Sample records for ESTRUCTURA FINA (fine structure)
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1

Estructura fina de poliéster de diferente uso final

Gacén Guillén, Joaquín; Cayuela Marín, Diana; Tzvetkova, Milena
2002-07-01

Digital.CSIC (Spain)

2

Diferencias de estructura fina en un mismo tipo de hilo de poliéster fabricado por una misma productora en diferentes condiciones

Gacén Guillén, Joaquín; Cayuela Marín, Diana; Manich, Albert M.; Gacén Esbec, Isabel
2000-07-01

Digital.CSIC (Spain)

3

Variación de la estructura fina de las fibras acrílicas en la hilatura

Gacén Guillén, Joaquín; Maíllo, Josefina; Manich, Albert M.; Ussmane, Mohamed
2002-01-01

Digital.CSIC (Spain)

4

Diseño de Filtros FIR de Retraso Fraccionario Mediante Optimización en Frecuencia/ Fractional Delay FIR Filter Design using Frequency-Based Optimization

Díaz-Carmona, J.; Jovanovic-Dolecek, G.
2005-01-01

Resumen en español En este artículo se describe el diseño en el dominio de la frecuencia de filtros digitales FIR de retraso fraccionario (Fractional Delay Filter, FDF) con características de ancho de banda amplio y una resolución fina de retraso. El método de diseño en frecuencia utilizado está basado en optimización con mínimos cuadrados en la aproximación de series de Taylor de la señal de entrada. La propuesta consiste en reducir la complejidad de la optimización en frecuenc (mas) ia al momento de diseñar el FDF. Lo anterior se logra con la combinación de una estructura multirazón (multirate) y una estructura Farrow modificada. El filtro resultante presenta como ventajas un número reducido de operaciones por muestra de salida y una reducción notable en la carga computacional de diseño Resumen en inglés A frequency domain design method for fractional delay FIR filters (Fractional Delay Filter, FDF) with wide bandwidth and fine delay resolution is described. The frequency domain method is based on a least square Taylor series approximation of the input signal. The proposed design method consists of reducing the complexity of the frequency optimization workload in the design of the FDF. This is obtained by the combination of a multirate structure and a modified Farrow stru (mas) cture. The resulting filter has a reduced number of arithmetic operations per output sample and yields a significant reduction in the design computational workload

Scientific Electronic Library Online (Spanish)

5

Variabilidad espacial y diaria del contenido de humedad en el suelo en tres sistemas agroforestales/ Spatial and daily variability of soil moisture content in three agroforestry systems

Rivera Peña, Mariela; Amézquita Collazos, Edgar; Rao, Idupulapati; Menjivar Flores, Juan Carlos
2009-04-01

Resumen en español En seis puntos de tres transectos (102 m) paralelos (9 m) en tres sistemas de uso del terreno (Quesungual menor de dos años, SAQ(mas) El coeficiente de variación de los parámetros evaluados presentó rangos para densidad aparente (0.76 y 15.1%), carbono orgánico (30.4 y 54.3%), humedad volumétrica (9.5 y 23.5%), arena (12.8 y 22.5%) y arcilla (14.0 y 29.2%). En los análisis geoestadísticos el componente al azar de la dependencia espacial predominó sobre el efecto pepita (nugget). Con las funciones de los semivariogramas estructurados para cada variable se generaron mapas de contorno interpolados a escala fina los cuales mostraron heterogeneidad en las propiedades evaluadas. La autocorrelación de Morán (I) indicó que rangos de muestreo menores a 9 m podrían ser adecuados para detectar la estructura espacial de la variable humedad volumétrica. Resumen en inglés The objective of this study was to determine the level of soil spatial variability in an area consisting of the land uses: Quesungual slash and mulch agroforestry system with less than two years (QSMAS(mas) 1 am and 05) during 9 days. Coefficient of variation for soil properties varied for bulk density (0.76 and 15.1%), organic carbon (30.4 and 54.3%), volumetric moisture (9.5 and 23.5%), sand (12.8 and 22.5%) and clay (14.0 and 29.2%). The geo-statistical analysis showed that the random component of the spatial dependence was predominant over the nugget effect. The functions of semivariograms, structured for each variable were used to generate maps of interpolated contours at a fine scale. The Moran (I) autocorrelation indicated that sampling ranges less than 9 m would be adequate to detect spatial structure of the volumetric moisture variable.

Scientific Electronic Library Online (Spanish)

6

Análisis de la materia orgánica alóctona y organización funcional de macroinvertebrados en relación con el tipo de hábitat en ríos de montaña de Patagonia/ Allochthonous organic matter and functional organization of macroinvertebrates at habitat scale in Patagonian mountain rivers

Velásquez, Stella M; Miserendino, M Laura
2003-06-01

Resumen en español El propósito de este trabajo fue examinar la composición, estructura y los grupos funcionales de macroinvertebrados en distintos tipos de hábitat de ríos de montaña en Patagonia. Los ríos estudiados fueron Blanco, Baguilt, Los Rifleros y Nant y Fall; en cada de uno de ellos se seleccionó un sector representativo que se muestreó en aguas altas y en aguas bajas. Se tomaron muestras de macroinvertebrados y de materia orgánica particulada gruesa y fina en siete tipos (mas) de hábitat: bloque, guijón, guijarro y grava (en áreas de rápidos), y arena, paquetes de hojas y macrófitas (en pozas). En cada hábitat se colectaron tres muestras de macroinvertebrados, en cada río y en cada fecha. Los hábitats en rápidos presentaron mayor densidad y biomasa de macroinvertebrados respecto a los hábitats en pozas. El grupo funcional dominante fue el de colectores-recolectores, seguido por los colectores-filtradores. Los desmenuzadores presentaron mayor densidad en bloques y gravas durante todo el estudio. Los filtradores exhibieron mayor dominancia en macrófitas y gravas, y su biomasa fue mayor en bloques, macrófitas, guijones y guijarros. Los raspadores dominaron en bloques, guijarros y guijones, aunque su biomasa fue mayor en gravas. En los paquetes de hojas co-dominaron los desmenuzadores y los colectores-recolectores, mientras que en las arenas los colectores-recolectores fueron básicamente el único grupo funcional representado. La materia orgánica particulada gruesa en rápidos estuvo asociada principalmente a sustratos de tamaño medio, mientras que la materia orgánica particulada fina estuvo asociada a grava y paquetes de hojas en pozones. Los resultados sugieren que la estructura y la organización funcional de la comunidad de macroinvertebrados son distintivas a escala de hábitat en ríos de bajo orden en Patagonia y, en su mayoría, dependerían de la calidad y disponibilidad de los recursos orgánicos alóctonos. Resumen en inglés In this paper we examined the composition, structure and functional feeding groups of invertebrates in different habitats of four Patagonian mountain rivers (Blanco, Baguilt, Los Rifleros and Nant y Fall). At each river, a representative sector was selected and sampled during high and low water periods. Samples of macroinvertebrates, coarse particulate organic matter and fine particulate organic matter were obtained. Seven habitat types were analyzed: boulder, cobble, peb (mas) ble, and gravel (in riffle areas), and sand, leaf-packs, and macrophytes (in pools). At each habitat, three samples were collected per river and date. Riffle areas had higher density and biomass of macroinvertebrates than pools. Collector-gatherers were the dominant functional group followed by collector-filterers. Shredders showed high density in boulder and gravel during the study. Filterers were dominant in macrophytes and gravel, and their biomass was high in boulder, macrophytes, cobble and pebble. Scrapers were common in boulder, pebble and cobble, but showed high biomass in gravel. Both shredders and collector-gatherers co-dominated in leaf-packs. Collector-gatherers were the only functional feeding group represented in sand. The coarse particulate organic matter in riffles was associated mainly with habitats of medium size substrates, while fine particulate organic matter was related to gravel and leaf-pack habitats. Local geomorphology and related physical parameters influenced the distribution and biomass of organic matter. The results suggest that community structure and functional organization are distinctive at habitat scale in low order streams of Patagonia, and they depend on the quality and availability of allochthonous organic resources.

Scientific Electronic Library Online (Spanish)

7

Los anticuerpos y su papel como herramientas analíticas en los ensayos inmunoenzimáticos/ The antibodies and their role as analytic tools in immunoenzymatic assays

Otero González, Anselmo J.
2010-08-01

Resumen en español En este trabajo se presentó la historia y evolución, desde el descubrimiento, de los anticuerpos, así como la elucidación de su compleja estructura y función que ha servido de base metodológica para crear paradigmas inimaginables en su momento, como la fina especificidad de reconocimiento; también derrumbar otros, aparentemente inamovibles, como la invariabilidad y universalidad del genoma celular. Se revisó la evolución de los sistemas analíticos basados en la (mas) reacción antígeno-anticuerpos para llegar al estado actual y problemática de las enfermedades infecciosas y el determinante papel que desempeñan en su control la detección y el monitoreo de agentes infecciosos. La extraordinaria capacidad de los anticuerpos para discriminar estructuras antigénicamente similares, les permite ser parte fundamental de los inmunoensayos como herramientas básicas de lo que es hoy día una disciplina productiva muy bien establecida: la inmunotecnología. Resumen en inglés This paper presented the history and evolution of the antibodies since their discovery. It also elucidated their complex structure and function that have served at a given time as methodological basis for creating unimaginable paradigms such as fine recognition specificity, and also for destroying other apparently immutable ones as invariability and universality of the cellular genome. A review was made of the evolution of antigen-antibody reaction-based analytical system (mas) s up to the present, the situation of infectious diseases and the determining role that detection and monitoring of infectious agents play in their control. The extraordinary capability of antibodies to discriminate antigenically similar structures allows them to be fundamental tools in immunoassays and also in a well-established discipline at present, that is, immunotechnology.

