Influence of Cytomegalovirus on Tissue-Specific Immune Responses in Non-Human Primate
Most studies in anti-infectious immunity focus on characterizing pathogen-specific immune responses and identifying strategies to optimize them. It is now essential to consider interindividual variability related to age, sex, metabolic status, and infectious history, which strongly influence these responses.
IDMIT’s expertise in preclinical modeling of viral infections provides an ideal framework to address these questions. Cytomegalovirus (CMV) infection represents a relevant model due to its high prevalence, its age-dependent effects, and its association with immune aging. Although epidemiological data suggest that CMV seroprevalence impacts responses to other infections and to vaccination, the underlying mechanisms remain poorly understood. We hypothesize heterogeneous effects related to the diversity of host–virus interactions across sites of viral persistence.
This project aims to characterize CMV-specific immune responses in blood and tissues of young and aged non-human primates, and in the context of chronic SIV infection. The objectives are (i) to assess age-related differences in viral dissemination and immune responses, (ii) to evaluate the predictive value of blood markers relative to tissue parameters, and (iii) to study the reciprocal modulation of CMV and SIV responses during co-infection.
These studies will contribute to the development of vaccination strategies targeting the deleterious effects of CMV and the tissue-specific modulation of immune responses.
Active matter: self-organization of mitotic spindles
The mitotic spindle is an essential cytoskeletal structure that enables chromosome separation during cell division. This project seeks to identify the physical principles that control spindle assembly by using a simplified biomimetic system composed solely of microtubules and molecular motors. We will use motors of opposite polarities combined with dynamic microtubules to understand how these components organize through active phase separation. Indeed, preliminary experiments have demonstrated that such reconstituted systems can spontaneously form bipolar structures resembling mitotic spindles. We now propose to encapsulate these molecular components in compartments of controlled geometry to reconstruct a minimal bipolar structure capable of elongating, retracting, and separating its organizing poles. This multidisciplinary approach will combine biochemical and physicochemical techniques, advanced microscopy, and quantitative analysis of the spatial and temporal evolution of the system. The experimental work will be closely coupled with theoretical modeling in collaboration with Prof. Jean-François Joanny (Collège de France) to develop a physical model of active phase separation that will provide better understanding of self-organization mechanisms at the subcellular scale in living organisms.
Attosecond photoemission spectroscopy of molecular gases and liquids
The aim of the thesis is to perform attosecond photoemission spectroscopy on molecules in the gas and liquid phase exploiting a novel high repetition rate Ytterbium laser system. These studies will unveil the processes of photoionization of inner/outer shells and the dynamics of electron scattering in real time.
Multiscale modeling of rare earth ion emission from ionic liquids under intense electric fields
The main objective of this thesis is to model the mechanisms of rare earth ion emission from ionic liquids subjected to an intense electric field, in order to identify the conditions favorable to the emission of weakly complexed ions.
The aim is to establish rational criteria for the design of new ILIS sources suitable for the localized implantation of rare earths in photonic devices.
The thesis work will be based on large-scale molecular dynamics simulations, reproducing the emission region of a Taylor cone under an electric field.
The simulations will be compared with emission experiments conducted in parallel by the SIMUL group in collaboration with Orsay Physics TESCAN, using a prototype ILIS source doped with rare earths. Comparisons of measurements (mass spectrometry, energy distribution) will enable the models to be adjusted and the proposed mechanisms to be validated.
Study of uranium-235 fission induced by neutrons from 0.5 to 40 MeV at NFS-SPIRAL2 using the FALSTAFF spectrometer and the FIFRELIN code
The presented project has two main objectives. The first one is the realization (building, calibration, data taking and data analysis) of a first experiment with the FALSTAFF detector in its configuration with two detection arms. In such a configuration, FALSTAFF will be able to detect in coincidence both fragments emitted by fast-neutron triggered fission reactions. These neutrons will be provided by the neutron beam of SPIRAL2-NFS in GANIL. The advantage of using direct kinematics is the ability to determine on an event-by-event basis the excitation energy of the fissioning nucleus by the measurement of the incident-neutron kinetic energy.
