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Digital.CSIC (75,985 recursos)
Repositorio institucional del Consejo Superior de Investigaciones Científicas. Digital.CSIC es un depósito de documentos digitales, cuyo objetivo es organizar, archivar, preservar y difundir en modo de acceso abierto la producción intelectual resultante de la actividad investigadora del CSIC.

(IPNA) Artículos post-print

Mostrando recursos 1 - 20 de 206

1. Soil volatile mercury, boron and ammonium distribution at Cañadas caldera, Tenerife, Canary Islands, Spain - Hernández, Pedro A.; Pérez, Nemesio; Salazar, José M. L.; Ferrell, Ray; Álvarez, Carlos Enrique
Spatial distribution of soil Hg, B and NH4 was investigated in the soils of Cañadas caldera, Canary Islands, in the summer of 1992. Soil Hg, B and NH4 were also studied over several transects intersecting structural features. Soil Hg concentration ranged from 10.83 to 45,000 μg kg−1 whereas those of B and NH4 ranged from 8.45 to 4512 μg kg−1 and from 0.31 to 181 mg kg−1, respectively. Probability plot analysis identified 3 geochemical populations for Hg and B whereas only 2 were detected for NH4. Multivariate analysis (cluster, factor and multiple regression analysis) was used to identify subtle geochemical...

2. Organic matter accumulation during the Holocene in the Guadalquivir marshlands (SW Spain) - Ortiz, José E.; Torres, Trinidad José de; López-Pamo, José E.; Soler, Vicente; LLamas, Juan F.; Barettino, Daniel; García, María J.
The distribution of biomarker compounds and magnetic susceptibility observed in the sediment from a 20 m core drilled in the marshlands of the estuarine region of the Guadalquivir River (southwest coast of Spain) has allowed us to reconstruct the palaeoenvironmental evolution of this area during the Holocene. Several organic compounds (n-alkanes, n-ketones, n-alkanols, n-alkanoic acids and organic sulphur), as well as different biomarker ratios, have been used to show changing environmental conditions through time. These geochemical proxies suggest good preservation of the organic matter, although some diagenesis has occurred to particular organic compounds, especially the n-alkanoic acids. Our data indicate...

3. Digestive ecology of two omnivorous Canarian lizard species (Gallotia, Lacertidae) - Valido, Alfredo; Nogales, Manuel
Omnivorous endemic Canarian lacertids (Gallotia atlantica and G. galloti) do not present any specific digestive and physiological adaptations to herbivorous diet, compared to species and populations with a different degree of herbivory in the Canarian archipelago. The only charactristics that could be related to the type of diet were the number of cusps per tooth (between species) and the number of small stones contained in droppings (between species and populations). The rest of measured traits were correlated with lizard size and for this reason G. galloti has longer intestines, heavier stomachs and livers, more teeth and cusps, and longer gut...

4. Evidence for long-term uplift on the Canary Islands from emergent Mio–Pliocene littoral deposits - Meco, Joaquín; Scaillet, Stéphane; Guillou, Hervé; Lomoschitz, Alejandro; Carracedo, Juan Carlos; Ballester, Javier; Betancort, Juan Francisco; Cilleros, Antonio
Several islands in the Canarian archipelago show marine deposits with identical fossil faunas, which are generally assigned to different glacioeustatic marine episodes: mainly Pleistocene episodes in Lanzarote and Fuerteventura, and Mio–Pliocene ones in Gran Canaria.

5. Evolution of ocean-island rifts: The northeast rift zone of Tenerife, Canary Islands - Carracedo, Juan Carlos; Guillou, Hervé; Nomade, Sébastien; Rodríguez Badiola, Eduardo; Pérez Torrado, Francisco José; Rodríguez González, Alejandro; Paris, Raphael; Troll, Valentín R.; Wiesmaier, Sebastian; Delcamp, A.; Fernandez-Turiel, J. L.
The northeast rift zone of Tenerife presents a superb opportunity to study the entire cycle of activity of an oceanic rift zone. Field geology, isotopic dating, and magnetic stratigraphy provide a reliable temporal and spatial framework for the evolution of the NE rift zone, which includes a period of very fast growth toward instability (between ca. 1.1 and 0.83 Ma) followed by three successive large landslides: the Micheque and Güímar collapses, which occurred approximately contemporaneously at ca. 830 ka and on either side of the rift, and the La Orotava landslide (between 690 ± 10 and 566 ± 13 ka)....

6. Diastereoselective formal synthesis of the antifungal agent, (+)-Preussin. A new entry to chiral pyrrolidines - De Armas, Pedro; García-Tellado, Fernando; Marrero-Tellado, José Juan; Robles, Juana
A formal total synthesis of (+)-Preussin was achieved by using D-mannose as the starting material. The key step involved diastereoselective addition of allyltrimethylsilane to the bicyclic ketal 5

7. Etude de relation sol-plante sur les cultures de bananiers de l'ile de La Palma (Canaries) - García, V.; Bravo, J. J.; Robles, Juana; Alvarez, C. E.
On a réalisé une étude des résultats de l'analyse des feuilles et des sols de treize plantations de bananiers de l'ile de La Palma (Canries), oir l'on obtient les plus hauts rendements de l'archipel par plante et par unité de surface. on compare les résultats obtenus avec ceux qui ont été trouvés pour Ténérife dans des études similaires, et on remarque une valeur plus élevée du rapport Ca/Mg, tant dans les sols que dans les feuilles.

