Strong lensing by fermionic dark matter in galaxies

It has been shown that a self-gravitating system of massive keV fermions in thermodynamic equilibrium correctly describes the dark matter (DM) distribution in galactic halos and predicts a denser quantum core towards the center of the configuration. Such a quantum core, for a fermion mass in the range of $50$ keV $\lesssim m c^2 \lesssim 345$ keV, can be an alternative interpretation of the central compact object in Sgr A*. We present in this work the gravitational lensing properties of this novel DM model in Milky Way-like spiral galaxies. We describe the lensing effects of the pure DM component both on halo scales, where we compare them to the effects of the Navarro-Frenk-White and the Non-Singular Isothermal Sphere DM models, and near the galaxy center, where we compare them with the effects of a Schwarzschild BH. For the particle mass leading to the most compact DM core, $m c^2\approx 10^{2}$ keV, we draw the following conclusions. At distances $r\gtrsim 20$ pc from the center of the lens the effect of the central object on the lensing properties is negligible. However, we show that measurements of the deflection angle produced by the DM distribution in the outer region at a few kpc, together with rotation curve data, could help to discriminate between different DM models. We show that at distances $\sim 10^{-4}$ pc strong lensing effects, such as multiple images and Einstein rings, may occur. Large differences in the deflection angle produced by a DM central core and a central BH appear at distances $r\lesssim 10^{-6}$ pc; in this regime the weak-field formalism is no longer applicable and the exact general-relativistic formula has to be used. We find that quantum DM cores do not show a photon sphere what implies that they do not cast a shadow. Similar conclusions apply to the other DM distributions for other fermion masses in the above specified range and for other galaxy types.Comment: 10 pages, 8 figures. v2: Version published in PR

Field-induced phase transitions of repulsive spin-1 bosons in optical lattices

We study the phase diagram of repulsively interacting spin-1 bosons in optical lattices at unit filling, showing that an externally induced quadratic Zeeman effect may lead to a rich physics characterized by various phases and phase transitions. We find that the main properties of the system may be described by an effective field model, which provides the precise location of the phase boundaries for any dimension, being in excellent agreement with our numerical calculations for one-dimensional systems. Our work provides a quantitative guide for the experimental analysis of various types of field-induced quantum phase transitions in spin-1 lattice bosons. These transitions, which are precluded in spin-1/2 systems, may be realized using an externally modified quadratic Zeeman coupling, similar to recent experiments with spinor condensates in the continuum.Comment: 4 pages, 2 figure

Inclusión de un producto fermentado de pescado en la dieta de guineas (Numida meleagris): desempeño productivo y calidad de la carcasa