For this first experiment, we will have a uranium 235 target. 235U is the main source of fission neutrons in nuclear reactors and therefore at the heart of the system. Hence, the understanding of neutron-induced fission of 235U is essential and the rather exclusive data FALSTAFF will provide, with not only the identification of the fission fragments but also their kinematics will permit to reconstruct also the fissioning system. Such a measurmement in direct kinematics have never been done, to our knowledge, with the accuracy we are aiming at.
To perform this exepriment, we have improved and added detection capabilities to the FALSTAFF spectrometer, in particular with the financial support of the Région Normandie over the last two years. This experiment will be completed by a work to be done on a theoretical model developed by our collaborators of CEA-Cadarache. We will compare our detailled data with predictions of the model and have the model evolve, according to the laws of nuclear physics in order to obtain results from the model close to the data. Such a test of this model on as complete data as those we will obtain with FALSTAFF have never been done so far.
Precise time tagging and tracking of leptons in Enhanced Neutrino Beams with large area PICOSEC-Micromegas detectors
The ENUBET (Enhanced NeUtrino BEams from kaon Tagging) project aims to develop a monitored neutrino beam with a precisely known flux and flavor composition, enabling percent-level precision in neutrino cross-section measurements. This is achieved by instrumenting the decay tunnel to detect and identify charged leptons from kaon decays.
The PICOSEC Micromegas detector is a fast, double-stage micro-pattern gaseous detector that combines a Cherenkov radiator, a photocathode, and a Micromegas amplification structure. Unlike standard Micromegas, it operates with amplification also occurring in the drift region, where the electric field is even stronger than in the amplification gap. This configuration enables exceptional timing performance, with measured resolutions of about 12 ps for muons and ~45 ps for single photoelectrons, making it one of the fastest gaseous detectors ever developed.
Integrating large-area PICOSEC Micromegas modules in the ENUBET decay tunnel would provide sub-100 ps timing for lepton tagging, improving particle identification, reducing pile-up, and enhancing the association between detected leptons and their parent kaon decays — a key step toward precision-controlled neutrino beams.
Within the framework of this PhD work, the candidate will optimize and characterize 10 × 10 cm² PICOSEC Micromegas prototypes, and contribute to the design and development of larger-area detectors for the nuSCOPE experiment and the ENUBET hadron dump instrumentation.
Magnetic Tunnel Junctions at Boundaries
Spin electronics, thanks to the additional degree of freedom provided by electron spin, enables the deployment of a rich physics of magnetism on a small scale, but also provides breakthrough technological solutions in the field of microelectronics (storage, memory, logic, etc.) as well as for magnetic field measurement.
In the field of life sciences and health, giant magnetoresistance (GMR) devices have demonstrated the possibility of measuring the very weak fields produced by excitable cells on a local scale (Caruso et al, Neuron 2017, Klein et al, Journal of Neurophysiology 2025).
Measuring the information contained in the magnetic component associated with neural currents (or magnetophysiology) can, in principle, provide a description of the dynamic, directional and differentiating neural landscape. It could pave the way for new types of implants, thanks to their immunity to gliosis and their longevity.
The current bottleneck is the very small amplitude of the signal produced (<1nT), which requires averaging the signal in order to detect it.
Tunnel magnetoresistances (TMR), in which a spin-polarised tunnel current is measured, offer sensitivity performance that is more than an order of magnitude higher than GMR. However, they currently have too high a level of low-frequency noise to be fully beneficial, particularly in the context of measuring biological signals.
The aim of this thesis is to push back the current limits of TMRs by reducing low-frequency noise, positioning them as break sensors for measuring very weak signals and exploiting their potential as amplifiers for small signals.