Scientific Electronic Library Online (Spanish)

8

Cambios ultraestructurales del trofoblasto en los casos de hipoxia durante la preeclampsia

Castejón, Olivar; López, Ángela J; Castejón, Oliver C
2008-09-01

Resumen en español Objetivo: Examinar la ultraestructura del sincitiotrofoblasto en placentas de embarazadas complicadas con preeclampsia con especial referencia al efecto de la hipoxia sobre la estructura fina del tejido. Métodos: Diez placentas, a término, afectadas por preeclampsia, fueron tomadas inmediatamente después del parto por cesárea y de cada una de ellas tres biopsias de la superficie maternal se disecaron en sala de parto, en especímenes de 2 a 5 mm, y se fijaron por inme (mas) rsión en glutaraldehido al 4 %, pH 7,4, a 4º C. Posteriormente se dividieron en fragmentos de 1 mm y sumergidos en solución fresca fijadora por períodos variables de 2 a 72 horas seguidas por una fijación secundaria en tetraóxido de osmio al 1 % en buffer fosfato 0,1 M durante 1 hora. Las muestras se procesaron siguiendo los procedimientos convencionales de la microscopia electrónica de transmisión para su observación. Ambiente: Laboratorio de microscopia electrónica del Ciadana, Facultad de Ciencias de la Salud, Maracay. Resultados: Los hallazgos revelan proyecciones de la membrana plasmática del sincitio de diversas formas, que simulan desprenderse de la superficie. La membrana basal del sincitio se mostró engrosada. Mitocondrias en diversos grados de degeneración presentaron partículas electron densas en la matriz mitocondrial. Regiones apicales del citoplasma sincitial parecen desprenderse hacia el espacio intervelloso. Numerosas vacuolas intracitoplasmáticas y ampliaciones de las cisternas del retículo endoplásmico rugoso se destacan en el citoplasma. Interrupciones de la membrana sincitial y regiones citoplásmicas sin membrana plasmática se notaron. Conclusión: Fragmentos del sincitio desprendidos de la superficie del mismo sugieren ser los corpúsculos que dañan los endotelios de la unidad materna - feto - placentaria constituyendo uno de los estímulos para el mantenimiento de la patogénesis de la preeclampsia. Resumen en inglés Objective: To examine the ultrastructure of the syncytiotrophoblast in placentae of pregnant woman with pre-eclampsia is the objetive of this work with special reference to the effect of hypoxia on the fine structure of the tissue. Method: Ten placentae at term affected by pre-eclampsia were taken immediately after delivery by caesarea and from each one three biopsies from maternal surface were dissected in delivery room in specimens of 2 a 5 mm and fixed by immersion in (mas) 4 % glutaraldeyde - 0.1 M phosphate buffer, pH 7.4, at 4° C. Later, they were divided into 1- mm fragments and immersed in a fresh similar solution for periods varying from 2 to 72 hours followed by secondary fixation in 1 % osmium tetroxide - 0.1 M phosphate buffer for 1 hour. The samples were processed according to the conventional procedures of transmission electron microscopy for their observation. Setting: Laboratory of electron microscopy from CIADANA, Faculty of Sciences of Health, Maracay. Results: The findings reveal prolongations of the plasmamembrane or microvilli of the syncytium of different forms which seem release of the surface. The basal membrane of the syncytium appeared thickened. Swollen mitochondria in diverse degenerative grade were seen with particles electron dense in their matrix. Apical regions of cytoplasm seem detach to maternal circulation. Numerous intracytoplasmic vacuoles and dilated cisterns of the rough endoplasmic reticulum were seen into cytoplasm. Interruptions of the syncytial plasmamembrane and regions of cytoplasm withouth plasma membrana were observed. Conclusion: Fragments of syncytium detached from trophoblast surface suggest to be the corpuscles that damage the endothelium of the unity placental - feto - maternal and can be the stimulus to the perturbation of endothelial cell function in the pathogenesis of pre-eclampsia.

Scientific Electronic Library Online (Spanish)

9

Utilización del modelo 3-PG, un modelo basado en procesos, en el análisis de la productividad de plantaciones de pino radiata manejado con diferentes regímenes silviculturales/ Using the 3-PG in the analysis of productivity of radiata pine plantations under different silvicultural regimes

RODRIGUEZ LEIVA, ROLANDO; ESPINOSA BANCALARI, MIGUEL; REAL HERMOSILLA, PEDRO
2003-01-01

Resumen en español Se estudia el efecto de la estructura de copas y el régimen de fertilización en la producción de madera. Para ello se comparó el crecimiento y desarrollo de dos rodales, uno manejado con un sistema silvopastoral con respecto a uno manejado en forma tradicional para la producción de madera. Para estimar el crecimiento se utilizó un modelo basado en procesos denominado 3-PG, que se validó con un análisis fustal. Se concluyó que el índice de área foliar fue contro (mas) lado fuertemente por el diseño de plantación y la densidad final. El régimen de fertilización tuvo efectos positivos sobre el índice de área foliar, pero su potencial fue limitado por la estructura de copas. En el régimen forestal el incremento en biomasa fustal se presentó estrechamente relacionado con el índice de área foliar. Sin embargo, en rodales con manejo silvopastoral, su incremento se atribuye a un cambio de localización desde la biomasa de raíces finas, por efecto del régimen de fertilización. El raleo, por su efecto en la estructura de copas más que la disponibilidad de los recursos del sitio, afecta la producción final de madera. Por tanto, la maximización de la producción de madera dependerá del manejo conjunto de los recursos del sitio con la intensidad y oportunidad del raleo Resumen en inglés The effects of both crown structure and fertilization regime on productivity were studied. We compared the growth and development of stands managed with silvopastoral methods with those of a traditionally managed stand. A process-based model, designated 3-PG and validated by stem analysis, was used to estimate growth. We concluded that the leaf area index was strongly controlled by the design of the plantation and its final density. The fertilization regime had a positive (mas) effect on the leaf area index but its potential was limited by crown structure. Under the traditional forestry regime, the increase in stem-wood biomass was strongly related to the leaf area index. However, in stands under silvopastoral management, the increase is attributable to changes in allocation from the biomass of the fine roots, as an effect of the fertilization regime. Because of the effect of thinning on crown structure, the final wood production was more affected by thinning than by the availability of the site resources. Therefore, maximization of wood production will depend upon the combined management of site resources with the intensity of and opportunity for thinning

Scientific Electronic Library Online (Spanish)

10

ESTRUCTURA DE LA TAXOCENOSIS ANNELIDA-MOLLUSCA EN LA REGION DE MINGUEO, GUAJIRA (CARIBE, COLOMBIANO)/ STRUCTURE OF THE TAXOCOENOSIS ANNELLIDA-MOLLUSCA IN THE MINGUEO AREA, GUAJIRA (COLOMBIAN CARIBBEAN)

Guzmán-Alvis, Angela I.; David Solano, Oscar
1997-12-01

Resumen en español En una red de 10 estaciones que se ubicaron entre los 6 y 21.5 m de profundidad en la plataforma continental comprendida entre Dibulla y el Río Palomino (Colombia), se hizo una caracterización puntual de las comunidades del macrozoobentos de fondos blandos. En cada estación se hicieron cuatro lances de una draga van Veen, de los cuales uno se destinó para el análisis granulométrico y los tres restantes para el biológico. Los resultados que se presentan, incluyen el (mas) setenta y cinco por ciento de los organismos recolectados, comprendiendo los poliquetos el 69%, y moluscos el 6%. Los análisis se hicieron a nivel de familia de los taxa antes mencionados. Con fin de definir las taxocenosis, se realizó un análisis de clasificación entre estaciones y los grupos allí obtenidos se confrontaron en un ordenamiento multidimensional no métrico. Para cada ensamblaje se recalcularon abundancias, número de familias, familias dominantes, características y diversidad con base en las curvas de k-dominancia. Igualmente, se construyeron curvas ABC, con el fin de observar el grado de perturbación en cada ensamblaje. Finalmente, el patrón de distribución biológico hallado se relacionó con variables ambientales como profundidad y tamaños de grano del sedimento, usando la técnica del BIOENV. Los resultados mostraron dos taxocenosis, denominadas Cossuridae y Lumbrineridae dado que estas familias de poliquetos fueron características de cada una. La comunidad Cossuridae estaba asentada en cienos, localizada más lejos de la costa, fue la más diversa y presentó mayor biomasa que la comunidad Lumbrineridae. Esta última, estuvo asentada sobre arenas muy finas y era más somera. Las curvas ABC mostraron que ambos ensamblajes estaban perturbados, se cree que esta perturbación es de origen natural dado que en la zona no existe actividad antrópica. La profundidad y arenas muy finas fueron las variables que mejor explicaron el patrón de distribución espacial hallado. Resumen en inglés A punctual characterization of the soft-bottom macrobenthos was conducted on the continental shelf between Dibulla and Río Palomino (Colombia). A net of 10 sample sites, 4 van Venn grabs per site, placed in deeps between 6 and 21.5 m, was sampled for this purpose. The results include 75% of the collected organisms, of which 69% were polychaeta and 6% mollusks. Analysis were performed at family level, in order to identify assemblages, a classification analysis between sam (mas) ple sites was performed and the groups there were confronted with the picture obtained from a non metric multidimensional scaling (NMDS). For each assemblage abundance, number of families, family dominance and diversity (K-dominance) were determined. By means of ABC curves the disturbance status of the assemblages was assessed. Finally, the pattern of distribution was related with water column depth and grain size of the sediments by means of the BIOENV technique. Results showed two assemblages called "Cossuridae" and "Lumbrineridae" on the basis of the polychaeta families that characterize them. The "Cossuridae" assemblage occurs in silt sediments offshore. It was the most diverse and showed the highest biomass levels. The Lumbrineridae assemblage occurs in fine sand sediments and shallow waters. The ABC curves analysis suggests that both assemblages are disturbed by natural causes since there is no human activity in the area. Water depth and fine sand were the environmental variables with the highest explanatory power in relation to the spatial distribution of the assemblages.

Scientific Electronic Library Online (Spanish)

11

XBT profilers for operational purposes: application and validation in real exercises

Machín, Francisco; Emelianov, Mikhail; Salat, Jordi; Rodríguez, Pablo; García-Ladona, Emilio; Menéndez, Javier
2008-12-01

Digital.CSIC (Spain)

14

Vibrational quenching of CO2(010) by collisions with O(3P) at thermal energies: A quantum-mechanical study

Lara Castells, M. Pilar de; Hernández, Marta I.; Delgado Barrio, Gerardo; Villarreal, Pablo; López-Puertas, Manuel
2006-04-24

Digital.CSIC (Spain)

21

Ultraviolet behavior of transverse gravity

Álvarez, Enrique; Fernández Faedo, Antón; López-Villarejo, J.J.
2008-07-08

Digital.CSIC (Spain)

22

Thermobarometric implications of clinopyroxene chemistry in the Plio-Quaternary magmas of Gran Canaria (Canary Islands, Spain)

Seidl, Stefan; Högele, A.; Kroner, M.; Karrai, Khaled; Warburton, Richard J.; García, Jorge M.; Petroff, Pierre M.
2007-02-01

Digital.CSIC (Spain)

23

Thermal analysis and differential solubility of polyester fibers and yarns

Manich, Albert M.; Bosch, T.; Carilla Auguet, Josep; Ussman, M.; Maillo, Josefina; Gacén Guillén, Joaquín
2003-04-01

Digital.CSIC (Spain)

24

The outburst of the κ Cygnids in 2007: clues about the catastrophic break up of a comet to produce an Earth-crossing meteoroid stream

Trigo-Rodríguez, Josep Maria; Madiedo, José M.; Williams, Iwan P.; Castro-Tirado, Alberto J.
2009-01-01

Digital.CSIC (Spain)

26

The hydration of Cu2+: Can the Jahn-Teller effect be detected in liquid solution?

Chaboy, J.; Muñoz-Páez, Adela; Merkling, Patrick J.; Sánchez Marcos, Enrique
2006-02-01

Digital.CSIC (Spain)

29

Structural characterization of kerogen in 3.4 Ga Archaean cherts from the Pilbara Craton, Western Australia

Marshall, Craig P.; Love, Gordon D.; Snape, Colin E.; Hill, Andrew C.; Allwood, Abigail C.; Walter, Malcolm R.; Van Kranendonk, Martin J.; Bowden, Stephen A.; Sylva, Sean P.; Summons, Roger E.
2007-05-05

Digital.CSIC (Spain)

30

Strong philopatry derived from capture–recapture records does not lead to fine-scale genetic differentiation in lesser kestrels

Alcaide, Miguel; Serrano, David; Tella, José Luis; Negro Balmaseda, Juan José

8 pages, 4 figures. | 1. The integration of capture–recapture and molecular approaches can improve our understanding of the consequences of habitat fragmentation on population connectivity. Here we employed microsatellites to test dispersal hypotheses derived from intense and long-term ringing progr...

