Dynamical heterogeneities in an attraction driven colloidal glass

The dynamical heterogeneities (DH) in non-ergodic states of an attractive colloidal glass are studied, as a function of the waiting time. Whereas the fluid states close to vitrify showed strong DH, the distribution of squared displacements of the glassy states studied here only present a tail of particles with increased mobility for the lower attraction strength at short waiting times. These particles are in the surface of the percolating cluster that comprises all of the particles, reminiscent of the fastest particles in the fluid. The quench deeper into the attractive glass is dynamically more homogeneous, in agreement with repulsive glasses (i.e. Lennard-Jones glass).Comment: Proceedings of 5th IDMRCS - Lille 200

Symmetry breaking and the random-phase approximation in small quantum dots

The random-phase approximation has been used to compute the properties of parabolic two-dimensional quantum dots beyond the mean-field approximation. Special emphasis is put on the ground state correlation energy, the symmetry restoration and the role of the spurious modes within the random-phase approximation. A systematics with the Coulombic interaction strength is presented for the 2-electron dot, while for the 6- and 12-electron dots selected cases are discussed. The validity of the random-phase approximation is assessed by comparison with available exact results.Comment: 9 pages, 4 embedded + 6 gif Figs. Published versio

Teoría sociológica contemporánea : un debate inconcluso

1 archivo PDF (155 páginas)"Uno de los propósitos de este conjunto de ensayos es plantear, a los futuros sociólogos y a los interesados en el tema, que la sociología no es una disciplina homogénea lidereada por una corriente teórica dominante. Es una disciplina que se mantiene en un equilibrio imperfecto, donde coexisten autores que comparten el intento de crear una teoría sintetizadora y; autores que parecen estar fuera de la "corriente teórica principal", que muestran la diversidad interpretativa y de objetos de investigación que se incluyen en el quehacer sociológico. Así, aparece frente a nosotros, una disciplina heterogénea y polémica, aunque no por eso, perdida en la diversidad inagotable.

Structural and functional brain changes in middle-aged type 2 diabetic patients: a cross-sectional study.

Journal Article;BACKGROUND Type 2 diabetes mellitus (T2DM) is an emerging risk factor for cognitive impairment. Whether this impairment is a direct effect of this metabolic disorder on brain function, a consequence of vascular disease, or both, remains unknown. Structural and functional neuroimaging studies in patients with T2DM could help to elucidate this question. OBJECTIVE We designed a cross-sectional study comparing 25 T2DM patients with 25 age- and gender-matched healthy control participants. Clinical information, APOE genotype, lipid and glucose analysis, structural cerebral magnetic resonance imaging including voxel-based morphometry, and F-18 fluorodeoxyglucose positron emission tomography were obtained in all subjects. METHODS Gray matter densities and metabolic differences between groups were analyzed using statistical parametric mapping. In addition to comparing the neuroimaging profiles of both groups, we correlated neuroimaging findings with HbA1c levels, duration of T2DM, and insulin resistance measurement (HOMA-IR) in the diabetic patients group. Results: Patients with T2DM presented reduced gray matter densities and reduced cerebral glucose metabolism in several fronto-temporal brain regions after controlling for various vascular risk factors. Furthermore, within the T2DM group, longer disease duration, and higher HbA1c levels and HOMA-IR were associated with lower gray matter density and reduced cerebral glucose metabolism in fronto-temporal regions. CONCLUSION In agreement with previous reports, our findings indicate that T2DM leads to structural and metabolic abnormalities in fronto-temporal areas. Furthermore, they suggest that these abnormalities are not entirely explained by the role of T2DM as a cardiovascular risk factor.Ye

De la structure à la « fine pointe »

L'expression « fine pointe » est empruntée à Michel Vovelle, «La mémoire d'Ernest Labrousse », Annales historiques de la Révolution française, n°276, 1989, p. 104 : «le chantier d'une histoire des mentalités qui reste pour moi la fine pointe de l'histoire sociale

Gaia DR3 documentation

The data collected during the first 34 months of the Gaia mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC), resulting in Gaia's third data release, Gaia DR3. Gaia DR3 contains the astrometry and broad-band photometry already published as part of Gaia EDR3 and introduces a large variety of new data products. A summary of the release properties is provided in Gaia Collaboration et al. (2022). The overall scientific validation of the data is described in Babusiaux et al. (2022) and Fabricius et al. (2021) (astrometry and broad-band photometry). Background information on the Gaia mission and the spacecraft can be found in Gaia Collaboration et al. (2016). In addition, Gaia DR3 is accompanied by dedicated processing papers, all part of a Special Issue of A&A, that describe the processing and validation of the various data products. The data release documentation provides complementary information to the processing papers. Finally, nine performance verification papers accompanying Gaia DR3 co-authored by the Gaia Collaboration provide an impression on the immense scientific potential of this release