(4) Analysis of dynamical features and hydrodynamic description of condensed matter. We will study the dynamics of complex molecules as fluxes, the interface dynamics of a mixture of colloids and polymers in solution, and the forces induced by fluctuations. We will also perform experiments on the vitreous transition in polymers, both confined and non-confined, and on the behaviour of a two-dimensional granular system subject to vibrations. Apart from the clear implication this objective has for objectives 1, 2, and 3 it can produce results of potential application to our understanding of systems studied in objective 5, and systems extended in space or with geometrical restrictions (objectives 6 and 7).

(5) Study of vesicle properties through models involving realistic characteristics of the self-assemly process of amphiphilic aggregates, and of membrane duplication. We intend to formulate coarse-grained models for the molecular constituents of double-layer membranes (including a more realistic description of the solvent), with the goal of studying different features of the self-assembly of amphiphilic aggregates, among them aggregation kinetics, volumetric properties of the fluid and its properties in confinement, adsorption of aggregates on substrates versus the formation of Langmuir monolayers, the influence of composition in mixtures of aggregates, and the properties of simple aggregating processes versus the effects of interaction among vesicles at high volumetric fraction. Some of these processes involve dynamical phase transitions that will require the development of new methods. We expect to integrate the models of membrane deformation with those describing self-assembled filaments, with the eventual goal of characterizing the formation and dynamics of the septal ring. Part of the tasks to be developed in this objective rely on the knowledge provided by the investigation performed in objectives 2, 3, and 4. The study of how environmental and intrinsic conditions affect the final state attained by a population is shared by objectives 6 and 7.

(6) Study of environmental and molecular features responsible for the fast adaptation of quasispecies, with the end of identifying mechanisms inducing extinction. Quasispecies will be described through phenomenological models as well as through explicit populations of sequences. We intend to analyse the effect of different physical environments: explicit space, affecting individual transport; regular and stochastic fluctuations in selection pressures; and the presence of correlations of different character in the genome space. All these analyses are motivated by empirical observations in viral quasispecies, in molecular quasispecies (RNA) and in the distribution of diversity in other natural systems. The relationship between pattern and process is an important aspect of the study of these complex populations, shared by objectives 2, 3, and 5. The relationship with objectives 7 (through the relationship between quasispecies and metapopulations), 8 (topology of the genome space), 9 (dynamics on neutral networks) and 10 (defectors versus cooperators) is even closer.