69 research outputs found
Uncertainty Analysis Related to Beach Morphology and Storm Duration for More Reliable Early Warning Systems for Coastal Hazards
Early warning systems (EWSs) for coastal erosion are cost-effective instruments for risk reduction. Among other aspects, the selection of the pre-storm beach morphology and the definition of storm characteristics can affect EWS reliability. Here, XBeach simulations were used to assess the uncertainties in beach-dune erosion related to the variability of storm severity and duration and pre-storm morphology. Wave height return periods (from 5 to 50 years) determined the severity and the duration variability was established from confidence intervals after an adjustment with wave height. The variability of steep profiles included different berm morphologies (from fully developed to eroded berms). Three indicators, relative eroded volume, proportional berm retreat and proportional dune retreat, were evaluated. The experiments revealed that: (a) Relative eroded volume uncertainties related to the pre-storm morphology variability were slightly lower (maximum 8%) than the uncertainties related to storm duration (11%–18%). (b) Pre-storm profile variability can induce large uncertainties in the proportional berm retreat (up to 88%) for moderate events such as the 5- and 10-year events. Storm duration variability had less influence on this indicator (maximum 12%). (c) The uncertainties in the proportional dune retreat increased with storm severity and they ranged between 14% and 41% for pre-storm profile variability and between 2% and 40% for storm duration variability. Duration variability even governed the occurrence of dune breaching on eroded berm profiles in the most extreme event. Hence, the uncertainties related to initial/forcing conditions, namely pre-storm morphology and storm duration, must be assessed to develop reliable coastal erosion EWSs
A large area timing RPC prototype for ion collisions in the HADES spectrometer
We present a resistive plate chamber (RPC) prototype for time-of-flight measurements over large areas and at high occupancies, minimizing the inter-channel cross-talk.http://www.sciencedirect.com/science/article/B6TJM-4D75GPD-9/1/a6fe40c114a867a0f98e2fec0f13350
Association of Enteric Parasitic Infections with Intestinal Inflammation and Permeability in Asymptomatic Infants of São Tomé Island
The cumulative effect of repeated asymptomatic enteric infections on intestinal barrier is not fully understood in infants. We aimed to evaluate the association between previous enteric parasitic infections and intestinal inflammation and permeability at 24-months of age, in asymptomatic infants of São Tomé Island. A subset of infants from a birth cohort, with intestinal parasite evaluations in at least four points of assessment, was eligible. Intestinal inflammatory response and permeability were assessed using fecal S100A12 and alpha-1-antitrypsin (A1AT), respectively. The cutoff <-1SD for weight-for-length and length-for-age was used to define wasting and stunting. Multivariable linear regression analysis explored if cumulative enteric parasitic infections explained variability of fecal biomarkers, after adjusting for potential confounders. Eighty infants were included. Giardia duodenalis and soil-transmitted helminths (STH) were the most frequent parasites. The median (interquartile range) levels were 2.87 μg/g (2.41-3.92) for S100A12 and 165.1 μg/g (66.0-275.6) for A1AT. Weak evidence of association was found between S100A12 levels and G. duodenalis (p = 0.080) and STH infections (p = 0.089), and between A1AT levels and parasitic infection of any etiology (p = 0.089), at 24-months of age. Significant associations between A1AT levels and wasting (p = 0.006) and stunting (p = 0.044) were found. Previous parasitic infections were not associated with fecal biomarkers at 24 months of age. To summarize, previous asymptomatic parasitic infections showed no association with intestinal barrier dysfunction. Notwithstanding, a tendency toward increased levels of the inflammatory biomarker was observed for current G. duodenalis and STH infections, and increased levels of the permeability biomarker were significantly associated with stunting and wasting.info:eu-repo/semantics/publishedVersio
Cork oak and climate change: disentangling drought effects on cork chemical composition
Climate change induces in the Mediterranean region more frequent and extreme events, namely, heat
waves and droughts, disturbing forest species and affecting their productivity and product quality.
