1,337 research outputs found

    Climate-sensitive hydrological drought insurance for irrigated agriculture under deep uncertainty. Insightful results from the Cega River Basin in Spain

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    This paper assesses the feasibility and robustness of an index-based insurance scheme against hydrological droughts under climate change. To this end, we develop a grand ensemble that samples both modeling and scenario uncertainty in the estimation of the insurance risk premium, so to reveal potential unfavorable surprises and minimize regret in the design of the proposed insurance scheme. The grand ensemble combines four microeconomic models and seven GAMLSS models, which are run for three alternative climate change scenarios: stationary climate/no climate change, RCP 2.6, and RCP 8.5. Methods are illustrated with an application to the Cega River Sub-basin (CRS) in central Spain. Results indicate that for a conventional deductible of 30%, the proposed index-based insurance scheme would be actuarially feasible and affordable under all models for the stationary climate scenario (i.e., robust). For climate change scenarios RCP 2.6 and 8.5 and a 30% deductible, the suggested index-based insurance would be actuarially feasible under most models, albeit some outliers point towards potential unfavorable surprises. Lower deductibles decrease feasibility, particularly for deductibles <10%

    Exo1 phosphorylation inhibits exonuclease activity and prevents fork collapse in rad53 mutants independently of the 14-3-3 proteins

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    The S phase checkpoint is crucial to maintain genome stability under conditions that threaten DNA replication. One of its critical functions is to prevent Exo1-dependent fork degradation, and Exo1 is phosphorylated in response to different genotoxic agents. Exo1 seemed to be regulated by several post-translational modifications in the presence of replicative stress, but the specific contribution of checkpoint-dependent phosphorylation to Exo1 control and fork stability is not clear. We show here that Exo1 phosphorylation is Dun1-independent and Rad53-dependent in response to DNA damage or dNTP depletion, and in both situations Exo1 is similarly phosphorylated at multiple sites. To investigate the correlation between Exo1 phosphorylation and fork stability, we have generated phospho-mimic exo1 alleles that rescue fork collapse in rad53 mutants as efficiently as exo1-nuclease dead mutants or the absence of Exo1, arguing that Rad53-dependent phosphorylation is the mayor requirement to preserve fork stability. We have also shown that this rescue is Bmh1–2 independent, arguing that the 14-3-3 proteins are dispensable for fork stabilization, at least when Exo1 is downregulated. Importantly, our results indicated that phosphorylation specifically inhibits the 5' to 3'exo-nuclease activity, suggesting that this activity of Exo1 and not the flap-endonuclease, is the enzymatic activity responsible of the collapse of stalled replication forks in checkpoint mutantsSpanish Ministry of Economy and Competitiveness (MINECO) [FEDER-BFU2013-45182-P to C.M.C., M.S.]; University of Salamanca [KA6H/463AC01 to M.S.]; MINECO, AEI, Xunta de Galicia and FEDER [RYC-2012-10835, BFU2016-78121-P, ED431F-2016/019, ED431B-2016/016 to M.G.B.]; Junta de Castilla y León (JCyL), Program ‘Escalera de Excelencia’ [FEDER-CLU-2017-03]; JCyL Pre-doctoral Fellowship (to A.B.); MINECO Pre-Doctoral Fellowship (to E.C.M.); Xunta de Galicia Pre-doctoral Fellowship (ED481A-2018/041 to R.C.)S

    The tumor suppressor ING1 contributes to epigenetic control of cellular senescence

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    Cellular senescence is an effective tumor-suppressive mechanism that causes a stable proliferative arrest in cells with potentially oncogenic alterations. Here, we have investigated the role of the p33ING1 tumor suppressor in the regulation of cellular senescence in human primary fibroblasts. We show that p33ING1 triggers a senescent phenotype in a p53-dependent fashion. Also, endogenous p33ING1 protein accumulates in chromatin in oncogene- senescent fibroblasts and its silencing by RNA interference impairs senescence triggered by oncogenes. Notably, the ability to induce senescence is lost in a mutant version of p33ING1 present in human tumors. Using specific point mutants, we further show that recognition of the chromatin mark H3K4me3 is essential for induction of senescence by p33ING1. Finally, we demonstrate that ING1-induced senescence is associated to a specific genetic signature with a strong representation of chemokine and cytokine signaling factors, which significantly overlaps with that of oncogene-induced senescence. In summary, our results identify ING1 as a critical epigenetic regulator of cellular senescence in human fibroblasts and highlight its role in control of gene expression in the context of this tumor-protective response. Key words: cellular senescence; chromatin; ING1; p53; histone marks.This work is supported by grants from the Spanish Ministry of Science and Innovation to IP (BFU2006-10882, SAF2009-09031) and FJB (CTQ2008-03115 ⁄ BQU)

    Do Xpert MTB/RIF Cycle Threshold Values Provide Information about Patient Delays for Tuberculosis Diagnosis?

