Sources, transformations and controls of dissolved organic matter (DOM) in a Mediterranean catchment = Fonts, transformacions i controls de la matèria orgànica dissolta (DOM) a una conca Mediterrània

[spa]La materia orgánica disuelta (DOM) es transformada activamente en las aguas continentales. La cantidad y calidad de la DOM vienen definidas por el paisaje, que controla tanto su origen como los procesos que la transforman. Esta tesis busca desentrañar las fuentes, controles y transformaciones de la DOM en una cuenca mediterránea mediante el análisis de la variabilidad natural de la DOM y el uso de diseños experimentales de laboratorio. La región mediterránea presenta una marcada estacionalidad caracterizada por la intermitencia de flujo, como la que presentan los torrentes efímeros que drenan la cuenca estudiada, mientras que el cuerpo de agua receptor, es una laguna dominada por vegetación sumergida. La calidad de la DOM en los torrentes está definida por las propiedades del paisaje y varía de manera estacional. En otoño, la DOM presenta un carácter aromático relacionado con variables hidromorfológicas. En invierno y primavera, se acentúa el origen microbiano de la DOM y surgen diferencias espaciales ligadas a los diferentes tipos y usos del suelo. El efecto de los procesos de foto-y biodegradación son más fuertes sobre las fuentes alóctonas de DOM que sobre las autóctonas. Estas diferencias coinciden con los trabajos que cuestionan el paradigma clásico que relaciona la DOM alóctona con materiales no reactivos y la DOM autóctona con materiales lábiles. Las tasas de cambio instantáneas en las propiedades de la DOM muestran que no se puede asumir que los cambios cualitativos durante su degradación sigan un patrón regular en el tiempo. La adición de pequeñas cantidades de carbono lábil no incrementa la descomposición de la DOM natural presente en diferentes cuerpos de agua. No se han encontrado por lo tanto evidencias de la existencia de efecto priming en aguas dulces. Además, la disponibilidad de nutrientes y de mayor superficie para favorecer la unión celular no parece tener ningún papel significativo en el efecto priming. Diferentes fuentes y procesos se reflejan en la variabilidad de la DOM de la laguna. El ciclo fenológico de la vegetación sumergida y los pulsos de las aguas torrenciales de los torrentes efímeros son los principales determinantes de la calidad de la DOM.[eng]Dissolved organic matter (DOM) is a primary source of organic carbon in aquatic ecosystems. Inland waters actively transform DOM, having a relevant effect on the regional and global carbon budgets. DOM quantity and quality determine the efficiency of any transformation pathway and are intensely defined by the landscape, as it controls both the DOM origin and the transformations processes acting over it. This thesis aims to unravel the sources, controls and transformations of DOM in a Mediteranean catchment using both laboratory experimental designs to address the effects of degradation processes, and field monitoring approaches to study the natural DOM variability. The Mediterranean region presents a marked hydrological seasonality characterized by intermittent surface water flows like the ephemeral washes of the studied catchment. The receiving water body is, as most natural lentic waters in the Mediterranean region, a shallow system dominated by submerged vegetation. The characteristics of the study catchment allow assessing the interplay between the landscape properties, contrasted DOM sources and different mechanisms of control over DOM quality and quantity. The quality of the DOM present in ephemeral washes is influenced by landscape factors, and this influence varies in a seasonal basis. Two seasonal periods are distinguished in terms of DOM quality: autumn, showing an aromatic character related with hydromorphological variables, and winter-spring, with a microbial-like DOM derived from in-situ processes and linked to specific soil types and land uses. The effect of the biodegradation and the combined effect of photo- and biodegradation processes is stronger on allochthonous than on autochthonous DOM sources. These differences are related to distinct previous exposure to degradation pathways and to specific composition of each source. These results are in agreement with an increasing number of works questioning the classical paradigm linking allochthonous DOM with unreactive and autochthonous DOM with labile materials. The instantaneous rates of change in DOM properties showed that qualitative changes during degradation cannot be assumed to follow a regular decay pattern. The addition of small inputs of labile carbon to lake water does not enhance the decomposition rate of the DOM present in the receiving lake water, and thus no evidences of priming effect are found. Neither nutrient availability nor the available surface for cell attachment have any significant effect on the occurrence of priming effect. The fingerprint of different sources and processing mechanisms are reflected in the variability of the DOM in the studied lagoon. The phenological cycle of submerged vegetation and the pulses of torrential water inputs from the ephemeral washes are the main drivers of DOM quality in the lagoon

Persistence of ferroelectricity above the Curie temperature at the surface of Pb(Zn1/3Nb2/3)O3-12%PbTiO3

