284 research outputs found
Identification of the metallurgical parameters explaining the corrosion susceptibility in a 2050 aluminium alloy
The corrosion behaviour of a 2050 aluminium alloy was studied in a NaCl solution. The structure ofprecipitation did not fully explain the susceptibility to intergranular (in the -T34 state) and intragran-ular corrosion for the aged state (the -T8 state). A relationship between the nature of interfaces, thegrains characteristics (size, internal misorientation and orientation according to the plane exposed tothe electrolyte) on one hand and the corrosion susceptibility of the alloy on the other hand was clearlyestablished. Galvanic coupling between grains with different internal misorientations helped to explainthe intergranular corrosion susceptibility of the -T34 state
Les effets de la neuromodulation non invasive sur les acouphènes
Les acouphènes touchent une grande proportion de Canadiens. Cette condition est associée à de nombreuses comorbidités et affecte de manière significative la qualité de vie des patients qui en souffrent. Malheureusement, les mécanismes de génération et de persistance des acouphènes sont méconnus et il demeure de nombreux questionnements dans la communauté scientifique. Notamment, aucun traitement curatif n’est disponible pour l’instant. Ce mémoire fait état des différents types d’acouphènes qui peuvent se manifester ainsi que des diverses thérapies étudiées pour le traitement des acouphènes. Les grands modèles neurobiologiques prédominants dans la littérature sont aussi présentés. De plus, ce mémoire étudie la neuromodulation non invasive comme nouvelle avenue de traitement pour les acouphènes. Nous avons réalisé une méta-analyse et une étude de modélisation afin d’évaluer l’efficacité de ce traitement pour les acouphènes ainsi que les impacts sur les substrats neurobiologiques des acouphènes. Les résultats de cette étude montrent que la neuromodulation non invasive magnétique (SMTr) diminue de manière statistiquement significative les scores d’évaluation de l’acouphène, et que ces effets sont plus marqués chez les femmes. Les résultats montrent aussi que la neuromodulation du cortex auditif est l’approche qui diminue le plus les acouphènes et qu’elle génère un champ électrique plus fort dans l’insula en comparaison à d’autres régions d’intérêt. Finalement, ce mémoire discute des principales méthodes d’évaluation des acouphènes ainsi que de l’effet placébo présent lors du traitement des acouphènes. Des parallèles avec la douleur chronique sont établis, afin d’orienter la recherche sur de prochains traitements. Le futur de la neuromodulation non invasive pour le traitement des acouphènes est aussi discuté en marge de perspectives et de limites du travail.Tinnitus impacts a large proportion of Canadians. It is linked to various comorbidities that significantly affect the quality of life of those who suffer from it. Unfortunately, generation and maintenance mechanisms are still unclear and numerous questions remain in the scientific community. Notably, no cure is available for tinnitus as of now. This dissertation reports the different types of tinnitus that can occur, besides the diverse therapies that have been reviewed for the treatment of tinnitus. The main neurobiological models of tinnitus prevailing in the literature are also presented. Furthermore, this dissertation investigates noninvasive neuromodulation as a new approach to treat tinnitus. A meta-analysis and modeling study have evaluated the efficacy of this treatment for tinnitus along with its impact on neurobiological substrates of tinnitus. The results of the study show that repetitive transcranial magnetic stimulation (rTMS) decreases statistically significantly tinnitus scores and that those effects are more marked in women. The results also show that noninvasive neuromodulation of the auditory cortex is the approach that decreases tinnitus the most and that this approach generates a stronger electric field in the insula among other regions of interest. Finally, this dissertation discusses the main methods to rate tinnitus and the placebo effect measured during tinnitus treatment. We also draw parallels with chronic pain, to orient prospective research. The future of noninvasive neuromodulation is also discussed in terms of treatment for tinnitus alongside perspectives and limits of the work