8. Desequilibrios potásico-Magnésicos en los cultivos de plátanos de Tenerife - García, V.; Fernández Caldas, E.; Alvarez, C. E.; Robles, Juana
L'existence de rappons $/Mg très élevés dans les sols de quelques plantations du sud de l'ile de Ténérife donne lieu à une série de bouleversements physiologiques dans les plantes (remplissage déficient des fruits, symptómes de carence magnésienne, et.). La mesure de l'état nutritif de ces plantations indemnes des anomalies en question, montre que ce déséquilibre se manifeste très clairement dans l'analyse du limbe, mais pas dans celle de la nervure.

9. Factores que afectan a la asimilabilidad del potasio en los suelos de plátanos de Tenerife - García, V.; Díaz, A.; Fernández Caldas, E.; Robles, Juana

10. Los oligoelementos Fe, Mn, Zu y Ca en el plátano: factores que influyen en sus niveles foliares - Díaz, A.; Fernández Caldas, E.; García, V.; Robles, Juana
[ES] Se determinan los niveles foliares de Fe, Mn, Zn y Cu de la 3ª hoja (limbos y nervios) del plátano en la fase de floración en plantaciones de elevada producción de las dos zonas agrícolas mis importantes de la isla de Tenerife. Se determinan asimismo las concentraciones foIiares de Fe en plantas en fase de diferenciación floral con deficiencia en este elemento. Las concentraciones de Fe en la hoja dependen del pH y, por consigiuiente, de los contenidos de Na y Mg cambiables, cationes que gobiernan en gran parte las variaciones del pH en estos suelos. Los niveles de Mn en la hoja varían dentro de limites...

11. La dorsal NE de Tenerife: hacia un modelo del origen y evolución de los rifts de islas oceánicas - Carracedo, Juan Carlos; Guillou, Hervé; Rodríguez Badiola, Eduardo; Pérez Torrado, Francisco José; Rodríguez González, Alejandro; Paris, Raphael; Troll, Valentín R.; Wiesmaier, Sebastian; Delcamp, A.; Fernandez-Turiel, J. L.
[ES] El Rift NE de Tenerife, conocido localmente como la Dorsal de La Esperanza, es un excelente ejemplo de un rift persistente y recurrente. Su estudio ha aportado evidencias significativas del origen y dinámica de este tipo de estructuras volcánicas. Los rifts son posiblemente las estructuras más relevantes en la geología de las islas volcánicas oceánicas: 1. Controlan, tal vez desde su inicio, la construcción de los edificios insulares; 2. Son elementos sustanciales en la configuración (forma y topografía) de estas islas; 3. Dan origen a sus principales formas del relieve y el paisaje; 4. Al concentrar la actividad eruptiva,...

12. Aspectos volcanológicos y estructurales. Evolución petrológica e implicaciones en riesgo volcánico de la erupción de 1730 en Lanzarote. Islas Canarias - Carracedo, Juan Carlos; Rodríguez Badiola, Eduardo; Soler, Vicente
[ES] La erupción ocurrida en Lanzarote entre elide septiembre de 1730 y el 16 de abril de 1736 es por su duración (2.053 días), extensión (200 km2) y volumen (3-5 km3) de materiales emitidos, y longitud de la fisura eruptiva (al menos 14 km), muy diferente del resto de las erupciones históricas de Canarias (últimos 500 años), que presentan estos parámetros con valores muy inferiores. La evolución de los magmas (con claras tendencias toleíticas), es asimismo única en el volcanismo histórico del Archipiélago. No había sido objeto, sin embargo, hasta ahora de un estudio específico que intentara su reconstrucción. Para...

13. El volcanismo de Nuévalos (Zaragoza): situación morfoestructural y edad - Hoyos Gómez, Manuel; Gillot, P. Y.; Sanz-Rubio, Enrique; Soler, Vicente; Sánchez Moral, Sergio; Cañaveras, Juan Carlos
[ES] Los afloramientos volcánicos de Nuévalos se sitúan dentro del contexto morfoestructural de la Rama Castellana de la Cordillera Ibérica que constituye el borde occidental de la Cuenca de Calatayud. Este trabajo aporta evidencias morfoestructurales y radiométricas (K/Ar) que descartan la supuesta edad neógena atribuida a estos materiales por diversos autores. Los datos morfoestructurales demuestran una edad anterior al Oligoceno superior, mientras que las dataciones efectuadas por el método de K/Ar concretan esta edad en 183 ± 2,6 Ma (Jurásico inferior).

