Evaluating Graph Signal Processing for Neuroimaging Through Classification and Dimensionality Reduction

Graph Signal Processing (GSP) is a promising framework to analyze multi-dimensional neuroimaging datasets, while taking into account both the spatial and functional dependencies between brain signals. In the present work, we apply dimensionality reduction techniques based on graph representations of the brain to decode brain activity from real and simulated fMRI datasets. We introduce seven graphs obtained from a) geometric structure and/or b) functional connectivity between brain areas at rest, and compare them when performing dimension reduction for classification. We show that mixed graphs using both a) and b) offer the best performance. We also show that graph sampling methods perform better than classical dimension reduction including Principal Component Analysis (PCA) and Independent Component Analysis (ICA).Comment: 5 pages, GlobalSIP 201

Le risque de cancer du sein en France : un mode unique de prévention

Cet article porte sur l’élaboration du risque de cancer du sein en France et sur ses conséquences sociales. Il s’appuie sur des données historiques et sociologiques pour tracer l’évolution de sa prévention, de la fin du xixe siècle aux tests contemporains de prédisposition génétique. Il montre que la détection précoce s’est imposée comme la technique d’excellence de prévention du cancer du sein, dans un monde où les thérapeutiques évoluent peu en matière de guérison, d’une part, et dans lequel les discours alternatifs n’ont eu que très peu d’audience auprès des publics concernés, d’autre part. Basée exclusivement sur le dépistage, l’entreprise française de prévention du cancer du sein a progressivement transformé des personnes en bonne santé en patientes asymptomatiques — dans un processus de médicalisation du risque — et des populations ciblées de femmes en population à risque — dans un processus de naturalisation du même risque. L’entreprise de surveillance qui organise cette situation est l’oeuvre d’une autonomie médicale qui légitime un « faute de mieux », en l’absence de remède efficace.This paper concerns the study of the risk of breast cancer in France and its social consequences. It is based on historical and sociological data tracing the evolution of its prevention from the end of the 19th century to contemporary genetic predisposition tests. It shows that early screening has proved to be the best breast cancer prevention technique in a world where cure-ensuring treatments are not only slow to develop, but in which alternative methods have received little attention from the public most concerned. Based exclusively on screening, breast cancer prevention efforts in France have gradually transformed healthy individuals into asymptomatic patients — in a process of risk medicalization — and targeted groups of women into groups at risk — in a process of naturalization of the same risk. The supervisory body overseeing this situation is the work of an autonomous medical establishment that legitimizes a « lesser evil » in the absence of an effective cure.Este artículo se refiere a la elaboración del riesgo de cáncer del seno en Francia y sobre sus consecuencias sociales. Se basa en datos históricos y sociológicos para trazar la evolución de su prevención, de finales del siglo XIX a las pruebas contemporáneas de predisposición genética. Pone de manifiesto que la detección precoz se impuso como la técnica de excelencia de prevención del cáncer del seno, en un mundo donde las terapéuticas evolucionan poco en cuanto a curación, por una parte, y en el cual los discursos alternativos tuvieron muy poca audiencia para los públicos interesados, por otra parte. Basada exclusivamente en la detección, la empresa francesa de prevención del cáncer del seno transformó progresivamente personas en buena salud en pacientes asintomáticas - en un proceso de medicalización del riesgo — y poblaciones específicas de mujeres en población de riesgo — en un proceso de naturalización del mismo riesgo —. La empresa de vigilancia que organiza esta situación está en obra de autonomía médica que legitima el « a falta de algo mejor », en ausencia de remedio eficaz

Modulation of Rolandic Beta-Band Oscillations during Motor Simulation of Joint Actions

Successful joint actions require precise temporal and spatial coordination between individuals who aim to achieve a common goal. A growing number of behavioral data suggest that to efficiently couple and coordinate a joint task, the actors have to represent both own and the partner’s actions. However it is unclear how the motor system is specifically recruited for joint actions. To find out how the goal and the presence of the partner’s hand can impact the motor activity during joint action, we assessed the functional state of 16 participants’ motor cortex during observation and associated motor imagery of joint actions, individual actions, and non-goal-directed actions performed with either 1 or 2 hands. As an indicator of the functional state of the motor cortex, we used the reactivity of the rolandic magnetoencephalographic (MEG) beta rhythm following median-nerve stimulation. Motor imagery combined with action observation was associated with activation of the observer’s motor cortex, mainly in the hemisphere contralateral to the viewed (and at the same time imagined) hand actions. The motor-cortex involvement was enhanced when the goal of the actions was visible but also, in the ipsilateral hemisphere, when the partner’s hand was visible in the display. During joint action, the partner’s action, in addition to the participant’s own action, thus seems to be represented in the motor cortex so that it can be triggered by the mere presence of an acting hand in the peripersonal space.Peer reviewe