DRIVER (Spanish)

33

Soil aggregate stability and organic matter in clay and fine silt fractions in urban refuse-amended semiarid soils

Caravaca Ballester, María Fuensanta; Lax, Antonio; Albaladejo Montoro, Juan
2001-01-01

Digital.CSIC (Spain)

34

Sistemática, taxonomía y domesticación de alpacas y llamas: nueva evidencia cromosómica y molecular/ Systematics, taxonomy and domestication of alpaca and llama: new chromosomal and molecular evidence

MARÍN, JUAN C; ZAPATA, BEATRIZ; GONZÁLEZ, BENITO A; BONACIC, CRISTIAN; WHEELER, JANE C; CASEY, CIARA; BRUFORD, MICHAEL W; PALMA, R. EDUARDO; POULIN, ELIE; ALLIENDE, M. ANGÉLICA; SPOTORNO, ÁNGEL E
2007-06-01

Resumen en español Existen cuatro especies de camélidos sudamericanos, dos de ellos silvestres, guanaco (Lama guanicoe) y vicuña (Vicugna vicugna), y dos formas domésticas, alpaca (Lama pacos) y llama (Lama glama), cuyo origen ha sido objeto de debate. En el presente estudio la variación en el patrón de bandas G de los cromosomas de llamas y alpacas y la secuencia de dos genes mitocondriales han sido usados para estudiar el origen y la clasificación de llamas y alpacas. Patrones de ba (mas) ndas cromosómicas similares fueron observados en las cuatro especies de Lamini, incluso similares a los descritos para camello, Camelus bactrianus. Sin embargo, se encontraron finas y consistentes diferencias en los brazos cortos del cromosoma 1, permitiendo separar a camellos, guanacos y llamas, de las de vicuñas y alpacas. Este patrón fue consistente incluso en un híbrido guanaco x alpaca. Relaciones equivalentes fueron encontradas en las secuencias completas del gen para citocromo b, así como en el árbol de expansión mínima de las secuencias parciales de la región control, agrupando a guanacos con llamas y a vicuñas con alpacas. Los análisis filogenéticos mostraron a V. vicugna y a L. guanicoe como grupos recíprocamente monofHéticos. El análisis de las secuencias de ambos genes mostró dos ciados entre las vicuñas, concordantes con las subespecies reconocidas para esta especie, pero los resultados obtenidos para guanacos no reflejaron la existencia de las cuatro subespecies previamente propuestas. El análisis combinado de variaciones cromosómicas y moleculares demostraron una alta similitud genética entre alpacas y vicuñas, así como entre llamas y guanacos. Aunque se revela hibridización direccional, nuestros resultados apoyan fuertemente la hipótesis de que la llama se deriva de L. guanicoe, y la alpaca de V. vicugna, apoyando la reclasificación de la alpaca como V. pacos Resumen en inglés Four camelid species exist in South America: two wild, the guanaco (Lama guanicoe) and the vicuña (Vicugna vicugna), and two domestic, the alpaca (Lama pacos) and the llama (Lama glama). However, the origin of the domestic species has been a matter of debate. In the present study, variations in chromosome G banding patterns and in two mitochondrial gene sequences have been used to study the origin and classification of the llama and alpaca.-Similar patterns in chromosome (mas) G band structure were observed in all four Lamini species, and these in turn were similar to the bands described for camels, Camelus bactrianus. However, fine and consistent differences were found in the short arms of chromosome 1, separating camels, guanacos and llamas from vicuñas and alpacas. This pattern was consistent even in a hybrid guanaco x alpaca. Equivalent relationship showed the complete cytochrome b gene sequences, and the minimum expansion tree of the partial control region sequence, grouping guanaco with llama and vicuña with alpaca. Phylogenetic analyses showed V. vicugna and L. guanicoe as monophyletic groups. Analysis of both gene sequences revealed two clades within vicuña, concordant with the two described subspecies, but the results for guanaco did not confirm existence of the four previously proposed subspecies. The combined analysis of chromosomal and molecular variation showed close genetic similarity between alpacas and vicuñas, as well as between llamas and guanacos. Although directional hybridization was revealed, our results strongly support the hypothesis that the llama would have derived from L. guanicoe and the alpaca from V. vicugna, supporting reciassification as V. pacos

Scientific Electronic Library Online (Spanish)

35

Simple modeling of FtsZ polymers on flat and curved surfaces: correlation with experimental in vitro observations

Paez, Alfonso; Mateos-Gil, Pablo; Hörger, Ines; Mingorance, Jesús; Rivas, Germán; Vicente, Miguel; Vélez, Marisela; Tarazona, Pedro
2009-10-01

Digital.CSIC (Spain)

36

Sensitivity on earth core and mantle densities using atmospheric neutrinos

Borriello, E.; Mangano, G.; Marotta, A.; Miele, G.; Migliozzi, P.; Moura, C.; Pastor, Sergio; Pisanti, O.; Strolin, P.
2009-06-22

Digital.CSIC (Spain)

37

Seismic reflection along the path of the Mediterranean Undercurrent

Buffet, Grant; Biescas, Berta; Pelegrí, Josep Lluís; Machín, Francisco; Sallarès, Valentí; Carbonell, Ramón; Klaeschen, D.; Hobbs, R.
2009-07-10

Digital.CSIC (Spain)

39

Sediment accumulation in the western Gulf of Lions, France: The role of Cap de Creus Canyon in linking shelf and slope sediment dispersal systems

DeGeest, A. L.; Mullenbach, B. L.; Puig, Pere; Nittrouer, C. A.; Drexler, Tina M.; Durrieu de Madron, Xavier; Orange, D. L.
2008-08-30

Digital.CSIC (Spain)

40

Relic Density of Neutrinos with Primordial Asymmetries

Pastor, Sergio; Pinto Cejas, Teguayco; Raffelt, G.G.
2009-06-19

Digital.CSIC (Spain)

43

Pure luminescence transitions from a small InAs/GaAs quantum dot exhibiting a single electron level

Karlsson, K. F.; Holtz, P. O.; Moskalenko, E. S.; Monemar, B.; Schoenfeld, W. V.; García, Jorge M.; Petroff, P. M.
2003-01-01

Digital.CSIC (Spain)

44

Procesos de piping en el piedemonte distal de la Precordillera Oriental, provincia de San Juan: factores y relieve/ Piping processes in the eastern piedmont of the Eastern Precordillera, San Juan Province

Suvires, G.M.
2004-09-01

Resumen en español En la región, ubicada al norte del río San Juan, 31°30'S y 68°30'O, parte distal del piedemonte oriental de la Precordillera Oriental, sector La Laja - El Salado, se encontró la presencia de piping en sedimentos y sedimentitas finas rosadas pertenecientes a secuencias neógenas. Se investigan los condicionantes y factores que favorecieron su génesis. Se interpreta, que este proceso es la causa principal de la formación del relieve erosivo con desplomes, hundimiento (mas) s, caída de rocas en ladera y de la erosión retrocedente existente en las cabeceras y base de los barrancos. Se analizan los distintos factores ambientales: climáticos, litológicos y estructurales de la región. Entre los condicionantes favorables resultan: la presencia de sedimentos y afloramientos de argilitas con muy altos contenidos en sodio, en un clima árido-seco con amplia variación estacional de precipitaciones. Además, la actividad neotectónica presente en ese sitio coadyuva mediante la emergencia de agua subterránea con alta mineralización a contaminar los afloramientos de argilitas. El piping resulta ser entonces, en esta región árida y con actividad neotectónica, un peligro subsuperficial para tener en cuenta en la planificación territorial. Resumen en inglés Piping process in fine-grained, pink coloured Neogene sediments and sedimentary rocks were studied in the La Laja-El Salado area, northern Río San Juan, in the distal and eastern piedmont of the Eastern Precordillera. Conditions favourable to the genesis of piping were investigated through aerial photo interpretation and fieldwork, and it was concluded that the factors controlling its occurrence are lithology, climate, structure and landscape. The piping in the study are (mas) a took place mainly in fine clayey materials, with very high values of sodium, and in a dry and arid climatic environment. Neotectonic activity is particularly important for evaluation of the piping processes: some erosional geomorphological features are interpreted as being produced by piping, and the process thus represents a great subsurface hazard that needs to be taken into account in land use planning.

Scientific Electronic Library Online (Spanish)

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Primeros estudios micromorfológicos en sambaquís brasileños (sitio Jabuticabeira II, Estado de Santa Catarina)/ FIRST MICROMORPHOLOGICAL STUDIES OF BRAZILIAN SAMBAQUÍS, JABUTICABIERA II SITE, SANTA CATARINA STATE

Villagran, Ximena S.; eBlasis, Paulo; Giannini, Paulo C. F.
2009-12-01

Resumen en español En esta nota, se presentan los resultados preliminares del estudio micromorfológico realizado en el depósito ictiológico que recubre al sambaquí Jabuticabeira II, desarrollados en el marco del proyecto temático interdisciplinario Sambaquis e paisagem. El análisis microestratigráfico permitió identificar procesos pre-depositacionales antrópicos que actuaron en la formación de esta estructura, relacionada con la quema y transporte de material mineral (arenas terr� (mas) �genas) y residuos orgánicos (carbones) e inorgánicos de origen biológico (huesos, fitolitos, diatomeas, agregados silíceos). Los efectos de las alteraciones post-depositacionales sobre estas partículas pueden observarse a través de trazas de disolución en los huesos y la formación de un material mineral fino de composición fosfática. Esta articulación de evidencias confirma la compleja combinación de actividades y procesos de alteración involucrados en la formación de sitios sambaquís, que transciende antiguas dicotomías funcionales. Resumen en inglés In this note, preliminary results from the micromorphological study of the fish mound that covers the Jabuticabeira II sambaquí site, developed within the interdisciplinary research project Sambaquis e paisagem, are presented. Microstratigraphic analyses enabled the identification of anthropic pre-depositional processes that participated in the formation of this large structure, related to the burning and transport of mineral and organic material (terrigenous sand and ch (mas) arcoal) and inorganic residues of biological origin (bones, phytoliths, diatoms and siliceous aggregates). The effects of post-depositional alterations over these particles can be observed through dissolution traces in bone and the formation of a fine mineral material of phosphatic composition. The articulation of the evidence confirms the complex combination of activities and alteration processes involved in the formation of sambaquí sites, which transcends traditional functional dichotomies.

