Post-Reconstruction Deconvolution of PET Images by Total Generalized Variation Regularization

Improving the quality of positron emission tomography (PET) images, affected by low resolution and high level of noise, is a challenging task in nuclear medicine and radiotherapy. This work proposes a restoration method, achieved after tomographic reconstruction of the images and targeting clinical situations where raw data are often not accessible. Based on inverse problem methods, our contribution introduces the recently developed total generalized variation (TGV) norm to regularize PET image deconvolution. Moreover, we stabilize this procedure with additional image constraints such as positivity and photometry invariance. A criterion for updating and adjusting automatically the regularization parameter in case of Poisson noise is also presented. Experiments are conducted on both synthetic data and real patient images.Comment: First published in the Proceedings of the 23rd European Signal Processing Conference (EUSIPCO-2015) in 2015, published by EURASI

Élisabeth and Berthe Thuillier

Élisabeth Thuillier is best known by film historians for having colored Georges Méliès’s films and films produced by Pathé. In his overview essay on “French Film Colorists” written for this publication, Joshua Yumibe notes that Méliès “outsourced his hand-coloring work from 1897 to 1912 to a Vincennes firm in Paris run by Elisabeth Thuillier who managed a workforce of over 200 female colorists. Her daughter Marie-Berthe Thuillier, known as Berthe Thuillier, probably worked with Élisabeth and then took over the workshop after her death in either 1904 or 1907

Control of embryonic Xenopus morphogenesis by a Ral-GDS/Xral branch of the Ras signalling pathway.

Ras proteins mediate biological responses through various effectors and play a key role in relaying the Fibroblast Growth Factor (FGF) mesoderm induction signal during embryogenesis of the frog, Xenopus laevis. One Ras effector pathway involves the activation of the small G protein Ral. In the present study, we have investigated the role of key components in the Ral branch of FGF and Ras signalling during early Xenopus development. Treatment of animal caps with bFGF, which converts prospective ectoderm to mesoderm, activates Xral. The Ras mutant 12V37G, which can bind to Ral-GDS but not Raf, also activates Xral as well as causing developmental defects and cortical F-actin disassembly. A similar phenotype is induced by Ral-GDS itself. FGF-induced expression of several signature mesodermal genes, by contrast, is independent of Xral signalling. This and other data suggest that the RalB branch of Ras and FGF signalling regulates the actin cytoskeleton and morphogenesis in a transcriptionally independent manner. We also find Xral to be specifically activated in the marginal zone of Xenopus embryos, and find that disruption of the Ral pathway in this region prevents closure of the blastopore during gastrulation. We conclude that Ral signalling is autonomously required by mesodermal cells to effect essential morphogenetic changes during Xenopus gastrulation

Démarche d'autocompassion : un savoir disciplinaire au service des apprentissages

Il y a de ces moments en classe où certaines personnes étudiantes semblent être plus préoccupées par un désir de performer que d’une réelle motivation à développer les compétences ou réaliser les apprentissages. Devant les regards des autres dans le groupe, certaines ont tendance à diminuer leur participation pour éviter de commettre des erreurs ou encore à se lancer des critiques sévères sur leurs habiletés face à la tâche demandée. Dans le but de considérer le bien-être des personnes étudiantes et leur permettre d’avoir une meilleure disposition aux apprentissages, un projet d’innovation pédagogique a été conduit sur le thème de l’autocompassion. Appuyé par la démarche Scholarship of Teaching and Learning (SoTL), ce projet a été conduit à l’automne 2022 dès la première session du programme Techniques d’éducation spécialisée. L’article met donc en lumière l’expérimentation de la démarche d’autocompassion réalisée pendant toute la session en détaillant la structure de son implantation, les outils et la collecte de données, de même que les retombées envisagées

RLIP mediates downstream signalling from RalB to the actin cytoskeleton during Xenopus early development.

The Ras protein activates at least three different pathways during early development. Two of them regulate mesodermal gene expression and the third is thought to participate in the control of actin cytoskeleton dynamics via the Ral protein. From a yeast two-hybrid screen of a Xenopus maternal cDNA library, we identified the Xenopus orthologue of the Ral interacting protein (RLIP, RIP1 or RalBP1), a putative effector of small G protein Ral. Previously we observed that a constitutively activated form of Ral GTPase (XralB G23V) induced bleaching of the animal hemisphere and disruption of the cortical actin cytoskeleton. To demonstrate that RLIP is the effector of RalB in early development, we show that the artificial targeting of RLIP to the membrane induces a similar phenotype to that of activated RalB. We show that overexpression of the Ral binding domain (RalBD) of XRLIP, which binds to the effector site of Ral, acts in competition with the endogenous effector of Ral and protects against the destructive effect of XralB G23V on the actin cytoskeleton. In contrast, the XRLIP has a synergistic effect on the activated form of XralB, which is dependent on the RalBD of RLIP. We provide evidence for the involvement of RLIP by way of its RalBD on the dynamics of the actin cytoskeleton and propose that signalling from Ral to RLIP is required for gastrulation

Créer, préserver, communiquer. Une étude comparative du records management et des plans de gestion des données.

