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.

Human telomerase RNA and box H/ACA scaRNAs share a common Cajal body-specific localization signal.

Abstract: Telomerase is a ribonucleoprotein reverse transcriptase that uses its RNA component as a template for synthesis of telomeric DNA repeats at the ends of linear eukaryotic chromosomes. Here, fluorescence in situ hybridization demonstrates that in HeLa cancer cells, human telomerase RNA (hTR) accumulates in the nucleoplasmic Cajal bodies (CBs). Localization of transiently expressed hTR to CBs is supported by a short sequence motif (411-UGAG-414) that is located in the 3′-terminal box H/ACA RNA-like domain of hTR and that is structurally and functionally indistinguishable from the CB-specific localization signal of box H/ACA small CB-specific RNAs. In synchronized HeLa cells, hTR shows the most efficient accumulation in CBs during S phase, when telomeres are most likely synthesized. CBs may function in post-transcriptional maturation (e.g., cap hypermethylation of hTR), but they may also play a role in the assembly and/or function of telomerase holoenzyme.

Effects of Rapid Global Warming at the Paleocene-Eocene Boundary on Neotropical Vegetation

Abstract: Temperatures in tropical regions are estimated to have increased by 3° to 5°C, compared with Late Paleocene values, during the Paleocene-Eocene Thermal Maximum (PETM, 56.3 million years ago) event. We investigated the tropical forest response to this rapid warming by evaluating the palynological record of three stratigraphic sections in eastern Colombia and western Venezuela. We observed a rapid and distinct increase in plant diversity and origination rates, with a set of new taxa, mostly angiosperms, added to the existing stock of low-diversity Paleocene flora. There is no evidence for enhanced aridity in the northern Neotropics. The tropical rainforest was able to persist under elevated temperatures and high levels of atmospheric carbon dioxide, in contrast to speculations that tropical ecosystems were severely compromised by heat stress.

What are the best outcome measures for assessing plaque psoriasis severity? A systematic review of the literature.

Abstract: Background A wide variety of scoring systems have been proposed to assess severity of psoriasis. Given its importance as a health issue both for patients and health care systems, it is critically important to evaluate the validity and reliability of existing outcome measures. Objective The objective of this systematic review was to assess the extent of validation including the validity, reliability, sensitivity to change and ease of use of available outcome measures for psoriasis. Materials and Methods We conducted a systematic review of all clinical studies (prospective and retrospective) investigating the severity of psoriasis patients and published between January 1980 and June 2009. The following methodological validation and quality criteria were recorded systematically: construct validity, content validity and internal consistency, intra-observer variation and inter-observer variation, sensitivity to change and acceptability/ease of use assessed as time required to perform measurement. Results Based on methodological validation and quality criteria, six clinical severity scores were selected and analysed (PASI, BSA, PGA, LS-PGA, SPI and SAPASI scores). We did not find substantial evidence of construct validity for any of the psoriasis clinical severity scores. Content validity was studied by considering the PASI score as gold standard. The relative content validity was good for the LS-PGA, PGA, and SPI scores, which correlated strongly with the PASI score. The SAPASI and PASI scores showed moderate correlation. Internal consistency was good for the PASI and LS-PGA scores. The PASI, BSA, PGA and LS-PGA scores displayed limited intra-observer variation. The inter-observer variation was low for LS-PGA (ICC 0.8). The PASI score and the SAPASI displayed moderate sensitivity to change. Discussion Based on this systematic review, it appears that none of the severity scores used for psoriasis meets all of the validation criteria required for an ideal score. However, we can conclude that the PASI score is the most extensively studied psoriasis clinical severity score and the most thoroughly validated according to methodological validation criteria. Despite certain limitations, use of the PASI score can be recommended for scientific evaluation of the clinical severity of psoriasis.

Change in the chemical composition of infalling gas forming a disk around a protostar

Abstract: IRAS 04368+2557 is a solar-type (low-mass) protostar embedded in a protostellar core (L1527) in the Taurus molecular cloud, which is only 140 parsecs away from Earth, making it the closest large star-forming region. The protostellar envelope has a flattened shape with a diameter of a thousand astronomical units (1 AU is the distance from Earth to the Sun), and is infalling and rotating. It also has a protostellar disk with a radius of 90 AU (ref. 6), from which a planetary system is expected to form. The interstellar gas, mainly consisting of hydrogen molecules, undergoes a change in density of about three orders of magnitude as it collapses from the envelope into the disk, while being heated from 10 kelvin to over 100 kelvin in the mid-plane, but it has hitherto not been possible to explore changes in chemical composition associated with this collapse. Here we report that the unsaturated hydrocarbon molecule cyclic-C3H2 resides in the infalling rotating envelope, whereas sulphur monoxide (SO) is enhanced in the transition zone at the radius of the centrifugal barrier (100 ± 20 AU), which is the radius at which the kinetic energy of the infalling gas is converted to rotational energy. Such a drastic change in chemistry at the centrifugal barrier was not anticipated, but is probably caused by the discontinuous infalling motion at the centrifugal barrier and local heating processes there.