ESTIMATION OF INCOME DISTRIBUTION AND DETECTION OF SUBPOPULATIONS: AN EXPLANATORY MODEL

Inequality and polarization analyses are complementary but conceptually different. They are usually implemented independently in practic e, with different a priori assumptions and different tools. In this paper, we develop a unique method to study simultaneously these different and complementary concerns. Based on mixture models, the method we develop includes at the same time : an estimation of income distribution with no a priori assumptions - a decomposition in several homogeneous subpopulations - an explanatory model to study the structure of the income distribution.

Asymptotic properties for a simulated pseudo maximum likelihood estimator

We propose an estimator for parameters of nonlinear mixed effects model, obtained by maximization of a simulated pseudo likelihood. This simulated criterion is constructed from the likelihood of a Gaussian model whose means and variances are given by Monte Carlo approximations of means and variances of the true model. If the number of experimental units and the sample size of Monte Carlo simulations are respectively denoted by N and K, we obtained the strong consistency and asymptotic normality of the estimator when the ratio NJ/2 /K tends to zero

Histone deacetylase inhibitors induce invasion of human melanoma cells in vitro via differential regulation of N-cadherin expression and RhoA activity

Background: Histone deacetylase inhibitors (HDACi) exert multiple cytotoxic actions on cancer cells. Currently, different synthetic HDACi are in clinical use or clinical trials; nevertheless, since both pro-invasive and anti-invasive activities have been described, there is some controversy about the effect of HDACi on melanoma cells. Methods: Matrigel and Collagen invasion assays were performed to evaluate the effect of several HDACi (Butyrate, Trichostatin A, Valproic acid and Vorinostat) on two human melanoma cell line invasion (A375 and HT-144). The expression of N- and E-Cadherin and the activity of the RhoA GTPase were analyzed to elucidate the mechanisms involved in the HDACi activity. Results: HDACi showed a pro-invasive effect on melanoma cells in vitro. This effect was accompanied by an up-regulation of N-cadherin expression and an inhibition of RhoA activity. Moreover, the down-regulation of N-cadherin through blocking antibodies or siRNA abrogated the pro-invasive effect of the HDACi and, additionally, the inhibition of the Rho/ROCK pathway led to an increase of melanoma cell invasion similar to that observed with the HDACi treatments. Conclusion: These results suggest a role of N-cadherin and RhoA in HDACi induced invasion and call into question the suitability of some HDACi as antitumor agents for melanoma patients

Schwarzschild black holes can wear scalar wigs

We study the evolution of a massive scalar field surrounding a Schwarzschild black hole and find configurations that can survive for arbitrarily long times, provided the black hole or the scalar field mass is small enough. In particular, both ultra-light scalar field dark matter around supermassive black holes and axion-like scalar fields around primordial black holes can survive for cosmological times. Moreover, these results are quite generic, in the sense that fairly arbitrary initial data evolves, at late times, as a combination of those long-lived configurations.Comment: 5 pages, 3 figures. Accepted for publication in Physical Review Letter

Le groupe de Galois absolu de C(t)

La théorie de Galois des corps a des relations étroites avec celle des revêtements topologiques. Les actions d’un groupe et les revêtements ramifiés des surfaces de Riemann ont aussi des caractéristiques similaires. Ces connexions s’expriment de façon très précise comme des équivalences de catégories.Dans ce travail, on présente et démontre ces équivalences. Elles fournissent un dictionnaire qui permet de regarder le même problème avec des points de vue très différents. Ce changement de cadre peut être une méthode puissante. On s’en sert pour montrer que tout groupe fini se réalise comme le groupe de Galois d’une extension galoisienne du corps C(t) des fractions rationnelles complexes. Finalement, on calcule son groupe de Galois absolu, toujours à l’aide des équivalences de catégories entre extensions des corps de fonctions méromorphes, revêtements ramifiés des surfaces de Riemann, revêtements topologiques et actions des groupes.La teoría de Galois de cuerpos tiene estrechas relaciones con la de recubrimientos topológicos. Las acciones de un grupo y los recubrimientos ramificados de superficies de Riemann también tienen características similares. Estas conexiones se expresan de manera muy precisa como equivalencias de categorías.En este trabajo, presentamos y demostramos estas equivalencias, que nos dan un diccionario que permite mirar el mismo problema con dos puntos de vista muy diferentes. Utilizamos esta potencia para mostrar que todo grupo finito se realiza como el grupo de Galois de una extensión de Galois del cuerpo C(t) de fracciones racionales complejas. Finalmente, calculamos su grupo de Galois absoluto, siempre con la ayuda de las equivalencias de categorías entre extensiones de cuerpos de funciones meromorfas, recubrimientos ramificados de superficies de Riemann, recubrimientos topológicos y acciones de grupos.<br /

