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Digital.CSIC (58,051 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.

(IRN) Artículos post-print

Mostrando recursos 1 - 20 de 93

1. Cubiertas vegetales en olivar y viñedo: balance de diez años en relación al agua del suelo y su monitorización - Pastor Piñeiro, Jesús; Benítez, M.; Hernández, A. J.
Abstract Plant covers in olive grove and vineyard: ten years balance in relation to soil water and its monitoring The conceptual framework affects necessary ecológica! engineering for the sustainability of woody cultivations in semiarid Mediterranean environments and tries to articúlate the management of several components of these ecological agroecosystems to optimize soil water without covers irrigation. This report describes ways of managing plant covers ("weeds" or native legumes) in relation to the prevailing rainfall régimen. Over the past 10 years, we have been monitoring soil moisture levéis in an extensive olive plantation and vineyard at different depths under the different plant canopies through standard procedures (gravimetric followed by...

2. Preparation and properties of a cross-linked complex between ferredoxin - NADP+ reductase and flavodoxin - Pueyo, José J.; Sancho, Javier; Edmondson, Dale E.; Gómez-Moreno, Carlos
The electrostatically stabilized complex between Anahaena variabilis ferredoxin - NADP' reductase and Azotobacter vinelandii flavodoxin has been covalently cross-linked by treatment with l-ethyl-3-(3-dimethylaminopropy1) carbodiimide. The covalent complex exhibits a molecular mass and FMN/FAD content consistent with that expected for a 1 : 1 stoichiometry of the two flavoproteins. lmmunochemical cross-reactivity is exhibited by the covalent complex with rabbit antisera prepared separately against each protein. The complex retains NADPH - ferricyanide diaphorase activity although the K,,, for ferricyanide is increased twofold and the turnover number is decreased by a factor of two when compared to native reductase. NADPH -cytochrome-c reductase activity of the complex is observed at a...

3. An unusual infection mechanism and nodule morphogenesis in white lupin (Lupinus albus) - González-Sama, Alfonso; Lucas, M. Mercedes; Felipe, Mª Rosario de; Pueyo, José J.
The infection of white lupin ( Lupinus albus ) roots and the early stages in organogenesis of the lupinoid nodule are characterized in detail in this work. • Immunolabelling of Bradyrhizobium sp. ( Lupinus ) ISLU16 and green fluorescent protein labelling of Mesorhizobium loti NZP2037, two strains that induce nodulation in L. albus , allowed us to monitor the infection and morphogenesis process. Light and transmission electron microscopy, low-temperature scanning electron microscopy, fluorescence and confocal microscopy were employed. • Rhizobia penetrated the root intercellularly at the junction between the root hair base and an adjacent epidermal cell. Bacteria invaded the subepidermal cortical cell immediately beneath the root hair through structurally altered cell wall regions. The newly infected cell divided repeatedly...

4. Legume nodule senescence: roles for redox and hormone signalling in the orchestration of the natural aging process - Puppo, Alain; Groten, Karin; Bastian, Fabiola; Carzaniga, Raffaella; Soussi, Mariam; Lucas, M. Mercedes; Felipe, Mª Rosario de; Harrison, Judith; Vanacker, Helene; Foyer, Christine H.
Research on legume nodule development has contributed greatly to our current understanding of plant–microbe interactions. However, the factors that orchestrate root nodule senescence have received relatively little attention. Accumulating evidence suggests that redox signals contribute to the establishment of symbiosis and senescence. Although degenerative in nature, nodule senescence is an active process programmed in development in which reactive oxygen species (ROS), antioxidants, hormones and proteinases have key roles. Nodules have high levels of the redox buffers, ascorbate and glutathione, which are important in the nodulation process and in senescence. These metabolites decline with N-fixation as the nodule ages but the resultant decrease in redox buffering capacity does not necessarily lead...

