627 research outputs found
Plant genetic resources and food security: Stakeholder perspectives on the international treaty on plant genetic resources for food and agriculture
The International Treaty on Plant Genetic Resources for Food and Agriculture is a pivotal piece of recent legislation, providing a route map for the use of such resources for sustainable agriculture and food security. This book explains clearly the different interests and views at stake between all players in the global food chain. It touches upon many issues such as international food governance and policy, economic aspects of food and seed trade, conservation and sustainable use of food and agricultural biodiversity, hunger alleviation, ecological concerns, consumers' protection, fairness and equity between nations and generations, plant breeding techniques and socio-economic benefits related to food local economies. The book shows that despite the conflicting interests at stake, players managed to come to an agreement on food and agriculture for the sake of food security and hunger alleviation in the world
Biogeochemistry of surface sediments in mud volcanoes of the Gulf of Cádiz
The shallowest sediment of three mud volcanoes (MVs) located in the middle slope of the Gulf of Cádiz, Anastasya, Pipoca and St. Petersburg, have been seasonally studied during June and December 2016. These structures are locally important contributors of many biogeochemical active substances to the water column, with a special attention in the emission of methane (CH4). Along this study, the role of organic matter diagenesis and its contribution to the diffusive fluxes estimated in the sediment–water interface from the three MVs have been investigated mainly. For this, the first combined analyses of sediment properties (granulometry, porosity, density, organic carbon) and pore water chemistry (major elements, dissolved inorganic carbon (DIC), nutrients, CH4 and nitrous oxide) have been carried out. Anastasya and St. Petersburg MVs presented similar behaviours, with a slight concentration variation for the chemical variables in the top layers of the sedimentary record followed by a more intense vertical variation in deeper layers. Anastasya MV showed some typical processes of these structures, such as the clay dehydration, the dissolution of halite and the precipitation of authigenic carbonates, which was also observed in St. Petersburg MV. Organic matter diagenesis clearly altered the biogeochemical profiles, except for Pipoca MV. Moreover, mud breccia with a mousse-like texture has been identified in the deepest levels of Anastasya and St. Petersburg MVs. Here, anaerobic oxidation of methane is linked to the decrease of SO2−4 and the increases of CH4 and DIC with the core depth. Changes across the sediment–water interface presented low diffusive fluxes in the three MVs due to the presence of other processes as the irrigation by benthic macrofauna, the action of bottom currents and/or the upward fluid migration. From the obtained results, we can conclude that Anastasya MV presents a certain venting activity at present.En prensa1,47
Minimal invasive surgery in craniostenosis
En el presente trabajo se describe la experiencia en craneoestenosis con cirugía mínimamente invasiva, evaluando el diseño y eficacia de un nuevo craneotomo en cadáveres así como su aplicación clínica en un caso de sinostósis sagital con instrumentación endoscópica. Este procedimiento es sin duda un gran recurso en el tratamiento de las craneoestenosis brindando los beneficios de la cirugía mínimamente invasiva, eliminando la necesidad de grandes incisiones, disminuyendo el sangrado quirúrgico, reduciendo estancia hospitalaria y disminuyendo la morbilidad operatoria In this paper, we describe the experience with the use of endoscopic craniofacial procedures, evaluating the design and the efficacy of a new craniotome in cadavers and his clinical application in a case of sagittal synostosis for an endoscopic assisted cranioplasty. This procedure is a great option in the treatment of craniosynostosis, giving the benefits of minimal invasive surgery and eliminating the needing of big incisions, long hospital stay and reducing the postoperative morbidit
Formation of Mass Transport Deposits on the Submarine Bank of Portimão (Gulf of Cadiz, SW Iberia)
European Geosciences Union General Assembly (2017. Viena)The development of submarine mass transport deposits (MTDs) plays an important geo-hazards role along continental margins. Accordingly, their identification and characterization is crucial to understand their sources, dynamics, frequency and spatial distribution. In this work a piston core located at the slope (2876 m water depth) of the southern flank of Portimao Bank (Portugal, Gulf of Cadiz, SW Iberia) underwent detailed magnetic (fabric and rock magnetism) and sedimentological (grain-size, carbonates, organic matter) analyses complemented by AMS 14C dating. Such multidisciplinary study identified about one meter of sediments that is unconformable with the ages obtained above and below this layer. Its magnetic fabric, as determined by anisotropy of magnetic
susceptibility, indicates sharply changes from oblate to neutral shape, decrease of the anisotropy and preferred orientation of the magnetic susceptibility ellipsoid. Such layer is also individualized by sedimentary parameters, especially in its upper part by a lighter colour and decrease of the mean grain size than the rest of the core. Based on these results it is possible to conclude that the sedimentary column analyzed here shows evidence of an on-going development of a slide, which is well individualized and characterized by magnetic fabric studies.Instituto Dom Luiz, University of Lisbon, PortugalInstituto Superior de Engenharia de Lisboa, PortugalEstrutura de Missão para a Extensão da Plataforma Continental, PortugalInstituto Português do Mar e da Atmosfera, PortugalInstituto de Ciencias del Mar, Consejo Superior de Investigaciones Científicas, EspañaCentro Oceanográfico de Málaga, Instituto Español de Oceanografía, EspañaInstituto Geológico y Minero de España, Españ
Magnetic and Sedimentological data as a contribution for mass transport deposits identification on Southern Portuguese Margin
Zonación vertical de la bioturbación y movimientos en masa en el Banco de Portimão (Golfo de Cádiz, SO de Iberia)
This work presents results from bioturbation intensity and trace fossil analysis of the piston
core PC07, recovered at Portimão Bank during the MONTERA cruise in 2012. The aim was to
investigate the potential of bioturbation analysis as an indicator for mass movement events.
