Dynamics and Performance of Susceptibility Propagation on Synthetic Data

We study the performance and convergence properties of the Susceptibility Propagation (SusP) algorithm for solving the Inverse Ising problem. We first study how the temperature parameter (T) in a Sherrington-Kirkpatrick model generating the data influences the performance and convergence of the algorithm. We find that at the high temperature regime (T>4), the algorithm performs well and its quality is only limited by the quality of the supplied data. In the low temperature regime (T<4), we find that the algorithm typically does not converge, yielding diverging values for the couplings. However, we show that by stopping the algorithm at the right time before divergence becomes serious, good reconstruction can be achieved down to T~2. We then show that dense connectivity, loopiness of the connectivity, and high absolute magnetization all have deteriorating effects on the performance of the algorithm. When absolute magnetization is high, we show that other methods can be work better than SusP. Finally, we show that for neural data with high absolute magnetization, SusP performs less well than TAP inversion.Comment: 9 pages, 7 figure

CoRe: Color Regression for Multicolor Fashion Garments

Developing deep networks that analyze fashion garments has many real-world applications. Among all fashion attributes, color is one of the most important yet challenging to detect. Existing approaches are classification-based and thus cannot go beyond the list of discrete predefined color names. In this paper, we handle color detection as a regression problem to predict the exact RGB values. That's why in addition to a first color classifier, we include a second regression stage for refinement in our newly proposed architecture. This second step combines two attention models: the first depends on the type of clothing, the second depends on the color previously detected by the classifier. Our final prediction is the weighted spatial pooling over the image pixels RGB values, where the illumination has been corrected. This architecture is modular and easily expanded to detect the RGBs of all colors in a multicolor garment. In our experiments, we show the benefits of each component of our architecture.Comment: 6 pages,3 figures,1 tabl

Caractérisation des cellules dendritiques humaines BDCA3high et de leur modulation par le microenvironnement tumoral

Dendritic cells {DC) play a major role in the induction of antigen {Ag) specific anti-tumoral immunity. Recently, human BDCA3high DC appeared to be homologous with CD8a+ DC known to activate very efficiently T CD8 lymphocyte by Ag cross-presentation in mice. Moreover, those two DC populations are the main producers of interferon-λ {IFN-λ), a recently discovered cytokine family with antiviral, anti-proliferative and anti-tumoral properties. My works participated to better characterize cell derived Ag cross-presentation by BDCA3high DC using an in vitro model and enlightened the role of NK cells in its induction. This works also end up in revealing the presence of BDCA3high DC in breast tumors and the inhibition of their IFN-λsecretion by soluble factor from tumor microenvironment. Altogether, those results should allow designing new anti-tumoral immunotherapeutic strategies based on BDCA3high DC targetingLes cellules dendritiques {DC) jouent un rôle majeur dans l'induction de l'immunité anti-tumorale spécifique de l'antigène {Ag). Récemment, les DC BDCA3high humaines sont apparues comme étant homologues aux DC CD8a+ connues pour activer très efficacement les lymphocytes T CD8 par présentation croisée d'Ag chez la souris. Par ailleurs, ces deux populations de DC sont les productrices principales d'interféron-λ{IFN-λ), une cytokine récemment découverte et possédant des propriétés antivirales, antiprolifératives et anti-tumorales. Mon travail de thèse a permis de mieux caractériser la présentation croisée d'Ag cellulaire par les DC BDCA3high à l'aide d'un modèle in vitro et de mettre en lumière le rôle des cellules NK dans l'induction de ce processus. Ce travail a également aboutit à la mise en évidence des DC BDCA3high dans les tumeurs de sein et de révéler l'inhibition de leur sécrétion d'IFN-λ par des facteurs solubles présents dans le microenvironnement tumoral. L'ensemble de ces résultats devraient permettre de concevoir de nouvelles stratégies thérapeutiques basées sur le ciblage des DC BDCA3hig

The Superiority of Economists

In this essay, we analyze the dominant position of economics within the network of the social sciences in the United States. We begin by documenting the relative insularity of economics, using bibliometric data. Next we analyze the tight management of the field from the top down, which gives economics its characteristic hierarchical structure. Economists also distinguish themselves from other social scientists through their much better material situation (many teach in business schools, have external consulting activities), their more individualist worldviews, and their confidence in their discipline's ability to fix the world's problems. Taken together, these traits constitute what we call the superiority of economists, where economists' objective supremacy is intimately linked with their subjective sense of authority and entitlement. While this superiority has certainly fueled economists' practical involvement and their considerable influence over the economy, it has also exposed them more to conflicts of interests, political critique, even derision

