio-Flores, P. Baruk; Vargas-Torres, Apolonio; Gutiérrez-Meraz, Felipe; Bello-Pérez, Luis A.
2010-05-01

Resumen en español Dentro de las materias primas para elaborar plásticos biodegradables, el almidón tiene un alto potencial; sin embargo, éste debe ser modificado para mejorar sus propiedades de formación de película. En el presente estudio almidón aislado de plátano macho (Musa paradisiaca L.) en estado fisiológico inmaduro fue modificado químicamente mediante una oxidación con NaOCl con tres concentraciones de cloro activo (0.5, 1.0 y 1.5 % v/v) y se acetiló usando anhídrido a (mas) cético. Los almidones se caracterizaron química, física y térmicamente: cuantificación de grupos carbonilos, carboxilos y acetilos; análisis químico proximal; análisis de espectroscopia de infrarrojo con transformada de Fourier; determinación de color; y análisis de variables térmicas mediante calorimetría diferencial de barrido. Los valores cuantificados de grupos funcionales carbonilos, carboxilos y acetilos corroboraron la efectividad de los tratamientos químicos, lo cual se verificó mediante el análisis de espectroscopia de infrarrojo con transformada de Fourier. La modificación por oxidación redujo el contenido de proteínas, lípidos y cenizas. El parámetro L* caracterizó el color de los almidones ya que fue una medida directa de su blancura. Este valor incrementó a medida que aumentó el nivel de oxidación, sin que la modificación por acetilación influyera significativamente en este parámetro. Los parámetros térmicos de temperatura de inicio, pico y final de gelatinización aumentaron cuando se incrementó la concentración de cloro activo, mientras que la entalpía de gelatinización disminuyó indicando una alteración estructural en los almidones modificados, lo cual se confirmó con el perfil amilográfico de estos almidones. Con la doble modificación química fue posible mejorar las propiedades físicas y químicas del almidón nativo de plátano. Resumen en inglés Among the raw materials used to make biodegradable plastics, starch has high potential; however, it must be modified to improve its film-forming properties. In this study, starch isolated from physiologically immature plantains (Musa paradisiaca L.) was modified chemically by oxidation with NaOCl with three concentrations of active chlorine (0.5, 1.0 and 1.5 % v/v) and acetylation using acetic anhydride. The starches were characterized chemically, physically, and thermall (mas) y: quantification of carbonyl, carboxyl and acetyl groups; proximal chemical analysis; Fourier transform infrared spectroscopy; color determination; and analysis of thermal variables using differential scanning calorimetry. The values of quantified functional carbonyl, carboxyl and acetyl groups corroborated the effectiveness of the chemical treatments, which was verified by Fourier transform infrared spectroscopy. Modification by oxidation reduced the content of proteins, lipids and ash. The L* parameter characterized starch color since it was a direct measure of its whiteness. This value increased with increasing levels of oxidation; modification by acetylation did not significantly affect this parameter. The thermal parameters initial, peak and final gelatinization temperatures increased when the active chlorine concentration increased, while gelatinization enthalpy decreased, indicating a structural alteration of the modified starches. This was confirmed by their amylographic profile. With dual chemical modification, it was possible to improve the physical and chemical properties of native plantain starch.

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Caracterización de la cuenca del Río Canoabo en el estado Carabobo, Venezuela. II: Suelos y tierras/ Characterization of the river basin canoabo in the Carabobo state, Venezuela. II: Grounds and earth

