On the Conformal Geometry of Transverse Riemann-Lorentz Manifolds

Physical reasons suggested in \cite{Ha-Ha} for the \emph{Quantum Gravity Problem} lead us to study \emph{type-changing metrics} on a manifold. The most interesting cases are \emph{Transverse Riemann-Lorentz Manifolds}. Here we study the conformal geometry of such manifolds

Thermophysical study of 2-acetylthiophene: experimental and modelled results

Several thermophysical properties have been studied for 2-acetylthiophene: (i) vapour pressure was determined at temperatures within 336.16–445.02 K; (ii) density, speed of sound, static permittivity, refractive index, surface tension, and kinematic viscosity were measured at p = 0.1 MPa and at temperatures from 278.15 K (or 283.15 K for the refractive index) to 338.15 K; (iii) volumetric properties were also determined at temperatures in the (283.15–338.15) K range and at pressures up to 65.0 MPa. From these experimental values, different derivative properties have been calculated such as enthalpy of vaporization, isobaric expansibility, isothermal and isentropic compressibility, dipole moment, entropy and enthalpy of surface formation, and dynamic viscosity. All experimental properties were correlated and the results were explained through the intermolecular interactions. Moreover PC-SAFT EoS was used to model the thermodynamic behaviour of the compound. Finally, this EoS combined with the Density Gradient Theory allowed obtaining the influence parameter for the surface tension of 2-acetylthiophene

Density functional theory for nearest-neighbor exclusion lattice gasses in two and three dimensions

To speak about fundamental measure theory obliges to mention dimensional crossover. This feature, inherent to the systems themselves, was incorporated in the theory almost from the beginning. Although at first it was thought to be a consistency check for the theory, it rapidly became its fundamental pillar, thus becoming the only density functional theory which possesses such a property. It is straightforward that dimensional crossover connects, for instance, the parallel hard cube system (three-dimensional) with that of squares (two-dimensional) and rods (one-dimensional). We show here that there are many more connections which can be established in this way. Through them we deduce from the functional for parallel hard (hyper)cubes in the simple (hyper)cubic lattice the corresponding functionals for the nearest-neighbor exclusion lattice gases in the square, triangular, simple cubic, face-centered cubic, and body-centered cubic lattices. As an application, the bulk phase diagram for all these systems is obtained.Comment: 13 pages, 13 figures; needs revtex

pVT behaviour of hydrophilic and hydrophobic eutectic solvents

Among the basic principles of green chemistry is the search for less harmful alternative solvents than conventional solvents. Knowing the thermophysical properties of fluids under different pressure and temperature conditions is essential to propose them. Herein, we present data on the densities at several pressures (from 0.1 to 65 MPa) and temperatures (from 283.15 to 338.15 K) of two deep eutectic solvents with hydrophilic characteristics (choline chloride + ethylene glycol or glycerol) and two eutectic solvents with hydrophobic characteristics (camphor + thymol or menthol). We used the Tait equation of state to correlate and calculate derived properties. Moreover, we modelled the mixtures with the PC-SAFT equation of state. The results showed that the hydrophilic solvents were more compact than the hydrophobic ones. The former exhibited an abnormal thermal behaviour of the isobaric thermal expansibility. The deviations in the correlation of densities with the thermodynamic model were between 0.5 and 3%. They were lower for the mixtures with weaker interactions

Highly sensitive SERS quantification of organophosphorous chemical warfare agents: A major step towards the real time sensing in the gas phase

A surface-enhanced Raman scattering (SERS)-based sensor was developed for the label-free real-time gas phase detection of dimethyl methylphosphonate (DMMP); a surrogate molecule of the G-series nerve agents which are of particular concern due to its extreme toxicity, persistence and previous deployment. The SERS platform was designed using simple elements (Au nano-particles) coated with a citrate layer, and a self-assembly procedure that yields near- optimum distances among the nanoparticles. The citrate coating acts as an effective trap of the target molecules on the immediate vicinity of the Au nanoparticle surface under ambient conditions by reversible hydrogen bonding type interactions. For the first time, we have been able to detect sub-ppm concentrations of DMMP in gas phase (130 parts-per-billion), as might be found on potential emergency scenarios. The high sensitivity, simple preparation and reusability of the SERS platforms developed in this work open up the way for immediate detection of chemical warfare agents in realistic scenarios

