Equivalence between various versions of the self-dual action of the Ashtekar formalism

Different aspects of the self-dual (anti-self-dual) action of the Ashtekar canonical formalism are discussed. In particular, we study the equivalences and differences between the various versions of such an action. Our analysis may be useful for the development of an Ashtekar formalism in eight dimensions.Comment: 10 pages, Latex, minor correction

Wedge splitting test method: quantification of influence of glued marble plates by two-parameter fracture mechanics

In the present paper, the well-known wedge splitting test (WST) is applied on specimens with different geometries (S= 150, 200, 300 mm) and variants of the specimens’ configurations. K-calibration (B1) and T-stress (B2) calibration curves for such specimens are introduced. The objective was to compare and discuss the values of the calibration curves dependent on the specimen’s geometries and on three different specimens' configurations: homogenous specimen; specimen with marble plates forming the groove for load application and specimen with glued marble plates

Self-dual gravity and self-dual Yang-Mills in the context of Macdowell-Mansouri formalism

In this work we propose an action which unifies self-dual gravity and self-dual Yang-Mills in the context of the Macdowell-Mansouri formalism. We claim that such an action may be used to find the S-dual action for both self-dual gravity and self-dual Yang-Mills.Comment: 8 pages, Revtex, no figures, submitted to Phys. Rev.

Algoritmo Evolutivo Multi-Objectivo para la Toma de Decisiones Interactiva en Optimización Dinámica

Debido al creciente interés en el análisis de datos en streaming en entornos Big Data para la toma de decisiones, cada vez es más común la aparición de problemas de optimización dinámica que involucran dos o más objetivos en conflicto. Sin embargo, los enfoques que combinan optimización dinámica multi-objetivo con la articulación de preferencias para la toma de decisiones son todavía escasos. En este artículo, proponemos un nuevo algoritmo de optimización dinámica multi-objetivo llamado InDM2, que permite incorporar preferencias del experto (humano) de cara a la toma de decisiones para guiar el proceso de búsqueda. Con InDM2, el decisor no solo puede expresar sus preferencias mediante uno o más puntos de referencia (que definen la la región de interés deseada), sino que estos puntos también se pueden modificar de manera interactiva. La propuesta incorpora métodos para mostrar gráficamente las diferentes aproximaciones de la región de interés obtenidas durante el proceso de optimización. El decisor puede así inspeccionar y cambiar, en tiempo de optimización, la región de interés de acuerdo con la información mostrada. Las principales características de InDM2 son descritas y se analiza su funcionamiento mediante casos de uso académicos.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Iso-spectral potential and inflationary quantum cosmology

Using the factorization approach of quantum mechanics, we obtain a family of isospectral scalar potentials for power law inflationary cosmology. The construction is based on a scattering Wheeler-DeWitt solution. These iso-spectrals have new features, they give a mechanism to end inflation, as well as the possibility to have new inflationary epochs. The procedure can be extended to other cosmological models.Comment: 14 pages, 5 figure

Hepatic encephalopathy-associated cerebral vasculopathy in acute-on-chronic liver failure: Alterations on endothelial factor release and influence on cerebrovascular function

The acute-on-chronic liver failure (ACLF) is a syndrome characterized by liver decompensation, hepatic encephalopathy (HE) and high mortality. We aimed to determine the mechanisms implicated in the development of HE-associated cerebral vasculopathy in a microsurgical liver cholestasis (MHC) model of ACLF. Microsurgical liver cholestasis was induced by ligating and extracting the common bile duct and four bile ducts. Sham-operated and MHC rats were maintained for eight postoperative weeks Bradykinin-induced vasodilation was greater in middle cerebral arteries from MHC rats. Both Nω-Nitro-L-arginine methyl ester and indomethacin diminished bradykinin-induced vasodilation largely in arteries from MHC rats. Nitrite and prostaglandin (PG) F releases were increased, whereas thromboxane (TX) B was not modified in arteries from MHC. Expressions of endothelial nitric oxide synthase (eNOS), inducible NOS, and cyclooxygenase (COX) 2 were augmented, and neuronal NOS (nNOS), COX-1, PGI synthase, and TXA S were unmodified. Phosphorylation was augmented for eNOS and unmodified for nNOS. Altogether, these endothelial alterations might collaborate to increase brain blood flow in HE. 1α 2 2 2This research was funded by the Ministerio de Economía y Competitividad (SAF2016-80305-P), CiberCV (Grant number: CB16/11/00286), the European Regional Development Grant (FEDER) (Comunidad de Madrid, grant number B2017/BMD- 3676), and R C D projects for young researchers, Universidad Autónoma de Madrid-Comunidad de Madrid (SI1-PJI-2019- 00321). RR-D received a fellowship from Juan de la Cierva Program (IJCI-2017-31399)