Dynamique de l'organisation nucléaire des séquences d'ADN répétées centromériques humaines au cours du cycle cellulaire

Le noyau des cellules est une structure très organisée, dont l'organisation joue un rôle important dans la régulation de l'expression des gènes. La compréhension des mécanismes à l'origine de cette organisation est donc essentielle à la compréhension du fonctionnement des génomes. De nombreuses expériences conduites chez la souris ont montré que les régions centromériques (RC) des chromosomes jouent un rôle dans l'organisation du noyau. L'organisation spatiale des RCs humaines est beaucoup moins étudiée, principalement à cause de la complexité des séquences qui les composent, qui rend plus difficile leur détection. Nous avons développé des outils de traitement et d'analyse quantitative d'image, qui, combinés à des nouveaux marqueurs des RCs humaines, nous ont permis de mieux décrire deux aspects de leur organisation spatiale. D'une part nous avons montré qu'elles se positionnent préférentiellement en périphérie du noyau ou aux bords des nucléoles, avec des fréquences qui dépendent des chromosomes. D'autre part nous avons montré qu'elles s'agrègent dans le noyau pour former un compartiment d'hétérochromatine, qui présente des caractéristiques similaires à celui observé dans d'autres espèces telles que la souris. Ces deux aspects sont tous deux inter-dépendants et varient au cours du cycle cellulaire. Cette description nouvelle met sur la piste de mécanismes responsables de l'organisation particulière des RCs, qui pourront être étudiés grâce à la méthode d'analyse et aux observables que nous avons développées. L'étude de ces mécanismes permettra de mieux comprendre la fonction des RCs humaines dans l'organisation du noyau.The cell nucleus is a highly organized structure, playing an important role in gene regulation. Understanding the underlying mechanisms is therefore essential for understanding genome function. Numerous studies conducted in mouse cells have shown that centromeric regions (RC) of chromosomes play a role in nuclear organization. The spatial organization of human RCs is less studied, mainly because of the complexity of the underlying DNA sequences that make them hard to detect. We have developed image processing and analysis tools, that, combined with new markers for human RCs, have allowed us to draw a better description of two features of their spatial organization. On the one hand, we have shown that they are preferentially located close to the nuclear periphery or nucleoli borders, with chromosome-dependent frequencies. On the other hand, we have shown that they cluster to form a heterochromatic compartment that displays similar properties as the one observed in other species such as mouse. Both features are inter-dependent, and vary throughout the cell-cycle. This new description puts on the track of mechanisms responsible for the peculiar organization of RCs. Those mechanisms could be studied using the methodology and the observables we have developed. The study of those mechanisms will provide a better understanding of human RC function in nuclear organization.PARIS-JUSSIEU-Bib.électronique (751059901) / SudocSudocFranceF

La superioridad de los economistas

In this essay, we investigate the dominant position of economics within the network of the social sciences in the United States. We begin by documenting the relative insularity of economics, using bibliometric data. Next we analyze the tight management of the field from the top down, which gives economics its characteristic hierarchical structure. Economists also distinguish themselves from other social scientists through their much better material situation (many teach in business schools, have external consulting activities), their more individualist worldviews, and in the confidence they have in their discipline’s ability to fix the world’s problems. Taken together, these traits constitute what we call the superiority of economists, where economists’ objective supremacy is intimately linked with their subjective sense of authority and entitlement. While this superiority has certainly fueled economists’ practical involvement and their considerable influence over the economy, it has also exposed them more to conflicts of interests, political critique, even derision.Este artículo examina la posición dominante de la economía en la red de ciencias sociales en Estados Unidos. Primero documenta su insularidad relativa usando datos bibliométricos y luego analiza el rígido control desde arriba que le da su estructura jerárquica característica. Los economistas también se distinguen de otros científicos sociales por su mejor situación material, su visión del mundo más individualista y su confianza en la disciplina para resolver los problemas de mundo. Estas características constituyen lo que aquí se llama la superioridad de los economistas, cuya supremacía objetiva está ligada íntimamente a la sensación subjetiva de tener autoridad y derecho a ella. Esa superioridad alienta su intervención práctica y su gran influencia en la economía, pero también los expone a conflictos de interés, a la crítica política e incluso al ridículo