Bioturbation and trace fossil identification was complemented with results from sedimentological
analysis (grain-size, carbonates, organic matter), measurements of magnetic fabric parameters (mass
magnetic susceptibility and anisotropy of magnetic susceptibility), and AMS 14C dating. Considering
the vertical zonation of bioturbation, magnetic fabric changes, sedimentology and AMS radiocarbon
dating, two intervals were identified, Interval A (0-180 cm) and Interval B (180-356 cm), being the
limit between them placed at 180-181cm. These intervals seem to replicate almost the same vertical
zonation of bioturbation and the trend of carbonates and organic matter changes downcore. The
magnetic fabric parameters (degree of anisotropy – Pj and shape – T of the magnetic susceptibility
ellipsoid) show the major change at about 180 cm. Geochronological results indicate that the age of
sediments in Interval A is 8590 yr BP (31-32 cm) and 14 300 yr BP (103-104 cm). Otherwise, ages in
Interval B are the following: 5035 yr BP (181-182 cm), 8900±50 yr BP (219-220 cm), 18999±120 yr BP
(303-305 cm). These results point to the emplacement of sediments of Interval A on top of youngest
sediments of Interval due to landsliding. Since no internal deformation is seen, probably this
indicates translational movement and short transport from the source.Versión del edito
Morphological characterization of contourite and mass-wasting recent processes at the Guadalquivir Bank Margin uplift, Gulf of Cádiz
The Gulf of Cadiz records the interplay of a variety of sedimentary processes related to the
circulation of water masses. The most important one is the Mediterranean Outflow Water (MOW) that
exits the Mediterranean Sea, but other water masses also affect the seafloor, with complex variations
along time and space. This work studies the interplay between oceanographic and gravitational
sedimentary processes on the Guadalquivir Ridge, based on bathymetry and high-resolution seismic
profiles. A series of morphological features including flat terraces, circular/elliptical depressions, semicircular
scarps and valley-shaped features are analysed in order to better understand the interaction
between water masses circulation and mass-wasting processes of the Gulf of Cadiz.Versión del edito
Modelización de los end-members para reconocer fuentes de aporte sedimentario en contornitas: un caso de estudio en el Mar de Alborán
Contourite drifts are one the main morphosedimentary features in the Alboran Sea and
their sediments are important archives of the past oceanographic conditions and sedimentary
processes. The end-member modelling approach lets to decompose multimodal grain-size
distribution into genetically meaningful subpopulation that may be related to different sediment
transport mechanisms and source areas. Three end-members have been identified in the contourite
drift and moat system located at the southern side of the Dijbouti Ville seamount that have been
interpreted in terms of sediment sources. Two end-members point to an eolian source and comprise
fine silt (EM1) and coarse silt (EM2) as modal grain-sizes, characterized by high and low contents,
respectively, of terrigenous elements (Al, Si, Ti and K). The third end-member (EM3) indicates a
fluvial origin and is mainly defined by a clay modal grain-size of intermediate and homogeneous
content in terrigenous elements. Downcore variation of the relative proportion of these EMs can be
used to decipher paleocenographic and paleoclimatic conditions in the Alboran Sea.Versión del edito
Seabed morphology and bottom water masses related to benthic habitats at the Cristóbal Colón diapir (NW of the Guadalquivir ridge, Gulf of Cádiz)
The seabed morphology and the sub-superficial characteristics of the Cristóbal Colón diapir
located on the continental slope of the Gulf of Cadiz have been analysed from data obtained in the
framework of the LIFE+INDEMARES/CHICA project. The aim of this study is to recognize the
morphological features and the geological processes generated by the bottom water masses and their
influence on the habitats and associated benthic communities. The NACW affects the generation of
morphological features on the summit, revealing that different oceanographic conditions favoured the
carbonate mound growth in the past. The interface between the NACW and the MOW sweeps the bottom
from the SE to the NW and the presence of benthic communities dominated by filter feeders on the
contouritic drift indicates that this current is strong enough to favour the availability of nutrients and
organic particles and to develop both the contouritic deposits on the SE flank and the moats on the N and
W flanks.Versión del edito
An experimental study to discriminate between the validity of diffraction theories for off-Bragg replay
We show that experiments clearly verify the assumptions made by the
first-order two-wave coupling theory for one dimensional lossless unslanted
planar volume holographic gratings using the beta-value method rather than
Kogelnik's K-vector closure method. Apart from the fact that the diffraction
process is elastic, a much more striking difference between the theories
becomes apparent particularly in the direction of the diffracted beam in
off-Bragg replay. We therefore monitored the direction of the diffracted beam
as a function of the off-Bragg replay angle in two distinct cases: [a] the
diffracted beam lies in the plane of incidence and [b] the sample surface
normal, the grating vector and the incoming beam do not form a plane which
calls for the vectorial theory and results in conical scattering.Comment: Corrected Eqs. (3) & (6); 14 pages, 8 figure
- …