S-Duality, SL(2,Z) Multiplets and Killing Spinors

The S-duality transformations in type IIB string theory can be seen as local U(1) transformations in type IIB supergravity. We use this approach to construct the $SL(2,Z)$ multiplets associated to supersymmetric backgrounds of type IIB string theory and the transformation laws of their corresponding Killing spinors.Comment: 13 pages, Harvma

Optimal scheduling and management of pumped hydro storage integrated with grid-connected renewable power plants

Pumped hydro-energy storage will become a fundamental element of power systems in the coming years by adding value to each link in electricity production and the supply chain. The growth of these systems is essential for improving the integration of renewables and avoiding dependence on fossil fuel sources, such as gas or oil. This paper presents the modeling and application of an optimal hourly management model of grid-connected photovoltaic and wind power plants integrated with reversible pump-turbine units to maximize the monthly operating profits of the energy system and meet electricity demand. The techno-economic dispatch model is formulated as a mixed-integer optimization problem. To assess the proposed model, it is applied to a Spanish case study system, and the results are obtained for an entire year. The combination of renewable energy and pumped hydro energy storage reduces energy dependence by decreasing energy costs by 27 % compared with a system without storage to satisfy the required electricity demand. The findings confirm that storage plays a key role in energy transition to ensure the security and stability of power systems with a higher share of renewable generation

Late vacuum choice and slow roll approximation in gravitational particle production during reheating

In the transition between inflation and reheating, the curvature scalar typically undergoes oscillations which have significant impact on the density of gravitationally produced particles. The commonly used adiabatic vacuum prescription for the extraction of produced particle spectra becomes a non-reliable definition of vacuum in the regimes for which this oscillatory behavior is important. In this work, we study particle production for a scalar field non-minimally coupled to gravity, taking into account the complete dynamics of spacetime during inflation and reheating. We derive an approximation for the solution to the mode equation during the slow-roll of the inflaton and analyze the importance of Ricci scalar oscillations in the resulting spectra. Additionally, we propose a prescription for the vacuum that allows to safely extrapolate the result to the present, given that the test field interacts only gravitationally. Lastly, we calculate the abundance of dark matter this mechanism yields and compare it to observations.Comment: 24 pages, 11 figure

Fermion production at the boundary of an expanding universe: a cold-atom gravitational analogue

We study the phenomenon of cosmological particle production of Dirac fermions in a Friedman-Robertson-Walker spacetime, focusing on a (1+1)-dimensional case in which the evolution of the scale factor is set by the equations of Jackiw-Teitelboim gravity. As a first step towards a quantum simulation of this phenomenon, we consider two possible lattice regularizations, which allow us to explore the interplay of particle production and topological phenomena in spacetimes with a boundary. In particular, for a Wilson-type discretization of the Dirac field, the asymptotic Minkowski vacua connected by the intermediate expansion corresponds to symmetry-protected topological groundstates, and have a boundary manifestation in the form of zero-modes exponentially localized to the spatial boundaries. We show that particle production can also populate these zero modes, which contrasts with the situation with a na\"ive-fermion discretization, in which conformal zero-mass fields exhibit no particle production. We present a scheme for the quantum simulation of this gravitational analogue by means of ultra-cold atoms in Raman optical lattices, which requires real-time control of the Raman-beam detuning according to the scale factor of the simulated spacetime, as well as band-mapping measurements.Comment: 25 pages, 11 figure

Electronic cigarette use among adult population: a cross-sectional study in Barcelona, Spain (2013–2014)

Objective: This study seeks to analyse the prevalence and correlates of electronic cigarette (e-cigarette) use, purchase location and satisfaction with its use in a sample of the general population of the city of Barcelona, Spain. Design, setting and participants We used participants from a longitudinal study of a representative sample of the adult (≥16 years old) population of Barcelona (336 men and 400 women). The field work was conducted between May 2013 and February 2014. We computed the prevalence, adjusted odds ratios (ORs) and their corresponding 95% confidence interval (CI). Results: The prevalence of ever e-cigarette use was 6.5% (95% CI 4.7% to 8.3%): 1.6% current use, 2.2% past use and 2.7% only e-cigarette experimentation. 75% (95% CI 62.8% to 87.3%) of ever e-cigarette users were current cigarette smokers at the moment of the interview. E-cigarette use was more likely among current smokers (OR=54.57; 95% CI 7.33 to 406.38) and highly dependent cigarette smokers (OR=3.96; 95% CI 1.60 to 9.82). 62.5% of the ever users charged their e-cigarettes with nicotine with 70% of them obtaining the liquids with nicotine in a specialised shop. 39.6% of ever e-cigarette users were not satisfied with their use, a similar percentage of not satisfied expressing the smokers (38.9%) and there were no statistically significant differences in the satisfaction between the users of e-cigarettes with and without nicotine. Conclusions: E-cigarette use is strongly associated with current smoking (dual use) and most users continue to be addicted to nicotine. Six out of 10 e-cigarette users preferred devices that deliver nicotine. The satisfaction with e-cigarette use is very low

