Mucinosis and Disorders of Collagen and Elastic Fibers

Cutaneous mucinoses are a heterogeneous group of disorders having as a common denominator the deposition of an excess of mucin (acid glycosaminoglycans, mostly hyaluronic acid) in the dermis or in the hair follicles. They are divided into primary and secondary forms. Primary cutaneous mucinoses are characterized by specific clinical lesions in which mucin deposition is the distinctive histological sign, while in secondary mucinoses, mucin deposition is simply an accessory histological sign. Disorders of collagen and elastic fibers are divided into hereditary and acquired forms. Both forms can be further divided into those diseases characterized by an increase and those by a decrease in collagen and elastic tissue. A peculiar variant of disorders of dermal connective tissue includes the primary perforating dermatoses

MAGIC constraints on g-ray emission from Cygnus X−3X-3

Cygnus X-3 is a microquasar consisting of an accreting compact object orbiting around a Wolf-Rayet star. It has been detected at radio frequencies and up to high-energy gamma rays (above 100 MeV). However, many models also predict a very high energy (VHE) emission (above hundreds of GeV) when the source displays relativistic persistent jets or transient ejections. Therefore, detecting such emission would improve the understanding of the jet physics. The imaging atmospheric Cherenkov telescope MAGIC observed Cygnus X-3 for about 70 hours between 2006 March and 2009 August in different X-ray/radio spectral states and also during a period of enhanced gamma-ray emission. MAGIC found no evidence for a VHE signal from the direction of the microquasar. An upper limit to the integral flux for energies higher than 250 GeV has been set to 2.2 x 10-12 photons cm-2 s-1 (95% confidence level). This is the best limit so far to the VHE emission from this source. The non-detection of a VHE signal during the period of activity in the high-energy band sheds light on the location of the possible VHE radiation favoring the emission from the innermost region of the jets, where absorption is significant. The current and future generations of Cherenkov telescopes may detect a signal under precise spectral conditions.Comment: 14 pages, 11 figures, This manuscript has been accepted by ApJ (2010