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    INTRODUCTION: Early diagnosis and initiation to appropriate treatment is vital for tuberculosis (TB) control. The XpertMTB/RIF (Xpert) assay offers rapid TB diagnosis and quantitative estimation of bacterial burden through Cycle threshold (Ct) values. We assessed whether the Xpert Ct value is associated with delayed TB diagnosis as a potential monitoring tool for TB control programme performance. MATERIALS AND METHODS: This analysis was nested in a prospective study under the routine TB surveillance procedures of the National TB Control Program in Manhica district, Maputo province, Mozambique. Presumptive TB patients were tested using smear microscopy and Xpert. We explored the association between Xpert Ct values and self-reported delay of Xpert-positive TB patients as recorded at the time of diagnosis enrolment. Patients with >60 days of TB symptoms were considered to have long delays. RESULTS: Of 1,483 presumptive TB cases, 580 were diagnosed as TB of whom 505 (87.0%) were due to pulmonary TB and 302 (94.1%) were Xpert positive. Ct values (range, 9.7-46.4) showed a multimodal distribution. The median (IQR) delay was 30 (30-45) days. Ct values showed no correlation with delay (R2 = 0.001, p = 0.621), nor any association with long delays: adjusted odds ratios (AOR) (95% confidence interval [CI]) comparing to >28 cycles 0.99 (0.50-1.96; p = 0.987) for 23-28 cycles, 0.93 (0.50-1.74; p = 0.828) for 16-22 cycles; and 1.05 (0.47-2.36; p = 0.897) for <16 cycles. Being HIV-negative (AOR [95% CI]), 2.05 (1.19-3.51, p = 0.009) and rural residence 1.74 (1.08-2.81, p = 0.023), were independent predictors of long delays. CONCLUSION: Xpert Ct values were not associated with patient delay for TB diagnosis and cannot be used as an indicator of TB control program performance

    Oxysterol-induced soluble endoglin release and its involvement in hypertension

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    [Background]: Ischemia in the placenta is considered the base of the pathogenesis of preeclampsia, a pregnancy-specific syndrome in which soluble endoglin (sEng) is a prognostic marker and plays a pathogenic role. Here, we investigated the effects of hypoxia and the downstream pathways in the release of sEng. [Methods and Results]: Under hypoxic conditions, the trophoblast-like cell line JAR showed an increase in sEng parallel to an elevated formation of reactive oxygen species. Because reactive oxygen species are related to the formation of oxysterols, we assessed the effect of 22-(R)-hydroxycholesterol, a natural ligand of the liver X receptor (LXR), and the LXR synthetic agonist T0901317. Treatment of JAR cells or human placental explants with 22-(R)-hydroxycholesterol or T0901317 resulted in a clear increase in sEng that was dependent on LXR. These LXR agonists induced an increased matrix metalloproteinase-14 expression and activity and a significant reduction of its endogenous inhibitor, tissue inhibitor of metalloproteinase-3. In addition, mice treated with LXR agonists underwent an increase in the plasma sEng levels, concomitant with an increase in arterial pressure. Moreover, transgenic mice overexpressing sEng displayed high blood pressure. Finally, administration of an endoglin peptide containing the consensus matrix metalloproteinase-14 cleavage site G-L prevented the oxysterol-dependent increase in arterial pressure and sEng levels in mice. [Conclusions]: These studies provide a clue to the involvement of the LXR pathway in sEng release and its pathogenic role in vascular disorders such as preeclampsia. © 2012 American Heart Association, Inc.This work was supported by grants from the Ministerio de Ciencia e Innovación of Spain (SAF2010-61827 to Dr Bernabeu, SAF2011-29244 to Dr Castrillo, and SAF2010-15881 to Dr Lopez-Novoa), Genoma España (MEICA; Dr Bernabeu), Instituto Reina Sofía de Investigación Nefrológica (FRIAT; Dr Lopez-Novoa), Junta de Castilla and Leon (Excellence Group Grant GR-100 to Dr Lopez-Novoa), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER; Dr Bernabeu), and Red de Investigación Cooperativa en Enfermedades Renales (REDINREN; Dr Lopez-Novoa). CIBERER and REDINREN are initiatives of the Instituto de Salud Carlos III of Spain supported by European Regional Development Funds (FEDER). The cardiovascular phenotyping unit, including the telemetry equipment, has been acquired with the support of FEDER. Dr Llano is recipient of a Ramón y Cajal Research contract.Peer Reviewe

