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Bernard Ciraulo

Publications and source records attributed to Bernard Ciraulo.

2 recordsLinked to original sources

Joint Flow Matching Enables Continuous Dose-Conditioned Cell Morphing

Generative modeling has shown increasing promise for predicting cellular perturbation effects under chemical compound treatments. Existing approaches either model perturbation as a distribution-to-distribution mapping without explicit concentration handling, or treat concentration as a discrete class label, precluding continuous dose control. We introduce a joint flow matching approach that simultaneously models cell latents and drug concentration via a dual-timestep formulation, enabling dose-conditioned single-cell morphing through the invertibility of flow matching. The joint formulation induces a monotonic dose-response geometry in latent space and additionally supports concentration estimation from cell morphology. As proof of concept, we further demonstrate generalization to an unseen dose held out during training. Empirically, our method achieves competitive or improved per-concentration metrics on two compounds compared with representative baselines, while enabling capabilities structurally unavailable to discrete-class methods.

cs.CV

Non steady-state thermometry with optical diffraction tomography

Measurement of local temperature using label-free optical methods has gained importance as a pivotal tool in both fundamental and applied research. Yet, most of these approaches are limited to steady-state measurements of planar heat sources. However, the time taken to reach steady-state is a complex function of the volume of the heated system, the size of the heat source, and the thermal conductivity of the surroundings. As such, said time can be significantly longer than expected and many relevant systems involve 3D heat sources, thus compromising reliable temperature retrieval. Here, we systematically study the thermal landscape in a model system consisting of optically excited gold nanorods (AuNRs) in a microchamber using optical diffraction tomography (ODT) thermometry. We experimentally unravel the effect of thermal conductivity of the surroundings, microchamber height, and pump pulse duration on the thermodynamics of the microchamber. We benchmark our experimental observations against 2D numerical sumulations and quantitative phase imaging (QPI) thermometry. We also demonstrate the advantage of ODT thermometry by measuring thermal landscapes inaccessible by QPI thermometry in the form of non-planar heat sources embedded in complex environments such as biological cells. Finally, we apply ODT thermometry to a complex dynamic system consisting of colloidal AuNRs in a microchamber.

physics.optics