Arsenic and chromium topsoil levels and cancer mortality in Spain

Spatio-temporal cancer mortality studies in Spain have revealed patterns for some tumours which display a distribution that is similar across the sexes and persists over time. Such characteristics would be common to tumours that shared risk factors, including the chemical soil composition. The objective of the present study is to assess the association between levels of chromium and arsenic in soil and the cancer mortality. This is an ecological cancer mortality study at municipal level, covering 861,440 cancer deaths in 7917 Spanish mainland towns from 1999 to 2008. Chromium and arsenic topsoil levels (partial extraction) were determined by ICP-MS at 13,317 sampling points. To estimate the effect of these concentrations on mortality, we fitted Besag, York and Mollié models, which included, as explanatory variables, each town’s chromium and arsenic soil levels, estimated by kriging. In addition, we also fitted geostatistical-spatial models including sample locations and town centroids (non-aligned data), using the integrated nested Laplace approximation (INLA) and stochastic partial differential equations (SPDE). All results were adjusted for socio-demographic variables and proximity to industrial emissions. The results showed a statistical association in men and women alike, between arsenic soil levels and mortality due to cancers of the stomach, pancreas, lung and brain and non-Hodgkin’s lymphomas (NHL). Among men, an association was observed with cancers of the prostate, buccal cavity and pharynx, oesophagus, colorectal and kidney. Chromium topsoil levels were associated with mortality among women alone, in cancers of the upper gastrointestinal tract, breast and NHL. Our results suggest that chronic exposure arising from low levels of arsenic and chromium in topsoil could be a potential risk factor for developing cancer. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11356-016-6806-y) contains supplementary material, which is available to authorized users

Dynamical evolutions of ℓ-boson stars in spherical symmetry

In previous work, we have found new static, spherically symmetric boson star solutions which generalize the standard boson stars (BSs) by allowing a particular superposition of scalar fields in which each of the fields is characterized by a fixed value of its non-vanishing angular momentum number. We call such solutions 'boson stars'. Here, we perform a series of fully non-linear dynamical simulations of perturbed BSs in order to study their stability, and the final fate of unstable configurations. We show that for each value of, the configuration of maximum mass separates the parameter space into stable and unstable regions. Stable configurations, when perturbed, oscillate around the unperturbed solution and very slowly return to a stationary configuration. Unstable configurations, in contrast, can have three different final states: collapse to a black hole, migration to the stable branch, or explosion (dissipation) to infinity. Just as it happens with BSs, migration to the stable branch or dissipation to infinity depends on the sign of the total binding energy of the star: bound unstable stars collapse to black holes or migrate to the stable branch, whereas unbound unstable stars either collapse to a black hole or explode to infinity. Thus, the parameter allows us to construct a new set of stable configurations. All our simulations are performed in spherical symmetry, leaving a more detailed stability analysis including non-spherical perturbations for future work.Fil: Alcubierre, Miguel. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Barranco, Juan. Universidad de Guanajuato; MéxicoFil: Bernal, Argelia. Universidad de Guanajuato; MéxicoFil: Degollado, Juan Carlos. Universidad Nacional Autónoma de México; MéxicoFil: Diez Tejedor, Alberto. Universidad de Guanajuato; MéxicoFil: Megevand Politano, Miguel Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Núñez, Darío. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Sarbach, Olivier. Universidad Michoacana de San Nicolás de Hidalgo; Méxic

ℓ-boson stars

We present new, fully nonlinear numerical solutions to the static, spherically symmetric Einstein-Klein-Gordon system for a collection of an arbitrary odd number N of complex scalar fields with an internal symmetry and no self-interactions. These solutions, which we dub -boson stars, are parametrized by an angular momentum number ℓ =(N - 1)/2, an excitation number n, and a continuous parameter representing the amplitude of the fields. They are regular at every point and possess a finite total mass. For ℓ = 0the standard spherically symmetric boson stars are recovered. We determine their generalizations for ℓ ≤ 0, and show that they give rise to a large class of new static configurations which might have a much larger compactness ratio than stars.Fil: Alcubierre, Miguel. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Barranco, Juan. Universidad de Guanajuato; MéxicoFil: Bernal, Argelia. Universidad de Guanajuato; MéxicoFil: Degollado, Juan Carlos. Universidad Nacional Autónoma de México; MéxicoFil: Diez Tejedor, Alberto. Universidad de Guanajuato; MéxicoFil: Megevand Politano, Miguel Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Núñez, Darío. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Sarbach, Olivier. Universidad Michoacana de San Nicolás de Hidalgo; Méxic

A CMOS-compatible oscillation-based VO₂ Ising machine solver

Phase-encoded oscillating neural networks offer compelling advantages over metal-oxide-semiconductor-based technology for tackling complex optimization problems, with promising potential for ultralow power consumption and exceptionally rapid computational performance. In this work, we investigate the ability of these networks to solve optimization problems belonging to the nondeterministic polynomial time complexity class using nanoscale vanadium-dioxide-based oscillators integrated onto a Silicon platform. Specifically, we demonstrate how the dynamic behavior of coupled vanadium dioxide devices can effectively solve combinatorial optimization problems, including Graph Coloring, Max-cut, and Max-3SAT problems. The electrical mappings of these problems are derived from the equivalent Ising Hamiltonian formulation to design circuits with up to nine crossbar vanadium dioxide oscillators. Using sub-harmonic injection locking techniques, we binarize the solution space provided by the oscillators and demonstrate that graphs with high connection density (η &gt; 0.4) converge more easily towards the optimal solution due to the small spectral radius of the problem’s equivalent adjacency matrix. Our findings indicate that these systems achieve stability within 25 oscillation cycles and exhibit power efficiency and potential for scaling that surpasses available commercial options and other technologies under study. These results pave the way for accelerated parallel computing enabled by large-scale networks of interconnected oscillators.</p