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État actuel des connaissances sur la relation entre l'épilepsie idiopathique et le microbiome intestinal chez le chien
No full textThe rapid development of analysis techniques over the last ten years has enabled in-depth exploration of the intestinal microbiota and its genome. Sometimes described as a ‘second brain', the digestive tract has its own enteric nervous system and communicates bidirectionally with the central nervous system. The aim of this literature review is to bring together the current evidence for a link between the intestinal microbiota and idiopathic epilepsy in dogs, also based on those found in humans and rodents. The intestinal microbiota plays a key role in stimulating the immune system and in the metabolism of proteins, vitamins and carbohydrates. This microbiota changes according to breed, age, diet, stress and possible chronic intestinal disorders. In humans, altered diversity and dynamics of bacterial populations have been observed, particularly in drug resistant epileptic patients. The only available study in dogs shows a reduction in the abundance of bacteria producing short-chain fatty acids, which is antioxidant, and GABA, an inhibitory neurotransmitter. Epilepsy activates the immune system, the hypothalamic-pituitary-adrenal axis, the enteric nervous system and the autonomic nervous system, modifying intestinal mucus secretion, intestinal motility, as well as the composition of the intestinal microbiota and its production of metabolites. Conversely, alteration of the microbiota can influence intestinal inflammation through the production of pro-inflammatory cytokines, permeability of the intestinal barrier leading to leakage of lipopolysaccharides, secretion of neurotransmitters by intestinal cells, and production of protective antioxidant molecules. Around 30% of dogs with idiopathic epilepsy are drug resistant, which makes the exploration of other therapeutic approaches particularly interesting. Several pilot studies in dogs focus on methods such as faecal transplantation, transcutaneous vagal stimulation, probiotics and dietary supplements. The majority of studies on dogs focus on the application of a so-called ketogenic diet, which modifies the composition of the intestinal microbiota and is likely to reduce the frequency of seizures. However, the narrow amplitude of the biological effect and the inclusion of dogs whose seizure frequency is not stabilised make any small modification difficult to interpret. These factors underline the need for future studies on this subject.L'évolution rapide des techniques d'analyse au cours des dix dernières années a permis une exploration approfondie du microbiote intestinal et de son génome. Parfois décrit comme un "deuxième cerveau", le tractus digestif possède en effet son propre système nerveux entérique et communique de manière bidirectionnelle avec le système nerveux central. Cette étude bibliographique a pour objectif de rassembler les preuves actuelles de l'existence du lien entre le microbiote intestinal et l'épilepsie idiopathique chez le chien en se basant également sur celles retrouvées chez l'homme et les rongeurs. Le microbiote intestinal joue un rôle clé dans la stimulation du système immunitaire, le métabolisme des protéines, des vitamines, ainsi que des glucides. Ce microbiote varie selon la race, l'âge, le régime alimentaire, l'état de stress et les possibles affections plus ou moins chroniques de l'intestin. Chez l'homme, une diversité et une dynamique modifiées des populations bactériennes ont été observées, notamment chez les patients épileptiques réfractaires à certains traitements. La seule étude disponible chez le chien montre une diminution de l'abondance en bactéries productrices d'acides gras à chaînes courtes, aux propriétés notamment antioxydantes, et de GABA, un neurotransmetteur inhibiteur. L'épilepsie active le système immunitaire, l'axe hypothalamo-hypophysaire- surrénalien, le système nerveux entérique et le système nerveux autonome, modifiant la sécrétion intestinale de mucus, la motilité intestinale, ainsi que la composition du microbiote intestinal et sa production de métabolites. Inversement, une altération du microbiote peut influencer l'inflammation intestinale par la production de cytokines pro-inflammatoires, la perméabilité de la barrière intestinale provoquant une fuite de lipopolysaccharides, la sécrétion de neurotransmetteurs par les cellules intestinales, ainsi que la production de molécules antioxydantes protectrices. Environ 30 % des chiens atteints d'épilepsie idiopathique sont réfractaires aux traitements médicamenteux, justifiant l'exploration d'autres approches thérapeutiques particulièrement intéressantes. Plusieurs études pilotes chez le chien orientent les recherches vers certaines méthodes comme la transplantation fécale, la stimulation vagale transcutanée, les probiotiques, les compléments alimentaires. Une majorité des études sur les chiens se concentre sur l'application d'un régime dit cétogénique, modifiant la composition du microbiote intestinal et susceptible de réduire la fréquence des crises. Cependant, l'étroite amplitude de l'effet biologique et l'inclusion de chiens dont la fréquence des crises n'est pas stabilisée rend toute faible modification difficilement interprétable. Ces éléments soulignent la nécessité de mener des futures études sur le sujet
Symposium "La formation des enseignants au défi de l'intégration. Dispositifs, contenus, pratiques, modalités ... pour quels effets ?": Communication "La circulation des savoirs au sein des "constellations" : le cas des formateurs en formation.
