Aditivos alimentarios adicionados en alimentos envasados o enlatados en México ¿información confiable?

Introduction: Food additives (AA) are ingredients that are added to foods to modify their physical and chemical characteristics. Approximately 1,000 AA are used under the “Generally Recognized as Safe” designation without approval from the US Food and Drug Administration. There is evidence that some AA can be potentially toxic to health. The person in charge of regulating AA worldwide is the Food and Agriculture Organization of the United Nations and the World Health Organization, through the Codex Alimentarius Commission. However, in Mexico there are no studies on the toxicity of AA in the population, given the impossibility of estimating its consumption taking the "Admissible Daily Intake" as a reference (IDA). Objective: Identify the information on the concentration of various AAs on the labels of food products in Mexico. Methods: A descriptive cross-sectional study was carried out, packaged or canned foods (AEE) were selected, available in leading self-service store chains in Mexico, in 10 states of the Mexican Republic (Baja California, Campeche, Guadalajara, Mexico, Monterrey, Querétaro, Quintana Roo, Tabasco, Veracruz and Yucatan). The AEE selection criteria were a) that they were simultaneously available for sale nationwide in at least two of three self-service stores, b) based on the information available on the nutritional labeling, which mentioned the added AA, commonly used in multiple AEE. Results: An average of 900 AEE that did not meet the inclusion criteria were found. More than 120 AEE mention the added AA (˃ 98%), but only 2 AEE mention the concentration (<1.5%). Conclusions: The lack of information on the concentration of AA added to AEE does not allow the ADI to be taken as a reference in the intake of AA in the Mexican population.Introducción: Los aditivos alimentarios (AA) son ingredientes que se agregan a los alimentos para modificar sus características físicas y químicas. Aproximadamente 1000 AA se utilizan bajo la denominación “Generalmente Reconocido como seguro” sin la aprobación de la Administración de Drogas y Alimentos de los Estados Unidos. Se encuentra evidencia de que algunos AA pueden ser potencialmente tóxicos para la salud. El responsable de regular los AA a nivel mundial es la Organización de las Naciones Unidas para la Agricultura y la Alimentación y la Organización Mundial de la Salud, a través de la Comisión del Codex alimentarius. Sin embargo, en México no se encuentran estudios sobre la toxicidad de AA en la población, ante la imposibilidad de estimar su consumo tomando como referente la “Ingesta Diaria Admisible” (IDA). Objetivo: Identificar la información de la concentración de diversos AA en las etiquetas de los productos alimenticios en México. Métodos: Se realizó estudio transversal descriptivo, se seleccionaron alimentos envasados o enlatados (AEE), disponibles en cadenas de tiendas de autoservicio líderes de ventas en México, en 10 estados de la república mexicana (Baja California, Campeche, Guadalajara, México, Monterrey, Querétaro, Quintana Roo, Tabasco, Veracruz y Yucatán). Los criterios de selección de los AEE fueron: a) que se encontraran disponibles simultáneamente a la venta a nivel nacional en al menos dos de tres tiendas de autoservicio, b) basados en la información disponible en el etiquetado nutricional, que mencionara los AA adicionados, comúnmente utilizado en múltiples AEE. Resultados: Se encontraron en promedio 900 AEE que no cumplieron con los criterios de inclusión. Más de 120 AEE mencionan el AA adicionado (˃ 98%), pero solo 2 AEE mencionan la concentración (<1.5%). Conclusiones: La carencia de información de la concentración de los AA adicionados a los AEE, no permite tomar como referente la IDA en la ingestión de AA en la población mexicana

Propuesta y recomendaciones para la delimitación de la Zona Marítimo Terrestre de playas abiertas con baja carrera de marea según la legislación vigente.

En los últimos años, ha entrado en vigor la Ley 2/2013 de protección y uso sostenible del litoral y modificación de la Ley 22/1988 de Costas (BOE, 1988, 2013), junto con el Reglamento que la desarrolla (BOE, 2014) aprobado mediante el Real Decreto 876/2014 (RGC). Entre otras modificaciones y aportaciones de esta legislación, destaca el nuevo procedimiento de estimación de la Zona Marítimo Terrestre, qué se define como aquella que en 5 años es alcanzada por al menos 5 temporales (art. 4.a del RGC). Esta definición es más exacta que la anterior, heredada de legislaciones anteriores: “el límite hasta donde alcancen las olas en los mayores temporales conocidos…” (art. 3.a de la Ley de Costas del año 1988). Pero, por el contrario, supone el calcular un valor exacto sin especificar un procedimiento perfectamente definido y objetivo. Existen muchas variables indeterminadas. La primera y principal es la extensa posibilidad de consulta de datos en las diferentes redes de boyas y de mareógrafos en series temporales muy superiores a 5 años. Además, existen diversos y numerodos modelos y fórmulas de cálculo del alcance de un evento de temporal, con resultados muy variables entre ellos. Todo esto determina que el diferente criterio a la hora de tomar decisiones entre un técnico u otro, implica que se puedan obtener resultados muy dispares en el resultado de la cota final que delimita la Zona Marítimo Terrestre de un tramo de playa. Pero técnicamente, pueden ser todos ellos procedimientos a priori igualmente válidos. El objeto de esta ponencia es proponer una metodología única y establecer una serie de recomendaciones generales para eliminar la subjetividad de la persona que aborde este problema

