153 research outputs found

    Facies control on seismites in an alluvial–aeolian system: the Pliocene dunefield of the Teruel half-graben basin (eastern Spain)

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    The recognition of seismically induced soft-sediment deformation structures (SSDS) in sedimentary successions characterized by different facies, and hence by different rheology, is challenging. This is the case for high porosity and high permeability aeolian facies interbedded with muddy wet interdune deposits and alluvial conglomerates and sandstones. Several types of SSDS have been studied in two exposures of the Upper Pliocene (2.9–2.6 Ma) sediments of a fault-bounded intracontinental aeolian dune field in the Teruel Basin (Iberian Chain, eastern Spain). Among SSDS, load and fluid-escape structures, apart from several animal tracks, have been recognized. Those structures show an irregular distribution through the studied stratigraphic sections, being scarce in homogenous aeolian sands and frequent in water-related facies. A detailed study of the distribution and geometry of SSDS and their relationships with respect to the stratigraphic architecture and facies has allowed a critical discrimination of trigger mechanisms, i.e. biological or physical overloading vs. earthquakes. The seismically induced structures are concentrated into seven deformed beds, showing an uneven lateral distribution and geometry closely controlled by the hosting sedimentary facies and their rheology. These seismites resulted from liquefaction during moderate earthquakes (estimated magnitude from 5.0 to 6.8). The most probable seismogenic source was the Sierra del Pobo normal fault zone, located 2 km to the East. Results show how an appropriate recognition of sedimentary facies is crucial to understand the lateral variability of seismites in sedimentary environments characterized by sharp facies changes

    Tomato geranylgeranyl diphosphate synthase isoform 1 is involved in the stress-triggered production of diterpenes in leaves and strigolactones in roots

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    Carotenoids are photoprotectant pigments and precursors of hormones such as strigolactones (SL). Carotenoids are produced in plastids from geranylgeranyl diphosphate (GGPP), which is diverted to the carotenoid pathway by phytoene synthase (PSY). In tomato (Solanum lycopersicum), three genes encode plastid-targeted GGPP synthases (SlG1 to SlG3) and three genes encode PSY isoforms (PSY1 to PSY3). Here, we investigated the function of SlG1 by generating loss-of-function lines and combining their metabolic and physiological phenotyping with gene co-expression and co-immunoprecipitation analyses. Leaves and fruits of slg1 lines showed a wild-type phenotype in terms of carotenoid accumulation, photosynthesis, and development under normal growth conditions. In response to bacterial infection, however, slg1 leaves produced lower levels of defensive GGPP-derived diterpenoids. In roots, SlG1 was co-expressed with PSY3 and other genes involved in SL production, and slg1 lines grown under phosphate starvation exuded less SLs. However, slg1 plants did not display the branched shoot phenotype observed in other SL-defective mutants. At the protein level, SlG1 physically interacted with the root-specific PSY3 isoform but not with PSY1 and PSY2. Our results confirm specific roles for SlG1 in producing GGPP for defensive diterpenoids in leaves and carotenoid-derived SLs (in combination with PSY3) in roots

    Primeros datos magnetoestratigráficos y nuevos yacimientos del Maastrichtiense superior en Huesca (sector noroccidental de la Cuenca de Tremp).

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    Las facies continentales de la Cuenca de Tremp contienen uno de los abundantes registros con vertebrados continentales del final del Cretácico en Europa. Esta área de los Pirineos es un lugar excepcional para estudiar la extinción de los vertebrados continentales en el límite Cretácico-Paleógeno (K-Pg) al ser uno de los pocos lugares de Europa con un registro sedimentario continuo de depósitos continentales del Campaniense superior al Daniense. En el entorno de Serraduy, localizado en el flanco noroeste del sinclinal de Tremp, se han recuperado abundantes restos de vertebrados en los últimos años, destacando la presencia de dinosaurios hadrosáuridos y crocodilomofos eusuquios. Sin embargo, aunque provisionalmente estos yacimientos se han situado en el Maastrichtiense superior, nunca habían sido datados con métodos absolutos o relativos. En este trabajo se exponen por primera vez los resultados preliminares de datación magnetoestratigráfica en este sector, permitiendo asignar estos yacimientos a una edad Maastrichtiense superior dentro de los crones C30n y C29r. Estos resultados confirmarían que los yacimientos de vertebrados del área de Serraduy son unos de los más modernos del Cretácico Superior de Europa estando muy cercanos al límite K-Pg. The continental facies of the Tremp Basin contain one of the best continental vertebrate record from the Upper Cretaceous of Europe. Therefore, this area of the Pyrenees is an exceptional place to study the extinction of continental vertebrates across the Cretaceous-Paleogene boundary (K-Pg) being one of the few places in Europe that has a continuous record of continental deposits ranging from the upper Campanian to Danian. The area of Serraduy, located on the northwest flank of the Tremp syncline, has reported abundant vertebrate remains in recent years, highlighting the presence of hadrosaurid dinosaurs and eusuchian crocodylomorphs. Nevertheless, although these deposits have been provisionally assigned as Maastrichtian, they never had been dated with absolute or relative methods. This paper presents for the first time the preliminary magnetostratigraphic dating results in this sector, allowing to assign these vertebrate sites to a late Maastrichtian age within the polarity chrons C30n and C29r. These results confirm that the vertebrate sites of the Serraduy area are among the most modern in the Upper Cretaceous of Europe, being very close to the K-Pg boundary

