An X-ray Survey of Wolf-Rayet Stars in the Magellanic Clouds. II. The ROSAT PSPC and HRI Datasets

Wolf-Rayet (WR) stars in the Magellanic Clouds (MCs) are ideal for studying the production of X-ray emission by their strong fast stellar winds. We have started a systematic survey for X-ray emission from WR stars in the MCs using archival Chandra, ROSAT, and XMM-Newton observations. In Paper I, we reported the detection of X-ray emission from 29 WR stars using Chandra ACIS observations of 70 WR stars in the MCs. In this paper, we report the search and analysis of archival ROSAT PSPC and HRI observations of WR stars. While useful ROSAT observations are available for 117 WR stars in the MCs, X-ray emission is detected from only 7 of them. The detection rate of X-ray emission from MCs WR stars in the ROSAT survey is much smaller than in the Chandra ACIS survey, illustrating the necessity of high angular resolution and sensitivity. LMC-WR 101-102 and 116 were detected by both ROSAT and Chandra, but no large long-term variations are evident.Comment: To appear in The Astrophysical Journal Supplement. A version with full resolution figures can be obtained upon request to [email protected]

Arginine-rich peptides destabilize the plasma membrane, consistent with a pore formation translocation mechanism of cell-penetrating peptides

Recent molecular-dynamics simulations have suggested that the arginine-rich HIV Tat peptides translocate by destabilizing and inducing transient pores in phospholipid bilayers. In this pathway for peptide translocation, Arg residues play a fundamental role not only in the binding of the peptide to the surface of the membrane, but also in the destabilization and nucleation of transient pores across the bilayer. Here we present a molecular-dynamics simulation of a peptide composed of nine Args (Arg-9) that shows that this peptide follows the same translocation pathway previously found for the Tat peptide. We test experimentally the hypothesis that transient pores open by measuring ionic currents across phospholipid bilayers and cell membranes through the pores induced by Arg-9 peptides. We find that Arg-9 peptides, in the presence of an electrostatic potential gradient, induce ionic currents across planar phospholipid bilayers, as well as in cultured osteosarcoma cells and human smooth muscle cells. Our results suggest that the mechanism of action of Arg-9 peptides involves the creation of transient pores in lipid bilayers and cell membranes.Facultad de Ciencias Exacta

Classical and semi-classical energy conditions

The standard energy conditions of classical general relativity are (mostly) linear in the stress-energy tensor, and have clear physical interpretations in terms of geodesic focussing, but suffer the significant drawback that they are often violated by semi-classical quantum effects. In contrast, it is possible to develop non-standard energy conditions that are intrinsically non-linear in the stress-energy tensor, and which exhibit much better well-controlled behaviour when semi-classical quantum effects are introduced, at the cost of a less direct applicability to geodesic focussing. In this article we will first review the standard energy conditions and their various limitations. (Including the connection to the Hawking--Ellis type I, II, III, and IV classification of stress-energy tensors). We shall then turn to the averaged, nonlinear, and semi-classical energy conditions, and see how much can be done once semi-classical quantum effects are included.Comment: V1: 25 pages. Draft chapter, on which the related chapter of the book "Wormholes, Warp Drives and Energy Conditions" (to be published by Springer), will be based. V2: typos fixed. V3: small typo fixe

Large scale grain mantle disruption in the Galactic Center

We present observations of C2H5OH toward molecular clouds in Sgr A, Sgr B2 and associated with thermal and non-thermal features in the Galactic center. C2H5OH emission in Sgr A and Sgr B2 is widespread, but not uniform. C2H5OH emission is much weaker or it is not detected in some molecular clouds in both complexes, in particular those with radial velocities between 70 and 120 km/s. While most of the clouds associated with the thermal features do not show C2H5OH emission, that associated with the Non-Thermal Radio Arc shows emission. The fractional abundance of C2H5OH in most of the clouds with radial velocities between 0 and 70 km/s in Sgr A and Sgr B2 is relatively high, of few 1e-8. The C2H5OH abundance decreases by more than one order of magnitude (aprox. 1e-9) in the clouds associated with the thermal features. The large abundance of C2H5OH in the gas-phase indicates that C2H5OH has formed in grains and released to gas-phase by shocks in the last aprox. 1e5 years.Comment: In press in Astrophysical Journal Letters 7 pages, 1 table, 1 figur

Cognitive Effects of Combined Amisulpride and Quetiapine Treatment in Patients With Refractory Schizophrenia: A Naturalistic, Prospective Study.