Scientific Electronic Library Online (Spanish)

46

Preferencia de forofito por los líquenes en el bosque chaqueño oriental/ Preference of phorophyte by the lichens in the eastern Chaco forest

Estrabou, Cecilia
2007-01-01

Resumen en español Los líquenes epifitos y corticícolas dependen del sustrato para su supervivencia, crecen sobre árboles, son un recurso no maderero y sobre ellos se desarrollan gran cantidad de insectos. Una gran área del norte de la República Argentina es ocupada por el bosque chaqueño, con árboles de buena madera. La tala indiscriminada de este bosque pone en peligro su subsistencia y la de las especies liquénicas que viven en él. Se describió la comunidad liquénica del Chaco (mas) oriental, un ambiente xerofítico, sobre los tres forofitos (especies arbóreas dominantes) más favorables de ese bosque. Se utilizó la técnica de Braun Blanquet en la obtención de los datos, técnica de ordenación (análisis de componentes principales), índice de Shannon y estadística descriptiva para el análisis de los mismos. Se encontró un total de 21 especies, siendo el sustrato más favorable para el desarrollo de líquenes Zizyphus mistol, con un total de 20 especies. Sobre Prosopis pugionata se registraron 16 especies y 15 sobre Aspidosperma quebracho-blanco. Se discute la existencia de comunidades de líquenes presentes en el bosque chaqueño Resumen en inglés The epiphyte, corticolous lichen community depends on substrate to survive, they grow on trees being a non-timber resource. Many insects develop on it. The Chaco forest, a xerophytes environment, covers an extensive area in the north of Argentina with fine wood trees. The destruction of the forest jeopardizes the lichen community. The lichen community (life forms, structure and cover) is analyzed on the three most important phorophyte (dominant trees) in Chaco forest. Bra (mas) un Blanquet techniques were used to obtain the data, an ordination technique (Principal Components Analysis), and Shannon index descriptive statistics to analyze them. 21 species are reported, the most favorable substrate was Zizyphus mistol with a total of 20 species. 16 species were registered on Prosopis pugionata, and 15 on Aspidosperma quebracho-blanco. The presence of lichen communities in the Chaco forest is discussed

Scientific Electronic Library Online (Spanish)

47

Predicting Spatial Patterns of Plant Recruitment Using Animal-Displacement Kernels

Santamaría, Luis; Rodríguez-Pérez, Javier; Rodríguez Larrinaga, Asier; Pias, Beatriz
2007-10-10

Digital.CSIC (Spain)

48

Poblaciones de araucaria enana (Araucaria araucana) en la Cordillera de Nahuelbuta, Chile/ Populations of dwarf araucaria (Araucaria araucana) in the Nahuelbuta coastal range, Chile

Donoso, Claudio; González, Mauro E; Cortés, Marco; González, Conrado; Donoso, Pablo; Hernández, Marcelo
2008-01-01

Resumen en español Araucaria araucana (araucaria o pehuén) desarrolla normalmente en su hábitat natural un crecimiento arbóreo con altura > 20 m. Sin embargo, en 1984, en la cima de la Cordillera de Nahuelbuta se encontraron dos poblaciones enanas. En este trabajo se caracterizó la estructura, composición y edades de ambas poblaciones de A. araucana y Nothofagus dombeyi como especie asociada más importante, así como las características físicas y químicas de los suelos donde crecen (mas) . El enanismo se manifestó en ambas especies. En A. araucana los individuos raramente sobrepasaron 10 m de altura con una alta relación diámetro/altura respecto a la de árboles normales de edad similar. El crecimiento diametral anual fue Resumen en inglés Araucaria araucana (araucaria or pehuén) can normally reach > 20 m in height in most sites where it grows. However, two dwarf populations of A. Araucana were found at the top of the Nahuelbuta coastal range. This study had the goal of characterizing the structure, composition, ages and chemical and physical soil properties of both populations. These populations are dominated by A. araucana, with Nothofagus dombeyi as the main associated species. Dwarfism is clear in both (mas) species. Individuals of A. araucana rarely exceeded 10 m in height with a high diameter/height relationship compared with similarly-aged normal trees. The diameter annual growth is lower than 0.12 cm for trees 300 years in age and basal diameters of 36 cm. The presence of short stems and extended and fine branches, like spider legs, confirms the dwarf features of the A. araucana trees. In N. dombeyi 36 to 37 years in age the diameter annual growth is between 0.26 and 0.27 cm, where most individuals (60-75%) present basal diameters lower than 15 cm and heights between 1 and 6.5 m. The location of these populations at the top of the Nahuelbuta coastal range over 1,000 m and openly exposed to the Pacific ocean results from extreme weather conditions that combined with poor and thin soils determine the low tree growth, reduced size and tortuous shapes of trees

Scientific Electronic Library Online (Spanish)

49

Plasmon molecules in overlapping nanovoids

Romero Pérez, Isabel; Teperik, Tatiana V.; García de Abajo, F. Javier
2008-03-07

Digital.CSIC (Spain)

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52

Palaeoenvironmental and palaeoseismic implications of a 3700-year sedimentary record from proglacial Lake Barrancs (Maladeta Massif, Central Pyrenees, Spain)

Larrasoaña, Juan Carlos; Ortuño, María; Birks, Hilary H.; Valero-Garcés, Blas L.; Parés, Josep M.; Copons, Ramon; Camarero, Lluís; Bordonau, Jaume
2010-08-01

Digital.CSIC (Spain)

54

Optical, Redox, and NLO Properties of Tricyanovinyl Oligothiophenes: Comparisons between Symmetric and Asymmetric Substitution Patterns

Casado, Juan; Ruiz Delgado, M. Carmen; Rey Merchán, M. Carmen; Hernández, Víctor; López Navarrete, Juan T.; Pappenfus, Ted M.; Williams, Nathaniel; Stegner, William J.; Johnson, Jared C.; Edlund, Brett A.; Janzen, Daron E.; Mann, Kent R.; Orduna, Jesús; Villacampa, Belén
2006-04-21

Digital.CSIC (Spain)

56

Nonlinear magnetoimpedance and parametric excitation of standing spin waves in a glass-covered microwire

Kraus, L.; Vázquez Villalabeitia, Manuel; Infante, G.; Badini-Confalonieri, Giovanni Andrea; Torrejón, J.
2009-02-09

Digital.CSIC (Spain)

58

Modificaciones inducidas por la adición de puzolanas naturales zeolíticas en las pastas de cemento

Blanco Varela, M.ª Teresa; Martínez-Ramírez, Sagrario; Gener, Marta; Vázquez Moreno, Tomás
2005-12-30

Digital.CSIC (Spain)

59

Microstructural Characterization of Cyanobacterial Mats from the McMurdo Ice Shelf, Antarctica

Ríos, Asunción de los; Ascaso, Carmen; Wierzchos, Jacek; Fernández-Valiente, Eduardo; Quesada, Antonio
2004-01-01

Digital.CSIC (Spain)

60

Manipulating exciton fine structure in quantum dots with a lateral electric field

Gerardot, B.D.; Seidl, S.; Dalgarno, P.A.; Warburton, R.J.; Granados, Daniel; García, J.M.; Kowalik, K.

The fine structure of the neutral exciton in a single self-assembled InGaAs quantum dot is investigated under the effect of a lateral electric field. Stark shifts up to 1.5 meV, an increase in linewidth, and a decrease in photoluminescence intensity were observed due to the electric field. The auth...

DRIVER (Spanish)

61

Manipulating exciton fine structure in quantum dots with a lateral electric field

Gerardot, B. D.; Seidl, Stefan; Dalgarno, P. A.; Warburton, Richard J.; Granados, Daniel; García, Jorge M.; Kowalik, K.; Krebs, O.; Karrai, Khaled; Badolato, Antonio; Petroff, Pierre M.
2007-01-22

Digital.CSIC (Spain)

62

Magnetic properties of ultrathin FexCo(1-x) films on Pt(111)

Moulas, G.; Lehnert, A.; Rusponi, S.; Zabloudil, J.; Etz, C.; Ouazi, S.; Etzkorn, M.; Bencok, Peter; Gambardella, Pietro; Weinberger, P.; Brune, H.
2008-12-17

Digital.CSIC (Spain)

63

Magnetic characterization of Cretaceous-Tertiary boundary sediments

Villasante-Marcos, Víctor; Martínez-Ruiz, Francisca; Osete, María Luisa; Urrutia-Fucugauchi, Jaime
2007-09-01

Digital.CSIC (Spain)

64

Macrofauna del curso inferior y estuario del río Biobío (Chile): cambios asociados a variabilidad estacional del caudal hídrico/ Macrofauna of the lower reach and estuary of Biobío river (Chile): changes associated to seasonal changes of the river flow

BERTRÁN, CARLOS; ARENAS, JOSÉ; PARRA, OSCAR
2001-06-01

Resumen en español Uno de los sistemas lóticos chilenos de mayor importancia de acuerdo a su caudal es el río Biobío (ca. 37º S). Su estuario es reducido, especialmente en las épocas de máximo caudal. Con el objetivo de poner a prueba la hipótesis de que en verano la disminución del caudal del río Biobío, determina una mayor depositación del material particulado fino y que el aumento del caudal en invierno resulta en el lavado y transporte del material depositado hacia el mar, y (mas) consecuentemente en una disminución de la macrofauna bentónica, se recolectaron muestras para análisis sedimentológicos y faunísticos en el curso inferior y estuario del río Biobío, durante agosto de 1993 y marzo de 1994. Los análisis sedimentológicos indican que el tamaño medio del sedimento correspondió a arenas gruesas. La depositación del material fino suspendido, que ocurre durante el verano se manifiesta en el mayor porcentaje de finos y materia orgánica durante este período. La macrofauna bentónica estuvo compuesta por 16 taxa en el muestreo de invierno y 42 taxa en el de verano. Durante el invierno, la mayoría de ellas estuvo representada por muy pocos individuos. Durante el verano aumentó la riqueza específica y abundancias totales de la macrofauna. Los taxa más abundantes fueron un Archiannelida indeterminado y el poliqueto Perinereis gualpensis. El aumento del caudal en la época invernal, determina el transporte del material depositado hacia el mar y consecuentemente el arrastre de organismos bentónicos. Aún cuando los valores de abundancia y biomasa de macrofauna durante el verano fueron de un orden de magnitud mayor que en la fase invernal, fueron menores que los citados para otros estuarios del centro-sur de Chile (ca. 39º S). Eso contribuye a confirmar el carácter atípico del estuario del río Biobío, el que debido a sus cambios estacionales de caudal genera cambios significativos en la estructura comunitaria de la macrofauna bentónica Resumen en inglés The Biobío river (ca. 37º S) is one of the most important Chilean lotic systems with regard to their water flow. Its estuary is reduced, especially during maximum flow. With the purpose of testing the hypothesis that during summer, the decrease of river flow results in a higher deposition of fine particles, and that the increase in river flow during winter results in the washing and transport of deposited particles, and consequently in a decrease of the benthic macrofau (mas) na. Sediment samples were collected for sedimentological and faunistical analysis during August 1993 and March 1994. The sedimentological analyses indicate that mean size of sediment corresponded to coarse sands. During summer, the deposition of suspended particles is facilitated by the decrease in the river flow and results in higher percentage of fine particles and organic matter in the sediment. The benthic macrofauna was composed by 16 taxa during winter and 42 taxa during summer. During winter, that macrofauna was represented by just a few individuals. During summer, the species richness and macrofaunal abundances increased. The most abundant taxa were an archiannelid species and the polychaete Perinereis gualpensis. The increase of river flow during winter determines the transport of the deposited material toward the sea and consequently, the washing of benthic organisms. Even though, values of macrofaunal abundance and biomass during summer were about one order of magnitude higher than during winter, they are still lower than those mentioned for other estuaries of south-central Chile (ca. 39º S). That confirms the atypical character of the Biobío river estuary, which due to its seasonal changes, significantly affects the community structure of the benthic macrofauna

Scientific Electronic Library Online (Spanish)

