2,418 research outputs found

    VISIR-VLT Images of the Water Maser Emitting Planetary Nebula K 3-35

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    K3-35 is an extremely young bipolar planetary nebula that contains a precessing bipolar jet and a small (radius 80 AU) water maser equatorial ring. We have obtained VISIR- VLT images of K 3-35 in the PAH1 ({\lambda}=8.6 {\mu}m), [S iv] ({\lambda}=10.6 {\mu}m), and SiC ({\lambda}=11.85 {\mu}m) filters to analize the mid-IR morphology and the temperature structure of its dust emission. The images show the innermost nebular regions undetected at optical wavelegths and the precessing bipolar jets. The temperature map shows variations in the temperature in the equatorial zone and in regions associated to its jets.Comment: 2 pages, 2 figures, 283 IAU Symp. Planetary Nebulae an Eye to the Futur

    TBL1 is required for the mesenchymal phenotype of transformed breast cancer cells

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    The epithelial-to-mesenchymal transition (EMT) and its reversion (MET) are related to tumor cell dissemination and migration, tumor circulating cell generation, cancer stem cells, chemoresistance, and metastasis formation. To identify chromatin and epigenetic factors possibly involved in the process of EMT, we compare the levels of expression of epigenetic genes in a transformed human breast epithelial cell line (HMEC-RAS) versus a stable clone of the same cell line expressing the EMT master regulator ZEB1 (HMEC-RAS-ZEB1). One of the factors strongly induced in the HMEC-RAS-ZEB1 cells was Transducin beta-like 1 (TBL1), a component of the NCoR complex, which has both corepressor and coactivator activities. We show that TBL1 interacts with ZEB1 and that both factors cooperate to repress the promoter of the epithelial gene E-cadherin (CDH1) and to autoactivate the ZEB1 promoter. Consistent with its central role, TBL1 is required for mesenchymal phenotypes of transformed breast epithelial and breast cancer cell lines of the claudin-low subtype. Importantly, a high expression of the TBL1 gene correlates with poor prognosis and increased proportion of metastasis in breast cancer patients, indicating that the level of TBL1 expression can be used as a prognostic marker.Ministerio de Economía y Competitividad BFU2014-53543-P, BFU2017-85420-RJunta de Andalucía BIO-32

    VISIR-VLT high resolution study of the extended emission of four obscured post-AGB candidates

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    The onset of the asymmetry of planetary nebulae (PNe) is expected to occur during the late Asymptotic Giant Branch (AGB) and early post-AGB phases of low- and intermediate-mass stars. Among all post-AGB objects, the most heavily obscured ones might have escaped the selection criteria of previous studies detecting extreme axysimmetric structures in young PNe. Since the most heavily obscured post-AGB sources can be expected to descend from the most massive PN progenitors, these should exhibit clear asymmetric morphologies. We have obtained VISIR-VLT mid-IR images of four heavily obscured post-AGB objects barely resolved in previous Spitzer IRAC observations to analyze their morphology and physical conditions across the mid-IR. The VISIR-VLT images have been deconvolved, flux calibrated, and used to construct RGB composite pictures as well as color and optical depth maps that allow us to study the morphology and physical properties of the extended emission of these sources. We have detected extended emission from the four objects in our sample and resolved it into several structural components that are greatly enhanced in the temperature and optical depth maps. They reveal the presence of asymmetry in three young PNe (IRAS 15534-5422, IRAS 17009-4154, and IRAS 18454+0001), where the asymmetries can be associated with dusty torii and slightly bipolar outflows. The fourth source (IRAS 18229-1127), a possible post-AGB star, is better described as a rhomboidal detached shell. The heavily obscured sources in our sample do not show extreme axisymmetric morphologies. This is at odds with the expectation of highly asymmetrical morphologies in post-AGB sources descending from massive PN progenitors. The sources presented in this paper may be sampling critical early phases in the evolution of massive PN progenitors, before extreme asymmetries develop.Comment: 9 pages, 4 figure

    Building a Composite Indicator to Measure Environmental Sustainability Using Alternative Weighting Methods

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    Environmental sustainability in agriculture can be measured through the construction of composite indicators. However, this is a challenging task because these indexes are heavily dependent on how the individual base indicators are weighted. The main aim of this paper is to contribute to the existing literature regarding the robustness of subjective (based on experts’ opinions) weighting methods when constructing a composite indicator for measuring environmental sustainability at the farm level. In particular, the study analyzes two multi-criteria techniques, the analytic hierarchy process and the recently developed best-worst method, as well as the more straightforward point allocation method. These alternative methods have been implemented to empirically assess the environmental performance of irrigated olive farms in Spain. Data for this case study were collected from a panel of 22 experts and a survey of 99 farms. The results obtained suggest that there are no statistically significant differences in the weights of the individual base indicators derived from the three weighting methods considered. Moreover, the ranking of the sampled farms, in terms of their level of environmental sustainability measured through the composite indicators proposed, is not dependent on the use of the different weighting methods. Thus, the results support the robustness of the three weighting methods considered