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Influence of chemical and morphological properties on the mid-infrared refractive indices of Titan aerosol analogs
No full textInternational audienceIn the atmosphere of Saturn's largest satellite, Titan, the solid particles in suspension (photochemistry organic aerosols) play an important role notably to the attenuation of the solar spectrum by absorption and scattering. To constrain these interactions, the optical properties of Titan’s atmospheric aerosols, refractive index n and extinction coefficient k were recovered from observations [1, 2, 3, 4]. The refractive indices database has been expanded using solid analogs of Titan's aerosols produced and analyzed in laboratory [5, 6, 7]. The experimental data are generally consistent with the optical properties derived from Titan’s aerosols, including the contribution to the extinction and albedo of Saturn's moon [5, 7, 8]. However, comparisons of vibrational modes in the mid-infrared (MIR) suggest a difference in composition between laboratory analogs and Titan’s aerosols [9, 10]. These discrepancies in the refractive indices of solids can originate from their morphological and chemical properties. Indeed, numerous experimental studies have revealed the variability in the morphology and chemical composition of solid analogs formed in simulations of Titan's atmospheric chemistry
Impact of tropical waves on the atmospheric structure and composition above Cabo Verde during the CADDIWA campaign
No full textInternational audienceThe Cabo Verde region is subject to the activity of many tropical waves during the boreal summer. They are known to favour or inhibit convective activity, and to play a role in the formation of Tropical Cyclones. A frequency-wavenumber filtering method is used to identify the different waves. A novel tracking protocol is used to distinguish African Easterly Waves propagating north and south of the African Easterly Jet based on their frequencies within the Mixed-Rossby Gravity - Tropical Disturbance (MRG-TD) domain, labeled MRG-TD1 and MRG-TD2, respectively. Based on in-situ and satellite measurements from the Cloud Atmospheric Dynamics Dust Interactions in West Africa (CADDIWA) campaign which took place in Cape Verde in September 201, the impact of each tropical type on the atmosphere vertical structure and dust content is discussed. Our results show that Equatorial Rossby waves mainly impact thermodynamics above 750 hPa, while MRG-TD1 affect jet-level thermodynamics, and MRG-TD2 modulate moisture in the lower troposphere. Dust event are mainly driven by MRG-TD2. The importance of the interaction between waves for tropical cyclogenesis is also highlighted which provides new outlooks for improving tropical cyclogenesis forecasting in the region.
