611 research outputs found

    Quantization of massive scalar fields over static black string backgrounds

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    The renormalized mean value of the corresponding components of the Energy-Momentum tensor for massive scalar fields coupled to an arbitrary gravitational field configuration having cylindrical symmetry are analytically evaluated using the Schwinger-DeWitt approximation, up to second order in the inverse mass value. The general results are employed to explicitly derive compact analytical expressions for the Energy-Momentum tensor in the particular background of the Black-String spacetime. In the case of the Black String considered in this work, we proof that a violation of the weak energy condition occur at the horizon of the space-time for values of the coupling constant, that include as particular cases the most interesting of minimal and conformal coupling.Comment: 4 page

    Insuficiencia cardíaca congestiva en la clínica de pequeños animales : terapéutica práctica moderna III. Diuréticos y bases xánticas en la clínica diaria

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    En el presente trabajo revisamos los medicamentos de efectos diuréticos más usados en la clínica de animales de compañía y aportamos nuestra experiencia personal en su uso y en la posible utilización de otros productos menos difundidos. Junto a ellos, y como una parte importante del tratamiento de muchos casos de insuficiencia cardíaca congestiva en el perro, una breve revisión de efectos, usos y problemas que pueden aportar las Xantinas de la clínica diaria.This paper reviews the diuretic drugs most often used in small animal practice and discloses the authors' personal experience in their application and the possible use of other less common products. A brief review of effects, uses and problems of Xantines in routine practice is also made, as an important element of the treatment of many cases of Congestivo Heart Failure in dogs

    The SED of Low-Luminosity AGNs at high-spatial resolution

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    The inner structure of AGNs is expected to change below a certain luminosity limit. The big blue bump, footprint of the accretion disk, is absent for the majority of low-luminosity AGNs (LLAGNs). Moreover, recent simulations suggest that the torus, a keystone in the Unified Model, vanishes for nuclei with L_bol < 10^42 erg/s. However, the study of LLAGN is a complex task due to the contribution of the host galaxy, which light swamps these faint nuclei. This is specially critical in the IR range, at the maximum of the torus emission, due to the contribution of the old stellar population and/or dust in the nuclear region. Adaptive optics imaging in the NIR (VLT/NaCo) together with diffraction limited imaging in the mid-IR (VLT/VISIR) permit us to isolate the nuclear emission for some of the nearest LLAGNs in the Southern Hemisphere. These data were extended to the optical/UV range (HST), radio (VLA, VLBI) and X-rays (Chandra, XMM-Newton, Integral), in order to build a genuine spectral energy distribution (SED) for each AGN with a consistent spatial resolution (< 0.5") across the whole spectral range. From the individual SEDs, we construct an average SED for LLAGNs sampled in all the wavebands mentioned before. Compared with previous multiwavelength studies of LLAGNs, this work covers the mid-IR and NIR ranges with high-spatial resolution data. The LLAGNs in the sample present a large diversity in terms of SED shapes. Some of them are very well described by a self-absorbed synchrotron (e.g. NGC 1052), while some other present a thermal-like bump at ~1 micron (NGC 4594). All of them are significantly different when compared with bright Seyferts and quasars, suggesting that the inner structure of AGNs (i.e. the torus and the accretion disk) suffers intrinsic changes at low luminosities.Comment: 8 pages, 5 figures. To appear in the proceedings of "Astrophysics at High Angular Resolution" (AHAR 2011

    Role of Klotho and AGE/RAGE-Wnt/β-catenin signalling pathway on the development of cardiac and renal fibrosis in diabetes

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    Fibrosis plays an important role in the pathogenesis of long-term diabetic complications and contributes to the development of cardiac and renal dysfunction. The aim of this experimental study, performed in a long-term rat model, which resembles type 1 diabetes mellitus, was to investigate the role of soluble Klotho (sKlotho), advanced glycation end products (AGEs)/receptor for AGEs (RAGE), fibrotic Wnt/β-catenin pathway, and pro-fibrotic pathways in kidney and heart. Diabetes was induced by streptozotocin. Glycaemia was maintained by insulin administration for 24 weeks. Serum and urine sKlotho, AGEs, soluble RAGE (sRAGE) and biochemical markers were studied. The levels of Klotho, RAGEs, ADAM10, markers of fibrosis (collagen deposition, fibronectin, TGF-β1, and Wnt/β-catenin pathway), hypertrophy of the kidney and/or heart were analysed. At the end of study, diabetic rats showed higher levels of urinary sKlotho, AGEs and sRAGE and lower serum sKlotho compared with controls without differences in the renal Klotho expression. A significant positive correlation was found between urinary sKlotho and AGEs and urinary albumin/creatinine ratio (uACR). Fibrosis and RAGE levels were significantly higher in the heart without differences in the kidney of diabetic rats compared to controls. The results also suggest the increase in sKlotho and sRAGE excretion may be due to polyuria in the diabetic rats

    Catalytic Performance and Electrophoretic Behavior of an Yttrium-Organic Framework Based on a Tricarboxylic Asymmetric Alkyne

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    A new Y-based metal-organic framework (MOF) GR-MOF-6 with a chemical formula of {[YL(DMF)2]·(DMF)}n {H3L = 5-[(4-carboxyphenyl)ethynyl] isophthalic acid; DMF = N,N-dimethylformamide} has been prepared by a solvothermal route. Structural characterization reveals that this novel material is a three-dimensional MOF in which the coordination of the tritopic ligand to Y(III) metal ions leads to an intercrossing channel system extending over three dimensions. This material has proven to be a very efficient catalyst in the cyanosilylation of carbonyls, ranking second in catalytic activity among the reported rare earth metal-based MOFs described so far but with the lowest required catalyst loading. In addition, its electrophoretic behavior has been studied in depth, providing a zero-charge point between pH 4 and 5, a peak electrophoretic mobility of -1.553 μm cm V-1 s-1, and a ζ potential of -19.8 mV at pH 10.This research has been funded by the State Research Agency (Grants RTC-2016-5239-2, CTQ2017-84334-R, PGC2018-102052-A-C22, and PGC2018-102052-B-C21) of the Spanish Ministry of Science, Innovation and Universities, the European Union [European Regional Development Fund (ERDF)], and Junta de Andalucía (FQM-376 and FQM-394). S.R. acknowledges the Juan de la Cierva Incorporación Fellowship (Grant Agreement IJC2019-038894-I)

    Comparison of RGB-D and IMU-based gesture recognition for human-robot interaction in remanufacturing

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    With product life-cycles getting shorter and limited availability of natural resources, the paradigm shift towards the circular economy is being impulsed. In this domain, the successful adoption of remanufacturing is key. However, its associated process efficiency is to date limited given high flexibility requirements for product disassembly. With the emergence of Industry 4.0, natural human-robot interaction is expected to provide numerous benefits in terms of (re)manufacturing efficiency and cost. In this regard, vision-based and wearable-based approaches are the most extended when it comes to establishing a gesture-based interaction interface. In this work, an experimental comparison of two different movementestimation systems—(i) position data collected from Microsoft Kinect RGB-D cameras and (ii) acceleration data collected from inertial measurement units (IMUs)—is addressed. The results point to our IMU-based proposal, OperaBLE, having recognition accuracy rates up to 8.5 times higher than these of Microsoft Kinect, which proved to be dependent on the movement’s execution plane, subject’s posture, and focal distanc
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