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Search Results: 1 - 10 of 15721 matches for " Karen; Mu?oz Concha "
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Del texto al hipertexto: las bibliotecas universitarias ante el reto de la digitalización (F. Alía Miranda, coordinador)
Muoz Tinoco, Concha
Revista Espa?ola de Documentación Científica , 2005,
Abstract:
Cocharene Library Plus, contenidos y posiblidades de la base de datos de medicina basada en la evidencia
Muoz Tinoco, Concha
Revista Espa?ola de Documentación Científica , 2004,
Abstract:
LA EDUCACION CIENTIFICA COMO APOYO A LA MOVILIDAD SOCIAL: DESAFIOS EN TORNO AL ROL DEL PROFESOR SECUNDARIO EN LA IMPLEMENTACION DE LA INDAGACION CIENTIFICA COMO ENFOQUE PEDAGOGICO
González Weil,Corina; Martínez Larraín,María Teresa; Martínez Galaz,Carolina; Cuevas Solís,Karen; Muoz Concha,Liber;
Estudios pedagógicos (Valdivia) , 2009, DOI: 10.4067/S0718-07052009000100004
Abstract: education is one of the main factors that promote social mobility. secondary education is important for the development of upper cognitive processes as for the destiny of the individuals, once they graduate of the school system. scientific education, by means of the generation of scientific competence, can collaborate strongly in this development. at international and national level, the use of scientific inquiry is promoted as an effective pedagogical focus in the development of these competences, especially, at contexts of high vulnerability. the present work exposes some key features that teachers should have to implement this pedagogical focus. finally, the role of science secondary teacher education is discussed.
Células Troncales en el Desarrollo y las Perspectivas de Reprogramación Celular para la Regeneración Stem Cells in Development and the Perspectives of Cellular Reprogramming for Regeneration
L Muoz,M. L Concha
International Journal of Morphology , 2012,
Abstract: Los organismos multicelulares se desarrollan a partir de una sola célula: el cigoto. A lo largo de su ontogenia, las células que derivan del cigoto despliegan distintos programas celulares, los cuales son estabilizados por mecanismos epigenéticos. Los programas de las células troncales son más inclusivos, siendo mayor el silenciamiento que la activación de genes durante el proceso de diferenciación celular. Experimentalmente, se ha logrado que células en estado de diferenciación terminal reactiven el programa de células troncales y recuperen su pluripotencialidad, proceso llamado reprogramación. Esto despierta esperanzas en el avance de una medicina regenerativa con nuevas capacidades para el tratamiento de enfermedades crónicas, sin las restricciones éticas del uso de células embrionarias. Multicellular organisms develop from one cell: the zygote. During ontogeny, cells derived from the zygote display different cellular programs that are stabilized through epigenetic mechanisms. The programs of stem cells seem more inclusive, and during the process of differentiation a larger number of genes are silenced than activated. The reactivation of pluripotency recovers of the stem cell program in terminally differentiated cells has been achieved experimentally. This process, called reprogramming, brings new hope for the development of a regenerative medicine with new capabilities for the treatment of chronic diseases, without the ethic restrains imposed by the use of embryonic cells.
Impacto de las fusiones bancarias en los clientes externos. Caso: Fondo Común Banco Universal-Venezuela
José Muoz,Karen Requena
Revista Venezolana de Gerencia , 2003,
Abstract: En los últimos a os, las instituciones financieras venezolanas han pasado por varias etapas, tratando de adaptarse a los cambios de la economía nacional. Inicialmente, pasaron de ser empresas financieras regionales a nacionales y luego de especializadas a universales, sin embargo, estas estrategias no resultaron del todo, teniendo que buscar otras alternativas como las fusiones. La investigación se orientó a determinar el impacto que causan las fusiones bancarias en sus clientes externos, tomando como caso específico a la entidad financiera venezolana: Fondo Común Banco Universal, para lo cual se utilizó una metodología de carácter descriptivo y una combinación de estrategia documental y de campo. Se aplicó un muestreo no probabilístico de tipo intencional, seleccionando los elementos con base en criterios o juicios de los investigadores. De acuerdo a la opinión generalizada por los consultados, el nuevo banco es percibido por los clientes como una entidad menos ágil a la hora de prestar sus servicios.