    Nature of the f_0(600) from its N_c dependence at two loops in unitarized Chiral Perturbation Theory

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    By using unitarized two-loop Chiral Perturbation Theory partial waves to describe pion-pion scattering we find that the dominant component of the lightest scalar meson does not follow the q-qbar dependence on the number of colors that, in contrast, is obeyed by the lightest vectors. The method suggests that a subdominant q-qbar component of the f_0(600) possibly originates around 1 GeV.Comment: 4 pages, 1 Figure. To appear in Phys. Rev. Let

    Precautionary savings as an instrument to hedge the risk of hydrological drought in irrigated agriculture

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    This paper explores the use of precautionary savings as a new risk management instrument that can be implemented to hedge hydrological drought risk in irrigated agriculture, a risk currently not covered by any policy instrument. For this purpose, the Drought Savings Account (DSA) is proposed as a personal savings account to which farmers make regular contributions, with withdrawals allowed in the event of irrigation water supply gaps in order to guarantee a minimum income. The implementation of the DSA is empirically assessed in a Mediterranean-climate irrigation district using an innovative simulation approach. Based on the results obtained, the DSA has proved to be a theoretically suitable policy instrument that can overcome the problems hindering the implementation of agricultural insurance, managing the risk in a more cost-effective way. This cost-effectiveness is a key advantage of precautionary savings over agricultural insurance, since the former instrument minimizes moral hazard and adverse selection problems, and the transaction costs of risk-sharing. Moreover, in this context, precautionary savings may play a significant role as an efficient climate change adaptation measure since the self-insurance strategy adopted does not distort the signals underlying farmers’ own risk exposure, leading to better individual assessment and an adequate management of water supply gaps

    Acute necrotizing esophagitis (black esophagus) with secondary severe stenosis

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    Se presenta el caso clínico de un paciente de 67 años, con antecedentes de diabetes mellitus, fibrilación auricular e insuficiencia renal crónica, quien desarrolló cuadro de cetoacidosis diabética y sepsis severa, presentando posteriormente una esofagitis necrotizante aguda, y desarrollo luego de estenosis esofágica que requirió tratamiento con prótesis esofágica metálica autoexpandible con buen resultado clínico.Q4We report the case of a 67 years old patient with a history of diabetes mellitus, atrial fibrillation and chronic renal failure, who developed diabetic ketoacidosis and severe sepsis, later presenting an acute necrotizing esophagitis, and then a esophageal stenosis requiring treatment with self-expanding esophageal prosthesis with good clinical results.https://orcid.org/0000-0002-9219-4548https://orcid.org/0000-0003-2938-7731Revista Internacional - Indexad

    ToCo: An ontology for representing hybrid telecommunication networks

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    The TOUCAN project proposed an ontology for telecommunication networks with hybrid technologies – the TOUCAN Ontology (ToCo), available at http://purl.org/toco/, as well as a knowledge design pattern Device-Interface-Link (DIL) pattern. The core classes and relationships forming the ontology are discussed in detail. The ToCo ontology can describe the physical infrastructure, quality of channel, services and users in heterogeneous telecommunication networks which span multiple technology domains. The DIL pattern is observed and summarised when modelling networks with various technology domains. Examples and use cases of ToCo are presented for demonstration

    The predictive power of farmers’ risk attitude measures elicited by experimental methods

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    Aim of study: Farmers’ behavior is shaped by their individual attitudes towards risk. Consequently, an understanding of the heterogeneous risk attitudes among farmers is key to predicting their decision-making. Therefore, there is a need for reliable methods to assess individuals’ risk attitudes. The main objective of this paper was to contribute to the existing literature about the external validity of risk attitude measures obtained with diverse experimental methods.Area of study: Irrigated agriculture in a Mediterranean climate region.Material and methods: Two different experimental methods widely applied in the agricultural sector were used to elicit farmers’ risk attitudes in a sample of irrigators in southern Spain: the Eckel and Grossman lottery-choice task and a self-assessment general risk question. We evaluated the explanatory power of both measures for the farming risk borne by farmers, using an approach based on dispersion measures of farming returns.Main results: Results revealed stability across these elicitation methods, but the study yielded no evidence of statistical correlation with the farming risk actually borne by farmers, suggesting that it may not be advisable to use these methods for directly predicting farmers’ decision-making in modeling exercises.Research highlights: The most relevant innovation of this paper was the validation approach followed, based on measures assessing the overall level of farming risk borne by individual producers, and the complementary analyses controlling for key variables that could affect farmer risk-taking
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