More examples of structure formation in the Lemaitre-Tolman model

In continuing our earlier research, we find the formulae needed to determine the arbitrary functions in the Lemaitre-Tolman model when the evolution proceeds from a given initial velocity distribution to a final state that is determined either by a density distribution or by a velocity distribution. In each case the initial and final distributions uniquely determine the L-T model that evolves between them, and the sign of the energy-function is determined by a simple inequality. We also show how the final density profile can be more accurately fitted to observational data than was done in our previous paper. We work out new numerical examples of the evolution: the creation of a galaxy cluster out of different velocity distributions, reflecting the current data on temperature anisotropies of CMB, the creation of the same out of different density distributions, and the creation of a void. The void in its present state is surrounded by a nonsingular wall of high density.Comment: LaTeX 2e with eps figures. 30 pages, 11 figures, 30 figure files. Revision matches published versio

Aplasia del arco posterior del Atlas

Las anomalías congénitas del arco posterior del Atlas son poco frecuentes. Se presenta el caso de una paciente, que tras sufrir un accidente se diagnosticó de aplasia parcial del atlas. Esta lesión es considerada como una variante anatómica benigna de la región cráneovertebral. Se expone el desarrollo y el significado de esta anomalía.Congenital anomalies of the posterior arch of the atlas are uncommon. This paper presents the case of a patient who, as result of an accident, was diagnosed as having a congenital partial agenesia of the posterior arch of the atlas. This finding is considered as a benign anatomical variation of the craniovertebral junction region. The development and clinical significance of this anomaly are discussed

Gamma rays from dark matter annihilation in the Draco and observability at ARGO

The CACTUS experiment recently observed a gamma ray excess above 50 GeV from the direction of the Draco dwarf spheroidal galaxy. Considering that Draco is dark matter dominated the gamma rays may be generated through dark matter annihilation in the Draco halo. In the framework of the minimal supersymmetric extension of the standard model we explore the parameter space to account for the gamma ray signals at CACTUS. We find that the neutralino mass is constrained to be approximately in the range between 100 GeV ~ 400 GeV and a sharp central cuspy of the dark halo profile in Draco is necessary to explain the CACTUS results. We then discuss further constraints on the supersymmetric parameter space by observations at the ground based ARGO detector. It is found that the parameter space can be strongly constrained by ARGO if no excess from Draco is observed above 100 GeV.Comment: 15 pages, 4 figure

Cluster Masses Accounting for Structure along the Line of Sight

Weak gravitational lensing of background galaxies by foreground clusters offers an excellent opportunity to measure cluster masses directly without using gas as a probe. One source of noise which seems difficult to avoid is large scale structure along the line of sight. Here I show that, by using standard map-making techniques, one can minimize the deleterious effects of this noise. The resulting uncertainties on cluster masses are significantly smaller than when large scale structure is not properly accounted for, although still larger than if it was absent altogether.Comment: 5 pages, 5 figure

Fracturas diafisarias de húmero en adultos: estudio retrospectivo de 53 casos

Se estudian retrospectivamente 53 pacientes adultos con fractura diafisaria de húmero, 36 de los cuales siguieron el tratamiento ortopédico funcional. En otros 17 casos, pacientes politraumatizados o con fracturas de tercio medio transversas, realizamos tratamiento quirúrgico. La edad media de los pacientes fue 48 ± 2 2 años. Se afectó más el lado derecho, siendo el antecedente etiológico más frecuente el accidente casual. No hubo diferencia entre el tiempo de consolidación con el tratamiento ortopédico-funcional (60 ± 14 días) y el tratamiento quirúrgico (56 ±1 2 días). Como complicaciones hubo 7 pseudoartrosis (4 tras tratamiento ortopédico-funcional y 3 tratamiento quirúrgico). La edad media de los pacientes con pseudoartrosis fue superior a la de los pacientes con consolidación completa. Ocho casos cursaron con lesión del nervio radial, obteniendo una recuperación funcional del 100% en un tiempo medio de 38 ± 30 semanas. Valorando los resultados con arreglo a los criterios de Gayet, hemos obtenido un 80% de buenos y muy buenos resultados con tratamiento ortopédico funcional y un 70% con tratamiento quirúrgico.Fifty three adult patients with fracture of the humeral shaft were retrospectively studied. Orthopaedic-functional treatment was applied in 36 cases. Seventeen patients with either multiple injuries or transverse middle-shaft fractures were surgically treated. The mean age of patients was 48 ± 21 years. Right side was most frecuently affected and casual fall was the predominated etiology. There were no differences regarding the average consolidation period between fractures treated conservatively (60 ± 14 days) and those undergoing surgery (56 ± 12 days). As complications, there were 7 monounions (4 conservative and 3 operative treatment). The mean age of patients with non-unions was higther than those with complete fracture consolidation. Radial nerve injury was seen in 8 cases. In all there patients, a complete functional were recovery was obtained with a mean average time of 38 ± 30 weeks. When evaluating functional results according to Gayet, satisfactory results were found in 80 per cent of patients with conservative treatment and 70 per cent of those surgically treated