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).Relaxor-based ferroelectrics have been known for decades to possess a relatively thick surface layer ("skin") that is distinct from its interior. Yet while there is consensus about its existence, there are controversies about its symmetry, phase stability, and origin. In an attempt to clarify these issues, we have examined the surface layer of PZN-12%PT. While the bulk transitions from a ferroelastically twinned tetragonal ferroelectric state with in-plane polarization to a cubic paraphase at Tc=200C, the skin layer shows a robust labyrinthine nanodomain structure with out-of-plane polarization that persists hundreds of degrees above the bulk Curie temperature. Cross-sectional transmission electron microscopy analysis shows that the resilience of the skin's polarization is correlated with a compositional imbalance: lead vacancies at the surface are charge-compensated by niobium enrichment; the excess of Nb5+ - a small ion with d0 orbital occupancy - stabilizes the ferroelectricity of the skin layer.We acknowledge financial support from the Spanish Ministerio de Ciencia e Innovación (Contracts No. MAT2010-17771, No. MAT2011-29081-C02, and No. FIS2013-48668- C2-1-P), and the Generalitat de Catalunya (Project 2014 SGR 1216). N.D. thanks the Spanish Ministerio de Ciencia e Innovación for the Ramon y Cajal Research Grant (No. RYC-2010-06365), and G.C. acknowledges an ERC Starting Grant (Project reference: ERC-SG-308023). ICN2 acknowledges support from the Severo Ochoa Program (MINECO, Grant SEV-2013-0295).Peer Reviewe

La casa Solsona: paradigma de las artes decorativas del Modernismo en Cervera

[spa]A finales del siglo XIX el gusto por el Modernismo se extendió por todo el territorio catalán, siendo muchas las poblaciones que adoptaron su riqueza decorativa, tanto en las obras de nueva planta como en las reformas de antiguas casas solariegas. Este es el caso de la casa que presentamos, conocida como 'Can Solsona', localizada en Cervera (Lleida). Su propietario, Feliciano Solsona y Matz, político e importante empresario agrícola, con motivo de su enlace con Montserrat Duran i Sanpere, mandó reformar en 1905 la casa familiar, realizando una importante reestructuración de los espacios interiores y renovando por completo su decoración de acuerdo con la nueva moda modernista. Para ello contrató a importantes artistas e industriales venidos de Barcelona. La casa ha continuado en manos de la familia y no ha sufrido apenas intervenciones a lo largo de los años, conservando la decoración original. Este estudio se centra en analizar todos estos elementos que convierten a Can Solsona en una obra de arte total.[eng] At the end of the XIX century, the taste for Modernism became increasingly popular throughout Catalonia. Many villages embraced its decorative richness both building new houses and renovating the old manors. This is the case of the house presented in this paper, known as "Can Solsona" of Cervera (Lleida). Its owner, Feliciano Solsona Matz, was an important politician and agricultural businessman who in 1905, on the occasion of his wedding to Montserrat Duran y Santpere, commissioned a renovation of the family mansion making an important restructuring of the interior spaces and completely renewing its decoration according to the new modernist fashion. For this purpose he hired important artists and construction professionals from Barcelona. The house has remained in the hands of the family until today without suffering any major changes over the years and preserving its original decoration. This study focuses on performing an analysis of all the elements that make Can Solsona a total work of art

Domótica con el PLC S7-200

2002/200

Evaluation of anti-inflammatory activity of food compounds using zebrafish

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/128014The principal aim of this work was to optimize and apply a zebrafish experimental model for the screening of anti-inflammatory substances present in the Mediterranean diet. The zebrafish is an organism widely used in various fields of experimental biology. The inflammation is easily inducible, reproducible and visualized in their early stages of development. Specifically, the migration of neutrophils to the injured caudal fin, one of the first steps of the inflammatory response, is quantitatively measured by image analysis. The anti-inflammatory effect of natural compounds can be evaluated as a decrease of migration. Adverse effects triggered by inflammation are mainly mediated by reactive oxygen species. The anti-oxidant activity of compounds was evaluated in zebrafish embryo measuring their protective effect against tert-butyl hydroperoxide toxicity. Several phenolic compounds have been assayed. Our results showed that the compounds with the greatest decrease on neutrophil migration were chlorogenic acid and cyanidin. The activity of these two polyphenols was quite similar to that observed with anti-inflammatory drugs (indomethacin, piroxicam) and NADPH oxidase inhibitor compounds (dibenzoidolium, apocynin). The anti-inflammatory and the anti-oxidant activity of the assayed polyphenols did not show a clear correlation