Sevilla L, Victor A; Comerma G, Juan A
2009-06-01

Resumen en español En un trabajo anterior se realizó una caracterización climática de la cuenca del rio Canoabo, en sus suelos y la capacidad de uso de sus tierras, para dar bases a una mejor planificacion agroambiental de la misma. Con ese objetivo se estudiaron los factores formadores de suelo, incluyendo la fotointerpretacion de imagenes de satelite, un modelo digital de terreno, mapa de vegetacion y cobertura actual y una identificacion de materiales parentales. Todas esas capas digi (mas) talizadas se sobrepusieron en un Sistema de Informacion Geografico (SIG) y se elaboro el mapa preliminar de unidades de suelo. Se chequearon 50 puntos en campo tanto del entorno geomorfologico, pendiente, cobertura, erosion, drenaje, como de sus perfiles de suelo, taxonomia y capacidad de uso. Los resultados mostraron una clara climosecuencia de suelos, con Humic Haplustults en las zonas de bosques altos mas humedos; mas lavados en las zonas altas y mas erosionados en las zonas inferiores con gran intervencion antropica, y finalmente Haplustepts, en los valles con materiales aluviales mas recientes. La clasificacion de las tierras por capacidades de uso arrojo un 12% de tierras clases I a IV, en los valles separandose por pendientes, un 60% de tierras clase V y VI, dominando esta ultima en laderas intermedias, principalmente por pendiente, mostrando gran intervencion; y finalmente un 28% de tierras clase VII y VIII, que son las menos intervenidas y afortunadamente con gran cobertura boscosa. El principal conflicto de uso es la sobreutilizacion con los usos ganaderos, usualmente precedido por conucos de ocumo o name, y en menor medida con citricas en laderas. Por otra parte, se tiene la subutilizacion en el valle principalmente con ganaderia. Por ello la principal recomendacion es la de intensificar el uso de la tierra en el valle e incorporar sistemas silvopastoriles y agroforestales en las laderas con practicas de conservacion de suelos y agua Resumen en inglés The main land uses are citrus and bananas as well as extensive areas of grassland. In a previous paper a characterization of its climate was published. The objective of this paper is to present a soil characterization and a land capability that supports a better agroecological planning. For this purpose a characterization of the main soil forming factors was carried out; this included a phtointerpretation of satellite imagery, a digital elevation model, a map of vegetatio (mas) n and land cover, and a map of parent materials. All these digitized layers were superimposed with a Geographical Information System (GIS) to produce a preliminary soil cartographic map. Fifty field sites were analyzed including its geomorphology, land use, erosion, drainage, soil profile, taxonomy and a land capability classification. Results showed a clear climosequence expressed by a Humic Haplustult in the more humid higher mountains, Haplustalf dominating the intermediate sideslopes, somewhat more leached in the higher slopes and shallower and eroded in the lower ones, and finally, Haplustepts in the lower valleys derived from more recent alluvial materials. Land Capability showed that in the valleys dominated the classes I to IV, while the sideslopes were mostly Class VI, and the high mountains, covered with forests, had class VII and VIII. Slope was the dominant factor to differentiate classes. The main land use conflict is overutilization of steep slopes by cattle and citrus, as well as underutilization of flat slopes en the valley. Consequently, the main recommendation is to intensify land use in the valleys and to develop more sustainable land use systems in the slopes, including soil conservation practices

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CORDIERITA 2MgO.2A12 O3 .5SiO2 SINTETIZADA POR LA RUTA DE LOS HIDROXIGELES/ CORDIERITE 2MgO. 2A12 O3. 5SiO2 SYNTHETIZED BY HYDROXYHYDROGEL ROUTE

PAUCAR ÁLVAREZ, CARLOS G.; DÍAZ GARZÓN, ANA I.; RIBERO RODRÍGUEZ, DANIEL; QUINTERO ALVAREZ, KATERINE; GARCÍA GARCÍA, CLAUDIA P.
2009-11-01

Resumen en español Los materiales basados en cordierita 2MgO 2Al 2 O 3 5SiO 2 son utilizados comúnmente en refractarios y procesos catalíticos a temperaturas superiores a los 500 grados Celsius; dichas aplicaciones requieren de alta resistencia al choque térmico, bajo coeficiente de expansión térmica, alta resistencia a la acción corrosiva de los gases, baja constante dieléctrica y buenas propiedades mecánicas. En el presente trabajo, se reporta la síntesis y caracterización (mas) de cordierita a partir de hidrogeles por la ruta de química coloidal de hidroxihidrogeles. Las materias primas fueron dispersadas mecánicamente en un equipo de alta cizalla del tipo rotor stator, allí mismo se llevó a cabo el proceso de gelación. Los polvos obtenidos en la etapa de secado fueron sinterizados mediante variaciones de tiempo y temperaturas: 1200, 1300 y 1350 grados Celsius. Se conformaron monolitos de cordierita y se caracterizaron mediante análisis microquímico, análisis térmico diferencial (DTA), difracción de rayos X (XRD), microscopía electrónica de barrido (SEM) y medidas de absorción de agua. En este estudio se disminuyeron las temperaturas de cristalización de la cordierita 2MgO 2A12 O3 5SiO2 la cual se produce hasta 1200 grados Celsius; bajo los procesos de sinterización se generan monolitos con una baja porosidad en función de la temperatura hasta los 1350 grados Celsius. Resumen en inglés Materials based on cordierite 2MgO 2A12 O3 5SiO2 are used for refractoriness and catalytic processes at temperatures above 500 Celsius degrees where high thermal shock resistance, low thermal expansion coefficient, high resistance to corrosion gas, low dielectric constant and good mechanical properties are required. In the present work, the synthesis of cordierite by a colloidal chemistry route forming hydroxyhydrogels is reported, which were dispersed mechanically with a (mas) rotor stator. The powders obtained were sintered with variation of time at 1200, 1300 and 1350 Celsius degrees. The monoliths were characterized by microchemical analysis, differential thermal analysis (DTA), Xray diffraction (XRD), scanning electronic microscopy (SEM) and water absorption measurements. In this study the temperature of crystallization of cordierite of cordierite 2MgO 2A12 O3 5SiO2 was lowered which occurs at about 1200 degrees Celsius, and monoliths with low porosity were generated by sintering processes as a function of temperature, up to the 1350 degrees Celsius.