Les habiletés olfactives des aveugles de naissance : organisation anatomo-fonctionnelle et aspects comportementaux
La littérature décrit certains phénomènes de réorganisation physiologique et fonctionnelle dans le cerveau des aveugles de naissance, notamment en ce qui a trait au traitement de l’information tactile et auditive. Cependant, le système olfactif des aveugles n’a reçu que très peu d’attention de la part des chercheurs. Le but de cette étude est donc de comprendre comment les aveugles traitent l’information olfactive au niveau comportemental et d’investiguer les substrats neuronaux impliqués dans ce processus. Puisque, en règle générale, les aveugles utilisent leurs sens résiduels de façon compensatoire et que le système olfactif est extrêmement plastique, des changements au niveau de l’organisation anatomo-fonctionnelle pourraient en résulter. Par le biais de méthodes psychophysiques et d’imagerie cérébrale (Imagerie par Résonance Magnétique fonctionnelle-IRMf), nous avons investigué les substrats anatomo-fonctionnels sollicités par des stimuli olfactifs. Nous avons trouvé que les aveugles ont un seuil de détection plus bas que les voyants, mais que leur capacité à discriminer et identifier des odeurs est similaire au groupe contrôle. Ils ont aussi plus conscience de l’environnement olfactif. Les résultats d’imagerie révèlent un signal BOLD plus intense dans le cortex orbitofrontal droit, le thalamus, l’hippocampe droit et le cortex occipital lors de l’exécution d’une tâche de détection d’odeur. Nous concluons que les individus aveugles se fient d’avantage à leur sens de l’odorat que les voyants afin d’évoluer dans leur environnement physique et social. Cette étude démontre pour la première fois que le cortex visuel des aveugles peut être recruté par des stimuli olfactifs, ce qui prouve que cette région assume des fonctions multimodales.It is generally acknowledged that people blind from birth develop supra-normal sensory abilities in order to compensate for their visual deficit. While extensive research has been done on the somatosensory and auditory modalities of the blind, information about their sense of smell remains scant. The goal of this study was therefore to understand olfactory processing in the blind at the behavioral and the neuroanatomical levels. Since blind individuals use their remaining senses in a compensatory way to assess their environment and since the olfactory system is highly plastic, it is likely to be susceptible to changes similar to those observed for tactile and auditory modalities. We used psychophysical testing and functional magnetic resonance imaging (fMRI) to investigate the neuronal substrates responsible for odor processing. Our data showed that blind subjects had a lower odor detection threshold compared to the sighted. However, no group differences were found for odor discrimination and odor identification. Interestingly, the OAS revealed that blind participants scored higher for odor awareness. Our fMRI data revealed stronger BOLD responses in the right lateral orbitofrontal cortex, bilateral medio-dorsal thalamus, right hippocampus and left occipital cortex in the blind participants during an odor detection task. We conclude that blind subjects rely more on their sense of smell than the sighted in order to assess their environment and to recognize places and people. This is the first demonstration that the visual cortex of the blind can also be recruited by odorants, thus adding new evidence to its multimodal function
La chambre de commerce de Cambrai, vitrine de la reconstruction réussie d’une ville du Nord