Luxación Traumática de Cadera en el Niño

La luxación traumática de cadera en el niño es una lesión poco frecuente. Los autores presentan un caso de luxación anterior de cadera en un niño de 4 años producida por traumatismo mínimo. La exploración realizada en urgencias mostró impotencia funcional para la deambulación y gran dolor. El seguimiento ha sido de 18 meses tras los cuales el paciente no presenta complicaciones. Exponen su experiencia en el caso y revisión de la bibliografía.Traumatic hip dislocation of the hip is rare in children. The authors report a case of anterior hip dislocation in a 4-year-old boy who received relatively minor trauma. He was unable to walk and was in severe pain when seen in emergency room. He was followed-up for 18 months and no complications have appeared. They report here their experience with one case and review the literature

Systematic variation of central mass density slope in early-type galaxies

We study the total density distribution in the central regions ($<\, 1$ effective radius, $R_{\rm e}$) of early-type galaxies (ETGs), using data from the SPIDER survey. We model each galaxy with two components (dark matter halo + stars), exploring different assumptions for the dark matter (DM) halo profile, and leaving stellar mass-to-light ($M_{\rm \star}/L$) ratios as free fitting parameters to the data. For a Navarro et al. (1996) profile, the slope of the total mass profile is non-universal. For the most massive and largest ETGs, the profile is isothermal in the central regions ($\sim R_{\rm e}/2$), while for the low-mass and smallest systems, the profile is steeper than isothermal, with slopes similar to those for a constant-M/L profile. For a concentration-mass relation steeper than that expected from simulations, the correlation of density slope with mass tends to flatten. Our results clearly point to a "non-homology" in the total mass distribution of ETGs, which simulations of galaxy formation suggest may be related to a varying role of dissipation with galaxy mass.Comment: 3 pages, 1 figure, to appear on the refereed Proceeding of the "The Universe of Digital Sky Surveys" conference held at the INAF--OAC, Naples, on 25th-28th november 2014, to be published on Astrophysics and Space Science Proceedings, edited by Longo, Napolitano, Marconi, Paolillo, Iodic

Lensing in an interior Kottler solution

We derive the interior Kottler solution of the incompressible fluid and show that the bending of light in this solution does depend on the cosmological constant.Comment: The inner Kottler solution derived and used in this paper is not new. Corresponding references to Stuchlik (2000) and Boehmer (2003) are added. Also added: a numerical example and a figure. This is the version accepted by Gen. Rel. Grav. However it includes a short passage that an anonymous referee had me suppress

On the Importance of Electroweak Corrections for Majorana Dark Matter Indirect Detection

Recent analyses have shown that the inclusion of electroweak corrections can alter significantly the energy spectra of Standard Model particles originated from dark matter annihilations. We investigate the important situation where the radiation of electroweak gauge bosons has a substantial influence: a Majorana dark matter particle annihilating into two light fermions. This process is in p-wave and hence suppressed by the small value of the relative velocity of the annihilating particles. The inclusion of electroweak radiation eludes this suppression and opens up a potentially sizeable s-wave contribution to the annihilation cross section. We study this effect in detail and explore its impact on the fluxes of stable particles resulting from the dark matter annihilations, which are relevant for dark matter indirect searches. We also discuss the effective field theory approach, pointing out that the opening of the s-wave is missed at the level of dimension-six operators and only encoded by higher orders.Comment: 25 pages, 6 figures. Minor corrections to match version published in JCA

Robust implications on Dark Matter from the first FERMI sky gamma map

We derive robust model-independent bounds on DM annihilations and decays from the first year of FERMI gamma-ray observations of the whole sky. These bounds only have a mild dependence on the DM density profile and allow the following DM interpretations of the PAMELA and FERMI electron/positron excesses: primary channels mu+ mu-, mu+ mu-mu+mu- or e+ e- e+ e-. An isothermal-like density profile is needed for annihilating DM. In all such cases, FERMI gamma spectra must contain a significant DM component, that may be probed in the future.Comment: 16 pages, 8 figures. Final versio