The cork oak (Quercus suber) is present along the western Mediterranean basin and its outer bark
(cork) is sustainably collected and used for several products, mainly wine bottle stoppers. Since most
cork properties arise from its chemical composition, this research studies the effect of drought on cork
chemical composition (suberin, lignin, polysaccharides and extractives) and on polysaccharide and
suberin monomeric composition. Three sets of cork samples, from the same site, were examined: in one
set the cork grew without drought; in another two drought events occurred during cork growth and in
the third one drought event happened. The results show that, in general, drought does not affect the
proportion of the main components of cork, the monomers of suberin or of polysaccharides, with few
exceptions e.g. drought increased ethanol extractives and xylose in polysaccharides and decreased
arabinose in polysaccharides. The variability associated to the tree is much more relevant than the
effect of drought conditions and affects all the parameters analyzed. Therefore, our research suggests
that the tree genetic information, or its expression, plays a much more important role on the chemical
composition of cork than the drought conditions occurring during cork growth. In practical terms, the
potential increased occurrence of droughts arising from climatic changes will not compromise the
performance of cork as a sealant for wine bottlesinfo:eu-repo/semantics/publishedVersio
The caribbean coastal marine productivity program (CARICOMP)
CARICOMP is a regional scientific program to study land-sea interaction processes in the Caribbean coastal zone. It has been collecting data since 1992, when a Data Management Centre was established at the University of the West Indies in Jamaica. Initially it focuses on documenting the structure and productivity of major coastal communities (mangrove forests, seagrass meadows and coral reefs) at relatively undisturbed sites in diverse physical settings. Second, by regular recording of physical and biological parameters, it monitors for change, seeking to distinguish natural from anthropogenic disturbance. Third, it constitutes a regional network of observers, able to collaborate on studies of region-wide events. Examples are presented of the diverse data sets collected by the Program.Fil: Alcolado, Pedro M.. Instituto de Oceanología; CubaFil: Alleng, Gerard. No especifíca;Fil: Bonair, Kurt. No especifíca;Fil: Bone, David. Universidad Simón Bolívar; VenezuelaFil: Buchan, Kenneth. No especifíca;Fil: Bush, Phillippe G.. Protection and Conservation Unit; Islas CaimánFil: De Meyer, Kalli. No especifíca;Fil: Garcia, Jorge R.. Universidad de Puerto Rico; Puerto RicoFil: Garzón Ferreira, Jaime. Instituto de Investigaciones Marinas y Costeras; ColombiaFil: Gayle, Peter M. H.. Discovery Bay Marine Laboratory; JamaicaFil: Gerace, Donald T.. Bahamian Field Station; BahamasFil: Geraldes, Francisco X.. Universidad Autonoma de Santo Domingo.; República DominicanaFil: Dahlgren, Eric Jordán. Universidad Nacional Autónoma de México; MéxicoFil: Kjferve, Björn. University of South Carolina; Estados UnidosFil: Klein, Eduardo. Universidad Simón Bolívar; VenezuelaFil: Koltes, Karen. Smithsonian Institution; Estados UnidosFil: Laydoo, Richard S.. No especifíca;Fil: Linton, Dulcie M.. University of the West Indies ; JamaicaFil: Ogden, John C.. Florida Institute of Oceanography; Estados UnidosFil: Oxenford, Hazel A.. McGill University; BarbadosFil: Parker, Christoph. McGill University; BarbadosFil: Penchaszadeh, Pablo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pors, Leon P. P. J.. Universidad Simón Bolívar; VenezuelaFil: Ramírez Ramírez, Javier. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados. Departamento de Física; MéxicoFil: Ruiz Rentería, Francisco. Universidad Nacional Autónoma de México; MéxicoFil: Ryan, Joseph D.. Centro de Investigación y Documentación de la Costa Atlántica; NicaraguaFil: Smith, Struan R.. Bermuda Biological Station for Research; BermudasFil: Tschirky, John. Latin American and Caribbean Division; Estados UnidosFil: Varela, Ramon. Estación de Investigaciones Marinas de Margarita; VenezuelaFil: Walker, Susan. No especifíca;Fil: Weil, Ernesto. Universidad de Puerto Rico; Puerto RicoFil: Wiebe, William J.. University of Georgia; Estados UnidosFil: Woodley, Jeremy D.. University of the West Indies; JamaicaFil: Zieman, Joseph C.. University of Virginia; Estados Unido
Measurement of low-mass e + e − pair production in 1 and 2 A GeV C–C collision with HADES
HADES is a secondary generation experiment operated at GSI Darmstadt with the main goal to study dielectron production in proton, pion and heavy ion induced reactions. The first part of the HADES mission is to reinvestigate the puzzling pair excess measured by the DLS collaboration in C+C and Ca+Ca collisions at 1A GeV. For this purpose dedicated measurements with the C+C system at 1 and 2A GeV were performed. The pair excess above a cocktail of free hadronic decays has been extracted and compared to the one measured by DLS. Furthermore, the excess is confronted with predictions of various model calculations. © 2009 Springer-Verlag / Società Italiana di Fisica. 62 1 81 84 Cited By :
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
Sistema de evaluación institucional en enseñanza obligatoria en Iberoamérica
La presente aportación se focaliza, en este contexto, en la evaluación institucional externa (vinculada o no a la autoevaluación interna) y, por tanto, considera prioritariamente la manera como se evalúan los centros educativos como totalidad y no tanto alguno de sus aspectos (evaluación de la dirección, de los profesores, de los programas, etc.), que también pueden estar considerados. El énfasis también está en conocer la organización y desarrollo del sistema de evaluación. Recoge la visión de 43 especialistas de trece países iberoamericanos sobre las formas de entender y promover la evaluación institucional en sus centros educativos. Sus aportaciones, que deben contextualizarse en las particularidades educativas de sus países (ya presentadas en anteriores informes de la RedAGE), presentan los aspectos generales y normativos de la evaluación, las formas cómo se organiza, los efectos institucionales que tienen y algunas reflexiones, retos y propuestas para la mejora. Su orientación es claramente práctica y se vincula al encuentro anual que la RedAGE realizado los días 16 y 17 de mayo de 2016 en la ciudad de Leiria (Portugal). Allí, los representantes de las organizaciones miembro seleccionaron la temática por su interés actual (con clara vinculación a la mejora de los sistemas educativos y la acreditación institucional), consensuaron la estructura de las aportaciones y realizaron un intercambio de posibles ideas sobre la temática. Se cubre así y como en ocasiones anteriores el propósito fundamental de la RedAGE, como es el de fomentar el intercambio de experiencias, la promoción del conocimiento sobre administración y gestión educativa y la reflexión sobre la práctica de la gestión. La finalidad última sigue siendo la de mejorar el funcionamiento de los centros educativos (y, a través de ellos, de los sistemas educativos), procurando sean de calidad y un instrumento para el cambio profesional y social
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