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Arquitectura y paleoambientes de los depósitos fluviales gravosos de la Formación Las Cumbres (Neógeno), en Villa Mervil, La Rioja, Argentina/ Architecture and paleoenvironment of the fluvial gravel deposits of Las Cumbres formation (neogene), Mervil Village, La Rioja, nw-Argentina

Bossi, G.E.; Georgieff, S.M.; Vides, M.E.
2007-07-01

Resumen en español Un corte de la ruta nacional 60, 500 m al oeste de Villa Mervil (Sierras de Mazán, La Rioja) muestra el contacto entre las Formaciones Salicas y Las Cumbres, con excelente exposición de la arquitectura fluvial que pudo ser extendida en tres dimensiones y por más de 700 m en sentido N-S, a ambos lados de la ruta. El corte muestra el contacto entre las Formaciones Salicas (Plioceno) y Las Cumbres (Plio-Pleistoceno). Pueden ser reconocidos cinco estadios de sedimentación (mas) : A-S, el inferior, constituido por areniscas friables fluviales y eólicas; F, de capas tabulares consistentes en limos de barreal y areniscas de planicie de distributarios (escorrenteras y barras efímeras) con abundantes calcretos y rizoconcreciones; B, el mejor preservado y que ha permitido el análisis 3D, de conglomerados arenosos, que corta profundamente los dos estadios inferiores. El Estadio B está organizado en una serie de mesoformas de canal, con barrancas izquierdas (al Oeste) bien definidas. En su etapa final de abandono (Estadio L), fue rellenado por capas tabulares de arenas finas limos pardos, que contienen una arcilita verde y una capa de micrita blanca, que pueden asignarse a un depósito lacustre somero. Finalmente yace sobre todo el conjunto anterior, el Estadio C, de conglomerados finos arenosos que forman un extenso sistema de canales y planicie aluvial pero mal representado en estos afloramientos. Las particularidades de estos depósitos pueden ser comparadas con expresiones locales del ambiente actual: el río Pituil (al oeste de la Sierra de Velasco) la llanura arenosa del Bolsón de Pipanaco y el barreal del Señor de la Peña, donde impera un clima árido con una escasas lluvias estivales, indicado condiciones climáticas similares. Resumen en inglés A cut along the National Road 60, 400 m west of the Mervil Village, a small town located at the southern end of the "Bolsón de Pipanaco" (Pampean Ranges of NW-Argentina) unveils a 3-D fluvial and eolian architecture in beds that belong to the stratigraphic passage between the Salicas (Pliocene) and Las Cumbres (Plio- Pleistocene) Formations (Fig. 1 and 2). Fossil mammals found in the Salicas Formation belong to the Huayquerian fauna that could be dated in the Pliocene (B (mas) ossi et al., 1996). A four-fold classification of contacts hierarchy (Allen, 1983) was used to define individual sedimentary bodies and their associations: order 0, are the contacts between laminas within a laminaset; order 1 are the contacts between laminasets (represented by parallel or crossbedded cogenetic packages); order 2 contacts, cut order 1 contacts and embrace bedded packages or storeys, limited themselves by order 1 contacts, that show a similar genetic emplacement (similar features in outcrops); finally the order 3 contacts, cut and embrace sedimentary bodies limited by order 2 contacts, defining major groups or stages. Five distinct stages were recognized (Fig. 3): a lower A-S stage, covered by an extended floodplain F stage, cut deeply by the gravelly stage B, partially filled by L stage, and covered by the fluvial gravelly C stage at top (Fig. 4 and 5). The sandy A-S stage consists of channel and sandflat deposits formed by alternating fluvial (A) and eolian (S) storeys. Facies assamblage "A" is an association of 9 storeys (Fig. 3) composed of moderate sorted massive or cross-bedded sandstones, with few subrounded pebbles (schists and granites) in or near their concave bases. Most of the A storeys bottoms, are covered by a 1-5 cm thick silty shale drapes slightly disturbed or forming clay galls partially curled and/or removed (Fig. 4b and c). The facies assemblage S, is an association of 6 storeys (painted white in Fig. 5b and c) formed by well-sorted fine to medium size sandstones