Cartilaginous metaplasia of varicose veins: a case report

Cartilaginous metaplasia of superficial veins was found in a 64-year-old woman who underwent surgery for varicose veins. At operation, some varicose veins of the medial thigh were semi-rigid and fibroelastic to the touch. Histology revealed that half the lumen was occupied by chondroid tissue. The other half was obliterated by fibrous tissue, typical of post-thrombotic involution. Possible causes of cartilaginous metaplasia are briefly discussed

A new method to unveil blazars among multi-wavelength counterparts of Unassociated Fermi gamma-ray Sources

We discuss a new method for unveiling the possible blazar AGN nature among the numerous population of Unassociated Gamma-ray sources (UGS) in the Fermi catalogues. Our tool relies on positional correspondence of the Fermi object with X-ray sources (mostly from Swift-XRT), correlated with other radio, IR and optical data in the field. We built a set of Spectral Energy Distributions (SED) templates representative of the various blazar classes, and we quantitatively compared them to the observed multi-wavelength flux density data for all Swift-XRT sources found within the Fermi error-box, by taking advantage of some well-recognised regularities in the broad-band spectral properties of the objects. We tested the procedure by comparison with a few well-known blazars, and tested the chance for false positive recognition of UGS sources against known pulsars and other Galactic and extragalactic sources. Based on our spectral recognition tool, we find the blazar candidate counterparts for 14 2FGL UGSs among 183 selected at high galactic latitudes. Further our tool also allows us rough estimates of the redshift for the candidate blazar. In a few cases in which this has been possible (i.e. when the counterpart was a SDSS object), we verified that our estimate is consistent with the measured redshift. The estimated redshifts of the proposed UGS counterparts are larger, on average, than those of known Fermi blazars, a fact that might explain the lack of previous association or identification in published catalogues.Comment: 41 pages, 40 figures, 3 tables, accepted for publication in MNRA

An empirical approach to the extragalactic background light from AEGIS galaxy SED-type fractions

The extragalactic background light (EBL) is of fundamental importance both for understanding the entire process of galaxy evolution and for gamma-ray astronomy. However, the overall spectrum of the EBL between 0.1 and 1000 microns has never been determined directly neither from observed luminosity functions (LFs), over a wide redshift range, nor from any multiwavelength observation of galaxy spectral energy distributions (SEDs). The evolving, overall spectrum of the EBL is derived here utilizing a novel method based on observations only. It is emphasized that the local EBL seems already well constrained from the UV up to the mid-IR. Since different independent methodologies such as direct measurement, galaxy counts, gamma-ray attenuation and realistic EBL modelings point towards the same EBL intensity level. A relevant contribution from Pop III stars to the local EBL seems unlikely.Comment: Contributed talk at the IAU 284 SED2011 Symposium, Preston, UK, September 5-9, 2011; 4 pages, 1 figure. Online material available at http://side.iaa.es/EB

The SWIRE SIRTF Legacy Program: Studying the Evolutionary Mass Function and Clustering of Galaxies

The SIRTF Wide-area Infrared Extragalactic (SWIRE) survey is a "Legacy Program" using 851 hours of SIRTF observing time to conduct a set of large-area (67 sq. deg. split into 7 fields) high Galactic latitude imaging surveys, achieving 5-sigma sensitivities of 0.45/2.75/17.5 mJy at 24/70/160 micron with MIPS and of 7.3/9.7/27.5/32.5 microJy at 3.6/4.5/5.8/8.0 micron with IRAC. These data will yield highly uniform source catalogs and high-resolution calibrated images, providing an unprecedented view of the universe on co-moving scales up to several hundreds Mpc and to substantial cosmological depths (z\simeq 2.5 for luminous sources). SWIRE will, for the first time, study evolved stellar systems (from IRAC data) versus active star-forming systems and AGNs (from MIPS data) in the same volume, generating catalogues with of order of 2 million infrared-selected galaxies. These fields will have extensive data at other wavebands, particularly in the optical, near-IR and X-rays. SWIRE will provide a complement to smaller and deeper observations in the SIRTF Guaranteed Time and the Legacy Program GOODS, by allowing the investigation of the effect of environment on galaxy evolution. We expand here on capabilities of SWIRE to study with IRAC the evolution of the bright end of the galaxy mass function as a function of cosmic time.Comment: 6 pages, Latex, special macros. To appear in the Proceedings of the ESO Workshop "The Mass of Galaxies at Low and High Redshift", R. Bender and A. Renzini Eds., Springer-Verlag Series "ESO Astrophysics Symposia