Guinea fowl (Numida meleagris) is a poultry species suitable for use in meat production to expand and diversify the local poultry industry because of its advantages of high consumer acceptance, resistance to common poultry diseases, and tolerance to poor management conditions. However, the poor feed conversion of this species increases feed costs and limits production. To reduce feed costs it is imperative to find locally available feedstuffs of low cost but with adequate nutritional value. The use of a fermented fish by-product meal (FFBPM) as a protein source in guinea diets could satisfy these criteria and reduce feed costs. This study with 180 birds was undertaken to evaluate the effects of the inclusion of a FFBPM in guinea diets on productive performance and carcass quality. Treatments consisted of FFBPM inclusion at levels of 0 (control), 5, and 10% in each of the starter, grower, and finisher diets. Feed and birds were weighed at 0, 35, 63, and 84 d to determine body weight (BW) and feed conversion. At 84 d, half the birds of each treatment were processed for evaluating carcass composition and determining yields of carcass and major cuts. Fasted live body weights, and plucked and dressed carcass weights were recorded and yields calculated. No significant differences in BW were observed among treatments at 0,63, and 84 d. At 35 d, BW was lower (P < 0.05) in birds with a 10% FFBPM inclusion. Feed conversion at 35 d was also higher with 10% FFBPM and lower in control birds, whereas those receiving 5% FFBPM did not differ from those of the other treatments. Birds fed 10% FFBPM showed significantly lower live, plucked, and dressed weights than those of the control and those fed 5% FFBPM. No differences among treatments were observed in yields of dressed carcass, major cuts, and the proportions of flesh, skin, and bone. However, the percentage of abdominal fats was significantly lower in birds fed a 10% FFBPM than in birds of the control and in those fed the 5% FFBPM level. The results of this study indicate that the inclusion of up to 5% FFBPM in guinea diets has no detrimental effect on bird performance and carcass quality. Thus, FFBPM could be a valuable feed ingredient to supply part of the dietary protein requirements of guinea fowl. La crianza de guinea (Numida meleagris) es una alternativa viable para aumentar la producción local de carne de aves debido a su buena aceptación por el consumidor, resistencia a enfermedades y tolerancia a condiciones de manejo adversas. Sin embargo, la pobre conversión alimenticia de estas aves aumenta los costos de alimentación, limitando su producción. Para reducir dichos costos es necesario utilizar ingredientes poco costosos pero de valor nutricional adecuado. La utilización de un subproducto fermentado de pescado (SPFP) como fuente de proteína en dietas de guinea podría satisfacer estos requisitos y reducir los costos de alimentación. El propósito de esta investigación fue evaluar el efecto de la inclusión de SPFP en dietas de guineas sobre el desempeño productivo y la calidad de la carcasa. Los tratamientos consistieron en la inclusión de 0, 5 y 10% SPFP en las dietas de iniciación, crecimiento y terminación. Se pesó el alimento y las aves a los 0, 35, 63 y 84 d para determinar el peso corporal y la conversión alimenticia. A los 84 d, se procesaron 90 aves para evaluar la calidad de la carcasa y determinar el rendimiento de la misma y sus componentes principales. Se midió su peso vivo en ayuno, peso desplumado y peso listo para cocinar y se calcularon los rendimientos. No se observaron diferencias significativas en peso corporal entre los tratamientos a los 0, 63 y 84 d. A los 35 d el peso corporal fue menor (P < 0.05) en aves a las que se les suministró un 10% SPFP. La conversión alimenticia a los 35 d fue mayor en aves a las que se les suministró 10% SPFP y menor en las aves control, mientras la de aquellas a las que se les suministró 5% SPFP fue similar a la del resto de los tratamientos. Las aves con 10% SPFP registraron un peso vivo, desplumado y listo para cocinar más bajo (P < 0.05) que las aves control y aquéllas con 5% SPFP. No se encontraron diferencias en el rendimiento de la carcasa, cortes principales ni en la proporción de carne, hueso y piel. Sin embargo, el porcentaje de grasa abdominal fue menor (P < 0.05) para las aves a las que se les suministró 10% SPFP y mayor en aves del grupo control. Los resultados de este experimento indican que la inclusión de hasta 5% SPFP en la dieta no tiene efectos detrimentales sobre el desempeño productivo y la calidad de carcasa. El SPFP podría ser un recurso alimentario útil para suplir parcialmente los requisitos proteicos de la guinea

La Ecografía de Partes Blandas como Técnica Diagnóstica de los Quistes Poplíteos

Se presentan 39 casos de quistes poplíteos estudiados mediante ultrasonografía durante los últimos 5 años en el Hospital Clínico de Valencia. Se discute acerca de la utilidad de la ecografía de partes blandas en el diagnóstico de las patologías del hueco poplíteo, haciendo hincapié en sus ventajas respecto a otras técnicas más costosas e invasivas.The authors report 39 cases of popliteal's cysts diagnosed with ultrasonography along the last five years in the Hospital Clínico of Valencia. They argue about the usefulness of ultrasonography of soft-tissues in the diagnosis of popliteal pathologies, urging on his advantages over other techniques more aggresive and expensive