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Las bentonitas de la zona sur de Cabo de Gata (Almería). Geoquímica y Mineralogía

Caballero, E.; Reyes, E.; Yusta, A.; Huertas, F.; Linares, J.
1985-01-01

Digital.CSIC (Spain)

67

Lack of Jahn-Teller distortion in highly diluted LaMn1–xGaxO3 (x>0.6)

Sánchez, María Concepción; García, Joaquín; Subías, G.; Blasco, Javier
2006-03-01

Digital.CSIC (Spain)

71

La cuenca cenozoica del río Grande y Palauco: edad, evolución y control estructural, faja plegada de Malargüe/ The Río Grande and Palauco Cenozoic basin: Age, evolution and structural control, Malargue fold-belt (36°S)

Silvestro, José; Atencio, Mario
2009-10-01

Resumen en español La región del valle del Río Grande y Palauco a los 36° de latitud sur, forma parte de la faja plegada y corrida de Malargüe, en la Cordillera Principal. La evolución tectónica de este sector durante el Cenozoico quedó registrada en los depósitos volcaniclásticos preservados en las cuencas sinorogénicas. La configuración de estas cuencas estuvo controlada por las estructuras de basamento, que a esta latitud definen un sector interno ocupado por la subcuenca Río (mas) Grande y un sector frontal ocupado por la subcuenca Palauco. El relleno de estas cuencas muestra una etapa preorogénica que se extendió por lo menos hasta los 23 Ma dominada por secuencias basálticos. Desde los 18 Ma las principales estructuras comenzaron a levantarse provocando que en una primera etapa cada subcuenca evolucione de forma independiente. De esta forma, la subcuenca Río Grande recibió el aporte de sedimentos clásticos gruesos desde el oeste, producto de la erosión de la sierra Azul, que gradan a depósitos finos y evaporíticos distales en la parte oriental de la subcuenca, para finalmente acuñarse contra el borde occidental del anticlinal Pampa Palauco-Ranquil Co. Esta estructura ya constituía una barrera interna, posibilitando que en la subcuenca Palauco queden retenidos los depósitos basálticos alimentados desde centros efusivos activos presentes en este sector. Esta etapa finalizó aproximadamente a los 11 Ma, edad a partir de la cual ambas subcuencas presentan nuevamente un relleno similar dominado por depósitos volcánicos presentes en toda el área. En esta nueva etapa diferentes eventos de reactivación del anticlinal Pampa Palauco-Ranquil Co quedaron registrados en discordancias angulares observadas en el campo, que a partir de dataciones en niveles guía pudieron ser acotadas a los 11 Ma y 8 Ma. Estos eventos generaron también el desarrollo de un nuevo frente de deformación hacia el este, con el levantamiento de los anticlinales Cerro Fortunoso, Loma Amarilla y Rincón Colorido, dando la configuración definitiva a la cuenca. Resumen en inglés The Palauco and Rio Grande valley area at 36° south latitude is part of the Malargüe fold-belt in southern Cordillera Principal. The Cenozoic tectonic evolution of this area was recorded by volcaniclastic sediments deposited in syntectonic basins. The structural configuration of basement-involved structures at this latitude, defines an internal part where the Rio Grande sub-basin was developed and a frontal part where Palauco sub-basin was paced. The filling of these ba (mas) sins shows a pre-growth stage dominated by basaltic sequences that was present up to about 23 Ma. From 18 Ma with the uplift of the main structures, each subbasin evolved in an independent way. Therefore, the western part of Rio Grande sub-basin was fed by coarse proximal facies related to the uplift of the Sierra Azul anticline, while the distal fine-sediments and evaporates located in the eastern part of the basin wedged-up against Pampa Paluco-Ranquil Co anticline, showing that this structure was already an internal barrier. This stage finished approximately at 11 Ma, age from which both sub basins show again a similar filling dominated by volcanic deposits present in the whole area. During this new stage, different events of reactivation of the Pampa Palauco-Ranquil Co anticline were recorded by angular unconformities observed in the field, which were constrained at 11 Ma and 8 Ma from radiometric determinations. These events also have generated the development of the new deformation front to the east, with the uplift of the Cerro Fortunoso, Loma Amarilla and Rincón Colorido anticlines, giving the definitive configuration to the basin.

Scientific Electronic Library Online (Spanish)

73

Invertebrados bentónicos como indicadores de calidad del agua en ríos urbanos (Paraná-Entre Ríos, Argentina)/ Benthic invertebrates as indicators of water quality in urban rivers (Paraná-Entre Ríos, Argentina)

Pave, Paola J; Marchese, Mercedes
2005-12-01

Resumen en español Se estudió la incidencia de los efluentes industriales y cloacales sobre la estructura del bentos en el río Las Tunas y su afluente Saucesito (Paraná, Provincia de Entre Ríos, Argentina). Se determinaron las especies y asociaciones de especies en gradientes de buena a mala calidad del agua de estos ríos urbanos. Se realizaron cuatro muestreos, entre julio de 2000 y febrero de 2002, en cuatro estaciones a lo largo del curso. Los resultados obtenidos revelaron que, tan (mas) to la densidad como la diversidad específica fueron influenciadas por la contaminación orgánica, con una disminución brusca en la estación afectada por el vertido de los efluentes del parque industrial. Se registraron 85 taxa, siendo los oligoquetos y quironómidos los dominantes. Del análisis de componentes principales, se infirió que la demanda biológica de oxígeno fue el factor que más incidió en la distribución y composición de organismos bentónicos. El río Las Tunas presentó altos valores de DBO5, la menor densidad, riqueza y diversidad específica, sin recuperación de la calidad del agua en todo el tramo. Aguas arriba, el río Saucesito presentó una mejor calidad, principalmente en la estación de referencia ubicada antes del parque industrial. Resumen en inglés The aim of this study is to assess the effects of industrial and sewage discharges on the benthic structure of urban rivers. Also, the species assemblages associated to different water quality conditions were studied. Four sampling sites were analyzed, from July 2000 to February 2002, during high water level in two urban rivers. In order to determine the quality of the water and the species assemblages, ANOVA, principal components analysis, species diversity and distance (mas) index among sites were applied. Eighty-five species or morphospecies were identified, dominated by Oligochaeta and Chironomidae. Average density of benthic invertebrates varied between 233 ind/m² and 29265 ind/m², with higher densities registered in the reference sampling site than in the ones affected by industrial discharges. The species richness ranged from four to 43 taxa, and the Shannon-Wiener index, from 1.37 to 3.95, with the highest value registered in Saucesito river. Filtering and gathering collectors were the dominant feeding groups in all the sites because of the high fine particulate organic matter content. The biological oxygen demand was the main factor in determinating the benthic invertebrates distribution and composition. Las Tunas River is hardly polluted, with low benthic density, species richness and diversity, and high DBO5 values. Saucesito River shows a better water quality, mainly upstream of the industrial discharges. The gradient from clean to polluted water quality, was characterized by the species assemblages Ostracods Podocopida, Tanytarsus sp., D. (D.) obtusa, Djalmabatista sp. 2, Rheotanytarsus sp. 1, S. fossularis and Cricotopus sp. 1 → N. variabilis, C. xanthus and L. hoffmeisteri.

Scientific Electronic Library Online (Spanish)

74

Infrared and Millimetric Study of the Young Outflow Cepheus E

Moro-Martin, A.; Noriega-Crespo, A.; Molinari, S.; Testi, L.; Cernicharo, José; Sargent, A.
2001-03-05

Digital.CSIC (Spain)

75

In situ and ex situ grazing incidence diffraction anomalous fine structure study of GaN/AlN quantum dots

Coraux, J.; Renevier, H.; Proietti, M. G.; Favre-Nicolin, V.; Daudin, B.; Renaud, G.
2006-06-01

Digital.CSIC (Spain)

76

Identifying transition metal contribution to the rare-earth L2-edge XMCD spectra in R-T intermetallics

Laguna-Marco, M. A.; Chaboy, J.; Piquer, Cristina; Maruyama, H.; Ishimatsu, N.; Kawamura, N.
2007-02-01

Digital.CSIC (Spain)

80

HSQC-NMR analysis of lignin in woody (Eucalyptus globulus and Picea abies) and non-woody (Agave sisalana) ball-milled plant materials at the gel state

Rencoret, Jorge; Marques, Gisela; Gutiérrez Suárez, Ana; Nieto, Lidia; Santos, José Ignacio; Jiménez-Barbero, Jesús; Martínez Ferrer, Ángel Tomás; Río Andrade, José Carlos del
2009-01-01

Digital.CSIC (Spain)

81

HCA and HML isolated from the red marine algae Hypnea cervicornis and Hypnea musciformis define a novel lectin family

Nagano, Celso S.; Debray, Henri; Nascimento, Kyria S.; Pinto, Vicente P.T.; Cavada, Benildo S.; Saker-Sampaio, Silvana; Farias, Wladimir R.L.; Sampaio, Alexandre H.; Calvete, Juan J.
2005-08-01

Digital.CSIC (Spain)

82

Grazing-incidence diffraction anomalous fine structure of InAs/InP(001) self-assembled quantum wires

Grenier, S.; Proietti, M. G.; Renevier, H.; González, Luisa; García, Jorge M.; García, J.
2002-02-15

Digital.CSIC (Spain)

83

Grazing incidence diffraction anomalous fine structure: a tool for investigating strain distribution and interdiffusion in InAs/InP quantum wires

Letoublon, A.; Renevier, H.; Proietti, M. G.; Priester, C.; García, Jorge M.; González, Luisa
2003-04-01

Digital.CSIC (Spain)

84

Grazing incidence diffraction anomalous fine structure study of GaN/AlN quantum dots

Coraux, J.; Favre-Nicolin, V.; Proietti, M. G.; Renevier, H.; Daudin, B.
2006-05-01

Digital.CSIC (Spain)

85

Grazing incidence diffraction anomalous fine structure of self-assembled semiconductor nanostructures

Grenier, S.; Letoublon, A.; Proietti, M. G.; Renevier, H.; González, Luisa; García, Jorge M.; Priester, C.; García, J.
2003-01-01

Digital.CSIC (Spain)

86

Glancing-angle diffraction anomalous fine structure of InAs quantum dots and quantum wires

Grenier, S.; Proietti, M. G.; Renevier, H.; González, Luisa; García, Jorge M.; Gérard, J. M.; García, J.
2001-01-01

Digital.CSIC (Spain)

87

Glancing angle EXAFS of encapsulated self-assembled InAs/InP quantum wires and InAs/GaAs quantum dots

Renevier, H.; Proietti, M. G.; Grenier, S.; Ciatto, G.; González, Luisa; García, Jorge M.; Gérard, J. M.; García, J.
2003-08-15

Digital.CSIC (Spain)

88

Geología de la región del Río Bonete en el antepaís andino (27º30'LS): extremo norte del Terreno de Precordillera/ Geology of the region of Rio Bonete: Northern edge of the Precordillera terrane