Les destructions de la Grande Guerre laissent la ville de Cambrai en ruines. En 1919, Pierre Leprince-Ringuet, Jacques Debat-Ponsan et Germain Debré remportent le concours pour le plan d’agrandissement et d’embellissement de Cambrai. Architecte de la reconstruction, Pierre Leprince-Ringuet veillera à conserver l’esprit de la ville ancienne, refondant les artères et créant de nouveaux espaces urbains en utilisant la tradition architecturale flamande. Avec René Herscher, il réalise la nouvelle chambre de commerce située sur une place à l’arrière de l’hôtel de ville. Le programme intègre en outre un bureau de poste et une salle de conférences. La complexité du règlement des dommages de guerre retarde le démarrage des travaux jusqu’en 1923. Les architectes font appel à des artistes renommés, Marcel Gaumont pour la sculpture et Auguste Labouret pour les vitraux et ces interventions contribueront fortement à imprimer un caractère Art Déco mais également néo-régionaliste au palais consulaire cambrésien inauguré en 1930.Destruction caused by the Great War had left the city of Cambrai in ruins. In 1919, Pierre Leprince-Ringuet, Jacques Debat-Ponsan and Germain Debré won the competition for the plan for the extension and improvements of Cambrai. As architect of the Reconstruction, Pierre Leprince-Ringuet saw to it that the spirit of the old city was preserved: he built the roads on new foundations and created new urban spaces while using Flemish architectural tradition. In collaboration with René Herscher, he achieved the new Chamber of Commerce located on a place behind the town hall. The program also included a post office and a lecture room. The construction work was delayed to 1923, owing to the complex settlement of war damages. The architects called on some well-known artists such as Marcel Gaumont for sculpture and Auguste Labouret for stained-glass windows: these works will definitely give an Art Deco but also Neo-Regionalism character to the consular palace of Cambrai inaugurated in 1930.Nach den Zerstörungen des ersten Weltkrieges lag die Stadt Cambrai in Trümmern. 1919 gewannen Pierre Leprince-Ringuet, Jacques Debat-Ponsan und Germain Debré den Wettbewerb für die Planung der Erweiterung und der Verschönerung Cambrais. Pierre Leprince-Ringuet, Architekt des Wiederaufbaus, sorgte dafür, den Geist der früheren Stadt zu bewahren, indem er Straßen neu fasste und neue Stadträume schuf, die die flämische architektonische Tradition übernahmen. Gemeinsam mit René Herscher erstellte er die neue Handelskammer auf einem Platz hinter dem Rathaus. Das Programm beinhaltete auβerdem ein Postamt und einen Konferenzraum. Die Umständlichkeit der Regelung von Kriegsschäden verzögerte das Starten der Bauarbeiten bis 1923. Die Architekten beriefen dazu renommierte Künstler, den Bildhauer Marcel Gaumont und den Glasmaler Auguste Labouret. Deren Beiträge verliehen dem konsularischen Palast von Calais, 1930 eingeweiht, ein starkes Art-Deco-Gepräge, ebenso einen neoregionalistischen Charakter
International Conference “Melville’s Measures”
The international conference “Melville’s Measures” was initiated by Ronan Ludot-Vlasak (Université de Lille) and Cécile Roudeau (Université de Paris), with the support of the research units CECILLE (Université de Lille) and LARCA (Université de Paris), and the contribution of the MESHS, the CNRS and the IUF. It took place between October 17th and October 19th, 2019, at both the Maison des Sciences de l’Homme et de la Société (MESHS) in Lille and the Université de Paris. Held on the occasion o..
A multicentric real-world observational study to describe the use and efficacy of follitropin delta for IVF/ICSI procedures in patients at risk of hypo-response
BackgroundAround 20% of patients undergoing assisted reproductive technology are at risk of hypo-response to ovarian stimulation. The aim of this study was to describe the real-world use of follitropin delta for ovarian stimulation in these patients, as defined by POSEIDON groups 3 and 4 [an anti-Müllerian hormone (AMH) level of <1.2 ng/ml].Materials and methodsThis study was a post-hoc analysis of participants from DELTA, a multi-centre, prospective, observational study conducted in normal care settings in fertility clinics at 14 active sites in France. A subset of 35 patients at risk of hypo-response to ovarian stimulation (mean AMH 0.7 ± 0.29 ng/ml) and treated with follitropin delta were included. Patients were followed for 10–11 weeks after the first fresh or frozen embryo transfer in case of subsequent pregnancy, and data on real-world follitropin delta use collected.ResultsMost patients (92.9%) had undergone their first IVF or ICSI. The prescribed daily dose was usually based on the approved algorithm (N = 26; 74.3%) with a mean daily dose of 14.2 ± 4.1 mcg, resulting in a mean total dose of 187.7 ± 135.6 mcg. The