with occasional mud intraclasts (pebble sizes, not eolian materials probably incorporated by gravity collapse or sudden water sheets). The meter thick silty "F1" storey (Fig. 4 b and e) is composed of 10 to 11 tabular decimeter slightly endurated beds, interpreted as playa lake ("barreal") deposits by comparation with very similar sediments that fill the nearby barreal "El Señor de la Peña" a typical endorheic depression. This "F1" horizon is the source of most irregular blocks found at the foot of the left margin bank cuts of the B stage. The F2 storey (Figs. 3 and 4b) is composed of 0.90 m tabular to lenticular coarse sandstone horizon crowded of calcretes and rhyzoconcretions defining a paleosol horizon. The F3 storey is also composed of massive to crossbedded ill-sorted pebble coarse sandstones. Both F2 and F3 storeys were deposited by sudden floodings not conected to visible channel locations. The F3 storey is not related with the F2 storey calcretization. There are six irregular and lenticular storeys in the "B" stage, defined by concave and convex stratification designs. These storeys could be considered mesoforms in the sense of Bridge (1985, 1993) of the macroform "B". A close correlation of the contacts shown in the two walls of the road cut associated with contact orientation measurements and paleocurrents, allowed to built models of the 3D situation in several evolution steps starting with storey B2 ending up in storey B6 (Figs. 6 a-c). The B channel stage is deeply incised on the F and A-S stages indicating a change of the equilibrium profile. The B stage itself, represented by storeys B5 and B6, were mapped beyond the road cut for an extension of 700 m (in N-S sense) yielding a map that shows a NE-trending low sinuosity river with cut banks, lateral bar deposits, overbank deposits deposits with variable width.The last block (Fig. 6d) shows the abandon "L" stage of lacustrine fillings (see Fig. 3 for stratigraphy relations and Fig. 4 for details), composed of at leat four storeys, three of them (L1, L2 and L3) are fillings of the central part of the pond and a fourth (L4) a clinoform, is a lateral deposit. The stage C outcrops at the top of the wall cuts covering though a third order contact, the stages F, L and B. It is composed of fine to medium size fluvial gravels without visible bank cuts. The very limited lateral and vertical exposures preclude it, from a further discussion. Most paleocurrent measurements were taken in the axis of concave structures (crossbeddings) and the points where the order 2 contacts merge into the basal order 3 contact. The point of merging of the order 2 and 3 contacts in convex stratified bodies, indicates the position of the bar structure, the paleocurrents at their bases show the local direction of the bar slope in this particular stage of growing (Fig. 7). Converging or diverging paleocurrent patterns at the outcrop face combined with vertical textural variations, unveil the position of the outcrop cut in relation to the hidden 3D structure. Most of the mapped architectural features yielded also paleocurrents measurements on cross-bedding and pebble imbrications that were integrated with the textural and structural evidences (Fig. 9). The scheme of Fig. 7 was used in the model of Fig. 9 to position the bar designs on the plan. The model of Fig. 9b, is a cartoon of a slightly ondulate landscape crossed from SSW to NNE by the B stage river channel. Fig. 8 shown the succesive bank cuts created by the B stage channel during its migration to west. Calcretes and rhizoconcretions over convex or tabular gravels storeys, mapped as inside features of channel "B", indicate an ephemeral regime with riparian vegetation (Fig. 9). The Pituil River (Fig. 10) draining the northwest end of the Velasco Range and the sandy plains located north of the Mazán Range and near the center of the "Bolsón de Pipanaco" were used as modern analogs of the ancient Mervil channel system (stages B and A-S respectively). The structural details shown by the Salicas Formation at the Mervil area around the road cut, are also present in the modern analogs, indicating a similar arid climate.

