Application de la théorie de l'évidence à la combinaison de segmentations en régions

Cet article présente un algorithme de combinaison de segmentations décrites sous la forme de régions. La théorie de l'évidence est le cadre théorique de cette étude. La probabilité d'appartenance de chaque pixel à une région voisine permet de déduire le jeu de masse associé à une segmentation. Les jeux de masse ainsi obtenus sont combinés par la règle de Dempster. Le critère du maximum de plausibilité permet de choisir l'étiquette définitive du pixel. Une évaluation quantitative et comparative de l'apport de la combinaison a été menée sur un jeu de 40 images réelles

Control of the organization of 4,4′-bis(carbazole)-1,1′-biphenyl (CBP) molecular materials through siloxane functionalization

Funding: This research was funded by the French National Research Agency (ANR) through the Programme d’Investissement d’Avenir under contract ANR-11-LABX-0058-NIE within the Investissement d’Avenir program ANR-10-IDEX-0002-02.We show that through the introduction of short dimethylsiloxane chains, it was possible to suppress the crystalline state of CBP in favor of various types of organization, transitioning from a soft crystal to a fluid liquid crystal mesophase, then to a liquid state. Characterized by X-ray scattering, all organizations reveal a similar layered configuration in which layers of edge-on lying CBP cores alternate with siloxane. The difference between all CBP organizations essentially lay on the regularity of the molecular packing that modulates the interactions of neighboring conjugated cores. As a result, the materials show quite different thin film absorption and emission properties, which could be correlated to the features of the chemical architectures and the molecular organizations.Peer reviewe

Control of the Organization of 4,4′-bis(carbazole)-1,1′-biphenyl (CBP) Molecular Materials through Siloxane Functionalization

International audienceWe show that through the introduction of short dimethylsiloxane chains, it was possible to suppress the crystalline state of CBP in favor of various types of organization, transitioning from a soft crystal to a fluid liquid crystal mesophase, then to a liquid state. Characterized by X-ray scattering, all organizations reveal a similar layered configuration in which layers of edge-on lying CBP cores alternate with siloxane. The difference between all CBP organizations essentially lay on the regularity of the molecular packing that modulates the interactions of neighboring conjugated cores. As a result, the materials show quite different thin film absorption and emission properties, which could be correlated to the features of the chemical architectures and the molecular organizations

Assessing Long-term Treatment Benefits Using Complementary Statistical Approaches: An In Silico Analysis of the Phase III Keynote-045 and Checkmate-214 Immune Checkpoint Inhibitor Trials

International audienceBackgroundThe Keynote-045 trial illustrates that the long-term benefit (LTB) of treatment does not always translate to improved progression-free survival (PFS). Milestone survival and flexible parametric survival model with cure (FPCM) have been proposed as complementary statistical approaches to more comprehensively evaluate LTBs of treatments.ObjectiveThe current study compares milestone survival and FPCM analyses to evaluate treatment effects of immune checkpoint inhibitor (ICI) phase III trials.Design, setting, and participantsIndividual patient data, from initial and follow-up analyses of Keynote-045 (urothelial cancer) and Checkmate-214 (advanced renal cell carcinoma), were reconstructed for PFS.Outcome measurements and statistical analysisEach trial was reanalyzed using the Cox proportional hazard regression and two complementary methods (milestone survival and FPCM) to estimate treatment impact on the LTB.Results and limitationsFor each trial, there was evidence of nonproportional hazards. For the long-term analysis of the Keynote-045 trial, FPCM identified a time-dependent effect on PFS, but the Cox model found no statistical difference in PFS (hazard ratio, 0.90; 95% confidence interval, 0.75–1.08). Milestone survival and FPCM identified improvements in the LTB fractions. This was consistent with the results from the reanalysis of Keynote-045, based on the shorter follow-up, although the LTB fraction was not retained. The increase in PFS in Checkmate-214 was identified by both Cox model and FPCM. Experimental treatment-dependent improvement in the LTB fraction was demonstrated using milestone survival and FPCM. The LTB fraction estimated with FPCM was consistent with the results from the reanalysis of the shorter follow-up period.ConclusionsAlthough ICIs show substantial shifts toward LTBs in terms of PFS, based on a conventional Kaplan-Meier or Cox model analysis, our approach provides an alternative assessment of benefit-risk ratios for new therapeutics and facilitates communicating risk to patients. Kidney patients treated with ICIs can be counseled that they are potentially cured, but future work will need to definitively validate this conclusion

Photoactive Organic/Inorganic Hybrid Materials with Nanosegregated Donor-Acceptor Arrays

International audienc

Bringing together social-ecological system and territoire concepts to explore nature-society dynamics

We examine two academic traditions that address the nature-society interface. These traditions are organized around two main concepts: social-ecological system and territoire. These traditions have grown independently and are rooted respectively in ecology and social geography. We show that they have much in common: Both come with a systemic view of the nature-society interface and have the intention of understanding better the relations between nature and society and improving their sustainability. However, they differ in how they deal with space and society. We foresee that the combination of both traditions could improve the understanding of these systems, their definition, and their evolution, and hence, the capacity to assess and manage their resilience

Enhanced Light–Matter Interaction and Polariton Relaxation by the Control of Molecular Orientation

Exciton-polaritons, in which the electronic state of an excited organic molecule and a photonic state are strongly coupled, can form a Bose–Einstein condensate (BEC) at room temperature. However, so far, the reported thresholds of organic polariton BECs under optical excitation are as high as Pth = 11–500 μJ cm–2. One route toward lowering the condensation threshold is to increase the Rabi energy by aligning the molecular transition dipole moments. In this report, it is demonstrated that control of the orientation of a perylene-based discotic dye, which is able to self-organize in mesogenic columnar structures, can significantly enhance exciton–photon interaction and polariton relaxation rate in optical cavities. These results show the importance of the molecular orientation for strong light–matter interactions and provide a promising strategy toward the realization of an organic low threshold polariton BEC system and electrically driven organic polariton BEC

Enhanced Light–Matter Interaction and Polariton Relaxation by the Control of Molecular Orientation

International audienceExciton-polaritons, in which the electronic state of an excited organic molecule and a photonic state are strongly coupled, can form a Bose–Einstein condensate (BEC) at room temperature. However, so far, the reported thresholds of organic polariton BECs under optical excitation are as high as Pth = 11–500 μJ cm–2. One route toward lowering the condensation threshold is to increase the Rabi energy by aligning the molecular transition dipole moments. In this report, it is demonstrated that control of the orientation of a perylene-based discotic dye, which is able to self-organize in mesogenic columnar structures, can significantly enhance exciton–photon interaction and polariton relaxation rate in optical cavities. These results show the importance of the molecular orientation for strong light–matter interactions and provide a promising strategy toward the realization of an organic low threshold polariton BEC system and electrically driven organic polariton BEC