Strong lensing by fermionic dark matter in galaxies

It has been shown that a self-gravitating system of massive keV fermions in thermodynamic equilibrium correctly describes the dark matter (DM) distribution in galactic halos (from dwarf to spiral and elliptical galaxies) and that, at the same time, it predicts a denser quantum core towards the center of the configuration. Such a quantum core, for a fermion mass in the range of 50 keV ≲m c2≲345 keV , can be an alternative interpretation of the central compact object in Sgr A*, traditionally assumed to be a black hole (BH). We present in this work the gravitational lensing properties of this novel DM configuration in nearby Milky-Way-like spiral galaxies. We describe the lensing effects of the pure DM component both on halo scales, where we compare them to the effects of the Navarro-Frenk-White and the nonsingular isothermal sphere DM models, and near the galaxy center, where we compare them with the effects of a Schwarzschild BH. For the particle mass leading to the most compact DM core, m c2≈1 02 keV , we draw the following conclusions. At distances r ≳20 pc from the center of the lens the effect of the central object on the lensing properties is negligible. However, we show that measurements of the deflection angle produced by the DM distribution in the outer region at a few kpc, together with rotation curve data, could help to discriminate between different DM models. In the inner regions 1 0-6≲r ≲20 pc , the lensing effects of a DM quantum core alternative to the BH scenario becomes a theme of an analysis of unprecedented precision which is challenging for current technological developments. We show that at distances ?1 0-4 pc strong lensing effects, such as multiple images and Einstein rings, may occur. Large differences in the deflection angle produced by a DM central core and a central BH appear at distances r ≲1 0-6 pc ; in this regime the weak-field formalism is no longer applicable and the exact general-relativistic formula has to be used for the deflection angle which may become bigger than 2 π . An important difference in comparison to BHs is in the fact that quantum DM cores do not show a photon sphere; this implies that they do not cast a shadow (if they are transparent). Similar conclusions apply to the other DM distributions for other fermion masses in the above-specified range and for other galaxy types.Facultad de Ciencias Astronómicas y Geofísica

Degeneración Basal versus Degeneración Superficial en la Condromalacia Rotuliana

Se hace un estudio en base a las muestras tisulares procedentes de pacientes afectos de condromalacia rotuliana, artrosis y dos casos considerados como testigos. Los hallazgos morfológicos son bastantes similares en los casos de condromalacia rotuliana y artrosis, lo que parece indicar que la condromalacia puede considerarse como un estado preartrósico patelar, si bien en esta son más acusados los fenómenos de rarefacción de la matriz del cartílago superficial y medio de la rótula.A special study with samples of tissue s from some patients suffering chondromalacia patellae, arthrosis, and two patients as control, is made. The morphological findings are quite similar in both case s of chondromalacia patellae and arthrosis. Therefore chondromalacia can be consider as a prearthrosis patellar stadium, although in the chondromalacia state, the fenomenous of rarefaction in the matrix of cartilage, superficial and middle of the rotula, are more important

MECANISMOS MOLECULARES INVOLUCRADOS EN LA DIFERENCIACIÓN DE CÉLULAS MADRE EN LINAJES GLIALES

A pesar del hecho que diferentes tipos de células tienen diferentes funciones y morfologías, todas descienden de una célula ancestral común, conocidas también como células madre, por lo que esencialmente comparten el mismo ADN. Lo que las diferencia es la dinámica molecular, lo cual implica regular modificaciones químicas en el microambiente interno de las células con el fin de modular el nicho de un tejido o un órgano.  Uno de los principales objetivos de este artículo de revisión, es recapitular el desarrollo normal del organismo y como se puede aprovechar la capacidad regenerativa endógena de las células madre. Este articulo define los conceptos claves en biología de células madre con respecto al sistema nervioso, presenta una descripción general del desarrollo de las células oligodendrociticas y su importancia en el desarrollo de la mielinización, el cual requiere un modelo experimental en el que los axones neuronales y los oligodendrocitos se puedan controlar y manipular durante el proceso.