To achieve this objective, an initial approach based on exploring the materials composing the tunnel junction, in particular those of the so-called free magnetic layer, or on improving the crystallinity of the tunnel barrier, will be deployed. A second approach, consisting of studying the intrinsic properties of low-frequency noise, particularly in previously unexplored limits, at very low temperatures where intrinsic mechanisms are reached, will guide the most promising solutions.
Finally, the most advanced structures and approaches at the state of the art thus obtained will be integrated into devices that will provide the building blocks for going beyond the state of the art and offering new possibilities for spin electronics applications. These elements will also be integrated into systems for 2D (or even 3D) mapping of the activity of a global biological system (neural network) and for evaluating capabilities for clinical cases (such as epilepsy or motor rehabilitation).
It should be noted that these improved TMRs may have other applications in the fields of physical instrumentation, non-destructive testing, and magnetic imaging.
Explainable observers and interpretable AI for superconducting accelerators and radioactive isotope identification
GANIL’s SPIRAL1 and SPIRAL2 facilities produce complex data that remain hard to interpret. SPIRAL2 faces instabilities in its superconducting cavities, while SPIRAL1 requires reliable isotope identification under noisy conditions.
This PhD will develop observer-based interpretable AI, combining physics models and machine learning to detect, explain, and predict anomalies. By embedding causal reasoning and explainability tools such as SHAP and LIME, it aims to improve the reliability and transparency of accelerator operations.
Electronic excitations in unidimensional nano-objects: an ab initio description and connection with quantum entanglement
Understanding the electronic properties of valence electrons in nano-objects is not only of fundamental interest but also essential for the design of next-generation optoelectronic devices. In such systems, electron confinement in low-dimensional structures gives rise to unique properties.
These properties are inherently linked to fundamental characteristics of matter and the associated quantum fluctuations. More recently, concepts such as quantum entanglement and Fisher quantum information have been connected to spectroscopic properties. On the other hand, these spectroscopic properties can be probed through experimental techniques, including absorption, photoemission, and inelastic X-ray scattering.
Recently, we demonstrated that the widely used formalism to study isolated nano-objects was not adapted, and that it affected the calculated optical properties. We evidenced, theoretically and experimentally, that for the two-dimensional objects, the optical response contained, beyond the transverse contribution, a resonance coming from the plasmon, which corresponds to a longitudinal response. The role of the interfaces revealed to be determinant. The project of this year is to have a critical analysis of the optical properties of unidimensional objects.
Beyond the fundamental characterization of the 1D dielectric function, this research will explore its connection to quantum entanglement and Fisher quantum information—concepts that, to date, have not been investigated in low-dimensional systems.
Origins and evolution of prion-like proteins (PrLPs) in eukaryotes
Initially associated with neurodegenerative diseases, prion-like proteins (PrLPs) are now recognized as key physiological players in cellular plasticity and stress response. These proteins often contain an intrinsically disordered domain rich in glutamine and asparagine, known as a prion-like domain (PrLD), capable of switching between soluble, condensed, or amyloid states. Notable examples include CPEB in Aplysia, involved in synaptic memory, MAVS in antiviral defense, MED15 and FUS in transcriptional regulation and nucleocytoplasmic condensate dynamics, and ELF3 in plants, whose amyloid polymerization controls flowering and photoperiodic responses. In fungi, Sup35, Ure2p, and HET-s serve as experimental models of functional prions, demonstrating that reversible aggregation can act as a regulatory or adaptive mechanism. These conformational transitions are now viewed as adaptive molecular strategies rather than pathological anomalies.
This PhD project aims to trace the origin and diversification of prion-like proteins across eukaryotes, testing the hypothesis that major paleoclimatic crises have episodically promoted the emergence and duplication of genes encoding PrLDs through microsatellite expansion and transposable element activity. The project will combine large-scale phylogenomic analyses, PrLD domain detection, and modeling of selective pressures to map the key stages in the functional evolution of PrLPs and their links to stress tolerance.