    Stakeholders’ Perspective on Groundwater Management in Four Water-Stressed Mediterranean Areas: Priorities and Challenges

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    Recent studies highlight the fragility of the Mediterranean basin against climate stresses and the difficulties of managing the sustainable development of groundwater resources. In this work, the main issues related to groundwater management have been identified from the stake-holder’s perspective in the following four representative water-stressed Mediterranean areas: the coastal aquifer of Comacchio (Italy), the Alto Guadalentín aquifer (Spain), the alluvial aquifer of the Gediz River basin (Turkey), and the Azraq aquifer (Azraq Wetland Reserve, Jordan). This has been achieved by designing a methodology to involve and engage a representative set of stakeholders, including a questionnaire to learn their point of view concerning the current management of aquifer systems and their experience with the already available tools for groundwater resource manage-ment, such as monitoring networks and numerical models. The outcome of the survey has allowed us to identify both particular and common challenges among the four study sites and among the various groups of stakeholders. This information provides valuable insights to improve the transfer of scientific knowledge from the research centers to the authorities managing the groundwater resources and it will help to plan more effective research activities on aquifer management. The proposed methodology could be applied in other aquifers facing similar problems

    A synthetic peptide from transforming growth factor beta type III receptor inhibits liver fibrogenesis in rats with carbon tetrachloride liver injury

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    Transforming growth factor beta1 (TGF-beta1) is a pleiotropic cytokine, which displays potent profibrogenic effects and is highly expressed in fibrotic livers. For this reason, development of TGF-B1 inhibitors might be of great importance to control liver fibrogenesis as well as other undesired side effects due to this cytokine. Potential peptide inhibitors of TGF-beta1 (derived from TGF-beta1 and from its type III receptor) were tested in vitro and in vivo using different assays. Peptides P11 and P12, derived from TGF-beta1, and P54 and P144, derived from its type III receptor, prevented TGF-beta1-dependent inhibition of MV1Lu proliferation in vitro and markedly reduced binding of TGF-beta1 to its receptors. P144 blocked TGF-beta1-dependent stimulation of a reporter gene under the control of human alpha2(I) collagen promoter. Intraperitoneal administration of P144 also showed potent antifibrogenic activity in vivo in the liver of rats receiving CCl4. These rats also showed a significant decrease in the number of activated hepatic stellate cells as compared with those treated with saline only. These results suggest that short synthetic peptides derived from TGF-beta1 type III receptor may be of value in reducing liver fibrosis in chronic liver injury

    The RNA Polymerase PB2 Subunit of Influenza A/HongKong/156/1997 (H5N1) Restrict the Replication of Reassortant Ribonucleoprotein Complexes

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    BACKGROUND: Genetic reassortment plays a critical role in the generation of pandemic strains of influenza virus. The influenza virus RNA polymerase, composed of PB1, PB2 and PA subunits, has been suggested to influence the efficiency of genetic reassortment. However, the role of the RNA polymerase in the genetic reassortment is not well understood. METHODOLOGY/PRINCIPAL FINDINGS: Here, we reconstituted reassortant ribonucleoprotein (RNP) complexes, and demonstrated that the PB2 subunit of A/HongKong/156/1997 (H5N1) [HK PB2] dramatically reduced the synthesis of mRNA, cRNA and vRNA when introduced into the polymerase of other influenza strains of H1N1 or H3N2. The HK PB2 had no significant effect on the assembly of the polymerase trimeric complex, or on promoter binding activity or replication initiation activity in vitro. However, the HK PB2 was found to remarkably impair the accumulation of RNP. This impaired accumulation and activity of RNP was fully restored when four amino acids at position 108, 508, 524 and 627 of the HK PB2 were mutated. CONCLUSIONS/SIGNIFICANCE: Overall, we suggest that the PB2 subunit of influenza polymerase might play an important role for the replication of reassortant ribonucleoprotein complexes
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