1,908 research outputs found

    Inundaciones y cambio climático

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    Las inundaciones de los ríos han sucedido de forma tradicional en numerosos ríos de la Península Ibérica, aportando grandes beneficios en la agricultura y en la disponibilidad de recursos hídricos, pero en la historia más reciente han originado graves daños en personas y bienes haciendo que hoy día predomine una percepción de las inundaciones como “catástrofes”. En el origen del incremento de la frecuencia de las inundaciones hay que mencionar la intensificación del uso del territorio, sellando y compactando los suelos haciendo que aumenten las escorrentías rápidas, y la alteración hidromorfológica de los ríos, concentrando las aguas y favoreciendo la ocurrencia de avenidas y desbordamientos. En el incremento exponencial de las pérdidas que las inundaciones han originado en los últimos años hay que referirse a la intensa ocupación de las riberas de los ríos y sus llanuras de inundación por personas y actividades económicas, con un desarrollo en dichas zonas no compatible con la dinámica fluvial. El cambio climático es considerado un factor de riesgo adicional muy variable según las regiones, y la estimación de sus efectos sobre las inundaciones presenta todavía numerosas incertidumbres. Atendiendo a ello se revisan algunos estudios e informes relacionados con el fenómeno de las inundaciones y su posible relación con el cambio climático, y se propone la restauración de los sistemas fluviales y la restricción de usos en las zonas inundables como estrategias más acertadas para hacer frente a la mencionada problemática de las inundaciones y a la incertidumbre creada con el cambio climático. El análisis de los sucesivos paradigmas históricos planteados por el hombre frente a las inundaciones de los ríos pone en evidencia el interés de cambiar unas estrategias de “defensa” en contra de ellas, tratando de evitar que ocurran, por otras de “convivencia” con las mismas gestionando de la forma más apropiada el riesgo de los daños que pueden generar, atendiendo al espíritu de las Directivas europeas Marco del Agua y de evaluación y gestión del riesgo de la inundación

    Characterization of the GacS/GacA system in the virulence regulation in Pseudomonas savastanoi.

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    The two-component regulatory system GacS/GacA is one of the main mechanisms for global regulation in bacteria. GacS/GacA is a highly conserved system that has been studied in many pathogenic bacteria. However, its characterization has been mainly focused on pathogenic bacteria of herbaceous plants. Despite previous works have reported that GacS/GacA regulates the expression of virulence factors, its role in virulence varies among different species and strains. The aim of this work was the identification of virulence factors regulated by the GacS/GacA system in the model bacterium Pseudomonas savastanoi pv. savastanoi (Psv), causal agent of olive knot disease. To this end, we generated a gacA deletion mutant in the strain Psv NCPPB 3335, whose transcriptomic profile was further analyzed using a massive RNA sequencing (RNA-seq) strategy. The bioinformatic analysis of RNA-seq data showed that the Psv GacS/GacA system regulates a large number of genes, including some virulence factors already described, such as those related to the type III secretion system, the biosynthesis of phytohormones and the catabolism of aromatic compounds, among others. In addition, small Rsm-type RNAs and regulatory proteins (RsmA) were identified in the regulatory cascade of the GacS/GacA system. Finally, the involvement of some of the virulence factors of Psv NCPP 3335 were further studied through different phenotypic assays, such as plant virulence assays, induction of hypersensitive response, leaf adhesion tests and translocation of type III effectors. Results obtained in this work indicate that GacS/GacA system presents a role in regulation of virulence factors of Psv NCPPB 3335.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Caracterización del sistema de dos componentes GacS/GacA en Pseudomonas savastanoi pv. savastanoi

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    El sistema de dos componentes GacS/GacA es considerado uno de los principales mecanismos de regulación global en bacterias. Mayoritariamente, los trabajos de caracterización del sistema GacS/GacA se han centrado en bacterias patógenas de plantas herbáceas, donde su papel en virulencia es variable entre distintas especies y cepas. En este trabajo, nos hemos centrado en la identificación de los factores de virulencia regulados por el sistema GacS/GacA en la bacteria modelo Pseudomonas savastanoi pv. savastanoi (Psv), agente causal de la tuberculosis del olivo. Para ello, hemos llevado a cabo un análisis de secuenciación masiva del RNA (RNA-seq) utilizando la cepa silvestre Psv NCPPB 3335 y un mutante gacA. El análisis bioinformático de los resultados obtenidos muestra que el sistema GacS/GacA de Psv participa en la regulación de un gran número de genes, incluyendo varios factores de virulencia previamente descritos, como el sistema de secreción tipo III, las fitohormonas o una región genómica implicada en el catabolismo de compuesto aromáticos. Además, se han identificado los pequeños RNAs tipo Rsm y las proteínas reguladoras (RsmA) que participan en la cascada de regulación del sistema GacS/GacA. Finalmente, hemos realizado ensayos fenotípicos (ensayos de virulencia en planta, inducción de respuesta hipersensible, síntesis de auxinas, adhesión a hojas y translocación de efectores) para determinar la implicación de algunos de los factores de virulencia identificados por RNAseq en la virulencia de Psv NCPP 3335