Martina, Federico; Astini, Ricardo A.
2009-04-01

Resumen en español En la región del antepaís andino en la provincia de La Rioja (28º31'S - 68º30'W) aflora una faja de deformación dúctil con orientación NW, parcialmente expuesta en el río Bonete, conocida con el nombre de faja de deformación de Jagüé. Trabajos previos sugieren que constituiría el límite norte del terreno de Precordillera. Está fundamentalmente compuesta por ortoanfibolitas intensamente foliadas que gradan a gabros, granitos milonitizados y ultra-milonitizado (mas) s de edad grenviliana y lentes de mármol bandeado y de grano fino, cálcicos y dolomíticos. El conjunto fue tradicionalmente incluido dentro de la Formación Río Bonete, separándose a los mármoles como Miembro Caliza Las Damas. La Formación Río Bonete incluía, además, una sucesión de areniscas y pelitas con arreglo rítmico y afectado por muy bajo grado metamórfico de edad ordovícica superior. De acuerdo a un nuevo mapeo, se trataría de dos unidades distintas separadas por discordancia, considerando conveniente utilizar el término Complejo Metamórfico Río Bonete para la unidad con deformación dúctil y Formación Chuscho para las metasedimentitas interdigitadas con vulcanitas básicas incluidas en la faja ofiolítica famatiniana. Por su parte, y para evitar confusiones, se propone reemplazar el término Miembro Calizas Las Damas por el de Mármol Las Damas que refleja mejor su composición. Considerando que la Formación Chuscho, a pesar de su muy bajo grado de metamorfismo, no ha sido involucrada en la deformación dúctil y que los mármoles por su bandeado composicional se correlacionarían con unidades cámbricas de la plataforma del terreno de Precordillera, la edad de la faja quedaría acotada al Paleozoico inferior, consistente con la orogenia oclóyica. Análisis estructurales permiten interpretar una cinemática sinistral a normal para esta cizalla dúctil que, desde el punto de vista regional, se vincularía con el emplazamiento del terreno de Precordillera al margen occidental de Gondwana. El marcado contraste geológico observado al norte y sur de la faja de deformación de Jagüé es consistente con la hipótesis de límite norte del terreno de Precordillera. Resumen en inglés The Jagüé shear zone is an important structure with NW strike within the Andean foreland in the La Rioja Province (28º31'S - 68º30'W), partly exposed along the Río Bonete. It has been suggested that this structure represents the northern boundary of the Precordillera Terrane. Consists of intensely deformed foliated ortho-amphibolites locally grading into gabbros, Grenville mylonitized and ultramylonitized granites and pods of banded, fine grained, calcitic and dolomi (mas) tic marbles. These rocks were traditionally included within the Río Bonete Formation, whereas the marbles were separated as Member Caliza Las Damas. In addition, the Río Bonete Formation included a rhythmic succession of greywackes and shales of Late Ordovician age, affected by very low-grade metamorphism. According to new mapping these would represent two different units separated by an unconformity. For this reason, we suggest the use of Río Bonete Metamorphic Complex for the highly-sheared metamorphic unit and Chuscho Formation for the metasedimentary rocks, which are in turn, overlain by basic pillow lavas included in the Famatinan ophiolite belt. Also in order to avoid confusions, we propose replacing the term Caliza Las Damas for Mármol Las Damas that better represents their composition. Considering that the Chuscho Formation, despite its subgreenschist facies metamorphism, has not been affected by the ductile deformation and the fact that given the banded composition the marbles would correlate with the Cambrian units of the Precordillera terrane platform, the age of the shear zone is restricted to the Lower Paleozoic, and included within the Ocloyic Orogeny. Structural analysis allows interpreting a left-lateral to normal kinematics for the regional ductile shear linked to the emplacement of the Precordillera terrane with the western margin of Gondwana. The striking geological contrast observed to the north and south of the Jagüé Shear Zone is consistent with the hypothesis that indicates this region as the northern boundary of the Precordillera terrane.

Scientific Electronic Library Online (Spanish)

89

Fine-tuning the space, time, and host distribution of mycobacteria in wildlife

Gortázar, Christian; Torres, María José; Acevedo, Pelayo; Aznar Martín, Javier; Negro Balmaseda, Juan José; Fuente García, José de la; Vicente Baños, Joaquín
2011-02-02

Digital.CSIC (Spain)

91

Fine structure of the egg of Ceratitis capitata Wied.

Mayo, I.; Robles-Chillida, E.M.; Muñiz, M.; Anderson, M.

The chorion of the eggs of Ceratitis capitata, has been studied with scanning and transmission electron microscopy.This study reveals some srructural differences between the micropylar area and main body of the egg. The chorion consists of three layers: Exochorion, endochorion and innermost chorioni...

DRIVER (Spanish)

92

Fine structure of the egg of Ceratitis capitata Wied.

Mayo, I.; Robles-Chillida, E.M.; Muñiz, M.; Anderson, M.
1989-01-01

Digital.CSIC (Spain)

93

Fine structure of the Thalloconidia of the Lichen Genus Umbilicaria

Ascaso, Carmen; Sancho, Leopoldo G.; Valladares, Fernando
1992-01-01

Digital.CSIC (Spain)

94

Fine structure of highly charged quantum dot excitons: turning dark into bright states

Urbaszek, B.; Warburton, Richard J.; Karrai, Khaled; Gerardot, B. D.; Petroff, Pierre M.; García, Jorge M.
2004-02-01

Digital.CSIC (Spain)

95

Fine structure in the beta-delayed proton decay of Ar-33

Honkanen, A.; Axelsson, L.; Äystö, J.; García Borge, María José; Jonson, B.; Jokinen, A.; Martel, Ismael

9 pages, 2 figures, 2 tables.-- PACS nrs.: 21.60.Cs; 23.40.−s; 27.30.+t; 29.30.Ep. | Low-energy beta-delayed protons from Ar-33 have been measured for the first time. The data reveal states, which, despite unfavourable barrier penetrability values, strongly decay to the first excited 2+ state in S-3...

DRIVER (Spanish)

96

Fine structure in the beta-delayed proton decay of Ar-33

Honkanen, A.; Axelsson, L.; Äystö, J.; García Borge, María José; Jonson, B.; Jokinen, A.; Martel, Ismael; Martínez Pinedo, Gabriel; Mukha, I.; Nilsson, T.; Nyman, G.; Petersen, B.; Poves, A.; Smedberg, M. H.; Teijeiro, A.; Tengblad, Olof; [ISOLDE Collaboration]
1996-12-16

Digital.CSIC (Spain)

98

Fine Structure of Highly Charged Excitons in Semiconductor Quantum Dots

Urbaszek, B.; Warburton, Richard J.; Karrai, Khaled; Gerardot, B. D.; Petroff, Pierre M.; García, Jorge M.
2003-06-20

Digital.CSIC (Spain)

99

Far-IR spectroscopy towards Sagittarius B2

Goicoechea, Javier R.; Cernicharo, José
2004-02-06

Digital.CSIC (Spain)

100

Extended photoionization and photodissociation in Sgr B2

Goicoechea, Javier R.; Rodríguez-Fernández, Nemesio J.; Cernicharo, José
2003-03-05

Digital.CSIC (Spain)

101

Experiments on layer formation in stratified shear flow

Pelegrí, Josep Lluís; Sangrà, P.; Cisneros-Aguirre, J.
2001-01-01

Digital.CSIC (Spain)

103

Estudio micromorfológico de vitrandepts (I. Tenerife)

Benayas, J.; Fernández Caldas, E.; Tejedor Salguero, Mª L.
1978-01-01

Digital.CSIC (Spain)

104

Estratigrafía del Grupo Mina Verdun, Proterozoico de Minas, Uruguay/ Stratigraphy of the Mina Verdún Group, Proterozoic of Minas, Uruguay

Poiré, Daniel G.; González, Pablo D.; Canalicchio, José M.; García Repetto, Flavio
2005-12-01

