Relating quarks and leptons without grand-unification

In combination with supersymmetry, flavor symmetry may relate quarks with leptons, even in the absence of a grand-unification group. We propose an SU(3)xSU(2)xU(1) model where both supersymmetry and the assumed A4 flavor symmetries are softly broken, reproducing well the observed fermion mass hierarchies and predicting: (i) a relation between down-type quarks and charged lepton masses, and (ii) a correlation between the Cabibbo angle in the quark sector, and the reactor angle characterizing CP violation in neutrino oscillations.Comment: 4 pages, 2 figures, version published in PR

Flavour-symmetric type-II Dirac neutrino seesaw mechanism

We propose a Standard Model extension with underlying A4 flavour symmetry where small Dirac neutrino masses arise from a Type-II seesaw mechanism. The model predicts the "golden" flavour-dependent bottom-tau mass relation, requires an inverted neutrino mass ordering and non-maximal atmospheric mixing angle. Using the latest neutrino oscillation global fit we derive restrictions on the oscillation parameters, such as a correlation between Dirac CP phase and the lightest neutrino mass.Comment: 10 pages, 4 figure

Discrete dark matter

We propose a new motivation for the stability of dark matter (DM). We suggest that the same non-abelian discrete flavor symmetry which accounts for the observed pattern of neutrino oscillations, spontaneously breaks to a Z2 subgroup which renders DM stable. The simplest scheme leads to a scalar doublet DM potentially detectable in nuclear recoil experiments, inverse neutrino mass hierarchy, hence a neutrinoless double beta decay rate accessible to upcoming searches, while reactor angle equal to zero gives no CP violation in neutrino oscillations.Comment: minor changes to match version accepted in PRD, one reference adde

A mesoscopic stochastic model for the specific consumption rate in substrate-limited microbial growth

The specific consumption rate of substrate, as well as the associated specific growth rate, is an essential parameter in the mathematical description of substrate-limited microbial growth. In this paper we develop a completely new kinetic model of substrate transport, based on recent knowledge on the structural biology of transport proteins, which correctly describes very accurate experimental results at near-zero substrate concentration values found in the literature, where the widespread Michaelis-Menten model fails. Additionally, our model converges asymptotically to Michaelis-Menten predictions as substrate concentration increases. Instead of the single active site enzymatic reaction of Michaelis-Menten type, the proposed model assumes a multi-site kinetics, simplified as an apparent all-or-none mechanism for the transport, which is controlled by means of the local substrate concentration in the close vicinity of the transport protein. Besides, the model also assumes that this local concentration is not equal to the mean substrate concentration experimentally determined in the culture medium. Instead, we propose that it fluctuates with a mostly exponential distribution of Weibull type

A new neutrino mass sum rule from inverse seesaw

A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). One of these implies in a lower bound on the effective neutrinoless double beta mass parameter, even for normal hierarchy neutrinos. Here we propose a new model based on the S4 flavor symmetry that leads to the new neutrino mass sum-rule and discuss how to generate a nonzero value for the reactor mixing angle indicated by recent experiments, and the resulting correlation with the solar mixing angle.Comment: 14 pages, 4 figure

Employment, wage and price reactions to the crisis in Spain : firm-level evidence from the WDN survey

Este documento describe los principales resultados de la tercera ola de la encuesta española sobre formación de salarios realizada en el marco de la red de investigación del ESCB sobre la dinámica salarial (WDN, por sus siglas en inglés). Su principal objetivo es proporcionar información sobre la demanda, las condiciones de financiación y otros factores que determinan la actividad económica, obre los ajustes salariales, de precios y de empleo en el período 2010-2013, y sobre la percepción de los cambios institucionales en el mercado de trabajo de las empresas. La encuesta se realizó a finales de 2014 a partir de una muestra representativa de 1.975 empresas españolas que cubren los sectores de manufactura, la energía y los servicios de mercado. Los principales resultados muestran que el ajuste de las empresas españolas a la caída de la demanda y otras condiciones negativas desde 2010 se basó en gran medida en el despido de los empleados con contratos temporales, aunque las empresas más afectadas por la crisis también redujeron significativamente el empleo permanente. Por el contrario, los ajustes de salarios y horas fueron limitados, incluso en aquellas empresas más afectadas por los shocks negativos.

Polyunsaturated fatty acids in atrial fibrillation: Looking for the proper candidates

This Document is Protected by copyright and was first published by Frontiers. All rights reserved. it is reproduced with permissionAtrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice with growing prevalence in developed countries. Several medical and interventional therapies, such as atrial specific drugs and pulmonary vein isolation, have demonstrated prevention of recurrences. However, their suboptimal long-term success and significant rate of secondary effects have led to intensive research in the last decade focused on novel alternative and supplemental therapies. One such candidate is polyunsaturated fatty acids (PUFAs). Because of their biological properties, safety, simplicity, and relatively cheap cost, there is a special clinical interest in omega-3 PUFAs as a possible antiarrhythmic agent. Obtained from diets rich in fish, they represent one of the current supplemental therapies. At the cellular level, an increasing body of evidence has shown that n-3 PUFAs exert a variety of effects on cardiac ion channels, membrane dynamic properties, inflammatory cascade, and other targets related to AF prevention. In this article, we review the current basic and clinical evidence pertinent to n-3 PUFAs in AF treatment and prevention.We also discuss controversial outcomes among clinical studies and propose specific subsets of AF patients who will benefit most from n-3 PUFAsNHLBI Grant K99-HL105574 to SFN and the Alfonso Martín Escudero Foundation Grant to DF

