Gauge invariant structures and Confinement

By looking at cooled configurations on the lattice, we study the presence of peaks in the action density, or its electric and magnetic components, in the SU(2) gauge vacuum. The peaks are seen to be of instanton-like nature and their number variation takes care of the drop in the string tension observed when cooling. Possible explanations of this finding are analysed.Comment: uuencoded and compressed file of the Postcript file newpaper.ps, fig1.ps,fig2.eps,fig3.ps and fig4.ps. 13 pages of text and 4 figures Style modifications and misprints correcte

From Perturbation Theory to Confinement: How the String Tension is built up

We study the spatial volume dependence of electric flux energies for SU(2) Yang-Mills fields on the torus with twisted boundary conditions. The results approach smoothly the rotational invariant Confinement regime. The would-be string tension is very close to the infinite volume result already for volumes of $(1.2 \ {\rm fm.})^3$. We speculate on the consequences of our result for the Confinement mechanism.Comment: 6p, ps-file (uuencoded). Contribution to Lattice'93 Conference (Dallas, 1993). Preprint INLO-PUB 18/93, FTUAM-93/4

Pennella filosa (Linnaeus, 1758) (Copepoda, Siphonostomatoida, Pennellidae) from Coryphaena hippurus Linnaeus, 1758 (Pisces, Coryphaenidae) captured in western Mediterranean (Balearic Islands). Morphological and biological aspects

Sixty one fishes of the species Coryphaena hippurus (Linneo, 1758) have been examined for the presence of the pennellid copepod Pennella filosa (Linneo, 1758) from western Mediterranean (Balearic Islands). Prevalence was 46%. Head, neck, genital complex and abdomen were measured as well as horns. The cefalotorax of the parasites were attached in different locations on fishes but mainly on fins and dorsolateral muscles. Mean intensity, mean abundance and range were determined and data has been analysed by means of Pearson Correlation Coefficient. Likewise ecological aspects of the parasitism and some data of biological cycle were examined.Se han examinado sesenta y un especímenes de Coryphaena hippurus (Linneo, 1758) para hallar la presencia del copépodo del género Pennella Pennella filosa (Linneo, 1758) del Mediterráneo occidental (Islas Baleares). La prevalencia fue del 46%. Se realizaron mediciones de cabeza, cuello, complejo genital y abdomen, así como de los “cuernos”. El cefalotórax de los parásitos estaba adherido a diferentes partes del cuerpo de los peces, pero principalmente a las aletas y a los músculos dorsolaterales. Se determinaron la intensidad media, la abundancia media y el rango, y se analizaron los datos mediante el coeficiente de correlación de Pearson. Igualmente, se examinaron aspectos ecológicos del parasitismo y algunos datos del ciclo biológico.Ciencias del Ma

Tipificación y caracterización de granjas cinegéticas de faisán (Phasianus colchicus) en España

This research typified and characterised the pheasant (Phasianus colchicus) game farms in Spain using structural and marketing variables. A structured survey was given to 25 private-owned farms in May 2010. A categorical principal components analysis performed to typify the farms yielded two dimensions. First dimension explained 50.5% of the variance and included the variables “number of females in the breeding flock”, and “the farm is of complete-cycle or not”. Second dimension explained 32.3% of the variance and included the variables “age of the farm” and “the farm advertises its activity in the game press”. A cluster analysis differentiated four farm typologies. Farm type 1 included 28% of the farms, being recent (established between 1990 and 2003), complete-cycle and medium-sized (breeding flock of 15 to 300 females), with low advertising activity in the game press and without a hunting preserve. Farm type 2 included 28% of the farms, being the most recent (established between 1994 and 2008), without breeding flock, with low advertising activity, and most have hunting preserve. Farm type 3 included 20% of the farms, being old (established between 1983 and 1992), without breeding flock and with high advertising activity; 40% of them have hunting preserve. Farm type 4 included 24% of the farms, being old (established between 1980 and 1995), complete-cycle and high-sized (breeding flock of 50 to 1,000 females), with high advertising activity; most have hunting preserve. In conclusion, this is an alternative poultry sub-sector consolidated in Spain, despite being only three decades old.Se tipificaron y caracterizaron granjas cinegéticas de faisán (Phasianus colchicus) en España usando variables de estructura y comercialización obtenidas mediante encuesta a 25 granjas privadas en 2010. Un análisis de componentes principales categóricos realizado para tipificar las granjas generó dos dimensiones. La primera dimensión explicó el 50,5% de la varianza e incluyó las variables “número de hembras reproductoras” y “la granja es de ciclo completo o no”. La segunda dimensión explicó el 32,3% de la varianza e incluyó las variables “edad de la granja” y “la granja se publicita en prensa cinegética”. Un análisis de conglomerados subsiguiente diferenció cuatro tipologías de granjas. La tipología 1 incluyó al 28% de las granjas, siendo recientes (fundadas entre 1990 y 2003), de ciclo completo y tamaño medio (15 a 300 hembras reproductoras), con baja actividad publicitaria en prensa cinegética y sin coto de caza. La tipología 2 incluyó un 28% de las granjas, siendo las más recientes (fundadas entre 1994 y 2008), sin reproductores, con baja actividad publicitaria y la mayoría con coto. La tipología 3 incluyó un 20% de las granjas, siendo antiguas (fundadas entre 1983 y 1992), sin plantel reproductor y con elevada actividad publicitaria; el 40% tienen coto. La tipología 4 incluyó un 24% de las granjas, siendo antiguas (fundadas entre 1980 y 1995), de ciclo completo y gran tamaño (50 a 1.000 hembras reproductoras), con elevada actividad publicitaria y la mayoría con coto. Con sólo tres décadas de existencia este subsector avícola alternativo está consolidado en Españ