Resumen en español El objetivo del presente trabajo es el de presentar un cuadro estratigráfico para las sedimentitas del área del Cerro Verdún, Minas, Uruguay. Asimismo presentar algunas consideraciones sobre sus características sedimentológicas y sus estromatolitos, a fin de discutir sus condiciones paleoambientales. En el mismo sentido, se realizan inferencias sobre la edad abarcada por estas rocas y sus potenciales correlaciones regionales. Esta sucesión ha permanecido indefinida (mas) en general, mientras que sus calizas fueron alternativamente asignadas a diversas unidades litoestratigráficas. En esta contribución se incluye al conjunto en el Grupo Mina Verdún, el cual está conformado de base a techo por: i) Formación Don Mario (40 m, base no expuesta, lutitas negras), ii) Formación La Toma (15 m, margas verdes oscuras a negras), iii) Formación El Calabozo (170 m, calizas grises, masivas, laminadas y estromatolíticas) y iv) Formación Gibraltar (60 m, techo no expuesto, dolomías en tonalidades pálidas amarillentas, verdes y rosas hasta gris oscuras más calizas rosas y pelitas y margas negras). Conglomerados polimícticos de la Formación Las Palmas cubren a esta unidad mediante una discordancia angular. En contraposición, las cuarcitas del Cerro Verdún se apoyan sobre el Grupo Mina Verdún por contacto tectónico. Las pelitas negras de la Formación Don Mario se habrían depositado en un ambiente reductor de aguas calmas. Se identifica para las mismas, de manera preliminar, un aporte desde una corteza continental superior diferenciada que sufrió una importante meteorización y retrabajo. Las margas de la Formación La Toma reflejan un cambio en la sedimentación, con un pasaje hacia un ambiente de rampa carbonática. Niveles con estromatolitos aparecen en las calizas de la Formación El Calabozo, constituidos esencialmente por columnas de laminación cónica asignables a Conophyton fm. y muy escasos estromatolitos columnares dendroides, mal preservados. Conophyton es considerado como un estromatolito submareal de aguas relativamente profundas. Esto último, sumado a la baja diversidad, sugiere un ambiente marino submareal externo para esta unidad. Correlaciones entre afloramientos locales, definirían una evolución desde una rampa carbonática hasta una plataforma, en las inmediaciones del talud de la misma. La edad de esta unidad aún no se conoce con precisión. Sin embargo, interpretaciones geológicas regionales, sobre la base de los estromatolitos presentes y de datos geoquímicos, sugieren un tiempo de depositación post-arqueano a pre-ediacareano. Resumen en inglés The aim of this contribution is to introduce the stratigraphic framework of the Mina Verdún Quarry, located in the eastern side of Verdún Hill, Minas, Uruguay (Fig. 1), and to characterise their sedimentary units. The paleoenvironments involved are outlined as well as the sedimentological significance of the very well developed stromatolites. The stratigraphic position and composition of this sedimentary succession used to be uncertain and the limestone from the Mina Ve (mas) rdún Quarry was alternatively considered part of diverse litostratigraphic units (Mac Millan, 1933; Caorsi and Goñi, 1958; Bossi et al., 1965; Midot, 1984; Preciozzi et al., 1985; Bossi and Navarro, 2000; Sánchez Betucci, 1998; Sánchez Betucci et al., 2001). From the base to the top (Fig. 2), the sedimentary succession consists of the Mina Verdún Group, Las Palmas Formation and the quartzites of the Verdún Hill (Fig. 3). Mina Verdún Group (Poiré et al., 2003b) is conformed by: Don Mario Formation (Poiré et al., 2003b): 40 m thick, base not exposed; massive and laminated, black shales (Fig 4a), which are rich in organic matter (Fig. 5a). XRD analysis shows manly quartz, with scarce calcite, clay (illite, chlorite, and IS and CS interlayer) and feldspars (Fig. 6). Applying the Bhatia and Crook (1986), Taylor and McLennan (1985) and McLennan et al. (1990, 1993) plots (Fig. 7) their geochemistry suggests a high degree of weathering and reworking in the source area compose of a differentiated upper continental crust. La Toma Formation (Poiré et al., 2003b): 15 m thick; fine-grained, dark green marls (Fig. 4b and c), bearing up to 45 % of silica and 35 % of CaCO3. Petrographically they show micritic crystals of calcite and dolomite, quartz and feldspars (Fig. 5b); lamination is interrupted by stilolytes. Clay minerals are composed mainly by illite and scarce chlorite (Fig. 6). El Calabozo Formation (Poiré et al., 2003b): 170 m thick; grey massive, laminated, and stromatolite limestones (Fig. 4d), bearing up to 93 % of CaCO3 with some collapse breccias as resulting of probably karstic phenomena. In thin section they show homogeneous mosaic of micrite and subsparite calcite (Fig. 5 c and d) with stilolites and corrugated stromatolite lamination. Very abundant calcite with rare quartz, feldspars and illite have been recorded by XRD (Fig. 6). This sedimentary sequence is affected by diagenetic features and a fragile deformation (cleavage foliation, shear zones) which are slightly hiding the stromatolite morphologies (Fig. 8), but the main features of the stromatolites from El Calabozo Formation are still well preserved. Columnar stromatolites assignable to Conophyton fm. are the most abundant group of these organic sedimentary structures. This Conophyton fm. consists of unbranching subcylindrical columnar stromatolites with strikingly conical internal laminae whose apexes define a distinctive axial zone (Figs. 10a, b, c) and their horizontal section display a conspicuously and regularly concentric structure (Figs. 10c, d, f). The internal laminae are commonly continuous from one column to another, in which case vertical sections show upward laminae apexing. Their profile is angulate to geniculate and their plant outline could be round circular to oblong, in which case the axes are strongly orientated. The attitude of the columns is usually straight but sometimes they adopt a recumbent and sinuous posture. The column height is up to 70 cm and the column width is 5 to 20 cm. However, scarce but preserved dendroid branching style stromatolites have been recorded on the field, as well as small, rounded plant outline columnar stromatolites have been observed in cores, which could represent digitate branching stromatolites. Five kilometres to the south, this stromatolitic limestone facies change to deformed laminate limestones (Figs. 4e, f). Furthermore, 40 km to south, the El Calabozo Formation bearing Conophyton stromatolites has been reported by Gaucher et al. (2004a). Gibraltar Formation (Poiré et al., 2003b): 60 m, top not exposed; black marls and shales (Figs, 10a, b, c), pink limestones and dolomite limestones, and light yellow, green, reddish, black and grey dolomites (Fig. 10d, e). The unconformity between the El Calabozo and Gibraltar formations is very irregular, which is interpreted as a karstic palaeorelief. A 4 m thick diagenetic breccia is often in the base of the unit. The Mina Verdún Group is overlaid by red polymictic conglomerates and sandstones (Fig. 10f) of Las Palmas Formation (Poiré et al., 2003b) and is intruded by a subvolcanic longitudinal (E-W) dike swarm. This shows a K-Ar whole rock datum of 485,2 ± 12,5 Ma considered as a minimum cooling (Gonzalez et al., 2004). The quarzites from the Verdún Hill are overlying these units by a tectonic contact. They have been assigned to the Cerro Espuelitas Formation by Gaucher (2000), which are Ediacarean in age. Sedimentological and stratigraphic implications The black shales and claystones of the Don Mario Formation are interpreted as fine deposits in a low energy environment with euxinic conditions, which becomes calcareous to form a carbonatic ramp (La Toma Formation). The latter shows and evolution to a carbonatic algae platform very rich in stromatolites. From a sedimentological point of view, the group Conophyton has been assigned as a deep subtidal stromatolite by Poiré (1987, 2002) based on Precambrian stromatolite cycles from Villa Mónica Formation, Buenos Aires Province, Argentina, and Logan et al. (1964) and Donaldson (1976) ideas. In this sense, the low biodiversity, Conophyton abundance and the plant view axes orientation allow to suggest a subtidal marine environment for the El Calabozo Formation, with tidal currents influence (Fig. 11). The strong dolomitization of the Gibraltar Formation and their poor exposure do not allow doing detailed interpretation about paleoenvironments. The age of the Mina Verdún Group is Precambrian but there are not major precisions about that. Unfortunately, the group Conophyton has a wide range during the Precambrian, from Early Proterozoic to Ediacarean, being impossible to define the age of these limestones. More detailed future studies about microstructure of this Conophyton could be useful to distinguish the taxonomy and to determinate its possible age. Pre-Ediacarean stromatolites have also been described 30 km to the north by Sprechmann et al. (1994) and Gaucher et al. (1996) in the Villalba Formation of the Basal Group (Gaucher y Sprechmann, 1995), but their morphologies are completely different. They have recorded stratiform, nodular-stratiform (LLH-C, LLHV) and columnar (SH-V) stromatolites associated with stromatolitic breccias, which were interpreted as intertidal to supratidal deposits. It could represent shallower stromatolite assemblages than the stromatolites from the Mina Verdún. Unfortunately, there are no radiometric data to prove this idea. Very well developed Conophyton ?ressotti and Conophyton fm. have been also recorded in the dolomites of the Villa Mónica Formation (Poiré, 1993) companied by Colonella fm., Cryptozoon fm., Gongylina fm., Gymnosolem fm., Inzeria fm., Jacutophyton fm., Jurusonia nisvensis, Katavia fm., Kotuikania fm., Kussiella fm., Minjaria fm., Parmites fm., Parmites Cf. cocrescens and Stratifera fm. (Poiré, 1989 y 1993), which radiometric age for diagenesis is 795 My (Cingolani y Bonhomme, 1988). This sequence could be correlated with El Calabozo Formation but it shows a poor biodiversity. The Mina Verdún Group is considered as a new lithostratigraphic unit in the Uruguayan stratigraphic framework, which is probably located somewhere between the Basal and Arroyo del Soldado groups.

Scientific Electronic Library Online (Spanish)

105

Espectroscopía Raman de nanotubos de carbono

Santoro, Gonzalo; Domingo, Concepción
2007-01-01

Digital.CSIC (Spain)

106

Espectros de emisión de radioluminiscencia y termoluminiscencia de una leucita de Monte Somma (Italia)

Valle Fuentes, Francisco José; García Guinea, Javier; Correcher, Virgilio
2004-11-01

Digital.CSIC (Spain)

107

Esculpido exocoriónico del huevo de dos poblaciones de Lutzomyia longipalpis s.l. (Diptera: Psychodidae) de Venezuela/ Chorionic sculpturing in eggshells from two populations of Lutzomyia longipalpis (Diptera: Psychodidae) from Venezuela

Oviedo, Milagros; Feliciangeli, M. Dora
2007-12-01

Resumen en español Estudios de los patrones del exocorión en insectos, utilizando microscopia electrónica de barrido (MEB), refieren que las diferencias entre éstos son marcadores taxonómicos útiles para separar especies relacionadas. En el presente trabajo se examinó el patrón del exocorión del huevo de dos poblaciones venezolanas de Lutzomyia longipalpis s.l., principal vector de la leishmaniasis visceral americana, una procedente del Estado Trujillo y la otra del Estado Guárico. (mas) El esculpido del exocorión del material estudiado estuvo caracterizado por un patrón de crestas paralelas, pero el huevo de la población de Trujillo presentó irregularidades y crestas conectadas, mientras que en la población del Guárico, las crestas son más regulares y no se observaron conexiones. Siendo L. longipalpis un complejo de especies, es necesario realizar estudios comparativos con otras poblaciones del complejo de diferentes paises neotropicales, incluyendo Lutzomyia pseudolongipalpis, la primera especie descrita en el complejo, para tratar de dilucidar el significado de estas diferencias y su utilidad como herramienta taxonómica para este complejo. Resumen en inglés Scanning electron microscope (SEM) studies of eggshell morphology have shown that differences between related species of insects are reliable taxonomic markers. In the present study, the eggshell fine structure of two Venezuelan populations of Lutzomyia longipalpis s.l., vector of American visceral leishmaniasis, was examined by SEM. Newly laid eggs of L. longipalpis s.l.were obtained from a colony from Trujillo state a nd from field females collected in Guárico state. T (mas) he chorionic egg sculpturing of both populations was characterized as a pattern of parallel ridging, but in the population from Trujillo the pattern was irregular and the ridges appeared connected, while those from Guarico were more regular and no connections were observed. As L. longipalpis s.l. is recognised as a species complex, further studies are needed to compare the chorionic sculpturing of eggs from different populations of L. longipalpis in Venezuela and other Neotropic countries, including L. pseudolongipalpis, the first described species in the complex, in order to clarify the significance of such differences and the usefulness of the eggshell chorionic sculpturing as a taxonomic tool in the complex.

Scientific Electronic Library Online (Spanish)

109

Effect of the Air-Jet and the False-Twist Texturing Processes on the Stress-Relaxation of Polyamide 6.6 Yarns

Manich, Albert M.; Maíllo, Josefina; Cayuela Marín, Diana; Gacén Guillén, Joaquín; Castellar Bertrán, María Dolors; Ussman, M.
2007-05-08

Digital.CSIC (Spain)

111

Effect of polycarboxylate admixture structure on cement paste rheology

Alonso López, María del Mar; Palacios, M.; Puertas, F.; Torre, A. G. de la; Aranda, M. A. G.
2007-06-30

Digital.CSIC (Spain)

113

Desarrollo y validación de una escala para medir imagen corporal en mujeres jóvenes/ Development of a scale to measure body image in young women

Rodriguez Aguilar, Brenda; van Barneveld, Hans Oudhof; Gonzalez-Arratia, Norma Ivonne; Unikel-Santoncini, Claudia
2010-08-01