Time trends in the impact factor of Public Health journals
Gonzalo López-Abente, Concha Muoz-Tinoco
BMC Public Health , 2005, DOI: 10.1186/1471-2458-5-24
Abstract: We used the IFs of 80 public health journals that were registered by the Science Citation Index from 1992 through 2003 and had been listed for a minimum period of the previous 3 years. Impact factor time trends were assessed using a linear regression model, in which the dependent variable was IF and the independent variable, the year. The slope of the model and its statistical significance were taken as the indicator of annual change.The IF range for the journals covered went from 0.18 to 5.2 in 2003. Although there was no statistical association between annual change and mean IF, most of the fastest growing journals registered mean IFs in excess of 1.5, and some represented emerging areas of public health research. Graphs displaying IF trends are shown.In view of the delay between the publication of IFs and that of any given paper, knowing the trend in IF is essential in order to make a correct choice of journal.Scientific journal impact factor (IF) is directly linked to the probability of a paper being cited. It is currently accepted that a higher IF indicates a better journal quality, existing a correlation among IF and quality indicators at least in some health disciplines [1]. As a result these indices are progressively becoming incorporated into researchers' curricula vitae. In Spain, publication in top-IF journals has occupational implications in terms of academic careers and obtaining research grants [2]. The most widespread and important bibliometric indicators are those referring to the repercussion of scientific activity, and among these, IF has a leading role [3].This pressure means that when it comes to having to select a journal in which to publish their studies, researchers turn to journals with IF, and assess the possibility of publishing in those that have the highest IF possible. Journals having the top IF within each medical specialty tend to be those with the greatest international prestige and highest profile, i.e., the most widely read by resea
Variación de compuestos químicos en hojas de poblaciones de Drimys spp. (Magnoliophyta: Winteraceae) en Chile
MUOZ-CONCHA,DIEGO; VOGEL,HERMINE; RAZMILI,IVáN;
Revista chilena de historia natural , 2004, DOI: 10.4067/S0716-078X2004000100005
Abstract: canelo (drimys winteri) is a chilean native tree with medicinal properties and sacred to mapuche people. this species contains chemical compounds with biological activity such as: essential oils, terpenes and flavonoids, which were quantified in leaves of five d. winteri and one d. andina populations by hydrodistillation (essential oils), hexane soxhlet extraction (terpenes), and spectrophotometry (flavonoids). mean concentrations of 0.5 ml 100 g-1 for essential oils, 7.1 % for terpenes and 1.8 % for flavonoids in leaves (dry mass) were determined. despite the great variation found, significant differences among populations were detected in concentrations of all groups of chemical compounds studied. populations from the central region of chile presented the highest values of essential oils (0.68 ml 100 g-1 in huerta de maule population), terpenes, and flavonoids (9.47 and 2.37 %, respectively, both in the pangal population). the southernmost population, located in chiloé island, showed the lowest values for the three groups of compounds: 0.22 ml 100 g-1 for essential oils, 3.36 % for terpenes and 1.21 % for flavonoids. d. winteri and d. andina populations from the ix region, geographically close to each other, had different concentrations of essential oils and flavonoids. it is concluded that different drimys populations actually contain different quantities of essential oils, terpenes, and flavonoids
Variación de compuestos químicos en hojas de poblaciones de Drimys spp. (Magnoliophyta: Winteraceae) en Chile Variation of chemical compounds in leaves of Drimys spp. (Magnoliophyta: Winteraceae) populations in Chile
DIEGO MUOZ-CONCHA,HERMINE VOGEL,IVáN RAZMILI
Revista chilena de historia natural , 2004,
Abstract: El canelo (Drimys winteri) es un árbol nativo de Chile con propiedades medicinales y sagrado para el pueblo mapuche. Se ha descrito en esta especie la presencia de compuestos químicos con actividad biológica como aceites esenciales, terpenos y flavonoides. Estos grupos de compuestos fueron cuantificados en hojas de cinco poblaciones de D. winteri y una de D. andina de Chile mediante hidrodestilación (aceites volátiles), extracción Soxhlet con hexano (terpenos) y espectrofotometría (flavonoides). El contenido promedio de aceites esenciales fue de 0,5 mL 100 g-1, el de terpenos de 7,1 %, y el de flavonoides de 1,8 %, en base a peso seco. A pesar de las importantes variaciones observadas dentro y entre poblaciones, las diferencias de poblaciones fueron significativas para los tres grupos de compuestos estudiados. Las poblaciones de la Séptima Región de Chile presentaron los valores más altos de aceites esenciales (0,68 mL 100 g-1 en la población de Huerta de Maule), terpenos y flavonoides (9,47 y 2,37 %, respectivamente, ambos en la población de Pangal). La población más austral estudiada, ubicada en Huillinco, Chiloé, presentó valores significativamente más bajos para los tres grupos de compuestos: 0,22 ml/100g de aceites esenciales, 3,36 % de terpenos y 1,21 % de flavonoides. Las