Competition between hydrogen bonding and electric field in single-file transport of water in carbon nanotubes

Recent studies have shown the possibility of water transport across carbon nanotubes, even in the case of nanotubes with small diameter (0.822 nm). In this case, water shows subcontinuum transport following an ordered 1D structure stabilized by hydrogen bonds. In this work, we report MD simulations describing the effect of a perpendicular electric field in this single-file water transport in carbon nanotubes. We show that water permeation is substantially reduced for field intensities of 2-3 V/nm and it is no longer possible under perpendicular fields of 4 V/nm.Comment: Accepted in Molecular Simulatio

Modelling self-consistently beyond General Relativity

The majority of extensions to General Relativity display mathematical pathologies (higher derivatives, character change in equations that can be classified within PDE theory, and even unclassifiable ones) that cause severe difficulties to study them, especially in dynamical regimes. We present here an approach that enables their consistent treatment and extraction of physical consequences. We illustrate this method in the context of single and merging black holes in a highly challenging beyond GR theory.Comment: 10 pages, 8 figure

Mixtures of controlled Gaussian processes for dynamical modeling of deformable objects

Control and manipulation of objects is a highly relevant topic in Robotics research. Although significant advances have been made over the manipulation of rigid bodies, the manipulation of non-rigid objects is still challenging and an open problem. Due to the uncertainty of the outcome when applying physical actions to non-rigid objects, using prior knowledge on objects’ dynamics can greatly improve the control performance. However, fitting such models is a challenging task for materials such as clothing, where the state is represented by points in a mesh, resulting in very large dimensionality that makes models difficult to learn, process and predict based on measured data. In this paper, we expand previous work on Controlled Gaussian Process Dynamical Models (CGPDM), a method that uses a non-linear projection of the state space onto a much smaller dimensional latent space, and learns the object dynamics in the latent space. We take advantage of the variability in training data by employing Mixture of Experts (MoE), and we devise theory and experimental validations that demonstrate significant improvements in training and prediction times, plus robustness and error stability when predicting deformable objects exposed to disparate movement ranges.This work was partially developed in the context of the project CLOTHILDE (”CLOTH manIpulation Learning from DEmonstrations”), which has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Advanced Grant agreement No 741930). We would like to thank the members of the HCRL Lab and the Department of Aerospace Engineering and Engineering Mechanics at The University of Texas at Austin for their feedback during the development of this work.Peer ReviewedPostprint (published version

Increased seismic hazard in Barcelona (Spain) due to soil-building resonance effects

In this study, previous microzonation studies in Barcelona (Spain) were revisited, and available data on the predominant periods of soils in the city were compiled to develop an updated microzonation map of the city. In addition, the building database was updated and used to create a map of building fundamental periods. The crossing of soil predominant period and building fundamental period maps led to the detection of areas in which resonance phenomena and, indeed, increased amplification of the structural response are expected. Thus, zones of Barcelona were identified in which the seismic hazard is probably greater due to resonance effects. The improved microzonation maps and the detection of soil-building resonance areas contribute significantly to enhanced precision and awareness of seismic hazard and risk in Barcelona.We thank Lucille Banham for her assistance in the preparation of the English manuscript. This research was partially funded by the Spanish Government’s Ministry of Economy and Competitiveness (MINECO) and by the European Regional Development Fund (ERDF) of the European Union (EU) through the project referenced as CGL2015-65913-P (MINECO/ ERDF, EU). The first author is supported by a Ph.D. scholarship grant from the Government of Panama’s Institute for the Training and Development of Human Resources (IFARHU) and the National Secretariat of Science, Technology, and Innovation (SENACYT).Peer ReviewedPostprint (author's final draft

Detection of satellite remnants in the Galactic Halo with Gaia III. Detection limits for Ultra Faint Dwarf Galaxies

