The COLORI proposal is devoted to the theoretical description, the numerical modeling, and the experimental study of cold and ultracold molecular collisions driven by long-range forces in the presence of strongly confining external potentials. The project brings together one theoretical and one experimental team. The coordinator IPR-Rennes has a strong theoretical background in the molecular dynamics field, the LENS-Florence partner is internationally recognized for its experimental contribution to the study of atomic and molecular gases in the ultracold domain. Experimental groups worldwide have developed the capability to cool and manipulate a large variety of atomic, molecular, and ionic species, forming the extremely active quantum gases community. Binary collisions occupy a pivotal position in the ultracold gas realm. It suffices to mention that the efficacity of cooling schemes and the quantum phases of an ultracold gas are controlled by two-body elastic and inelastic scattering amplitudes. The quantitative understanding of cold collisions is therefore essential to interpret ongoing experiments on quantum gases. Fortunately, cold collisions can not only be accurately understood, but even accurately controlled. External fields are the tool of choice, capable of influencing the outcome of a collision either by directly modifying the translational motion or by manipulating the internal structure of the colliding partners. Two main research topics can be identified in our proposal. The first one is a joint theoretical and experimental study of confinement effects on collisions of polar KRb bosonic molecules. The experimental developments ongoing at LENS include the set-up of an extremely stable laser system for two-photon transfer of weakly bound molecules to the absolute ground state. This study should allow us to shed light on the long-range interplay between dipolar, electric and optical forces, an extremely interesting topic in view of controlling unwanted reactive chemical processes expected to limit the gas lifetime. Confinement effects will be studied in particular in optical lattices of different dimensionality and crystal symmetry. We expect a wealth of geometric resonance phenomena and lattice-induced scattering events to be accurately described using the numerical tools developed during the project. Novel methodological and computational approaches will have to be proposed to this aim. Inclusion of hyperfine couplings in molecular collisions should allow novel resonance patterns and quantum interference phenomena to be studied. The second part of the COLORI proposal will consider atom-ion collisions in the presence of hyperfine and dynamical ion trap effects. Novel routes to collision control will be investigated by taking into account the interplay of resonances due to internal hyperfine couplings with Landau quantization of motional ion states in a magnetic field. Yet unexplored micromotion effects will be studied in collisions of atoms with ions trapped in Paul traps using both time-independent and time-dependent wavepacket methods. The realization of atom-ion quantum gates and sympathetic cooling of ions by ultracold atoms are only few examples for which a quantitative modeling of collisions is strongly needed. Finally, the numerical codes we propose to develop are expected to set a benchmark for theories based on effective and perturbative approaches to scattering in confined environments. COLORI presents a good equilibrium of scientific tasks between the IPR and LENS partners in the proposal, and between senior and young researchers. Periodic informal meetings are foreseen for coordination purposes. Publications in peer-reviewed journals and presentations in international meetings should help disseminating the main results of the present cooperative project.

Foams, emulsions, pastes, porous media, biological suspensions or living tissues, are involved in many industrial processes and are largely studied since several decades. However, mainly two questions are still a challenge for the physicists: the stability and the dynamic of these systems. These questions have been classically addressed in the frame of classical low Reynolds hydrodynamics. However, they have been entirely renewed thanks to experimental improvements these last years: the considerable developments of nanoscale fluid dynamics, allowing to probe fluid transport down to nanoscales, as well as the fine control of the physico-chemical properties of interfaces, has provided refreshed views on these questions. The physical phenomena involved in these nano-films call upon studies often addressed separately: local shear rates that can overcome the imposed shear rate by orders of magnitude, intermolecular forces (DLVO theory), surface rheology, or electro-/diffusio-/thermo-osmosis, to cite a few. These topics have been largely addressed by the four groups of the consortium leading to important contributions using innovative experimental tools: M.-C. Jullien and O. Theodoly showed the importance of intermolecular forces effects on droplet dynamics and more recently the non homogeneous surfactant surface concentration along a traveling droplet using RICM; while A. Colin and L. Bocquet provided a clear view of discontinuous shear-thickening transition as the breakdown of lubricated contact between particles, at a critical normal force using a tuning fork apparatus, these observations are clearly correlated to macroscopic measurements At this stage of the state the art, a major issue is the coupling of these mechanisms taking place at nano-scales on larger scale transport dynamics (droplet, cell, suspension). We therefore feel that, in view of the recent experimental and theoretical progress, it is timely to address these questions, which are shared by various systems; and therefore to address these questions from a unified and intertwinned point of view and methodology. This is the objective of the ILIAAD project. Interestingly, the observables that are analyzed to study these systems are very similar, if not identical, for these different systems, such as interface velocity, object velocity, normal stress as function of film thickness to cite a few. As a whole, this fully justifies studying these systems, more precisely their stability and dynamics, in a concerted and concomitant manner. There is no doubt that the expertise of each partner will significantly enrich the understanding of all experimental configurations. As such, the consortium is able to fully address the stability and dynamics of two-phase systems in a general framework. We will especially focus on the coupling between the interface, the transport within the thin films, and the flow: role and transport of the surfactant for fluid interfaces; coupling of the flow in the thin liquid film with the elastic deformations for solid boundaries; coupling of the flow in the thin liquid film with the visco-elastic deformation and external membrane treadmilling motion with living cells; role of the intermolecular forces and; at the most nanoscopic limit, role and specificities of the thermal fluctuations in both phases. The different partners will closely interact all along the project in order to share their results and address the global objective: deriving a comprehensive framework describing/predicting the dynamics and stability of confined films with interfaces (whether deformable or not) to improve our understanding of multi-phase systems. This project will identify generic flow properties associated to confinement at the smallest scales, which are shared by these systems despite the variety of geometrical, mechanical and physico-chemical properties of their confining interfaces.