Derivative couplings in gravitational production in the early universe

Gravitational particle production in the early universe is due to the coupling of matter fields to curvature. This coupling may include derivative terms that modify the kinetic term. The most general first order action contains derivative couplings to the curvature scalar and to the traceless Ricci tensor, which can be dominant in the case of (pseudo-)Nambu-Goldstone bosons or disformal scalars, such as branons. In the presence of these derivative couplings, the density of produced particles for the adiabatic regime in the de Sitter phase (which mimics inflation) is constant in time and decays with the inverse effective mass (which in turn depends on the coupling to the curvature scalar). In the reheating phase following inflation, the presence of derivative couplings to the background curvature modifies in a nontrivial way the gravitational production even in the perturbative regime. We also show that the two couplings -- to the curvature scalar and to the traceless Ricci tensor -- are drastically different, specially for large masses. In this regime, the production becomes highly sensitive to the former coupling while it becomes independent of the latter.Comment: 24 pages, 6 figure

Dual Commitment to Leader and Organization: Alternative Models Based on the Employees’ Emotional Awareness

Management has been considering employee commitment as one of the strategic priorities, due to many studies suggesting the positive influence of commitment on high performance, innovative work behavior, employee retention, and many other important business outcomes. Nevertheless, commitment is considered an abstract construct, from which human resources management needs to create policies and practices that effectively support the business strategy and organizational culture. The existence of many foci of commitment in the workplace has been a challenge in that scenario, being important to understand how different foci relate to each other and how they influence the employee commitment process. To contribute to filling this gap, this research aims to compare two different models, analyzing the relationship between two foci of commitment, namely the affective commitment to the leader and organizational commitment. For this purpose, the employees’ emotional awareness has been considered as an independent variable. Hence, this study seeks to identify which model has higher explanatory power, and consequently, a more significant impact on the process of the employees’ commitment. The implications for theory and practice are discussed.info:eu-repo/semantics/publishedVersio

Smoking behaviour, involuntary smoking, attitudes towards smoke-free legislations, and tobacco control activities in the European Union

The six most important cost-effective policies on tobacco control can be measured by the Tobacco Control Scale (TCS). The objective of our study was to describe the correlation between the TCS and smoking prevalence, self-reported exposure to secondhand smoke (SHS) and attitudes towards smoking restrictions in the 27 countries of the European Union (EU27)

Ala397Asp Mutation of Myosin VIIA Segregating in a Spanish Family with Usher Syndrome Type Ib

[EN] In the current study, 12 Spanish families affected by type-I Usher syndrome, that was previously linked to chromosome 11q, were screened for the presence of mutations in the N-terminal coding portion of the motor domain of the myosin VIIA gene by single-strand conformation polymorphism analysis of the first 14 exons. A mutation (Ala397Asp) segregating with the disease was identified, and several polymorphisms were also detected. It is presumed that the other USH1B mutations in these families could be located in the unscreened regions of the gene.The authors would like to thank the Fondo de Investigaciones Sanitarias (FISS n0 95/1814), the ONCE and the Fundación ONCE for financial support. We acknowledge patients and their family members, as well as the Asociación de retinosis pigmentaria de la Comunidad Valenciana and the FAARPEE, for their help and cooperation.Espinós-Armero, CÁ.; Millán, JM.; Sánchez, F.; Beneyto, M.; Nájera, C. (1998). Ala397Asp Mutation of Myosin VIIA Segregating in a Spanish Family with Usher Syndrome Type Ib. Human Genetics. 102(6):691-694. https://doi.org/10.1007/s004390050763691694102