Tunneling splitting of Jahn-Teller ions in oxides

The magnitude of tunneling splitting, 3?, that governs decoherence in quantum systems under symmetric potentials, is frequently unknown. Using first-principles calculations, we have obtained 3? for a number of E?e Jahn-Teller impurities in solids. Calculated values span 6 orders of magnitude on passing from KCl?Ag2+ to MgO?Cu2+. Values associated with Cu2+- and Ag2+-doped MgO are 2 orders of magnitude larger than those previously assumed and consistent with the existence of a dynamic Jahn-Teller effect. The origin and enhancement with pressure of these high 3? values is discussed in detail.The support by the Spanish Ministerio de Ciencia y Tecnología under Projects FIS2006-02261 and FIS2009- 07083 is acknowledged

Analytical Framework to Model Reconfigurable Metasurfaces including Lumped Elements.

This manuscript introduces an analytical framework for the design of reconfigurable metasurfaces rooted in 2D periodic structures. Incorporating lumped elements into the model streamlines the design process for such devices, offering significantly improved efficiency compared to designs reliant on full-wave software. The theoretical framework, founded on Floquet modal expansions, also guarantees robust performance even under oblique incidence conditions, far beyond the onset of the first grating lobe. In practical applications, an absorber has been devised by integrating a resistor into the model. Nevertheless, circuit analysis extends the possibilities for crafting more intricate structures utilizing diodes or tunable varactors, enabling the design of phase shifters, polarizers, and reconfigurable intelligent surfaces (RIS)

Analytical Method to Model Spatiotemporal Metasurfaces.

This work introduces a theoretical framework to develop fully-analytical and multi-modal equivalent circuits that are applicable to spatiotemporal metasurfaces. Here, time is considered a periodic variable. Thus, classical models for purely spatial structures are generalized to cover space-time scenarios. This paper explores various periodic metastructures from a circuital perspective, considering just time periodicity or space-time periodicities. The performance of the analytical equivalent circuits is validated through an external FDTD code. The results suggest that our analytical model is a powerful tool to describe and design novel and advanced space-time microwave and photonic systems.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Maxillary sinus dimensions with respect to the posterior superior alveolar artery decrease with tooth loss

Background: The posterior superior alveolar (PSA) artery is frequently encountered in the area where the lateral osteotomy is performed during direct sinus augmentation procedures. Objective: To investigate the correlation between patient-dependent variables and measurements related to PSA using cone beam computed tomography (CBCT) data. Methods: Three hundred ninety-four CBCT scans were evaluated to assess the PSA artery diameter and distances to the sinus floor and to alveolar crest. Patient's age, gender, and edentulism status were recorded. Results: The PSA artery tends to be wider in older patients. Distances to the sinus floor or the alveolar crest tend to be shorter in women and in partially and completely edentulous patients. Also, as those distances decrease, the mediolateral width of the sinus increases. Conclusion: Tooth loss leads to maxillary sinus vertical collapse with respect to the PSA artery. The position of the artery is stable; so, the mediolateral dimensions at different heights from the floor increase. Practical implications: The reduced distances from the PSA to the sinus floor and the alveolar crest in edentulous patients potentially increase the risk of injury during maxillary sinus lift. Additionally, when the distance to the sinus floor decreases, the mediolateral dimensions of the sinus at different heights increase, which may complicate the technique and challenge the outcomes.Junta de Andalucía #CTS-138 and #CTS-58

Impurities bound to vacancies in insulators: electronic relaxation and physical properties of the Cr 3 + − V M model center in K M F 3 ( M = Mg, Zn)

This work is aimed at gaining a better insight into the influence of a close vacancy, V, on the properties of impurities in insulating materials. To achieve this goal the Cr3+−VM model center formed in KMF3 (M = Mg, Zn) fluoroperovskites has been explored in detail by means of ab initio calculations on clusters involving up to 87 ions. It is shown that the presence of the M2+ vacancy, VM, induces a significant structural relaxation on the CrF3−6 cubic complex which cannot be fully understood assuming that ions were rigid spheres that could not be polarized. Thus, although VM forces all the ligands to move away, the Cr3+−F− distance corresponding to the furthest ligand, Ffar, is found to be slightly higher than that for the closer equatorial ions. This unexpected fact is shown to be due to the electronic relaxation also induced by VM on the CrF3−6 complex, causing a charge of 0.2e to be transferred from the closest ligand to VM, Fnext, mainly to Ffar, and, to a lesser extent, to any equatorial ligand. This transfer of charge is mainly accomplished through orbitals lying in planes containing the C4 axis. In spite of these changes due to the vacancy, the 4A2g→4T2g optical transition is found to be weakly altered, a fact that concurs with available experimental data and whose origin is discussed. In contrast, electron paramagnetic resonance parameters such as gyromagnetic or superhyperfine tensors, which do depend on the electronic density around a point of the CrF3−6 complex, are shown to be particularly sensitive to the electronic relaxation induced by VM. In particular, the present study explains that the dominant component of the superhyperfine tensor for the Fnext ligand is clearly higher than that for Ffar, in agreement with experimental data. The relevance of the present results for understanding the electronic properties of other systems involving vacancies is also discussed. Some results on the Cr3+−Li+ center formed in KMgF3 are also discussed for comparison.The support by the Spanish Ministerio de Ciencia y Tecnología under Project FIS2009-07083 is acknowledge