Carbon dioxide efflux during the flooding phase of temporary ponds

Small water bodies, such as temporary ponds, have a high carbon processing potential. Nevertheless, despite the global occurrence of these systems, the carbon effluxes from such water bodies have been largely overlooked. In this study, we examined the intra- and intersystem variability of carbon dioxide (CO2) effluxes from a set of Mediterranean temporary ponds during the flooding phase, a hot-spot for biogeochemical cycling in temporary systems. The CO2 effluxes showed higher variability among the various sections of each pond (i.e., inundated, emerged-unvegetated and emerged-vegetated) than among the ponds. The emerged-vegetated sections showed the highest CO2 effluxes per unit area and tended to drive the total effluxes at the whole-ecosystem scale. The mean CO2 efflux (121.3 ± 138.1 mmol m 2 d 1) was in the upper range for freshwater ecosystems. The CO2 effluxes were not related to catchment properties but rather to the organic content of the sediments, especially in the emerged sections of the ponds. Our results indicate that temporary ponds, especially their emerged sections, are important sources of CO2 to the atmosphere, highlighting the need to include the dry phases of these and other temporary aquatic systems in regional carbon budgets

Zebrafish as a model for developmental toxicity assessment

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/67430The zebrafish embryo has emerged as promising alternative model for traditional in vivo developmental toxicological screening due to their advantageous characteristics as their small size and transparency. In this paper, we reviewed the applicability of the zebrafish embryo model in some relevant areas to human t oxicology as developmental toxicity, cardiovascular toxicity and neurotoxicity (behavioral assessment). Despite the promising results, further optimization and testing of more substances as well as a harmonized methodology is needed to streamline the metho ds and make the assay conducive to medium - throughput

Modulation and Protection Effects of Antioxidant Compounds against Oxidant Induced Developmental Toxicity in Zebrafish

The antioxidant effect of compounds is regularly evaluated by in vitro assays that do not have the capability to predict in vivo protective activity or to determine their underlying mechanisms of action. The aim of this study was to develop an experimental system to evaluate the in vivo protective effects of different antioxidant compounds, based on the zebrafish embryo test. Zebrafish embryos were exposed to tert-butyl hydroperoxide (tBOOH), tetrachlorohydroquinone (TCHQ) and lipopolysaccharides from Escherichia coli (LPS), chemicals that are known inducers of oxidative stress in zebrafish. The developmental toxic effects (lethality or dysmorphogenesis) induced by these chemicals were modulated with n-acetyl l-cysteine and Nω-nitro l-arginine methyl ester hydrochloride, dimethyl maleate and dl-buthionine sulfoximine in order to validate the oxidant mechanism of oxidative stress inducers. The oxidant effects of tBOOH, TCHQ, and LPS were confirmed by the determination of significant differences in the comparison between the concentration-response curves of the oxidative stress inducers and of the modulators of antioxidant status. This concept was also applied to the study of the effects of well-known antioxidants, such as vitamin E, quercetin, and lipoic acid. Our results confirm the zebrafish model as an in vivo useful tool to test the protective effects of antioxidant compounds

Emissions from dry inland waters are a blind spot in the global carbon cycle

A large part of the world's inland waters, including streams, rivers, ponds, lakes and reservoirs is subject to occasional, recurrent or even permanent drying. Moreover, the occurrence and intensity of drying events are increasing in many areas of the world because of climate change, water abstraction, and land use alteration. Yet, information on the gaseous carbon (C) fluxes from dry inland waters is scarce, thus precluding a comprehensive assessment of C emissions including all, also intermittently dry, inland waters. Here, we review current knowledge on gaseous C fluxes from lotic (streams and rivers) and lentic (ponds, lakes, and reservoirs) inland waters during dry phases and the response to rewetting, considering controls and sources as well as implications of including 'dry' fluxes for local and global scale estimates. Moreover, knowledge gaps and research needs are discussed. Our conservative estimates indicate that adding emissions from dry inland waters to current global estimates of CO2 emissions from inland waters could result in an increase of 0.22 Pg C year−1, or ~10% of total fluxes. We outline the necessary conceptual understanding to successfully include dry phases in a more complete picture of inland water C emissions and identify potential implications for global C cycle feedbacks

¿La presencia de cannabis en saliva es suficiente para confirmar la conducción bajo sus efectos?

In Spain today, the presence of drugs in saliva is considered sufficient to confirm driving under its effects, although the concentration obtained is near the threshold limits of the analytic system. This legal approach entails accepting that there is no concentration threshold below which the drug does not affect driving capacity, and that oral fluid concentration is a reliable parameter to value its effect. In the case of cannabis, some experimental studies in humans and in intercepted drivers have suggested blood tetrahydrocannabinol concentrations from which effects that can affect driving are observed. Furthermore, correlation between tetrahydrocannabinol concentration in oral fluid and in blood shows a high variability. To resolve disagreement between these types of samples, some countries have harmonized their legislation establishing presumptive oral fluid cannabis values at the same time as blood concentration limit values from which it can be clearly considered that driving capacities are affected. In this work, we consider that the Spanish road safety law should, following trends adopted by other countries, establish a limit value for cannabis and other abused drugs, which allows evidence that the driver has not only consumed the drug, but is also driving under its effects