Gestion de l'opposition de la famille dans la prise de décision des rapatriés auto-initiés (RA) Sénégalais
No full textInternational audienceThe aim of this study is to understand the influence of family opposition on the repatriation decisions of self-initiated expatriates (SIEs). Based on 28 interviews with Senegalese self initiated repatriates (SIRs), we identify a three-stage process for managing this constraint. In the first stage, we have the projection, where the self-initiated repatriate tries to predict and understand family opposition. In the second stage, there is preparation, which is a time for adopting proactive behaviours towards the family. In this process, there are two different strategies: a strategy of rapprochement with the extended family, and a strategy of distancing oneself from the extended family. Rapprochement is achieved through tactics intended to be prepared for this opposition. Distancing occurs in the case of repatriates married to foreign women. It takes the form of concentrating on the opposition of this partner, to the detriment of that of the extended family. Finally, we have the confrontation, where the repatriate tries to convince rationally and emotionally a small number of opponents, mostly his two parents and/or his wife, who is more important to him. This research makes a triple contribution to the literature. Firstly, it enriches the literature on repatriate adjustment during the anticipatory phase, with an understanding of the family not as a resource but also as an obstacle. Secondly, it extends this existing theory of repatriate adjustment process, by proposing a decision-making process in the anticipatory phase. Finally, based on the case of self-initiated Senegalese returnees, this research opens the reality of repatriation in the African context, with the influence of the extended family in the professional world, thus complementing existing work, most which focuses on cases from Western countries.Ce travail a pour objectif de comprendre l'influence de l'opposition de la famille dans la prise de décision de rapatriement des expatriés auto-initiés (EA). Se fondant sur 28 entretiens avec des rapatriés auto-initiés sénégalais (RA), nous dégageons un processus de gestion de cette contrainte, en trois étapes. Dans un premier temps, nous avons la projection où le rapatrié autoinitié tente de prédire et de comprendre l'opposition familiale. Dans une seconde étape, il y'a la préparation qui est un moment d'adoption de comportements proactifs à l'égard de la famille. Dans ce procédé deux stratégies différentes se posent : une stratégie de rapprochement de la famille élargie et une stratégie d'éloignement de la famille élargie. Le rapprochement se fait par des tactiques destinant à se préparer à cette opposition. L'éloignement se manifeste dans le cas des rapatriés mariés à des femmes étrangères. Il se traduit par une concentration sur l'opposition de cette partenaire, au détriment de celle de la famille élargie. Enfin, dans un dernier temps, nous avons la confrontation où le rapatrié tente de convaincre rationnellement et émotionnellement un petit nombre d'opposants composé majoritairement de ses deux parents et/ ou de sa femme, lequel est plus important à ses yeux. Cette recherche réalise une triple contribution à la littérature. Premièrement, elle enrichit la littérature sur l'ajustement des rapatriés lors de la phase anticipatoire, d'une compréhension de la famille non pas comme une ressource mais aussi comme un obstacle. Deuxièmement, elle élargit cette théorie existante du processus d'ajustement des rapatriés, en proposant un processus de prise de décision dans la phase anticipatoire. Enfin, en se fondant sur le cas de rapatriés auto-initiés sénégalais, cette recherche ouvre sur la réalité du rapatriement dans le contexte africain, avec l'influence de la famille élargie dans le monde professionnel, ce qui complète les travaux existants dont l'essentiel se concentre sur des cas de pays occidentau
Comparison between accelerated and standard or sham rTMS in the treatment of depression: A systematic review
No full textInternational audienceMajor depressive disorder (MDD) represents a major global health challenge, with a significant proportion of patients being resistant to drug treatment (TRD). Repetitive transcranial magnetic stimulation (rTMS) has shown promise in the treatment of MDD/TRD, with a single stimulation session per day for five days per week over several weeks (the "standard" protocol). The two main paradigms used are high-frequency rTMS and intermittent theta burst stimulation (iTBS) delivered to the left dorsolateral prefrontal cortex (DLPFC). Accelerated TMS (aTMS) protocols aim to make the treatment more effective, or at least more rapidly effective, by delivering more stimulations in a shorter time, which could also facilitate the implementation of the protocols for a larger number of patients. In this systematic literature review, articles comparing in the same study an aTMS protocol to a standard or sham rTMS protocol were retained for analysis. Thus, 23 articles were retained and the analysis focused on the efficacy of aTMS protocols used for the treatment of depression (MDD/TRD) as well as on the impact of various stimulation parameters, such as stimulation pattern, intersession interval, dosage, and methods of cortical targeting. Although some studies did not report significant differences between aTMS and standard or sham protocols, others suggested potential advantages of aTMS, such as twice-daily HF-rTMS of the left DLPFC or more intensive iTBS protocols with a long interval between two sessions and personalized cortical targeting. Our results highlight the influence of the number of sessions or pulses per session (dosage), the duration of the interval between sessions, and the precision of target localization (using image-guided neuronavigation) on therapeutic efficacy. However, limitations in sample size, few independent studies replicating the same methodology, and variability in the clinical profile of treated patients, given different definitions of treatment resistance or the presence of comorbidities, hamper definitive conclusions
