A new theory of hydrodynamics of uniaxial nematic liquid crystal films in the
presence of defects is developed. A gauge field incorporating screening is
introduced, resulting in the static elastic free energy having the form of a
two-dimensional Abelian-Higgs model. Hydrodynamic equations are derived via the
standard methods of de~Groot and Mazur. By working in the vicinity of the
Bogomol'nyi equations consequences for defect centre motion are outlined.Comment: 12 page