Solving dynamic stochastic economic models by mathematical programming decomposition methods.

Discrete-time optimal control problems arise naturally in many economic problems. Despite the rapid growth in computing power and new developments in the literature, many economic problems are still quite challenging to solve. Economists are aware of the limitations of some of these approaches for solving these problems due to memory and computational requirements. However, many of the economic models present some special structure that can be exploited in an efficient manner. This paper introduces a decomposition methodology, based on a mathematical programming framework, to compute the equilibrium path in dynamic models by breaking the problem into a set of smaller independent subproblems. We study the performance of the method solving a set of dynamic stochastic economic models. The numerical results reveal that the proposed methodology is efficient in terms of computing time and accuracyDynamic stochastic economic model; Computation of equilibrium; Mathematical programming; Decomposition techniques;

A chiral route to spontaneous entanglement generation

We study the generation of spontaneous entanglement between two qubits chirally coupled to a waveguide. The maximum achievable concurrence is demonstrated to increase by a factor of $4/e \sim 1.5$ as compared to the non-chiral coupling situation. The proposed entanglement scheme is shown to be robust against variation of the qubit properties such as detuning and separation, which are critical in the non-chiral case. This result relaxes the restrictive requirements of the non-chiral situation, paving the way towards a realistic implementation. Our results demonstrate the potential of chiral waveguides for quantum entanglement protocols.Comment: 5 pages + 1 page supplemental, 4 figure

Solving dynamic stochastic economic models by mathematical programming decomposition methods

Discrete-time optimal control problems arise naturally in many economic problems. Despite the rapid growth in computing power and new developments in the literature, many economic problems are still quite challenging to solve. Economists are aware of the limitations of some of these approaches for solving these problems due to memory and computational requirements. However, many of the economic models present some special structure that can be exploited in an efficient manner. This paper introduces a decomposition methodology, based on a mathematical programming framework, to compute the equilibrium path in dynamic models by breaking the problem into a set of smaller independent subproblems. We study the performance of the method solving a set of dynamic stochastic economic models. The numerical results reveal that the proposed methodology is efficient in terms of computing time and accuracyPublicad

Harvesting Excitons Through Plasmonic Strong Coupling

Exciton harvesting is demonstrated in an ensemble of quantum emitters coupled to localized surface plasmons. When the interaction between emitters and the dipole mode of a metallic nanosphere reaches the strong coupling regime, the exciton conductance is greatly increased. The spatial map of the conductance matches the plasmon field intensity profile, which indicates that transport properties can be tuned by adequately tailoring the field of the plasmonic resonance. Under strong coupling, we find that pure dephasing can have detrimental or beneficial effects on the conductance, depending on the effective number of participating emitters. Finally, we show that the exciton transport in the strong coupling regime occurs on an ultrafast timescale given by the inverse Rabi splitting ($\sim10~$fs), orders of magnitude faster than transport through direct hopping between the emitters.Comment: 5 pages, 3 figure

Uso de las terapias biológicas en las enfermedades autoinmunes sistémicas

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Breaking the misery wheel? Fertility control, social mobility, and biological well-being in rural Spain (1835–1959)

Abstract Fertility control strategies became widespread in rural Spain through the twentieth century: a significant number of parents decided to reduce their marital fertility once the advantages of control strategies became widely known. This paper explores the impact of those practices on children through a comparative study of the heights and occupations of grandparents, parents, and children. We analyze more than 1,200 individuals from three different generations born between 1835 and 1959 in 14 rural Spanish villages, studying whether the advantages associated with fertility control were maintained over time favoring a better family status or whether they were diluted in the next generation. The largest increases in height were among children whose parents controlled their fertility by stopping having children before the mother's 36th birthday. However, it does not seem that this increase in biological well-being was accompanied by major episodes of upward social mobility

Altered electrochemistry of poly(3,4-ethylenedioxythiophene) after activation of the inserted cobalt ions