mean duration of ovarian stimulation was 11.6 ± 6.7 days with no premature discontinuations, while the mean number of oocytes retrieved among patients that started stimulation was 6.3 ± 4.3. A fresh transfer was performed for 21 patients (84.0%), with a mean of 1.04 ± 0.98 embryos transferred per patient. Seven patients (20.0%) achieved an ongoing pregnancy (28% per transfer). No adverse drug reactions were reported.ConclusionsThe results describe the real-world use of follitropin delta and demonstrate its suitability for POSEIDON group 3 and 4 patients. These data complement clinical trial outcomes, supporting clinician decision-making and improving IVF/ICSI outcomes
Prenatal presentation of multiple anomalies associated with haploinsufficiency for ARID1A
The ARID1A gene is an infrequent cause of Coffin-Siris syndrome (CSS) and has been associated with severe to profound developmental delays and hypotonia in addition to characteristic craniofacial and digital findings. We present three fetuses and a male neonate with ventriculomegaly/hydrocephalus, absence of the corpus callosum (ACC), cerebellar hypoplasia, retinal dysplasia, lung lobulation defects, renal dysplasia, imperforate or anteriorly placed anus, thymus hypoplasia and a single umbilical artery. Facial anomalies included downslanting palpebral fissures, wide-spaced eyes, low-set and posteriorly rotated ears, a small jaw, widely spaced nipples and hypoplastic nails. All fetuses had heterozygous variants predicting premature protein truncation in ARID1A (c.4886dup:p.Val1630Cysfs*18; c.4860dup:p.Pro1621Thrfs*27; and c.175G>T:p.Glu59*) and the baby's microarray demonstrated mosaicism for a deletion at chromosome 1p36.11 (arr[GRCh37] 1p36.11(26,797,508_27,052,080)×1∼2), that contained the first exon of ARID1A. Although malformations, in particular ACC, have been described with CSS caused by pathogenic variants in ARID1A, prenatal presentations associated with this gene are rare. Retinal dysplasia, lung lobulation defects and absent thymus were novel findings in association with ARID1A variants. Studies in cancer have demonstrated that pathogenic ARID1A variants hamper nuclear import of the protein and/or affect interaction with the subunits of SWI/SNF complex, resulting in dysregulation of the PI3K/AKT pathway and perturbed PTEN and PIKC3A signaling. As haploinsufficiency for PTEN and PIKC3A can be associated with ventriculomegaly/hydrocephalus, aberrant expression of these genes is a putative mechanism for the brain malformations demonstrated in patients with ARID1A variants
A lexical-semantic impairment screening in mild neurocognitive disorder: Presentation of the relevance of two tools, the SNT-AD and the mini-SKQ
peer reviewe
Extending the clinical spectrum of X-linked Tonne-Kalscheuer syndrome (TOKAS):new insights from the fetal perspective
INTRODUCTION: Tonne-Kalscheuer syndrome (TOKAS) is a recessive X-linked multiple congenital anomaly disorder caused by RLIM variations. Of the 41 patients reported, only 7 antenatal cases were described.METHOD: After the antenatal diagnosis of TOKAS by exome analysis in a family followed for over 35 years because of multiple congenital anomalies in five male fetuses, a call for collaboration was made, resulting in a cohort of 11 previously unpublished cases.RESULTS: We present a TOKAS antenatal cohort, describing 11 new cases in 6 French families. We report a high frequency of diaphragmatic hernia (9 of 11), differences in sex development (10 of 11) and various visceral malformations. We report some recurrent dysmorphic features, but also pontocerebellar hypoplasia, pre-auricular skin tags and olfactory bulb abnormalities previously unreported in the literature. Although no clear genotype-phenotype correlation has yet emerged, we show that a recurrent p.(Arg611Cys) variant accounts for 66% of fetal TOKAS cases. We also report two new likely pathogenic variants in RLIM, outside of the two previously known mutational hotspots.CONCLUSION: Overall, we present the first fetal cohort of TOKAS, describe the clinical features that made it a recognisable syndrome at fetopathological examination, and extend the phenotypical spectrum and the known genotype of this rare disorder.</p
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