DiVinE-CUDA - A Tool for GPU Accelerated LTL Model Checking

In this paper we present a tool that performs CUDA accelerated LTL Model Checking. The tool exploits parallel algorithm MAP adjusted to the NVIDIA CUDA architecture in order to efficiently detect the presence of accepting cycles in a directed graph. Accepting cycle detection is the core algorithmic procedure in automata-based LTL Model Checking. We demonstrate that the tool outperforms non-accelerated version of the algorithm and we discuss where the limits of the tool are and what we intend to do in the future to avoid them

Medical students learning styles in Latin American and Spanish universities: relation with geographical and curricular contexts

Objetivo. Determinar si los estilos de aprendizaje (EA) de los estudiantes de medicina se correlacionan con el contexto geográfico, con el contexto curricular o con el nivel de la carrera. Sujetos y métodos. El estudio se realizó en 490 estudiantes de las Escuelas de Medicina de las Universidades de Chile (Santiago, Chile), Nacional de Cuyo (Mendoza, Argentina), San Francisco Xavier (Sucre, Bolivia), Zaragoza y País Vasco (España). Se aplicó el cuestionario Honey-Alonso, que valora la preferencia por cada uno de cuatro EA: activo, reflexivo, teórico y pragmático. También se evaluó el EA de acuerdo al modelo de Kolb. Resultados. Al relacionar el EA con el contexto geográfico se observó que mientras los estudiantes de universidades españolas muestran un estilo preferentemente asimilador, siguiendo la denominación de Kolb, para Chile fue el acomodador y para Bolivia los estudiantes se distribuyen entre los estilos asimilador y divergente. Al comparar la distribución de los EA durante el tercer curso de medicina en dos facultades que poseen diferente currículo, no se observaron diferencias significativas. Los EA en una Facultad de Medicina con un currículo basado en asignaturas (Chile) no mostraron diferencias en los tres cursos del estudio (1.o, 3.o y 5.o), siendo preferentes los estilos reflexivo y teórico. Conclusiones. El estudio permitió establecer diferencias significativas entre los estilos de aprendizaje de los estudiantes de Medicina en relación con el contexto geográfico, más que con los diferentes currículos, o a lo largo de los distintos cursos de la carrera.Aim. To establish a correlation between medical student learning styles (LS) and the geographical context, the curricular context and different academic levels. Subjects and methods. The study was performed in 490 undergraduate students from Medical Schools of the Universities of Chile (Santiago, Chile), Nacional de Cuyo (Mendoza, Argentina), San Francisco Xavier (Sucre, Bolivia), Zaragoza and País Vasco (Spain). The instrument used was the Honey-Alonso learning style questionnaire that assesses the student preference for one of four LS: active, reflexive, theoretic and pragmatic. In addition, LS according to the Kolb inventory were also assessed. Results. Using the Kolb inventory, significant differences were found when the LS were correlated with the geographical context. While Spanish students showed a high preference for the assimilator style of learning, Chilean students resulted to be mainly accommodators, and Bolivian students were both assimilators and divergent. Comparing the LS distribution during the third course in two universities with different curricula (problem and lecture based learning), there were no significant differences. LS of medical students from a Medical School with a lecture based curriculum (University of Chile) were not significantly different during the first, the third and the fifth level of their undergraduate students. They showed a significant preference for reflexive and theoretic styles of learning. Conclusions. The present study allowed demonstrating that significant differences among the styles of learning of medical students correlated with the geographical context more than with the different curricula, or along the different courses of the career.Fil: Diaz Veliz, G.. Universidad de Chile; ChileFil: Mora, S.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Lafuente Sanchez, J. V.. Universidad del País Vasco; EspañaFil: Gargiulo, Pascual Angel. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Bianchi, R.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Teran, C.. Universidad Andina Simón Bolívar; BoliviaFil: Gorena, D.. Universidad Andina Simón Bolívar; BoliviaFil: Arce, J.. Universidad San Francisco Xavier; BoliviaFil: Escanero Marcen, J. F.. Universidad de Zaragoza; Españ

