2,804 research outputs found
Effects of the environment on galaxies in the Catalogue of Isolated Galaxies: physical satellites and large scale structure
We aim to identify and quantify the effects of the satellite distribution
around a sample of galaxies in the Catalogue of Isolated Galaxies (CIG), as
well as the effects of the Large Scale Structure (LSS) using the SDSS-DR9. To
recover the physically bound galaxies we focus on the satellites which are
within the escape speed of each CIG galaxy. We also propose a more conservative
method using the stacked Gaussian distribution of the velocity difference of
the neighbours. The tidal strengths affecting the primary galaxy are estimated
to quantify the effects of the local and LSS environments. We also define the
projected number density parameter at the 5 nearest neighbour to
characterise the LSS around the CIG galaxies. Out of the 386 CIG galaxies
considered in this study, at least 340 (88\% of the sample) have no physically
linked satellite. Out of the 386 CIG galaxies, 327 (85\% of the sample) have no
physical companion within a projected distance of 0.3 Mpc. The CIG galaxies are
distributed following the LSS of the local Universe, although presenting a
large heterogeneity in their degree of connection with it. A clear segregation
appears between early-type CIG galaxies with companions and isolated late-type
CIG galaxies. Isolated galaxies are in general bluer, with likely younger
stellar populations and rather high star formation with respect to older,
redder CIG galaxies with companions. Reciprocally, the satellites are redder
and with an older stellar populations around massive early-type CIG galaxies,
while they have a younger stellar content around massive late-type CIG
galaxies. This suggests that the CIG is composed of a heterogeneous population
of galaxies, sampling from old to more recent, dynamical systems of galaxies.Comment: 19 pages, 10 figures, 1 table, accepted for publication in Astronomy
& Astrophysic
Clinical characterization of patients with anal fistula during follow-up of anorectal abscess: a large population-based study
PurposeApproximately 15-50% of patients with an anorectal abscess will develop an anal fistula, but the true incidence of this entity is currently unknown. The aim of the study was to determine the incidence of anorectal abscess and development of a fistula in a specific population area and to identify potential risk factors associated with demographic, socioeconomic and pre-existing disease (e.g. diabetes and inflammatory bowel disease).MethodsA longitudinal observational study was designed including a large cohort study in an area with 7,553,650 inhabitants in Spain 1st january 2014 to 31st december 2019. Adults who attended for the first time with an anorectal abscess and had a minimum of 1-year follow-up were included. The diagnosis was made using ICD-10 codes for anorectal abscess and anal fistula.ResultsDuring the study period, we included 27,821 patients with anorectal abscess. There was a predominance of men (70%) and an overall incidence of 596 per million population. The overall incidence of anal fistula developing from abscesses was 20%, with predominance in men, and a lower incidence in the lowest income level. The cumulative incidence of fistula was higher in men and in younger patients (p < 0.0001). On multivariate analysis, patients aged 60-69 years (hazard ratio 2.0) and those with inflammatory bowel disease (hazard ratio 1.8-2.0) had a strong association with fistula development (hazard ratio 2.0).ConclusionsOne in five patients with an anorectal abscess will develop a fistula, with a higher likelihood in men. Fistula formation was strongly associated with inflammatory bowel disease
A colour atlas of diseases of the vulva and perigenital area
This international congress will put a lot of work into female health. We therefore de\uaccided to present our clinical experience about an issue that is rarely discussed in der\uacmatological congresses, i.e. the diseases of the vulva and perigenital area.
The diseases will be divided into different chapters: hereditary diseases (Darier disease); infectious diseases (herpes genitalis, genital warts, candidiasis, impetigo, erysipelas, syphilis); inflammatory diseases (allergic contact dermatitis, fixed drug eruption, psoriasis, lichen planus, lichen sclerosus, pemphigus) and neoplastic dis\uaceases (bowenoid papulosis, basal cell carcinoma, Bowen's disease, squamous cell carcinoma, extra-mammary Paget's disease, melanoma, Kaposi's sarcoma, T-cell lym\uacphoma and Langerhans' cell histiocytosis). All these diseases will be discussed ac\uaccording to clinical, histopathological and therapeutical points of view
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