On the Entanglement Entropy in Gaussian cMERA

The continuous Multi Scale Entanglement Renormalization Anstaz (cMERA) consists of a variational method which carries out a real space renormalization scheme on the wavefunctionals of quantum field theories. In this work we calculate the entanglement entropy of the half space for a free scalar theory through a Gaussian cMERA circuit. We obtain the correct entropy written in terms of the optimized cMERA variational parameter, the local density of disentanglers. Accordingly, using the entanglement entropy production per unit scale, we study local areas in the bulk of the tensor network in terms of the differential entanglement generated along the cMERA flow. This result spurs us to establish an explicit relation between the cMERA variational parameter and the radial component of a dual AdS geometry through the Ryu-Takayanagi formula. Finally, we argue that the entanglement entropy for the half space can be written as an integral along the renormalization scale whose measure is given by the Fisher information metric of the cMERA circuit. Consequently, a straightforward relation between AdS geometry and the Fisher information metric is also established.We thank Esperanza López for very fruitful discussions and a careful reading that helped to improve the manuscript. The work of JJFM is supported by Universidad de Murcia-Plan Propio Postdoctoral, the Spanish Ministerio de Economía y Competitividad and CARM Fundación Séneca under grants FIS2015-28521 and 21257/PI/19. JMV is funded by Ministerio de Ciencia, Innovación y Universidades PGC2018-097328-B-100 and Programa de Excelencia de la Fundación Séneca Región de Murcia 19882/GERM/15

Entanglement renormalization for interacting field theories

A general method to build the entanglement renormalization (cMERA) for interacting quantum field theories is presented. We improve upon the well-known Gaussian formalism used in free theories through a class of variational non-Gaussian wave functionals for which expectation values of local operators can be efficiently calculated analytically and in a closed form. The method consists of a series of scale-dependent nonlinear canonical transformations on the fields of the theory under consideration. Here, the lambda phi(4) and the sine-Gordon scalar theories are used to illustrate how nonperturbative effects far beyond the Gaussian approximation are obtained by considering the energy functional and the correlation functions of the theory.J.J.F.M. acknowledges A. Bhattacharyya and T. Takayanagi for useful discussions and comments. J.M.V. thanks J. Cotler and M. Muller for many fruitful discussions. The work of J.J.F. M. is supported by Universidad de Murcia. J.M.V. is supported by Ministerio de Economia y Competitividad FIS2015-69512-R and Programa de Excelencia de la Fundacion Seneca 19882/GERM/15. J.J.F. M. and E.T.L. acknowledge the financial support of Spanish Ministerio de Economia y Competitividad and CARM Fundacion Seneca under Grants No. FIS2015-28521 and No. 21257/PI/19

Fracton-elasticity duality on curved manifolds

Mechanical properties of crystals on curved substrates mix elastic, geometric and topological degrees of freedom. In order to elucidate properties of such crystals we formulate the low-energy effective action that combines metric degrees of freedom with displacement fields and defects. We propose new dualities for elasticity coupled to curved geometry formulated in terms of tensor gauge theories. We show that the metric degrees of freedom, evolving akin to linearized gravity are mapped to tensors with three indices. When coupled to crystals these degrees of freedom become gapped and, in the presence of dislocations and disclinations, multivalued. The elastic degrees of freedom remain gapless and mapped to symmetric gauge fields with two indices. In the dual formulation, topological defects, which act as sources for the gauge fields, are fractons or excitations with restricted mobility. We show that mobility restrictions are manifest only when singularities in both displacement fields and metric are taken into account.Comment: 5 pages, 1 figur

Analysis and alternatives to alleviate water deficit in the Segura River Basin (2022-2027), South-east of Spain