14. Seed dispersal networks in the Galápagos and the consequences of alien plant invasions - Heleno, Rubén H.; Olesen, Jens M.; Nogales, Manuel; Vargas, Pablo; Traveset, Anna
Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were Lantana camara, Rubus niveus and Psidium guajava, the latter two likely benefiting from an asynchronous fruit production with most native plants, which facilitate their consumption and spread. Lava lizards dispersed the seeds of 27 species, being the most important dispersers, followed by small ground finch, two mockingbirds,...

15. Seed dispersal interactions in the Mediterranean Region: Contrasting patterns between islands and mainland - González-Castro, Aarón; Traveset, Anna; Nogales, Manuel
Aim We studied, for the first time, the effect of insularity on plant-seed disperser networks at both the community and species level. We focused on the Mediterranean shrubland, comparing different biogeographical scenarios (insular and continental) that share the same basic species composition. Location The study was conducted within one mainland (southern Spain) and four island localities: two in the Canary Islands (oceanic origin) and two in the Balearic Islands (continental origin). Methods We built qualitative (presence/absence of interaction) and quantitative seed dispersal networks (number of consumed fruits) and used different descriptor parameters, such as connectance, nestedness, interaction asymmetry and various...

16. Plant colonization across the Galápagos Islands: Success of the sea dispersal syndrome - Vargas, Pablo; Nogales, Manuel; Jaramillo, Patricia; Olesen, Jens M.; Traveset, Anna; Heleno, Rubén H.
A new approach for investigating evidence for the capacity of plant colonization between islands and the success of plant morphological traits associated with seed dispersal is presented. As colonization is the result of dispersal and establishment, oceanic archipelagos provide an ideal spatio-temporal system in which to analyse plant dispersal traits related to current distributions of species across islands. The Galápagos archipelago comprises 12 islands >10 km2 that harbour 403 native angiosperms, of which 313 native species occupy lowland habitats that are present on all islands. We inferred the minimum number of colonization events within the archipelago for the species (289...

17. Invaders of pollination networks in the Galápagos Islands: Emergence of novel communities - Traveset, Anna; Heleno, Rubén H.; Chamorro, Susana; Vargas, Pablo; McMullen, Conley K.; Castro-Urgal, Rocío; Nogales, Manuel; Herrera, Henri W.; Olesen, Jens M.
The unique biodiversity of most oceanic archipelagos is currently threatened by the introduction of alien species that can displace native biota, disrupt native ecological interactions, and profoundly affect community structure and stability. We investigated the threat of aliens on pollination networks in the species-rich lowlands of five Galápagos Islands. Twenty per cent of all species (60 plants and 220 pollinators) in the pooled network were aliens, being involved in 38 per cent of the interactions. Most aliens were insects, especially dipterans (36%), hymenopterans (30%) and lepidopterans (14%). These alien insects had more links than either endemic pollinators or non-endemic natives,...

18. Asphodelin and microcarpin, two new bianthraquinones from Asphodelus microcarpus - González, Antonio G.; Freire, Raimundo; Salazar, José A.; Hernández, Rosendo; Suárez, Ernesto
A recent Communication on anthraquinones from Asphodelus microcarpus Salzm. et Viv. prompts this report on the isolation of two new bianthraquinones (named asphodelin and microcarpin): they are obtained by Soxhlet extraction of the tubers of this plant with ethyl acetate.

19. Synthesis and Chemistry of Tetronic Acids - Tejedor, David; García-Tellado, Fernando
Tetronic acids (4-hydroxy-2(5H)-furanones) form a subclass of β-hydroxybutenolides with the generic structure 1. The best known members of this family are vitamin C (ascorbic acid) 2 and pennicillic acid 3. A great number of these compounds and their metabolites are found in many natural products, which exhibit a wide array of biological properties. The aim of this review is to cover the current synthetic methodologies developed to build these molecules and their specific chemistry more than biological and pharmaceutical aspects of these products.

20. Mineralumwandlung im zuge der genese der kanarischen andosole (Tenerife) - Fernández Caldas, E.; Schwaighofer, Bernd
[AL] In vier Bodenprofilen über vulkanischen Gesteinen als Ausgangsmaterial wurden Mineralumwandlungen unter z. T. unterschiedlichen und z. T. gleichen klimatischen bedingungen untersucht. Die veränderungen im Mineralbestand vom Muttergestein bis zum Boden wurden durch Röntgendiffraktometrie, Differential-Thermoanalyse, Licht- und Elektronenmikroskopie verfolgt. Dabei konnte die Abfolge Allophan - Halloysit - Kaolinit unabhängig von den verschiedenen klimatischen und petrographischen Bedingungen festgestellt werden. Unterschiede, die auf das Klima zurückzuführen sind, fanden sich zwischen den Profilen 1 und 2 (Positionen mit höherem Niederschlag und geringeren Temperaturunterschieden) und den Profilen 3 und 4 (geringer niederschlag, hohe Temeperaturunterschiede). In diesen Profilen kam es im gegensatz zu den Böden der Nordseite...

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