Upregulation of cardiac NO/NOS system during short-term hypoxia and the subsequent reoxygenation period

Hypoxia/reoxygenation (H/R) reportedly influences nitric oxide (NO) production and NO synthase (NOS) expression in the heart. Nonetheless, a number of works have shown controversial results regarding the changes that the cardiac NO/NOS system undergoes under such situations. Therefore, this study aims to clarify the behaviour of this system in the hypoxic heart by investigating seven different reoxygenation times. Wistar rats were submitted to H/R (hypoxia for 30 min; reoxygenation of 0, 2, 12, 24, 48, 72 h, and 5 days) in a novel approach to address the events provoked by assaults under such circumstances. Endothelial and inducible NOS (eNOS and iNOS) mRNA and protein expression, as well as enzymatic activity and enzyme location were determined. NO levels were indirectly quantified as nitrate/nitrite, and other S-nitroso compounds (NOx), which would act as NO-storage molecules. The results showed a significant increase in eNOS mRNA, protein and activity, as well as in NOx levels immediately after hypoxia, while iNOS protein and activity were induced throughout the reoxygenation period. These findings indicate that, not only short-term hypoxia, but also the subsequent reoxygenation period upregulate cardiac NO/NOS system until at least 5 days after the hypoxic stimulus, implying major involvement of this system in the changes occurring in the heart in response to H/R

Fluorescent Probes for Monitoring the UV Curing of Acrylic Adhesives, 1. FTIR and Fluorescence in Real Time

The use of the fluorescence technique for monitoring the UV-curing of two polyurethane-based adhesives containing acrylic monomers is described in this paper. The increase of the fluorescence intensity as well as the maximum wavelength shift on emission was measured in real time during the photopolymerisation process. The established relationship between fluorescence and conversion allowed monitoring of the course of the process beyond vitrification. In that sense, all the fluorescent probes studied were sensitive to the formulation curing and in some cases, the range of conversions in which they were useful was limited by their size and probably, by the free volume fraction in the polymeric matrix. Moreover, polymerisation rates were obtained from fluorescent kinetic profiles and used to carry out a comparative study of the different photosensitive formulations. The real time FTIR (RTIR) results show the highest photoinitiation efficiency of the photoinitiator 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone (Irgacure 369) compared to that of 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651). The limitation of RTIR method for monitoring slow post-reactions was overcome by the use of the fluorescence-based method. Thus, a fluorescence intensity increase and a blue-shift of the emission band were measured after the limiting conversion was attained. Dynamic mechanical analysis showed that the glass transition temperature of the polymer increases during prolonged exposure to irradiation confirming the increase of the system rigidity.The authors would like to thank the Union European Commission for funding through the BRITE-Euram Project (BE97-4472). Gratitude is also extended to Comisión Interministerial de Ciencia y Tecnología (CICYT) for financial support (MAT97-0727) and to Comunidad Autónoma de Madrid, CAM (07N/0002/1998), as well as to the Spanish Ministerio de Educación y Cultura. We thank Dr. K. Dietliker, from Ciba Speciality Chemicals, for providing the photoinitiators and also the Loctite Corporation for the adhesives

Spain : from immigration to emigration?

Desde el inicio de la Gran Recesión la tasa de desempleo en España ha aumentado en casi 18 puntos porcentuales. El aumento del desempleo está afectando a todos los grupos de población, incluyendo a los individuos de mayor nivel educativo y, en mayor medida, a la población extranjera, cuya tasa de desempleo es de alrededor del 40 %. Esta situación se ha producido después de un período en el que tuvieron lugar flujos de inmigración muy elevados (1995-2007) que llevaron a la población extranjera residente en España a alcanzar el 11 % de la población total. En este artículo se documentan las características de los flujos migratorios recientes observados en España y se analiza el modo en que la población extranjera, en relación con la población española, está cambiando sus pautas migratorias en respuesta al aumento del desempleo. Con base en esta comparación, se extraen algunas conclusiones acerca de la composición de la población emigrante española por nivel educativo y se conjeturan algunas de sus implicacionesSince the start of the Great Recession the unemployment rate in Spain has risen by almost 18 percentage points. The unemployment crisis is affecting all population groups, including the more highly educatedbut it is even more acute for the foreign population, whose unemployment rate is close to 40%. This situation follows a period of very high immigration flows (1995-2007) that set the number of foreigners living in Spain at 11% of the population. This paper documents the characteristics of recent migration flows to Spain and compares how foreign and Spanish nationals are moving abroad and across Spanish regions in response to the unemployment crisis. Building on this comparison, we shed some light on the selection of migrants by educational level and offer conjecture as to the implications of the migration outflows observed in recent year