The role of ketamine in major depressive disorders: Effects on parvalbumin-positive interneurons in hippocampus

Major depressive disorder (MDD) is a complex illness that is arising as a growing public health concern. Although several brain areas are related to this type of disorders, at the cellular level, the parvalbumin-positive cells of the hippocampus interplay a very relevant role. They control pyramidal cell bursts, neuronal networks, basic microcircuit functions, and other complex neuronal tasks involved in mood disorders. In resistant depressions, the efficacy of current antidepressant treatments drops dramatically, so the new rapid-acting antidepressants (RAADs) are being postulated as novel treatments. Ketamine at subanesthetic doses and its derivative metabolites have been proposed as RAADs due to their rapid and sustained action by blocking N-methyl-d-aspartate (NMDA) receptors, which in turn lead to the release of brain-derived neurotrophic factor (BDNF). This mechanism produces a rapid plasticity activation mediated by neurotransmitter homeostasis, synapse recovery, and increased dendritic spines and therefore, it is a promising therapeutic approach to improve cognitive symptoms in MDD.Fil: Barrutieta Arberas, I.. Universidad del País Vasco; EspañaFil: Ortuzar, N.. Universidad del País Vasco; EspañaFil: Vaquero Rodríguez, A.. Universidad del País Vasco; EspañaFil: Picó-Gallardo, M.. Universidad del País Vasco; EspañaFil: Bengoetxea, H.. Universidad del País Vasco; EspañaFil: Guevara, M. A.. Universidad Nacional de Cuyo; ArgentinaFil: Gargiulo, Pascual Angel. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Lafuente, J. V.. Universidad del País Vasco; Españ

Mineralogy of Vera Rubin Ridge in Gale Crater from the Mars Science Laboratory CheMin instrument

Gale crater was selected as the landing site for the Mars Science Laboratory Curiosity rover because of orbital evidence for a variety of secondary minerals in the lower slopes of Aeolis Mons (aka Mount Sharp) that indicate changes in aqueous conditions over time. Distinct units demonstrate orbital spectral signatures of hematite, phyllosilicate (smectite), and sulfate minerals, which suggest that ancient aqueous environments in Gale crater varied in oxidation potential, pH, and water activity. Vera Rubin ridge (VRR) is the first of these units identified from orbit to have been studied by Curiosity. Orbital near-infrared data from VRR show a strong band at 860 nm indicative of hematite. Before Curiosity arrived at VRR, the hypotheses to explain the formation of hematite included (1) precipitation at a redox interface where aqueous Fe2+ was oxidized to Fe3+, and (2) acidic alteration of olivine in oxic fluids. Studying the composition and sedimentology of the rocks on VRR allow us to test and refine these hypotheses and flesh out the depositional and diagenetic history of the ridge. Here, we focus on the mineralogical results of four rock powders drilled from and immediately below VRR as determined by CheMin

Periodogram Connectivity of EEG Signals for the Detection of Dyslexia

Electroencephalography (EEG) signals provide an important source of information of brain activity at different areas. This information can be used to diagnose brain disorders according to different activation patterns found in controls and patients. This acquisition technology can be also used to explore the neural basis of less evident learning disabilities such as Developmental Dyslexia (DD). DD is a specific difficulty in the acquisition of reading skills not related to mental age or inadequate schooling, whose prevalent is estimated between 5% and 12% of the population. In this paper we propose a method to extract discriminative features from EEG signals based on the relationship among the spectral density at each channel. This relationship is computed by means of different correlation measures, inferring connectivity-like markers that are eventually selected and classified by a linear support vector machine. The experiments performed shown AUC values up to 0.7, demonstrating the applicability of the proposed approach for objective DD diagnosis