Studying the structure and dynamics of proteins is a prerequisite for understanding their function in a cellular context. X-ray sources of a completely new kind, so called X-ray free electron lasers (XFEL), extend synchrotron-based crystallography and may eventually allow the determination of both the structure and dynamics of individual protein molecules. Today, two XFELs (LCLS, USA and SACLA, Japan) already provide the extremely intense and ultra-short X-ray pulses needed to study protein microcrystals with femtosecond (fs) time resolution. In 2016, the European XFEL (Hamburg) will start operation, offering European scientists privileged access to these new sources that are revolutionizing structural biology. The strategic aim of our proposal is to create a French Consortium and pave the way for using XFELs in structural biology, by acquiring XFEL expertise through an ambitious research project. Our scientific aim is to investigate the hitherto unexplored ultra-fast photochemistry at play in fluorescent proteins. In particular, we propose to elucidate structural intermediates in two reversibly photoswitchable fluorescent proteins, IrisFP and rsEGFP2, at atomic resolution and in the fs time window, by making use of pump-probe XFEL-based serial femtosecond crystallography (SFX) and ultra-fast UV-visible and infrared spectroscopies. IrisFP and rsEGFP2 are crucial molecular tools to study sub-cellular structures by super-resolution microscopy techniques such as RESOLFT, non-linear SIM or PALM (Chemistry Nobel Prize 2014). Static structures of the various dark and fluorescent states of IrisFP and rsEGFP2 have been determined by the coordinating laboratory using synchrotron X-ray crystallography. Photoswitching has been shown to involve cis-trans isomerization of the chromophore, proton transfer and rearrangements of residues in the chromophore cavity. However, mechanistic details about the sequence of molecular events remain elusive, as no crystallographic structure of a reaction intermediate has been determined so far. Our preliminary spectroscopic experiments show that photoswitching in both proteins involves transient species with characteristic time constants in the fs – ps range, too short to be structurally resolved using time-resolved Laue crystallography at a synchrotron, since that time-resolution is currently limited to 100 ps. Therefore, fs XFEL pulses are required to uncover the structural reaction intermediates. We propose to use XFELs to carry out SFX in an optical pump/X-ray probe scheme to collect diffraction patterns of light-induced reaction intermediates during IrisFP and rsEGFP2 photoswitching. Ultra-fast UV-Visible and infrared spectroscopies of protein in solution and in microcrystals will unravel the number of intermediates and their characteristic lifetimes. The structural nature of spectroscopically identified intermediates will then be identified in subsequent SFX XFEL experiments on the fs – ps and nanosecond-microsecond (ns-µs) timescales. Preliminary experiments have substantiated the feasibility of our project. In particular, well-diffracting IrisFP and rsEGFP2 microcrystals have been produced and datasets collected at the SACLA and LCLS XFELs that allowed structure solution of the static fluorescent on state of both proteins. UV-Visible transient absorption on IrisFP and rsEGFP2 in solution provided evidence for the existence of several spectroscopic intermediate states on the fs-ps and ns-ms timescales. Our consortium has obtained beamtime for the proposed experiments at the XFELs at LCLS (# LI56; 29 April – 3 May 2015) and SACLA (#29944; 23-25 July 2015). The proposed experiments will provide unprecedented insight into the molecular functioning of fluorescent proteins. If successful, our project will open a new field in structural biology, where the macromolecular structures of femtosecond intermediate states can be characterized at atomic resolution by using XFEL radiation.