Bases neuronales des interactions sociales non-verbales : implication du système moteur & hyperscanning

This research investigated the impact of social interaction on motor activity, both ona behavioural and cerebral level. More precisely, the aim of the thesis was to characterise this modulation during simultaneous actions, when two participants interact, jointly or not, and to determine its functions. First , we studied the effect of action observation on motor execution. Coupling kinematics analysis and EEG recording, we gave evidence that the temporal time course of motor system activation was crucial for motor interference. We found that motor performances were facilitated by the observation of an action, only when execution and observation events were temporally coordinated. Second, we sought to characterise the influence of an interactive context on brain activity of two interacting participants through the coupling of dual-EEG and kinematic recordings. Thanks to the comparison of intra- and inter-individual brain activity of two participants that observed or performed individual or joint actions, we were able to highlight modulations of cerebral motor activity common in both participants as well as modulations of brain activity specific to the social context (human vs robot) and the role in the interaction (actor vs observer). Moreover, the inter-individual analysis revealed a coupling between the two participants' visual and motor brain areas during the joint action condition. Taken toghther, these results suggest that the motor system allows a tight coupling between interacting participants, mediated by temporal coupling that could facilitate the interaction and through an action-perception loop forming a common motor representation of the joint action.Cette thèse s'est intéressée à l'impact des interactions sociales sur l'acitivité motrice, à la fois au niveau comportempentale et cérébral et de caractériser cette modulation au cours d'actions simultanées et d'actions conjointes. Dans un premier temps, nous avons étudié les effets de l'observation d'une activation sur l'exécution motrice. En couplant analyse cinématique et enregistrement EEG, nous avons mis en évidence que l'activation du système des neurones miroirs facilitait l'action seulement lorsque les événements d'exécution et d'observation étaient temporellement coordonnées. Dans un deuxième temps, nous avons cherché à meiux caractériser l'influence du contexte interactif sur l'activité cérébrale de deux participants d'une interaction grâce à une étude en double-EEG et cinématique. Grâce à la comparaison des activités cérébrales motrices intra- et inter-individuelles chez deux participants qui effectuaient ou observaient des actions isolées ou des actions conjointes, nous avons pu mettre en évidence des modulations de l'activité motrice similaires chez les deux particiapnts ainsi que certaines modulations spécifiques à la fois du contexte social (humain vs robot) et du rôle dans l'interaction. L'analyse inter-individuelle a par ailleurs mis en évidence un couplage entre les aires visuelles et motrices des deux particiapnts pendant la condition d'action conjointe. L'ensemble des résultats suggère que le système moteur permet un couplage fin entre les participants d'une interaction, à la fois au travers d'un couplage temporel qui pourrait faciliter l'interaction et également au travers d'une boucle d'action-perception formant une représentation commune de l'action conjointe