poblaciones de D. winteri y D. andina de la IX Región, cercanas geográficamente, presentaron diferentes contenidos de aceites esenciales y flavonoides. Se concluye que efectivamente poblaciones distintas de especies de Drimys poseen cantidades significativamente diferentes de aceites esenciales, terpenos y flavonoides Canelo (Drimys winteri) is a Chilean native tree with medicinal properties and sacred to mapuche people. This species contains chemical compounds with biological activity such as: essential oils, terpenes and flavonoids, which were quantified in leaves of five D. winteri and one D. andina populations by hydrodistillation (essential oils), hexane Soxhlet extraction (terpenes), and spectrophotometry (flavonoids). Mean concentrations of 0.5 mL 100 g-1 for essential oils, 7.1 % for terpenes and 1.8 % for flavonoids in leaves (dry mass) were determined. Despite the great variation found, significant differences among populations were detected in concentrations of all groups of chemical compounds studied. Populations from the central region of Chile presented the highest values of essential oils (0.68 mL 100 g-1 in Huerta de Maule population), terpenes, and flavonoids (9.47 and 2.37 %, respectively, both in the Pangal population). The southernmost population, located in
Análisis mecánico del compuesto polietileno aluminio reforzado con fibras cortas de fique en disposición bidimensional Mechanical analysis of polyethylene aluminum composite reinforced with short fique fibers available a in two-dimensional arrangement
Miguel Hidalgo,Mario Muoz,Karen Quintana
Revista Latinoamericana de Metalurgia y Materiales , 2012,
Abstract: En este artículo se presenta el estudio del comportamiento físico-mecánico de la fracción de PEBD/Al reciclado de empaques de Tetra Pak, de origen post consumo, reforzado con fibras de fique, en el cual se enfatiza en el reforzamiento del material con fibras cortas en disposición bidimensional aleatoria. Para observar el efecto producido por la incorporación de fibras en las propiedades físico-mecánicas, se fabricaron tableros, por medio del proceso de moldeo en prensa, de platos calientes controlada por computador, con porcentajes de 10, 30 y 50 % v/v de fibra, y se realizó una comparación de las propiedades obtenidas, con las del PEBD/Al sin refuerzo. Siguiendo esta metodología, fué posible obtener un incremento de la resistencia, y el módulo a tensión del material en un 216 y 515 % respectivamente, cuando se incorporó 50 % de fibra, sin embargo los mejores resultados a flexión alcanzados se presentaron con 30 % de fique. Por otra parte, se puede apreciar una tendencia incremental de absorción de agua con la incorporación de fibra en el material. Adicionalmente se observó el compuesto utilizando la técnica MEB, con el objeto de cualificar la adherencia de la fibra a la matriz, la homogeneidad y porosidad del compuesto. The study of the behavior of the physical-mechanical fraction of recycled LDPE/AL recovered from Tetra Pak packing from a post-consumer source, reinforced with fique fiber is presented in this paper, which emphasizes in the reinforcement of the material with short fibers on dimensional random arrangement. To observe the effect produced on physicalmechanical properties due to the fiber’s addition, boards were made through the molding process in a hot press controlled by computer, with percentages of 10, 30 and 50 % v/v of fiber and a comparison was made between the properties obtained and the obtained with the LDPE/Al without reinforcement. Following this methodology, it was possible to obtain an increase on strength and tensile modulus of the material in a percentage of 216 and 515 % respectively, when 50 % of fiber was incorporated. However the best results achieved were presented in flexion with 30 % of fique. Moreover, an increasing trend on water absorption can be observed with the addition of fiber in the material. Additionally, the compound was observed using SEM technique in order to qualify the fiber adhesion, to the matrix, the homogeneity and porosity of the compound.
Análisis de la dieta de Diplomystes (Siluriformes: Diplomystidae) de Chile
Beltrán-Concha,M; Muoz-Ramírez,C; Ibarra,J; Habit,E;
Gayana (Concepción) , 2012,
Abstract: diplomystidae is well known as the oldest catfish family in the order siluriformes. in chile three of the six described species are present (genus dyplomystes), distributed allopatrically in rivers from the rapel basin to the valdivia basin (34°s -40°s), and some isolated populations of unidentified diplomystids in the baker basin (47°s). in this study we analyze the stomach content of individuals of diplomystes from all hydrological drainages in which populations are currently present in chile, including the baker river. a total of 175 individuals were analyzed from which 90.3% were juveniles. results show that, regardless of the provenance of individuals analyzed, larvae of the insect family chironomidae were the most consumed item. the only exception occurred in the toltén basin, whose population consumed mostly larvae of the insect family simulidae. no marked differences were found between the diet of juveniles and adults, except for the presence of crustaceans of the genus aegla in adults. these results confirm a carnivore and generalist diet for the genus diplomystes, with no changes along the latitudinal gradient in chile.
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