Background: There are different treatment options, but little support of evidence in the treatment of patients with resistant schizophrenia. In this study we used antipsychotic polypharmacy (AP) comprising 1200 mg of amisulpride and 600 mg of quetiapine, using neurocognitive evaluations to measure clinical change. Study Question: The AP of amisulpride and quetiapine implicará una mejoría clínica en pacientes with resistant schizophrenia que reflejará especialmente en una mejoría cognitiva. Study Design: Naturalistic and prospective study. 26 patients with no biological response to medication, high social maladjustment, a long history of the disease, to whom Kane's and Brenner's criteria for treatment-resistant schizophrenia were applied and assessed by a battery of neurocognitive evaluations desde a pre-treatment baseline y a los six months treatment. Measures and Outcomes: La mejoría cognitiva implicara una mejora significativa in the cognitive test: Stroop test, WAIS Coding Subtest, Continuous Trail Making Test (CTMT) desde la línea base y los 6 meses de tratamiento. También implicará mejoría en las escalas de Calgary Depression Scale (CDS), Simpson-Angus Scale (SAS) and a Visual Analogue Scale (EVA) con las que fueron evaluados en línea base, a los 3 meses y a los 6 meses. Results: Subjects, after six months treatment with amisulpride and quetiapine, did statistically significant difference in the assessed areas: WAIS Coding Subtest (P <0.001), CTMT A & B (CTMTA P< 0,034; CTMTB P< 0,000) and in Stroop tests: Word (P< 0,001), word-color (P< 0,007) and interference (P< 0,039). Furthermore they showed a statistically significant difference in CDS (P< 0,002), SAS (P< 0,019), and EVA (P < 0.001). Conclusion: The results of this report show a cognitive and clinical improvement in refractory patients after the administration of amisulpride and quetiapine.pre-print523 K

Incorporating chemical signalling factors into cell-based models of growing epithelial tissues

In this paper we present a comprehensive computational framework within which the effects of chemical signalling factors on growing epithelial tissues can be studied. The method incorporates a vertex-based cell model, in conjunction with a solver for the governing chemical equations. The vertex model provides a natural mesh for the finite element method (FEM), with node movements determined by force laws. The arbitrary Lagrangian–Eulerian formulation is adopted to account for domain movement between iterations. The effects of cell proliferation and junctional rearrangements on the mesh are also examined. By implementing refinements of the mesh we show that the finite element (FE) approximation converges towards an accurate numerical solution. The potential utility of the system is demonstrated in the context of Decapentaplegic (Dpp), a morphogen which plays a crucial role in development of the Drosophila imaginal wing disc. Despite the presence of a Dpp gradient, growth is uniform across the wing disc. We make the growth rate of cells dependent on Dpp concentration and show that the number of proliferation events increases in regions of high concentration. This allows hypotheses regarding mechanisms of growth control to be rigorously tested. The method we describe may be adapted to a range of potential application areas, and to other cell-based models with designated node movements, to accurately probe the role of morphogens in epithelial tissues