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Alcohólicos Anónimos (AA): aspectos relacionados con la adherencia (afiliación) y diferencias entre recaídos y no recaídos/ Alcoholics Anomymous (AA): affiliation and related aspects, differences between relapsed and non-relapsed alcoholics in process of recovery

Gutiérrez Reynaga, Reyna; Andrade Palos, Patricia; Jiménez Tapia, Alberto; Saldívar Hernández, Gabriela; Juárez García, Francisco
2009-10-01

Resumen en español La labor realizada por los grupos de Alcohólicos Anónimos (AA) para combatir el problema del alcoholismo los ha convertido en una de las opciones importantes. La adherencia o afiliación a estos grupos puede ser benéfica para ciertos alcohólicos, por lo que la investigación ha buscado identificar los aspectos que contribuyen a su establecimiento. Aunque la investigación aún no aclara el proceso mediante el que se logra, la ha destacado como un constructo que entrel (mas) aza la asistencia a las reuniones y el nivel de participación en los grupos, y se menciona que, cuanto mayor es el involucramiento, tiende a mejorar el pronóstico del alcohólico. A pesar de este panorama, en nuestro contexto, el tema de los componentes específicos de la afiliación a AA, así como su relevancia para mantener la abstinencia en comparación con la recaída, no ha recibido atención suficiente por parte de los investigadores en alcoholismo. Este trabajo tiene como objetivos: explorar elementos que pueden constituir un perfil de afiliación a AA, conocer si esos elementos son diferentes o forman parte de un mismo constructo y si la graduación de afiliación (clasificación de la forma en que el alcohólico se involucra en las diferentes actividades de los grupos) puede diferenciar entre quienes han recaído o no en el consumo de alcohol. Método La muestra fue no probabilística intencional; incluyó a 192 miembros de AA (87% hombres y 1 3% mujeres). Se formaron dos grupos: no recaídos y recaídos (143 no consumieron ninguna cantidad de alcohol y 49 consumieron cualquier cantidad de alcohol después de por lo menos tres meses de abstinencia). Se diseñó un cuestionario para evaluar la afiliación a AA; en éste se indaga el servicio, el apadrinamiento, la práctica de los 12 pasos, el >, el tiempo en AA, la frecuencia de asistencia y la lectura de literatura de AA. Resultados Hubo diferencias significativas en el tiempo promedio de participación (t = -3.225, gl = 181, p> (tenerlo: χ² = 7.76, p> ( χ²=15.06, p> ( χ² = 4.282, p>, se encontró una consistencia interna adecuada (α =.67) y un análisis factorial mostró que los reactivos se agrupaban en una sola dimensión, con una varianza explicada de 43.6%. Se construyó un indicador del grado de afiliación usando la sumatoria de los puntajes de las variables agrupadas y se trabajó una comparación por quintiles, la cual mostró diferencias significativas según el grado de involucramiento en AA (Z = -3.367, p Resumen en inglés The work of Alcoholics Anonymous (AA) in fighting against alcohol abuse and alcoholism has placed it as an institution of great importance in Mexico and around the world. Although its labor has been subject for controversy, there is a lot of evidence that frequent attendance and affiliation to the groups and sessions can be very helpful for many individuals. Research has been dedicated to the identification of the elements contributing to affiliation, such as involvement, (mas) commitment, and participation, or the level of adherence to the program's beliefs and activities. Some studies have used the time of membership and the frequency of attendance to AA as indicators of affiliation, but there are some authors who think that it is difficult to explore it using only these variables. Other authors have mentioned that alcoholics can go to AA for many reasons, but that mere attendance is not enough for reaching or maintaining abstinence. It has been established that when the impact of AA is measured only by the time of membership or the frequency of attendance, it is not possible to comprehend the essence of the subjective and behavioral characteristics involved in the process. Thus, it is important to differentiate between these and the true affiliation. There are only a few researches about the elements forming the affiliation to AA, and the ones available do not bring light over the process of its beginning. Some authors say that it is something more than the time or the frequency of attendance to meetings, and that is possible that it is a complex and heterogeneous phenomenon formed by several behaviors and beliefs about the 12 steps. Some studies have pointed out the interaction of different factors to achieve affiliation, but they have also remarked the need for including more variables in measuring it. One conclusion is that affiliation is a whole dimension that encompasses attendance and the level of participation in the activities. There are different questionnaires to measure the affiliation process, but most of them are difficult to interpret, and little is known about their fitting to AA members' perspective of things. Research in Mexico is complicated because of a lack of instruments developed from the local situation and experience. There are data that about 14 000 alcoholics enter AA every year. Relapse is high during the first three months (near 50%), but almost half of the persons that stay show adherence to the program, and eventually reach abstinence. Yet, the topic of the specific elements of affiliation, as well as their influence to maintain abstinence, has not received enough attention. The objectives of this study were: 1. to analyze the elements that constitute an affiliation profile, 2. to know if such elements are different or if they are part of a single construct, and 3. to find out if the amount of affiliation (the way an alcoholic involves him/herself in the activities of the group) can distinguish between those who have relapsed and those who have not. Method The sample was non-probabilistic; it included 192 AA members (87% men and 13% women). Average age was 42 years old. Two groups were formed: relapsed and non-relapsed (143 who did not consume any amount of alcohol since they entered AA or 10 years or more ago, and 49 who consumed any amount of alcohol within the four years prior to the interview). The questionnaire included scales to measure the service, the practice of the 12 steps, the spiritual awakening, sponsoring, time spent in AA, frequency of attendance, and reading of the materials. The questionnaire was specifically designed for measuring affiliation. Results There were significative differences in the mean participation time (it was higher in the non-relapsed subjects: t = -3.225, df=181, p> (they were more frequent and more extended in time in the non-relapsed subjects: X² = 7.76, p> (most of the non-relapsed subjects are one: X² = 15.06, p

