Trustworthiness of Laser-Induced Breakdown Spectroscopy Predictions via Simulation-based Synthetic Data Augmentation and Multitask Learning

We consider quantitative analyses of spectral data using laser-induced breakdown spectroscopy. We address the small size of training data available, and the validation of the predictions during inference on unknown data. For the purpose, we build robust calibration models using deep convolutional multitask learning architectures to predict the concentration of the analyte, alongside additional spectral information as auxiliary outputs. These secondary predictions can be used to validate the trustworthiness of the model by taking advantage of the mutual dependencies of the parameters of the multitask neural networks. Due to the experimental lack of training samples, we introduce a simulation-based data augmentation process to synthesise an arbitrary number of spectra, statistically representative of the experimental data. Given the nature of the deep learning model, no dimensionality reduction or data selection processes are required. The procedure is an end-to-end pipeline including the process of synthetic data augmentation, the construction of a suitable robust, homoscedastic, deep learning model, and the validation of its predictions. In the article, we compare the performance of the multitask model with traditional univariate and multivariate analyses, to highlight the separate contributions of each element introduced in the process.Comment: 35 pages, appendix with supplementary materia

Selective vibrational excitations in the OX (X = F, Cl, Br, I) molecules

Using ab initio calculated potential energy and electric dipole moment functions for the X(2)Pi states of OF, OCl, OBr and OI, two models have been tested to selectively populate their vibrational modes by ultrashort coherent light pulses. For a given form of the pulses either a perturbative approach using discrete vibrational eigenstates and electric dipole transition moment matrix elements or a wavepacket propagation technique were used. The optimisation of the pulse parameters and the mechanisms of the multiphoton processes are discussed. For the target level v=10 populations of more than 60% have been achieved in all four molecules. For OCl it was possible to populate selectively all target levels between v=2 and v=15 using chirped pulses.Financial support from the EEC as part of the TMR network Potential Energy Surfaces for Spectroscopy and Dynamics, contract No. FMRXCT96-088(DG12-BIUO) is gratefully acknowledged.Peer Reviewe

Spin-dependent and Coriolis interactions by an improved configuration interaction treatment: predissociation of excited fine structure levels of OH/OD

The state specific predissociation of OH/OD in its lowest electronically excited state (A (2)Sigma (+), nu', N', F-1/F-2) is investigated by time dependent wave packet propagation techniques. To improve the accuracy of the potential energy curves, spin-orbit, spin-spin and rotational interactions required for the treatment, we have refined our CI techniques, using optimal orbitals for each of the electronic states. Potential energy curves, matrix elements and lifetimes of the rotational sublevels are compared with experiment and with theoretical values from multichannel scattering theory.The MURST of Italy and EEC under the TMR Program (Contract No. ERBFMRXCT960088) have supported this work.Peer Reviewe

Towards a universal definition of the dendritic cell subsets using comparative transcriptomics across warm blooded vertebrates

International audienc

Long-term outcomes of isolated superficial vein thrombosis in patients with active cancer

International audienceBACKGROUND: Cancer patients who develop a deep-vein thrombosis (DVT) or a pulmonary embolism (PE) are at higher risk of death than similar cancer patients who do not develop DVT or PE. The impact of isolated superficial venous thrombosis (SVT) (i.e. without DVT or PE) on the prognosis of cancer patients is unknown. METHODS: Data from the OPTIMEV, multicentre, observational study, to compare at 3 years the incidences of death, DVT-PE recurrence and bleeding of cancer patients with objectively confirmed SVT vs. cancer patients with DVT (matched 1:2 on age, sex, cancer stage) and vs. patients with SVT without cancer (matched 1:3 on age and sex). RESULTS: Cancer patients with SVT (n = 34) had a high risk of death (23.2%patient-year(PY)), that was similar to that of cancer patients with DVT (aHR = 1.0[0.6-1.9]) and higher to that of SVT patients without cancer (aHR = 9.0[3.5-23.1]). Cancer patients with SVT received anticoagulants for a median duration of 45 days and had a high risk of DVT-PE recurrence (6.0%PY), similar to that of cancer patients with DVT (adjusted cause-specific HR (aCHR) = 1.5[0.4-5.8]) and higher to that of SVT patients without cancer (aCHR = 2.9[0.7-11.9]). In our population, venous thrombosis on varicose veins was associated with a lower risk of death (aHR = 0.6[0.3-1.0]) and DVT-PE recurrence (aCHR = 0.6[0.2-1.7]). CONCLUSION: Our results suggest that cancer patients with SVT have a poor prognosis, similar to that of patients with cancer-related DVT. The high rate of DVT-PE recurrence suggests that such patients may need longer duration of anticoagulant treatment