Demographic change, pension reform and redistribution in Spain

Recent demographic changes have spurred pension reforms aimed at restoring the financial sustainability of PAYG systems. In Spain, the most significant reforms were undertaken in 1997 and in 2002, entailing an increase in the length of the averaging period in the pension formula, an increase in the penalties for early retirement and for retirement with short contributive records, a bonus for retirement after the age of 65, and a change in the eligibility conditions. In this paper we use an Applied General Equilibrium model populated by two-earners households to evaluate the redistributive impact of the pension system and the financial and welfare consequences of these reforms on households that differ in their education, region of residence and year of birth. The initial redistribution is assessed by comparing the internal rate of return provided to different households. We find that they vary considerable depending on education and cohort. Regarding the reforms, we find an increase in the implicit debt of the pension system after the reforms, and important changes in welfare. Households up to secondary education born between 1935 and 1975 are predicted to benefit from the reform, while the welfare of younger cohorts will be hit by higher taxes and unfavorable macroeconomic changes.Social Security, Pension Reform, Applied General Equilibrium, Redistribution

Perspectiva sociosanitaria en torno a la atención al parto en NIkki, Benín (África)

El presente estudio tiene como objetivo valorar las consultas prenatales, las ecografías y el lugar de atención de los partos en Nikki (norte de Benín, África), e identificar los posibles factores que puedan estar influyendo sobre la calidad de la atención. Estudio descriptivo observacional de metodología mixta. Análisis cuantitativo a través de cuestionarios a mujeres mediante entrevistador; análisis cualitativo mediante entrevistas semiestructuradas individuales y grupales a los agentes implicados en la salud reproductiva. Por un lado, la existencia de tres centros sanitarios en la ciudad, y la aún presente medicina tradicional, posibilitan la elección del lugar a la hora del parto, siendo el centro de salud el recurso con mayor número de partos atendidos. La satisfacción de la atención en las mujeres es alta. Sin embargo, factores como el trato del personal en situaciones anteriores, las diferencias de precios y la falta de infraestructuras de transporte, y de recursos económicos condicionan las posibilidades de elección de las familias. Los responsables sanitarios consideran que existen una adecuada formación y experiencia en los profesionales. La calidad en la atención se ve limitada por la sobrecarga laboral y falta de recursos materiales, así como la inadecuada comunicación y cooperación entre centros. Por otro lado, se identifican problemas importantes en recursos sanitarios privados sin licencia. Estos factores socioeconómicos y organizativos deben tenerse muy presentes antes de intentar intervenir de manera externa a través de proyectos de cooperación.Grado en Medicin

Coupled Landau-Zener-Stuckelberg Quantum Dot Interferometers

We investigate the interplay between long-range and direct photon-assisted transport in a triple quantum dot chain where local ac voltages are applied to the outer dots. We propose the phase difference between the two ac voltages as an external parameter, which can be easily tuned to manipulate the current characteristics. For gate voltages in phase opposition we find quantum destructive interferences analogous to the interferences in closed-loop undriven triple dots. As the voltages oscillate in phase, interferences between multiple paths give rise to dark states. Those totally cancel the current, and could be experimentally resolved.Comment: 6 pages, 4 figure

Superexchange blockade in triple quantum dots

We propose the interaction of two electrons in a triple quantum dot as a minimal system to control long range superexchange transitions. These are probed by transport spectroscopy. Narrow resonances appear indicating the transfer of charge from one side of the sample to the other with the central one being occupied only virtually. We predict that two different intermediate states establish the two arms of a one dimensional interferometer. Configurations of destructive interference of the two superexchage trajectories totally block the current through the system. We emphasize the role of spin correlations giving rise to lifetime-enhanced resonances.Comment: 5 pages, 4 figures. Published versio

Intervenir en el mundo de los átomos: Feynman y los fulerenos

Hace medio siglo el físico Richard Feynman, ganador del Premio Nóbel, fue invitado a pronunciar un discurso en una institución tecnológica de California. Lo que manifestó en aquella intervención influiría para siempre en las generaciones futuras interesadas por la exploración del enorme potencial de un universo a escala atómica. Una derivada de aquel momento y punto de desarrollo es el descubrimiento de los fulerenos (también conocidos como "bucicyballs"), que ha abierto un nuevo campo para la química del carbono, y que han beneficiado a diversos campos científicos, entre ellos la Biomedicina, como se pone de manifiesto en el presente artícul

