Ficus elastica leaves the latex of the plant oozing, is coated with cuttings hormones and tightly wrapped with moist foam. The whole is covered with a plastic film and left a few months at the end of which new roots have developed from the axillary buds. The stem is then weaned and the new plant can be repotted. All parts of the plant contain an abundant milky white latex, which has been tested for use in the manufacture of rubber, but without economic and technical results; the rubber is actually produced from the sap of the rubber tree . In cultivation, it
Fermi liquid theory involve, e.g., a change in the effective mass of particles. The quadratic terms correspond to a sort of "mean-field" interaction between quasiparticles, which is parametrized by so-called Landau Fermi liquid parameters and determines the behaviour of density oscillations (and spin-density oscillations) in the Fermi liquid. Still, these mean-field interactions do not lead to a scattering of quasi-particles with a transfer of particles between different momentum states. The renormalization of the mass of a fluid of interacting fermions can be calculated from first principles using many-body computational techniques. For the two-dimensional homogeneous electron gas, GW calculations and quantum Monte Carlo methods