The centres of M83 and the Milky Way: opposite extremes of a common star formation cycle

In the centres of the Milky Way and M83, the global environmental properties thought to control star formation are very similar. However, M83's nuclear star formation rate (SFR), as estimated by synchrotron and H-alpha emission, is an order of magnitude higher than the Milky Way's. To understand the origin of this difference we use ALMA observations of HCN (1-0) and HCO+ (1-0) to trace the dense gas at the size scale of individual molecular clouds (0.54", 12pc) in the inner ~500 pc of M83, and compare this to gas clouds at similar resolution and galactocentric radius in the Milky Way. We find that both the overall gas distribution and the properties of individual clouds are very similar in the two galaxies, and that a common mechanism may be responsible for instigating star formation in both circumnuclear rings. Given the considerable similarity in gas properties, the most likely explanation for the order of magnitude difference in SFR is time variability, with the Central Molecular Zone (CMZ) currently being at a more quiescent phase of its star formation cycle. We show M83's SFR must have been an order of magnitude higher 5-7 Myr ago. M83's `starburst' phase was highly localised, both spatially and temporally, greatly increasing the feedback efficiency and ability to drive galactic-scale outflows. This highly dynamic nature of star formation and feedback cycles in galaxy centres means (i) modeling and interpreting observations must avoid averaging over large spatial areas or timescales, and (ii) understanding the multi-scale processes controlling these cycles requires comparing snapshots of a statistical sample of galaxies in different evolutionary stages

Quoi de neuf dans la prise en charge de la dermatite atopique de l’enfant et de l’adolescent ? [What's new in the management of atopic dermatitis in children and adolescents ?]

A better understanding of the atopic dermatitis (AD) pathogenesis and the need for more efficient and safer treatments in severe AD promoted the development of new therapies. Several underwent and are still undergoing clinical trials, but due to safety reasons, they include mainly adults for now. AD is however predominant in childhood with a prevalence 20 % in children compared to only 5 % in adults. Regarding the pediatric population, the new pipeline relies on two selective immunosuppressive agents, notably crisaborole (phosphodiesterase-4 inhibitor) and dupilumab (IL-4 and IL-13 inhibitor). In order to strengthen the medical treatment, therapeutic patient education plays a supportive role in the global approach, allowing an optimized care. The Lausanne model of the Pediatric Dermatology Unit is described in this article

Diagnostics differentiels de l'infection a Mycobacterium ulcerans : cas cliniques d'Akonolinga, Cameroun

The authors describe the results of a program for the management of Buruli ulcers in Akonolinga (Cameroon). Its principal objective is to improve the diagnosis of dermatologic lesions and thereby to improve the indications for specific antibiotic therapy. This study, conducted in February, 2013, included 271 patients. Differential diagnosis of suspicious lesions was best with diagnostic examinations completed by histologic examination of a punch biopsy sample and advice from expert dermatologists

Genetic dysregulation of glutathione synthesis predicts alteration of plasma thiol redox status in schizophrenia.

Abstract Genetic studies have shown an association between schizophrenia and a GAG trinucleotide repeat (TNR) polymorphism in the catalytic subunit (GCLC) of the glutamate cysteine ligase (GCL), the key enzyme for glutathione (GSH) synthesis. The present study was aimed at analyzing the influence of a GSH dysregulation of genetic origin on plasma thiols (total cysteine, homocysteine, and cysteine-glycine) and other free amino acid levels as well as fibroblast cultures GSH levels. Plasma thiols levels were also compared between patients and controls. As compared with patients with a low-risk GCLC GAG TNR genotype, patients with a high-risk genotype, having an impaired GSH synthesis, displayed a decrease of fibroblast GSH and plasma total cysteine levels, and an increase of the oxidized form of cysteine (cystine) content. Increased levels of plasma free serine, glutamine, citrulline, and arginine were also observed in the high-risk genotype. Taken together, the high-risk genotypes were associated with a subgroup of schizophrenia characterized by altered plasma thiols and free amino acid levels that reflect a dysregulation of redox control and an increased susceptibility to oxidative stress. This altered pattern potentially contributes to the development of a biomarker profile useful for early diagnosis and monitoring the effectiveness of novel drugs targeting redox dysregulation in schizophrenia. Antioxid. Redox Signal. 15, 2003-2010