  Dark matter effects may be attributed to interactions between the Machian
strings connecting every pair of elementary particles in the observable
Universe. A simple model for the interaction between Machian strings is
proposed. In the early Universe, the Machian strings of a density perturbation
had a spherically symmetric distribution and the interaction with the Machian
strings of a test particle is found to give a multiple of the Newtonian
gravitational acceleration. In a strong gravitational field, the interaction
between Machian strings tends to a constant limit in order to ensure the
absence of dark matter effects in the Solar System. Dark matter effects on a
galactic scale may be attributed to a change in the distribution of the Machian
strings around a galaxy during the process of galaxy formation. The interaction
between the Machian strings of a test mass and the Machian strings of a galaxy
is considered in detail and the MOND phenomenology for galaxy rotation curves
is obtained.