Bayesian Nonparametric Crowdsourcing

Crowdsourcing has been proven to be an effective and efficient tool to annotate large data-sets. User annotations are often noisy, so methods to combine the annotations to produce reliable estimates of the ground truth are necessary. We claim that considering the existence of clusters of users in this combination step can improve the performance. This is especially important in early stages of crowdsourcing implementations, where the number of annotations is low. At this stage there is not enough information to accurately estimate the bias introduced by each annotator separately, so we have to resort to models that consider the statistical links among them. In addition, finding these clusters is interesting in itself as knowing the behavior of the pool of annotators allows implementing efficient active learning strategies. Based on this, we propose in this paper two new fully unsupervised models based on a Chinese restaurant process (CRP) prior and a hierarchical structure that allows inferring these groups jointly with the ground truth and the properties of the users. Efficient inference algorithms based on Gibbs sampling with auxiliary variables are proposed. Finally, we perform experiments, both on synthetic and real databases, to show the advantages of our models over state-of-the-art algorithms.Pablo G. Moreno is supported by an FPU fellowship from the Spanish Ministry of Education (AP2009-1513). This work has been partly supported by Ministerio de Economía of Spain (’COMONSENS’, id. CSD2008-00010, ’ALCIT’, id. TEC2012-38800-C03-01, ’COMPREHENSION’, id. TEC2012-38883-C02-01) and Comunidad de Madrid (project ’CASI-CAM-CM’, id. S2013/ICE-2845). This work was also supported by the European Union 7th Framework Programme through the Marie Curie Initial Training Network ”Machine Learning for Personalized Medicine” MLPM2012, Grant No. 316861. Yee Why Teh’s research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC grant agreement no. 617411

Insulators containing CuCl4X22? (X = H2O, NH3) units: Origin of the orthorhombic distortion observed only for CuCl4(H2O)2 2?

The origin of the difference in structure between compounds containing CuCl4X22? (X=H2O, NH3) units is analyzed by means of first-principles calculations. While NH3-containing compounds display tetragonal symmetry, H2O-containing ones display an orthorhombic distortion at low temperature where the equatorial Cl? ions are no longer equivalent. Our simulations of optical and vibrational transitions show good agreement with all available experimental optical absorption and Raman data. As a salient feature, the value of the force constant for the B1g mode, K(B1g), driving the orthorhombic distortion in the CuCl4(H2O)22? unit is found to be four times smaller than that calculated for CuCl4(NH3)22?, stressing that CuCl4(H2O)22? is in the verge of the D4h?D2h instability. The analysis of results obtained for different values of the distortion coordinate, Q(B1g), clearly shows that the softening undergone by K(B1g) in CuCl4(H2O)22? comes mainly from the vibronic admixture of the antibonding a?1g(?3z2-r2) orbital with the bb1g bonding (or charge transfer) level. This mechanism is thus similar to that responsible for distortions observed in some fluoroperovskites and oxoperovskites. The present results, quantifying the importance of vibronic effects in structural instabilities, clearly demonstrate that, contrary to what was suggested by several authors, the instability in CuCl4(H2O)22? is not related to the Jahn-Teller effect and that the orthorhombic distortion observed in the pure compound Rb2CuCl4(H2O)2 has a local origin.The support by the Spanish Ministerio de Ciencia y Tecnología under Project No. FIS2009-07083 is acknowledged

Pressure-induced changes in Cr3+-doped elpasolites and LiCaAlF6: interpretation of macroscopic data

In the research of pressure effects on Cr3+-doped insulating lattices, it is crucial to understand the dependence of the 10Dq parameter on the sample volume, V. This problem is explored in the present work through ab initio calculations on Cr3+-doped K2NaScF6, Cs2NaYCl6, and Cs2NaYBr6 elpasolite lattices as a function of pressure in the 0?5 GPa range. From the calculated values of the lattice parameter and the Cr3+?X? (X=F, Cl, and Br) distance, R, it is found that R varies with the cell volume, vc, as v(1/3?)c where ? lies around 2.6. These results allow one to understand quantitatively the 10Dq dependence on V?m/3 for LiCaAlF 6:Cr3+ where the measured exponent m=2.3 is seemingly anomalous when compared to the values found for ruby (m=4.5) or NiO (m=5).The support by the Spanish Ministerio de Ciencia y Tecnología under Project No. FIS2009-07083 is acknowledged