We present a method to identify Ultra Faint Dwarf Galaxy (UFDG) candidates in the halo of the Milky Way using the future Gaia catalogue and we explore its detection limits and completeness. The method is based on the Wavelet Transform and searches for over-densities in the combined space of sky coordinates and proper motions, using kinematics in the search for the first time. We test the method with a Gaia mock catalogue that has the Gaia Universe Model Snapshot (GUMS) as a background, and use a library of around 30 000 UFDGs simulated as Plummer spheres with a single stellar population. For the UFDGs we use a wide range of structural and orbital parameters that go beyond the range spanned by real systems, where some UFDGs may remain undetected. We characterize the detection limits as function of the number of observable stars by Gaia in the UFDGs with respect to that of the background and their apparent sizes in the sky and proper motion planes. We find that the addition of proper motions in the search improves considerably the detections compared to a photometric survey at the same magnitude limit. Our experiments suggest that Gaia will be able to detect UFDGs that are similar to some of the known UFDGs even if the limit of Gaia is around 2 magnitudes brighter than that of SDSS, with the advantage of having a full-sky catalogue. We also see that Gaia could even find some UFDGs that have lower surface brightness than the SDSS limit.Comment: Accepted for publication in MNRA

La dinámica de crecimiento en las economías provinciales: un análisis de largo plazo

Despite the marginalization of regional issues in contemporary literature, its importance is not negligible: they mark the evolution of the overall national economy, in addition to the local communities. With this concern, the authors offer us an essay about the dynamics of growth of regional economies: the so-called phenomenon of convergence, both conditioned and non-conditioned. First, conducting a tour through the literature on the topic, and then reviewing the results of different authors for the Argentine case. After referring to studies of regional distribution of income per capita in “dynamic terms”, according to the application of the “Markov chains”, the article ends with a series of conclusions that arise from the undertakenargument.Pese a la marginación de los temas regionales en la literatura contemporánea, su importancia no es nada despreciable: marcan el devenir del conjunto de la economía nacional, además del de las comunidades locales. Con esta preocupación, los autores nos ofrecen un ensayo sobre la dinámica de crecimiento de las economías regionales: el llamado fenómeno de la convergencia, tanto condicionada como no condicionada. En primer lugar, realizan un recorrido por la literatura sobre el tema, para luego pasar revista a los resultados de los diferentes autores para el caso argentino con referencia a estudios de distribución regional del ingreso por habitante en “términos dinámicos”, según la aplicación de las “cadenas de Markov”. El artículo finaliza con una serie de reflexiones que surgen del recorrido realizado

Valoración de técnicas de diagnóstico y estudio de posibles tratamientos de la rinitis crónica proliferativa en ganado ovino.

La patología respiratoria engloba un gran número de afecciones siendo una de las principales causas de mortalidad y pérdidas económicas en el ganado ovino. Existen procesos como el complejo respiratorio ovino, muy bien estudiados por gran su importancia. Sin embargo, otras patologías son menos conocidas, bien por su baja prevalencia, incidencia o morbilidad, es el caso de la rinitis crónica proliferativa (RCP). La rinitis crónica proliferativa afecta a las vías respiratorias altas del ganado ovino, concretamente a los cornetes ventrales. Se trata de un proceso inflamatorio proliferativo que produce en los animales unos signos clínicos muy característicos. Es una enfermedad de curso lento y progresivo que acaba irremediablemente con la vida del animal. En la bibliografía se cita a Salmonella enterica subsp. diarizonae serotipo 61:k:1,5,(7) como posible agente causal de esta patología, ya que se ha demostrado una estrecha relación entre la enfermedad clínica y la localización de este germen, mediante inmunohistoquímica, en el interior de células epiteliales y macrófagos. Esta bacteria se aísla frecuentemente de manera extracelular en animales asintomáticos. No obstante, el mecanismo de acción y patogenia todavía es desconocido. El diagnóstico clínico en la fase avanzada de la enfermedad es muy evidente, pero en esta fase los tratamientos antibióticos no llegan a ser efectivos. Los objetivos de este trabajo son mejorar la precocidad del diagnóstico usando y comparando los resultados de distintas técnicas de diagnóstico complementarias, así como buscar antibióticos o pautas de tratamiento que nos permitan curar a los animales afectados. Para este estudio se utilizarán los animales remitidos al Servicio de Clínica de Rumiantes (SCRUM) de la Facultad de Veterinaria de Zaragoza, con clínica compatible con RCP y los diferentes aparatos de diagnóstico por imagen que se utilizan en el servicio, utilizados con la metodología convencional de rutina