Mémoire de Master traitant du records management et des plans de gestion des données

Language evaluation and use during early childhood: Adhesion to social norms or integration of environmental regularities?

International audienceWhether social uses of language, in concert with their acquisition, are driven by the awareness of the social value assigned to linguistic variants remains unanswered. The present study examines how 185 French native speakers, aged from 2 to 6 years from different social backgrounds, produce and evaluate a well-known French phonological alternation, the liaison: obligatory liaisons, which are categorical and do not vary sociolinguistically for adults, and variable liaisons, which are a sociolinguistic variable and are more frequently produced by higher-class adults. Different developmental and social patterns were found for obligatory and variable liaisons. Children's productions of obligatory liaisons were related to their judgments when 3-4 years old, regardless of the children's social backgrounds. However, a developmental gap was observed between higher- and lower-class children that appeared earlier in production than in evaluation. For variable liaisons, children's productions were related to their judgments, irrespective of their social backgrounds, at 4-5 years. Social differences appeared in both children's productions and judgments a year later. Although the ability to evaluate different linguistic forms emerges at an early developmental stage, the awareness of the social value of the variants does not seem to precede the ability to select the standard varieties in formal situations

ROLE OF BENZODIAZEPINES IN THE TREATMENT OF ANXIETY DISORDERS IN 2014

Background: This article aims at determining the place of benzodiazepines in the current treatment of anxiety disorders in opposition to antidepressants, neuroleptics and anticonvulsants. Belgium and France are the only two European countries which prescribe the most benzodiazepines despite the dissuasion of the international guidelines (NICE) issued in the nineties concerning the high risk of dependance of these molecules. What about the respect of these guidelines and the use of benzodiazepines in general practice in 2014? Methods: Review of the literature with the following key words «anxiety disorder, benzodiazepines, anxiolytic, treatment» in the international database of PubMed, Medline, PsycINFO, PsycARTICLES and consulting of various reference books. Results: No class of molecules could measure up to benzodiazepines until now, neither from the point of view of efficiency, nor from the point of view of cost-efficiency. This is why the guidelines (NICE) discourage the few available alternatives in the general practice. International figures from Belgium and France show a continuous increase in the use of benzodiazepines in the treatment of anxiety disorders, even after the nineties. Given the fact that benzodiazepines differ from one another at the level of their action profile (graphical representation in “stars”) and are therefore able to relieve several symptoms simultaneously, these molecules still respond nowadays to many expectations of the clinical practitioners. Conclusions: The divergence between the guidelines and the practice confirm the irreplaceability of benzodiazepines at the present time. Nevertheless, the expectation of new molecules with fewer side effects should be investigated in further research

Differences in pelvic floor morphology between continent, stress urinary incontinent, and mixed urinary incontinent elderly women : an MRI study

Aims To compare magnetic resonance imaging (MRI) of the pelvic floor musculature (PFM), bladder neck and urethral sphincter morphology under three conditions (rest, PFM maximal voluntary contraction (MVC), and straining) in older women with symptoms of stress (SUI) or mixed urinary incontinence (MUI) or without incontinence. Methods This 2008–2012 exploratory observational cohort study was conducted with community-dwelling women aged 60 and over. Sixty six women (22 per group), mean age of 67.7 ± 5.2 years, participated in the study. A 3 T MRI examination was conducted under three conditions: rest, PFM MVC, and straining. ANOVA or Kruskal–Wallis tests (data not normally distributed) were conducted, with Bonferroni correction, to compare anatomical measurements between groups. Results Women with MUI symptoms had a lower PFM resting position (M-Line P = 0.010 and PC/H-line angle P = 0.026) and lower pelvic organ support (urethrovesical junction height P = 0.013) than both continent and SUI women. Women with SUI symptoms were more likely to exhibit bladder neck funneling and a larger posterior urethrovesical angle at rest than both continent and MUI women (P = 0.026 and P = 0.008, respectively). There were no significant differences between groups on PFM MVC or straining. Conclusions Women with SUI and MUI symptoms present different morphological defects at rest. These observations emphasize the need to tailor UI interventions to specific pelvic floor defects and UI type in older women