Cobalt ions were inserted into poly(3,4-ethylenedioxythiophene) by cyclic voltammetry in a 0.1M Co(NO3)2 aqueous solution (PEDOT(Co)). After activation of the inserted cobalt, the PEDOT(aCo) system was investigated by cyclic voltammetry, digital video electrochemistry, spectroelectrogravimetry, and coupled impedance techniques (ac-electrogravimetry) to elucidate the key role of inserted cobalt ions in the altered electrochemistry of PEDOT. The incorporation of Co2+ involves slow transfer of cations for charge compensation during 2+⇄3+ conversion inside the PEDOT. This fact explains the enhanced charge storage showed by PEDOT(aCo) compared with pristine PEDOT at similar potentials. Finally, the stability of PEDOT(aCo) was investigated by cyclic voltammetry measuring at the same time current, mass and motional resistance variation during 100 cycles offering high stability at all times.This work was supported by the Spanish E3TECH-PLUS Research Network RED2022-134552-T (MICINN/AEI, Spain). SEM was carried out in the Microscopy Section of Central Service for Experimental Research (SCSIE) of the University of Valencia. Esteban Guillén acknowledges the support from the Generalitat Valenciana (INVEST/2022/431)

Comparison of four strategies of ram management in a semen collection centre

Thirty Merino rams were used to determine the effect of four management systems of rams on semen quality during the anoestrous season. Animals were divided into four groups: Artificial-Photoperiod group (AP; n = 8), which were isolated from females and exposed to artificial long days (16 hr/d) from 1 Feb to 15 Mar; Natural-Photoperiod (NP; n = 8), isolated from females and exposed to the natural photoperiod throughout the experiment; Oestrous-Ewe group (EE; n = 7), housed in a pen adjacent to another pen that housed three ewes in oestrus, and Anestric-Ewe group (AE; n = 7), housed adjacent to another pen that housed three ovariectomized ewes. From 20 Mar to the end of May (10 weeks), semen samples were collected weekly, and blood samples were collected to determine plasma testosterone concentrations. Mean plasma testosterone concentrations, ejaculate volume and reaction time were not affected either by treatment or week. There was a significant effect (p < .01) of ram treatment on sperm concentration, and both TM y PM, and their interaction, were significantly affected by group and week (p < .001). Rams exposed to ewes in oestrus presented the largest sperm concentration (p < .05) compared with the other three groups, although they had the lowest total and progressive motilities (p < .01). In conclusion, management strategy in spring affects semen quality of rams, with the presence of ewes in oestrus being the best plan to increase sperm concentration

Geochemistry of the Zn-Pb-Cu-(Ag)-(Au) epithermal deposits from San José (SE Spain)

Versión preprintAbstracts of the 19th Annual V.M. Goldschmidt Conference (2009): "Challenges to our volatile planet". June 21-26 in Davos (Switzerland).The San José Zn-Pb-Cu-(Ag-Au) vein systems, previously described as low-sulfidation [1], are located in the Cabo de Gata Volcanic Field (SE Spain). These deposits comprise mainly base metal bearing sulfide/sulfosalts quartz veins, while disseminated pyrite with small quantities of gold appear in areas of vuggy silica alteration. Wallrock alteration includes silicification, advanced argillic, argillic and propylitic zones. Very abundant, penetrative, stockwork-like Fe-Al sulfate veins are found in the argillic and advanced argillic alteration, but ore veins do not show a clear relationship with the alteration zone. Mass balance using the isocone method reveals a gradual lixiviation of most of the elements (except silica) in the highly altered volcanic rocks involving a generalized loss of mass and an increase in the content of some metallic elements (Zn, Pb, Cu) in the less altered zones. Vein sulfides show a similar or slighty heavier sulfur signature (δ34S: 6-12‰) compared to the dominant volcanic signature of the zone (δ34S: 1-7‰[1]), suggesting a magmatic source but with possible incorporation of sea water sulfate via inorganic reduction. Such magamtic input could also be related to the gold mineralization. The barite signature (δ34S: 19-21‰) also supports sea water involvement. Pyrite in silicification shows depleted sulfur (δ34S: 2-6‰) perhaps as product of the disproportionation of magmatic SO2 which produced the acid alteration. Abundant alunite-jarosite has light sulphur (δ34S: 4-10‰), but its abundance and ocurrence rule out a simple supergene origin. Meanwhile, oxygen isotopes in quartz (δ18O: 8-18‰) indicate the likely involvement of magmatic and non-magmatic fluids in ore mineralization. The field, mineralogical and geochemical data suggest a complex mineralization history in the San José area, with evidence of both low and high sulfidation hydrothermal systems and the involvement of magmatic and seawater fluids.Departamento de Mineralogía y Petrología (Universidad de Granada). Departamento de Didáctica de las Ciencias Experimentales (Universidad de Granada). Instituto Andaluz de Ciencias de la Tierra (Universidad de Granada- Centro Superior de Investigaciones Científicas