How Bees Respond Differently to Field Margins of Shrubby and Herbaceous Plants in Intensive Agricultural Crops of the Mediterranean Area

(1) Intensive agriculture has a high impact on pollinating insects, and conservation strategies targeting agricultural landscapes may greatly contribute to their maintenance. The aim of this work was to quantify the effect that the vegetation of crop margins, with either herbaceous or shrubby plants, had on the abundance and diversity of bees in comparison to non-restored margins. (2) The work was carried out in an area of intensive agriculture in southern Spain. Bees were monitored visually and using pan traps, and floral resources were quantified in crop margins for two years. (3) An increase in the abundance and diversity of wild bees in restored margins was registered, compared to non-restored margins. Significant differences in the structure of bee communities were found between shrubby and herbaceous margins. Apis mellifera and mining bees were found to be more polylectic than wild Apidae and Megachilidae. The abundance of A. mellifera and mining bees was correlated to the total floral resources, in particular, to those offered by the Boraginaceae and Brassicaceae; wild Apidae and Megachilidae were associated with the Lamiaceae. (4) This work emphasises the importance of floral diversity and shrubby plants for the maintenance of rich bee communities in Mediterranean agricultural landscapes

A hydrated ion model of [UO2]2+ in water: Structure, dynamics, and spectroscopy from classical molecular dynamics

A new ab initio interaction potential based on the hydrated ion concept has been developed to obtain the structure, energetics, and dynamics of the hydration of uranyl in aqueous solution. It is the first force field that explicitly parameterizes the interaction of the uranyl hydrate with bulk water molecules to accurately define the second-shell behavior. The [UO2(H2O)5 ] 2+ presents a first hydration shell U–O average distance of 2.46 Å and a second hydration shell peak at 4.61 Å corresponding to 22 molecules using a coordination number definition based on a multisite solute cavity. The second shell solvent molecules have longer mean residence times than those corresponding to the divalent monatomic cations. The axial regions are relatively de-populated, lacking direct hydrogen bonding to apical oxygens. Angle-solved radial distribution functions as well as the spatial distribution functions show a strong anisotropy in the ion hydration. The [UO2(H2O)5 ] 2+ solvent structure may be regarded as a combination of a conventional second hydration shell in the equatorial and bridge regions, and a clathrate-like low density region in the axial region. Translational diffusion coefficient, hydration enthalpy, power spectra of the main vibrational modes, and the EXAFS spectrum simulated from molecular dynamics trajectories agree fairly well with the experiment.Junta de Andalucía de España, Proyecto de Excelencia-P11-FQM 760

A general study of actinyl hydration by molecular dynamics simulations using ab initio force fields

A set of new ab initio force fields for aqueous [AnO2] 2+/+ (An = Np(VI,V), Pu(VI), Am(VI)) has been developed using the Hydrated Ion (HI) model methodology previously used for [UO2] 2+. Except for the non-electrostatic contribution of the HI-bulk water interaction, the interaction potentials are individually parameterized. Translational diffusion coefficients, hydration enthalpies, and vibrational normal mode frequencies were calculated from the MD simulations. Physico-chemical properties satisfactorily agree with experiments validating the robustness of the force field strategy. The solvation dynamics and structure for all hexavalent actinoids are extremely similar and resemble our previous analysis of the uranyl cation. This supports the idea of using the uranyl cation as a reference for the study of other minor actinyls. The comparison between the NpO2+ 2 and NpO+ 2 hydration only provides significant differences in first and second shell distances and second-shell mean residence times. We propose a single general view of the [AnO2] 2+/+ hydration structure: aqueous actinyls are amphiphilic anisotropic solutes which are equatorially conventional spherically symmetric cations capped at the poles by clathrate-like water structures.Junta de Andalucía de España, Plan Andaluz de Investigación-FQM-28