Noncommutative Topological Theories of Gravity

The possibility of noncommutative topological gravity arising in the same manner as Yang-Mills theory is explored. We use the Seiberg-Witten map to construct such a theory based on a SL(2,C) complex connection, from which the Euler characteristic and the signature invariant are obtained. This gives us a way towards the description of noncommutative gravitational instantons as well as noncommutative local gravitational anomalies.Comment: 17+1 pages, LaTeX, no figures, some clarifications, comments and references added, style improve

Synthesis, antioxidant properties and neuroprotection of α-phenyl-tert-butylnitrone derived HomoBisNitrones in in vitro and in vivo ischemia models

We herein report the synthesis, antioxidant power and neuroprotective properties of nine homo-bis-nitrones HBNs1–9 as alpha-phenyl-N-tert-butylnitrone (PBN) analogues for stroke therapy. In vitro neuroprotection studies of HBNs1–9 against Oligomycin A/Rotenone and in an oxygen-glucose-deprivation model of ischemia in human neuroblastoma cell cultures, indicate that (1Z,1′Z)-1,1′-(1,3-phenylene)bis(N-benzylmethanimine oxide) (HBN6) is a potent neuroprotective agent that prevents the decrease in neuronal metabolic activity (EC = 1.24 ± 0.39 μM) as well as necrotic and apoptotic cell death. HBN6 shows strong hydroxyl radical scavenger power (81%), and capacity to decrease superoxide production in human neuroblastoma cell cultures (maximal activity = 95.8 ± 3.6%), values significantly superior to the neuroprotective and antioxidant properties of the parent PBN. The higher neuroprotective ability of HBN6 has been rationalized by means of Density Functional Theory calculations. Calculated physicochemical and ADME properties confirmed HBN6 as a hit-agent showing suitable drug-like properties. Finally, the contribution of HBN6 to brain damage prevention was confirmed in a permanent MCAO setting by assessing infarct volume outcome 48 h after stroke in drug administered experimental animals, which provides evidence of a significant reduction of the brain lesion size and strongly suggests that HBN6 is a potential neuroprotective agent against stroke.We would like to thank Soledad Martinez Montero for the excellent technical assistance. This work was supported by grants from the Spanish Ministry of Economy and Competitiveness (SAF2015-65586-R to JMC; CTQ2016- 78205-P and CTQ2016-81797-REDC to IF, and NEUROCENTRO-CM S2017/BMD3760 to RMM and DNG), and Camilo José Cela University (UCJC-2018-04) to MJOG. DDI thanks the University of Alcalá and Spanish Ministry of Science, Innovation and Universities for pre-doctoral FPU grants. BCG thanks the Spanish Ministr

Insights into the catalytic production of hydrogen from propane in the presence of oxygen: cooperative presence of vanadium and gold catalysts

[EN] H-2 and propylene can be obtained from propane and oxygen in defect using appropriate catalysts. Meanwhile propylene is formed from propane via oxidative or non-oxidative dehydrogenation, molecular hydrogen can be obtained from several reactions such as propane dehydrogenation, coke formation and water gas shift. It has been observed that a gold catalyst hardly activates propane and no H-2 was detected, whereas using vanadium oxide a relatively high concentration of propylene and H-2 was obtained. Interestingly, the simultaneous use of vanadium oxide and gold has meant a higher hydrogen production, higher in a 40% than that of the catalyst containing only vanadium oxide. This performance has been. related to the capacity of gold to activate CO in the water gas shift reaction. (C) 2015 Elsevier B.V. All rights reserved.The authors would like to acknowledge the DGICYT in Spain (CTQ2012-37925-C03-1, CTQ2012-37925-C03-2 and CTQ2012-37984-C02-01) for financial support We also thank the University of Valencia and SCSIE-UV for assistance. J.M. Lopez would also like to thank Spanish MICINN and CSIC for funding his Ramon y Cajal contract (RYC-2009-04483).Garcia, T.; Lopez, JM.; López Nieto, JM.; Sanchis, R.; Dejoz, A.; Vazquez, MI.; Solsona, B. (2015). Insights into the catalytic production of hydrogen from propane in the presence of oxygen: cooperative presence of vanadium and gold catalysts. Fuel Processing Technology. 134:290-296. https://doi.org/10.1016/j.fuproc.2015.02.012S29029613

On S-duality in (2+1)-Chern-Simons Supergravity

Strong/weak coupling duality in Chern-Simons supergravity is studied. It is argued that this duality can be regarded as an example of superduality. The use of supergroup techniques for the description of Chern-Simons supergravity greatly facilitates the analysis.Comment: 10+1 pages, latex, no figure