En el sureste de España se sitúa la Demarcación Hidrográfica del Segura, afectada por un escenario de déficit estructural, como consecuencia de contar con una precipitación muy baja —la menor del continente— y que, ante los escenarios de cambio climático, puede agravarse durante los próximos años. Esta situación de escasez ha requerido la combinación de recursos de diversos orígenes, que pueden clasificarse en los naturales y los no convencionales, que intentan alcanzar en conjunto un grado satisfactorio de atención de las demandas, principalmente en las más importantes por su volumen, como son el regadío y el abastecimiento. El objetivo principal del presente estudio es el análisis detallado del déficit mediante la información recogida por la planificación hidrológica, identificando aquellas áreas donde se concentra esta anomalía y que coinciden en gran medida con las zonas regables del Trasvase Tajo-Segura. Como objetivo secundario, se plantean las alternativas que permitan la movilización de nuevos recursos que consigan aumentar la oferta actual, específicamente, aquellos procedentes de la desalinización. Para ello, será necesaria la ejecución de nuevas infraestructuras, que ya contempla la planificación actual, pero que pueden añadir nuevos condicionantes, esencialmente económicos, motivados por los sobrecostes sobre el ya elevado precio del agua desalinizada y que cuestionaría la viabilidad económica del sector agroalimentario dependiente de este insumo fundamental.The Segura River Basin is located in the South-east of Spain and is affected by a situation of structural deficit, due to a very low rainfall (the lowest on the continent). Given the climate change scenarios, this deficit could worsen over the coming years. This situation of scarcity has required the combination of resources from various sources, which can be classified as natural and non-conventional. This action constitutes an attempt to satisfactorily meet demands, mainly the most important due to their volume, such as irrigation and supply. The main objective of this study is the detailed analysis of the deficit based on the information collected in hydrological planning, identifying those areas where it is concentrated, which largely coincide with the irrigation areas of the Tajo-Segura Transfer. As a secondary objective, alternatives are proposed that allow the mobilization of new resources that are able to increase the current supply, specifically, those from desalination. For this, the execution of new infrastructure projects will be necessary, which is already contemplated in the current planning, but which may add new conditions, essentially economic, motivated by the extra costs on the already high price of desalinated water and which would question the economic viability of the dependent agri-food sector of this essential input.Esta investigación ha sido financiada por la Cátedra del Agua de la Universidad de Alicante-Diputación Provincial de Alicante y por la red de excelencia Campus Hábitat 5U

Oferta de vegetales y frutas en la alimentación escolar a partir de la adquisición local de alimentos: el caso de un municipio brasileño

Antecedentes/Objetivos: Los Programas de Alimentación Escolar (PAE) vinculados a la adquisición de alimentos locales se consideran estratégicos para la promoción de la Seguridad Alimentaria y Nutricional. En el año 2009 el gobierno brasileño implementó una legislación nacional para el PAE que hace obligatoria la adquisición local de alimentos de la agricultura familiar. El objetivo de esta investigación fue evaluar el impacto de la adquisición local de alimentos de la agricultura familiar en la oferta de vegetales y frutas en la alimentación escolar en un municipio de Santa Catarina/Brasil. Métodos: Estudio cuasi experimental, donde se analizaron las cantidades per cápita (kilogramo/alumno/año) y las variedades (n) de frutas y vegetales adquiridas en dos años anteriores (2008/2009) y dos posteriores (2010/2011) a la implementación de la actual legislación del programa. Se realizó un análisis descriptivo. Resultados: Los resultados muestran una reducción progresiva en la cantidad per cápita anual de frutas en los años analizados: 7 kg (2008); 5,8 kg (2009); 5,5 kg (2010) 4,4 kg (2011), con una tasa de variación de –37% en relación a 2008. Respecto a la variedad de las frutas, fueron adquiridas 6 en 2008, 2009 y 2010 y 5 en 2011. En 2010 y 2011, la agricultura familiar suministró 2 y 1 variedad respectivamente. En los vegetales se observó reducción en la cantidad en los dos primeros años y aumento en los dos posteriores: 1,9 kg (2008); 1,8 kg (2009); 2,9 kg (2010); 3,05 kg (2011), con una tasa de variación de 60% en relación a 2008. Además se observó un aumento en la variedad: 7 (2008), 6 (2009) y 11 (2010/2011), que puede atribuirse a la adquisición de alimentos de la agricultura familiar, ya que aportó 7 de las variedades en 2010 y 2011. Conclusiones: Aunque la legislación del programa parece no revertir la reducción en la adquisición de frutas del período estudiado, se evidencia un incremento de la cantidad y variedad de vegetales que redundan en la mejora de la calidad alimentaria. Estos resultados sugieren que la adquisición de alimentos locales influye positivamente en la alimentación escolar.Convocatoria MCT/MDS/SAGI/CNPq Nº36/2010

An Alternative Scenario on the Origin of Ultra-High Pressure (UHP) and Super-Reduced (SuR) Minerals in Ophiolitic Chromitites: A Case Study from the Mercedita Deposit (Eastern Cuba)

