Daniel Forthomme, l’optométriste, le professeur, le chercheur, le directeur et l’ami (1938-2019)

Our friend, Daniel Forthomme, passed away last November 25. This text, dedicated to his memory, list his numerous contributions to optometrists and optometry. Notre ami, Daniel Forthomme, est décédé le 25 novembre dernier. Ce texte, dédié à sa mémoire, énumère ses nombreuses contributions aux optométristes et à l’optométrie

Daniel Forthomme, optometrist, professor, researcher, director and friend (1938-2019)

Daniel Forthomme had a profound influence on many of us and on our profession. Throughout his long career as an optometrist, professor, di-rector of the School of Optometry and of Optométristes Sans Frontières, he adapted to change, always giving his best; hence his remarkable influence on all Quebec op-tometrists and on our profession

Spin liquid correlations in Nd-langasite anisotropic Kagom\'e antiferromagnet

Dynamical magnetic correlations in the geometrically frustrated Nd$\_3$Ga$\_5$SiO$\_{14}$ compound were probed by inelastic neutron scattering on a single crystal. A scattering signal with a ring shape distribution in reciprocal space and unprecedented dispersive features was discovered. Comparison with calculated static magnetic scattering from models of correlated spins suggests that the observed phase is a spin liquid inherent to an antiferromagnetic kagom\'e-like lattice of anisotropic Nd moments.Comment: 4 page

De la trace du mouvement à l'image du sport

Il ne fait aucun doute que l’acte de naissance de l’audiovisuel sportif en France a été établi au sein de l’École normale de gymnastique et d’escrime de Joinville-le-Pont. Les collections photographiques détenues par l’Iconothèque et qui constituent des jalons importants de l’histoire de la photographie, représentent aujourd’hui un témoignage unique sur l’itinéraire de ces établissements civils et militaires et plus globalement sur l’histoire du sport et de l’éducation physique en France

Parity Broken Chiral Spin Dynamics in Ba3_3NbFe3_3Si2_2O14_{14}

The spin wave excitations emerging from the chiral helically modulated 120$^{\circ}$ magnetic order in a langasite Ba$_3$NbFe$_3$Si$_2$O$_{14}$ enantiopure crystal were investigated by unpolarized and polarized inelastic neutron scattering. A dynamical fingerprint of the chiral ground state is obtained, singularized by (i) spectral weight asymmetries answerable to the structural chirality and (ii) a full chirality of the spin correlations observed over the whole energy spectrum. The intrinsic chiral nature of the spin waves elementary excitations is shown in absence of macroscopic time reversal symmetry breaking

Age and quality of in-hospital care of patients with heart failure

Background: Elderly patients may be at risk of suboptimal care. Thus, the relationship between age and quality of care for patients hospitalized for heart failure was examined. Methods: A cross-sectional study based on retrospective chart review was performed among a random sample of patients hospitalized between 1996 and 1998 in the general internal medicine wards, with a principal diagnosis of congestive heart failure, and discharged alive. Explicit criteria of quality of care, grouped into three scores, were used: admission work-up (admission score); evaluation and treatment during the stay (evaluation and treatment score); and readiness for discharge (discharge score). The associations between age and quality of care scores were analysed using linear regression models. Results: Charts of 371 patients were reviewed. Mean age was 75.7 (±11.1) years and 52% were men. There was no relationship between age and admission or readiness for discharge scores. The evaluation and treatment score decreased with age: compared with patients less than 70 years old, the score was lower by −2.6% (95% CI: −7.1 to 1.9) for patients aged 70 to 79, by −8.7% (95% CI: −13.0 to −4.3) for patients aged 80 to 89, and by −19.0% (95% CI: −26.6 to −11.5) for patients aged 90 and over. After adjustment for possible confounders, this relationship was not significantly modified. Conclusions: In patients hospitalized for congestive heart failure, older age was not associated with lower quality of care scores except for evaluation and treatment. Whether this is detrimental to elderly patients remains to be evaluate