5. Soil factors and Fe content in wild herbaceous plants - Pastor Piñeiro, Jesús; Hernández, A. J.; Estalrich, E.; Oliver, Salvador
We study the average and range Fe contents in wild plants from pastures located in West and Central Spain, and how its Fe content is affected by some environmental factors, specially the soil variables: lithology, clay, pH, organic matter, free CaCOs, exchangeable Ca, Mg, K and Al, available P, total N, water, climate, rainfall, temperature range and light intensity. Nine species were studied, four legumes: Trifolium subterraneum L. brachycalycinum Katzn. et Morley, Trifolium subterraneum L. subterraneum, Trifolium cemuum and Ornithopus compressus; and five grasses: Agrostis castellana, Bromus hordaceus, Cynodon dactylon, Dactylis glomerata and Holcus lanatus. In Western Spain, the Fe mean content in T. subterraneum is 171.1...

6. Factorial analysis of the effect of sugarbeet vinasses on agroecological indices in horticultural field - Díez-Rojo, M. A.; López-Pérez, J. A.; González-López, M. R.; Piedra Buena, A.; Bello, A.; Almendros, G.
The impact on soil of applying sugarbeet vinasses (V) was analyzed through a field experiment in horticulture greenhouse, arranged in a 23 factorial design. Two levels of three independent variables —application of V, use of polyethylene cover (PC) on the soil, and soil depth (D)— on various dependent variables were studied. Vinasses favoured crop yield and reduced the number of Meloidogyne incognita juveniles in soil. The concentrations of N, P and K increased with the interaction VõD, with PC also increasing N concentration. The amounts of humic acids and humin decreased with D; fulvic acid concentration increased with V, but decreased with the interaction VõPC....

7. The topographic data source of digital terrain models as a key element in the accuracy of hydraulic flood modelling - Casas Planes, M. A.; Benito, Gerardo; Thorndycraft, V. R.; Rico, Mayte
The effects of the topographic data source and resolution on the hydraulic modelling of floods were analysed. Seven digital terrain models (DTMs) were generated from three different altimetric sources: a global positioning system (GPS) survey and bathymetry; high-resolution laser altimetry data LiDAR (light detection and ranging); and vectorial cartography (1:5000). Hydraulic results were obtained, using the HEC-RAS one-dimensional model, for all seven DTMs. The importance of the DTM's accuracy on the hydraulic modelling results was analysed within three different hydraulic contexts: (1) the discharge and water surface elevation results from the hydraulic model; (2) the delineation of the flooded area;...

8. Historical hydrology for studying flood risk in Europe - Brázdil, Rudolf; Kundzewicz, Zbigniew W.; Benito, Gerardo
[EN] Historical hydrology can be defined as a research field occupying the interface between hydrology and history, with the objectives: to reconstruct temporal and spatial patterns of river flow and, in particular, extreme events (floods, ice phenomena, hydrological droughts) mainly for the period prior to the creation of national hydrological networks; and to investigate the vulnerability of past societies and economies to extreme hydrological events. It is a significant tool for the study of flood risk. Basic sources of documentary data on floods and methods of data collection and analysis are discussed. Research progress achieved in Europe in reconstructing past...

9. The catastrophic floods of AD 1617 in Catalonia (northeast Spain) and their climatic context - Thorndycraft, V. R.; Barriendos, M.; Benito, Gerardo; Rico, Mayte; Casas Planes, M. A.
[EN] This paper presents a reconstruction of the catastrophic floods of AD 1617 in Catalonia (northeast Spain). Compilation of archival data sources shows that heavy rainfall occurred from 2 to 6 November 1617 and that the resultant flooding caused severe damage throughout the region, including the destruction of at least 389 houses, 22 bridges and 17 water mills. Discharges of 2700–4500 m3 s−1 and ≤2000 m3 s−1 were estimated from dated palaeostage indicators for the Ter and Segre rivers, respectively, whilst 4680 m3 s−1 was calculated for the Llobregat River flood in a previous study (Thorndycraft et al., 2005). The...