The origin of the assemblage of ultra-high pressure (UHP), super-reduced (SuR) and several crustally derived phases in ophiolitic chromitites is still hotly debated. In this paper, we report, for the first time, this assemblage of phases in ophiolitic chromitites of the Caribbean. We studied the Mercedita chromitite deposit in the eastern Cuban ophiolitic complexes. The mineral phases were characterized using microRaman spectroscopy, energy-dispersive spectroscopy with a scanning electron microscope (SEM-EDS), X-ray microdiffraction and electron microprobe analyses. Mineral concentrates were prepared using hydroseparation techniques. We have identified oriented clinopyroxene lamellae in chromite, oriented rutile lamellae in chromite, moissanite hosted in the altered matrix of the chromitite, graphite-like amorphous carbon, corundum and SiO2 hosted in healed fractures in chromite grains, and native Cu and Fe-Mn alloy recovered in heavy-mineral concentrates obtained by hydroseparation. This assemblage may correspond to UHP-SuR conditions, implying recycling of chromitite in the mantle or formation of the chromite grains at deep mantle depths, followed by emplacement at a shallow level in the mantle. However, the chromitite bodies contain gabbro sills oriented parallel to the elongation of the chromitite lenses, and these show no evidence of HP/UHP metamorphism. Therefore, the identified "exotic" phases may not be indicative of UHP. They formed independently as oriented clinopyroxene lamellae in chromite during cooling (clinopyroxene and rutile), in super-reduced microenvironments during the serpentinization processes, and by transference of subducted crustal material to the mantle wedge via cold plume

Generalization and Regularization for Inverse Cardiac Estimators

Electrocardiographic Imaging (ECGI) aims to estimate the intracardiac potentials noninvasively, hence allowing the clinicians to better visualize and understand many arrhythmia mechanisms. Most of the estimators of epicardial potentials use a signal model based on an estimated spatial transfer matrix together with Tikhonov regularization techniques, which works well specially in simulations, but it can give limited accuracy in some real data. Based on the quasielectrostatic potential superposition principle, we propose a simple signal model that supports the implementation of principled out-of-sample algorithms for several of the most widely used regularization criteria in ECGI problems, hence improving the generalization capabilities of several of the current estimation methods. Experiments on simple cases (cylindrical and Gaussian shapes scrutinizing fast and slow changes, respectively) and on real data (examples of torso tank measurements available from Utah University, and an animal torso and epicardium measurements available from Maastricht University, both in the EDGAR public repository) show that the superposition-based out-of-sample tuning of regularization parameters promotes stabilized estimation errors of the unknown source potentials, while slightly increasing the re-estimation error on the measured data, as natural in non-overfitted solutions. The superposition signal model can be used for designing adequate out-of-sample tuning of Tikhonov regularization techniques, and it can be taken into account when using other regularization techniques in current commercial systems and research toolboxes on ECG

Highly Versatile Polyelectrolyte Complexes for Improving the Enzyme Replacement Therapy of Lysosomal Storage Disorders

Lysosomal storage disorders are currently treated by enzyme replacement therapy (ERT) through the direct administration of the unprotected recombinant protein to the patients. Herein we present an ionically cross-linked polyelectrolyte complex (PEC) composed of trimethyl chitosan (TMC) and α-galactosidase A (GLA), the defective enzyme in Fabry disease, with the capability of directly targeting endothelial cells by incorporating peptide ligands containing the RGD sequence. We assessed the physicochemical properties, cytotoxicity, and hemocompatibility of RGD-targeted and untargeted PECs, the uptake by endothelial cells and the intracellular activity of PECs in cell culture models of Fabry disease. Moreover, we also explored the effect of different freeze-drying procedures in the overall activity of the PECs. Our results indicate that the use of integrin-binding RGD moiety within the PEC increases their uptake and the efficacy of the GLA enzyme, while the freeze-drying allows the activity of the therapeutic protein to remain intact. Overall, these results highlight the potential of TMC-based PECs as a highly versatile and feasible drug delivery system for improving the ERT of lysosomal storage disorders

Highly versatile polyelectrolyte complexes for improving the enzyme replacement therapy of lysosomal storage disorders

Lysosomal storage disorders are currently treated by enzyme replacement therapy (ERT) through the direct administration of the unprotected recombinant protein to the patients. Herein we present an ionically crosslinked polyelectrolyte complex (PEC) composed of trimethyl chitosan (TMC) and -galactosidase A (GLA), the defective enzyme in Fabry disease, with the capability of directly targeting endothelial cells by incorporating peptide ligands containing the RGD sequence. We assessed the physicochemical properties, cytotoxicity and hemocompatibility of RGD-targeted and un-targeted PECs, the uptake by endothelial cells and the intracellular activity of PECs in cell culture models of Fabry disease. Moreover, we also explored the effect of different freezedrying procedures in the overall activity of the PECs. Our results indicate that the use of integrin-binding RGD moiety within the PEC increases their uptake and the efficacy of the GLA enzyme, while the freeze-drying allows keeping intact the activity of the therapeutic protein. Overall, these results highlight the potential of TMC-based PECs as a highly versatile and feasible drug delivery system for improving the ERT of lysosomal storage disorders