Paul Sabatier University

About: Paul Sabatier University is a education organization based out in Toulouse, France. It is known for research contribution in the topics: Population & Adipose tissue. The organization has 15431 authors who have published 23386 publications receiving 858364 citations.

Quantification of Demodex folliculorum by PCR in rosacea and its relationship to skin innate immune activation.

Abstract: The aim of this study is to quantify D. folliculorum colonisation in rosacea subtypes and age-matched controls and to determine the relationship between D. folliculorum load, rosacea subtype and skin innate immune system activation markers. We set up a multicentre, cross-sectional, prospective study in which 98 adults were included: 50 with facial rosacea, including 18 with erythematotelangiectatic rosacea (ETR), and 32 with papulopustular rosacea (PPR) and 48 age- and sex-matched healthy volunteers. Non-invasive facial samples were taken to quantify D. folliculorum infestation by quantitative PCR and evaluate inflammatory and immune markers. Analysis of the skin samples show that D. folliculorum was detected more frequently in rosacea patients than age-matched controls (96% vs 74%, P < 0.01). D. folliculorum density was 5.7 times higher in rosacea patients than in healthy volunteers. Skin sample analysis showed a higher expression of genes encoding pro-inflammatory cytokines (Il-8, Il-1b, TNF-a) and inflammasome-related genes (NALP-3 and CASP-1) in rosacea, especially PPR. Overexpression of LL-37 and VEGF, as well as CD45RO, MPO and CD163, was observed, indicating broad immune system activation in patients with rosacea. In conclusion, D. folliculorum density is highly increased in patients with rosacea, irrespective of rosacea subtype. There appears to be an inverse relationship between D. folliculorum density and inflammation markers in the skin of rosacea patients, with clear differences between rosacea subtypes.

Spectral analysis of the Galactic e+e- annihilation emission

Abstract: We present a spectral analysis of the e+e- annihilation emission from the Galactic Centre region based on the first year of measurements made with the spectrometer SPI of the INTEGRAL mission. We have found that the annihilation spectrum can be modelled by the sum of a narrow and a broad 511 keV line plus an ortho-positronium continuum. The broad line is detected (significance 3.2?) with a flux of (0.35 ± 0.11) × 10-3 photons s-1 cm-2. The measured width of 5.4±1.2 keV FWHM is in agreement with the expected broadening of 511 keV photons emitted in the annihilation of positroniums that are formed by the charge exchange process of slowing down positrons with hydrogen atoms. The flux of the narrow line is (0.72 ± 0.12) × 10-3 photons s-1 cm-2 and its width is 1.3±0.4 keV FWHM. The measured ortho-positronium continuum flux yields a fraction of positronium of (96.7±2.2)%. To derive in what phase of the interstellar medium positrons annihilate, we have fitted annihilation models calculated for each phase to the data. We have found that 49+2-23% of the annihilation emission comes from the warm neutral phase and 51+3-2% from the warm ionized phase. While we may not exclude that less than 23% of the emission might come from cold gas, we have constrained the fraction of annihilation emission from molecular clouds and hot gas to be less than 8% and 0.5%, respectively. We have compared our knowledge of the interstellar medium in the bulge (size, density, and filling factor of each phase) and the propagation of positrons with our results and found that they are in good agreement if the sources are diffusively distributed and if the initial kinetic energy of positrons is lower than a few MeV. Despite its large filling factor, the lack of annihilation emission from the hot gas is due to its low density, which allows positrons to escape this phase.

Increased soldier production in ant colonies exposed to intraspecific competition

Abstract: THE success of organisms and their increasing complexity throughout the course of evolution are thought to have depended on a small number of important transitions, one of which was the shift from a solitary lifestyle to societies of organisms exhibiting division of labour and having specialized castes1,2. The most familiar examples of the advantages arising from division of labour and caste differentiation come from social insects3. It has been suggested that the proportion of workers of various physical castes has evolved to enhance the fitness of colony members4,6 with the prediction that caste ratios should vary with environmental factors such as predation, competition and food availability. However, because it has been difficult to manipulate experimentally the environmental factors believed to influence optimal caste ratio, demonstration of adaptive caste distribution has remained elusive7–10. Here we show that colonies of the ant Pheidole pallidula increase the relative investment in soldier production after perceiving the presence of foreign con-specific colonies. This is the first experimental demonstration of a social insect altering physical caste ratios in an adaptive manner.