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.

Self-organization in multi-agent systems

Abstract: This paper is the synthesis of joint work realised in a technical forum group within the AgentLink III NoE framework, which elaborated on issues concerning self-organization and emergence in multi-agent systems (MAS). The work concluded on a common definition of the concepts of self-organization and emergence in MAS and the associated properties and characteristics. Also it developed towards an approach for selecting self-organization mechanisms using a number of selected reference case studies and a set of evaluation criteria.

CENP-A Is Required for Accurate Chromosome Segregation and Sustained Kinetochore Association of BubR1

Abstract: CENP-A is an evolutionarily conserved, centromere-specific variant of histone H3 that is thought to play a central role in directing kinetochore assembly and in centromere function. Here, we have analyzed the consequences of disrupting the CENP-A gene in the chicken DT40 cell line. In CENP-A-depleted cells, kinetochore protein assembly is impaired, as indicated by mislocalization of the inner kinetochore proteins CENP-I, CENP-H, and CENP-C as well as the outer components Nuf2/Hec1, Mad2, and CENP-E. However, BubR1 and the inner centromere protein INCENP are efficiently recruited to kinetochores. Following CENP-A depletion, chromosomes are deficient in proper congression on the mitotic spindle and there is a transient delay in prometaphase. CENP-A-depleted cells further proceed through anaphase and cytokinesis with unequal chromosome segregation, suggesting that some kinetochore function remains following substantial depletion of CENP-A. We furthermore demonstrate that CENP-A-depleted cells exhibit a specific defect in maintaining kinetochore localization of the checkpoint protein BubR1 under conditions of checkpoint activation. Our data thus point to a specific role for CENP-A in assembly of kinetochores competent in the maintenance of mitotic checkpoint signaling.

Fluoride ion chelation by a bidentate phosphonium/borane Lewis acid.

Abstract: The phosphonium borane [1-Mes2B-2-MePh2P-(C6H4)]+ ([2]+) has been synthesized as an iodide salt by alkylation of 1-Mes2B-2-Ph2P-(C6H4) with MeI. This novel cationic borane complexes fluoride to afford the corresponding zwitterionic fluoroborate complex 1-FMes2B-2-MePh2P-(C6H4) (2-F) with a binding constant in MeOH exceeding that of 1-Mes2B-4-MePh2P-(C6H4) ([1]+) by at least 4 orders of magnitude. Structural and computational results indicate that the high fluorophilicity of [2]+ arises from both Coulombic and cooperative effects which lead to formation of a B−F→P interaction with a F→P distance of 2.666(2) A. These results, which are supported by NBO and AIM analyses, show that the latent phosphorus-centered Lewis acidity of the phosphonium moiety in [2]+ can be exploited to enhance fluoride binding via chelation.

Patterns of genetic diversity and migration in increasingly fragmented and declining orang-utan (Pongo pygmaeus) populations from Sabah, Malaysia.

Abstract: We investigated the genetic structure within and among Bornean orang-utans ( Pongo pygmaeus ) in forest fragments of the Lower Kinabatangan flood plain in Sabah, Malaysia. DNA was extracted from hair and faecal samples for 200 wild individuals collected during boat surveys on the Kinabatangan River. Fourteen microsatellite loci were used to characterize patterns of genetic diversity. We found that genetic diversity was high in the set of samples (mean H E = 0.74) and that genetic differentiation was significant between the samples (average F ST = 0.04, P < 0.001) with F ST values ranging from low (0.01) to moderately large (0.12) values. Pairwise F ST values were significantly higher across the Kinabatangan River than between samples from the same river side, thereby confirming the role of the river as a natural barrier to gene flow. The correlation between genetic and geographical distance was tested by means of a series of Mantel tests based on different measures of geographical distance. We used a Bayesian method to estimate immigration rates. The results indicate that migration is unlikely across the river but cannot be completely ruled out because of the limited F ST values. Assignment tests confirm the overall picture that gene flow is limited across the river. We found that migration between samples from the same side of the river had a high probability indicating that orang-utans used to move relatively freely between neighbouring areas. This strongly suggests that there is a need to maintain migration between isolated forest fragments. This could be done by restoring forest corridors alongside the river banks and between patches.

Seismic versus aseismic deformation in Iran inferred from earthquakes and geodetic data

Abstract: SUMMARY A combined analysis of the geodetic strain-rate field and the strain-rate field deduced from the seismicity allows us to define the style of deformation and to distinguish seismic from aseismic deformation. We perform this analysis in Iran where the present-day tectonics results from the north‐south convergence between the plates of Arabia to the south and Eurasia to the north. The data consist of velocities measured with a GPS network of 28 benchmarks and of instrumental and historical earthquake catalogues. The axes of the seismic strain-rate tensor have similar orientations to those deduced from the GPS velocity field. This indicates that the seismicity can be used to improve GPS information on the style and the orientation of the deformation. Comparison of seismic and geodetic strain rates indicates that highly strained zones experience mainly aseismic deformation in southern Iran and seismic deformation in northern Iran. A large contrast is observed between the Zagros (less than 5 per cent seismic deformation) and the Alborz‐Kopet-Dag regions (more than 30‐100 per cent seismic deformation). The distribution of the seismic/geodetic ratio correlates with the distribution of large earthquakes: intensive, low-magnitude seismicity is observed in the Zagros whereas the largest earthquakes occur in northern Iran. The contrast of seismic deformation between the Zagros and peri-Caspian mountains is confirmed considering 300 or 1000 yr of seismicity rather than 100 or 200 yr.