Louise de Savoie et la chambre des Bucoliques

in Brioist, Pascal; Fagnart, Laure; Michon, Cédric (Eds.) Louise de Savoie (1476-1531) (in press)

Cell-free preparations of Lactobacillus acidophilus strain La-5 and Bifidobacterium longum strain NCC-2705 affect virulence gene expression in Campylobacter jejuni

in Journal of Food Protection (in press)

Emotional Facial Expression Recognition and Expressivity in Type I and Type II Alcohol Dependent Patients

in Journal of Nonverbal Behavior (in press)

Objective: Alcohol dependent patients (ADs) are known to encounter severe interpersonal problems. Nonverbal communication skills are important for the development of healthy relationships. The present ... [more ▼]

Objective: Alcohol dependent patients (ADs) are known to encounter severe interpersonal problems. Nonverbal communication skills are important for the development of healthy relationships. The present study aimed to explore emotional facial expression (EFE) recognition and posed and spontaneous EFE expressivity in male ADs divided into two groups according to Cloninger’s typology and the impact of their interpersonal relationship quality on the potential nonverbal deficits. Method: Twenty type I ADs, twenty-one type II ADs, and twenty control participants took part in an EFE recognition task and an EFE expressivity task that considered personal emotional events (spontaneous expressivity) and EFE in response to a photo or word cue (posed expressivity). Coding was based on judges’ ratings of participants’ emotional facial expressions. Participants additionally completed a questionnaire on interpersonal relationship quality. Results: No difference between the three groups emerged in the EFE recognition task. Type II ADs showed heightened deficits compared with type I ADs in EFE expressivity: Judges perceived less accurate posed EFE in response to a cue word and less intense and positive spontaneous EFE in type II ADs compared to control participants. In addition, type II ADs reported more relationship difficulties compared to both type I ADs and control participants. These interpersonal relationship difficulties were related to some of the EFE expressivity deficits of AD-IIs. Conclusions: This study underlines the important differences between the interpersonal functioning of AD subtypes. [less ▲]

Effect of head-to-head addition in vinyl acetate controlled radical polymerization: why is Co(acac)2-mediated polymerization so much better?

in Macromolecules (in press)

The controlled polymerization of vinyl acetate has been recently achieved by several techniques, but PVAc with targeted Mn and low dispersity up to very high monomer conversions and high degrees of ... [more ▼]

The controlled polymerization of vinyl acetate has been recently achieved by several techniques, but PVAc with targeted Mn and low dispersity up to very high monomer conversions and high degrees of polymerization was only obtained with Co(acac)2 as controlling agent in the so-called CMRP, a type of organometallic mediated radical polymerization (OMRP). Other techniques (including ATRP, ITP, TERP, and RAFT/MADIX) have shown a more or less pronounced slowdown in the polymerization kinetics, which was attributed to the higher strength of the C−X bond between the radical PVAc chain and the trapping agent (X) in the dormant species and to a consequent slower reactivation after a less frequent head-to-head monomer addition. The reason for the CMRP exception is clarified by the present contribution. First, a detailed investigation by 1H, 13C and multiplicity-edited HSQC and DEPT-135 NMR of the PVAc obtained by CMRP, in comparison with a regular polymer made by free radical polymerization under the same conditions, has revealed that Co(acac)2 does not significantly alter the fraction of head-to-head sequences in the polymer backbone and that there is no accumulation of Co(acac)2-capped chains with a head-to-head ω end. Hence, both dormant chains (following the head-to-head and the head-to-tail monomer additions) must be reactivated at similar rates. A DFT study shows that this is possible because the dormant chains are stabilized not only by the C−Co σ bond but also by formation of a chelate ring through coordination of the ω monomer carbonyl group. The head-to-head dormant chain contains an inherently stronger C−Co bond but forms a weaker 6-membered chelate ring, whereas the weaker C−Co bond in the head-to-tail dormant chain is compensated by a stronger 5-membered chelate ring. Combination of the two effects leads to similar activation enthalpies, as verified by DFT calculations using a variety of local, gradient-corrected, hybrid and “ad hoc” functionals (BPW91, B3PW91, BPW91*, M06 and M06L). While the BDE(C−X) of model H-VAc−X molecules [X = Cl, I, MeTe, EtOC(S)S and Co(acac)2] are functional dependent, the BDE difference between head-to-head and head-to-tail dormant chain models is almost functional insensitive, with values of 5−9 kcal/mol for the ATRP, ITP and TERP models, 3−6 for the RAFT/MADIX model, and around zero for CMRP. [less ▲]

Emerging drugs for prevention of graft failure after allogeneic hematopoietic stem cell transplantation

in Expert Opinion on Emerging Drugs (in press)

Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the treatment of choice for many patients suffering from hematological malignancies, severe hemoglobinopathies, bone marrow ... [more ▼]

Introduction: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the treatment of choice for many patients suffering from hematological malignancies, severe hemoglobinopathies, bone marrow failures or severe primary immunodeficiencies. Graft rejection/failure (GF) is a life-threatening complication following allo-HSCT that is most commonly caused by the reactivity of recipient T cells, natural killer (NK) cells or antibodies against donor grafted hematopoietic cells. The increasing use of allo-HSCT following reduced-intensity conditioning (RIC) and the increasing use of alternative donors (unrelated cord blood and human leukocyte antigen (HLA)-mismatched donor) have resulted in higher frequency of GF. Areas covered: This review describes the pathogenesis and current prevention and treatment of GF as well as agents in development for GF prevention or treatment. Expert opinion: The risk of GF may be reduced in the future by optimizing the conditioning regimens and post-grafting immunosuppression, increasing the number of hematopoietic stem cells (HSCs) and/or immune cells transplanted, optimizing HSC homing and better detecting patients at high risk of GF by searching for pre-transplant donor-specific anti-HLA antibodies in patients given grafts from HLA-mismatched donors, or by closely monitoring donor T- and/or NK-cell chimerism after allo-HSCT following RIC. [less ▲]

Schematic representations in arithmetical problem solving: Analysis of their impact on grade 4 students

in Educational Studies in Mathematics (in press)

While the value of ‘schematic representations’ in problem solving requires no further demonstration, the way in which students should be taught how to construct these representations invariably gives rise ... [more ▼]

While the value of ‘schematic representations’ in problem solving requires no further demonstration, the way in which students should be taught how to construct these representations invariably gives rise to various debates. This study, conducted on 146 grade 4 students in Luxembourg, analyzes the effect of two types of ‘schematic representation’ (diagrams vs. schematic drawings) on the solving of arithmetical problems. The results show that the presence of schematic representations has a clear positive effect on overall student performance and that a non negligible proportion of students manage to reuse the representations encountered in order to solve new problems. While showing an effect slightly in favor of diagrams as opposed to schematic drawings, our results do not really permit us to draw any conclusions about the form that these representations should take, in particular since a differential effect was observed depending on the type of problem. [less ▲]

Structural Determinants of Specificity and Catalytic Mechanism in mammalian 25-kDa Thiamine Triphosphatase

in Biochimica et Biophysica Acta - General Subjects (in press)

Background: Thiamine triphosphate (ThTP) is present in most organisms and might be involved in intracellular signaling. In mammalian cells, the cytosolic ThTP level is controlled by a specific thiamine ... [more ▼]

Background: Thiamine triphosphate (ThTP) is present in most organisms and might be involved in intracellular signaling. In mammalian cells, the cytosolic ThTP level is controlled by a specific thiamine triphosphatase (ThTPase), belonging to the CYTH superfamily of proteins. CYTH proteins are present in all superkingdoms of life and act on various triphosphorylated substrates. Methods: Using crystallography, mass spectrometry and mutational analysis, we identified the key structural determinants of the high specificity and catalytic efficiency of mammalian ThTPase. Results: Triphosphate binding requires three conserved arginines while the catalytic mechanism relies on an unusual lysine-tyrosine dyad. By docking of the ThTP molecule in the active site, we found that Trp-53 should interact with the thiazole part of the substrate molecule, thus playing a key role in substrate recognition and specificity. Sea anemone and zebrafish CYTH proteins, which retain the corresponding Trp residue, are also specific ThTPases. Surprisingly, the whole chromosome region containing the ThTPase gene is lost in birds. Conclusion: The specificity for ThTP is linked to a stacking interaction between the thiazole heterocycle of thiamine and a tryptophan residue. The latter likely plays a key role in the secondary acquisition of ThTPase activity in early metazoan CYTH enzymes, in the lineage leading from cnidarians to mammals. General significance: We show that ThTPase activity is not restricted to mammals as previously thought but is an acquisition of early metazoans. This, and the identification of critically important residues, allows us to draw an evolutionary perspective of the CYTH family of proteins. [less ▲]

Comment comprendre l’influence au sein de groupes d’adolescents ? Le conflit socio-cognitif en appui de la théorie de l’apprentissage social

in Canadian Journal of Behavioural Science = Revue Canadienne des Sciences du Comportement (in press)

Influence of microfabric evolution on the retention behaviour of compacted clayey soils

in Unsaturated Soils: Research & Applications (2014, July)

Changement, disparition ou éternel retour ?

Scientific conference (2014, January 27)