    Uncovering cold disruption of the circadian clock in poplar

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    Dormancy is an adaptive mechanism that allows woody plants to survive at low temperatures during the winter. Disruption of circadian clock genes in winter or under low temperatures, both in long days as in short days, were described in our group few years ago (Ramos et al., 2005). Basic mechanisms of the circadian clock function are similar in herbaceous as well as in woody plants although there are differences in their response to low temperatures (Bieniawska et al., 2008). Woody plants growing in daylight conditions should have a specific transcriptional control above the circadian clock genes, which is responsible of their constitutive transcriptional activation observed under low temperatures conditions. In order to understand this regulatory process, we are analyzing the behavior of a circadian clock gene in poplar. To this aim, we have isolated its promoter region and fused to the luciferase reporter gene. This construct has been transformed into Populus tremula x P. alba 717-1B4 INRA clone. Here we present the characterization of these transgenic lines under different conditions of light and temperature

    El sistema de dos componentes GacS/GacA regula la expresión de factores de virulencia y patogenicidad en Pseudomonas savastanoi pv. savastanoi NCPPB3335.

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    GacS/GacA es uno de los principales sistemas de regulación global en bacterias gramnegativas. Trabajos previos realizados con bacterias patógenas de plantas herbáceas han descrito cómo el sistema GacS/GacA interviene en la regulación de diversos factores de virulencia. Sin embargo, la regulación de estos factores muestra variabilidad no solo entre especies, sino también entre cepas. En este trabajo, hemos estudiado el papel regulador del sistema GacS/GacA en la virulencia y patogenicidad de la cepa NCPPB 3335 de P. savastanoi pv. savastanoi (Psv), agente causal de la enfermedad conocida como tuberculosis del olivo. Para ello, se construyó un mutante por deleción del gen gacA, en la cepa Psv NCPPB3335, cuyo perfil transcriptómico se analizó globalmente mediante una estrategia de secuenciación masiva de ARN (RNA-seq). El análisis bioinformático de los datos de RNA-seq mostró que el sistema GacS/GacA de Psv regula la expresión de genes relacionados con el sistema de secreción tipo III (T3SS), la síntesis de auxinas, locomoción y quimiotaxis bacteriana, y la degradación de compuestos fenólicos asociada a la invasión de huéspedes leñosos. Además, se identificaron variaciones en los niveles de expresión de pequeños ARN de tipo Rsm y proteínas reguladoras (RsmA), elementos que intervienen en la cascada de regulación del sistema GacS/GacA. Con la intención de profundizar en la caracterización de este sistema, se han llevado a cabo ensayos fenotípicos complementantes, como ensayos de virulencia en plantas, inducción de respuesta hipersensible, sensibilidad a peróxido de hidrógeno y translocación de efectores tipo III.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    A Comparison of Total Thoracoscopic and Robotic Surgery for Lung Cancer Lymphadenectomy

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    Background: Robotic-assisted thoracic surgery (RATS) is used increasingly frequently in major lung resection for early stage non-small-cell lung cancer (NSCLC) but has not yet been fully evaluated. The aim of this study was to compare the surgical outcomes of lymph node dissection (LND) performed via RATS with those from totally thoracoscopic (TT) four-port videothoracoscopy. Methods: Clinical and pathological data were collected retrospectively from patients with clinical stage N0 NSCLC who underwent pulmonary resection in the form of lobectomy or segmental resection between June 2010 and November 2022. The assessment criteria were number of mediastinal lymph nodes and number of mediastinal stations dissected via the RATS approach compared with the four-port TT approach. Results: A total of 246 pulmonary resections with LND for clinical stages I-II NSCLC were performed: 85 via TT and 161 via RATS. The clinical characteristics of the patients were similar in both groups. The number of mediastinal nodes dissected and mediastinal stations dissected was significantly higher in the RATS group (TT: mean ± SD, 10.72 ± 3.7; RATS, 14.74 ± 6.3 [p < 0.001]), except in the inferior mediastinal stations. There was no difference in terms of postoperative complications. Conclusions: In patients with early stage NSCLC undergoing major lung resection, the quality of hilomediastinal LND performed using RATS was superior to that performed using TT