    CFD modelling of particle matter dispersion in a real hot-spot

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    Urban air quality is one of the main environmental concerns. The interaction between atmosphere and buildings induces complex flows within the streets and squares. This fact joint with the traffic emissions produce a heterogeneous distribution of pollutants with high gradients of concentration. The main objective of this work is to obtain high resolution maps of particle matter concentration using a CFD model so as to analyze air quality and population exposure. This study is focused on a heavily trafficked roundabout in Madrid (Fernandez Ladreda square). To achieve this objective, CFD modelling coupled with detailed emissions of PM10 and PM2.5 and outputs from WRF meteorological mesoscale model is performed. Emissions from vehicle exhaust and particle resuspension are considered with a resolution of 5 m x 5 m. The simulated mesoscale vertical profiles of wind velocity and turbulent kinetic energy, previously checked with onsite meteorological measurements, are used as boundary conditions. The effects of urban vegetation are modelled and moreover, the CFD modelling is improved implementing vehicle induced turbulence as a source of turbulence on the roads. Modelling results are evaluated for several periods of summer and winter by using data from experimental campaigns carried out in this zone in the framework of the TECNAIRE research project

    TWEAK Activates the Non-Canonical NFκB Pathway in Murine Renal Tubular Cells: Modulation of CCL21

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    TWEAK is a member of the TNF superfamily of cytokines that contribute to kidney tubulointerstitial injury. It has previously been reported that TWEAK induces transient nuclear translocation of RelA and expression of RelA-dependent cytokines in renal tubular cells. Additionally, TWEAK induced long-lasting NFκB activation suggestive of engagement of the non-canonical NFκB pathway. We now explore TWEAK-induced activation of NFκB2 and RelB, as well as expression of CCL21, a T-cell chemotactic factor, in cultured murine tubular epithelial cells and in healthy kidneys in vivo. In cultured tubular cells, TWEAK and TNFα activated different DNA-binding NFκB complexes. TWEAK-induced sustained NFκB activation was associated with NFκB2 p100 processing to p52 via proteasome and nuclear translocation and DNA-binding of p52 and RelB. TWEAK, but not TNFα used as control), induced a delayed increase in CCL21a mRNA (3.5±1.22-fold over control) and CCL21 protein (2.5±0.8-fold over control), which was prevented by inhibition of the proteasome, or siRNA targeting of NIK or RelB, but not by RelA inhibition with parthenolide. A second NFκB2-dependent chemokine, CCL19, was upregulates by TWEAK, but not by TNFα. However, both cytokines promoted chemokine RANTES expression (3-fold mRNA at 24 h). In vivo, TWEAK induced nuclear NFκB2 and RelB translocation and CCL21a mRNA (1.5±0.3-fold over control) and CCL21 protein (1.6±0.5-fold over control) expression in normal kidney. Increased tubular nuclear RelB and tubular CCL21 expression in acute kidney injury were decreased by neutralization (2±0.9 vs 1.3±0.6-fold over healthy control) or deficiency of TWEAK (2±0.9 vs 0.8±0.6-fold over healthy control). Moreover, anti-TWEAK treatment prevented the recruitment of T cells to the kidney in this model (4.1±1.4 vs 1.8±1-fold over healthy control). Our results thus identify TWEAK as a regulator of non-canonical NFκB activation and CCL21 expression in tubular cells thus promoting lymphocyte recruitment to the kidney during acute injury

    Vertical distribution of Atlantic bluefin tuna Thunnus thynnus and bonito Sarda sarda larvae is related to temperature preference

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    As part of the endeavor aiming at the domestication of Atlantic bluefin tuna (BFT; Thunnus thynnus), first sexual maturity in captivity was studied by documenting its occurrence and by characterizing the key hormones of the reproductive axis: follicle stimulating hormone (FSH) and luteinizing hormone (LH). The full length sequence encoding for the related hormone b-subunits, bftFSHb and bftLHb, were determined, revealing two bftFSHb mRNA variants, differing in their 50 untranslated region. A quantitative immuno-dot-blot assay to measure pituitary FSH content in BFT was developed and validated enabling, for the first time in this species, data sets for both LH and FSH to be compared. The expression and accumulation patterns of LH in the pituitary showed a steady increase of this hormone, concomitant with fish age, reaching higher levels in adult females compared to males of the same age class. Conversely, the pituitary FSH levels were elevated only in 2Y and adult fish. The pituitary FSH to LH ratio was consistently higher (>1) in immature than in maturing or pubertal fish, resembling the situation in mammals. Nevertheless, the results suggest that a rise in the LH storage level above a minimum threshold may be an indicator of the onset of puberty in BFT females. The higher pituitary LH levels in adult females over males may further support this notion. In contrast three year-old (3Y) males were pubertal while cognate females were still immature. However, it is not yet clear whether the advanced puberty in the 3Y males was a general feature typifying wild BFT populations or was induced by the culture conditions. Future studies testing the effects of captivity and hormonal treatments on precocious maturity may allow for improved handling of this species in a controlled environment which would lead to more cost-efficient farmingVersión del edito
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