10. Palaeoflood hydrology: insight into rare events and extreme flood discharges - Benito, Gerardo; Thorndycraft, V. R.
Les études paléohydrologiques permettent la reconstitution de chronologies de crue à partir des traces laissées par les sédiments de crue ou l'érosion du courant. Ces marques géologiques donnent une indication sur le niveau atteint par des crues anciennes, sur des périodes de quelques siècles à plusieurs millénaires. La datation des sédiments s'effectue à partir des matériaux présents dans les dépôts de crue (isotope 14 du carbone ou thermoluminescence de grains de minéraux). Les données paléohydrologiques peuvent ensuite être exploitées d'un point de vue probabiliste, en considérant que les événements recensés ont dépassé un ou plusieurs seuils de niveau. Les différentes...

11. Evaluation of soil biodesinfestation with crop and garden residues in the control of root-knot nematodes populations. - López-Cepero, J.; Piedra Buena, A.; Díez-Rojo, M. A.; Regalado, R.; Brito, E.; Hernández, Zulimar; Figueredo, M.; Almendros, G.; Bello, A.
Fresh crop and garden residues were applied both under laboratory conditions and in commercial greenhouse in order to asses their effect on soil nematodes populations and soil fertility. In the laboratory experiments, dosages of 5 to 20 g of cabbage residues, chicken manure, cabbage residues+chicken manure, grass+chicken manure, as well as leaves and stems of orange tree, pine tree, oleander, olive tree, palm tree and boxwood were mixed with 500 g soil having root-knot nematodes (Meloidogyne incognita) and soil moisture was adjusted at field capacity. A control treatment without residues was also included. The mixtures were kept into plastic bags,...

12. Nitrate uptake rates in freshwater plankton: the effect of food web structure - Rojo, Carmen; Rodrigo, María A.; Salazar, Guillem; Álvarez Cobelas, Miguel
Nitrate incorporation rates by primary producers and the transfer of nitrogen to upper planktonic food web levels in different seasons (spring and summer of different years) were studied using a microcosm experimental approach. The study communitieswere natural plankton communities from Colgada Lake (central Spain),which is heavily polluted by nitrate. Natural δ15N in phytoplankton and zooplankton was measured and experiments were performed on the 15N supply. Naturally derived δ15N varied from 7.4 to 8.6‰ and from 10.0 to 16.8‰ in phytoplankton and zooplankton respectively. Nitrogen incorporation rates ranged from 0.006 to 0.036μMh−1 and from 0.0004 to 0.0014μMh−1 in phytoplankton and zooplankton respectively. The differences in natural δ15N...

13. Microinvertebrate and plant beta diversity in dry soils of a semiarid agricultural wetland complex - Angeler, D. G.; Viedma, Olga; Cirujano, Santos; Álvarez Cobelas, Miguel; Sánchez Carrillo, Salvador
The relationship between environmental features and the β diversity of the propagule bank of dry soils of temporary wetlands has relevance to ecological theories of community structure and to the conservation of wetland biodiversity. The correlation of β diversity of microinvertebrates and macrophytes derived from propagules in dry soils with wetland habitat characteristics, catchment land-use, and the distance between wetlands in a remnant pond complex in central Spain was assessed. Redundancy analyses showed that β diversity of both groups correlated with habitat characteristics, whereas associations with catchment agricultural practices were weaker. Nestedness analyses showed that species-poor communities from degraded sites tended to form nested subsets of...

14. Effects of the Lipoxygenase enzyme on morphological changes of the ef face in the Plasmalemma of the Evernia Prunastri Phycobiont - Rapsch, S.; Ascaso, Carmen; Cifuentes, B.
Evernia prunastri (L.) Ach. thalli are subjected to the activity oía lipoxygenase enzyme (Linoleate : oxygen oxidoreductase, EC 1.13.11.12) which usually takes place in phycobiont cells. This activity increases when exposed to light for a period of 9 hours. In such incubation conditions, the dimeric partióles on the EF face of the phycobiont plasmalemma are splitted by which the particle size is reduced while their distribution frequency increases.

