"In simple flows with mild mean deformation rates the turbulence has time to come to equilibrium with mean flow and the Reynolds stresses are determined by the strain rate, in the basis of eddy-viscosity representation. On the other hand, when the mean deformation is very rapid, the turbulent structure takes some time to respond and the Reynolds stresses are determined by the rapid distortion theory. A complete turbulence model should exhibit this visco-elastic character of turbulence, matching the two limiting behaviors and providing a reasonable blend in between. Our aim is the development of a complete one-point model with the proper visco-elastic character for use in environmental and engineering applications. The core of the model will be the particle representation model (PRM). PRM is a modern structure-based model, making use of new approaches on the description of the morphology of the turbulent structures, which offers an alternative method for computing the linear RDT one-point statistics efficiently, and without excessive computation. The scope of this proposal is the continuation of the valuable past work for the extension of the PRM approach to weak deformation rates, including more types of deformations in homogeneous and inhomogeneous flows. The resulted model is expected to improve Reynolds stress modeling for wide applications, contributing to a better understanding in atmospheric phenomena (like the passage of the flow above an obstacle), in astrophysics (star formation), and in engineering design."