Resumen en español Introducción La imagen corporal es la representación mental del cuerpo que cada individuo construye en términos de sentimiento y actitudes hacia el propio cuerpo. El propósito de este estudio es: desarrollar, validar y encontrar el grado de confiabilidad de una escala para medir la imagen corporal en dos grupos de mujeres estudiantes de nivel universitario, uno con conductas alimentarias de riesgo (CAR) y otro sin ellas, así como establecer comparaciones respecto a l (mas) a edad y al índice de masa corporal (IMC). Material y método El trabajo se realizó en una muestra probabilística estratificada de 508 mujeres que estudian en la Universidad Autónoma del Estado de México. Para realizar la integración del constructo de imagen corporal se definieron tres indicadores: insatisfacción corporal, influencia social e interiorización del ideal estético de delgadez. Primero se piloteó la escala de imagen corporal compuesta por 40 reactivos aplicándose a una muestra de tipo intencional en 100 mujeres universitarias de nivel superior. Una vez modificada la escala se llevó a cabo una validación de contenido a través del método de expertos. Asimismo, para medir las conductas alimentarias de riesgo se utilizó el Cuestionario Breve para medir Conductas Alimentarias de Riesgo (CBCAR) de Unikel, Bojórquez y Carreño. Para el procesamiento de los datos se llevaron a cabo análisis de consistencia interna (Alfa de Cronbach) y análisis factorial de componentes principales con rotación varimax. Para la comparación de medias se utilizó la t de Student y para la exploración de la diferencia entre las variables de imagen corporal, una prueba de análisis de varianza (Anova de una vía) y la prueba a posteriori de Scheffé para la diferenciación entre imagen corporal, edad e IMC. Resultados La composición de la versión final de la prueba fue de 26 reactivos, integrados en tres factores: El factor I se denominó insatisfacción corporal, consta de 10 reactivos con una media de 3.1 (d.e.=0.8), un total de la varianza explicada de 17.9% y un Alfa de Cronbach de 0.84. El factor II se denominó interiorización del ideal estético de delgadez, se formó por 10 reactivos, con una media de 3.5 (d.e.=0.9), varianza explicada de 15.2% y un Alfa de Cronbach de 0.89. El factor III se denominó influencia social, se formó de seis reactivos, con una media de 3.8 (d.e =0.8), varianza explicada de 9.9% y un alfa de Cronbach de 0.82. Para observar el nivel de confiabilidad total del instrumento se realizó un análisis de consistencia interna de los 26 reactivos restantes con el cual se obtuvo un valor alfa de Cronbach de 0.94. Se llevó a cabo un análisis de comparación con la prueba t de Student la cual indicó que las mujeres con CAR mostraron mayor insatisfacción corporal, interiorización del ideal estético de la delgadez e influencia social. No se presentaron diferencias estadísticamente significativas respecto a la comparación por edad, mientras que resultaron significativas las comparaciones entre el IMC y los factores de insatisfacción corporal e interiorización del ideal estético de delgadez. Discusión La evidencia indica que la escala de medición de imagen corporal cuenta con valores de validez y confiabilidad adecuados. De la misma manera se observó una validez predictiva aceptable que permitió clasificar correctamente una elevada proporción de los casos (97.4%). Estos resultados pusieron de manifiesto que la insatisfacción corporal es un factor presente en la mayoría de la muestra estudiada. Respecto a la diferencia de medias de la imagen corporal entre mujeres que presentan CAR y las que no, se encontró que en las primeras las puntuaciones fueron mayores. En cuanto a la insatisfacción corporal y el IMC, se observó que los grupos con mayor grado de insatisfacción fueron los de las mujeres con bajo peso seguidos de las mujeres con obesidad. Resumen en inglés Introduction Body image is a concept which involves the feelings, attitudes and perceptions people have about their own body, and is influenced by the adoption of social standards. Body image studies are used in the field of eating disorders research in order to analyze the degree of body dissatisfaction. However, most of the scales proposed to assess body image have been developed in Anglo-Saxon and European countries. Therefore, research on this topic in other socio-cul (mas) tural contexts requires the standardization and validation of culturally adapted instruments. The aim of the present study was to determine and discuss the reliability and validity of a Mexican scale which measures body image. Additionally, comparisons regarding body dissatisfaction, internalization of the aesthetic ideal of thinness, social influence, age and Body Mass Index (BMI) were made between groups of female college students with and without disordered eating. Materials and methods The sample of this study comprised 508 female college students from the Universidad Autónoma del Estado de México, selected by means of a probabilistic stratification procedure taking into account the proportion of female students enrolled in each academic area of the university. Their average age was 20.1 years; their mean weight was 57.2 kg with an average height of 1.58 m, whereas the average BMI was 22.8. Based on the theoretical assumptions, three indicators were defined to structure the Body Image Scale: body dissatisfaction, social influence and the internalization of the aesthetic ideal of thinness, measured by a five-point Likert-type scale ranging from never (1) to always (5). A pilot study was carried out in a population of 100 college women; as a result, some adjustments were made in the instructions and in the order of the items. Additionally, a content validation was conducted through the judgments of four professional experts in the clinical mental health area. The scale contains thirty-three items; six of them refer to criticism and family pressure to maintain a slim silhouette and twelve address body dissatisfaction. The remaining fifteen items were taken from the Attitudes Towards Body Figure Questionnaire developed by Unikel, Gomez Peresmitré and Juarez. Results After using Kaiser-Meyer-Olkin's (KMO) and Bartlett's tests for establishing the factor structure of the instrument and obtaining a value of 0.94 (p

Scientific Electronic Library Online (Spanish)

114

Concepts and schemes for the re-engineering of physical protein modules: generating nanodevices via targeted replacements with constrained amino acids

Alemán, Carlos; Zanuy, David; Jiménez, Ana I.; Cativiela, Carlos; Haspel, Nurit; Zheng, Jie; Casanovas, Jordi; Wolfson, Haim; Nussinov, Ruth
2006-02-22

Digital.CSIC (Spain)

117

Combustion synthesis and EIS characterization of TiO2–SnO2 system

Chinarro Martín, Eva; Moreno Burriel, Berta; Jurado Egea, José Ramón
2007-01-01

Digital.CSIC (Spain)

118

Bacterially-Mediated Authigenesis of clays in Phosphate Stromatolites

Sánchez-Navas, A.; Martín Algarra, A.; Nieto, F.
1998-05-01

Digital.CSIC (Spain)

119

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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120

Anomalous x-ray diffraction studies of Sr2+ hydration in aqueous solution

Ramos, S.; Neilson, G. W.; Barnes, A. C.; Capitán, M. J.
2003-03-22

Digital.CSIC (Spain)

121

ASPECTOS ULTRAESTRUTURALES DE TROMBOCITOS, EOSINOFILOS Y HETEROFILOS DE Caiman crocodilus yacare (Daudin, 1802) (Reptilia, Crocodilia)/ ULTRASTRUCTURAL OBSERVATIONS OF THROMBOCYTES, HETEROPHILS AND EOSINOPHILS IN Caiman crocodilus yacare (Daudin, 1802) (Reptilia, Crocodilia)

de Moura, Weber Leal; Oliveira, Luiz Waldemar; Egami, Mizue Imoto
1997-01-01

Resumen en español Fueron utilizados 10 ejemplares de Caiman crocodilus yacare provenientes del municipio de Cáceres (Estado de Mato Grosso do Sul, Brasil), a cada uno de los cuales les fueron extraidos 5ml de sangre periférica. Las muestras obtenidas fueron utilizadas para análisis ultraestructurales, referentes a trombocitos, eosinófilos y heterófilos. Los trombocitos son de forma elíptica, poseen citoplasma abundante sólo en los polos y su núcleo presenta surcos profundos o hendi (mas) duras acentuadas, mostrando algunos poros en su envoltura. Su citoplasma contiene abundantes túbulos y vesículas electrolúcidas del sistema canalicular. Son observados vacúolas con cuerpos densos y microtúbulos. Los heterófilos poseen formato aproximadamente esférico y núcleo excéntrico o periférico. Su citoplasma está repleto de gránulos polimórficos de formas de huso, en baqueta, oval o esférica, con superficie, en general, irregular. Los eosinófilos son esféricos y de núcleo lenticular excéntrico o periférico. El citoplasma contiene gránulos esféricos u ovales. Cabe destacar la presencia de gránulos citoplasmáticos voluminosos con diferencias en la electrodensidad, de superficie uniforme, pudiendo contener una estructura interna heterogénea. En heterófilos y eosinófilos, el núcleo presenta heterocromatina, eucromatina, nucléolo y la envoltura nuclear es porosa Resumen en inglés Little information is available on the ultrastructural characteristics of the blood cells in reptiles. In the present study we have examined the fine structure of heterophils, eosinophils and thrombocytes from the blood of a crocodile (Caiman crocodilus yacare). Samples of peripheral blood from healthy young were collected with EDTA and centrifuged. The buff coat was collected and fixed in half strength Karnovsky solution. Spindl-eshaped thrombocytes showed large nuclei w (mas) ith prominent heterochromatin juxtaposed to the nuclear envelop. Cytoplasmic organelles were scarce: there were mitochondria, some profiles of roughsurface endoplasmic reticulum, free ribosomes and microtubules. Many tubular structures and vacuoles were distributed throughout the cytoplasm, forming the open canalicular membrane system. Heterophils and eosinphils revealed round eccentric nuclei with prominent nucleoli. The cytoplasm of heterophils contained many polymorphic granules with homogeneous electrondense matrix. Ribosomes, roug-surfaced endoplasmic reticulum and many clear vesicles were observed. Some fibrillar structures were also present. In addition to the usual organelles, the cytoplasm of eosinophils were essentially filled with many round or slightly oval granules with heterogeneous electron-dense matrix; in some of them a fine granular structure was visible. Both heterophils and eosinophils showed long numerous pseudopodia

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122

ASPECTOS HISTOLOGICOS DE LA ARTICULACION MANUBRIOESTERNAL/ HISTOLOGIC ASPECTS OF THE MANUBRIOSTERNAL JOINT

del Sol, Mariano; Vasconcellos, Adriana; Olave, Enrique
1999-01-01

Resumen en inglés The manubriosternal joint has been a matter of histological and anatomical discussion due to diversity of clasifications. It has been described as sinfisis, cartilagonous primary joint, synchondrosis or as a synovial joint. The objetive of this study was to determine the type of tissue that from this structure. Sternons were obtained from 10 chilean male cadavers ( 7 fresh and 3 formalized), 40 to 60 years old. The manubriosternal joint was examined macro and microscopal (mas) ly. Each joint was identified and the manubriosternal joint was examined sectioning the bone 1 cm above and 1 cm below the inter articular line. The segments were descalcified and 9 pieces were obtained in anteroposterior sections: 3 from the median part of the joint and 3 from each lateral proximal part of the sternocostal joint. The samples were stained with hematoxiline-eosin stain and van Giesson. The histologic examination determined, that in 5 cases (50%) the was a fine periferic layer of hialinic tissue. This tissue covered the surfaces articulars of the manubrium and sternal body. It was also found, between both surfaces a moderate (+++) fibrocartilaginous tissue in 3 cases (30%) was found a hialinic tissue between the articulars surfaces and abound fibrocartilaginosus tissue (+++) and in 2 cases (20%), the cartilaginosus tissues thar covered the articulars surfaces was abound with minimum fibrocartilaginous (++) in the central region. In 6 cases (60%) there was a small cavity in the fibrocartilaginous. The manubriosternal joint presented their surfaces covered with cartilaginosus tissue of hialinic type in relation with fibrocartilaginous tissue. This last tissue was a real disc between the articulars surface. In the majority of the cases was found a small cavity, perhaps due to the absortion that its central part suffers this loock more like a synovial joint than a synchondrosis. This could be due to a periferic calcification or to a sinostosis manubriosternal. In conclusion, this joint could be defined as a sinfisis. This reminded an old clasification that defined it as "diartroanfiartrosis", a transition joint between the synovial articulations and cartilaginosus

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123

A new Unidentified Far Infrared Band in NGC 7027

Senent Díez, María Luisa; Massó, Helena; Goicoechea, Javier R.; Cernicharo, José
2004-06-18

Digital.CSIC (Spain)

124

A far-infrared molecular and atomic line survey of the Orion KL region

Polehampton, Edward T.; Lerate, M.R.; Barlow, Michael J.; Swinyard, Bruce M.; Goicoechea, Javier R.; Cernicharo, José; Grundy, Timothy W.; Lim, Tanya L.; Baluteau, Jean-Paul; Viti, S.; Yates, J.
2006-05-17

Digital.CSIC (Spain)

125

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.

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