217 research outputs found
Relationship between the offlap-break location of Holocene prograding wedges on wave climate in southeastern Iberian Peninsula
Wave climate exerts a significant influence on the development of Holocene sedimentary prograding wedges. This is demonstrated by
the fact that near-bed orbital velocities between 0.10 and 0.14 m/s (threshold for resuspension) occur in the vicinity of the infralittoral
prograding wedges (IPW) offlap-breaks during storm-weather conditions, but during medium wave energy conditions in the case of
prodeltaic wedges
Submarine deltaic geometries linked to steep, mountainous drainage basins in the northern shelf of the Alboran Sea: Filling the gaps in the spectrum of deltaic deposition
A comprehensive analysis of small deltaic environments linked to short, mountainous, and seasonal fluvial systems
in the northern shelf of the Alboran Sea was undertaken in order to define the controlling parameters of
the geomorphological variability. The database includes multibeam and backscatter imagery, surficial sediment
samples, and high-resolution seismic profiles. Additionally, geomorphological and hydrodynamic modeling
and statistical analysis (principal component and cluster analysis) of hydrological and physiographic variables
were performed.Most of the studied deltaic systems have high-gradient, coarse-grained deposits with preferential
development of the submarine portions to the detriment of the deltaic plains. The geomorphological analysis
identified three basic types of plan-viewdistributions according to the length-to-width ratios: elongate, linguoid
and lobate. Cross-slope profiles evidence dominant concave-upward geometries, fewer occurrences of planar geometries,
and no sigmoid profiles. Sediment depocenters are extremely thick in proximal locations, but thin out
rapidly seawards. The geometric distribution patterns of the deltaic systems are characterized by a predictable
pattern in plan-view according to the type of fluvial system, ranging from a relatively large river to ephemeral
creeks. Prevailing concave and secondary planar profiles support strong sediment progradation in the submarine
realmand lowsediment retention in the emerged deltaic environment. Two different types of systems are distinguished:
(1) larger rivers,where deltaic deposition is largely controlled by basin dimensions, ultimately dictating
themagnitude of water and sediment discharges; and (2) smaller rivers and creeks,where deltaic geometries are
related to the basin slopes. The influence of hydrodynamic variables on defining the submarine deltaic geometry
has been observed in the case of concave-upward geometries, where geomorphological boundaries are defined
by medium- and high-energy wave conditions.Versión del editor2,520
Episodios de construcción de un delta mediterráneo: Cambio climático y modificaciones antropogénicas en el delta del río Adra
The evolutionary stages of the submarine delta off the Adra River are investigated in this
study, under the context of climatic fluctuations entangled with increasing human activities and
interventions in the drainage basins and adjacent shores during the Middle to Late Holocene. To
achieve that goal, we used an extensive database comprising a set of bathymetric data covering
different time slices, a dense grid of high-resolution seismic data and several sediment cores
collected in the two submarine lobes of the Adra River delta. Two main evolutionary phases can be
identified. The first one extended through most of the construction history and was mediated by
major climatic events at the Mediterranean scale; this phase included three major progradational
events occurring during the Mid Holocene, the Roman time and the Little Ice Age. The most recent
phase is strongly determined by human modifications of the fluvial channels, and resulted in a
drastic transformation of the submarine sedimentary environment.Versión del edito
Estudio morfometrico comparativo entre las ondulaciones de los prodeltas de los rios de Andalucia Oriental
A partir de un estudio detallado de datos de batimetría multihaz se ha realizado el análisis morfométrico de 8 campos de ondulaciones desarrollados sobre prodeltas ubicados en la plataforma continental del margen norte del Mar de Alborán. Los parámetros morfológicos obtenidos se han relacionado con el régimen hídrico asociado a los sistemas fluviales estudiados, caracterizado por un patrón estacional influenciado por el clima regional. Los resultados indican que existe una clara relación entre las ondulaciones y la localización de los cauces fluviales, lo cual indicaría una influencia directa de las descargas fluviales en la generación de las ondas. Por otro lado, se ha comprobado que las ondulaciones asociadas a los ríos con mayor longitud y cuenca de drenaje alcanzan un mayor desarrollo que aquellas identificadas sobre cuerpos prodeltaicos asociados a ríos pequeños y ramblas, posiblemente indicando la existencia de diferentes tasas de aporte sedimentario en la plataforma continental.Publicado
A Case Study of available methodology for the identification of Vulnerable Ecosystems/Habitats in bottom deep-sea fisheries: Possibilities to apply this method in the NAFO Regulatory Area in order to select Marine Protected Areas
Information is critical to Ecosystem Approach and to research about Vulnerable Marine Ecosystems/Habitats
(VME/Hs), fishing impacts on habitats and ad-hoc management measures are high-priority. Therefore, this paper
presents the ECOVUL/ARPA Interdisciplinary Approach, a case study of methodology for the identification of
VME/Hs in order to advise on conservation measures such as marine protected areas (MPAs). By means of an
interactive process involving Conventional Fisheries Science, Geomorphology, Sedimentology and Benthic
Ecology, the methodology developed under the ECOVUL/ARPA project, has been useful in order to contribute to
define practical criteria to the identification of VME/Hs, to improve the knowledge about VME/Hs distribution and
the adverse impacts of bottom trawl fisheries and to produce high quality advice on habitat protection. Applying an
interdisciplinary approach, the project identified the deep-water bottom trawl fishery footprint on the Hatton Bank
Western slope (NEAFC Regulatory Area), mapped the main fishing grounds and related seabed habitats and studied
the interactions between fishing and cold-water corals. This approach was used to suggest, with high level of
precision, the spatial limits of an area closed to bottom fishing, as an essential conservation measure to protect the
cold-water corals in the framework of the Ecosystem Approach to Fisheries management. We present here the
methods used, the main results obtained and discuss on the utility of this approach and the possibilities to apply it in
the NAFO Regulatory Area, with the aim to advise on measures for reducing the interactions of bottom fishing with
sensitive high-seas habitats and to contribute to implement the UNGA recommendations about habitat conservation
Dietary Intervention Modulates the Expression of Splicing Machinery in Cardiovascular Patients at High Risk of Type 2 Diabetes Development: From the CORDIOPREV Study
Type-2 diabetes mellitus (T2DM) has become a major health problem worldwide. T2DM risk can be reduced with healthy dietary interventions, but the precise molecular underpinnings behind this association are still incompletely understood. We recently discovered that the expression profile of the splicing machinery is associated with the risk of T2DM development. Thus, the aim of this work was to evaluate the influence of 3-year dietary intervention in the expression pattern of the splicing machinery components in peripheral blood mononuclear cells (PBMCs) from patients within the CORDIOPREV study. Expression of splicing machinery components was determined in PBMCs, at baseline and after 3 years of follow-up, from all patients who developed T2DM (Incident-T2DM, n = 107) and 108 randomly selected non-T2DM subjects, who were randomly enrolled in two healthy dietary patterns (Mediterranean or low-fat diets). Dietary intervention modulated the expression of key splicing machinery components (i.e., up-regulation of SPFQ/RMB45/RNU6, etc., down-regulation of RNU2/SRSF6) after three years, independently of the type of healthy diet. Some of these changes (SPFQ/RMB45/SRSF6) were associated with key clinical features and were differentially induced in Incident-T2DM patients and non-T2DM subjects. This study reveals that splicing machinery can be modulated by long-term dietary intervention, and could become a valuable tool to screen the progression of T2DM
Advances in geobotany and new tools in biogeographic and bioclimatic maps: Sierra de Guadarrama National Park
20 páginas, 14 tablas, 3 mapas
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