Refined genotype–phenotype correlations in neurofibromatosis type 1 patients with NF1 point variants
No full textInternational audienceNeurofibromatosis type 1 (NF1) is one of the most frequent genetic disorders. NF1 is caused by dominant loss-of-function pathogenic variants (PVs) of the tumour-suppressor gene NF1, which encodes neurofibromin, a negative regulator of rat sarcoma proteins. NF1 is an autosomal dominant disorder with complete penetrance, but a highly variable expression. Identification of genotype-phenotype correlations is challenging because of the wide clinical variability, the progressive nature of the disorder and the extreme diversity of the mutation spectrum. Only a few NF1 point variants have been associated with a specific phenotype in NF1 patients.Methods: We investigated a large, well-phenotyped NF1 cohort.Results: We report analyses of genotype-phenotype correlations in 112 NF1 patients with specific NF1 point variants: p.Arg1809 missense variants were associated with a mild form of NF1 (n=24), while a more severe phenotype was associated with codons 844-848 (n=27), p.Arg1276 (n=25) and p.Lys1423 (n=35) missense variants. We describe a new correlation for p.Arg1204 missense variants (n=11), with no neurofibroma observed in patients. Functional studies will be critical for drawing conclusions on the potential hypomorphic or dominant-negative effects of these variants.Conclusion: The current data confirms several genotype-phenotype correlations in NF1, which may be relevant to the management and surveillance of NF1 patients with specific NF1 PVs
Litter in French urban areas — Part 2: transport dynamic and fluxes in stormwater
No full textInternational audienceUrban areas constitute a major hotspot of litter, including plastic litter, that stormwater can wash off towards waterways. However, few studies quantified and characterized litter densities in urban areas and fluxes transported by stormwater networks. Moreover, little information is available on litter transport dynamics in stormwater, and on the factors driving this transport. This study aims at characterizing and quantifying litter amounts transported by stormwater of two nested French urban catchments (total surface area of 105 ha). Litter densities relative to land uses and rain events were investigated in the same catchments as in a compagnon paper (Ledieu et al., 2024). The present study explores the impact of rain events on the transport of urban litter in stormwater. Litter collection and characterization combined with a capture/recapture experiment using tagged litter placed in stormwater inlets show total litter fluxes of 29 kg/year, in which 14 kg/year are plastics, exported at the stormwater outlet. These fluxes confirm that stormwater runoff is a considerable pathway from urban surfaces to waterways, especially regarding small plastic litter (< 2.5 cm). Item transport dynamic is however not linear and only 0.3% of the urban litter appear remobilized. Litter transport dynamics depends on several factors (urban litter densities, hydrometeorological parameters, item composition and morphologies, and stormwater management systems) that should be considered in global models
Une lecture sensible de l’entrepreneuring des femmes : entre résonance et subjectivité des crises
No full textInternational audienceDans cette recherche, nous souhaitons discuter de la relation entre les crises et l’entrepreneuriat des femmes en train de se faire pour mettre en évidence la manière dont, parfois, les femmes s’emparent de ces moments instables. Cet article souhaite ainsi donner à voir des relations plus ou moins denses entretenues entre l’entrepreneuring et la crise et répondre à la problématique suivante : En quoi les crises peuvent orienter un devenir entrepreneuse ? Notre objectif est d’offrir une lecture du devenir entrepreneuse, en insistant sur le rôle joué par les multiples crises, qui, au fil du temps, permet de saisir dans l’entrepreneuring les trajectoires et bifurcations entrepreneuriales. Cet article propose de rendre compte de l’importance de la représentation subjective de la crise, dans une perspective processuelle, du devenir entrepreneuse.La posture phénoménologique retenue est justifiée pour explorer deux cas singuliers d’entrepreneuses. La granularité fine de l’étude de ces deux récits met à jour les différentes rencontres, événements au sens deleuzien et crises de leur chemin. Nos résultats de recherche mettent en évidence comment il est possible de composer avec, voire de transcender les crises et se construire en fonction d’elles. Enfin, nous discutons de l'apport de la prise en compte de la dimension temporelle et des trajectoires aux logiques spatiales et sensibles, parfois sinueuses qui se dessinent au fil des heurts et de leur résonance interne, avec les crises.La relation au monde, la subjectivité de l’entrepreneuse permettent de saisir l’amplitude de la caisse de résonance de la crise. Cette lecture subjective du parcours que nous avons cherché à restituer dans les résultats invite à dépasser la lecture statique de l’entrepreneuriat. Elle encourage à éclairer la relation réciproque entre l’entrepreneuse, son environnement et son “rapport au monde” afin de saisir “l’entretissage” de l’entrepreneuring et du devenir entrepreneuse