15. Laser Flash-Induced Photoreduction of Photosynthetic Ferredoxins and Flavodoxin By 5-Deazariboflavin and by a Viologen Analogue - Navarro, José A.; Hervás, Manuel; Pueyo, José J.; Medina, Milagros; Gómez-Moreno, Carlos; Rosa, Miguel A. de la; Tollin, Gordon
Lase flash photolysis has been used to compare the kinetics of reduction of ferredoxin isoforms from the green alga Monoraphidium braunii, and the ferredoxin and flavodixin from the cyanobacterium Anabaena PCC7119, by 5-deazariboflavin semiquinone ((dRfH)

16. The effect of desiccation on Pyrenoid structure in the Oceanic lichen Parmelia Laevigata - Brown, D. H.; Ascaso, Carmen; Rapsch, S.
Phycobiont cells of Parmelia laemgata contain chloroplasts with pyrenoids penetrated by a reticulum of tubules. The occurrence and significance of such tubules in algae is discussed. Although these tubules collapsed in desiccated cells, their lumen reappeared on rehydration. However, in such desiccated cells, pyrenoglobuli did not become peripherally located within the pyrenoid, except when damage occurred to the pyrenoid matrix. Rehydration of desiccated cells reduced the number of pyrenoglobuli per pyrenoid.

17. Bioconstructions in ochreous speleothems from lava tubes on Terceira Island (Azores) - Ríos, Asunción de los; Bustillo, Mª Ángeles; Ascaso, Carmen; Carvalho, M. R.
The ochreous speleothems examined here were obtained from a lava tube on Terceira Island (Azores) and show compact mineralized areas intermixed with zones in which bacterial structures are evident. Bacterial layers of filament-like structures are common throughout the deposits but differences in microstructure among the different speleothems were observed, reflecting a broad morphological range of deposits. The structures and minerals detected in the speleothems betray their biogenic origin. Gallionella and Leptothrix were the two most frequently observed morphotypes and probably the main contributors to speleothem formation. However, DGGE analysis indicated the presence of another bacterial population (with a predominance of proteobacteria) that could also contribute to iron...

18. Impactos sobre los ecosistemas terrestres - Valladares, Fernando; Peñuelas, J.; Luis Calabuig, E. de
España presenta una gran variedad de ecosistemas terrestres, muchos de ellos únicos y todos ellos proporcionando un amplio número de bienes y servicios. Estos ecosistemas han estado sometidos a intensos cambios climáticos en el pasado pero el ritmo de estos cambios se ha acelerado de forma excepcional. El cambio climático acelerado está dando lugar a un abanico de efectos directos e indirectos que se ven acentuados por la interacción con otros motores del cambio global (cambios de uso del territorio, contaminación, intercambio biótico). Los efectos difieren para los ecosistemas de la región Atlántica, limitados por temperatura, y para los de la región Mediterránea, limitados por agua. Mientras...

19. Action of humic Acid Preparations on Leaf Development, Mineral Elements Contents and Chloroplast Ultrastructure of Ryegrass Plants - Fortun, C.; Rapsch, S.; Ascaso, Carmen
The action of humic acid preparations obtained from straw or peal fermented under controlled conditions on mineral elements contents, área and dimensions of leaves, and ultrastructure of chloroplasts of Lolium perenne L. plants was studied. The naturally fermented organic materials were the source of most effective humic acid preparations. Quantitative transmission electrón microscopy indicated that the treatment of Lolium plants with humic acid from peal incubated without additives induced the most important increase of photosynthetic structures.

20. Chloroplast Crystalloids and Other Alterations in Response to Lichen Substances - Ascaso, Carmen; Orus, I.; Estévez, P.
Many lichen phenolics act as allelopathic substances, lowering germination and growth rates of higher plants or even promoting their decay. Physiological observations previously made on the effect of Evernia prunastri (L.) Ach. lichen compounds on Quercus rotundifolia Lam. explants were correlated in this work with the ultrastructural alterations in chloroplasts. The degenerative changes included the swelling and collapse of granal and agranal thylakoids, with a peripheric display of lamellae and an increase in the number and size of plastoglobuli, though not as high as described elsewhere. Besides these eífects, that are in line with the pattern of breakdown of chloroplasts of leaves senescing under natural conditions, bundles...

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