5G Visualization: The METIS-II Project Approach

[EN] One of the main objectives of the METIS-II project was to enable 5G concepts to reach and convince a wide audience from technology experts to decision makers from non-ICT industries. To achieve this objective, it was necessary to provide easy-to-understand and insightful visualization of 5G. This paper presents the visualization platform developed in the METIS-II project as a joint work of researchers and artists, which is a 3D visualization tool that allows viewers to interact with 5G-enabled scenarios, while permitting simulation driven data to be intuitively evaluated. The platform is a game-based customizable tool that allows a rapid integration of new concepts, allows real-time interaction with remote 5G simulators, and provides a virtual reality-based immersive user experience. As a result, the METIS-II visualization platform has successfully contributed to the dissemination of 5G in different fora and its use will be continued after METIS-II.This work has been performed in the framework of the H2020/5G-PPP project METIS-II cofunded by the EU. The authors wish to thank the rest of METIS-II colleagues who contributed to the development of the METIS-II visualization platform.Martín-Sacristán, D.; Herranz Claveras, C.; Monserrat Del Río, JF.; Szczygiel, A.; Kuruvatti, NP.; Garcia-Roger, D.; Prado-Alvarez, D.... (2018). 5G Visualization: The METIS-II Project Approach. Mobile Information Systems. 1-8. https://doi.org/10.1155/2018/2084950S18Zyda, M. (2005). From visual simulation to virtual reality to games. Computer, 38(9), 25-32. doi:10.1109/mc.2005.297Johnson, C. (2004). Top scientific visualization research problems. IEEE Computer Graphics and Applications, 24(4), 13-17. doi:10.1109/mcg.2004.20Tullberg, H., Popovski, P., Li, Z., Uusitalo, M. A., Hoglund, A., Bulakci, O., … Monserrat, J. F. (2016). The METIS 5G System Concept: Meeting the 5G Requirements. IEEE Communications Magazine, 54(12), 132-139. doi:10.1109/mcom.2016.1500799cmLee, B., Riche, N. H., Isenberg, P., & Carpendale, S. (2015). More Than Telling a Story: Transforming Data into Visually Shared Stories. IEEE Computer Graphics and Applications, 35(5), 84-90. doi:10.1109/mcg.2015.99Yi, J. S., Kang, Y. ah, & Stasko, J. (2007). Toward a Deeper Understanding of the Role of Interaction in Information Visualization. IEEE Transactions on Visualization and Computer Graphics, 13(6), 1224-1231. doi:10.1109/tvcg.2007.70515Campbell, B. D. (2016). Immersive Visualization to Support Scientific Insight. IEEE Computer Graphics and Applications, 36(3), 17-21. doi:10.1109/mcg.2016.6

Structural and compositional properties of brown dwarf disks: the case of 2MASS J04442713+2512164

In order to improve our understanding of substellar formation, we have performed a compositional and structural study of a brown dwarf disk. We present the result of photometric, spectroscopic and imaging observations of 2MASS J04442713+2512164, a young brown dwarf (M7.25) member of the Taurus association. Our dataset, combined with results from the literature, provides a complete coverage of the spectral energy distribution from the optical to the millimeter including the first photometric measurement of a brown dwarf disk at 3.7mm, and allows us to perform a detailed analysis of the disk properties. The target was known to have a disk. High resolution optical spectroscopy shows that it is intensely accreting, and powers a jet and an outflow. The disk structure is similar to that observed for more massive TTauri stars. Spectral decomposition models of Spitzer/IRS spectra suggest that the mid-infrared emission from the optically thin disk layers is dominated by grains with intermediate sizes (1.5micron). Crystalline silicates are significantly more abondant in the outer part and/or deeper layers of the disk, implying very efficient mixing and/or additional annealing processes. Sub-millimeter and millimeter data indicate that most of the disk mass is in large grains (>1mm)Comment: 17 pages, 10 figures, 7 tables, accepted for A&

El subproducto ensilado de alcachofa como alimento para ovejas

La utilización de subproductos agroindustriales de alcachofa permite reducir el contenido de alfalfa y cereales en la ración de las ovejas. Antes de utilizar una materia prima no convencional como alimento, se deben conocer los efectos que su inclusión va a tener sobre la salud del animal, el rendimiento productivo y la calidad de los productos derivados.Pérez Baena, I.; Piquer, O.; Ferrer, A.; Trujillo, AJ.; Jaramillo, DP.; Rodríguez Garcia, M. (2011). El subproducto ensilado de alcachofa como alimento para ovejas. Albeitar. (143):46-48. http://hdl.handle.net/10251/38832S464814