Inequality in the face of death: The income gradient in mortality of the spanish pre-recession working-age population

The purpose of this paper is to evaluate the association between socioeconomic status (SES) and mortality over a three-year period for working-age Spaniards (2007–2009), paying particular attention to the effect of income level. The analysis is relatively new in Spain, and the studies are limited. Neither income nor wealth are included in existing Spanish mortality studies. The main reason for this limitation is the nature of the data sets used, mainly Census Records. We overcome this problem by using data on 693, 994 individuals taken from a Social Security sampling and used to estimate the probabilities of death for each income decile and the mortality rate ratios in three different models: (1) using only income, controlled by age and sex, (2) adding socio-economic and geographical variables, and (3) adding level of education. However, the data used here also have some limitations. They do not include government employees, the military or the Department of Justice personnel, whose exclusion we believe causes an under-representation of highly educated people in our sample. The results confirm that there is a non-linear relationship between mortality and income. This non-linear relationship implies that income redistribution resulting from progressive taxation systems could lead to higher reductions in mortality for low-income groups than the reductions induced in the mortality of the high-income population, thus reducing overall mortality. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Generation of rotationally dominated galaxies by mergers of pressure-supported progenitors

Through the analysis of a set of numerical simulations of major mergers between initially non-rotating, pressure supported progenitor galaxies with a range of central mass concentrations, we have shown that: (1) it is possible to generate elliptical-like galaxies, with v/sigma > 1 outside one effective radius, as a result of the conversion of orbital- into internal-angular momentum; (2) the outer regions acquire part of the angular momentum first; (3) both the baryonic and the dark matter components of the remnant galaxy acquire part of the angular momentum, the relative fractions depend on the initial concentration of the merging galaxies. For this conversion to occur the initial baryonic component must be sufficiently dense and/or the encounter should take place on a orbit with high angular momentum. Systems with these hybrid properties have been recently observed through a combination of stellar absorption lines and planetary nebulae for kinematic studies of early-type galaxies. Our results are in qualitative agreement with such observations and demonstrate that even mergers composed of non-rotating, pressure-supported progenitor galaxies can produce early-type galaxies with significant rotation at large radii.Comment: 5 pages, 6 figures, 2 tables. Accepted for publication in A&A Letter

Investigating Yang-Mills theory and Confinement as a function of the spatial volume

We study the volume dependence of electric flux energies for SU(2) gauge theory with twisted boundary conditions. The curves interpolate smoothly between the perturbative semiclassicalresults and the Confinement regime. On the basis of our results, we propose that the Confinement property might be caused by a class of non-dilute multi-instanton configurations.Comment: Postscript - paper.ps and sig_lt3c.eps (Fig 1). 25 pages of text and 1 figur

First-Principle Description of Correlation Effects in Layered Materials

We present a first-principles description of anisotropic materials characterized by having both weak (dispersion-like) and strong covalent bonds, based on the Adiabatic--Connection Fluctuation--Dissipation Theorem within Density Functional Theory. For hexagonal boron nitride the in-plane and out of plane bonding as well as vibrational dynamics are well described both at equilibrium and when the layers are pulled apart. Also bonding in covalent and ionic solids is described. The formalism allows to ping-down the deficiencies of common exchange-correlation functionals and provides insight towards the inclusion of dispersion interactions into the correlation functional.Comment: Accepted for publication in Physical Review Letter

Análisis Económico de las Telecomunicaciones en España: Fortalezas y Debilidades

El sector de las telecomunicaciones es uno de los que están avanzando más rápidamente hacia un mercado liberalizado, si lo comparamos con otros como el eléctrico, gas, transporte, servicio postal, etcétera. Las telecomunicaciones son fundamentales para fomentar el crecimiento del producto interior bruto y conseguir reducciones en costes y mejoras de eficiencia productiva y asignativa en otros sectores. Esto es así por la rápida incorporación de innovaciones tecnológicas, y especialmente las relacionadas con las tecnologías de la información y la comunicación (TIC). En este artículo se da una rápida visión de la evolución histórica de la regulación de las telecomunicaciones en España desde 1924 hasta 2003. Se presenta un análisis cuantitativo sobre la evolución reciente del sector en términos del tráfico por tipo de llamada,de las cuotas de mercado de las empresas, de los precios finales (price cap) y de la inversión en relación con el ciclo de vida de los nuevos productos. Por último, se presenta un breve estudio comparativo entre España, la Unión Europea y Estados Unidos desde 1990 hasta 2000, que servirá de base para hacer una reflexión final sobre las debilidades, amenazas, fortalezas y oportunidades (DAFO) del sector.Publicad

Vertex corrections in localized and extended systems

Within many-body perturbation theory we apply vertex corrections to various closed-shell atoms and to jellium, using a local approximation for the vertex consistent with starting the many-body perturbation theory from a DFT-LDA Green's function. The vertex appears in two places -- in the screened Coulomb interaction, W, and in the self-energy, \Sigma -- and we obtain a systematic discrimination of these two effects by turning the vertex in \Sigma on and off. We also make comparisons to standard GW results within the usual random-phase approximation (RPA), which omits the vertex from both. When a vertex is included for closed-shell atoms, both ground-state and excited-state properties demonstrate only limited improvements over standard GW. For jellium we observe marked improvement in the quasiparticle band width when the vertex is included only in W, whereas turning on the vertex in \Sigma leads to an unphysical quasiparticle dispersion and work function. A simple analysis suggests why implementation of the vertex only in W is a valid way to improve quasiparticle energy calculations, while the vertex in \Sigma is unphysical, and points the way to development of improved vertices for ab initio electronic structure calculations.Comment: 8 Pages, 6 Figures. Updated with quasiparticle neon results, extended conclusions and references section. Minor changes: Updated references, minor improvement