WeakPolyp: You Only Look Bounding Box for Polyp Segmentation

Limited by expensive pixel-level labels, polyp segmentation models are plagued by data shortage and suffer from impaired generalization. In contrast, polyp bounding box annotations are much cheaper and more accessible. Thus, to reduce labeling cost, we propose to learn a weakly supervised polyp segmentation model (i.e., WeakPolyp) completely based on bounding box annotations. However, coarse bounding boxes contain too much noise. To avoid interference, we introduce the mask-to-box (M2B) transformation. By supervising the outer box mask of the prediction instead of the prediction itself, M2B greatly mitigates the mismatch between the coarse label and the precise prediction. But, M2B only provides sparse supervision, leading to non-unique predictions. Therefore, we further propose a scale consistency (SC) loss for dense supervision. By explicitly aligning predictions across the same image at different scales, the SC loss largely reduces the variation of predictions. Note that our WeakPolyp is a plug-and-play model, which can be easily ported to other appealing backbones. Besides, the proposed modules are only used during training, bringing no computation cost to inference. Extensive experiments demonstrate the effectiveness of our proposed WeakPolyp, which surprisingly achieves a comparable performance with a fully supervised model, requiring no mask annotations at all.Comment: accepted by MICCAI 2023, codes are available at https://github.com/weijun88/WeakPoly

Cell therapy process development with a 2 mL perfusion bioreactor

Please click Additional Files below to see the full abstract

Low temperature structure and the ferroelectric phase transitions in the CdTiO3 perovskite

The paraelectric-ferroelectric transition in CdTiO3 has been monitored using high resolution neutron diffraction data. This necessitated preparing a sample enriched in 114Cd. A subtle, but significant, anisotropy in the thermal expansion of the lattice parameters for CdTiO3 associated with the transition to the polar structure was observed. First-principles calculations are presented to understand energies, phonon dispersion, and structures of possible phases with different symmetries.Australian Research Counci