Helical bunching and symmetry lowering inducing multiferroicity in Fe langasites

International audienceThe chiral Fe-based langasites represent model systems of triangle-based frustrated magnets with a strong potential for multiferroicity. We report neutron scattering measurements for the multichiral Ba3MFe3Si2O14 (M = Nb, Ta) langasites revealing new important features of the magnetic order of these systems: the bunching of the helical modulation along the c-axis and the in-plane distortion of the 120° Fe-spin arrangement. We discuss these subtle features in terms of the microscopic spin Hamiltonian, and provide the link to the magnetically-induced electric polarization observed in these systems. Thus, our findings put the multiferroicity of this attractive family of materials on solid ground

Disruption of phenylalanine hydroxylase reduces adult lifespan and fecundity, and impairs embryonic development in parthenogenetic pea aphids

International audiencePhenylalanine hydroxylase (PAH) is a key tyrosine-biosynthetic enzyme involved in neurological and melanin-associated physiological processes. Despite extensive investigations in holometabolous insects, a PAH contribution to insect embryonic development has never been demonstrated. Here, we have characterized, for the first time, the PAH gene in a hemimetabolous insect, the aphid Acyrthosiphon pisum. Phylogenetic and sequence analyses confirmed that ApPAH is closely related to metazoan PAH, exhibiting the typical ACT regulatory and catalytic domains. Temporal expression patterns suggest that ApPAH has an important role in aphid developmental physiology, its mRNA levels peaking at the end of embryonic development. We used parental dsApPAH treatment to generate successful knockdown in aphid embryos and to study its developmental role. ApPAH inactivation shortens the adult aphid lifespan and considerably affects fecundity by diminishing the number of nymphs laid and impairing embryonic development, with newborn nymphs exhibiting severe morphological defects. Using single nymph HPLC analyses, we demonstrated a significant tyrosine deficiency and a consistent accumulation of the upstream tyrosine precursor, phenylalanine, in defective nymphs, thus confirming the RNAi-mediated disruption of PAH activity. This study provides first insights into the role of PAH in hemimetabolous insects and demonstrates that this metabolic gene is essential for insect embryonic development

Bacteriocyte cell death in the pea aphid/ Buchnera symbiotic system

International audienceSymbiotic associations play a pivotal role in multicellular life by facilitating acquisition of new traits and expanding the ecological capabilities of organisms. In insects that are obligatorily dependent on intracellular bacterial symbionts, novel host cells (bacteriocytes) or organs (bacteriomes) have evolved for harboring beneficial microbial partners. The processes regulating the cellular life cycle of these endosymbiont-bearing cells, such as the cell-death mechanisms controlling their fate and elimination in response to host physiology, are fundamental questions in the biology of symbiosis. Here we report the discovery of a cell-death process involved in the degeneration of bacteriocytes in the hemipteran insect Acyrthosiphon pisum This process is activated progressively throughout aphid adulthood and exhibits morphological features distinct from known cell-death pathways. By combining electron microscopy, immunohistochemistry, and molecular analyses, we demonstrated that the initial event of bacteriocyte cell death is the cytoplasmic accumulation of nonautophagic vacuoles, followed by a sequence of cellular stress responses including the formation of autophagosomes in intervacuolar spaces, activation of reactive oxygen species, and Buchnera endosymbiont degradation by the lysosomal system. We showed that this multistep cell-death process originates from the endoplasmic reticulum, an organelle exhibiting a unique reticular network organization spread throughout the entire cytoplasm and surrounding Buchnera aphidicola endosymbionts. Our findings provide insights into the cellular and molecular processes that coordinate eukaryotic host and endosymbiont homeostasis and death in a symbiotic system and shed light on previously unknown aspects of bacteriocyte biological functioning

French Roadmap for complex Systems 2008-2009

This second issue of the French Complex Systems Roadmap is the outcome of the Entretiens de Cargese 2008, an interdisciplinary brainstorming session organized over one week in 2008, jointly by RNSC, ISC-PIF and IXXI. It capitalizes on the first roadmap and gathers contributions of more than 70 scientists from major French institutions. The aim of this roadmap is to foster the coordination of the complex systems community on focused topics and questions, as well as to present contributions and challenges in the complex systems sciences and complexity science to the public, political and industrial spheres