    The role of PGC-1α and mitochondrial biogenesis in kidney diseases

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    Chronic kidney disease (CKD) is one of the fastest growing causes of death worldwide, emphasizing the need to develop novel therapeutic approaches. CKD predisposes to acute kidney injury (AKI) and AKI favors CKD progression. Mitochondrial derangements are common features of both AKI and CKD and mitochondria-targeting therapies are under study as nephroprotective agents. PGC-1α is a master regulator of mitochondrial biogenesis and an attractive therapeutic target. Low PGC-1α levels and decreased transcription of its gene targets have been observed in both preclinical AKI (nephrotoxic, endotoxemia, and ischemia-reperfusion) and in experimental and human CKD, most notably diabetic nephropathy. In mice, PGC-1α deficiency was associated with subclinical CKD and predisposition to AKI while PGC-1α overexpression in tubular cells protected from AKI of diverse causes. Several therapeutic strategies may increase kidney PGC-1α activity and have been successfully tested in animal models. These include AMP-activated protein kinase (AMPK) activators, phosphodiesterase (PDE) inhibitors, and anti-TWEAK antibodies. In conclusion, low PGC-1α activity appears to be a common feature of AKI and CKD and recent characterization of nephroprotective approaches that increase PGC-1α activity may pave the way for nephroprotective strategies potentially effective in both AKI and CKD.Supported by ISCIII-FIS, FEDER funds, CP14/00133, PI16/02057, PI16/01900, PI18/01366, PI19/00588, PI19/00815, DTS18/00032, ERA-PerMed-JTC2018 (KIDNEY ATTACK AC18/00064 and PERSTIGAN AC18/00071, ISCIII-RETIC REDinREN RD016/0009, Sociedad Española de Nefrología, Fundacion Renal Iñigo Álvarez de Toledo (FRIAT), ISCIII Miguel Servet (A.B.S., M.D.S.-N.), ISCIII Sara Borrell (J.M.M.-M.), Comunidad de Madrid CIFRA2 B2017/BMD-3686 (M.F.-B. and D.M.-S.

    Knots untie: molecular determinants involved in knot formation Induced by Pseudomonas savastanoi in woody hosts

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    The study of the molecular basis of tree diseases is lately receiving a renewed attention, especially with the emerging perception that pathogens require specific pathogenicity and virulence factors to successfully colonize woody hosts. Pathosystems involving woody plants are notoriously difficult to study, although the use of model bacterial strains together with genetically homogeneous micropropagated plant material is providing a significant impetus to our understanding of the molecular determinants leading to disease. The gammaproteobacterium Pseudomonas savastanoi belongs to the intensively studied Pseudomonas syringae complex, and includes three pathogenic lineages causing tumorous overgrowths (knots) in diverse economically relevant trees and shrubs. As it occurs with many other bacteria, pathogenicity of P. savastanoi is dependent on a type III secretion system, which is accompanied by a core set of at least 20 effector genes shared among strains isolated from olive, oleander, and ash. The induction of knots of wild-type size requires that the pathogen maintains adequate levels of diverse metabolites, including the phytohormones indole-3-acetic acid and cytokinins, as well as cyclic-di-GMP, some of which can also regulate the expression of other pathogenicity and virulence genes and participate in bacterial competitiveness. In a remarkable example of social networking, quorum sensing molecules allow for the communication among P. savastanoi and other members of the knot microbiome, while at the same time are essential for tumor formation. Additionally, a distinguishing feature of bacteria from the P. syringae complex isolated from woody organs is the possession of a 15 kb genomic island (WHOP) carrying four operons and three other genes involved in degradation of phenolic compounds. Two of these operons mediate the catabolism of anthranilate and catechol and, together with another operon, are required for the induction of full-size tumors in woody hosts, but not in non-woody micropropagated plants. The use of transposon mutagenesis also uncovered a treasure trove of additional P. savastanoi genes affecting virulence and participating in diverse bacterial processes. Although there is still much to be learned on what makes a bacterium a successful pathogen of trees, we are already untying the knots.This work was supported by the Spanish Plan Nacional I+D+i grants AGL2014-53242-C2-1-R and AGL2014-53242-C2-2-R from the Spanish Ministerio de Economía y Competitividad (MINECO) and was co-financed by FEDER. AP was supported by a FPU Ph.D. fellowship and AM-P and EC-P by FPI Ph.D. fellowships from the Spanish Ministerio de Educación, Cultura y Deporte (MECD) and MINECO

    HuR biological function involves RRM3-mediated dimerization and RNA binding by all three RRMs

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    HuR/ELAVL1 is an RNA-binding protein involved in differentiation and stress response that acts primarily by stabilizing messenger RNA (mRNA) targets. HuR comprises three RNA recognition motifs (RRMs) where the structure and RNA binding of RRM3 and of full-length HuR remain poorly understood. Here, we report crystal structures of RRM3 free and bound to cognate RNAs. Our structural, NMR and biochemical data show that RRM3 mediates canonical RNA interactions and reveal molecular details of a dimerization interface localized on the -helical face of RRM3. NMR and SAXS analyses indicate that the three RRMs in full-length HuR are flexibly connected in the absence of RNA, while they adopt a more compact arrangement when bound to RNA. Based on these data and crystal structures of tandem RRM1,2- RNA and our RRM3-RNA complexes, we present a structural model of RNA recognition involving all three RRM domains of full-length HuR. Mutational analysis demonstrates that RRM3 dimerization and RNA binding is required for functional activity of fulllength HuR in vitro and to regulate target mRNAs levels in human cells, thus providing a fine-tuning for HuR activity in vivo.Peer reviewe
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