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Aislamiento de hongos celulolíticos causantes del biodeterioro de la Biblioteca Central de la Universidad del Valle (Cali-Colombia)/ Isolation of cellulolytic fungi causing biodeterioration of the Central Library of the Universidad del Valle (Cali-Colombia)

Giraldo-Castrillón, Marinés; Torres-Gonzáles, Celina; Díaz-Ortiz, Jaime E.
2009-06-01

Resumen en español En la Universidad del Valle, se realizó un estudio de la población fúngica para aislar los hongos presentes en los libros y el ambiente de la biblioteca. El muestreo se efectuó en libros con signos de bio-deterioro depositados en cuatro secciones de la Biblioteca (Depósito General, Colección de Libros Antiguos, Colección de la Hemeroteca y Depósito de la Hemeroteca). Se aislaron un total de 409 unidades formadoras de colonias (UFC) en agar con dextrosa y papa y ag (mas) ar celulosa, localizadas en el ambiente (89.7%) y en los libros (10.3%). El 37.16% de las UFC se detectaron en el Depósito General, el 9.78% en el Depósito de la Hemeroteca y un 34.97% en la Colección de Libros Antiguos. Se encontraron 17 géneros, predominando Cladosporium (59.72%), Fusarium (9,31%), Curvularia (6,62%), Aspergillus (6,37%) y Chaetomium (5,64%). Todos mostraron capacidad para crecer en agar celulosa. La prueba de Kruskal-Wallis (p=0.552) no encontró diferencias significativas en el número de UFC/m²/min en las colonias aisladas del ambiente, para las cuatro secciones de la Biblioteca. Resumen en inglés The fungi use the various substrates such as carbon and energy source, are one of the major causative agents biodeterioration of bibliographic materials in archives and libraries. In the Universidad del Valle, a study of fungal populations with the aim of isolating the fungi on the surface of the books and in the environment of the library. We performed a sampling of books with signs of bio-deterioration of four sections (General Books Store, Antiques Books Collection, Pe (mas) riodical Library Collection and Periodical Library Store). A total of 409 colony-forming units (UFC) on potato dextrose agar and cellulose agar were isolated, locating (89.7%) in the environment and in the books (10.3%). The 37.16% of UFC were detected in the General Books Store, 9.78% at Periodical Library and a 34.97% at Antiques Books Collection. There were 17 genera of fungi as the most abundant, Cladosporium (59.72%), Fusarium (9.31%), Curvularia (6.62%), Aspergillus (6.37%) and Chaetomium (5.64%). All genera showed ability to grow in agar cellulose. The Kruskal-Wallis test (p=0.552) determined that there were no significant differences in the number of colonies in UFC/m2/min isolated environment for the four sections of the Library.

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