The global shift towards a greener economic model requires replacing non-renewable chemicals with sustainable ones, whose performance at least matches that of their predecessors while they meet the most up-to-date norms. Rapid standard adaptability is critical in many fields such as cosmetics, oil recovery, construction, food and the automotive industry. In this ever-changing context, methods that speed up chemical synthesis, characterization and optimization are highly desirable. The goal of the CARANGONI proposal is to address this challenge. We propose to investigate how Marangoni flows could be used as the basis for a fast and cheap characterization tool for the solubility of chemical species. Some of us have shown in the past that the size of Marangoni flows induced by the injection of simple water-solube and surface-active species at the surface of a water layer was set by both the flow rate at which molecules were injected and their solubility limit in water before aggregation, also known as the critical micelle concentration. The relation between these three quantities was a simple scaling law. Thus, using a pocket calculator, we can deduce a thermodynamic property of surface-active molecules in solutions from the measurement of the size of a flow with a ruler. Besides, a single measurement is required. This feature must be contrasted with the need of large amounts of material and time necessary to perform measurements of the cmc with classical mehtods (pendent drop, conductometry,...). So far, we have tested simple molecules that are far from the molecular systems used in the industry. In the CARANGONI proposal, we want to generalize Marangoni characterization to complex and closer-to-application molecular systems, such as surfactant-polymer mixtures or surfactants in the presence of salts. We also want to explore extensions of the Marangoni set-up to the removal of impurities in surfactants and to DNA-based nanoparticle synthesis. Finally, we want to benefit from the beauty of the experiment to develop outreach tools around interface science. Our consortium involves four groups from three labs, Matière et Systèmes Complexes, Laboratoire de Physique des Solides and Institut de Physique de Rennes, in Paris and Rennes. The consortium gathers expertise in both experimental and theoretical approaches to interface sciences, hydrodynamics, and self-assembly. Popularization has a significant place in this project, and the proposal includes a specific task dedicated to dissemination. The consortium involves researchers in this field who have developed innovative strategies to popularize other topics of physics such as quantum mechanics. The proposal benefits from the support of the french company TECLIS, based in Lyon, who is a leading manufacturer of interface characterization devices. The members of the consortium have already started developing a prototype device based on the automation of the measurement of Maragoni flows for the fast characterization of the solubility of chemical species. The aim of this device is at the formulation level and in quality control.

Sandy coasts are complex and poorly understood environments that are under unprecedented threat posed by anthropogenic pressures and climate change. Most beaches worldwide are backed by coastal dunes, with the composite beach-dune system both buffering the hinterlands from severe storm waves and providing outstanding ecosystem services. However, most dunes on developed shores worldwide have been managed intensively for decades to minimize marine and aeolian erosion, which sometimes reduced vegetation dynamics and natural community diversity. Coastal dune management doctrine is progressively switching to a softer approach reinstating natural dynamic processes. Many coastal dune managers nowadays suggest that in certain coastal dune environments dunes maintained as dynamic systems are more resistant to marine erosion and more resilient than fixed dunes, although this has never been demonstrated nor even studied quantitatively. The major advances in unmanned vehicles technologies, satellite remote sensing of the Earth and in the modelling of complex systems suggest that we are at a tipping point. At the crossroad of Oceanography, Geomorphology and Ecology, the challenging objective of SONO is to make fundamental progress in the understanding of the interactions between aeolian, marine and biotic processes driving coastal dune evolution using systematic innovative field and remotely sensed measurements and well-adapted mesoscale modelling techniques. SONO is designed to provide quantitative estimates of the beach-dune system behaviour, including resilience to extreme events and ecosystem shifts in a context of climate change and increasing anthropogenic pressure, ultimately to designing optimal management strategies. Field work will be carried out at 2 primary sites in SW France (Truc Vert and Hourtin), which are under contrasting chronic erosion and free evolution states, with adjacent sections of managed dune providing accurate comparison with fixed dunes. Measurements will involve the collection of quarterly and pre/post-storm UAV-photogrammetry-derived digital elevation models over 4 km of dunes completed by long-term sediment transport measurements using a dense array of acoustic sensors; seasonal vegetation composition surveys at the most dynamic ecotones; regular beach topographic surveys using DGPS and nearshore bathymetries collected by a very first single-beam-sounding-equipped USV. Directional wave data, tidal elevation, wind speed and direction will be collected throughout the project at nearby stations. Using relevant physical and biological indicators, the influence of coastal dune management strategies on coastal safety and ecosystem services will be addressed. In addition, quarterly UAV-based topographic surveys will be collected at the 2 secondary sites of Anse du Gurp and Trencat, which are at a late stage of free behaviour. Large-scale (> 10 km) digital elevation models of the beach dune system will also be generated through 0.5-m resolution Pléiades tri-stereo satellite images in SW France, and along different coastal dunes systems worldwide in Australia, the US, the Netherlands and UK, covering transgressive barrier islands, coastal transgressive dunefields including those with star dunes, strongly managed sectors or highly-disturbed systems through notches excavated to excite free behaviour. This outstanding dataset will be used to develop and further test a new class of cellular automaton model for the composite beach-dune system, which will be used to quantify feedbacks and interaction patterns between biotic and abiotic processes in order to provide generic solutions applicable on wave-dominated beach-dune systems worldwide. Overall, in close collaboration with coastal dune stakeholders SONO will provide new fundamental and practical insights into coastal resilience to storms covering geomorphological and ecosystem aspects in a worldwide context of climate change and increase in anthropogenic pressure.