Cure in cancer: an improbable ambition

Cet article propose une réflexion sur la notion de guérison et sur ses usages en cancérologie. Un premier point ausculte sa mise en œuvre en tant qu’ambition à la fois médicale et politique suprême de la mission fondatrice de la cancérologie française. Un deuxième axe pointe ses divers accommodements sociaux, en observant les différentes figures et mésaventures du concept confronté à l’épreuve de l’incurabilité d’un certain nombre de cancers. Enfin, une troisième partie de l’article s’intéresse aux effets de l’incertitude chronique inhérente à l’oncologie. Fondée sur des recherches empiriques inspirées par la grounded theory, par l’interactionnisme et sous l’influence revendiquée d’Anselm Strauss, cette réflexion peut être vue comme un abrégé des travaux de l’auteure, réalisés de la fin des années 1990 à nos jours, sur la cancérologie française. L’incertitude médicale et sa gestion, individuelle et collective, sont au cœur de ce travail.This article proposes a reflection about the notion of cure and its uses in oncology. A first point examines its implementation as the utmost medical and political ambition of the founding mission of French oncology. A second axis points to its various social accommodations, observing the different figures and misadventures of the concept confronted with the test of the incurability of numerous cancers. Finally, a third part of the article focuses on the effects of the chronic uncertainty inherent in oncology. Based on empirical research made from the late 1900s to our days, inspired by grounded theory, interactionism and under the influence of Anselm Strauss, this reflection can be seen as an abstract of the author’s work on French oncology. Medical uncertainty and its individual and collective management are at the core of this work.Este artigo propõe uma reflexão sobre a noção de cura e seus usos em oncologia. Um primeiro ponto examina sua implementação como uma ambição suprema tanto médica quanto política da missão fundadora da oncologia francesa. Um segundo eixo aponta suas diversas acomodações sociais, observando as diferentes figuras e desventuras do conceito confrontado com o teste de incurabilidade de um certo número de cânceres. Finalmente, a terceira parte do artigo se centra sobre os efeitos da incerteza crônica inerente à oncologia. Com base em pesquisas empíricas inspiradas pela grounded theory, pelo interacionismo e sob a influência reivindicada de Anselm Strauss, esta reflexão pode ser vista como um resumo da obra do autor, feitas desde o final de 1900 até atualmente, sobre oncologia francesa. A incerteza médica e sua gestão, individual e coletiva, estão no centro deste trabalho

Tranilast, an analogue of tryptophan catabolites, induces allograft tolerance by CD161+ cells

International audiencen.

Immunosuppressive role of fibrinogen-like protein 2 (FGL2) in CD8+regulatory T cells-mediated long-term graft survival

International audienc

De l'inefficacité du réseau social : des liens sociaux non mobilisés chez les patients atteints de cancer

International audienceDe nombreuses études sur les réseaux sociaux portent sur la question des ressources auxquelles un individu peut avoir accès à travers ses relations sociales. En s'intéressant aux réseaux qui ont « fonctionné », elles tentent alors de spécifier les facteurs ayant permis l'accès aux ressources. Mais peu de travaux se sont penchés sur les réseaux ayant échoué à fournir à l'individu le bien ou le service qu'il recherchait. Cet article se propose de discuter de ces réseaux « inefficaces » à travers le cas de patients atteints de cancer recherchant des informations relatives à leur pathologie. Les résultats indiquent que les causes de l'inefficacité du réseau sont à rechercher dans la non mobilisation des liens de la part des malades rencontrés. Un certain nombre de contraintes pèsent sur ces liens empêchant ainsi leur mobilisation

Dual-wavelength laser source for onboard atom interferometry

We present a compact and stable dual-wavelength laser source for onboard atom interferometry with two different atomic species. It is based on frequency-doubled telecom lasers locked on a femtosecond optical frequency comb. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components which are intrinsically less stable, and to make the setup immune to vibrations and thermal fluctuations. The source provides the frequency agility and phase stability required for atom interferometry and can easily be adapted to other cold atom experiments. We have shown its robustness by achieving the first dual-species K-Rb magneto optical trap in microgravity during parabolic flights

Homology-directed repair in rodent zygotes using Cas9 and TALEN engineered proteins

International audienceThe generation of genetically-modified organisms has been revolutionized by the development of new genome editing technologies based on the use of gene-specific nucleases, such as meganucleases, ZFNs, TALENs and CRISPRs-Cas9 systems. The most rapid and cost-effective way to generate genetically-modified animals is by microinjection of the nucleic acids encoding gene-specific nucleases into zygotes. However, the efficiency of the procedure can still be improved. In this work we aim to increase the efficiency of CRISPRs-Cas9 and TALENs homology-directed repair by using TALENs and Cas9 proteins, instead of mRNA, microinjected into rat and mouse zygotes along with long or short donor DNAs. We observed that Cas9 protein was more efficient at homology-directed repair than mRNA, while TALEN protein was less efficient than mRNA at inducing homology-directed repair. Our results indicate that the use of Cas9 protein could represent a simple and practical methodological alternative to Cas9 mRNA in the generation of genetically-modified rats and mice as well as probably some other mammals